From 94f7531430285b4ec600693f7222c2ca29bd7472 Mon Sep 17 00:00:00 2001 From: "Yury Norov [NVIDIA]" Date: Thu, 15 May 2025 16:58:34 +0000 Subject: x86/resctrl: Optimize cpumask_any_housekeeping() With the lack of cpumask_any_andnot_but(), cpumask_any_housekeeping() has to abuse cpumask_nth() functions. Update cpumask_any_housekeeping() to use the new cpumask_any_but() and cpumask_any_andnot_but(). These two functions understand RESCTRL_PICK_ANY_CPU, which simplifies cpumask_any_housekeeping() significantly. Signed-off-by: Yury Norov [NVIDIA] Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: James Morse Reviewed-by: Reinette Chatre Reviewed-by: Shaopeng Tan Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: James Morse Tested-by: Shaopeng Tan Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-5-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/internal.h | 28 +++++++--------------------- 1 file changed, 7 insertions(+), 21 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index eaae99602b61..25b61e466715 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -47,30 +47,16 @@ static inline unsigned int cpumask_any_housekeeping(const struct cpumask *mask, int exclude_cpu) { - unsigned int cpu, hk_cpu; - - if (exclude_cpu == RESCTRL_PICK_ANY_CPU) - cpu = cpumask_any(mask); - else - cpu = cpumask_any_but(mask, exclude_cpu); - - /* Only continue if tick_nohz_full_mask has been initialized. */ - if (!tick_nohz_full_enabled()) - return cpu; - - /* If the CPU picked isn't marked nohz_full nothing more needs doing. */ - if (cpu < nr_cpu_ids && !tick_nohz_full_cpu(cpu)) - return cpu; + unsigned int cpu; /* Try to find a CPU that isn't nohz_full to use in preference */ - hk_cpu = cpumask_nth_andnot(0, mask, tick_nohz_full_mask); - if (hk_cpu == exclude_cpu) - hk_cpu = cpumask_nth_andnot(1, mask, tick_nohz_full_mask); - - if (hk_cpu < nr_cpu_ids) - cpu = hk_cpu; + if (tick_nohz_full_enabled()) { + cpu = cpumask_any_andnot_but(mask, tick_nohz_full_mask, exclude_cpu); + if (cpu < nr_cpu_ids) + return cpu; + } - return cpu; + return cpumask_any_but(mask, exclude_cpu); } struct rdt_fs_context { -- cgit v1.2.3-59-g8ed1b From dcb1d3d3b77bdb30d2ec97f540d58ee35f1b1c82 Mon Sep 17 00:00:00 2001 From: Amit Singh Tomar Date: Thu, 15 May 2025 16:58:35 +0000 Subject: x86/resctrl: Remove the limit on the number of CLOSID Resctrl allocates and finds free CLOSID values using the bits of a u32. This restricts the number of control groups that can be created by user-space. MPAM has an architectural limit of 2^16 CLOSID values, Intel x86 could be extended beyond 32 values. There is at least one MPAM platform which supports more than 32 CLOSID values. Replace the fixed size bitmap with calls to the bitmap API to allocate an array of a sufficient size. ffs() returns '1' for bit 0, hence the existing code subtracts 1 from the index to get the CLOSID value. find_first_bit() returns the bit number which does not need adjusting. [ morse: fixed the off-by-one in the allocator and the wrong not-found value. Removed the limit. Rephrase the commit message. ] Signed-off-by: Amit Singh Tomar Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Fenghua Yu Reviewed-by: Reinette Chatre Tested-by: Fenghua Yu Tested-by: Peter Newman Tested-by: Shaopeng Tan Tested-by: Amit Singh Tomar # arm64 Tested-by: Shanker Donthineni # arm64 Tested-by: Babu Moger Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-6-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 51 +++++++++++++++++++++++----------- 1 file changed, 35 insertions(+), 16 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index cc4a54145c83..53213cae30ec 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -130,8 +130,8 @@ static bool resctrl_is_mbm_event(int e) } /* - * Trivial allocator for CLOSIDs. Since h/w only supports a small number, - * we can keep a bitmap of free CLOSIDs in a single integer. + * Trivial allocator for CLOSIDs. Use BITMAP APIs to manipulate a bitmap + * of free CLOSIDs. * * Using a global CLOSID across all resources has some advantages and * some drawbacks: @@ -144,7 +144,7 @@ static bool resctrl_is_mbm_event(int e) * - Our choices on how to configure each resource become progressively more * limited as the number of resources grows. */ -static unsigned long closid_free_map; +static unsigned long *closid_free_map; static int closid_free_map_len; int closids_supported(void) @@ -152,20 +152,35 @@ int closids_supported(void) return closid_free_map_len; } -static void closid_init(void) +static int closid_init(void) { struct resctrl_schema *s; - u32 rdt_min_closid = 32; + u32 rdt_min_closid = ~0; + + /* Monitor only platforms still call closid_init() */ + if (list_empty(&resctrl_schema_all)) + return 0; /* Compute rdt_min_closid across all resources */ list_for_each_entry(s, &resctrl_schema_all, list) rdt_min_closid = min(rdt_min_closid, s->num_closid); - closid_free_map = BIT_MASK(rdt_min_closid) - 1; + closid_free_map = bitmap_alloc(rdt_min_closid, GFP_KERNEL); + if (!closid_free_map) + return -ENOMEM; + bitmap_fill(closid_free_map, rdt_min_closid); /* RESCTRL_RESERVED_CLOSID is always reserved for the default group */ - __clear_bit(RESCTRL_RESERVED_CLOSID, &closid_free_map); + __clear_bit(RESCTRL_RESERVED_CLOSID, closid_free_map); closid_free_map_len = rdt_min_closid; + + return 0; +} + +static void closid_exit(void) +{ + bitmap_free(closid_free_map); + closid_free_map = NULL; } static int closid_alloc(void) @@ -182,12 +197,11 @@ static int closid_alloc(void) return cleanest_closid; closid = cleanest_closid; } else { - closid = ffs(closid_free_map); - if (closid == 0) + closid = find_first_bit(closid_free_map, closid_free_map_len); + if (closid == closid_free_map_len) return -ENOSPC; - closid--; } - __clear_bit(closid, &closid_free_map); + __clear_bit(closid, closid_free_map); return closid; } @@ -196,7 +210,7 @@ void closid_free(int closid) { lockdep_assert_held(&rdtgroup_mutex); - __set_bit(closid, &closid_free_map); + __set_bit(closid, closid_free_map); } /** @@ -210,7 +224,7 @@ bool closid_allocated(unsigned int closid) { lockdep_assert_held(&rdtgroup_mutex); - return !test_bit(closid, &closid_free_map); + return !test_bit(closid, closid_free_map); } /** @@ -2765,20 +2779,22 @@ static int rdt_get_tree(struct fs_context *fc) goto out_ctx; } - closid_init(); + ret = closid_init(); + if (ret) + goto out_schemata_free; if (resctrl_arch_mon_capable()) flags |= RFTYPE_MON; ret = rdtgroup_add_files(rdtgroup_default.kn, flags); if (ret) - goto out_schemata_free; + goto out_closid_exit; kernfs_activate(rdtgroup_default.kn); ret = rdtgroup_create_info_dir(rdtgroup_default.kn); if (ret < 0) - goto out_schemata_free; + goto out_closid_exit; if (resctrl_arch_mon_capable()) { ret = mongroup_create_dir(rdtgroup_default.kn, @@ -2829,6 +2845,8 @@ out_mongrp: kernfs_remove(kn_mongrp); out_info: kernfs_remove(kn_info); +out_closid_exit: + closid_exit(); out_schemata_free: schemata_list_destroy(); out_ctx: @@ -3076,6 +3094,7 @@ static void rdt_kill_sb(struct super_block *sb) rmdir_all_sub(); rdt_pseudo_lock_release(); rdtgroup_default.mode = RDT_MODE_SHAREABLE; + closid_exit(); schemata_list_destroy(); rdtgroup_destroy_root(); if (resctrl_arch_alloc_capable()) -- cgit v1.2.3-59-g8ed1b From 7704fb81bc87254e8772f387b62153b135bb1932 Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:36 +0000 Subject: x86/resctrl: Rename resctrl_sched_in() to begin with "resctrl_arch_" resctrl_sched_in() loads the architecture specific CPU MSRs with the CLOSID and RMID values. This function was named before resctrl was split to have architecture specific code, and generic filesystem code. This function is obviously architecture specific, but does not begin with 'resctrl_arch_', making it the odd one out in the functions an architecture needs to support to enable resctrl. Rename it for consistency. This is purely cosmetic. Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Shaopeng Tan Reviewed-by: Tony Luck Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Carl Worth # arm64 Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Amit Singh Tomar # arm64 Tested-by: Shanker Donthineni # arm64 Tested-by: Babu Moger Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-7-james.morse@arm.com --- arch/x86/include/asm/resctrl.h | 4 ++-- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 12 ++++++------ arch/x86/kernel/process_32.c | 2 +- arch/x86/kernel/process_64.c | 2 +- 4 files changed, 10 insertions(+), 10 deletions(-) (limited to 'arch') diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h index 011bf67a1866..7a39728b0743 100644 --- a/arch/x86/include/asm/resctrl.h +++ b/arch/x86/include/asm/resctrl.h @@ -175,7 +175,7 @@ static inline bool resctrl_arch_match_rmid(struct task_struct *tsk, u32 ignored, return READ_ONCE(tsk->rmid) == rmid; } -static inline void resctrl_sched_in(struct task_struct *tsk) +static inline void resctrl_arch_sched_in(struct task_struct *tsk) { if (static_branch_likely(&rdt_enable_key)) __resctrl_sched_in(tsk); @@ -212,7 +212,7 @@ void resctrl_cpu_detect(struct cpuinfo_x86 *c); #else -static inline void resctrl_sched_in(struct task_struct *tsk) {} +static inline void resctrl_arch_sched_in(struct task_struct *tsk) {} static inline void resctrl_cpu_detect(struct cpuinfo_x86 *c) {} #endif /* CONFIG_X86_CPU_RESCTRL */ diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 53213cae30ec..88197afbbb8a 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -376,7 +376,7 @@ static int rdtgroup_cpus_show(struct kernfs_open_file *of, } /* - * This is safe against resctrl_sched_in() called from __switch_to() + * This is safe against resctrl_arch_sched_in() called from __switch_to() * because __switch_to() is executed with interrupts disabled. A local call * from update_closid_rmid() is protected against __switch_to() because * preemption is disabled. @@ -395,7 +395,7 @@ void resctrl_arch_sync_cpu_closid_rmid(void *info) * executing task might have its own closid selected. Just reuse * the context switch code. */ - resctrl_sched_in(current); + resctrl_arch_sched_in(current); } /* @@ -620,7 +620,7 @@ static void _update_task_closid_rmid(void *task) * Otherwise, the MSR is updated when the task is scheduled in. */ if (task == current) - resctrl_sched_in(task); + resctrl_arch_sched_in(task); } static void update_task_closid_rmid(struct task_struct *t) @@ -678,7 +678,7 @@ static int __rdtgroup_move_task(struct task_struct *tsk, * Ensure the task's closid and rmid are written before determining if * the task is current that will decide if it will be interrupted. * This pairs with the full barrier between the rq->curr update and - * resctrl_sched_in() during context switch. + * resctrl_arch_sched_in() during context switch. */ smp_mb(); @@ -2994,8 +2994,8 @@ static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to, /* * Order the closid/rmid stores above before the loads * in task_curr(). This pairs with the full barrier - * between the rq->curr update and resctrl_sched_in() - * during context switch. + * between the rq->curr update and + * resctrl_arch_sched_in() during context switch. */ smp_mb(); diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 4636ef359973..f1429fdac11c 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -211,7 +211,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) switch_fpu_finish(next_p); /* Load the Intel cache allocation PQR MSR. */ - resctrl_sched_in(next_p); + resctrl_arch_sched_in(next_p); return prev_p; } diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 7196ca7048be..642fc3232cec 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -707,7 +707,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) } /* Load the Intel cache allocation PQR MSR. */ - resctrl_sched_in(next_p); + resctrl_arch_sched_in(next_p); return prev_p; } -- cgit v1.2.3-59-g8ed1b From 8eb7ad66badc71e0d8547cf6195a2a6190090152 Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:37 +0000 Subject: x86/resctrl: Check all domains are offline in resctrl_exit() resctrl_exit() removes things like the resctrl mount point directory and unregisters the filesystem prior to freeing data structures that were allocated during resctrl_init(). This assumes that there are no online domains when resctrl_exit() is called. If any domain were online, the limbo or overflow handler could be scheduled to run. Add a check for any online control or monitor domains, and document that the architecture code is required to offline all monitor and control domains before calling resctrl_exit(). Suggested-by: Reinette Chatre Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Babu Moger Tested-by: Shaopeng Tan Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-8-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 88197afbbb8a..29f76ad21f1c 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -4420,8 +4420,41 @@ cleanup_mountpoint: return ret; } +static bool __exit resctrl_online_domains_exist(void) +{ + struct rdt_resource *r; + + /* + * Only walk capable resources to allow resctrl_arch_get_resource() + * to return dummy 'not capable' resources. + */ + for_each_alloc_capable_rdt_resource(r) { + if (!list_empty(&r->ctrl_domains)) + return true; + } + + for_each_mon_capable_rdt_resource(r) { + if (!list_empty(&r->mon_domains)) + return true; + } + + return false; +} + +/* + * resctrl_exit() - Remove the resctrl filesystem and free resources. + * + * When called by the architecture code, all CPUs and resctrl domains must be + * offline. This ensures the limbo and overflow handlers are not scheduled to + * run, meaning the data structures they access can be freed by + * resctrl_mon_resource_exit(). + */ void __exit resctrl_exit(void) { + cpus_read_lock(); + WARN_ON_ONCE(resctrl_online_domains_exist()); + cpus_read_unlock(); + debugfs_remove_recursive(debugfs_resctrl); unregister_filesystem(&rdt_fs_type); sysfs_remove_mount_point(fs_kobj, "resctrl"); -- cgit v1.2.3-59-g8ed1b From 8c992e24a0627a6ba508184c07766862c8bb3e54 Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:38 +0000 Subject: x86/resctrl: Resctrl_exit() teardown resctrl but leave the mount point resctrl_exit() was intended for use when the 'resctrl' module was unloaded. resctrl can't be built as a module, and the kernfs helpers are not exported so this is unlikely to change. MPAM has an error interrupt which indicates the MPAM driver has gone haywire. Should this occur tasks could run with the wrong control values, leading to bad performance for important tasks. In this scenario the MPAM driver will reset the hardware, but it needs a way to tell resctrl that no further configuration should be attempted. In particular, moving tasks between control or monitor groups does not interact with the architecture code, so there is no opportunity for the arch code to indicate that the hardware is no-longer functioning. Using resctrl_exit() for this leaves the system in a funny state as resctrl is still mounted, but cannot be un-mounted because the sysfs directory that is typically used has been removed. Dave Martin suggests this may cause systemd trouble in the future as not all filesystems can be unmounted. Add calls to remove all the files and directories in resctrl, and remove the sysfs_remove_mount_point() call that leaves the system in a funny state. When triggered, this causes all the resctrl files to disappear. resctrl can be unmounted, but not mounted again. Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Shaopeng Tan Reviewed-by: Tony Luck Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Carl Worth # arm64 Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Amit Singh Tomar # arm64 Tested-by: Shanker Donthineni # arm64 Tested-by: Babu Moger Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-9-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 48 ++++++++++++++++++++++++++++------ 1 file changed, 40 insertions(+), 8 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 29f76ad21f1c..1e48c61db2aa 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -3078,6 +3078,22 @@ static void rmdir_all_sub(void) kernfs_remove(kn_mondata); } +static void resctrl_fs_teardown(void) +{ + lockdep_assert_held(&rdtgroup_mutex); + + /* Cleared by rdtgroup_destroy_root() */ + if (!rdtgroup_default.kn) + return; + + rmdir_all_sub(); + rdt_pseudo_lock_release(); + rdtgroup_default.mode = RDT_MODE_SHAREABLE; + closid_exit(); + schemata_list_destroy(); + rdtgroup_destroy_root(); +} + static void rdt_kill_sb(struct super_block *sb) { struct rdt_resource *r; @@ -3091,12 +3107,7 @@ static void rdt_kill_sb(struct super_block *sb) for_each_alloc_capable_rdt_resource(r) resctrl_arch_reset_all_ctrls(r); - rmdir_all_sub(); - rdt_pseudo_lock_release(); - rdtgroup_default.mode = RDT_MODE_SHAREABLE; - closid_exit(); - schemata_list_destroy(); - rdtgroup_destroy_root(); + resctrl_fs_teardown(); if (resctrl_arch_alloc_capable()) resctrl_arch_disable_alloc(); if (resctrl_arch_mon_capable()) @@ -4127,6 +4138,8 @@ static int rdtgroup_setup_root(struct rdt_fs_context *ctx) static void rdtgroup_destroy_root(void) { + lockdep_assert_held(&rdtgroup_mutex); + kernfs_destroy_root(rdt_root); rdtgroup_default.kn = NULL; } @@ -4441,23 +4454,42 @@ static bool __exit resctrl_online_domains_exist(void) return false; } -/* +/** * resctrl_exit() - Remove the resctrl filesystem and free resources. * + * Called by the architecture code in response to a fatal error. + * Removes resctrl files and structures from kernfs to prevent further + * configuration. + * * When called by the architecture code, all CPUs and resctrl domains must be * offline. This ensures the limbo and overflow handlers are not scheduled to * run, meaning the data structures they access can be freed by * resctrl_mon_resource_exit(). + * + * After resctrl_exit() returns, the architecture code should return an + * error from all resctrl_arch_ functions that can do this. + * resctrl_arch_get_resource() must continue to return struct rdt_resources + * with the correct rid field to ensure the filesystem can be unmounted. */ void __exit resctrl_exit(void) { cpus_read_lock(); WARN_ON_ONCE(resctrl_online_domains_exist()); + + mutex_lock(&rdtgroup_mutex); + resctrl_fs_teardown(); + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); debugfs_remove_recursive(debugfs_resctrl); + debugfs_resctrl = NULL; unregister_filesystem(&rdt_fs_type); - sysfs_remove_mount_point(fs_kobj, "resctrl"); + + /* + * Do not remove the sysfs mount point added by resctrl_init() so that + * it can be used to umount resctrl. + */ resctrl_mon_resource_exit(); } -- cgit v1.2.3-59-g8ed1b From bc740420d7ae7878696d5ad9f3dbcb11e2599b2e Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:39 +0000 Subject: x86/resctrl: Drop __init/__exit on assorted symbols Because ARM's MPAM controls are probed using MMIO, resctrl can't be initialised until enough CPUs are online to have determined the system-wide supported num_closid. Arm64 also supports 'late onlined secondaries', where only a subset of CPUs are online during boot. These two combine to mean the MPAM driver may not be able to initialise resctrl until user-space has brought 'enough' CPUs online. To allow MPAM to initialise resctrl after __init text has been free'd, remove all the __init markings from resctrl. The existing __exit markings cause these functions to be removed by the linker as it has never been possible to build resctrl as a module. MPAM has an error interrupt which causes the driver to reset and disable itself. Remove the __exit markings to allow the MPAM driver to tear down resctrl when an error occurs. Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Shaopeng Tan Reviewed-by: Tony Luck Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Carl Worth # arm64 Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Amit Singh Tomar # arm64 Tested-by: Shanker Donthineni # arm64 Tested-by: Babu Moger Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-10-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/core.c | 6 +++--- arch/x86/kernel/cpu/resctrl/internal.h | 4 ++-- arch/x86/kernel/cpu/resctrl/monitor.c | 2 +- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 8 ++++---- include/linux/resctrl.h | 6 +++--- 5 files changed, 13 insertions(+), 13 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index cf29681d01e0..31538c65d9a2 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -737,7 +737,7 @@ struct rdt_options { bool force_off, force_on; }; -static struct rdt_options rdt_options[] __initdata = { +static struct rdt_options rdt_options[] __ro_after_init = { RDT_OPT(RDT_FLAG_CMT, "cmt", X86_FEATURE_CQM_OCCUP_LLC), RDT_OPT(RDT_FLAG_MBM_TOTAL, "mbmtotal", X86_FEATURE_CQM_MBM_TOTAL), RDT_OPT(RDT_FLAG_MBM_LOCAL, "mbmlocal", X86_FEATURE_CQM_MBM_LOCAL), @@ -777,7 +777,7 @@ static int __init set_rdt_options(char *str) } __setup("rdt", set_rdt_options); -bool __init rdt_cpu_has(int flag) +bool rdt_cpu_has(int flag) { bool ret = boot_cpu_has(flag); struct rdt_options *o; @@ -797,7 +797,7 @@ bool __init rdt_cpu_has(int flag) return ret; } -__init bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt) +bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt) { if (!rdt_cpu_has(X86_FEATURE_BMEC)) return false; diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 25b61e466715..576383a808a2 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -472,13 +472,13 @@ int alloc_rmid(u32 closid); void free_rmid(u32 closid, u32 rmid); int rdt_get_mon_l3_config(struct rdt_resource *r); void resctrl_mon_resource_exit(void); -bool __init rdt_cpu_has(int flag); +bool rdt_cpu_has(int flag); void mon_event_count(void *info); int rdtgroup_mondata_show(struct seq_file *m, void *arg); void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, struct rdt_mon_domain *d, struct rdtgroup *rdtgrp, cpumask_t *cpumask, int evtid, int first); -int __init resctrl_mon_resource_init(void); +int resctrl_mon_resource_init(void); void mbm_setup_overflow_handler(struct rdt_mon_domain *dom, unsigned long delay_ms, int exclude_cpu); diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index a93ed7d2a160..73e3fe4f4c87 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -1204,7 +1204,7 @@ static __init int snc_get_config(void) * * Returns 0 for success, or -ENOMEM. */ -int __init resctrl_mon_resource_init(void) +int resctrl_mon_resource_init(void) { struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); int ret; diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 1e48c61db2aa..cfd846cc861e 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -4144,7 +4144,7 @@ static void rdtgroup_destroy_root(void) rdtgroup_default.kn = NULL; } -static void __init rdtgroup_setup_default(void) +static void rdtgroup_setup_default(void) { mutex_lock(&rdtgroup_mutex); @@ -4376,7 +4376,7 @@ out_unlock: * * Return: 0 on success or -errno */ -int __init resctrl_init(void) +int resctrl_init(void) { int ret = 0; @@ -4433,7 +4433,7 @@ cleanup_mountpoint: return ret; } -static bool __exit resctrl_online_domains_exist(void) +static bool resctrl_online_domains_exist(void) { struct rdt_resource *r; @@ -4471,7 +4471,7 @@ static bool __exit resctrl_online_domains_exist(void) * resctrl_arch_get_resource() must continue to return struct rdt_resources * with the correct rid field to ensure the filesystem can be unmounted. */ -void __exit resctrl_exit(void) +void resctrl_exit(void) { cpus_read_lock(); WARN_ON_ONCE(resctrl_online_domains_exist()); diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 880351ca3dfc..b8f8240050b4 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -358,7 +358,7 @@ u32 resctrl_arch_get_num_closid(struct rdt_resource *r); u32 resctrl_arch_system_num_rmid_idx(void); int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid); -__init bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt); +bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt); /** * resctrl_arch_mon_event_config_write() - Write the config for an event. @@ -514,7 +514,7 @@ void resctrl_arch_reset_all_ctrls(struct rdt_resource *r); extern unsigned int resctrl_rmid_realloc_threshold; extern unsigned int resctrl_rmid_realloc_limit; -int __init resctrl_init(void); -void __exit resctrl_exit(void); +int resctrl_init(void); +void resctrl_exit(void); #endif /* _RESCTRL_H */ -- cgit v1.2.3-59-g8ed1b From 6c72fb8d8bd7bfaafdeda3a91c535ecf52283ec9 Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:40 +0000 Subject: x86/resctrl: Move is_mba_sc() out of core.c is_mba_sc() is defined in core.c, but has no callers there. It does not access any architecture private structures. Move this to rdtgroup.c where the majority of callers are. This makes the move of the filesystem code to /fs/ cleaner. Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Shaopeng Tan Reviewed-by: Tony Luck Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Carl Worth # arm64 Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Amit Singh Tomar # arm64 Tested-by: Shanker Donthineni # arm64 Tested-by: Babu Moger Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-11-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/core.c | 15 --------------- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 15 +++++++++++++++ 2 files changed, 15 insertions(+), 15 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 31538c65d9a2..58d7c6accdf2 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -164,21 +164,6 @@ static inline void cache_alloc_hsw_probe(void) rdt_alloc_capable = true; } -bool is_mba_sc(struct rdt_resource *r) -{ - if (!r) - r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); - - /* - * The software controller support is only applicable to MBA resource. - * Make sure to check for resource type. - */ - if (r->rid != RDT_RESOURCE_MBA) - return false; - - return r->membw.mba_sc; -} - /* * rdt_get_mb_table() - get a mapping of bandwidth(b/w) percentage values * exposed to user interface and the h/w understandable delay values. diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index cfd846cc861e..e2999f668593 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1535,6 +1535,21 @@ unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, return size; } +bool is_mba_sc(struct rdt_resource *r) +{ + if (!r) + r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); + + /* + * The software controller support is only applicable to MBA resource. + * Make sure to check for resource type. + */ + if (r->rid != RDT_RESOURCE_MBA) + return false; + + return r->membw.mba_sc; +} + /* * rdtgroup_size_show - Display size in bytes of allocated regions * -- cgit v1.2.3-59-g8ed1b From d4fb6b8e4640adeff9673ae398525be7382d3197 Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:41 +0000 Subject: x86/resctrl: Add end-marker to the resctrl_event_id enum The resctrl_event_id enum gives names to the counter event numbers on x86. These are used directly by resctrl. To allow the MPAM driver to keep an array of these the size of the enum needs to be known. Add a 'num_events' enum entry which can be used to size an array. This is added to the enum to reduce conflicts with another series, which in turn requires get_arch_mbm_state() to have a default case. Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Babu Moger Tested-by: Shaopeng Tan Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-12-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/monitor.c | 9 ++++----- include/linux/resctrl_types.h | 3 +++ 2 files changed, 7 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 73e3fe4f4c87..4962ae4bc596 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -260,12 +260,11 @@ static struct arch_mbm_state *get_arch_mbm_state(struct rdt_hw_mon_domain *hw_do return &hw_dom->arch_mbm_total[rmid]; case QOS_L3_MBM_LOCAL_EVENT_ID: return &hw_dom->arch_mbm_local[rmid]; + default: + /* Never expect to get here */ + WARN_ON_ONCE(1); + return NULL; } - - /* Never expect to get here */ - WARN_ON_ONCE(1); - - return NULL; } void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_mon_domain *d, diff --git a/include/linux/resctrl_types.h b/include/linux/resctrl_types.h index f26450b3326b..69bf740130ac 100644 --- a/include/linux/resctrl_types.h +++ b/include/linux/resctrl_types.h @@ -49,6 +49,9 @@ enum resctrl_event_id { QOS_L3_OCCUP_EVENT_ID = 0x01, QOS_L3_MBM_TOTAL_EVENT_ID = 0x02, QOS_L3_MBM_LOCAL_EVENT_ID = 0x03, + + /* Must be the last */ + QOS_NUM_EVENTS, }; #endif /* __LINUX_RESCTRL_TYPES_H */ -- cgit v1.2.3-59-g8ed1b From 2a65660385444e9d9deffe995c71ee20443ef76e Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:42 +0000 Subject: x86/resctrl: Expand the width of domid by replacing mon_data_bits MPAM platforms retrieve the cache-id property from the ACPI PPTT table. The cache-id field is 32 bits wide. Under resctrl, the cache-id becomes the domain-id, and is packed into the mon_data_bits union bitfield. The width of cache-id in this field is 14 bits. Expanding the union would break 32bit x86 platforms as this union is stored as the kernfs kn->priv pointer. This saved allocating memory for the priv data storage. The firmware on MPAM platforms have used the PPTT cache-id field to expose the interconnect's id for the cache, which is sparse and uses more than 14 bits. Use of this id is to enable PCIe direct cache injection hints. Using this feature with VFIO means the value provided by the ACPI table should be exposed to user-space. To support cache-id values greater than 14 bits, convert the mon_data_bits union to a structure. These are shared between control and monitor groups, and are allocated on first use. The list of allocated struct mon_data is free'd when the filesystem is umount()ed. Co-developed-by: Tony Luck Signed-off-by: Tony Luck Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Babu Moger Tested-by: Shaopeng Tan Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-13-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 24 ++++++---- arch/x86/kernel/cpu/resctrl/internal.h | 39 ++++++++------- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 79 ++++++++++++++++++++++++++++--- 3 files changed, 106 insertions(+), 36 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c index 0a0ac5f6112e..110b534d400c 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -661,14 +661,15 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, int rdtgroup_mondata_show(struct seq_file *m, void *arg) { struct kernfs_open_file *of = m->private; + enum resctrl_res_level resid; + enum resctrl_event_id evtid; struct rdt_domain_hdr *hdr; struct rmid_read rr = {0}; struct rdt_mon_domain *d; - u32 resid, evtid, domid; struct rdtgroup *rdtgrp; struct rdt_resource *r; - union mon_data_bits md; - int ret = 0; + struct mon_data *md; + int domid, ret = 0; rdtgrp = rdtgroup_kn_lock_live(of->kn); if (!rdtgrp) { @@ -676,17 +677,22 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) goto out; } - md.priv = of->kn->priv; - resid = md.u.rid; - domid = md.u.domid; - evtid = md.u.evtid; + md = of->kn->priv; + if (WARN_ON_ONCE(!md)) { + ret = -EIO; + goto out; + } + + resid = md->rid; + domid = md->domid; + evtid = md->evtid; r = resctrl_arch_get_resource(resid); - if (md.u.sum) { + if (md->sum) { /* * This file requires summing across all domains that share * the L3 cache id that was provided in the "domid" field of the - * mon_data_bits union. Search all domains in the resource for + * struct mon_data. Search all domains in the resource for * one that matches this cache id. */ list_for_each_entry(d, &r->mon_domains, hdr.list) { diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 576383a808a2..01cb0ff89c85 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -89,27 +89,26 @@ struct mon_evt { }; /** - * union mon_data_bits - Monitoring details for each event file. - * @priv: Used to store monitoring event data in @u - * as kernfs private data. - * @u.rid: Resource id associated with the event file. - * @u.evtid: Event id associated with the event file. - * @u.sum: Set when event must be summed across multiple - * domains. - * @u.domid: When @u.sum is zero this is the domain to which - * the event file belongs. When @sum is one this - * is the id of the L3 cache that all domains to be - * summed share. - * @u: Name of the bit fields struct. + * struct mon_data - Monitoring details for each event file. + * @list: Member of the global @mon_data_kn_priv_list list. + * @rid: Resource id associated with the event file. + * @evtid: Event id associated with the event file. + * @sum: Set when event must be summed across multiple + * domains. + * @domid: When @sum is zero this is the domain to which + * the event file belongs. When @sum is one this + * is the id of the L3 cache that all domains to be + * summed share. + * + * Pointed to by the kernfs kn->priv field of monitoring event files. + * Readers and writers must hold rdtgroup_mutex. */ -union mon_data_bits { - void *priv; - struct { - unsigned int rid : 10; - enum resctrl_event_id evtid : 7; - unsigned int sum : 1; - unsigned int domid : 14; - } u; +struct mon_data { + struct list_head list; + enum resctrl_res_level rid; + enum resctrl_event_id evtid; + int domid; + bool sum; }; /** diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index e2999f668593..d48078410d77 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -45,6 +45,12 @@ LIST_HEAD(rdt_all_groups); /* list of entries for the schemata file */ LIST_HEAD(resctrl_schema_all); +/* + * List of struct mon_data containing private data of event files for use by + * rdtgroup_mondata_show(). Protected by rdtgroup_mutex. + */ +static LIST_HEAD(mon_data_kn_priv_list); + /* The filesystem can only be mounted once. */ bool resctrl_mounted; @@ -3093,6 +3099,63 @@ static void rmdir_all_sub(void) kernfs_remove(kn_mondata); } +/** + * mon_get_kn_priv() - Get the mon_data priv data for this event. + * + * The same values are used across the mon_data directories of all control and + * monitor groups for the same event in the same domain. Keep a list of + * allocated structures and re-use an existing one with the same values for + * @rid, @domid, etc. + * + * @rid: The resource id for the event file being created. + * @domid: The domain id for the event file being created. + * @mevt: The type of event file being created. + * @do_sum: Whether SNC summing monitors are being created. + */ +static struct mon_data *mon_get_kn_priv(enum resctrl_res_level rid, int domid, + struct mon_evt *mevt, + bool do_sum) +{ + struct mon_data *priv; + + lockdep_assert_held(&rdtgroup_mutex); + + list_for_each_entry(priv, &mon_data_kn_priv_list, list) { + if (priv->rid == rid && priv->domid == domid && + priv->sum == do_sum && priv->evtid == mevt->evtid) + return priv; + } + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return NULL; + + priv->rid = rid; + priv->domid = domid; + priv->sum = do_sum; + priv->evtid = mevt->evtid; + list_add_tail(&priv->list, &mon_data_kn_priv_list); + + return priv; +} + +/** + * mon_put_kn_priv() - Free all allocated mon_data structures. + * + * Called when resctrl file system is unmounted. + */ +static void mon_put_kn_priv(void) +{ + struct mon_data *priv, *tmp; + + lockdep_assert_held(&rdtgroup_mutex); + + list_for_each_entry_safe(priv, tmp, &mon_data_kn_priv_list, list) { + list_del(&priv->list); + kfree(priv); + } +} + static void resctrl_fs_teardown(void) { lockdep_assert_held(&rdtgroup_mutex); @@ -3102,6 +3165,7 @@ static void resctrl_fs_teardown(void) return; rmdir_all_sub(); + mon_put_kn_priv(); rdt_pseudo_lock_release(); rdtgroup_default.mode = RDT_MODE_SHAREABLE; closid_exit(); @@ -3208,19 +3272,20 @@ static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d, bool do_sum) { struct rmid_read rr = {0}; - union mon_data_bits priv; + struct mon_data *priv; struct mon_evt *mevt; - int ret; + int ret, domid; if (WARN_ON(list_empty(&r->evt_list))) return -EPERM; - priv.u.rid = r->rid; - priv.u.domid = do_sum ? d->ci->id : d->hdr.id; - priv.u.sum = do_sum; list_for_each_entry(mevt, &r->evt_list, list) { - priv.u.evtid = mevt->evtid; - ret = mon_addfile(kn, mevt->name, priv.priv); + domid = do_sum ? d->ci->id : d->hdr.id; + priv = mon_get_kn_priv(r->rid, domid, mevt, do_sum); + if (WARN_ON_ONCE(!priv)) + return -EINVAL; + + ret = mon_addfile(kn, mevt->name, priv); if (ret) return ret; -- cgit v1.2.3-59-g8ed1b From 270f00bcc9525c8ba667349ba3e8c4dbcbbf70fb Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:43 +0000 Subject: x86/resctrl: Split trace.h trace.h contains all the tracepoints. After the move to /fs/resctrl, some of these will be left behind. All the pseudo_lock tracepoints remain part of the architecture. The lone tracepoint in monitor.c moves to /fs/resctrl. Split trace.h so that each C file includes a different trace header file. This means the trace header files are not modified when they are moved. Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Shaopeng Tan Reviewed-by: Tony Luck Reviewed-by: Fenghua Yu Reviewed-by: Reinette Chatre Tested-by: Fenghua Yu Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Amit Singh Tomar # arm64 Tested-by: Shanker Donthineni # arm64 Tested-by: Babu Moger Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-14-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/Makefile | 3 ++ arch/x86/kernel/cpu/resctrl/monitor.c | 4 +- arch/x86/kernel/cpu/resctrl/monitor_trace.h | 31 +++++++++++++ arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 2 +- arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h | 43 ++++++++++++++++++ arch/x86/kernel/cpu/resctrl/trace.h | 59 ------------------------- 6 files changed, 81 insertions(+), 61 deletions(-) create mode 100644 arch/x86/kernel/cpu/resctrl/monitor_trace.h create mode 100644 arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h delete mode 100644 arch/x86/kernel/cpu/resctrl/trace.h (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/Makefile b/arch/x86/kernel/cpu/resctrl/Makefile index 0c13b0befd8a..909be78ec6da 100644 --- a/arch/x86/kernel/cpu/resctrl/Makefile +++ b/arch/x86/kernel/cpu/resctrl/Makefile @@ -2,4 +2,7 @@ obj-$(CONFIG_X86_CPU_RESCTRL) += core.o rdtgroup.o monitor.o obj-$(CONFIG_X86_CPU_RESCTRL) += ctrlmondata.o obj-$(CONFIG_RESCTRL_FS_PSEUDO_LOCK) += pseudo_lock.o + +# To allow define_trace.h's recursive include: CFLAGS_pseudo_lock.o = -I$(src) +CFLAGS_monitor.o = -I$(src) diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 4962ae4bc596..ac1cec61829c 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -26,7 +26,9 @@ #include #include "internal.h" -#include "trace.h" + +#define CREATE_TRACE_POINTS +#include "monitor_trace.h" /** * struct rmid_entry - dirty tracking for all RMID. diff --git a/arch/x86/kernel/cpu/resctrl/monitor_trace.h b/arch/x86/kernel/cpu/resctrl/monitor_trace.h new file mode 100644 index 000000000000..ade67daf42c2 --- /dev/null +++ b/arch/x86/kernel/cpu/resctrl/monitor_trace.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM resctrl + +#if !defined(_FS_RESCTRL_MONITOR_TRACE_H) || defined(TRACE_HEADER_MULTI_READ) +#define _FS_RESCTRL_MONITOR_TRACE_H + +#include + +TRACE_EVENT(mon_llc_occupancy_limbo, + TP_PROTO(u32 ctrl_hw_id, u32 mon_hw_id, int domain_id, u64 llc_occupancy_bytes), + TP_ARGS(ctrl_hw_id, mon_hw_id, domain_id, llc_occupancy_bytes), + TP_STRUCT__entry(__field(u32, ctrl_hw_id) + __field(u32, mon_hw_id) + __field(int, domain_id) + __field(u64, llc_occupancy_bytes)), + TP_fast_assign(__entry->ctrl_hw_id = ctrl_hw_id; + __entry->mon_hw_id = mon_hw_id; + __entry->domain_id = domain_id; + __entry->llc_occupancy_bytes = llc_occupancy_bytes;), + TP_printk("ctrl_hw_id=%u mon_hw_id=%u domain_id=%d llc_occupancy_bytes=%llu", + __entry->ctrl_hw_id, __entry->mon_hw_id, __entry->domain_id, + __entry->llc_occupancy_bytes) + ); + +#endif /* _FS_RESCTRL_MONITOR_TRACE_H */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . +#define TRACE_INCLUDE_FILE monitor_trace +#include diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c index 92ea1472bde9..f7bb586a83f9 100644 --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c @@ -30,7 +30,7 @@ #include "internal.h" #define CREATE_TRACE_POINTS -#include "trace.h" +#include "pseudo_lock_trace.h" /* * The bits needed to disable hardware prefetching varies based on the diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h b/arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h new file mode 100644 index 000000000000..5a0fae61d3ee --- /dev/null +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM resctrl + +#if !defined(_X86_RESCTRL_PSEUDO_LOCK_TRACE_H) || defined(TRACE_HEADER_MULTI_READ) +#define _X86_RESCTRL_PSEUDO_LOCK_TRACE_H + +#include + +TRACE_EVENT(pseudo_lock_mem_latency, + TP_PROTO(u32 latency), + TP_ARGS(latency), + TP_STRUCT__entry(__field(u32, latency)), + TP_fast_assign(__entry->latency = latency), + TP_printk("latency=%u", __entry->latency) + ); + +TRACE_EVENT(pseudo_lock_l2, + TP_PROTO(u64 l2_hits, u64 l2_miss), + TP_ARGS(l2_hits, l2_miss), + TP_STRUCT__entry(__field(u64, l2_hits) + __field(u64, l2_miss)), + TP_fast_assign(__entry->l2_hits = l2_hits; + __entry->l2_miss = l2_miss;), + TP_printk("hits=%llu miss=%llu", + __entry->l2_hits, __entry->l2_miss)); + +TRACE_EVENT(pseudo_lock_l3, + TP_PROTO(u64 l3_hits, u64 l3_miss), + TP_ARGS(l3_hits, l3_miss), + TP_STRUCT__entry(__field(u64, l3_hits) + __field(u64, l3_miss)), + TP_fast_assign(__entry->l3_hits = l3_hits; + __entry->l3_miss = l3_miss;), + TP_printk("hits=%llu miss=%llu", + __entry->l3_hits, __entry->l3_miss)); + +#endif /* _X86_RESCTRL_PSEUDO_LOCK_TRACE_H */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . +#define TRACE_INCLUDE_FILE pseudo_lock_trace +#include diff --git a/arch/x86/kernel/cpu/resctrl/trace.h b/arch/x86/kernel/cpu/resctrl/trace.h deleted file mode 100644 index 2a506316b303..000000000000 --- a/arch/x86/kernel/cpu/resctrl/trace.h +++ /dev/null @@ -1,59 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#undef TRACE_SYSTEM -#define TRACE_SYSTEM resctrl - -#if !defined(_TRACE_RESCTRL_H) || defined(TRACE_HEADER_MULTI_READ) -#define _TRACE_RESCTRL_H - -#include - -TRACE_EVENT(pseudo_lock_mem_latency, - TP_PROTO(u32 latency), - TP_ARGS(latency), - TP_STRUCT__entry(__field(u32, latency)), - TP_fast_assign(__entry->latency = latency), - TP_printk("latency=%u", __entry->latency) - ); - -TRACE_EVENT(pseudo_lock_l2, - TP_PROTO(u64 l2_hits, u64 l2_miss), - TP_ARGS(l2_hits, l2_miss), - TP_STRUCT__entry(__field(u64, l2_hits) - __field(u64, l2_miss)), - TP_fast_assign(__entry->l2_hits = l2_hits; - __entry->l2_miss = l2_miss;), - TP_printk("hits=%llu miss=%llu", - __entry->l2_hits, __entry->l2_miss)); - -TRACE_EVENT(pseudo_lock_l3, - TP_PROTO(u64 l3_hits, u64 l3_miss), - TP_ARGS(l3_hits, l3_miss), - TP_STRUCT__entry(__field(u64, l3_hits) - __field(u64, l3_miss)), - TP_fast_assign(__entry->l3_hits = l3_hits; - __entry->l3_miss = l3_miss;), - TP_printk("hits=%llu miss=%llu", - __entry->l3_hits, __entry->l3_miss)); - -TRACE_EVENT(mon_llc_occupancy_limbo, - TP_PROTO(u32 ctrl_hw_id, u32 mon_hw_id, int domain_id, u64 llc_occupancy_bytes), - TP_ARGS(ctrl_hw_id, mon_hw_id, domain_id, llc_occupancy_bytes), - TP_STRUCT__entry(__field(u32, ctrl_hw_id) - __field(u32, mon_hw_id) - __field(int, domain_id) - __field(u64, llc_occupancy_bytes)), - TP_fast_assign(__entry->ctrl_hw_id = ctrl_hw_id; - __entry->mon_hw_id = mon_hw_id; - __entry->domain_id = domain_id; - __entry->llc_occupancy_bytes = llc_occupancy_bytes;), - TP_printk("ctrl_hw_id=%u mon_hw_id=%u domain_id=%d llc_occupancy_bytes=%llu", - __entry->ctrl_hw_id, __entry->mon_hw_id, __entry->domain_id, - __entry->llc_occupancy_bytes) - ); - -#endif /* _TRACE_RESCTRL_H */ - -#undef TRACE_INCLUDE_PATH -#define TRACE_INCLUDE_PATH . -#define TRACE_INCLUDE_FILE trace -#include -- cgit v1.2.3-59-g8ed1b From bff70402d6d67843fe319338e4c56e1cba13fbd8 Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:45 +0000 Subject: fs/resctrl: Add boiler plate for external resctrl code Add Makefile and Kconfig for fs/resctrl. Add ARCH_HAS_CPU_RESCTRL for the common parts of the resctrl interface and make X86_CPU_RESCTRL select this. Adding an include of asm/resctrl.h to linux/resctrl.h allows the /fs/resctrl files to switch over to using this header instead. Co-developed-by: Dave Martin Signed-off-by: Dave Martin Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Shaopeng Tan Reviewed-by: Tony Luck Reviewed-by: Fenghua Yu Reviewed-by: Reinette Chatre Tested-by: Fenghua Yu Tested-by: Carl Worth # arm64 Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Amit Singh Tomar # arm64 Tested-by: Shanker Donthineni # arm64 Tested-by: Babu Moger Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-16-james.morse@arm.com --- MAINTAINERS | 1 + arch/Kconfig | 8 +++++++ arch/x86/Kconfig | 11 +++------ arch/x86/kernel/cpu/resctrl/internal.h | 2 -- arch/x86/kernel/cpu/resctrl/monitor.c | 2 +- arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 2 +- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 2 +- fs/Kconfig | 1 + fs/Makefile | 1 + fs/resctrl/Kconfig | 39 +++++++++++++++++++++++++++++++ fs/resctrl/Makefile | 6 +++++ fs/resctrl/ctrlmondata.c | 0 fs/resctrl/internal.h | 0 fs/resctrl/monitor.c | 0 fs/resctrl/monitor_trace.h | 0 fs/resctrl/pseudo_lock.c | 0 fs/resctrl/pseudo_lock_trace.h | 0 fs/resctrl/rdtgroup.c | 0 include/linux/resctrl.h | 4 ++++ 19 files changed, 66 insertions(+), 13 deletions(-) create mode 100644 fs/resctrl/Kconfig create mode 100644 fs/resctrl/Makefile create mode 100644 fs/resctrl/ctrlmondata.c create mode 100644 fs/resctrl/internal.h create mode 100644 fs/resctrl/monitor.c create mode 100644 fs/resctrl/monitor_trace.h create mode 100644 fs/resctrl/pseudo_lock.c create mode 100644 fs/resctrl/pseudo_lock_trace.h create mode 100644 fs/resctrl/rdtgroup.c (limited to 'arch') diff --git a/MAINTAINERS b/MAINTAINERS index f21f1dabb5fe..ed96cc7ad662 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -20427,6 +20427,7 @@ S: Supported F: Documentation/arch/x86/resctrl* F: arch/x86/include/asm/resctrl.h F: arch/x86/kernel/cpu/resctrl/ +F: fs/resctrl/ F: include/linux/resctrl*.h F: tools/testing/selftests/resctrl/ diff --git a/arch/Kconfig b/arch/Kconfig index b0adb665041f..a3308a220f86 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1518,6 +1518,14 @@ config STRICT_MODULE_RWX config ARCH_HAS_PHYS_TO_DMA bool +config ARCH_HAS_CPU_RESCTRL + bool + help + An architecture selects this option to indicate that the necessary + hooks are provided to support the common memory system usage + monitoring and control interfaces provided by the 'resctrl' + filesystem (see RESCTRL_FS). + config HAVE_ARCH_COMPILER_H bool help diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5873c9e39919..52cfb69c343f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -507,8 +507,9 @@ config X86_MPPARSE config X86_CPU_RESCTRL bool "x86 CPU resource control support" depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) - select KERNFS - select PROC_CPU_RESCTRL if PROC_FS + depends on MISC_FILESYSTEMS + select ARCH_HAS_CPU_RESCTRL + select RESCTRL_FS select RESCTRL_FS_PSEUDO_LOCK help Enable x86 CPU resource control support. @@ -526,12 +527,6 @@ config X86_CPU_RESCTRL Say N if unsure. -config RESCTRL_FS_PSEUDO_LOCK - bool - help - Software mechanism to pin data in a cache portion using - micro-architecture specific knowledge. - config X86_FRED bool "Flexible Return and Event Delivery" depends on X86_64 diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 01cb0ff89c85..348895d3b4b8 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -9,8 +9,6 @@ #include #include -#include - #define L3_QOS_CDP_ENABLE 0x01ULL #define L2_QOS_CDP_ENABLE 0x01ULL diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index ac1cec61829c..8847c23e9ac1 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -19,11 +19,11 @@ #include #include +#include #include #include #include -#include #include "internal.h" diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c index f7bb586a83f9..db0b75b45fe4 100644 --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c @@ -18,12 +18,12 @@ #include #include #include +#include #include #include #include #include -#include #include #include "../../events/perf_event.h" /* For X86_CONFIG() */ diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index d48078410d77..3a4a0bb70f6a 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -28,7 +29,6 @@ #include -#include #include "internal.h" DEFINE_STATIC_KEY_FALSE(rdt_enable_key); diff --git a/fs/Kconfig b/fs/Kconfig index 5b4847bd2fbb..44b6cdd36dc1 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -335,6 +335,7 @@ source "fs/omfs/Kconfig" source "fs/hpfs/Kconfig" source "fs/qnx4/Kconfig" source "fs/qnx6/Kconfig" +source "fs/resctrl/Kconfig" source "fs/romfs/Kconfig" source "fs/pstore/Kconfig" source "fs/ufs/Kconfig" diff --git a/fs/Makefile b/fs/Makefile index 77fd7f7b5d02..79c08b914c47 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -128,3 +128,4 @@ obj-$(CONFIG_EROFS_FS) += erofs/ obj-$(CONFIG_VBOXSF_FS) += vboxsf/ obj-$(CONFIG_ZONEFS_FS) += zonefs/ obj-$(CONFIG_BPF_LSM) += bpf_fs_kfuncs.o +obj-$(CONFIG_RESCTRL_FS) += resctrl/ diff --git a/fs/resctrl/Kconfig b/fs/resctrl/Kconfig new file mode 100644 index 000000000000..478a8e2ad99f --- /dev/null +++ b/fs/resctrl/Kconfig @@ -0,0 +1,39 @@ +config RESCTRL_FS + bool "CPU Resource Control Filesystem (resctrl)" + depends on ARCH_HAS_CPU_RESCTRL + select KERNFS + select PROC_CPU_RESCTRL if PROC_FS + help + Some architectures provide hardware facilities to group tasks and + monitor and control their usage of memory system resources such as + caches and memory bandwidth. Examples of such facilities include + Intel's Resource Director Technology (Intel(R) RDT) and AMD's + Platform Quality of Service (AMD QoS). + + If your system has the necessary support and you want to be able to + assign tasks to groups and manipulate the associated resource + monitors and controls from userspace, say Y here to get a mountable + 'resctrl' filesystem that lets you do just that. + + If nothing mounts or prods the 'resctrl' filesystem, resource + controls and monitors are left in a quiescent, permissive state. + + On architectures where this can be disabled independently, it is + safe to say N. + + See for more information. + +config RESCTRL_FS_PSEUDO_LOCK + bool + depends on RESCTRL_FS + help + Software mechanism to pin data in a cache portion using + micro-architecture specific knowledge. + +config RESCTRL_RMID_DEPENDS_ON_CLOSID + bool + depends on RESCTRL_FS + help + Enabled by the architecture when the RMID values depend on the CLOSID. + This causes the CLOSID allocator to search for CLOSID with clean + RMID. diff --git a/fs/resctrl/Makefile b/fs/resctrl/Makefile new file mode 100644 index 000000000000..e67f34d2236a --- /dev/null +++ b/fs/resctrl/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_RESCTRL_FS) += rdtgroup.o ctrlmondata.o monitor.o +obj-$(CONFIG_RESCTRL_FS_PSEUDO_LOCK) += pseudo_lock.o + +# To allow define_trace.h's recursive include: +CFLAGS_monitor.o = -I$(src) diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c new file mode 100644 index 000000000000..e69de29bb2d1 diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h new file mode 100644 index 000000000000..e69de29bb2d1 diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c new file mode 100644 index 000000000000..e69de29bb2d1 diff --git a/fs/resctrl/monitor_trace.h b/fs/resctrl/monitor_trace.h new file mode 100644 index 000000000000..e69de29bb2d1 diff --git a/fs/resctrl/pseudo_lock.c b/fs/resctrl/pseudo_lock.c new file mode 100644 index 000000000000..e69de29bb2d1 diff --git a/fs/resctrl/pseudo_lock_trace.h b/fs/resctrl/pseudo_lock_trace.h new file mode 100644 index 000000000000..e69de29bb2d1 diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c new file mode 100644 index 000000000000..e69de29bb2d1 diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index b8f8240050b4..5c7c8bf2c47f 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -8,6 +8,10 @@ #include #include +#ifdef CONFIG_ARCH_HAS_CPU_RESCTRL +#include +#endif + /* CLOSID, RMID value used by the default control group */ #define RESCTRL_RESERVED_CLOSID 0 #define RESCTRL_RESERVED_RMID 0 -- cgit v1.2.3-59-g8ed1b From 3d95a49b365e06d1b4c4e5a426fdc70449a334f3 Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:46 +0000 Subject: x86/resctrl: Move the filesystem bits to headers visible to fs/resctrl Once the filesystem parts of resctrl move to fs/resctrl, it cannot rely on definitions in x86's internal.h. Move definitions in internal.h that need to be shared between the filesystem and architecture code to header files that fs/resctrl can include. Doing this separately means the filesystem code only moves between files of the same name, instead of having these changes mixed in too. Co-developed-by: Dave Martin Signed-off-by: Dave Martin Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Shaopeng Tan Reviewed-by: Tony Luck Reviewed-by: Fenghua Yu Reviewed-by: Reinette Chatre Tested-by: Fenghua Yu Tested-by: Carl Worth # arm64 Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Amit Singh Tomar # arm64 Tested-by: Shanker Donthineni # arm64 Tested-by: Babu Moger Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-17-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/internal.h | 9 --------- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 5 +++++ include/linux/resctrl.h | 3 +++ include/linux/resctrl_types.h | 3 +++ 4 files changed, 11 insertions(+), 9 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 348895d3b4b8..dc63ac538a81 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -16,8 +16,6 @@ #define CQM_LIMBOCHECK_INTERVAL 1000 #define MBM_CNTR_WIDTH_BASE 24 -#define MBM_OVERFLOW_INTERVAL 1000 -#define MAX_MBA_BW 100u #define MBA_IS_LINEAR 0x4 #define MBM_CNTR_WIDTH_OFFSET_AMD 20 @@ -396,13 +394,6 @@ extern struct rdtgroup rdtgroup_default; extern struct dentry *debugfs_resctrl; extern enum resctrl_event_id mba_mbps_default_event; -static inline bool resctrl_arch_get_cdp_enabled(enum resctrl_res_level l) -{ - return rdt_resources_all[l].cdp_enabled; -} - -int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable); - void arch_mon_domain_online(struct rdt_resource *r, struct rdt_mon_domain *d); /* CPUID.(EAX=10H, ECX=ResID=1).EAX */ diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 3a4a0bb70f6a..ac4baf172269 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2541,6 +2541,11 @@ int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable) return 0; } +bool resctrl_arch_get_cdp_enabled(enum resctrl_res_level l) +{ + return rdt_resources_all[l].cdp_enabled; +} + /* * We don't allow rdtgroup directories to be created anywhere * except the root directory. Thus when looking for the rdtgroup diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 5c7c8bf2c47f..b9d1f2916e9c 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -403,6 +403,9 @@ static inline u32 resctrl_get_config_index(u32 closid, } } +bool resctrl_arch_get_cdp_enabled(enum resctrl_res_level l); +int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable); + /* * Update the ctrl_val and apply this config right now. * Must be called on one of the domain's CPUs. diff --git a/include/linux/resctrl_types.h b/include/linux/resctrl_types.h index 69bf740130ac..a66e7936943e 100644 --- a/include/linux/resctrl_types.h +++ b/include/linux/resctrl_types.h @@ -7,6 +7,9 @@ #ifndef __LINUX_RESCTRL_TYPES_H #define __LINUX_RESCTRL_TYPES_H +#define MAX_MBA_BW 100u +#define MBM_OVERFLOW_INTERVAL 1000 + /* Reads to Local DRAM Memory */ #define READS_TO_LOCAL_MEM BIT(0) -- cgit v1.2.3-59-g8ed1b From 272ed1c28c9db60b9bd50d49feae463df50b3ef6 Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:48 +0000 Subject: x86/resctrl: Fix types in resctrl_arch_mon_ctx_{alloc,free}() stubs resctrl_arch_mon_ctx_alloc() and resctrl_arch_mon_ctx_free() take an enum resctrl_event_id that is already defined in resctrl_types.h to be accessible to asm/resctrl.h. The x86 stubs take an int. Fix that. Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Babu Moger Tested-by: Shaopeng Tan Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-19-james.morse@arm.com --- arch/x86/include/asm/resctrl.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h index 7a39728b0743..a2e20fe90a2c 100644 --- a/arch/x86/include/asm/resctrl.h +++ b/arch/x86/include/asm/resctrl.h @@ -194,14 +194,16 @@ static inline u32 resctrl_arch_rmid_idx_encode(u32 ignored, u32 rmid) /* x86 can always read an rmid, nothing needs allocating */ struct rdt_resource; -static inline void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, int evtid) +static inline void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, + enum resctrl_event_id evtid) { might_sleep(); return NULL; -}; +} -static inline void resctrl_arch_mon_ctx_free(struct rdt_resource *r, int evtid, - void *ctx) { }; +static inline void resctrl_arch_mon_ctx_free(struct rdt_resource *r, + enum resctrl_event_id evtid, + void *ctx) { } u64 resctrl_arch_get_prefetch_disable_bits(void); int resctrl_arch_pseudo_lock_fn(void *_plr); -- cgit v1.2.3-59-g8ed1b From 279f225951e3c77a1708d77f557b4cc7bdbd76ed Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:49 +0000 Subject: x86/resctrl: Move pseudo lock prototypes to include/linux/resctrl.h The resctrl pseudo-lock feature allows an architecture to allocate data into particular cache portions, which are then treated as reserved to avoid that data ever being evicted. Setting this up is deeply architecture specific as it involves disabling prefetchers etc. It is not possible to support this kind of feature on arm64. Risc-V is assumed to be the same. The prototypes for the architecture code were added to x86's asm/resctrl.h, with other architectures able to provide stubs for their architecture. This forces other architectures to provide identical stubs. Move the prototypes and stubs to linux/resctrl.h, and switch between them using the existing Kconfig symbol. Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Babu Moger Tested-by: Shaopeng Tan Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-20-james.morse@arm.com --- arch/x86/include/asm/resctrl.h | 5 ----- include/linux/resctrl.h | 13 +++++++++++++ 2 files changed, 13 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h index a2e20fe90a2c..ad497ab196d1 100644 --- a/arch/x86/include/asm/resctrl.h +++ b/arch/x86/include/asm/resctrl.h @@ -205,11 +205,6 @@ static inline void resctrl_arch_mon_ctx_free(struct rdt_resource *r, enum resctrl_event_id evtid, void *ctx) { } -u64 resctrl_arch_get_prefetch_disable_bits(void); -int resctrl_arch_pseudo_lock_fn(void *_plr); -int resctrl_arch_measure_cycles_lat_fn(void *_plr); -int resctrl_arch_measure_l2_residency(void *_plr); -int resctrl_arch_measure_l3_residency(void *_plr); void resctrl_cpu_detect(struct cpuinfo_x86 *c); #else diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 5ef972cbf56b..9ba771f2ddea 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -534,4 +534,17 @@ extern unsigned int resctrl_rmid_realloc_limit; int resctrl_init(void); void resctrl_exit(void); +#ifdef CONFIG_RESCTRL_FS_PSEUDO_LOCK +u64 resctrl_arch_get_prefetch_disable_bits(void); +int resctrl_arch_pseudo_lock_fn(void *_plr); +int resctrl_arch_measure_cycles_lat_fn(void *_plr); +int resctrl_arch_measure_l2_residency(void *_plr); +int resctrl_arch_measure_l3_residency(void *_plr); +#else +static inline u64 resctrl_arch_get_prefetch_disable_bits(void) { return 0; } +static inline int resctrl_arch_pseudo_lock_fn(void *_plr) { return 0; } +static inline int resctrl_arch_measure_cycles_lat_fn(void *_plr) { return 0; } +static inline int resctrl_arch_measure_l2_residency(void *_plr) { return 0; } +static inline int resctrl_arch_measure_l3_residency(void *_plr) { return 0; } +#endif /* CONFIG_RESCTRL_FS_PSEUDO_LOCK */ #endif /* _RESCTRL_H */ -- cgit v1.2.3-59-g8ed1b From 556f48a5093b1edb1b8a594af633303269dec329 Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Thu, 15 May 2025 16:58:50 +0000 Subject: x86/resctrl: Squelch whitespace anomalies in resctrl core code checkpatch.pl complains about some whitespace anomalies in the resctrl core code. This doesn't matter, but since this code is about to be factored out and made generic, this is a good opportunity to fix these issues and so reduce future checkpatch fuzz. Fix them. No functional change. Signed-off-by: Dave Martin Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Fenghua Yu Reviewed-by: Reinette Chatre Tested-by: Fenghua Yu Tested-by: Peter Newman Tested-by: Shaopeng Tan Tested-by: Amit Singh Tomar # arm64 Tested-by: Shanker Donthineni # arm64 Tested-by: Babu Moger Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-21-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index ac4baf172269..02c5f626bce1 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1024,7 +1024,7 @@ static int rdt_num_closids_show(struct kernfs_open_file *of, } static int rdt_default_ctrl_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) + struct seq_file *seq, void *v) { struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); struct rdt_resource *r = s->res; @@ -1034,7 +1034,7 @@ static int rdt_default_ctrl_show(struct kernfs_open_file *of, } static int rdt_min_cbm_bits_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) + struct seq_file *seq, void *v) { struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); struct rdt_resource *r = s->res; @@ -1150,7 +1150,7 @@ static int rdt_bit_usage_show(struct kernfs_open_file *of, } static int rdt_min_bw_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) + struct seq_file *seq, void *v) { struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); struct rdt_resource *r = s->res; @@ -1185,7 +1185,7 @@ static int rdt_mon_features_show(struct kernfs_open_file *of, } static int rdt_bw_gran_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) + struct seq_file *seq, void *v) { struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); struct rdt_resource *r = s->res; @@ -1195,7 +1195,7 @@ static int rdt_bw_gran_show(struct kernfs_open_file *of, } static int rdt_delay_linear_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) + struct seq_file *seq, void *v) { struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); struct rdt_resource *r = s->res; @@ -2068,7 +2068,6 @@ static struct rftype res_common_files[] = { .seq_show = rdtgroup_closid_show, .fflags = RFTYPE_CTRL_BASE | RFTYPE_DEBUG, }, - }; static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags) @@ -3628,7 +3627,6 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) rdt_last_cmd_puts("Failed to initialize allocations\n"); goto out; } - } rdtgrp->mode = RDT_MODE_SHAREABLE; -- cgit v1.2.3-59-g8ed1b From df3dc0efcc01d6aae8ebd3e479fe0d55f894854b Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Thu, 15 May 2025 16:58:51 +0000 Subject: x86/resctrl: Prefer alloc(sizeof(*foo)) idiom in rdt_init_fs_context() rdt_init_fs_context() sizes a typed allocation using an explicit sizeof(type) expression, which checkpatch.pl complains about. Since this code is about to be factored out and made generic, this is a good opportunity to fix the code to size the allocation based on the target pointer instead, to reduce the chance of future mis- maintenance. Fix it. No functional change. Signed-off-by: Dave Martin Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Fenghua Yu Reviewed-by: Reinette Chatre Tested-by: Fenghua Yu Tested-by: Peter Newman Tested-by: Shaopeng Tan Tested-by: Amit Singh Tomar # arm64 Tested-by: Shanker Donthineni # arm64 Tested-by: Babu Moger Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-22-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 02c5f626bce1..ace86b6dcede 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2951,7 +2951,7 @@ static int rdt_init_fs_context(struct fs_context *fc) { struct rdt_fs_context *ctx; - ctx = kzalloc(sizeof(struct rdt_fs_context), GFP_KERNEL); + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) return -ENOMEM; -- cgit v1.2.3-59-g8ed1b From b7b57edbf5681c7d0ed504a3a4e912bb68661ab9 Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Thu, 15 May 2025 16:58:52 +0000 Subject: x86/resctrl: Relax some asm #includes checkpatch.pl identifies some direct #includes of asm headers that can be satisfied by including the corresponding header instead. Fix them. No intentional functional change. Signed-off-by: Dave Martin Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Peter Newman Tested-by: Shaopeng Tan Tested-by: Amit Singh Tomar # arm64 Tested-by: Shanker Donthineni # arm64 Tested-by: Babu Moger Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-23-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c index db0b75b45fe4..bb39ffdd8524 100644 --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c @@ -11,6 +11,8 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include +#include #include #include #include @@ -22,7 +24,6 @@ #include #include -#include #include #include -- cgit v1.2.3-59-g8ed1b From f6b25be204b8661e4c32fa770a4c9e3a113ee325 Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:53 +0000 Subject: x86/resctrl: Always initialise rid field in rdt_resources_all[] x86 has an array, rdt_resources_all[], of all possible resources. The for-each-resource walkers depend on the rid field of all resources being initialised. If the array ever grows due to another architecture adding a resource type that is not defined on x86, the for-each-resources walkers will loop forever. Initialise all the rid values in resctrl_arch_late_init() before any for-each-resource walker can be called. Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Babu Moger Tested-by: Shaopeng Tan Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-24-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/core.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 58d7c6accdf2..224bed28f341 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -60,7 +60,6 @@ struct rdt_hw_resource rdt_resources_all[RDT_NUM_RESOURCES] = { [RDT_RESOURCE_L3] = { .r_resctrl = { - .rid = RDT_RESOURCE_L3, .name = "L3", .ctrl_scope = RESCTRL_L3_CACHE, .mon_scope = RESCTRL_L3_CACHE, @@ -74,7 +73,6 @@ struct rdt_hw_resource rdt_resources_all[RDT_NUM_RESOURCES] = { [RDT_RESOURCE_L2] = { .r_resctrl = { - .rid = RDT_RESOURCE_L2, .name = "L2", .ctrl_scope = RESCTRL_L2_CACHE, .ctrl_domains = ctrl_domain_init(RDT_RESOURCE_L2), @@ -86,7 +84,6 @@ struct rdt_hw_resource rdt_resources_all[RDT_NUM_RESOURCES] = { [RDT_RESOURCE_MBA] = { .r_resctrl = { - .rid = RDT_RESOURCE_MBA, .name = "MB", .ctrl_scope = RESCTRL_L3_CACHE, .ctrl_domains = ctrl_domain_init(RDT_RESOURCE_MBA), @@ -96,7 +93,6 @@ struct rdt_hw_resource rdt_resources_all[RDT_NUM_RESOURCES] = { [RDT_RESOURCE_SMBA] = { .r_resctrl = { - .rid = RDT_RESOURCE_SMBA, .name = "SMBA", .ctrl_scope = RESCTRL_L3_CACHE, .ctrl_domains = ctrl_domain_init(RDT_RESOURCE_SMBA), @@ -996,7 +992,11 @@ void resctrl_cpu_detect(struct cpuinfo_x86 *c) static int __init resctrl_arch_late_init(void) { struct rdt_resource *r; - int state, ret; + int state, ret, i; + + /* for_each_rdt_resource() requires all rid to be initialised. */ + for (i = 0; i < RDT_NUM_RESOURCES; i++) + rdt_resources_all[i].r_resctrl.rid = i; /* * Initialize functions(or definitions) that are different -- cgit v1.2.3-59-g8ed1b From 7168ae330e8105296210b2b2d31d791d5c073345 Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 15 May 2025 16:58:54 +0000 Subject: x86,fs/resctrl: Move the resctrl filesystem code to live in /fs/resctrl Resctrl is a filesystem interface to hardware that provides cache allocation policy and bandwidth control for groups of tasks or CPUs. To support more than one architecture, resctrl needs to live in /fs/. Move the code that is concerned with the filesystem interface to /fs/resctrl. Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-25-james.morse@arm.com --- Documentation/arch/x86/index.rst | 1 - Documentation/arch/x86/resctrl.rst | 1523 -------- Documentation/filesystems/index.rst | 1 + Documentation/filesystems/resctrl.rst | 1523 ++++++++ MAINTAINERS | 2 +- arch/x86/kernel/cpu/resctrl/Makefile | 1 - arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 641 ---- arch/x86/kernel/cpu/resctrl/internal.h | 371 +- arch/x86/kernel/cpu/resctrl/monitor.c | 909 +---- arch/x86/kernel/cpu/resctrl/monitor_trace.h | 31 - arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 1087 +----- arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h | 2 + arch/x86/kernel/cpu/resctrl/rdtgroup.c | 4597 +---------------------- fs/resctrl/Kconfig | 2 +- fs/resctrl/ctrlmondata.c | 661 ++++ fs/resctrl/internal.h | 426 +++ fs/resctrl/monitor.c | 929 +++++ fs/resctrl/monitor_trace.h | 33 + fs/resctrl/pseudo_lock.c | 1105 ++++++ fs/resctrl/pseudo_lock_trace.h | 0 fs/resctrl/rdtgroup.c | 4353 +++++++++++++++++++++ 21 files changed, 9186 insertions(+), 9012 deletions(-) delete mode 100644 Documentation/arch/x86/resctrl.rst create mode 100644 Documentation/filesystems/resctrl.rst delete mode 100644 arch/x86/kernel/cpu/resctrl/monitor_trace.h delete mode 100644 fs/resctrl/pseudo_lock_trace.h (limited to 'arch') diff --git a/Documentation/arch/x86/index.rst b/Documentation/arch/x86/index.rst index 8ac64d7de4dc..00f9a99689fb 100644 --- a/Documentation/arch/x86/index.rst +++ b/Documentation/arch/x86/index.rst @@ -31,7 +31,6 @@ x86-specific Documentation pti mds microcode - resctrl tsx_async_abort buslock usb-legacy-support diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst deleted file mode 100644 index c7949dd44f2f..000000000000 --- a/Documentation/arch/x86/resctrl.rst +++ /dev/null @@ -1,1523 +0,0 @@ -.. SPDX-License-Identifier: GPL-2.0 -.. include:: - -===================================================== -User Interface for Resource Control feature (resctrl) -===================================================== - -:Copyright: |copy| 2016 Intel Corporation -:Authors: - Fenghua Yu - - Tony Luck - - Vikas Shivappa - - -Intel refers to this feature as Intel Resource Director Technology(Intel(R) RDT). -AMD refers to this feature as AMD Platform Quality of Service(AMD QoS). - -This feature is enabled by the CONFIG_X86_CPU_RESCTRL and the x86 /proc/cpuinfo -flag bits: - -=============================================== ================================ -RDT (Resource Director Technology) Allocation "rdt_a" -CAT (Cache Allocation Technology) "cat_l3", "cat_l2" -CDP (Code and Data Prioritization) "cdp_l3", "cdp_l2" -CQM (Cache QoS Monitoring) "cqm_llc", "cqm_occup_llc" -MBM (Memory Bandwidth Monitoring) "cqm_mbm_total", "cqm_mbm_local" -MBA (Memory Bandwidth Allocation) "mba" -SMBA (Slow Memory Bandwidth Allocation) "" -BMEC (Bandwidth Monitoring Event Configuration) "" -=============================================== ================================ - -Historically, new features were made visible by default in /proc/cpuinfo. This -resulted in the feature flags becoming hard to parse by humans. Adding a new -flag to /proc/cpuinfo should be avoided if user space can obtain information -about the feature from resctrl's info directory. - -To use the feature mount the file system:: - - # mount -t resctrl resctrl [-o cdp[,cdpl2][,mba_MBps][,debug]] /sys/fs/resctrl - -mount options are: - -"cdp": - Enable code/data prioritization in L3 cache allocations. -"cdpl2": - Enable code/data prioritization in L2 cache allocations. -"mba_MBps": - Enable the MBA Software Controller(mba_sc) to specify MBA - bandwidth in MiBps -"debug": - Make debug files accessible. Available debug files are annotated with - "Available only with debug option". - -L2 and L3 CDP are controlled separately. - -RDT features are orthogonal. A particular system may support only -monitoring, only control, or both monitoring and control. Cache -pseudo-locking is a unique way of using cache control to "pin" or -"lock" data in the cache. Details can be found in -"Cache Pseudo-Locking". - - -The mount succeeds if either of allocation or monitoring is present, but -only those files and directories supported by the system will be created. -For more details on the behavior of the interface during monitoring -and allocation, see the "Resource alloc and monitor groups" section. - -Info directory -============== - -The 'info' directory contains information about the enabled -resources. Each resource has its own subdirectory. The subdirectory -names reflect the resource names. - -Each subdirectory contains the following files with respect to -allocation: - -Cache resource(L3/L2) subdirectory contains the following files -related to allocation: - -"num_closids": - The number of CLOSIDs which are valid for this - resource. The kernel uses the smallest number of - CLOSIDs of all enabled resources as limit. -"cbm_mask": - The bitmask which is valid for this resource. - This mask is equivalent to 100%. -"min_cbm_bits": - The minimum number of consecutive bits which - must be set when writing a mask. - -"shareable_bits": - Bitmask of shareable resource with other executing - entities (e.g. I/O). User can use this when - setting up exclusive cache partitions. Note that - some platforms support devices that have their - own settings for cache use which can over-ride - these bits. -"bit_usage": - Annotated capacity bitmasks showing how all - instances of the resource are used. The legend is: - - "0": - Corresponding region is unused. When the system's - resources have been allocated and a "0" is found - in "bit_usage" it is a sign that resources are - wasted. - - "H": - Corresponding region is used by hardware only - but available for software use. If a resource - has bits set in "shareable_bits" but not all - of these bits appear in the resource groups' - schematas then the bits appearing in - "shareable_bits" but no resource group will - be marked as "H". - "X": - Corresponding region is available for sharing and - used by hardware and software. These are the - bits that appear in "shareable_bits" as - well as a resource group's allocation. - "S": - Corresponding region is used by software - and available for sharing. - "E": - Corresponding region is used exclusively by - one resource group. No sharing allowed. - "P": - Corresponding region is pseudo-locked. No - sharing allowed. -"sparse_masks": - Indicates if non-contiguous 1s value in CBM is supported. - - "0": - Only contiguous 1s value in CBM is supported. - "1": - Non-contiguous 1s value in CBM is supported. - -Memory bandwidth(MB) subdirectory contains the following files -with respect to allocation: - -"min_bandwidth": - The minimum memory bandwidth percentage which - user can request. - -"bandwidth_gran": - The granularity in which the memory bandwidth - percentage is allocated. The allocated - b/w percentage is rounded off to the next - control step available on the hardware. The - available bandwidth control steps are: - min_bandwidth + N * bandwidth_gran. - -"delay_linear": - Indicates if the delay scale is linear or - non-linear. This field is purely informational - only. - -"thread_throttle_mode": - Indicator on Intel systems of how tasks running on threads - of a physical core are throttled in cases where they - request different memory bandwidth percentages: - - "max": - the smallest percentage is applied - to all threads - "per-thread": - bandwidth percentages are directly applied to - the threads running on the core - -If RDT monitoring is available there will be an "L3_MON" directory -with the following files: - -"num_rmids": - The number of RMIDs available. This is the - upper bound for how many "CTRL_MON" + "MON" - groups can be created. - -"mon_features": - Lists the monitoring events if - monitoring is enabled for the resource. - Example:: - - # cat /sys/fs/resctrl/info/L3_MON/mon_features - llc_occupancy - mbm_total_bytes - mbm_local_bytes - - If the system supports Bandwidth Monitoring Event - Configuration (BMEC), then the bandwidth events will - be configurable. The output will be:: - - # cat /sys/fs/resctrl/info/L3_MON/mon_features - llc_occupancy - mbm_total_bytes - mbm_total_bytes_config - mbm_local_bytes - mbm_local_bytes_config - -"mbm_total_bytes_config", "mbm_local_bytes_config": - Read/write files containing the configuration for the mbm_total_bytes - and mbm_local_bytes events, respectively, when the Bandwidth - Monitoring Event Configuration (BMEC) feature is supported. - The event configuration settings are domain specific and affect - all the CPUs in the domain. When either event configuration is - changed, the bandwidth counters for all RMIDs of both events - (mbm_total_bytes as well as mbm_local_bytes) are cleared for that - domain. The next read for every RMID will report "Unavailable" - and subsequent reads will report the valid value. - - Following are the types of events supported: - - ==== ======================================================== - Bits Description - ==== ======================================================== - 6 Dirty Victims from the QOS domain to all types of memory - 5 Reads to slow memory in the non-local NUMA domain - 4 Reads to slow memory in the local NUMA domain - 3 Non-temporal writes to non-local NUMA domain - 2 Non-temporal writes to local NUMA domain - 1 Reads to memory in the non-local NUMA domain - 0 Reads to memory in the local NUMA domain - ==== ======================================================== - - By default, the mbm_total_bytes configuration is set to 0x7f to count - all the event types and the mbm_local_bytes configuration is set to - 0x15 to count all the local memory events. - - Examples: - - * To view the current configuration:: - :: - - # cat /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config - 0=0x7f;1=0x7f;2=0x7f;3=0x7f - - # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config - 0=0x15;1=0x15;3=0x15;4=0x15 - - * To change the mbm_total_bytes to count only reads on domain 0, - the bits 0, 1, 4 and 5 needs to be set, which is 110011b in binary - (in hexadecimal 0x33): - :: - - # echo "0=0x33" > /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config - - # cat /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config - 0=0x33;1=0x7f;2=0x7f;3=0x7f - - * To change the mbm_local_bytes to count all the slow memory reads on - domain 0 and 1, the bits 4 and 5 needs to be set, which is 110000b - in binary (in hexadecimal 0x30): - :: - - # echo "0=0x30;1=0x30" > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config - - # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config - 0=0x30;1=0x30;3=0x15;4=0x15 - -"max_threshold_occupancy": - Read/write file provides the largest value (in - bytes) at which a previously used LLC_occupancy - counter can be considered for re-use. - -Finally, in the top level of the "info" directory there is a file -named "last_cmd_status". This is reset with every "command" issued -via the file system (making new directories or writing to any of the -control files). If the command was successful, it will read as "ok". -If the command failed, it will provide more information that can be -conveyed in the error returns from file operations. E.g. -:: - - # echo L3:0=f7 > schemata - bash: echo: write error: Invalid argument - # cat info/last_cmd_status - mask f7 has non-consecutive 1-bits - -Resource alloc and monitor groups -================================= - -Resource groups are represented as directories in the resctrl file -system. The default group is the root directory which, immediately -after mounting, owns all the tasks and cpus in the system and can make -full use of all resources. - -On a system with RDT control features additional directories can be -created in the root directory that specify different amounts of each -resource (see "schemata" below). The root and these additional top level -directories are referred to as "CTRL_MON" groups below. - -On a system with RDT monitoring the root directory and other top level -directories contain a directory named "mon_groups" in which additional -directories can be created to monitor subsets of tasks in the CTRL_MON -group that is their ancestor. These are called "MON" groups in the rest -of this document. - -Removing a directory will move all tasks and cpus owned by the group it -represents to the parent. Removing one of the created CTRL_MON groups -will automatically remove all MON groups below it. - -Moving MON group directories to a new parent CTRL_MON group is supported -for the purpose of changing the resource allocations of a MON group -without impacting its monitoring data or assigned tasks. This operation -is not allowed for MON groups which monitor CPUs. No other move -operation is currently allowed other than simply renaming a CTRL_MON or -MON group. - -All groups contain the following files: - -"tasks": - Reading this file shows the list of all tasks that belong to - this group. Writing a task id to the file will add a task to the - group. Multiple tasks can be added by separating the task ids - with commas. Tasks will be assigned sequentially. Multiple - failures are not supported. A single failure encountered while - attempting to assign a task will cause the operation to abort and - already added tasks before the failure will remain in the group. - Failures will be logged to /sys/fs/resctrl/info/last_cmd_status. - - If the group is a CTRL_MON group the task is removed from - whichever previous CTRL_MON group owned the task and also from - any MON group that owned the task. If the group is a MON group, - then the task must already belong to the CTRL_MON parent of this - group. The task is removed from any previous MON group. - - -"cpus": - Reading this file shows a bitmask of the logical CPUs owned by - this group. Writing a mask to this file will add and remove - CPUs to/from this group. As with the tasks file a hierarchy is - maintained where MON groups may only include CPUs owned by the - parent CTRL_MON group. - When the resource group is in pseudo-locked mode this file will - only be readable, reflecting the CPUs associated with the - pseudo-locked region. - - -"cpus_list": - Just like "cpus", only using ranges of CPUs instead of bitmasks. - - -When control is enabled all CTRL_MON groups will also contain: - -"schemata": - A list of all the resources available to this group. - Each resource has its own line and format - see below for details. - -"size": - Mirrors the display of the "schemata" file to display the size in - bytes of each allocation instead of the bits representing the - allocation. - -"mode": - The "mode" of the resource group dictates the sharing of its - allocations. A "shareable" resource group allows sharing of its - allocations while an "exclusive" resource group does not. A - cache pseudo-locked region is created by first writing - "pseudo-locksetup" to the "mode" file before writing the cache - pseudo-locked region's schemata to the resource group's "schemata" - file. On successful pseudo-locked region creation the mode will - automatically change to "pseudo-locked". - -"ctrl_hw_id": - Available only with debug option. The identifier used by hardware - for the control group. On x86 this is the CLOSID. - -When monitoring is enabled all MON groups will also contain: - -"mon_data": - This contains a set of files organized by L3 domain and by - RDT event. E.g. on a system with two L3 domains there will - be subdirectories "mon_L3_00" and "mon_L3_01". Each of these - directories have one file per event (e.g. "llc_occupancy", - "mbm_total_bytes", and "mbm_local_bytes"). In a MON group these - files provide a read out of the current value of the event for - all tasks in the group. In CTRL_MON groups these files provide - the sum for all tasks in the CTRL_MON group and all tasks in - MON groups. Please see example section for more details on usage. - On systems with Sub-NUMA Cluster (SNC) enabled there are extra - directories for each node (located within the "mon_L3_XX" directory - for the L3 cache they occupy). These are named "mon_sub_L3_YY" - where "YY" is the node number. - -"mon_hw_id": - Available only with debug option. The identifier used by hardware - for the monitor group. On x86 this is the RMID. - -When the "mba_MBps" mount option is used all CTRL_MON groups will also contain: - -"mba_MBps_event": - Reading this file shows which memory bandwidth event is used - as input to the software feedback loop that keeps memory bandwidth - below the value specified in the schemata file. Writing the - name of one of the supported memory bandwidth events found in - /sys/fs/resctrl/info/L3_MON/mon_features changes the input - event. - -Resource allocation rules -------------------------- - -When a task is running the following rules define which resources are -available to it: - -1) If the task is a member of a non-default group, then the schemata - for that group is used. - -2) Else if the task belongs to the default group, but is running on a - CPU that is assigned to some specific group, then the schemata for the - CPU's group is used. - -3) Otherwise the schemata for the default group is used. - -Resource monitoring rules -------------------------- -1) If a task is a member of a MON group, or non-default CTRL_MON group - then RDT events for the task will be reported in that group. - -2) If a task is a member of the default CTRL_MON group, but is running - on a CPU that is assigned to some specific group, then the RDT events - for the task will be reported in that group. - -3) Otherwise RDT events for the task will be reported in the root level - "mon_data" group. - - -Notes on cache occupancy monitoring and control -=============================================== -When moving a task from one group to another you should remember that -this only affects *new* cache allocations by the task. E.g. you may have -a task in a monitor group showing 3 MB of cache occupancy. If you move -to a new group and immediately check the occupancy of the old and new -groups you will likely see that the old group is still showing 3 MB and -the new group zero. When the task accesses locations still in cache from -before the move, the h/w does not update any counters. On a busy system -you will likely see the occupancy in the old group go down as cache lines -are evicted and re-used while the occupancy in the new group rises as -the task accesses memory and loads into the cache are counted based on -membership in the new group. - -The same applies to cache allocation control. Moving a task to a group -with a smaller cache partition will not evict any cache lines. The -process may continue to use them from the old partition. - -Hardware uses CLOSid(Class of service ID) and an RMID(Resource monitoring ID) -to identify a control group and a monitoring group respectively. Each of -the resource groups are mapped to these IDs based on the kind of group. The -number of CLOSid and RMID are limited by the hardware and hence the creation of -a "CTRL_MON" directory may fail if we run out of either CLOSID or RMID -and creation of "MON" group may fail if we run out of RMIDs. - -max_threshold_occupancy - generic concepts ------------------------------------------- - -Note that an RMID once freed may not be immediately available for use as -the RMID is still tagged the cache lines of the previous user of RMID. -Hence such RMIDs are placed on limbo list and checked back if the cache -occupancy has gone down. If there is a time when system has a lot of -limbo RMIDs but which are not ready to be used, user may see an -EBUSY -during mkdir. - -max_threshold_occupancy is a user configurable value to determine the -occupancy at which an RMID can be freed. - -The mon_llc_occupancy_limbo tracepoint gives the precise occupancy in bytes -for a subset of RMID that are not immediately available for allocation. -This can't be relied on to produce output every second, it may be necessary -to attempt to create an empty monitor group to force an update. Output may -only be produced if creation of a control or monitor group fails. - -Schemata files - general concepts ---------------------------------- -Each line in the file describes one resource. The line starts with -the name of the resource, followed by specific values to be applied -in each of the instances of that resource on the system. - -Cache IDs ---------- -On current generation systems there is one L3 cache per socket and L2 -caches are generally just shared by the hyperthreads on a core, but this -isn't an architectural requirement. We could have multiple separate L3 -caches on a socket, multiple cores could share an L2 cache. So instead -of using "socket" or "core" to define the set of logical cpus sharing -a resource we use a "Cache ID". At a given cache level this will be a -unique number across the whole system (but it isn't guaranteed to be a -contiguous sequence, there may be gaps). To find the ID for each logical -CPU look in /sys/devices/system/cpu/cpu*/cache/index*/id - -Cache Bit Masks (CBM) ---------------------- -For cache resources we describe the portion of the cache that is available -for allocation using a bitmask. The maximum value of the mask is defined -by each cpu model (and may be different for different cache levels). It -is found using CPUID, but is also provided in the "info" directory of -the resctrl file system in "info/{resource}/cbm_mask". Some Intel hardware -requires that these masks have all the '1' bits in a contiguous block. So -0x3, 0x6 and 0xC are legal 4-bit masks with two bits set, but 0x5, 0x9 -and 0xA are not. Check /sys/fs/resctrl/info/{resource}/sparse_masks -if non-contiguous 1s value is supported. On a system with a 20-bit mask -each bit represents 5% of the capacity of the cache. You could partition -the cache into four equal parts with masks: 0x1f, 0x3e0, 0x7c00, 0xf8000. - -Notes on Sub-NUMA Cluster mode -============================== -When SNC mode is enabled, Linux may load balance tasks between Sub-NUMA -nodes much more readily than between regular NUMA nodes since the CPUs -on Sub-NUMA nodes share the same L3 cache and the system may report -the NUMA distance between Sub-NUMA nodes with a lower value than used -for regular NUMA nodes. - -The top-level monitoring files in each "mon_L3_XX" directory provide -the sum of data across all SNC nodes sharing an L3 cache instance. -Users who bind tasks to the CPUs of a specific Sub-NUMA node can read -the "llc_occupancy", "mbm_total_bytes", and "mbm_local_bytes" in the -"mon_sub_L3_YY" directories to get node local data. - -Memory bandwidth allocation is still performed at the L3 cache -level. I.e. throttling controls are applied to all SNC nodes. - -L3 cache allocation bitmaps also apply to all SNC nodes. But note that -the amount of L3 cache represented by each bit is divided by the number -of SNC nodes per L3 cache. E.g. with a 100MB cache on a system with 10-bit -allocation masks each bit normally represents 10MB. With SNC mode enabled -with two SNC nodes per L3 cache, each bit only represents 5MB. - -Memory bandwidth Allocation and monitoring -========================================== - -For Memory bandwidth resource, by default the user controls the resource -by indicating the percentage of total memory bandwidth. - -The minimum bandwidth percentage value for each cpu model is predefined -and can be looked up through "info/MB/min_bandwidth". The bandwidth -granularity that is allocated is also dependent on the cpu model and can -be looked up at "info/MB/bandwidth_gran". The available bandwidth -control steps are: min_bw + N * bw_gran. Intermediate values are rounded -to the next control step available on the hardware. - -The bandwidth throttling is a core specific mechanism on some of Intel -SKUs. Using a high bandwidth and a low bandwidth setting on two threads -sharing a core may result in both threads being throttled to use the -low bandwidth (see "thread_throttle_mode"). - -The fact that Memory bandwidth allocation(MBA) may be a core -specific mechanism where as memory bandwidth monitoring(MBM) is done at -the package level may lead to confusion when users try to apply control -via the MBA and then monitor the bandwidth to see if the controls are -effective. Below are such scenarios: - -1. User may *not* see increase in actual bandwidth when percentage - values are increased: - -This can occur when aggregate L2 external bandwidth is more than L3 -external bandwidth. Consider an SKL SKU with 24 cores on a package and -where L2 external is 10GBps (hence aggregate L2 external bandwidth is -240GBps) and L3 external bandwidth is 100GBps. Now a workload with '20 -threads, having 50% bandwidth, each consuming 5GBps' consumes the max L3 -bandwidth of 100GBps although the percentage value specified is only 50% -<< 100%. Hence increasing the bandwidth percentage will not yield any -more bandwidth. This is because although the L2 external bandwidth still -has capacity, the L3 external bandwidth is fully used. Also note that -this would be dependent on number of cores the benchmark is run on. - -2. Same bandwidth percentage may mean different actual bandwidth - depending on # of threads: - -For the same SKU in #1, a 'single thread, with 10% bandwidth' and '4 -thread, with 10% bandwidth' can consume upto 10GBps and 40GBps although -they have same percentage bandwidth of 10%. This is simply because as -threads start using more cores in an rdtgroup, the actual bandwidth may -increase or vary although user specified bandwidth percentage is same. - -In order to mitigate this and make the interface more user friendly, -resctrl added support for specifying the bandwidth in MiBps as well. The -kernel underneath would use a software feedback mechanism or a "Software -Controller(mba_sc)" which reads the actual bandwidth using MBM counters -and adjust the memory bandwidth percentages to ensure:: - - "actual bandwidth < user specified bandwidth". - -By default, the schemata would take the bandwidth percentage values -where as user can switch to the "MBA software controller" mode using -a mount option 'mba_MBps'. The schemata format is specified in the below -sections. - -L3 schemata file details (code and data prioritization disabled) ----------------------------------------------------------------- -With CDP disabled the L3 schemata format is:: - - L3:=;=;... - -L3 schemata file details (CDP enabled via mount option to resctrl) ------------------------------------------------------------------- -When CDP is enabled L3 control is split into two separate resources -so you can specify independent masks for code and data like this:: - - L3DATA:=;=;... - L3CODE:=;=;... - -L2 schemata file details ------------------------- -CDP is supported at L2 using the 'cdpl2' mount option. The schemata -format is either:: - - L2:=;=;... - -or - - L2DATA:=;=;... - L2CODE:=;=;... - - -Memory bandwidth Allocation (default mode) ------------------------------------------- - -Memory b/w domain is L3 cache. -:: - - MB:=bandwidth0;=bandwidth1;... - -Memory bandwidth Allocation specified in MiBps ----------------------------------------------- - -Memory bandwidth domain is L3 cache. -:: - - MB:=bw_MiBps0;=bw_MiBps1;... - -Slow Memory Bandwidth Allocation (SMBA) ---------------------------------------- -AMD hardware supports Slow Memory Bandwidth Allocation (SMBA). -CXL.memory is the only supported "slow" memory device. With the -support of SMBA, the hardware enables bandwidth allocation on -the slow memory devices. If there are multiple such devices in -the system, the throttling logic groups all the slow sources -together and applies the limit on them as a whole. - -The presence of SMBA (with CXL.memory) is independent of slow memory -devices presence. If there are no such devices on the system, then -configuring SMBA will have no impact on the performance of the system. - -The bandwidth domain for slow memory is L3 cache. Its schemata file -is formatted as: -:: - - SMBA:=bandwidth0;=bandwidth1;... - -Reading/writing the schemata file ---------------------------------- -Reading the schemata file will show the state of all resources -on all domains. When writing you only need to specify those values -which you wish to change. E.g. -:: - - # cat schemata - L3DATA:0=fffff;1=fffff;2=fffff;3=fffff - L3CODE:0=fffff;1=fffff;2=fffff;3=fffff - # echo "L3DATA:2=3c0;" > schemata - # cat schemata - L3DATA:0=fffff;1=fffff;2=3c0;3=fffff - L3CODE:0=fffff;1=fffff;2=fffff;3=fffff - -Reading/writing the schemata file (on AMD systems) --------------------------------------------------- -Reading the schemata file will show the current bandwidth limit on all -domains. The allocated resources are in multiples of one eighth GB/s. -When writing to the file, you need to specify what cache id you wish to -configure the bandwidth limit. - -For example, to allocate 2GB/s limit on the first cache id: - -:: - - # cat schemata - MB:0=2048;1=2048;2=2048;3=2048 - L3:0=ffff;1=ffff;2=ffff;3=ffff - - # echo "MB:1=16" > schemata - # cat schemata - MB:0=2048;1= 16;2=2048;3=2048 - L3:0=ffff;1=ffff;2=ffff;3=ffff - -Reading/writing the schemata file (on AMD systems) with SMBA feature --------------------------------------------------------------------- -Reading and writing the schemata file is the same as without SMBA in -above section. - -For example, to allocate 8GB/s limit on the first cache id: - -:: - - # cat schemata - SMBA:0=2048;1=2048;2=2048;3=2048 - MB:0=2048;1=2048;2=2048;3=2048 - L3:0=ffff;1=ffff;2=ffff;3=ffff - - # echo "SMBA:1=64" > schemata - # cat schemata - SMBA:0=2048;1= 64;2=2048;3=2048 - MB:0=2048;1=2048;2=2048;3=2048 - L3:0=ffff;1=ffff;2=ffff;3=ffff - -Cache Pseudo-Locking -==================== -CAT enables a user to specify the amount of cache space that an -application can fill. Cache pseudo-locking builds on the fact that a -CPU can still read and write data pre-allocated outside its current -allocated area on a cache hit. With cache pseudo-locking, data can be -preloaded into a reserved portion of cache that no application can -fill, and from that point on will only serve cache hits. The cache -pseudo-locked memory is made accessible to user space where an -application can map it into its virtual address space and thus have -a region of memory with reduced average read latency. - -The creation of a cache pseudo-locked region is triggered by a request -from the user to do so that is accompanied by a schemata of the region -to be pseudo-locked. The cache pseudo-locked region is created as follows: - -- Create a CAT allocation CLOSNEW with a CBM matching the schemata - from the user of the cache region that will contain the pseudo-locked - memory. This region must not overlap with any current CAT allocation/CLOS - on the system and no future overlap with this cache region is allowed - while the pseudo-locked region exists. -- Create a contiguous region of memory of the same size as the cache - region. -- Flush the cache, disable hardware prefetchers, disable preemption. -- Make CLOSNEW the active CLOS and touch the allocated memory to load - it into the cache. -- Set the previous CLOS as active. -- At this point the closid CLOSNEW can be released - the cache - pseudo-locked region is protected as long as its CBM does not appear in - any CAT allocation. Even though the cache pseudo-locked region will from - this point on not appear in any CBM of any CLOS an application running with - any CLOS will be able to access the memory in the pseudo-locked region since - the region continues to serve cache hits. -- The contiguous region of memory loaded into the cache is exposed to - user-space as a character device. - -Cache pseudo-locking increases the probability that data will remain -in the cache via carefully configuring the CAT feature and controlling -application behavior. There is no guarantee that data is placed in -cache. Instructions like INVD, WBINVD, CLFLUSH, etc. can still evict -“locked” data from cache. Power management C-states may shrink or -power off cache. Deeper C-states will automatically be restricted on -pseudo-locked region creation. - -It is required that an application using a pseudo-locked region runs -with affinity to the cores (or a subset of the cores) associated -with the cache on which the pseudo-locked region resides. A sanity check -within the code will not allow an application to map pseudo-locked memory -unless it runs with affinity to cores associated with the cache on which the -pseudo-locked region resides. The sanity check is only done during the -initial mmap() handling, there is no enforcement afterwards and the -application self needs to ensure it remains affine to the correct cores. - -Pseudo-locking is accomplished in two stages: - -1) During the first stage the system administrator allocates a portion - of cache that should be dedicated to pseudo-locking. At this time an - equivalent portion of memory is allocated, loaded into allocated - cache portion, and exposed as a character device. -2) During the second stage a user-space application maps (mmap()) the - pseudo-locked memory into its address space. - -Cache Pseudo-Locking Interface ------------------------------- -A pseudo-locked region is created using the resctrl interface as follows: - -1) Create a new resource group by creating a new directory in /sys/fs/resctrl. -2) Change the new resource group's mode to "pseudo-locksetup" by writing - "pseudo-locksetup" to the "mode" file. -3) Write the schemata of the pseudo-locked region to the "schemata" file. All - bits within the schemata should be "unused" according to the "bit_usage" - file. - -On successful pseudo-locked region creation the "mode" file will contain -"pseudo-locked" and a new character device with the same name as the resource -group will exist in /dev/pseudo_lock. This character device can be mmap()'ed -by user space in order to obtain access to the pseudo-locked memory region. - -An example of cache pseudo-locked region creation and usage can be found below. - -Cache Pseudo-Locking Debugging Interface ----------------------------------------- -The pseudo-locking debugging interface is enabled by default (if -CONFIG_DEBUG_FS is enabled) and can be found in /sys/kernel/debug/resctrl. - -There is no explicit way for the kernel to test if a provided memory -location is present in the cache. The pseudo-locking debugging interface uses -the tracing infrastructure to provide two ways to measure cache residency of -the pseudo-locked region: - -1) Memory access latency using the pseudo_lock_mem_latency tracepoint. Data - from these measurements are best visualized using a hist trigger (see - example below). In this test the pseudo-locked region is traversed at - a stride of 32 bytes while hardware prefetchers and preemption - are disabled. This also provides a substitute visualization of cache - hits and misses. -2) Cache hit and miss measurements using model specific precision counters if - available. Depending on the levels of cache on the system the pseudo_lock_l2 - and pseudo_lock_l3 tracepoints are available. - -When a pseudo-locked region is created a new debugfs directory is created for -it in debugfs as /sys/kernel/debug/resctrl/. A single -write-only file, pseudo_lock_measure, is present in this directory. The -measurement of the pseudo-locked region depends on the number written to this -debugfs file: - -1: - writing "1" to the pseudo_lock_measure file will trigger the latency - measurement captured in the pseudo_lock_mem_latency tracepoint. See - example below. -2: - writing "2" to the pseudo_lock_measure file will trigger the L2 cache - residency (cache hits and misses) measurement captured in the - pseudo_lock_l2 tracepoint. See example below. -3: - writing "3" to the pseudo_lock_measure file will trigger the L3 cache - residency (cache hits and misses) measurement captured in the - pseudo_lock_l3 tracepoint. - -All measurements are recorded with the tracing infrastructure. This requires -the relevant tracepoints to be enabled before the measurement is triggered. - -Example of latency debugging interface -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -In this example a pseudo-locked region named "newlock" was created. Here is -how we can measure the latency in cycles of reading from this region and -visualize this data with a histogram that is available if CONFIG_HIST_TRIGGERS -is set:: - - # :> /sys/kernel/tracing/trace - # echo 'hist:keys=latency' > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/trigger - # echo 1 > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/enable - # echo 1 > /sys/kernel/debug/resctrl/newlock/pseudo_lock_measure - # echo 0 > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/enable - # cat /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/hist - - # event histogram - # - # trigger info: hist:keys=latency:vals=hitcount:sort=hitcount:size=2048 [active] - # - - { latency: 456 } hitcount: 1 - { latency: 50 } hitcount: 83 - { latency: 36 } hitcount: 96 - { latency: 44 } hitcount: 174 - { latency: 48 } hitcount: 195 - { latency: 46 } hitcount: 262 - { latency: 42 } hitcount: 693 - { latency: 40 } hitcount: 3204 - { latency: 38 } hitcount: 3484 - - Totals: - Hits: 8192 - Entries: 9 - Dropped: 0 - -Example of cache hits/misses debugging -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -In this example a pseudo-locked region named "newlock" was created on the L2 -cache of a platform. Here is how we can obtain details of the cache hits -and misses using the platform's precision counters. -:: - - # :> /sys/kernel/tracing/trace - # echo 1 > /sys/kernel/tracing/events/resctrl/pseudo_lock_l2/enable - # echo 2 > /sys/kernel/debug/resctrl/newlock/pseudo_lock_measure - # echo 0 > /sys/kernel/tracing/events/resctrl/pseudo_lock_l2/enable - # cat /sys/kernel/tracing/trace - - # tracer: nop - # - # _-----=> irqs-off - # / _----=> need-resched - # | / _---=> hardirq/softirq - # || / _--=> preempt-depth - # ||| / delay - # TASK-PID CPU# |||| TIMESTAMP FUNCTION - # | | | |||| | | - pseudo_lock_mea-1672 [002] .... 3132.860500: pseudo_lock_l2: hits=4097 miss=0 - - -Examples for RDT allocation usage -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -1) Example 1 - -On a two socket machine (one L3 cache per socket) with just four bits -for cache bit masks, minimum b/w of 10% with a memory bandwidth -granularity of 10%. -:: - - # mount -t resctrl resctrl /sys/fs/resctrl - # cd /sys/fs/resctrl - # mkdir p0 p1 - # echo "L3:0=3;1=c\nMB:0=50;1=50" > /sys/fs/resctrl/p0/schemata - # echo "L3:0=3;1=3\nMB:0=50;1=50" > /sys/fs/resctrl/p1/schemata - -The default resource group is unmodified, so we have access to all parts -of all caches (its schemata file reads "L3:0=f;1=f"). - -Tasks that are under the control of group "p0" may only allocate from the -"lower" 50% on cache ID 0, and the "upper" 50% of cache ID 1. -Tasks in group "p1" use the "lower" 50% of cache on both sockets. - -Similarly, tasks that are under the control of group "p0" may use a -maximum memory b/w of 50% on socket0 and 50% on socket 1. -Tasks in group "p1" may also use 50% memory b/w on both sockets. -Note that unlike cache masks, memory b/w cannot specify whether these -allocations can overlap or not. The allocations specifies the maximum -b/w that the group may be able to use and the system admin can configure -the b/w accordingly. - -If resctrl is using the software controller (mba_sc) then user can enter the -max b/w in MB rather than the percentage values. -:: - - # echo "L3:0=3;1=c\nMB:0=1024;1=500" > /sys/fs/resctrl/p0/schemata - # echo "L3:0=3;1=3\nMB:0=1024;1=500" > /sys/fs/resctrl/p1/schemata - -In the above example the tasks in "p1" and "p0" on socket 0 would use a max b/w -of 1024MB where as on socket 1 they would use 500MB. - -2) Example 2 - -Again two sockets, but this time with a more realistic 20-bit mask. - -Two real time tasks pid=1234 running on processor 0 and pid=5678 running on -processor 1 on socket 0 on a 2-socket and dual core machine. To avoid noisy -neighbors, each of the two real-time tasks exclusively occupies one quarter -of L3 cache on socket 0. -:: - - # mount -t resctrl resctrl /sys/fs/resctrl - # cd /sys/fs/resctrl - -First we reset the schemata for the default group so that the "upper" -50% of the L3 cache on socket 0 and 50% of memory b/w cannot be used by -ordinary tasks:: - - # echo "L3:0=3ff;1=fffff\nMB:0=50;1=100" > schemata - -Next we make a resource group for our first real time task and give -it access to the "top" 25% of the cache on socket 0. -:: - - # mkdir p0 - # echo "L3:0=f8000;1=fffff" > p0/schemata - -Finally we move our first real time task into this resource group. We -also use taskset(1) to ensure the task always runs on a dedicated CPU -on socket 0. Most uses of resource groups will also constrain which -processors tasks run on. -:: - - # echo 1234 > p0/tasks - # taskset -cp 1 1234 - -Ditto for the second real time task (with the remaining 25% of cache):: - - # mkdir p1 - # echo "L3:0=7c00;1=fffff" > p1/schemata - # echo 5678 > p1/tasks - # taskset -cp 2 5678 - -For the same 2 socket system with memory b/w resource and CAT L3 the -schemata would look like(Assume min_bandwidth 10 and bandwidth_gran is -10): - -For our first real time task this would request 20% memory b/w on socket 0. -:: - - # echo -e "L3:0=f8000;1=fffff\nMB:0=20;1=100" > p0/schemata - -For our second real time task this would request an other 20% memory b/w -on socket 0. -:: - - # echo -e "L3:0=f8000;1=fffff\nMB:0=20;1=100" > p0/schemata - -3) Example 3 - -A single socket system which has real-time tasks running on core 4-7 and -non real-time workload assigned to core 0-3. The real-time tasks share text -and data, so a per task association is not required and due to interaction -with the kernel it's desired that the kernel on these cores shares L3 with -the tasks. -:: - - # mount -t resctrl resctrl /sys/fs/resctrl - # cd /sys/fs/resctrl - -First we reset the schemata for the default group so that the "upper" -50% of the L3 cache on socket 0, and 50% of memory bandwidth on socket 0 -cannot be used by ordinary tasks:: - - # echo "L3:0=3ff\nMB:0=50" > schemata - -Next we make a resource group for our real time cores and give it access -to the "top" 50% of the cache on socket 0 and 50% of memory bandwidth on -socket 0. -:: - - # mkdir p0 - # echo "L3:0=ffc00\nMB:0=50" > p0/schemata - -Finally we move core 4-7 over to the new group and make sure that the -kernel and the tasks running there get 50% of the cache. They should -also get 50% of memory bandwidth assuming that the cores 4-7 are SMT -siblings and only the real time threads are scheduled on the cores 4-7. -:: - - # echo F0 > p0/cpus - -4) Example 4 - -The resource groups in previous examples were all in the default "shareable" -mode allowing sharing of their cache allocations. If one resource group -configures a cache allocation then nothing prevents another resource group -to overlap with that allocation. - -In this example a new exclusive resource group will be created on a L2 CAT -system with two L2 cache instances that can be configured with an 8-bit -capacity bitmask. The new exclusive resource group will be configured to use -25% of each cache instance. -:: - - # mount -t resctrl resctrl /sys/fs/resctrl/ - # cd /sys/fs/resctrl - -First, we observe that the default group is configured to allocate to all L2 -cache:: - - # cat schemata - L2:0=ff;1=ff - -We could attempt to create the new resource group at this point, but it will -fail because of the overlap with the schemata of the default group:: - - # mkdir p0 - # echo 'L2:0=0x3;1=0x3' > p0/schemata - # cat p0/mode - shareable - # echo exclusive > p0/mode - -sh: echo: write error: Invalid argument - # cat info/last_cmd_status - schemata overlaps - -To ensure that there is no overlap with another resource group the default -resource group's schemata has to change, making it possible for the new -resource group to become exclusive. -:: - - # echo 'L2:0=0xfc;1=0xfc' > schemata - # echo exclusive > p0/mode - # grep . p0/* - p0/cpus:0 - p0/mode:exclusive - p0/schemata:L2:0=03;1=03 - p0/size:L2:0=262144;1=262144 - -A new resource group will on creation not overlap with an exclusive resource -group:: - - # mkdir p1 - # grep . p1/* - p1/cpus:0 - p1/mode:shareable - p1/schemata:L2:0=fc;1=fc - p1/size:L2:0=786432;1=786432 - -The bit_usage will reflect how the cache is used:: - - # cat info/L2/bit_usage - 0=SSSSSSEE;1=SSSSSSEE - -A resource group cannot be forced to overlap with an exclusive resource group:: - - # echo 'L2:0=0x1;1=0x1' > p1/schemata - -sh: echo: write error: Invalid argument - # cat info/last_cmd_status - overlaps with exclusive group - -Example of Cache Pseudo-Locking -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Lock portion of L2 cache from cache id 1 using CBM 0x3. Pseudo-locked -region is exposed at /dev/pseudo_lock/newlock that can be provided to -application for argument to mmap(). -:: - - # mount -t resctrl resctrl /sys/fs/resctrl/ - # cd /sys/fs/resctrl - -Ensure that there are bits available that can be pseudo-locked, since only -unused bits can be pseudo-locked the bits to be pseudo-locked needs to be -removed from the default resource group's schemata:: - - # cat info/L2/bit_usage - 0=SSSSSSSS;1=SSSSSSSS - # echo 'L2:1=0xfc' > schemata - # cat info/L2/bit_usage - 0=SSSSSSSS;1=SSSSSS00 - -Create a new resource group that will be associated with the pseudo-locked -region, indicate that it will be used for a pseudo-locked region, and -configure the requested pseudo-locked region capacity bitmask:: - - # mkdir newlock - # echo pseudo-locksetup > newlock/mode - # echo 'L2:1=0x3' > newlock/schemata - -On success the resource group's mode will change to pseudo-locked, the -bit_usage will reflect the pseudo-locked region, and the character device -exposing the pseudo-locked region will exist:: - - # cat newlock/mode - pseudo-locked - # cat info/L2/bit_usage - 0=SSSSSSSS;1=SSSSSSPP - # ls -l /dev/pseudo_lock/newlock - crw------- 1 root root 243, 0 Apr 3 05:01 /dev/pseudo_lock/newlock - -:: - - /* - * Example code to access one page of pseudo-locked cache region - * from user space. - */ - #define _GNU_SOURCE - #include - #include - #include - #include - #include - #include - - /* - * It is required that the application runs with affinity to only - * cores associated with the pseudo-locked region. Here the cpu - * is hardcoded for convenience of example. - */ - static int cpuid = 2; - - int main(int argc, char *argv[]) - { - cpu_set_t cpuset; - long page_size; - void *mapping; - int dev_fd; - int ret; - - page_size = sysconf(_SC_PAGESIZE); - - CPU_ZERO(&cpuset); - CPU_SET(cpuid, &cpuset); - ret = sched_setaffinity(0, sizeof(cpuset), &cpuset); - if (ret < 0) { - perror("sched_setaffinity"); - exit(EXIT_FAILURE); - } - - dev_fd = open("/dev/pseudo_lock/newlock", O_RDWR); - if (dev_fd < 0) { - perror("open"); - exit(EXIT_FAILURE); - } - - mapping = mmap(0, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, - dev_fd, 0); - if (mapping == MAP_FAILED) { - perror("mmap"); - close(dev_fd); - exit(EXIT_FAILURE); - } - - /* Application interacts with pseudo-locked memory @mapping */ - - ret = munmap(mapping, page_size); - if (ret < 0) { - perror("munmap"); - close(dev_fd); - exit(EXIT_FAILURE); - } - - close(dev_fd); - exit(EXIT_SUCCESS); - } - -Locking between applications ----------------------------- - -Certain operations on the resctrl filesystem, composed of read/writes -to/from multiple files, must be atomic. - -As an example, the allocation of an exclusive reservation of L3 cache -involves: - - 1. Read the cbmmasks from each directory or the per-resource "bit_usage" - 2. Find a contiguous set of bits in the global CBM bitmask that is clear - in any of the directory cbmmasks - 3. Create a new directory - 4. Set the bits found in step 2 to the new directory "schemata" file - -If two applications attempt to allocate space concurrently then they can -end up allocating the same bits so the reservations are shared instead of -exclusive. - -To coordinate atomic operations on the resctrlfs and to avoid the problem -above, the following locking procedure is recommended: - -Locking is based on flock, which is available in libc and also as a shell -script command - -Write lock: - - A) Take flock(LOCK_EX) on /sys/fs/resctrl - B) Read/write the directory structure. - C) funlock - -Read lock: - - A) Take flock(LOCK_SH) on /sys/fs/resctrl - B) If success read the directory structure. - C) funlock - -Example with bash:: - - # Atomically read directory structure - $ flock -s /sys/fs/resctrl/ find /sys/fs/resctrl - - # Read directory contents and create new subdirectory - - $ cat create-dir.sh - find /sys/fs/resctrl/ > output.txt - mask = function-of(output.txt) - mkdir /sys/fs/resctrl/newres/ - echo mask > /sys/fs/resctrl/newres/schemata - - $ flock /sys/fs/resctrl/ ./create-dir.sh - -Example with C:: - - /* - * Example code do take advisory locks - * before accessing resctrl filesystem - */ - #include - #include - - void resctrl_take_shared_lock(int fd) - { - int ret; - - /* take shared lock on resctrl filesystem */ - ret = flock(fd, LOCK_SH); - if (ret) { - perror("flock"); - exit(-1); - } - } - - void resctrl_take_exclusive_lock(int fd) - { - int ret; - - /* release lock on resctrl filesystem */ - ret = flock(fd, LOCK_EX); - if (ret) { - perror("flock"); - exit(-1); - } - } - - void resctrl_release_lock(int fd) - { - int ret; - - /* take shared lock on resctrl filesystem */ - ret = flock(fd, LOCK_UN); - if (ret) { - perror("flock"); - exit(-1); - } - } - - void main(void) - { - int fd, ret; - - fd = open("/sys/fs/resctrl", O_DIRECTORY); - if (fd == -1) { - perror("open"); - exit(-1); - } - resctrl_take_shared_lock(fd); - /* code to read directory contents */ - resctrl_release_lock(fd); - - resctrl_take_exclusive_lock(fd); - /* code to read and write directory contents */ - resctrl_release_lock(fd); - } - -Examples for RDT Monitoring along with allocation usage -======================================================= -Reading monitored data ----------------------- -Reading an event file (for ex: mon_data/mon_L3_00/llc_occupancy) would -show the current snapshot of LLC occupancy of the corresponding MON -group or CTRL_MON group. - - -Example 1 (Monitor CTRL_MON group and subset of tasks in CTRL_MON group) ------------------------------------------------------------------------- -On a two socket machine (one L3 cache per socket) with just four bits -for cache bit masks:: - - # mount -t resctrl resctrl /sys/fs/resctrl - # cd /sys/fs/resctrl - # mkdir p0 p1 - # echo "L3:0=3;1=c" > /sys/fs/resctrl/p0/schemata - # echo "L3:0=3;1=3" > /sys/fs/resctrl/p1/schemata - # echo 5678 > p1/tasks - # echo 5679 > p1/tasks - -The default resource group is unmodified, so we have access to all parts -of all caches (its schemata file reads "L3:0=f;1=f"). - -Tasks that are under the control of group "p0" may only allocate from the -"lower" 50% on cache ID 0, and the "upper" 50% of cache ID 1. -Tasks in group "p1" use the "lower" 50% of cache on both sockets. - -Create monitor groups and assign a subset of tasks to each monitor group. -:: - - # cd /sys/fs/resctrl/p1/mon_groups - # mkdir m11 m12 - # echo 5678 > m11/tasks - # echo 5679 > m12/tasks - -fetch data (data shown in bytes) -:: - - # cat m11/mon_data/mon_L3_00/llc_occupancy - 16234000 - # cat m11/mon_data/mon_L3_01/llc_occupancy - 14789000 - # cat m12/mon_data/mon_L3_00/llc_occupancy - 16789000 - -The parent ctrl_mon group shows the aggregated data. -:: - - # cat /sys/fs/resctrl/p1/mon_data/mon_l3_00/llc_occupancy - 31234000 - -Example 2 (Monitor a task from its creation) --------------------------------------------- -On a two socket machine (one L3 cache per socket):: - - # mount -t resctrl resctrl /sys/fs/resctrl - # cd /sys/fs/resctrl - # mkdir p0 p1 - -An RMID is allocated to the group once its created and hence the -below is monitored from its creation. -:: - - # echo $$ > /sys/fs/resctrl/p1/tasks - # - -Fetch the data:: - - # cat /sys/fs/resctrl/p1/mon_data/mon_l3_00/llc_occupancy - 31789000 - -Example 3 (Monitor without CAT support or before creating CAT groups) ---------------------------------------------------------------------- - -Assume a system like HSW has only CQM and no CAT support. In this case -the resctrl will still mount but cannot create CTRL_MON directories. -But user can create different MON groups within the root group thereby -able to monitor all tasks including kernel threads. - -This can also be used to profile jobs cache size footprint before being -able to allocate them to different allocation groups. -:: - - # mount -t resctrl resctrl /sys/fs/resctrl - # cd /sys/fs/resctrl - # mkdir mon_groups/m01 - # mkdir mon_groups/m02 - - # echo 3478 > /sys/fs/resctrl/mon_groups/m01/tasks - # echo 2467 > /sys/fs/resctrl/mon_groups/m02/tasks - -Monitor the groups separately and also get per domain data. From the -below its apparent that the tasks are mostly doing work on -domain(socket) 0. -:: - - # cat /sys/fs/resctrl/mon_groups/m01/mon_L3_00/llc_occupancy - 31234000 - # cat /sys/fs/resctrl/mon_groups/m01/mon_L3_01/llc_occupancy - 34555 - # cat /sys/fs/resctrl/mon_groups/m02/mon_L3_00/llc_occupancy - 31234000 - # cat /sys/fs/resctrl/mon_groups/m02/mon_L3_01/llc_occupancy - 32789 - - -Example 4 (Monitor real time tasks) ------------------------------------ - -A single socket system which has real time tasks running on cores 4-7 -and non real time tasks on other cpus. We want to monitor the cache -occupancy of the real time threads on these cores. -:: - - # mount -t resctrl resctrl /sys/fs/resctrl - # cd /sys/fs/resctrl - # mkdir p1 - -Move the cpus 4-7 over to p1:: - - # echo f0 > p1/cpus - -View the llc occupancy snapshot:: - - # cat /sys/fs/resctrl/p1/mon_data/mon_L3_00/llc_occupancy - 11234000 - -Intel RDT Errata -================ - -Intel MBM Counters May Report System Memory Bandwidth Incorrectly ------------------------------------------------------------------ - -Errata SKX99 for Skylake server and BDF102 for Broadwell server. - -Problem: Intel Memory Bandwidth Monitoring (MBM) counters track metrics -according to the assigned Resource Monitor ID (RMID) for that logical -core. The IA32_QM_CTR register (MSR 0xC8E), used to report these -metrics, may report incorrect system bandwidth for certain RMID values. - -Implication: Due to the errata, system memory bandwidth may not match -what is reported. - -Workaround: MBM total and local readings are corrected according to the -following correction factor table: - -+---------------+---------------+---------------+-----------------+ -|core count |rmid count |rmid threshold |correction factor| -+---------------+---------------+---------------+-----------------+ -|1 |8 |0 |1.000000 | -+---------------+---------------+---------------+-----------------+ -|2 |16 |0 |1.000000 | -+---------------+---------------+---------------+-----------------+ -|3 |24 |15 |0.969650 | -+---------------+---------------+---------------+-----------------+ -|4 |32 |0 |1.000000 | -+---------------+---------------+---------------+-----------------+ -|6 |48 |31 |0.969650 | -+---------------+---------------+---------------+-----------------+ -|7 |56 |47 |1.142857 | -+---------------+---------------+---------------+-----------------+ -|8 |64 |0 |1.000000 | -+---------------+---------------+---------------+-----------------+ -|9 |72 |63 |1.185115 | -+---------------+---------------+---------------+-----------------+ -|10 |80 |63 |1.066553 | -+---------------+---------------+---------------+-----------------+ -|11 |88 |79 |1.454545 | -+---------------+---------------+---------------+-----------------+ -|12 |96 |0 |1.000000 | -+---------------+---------------+---------------+-----------------+ -|13 |104 |95 |1.230769 | -+---------------+---------------+---------------+-----------------+ -|14 |112 |95 |1.142857 | -+---------------+---------------+---------------+-----------------+ -|15 |120 |95 |1.066667 | -+---------------+---------------+---------------+-----------------+ -|16 |128 |0 |1.000000 | -+---------------+---------------+---------------+-----------------+ -|17 |136 |127 |1.254863 | -+---------------+---------------+---------------+-----------------+ -|18 |144 |127 |1.185255 | -+---------------+---------------+---------------+-----------------+ -|19 |152 |0 |1.000000 | -+---------------+---------------+---------------+-----------------+ -|20 |160 |127 |1.066667 | -+---------------+---------------+---------------+-----------------+ -|21 |168 |0 |1.000000 | -+---------------+---------------+---------------+-----------------+ -|22 |176 |159 |1.454334 | -+---------------+---------------+---------------+-----------------+ -|23 |184 |0 |1.000000 | -+---------------+---------------+---------------+-----------------+ -|24 |192 |127 |0.969744 | -+---------------+---------------+---------------+-----------------+ -|25 |200 |191 |1.280246 | -+---------------+---------------+---------------+-----------------+ -|26 |208 |191 |1.230921 | -+---------------+---------------+---------------+-----------------+ -|27 |216 |0 |1.000000 | -+---------------+---------------+---------------+-----------------+ -|28 |224 |191 |1.143118 | -+---------------+---------------+---------------+-----------------+ - -If rmid > rmid threshold, MBM total and local values should be multiplied -by the correction factor. - -See: - -1. Erratum SKX99 in Intel Xeon Processor Scalable Family Specification Update: -http://web.archive.org/web/20200716124958/https://www.intel.com/content/www/us/en/processors/xeon/scalable/xeon-scalable-spec-update.html - -2. Erratum BDF102 in Intel Xeon E5-2600 v4 Processor Product Family Specification Update: -http://web.archive.org/web/20191125200531/https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-e5-v4-spec-update.pdf - -3. The errata in Intel Resource Director Technology (Intel RDT) on 2nd Generation Intel Xeon Scalable Processors Reference Manual: -https://software.intel.com/content/www/us/en/develop/articles/intel-resource-director-technology-rdt-reference-manual.html - -for further information. diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst index a9cf8e950b15..32618512a965 100644 --- a/Documentation/filesystems/index.rst +++ b/Documentation/filesystems/index.rst @@ -113,6 +113,7 @@ Documentation for filesystem implementations. qnx6 ramfs-rootfs-initramfs relay + resctrl romfs smb/index spufs/index diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst new file mode 100644 index 000000000000..c7949dd44f2f --- /dev/null +++ b/Documentation/filesystems/resctrl.rst @@ -0,0 +1,1523 @@ +.. SPDX-License-Identifier: GPL-2.0 +.. include:: + +===================================================== +User Interface for Resource Control feature (resctrl) +===================================================== + +:Copyright: |copy| 2016 Intel Corporation +:Authors: - Fenghua Yu + - Tony Luck + - Vikas Shivappa + + +Intel refers to this feature as Intel Resource Director Technology(Intel(R) RDT). +AMD refers to this feature as AMD Platform Quality of Service(AMD QoS). + +This feature is enabled by the CONFIG_X86_CPU_RESCTRL and the x86 /proc/cpuinfo +flag bits: + +=============================================== ================================ +RDT (Resource Director Technology) Allocation "rdt_a" +CAT (Cache Allocation Technology) "cat_l3", "cat_l2" +CDP (Code and Data Prioritization) "cdp_l3", "cdp_l2" +CQM (Cache QoS Monitoring) "cqm_llc", "cqm_occup_llc" +MBM (Memory Bandwidth Monitoring) "cqm_mbm_total", "cqm_mbm_local" +MBA (Memory Bandwidth Allocation) "mba" +SMBA (Slow Memory Bandwidth Allocation) "" +BMEC (Bandwidth Monitoring Event Configuration) "" +=============================================== ================================ + +Historically, new features were made visible by default in /proc/cpuinfo. This +resulted in the feature flags becoming hard to parse by humans. Adding a new +flag to /proc/cpuinfo should be avoided if user space can obtain information +about the feature from resctrl's info directory. + +To use the feature mount the file system:: + + # mount -t resctrl resctrl [-o cdp[,cdpl2][,mba_MBps][,debug]] /sys/fs/resctrl + +mount options are: + +"cdp": + Enable code/data prioritization in L3 cache allocations. +"cdpl2": + Enable code/data prioritization in L2 cache allocations. +"mba_MBps": + Enable the MBA Software Controller(mba_sc) to specify MBA + bandwidth in MiBps +"debug": + Make debug files accessible. Available debug files are annotated with + "Available only with debug option". + +L2 and L3 CDP are controlled separately. + +RDT features are orthogonal. A particular system may support only +monitoring, only control, or both monitoring and control. Cache +pseudo-locking is a unique way of using cache control to "pin" or +"lock" data in the cache. Details can be found in +"Cache Pseudo-Locking". + + +The mount succeeds if either of allocation or monitoring is present, but +only those files and directories supported by the system will be created. +For more details on the behavior of the interface during monitoring +and allocation, see the "Resource alloc and monitor groups" section. + +Info directory +============== + +The 'info' directory contains information about the enabled +resources. Each resource has its own subdirectory. The subdirectory +names reflect the resource names. + +Each subdirectory contains the following files with respect to +allocation: + +Cache resource(L3/L2) subdirectory contains the following files +related to allocation: + +"num_closids": + The number of CLOSIDs which are valid for this + resource. The kernel uses the smallest number of + CLOSIDs of all enabled resources as limit. +"cbm_mask": + The bitmask which is valid for this resource. + This mask is equivalent to 100%. +"min_cbm_bits": + The minimum number of consecutive bits which + must be set when writing a mask. + +"shareable_bits": + Bitmask of shareable resource with other executing + entities (e.g. I/O). User can use this when + setting up exclusive cache partitions. Note that + some platforms support devices that have their + own settings for cache use which can over-ride + these bits. +"bit_usage": + Annotated capacity bitmasks showing how all + instances of the resource are used. The legend is: + + "0": + Corresponding region is unused. When the system's + resources have been allocated and a "0" is found + in "bit_usage" it is a sign that resources are + wasted. + + "H": + Corresponding region is used by hardware only + but available for software use. If a resource + has bits set in "shareable_bits" but not all + of these bits appear in the resource groups' + schematas then the bits appearing in + "shareable_bits" but no resource group will + be marked as "H". + "X": + Corresponding region is available for sharing and + used by hardware and software. These are the + bits that appear in "shareable_bits" as + well as a resource group's allocation. + "S": + Corresponding region is used by software + and available for sharing. + "E": + Corresponding region is used exclusively by + one resource group. No sharing allowed. + "P": + Corresponding region is pseudo-locked. No + sharing allowed. +"sparse_masks": + Indicates if non-contiguous 1s value in CBM is supported. + + "0": + Only contiguous 1s value in CBM is supported. + "1": + Non-contiguous 1s value in CBM is supported. + +Memory bandwidth(MB) subdirectory contains the following files +with respect to allocation: + +"min_bandwidth": + The minimum memory bandwidth percentage which + user can request. + +"bandwidth_gran": + The granularity in which the memory bandwidth + percentage is allocated. The allocated + b/w percentage is rounded off to the next + control step available on the hardware. The + available bandwidth control steps are: + min_bandwidth + N * bandwidth_gran. + +"delay_linear": + Indicates if the delay scale is linear or + non-linear. This field is purely informational + only. + +"thread_throttle_mode": + Indicator on Intel systems of how tasks running on threads + of a physical core are throttled in cases where they + request different memory bandwidth percentages: + + "max": + the smallest percentage is applied + to all threads + "per-thread": + bandwidth percentages are directly applied to + the threads running on the core + +If RDT monitoring is available there will be an "L3_MON" directory +with the following files: + +"num_rmids": + The number of RMIDs available. This is the + upper bound for how many "CTRL_MON" + "MON" + groups can be created. + +"mon_features": + Lists the monitoring events if + monitoring is enabled for the resource. + Example:: + + # cat /sys/fs/resctrl/info/L3_MON/mon_features + llc_occupancy + mbm_total_bytes + mbm_local_bytes + + If the system supports Bandwidth Monitoring Event + Configuration (BMEC), then the bandwidth events will + be configurable. The output will be:: + + # cat /sys/fs/resctrl/info/L3_MON/mon_features + llc_occupancy + mbm_total_bytes + mbm_total_bytes_config + mbm_local_bytes + mbm_local_bytes_config + +"mbm_total_bytes_config", "mbm_local_bytes_config": + Read/write files containing the configuration for the mbm_total_bytes + and mbm_local_bytes events, respectively, when the Bandwidth + Monitoring Event Configuration (BMEC) feature is supported. + The event configuration settings are domain specific and affect + all the CPUs in the domain. When either event configuration is + changed, the bandwidth counters for all RMIDs of both events + (mbm_total_bytes as well as mbm_local_bytes) are cleared for that + domain. The next read for every RMID will report "Unavailable" + and subsequent reads will report the valid value. + + Following are the types of events supported: + + ==== ======================================================== + Bits Description + ==== ======================================================== + 6 Dirty Victims from the QOS domain to all types of memory + 5 Reads to slow memory in the non-local NUMA domain + 4 Reads to slow memory in the local NUMA domain + 3 Non-temporal writes to non-local NUMA domain + 2 Non-temporal writes to local NUMA domain + 1 Reads to memory in the non-local NUMA domain + 0 Reads to memory in the local NUMA domain + ==== ======================================================== + + By default, the mbm_total_bytes configuration is set to 0x7f to count + all the event types and the mbm_local_bytes configuration is set to + 0x15 to count all the local memory events. + + Examples: + + * To view the current configuration:: + :: + + # cat /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config + 0=0x7f;1=0x7f;2=0x7f;3=0x7f + + # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config + 0=0x15;1=0x15;3=0x15;4=0x15 + + * To change the mbm_total_bytes to count only reads on domain 0, + the bits 0, 1, 4 and 5 needs to be set, which is 110011b in binary + (in hexadecimal 0x33): + :: + + # echo "0=0x33" > /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config + + # cat /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config + 0=0x33;1=0x7f;2=0x7f;3=0x7f + + * To change the mbm_local_bytes to count all the slow memory reads on + domain 0 and 1, the bits 4 and 5 needs to be set, which is 110000b + in binary (in hexadecimal 0x30): + :: + + # echo "0=0x30;1=0x30" > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config + + # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config + 0=0x30;1=0x30;3=0x15;4=0x15 + +"max_threshold_occupancy": + Read/write file provides the largest value (in + bytes) at which a previously used LLC_occupancy + counter can be considered for re-use. + +Finally, in the top level of the "info" directory there is a file +named "last_cmd_status". This is reset with every "command" issued +via the file system (making new directories or writing to any of the +control files). If the command was successful, it will read as "ok". +If the command failed, it will provide more information that can be +conveyed in the error returns from file operations. E.g. +:: + + # echo L3:0=f7 > schemata + bash: echo: write error: Invalid argument + # cat info/last_cmd_status + mask f7 has non-consecutive 1-bits + +Resource alloc and monitor groups +================================= + +Resource groups are represented as directories in the resctrl file +system. The default group is the root directory which, immediately +after mounting, owns all the tasks and cpus in the system and can make +full use of all resources. + +On a system with RDT control features additional directories can be +created in the root directory that specify different amounts of each +resource (see "schemata" below). The root and these additional top level +directories are referred to as "CTRL_MON" groups below. + +On a system with RDT monitoring the root directory and other top level +directories contain a directory named "mon_groups" in which additional +directories can be created to monitor subsets of tasks in the CTRL_MON +group that is their ancestor. These are called "MON" groups in the rest +of this document. + +Removing a directory will move all tasks and cpus owned by the group it +represents to the parent. Removing one of the created CTRL_MON groups +will automatically remove all MON groups below it. + +Moving MON group directories to a new parent CTRL_MON group is supported +for the purpose of changing the resource allocations of a MON group +without impacting its monitoring data or assigned tasks. This operation +is not allowed for MON groups which monitor CPUs. No other move +operation is currently allowed other than simply renaming a CTRL_MON or +MON group. + +All groups contain the following files: + +"tasks": + Reading this file shows the list of all tasks that belong to + this group. Writing a task id to the file will add a task to the + group. Multiple tasks can be added by separating the task ids + with commas. Tasks will be assigned sequentially. Multiple + failures are not supported. A single failure encountered while + attempting to assign a task will cause the operation to abort and + already added tasks before the failure will remain in the group. + Failures will be logged to /sys/fs/resctrl/info/last_cmd_status. + + If the group is a CTRL_MON group the task is removed from + whichever previous CTRL_MON group owned the task and also from + any MON group that owned the task. If the group is a MON group, + then the task must already belong to the CTRL_MON parent of this + group. The task is removed from any previous MON group. + + +"cpus": + Reading this file shows a bitmask of the logical CPUs owned by + this group. Writing a mask to this file will add and remove + CPUs to/from this group. As with the tasks file a hierarchy is + maintained where MON groups may only include CPUs owned by the + parent CTRL_MON group. + When the resource group is in pseudo-locked mode this file will + only be readable, reflecting the CPUs associated with the + pseudo-locked region. + + +"cpus_list": + Just like "cpus", only using ranges of CPUs instead of bitmasks. + + +When control is enabled all CTRL_MON groups will also contain: + +"schemata": + A list of all the resources available to this group. + Each resource has its own line and format - see below for details. + +"size": + Mirrors the display of the "schemata" file to display the size in + bytes of each allocation instead of the bits representing the + allocation. + +"mode": + The "mode" of the resource group dictates the sharing of its + allocations. A "shareable" resource group allows sharing of its + allocations while an "exclusive" resource group does not. A + cache pseudo-locked region is created by first writing + "pseudo-locksetup" to the "mode" file before writing the cache + pseudo-locked region's schemata to the resource group's "schemata" + file. On successful pseudo-locked region creation the mode will + automatically change to "pseudo-locked". + +"ctrl_hw_id": + Available only with debug option. The identifier used by hardware + for the control group. On x86 this is the CLOSID. + +When monitoring is enabled all MON groups will also contain: + +"mon_data": + This contains a set of files organized by L3 domain and by + RDT event. E.g. on a system with two L3 domains there will + be subdirectories "mon_L3_00" and "mon_L3_01". Each of these + directories have one file per event (e.g. "llc_occupancy", + "mbm_total_bytes", and "mbm_local_bytes"). In a MON group these + files provide a read out of the current value of the event for + all tasks in the group. In CTRL_MON groups these files provide + the sum for all tasks in the CTRL_MON group and all tasks in + MON groups. Please see example section for more details on usage. + On systems with Sub-NUMA Cluster (SNC) enabled there are extra + directories for each node (located within the "mon_L3_XX" directory + for the L3 cache they occupy). These are named "mon_sub_L3_YY" + where "YY" is the node number. + +"mon_hw_id": + Available only with debug option. The identifier used by hardware + for the monitor group. On x86 this is the RMID. + +When the "mba_MBps" mount option is used all CTRL_MON groups will also contain: + +"mba_MBps_event": + Reading this file shows which memory bandwidth event is used + as input to the software feedback loop that keeps memory bandwidth + below the value specified in the schemata file. Writing the + name of one of the supported memory bandwidth events found in + /sys/fs/resctrl/info/L3_MON/mon_features changes the input + event. + +Resource allocation rules +------------------------- + +When a task is running the following rules define which resources are +available to it: + +1) If the task is a member of a non-default group, then the schemata + for that group is used. + +2) Else if the task belongs to the default group, but is running on a + CPU that is assigned to some specific group, then the schemata for the + CPU's group is used. + +3) Otherwise the schemata for the default group is used. + +Resource monitoring rules +------------------------- +1) If a task is a member of a MON group, or non-default CTRL_MON group + then RDT events for the task will be reported in that group. + +2) If a task is a member of the default CTRL_MON group, but is running + on a CPU that is assigned to some specific group, then the RDT events + for the task will be reported in that group. + +3) Otherwise RDT events for the task will be reported in the root level + "mon_data" group. + + +Notes on cache occupancy monitoring and control +=============================================== +When moving a task from one group to another you should remember that +this only affects *new* cache allocations by the task. E.g. you may have +a task in a monitor group showing 3 MB of cache occupancy. If you move +to a new group and immediately check the occupancy of the old and new +groups you will likely see that the old group is still showing 3 MB and +the new group zero. When the task accesses locations still in cache from +before the move, the h/w does not update any counters. On a busy system +you will likely see the occupancy in the old group go down as cache lines +are evicted and re-used while the occupancy in the new group rises as +the task accesses memory and loads into the cache are counted based on +membership in the new group. + +The same applies to cache allocation control. Moving a task to a group +with a smaller cache partition will not evict any cache lines. The +process may continue to use them from the old partition. + +Hardware uses CLOSid(Class of service ID) and an RMID(Resource monitoring ID) +to identify a control group and a monitoring group respectively. Each of +the resource groups are mapped to these IDs based on the kind of group. The +number of CLOSid and RMID are limited by the hardware and hence the creation of +a "CTRL_MON" directory may fail if we run out of either CLOSID or RMID +and creation of "MON" group may fail if we run out of RMIDs. + +max_threshold_occupancy - generic concepts +------------------------------------------ + +Note that an RMID once freed may not be immediately available for use as +the RMID is still tagged the cache lines of the previous user of RMID. +Hence such RMIDs are placed on limbo list and checked back if the cache +occupancy has gone down. If there is a time when system has a lot of +limbo RMIDs but which are not ready to be used, user may see an -EBUSY +during mkdir. + +max_threshold_occupancy is a user configurable value to determine the +occupancy at which an RMID can be freed. + +The mon_llc_occupancy_limbo tracepoint gives the precise occupancy in bytes +for a subset of RMID that are not immediately available for allocation. +This can't be relied on to produce output every second, it may be necessary +to attempt to create an empty monitor group to force an update. Output may +only be produced if creation of a control or monitor group fails. + +Schemata files - general concepts +--------------------------------- +Each line in the file describes one resource. The line starts with +the name of the resource, followed by specific values to be applied +in each of the instances of that resource on the system. + +Cache IDs +--------- +On current generation systems there is one L3 cache per socket and L2 +caches are generally just shared by the hyperthreads on a core, but this +isn't an architectural requirement. We could have multiple separate L3 +caches on a socket, multiple cores could share an L2 cache. So instead +of using "socket" or "core" to define the set of logical cpus sharing +a resource we use a "Cache ID". At a given cache level this will be a +unique number across the whole system (but it isn't guaranteed to be a +contiguous sequence, there may be gaps). To find the ID for each logical +CPU look in /sys/devices/system/cpu/cpu*/cache/index*/id + +Cache Bit Masks (CBM) +--------------------- +For cache resources we describe the portion of the cache that is available +for allocation using a bitmask. The maximum value of the mask is defined +by each cpu model (and may be different for different cache levels). It +is found using CPUID, but is also provided in the "info" directory of +the resctrl file system in "info/{resource}/cbm_mask". Some Intel hardware +requires that these masks have all the '1' bits in a contiguous block. So +0x3, 0x6 and 0xC are legal 4-bit masks with two bits set, but 0x5, 0x9 +and 0xA are not. Check /sys/fs/resctrl/info/{resource}/sparse_masks +if non-contiguous 1s value is supported. On a system with a 20-bit mask +each bit represents 5% of the capacity of the cache. You could partition +the cache into four equal parts with masks: 0x1f, 0x3e0, 0x7c00, 0xf8000. + +Notes on Sub-NUMA Cluster mode +============================== +When SNC mode is enabled, Linux may load balance tasks between Sub-NUMA +nodes much more readily than between regular NUMA nodes since the CPUs +on Sub-NUMA nodes share the same L3 cache and the system may report +the NUMA distance between Sub-NUMA nodes with a lower value than used +for regular NUMA nodes. + +The top-level monitoring files in each "mon_L3_XX" directory provide +the sum of data across all SNC nodes sharing an L3 cache instance. +Users who bind tasks to the CPUs of a specific Sub-NUMA node can read +the "llc_occupancy", "mbm_total_bytes", and "mbm_local_bytes" in the +"mon_sub_L3_YY" directories to get node local data. + +Memory bandwidth allocation is still performed at the L3 cache +level. I.e. throttling controls are applied to all SNC nodes. + +L3 cache allocation bitmaps also apply to all SNC nodes. But note that +the amount of L3 cache represented by each bit is divided by the number +of SNC nodes per L3 cache. E.g. with a 100MB cache on a system with 10-bit +allocation masks each bit normally represents 10MB. With SNC mode enabled +with two SNC nodes per L3 cache, each bit only represents 5MB. + +Memory bandwidth Allocation and monitoring +========================================== + +For Memory bandwidth resource, by default the user controls the resource +by indicating the percentage of total memory bandwidth. + +The minimum bandwidth percentage value for each cpu model is predefined +and can be looked up through "info/MB/min_bandwidth". The bandwidth +granularity that is allocated is also dependent on the cpu model and can +be looked up at "info/MB/bandwidth_gran". The available bandwidth +control steps are: min_bw + N * bw_gran. Intermediate values are rounded +to the next control step available on the hardware. + +The bandwidth throttling is a core specific mechanism on some of Intel +SKUs. Using a high bandwidth and a low bandwidth setting on two threads +sharing a core may result in both threads being throttled to use the +low bandwidth (see "thread_throttle_mode"). + +The fact that Memory bandwidth allocation(MBA) may be a core +specific mechanism where as memory bandwidth monitoring(MBM) is done at +the package level may lead to confusion when users try to apply control +via the MBA and then monitor the bandwidth to see if the controls are +effective. Below are such scenarios: + +1. User may *not* see increase in actual bandwidth when percentage + values are increased: + +This can occur when aggregate L2 external bandwidth is more than L3 +external bandwidth. Consider an SKL SKU with 24 cores on a package and +where L2 external is 10GBps (hence aggregate L2 external bandwidth is +240GBps) and L3 external bandwidth is 100GBps. Now a workload with '20 +threads, having 50% bandwidth, each consuming 5GBps' consumes the max L3 +bandwidth of 100GBps although the percentage value specified is only 50% +<< 100%. Hence increasing the bandwidth percentage will not yield any +more bandwidth. This is because although the L2 external bandwidth still +has capacity, the L3 external bandwidth is fully used. Also note that +this would be dependent on number of cores the benchmark is run on. + +2. Same bandwidth percentage may mean different actual bandwidth + depending on # of threads: + +For the same SKU in #1, a 'single thread, with 10% bandwidth' and '4 +thread, with 10% bandwidth' can consume upto 10GBps and 40GBps although +they have same percentage bandwidth of 10%. This is simply because as +threads start using more cores in an rdtgroup, the actual bandwidth may +increase or vary although user specified bandwidth percentage is same. + +In order to mitigate this and make the interface more user friendly, +resctrl added support for specifying the bandwidth in MiBps as well. The +kernel underneath would use a software feedback mechanism or a "Software +Controller(mba_sc)" which reads the actual bandwidth using MBM counters +and adjust the memory bandwidth percentages to ensure:: + + "actual bandwidth < user specified bandwidth". + +By default, the schemata would take the bandwidth percentage values +where as user can switch to the "MBA software controller" mode using +a mount option 'mba_MBps'. The schemata format is specified in the below +sections. + +L3 schemata file details (code and data prioritization disabled) +---------------------------------------------------------------- +With CDP disabled the L3 schemata format is:: + + L3:=;=;... + +L3 schemata file details (CDP enabled via mount option to resctrl) +------------------------------------------------------------------ +When CDP is enabled L3 control is split into two separate resources +so you can specify independent masks for code and data like this:: + + L3DATA:=;=;... + L3CODE:=;=;... + +L2 schemata file details +------------------------ +CDP is supported at L2 using the 'cdpl2' mount option. The schemata +format is either:: + + L2:=;=;... + +or + + L2DATA:=;=;... + L2CODE:=;=;... + + +Memory bandwidth Allocation (default mode) +------------------------------------------ + +Memory b/w domain is L3 cache. +:: + + MB:=bandwidth0;=bandwidth1;... + +Memory bandwidth Allocation specified in MiBps +---------------------------------------------- + +Memory bandwidth domain is L3 cache. +:: + + MB:=bw_MiBps0;=bw_MiBps1;... + +Slow Memory Bandwidth Allocation (SMBA) +--------------------------------------- +AMD hardware supports Slow Memory Bandwidth Allocation (SMBA). +CXL.memory is the only supported "slow" memory device. With the +support of SMBA, the hardware enables bandwidth allocation on +the slow memory devices. If there are multiple such devices in +the system, the throttling logic groups all the slow sources +together and applies the limit on them as a whole. + +The presence of SMBA (with CXL.memory) is independent of slow memory +devices presence. If there are no such devices on the system, then +configuring SMBA will have no impact on the performance of the system. + +The bandwidth domain for slow memory is L3 cache. Its schemata file +is formatted as: +:: + + SMBA:=bandwidth0;=bandwidth1;... + +Reading/writing the schemata file +--------------------------------- +Reading the schemata file will show the state of all resources +on all domains. When writing you only need to specify those values +which you wish to change. E.g. +:: + + # cat schemata + L3DATA:0=fffff;1=fffff;2=fffff;3=fffff + L3CODE:0=fffff;1=fffff;2=fffff;3=fffff + # echo "L3DATA:2=3c0;" > schemata + # cat schemata + L3DATA:0=fffff;1=fffff;2=3c0;3=fffff + L3CODE:0=fffff;1=fffff;2=fffff;3=fffff + +Reading/writing the schemata file (on AMD systems) +-------------------------------------------------- +Reading the schemata file will show the current bandwidth limit on all +domains. The allocated resources are in multiples of one eighth GB/s. +When writing to the file, you need to specify what cache id you wish to +configure the bandwidth limit. + +For example, to allocate 2GB/s limit on the first cache id: + +:: + + # cat schemata + MB:0=2048;1=2048;2=2048;3=2048 + L3:0=ffff;1=ffff;2=ffff;3=ffff + + # echo "MB:1=16" > schemata + # cat schemata + MB:0=2048;1= 16;2=2048;3=2048 + L3:0=ffff;1=ffff;2=ffff;3=ffff + +Reading/writing the schemata file (on AMD systems) with SMBA feature +-------------------------------------------------------------------- +Reading and writing the schemata file is the same as without SMBA in +above section. + +For example, to allocate 8GB/s limit on the first cache id: + +:: + + # cat schemata + SMBA:0=2048;1=2048;2=2048;3=2048 + MB:0=2048;1=2048;2=2048;3=2048 + L3:0=ffff;1=ffff;2=ffff;3=ffff + + # echo "SMBA:1=64" > schemata + # cat schemata + SMBA:0=2048;1= 64;2=2048;3=2048 + MB:0=2048;1=2048;2=2048;3=2048 + L3:0=ffff;1=ffff;2=ffff;3=ffff + +Cache Pseudo-Locking +==================== +CAT enables a user to specify the amount of cache space that an +application can fill. Cache pseudo-locking builds on the fact that a +CPU can still read and write data pre-allocated outside its current +allocated area on a cache hit. With cache pseudo-locking, data can be +preloaded into a reserved portion of cache that no application can +fill, and from that point on will only serve cache hits. The cache +pseudo-locked memory is made accessible to user space where an +application can map it into its virtual address space and thus have +a region of memory with reduced average read latency. + +The creation of a cache pseudo-locked region is triggered by a request +from the user to do so that is accompanied by a schemata of the region +to be pseudo-locked. The cache pseudo-locked region is created as follows: + +- Create a CAT allocation CLOSNEW with a CBM matching the schemata + from the user of the cache region that will contain the pseudo-locked + memory. This region must not overlap with any current CAT allocation/CLOS + on the system and no future overlap with this cache region is allowed + while the pseudo-locked region exists. +- Create a contiguous region of memory of the same size as the cache + region. +- Flush the cache, disable hardware prefetchers, disable preemption. +- Make CLOSNEW the active CLOS and touch the allocated memory to load + it into the cache. +- Set the previous CLOS as active. +- At this point the closid CLOSNEW can be released - the cache + pseudo-locked region is protected as long as its CBM does not appear in + any CAT allocation. Even though the cache pseudo-locked region will from + this point on not appear in any CBM of any CLOS an application running with + any CLOS will be able to access the memory in the pseudo-locked region since + the region continues to serve cache hits. +- The contiguous region of memory loaded into the cache is exposed to + user-space as a character device. + +Cache pseudo-locking increases the probability that data will remain +in the cache via carefully configuring the CAT feature and controlling +application behavior. There is no guarantee that data is placed in +cache. Instructions like INVD, WBINVD, CLFLUSH, etc. can still evict +“locked” data from cache. Power management C-states may shrink or +power off cache. Deeper C-states will automatically be restricted on +pseudo-locked region creation. + +It is required that an application using a pseudo-locked region runs +with affinity to the cores (or a subset of the cores) associated +with the cache on which the pseudo-locked region resides. A sanity check +within the code will not allow an application to map pseudo-locked memory +unless it runs with affinity to cores associated with the cache on which the +pseudo-locked region resides. The sanity check is only done during the +initial mmap() handling, there is no enforcement afterwards and the +application self needs to ensure it remains affine to the correct cores. + +Pseudo-locking is accomplished in two stages: + +1) During the first stage the system administrator allocates a portion + of cache that should be dedicated to pseudo-locking. At this time an + equivalent portion of memory is allocated, loaded into allocated + cache portion, and exposed as a character device. +2) During the second stage a user-space application maps (mmap()) the + pseudo-locked memory into its address space. + +Cache Pseudo-Locking Interface +------------------------------ +A pseudo-locked region is created using the resctrl interface as follows: + +1) Create a new resource group by creating a new directory in /sys/fs/resctrl. +2) Change the new resource group's mode to "pseudo-locksetup" by writing + "pseudo-locksetup" to the "mode" file. +3) Write the schemata of the pseudo-locked region to the "schemata" file. All + bits within the schemata should be "unused" according to the "bit_usage" + file. + +On successful pseudo-locked region creation the "mode" file will contain +"pseudo-locked" and a new character device with the same name as the resource +group will exist in /dev/pseudo_lock. This character device can be mmap()'ed +by user space in order to obtain access to the pseudo-locked memory region. + +An example of cache pseudo-locked region creation and usage can be found below. + +Cache Pseudo-Locking Debugging Interface +---------------------------------------- +The pseudo-locking debugging interface is enabled by default (if +CONFIG_DEBUG_FS is enabled) and can be found in /sys/kernel/debug/resctrl. + +There is no explicit way for the kernel to test if a provided memory +location is present in the cache. The pseudo-locking debugging interface uses +the tracing infrastructure to provide two ways to measure cache residency of +the pseudo-locked region: + +1) Memory access latency using the pseudo_lock_mem_latency tracepoint. Data + from these measurements are best visualized using a hist trigger (see + example below). In this test the pseudo-locked region is traversed at + a stride of 32 bytes while hardware prefetchers and preemption + are disabled. This also provides a substitute visualization of cache + hits and misses. +2) Cache hit and miss measurements using model specific precision counters if + available. Depending on the levels of cache on the system the pseudo_lock_l2 + and pseudo_lock_l3 tracepoints are available. + +When a pseudo-locked region is created a new debugfs directory is created for +it in debugfs as /sys/kernel/debug/resctrl/. A single +write-only file, pseudo_lock_measure, is present in this directory. The +measurement of the pseudo-locked region depends on the number written to this +debugfs file: + +1: + writing "1" to the pseudo_lock_measure file will trigger the latency + measurement captured in the pseudo_lock_mem_latency tracepoint. See + example below. +2: + writing "2" to the pseudo_lock_measure file will trigger the L2 cache + residency (cache hits and misses) measurement captured in the + pseudo_lock_l2 tracepoint. See example below. +3: + writing "3" to the pseudo_lock_measure file will trigger the L3 cache + residency (cache hits and misses) measurement captured in the + pseudo_lock_l3 tracepoint. + +All measurements are recorded with the tracing infrastructure. This requires +the relevant tracepoints to be enabled before the measurement is triggered. + +Example of latency debugging interface +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +In this example a pseudo-locked region named "newlock" was created. Here is +how we can measure the latency in cycles of reading from this region and +visualize this data with a histogram that is available if CONFIG_HIST_TRIGGERS +is set:: + + # :> /sys/kernel/tracing/trace + # echo 'hist:keys=latency' > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/trigger + # echo 1 > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/enable + # echo 1 > /sys/kernel/debug/resctrl/newlock/pseudo_lock_measure + # echo 0 > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/enable + # cat /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/hist + + # event histogram + # + # trigger info: hist:keys=latency:vals=hitcount:sort=hitcount:size=2048 [active] + # + + { latency: 456 } hitcount: 1 + { latency: 50 } hitcount: 83 + { latency: 36 } hitcount: 96 + { latency: 44 } hitcount: 174 + { latency: 48 } hitcount: 195 + { latency: 46 } hitcount: 262 + { latency: 42 } hitcount: 693 + { latency: 40 } hitcount: 3204 + { latency: 38 } hitcount: 3484 + + Totals: + Hits: 8192 + Entries: 9 + Dropped: 0 + +Example of cache hits/misses debugging +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +In this example a pseudo-locked region named "newlock" was created on the L2 +cache of a platform. Here is how we can obtain details of the cache hits +and misses using the platform's precision counters. +:: + + # :> /sys/kernel/tracing/trace + # echo 1 > /sys/kernel/tracing/events/resctrl/pseudo_lock_l2/enable + # echo 2 > /sys/kernel/debug/resctrl/newlock/pseudo_lock_measure + # echo 0 > /sys/kernel/tracing/events/resctrl/pseudo_lock_l2/enable + # cat /sys/kernel/tracing/trace + + # tracer: nop + # + # _-----=> irqs-off + # / _----=> need-resched + # | / _---=> hardirq/softirq + # || / _--=> preempt-depth + # ||| / delay + # TASK-PID CPU# |||| TIMESTAMP FUNCTION + # | | | |||| | | + pseudo_lock_mea-1672 [002] .... 3132.860500: pseudo_lock_l2: hits=4097 miss=0 + + +Examples for RDT allocation usage +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +1) Example 1 + +On a two socket machine (one L3 cache per socket) with just four bits +for cache bit masks, minimum b/w of 10% with a memory bandwidth +granularity of 10%. +:: + + # mount -t resctrl resctrl /sys/fs/resctrl + # cd /sys/fs/resctrl + # mkdir p0 p1 + # echo "L3:0=3;1=c\nMB:0=50;1=50" > /sys/fs/resctrl/p0/schemata + # echo "L3:0=3;1=3\nMB:0=50;1=50" > /sys/fs/resctrl/p1/schemata + +The default resource group is unmodified, so we have access to all parts +of all caches (its schemata file reads "L3:0=f;1=f"). + +Tasks that are under the control of group "p0" may only allocate from the +"lower" 50% on cache ID 0, and the "upper" 50% of cache ID 1. +Tasks in group "p1" use the "lower" 50% of cache on both sockets. + +Similarly, tasks that are under the control of group "p0" may use a +maximum memory b/w of 50% on socket0 and 50% on socket 1. +Tasks in group "p1" may also use 50% memory b/w on both sockets. +Note that unlike cache masks, memory b/w cannot specify whether these +allocations can overlap or not. The allocations specifies the maximum +b/w that the group may be able to use and the system admin can configure +the b/w accordingly. + +If resctrl is using the software controller (mba_sc) then user can enter the +max b/w in MB rather than the percentage values. +:: + + # echo "L3:0=3;1=c\nMB:0=1024;1=500" > /sys/fs/resctrl/p0/schemata + # echo "L3:0=3;1=3\nMB:0=1024;1=500" > /sys/fs/resctrl/p1/schemata + +In the above example the tasks in "p1" and "p0" on socket 0 would use a max b/w +of 1024MB where as on socket 1 they would use 500MB. + +2) Example 2 + +Again two sockets, but this time with a more realistic 20-bit mask. + +Two real time tasks pid=1234 running on processor 0 and pid=5678 running on +processor 1 on socket 0 on a 2-socket and dual core machine. To avoid noisy +neighbors, each of the two real-time tasks exclusively occupies one quarter +of L3 cache on socket 0. +:: + + # mount -t resctrl resctrl /sys/fs/resctrl + # cd /sys/fs/resctrl + +First we reset the schemata for the default group so that the "upper" +50% of the L3 cache on socket 0 and 50% of memory b/w cannot be used by +ordinary tasks:: + + # echo "L3:0=3ff;1=fffff\nMB:0=50;1=100" > schemata + +Next we make a resource group for our first real time task and give +it access to the "top" 25% of the cache on socket 0. +:: + + # mkdir p0 + # echo "L3:0=f8000;1=fffff" > p0/schemata + +Finally we move our first real time task into this resource group. We +also use taskset(1) to ensure the task always runs on a dedicated CPU +on socket 0. Most uses of resource groups will also constrain which +processors tasks run on. +:: + + # echo 1234 > p0/tasks + # taskset -cp 1 1234 + +Ditto for the second real time task (with the remaining 25% of cache):: + + # mkdir p1 + # echo "L3:0=7c00;1=fffff" > p1/schemata + # echo 5678 > p1/tasks + # taskset -cp 2 5678 + +For the same 2 socket system with memory b/w resource and CAT L3 the +schemata would look like(Assume min_bandwidth 10 and bandwidth_gran is +10): + +For our first real time task this would request 20% memory b/w on socket 0. +:: + + # echo -e "L3:0=f8000;1=fffff\nMB:0=20;1=100" > p0/schemata + +For our second real time task this would request an other 20% memory b/w +on socket 0. +:: + + # echo -e "L3:0=f8000;1=fffff\nMB:0=20;1=100" > p0/schemata + +3) Example 3 + +A single socket system which has real-time tasks running on core 4-7 and +non real-time workload assigned to core 0-3. The real-time tasks share text +and data, so a per task association is not required and due to interaction +with the kernel it's desired that the kernel on these cores shares L3 with +the tasks. +:: + + # mount -t resctrl resctrl /sys/fs/resctrl + # cd /sys/fs/resctrl + +First we reset the schemata for the default group so that the "upper" +50% of the L3 cache on socket 0, and 50% of memory bandwidth on socket 0 +cannot be used by ordinary tasks:: + + # echo "L3:0=3ff\nMB:0=50" > schemata + +Next we make a resource group for our real time cores and give it access +to the "top" 50% of the cache on socket 0 and 50% of memory bandwidth on +socket 0. +:: + + # mkdir p0 + # echo "L3:0=ffc00\nMB:0=50" > p0/schemata + +Finally we move core 4-7 over to the new group and make sure that the +kernel and the tasks running there get 50% of the cache. They should +also get 50% of memory bandwidth assuming that the cores 4-7 are SMT +siblings and only the real time threads are scheduled on the cores 4-7. +:: + + # echo F0 > p0/cpus + +4) Example 4 + +The resource groups in previous examples were all in the default "shareable" +mode allowing sharing of their cache allocations. If one resource group +configures a cache allocation then nothing prevents another resource group +to overlap with that allocation. + +In this example a new exclusive resource group will be created on a L2 CAT +system with two L2 cache instances that can be configured with an 8-bit +capacity bitmask. The new exclusive resource group will be configured to use +25% of each cache instance. +:: + + # mount -t resctrl resctrl /sys/fs/resctrl/ + # cd /sys/fs/resctrl + +First, we observe that the default group is configured to allocate to all L2 +cache:: + + # cat schemata + L2:0=ff;1=ff + +We could attempt to create the new resource group at this point, but it will +fail because of the overlap with the schemata of the default group:: + + # mkdir p0 + # echo 'L2:0=0x3;1=0x3' > p0/schemata + # cat p0/mode + shareable + # echo exclusive > p0/mode + -sh: echo: write error: Invalid argument + # cat info/last_cmd_status + schemata overlaps + +To ensure that there is no overlap with another resource group the default +resource group's schemata has to change, making it possible for the new +resource group to become exclusive. +:: + + # echo 'L2:0=0xfc;1=0xfc' > schemata + # echo exclusive > p0/mode + # grep . p0/* + p0/cpus:0 + p0/mode:exclusive + p0/schemata:L2:0=03;1=03 + p0/size:L2:0=262144;1=262144 + +A new resource group will on creation not overlap with an exclusive resource +group:: + + # mkdir p1 + # grep . p1/* + p1/cpus:0 + p1/mode:shareable + p1/schemata:L2:0=fc;1=fc + p1/size:L2:0=786432;1=786432 + +The bit_usage will reflect how the cache is used:: + + # cat info/L2/bit_usage + 0=SSSSSSEE;1=SSSSSSEE + +A resource group cannot be forced to overlap with an exclusive resource group:: + + # echo 'L2:0=0x1;1=0x1' > p1/schemata + -sh: echo: write error: Invalid argument + # cat info/last_cmd_status + overlaps with exclusive group + +Example of Cache Pseudo-Locking +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Lock portion of L2 cache from cache id 1 using CBM 0x3. Pseudo-locked +region is exposed at /dev/pseudo_lock/newlock that can be provided to +application for argument to mmap(). +:: + + # mount -t resctrl resctrl /sys/fs/resctrl/ + # cd /sys/fs/resctrl + +Ensure that there are bits available that can be pseudo-locked, since only +unused bits can be pseudo-locked the bits to be pseudo-locked needs to be +removed from the default resource group's schemata:: + + # cat info/L2/bit_usage + 0=SSSSSSSS;1=SSSSSSSS + # echo 'L2:1=0xfc' > schemata + # cat info/L2/bit_usage + 0=SSSSSSSS;1=SSSSSS00 + +Create a new resource group that will be associated with the pseudo-locked +region, indicate that it will be used for a pseudo-locked region, and +configure the requested pseudo-locked region capacity bitmask:: + + # mkdir newlock + # echo pseudo-locksetup > newlock/mode + # echo 'L2:1=0x3' > newlock/schemata + +On success the resource group's mode will change to pseudo-locked, the +bit_usage will reflect the pseudo-locked region, and the character device +exposing the pseudo-locked region will exist:: + + # cat newlock/mode + pseudo-locked + # cat info/L2/bit_usage + 0=SSSSSSSS;1=SSSSSSPP + # ls -l /dev/pseudo_lock/newlock + crw------- 1 root root 243, 0 Apr 3 05:01 /dev/pseudo_lock/newlock + +:: + + /* + * Example code to access one page of pseudo-locked cache region + * from user space. + */ + #define _GNU_SOURCE + #include + #include + #include + #include + #include + #include + + /* + * It is required that the application runs with affinity to only + * cores associated with the pseudo-locked region. Here the cpu + * is hardcoded for convenience of example. + */ + static int cpuid = 2; + + int main(int argc, char *argv[]) + { + cpu_set_t cpuset; + long page_size; + void *mapping; + int dev_fd; + int ret; + + page_size = sysconf(_SC_PAGESIZE); + + CPU_ZERO(&cpuset); + CPU_SET(cpuid, &cpuset); + ret = sched_setaffinity(0, sizeof(cpuset), &cpuset); + if (ret < 0) { + perror("sched_setaffinity"); + exit(EXIT_FAILURE); + } + + dev_fd = open("/dev/pseudo_lock/newlock", O_RDWR); + if (dev_fd < 0) { + perror("open"); + exit(EXIT_FAILURE); + } + + mapping = mmap(0, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, + dev_fd, 0); + if (mapping == MAP_FAILED) { + perror("mmap"); + close(dev_fd); + exit(EXIT_FAILURE); + } + + /* Application interacts with pseudo-locked memory @mapping */ + + ret = munmap(mapping, page_size); + if (ret < 0) { + perror("munmap"); + close(dev_fd); + exit(EXIT_FAILURE); + } + + close(dev_fd); + exit(EXIT_SUCCESS); + } + +Locking between applications +---------------------------- + +Certain operations on the resctrl filesystem, composed of read/writes +to/from multiple files, must be atomic. + +As an example, the allocation of an exclusive reservation of L3 cache +involves: + + 1. Read the cbmmasks from each directory or the per-resource "bit_usage" + 2. Find a contiguous set of bits in the global CBM bitmask that is clear + in any of the directory cbmmasks + 3. Create a new directory + 4. Set the bits found in step 2 to the new directory "schemata" file + +If two applications attempt to allocate space concurrently then they can +end up allocating the same bits so the reservations are shared instead of +exclusive. + +To coordinate atomic operations on the resctrlfs and to avoid the problem +above, the following locking procedure is recommended: + +Locking is based on flock, which is available in libc and also as a shell +script command + +Write lock: + + A) Take flock(LOCK_EX) on /sys/fs/resctrl + B) Read/write the directory structure. + C) funlock + +Read lock: + + A) Take flock(LOCK_SH) on /sys/fs/resctrl + B) If success read the directory structure. + C) funlock + +Example with bash:: + + # Atomically read directory structure + $ flock -s /sys/fs/resctrl/ find /sys/fs/resctrl + + # Read directory contents and create new subdirectory + + $ cat create-dir.sh + find /sys/fs/resctrl/ > output.txt + mask = function-of(output.txt) + mkdir /sys/fs/resctrl/newres/ + echo mask > /sys/fs/resctrl/newres/schemata + + $ flock /sys/fs/resctrl/ ./create-dir.sh + +Example with C:: + + /* + * Example code do take advisory locks + * before accessing resctrl filesystem + */ + #include + #include + + void resctrl_take_shared_lock(int fd) + { + int ret; + + /* take shared lock on resctrl filesystem */ + ret = flock(fd, LOCK_SH); + if (ret) { + perror("flock"); + exit(-1); + } + } + + void resctrl_take_exclusive_lock(int fd) + { + int ret; + + /* release lock on resctrl filesystem */ + ret = flock(fd, LOCK_EX); + if (ret) { + perror("flock"); + exit(-1); + } + } + + void resctrl_release_lock(int fd) + { + int ret; + + /* take shared lock on resctrl filesystem */ + ret = flock(fd, LOCK_UN); + if (ret) { + perror("flock"); + exit(-1); + } + } + + void main(void) + { + int fd, ret; + + fd = open("/sys/fs/resctrl", O_DIRECTORY); + if (fd == -1) { + perror("open"); + exit(-1); + } + resctrl_take_shared_lock(fd); + /* code to read directory contents */ + resctrl_release_lock(fd); + + resctrl_take_exclusive_lock(fd); + /* code to read and write directory contents */ + resctrl_release_lock(fd); + } + +Examples for RDT Monitoring along with allocation usage +======================================================= +Reading monitored data +---------------------- +Reading an event file (for ex: mon_data/mon_L3_00/llc_occupancy) would +show the current snapshot of LLC occupancy of the corresponding MON +group or CTRL_MON group. + + +Example 1 (Monitor CTRL_MON group and subset of tasks in CTRL_MON group) +------------------------------------------------------------------------ +On a two socket machine (one L3 cache per socket) with just four bits +for cache bit masks:: + + # mount -t resctrl resctrl /sys/fs/resctrl + # cd /sys/fs/resctrl + # mkdir p0 p1 + # echo "L3:0=3;1=c" > /sys/fs/resctrl/p0/schemata + # echo "L3:0=3;1=3" > /sys/fs/resctrl/p1/schemata + # echo 5678 > p1/tasks + # echo 5679 > p1/tasks + +The default resource group is unmodified, so we have access to all parts +of all caches (its schemata file reads "L3:0=f;1=f"). + +Tasks that are under the control of group "p0" may only allocate from the +"lower" 50% on cache ID 0, and the "upper" 50% of cache ID 1. +Tasks in group "p1" use the "lower" 50% of cache on both sockets. + +Create monitor groups and assign a subset of tasks to each monitor group. +:: + + # cd /sys/fs/resctrl/p1/mon_groups + # mkdir m11 m12 + # echo 5678 > m11/tasks + # echo 5679 > m12/tasks + +fetch data (data shown in bytes) +:: + + # cat m11/mon_data/mon_L3_00/llc_occupancy + 16234000 + # cat m11/mon_data/mon_L3_01/llc_occupancy + 14789000 + # cat m12/mon_data/mon_L3_00/llc_occupancy + 16789000 + +The parent ctrl_mon group shows the aggregated data. +:: + + # cat /sys/fs/resctrl/p1/mon_data/mon_l3_00/llc_occupancy + 31234000 + +Example 2 (Monitor a task from its creation) +-------------------------------------------- +On a two socket machine (one L3 cache per socket):: + + # mount -t resctrl resctrl /sys/fs/resctrl + # cd /sys/fs/resctrl + # mkdir p0 p1 + +An RMID is allocated to the group once its created and hence the +below is monitored from its creation. +:: + + # echo $$ > /sys/fs/resctrl/p1/tasks + # + +Fetch the data:: + + # cat /sys/fs/resctrl/p1/mon_data/mon_l3_00/llc_occupancy + 31789000 + +Example 3 (Monitor without CAT support or before creating CAT groups) +--------------------------------------------------------------------- + +Assume a system like HSW has only CQM and no CAT support. In this case +the resctrl will still mount but cannot create CTRL_MON directories. +But user can create different MON groups within the root group thereby +able to monitor all tasks including kernel threads. + +This can also be used to profile jobs cache size footprint before being +able to allocate them to different allocation groups. +:: + + # mount -t resctrl resctrl /sys/fs/resctrl + # cd /sys/fs/resctrl + # mkdir mon_groups/m01 + # mkdir mon_groups/m02 + + # echo 3478 > /sys/fs/resctrl/mon_groups/m01/tasks + # echo 2467 > /sys/fs/resctrl/mon_groups/m02/tasks + +Monitor the groups separately and also get per domain data. From the +below its apparent that the tasks are mostly doing work on +domain(socket) 0. +:: + + # cat /sys/fs/resctrl/mon_groups/m01/mon_L3_00/llc_occupancy + 31234000 + # cat /sys/fs/resctrl/mon_groups/m01/mon_L3_01/llc_occupancy + 34555 + # cat /sys/fs/resctrl/mon_groups/m02/mon_L3_00/llc_occupancy + 31234000 + # cat /sys/fs/resctrl/mon_groups/m02/mon_L3_01/llc_occupancy + 32789 + + +Example 4 (Monitor real time tasks) +----------------------------------- + +A single socket system which has real time tasks running on cores 4-7 +and non real time tasks on other cpus. We want to monitor the cache +occupancy of the real time threads on these cores. +:: + + # mount -t resctrl resctrl /sys/fs/resctrl + # cd /sys/fs/resctrl + # mkdir p1 + +Move the cpus 4-7 over to p1:: + + # echo f0 > p1/cpus + +View the llc occupancy snapshot:: + + # cat /sys/fs/resctrl/p1/mon_data/mon_L3_00/llc_occupancy + 11234000 + +Intel RDT Errata +================ + +Intel MBM Counters May Report System Memory Bandwidth Incorrectly +----------------------------------------------------------------- + +Errata SKX99 for Skylake server and BDF102 for Broadwell server. + +Problem: Intel Memory Bandwidth Monitoring (MBM) counters track metrics +according to the assigned Resource Monitor ID (RMID) for that logical +core. The IA32_QM_CTR register (MSR 0xC8E), used to report these +metrics, may report incorrect system bandwidth for certain RMID values. + +Implication: Due to the errata, system memory bandwidth may not match +what is reported. + +Workaround: MBM total and local readings are corrected according to the +following correction factor table: + ++---------------+---------------+---------------+-----------------+ +|core count |rmid count |rmid threshold |correction factor| ++---------------+---------------+---------------+-----------------+ +|1 |8 |0 |1.000000 | ++---------------+---------------+---------------+-----------------+ +|2 |16 |0 |1.000000 | ++---------------+---------------+---------------+-----------------+ +|3 |24 |15 |0.969650 | ++---------------+---------------+---------------+-----------------+ +|4 |32 |0 |1.000000 | ++---------------+---------------+---------------+-----------------+ +|6 |48 |31 |0.969650 | ++---------------+---------------+---------------+-----------------+ +|7 |56 |47 |1.142857 | ++---------------+---------------+---------------+-----------------+ +|8 |64 |0 |1.000000 | ++---------------+---------------+---------------+-----------------+ +|9 |72 |63 |1.185115 | ++---------------+---------------+---------------+-----------------+ +|10 |80 |63 |1.066553 | ++---------------+---------------+---------------+-----------------+ +|11 |88 |79 |1.454545 | ++---------------+---------------+---------------+-----------------+ +|12 |96 |0 |1.000000 | ++---------------+---------------+---------------+-----------------+ +|13 |104 |95 |1.230769 | ++---------------+---------------+---------------+-----------------+ +|14 |112 |95 |1.142857 | ++---------------+---------------+---------------+-----------------+ +|15 |120 |95 |1.066667 | ++---------------+---------------+---------------+-----------------+ +|16 |128 |0 |1.000000 | ++---------------+---------------+---------------+-----------------+ +|17 |136 |127 |1.254863 | ++---------------+---------------+---------------+-----------------+ +|18 |144 |127 |1.185255 | ++---------------+---------------+---------------+-----------------+ +|19 |152 |0 |1.000000 | ++---------------+---------------+---------------+-----------------+ +|20 |160 |127 |1.066667 | ++---------------+---------------+---------------+-----------------+ +|21 |168 |0 |1.000000 | ++---------------+---------------+---------------+-----------------+ +|22 |176 |159 |1.454334 | ++---------------+---------------+---------------+-----------------+ +|23 |184 |0 |1.000000 | ++---------------+---------------+---------------+-----------------+ +|24 |192 |127 |0.969744 | ++---------------+---------------+---------------+-----------------+ +|25 |200 |191 |1.280246 | ++---------------+---------------+---------------+-----------------+ +|26 |208 |191 |1.230921 | ++---------------+---------------+---------------+-----------------+ +|27 |216 |0 |1.000000 | ++---------------+---------------+---------------+-----------------+ +|28 |224 |191 |1.143118 | ++---------------+---------------+---------------+-----------------+ + +If rmid > rmid threshold, MBM total and local values should be multiplied +by the correction factor. + +See: + +1. Erratum SKX99 in Intel Xeon Processor Scalable Family Specification Update: +http://web.archive.org/web/20200716124958/https://www.intel.com/content/www/us/en/processors/xeon/scalable/xeon-scalable-spec-update.html + +2. Erratum BDF102 in Intel Xeon E5-2600 v4 Processor Product Family Specification Update: +http://web.archive.org/web/20191125200531/https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-e5-v4-spec-update.pdf + +3. The errata in Intel Resource Director Technology (Intel RDT) on 2nd Generation Intel Xeon Scalable Processors Reference Manual: +https://software.intel.com/content/www/us/en/develop/articles/intel-resource-director-technology-rdt-reference-manual.html + +for further information. diff --git a/MAINTAINERS b/MAINTAINERS index ed96cc7ad662..c56ab7d0b62b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -20424,7 +20424,7 @@ M: Tony Luck M: Reinette Chatre L: linux-kernel@vger.kernel.org S: Supported -F: Documentation/arch/x86/resctrl* +F: Documentation/filesystems/resctrl.rst F: arch/x86/include/asm/resctrl.h F: arch/x86/kernel/cpu/resctrl/ F: fs/resctrl/ diff --git a/arch/x86/kernel/cpu/resctrl/Makefile b/arch/x86/kernel/cpu/resctrl/Makefile index 909be78ec6da..d8a04b195da2 100644 --- a/arch/x86/kernel/cpu/resctrl/Makefile +++ b/arch/x86/kernel/cpu/resctrl/Makefile @@ -5,4 +5,3 @@ obj-$(CONFIG_RESCTRL_FS_PSEUDO_LOCK) += pseudo_lock.o # To allow define_trace.h's recursive include: CFLAGS_pseudo_lock.o = -I$(src) -CFLAGS_monitor.o = -I$(src) diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c index 110b534d400c..1189c0df4ad7 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -16,277 +16,9 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include -#include -#include -#include -#include #include "internal.h" -struct rdt_parse_data { - struct rdtgroup *rdtgrp; - char *buf; -}; - -typedef int (ctrlval_parser_t)(struct rdt_parse_data *data, - struct resctrl_schema *s, - struct rdt_ctrl_domain *d); - -/* - * Check whether MBA bandwidth percentage value is correct. The value is - * checked against the minimum and max bandwidth values specified by the - * hardware. The allocated bandwidth percentage is rounded to the next - * control step available on the hardware. - */ -static bool bw_validate(char *buf, u32 *data, struct rdt_resource *r) -{ - int ret; - u32 bw; - - /* - * Only linear delay values is supported for current Intel SKUs. - */ - if (!r->membw.delay_linear && r->membw.arch_needs_linear) { - rdt_last_cmd_puts("No support for non-linear MB domains\n"); - return false; - } - - ret = kstrtou32(buf, 10, &bw); - if (ret) { - rdt_last_cmd_printf("Invalid MB value %s\n", buf); - return false; - } - - /* Nothing else to do if software controller is enabled. */ - if (is_mba_sc(r)) { - *data = bw; - return true; - } - - if (bw < r->membw.min_bw || bw > r->membw.max_bw) { - rdt_last_cmd_printf("MB value %u out of range [%d,%d]\n", - bw, r->membw.min_bw, r->membw.max_bw); - return false; - } - - *data = roundup(bw, (unsigned long)r->membw.bw_gran); - return true; -} - -static int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s, - struct rdt_ctrl_domain *d) -{ - struct resctrl_staged_config *cfg; - u32 closid = data->rdtgrp->closid; - struct rdt_resource *r = s->res; - u32 bw_val; - - cfg = &d->staged_config[s->conf_type]; - if (cfg->have_new_ctrl) { - rdt_last_cmd_printf("Duplicate domain %d\n", d->hdr.id); - return -EINVAL; - } - - if (!bw_validate(data->buf, &bw_val, r)) - return -EINVAL; - - if (is_mba_sc(r)) { - d->mbps_val[closid] = bw_val; - return 0; - } - - cfg->new_ctrl = bw_val; - cfg->have_new_ctrl = true; - - return 0; -} - -/* - * Check whether a cache bit mask is valid. - * On Intel CPUs, non-contiguous 1s value support is indicated by CPUID: - * - CPUID.0x10.1:ECX[3]: L3 non-contiguous 1s value supported if 1 - * - CPUID.0x10.2:ECX[3]: L2 non-contiguous 1s value supported if 1 - * - * Haswell does not support a non-contiguous 1s value and additionally - * requires at least two bits set. - * AMD allows non-contiguous bitmasks. - */ -static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r) -{ - u32 supported_bits = BIT_MASK(r->cache.cbm_len) - 1; - unsigned int cbm_len = r->cache.cbm_len; - unsigned long first_bit, zero_bit, val; - int ret; - - ret = kstrtoul(buf, 16, &val); - if (ret) { - rdt_last_cmd_printf("Non-hex character in the mask %s\n", buf); - return false; - } - - if ((r->cache.min_cbm_bits > 0 && val == 0) || val > supported_bits) { - rdt_last_cmd_puts("Mask out of range\n"); - return false; - } - - first_bit = find_first_bit(&val, cbm_len); - zero_bit = find_next_zero_bit(&val, cbm_len, first_bit); - - /* Are non-contiguous bitmasks allowed? */ - if (!r->cache.arch_has_sparse_bitmasks && - (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)) { - rdt_last_cmd_printf("The mask %lx has non-consecutive 1-bits\n", val); - return false; - } - - if ((zero_bit - first_bit) < r->cache.min_cbm_bits) { - rdt_last_cmd_printf("Need at least %d bits in the mask\n", - r->cache.min_cbm_bits); - return false; - } - - *data = val; - return true; -} - -/* - * Read one cache bit mask (hex). Check that it is valid for the current - * resource type. - */ -static int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s, - struct rdt_ctrl_domain *d) -{ - struct rdtgroup *rdtgrp = data->rdtgrp; - struct resctrl_staged_config *cfg; - struct rdt_resource *r = s->res; - u32 cbm_val; - - cfg = &d->staged_config[s->conf_type]; - if (cfg->have_new_ctrl) { - rdt_last_cmd_printf("Duplicate domain %d\n", d->hdr.id); - return -EINVAL; - } - - /* - * Cannot set up more than one pseudo-locked region in a cache - * hierarchy. - */ - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP && - rdtgroup_pseudo_locked_in_hierarchy(d)) { - rdt_last_cmd_puts("Pseudo-locked region in hierarchy\n"); - return -EINVAL; - } - - if (!cbm_validate(data->buf, &cbm_val, r)) - return -EINVAL; - - if ((rdtgrp->mode == RDT_MODE_EXCLUSIVE || - rdtgrp->mode == RDT_MODE_SHAREABLE) && - rdtgroup_cbm_overlaps_pseudo_locked(d, cbm_val)) { - rdt_last_cmd_puts("CBM overlaps with pseudo-locked region\n"); - return -EINVAL; - } - - /* - * The CBM may not overlap with the CBM of another closid if - * either is exclusive. - */ - if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, true)) { - rdt_last_cmd_puts("Overlaps with exclusive group\n"); - return -EINVAL; - } - - if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, false)) { - if (rdtgrp->mode == RDT_MODE_EXCLUSIVE || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - rdt_last_cmd_puts("Overlaps with other group\n"); - return -EINVAL; - } - } - - cfg->new_ctrl = cbm_val; - cfg->have_new_ctrl = true; - - return 0; -} - -/* - * For each domain in this resource we expect to find a series of: - * id=mask - * separated by ";". The "id" is in decimal, and must match one of - * the "id"s for this resource. - */ -static int parse_line(char *line, struct resctrl_schema *s, - struct rdtgroup *rdtgrp) -{ - enum resctrl_conf_type t = s->conf_type; - ctrlval_parser_t *parse_ctrlval = NULL; - struct resctrl_staged_config *cfg; - struct rdt_resource *r = s->res; - struct rdt_parse_data data; - struct rdt_ctrl_domain *d; - char *dom = NULL, *id; - unsigned long dom_id; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - switch (r->schema_fmt) { - case RESCTRL_SCHEMA_BITMAP: - parse_ctrlval = &parse_cbm; - break; - case RESCTRL_SCHEMA_RANGE: - parse_ctrlval = &parse_bw; - break; - } - - if (WARN_ON_ONCE(!parse_ctrlval)) - return -EINVAL; - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP && - (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)) { - rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n"); - return -EINVAL; - } - -next: - if (!line || line[0] == '\0') - return 0; - dom = strsep(&line, ";"); - id = strsep(&dom, "="); - if (!dom || kstrtoul(id, 10, &dom_id)) { - rdt_last_cmd_puts("Missing '=' or non-numeric domain\n"); - return -EINVAL; - } - dom = strim(dom); - list_for_each_entry(d, &r->ctrl_domains, hdr.list) { - if (d->hdr.id == dom_id) { - data.buf = dom; - data.rdtgrp = rdtgrp; - if (parse_ctrlval(&data, s, d)) - return -EINVAL; - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - cfg = &d->staged_config[t]; - /* - * In pseudo-locking setup mode and just - * parsed a valid CBM that should be - * pseudo-locked. Only one locked region per - * resource group and domain so just do - * the required initialization for single - * region and return. - */ - rdtgrp->plr->s = s; - rdtgrp->plr->d = d; - rdtgrp->plr->cbm = cfg->new_ctrl; - d->plr = rdtgrp->plr; - return 0; - } - goto next; - } - } - return -EINVAL; -} - int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_ctrl_domain *d, u32 closid, enum resctrl_conf_type t, u32 cfg_val) { @@ -351,100 +83,6 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) return 0; } -static int rdtgroup_parse_resource(char *resname, char *tok, - struct rdtgroup *rdtgrp) -{ - struct resctrl_schema *s; - - list_for_each_entry(s, &resctrl_schema_all, list) { - if (!strcmp(resname, s->name) && rdtgrp->closid < s->num_closid) - return parse_line(tok, s, rdtgrp); - } - rdt_last_cmd_printf("Unknown or unsupported resource name '%s'\n", resname); - return -EINVAL; -} - -ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - struct resctrl_schema *s; - struct rdtgroup *rdtgrp; - struct rdt_resource *r; - char *tok, *resname; - int ret = 0; - - /* Valid input requires a trailing newline */ - if (nbytes == 0 || buf[nbytes - 1] != '\n') - return -EINVAL; - buf[nbytes - 1] = '\0'; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - rdtgroup_kn_unlock(of->kn); - return -ENOENT; - } - rdt_last_cmd_clear(); - - /* - * No changes to pseudo-locked region allowed. It has to be removed - * and re-created instead. - */ - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - ret = -EINVAL; - rdt_last_cmd_puts("Resource group is pseudo-locked\n"); - goto out; - } - - rdt_staged_configs_clear(); - - while ((tok = strsep(&buf, "\n")) != NULL) { - resname = strim(strsep(&tok, ":")); - if (!tok) { - rdt_last_cmd_puts("Missing ':'\n"); - ret = -EINVAL; - goto out; - } - if (tok[0] == '\0') { - rdt_last_cmd_printf("Missing '%s' value\n", resname); - ret = -EINVAL; - goto out; - } - ret = rdtgroup_parse_resource(resname, tok, rdtgrp); - if (ret) - goto out; - } - - list_for_each_entry(s, &resctrl_schema_all, list) { - r = s->res; - - /* - * Writes to mba_sc resources update the software controller, - * not the control MSR. - */ - if (is_mba_sc(r)) - continue; - - ret = resctrl_arch_update_domains(r, rdtgrp->closid); - if (ret) - goto out; - } - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - /* - * If pseudo-locking fails we keep the resource group in - * mode RDT_MODE_PSEUDO_LOCKSETUP with its class of service - * active and updated for just the domain the pseudo-locked - * region was requested for. - */ - ret = rdtgroup_pseudo_lock_create(rdtgrp); - } - -out: - rdt_staged_configs_clear(); - rdtgroup_kn_unlock(of->kn); - return ret ?: nbytes; -} - u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d, u32 closid, enum resctrl_conf_type type) { @@ -453,282 +91,3 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d, return hw_dom->ctrl_val[idx]; } - -static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid) -{ - struct rdt_resource *r = schema->res; - struct rdt_ctrl_domain *dom; - bool sep = false; - u32 ctrl_val; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - seq_printf(s, "%*s:", max_name_width, schema->name); - list_for_each_entry(dom, &r->ctrl_domains, hdr.list) { - if (sep) - seq_puts(s, ";"); - - if (is_mba_sc(r)) - ctrl_val = dom->mbps_val[closid]; - else - ctrl_val = resctrl_arch_get_config(r, dom, closid, - schema->conf_type); - - seq_printf(s, schema->fmt_str, dom->hdr.id, ctrl_val); - sep = true; - } - seq_puts(s, "\n"); -} - -int rdtgroup_schemata_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct resctrl_schema *schema; - struct rdtgroup *rdtgrp; - int ret = 0; - u32 closid; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (rdtgrp) { - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - list_for_each_entry(schema, &resctrl_schema_all, list) { - seq_printf(s, "%s:uninitialized\n", schema->name); - } - } else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - if (!rdtgrp->plr->d) { - rdt_last_cmd_clear(); - rdt_last_cmd_puts("Cache domain offline\n"); - ret = -ENODEV; - } else { - seq_printf(s, "%s:%d=%x\n", - rdtgrp->plr->s->res->name, - rdtgrp->plr->d->hdr.id, - rdtgrp->plr->cbm); - } - } else { - closid = rdtgrp->closid; - list_for_each_entry(schema, &resctrl_schema_all, list) { - if (closid < schema->num_closid) - show_doms(s, schema, closid); - } - } - } else { - ret = -ENOENT; - } - rdtgroup_kn_unlock(of->kn); - return ret; -} - -static int smp_mon_event_count(void *arg) -{ - mon_event_count(arg); - - return 0; -} - -ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - struct rdtgroup *rdtgrp; - int ret = 0; - - /* Valid input requires a trailing newline */ - if (nbytes == 0 || buf[nbytes - 1] != '\n') - return -EINVAL; - buf[nbytes - 1] = '\0'; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - rdtgroup_kn_unlock(of->kn); - return -ENOENT; - } - rdt_last_cmd_clear(); - - if (!strcmp(buf, "mbm_local_bytes")) { - if (resctrl_arch_is_mbm_local_enabled()) - rdtgrp->mba_mbps_event = QOS_L3_MBM_LOCAL_EVENT_ID; - else - ret = -EINVAL; - } else if (!strcmp(buf, "mbm_total_bytes")) { - if (resctrl_arch_is_mbm_total_enabled()) - rdtgrp->mba_mbps_event = QOS_L3_MBM_TOTAL_EVENT_ID; - else - ret = -EINVAL; - } else { - ret = -EINVAL; - } - - if (ret) - rdt_last_cmd_printf("Unsupported event id '%s'\n", buf); - - rdtgroup_kn_unlock(of->kn); - - return ret ?: nbytes; -} - -int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct rdtgroup *rdtgrp; - int ret = 0; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - - if (rdtgrp) { - switch (rdtgrp->mba_mbps_event) { - case QOS_L3_MBM_LOCAL_EVENT_ID: - seq_puts(s, "mbm_local_bytes\n"); - break; - case QOS_L3_MBM_TOTAL_EVENT_ID: - seq_puts(s, "mbm_total_bytes\n"); - break; - default: - pr_warn_once("Bad event %d\n", rdtgrp->mba_mbps_event); - ret = -EINVAL; - break; - } - } else { - ret = -ENOENT; - } - - rdtgroup_kn_unlock(of->kn); - - return ret; -} - -struct rdt_domain_hdr *resctrl_find_domain(struct list_head *h, int id, - struct list_head **pos) -{ - struct rdt_domain_hdr *d; - struct list_head *l; - - list_for_each(l, h) { - d = list_entry(l, struct rdt_domain_hdr, list); - /* When id is found, return its domain. */ - if (id == d->id) - return d; - /* Stop searching when finding id's position in sorted list. */ - if (id < d->id) - break; - } - - if (pos) - *pos = l; - - return NULL; -} - -void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, - struct rdt_mon_domain *d, struct rdtgroup *rdtgrp, - cpumask_t *cpumask, int evtid, int first) -{ - int cpu; - - /* When picking a CPU from cpu_mask, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - /* - * Setup the parameters to pass to mon_event_count() to read the data. - */ - rr->rgrp = rdtgrp; - rr->evtid = evtid; - rr->r = r; - rr->d = d; - rr->first = first; - rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid); - if (IS_ERR(rr->arch_mon_ctx)) { - rr->err = -EINVAL; - return; - } - - cpu = cpumask_any_housekeeping(cpumask, RESCTRL_PICK_ANY_CPU); - - /* - * cpumask_any_housekeeping() prefers housekeeping CPUs, but - * are all the CPUs nohz_full? If yes, pick a CPU to IPI. - * MPAM's resctrl_arch_rmid_read() is unable to read the - * counters on some platforms if its called in IRQ context. - */ - if (tick_nohz_full_cpu(cpu)) - smp_call_function_any(cpumask, mon_event_count, rr, 1); - else - smp_call_on_cpu(cpu, smp_mon_event_count, rr, false); - - resctrl_arch_mon_ctx_free(r, evtid, rr->arch_mon_ctx); -} - -int rdtgroup_mondata_show(struct seq_file *m, void *arg) -{ - struct kernfs_open_file *of = m->private; - enum resctrl_res_level resid; - enum resctrl_event_id evtid; - struct rdt_domain_hdr *hdr; - struct rmid_read rr = {0}; - struct rdt_mon_domain *d; - struct rdtgroup *rdtgrp; - struct rdt_resource *r; - struct mon_data *md; - int domid, ret = 0; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - ret = -ENOENT; - goto out; - } - - md = of->kn->priv; - if (WARN_ON_ONCE(!md)) { - ret = -EIO; - goto out; - } - - resid = md->rid; - domid = md->domid; - evtid = md->evtid; - r = resctrl_arch_get_resource(resid); - - if (md->sum) { - /* - * This file requires summing across all domains that share - * the L3 cache id that was provided in the "domid" field of the - * struct mon_data. Search all domains in the resource for - * one that matches this cache id. - */ - list_for_each_entry(d, &r->mon_domains, hdr.list) { - if (d->ci->id == domid) { - rr.ci = d->ci; - mon_event_read(&rr, r, NULL, rdtgrp, - &d->ci->shared_cpu_map, evtid, false); - goto checkresult; - } - } - ret = -ENOENT; - goto out; - } else { - /* - * This file provides data from a single domain. Search - * the resource to find the domain with "domid". - */ - hdr = resctrl_find_domain(&r->mon_domains, domid, NULL); - if (!hdr || WARN_ON_ONCE(hdr->type != RESCTRL_MON_DOMAIN)) { - ret = -ENOENT; - goto out; - } - d = container_of(hdr, struct rdt_mon_domain, hdr); - mon_event_read(&rr, r, d, rdtgrp, &d->hdr.cpu_mask, evtid, false); - } - -checkresult: - - if (rr.err == -EIO) - seq_puts(m, "Error\n"); - else if (rr.err == -EINVAL) - seq_puts(m, "Unavailable\n"); - else - seq_printf(m, "%llu\n", rr.val); - -out: - rdtgroup_kn_unlock(of->kn); - return ret; -} diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index dc63ac538a81..5e3c41b36437 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -3,24 +3,21 @@ #define _ASM_X86_RESCTRL_INTERNAL_H #include -#include -#include -#include -#include -#include #define L3_QOS_CDP_ENABLE 0x01ULL #define L2_QOS_CDP_ENABLE 0x01ULL -#define CQM_LIMBOCHECK_INTERVAL 1000 - #define MBM_CNTR_WIDTH_BASE 24 + #define MBA_IS_LINEAR 0x4 + #define MBM_CNTR_WIDTH_OFFSET_AMD 20 #define RMID_VAL_ERROR BIT_ULL(63) + #define RMID_VAL_UNAVAIL BIT_ULL(62) + /* * With the above fields in use 62 bits remain in MSR_IA32_QM_CTR for * data to be returned. The counter width is discovered from the hardware @@ -28,263 +25,6 @@ */ #define MBM_CNTR_WIDTH_OFFSET_MAX (62 - MBM_CNTR_WIDTH_BASE) -/** - * cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that - * aren't marked nohz_full - * @mask: The mask to pick a CPU from. - * @exclude_cpu:The CPU to avoid picking. - * - * Returns a CPU from @mask, but not @exclude_cpu. If there are housekeeping - * CPUs that don't use nohz_full, these are preferred. Pass - * RESCTRL_PICK_ANY_CPU to avoid excluding any CPUs. - * - * When a CPU is excluded, returns >= nr_cpu_ids if no CPUs are available. - */ -static inline unsigned int -cpumask_any_housekeeping(const struct cpumask *mask, int exclude_cpu) -{ - unsigned int cpu; - - /* Try to find a CPU that isn't nohz_full to use in preference */ - if (tick_nohz_full_enabled()) { - cpu = cpumask_any_andnot_but(mask, tick_nohz_full_mask, exclude_cpu); - if (cpu < nr_cpu_ids) - return cpu; - } - - return cpumask_any_but(mask, exclude_cpu); -} - -struct rdt_fs_context { - struct kernfs_fs_context kfc; - bool enable_cdpl2; - bool enable_cdpl3; - bool enable_mba_mbps; - bool enable_debug; -}; - -static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc) -{ - struct kernfs_fs_context *kfc = fc->fs_private; - - return container_of(kfc, struct rdt_fs_context, kfc); -} - -/** - * struct mon_evt - Entry in the event list of a resource - * @evtid: event id - * @name: name of the event - * @configurable: true if the event is configurable - * @list: entry in &rdt_resource->evt_list - */ -struct mon_evt { - enum resctrl_event_id evtid; - char *name; - bool configurable; - struct list_head list; -}; - -/** - * struct mon_data - Monitoring details for each event file. - * @list: Member of the global @mon_data_kn_priv_list list. - * @rid: Resource id associated with the event file. - * @evtid: Event id associated with the event file. - * @sum: Set when event must be summed across multiple - * domains. - * @domid: When @sum is zero this is the domain to which - * the event file belongs. When @sum is one this - * is the id of the L3 cache that all domains to be - * summed share. - * - * Pointed to by the kernfs kn->priv field of monitoring event files. - * Readers and writers must hold rdtgroup_mutex. - */ -struct mon_data { - struct list_head list; - enum resctrl_res_level rid; - enum resctrl_event_id evtid; - int domid; - bool sum; -}; - -/** - * struct rmid_read - Data passed across smp_call*() to read event count. - * @rgrp: Resource group for which the counter is being read. If it is a parent - * resource group then its event count is summed with the count from all - * its child resource groups. - * @r: Resource describing the properties of the event being read. - * @d: Domain that the counter should be read from. If NULL then sum all - * domains in @r sharing L3 @ci.id - * @evtid: Which monitor event to read. - * @first: Initialize MBM counter when true. - * @ci: Cacheinfo for L3. Only set when @d is NULL. Used when summing domains. - * @err: Error encountered when reading counter. - * @val: Returned value of event counter. If @rgrp is a parent resource group, - * @val includes the sum of event counts from its child resource groups. - * If @d is NULL, @val includes the sum of all domains in @r sharing @ci.id, - * (summed across child resource groups if @rgrp is a parent resource group). - * @arch_mon_ctx: Hardware monitor allocated for this read request (MPAM only). - */ -struct rmid_read { - struct rdtgroup *rgrp; - struct rdt_resource *r; - struct rdt_mon_domain *d; - enum resctrl_event_id evtid; - bool first; - struct cacheinfo *ci; - int err; - u64 val; - void *arch_mon_ctx; -}; - -extern struct list_head resctrl_schema_all; -extern bool resctrl_mounted; - -enum rdt_group_type { - RDTCTRL_GROUP = 0, - RDTMON_GROUP, - RDT_NUM_GROUP, -}; - -/** - * enum rdtgrp_mode - Mode of a RDT resource group - * @RDT_MODE_SHAREABLE: This resource group allows sharing of its allocations - * @RDT_MODE_EXCLUSIVE: No sharing of this resource group's allocations allowed - * @RDT_MODE_PSEUDO_LOCKSETUP: Resource group will be used for Pseudo-Locking - * @RDT_MODE_PSEUDO_LOCKED: No sharing of this resource group's allocations - * allowed AND the allocations are Cache Pseudo-Locked - * @RDT_NUM_MODES: Total number of modes - * - * The mode of a resource group enables control over the allowed overlap - * between allocations associated with different resource groups (classes - * of service). User is able to modify the mode of a resource group by - * writing to the "mode" resctrl file associated with the resource group. - * - * The "shareable", "exclusive", and "pseudo-locksetup" modes are set by - * writing the appropriate text to the "mode" file. A resource group enters - * "pseudo-locked" mode after the schemata is written while the resource - * group is in "pseudo-locksetup" mode. - */ -enum rdtgrp_mode { - RDT_MODE_SHAREABLE = 0, - RDT_MODE_EXCLUSIVE, - RDT_MODE_PSEUDO_LOCKSETUP, - RDT_MODE_PSEUDO_LOCKED, - - /* Must be last */ - RDT_NUM_MODES, -}; - -/** - * struct mongroup - store mon group's data in resctrl fs. - * @mon_data_kn: kernfs node for the mon_data directory - * @parent: parent rdtgrp - * @crdtgrp_list: child rdtgroup node list - * @rmid: rmid for this rdtgroup - */ -struct mongroup { - struct kernfs_node *mon_data_kn; - struct rdtgroup *parent; - struct list_head crdtgrp_list; - u32 rmid; -}; - -/** - * struct rdtgroup - store rdtgroup's data in resctrl file system. - * @kn: kernfs node - * @rdtgroup_list: linked list for all rdtgroups - * @closid: closid for this rdtgroup - * @cpu_mask: CPUs assigned to this rdtgroup - * @flags: status bits - * @waitcount: how many cpus expect to find this - * group when they acquire rdtgroup_mutex - * @type: indicates type of this rdtgroup - either - * monitor only or ctrl_mon group - * @mon: mongroup related data - * @mode: mode of resource group - * @mba_mbps_event: input monitoring event id when mba_sc is enabled - * @plr: pseudo-locked region - */ -struct rdtgroup { - struct kernfs_node *kn; - struct list_head rdtgroup_list; - u32 closid; - struct cpumask cpu_mask; - int flags; - atomic_t waitcount; - enum rdt_group_type type; - struct mongroup mon; - enum rdtgrp_mode mode; - enum resctrl_event_id mba_mbps_event; - struct pseudo_lock_region *plr; -}; - -/* rdtgroup.flags */ -#define RDT_DELETED 1 - -/* rftype.flags */ -#define RFTYPE_FLAGS_CPUS_LIST 1 - -/* - * Define the file type flags for base and info directories. - */ -#define RFTYPE_INFO BIT(0) -#define RFTYPE_BASE BIT(1) -#define RFTYPE_CTRL BIT(4) -#define RFTYPE_MON BIT(5) -#define RFTYPE_TOP BIT(6) -#define RFTYPE_RES_CACHE BIT(8) -#define RFTYPE_RES_MB BIT(9) -#define RFTYPE_DEBUG BIT(10) -#define RFTYPE_CTRL_INFO (RFTYPE_INFO | RFTYPE_CTRL) -#define RFTYPE_MON_INFO (RFTYPE_INFO | RFTYPE_MON) -#define RFTYPE_TOP_INFO (RFTYPE_INFO | RFTYPE_TOP) -#define RFTYPE_CTRL_BASE (RFTYPE_BASE | RFTYPE_CTRL) -#define RFTYPE_MON_BASE (RFTYPE_BASE | RFTYPE_MON) - -/* List of all resource groups */ -extern struct list_head rdt_all_groups; - -extern int max_name_width; - -/** - * struct rftype - describe each file in the resctrl file system - * @name: File name - * @mode: Access mode - * @kf_ops: File operations - * @flags: File specific RFTYPE_FLAGS_* flags - * @fflags: File specific RFTYPE_* flags - * @seq_show: Show content of the file - * @write: Write to the file - */ -struct rftype { - char *name; - umode_t mode; - const struct kernfs_ops *kf_ops; - unsigned long flags; - unsigned long fflags; - - int (*seq_show)(struct kernfs_open_file *of, - struct seq_file *sf, void *v); - /* - * write() is the generic write callback which maps directly to - * kernfs write operation and overrides all other operations. - * Maximum write size is determined by ->max_write_len. - */ - ssize_t (*write)(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off); -}; - -/** - * struct mbm_state - status for each MBM counter in each domain - * @prev_bw_bytes: Previous bytes value read for bandwidth calculation - * @prev_bw: The most recent bandwidth in MBps - */ -struct mbm_state { - u64 prev_bw_bytes; - u32 prev_bw; -}; - /** * struct arch_mbm_state - values used to compute resctrl_arch_rmid_read()s * return value. @@ -382,17 +122,7 @@ static inline struct rdt_hw_resource *resctrl_to_arch_res(struct rdt_resource *r return container_of(r, struct rdt_hw_resource, r_resctrl); } -extern struct mutex rdtgroup_mutex; - -static inline const char *rdt_kn_name(const struct kernfs_node *kn) -{ - return rcu_dereference_check(kn->name, lockdep_is_held(&rdtgroup_mutex)); -} - extern struct rdt_hw_resource rdt_resources_all[]; -extern struct rdtgroup rdtgroup_default; -extern struct dentry *debugfs_resctrl; -extern enum resctrl_event_id mba_mbps_default_event; void arch_mon_domain_online(struct rdt_resource *r, struct rdt_mon_domain *d); @@ -429,99 +159,14 @@ union cpuid_0x10_x_edx { unsigned int full; }; -void rdt_last_cmd_clear(void); -void rdt_last_cmd_puts(const char *s); -__printf(1, 2) -void rdt_last_cmd_printf(const char *fmt, ...); - void rdt_ctrl_update(void *arg); -struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn); -void rdtgroup_kn_unlock(struct kernfs_node *kn); -int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name); -int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name, - umode_t mask); -ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off); -int rdtgroup_schemata_show(struct kernfs_open_file *of, - struct seq_file *s, void *v); -ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off); -int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of, - struct seq_file *s, void *v); -bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d, - unsigned long cbm, int closid, bool exclusive); -unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, struct rdt_ctrl_domain *d, - unsigned long cbm); -enum rdtgrp_mode rdtgroup_mode_by_closid(int closid); -int rdtgroup_tasks_assigned(struct rdtgroup *r); -int closids_supported(void); -void closid_free(int closid); -int alloc_rmid(u32 closid); -void free_rmid(u32 closid, u32 rmid); -int rdt_get_mon_l3_config(struct rdt_resource *r); -void resctrl_mon_resource_exit(void); -bool rdt_cpu_has(int flag); -void mon_event_count(void *info); -int rdtgroup_mondata_show(struct seq_file *m, void *arg); -void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, - struct rdt_mon_domain *d, struct rdtgroup *rdtgrp, - cpumask_t *cpumask, int evtid, int first); -int resctrl_mon_resource_init(void); -void mbm_setup_overflow_handler(struct rdt_mon_domain *dom, - unsigned long delay_ms, - int exclude_cpu); -void mbm_handle_overflow(struct work_struct *work); -void __init intel_rdt_mbm_apply_quirk(void); -bool is_mba_sc(struct rdt_resource *r); -void cqm_setup_limbo_handler(struct rdt_mon_domain *dom, unsigned long delay_ms, - int exclude_cpu); -void cqm_handle_limbo(struct work_struct *work); -bool has_busy_rmid(struct rdt_mon_domain *d); -void __check_limbo(struct rdt_mon_domain *d, bool force_free); -void rdt_domain_reconfigure_cdp(struct rdt_resource *r); -void resctrl_file_fflags_init(const char *config, unsigned long fflags); -void rdt_staged_configs_clear(void); -bool closid_allocated(unsigned int closid); -int resctrl_find_cleanest_closid(void); - -#ifdef CONFIG_RESCTRL_FS_PSEUDO_LOCK -int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp); -int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp); -bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm); -bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d); -int rdt_pseudo_lock_init(void); -void rdt_pseudo_lock_release(void); -int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp); -void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp); -#else -static inline int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp) -{ - return -EOPNOTSUPP; -} -static inline int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp) -{ - return -EOPNOTSUPP; -} - -static inline bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm) -{ - return false; -} +int rdt_get_mon_l3_config(struct rdt_resource *r); -static inline bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d) -{ - return false; -} +bool rdt_cpu_has(int flag); -static inline int rdt_pseudo_lock_init(void) { return 0; } -static inline void rdt_pseudo_lock_release(void) { } -static inline int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp) -{ - return -EOPNOTSUPP; -} +void __init intel_rdt_mbm_apply_quirk(void); -static inline void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp) { } -#endif /* CONFIG_RESCTRL_FS_PSEUDO_LOCK */ +void rdt_domain_reconfigure_cdp(struct rdt_resource *r); #endif /* _ASM_X86_RESCTRL_INTERNAL_H */ diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 8847c23e9ac1..3fc4d9f56f0d 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -18,65 +18,12 @@ #define pr_fmt(fmt) "resctrl: " fmt #include -#include #include -#include -#include #include #include "internal.h" -#define CREATE_TRACE_POINTS -#include "monitor_trace.h" - -/** - * struct rmid_entry - dirty tracking for all RMID. - * @closid: The CLOSID for this entry. - * @rmid: The RMID for this entry. - * @busy: The number of domains with cached data using this RMID. - * @list: Member of the rmid_free_lru list when busy == 0. - * - * Depending on the architecture the correct monitor is accessed using - * both @closid and @rmid, or @rmid only. - * - * Take the rdtgroup_mutex when accessing. - */ -struct rmid_entry { - u32 closid; - u32 rmid; - int busy; - struct list_head list; -}; - -/* - * @rmid_free_lru - A least recently used list of free RMIDs - * These RMIDs are guaranteed to have an occupancy less than the - * threshold occupancy - */ -static LIST_HEAD(rmid_free_lru); - -/* - * @closid_num_dirty_rmid The number of dirty RMID each CLOSID has. - * Only allocated when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is defined. - * Indexed by CLOSID. Protected by rdtgroup_mutex. - */ -static u32 *closid_num_dirty_rmid; - -/* - * @rmid_limbo_count - count of currently unused but (potentially) - * dirty RMIDs. - * This counts RMIDs that no one is currently using but that - * may have a occupancy value > resctrl_rmid_realloc_threshold. User can - * change the threshold occupancy value. - */ -static unsigned int rmid_limbo_count; - -/* - * @rmid_entry - The entry in the limbo and free lists. - */ -static struct rmid_entry *rmid_ptrs; - /* * Global boolean for rdt_monitor which is true if any * resource monitoring is enabled. @@ -88,23 +35,12 @@ bool rdt_mon_capable; */ unsigned int rdt_mon_features; -/* - * This is the threshold cache occupancy in bytes at which we will consider an - * RMID available for re-allocation. - */ -unsigned int resctrl_rmid_realloc_threshold; - -/* - * This is the maximum value for the reallocation threshold, in bytes. - */ -unsigned int resctrl_rmid_realloc_limit; - #define CF(cf) ((unsigned long)(1048576 * (cf) + 0.5)) static int snc_nodes_per_l3_cache = 1; /* - * The correction factor table is documented in Documentation/arch/x86/resctrl.rst. + * The correction factor table is documented in Documentation/filesystems/resctrl.rst. * If rmid > rmid threshold, MBM total and local values should be multiplied * by the correction factor. * @@ -153,6 +89,7 @@ static const struct mbm_correction_factor_table { }; static u32 mbm_cf_rmidthreshold __read_mostly = UINT_MAX; + static u64 mbm_cf __read_mostly; static inline u64 get_corrected_mbm_count(u32 rmid, unsigned long val) @@ -164,33 +101,6 @@ static inline u64 get_corrected_mbm_count(u32 rmid, unsigned long val) return val; } -/* - * x86 and arm64 differ in their handling of monitoring. - * x86's RMID are independent numbers, there is only one source of traffic - * with an RMID value of '1'. - * arm64's PMG extends the PARTID/CLOSID space, there are multiple sources of - * traffic with a PMG value of '1', one for each CLOSID, meaning the RMID - * value is no longer unique. - * To account for this, resctrl uses an index. On x86 this is just the RMID, - * on arm64 it encodes the CLOSID and RMID. This gives a unique number. - * - * The domain's rmid_busy_llc and rmid_ptrs[] are sized by index. The arch code - * must accept an attempt to read every index. - */ -static inline struct rmid_entry *__rmid_entry(u32 idx) -{ - struct rmid_entry *entry; - u32 closid, rmid; - - entry = &rmid_ptrs[idx]; - resctrl_arch_rmid_idx_decode(idx, &closid, &rmid); - - WARN_ON_ONCE(entry->closid != closid); - WARN_ON_ONCE(entry->rmid != rmid); - - return entry; -} - /* * When Sub-NUMA Cluster (SNC) mode is not enabled (as indicated by * "snc_nodes_per_l3_cache == 1") no translation of the RMID value is @@ -347,769 +257,6 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_mon_domain *d, return 0; } -static void limbo_release_entry(struct rmid_entry *entry) -{ - lockdep_assert_held(&rdtgroup_mutex); - - rmid_limbo_count--; - list_add_tail(&entry->list, &rmid_free_lru); - - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) - closid_num_dirty_rmid[entry->closid]--; -} - -/* - * Check the RMIDs that are marked as busy for this domain. If the - * reported LLC occupancy is below the threshold clear the busy bit and - * decrement the count. If the busy count gets to zero on an RMID, we - * free the RMID - */ -void __check_limbo(struct rdt_mon_domain *d, bool force_free) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); - u32 idx_limit = resctrl_arch_system_num_rmid_idx(); - struct rmid_entry *entry; - u32 idx, cur_idx = 1; - void *arch_mon_ctx; - bool rmid_dirty; - u64 val = 0; - - arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID); - if (IS_ERR(arch_mon_ctx)) { - pr_warn_ratelimited("Failed to allocate monitor context: %ld", - PTR_ERR(arch_mon_ctx)); - return; - } - - /* - * Skip RMID 0 and start from RMID 1 and check all the RMIDs that - * are marked as busy for occupancy < threshold. If the occupancy - * is less than the threshold decrement the busy counter of the - * RMID and move it to the free list when the counter reaches 0. - */ - for (;;) { - idx = find_next_bit(d->rmid_busy_llc, idx_limit, cur_idx); - if (idx >= idx_limit) - break; - - entry = __rmid_entry(idx); - if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid, - QOS_L3_OCCUP_EVENT_ID, &val, - arch_mon_ctx)) { - rmid_dirty = true; - } else { - rmid_dirty = (val >= resctrl_rmid_realloc_threshold); - - /* - * x86's CLOSID and RMID are independent numbers, so the entry's - * CLOSID is an empty CLOSID (X86_RESCTRL_EMPTY_CLOSID). On Arm the - * RMID (PMG) extends the CLOSID (PARTID) space with bits that aren't - * used to select the configuration. It is thus necessary to track both - * CLOSID and RMID because there may be dependencies between them - * on some architectures. - */ - trace_mon_llc_occupancy_limbo(entry->closid, entry->rmid, d->hdr.id, val); - } - - if (force_free || !rmid_dirty) { - clear_bit(idx, d->rmid_busy_llc); - if (!--entry->busy) - limbo_release_entry(entry); - } - cur_idx = idx + 1; - } - - resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx); -} - -bool has_busy_rmid(struct rdt_mon_domain *d) -{ - u32 idx_limit = resctrl_arch_system_num_rmid_idx(); - - return find_first_bit(d->rmid_busy_llc, idx_limit) != idx_limit; -} - -static struct rmid_entry *resctrl_find_free_rmid(u32 closid) -{ - struct rmid_entry *itr; - u32 itr_idx, cmp_idx; - - if (list_empty(&rmid_free_lru)) - return rmid_limbo_count ? ERR_PTR(-EBUSY) : ERR_PTR(-ENOSPC); - - list_for_each_entry(itr, &rmid_free_lru, list) { - /* - * Get the index of this free RMID, and the index it would need - * to be if it were used with this CLOSID. - * If the CLOSID is irrelevant on this architecture, the two - * index values are always the same on every entry and thus the - * very first entry will be returned. - */ - itr_idx = resctrl_arch_rmid_idx_encode(itr->closid, itr->rmid); - cmp_idx = resctrl_arch_rmid_idx_encode(closid, itr->rmid); - - if (itr_idx == cmp_idx) - return itr; - } - - return ERR_PTR(-ENOSPC); -} - -/** - * resctrl_find_cleanest_closid() - Find a CLOSID where all the associated - * RMID are clean, or the CLOSID that has - * the most clean RMID. - * - * MPAM's equivalent of RMID are per-CLOSID, meaning a freshly allocated CLOSID - * may not be able to allocate clean RMID. To avoid this the allocator will - * choose the CLOSID with the most clean RMID. - * - * When the CLOSID and RMID are independent numbers, the first free CLOSID will - * be returned. - */ -int resctrl_find_cleanest_closid(void) -{ - u32 cleanest_closid = ~0; - int i = 0; - - lockdep_assert_held(&rdtgroup_mutex); - - if (!IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) - return -EIO; - - for (i = 0; i < closids_supported(); i++) { - int num_dirty; - - if (closid_allocated(i)) - continue; - - num_dirty = closid_num_dirty_rmid[i]; - if (num_dirty == 0) - return i; - - if (cleanest_closid == ~0) - cleanest_closid = i; - - if (num_dirty < closid_num_dirty_rmid[cleanest_closid]) - cleanest_closid = i; - } - - if (cleanest_closid == ~0) - return -ENOSPC; - - return cleanest_closid; -} - -/* - * For MPAM the RMID value is not unique, and has to be considered with - * the CLOSID. The (CLOSID, RMID) pair is allocated on all domains, which - * allows all domains to be managed by a single free list. - * Each domain also has a rmid_busy_llc to reduce the work of the limbo handler. - */ -int alloc_rmid(u32 closid) -{ - struct rmid_entry *entry; - - lockdep_assert_held(&rdtgroup_mutex); - - entry = resctrl_find_free_rmid(closid); - if (IS_ERR(entry)) - return PTR_ERR(entry); - - list_del(&entry->list); - return entry->rmid; -} - -static void add_rmid_to_limbo(struct rmid_entry *entry) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); - struct rdt_mon_domain *d; - u32 idx; - - lockdep_assert_held(&rdtgroup_mutex); - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - idx = resctrl_arch_rmid_idx_encode(entry->closid, entry->rmid); - - entry->busy = 0; - list_for_each_entry(d, &r->mon_domains, hdr.list) { - /* - * For the first limbo RMID in the domain, - * setup up the limbo worker. - */ - if (!has_busy_rmid(d)) - cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL, - RESCTRL_PICK_ANY_CPU); - set_bit(idx, d->rmid_busy_llc); - entry->busy++; - } - - rmid_limbo_count++; - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) - closid_num_dirty_rmid[entry->closid]++; -} - -void free_rmid(u32 closid, u32 rmid) -{ - u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); - struct rmid_entry *entry; - - lockdep_assert_held(&rdtgroup_mutex); - - /* - * Do not allow the default rmid to be free'd. Comparing by index - * allows architectures that ignore the closid parameter to avoid an - * unnecessary check. - */ - if (!resctrl_arch_mon_capable() || - idx == resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID, - RESCTRL_RESERVED_RMID)) - return; - - entry = __rmid_entry(idx); - - if (resctrl_arch_is_llc_occupancy_enabled()) - add_rmid_to_limbo(entry); - else - list_add_tail(&entry->list, &rmid_free_lru); -} - -static struct mbm_state *get_mbm_state(struct rdt_mon_domain *d, u32 closid, - u32 rmid, enum resctrl_event_id evtid) -{ - u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); - - switch (evtid) { - case QOS_L3_MBM_TOTAL_EVENT_ID: - return &d->mbm_total[idx]; - case QOS_L3_MBM_LOCAL_EVENT_ID: - return &d->mbm_local[idx]; - default: - return NULL; - } -} - -static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) -{ - int cpu = smp_processor_id(); - struct rdt_mon_domain *d; - struct mbm_state *m; - int err, ret; - u64 tval = 0; - - if (rr->first) { - resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid); - m = get_mbm_state(rr->d, closid, rmid, rr->evtid); - if (m) - memset(m, 0, sizeof(struct mbm_state)); - return 0; - } - - if (rr->d) { - /* Reading a single domain, must be on a CPU in that domain. */ - if (!cpumask_test_cpu(cpu, &rr->d->hdr.cpu_mask)) - return -EINVAL; - rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid, - rr->evtid, &tval, rr->arch_mon_ctx); - if (rr->err) - return rr->err; - - rr->val += tval; - - return 0; - } - - /* Summing domains that share a cache, must be on a CPU for that cache. */ - if (!cpumask_test_cpu(cpu, &rr->ci->shared_cpu_map)) - return -EINVAL; - - /* - * Legacy files must report the sum of an event across all - * domains that share the same L3 cache instance. - * Report success if a read from any domain succeeds, -EINVAL - * (translated to "Unavailable" for user space) if reading from - * all domains fail for any reason. - */ - ret = -EINVAL; - list_for_each_entry(d, &rr->r->mon_domains, hdr.list) { - if (d->ci->id != rr->ci->id) - continue; - err = resctrl_arch_rmid_read(rr->r, d, closid, rmid, - rr->evtid, &tval, rr->arch_mon_ctx); - if (!err) { - rr->val += tval; - ret = 0; - } - } - - if (ret) - rr->err = ret; - - return ret; -} - -/* - * mbm_bw_count() - Update bw count from values previously read by - * __mon_event_count(). - * @closid: The closid used to identify the cached mbm_state. - * @rmid: The rmid used to identify the cached mbm_state. - * @rr: The struct rmid_read populated by __mon_event_count(). - * - * Supporting function to calculate the memory bandwidth - * and delta bandwidth in MBps. The chunks value previously read by - * __mon_event_count() is compared with the chunks value from the previous - * invocation. This must be called once per second to maintain values in MBps. - */ -static void mbm_bw_count(u32 closid, u32 rmid, struct rmid_read *rr) -{ - u64 cur_bw, bytes, cur_bytes; - struct mbm_state *m; - - m = get_mbm_state(rr->d, closid, rmid, rr->evtid); - if (WARN_ON_ONCE(!m)) - return; - - cur_bytes = rr->val; - bytes = cur_bytes - m->prev_bw_bytes; - m->prev_bw_bytes = cur_bytes; - - cur_bw = bytes / SZ_1M; - - m->prev_bw = cur_bw; -} - -/* - * This is scheduled by mon_event_read() to read the CQM/MBM counters - * on a domain. - */ -void mon_event_count(void *info) -{ - struct rdtgroup *rdtgrp, *entry; - struct rmid_read *rr = info; - struct list_head *head; - int ret; - - rdtgrp = rr->rgrp; - - ret = __mon_event_count(rdtgrp->closid, rdtgrp->mon.rmid, rr); - - /* - * For Ctrl groups read data from child monitor groups and - * add them together. Count events which are read successfully. - * Discard the rmid_read's reporting errors. - */ - head = &rdtgrp->mon.crdtgrp_list; - - if (rdtgrp->type == RDTCTRL_GROUP) { - list_for_each_entry(entry, head, mon.crdtgrp_list) { - if (__mon_event_count(entry->closid, entry->mon.rmid, - rr) == 0) - ret = 0; - } - } - - /* - * __mon_event_count() calls for newly created monitor groups may - * report -EINVAL/Unavailable if the monitor hasn't seen any traffic. - * Discard error if any of the monitor event reads succeeded. - */ - if (ret == 0) - rr->err = 0; -} - -static struct rdt_ctrl_domain *get_ctrl_domain_from_cpu(int cpu, - struct rdt_resource *r) -{ - struct rdt_ctrl_domain *d; - - lockdep_assert_cpus_held(); - - list_for_each_entry(d, &r->ctrl_domains, hdr.list) { - /* Find the domain that contains this CPU */ - if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask)) - return d; - } - - return NULL; -} - -/* - * Feedback loop for MBA software controller (mba_sc) - * - * mba_sc is a feedback loop where we periodically read MBM counters and - * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so - * that: - * - * current bandwidth(cur_bw) < user specified bandwidth(user_bw) - * - * This uses the MBM counters to measure the bandwidth and MBA throttle - * MSRs to control the bandwidth for a particular rdtgrp. It builds on the - * fact that resctrl rdtgroups have both monitoring and control. - * - * The frequency of the checks is 1s and we just tag along the MBM overflow - * timer. Having 1s interval makes the calculation of bandwidth simpler. - * - * Although MBA's goal is to restrict the bandwidth to a maximum, there may - * be a need to increase the bandwidth to avoid unnecessarily restricting - * the L2 <-> L3 traffic. - * - * Since MBA controls the L2 external bandwidth where as MBM measures the - * L3 external bandwidth the following sequence could lead to such a - * situation. - * - * Consider an rdtgroup which had high L3 <-> memory traffic in initial - * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but - * after some time rdtgroup has mostly L2 <-> L3 traffic. - * - * In this case we may restrict the rdtgroup's L2 <-> L3 traffic as its - * throttle MSRs already have low percentage values. To avoid - * unnecessarily restricting such rdtgroups, we also increase the bandwidth. - */ -static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm) -{ - u32 closid, rmid, cur_msr_val, new_msr_val; - struct mbm_state *pmbm_data, *cmbm_data; - struct rdt_ctrl_domain *dom_mba; - enum resctrl_event_id evt_id; - struct rdt_resource *r_mba; - struct list_head *head; - struct rdtgroup *entry; - u32 cur_bw, user_bw; - - r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA); - evt_id = rgrp->mba_mbps_event; - - closid = rgrp->closid; - rmid = rgrp->mon.rmid; - pmbm_data = get_mbm_state(dom_mbm, closid, rmid, evt_id); - if (WARN_ON_ONCE(!pmbm_data)) - return; - - dom_mba = get_ctrl_domain_from_cpu(smp_processor_id(), r_mba); - if (!dom_mba) { - pr_warn_once("Failure to get domain for MBA update\n"); - return; - } - - cur_bw = pmbm_data->prev_bw; - user_bw = dom_mba->mbps_val[closid]; - - /* MBA resource doesn't support CDP */ - cur_msr_val = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE); - - /* - * For Ctrl groups read data from child monitor groups. - */ - head = &rgrp->mon.crdtgrp_list; - list_for_each_entry(entry, head, mon.crdtgrp_list) { - cmbm_data = get_mbm_state(dom_mbm, entry->closid, entry->mon.rmid, evt_id); - if (WARN_ON_ONCE(!cmbm_data)) - return; - cur_bw += cmbm_data->prev_bw; - } - - /* - * Scale up/down the bandwidth linearly for the ctrl group. The - * bandwidth step is the bandwidth granularity specified by the - * hardware. - * Always increase throttling if current bandwidth is above the - * target set by user. - * But avoid thrashing up and down on every poll by checking - * whether a decrease in throttling is likely to push the group - * back over target. E.g. if currently throttling to 30% of bandwidth - * on a system with 10% granularity steps, check whether moving to - * 40% would go past the limit by multiplying current bandwidth by - * "(30 + 10) / 30". - */ - if (cur_msr_val > r_mba->membw.min_bw && user_bw < cur_bw) { - new_msr_val = cur_msr_val - r_mba->membw.bw_gran; - } else if (cur_msr_val < MAX_MBA_BW && - (user_bw > (cur_bw * (cur_msr_val + r_mba->membw.min_bw) / cur_msr_val))) { - new_msr_val = cur_msr_val + r_mba->membw.bw_gran; - } else { - return; - } - - resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val); -} - -static void mbm_update_one_event(struct rdt_resource *r, struct rdt_mon_domain *d, - u32 closid, u32 rmid, enum resctrl_event_id evtid) -{ - struct rmid_read rr = {0}; - - rr.r = r; - rr.d = d; - rr.evtid = evtid; - rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid); - if (IS_ERR(rr.arch_mon_ctx)) { - pr_warn_ratelimited("Failed to allocate monitor context: %ld", - PTR_ERR(rr.arch_mon_ctx)); - return; - } - - __mon_event_count(closid, rmid, &rr); - - /* - * If the software controller is enabled, compute the - * bandwidth for this event id. - */ - if (is_mba_sc(NULL)) - mbm_bw_count(closid, rmid, &rr); - - resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx); -} - -static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d, - u32 closid, u32 rmid) -{ - /* - * This is protected from concurrent reads from user as both - * the user and overflow handler hold the global mutex. - */ - if (resctrl_arch_is_mbm_total_enabled()) - mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_TOTAL_EVENT_ID); - - if (resctrl_arch_is_mbm_local_enabled()) - mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_LOCAL_EVENT_ID); -} - -/* - * Handler to scan the limbo list and move the RMIDs - * to free list whose occupancy < threshold_occupancy. - */ -void cqm_handle_limbo(struct work_struct *work) -{ - unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL); - struct rdt_mon_domain *d; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - d = container_of(work, struct rdt_mon_domain, cqm_limbo.work); - - __check_limbo(d, false); - - if (has_busy_rmid(d)) { - d->cqm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask, - RESCTRL_PICK_ANY_CPU); - schedule_delayed_work_on(d->cqm_work_cpu, &d->cqm_limbo, - delay); - } - - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); -} - -/** - * cqm_setup_limbo_handler() - Schedule the limbo handler to run for this - * domain. - * @dom: The domain the limbo handler should run for. - * @delay_ms: How far in the future the handler should run. - * @exclude_cpu: Which CPU the handler should not run on, - * RESCTRL_PICK_ANY_CPU to pick any CPU. - */ -void cqm_setup_limbo_handler(struct rdt_mon_domain *dom, unsigned long delay_ms, - int exclude_cpu) -{ - unsigned long delay = msecs_to_jiffies(delay_ms); - int cpu; - - cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu); - dom->cqm_work_cpu = cpu; - - if (cpu < nr_cpu_ids) - schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay); -} - -void mbm_handle_overflow(struct work_struct *work) -{ - unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL); - struct rdtgroup *prgrp, *crgrp; - struct rdt_mon_domain *d; - struct list_head *head; - struct rdt_resource *r; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - /* - * If the filesystem has been unmounted this work no longer needs to - * run. - */ - if (!resctrl_mounted || !resctrl_arch_mon_capable()) - goto out_unlock; - - r = resctrl_arch_get_resource(RDT_RESOURCE_L3); - d = container_of(work, struct rdt_mon_domain, mbm_over.work); - - list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { - mbm_update(r, d, prgrp->closid, prgrp->mon.rmid); - - head = &prgrp->mon.crdtgrp_list; - list_for_each_entry(crgrp, head, mon.crdtgrp_list) - mbm_update(r, d, crgrp->closid, crgrp->mon.rmid); - - if (is_mba_sc(NULL)) - update_mba_bw(prgrp, d); - } - - /* - * Re-check for housekeeping CPUs. This allows the overflow handler to - * move off a nohz_full CPU quickly. - */ - d->mbm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask, - RESCTRL_PICK_ANY_CPU); - schedule_delayed_work_on(d->mbm_work_cpu, &d->mbm_over, delay); - -out_unlock: - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); -} - -/** - * mbm_setup_overflow_handler() - Schedule the overflow handler to run for this - * domain. - * @dom: The domain the overflow handler should run for. - * @delay_ms: How far in the future the handler should run. - * @exclude_cpu: Which CPU the handler should not run on, - * RESCTRL_PICK_ANY_CPU to pick any CPU. - */ -void mbm_setup_overflow_handler(struct rdt_mon_domain *dom, unsigned long delay_ms, - int exclude_cpu) -{ - unsigned long delay = msecs_to_jiffies(delay_ms); - int cpu; - - /* - * When a domain comes online there is no guarantee the filesystem is - * mounted. If not, there is no need to catch counter overflow. - */ - if (!resctrl_mounted || !resctrl_arch_mon_capable()) - return; - cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu); - dom->mbm_work_cpu = cpu; - - if (cpu < nr_cpu_ids) - schedule_delayed_work_on(cpu, &dom->mbm_over, delay); -} - -static int dom_data_init(struct rdt_resource *r) -{ - u32 idx_limit = resctrl_arch_system_num_rmid_idx(); - u32 num_closid = resctrl_arch_get_num_closid(r); - struct rmid_entry *entry = NULL; - int err = 0, i; - u32 idx; - - mutex_lock(&rdtgroup_mutex); - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { - u32 *tmp; - - /* - * If the architecture hasn't provided a sanitised value here, - * this may result in larger arrays than necessary. Resctrl will - * use a smaller system wide value based on the resources in - * use. - */ - tmp = kcalloc(num_closid, sizeof(*tmp), GFP_KERNEL); - if (!tmp) { - err = -ENOMEM; - goto out_unlock; - } - - closid_num_dirty_rmid = tmp; - } - - rmid_ptrs = kcalloc(idx_limit, sizeof(struct rmid_entry), GFP_KERNEL); - if (!rmid_ptrs) { - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { - kfree(closid_num_dirty_rmid); - closid_num_dirty_rmid = NULL; - } - err = -ENOMEM; - goto out_unlock; - } - - for (i = 0; i < idx_limit; i++) { - entry = &rmid_ptrs[i]; - INIT_LIST_HEAD(&entry->list); - - resctrl_arch_rmid_idx_decode(i, &entry->closid, &entry->rmid); - list_add_tail(&entry->list, &rmid_free_lru); - } - - /* - * RESCTRL_RESERVED_CLOSID and RESCTRL_RESERVED_RMID are special and - * are always allocated. These are used for the rdtgroup_default - * control group, which will be setup later in resctrl_init(). - */ - idx = resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID, - RESCTRL_RESERVED_RMID); - entry = __rmid_entry(idx); - list_del(&entry->list); - -out_unlock: - mutex_unlock(&rdtgroup_mutex); - - return err; -} - -static void dom_data_exit(struct rdt_resource *r) -{ - mutex_lock(&rdtgroup_mutex); - - if (!r->mon_capable) - goto out_unlock; - - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { - kfree(closid_num_dirty_rmid); - closid_num_dirty_rmid = NULL; - } - - kfree(rmid_ptrs); - rmid_ptrs = NULL; - -out_unlock: - mutex_unlock(&rdtgroup_mutex); -} - -static struct mon_evt llc_occupancy_event = { - .name = "llc_occupancy", - .evtid = QOS_L3_OCCUP_EVENT_ID, -}; - -static struct mon_evt mbm_total_event = { - .name = "mbm_total_bytes", - .evtid = QOS_L3_MBM_TOTAL_EVENT_ID, -}; - -static struct mon_evt mbm_local_event = { - .name = "mbm_local_bytes", - .evtid = QOS_L3_MBM_LOCAL_EVENT_ID, -}; - -/* - * Initialize the event list for the resource. - * - * Note that MBM events are also part of RDT_RESOURCE_L3 resource - * because as per the SDM the total and local memory bandwidth - * are enumerated as part of L3 monitoring. - */ -static void l3_mon_evt_init(struct rdt_resource *r) -{ - INIT_LIST_HEAD(&r->evt_list); - - if (resctrl_arch_is_llc_occupancy_enabled()) - list_add_tail(&llc_occupancy_event.list, &r->evt_list); - if (resctrl_arch_is_mbm_total_enabled()) - list_add_tail(&mbm_total_event.list, &r->evt_list); - if (resctrl_arch_is_mbm_local_enabled()) - list_add_tail(&mbm_local_event.list, &r->evt_list); -} - /* * The power-on reset value of MSR_RMID_SNC_CONFIG is 0x1 * which indicates that RMIDs are configured in legacy mode. @@ -1193,51 +340,6 @@ static __init int snc_get_config(void) return ret; } -/** - * resctrl_mon_resource_init() - Initialise global monitoring structures. - * - * Allocate and initialise global monitor resources that do not belong to a - * specific domain. i.e. the rmid_ptrs[] used for the limbo and free lists. - * Called once during boot after the struct rdt_resource's have been configured - * but before the filesystem is mounted. - * Resctrl's cpuhp callbacks may be called before this point to bring a domain - * online. - * - * Returns 0 for success, or -ENOMEM. - */ -int resctrl_mon_resource_init(void) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); - int ret; - - if (!r->mon_capable) - return 0; - - ret = dom_data_init(r); - if (ret) - return ret; - - l3_mon_evt_init(r); - - if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_TOTAL_EVENT_ID)) { - mbm_total_event.configurable = true; - resctrl_file_fflags_init("mbm_total_bytes_config", - RFTYPE_MON_INFO | RFTYPE_RES_CACHE); - } - if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_LOCAL_EVENT_ID)) { - mbm_local_event.configurable = true; - resctrl_file_fflags_init("mbm_local_bytes_config", - RFTYPE_MON_INFO | RFTYPE_RES_CACHE); - } - - if (resctrl_arch_is_mbm_local_enabled()) - mba_mbps_default_event = QOS_L3_MBM_LOCAL_EVENT_ID; - else if (resctrl_arch_is_mbm_total_enabled()) - mba_mbps_default_event = QOS_L3_MBM_TOTAL_EVENT_ID; - - return 0; -} - int __init rdt_get_mon_l3_config(struct rdt_resource *r) { unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset; @@ -1285,13 +387,6 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) return 0; } -void resctrl_mon_resource_exit(void) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); - - dom_data_exit(r); -} - void __init intel_rdt_mbm_apply_quirk(void) { int cf_index; diff --git a/arch/x86/kernel/cpu/resctrl/monitor_trace.h b/arch/x86/kernel/cpu/resctrl/monitor_trace.h deleted file mode 100644 index ade67daf42c2..000000000000 --- a/arch/x86/kernel/cpu/resctrl/monitor_trace.h +++ /dev/null @@ -1,31 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#undef TRACE_SYSTEM -#define TRACE_SYSTEM resctrl - -#if !defined(_FS_RESCTRL_MONITOR_TRACE_H) || defined(TRACE_HEADER_MULTI_READ) -#define _FS_RESCTRL_MONITOR_TRACE_H - -#include - -TRACE_EVENT(mon_llc_occupancy_limbo, - TP_PROTO(u32 ctrl_hw_id, u32 mon_hw_id, int domain_id, u64 llc_occupancy_bytes), - TP_ARGS(ctrl_hw_id, mon_hw_id, domain_id, llc_occupancy_bytes), - TP_STRUCT__entry(__field(u32, ctrl_hw_id) - __field(u32, mon_hw_id) - __field(int, domain_id) - __field(u64, llc_occupancy_bytes)), - TP_fast_assign(__entry->ctrl_hw_id = ctrl_hw_id; - __entry->mon_hw_id = mon_hw_id; - __entry->domain_id = domain_id; - __entry->llc_occupancy_bytes = llc_occupancy_bytes;), - TP_printk("ctrl_hw_id=%u mon_hw_id=%u domain_id=%d llc_occupancy_bytes=%llu", - __entry->ctrl_hw_id, __entry->mon_hw_id, __entry->domain_id, - __entry->llc_occupancy_bytes) - ); - -#endif /* _FS_RESCTRL_MONITOR_TRACE_H */ - -#undef TRACE_INCLUDE_PATH -#define TRACE_INCLUDE_PATH . -#define TRACE_INCLUDE_FILE monitor_trace -#include diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c index bb39ffdd8524..241d0d7e1cb5 100644 --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c @@ -12,17 +12,10 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include -#include #include -#include -#include -#include -#include #include #include #include -#include -#include #include #include @@ -31,6 +24,7 @@ #include "internal.h" #define CREATE_TRACE_POINTS + #include "pseudo_lock_trace.h" /* @@ -39,29 +33,6 @@ */ static u64 prefetch_disable_bits; -/* - * Major number assigned to and shared by all devices exposing - * pseudo-locked regions. - */ -static unsigned int pseudo_lock_major; -static unsigned long pseudo_lock_minor_avail = GENMASK(MINORBITS, 0); - -static char *pseudo_lock_devnode(const struct device *dev, umode_t *mode) -{ - const struct rdtgroup *rdtgrp; - - rdtgrp = dev_get_drvdata(dev); - if (mode) - *mode = 0600; - guard(mutex)(&rdtgroup_mutex); - return kasprintf(GFP_KERNEL, "pseudo_lock/%s", rdt_kn_name(rdtgrp->kn)); -} - -static const struct class pseudo_lock_class = { - .name = "pseudo_lock", - .devnode = pseudo_lock_devnode, -}; - /** * resctrl_arch_get_prefetch_disable_bits - prefetch disable bits of supported * platforms @@ -122,298 +93,6 @@ u64 resctrl_arch_get_prefetch_disable_bits(void) return prefetch_disable_bits; } -/** - * pseudo_lock_minor_get - Obtain available minor number - * @minor: Pointer to where new minor number will be stored - * - * A bitmask is used to track available minor numbers. Here the next free - * minor number is marked as unavailable and returned. - * - * Return: 0 on success, <0 on failure. - */ -static int pseudo_lock_minor_get(unsigned int *minor) -{ - unsigned long first_bit; - - first_bit = find_first_bit(&pseudo_lock_minor_avail, MINORBITS); - - if (first_bit == MINORBITS) - return -ENOSPC; - - __clear_bit(first_bit, &pseudo_lock_minor_avail); - *minor = first_bit; - - return 0; -} - -/** - * pseudo_lock_minor_release - Return minor number to available - * @minor: The minor number made available - */ -static void pseudo_lock_minor_release(unsigned int minor) -{ - __set_bit(minor, &pseudo_lock_minor_avail); -} - -/** - * region_find_by_minor - Locate a pseudo-lock region by inode minor number - * @minor: The minor number of the device representing pseudo-locked region - * - * When the character device is accessed we need to determine which - * pseudo-locked region it belongs to. This is done by matching the minor - * number of the device to the pseudo-locked region it belongs. - * - * Minor numbers are assigned at the time a pseudo-locked region is associated - * with a cache instance. - * - * Return: On success return pointer to resource group owning the pseudo-locked - * region, NULL on failure. - */ -static struct rdtgroup *region_find_by_minor(unsigned int minor) -{ - struct rdtgroup *rdtgrp, *rdtgrp_match = NULL; - - list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { - if (rdtgrp->plr && rdtgrp->plr->minor == minor) { - rdtgrp_match = rdtgrp; - break; - } - } - return rdtgrp_match; -} - -/** - * struct pseudo_lock_pm_req - A power management QoS request list entry - * @list: Entry within the @pm_reqs list for a pseudo-locked region - * @req: PM QoS request - */ -struct pseudo_lock_pm_req { - struct list_head list; - struct dev_pm_qos_request req; -}; - -static void pseudo_lock_cstates_relax(struct pseudo_lock_region *plr) -{ - struct pseudo_lock_pm_req *pm_req, *next; - - list_for_each_entry_safe(pm_req, next, &plr->pm_reqs, list) { - dev_pm_qos_remove_request(&pm_req->req); - list_del(&pm_req->list); - kfree(pm_req); - } -} - -/** - * pseudo_lock_cstates_constrain - Restrict cores from entering C6 - * @plr: Pseudo-locked region - * - * To prevent the cache from being affected by power management entering - * C6 has to be avoided. This is accomplished by requesting a latency - * requirement lower than lowest C6 exit latency of all supported - * platforms as found in the cpuidle state tables in the intel_idle driver. - * At this time it is possible to do so with a single latency requirement - * for all supported platforms. - * - * Since Goldmont is supported, which is affected by X86_BUG_MONITOR, - * the ACPI latencies need to be considered while keeping in mind that C2 - * may be set to map to deeper sleep states. In this case the latency - * requirement needs to prevent entering C2 also. - * - * Return: 0 on success, <0 on failure - */ -static int pseudo_lock_cstates_constrain(struct pseudo_lock_region *plr) -{ - struct pseudo_lock_pm_req *pm_req; - int cpu; - int ret; - - for_each_cpu(cpu, &plr->d->hdr.cpu_mask) { - pm_req = kzalloc(sizeof(*pm_req), GFP_KERNEL); - if (!pm_req) { - rdt_last_cmd_puts("Failure to allocate memory for PM QoS\n"); - ret = -ENOMEM; - goto out_err; - } - ret = dev_pm_qos_add_request(get_cpu_device(cpu), - &pm_req->req, - DEV_PM_QOS_RESUME_LATENCY, - 30); - if (ret < 0) { - rdt_last_cmd_printf("Failed to add latency req CPU%d\n", - cpu); - kfree(pm_req); - ret = -1; - goto out_err; - } - list_add(&pm_req->list, &plr->pm_reqs); - } - - return 0; - -out_err: - pseudo_lock_cstates_relax(plr); - return ret; -} - -/** - * pseudo_lock_region_clear - Reset pseudo-lock region data - * @plr: pseudo-lock region - * - * All content of the pseudo-locked region is reset - any memory allocated - * freed. - * - * Return: void - */ -static void pseudo_lock_region_clear(struct pseudo_lock_region *plr) -{ - plr->size = 0; - plr->line_size = 0; - kfree(plr->kmem); - plr->kmem = NULL; - plr->s = NULL; - if (plr->d) - plr->d->plr = NULL; - plr->d = NULL; - plr->cbm = 0; - plr->debugfs_dir = NULL; -} - -/** - * pseudo_lock_region_init - Initialize pseudo-lock region information - * @plr: pseudo-lock region - * - * Called after user provided a schemata to be pseudo-locked. From the - * schemata the &struct pseudo_lock_region is on entry already initialized - * with the resource, domain, and capacity bitmask. Here the information - * required for pseudo-locking is deduced from this data and &struct - * pseudo_lock_region initialized further. This information includes: - * - size in bytes of the region to be pseudo-locked - * - cache line size to know the stride with which data needs to be accessed - * to be pseudo-locked - * - a cpu associated with the cache instance on which the pseudo-locking - * flow can be executed - * - * Return: 0 on success, <0 on failure. Descriptive error will be written - * to last_cmd_status buffer. - */ -static int pseudo_lock_region_init(struct pseudo_lock_region *plr) -{ - enum resctrl_scope scope = plr->s->res->ctrl_scope; - struct cacheinfo *ci; - int ret; - - if (WARN_ON_ONCE(scope != RESCTRL_L2_CACHE && scope != RESCTRL_L3_CACHE)) - return -ENODEV; - - /* Pick the first cpu we find that is associated with the cache. */ - plr->cpu = cpumask_first(&plr->d->hdr.cpu_mask); - - if (!cpu_online(plr->cpu)) { - rdt_last_cmd_printf("CPU %u associated with cache not online\n", - plr->cpu); - ret = -ENODEV; - goto out_region; - } - - ci = get_cpu_cacheinfo_level(plr->cpu, scope); - if (ci) { - plr->line_size = ci->coherency_line_size; - plr->size = rdtgroup_cbm_to_size(plr->s->res, plr->d, plr->cbm); - return 0; - } - - ret = -1; - rdt_last_cmd_puts("Unable to determine cache line size\n"); -out_region: - pseudo_lock_region_clear(plr); - return ret; -} - -/** - * pseudo_lock_init - Initialize a pseudo-lock region - * @rdtgrp: resource group to which new pseudo-locked region will belong - * - * A pseudo-locked region is associated with a resource group. When this - * association is created the pseudo-locked region is initialized. The - * details of the pseudo-locked region are not known at this time so only - * allocation is done and association established. - * - * Return: 0 on success, <0 on failure - */ -static int pseudo_lock_init(struct rdtgroup *rdtgrp) -{ - struct pseudo_lock_region *plr; - - plr = kzalloc(sizeof(*plr), GFP_KERNEL); - if (!plr) - return -ENOMEM; - - init_waitqueue_head(&plr->lock_thread_wq); - INIT_LIST_HEAD(&plr->pm_reqs); - rdtgrp->plr = plr; - return 0; -} - -/** - * pseudo_lock_region_alloc - Allocate kernel memory that will be pseudo-locked - * @plr: pseudo-lock region - * - * Initialize the details required to set up the pseudo-locked region and - * allocate the contiguous memory that will be pseudo-locked to the cache. - * - * Return: 0 on success, <0 on failure. Descriptive error will be written - * to last_cmd_status buffer. - */ -static int pseudo_lock_region_alloc(struct pseudo_lock_region *plr) -{ - int ret; - - ret = pseudo_lock_region_init(plr); - if (ret < 0) - return ret; - - /* - * We do not yet support contiguous regions larger than - * KMALLOC_MAX_SIZE. - */ - if (plr->size > KMALLOC_MAX_SIZE) { - rdt_last_cmd_puts("Requested region exceeds maximum size\n"); - ret = -E2BIG; - goto out_region; - } - - plr->kmem = kzalloc(plr->size, GFP_KERNEL); - if (!plr->kmem) { - rdt_last_cmd_puts("Unable to allocate memory\n"); - ret = -ENOMEM; - goto out_region; - } - - ret = 0; - goto out; -out_region: - pseudo_lock_region_clear(plr); -out: - return ret; -} - -/** - * pseudo_lock_free - Free a pseudo-locked region - * @rdtgrp: resource group to which pseudo-locked region belonged - * - * The pseudo-locked region's resources have already been released, or not - * yet created at this point. Now it can be freed and disassociated from the - * resource group. - * - * Return: void - */ -static void pseudo_lock_free(struct rdtgroup *rdtgrp) -{ - pseudo_lock_region_clear(rdtgrp->plr); - kfree(rdtgrp->plr); - rdtgrp->plr = NULL; -} - /** * resctrl_arch_pseudo_lock_fn - Load kernel memory into cache * @_plr: the pseudo-lock region descriptor @@ -543,340 +222,6 @@ int resctrl_arch_pseudo_lock_fn(void *_plr) return 0; } -/** - * rdtgroup_monitor_in_progress - Test if monitoring in progress - * @rdtgrp: resource group being queried - * - * Return: 1 if monitor groups have been created for this resource - * group, 0 otherwise. - */ -static int rdtgroup_monitor_in_progress(struct rdtgroup *rdtgrp) -{ - return !list_empty(&rdtgrp->mon.crdtgrp_list); -} - -/** - * rdtgroup_locksetup_user_restrict - Restrict user access to group - * @rdtgrp: resource group needing access restricted - * - * A resource group used for cache pseudo-locking cannot have cpus or tasks - * assigned to it. This is communicated to the user by restricting access - * to all the files that can be used to make such changes. - * - * Permissions restored with rdtgroup_locksetup_user_restore() - * - * Return: 0 on success, <0 on failure. If a failure occurs during the - * restriction of access an attempt will be made to restore permissions but - * the state of the mode of these files will be uncertain when a failure - * occurs. - */ -static int rdtgroup_locksetup_user_restrict(struct rdtgroup *rdtgrp) -{ - int ret; - - ret = rdtgroup_kn_mode_restrict(rdtgrp, "tasks"); - if (ret) - return ret; - - ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus"); - if (ret) - goto err_tasks; - - ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list"); - if (ret) - goto err_cpus; - - if (resctrl_arch_mon_capable()) { - ret = rdtgroup_kn_mode_restrict(rdtgrp, "mon_groups"); - if (ret) - goto err_cpus_list; - } - - ret = 0; - goto out; - -err_cpus_list: - rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777); -err_cpus: - rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777); -err_tasks: - rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777); -out: - return ret; -} - -/** - * rdtgroup_locksetup_user_restore - Restore user access to group - * @rdtgrp: resource group needing access restored - * - * Restore all file access previously removed using - * rdtgroup_locksetup_user_restrict() - * - * Return: 0 on success, <0 on failure. If a failure occurs during the - * restoration of access an attempt will be made to restrict permissions - * again but the state of the mode of these files will be uncertain when - * a failure occurs. - */ -static int rdtgroup_locksetup_user_restore(struct rdtgroup *rdtgrp) -{ - int ret; - - ret = rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777); - if (ret) - return ret; - - ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777); - if (ret) - goto err_tasks; - - ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777); - if (ret) - goto err_cpus; - - if (resctrl_arch_mon_capable()) { - ret = rdtgroup_kn_mode_restore(rdtgrp, "mon_groups", 0777); - if (ret) - goto err_cpus_list; - } - - ret = 0; - goto out; - -err_cpus_list: - rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list"); -err_cpus: - rdtgroup_kn_mode_restrict(rdtgrp, "cpus"); -err_tasks: - rdtgroup_kn_mode_restrict(rdtgrp, "tasks"); -out: - return ret; -} - -/** - * rdtgroup_locksetup_enter - Resource group enters locksetup mode - * @rdtgrp: resource group requested to enter locksetup mode - * - * A resource group enters locksetup mode to reflect that it would be used - * to represent a pseudo-locked region and is in the process of being set - * up to do so. A resource group used for a pseudo-locked region would - * lose the closid associated with it so we cannot allow it to have any - * tasks or cpus assigned nor permit tasks or cpus to be assigned in the - * future. Monitoring of a pseudo-locked region is not allowed either. - * - * The above and more restrictions on a pseudo-locked region are checked - * for and enforced before the resource group enters the locksetup mode. - * - * Returns: 0 if the resource group successfully entered locksetup mode, <0 - * on failure. On failure the last_cmd_status buffer is updated with text to - * communicate details of failure to the user. - */ -int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp) -{ - int ret; - - /* - * The default resource group can neither be removed nor lose the - * default closid associated with it. - */ - if (rdtgrp == &rdtgroup_default) { - rdt_last_cmd_puts("Cannot pseudo-lock default group\n"); - return -EINVAL; - } - - /* - * Cache Pseudo-locking not supported when CDP is enabled. - * - * Some things to consider if you would like to enable this - * support (using L3 CDP as example): - * - When CDP is enabled two separate resources are exposed, - * L3DATA and L3CODE, but they are actually on the same cache. - * The implication for pseudo-locking is that if a - * pseudo-locked region is created on a domain of one - * resource (eg. L3CODE), then a pseudo-locked region cannot - * be created on that same domain of the other resource - * (eg. L3DATA). This is because the creation of a - * pseudo-locked region involves a call to wbinvd that will - * affect all cache allocations on particular domain. - * - Considering the previous, it may be possible to only - * expose one of the CDP resources to pseudo-locking and - * hide the other. For example, we could consider to only - * expose L3DATA and since the L3 cache is unified it is - * still possible to place instructions there are execute it. - * - If only one region is exposed to pseudo-locking we should - * still keep in mind that availability of a portion of cache - * for pseudo-locking should take into account both resources. - * Similarly, if a pseudo-locked region is created in one - * resource, the portion of cache used by it should be made - * unavailable to all future allocations from both resources. - */ - if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3) || - resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2)) { - rdt_last_cmd_puts("CDP enabled\n"); - return -EINVAL; - } - - /* - * Not knowing the bits to disable prefetching implies that this - * platform does not support Cache Pseudo-Locking. - */ - if (resctrl_arch_get_prefetch_disable_bits() == 0) { - rdt_last_cmd_puts("Pseudo-locking not supported\n"); - return -EINVAL; - } - - if (rdtgroup_monitor_in_progress(rdtgrp)) { - rdt_last_cmd_puts("Monitoring in progress\n"); - return -EINVAL; - } - - if (rdtgroup_tasks_assigned(rdtgrp)) { - rdt_last_cmd_puts("Tasks assigned to resource group\n"); - return -EINVAL; - } - - if (!cpumask_empty(&rdtgrp->cpu_mask)) { - rdt_last_cmd_puts("CPUs assigned to resource group\n"); - return -EINVAL; - } - - if (rdtgroup_locksetup_user_restrict(rdtgrp)) { - rdt_last_cmd_puts("Unable to modify resctrl permissions\n"); - return -EIO; - } - - ret = pseudo_lock_init(rdtgrp); - if (ret) { - rdt_last_cmd_puts("Unable to init pseudo-lock region\n"); - goto out_release; - } - - /* - * If this system is capable of monitoring a rmid would have been - * allocated when the control group was created. This is not needed - * anymore when this group would be used for pseudo-locking. This - * is safe to call on platforms not capable of monitoring. - */ - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - - ret = 0; - goto out; - -out_release: - rdtgroup_locksetup_user_restore(rdtgrp); -out: - return ret; -} - -/** - * rdtgroup_locksetup_exit - resource group exist locksetup mode - * @rdtgrp: resource group - * - * When a resource group exits locksetup mode the earlier restrictions are - * lifted. - * - * Return: 0 on success, <0 on failure - */ -int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp) -{ - int ret; - - if (resctrl_arch_mon_capable()) { - ret = alloc_rmid(rdtgrp->closid); - if (ret < 0) { - rdt_last_cmd_puts("Out of RMIDs\n"); - return ret; - } - rdtgrp->mon.rmid = ret; - } - - ret = rdtgroup_locksetup_user_restore(rdtgrp); - if (ret) { - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - return ret; - } - - pseudo_lock_free(rdtgrp); - return 0; -} - -/** - * rdtgroup_cbm_overlaps_pseudo_locked - Test if CBM or portion is pseudo-locked - * @d: RDT domain - * @cbm: CBM to test - * - * @d represents a cache instance and @cbm a capacity bitmask that is - * considered for it. Determine if @cbm overlaps with any existing - * pseudo-locked region on @d. - * - * @cbm is unsigned long, even if only 32 bits are used, to make the - * bitmap functions work correctly. - * - * Return: true if @cbm overlaps with pseudo-locked region on @d, false - * otherwise. - */ -bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm) -{ - unsigned int cbm_len; - unsigned long cbm_b; - - if (d->plr) { - cbm_len = d->plr->s->res->cache.cbm_len; - cbm_b = d->plr->cbm; - if (bitmap_intersects(&cbm, &cbm_b, cbm_len)) - return true; - } - return false; -} - -/** - * rdtgroup_pseudo_locked_in_hierarchy - Pseudo-locked region in cache hierarchy - * @d: RDT domain under test - * - * The setup of a pseudo-locked region affects all cache instances within - * the hierarchy of the region. It is thus essential to know if any - * pseudo-locked regions exist within a cache hierarchy to prevent any - * attempts to create new pseudo-locked regions in the same hierarchy. - * - * Return: true if a pseudo-locked region exists in the hierarchy of @d or - * if it is not possible to test due to memory allocation issue, - * false otherwise. - */ -bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d) -{ - struct rdt_ctrl_domain *d_i; - cpumask_var_t cpu_with_psl; - struct rdt_resource *r; - bool ret = false; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - if (!zalloc_cpumask_var(&cpu_with_psl, GFP_KERNEL)) - return true; - - /* - * First determine which cpus have pseudo-locked regions - * associated with them. - */ - for_each_alloc_capable_rdt_resource(r) { - list_for_each_entry(d_i, &r->ctrl_domains, hdr.list) { - if (d_i->plr) - cpumask_or(cpu_with_psl, cpu_with_psl, - &d_i->hdr.cpu_mask); - } - } - - /* - * Next test if new pseudo-locked region would intersect with - * existing region. - */ - if (cpumask_intersects(&d->hdr.cpu_mask, cpu_with_psl)) - ret = true; - - free_cpumask_var(cpu_with_psl); - return ret; -} - /** * resctrl_arch_measure_cycles_lat_fn - Measure cycle latency to read * pseudo-locked memory @@ -1169,433 +514,3 @@ out: wake_up_interruptible(&plr->lock_thread_wq); return 0; } - -/** - * pseudo_lock_measure_cycles - Trigger latency measure to pseudo-locked region - * @rdtgrp: Resource group to which the pseudo-locked region belongs. - * @sel: Selector of which measurement to perform on a pseudo-locked region. - * - * The measurement of latency to access a pseudo-locked region should be - * done from a cpu that is associated with that pseudo-locked region. - * Determine which cpu is associated with this region and start a thread on - * that cpu to perform the measurement, wait for that thread to complete. - * - * Return: 0 on success, <0 on failure - */ -static int pseudo_lock_measure_cycles(struct rdtgroup *rdtgrp, int sel) -{ - struct pseudo_lock_region *plr = rdtgrp->plr; - struct task_struct *thread; - unsigned int cpu; - int ret = -1; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - if (rdtgrp->flags & RDT_DELETED) { - ret = -ENODEV; - goto out; - } - - if (!plr->d) { - ret = -ENODEV; - goto out; - } - - plr->thread_done = 0; - cpu = cpumask_first(&plr->d->hdr.cpu_mask); - if (!cpu_online(cpu)) { - ret = -ENODEV; - goto out; - } - - plr->cpu = cpu; - - if (sel == 1) - thread = kthread_run_on_cpu(resctrl_arch_measure_cycles_lat_fn, - plr, cpu, "pseudo_lock_measure/%u"); - else if (sel == 2) - thread = kthread_run_on_cpu(resctrl_arch_measure_l2_residency, - plr, cpu, "pseudo_lock_measure/%u"); - else if (sel == 3) - thread = kthread_run_on_cpu(resctrl_arch_measure_l3_residency, - plr, cpu, "pseudo_lock_measure/%u"); - else - goto out; - - if (IS_ERR(thread)) { - ret = PTR_ERR(thread); - goto out; - } - - ret = wait_event_interruptible(plr->lock_thread_wq, - plr->thread_done == 1); - if (ret < 0) - goto out; - - ret = 0; - -out: - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - return ret; -} - -static ssize_t pseudo_lock_measure_trigger(struct file *file, - const char __user *user_buf, - size_t count, loff_t *ppos) -{ - struct rdtgroup *rdtgrp = file->private_data; - size_t buf_size; - char buf[32]; - int ret; - int sel; - - buf_size = min(count, (sizeof(buf) - 1)); - if (copy_from_user(buf, user_buf, buf_size)) - return -EFAULT; - - buf[buf_size] = '\0'; - ret = kstrtoint(buf, 10, &sel); - if (ret == 0) { - if (sel != 1 && sel != 2 && sel != 3) - return -EINVAL; - ret = debugfs_file_get(file->f_path.dentry); - if (ret) - return ret; - ret = pseudo_lock_measure_cycles(rdtgrp, sel); - if (ret == 0) - ret = count; - debugfs_file_put(file->f_path.dentry); - } - - return ret; -} - -static const struct file_operations pseudo_measure_fops = { - .write = pseudo_lock_measure_trigger, - .open = simple_open, - .llseek = default_llseek, -}; - -/** - * rdtgroup_pseudo_lock_create - Create a pseudo-locked region - * @rdtgrp: resource group to which pseudo-lock region belongs - * - * Called when a resource group in the pseudo-locksetup mode receives a - * valid schemata that should be pseudo-locked. Since the resource group is - * in pseudo-locksetup mode the &struct pseudo_lock_region has already been - * allocated and initialized with the essential information. If a failure - * occurs the resource group remains in the pseudo-locksetup mode with the - * &struct pseudo_lock_region associated with it, but cleared from all - * information and ready for the user to re-attempt pseudo-locking by - * writing the schemata again. - * - * Return: 0 if the pseudo-locked region was successfully pseudo-locked, <0 - * on failure. Descriptive error will be written to last_cmd_status buffer. - */ -int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp) -{ - struct pseudo_lock_region *plr = rdtgrp->plr; - struct task_struct *thread; - unsigned int new_minor; - struct device *dev; - char *kn_name __free(kfree) = NULL; - int ret; - - ret = pseudo_lock_region_alloc(plr); - if (ret < 0) - return ret; - - ret = pseudo_lock_cstates_constrain(plr); - if (ret < 0) { - ret = -EINVAL; - goto out_region; - } - kn_name = kstrdup(rdt_kn_name(rdtgrp->kn), GFP_KERNEL); - if (!kn_name) { - ret = -ENOMEM; - goto out_cstates; - } - - plr->thread_done = 0; - - thread = kthread_run_on_cpu(resctrl_arch_pseudo_lock_fn, plr, - plr->cpu, "pseudo_lock/%u"); - if (IS_ERR(thread)) { - ret = PTR_ERR(thread); - rdt_last_cmd_printf("Locking thread returned error %d\n", ret); - goto out_cstates; - } - - ret = wait_event_interruptible(plr->lock_thread_wq, - plr->thread_done == 1); - if (ret < 0) { - /* - * If the thread does not get on the CPU for whatever - * reason and the process which sets up the region is - * interrupted then this will leave the thread in runnable - * state and once it gets on the CPU it will dereference - * the cleared, but not freed, plr struct resulting in an - * empty pseudo-locking loop. - */ - rdt_last_cmd_puts("Locking thread interrupted\n"); - goto out_cstates; - } - - ret = pseudo_lock_minor_get(&new_minor); - if (ret < 0) { - rdt_last_cmd_puts("Unable to obtain a new minor number\n"); - goto out_cstates; - } - - /* - * Unlock access but do not release the reference. The - * pseudo-locked region will still be here on return. - * - * The mutex has to be released temporarily to avoid a potential - * deadlock with the mm->mmap_lock which is obtained in the - * device_create() and debugfs_create_dir() callpath below as well as - * before the mmap() callback is called. - */ - mutex_unlock(&rdtgroup_mutex); - - if (!IS_ERR_OR_NULL(debugfs_resctrl)) { - plr->debugfs_dir = debugfs_create_dir(kn_name, debugfs_resctrl); - if (!IS_ERR_OR_NULL(plr->debugfs_dir)) - debugfs_create_file("pseudo_lock_measure", 0200, - plr->debugfs_dir, rdtgrp, - &pseudo_measure_fops); - } - - dev = device_create(&pseudo_lock_class, NULL, - MKDEV(pseudo_lock_major, new_minor), - rdtgrp, "%s", kn_name); - - mutex_lock(&rdtgroup_mutex); - - if (IS_ERR(dev)) { - ret = PTR_ERR(dev); - rdt_last_cmd_printf("Failed to create character device: %d\n", - ret); - goto out_debugfs; - } - - /* We released the mutex - check if group was removed while we did so */ - if (rdtgrp->flags & RDT_DELETED) { - ret = -ENODEV; - goto out_device; - } - - plr->minor = new_minor; - - rdtgrp->mode = RDT_MODE_PSEUDO_LOCKED; - closid_free(rdtgrp->closid); - rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0444); - rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0444); - - ret = 0; - goto out; - -out_device: - device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, new_minor)); -out_debugfs: - debugfs_remove_recursive(plr->debugfs_dir); - pseudo_lock_minor_release(new_minor); -out_cstates: - pseudo_lock_cstates_relax(plr); -out_region: - pseudo_lock_region_clear(plr); -out: - return ret; -} - -/** - * rdtgroup_pseudo_lock_remove - Remove a pseudo-locked region - * @rdtgrp: resource group to which the pseudo-locked region belongs - * - * The removal of a pseudo-locked region can be initiated when the resource - * group is removed from user space via a "rmdir" from userspace or the - * unmount of the resctrl filesystem. On removal the resource group does - * not go back to pseudo-locksetup mode before it is removed, instead it is - * removed directly. There is thus asymmetry with the creation where the - * &struct pseudo_lock_region is removed here while it was not created in - * rdtgroup_pseudo_lock_create(). - * - * Return: void - */ -void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp) -{ - struct pseudo_lock_region *plr = rdtgrp->plr; - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - /* - * Default group cannot be a pseudo-locked region so we can - * free closid here. - */ - closid_free(rdtgrp->closid); - goto free; - } - - pseudo_lock_cstates_relax(plr); - debugfs_remove_recursive(rdtgrp->plr->debugfs_dir); - device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, plr->minor)); - pseudo_lock_minor_release(plr->minor); - -free: - pseudo_lock_free(rdtgrp); -} - -static int pseudo_lock_dev_open(struct inode *inode, struct file *filp) -{ - struct rdtgroup *rdtgrp; - - mutex_lock(&rdtgroup_mutex); - - rdtgrp = region_find_by_minor(iminor(inode)); - if (!rdtgrp) { - mutex_unlock(&rdtgroup_mutex); - return -ENODEV; - } - - filp->private_data = rdtgrp; - atomic_inc(&rdtgrp->waitcount); - /* Perform a non-seekable open - llseek is not supported */ - filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); - - mutex_unlock(&rdtgroup_mutex); - - return 0; -} - -static int pseudo_lock_dev_release(struct inode *inode, struct file *filp) -{ - struct rdtgroup *rdtgrp; - - mutex_lock(&rdtgroup_mutex); - rdtgrp = filp->private_data; - WARN_ON(!rdtgrp); - if (!rdtgrp) { - mutex_unlock(&rdtgroup_mutex); - return -ENODEV; - } - filp->private_data = NULL; - atomic_dec(&rdtgrp->waitcount); - mutex_unlock(&rdtgroup_mutex); - return 0; -} - -static int pseudo_lock_dev_mremap(struct vm_area_struct *area) -{ - /* Not supported */ - return -EINVAL; -} - -static const struct vm_operations_struct pseudo_mmap_ops = { - .mremap = pseudo_lock_dev_mremap, -}; - -static int pseudo_lock_dev_mmap(struct file *filp, struct vm_area_struct *vma) -{ - unsigned long vsize = vma->vm_end - vma->vm_start; - unsigned long off = vma->vm_pgoff << PAGE_SHIFT; - struct pseudo_lock_region *plr; - struct rdtgroup *rdtgrp; - unsigned long physical; - unsigned long psize; - - mutex_lock(&rdtgroup_mutex); - - rdtgrp = filp->private_data; - WARN_ON(!rdtgrp); - if (!rdtgrp) { - mutex_unlock(&rdtgroup_mutex); - return -ENODEV; - } - - plr = rdtgrp->plr; - - if (!plr->d) { - mutex_unlock(&rdtgroup_mutex); - return -ENODEV; - } - - /* - * Task is required to run with affinity to the cpus associated - * with the pseudo-locked region. If this is not the case the task - * may be scheduled elsewhere and invalidate entries in the - * pseudo-locked region. - */ - if (!cpumask_subset(current->cpus_ptr, &plr->d->hdr.cpu_mask)) { - mutex_unlock(&rdtgroup_mutex); - return -EINVAL; - } - - physical = __pa(plr->kmem) >> PAGE_SHIFT; - psize = plr->size - off; - - if (off > plr->size) { - mutex_unlock(&rdtgroup_mutex); - return -ENOSPC; - } - - /* - * Ensure changes are carried directly to the memory being mapped, - * do not allow copy-on-write mapping. - */ - if (!(vma->vm_flags & VM_SHARED)) { - mutex_unlock(&rdtgroup_mutex); - return -EINVAL; - } - - if (vsize > psize) { - mutex_unlock(&rdtgroup_mutex); - return -ENOSPC; - } - - memset(plr->kmem + off, 0, vsize); - - if (remap_pfn_range(vma, vma->vm_start, physical + vma->vm_pgoff, - vsize, vma->vm_page_prot)) { - mutex_unlock(&rdtgroup_mutex); - return -EAGAIN; - } - vma->vm_ops = &pseudo_mmap_ops; - mutex_unlock(&rdtgroup_mutex); - return 0; -} - -static const struct file_operations pseudo_lock_dev_fops = { - .owner = THIS_MODULE, - .read = NULL, - .write = NULL, - .open = pseudo_lock_dev_open, - .release = pseudo_lock_dev_release, - .mmap = pseudo_lock_dev_mmap, -}; - -int rdt_pseudo_lock_init(void) -{ - int ret; - - ret = register_chrdev(0, "pseudo_lock", &pseudo_lock_dev_fops); - if (ret < 0) - return ret; - - pseudo_lock_major = ret; - - ret = class_register(&pseudo_lock_class); - if (ret) { - unregister_chrdev(pseudo_lock_major, "pseudo_lock"); - return ret; - } - - return 0; -} - -void rdt_pseudo_lock_release(void) -{ - class_unregister(&pseudo_lock_class); - unregister_chrdev(pseudo_lock_major, "pseudo_lock"); - pseudo_lock_major = 0; -} diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h b/arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h index 5a0fae61d3ee..7c8aef08010f 100644 --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h @@ -39,5 +39,7 @@ TRACE_EVENT(pseudo_lock_l3, #undef TRACE_INCLUDE_PATH #define TRACE_INCLUDE_PATH . + #define TRACE_INCLUDE_FILE pseudo_lock_trace + #include diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index ace86b6dcede..c7a7f0ae373a 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -32,4547 +32,230 @@ #include "internal.h" DEFINE_STATIC_KEY_FALSE(rdt_enable_key); -DEFINE_STATIC_KEY_FALSE(rdt_mon_enable_key); -DEFINE_STATIC_KEY_FALSE(rdt_alloc_enable_key); - -/* Mutex to protect rdtgroup access. */ -DEFINE_MUTEX(rdtgroup_mutex); - -static struct kernfs_root *rdt_root; -struct rdtgroup rdtgroup_default; -LIST_HEAD(rdt_all_groups); - -/* list of entries for the schemata file */ -LIST_HEAD(resctrl_schema_all); - -/* - * List of struct mon_data containing private data of event files for use by - * rdtgroup_mondata_show(). Protected by rdtgroup_mutex. - */ -static LIST_HEAD(mon_data_kn_priv_list); - -/* The filesystem can only be mounted once. */ -bool resctrl_mounted; - -/* Kernel fs node for "info" directory under root */ -static struct kernfs_node *kn_info; - -/* Kernel fs node for "mon_groups" directory under root */ -static struct kernfs_node *kn_mongrp; - -/* Kernel fs node for "mon_data" directory under root */ -static struct kernfs_node *kn_mondata; - -/* - * Used to store the max resource name width to display the schemata names in - * a tabular format. - */ -int max_name_width; - -static struct seq_buf last_cmd_status; -static char last_cmd_status_buf[512]; -static int rdtgroup_setup_root(struct rdt_fs_context *ctx); -static void rdtgroup_destroy_root(void); +DEFINE_STATIC_KEY_FALSE(rdt_mon_enable_key); -struct dentry *debugfs_resctrl; +DEFINE_STATIC_KEY_FALSE(rdt_alloc_enable_key); /* - * Memory bandwidth monitoring event to use for the default CTRL_MON group - * and each new CTRL_MON group created by the user. Only relevant when - * the filesystem is mounted with the "mba_MBps" option so it does not - * matter that it remains uninitialized on systems that do not support - * the "mba_MBps" option. + * This is safe against resctrl_arch_sched_in() called from __switch_to() + * because __switch_to() is executed with interrupts disabled. A local call + * from update_closid_rmid() is protected against __switch_to() because + * preemption is disabled. */ -enum resctrl_event_id mba_mbps_default_event; - -static bool resctrl_debug; - -void rdt_last_cmd_clear(void) -{ - lockdep_assert_held(&rdtgroup_mutex); - seq_buf_clear(&last_cmd_status); -} - -void rdt_last_cmd_puts(const char *s) -{ - lockdep_assert_held(&rdtgroup_mutex); - seq_buf_puts(&last_cmd_status, s); -} - -void rdt_last_cmd_printf(const char *fmt, ...) -{ - va_list ap; - - va_start(ap, fmt); - lockdep_assert_held(&rdtgroup_mutex); - seq_buf_vprintf(&last_cmd_status, fmt, ap); - va_end(ap); -} - -void rdt_staged_configs_clear(void) +void resctrl_arch_sync_cpu_closid_rmid(void *info) { - struct rdt_ctrl_domain *dom; - struct rdt_resource *r; - - lockdep_assert_held(&rdtgroup_mutex); + struct resctrl_cpu_defaults *r = info; - for_each_alloc_capable_rdt_resource(r) { - list_for_each_entry(dom, &r->ctrl_domains, hdr.list) - memset(dom->staged_config, 0, sizeof(dom->staged_config)); + if (r) { + this_cpu_write(pqr_state.default_closid, r->closid); + this_cpu_write(pqr_state.default_rmid, r->rmid); } -} -static bool resctrl_is_mbm_enabled(void) -{ - return (resctrl_arch_is_mbm_total_enabled() || - resctrl_arch_is_mbm_local_enabled()); + /* + * We cannot unconditionally write the MSR because the current + * executing task might have its own closid selected. Just reuse + * the context switch code. + */ + resctrl_arch_sched_in(current); } -static bool resctrl_is_mbm_event(int e) -{ - return (e >= QOS_L3_MBM_TOTAL_EVENT_ID && - e <= QOS_L3_MBM_LOCAL_EVENT_ID); -} +#define INVALID_CONFIG_INDEX UINT_MAX -/* - * Trivial allocator for CLOSIDs. Use BITMAP APIs to manipulate a bitmap - * of free CLOSIDs. +/** + * mon_event_config_index_get - get the hardware index for the + * configurable event + * @evtid: event id. * - * Using a global CLOSID across all resources has some advantages and - * some drawbacks: - * + We can simply set current's closid to assign a task to a resource - * group. - * + Context switch code can avoid extra memory references deciding which - * CLOSID to load into the PQR_ASSOC MSR - * - We give up some options in configuring resource groups across multi-socket - * systems. - * - Our choices on how to configure each resource become progressively more - * limited as the number of resources grows. + * Return: 0 for evtid == QOS_L3_MBM_TOTAL_EVENT_ID + * 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID + * INVALID_CONFIG_INDEX for invalid evtid */ -static unsigned long *closid_free_map; -static int closid_free_map_len; - -int closids_supported(void) -{ - return closid_free_map_len; -} - -static int closid_init(void) +static inline unsigned int mon_event_config_index_get(u32 evtid) { - struct resctrl_schema *s; - u32 rdt_min_closid = ~0; - - /* Monitor only platforms still call closid_init() */ - if (list_empty(&resctrl_schema_all)) + switch (evtid) { + case QOS_L3_MBM_TOTAL_EVENT_ID: return 0; - - /* Compute rdt_min_closid across all resources */ - list_for_each_entry(s, &resctrl_schema_all, list) - rdt_min_closid = min(rdt_min_closid, s->num_closid); - - closid_free_map = bitmap_alloc(rdt_min_closid, GFP_KERNEL); - if (!closid_free_map) - return -ENOMEM; - bitmap_fill(closid_free_map, rdt_min_closid); - - /* RESCTRL_RESERVED_CLOSID is always reserved for the default group */ - __clear_bit(RESCTRL_RESERVED_CLOSID, closid_free_map); - closid_free_map_len = rdt_min_closid; - - return 0; -} - -static void closid_exit(void) -{ - bitmap_free(closid_free_map); - closid_free_map = NULL; + case QOS_L3_MBM_LOCAL_EVENT_ID: + return 1; + default: + /* Should never reach here */ + return INVALID_CONFIG_INDEX; + } } -static int closid_alloc(void) +void resctrl_arch_mon_event_config_read(void *_config_info) { - int cleanest_closid; - u32 closid; - - lockdep_assert_held(&rdtgroup_mutex); + struct resctrl_mon_config_info *config_info = _config_info; + unsigned int index; + u64 msrval; - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID) && - resctrl_arch_is_llc_occupancy_enabled()) { - cleanest_closid = resctrl_find_cleanest_closid(); - if (cleanest_closid < 0) - return cleanest_closid; - closid = cleanest_closid; - } else { - closid = find_first_bit(closid_free_map, closid_free_map_len); - if (closid == closid_free_map_len) - return -ENOSPC; + index = mon_event_config_index_get(config_info->evtid); + if (index == INVALID_CONFIG_INDEX) { + pr_warn_once("Invalid event id %d\n", config_info->evtid); + return; } - __clear_bit(closid, closid_free_map); - - return closid; -} - -void closid_free(int closid) -{ - lockdep_assert_held(&rdtgroup_mutex); + rdmsrl(MSR_IA32_EVT_CFG_BASE + index, msrval); - __set_bit(closid, closid_free_map); + /* Report only the valid event configuration bits */ + config_info->mon_config = msrval & MAX_EVT_CONFIG_BITS; } -/** - * closid_allocated - test if provided closid is in use - * @closid: closid to be tested - * - * Return: true if @closid is currently associated with a resource group, - * false if @closid is free - */ -bool closid_allocated(unsigned int closid) +void resctrl_arch_mon_event_config_write(void *_config_info) { - lockdep_assert_held(&rdtgroup_mutex); + struct resctrl_mon_config_info *config_info = _config_info; + unsigned int index; - return !test_bit(closid, closid_free_map); + index = mon_event_config_index_get(config_info->evtid); + if (index == INVALID_CONFIG_INDEX) { + pr_warn_once("Invalid event id %d\n", config_info->evtid); + return; + } + wrmsr(MSR_IA32_EVT_CFG_BASE + index, config_info->mon_config, 0); } -/** - * rdtgroup_mode_by_closid - Return mode of resource group with closid - * @closid: closid if the resource group - * - * Each resource group is associated with a @closid. Here the mode - * of a resource group can be queried by searching for it using its closid. - * - * Return: mode as &enum rdtgrp_mode of resource group with closid @closid - */ -enum rdtgrp_mode rdtgroup_mode_by_closid(int closid) +static void l3_qos_cfg_update(void *arg) { - struct rdtgroup *rdtgrp; - - list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { - if (rdtgrp->closid == closid) - return rdtgrp->mode; - } + bool *enable = arg; - return RDT_NUM_MODES; + wrmsrl(MSR_IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL); } -static const char * const rdt_mode_str[] = { - [RDT_MODE_SHAREABLE] = "shareable", - [RDT_MODE_EXCLUSIVE] = "exclusive", - [RDT_MODE_PSEUDO_LOCKSETUP] = "pseudo-locksetup", - [RDT_MODE_PSEUDO_LOCKED] = "pseudo-locked", -}; - -/** - * rdtgroup_mode_str - Return the string representation of mode - * @mode: the resource group mode as &enum rdtgroup_mode - * - * Return: string representation of valid mode, "unknown" otherwise - */ -static const char *rdtgroup_mode_str(enum rdtgrp_mode mode) +static void l2_qos_cfg_update(void *arg) { - if (mode < RDT_MODE_SHAREABLE || mode >= RDT_NUM_MODES) - return "unknown"; + bool *enable = arg; - return rdt_mode_str[mode]; + wrmsrl(MSR_IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL); } -/* set uid and gid of rdtgroup dirs and files to that of the creator */ -static int rdtgroup_kn_set_ugid(struct kernfs_node *kn) +static int set_cache_qos_cfg(int level, bool enable) { - struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID, - .ia_uid = current_fsuid(), - .ia_gid = current_fsgid(), }; - - if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) && - gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID)) - return 0; + void (*update)(void *arg); + struct rdt_ctrl_domain *d; + struct rdt_resource *r_l; + cpumask_var_t cpu_mask; + int cpu; - return kernfs_setattr(kn, &iattr); -} + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); -static int rdtgroup_add_file(struct kernfs_node *parent_kn, struct rftype *rft) -{ - struct kernfs_node *kn; - int ret; + if (level == RDT_RESOURCE_L3) + update = l3_qos_cfg_update; + else if (level == RDT_RESOURCE_L2) + update = l2_qos_cfg_update; + else + return -EINVAL; - kn = __kernfs_create_file(parent_kn, rft->name, rft->mode, - GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, - 0, rft->kf_ops, rft, NULL, NULL); - if (IS_ERR(kn)) - return PTR_ERR(kn); + if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) + return -ENOMEM; - ret = rdtgroup_kn_set_ugid(kn); - if (ret) { - kernfs_remove(kn); - return ret; + r_l = &rdt_resources_all[level].r_resctrl; + list_for_each_entry(d, &r_l->ctrl_domains, hdr.list) { + if (r_l->cache.arch_has_per_cpu_cfg) + /* Pick all the CPUs in the domain instance */ + for_each_cpu(cpu, &d->hdr.cpu_mask) + cpumask_set_cpu(cpu, cpu_mask); + else + /* Pick one CPU from each domain instance to update MSR */ + cpumask_set_cpu(cpumask_any(&d->hdr.cpu_mask), cpu_mask); } - return 0; -} + /* Update QOS_CFG MSR on all the CPUs in cpu_mask */ + on_each_cpu_mask(cpu_mask, update, &enable, 1); -static int rdtgroup_seqfile_show(struct seq_file *m, void *arg) -{ - struct kernfs_open_file *of = m->private; - struct rftype *rft = of->kn->priv; + free_cpumask_var(cpu_mask); - if (rft->seq_show) - return rft->seq_show(of, m, arg); return 0; } -static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf, - size_t nbytes, loff_t off) +/* Restore the qos cfg state when a domain comes online */ +void rdt_domain_reconfigure_cdp(struct rdt_resource *r) { - struct rftype *rft = of->kn->priv; - - if (rft->write) - return rft->write(of, buf, nbytes, off); - - return -EINVAL; -} - -static const struct kernfs_ops rdtgroup_kf_single_ops = { - .atomic_write_len = PAGE_SIZE, - .write = rdtgroup_file_write, - .seq_show = rdtgroup_seqfile_show, -}; + struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); -static const struct kernfs_ops kf_mondata_ops = { - .atomic_write_len = PAGE_SIZE, - .seq_show = rdtgroup_mondata_show, -}; + if (!r->cdp_capable) + return; -static bool is_cpu_list(struct kernfs_open_file *of) -{ - struct rftype *rft = of->kn->priv; + if (r->rid == RDT_RESOURCE_L2) + l2_qos_cfg_update(&hw_res->cdp_enabled); - return rft->flags & RFTYPE_FLAGS_CPUS_LIST; + if (r->rid == RDT_RESOURCE_L3) + l3_qos_cfg_update(&hw_res->cdp_enabled); } -static int rdtgroup_cpus_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) +static int cdp_enable(int level) { - struct rdtgroup *rdtgrp; - struct cpumask *mask; - int ret = 0; + struct rdt_resource *r_l = &rdt_resources_all[level].r_resctrl; + int ret; - rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!r_l->alloc_capable) + return -EINVAL; - if (rdtgrp) { - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - if (!rdtgrp->plr->d) { - rdt_last_cmd_clear(); - rdt_last_cmd_puts("Cache domain offline\n"); - ret = -ENODEV; - } else { - mask = &rdtgrp->plr->d->hdr.cpu_mask; - seq_printf(s, is_cpu_list(of) ? - "%*pbl\n" : "%*pb\n", - cpumask_pr_args(mask)); - } - } else { - seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n", - cpumask_pr_args(&rdtgrp->cpu_mask)); - } - } else { - ret = -ENOENT; - } - rdtgroup_kn_unlock(of->kn); + ret = set_cache_qos_cfg(level, true); + if (!ret) + rdt_resources_all[level].cdp_enabled = true; return ret; } -/* - * This is safe against resctrl_arch_sched_in() called from __switch_to() - * because __switch_to() is executed with interrupts disabled. A local call - * from update_closid_rmid() is protected against __switch_to() because - * preemption is disabled. - */ -void resctrl_arch_sync_cpu_closid_rmid(void *info) -{ - struct resctrl_cpu_defaults *r = info; - - if (r) { - this_cpu_write(pqr_state.default_closid, r->closid); - this_cpu_write(pqr_state.default_rmid, r->rmid); - } - - /* - * We cannot unconditionally write the MSR because the current - * executing task might have its own closid selected. Just reuse - * the context switch code. - */ - resctrl_arch_sched_in(current); -} - -/* - * Update the PGR_ASSOC MSR on all cpus in @cpu_mask, - * - * Per task closids/rmids must have been set up before calling this function. - * @r may be NULL. - */ -static void -update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r) +static void cdp_disable(int level) { - struct resctrl_cpu_defaults defaults, *p = NULL; + struct rdt_hw_resource *r_hw = &rdt_resources_all[level]; - if (r) { - defaults.closid = r->closid; - defaults.rmid = r->mon.rmid; - p = &defaults; + if (r_hw->cdp_enabled) { + set_cache_qos_cfg(level, false); + r_hw->cdp_enabled = false; } - - on_each_cpu_mask(cpu_mask, resctrl_arch_sync_cpu_closid_rmid, p, 1); } -static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask, - cpumask_var_t tmpmask) +int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable) { - struct rdtgroup *prgrp = rdtgrp->mon.parent, *crgrp; - struct list_head *head; + struct rdt_hw_resource *hw_res = &rdt_resources_all[l]; - /* Check whether cpus belong to parent ctrl group */ - cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask); - if (!cpumask_empty(tmpmask)) { - rdt_last_cmd_puts("Can only add CPUs to mongroup that belong to parent\n"); + if (!hw_res->r_resctrl.cdp_capable) return -EINVAL; - } - - /* Check whether cpus are dropped from this group */ - cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask); - if (!cpumask_empty(tmpmask)) { - /* Give any dropped cpus to parent rdtgroup */ - cpumask_or(&prgrp->cpu_mask, &prgrp->cpu_mask, tmpmask); - update_closid_rmid(tmpmask, prgrp); - } - /* - * If we added cpus, remove them from previous group that owned them - * and update per-cpu rmid - */ - cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask); - if (!cpumask_empty(tmpmask)) { - head = &prgrp->mon.crdtgrp_list; - list_for_each_entry(crgrp, head, mon.crdtgrp_list) { - if (crgrp == rdtgrp) - continue; - cpumask_andnot(&crgrp->cpu_mask, &crgrp->cpu_mask, - tmpmask); - } - update_closid_rmid(tmpmask, rdtgrp); - } + if (enable) + return cdp_enable(l); - /* Done pushing/pulling - update this group with new mask */ - cpumask_copy(&rdtgrp->cpu_mask, newmask); + cdp_disable(l); return 0; } -static void cpumask_rdtgrp_clear(struct rdtgroup *r, struct cpumask *m) +bool resctrl_arch_get_cdp_enabled(enum resctrl_res_level l) { - struct rdtgroup *crgrp; - - cpumask_andnot(&r->cpu_mask, &r->cpu_mask, m); - /* update the child mon group masks as well*/ - list_for_each_entry(crgrp, &r->mon.crdtgrp_list, mon.crdtgrp_list) - cpumask_and(&crgrp->cpu_mask, &r->cpu_mask, &crgrp->cpu_mask); + return rdt_resources_all[l].cdp_enabled; } -static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask, - cpumask_var_t tmpmask, cpumask_var_t tmpmask1) +void resctrl_arch_reset_all_ctrls(struct rdt_resource *r) { - struct rdtgroup *r, *crgrp; - struct list_head *head; + struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); + struct rdt_hw_ctrl_domain *hw_dom; + struct msr_param msr_param; + struct rdt_ctrl_domain *d; + int i; - /* Check whether cpus are dropped from this group */ - cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask); - if (!cpumask_empty(tmpmask)) { - /* Can't drop from default group */ - if (rdtgrp == &rdtgroup_default) { - rdt_last_cmd_puts("Can't drop CPUs from default group\n"); - return -EINVAL; - } + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); - /* Give any dropped cpus to rdtgroup_default */ - cpumask_or(&rdtgroup_default.cpu_mask, - &rdtgroup_default.cpu_mask, tmpmask); - update_closid_rmid(tmpmask, &rdtgroup_default); - } + msr_param.res = r; + msr_param.low = 0; + msr_param.high = hw_res->num_closid; /* - * If we added cpus, remove them from previous group and - * the prev group's child groups that owned them - * and update per-cpu closid/rmid. + * Disable resource control for this resource by setting all + * CBMs in all ctrl_domains to the maximum mask value. Pick one CPU + * from each domain to update the MSRs below. */ - cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask); - if (!cpumask_empty(tmpmask)) { - list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) { - if (r == rdtgrp) - continue; - cpumask_and(tmpmask1, &r->cpu_mask, tmpmask); - if (!cpumask_empty(tmpmask1)) - cpumask_rdtgrp_clear(r, tmpmask1); - } - update_closid_rmid(tmpmask, rdtgrp); - } + list_for_each_entry(d, &r->ctrl_domains, hdr.list) { + hw_dom = resctrl_to_arch_ctrl_dom(d); - /* Done pushing/pulling - update this group with new mask */ - cpumask_copy(&rdtgrp->cpu_mask, newmask); + for (i = 0; i < hw_res->num_closid; i++) + hw_dom->ctrl_val[i] = resctrl_get_default_ctrl(r); + msr_param.dom = d; + smp_call_function_any(&d->hdr.cpu_mask, rdt_ctrl_update, &msr_param, 1); + } - /* - * Clear child mon group masks since there is a new parent mask - * now and update the rmid for the cpus the child lost. - */ - head = &rdtgrp->mon.crdtgrp_list; - list_for_each_entry(crgrp, head, mon.crdtgrp_list) { - cpumask_and(tmpmask, &rdtgrp->cpu_mask, &crgrp->cpu_mask); - update_closid_rmid(tmpmask, rdtgrp); - cpumask_clear(&crgrp->cpu_mask); - } - - return 0; -} - -static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - cpumask_var_t tmpmask, newmask, tmpmask1; - struct rdtgroup *rdtgrp; - int ret; - - if (!buf) - return -EINVAL; - - if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) - return -ENOMEM; - if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) { - free_cpumask_var(tmpmask); - return -ENOMEM; - } - if (!zalloc_cpumask_var(&tmpmask1, GFP_KERNEL)) { - free_cpumask_var(tmpmask); - free_cpumask_var(newmask); - return -ENOMEM; - } - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - ret = -ENOENT; - goto unlock; - } - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - ret = -EINVAL; - rdt_last_cmd_puts("Pseudo-locking in progress\n"); - goto unlock; - } - - if (is_cpu_list(of)) - ret = cpulist_parse(buf, newmask); - else - ret = cpumask_parse(buf, newmask); - - if (ret) { - rdt_last_cmd_puts("Bad CPU list/mask\n"); - goto unlock; - } - - /* check that user didn't specify any offline cpus */ - cpumask_andnot(tmpmask, newmask, cpu_online_mask); - if (!cpumask_empty(tmpmask)) { - ret = -EINVAL; - rdt_last_cmd_puts("Can only assign online CPUs\n"); - goto unlock; - } - - if (rdtgrp->type == RDTCTRL_GROUP) - ret = cpus_ctrl_write(rdtgrp, newmask, tmpmask, tmpmask1); - else if (rdtgrp->type == RDTMON_GROUP) - ret = cpus_mon_write(rdtgrp, newmask, tmpmask); - else - ret = -EINVAL; - -unlock: - rdtgroup_kn_unlock(of->kn); - free_cpumask_var(tmpmask); - free_cpumask_var(newmask); - free_cpumask_var(tmpmask1); - - return ret ?: nbytes; -} - -/** - * rdtgroup_remove - the helper to remove resource group safely - * @rdtgrp: resource group to remove - * - * On resource group creation via a mkdir, an extra kernfs_node reference is - * taken to ensure that the rdtgroup structure remains accessible for the - * rdtgroup_kn_unlock() calls where it is removed. - * - * Drop the extra reference here, then free the rdtgroup structure. - * - * Return: void - */ -static void rdtgroup_remove(struct rdtgroup *rdtgrp) -{ - kernfs_put(rdtgrp->kn); - kfree(rdtgrp); -} - -static void _update_task_closid_rmid(void *task) -{ - /* - * If the task is still current on this CPU, update PQR_ASSOC MSR. - * Otherwise, the MSR is updated when the task is scheduled in. - */ - if (task == current) - resctrl_arch_sched_in(task); -} - -static void update_task_closid_rmid(struct task_struct *t) -{ - if (IS_ENABLED(CONFIG_SMP) && task_curr(t)) - smp_call_function_single(task_cpu(t), _update_task_closid_rmid, t, 1); - else - _update_task_closid_rmid(t); -} - -static bool task_in_rdtgroup(struct task_struct *tsk, struct rdtgroup *rdtgrp) -{ - u32 closid, rmid = rdtgrp->mon.rmid; - - if (rdtgrp->type == RDTCTRL_GROUP) - closid = rdtgrp->closid; - else if (rdtgrp->type == RDTMON_GROUP) - closid = rdtgrp->mon.parent->closid; - else - return false; - - return resctrl_arch_match_closid(tsk, closid) && - resctrl_arch_match_rmid(tsk, closid, rmid); -} - -static int __rdtgroup_move_task(struct task_struct *tsk, - struct rdtgroup *rdtgrp) -{ - /* If the task is already in rdtgrp, no need to move the task. */ - if (task_in_rdtgroup(tsk, rdtgrp)) - return 0; - - /* - * Set the task's closid/rmid before the PQR_ASSOC MSR can be - * updated by them. - * - * For ctrl_mon groups, move both closid and rmid. - * For monitor groups, can move the tasks only from - * their parent CTRL group. - */ - if (rdtgrp->type == RDTMON_GROUP && - !resctrl_arch_match_closid(tsk, rdtgrp->mon.parent->closid)) { - rdt_last_cmd_puts("Can't move task to different control group\n"); - return -EINVAL; - } - - if (rdtgrp->type == RDTMON_GROUP) - resctrl_arch_set_closid_rmid(tsk, rdtgrp->mon.parent->closid, - rdtgrp->mon.rmid); - else - resctrl_arch_set_closid_rmid(tsk, rdtgrp->closid, - rdtgrp->mon.rmid); - - /* - * Ensure the task's closid and rmid are written before determining if - * the task is current that will decide if it will be interrupted. - * This pairs with the full barrier between the rq->curr update and - * resctrl_arch_sched_in() during context switch. - */ - smp_mb(); - - /* - * By now, the task's closid and rmid are set. If the task is current - * on a CPU, the PQR_ASSOC MSR needs to be updated to make the resource - * group go into effect. If the task is not current, the MSR will be - * updated when the task is scheduled in. - */ - update_task_closid_rmid(tsk); - - return 0; -} - -static bool is_closid_match(struct task_struct *t, struct rdtgroup *r) -{ - return (resctrl_arch_alloc_capable() && (r->type == RDTCTRL_GROUP) && - resctrl_arch_match_closid(t, r->closid)); -} - -static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r) -{ - return (resctrl_arch_mon_capable() && (r->type == RDTMON_GROUP) && - resctrl_arch_match_rmid(t, r->mon.parent->closid, - r->mon.rmid)); -} - -/** - * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group - * @r: Resource group - * - * Return: 1 if tasks have been assigned to @r, 0 otherwise - */ -int rdtgroup_tasks_assigned(struct rdtgroup *r) -{ - struct task_struct *p, *t; - int ret = 0; - - lockdep_assert_held(&rdtgroup_mutex); - - rcu_read_lock(); - for_each_process_thread(p, t) { - if (is_closid_match(t, r) || is_rmid_match(t, r)) { - ret = 1; - break; - } - } - rcu_read_unlock(); - - return ret; -} - -static int rdtgroup_task_write_permission(struct task_struct *task, - struct kernfs_open_file *of) -{ - const struct cred *tcred = get_task_cred(task); - const struct cred *cred = current_cred(); - int ret = 0; - - /* - * Even if we're attaching all tasks in the thread group, we only - * need to check permissions on one of them. - */ - if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) && - !uid_eq(cred->euid, tcred->uid) && - !uid_eq(cred->euid, tcred->suid)) { - rdt_last_cmd_printf("No permission to move task %d\n", task->pid); - ret = -EPERM; - } - - put_cred(tcred); - return ret; -} - -static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp, - struct kernfs_open_file *of) -{ - struct task_struct *tsk; - int ret; - - rcu_read_lock(); - if (pid) { - tsk = find_task_by_vpid(pid); - if (!tsk) { - rcu_read_unlock(); - rdt_last_cmd_printf("No task %d\n", pid); - return -ESRCH; - } - } else { - tsk = current; - } - - get_task_struct(tsk); - rcu_read_unlock(); - - ret = rdtgroup_task_write_permission(tsk, of); - if (!ret) - ret = __rdtgroup_move_task(tsk, rdtgrp); - - put_task_struct(tsk); - return ret; -} - -static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - struct rdtgroup *rdtgrp; - char *pid_str; - int ret = 0; - pid_t pid; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - rdtgroup_kn_unlock(of->kn); - return -ENOENT; - } - rdt_last_cmd_clear(); - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - ret = -EINVAL; - rdt_last_cmd_puts("Pseudo-locking in progress\n"); - goto unlock; - } - - while (buf && buf[0] != '\0' && buf[0] != '\n') { - pid_str = strim(strsep(&buf, ",")); - - if (kstrtoint(pid_str, 0, &pid)) { - rdt_last_cmd_printf("Task list parsing error pid %s\n", pid_str); - ret = -EINVAL; - break; - } - - if (pid < 0) { - rdt_last_cmd_printf("Invalid pid %d\n", pid); - ret = -EINVAL; - break; - } - - ret = rdtgroup_move_task(pid, rdtgrp, of); - if (ret) { - rdt_last_cmd_printf("Error while processing task %d\n", pid); - break; - } - } - -unlock: - rdtgroup_kn_unlock(of->kn); - - return ret ?: nbytes; -} - -static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s) -{ - struct task_struct *p, *t; - pid_t pid; - - rcu_read_lock(); - for_each_process_thread(p, t) { - if (is_closid_match(t, r) || is_rmid_match(t, r)) { - pid = task_pid_vnr(t); - if (pid) - seq_printf(s, "%d\n", pid); - } - } - rcu_read_unlock(); -} - -static int rdtgroup_tasks_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct rdtgroup *rdtgrp; - int ret = 0; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (rdtgrp) - show_rdt_tasks(rdtgrp, s); - else - ret = -ENOENT; - rdtgroup_kn_unlock(of->kn); - - return ret; -} - -static int rdtgroup_closid_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct rdtgroup *rdtgrp; - int ret = 0; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (rdtgrp) - seq_printf(s, "%u\n", rdtgrp->closid); - else - ret = -ENOENT; - rdtgroup_kn_unlock(of->kn); - - return ret; -} - -static int rdtgroup_rmid_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct rdtgroup *rdtgrp; - int ret = 0; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (rdtgrp) - seq_printf(s, "%u\n", rdtgrp->mon.rmid); - else - ret = -ENOENT; - rdtgroup_kn_unlock(of->kn); - - return ret; -} - -#ifdef CONFIG_PROC_CPU_RESCTRL - -/* - * A task can only be part of one resctrl control group and of one monitor - * group which is associated to that control group. - * - * 1) res: - * mon: - * - * resctrl is not available. - * - * 2) res:/ - * mon: - * - * Task is part of the root resctrl control group, and it is not associated - * to any monitor group. - * - * 3) res:/ - * mon:mon0 - * - * Task is part of the root resctrl control group and monitor group mon0. - * - * 4) res:group0 - * mon: - * - * Task is part of resctrl control group group0, and it is not associated - * to any monitor group. - * - * 5) res:group0 - * mon:mon1 - * - * Task is part of resctrl control group group0 and monitor group mon1. - */ -int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns, - struct pid *pid, struct task_struct *tsk) -{ - struct rdtgroup *rdtg; - int ret = 0; - - mutex_lock(&rdtgroup_mutex); - - /* Return empty if resctrl has not been mounted. */ - if (!resctrl_mounted) { - seq_puts(s, "res:\nmon:\n"); - goto unlock; - } - - list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) { - struct rdtgroup *crg; - - /* - * Task information is only relevant for shareable - * and exclusive groups. - */ - if (rdtg->mode != RDT_MODE_SHAREABLE && - rdtg->mode != RDT_MODE_EXCLUSIVE) - continue; - - if (!resctrl_arch_match_closid(tsk, rdtg->closid)) - continue; - - seq_printf(s, "res:%s%s\n", (rdtg == &rdtgroup_default) ? "/" : "", - rdt_kn_name(rdtg->kn)); - seq_puts(s, "mon:"); - list_for_each_entry(crg, &rdtg->mon.crdtgrp_list, - mon.crdtgrp_list) { - if (!resctrl_arch_match_rmid(tsk, crg->mon.parent->closid, - crg->mon.rmid)) - continue; - seq_printf(s, "%s", rdt_kn_name(crg->kn)); - break; - } - seq_putc(s, '\n'); - goto unlock; - } - /* - * The above search should succeed. Otherwise return - * with an error. - */ - ret = -ENOENT; -unlock: - mutex_unlock(&rdtgroup_mutex); - - return ret; -} -#endif - -static int rdt_last_cmd_status_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - int len; - - mutex_lock(&rdtgroup_mutex); - len = seq_buf_used(&last_cmd_status); - if (len) - seq_printf(seq, "%.*s", len, last_cmd_status_buf); - else - seq_puts(seq, "ok\n"); - mutex_unlock(&rdtgroup_mutex); - return 0; -} - -static void *rdt_kn_parent_priv(struct kernfs_node *kn) -{ - /* - * The parent pointer is only valid within RCU section since it can be - * replaced. - */ - guard(rcu)(); - return rcu_dereference(kn->__parent)->priv; -} - -static int rdt_num_closids_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); - - seq_printf(seq, "%u\n", s->num_closid); - return 0; -} - -static int rdt_default_ctrl_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); - struct rdt_resource *r = s->res; - - seq_printf(seq, "%x\n", resctrl_get_default_ctrl(r)); - return 0; -} - -static int rdt_min_cbm_bits_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); - struct rdt_resource *r = s->res; - - seq_printf(seq, "%u\n", r->cache.min_cbm_bits); - return 0; -} - -static int rdt_shareable_bits_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); - struct rdt_resource *r = s->res; - - seq_printf(seq, "%x\n", r->cache.shareable_bits); - return 0; -} - -/* - * rdt_bit_usage_show - Display current usage of resources - * - * A domain is a shared resource that can now be allocated differently. Here - * we display the current regions of the domain as an annotated bitmask. - * For each domain of this resource its allocation bitmask - * is annotated as below to indicate the current usage of the corresponding bit: - * 0 - currently unused - * X - currently available for sharing and used by software and hardware - * H - currently used by hardware only but available for software use - * S - currently used and shareable by software only - * E - currently used exclusively by one resource group - * P - currently pseudo-locked by one resource group - */ -static int rdt_bit_usage_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); - /* - * Use unsigned long even though only 32 bits are used to ensure - * test_bit() is used safely. - */ - unsigned long sw_shareable = 0, hw_shareable = 0; - unsigned long exclusive = 0, pseudo_locked = 0; - struct rdt_resource *r = s->res; - struct rdt_ctrl_domain *dom; - int i, hwb, swb, excl, psl; - enum rdtgrp_mode mode; - bool sep = false; - u32 ctrl_val; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - hw_shareable = r->cache.shareable_bits; - list_for_each_entry(dom, &r->ctrl_domains, hdr.list) { - if (sep) - seq_putc(seq, ';'); - sw_shareable = 0; - exclusive = 0; - seq_printf(seq, "%d=", dom->hdr.id); - for (i = 0; i < closids_supported(); i++) { - if (!closid_allocated(i)) - continue; - ctrl_val = resctrl_arch_get_config(r, dom, i, - s->conf_type); - mode = rdtgroup_mode_by_closid(i); - switch (mode) { - case RDT_MODE_SHAREABLE: - sw_shareable |= ctrl_val; - break; - case RDT_MODE_EXCLUSIVE: - exclusive |= ctrl_val; - break; - case RDT_MODE_PSEUDO_LOCKSETUP: - /* - * RDT_MODE_PSEUDO_LOCKSETUP is possible - * here but not included since the CBM - * associated with this CLOSID in this mode - * is not initialized and no task or cpu can be - * assigned this CLOSID. - */ - break; - case RDT_MODE_PSEUDO_LOCKED: - case RDT_NUM_MODES: - WARN(1, - "invalid mode for closid %d\n", i); - break; - } - } - for (i = r->cache.cbm_len - 1; i >= 0; i--) { - pseudo_locked = dom->plr ? dom->plr->cbm : 0; - hwb = test_bit(i, &hw_shareable); - swb = test_bit(i, &sw_shareable); - excl = test_bit(i, &exclusive); - psl = test_bit(i, &pseudo_locked); - if (hwb && swb) - seq_putc(seq, 'X'); - else if (hwb && !swb) - seq_putc(seq, 'H'); - else if (!hwb && swb) - seq_putc(seq, 'S'); - else if (excl) - seq_putc(seq, 'E'); - else if (psl) - seq_putc(seq, 'P'); - else /* Unused bits remain */ - seq_putc(seq, '0'); - } - sep = true; - } - seq_putc(seq, '\n'); - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - return 0; -} - -static int rdt_min_bw_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); - struct rdt_resource *r = s->res; - - seq_printf(seq, "%u\n", r->membw.min_bw); - return 0; -} - -static int rdt_num_rmids_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct rdt_resource *r = rdt_kn_parent_priv(of->kn); - - seq_printf(seq, "%d\n", r->num_rmid); - - return 0; -} - -static int rdt_mon_features_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct rdt_resource *r = rdt_kn_parent_priv(of->kn); - struct mon_evt *mevt; - - list_for_each_entry(mevt, &r->evt_list, list) { - seq_printf(seq, "%s\n", mevt->name); - if (mevt->configurable) - seq_printf(seq, "%s_config\n", mevt->name); - } - - return 0; -} - -static int rdt_bw_gran_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); - struct rdt_resource *r = s->res; - - seq_printf(seq, "%u\n", r->membw.bw_gran); - return 0; -} - -static int rdt_delay_linear_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); - struct rdt_resource *r = s->res; - - seq_printf(seq, "%u\n", r->membw.delay_linear); - return 0; -} - -static int max_threshold_occ_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - seq_printf(seq, "%u\n", resctrl_rmid_realloc_threshold); - - return 0; -} - -static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); - struct rdt_resource *r = s->res; - - switch (r->membw.throttle_mode) { - case THREAD_THROTTLE_PER_THREAD: - seq_puts(seq, "per-thread\n"); - return 0; - case THREAD_THROTTLE_MAX: - seq_puts(seq, "max\n"); - return 0; - case THREAD_THROTTLE_UNDEFINED: - seq_puts(seq, "undefined\n"); - return 0; - } - - WARN_ON_ONCE(1); - - return 0; -} - -static ssize_t max_threshold_occ_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - unsigned int bytes; - int ret; - - ret = kstrtouint(buf, 0, &bytes); - if (ret) - return ret; - - if (bytes > resctrl_rmid_realloc_limit) - return -EINVAL; - - resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(bytes); - - return nbytes; -} - -/* - * rdtgroup_mode_show - Display mode of this resource group - */ -static int rdtgroup_mode_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct rdtgroup *rdtgrp; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - rdtgroup_kn_unlock(of->kn); - return -ENOENT; - } - - seq_printf(s, "%s\n", rdtgroup_mode_str(rdtgrp->mode)); - - rdtgroup_kn_unlock(of->kn); - return 0; -} - -static enum resctrl_conf_type resctrl_peer_type(enum resctrl_conf_type my_type) -{ - switch (my_type) { - case CDP_CODE: - return CDP_DATA; - case CDP_DATA: - return CDP_CODE; - default: - case CDP_NONE: - return CDP_NONE; - } -} - -static int rdt_has_sparse_bitmasks_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); - struct rdt_resource *r = s->res; - - seq_printf(seq, "%u\n", r->cache.arch_has_sparse_bitmasks); - - return 0; -} - -/** - * __rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other - * @r: Resource to which domain instance @d belongs. - * @d: The domain instance for which @closid is being tested. - * @cbm: Capacity bitmask being tested. - * @closid: Intended closid for @cbm. - * @type: CDP type of @r. - * @exclusive: Only check if overlaps with exclusive resource groups - * - * Checks if provided @cbm intended to be used for @closid on domain - * @d overlaps with any other closids or other hardware usage associated - * with this domain. If @exclusive is true then only overlaps with - * resource groups in exclusive mode will be considered. If @exclusive - * is false then overlaps with any resource group or hardware entities - * will be considered. - * - * @cbm is unsigned long, even if only 32 bits are used, to make the - * bitmap functions work correctly. - * - * Return: false if CBM does not overlap, true if it does. - */ -static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_ctrl_domain *d, - unsigned long cbm, int closid, - enum resctrl_conf_type type, bool exclusive) -{ - enum rdtgrp_mode mode; - unsigned long ctrl_b; - int i; - - /* Check for any overlap with regions used by hardware directly */ - if (!exclusive) { - ctrl_b = r->cache.shareable_bits; - if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) - return true; - } - - /* Check for overlap with other resource groups */ - for (i = 0; i < closids_supported(); i++) { - ctrl_b = resctrl_arch_get_config(r, d, i, type); - mode = rdtgroup_mode_by_closid(i); - if (closid_allocated(i) && i != closid && - mode != RDT_MODE_PSEUDO_LOCKSETUP) { - if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) { - if (exclusive) { - if (mode == RDT_MODE_EXCLUSIVE) - return true; - continue; - } - return true; - } - } - } - - return false; -} - -/** - * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware - * @s: Schema for the resource to which domain instance @d belongs. - * @d: The domain instance for which @closid is being tested. - * @cbm: Capacity bitmask being tested. - * @closid: Intended closid for @cbm. - * @exclusive: Only check if overlaps with exclusive resource groups - * - * Resources that can be allocated using a CBM can use the CBM to control - * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test - * for overlap. Overlap test is not limited to the specific resource for - * which the CBM is intended though - when dealing with CDP resources that - * share the underlying hardware the overlap check should be performed on - * the CDP resource sharing the hardware also. - * - * Refer to description of __rdtgroup_cbm_overlaps() for the details of the - * overlap test. - * - * Return: true if CBM overlap detected, false if there is no overlap - */ -bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d, - unsigned long cbm, int closid, bool exclusive) -{ - enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type); - struct rdt_resource *r = s->res; - - if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, s->conf_type, - exclusive)) - return true; - - if (!resctrl_arch_get_cdp_enabled(r->rid)) - return false; - return __rdtgroup_cbm_overlaps(r, d, cbm, closid, peer_type, exclusive); -} - -/** - * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive - * @rdtgrp: Resource group identified through its closid. - * - * An exclusive resource group implies that there should be no sharing of - * its allocated resources. At the time this group is considered to be - * exclusive this test can determine if its current schemata supports this - * setting by testing for overlap with all other resource groups. - * - * Return: true if resource group can be exclusive, false if there is overlap - * with allocations of other resource groups and thus this resource group - * cannot be exclusive. - */ -static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp) -{ - int closid = rdtgrp->closid; - struct rdt_ctrl_domain *d; - struct resctrl_schema *s; - struct rdt_resource *r; - bool has_cache = false; - u32 ctrl; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - list_for_each_entry(s, &resctrl_schema_all, list) { - r = s->res; - if (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA) - continue; - has_cache = true; - list_for_each_entry(d, &r->ctrl_domains, hdr.list) { - ctrl = resctrl_arch_get_config(r, d, closid, - s->conf_type); - if (rdtgroup_cbm_overlaps(s, d, ctrl, closid, false)) { - rdt_last_cmd_puts("Schemata overlaps\n"); - return false; - } - } - } - - if (!has_cache) { - rdt_last_cmd_puts("Cannot be exclusive without CAT/CDP\n"); - return false; - } - - return true; -} - -/* - * rdtgroup_mode_write - Modify the resource group's mode - */ -static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - struct rdtgroup *rdtgrp; - enum rdtgrp_mode mode; - int ret = 0; - - /* Valid input requires a trailing newline */ - if (nbytes == 0 || buf[nbytes - 1] != '\n') - return -EINVAL; - buf[nbytes - 1] = '\0'; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - rdtgroup_kn_unlock(of->kn); - return -ENOENT; - } - - rdt_last_cmd_clear(); - - mode = rdtgrp->mode; - - if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) || - (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) || - (!strcmp(buf, "pseudo-locksetup") && - mode == RDT_MODE_PSEUDO_LOCKSETUP) || - (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED)) - goto out; - - if (mode == RDT_MODE_PSEUDO_LOCKED) { - rdt_last_cmd_puts("Cannot change pseudo-locked group\n"); - ret = -EINVAL; - goto out; - } - - if (!strcmp(buf, "shareable")) { - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - ret = rdtgroup_locksetup_exit(rdtgrp); - if (ret) - goto out; - } - rdtgrp->mode = RDT_MODE_SHAREABLE; - } else if (!strcmp(buf, "exclusive")) { - if (!rdtgroup_mode_test_exclusive(rdtgrp)) { - ret = -EINVAL; - goto out; - } - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - ret = rdtgroup_locksetup_exit(rdtgrp); - if (ret) - goto out; - } - rdtgrp->mode = RDT_MODE_EXCLUSIVE; - } else if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK) && - !strcmp(buf, "pseudo-locksetup")) { - ret = rdtgroup_locksetup_enter(rdtgrp); - if (ret) - goto out; - rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP; - } else { - rdt_last_cmd_puts("Unknown or unsupported mode\n"); - ret = -EINVAL; - } - -out: - rdtgroup_kn_unlock(of->kn); - return ret ?: nbytes; -} - -/** - * rdtgroup_cbm_to_size - Translate CBM to size in bytes - * @r: RDT resource to which @d belongs. - * @d: RDT domain instance. - * @cbm: bitmask for which the size should be computed. - * - * The bitmask provided associated with the RDT domain instance @d will be - * translated into how many bytes it represents. The size in bytes is - * computed by first dividing the total cache size by the CBM length to - * determine how many bytes each bit in the bitmask represents. The result - * is multiplied with the number of bits set in the bitmask. - * - * @cbm is unsigned long, even if only 32 bits are used to make the - * bitmap functions work correctly. - */ -unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, - struct rdt_ctrl_domain *d, unsigned long cbm) -{ - unsigned int size = 0; - struct cacheinfo *ci; - int num_b; - - if (WARN_ON_ONCE(r->ctrl_scope != RESCTRL_L2_CACHE && r->ctrl_scope != RESCTRL_L3_CACHE)) - return size; - - num_b = bitmap_weight(&cbm, r->cache.cbm_len); - ci = get_cpu_cacheinfo_level(cpumask_any(&d->hdr.cpu_mask), r->ctrl_scope); - if (ci) - size = ci->size / r->cache.cbm_len * num_b; - - return size; -} - -bool is_mba_sc(struct rdt_resource *r) -{ - if (!r) - r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); - - /* - * The software controller support is only applicable to MBA resource. - * Make sure to check for resource type. - */ - if (r->rid != RDT_RESOURCE_MBA) - return false; - - return r->membw.mba_sc; -} - -/* - * rdtgroup_size_show - Display size in bytes of allocated regions - * - * The "size" file mirrors the layout of the "schemata" file, printing the - * size in bytes of each region instead of the capacity bitmask. - */ -static int rdtgroup_size_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct resctrl_schema *schema; - enum resctrl_conf_type type; - struct rdt_ctrl_domain *d; - struct rdtgroup *rdtgrp; - struct rdt_resource *r; - unsigned int size; - int ret = 0; - u32 closid; - bool sep; - u32 ctrl; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - rdtgroup_kn_unlock(of->kn); - return -ENOENT; - } - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - if (!rdtgrp->plr->d) { - rdt_last_cmd_clear(); - rdt_last_cmd_puts("Cache domain offline\n"); - ret = -ENODEV; - } else { - seq_printf(s, "%*s:", max_name_width, - rdtgrp->plr->s->name); - size = rdtgroup_cbm_to_size(rdtgrp->plr->s->res, - rdtgrp->plr->d, - rdtgrp->plr->cbm); - seq_printf(s, "%d=%u\n", rdtgrp->plr->d->hdr.id, size); - } - goto out; - } - - closid = rdtgrp->closid; - - list_for_each_entry(schema, &resctrl_schema_all, list) { - r = schema->res; - type = schema->conf_type; - sep = false; - seq_printf(s, "%*s:", max_name_width, schema->name); - list_for_each_entry(d, &r->ctrl_domains, hdr.list) { - if (sep) - seq_putc(s, ';'); - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - size = 0; - } else { - if (is_mba_sc(r)) - ctrl = d->mbps_val[closid]; - else - ctrl = resctrl_arch_get_config(r, d, - closid, - type); - if (r->rid == RDT_RESOURCE_MBA || - r->rid == RDT_RESOURCE_SMBA) - size = ctrl; - else - size = rdtgroup_cbm_to_size(r, d, ctrl); - } - seq_printf(s, "%d=%u", d->hdr.id, size); - sep = true; - } - seq_putc(s, '\n'); - } - -out: - rdtgroup_kn_unlock(of->kn); - - return ret; -} - -#define INVALID_CONFIG_INDEX UINT_MAX - -/** - * mon_event_config_index_get - get the hardware index for the - * configurable event - * @evtid: event id. - * - * Return: 0 for evtid == QOS_L3_MBM_TOTAL_EVENT_ID - * 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID - * INVALID_CONFIG_INDEX for invalid evtid - */ -static inline unsigned int mon_event_config_index_get(u32 evtid) -{ - switch (evtid) { - case QOS_L3_MBM_TOTAL_EVENT_ID: - return 0; - case QOS_L3_MBM_LOCAL_EVENT_ID: - return 1; - default: - /* Should never reach here */ - return INVALID_CONFIG_INDEX; - } -} - -void resctrl_arch_mon_event_config_read(void *_config_info) -{ - struct resctrl_mon_config_info *config_info = _config_info; - unsigned int index; - u64 msrval; - - index = mon_event_config_index_get(config_info->evtid); - if (index == INVALID_CONFIG_INDEX) { - pr_warn_once("Invalid event id %d\n", config_info->evtid); - return; - } - rdmsrl(MSR_IA32_EVT_CFG_BASE + index, msrval); - - /* Report only the valid event configuration bits */ - config_info->mon_config = msrval & MAX_EVT_CONFIG_BITS; -} - -static void mondata_config_read(struct resctrl_mon_config_info *mon_info) -{ - smp_call_function_any(&mon_info->d->hdr.cpu_mask, - resctrl_arch_mon_event_config_read, mon_info, 1); -} - -static int mbm_config_show(struct seq_file *s, struct rdt_resource *r, u32 evtid) -{ - struct resctrl_mon_config_info mon_info; - struct rdt_mon_domain *dom; - bool sep = false; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - list_for_each_entry(dom, &r->mon_domains, hdr.list) { - if (sep) - seq_puts(s, ";"); - - memset(&mon_info, 0, sizeof(struct resctrl_mon_config_info)); - mon_info.r = r; - mon_info.d = dom; - mon_info.evtid = evtid; - mondata_config_read(&mon_info); - - seq_printf(s, "%d=0x%02x", dom->hdr.id, mon_info.mon_config); - sep = true; - } - seq_puts(s, "\n"); - - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - - return 0; -} - -static int mbm_total_bytes_config_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct rdt_resource *r = rdt_kn_parent_priv(of->kn); - - mbm_config_show(seq, r, QOS_L3_MBM_TOTAL_EVENT_ID); - - return 0; -} - -static int mbm_local_bytes_config_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct rdt_resource *r = rdt_kn_parent_priv(of->kn); - - mbm_config_show(seq, r, QOS_L3_MBM_LOCAL_EVENT_ID); - - return 0; -} - -void resctrl_arch_mon_event_config_write(void *_config_info) -{ - struct resctrl_mon_config_info *config_info = _config_info; - unsigned int index; - - index = mon_event_config_index_get(config_info->evtid); - if (index == INVALID_CONFIG_INDEX) { - pr_warn_once("Invalid event id %d\n", config_info->evtid); - return; - } - wrmsr(MSR_IA32_EVT_CFG_BASE + index, config_info->mon_config, 0); -} - -static void mbm_config_write_domain(struct rdt_resource *r, - struct rdt_mon_domain *d, u32 evtid, u32 val) -{ - struct resctrl_mon_config_info mon_info = {0}; - - /* - * Read the current config value first. If both are the same then - * no need to write it again. - */ - mon_info.r = r; - mon_info.d = d; - mon_info.evtid = evtid; - mondata_config_read(&mon_info); - if (mon_info.mon_config == val) - return; - - mon_info.mon_config = val; - - /* - * Update MSR_IA32_EVT_CFG_BASE MSR on one of the CPUs in the - * domain. The MSRs offset from MSR MSR_IA32_EVT_CFG_BASE - * are scoped at the domain level. Writing any of these MSRs - * on one CPU is observed by all the CPUs in the domain. - */ - smp_call_function_any(&d->hdr.cpu_mask, resctrl_arch_mon_event_config_write, - &mon_info, 1); - - /* - * When an Event Configuration is changed, the bandwidth counters - * for all RMIDs and Events will be cleared by the hardware. The - * hardware also sets MSR_IA32_QM_CTR.Unavailable (bit 62) for - * every RMID on the next read to any event for every RMID. - * Subsequent reads will have MSR_IA32_QM_CTR.Unavailable (bit 62) - * cleared while it is tracked by the hardware. Clear the - * mbm_local and mbm_total counts for all the RMIDs. - */ - resctrl_arch_reset_rmid_all(r, d); -} - -static int mon_config_write(struct rdt_resource *r, char *tok, u32 evtid) -{ - char *dom_str = NULL, *id_str; - unsigned long dom_id, val; - struct rdt_mon_domain *d; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - -next: - if (!tok || tok[0] == '\0') - return 0; - - /* Start processing the strings for each domain */ - dom_str = strim(strsep(&tok, ";")); - id_str = strsep(&dom_str, "="); - - if (!id_str || kstrtoul(id_str, 10, &dom_id)) { - rdt_last_cmd_puts("Missing '=' or non-numeric domain id\n"); - return -EINVAL; - } - - if (!dom_str || kstrtoul(dom_str, 16, &val)) { - rdt_last_cmd_puts("Non-numeric event configuration value\n"); - return -EINVAL; - } - - /* Value from user cannot be more than the supported set of events */ - if ((val & r->mbm_cfg_mask) != val) { - rdt_last_cmd_printf("Invalid event configuration: max valid mask is 0x%02x\n", - r->mbm_cfg_mask); - return -EINVAL; - } - - list_for_each_entry(d, &r->mon_domains, hdr.list) { - if (d->hdr.id == dom_id) { - mbm_config_write_domain(r, d, evtid, val); - goto next; - } - } - - return -EINVAL; -} - -static ssize_t mbm_total_bytes_config_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, - loff_t off) -{ - struct rdt_resource *r = rdt_kn_parent_priv(of->kn); - int ret; - - /* Valid input requires a trailing newline */ - if (nbytes == 0 || buf[nbytes - 1] != '\n') - return -EINVAL; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - rdt_last_cmd_clear(); - - buf[nbytes - 1] = '\0'; - - ret = mon_config_write(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID); - - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - - return ret ?: nbytes; -} - -static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, - loff_t off) -{ - struct rdt_resource *r = rdt_kn_parent_priv(of->kn); - int ret; - - /* Valid input requires a trailing newline */ - if (nbytes == 0 || buf[nbytes - 1] != '\n') - return -EINVAL; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - rdt_last_cmd_clear(); - - buf[nbytes - 1] = '\0'; - - ret = mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID); - - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - - return ret ?: nbytes; -} - -/* rdtgroup information files for one cache resource. */ -static struct rftype res_common_files[] = { - { - .name = "last_cmd_status", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_last_cmd_status_show, - .fflags = RFTYPE_TOP_INFO, - }, - { - .name = "num_closids", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_num_closids_show, - .fflags = RFTYPE_CTRL_INFO, - }, - { - .name = "mon_features", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_mon_features_show, - .fflags = RFTYPE_MON_INFO, - }, - { - .name = "num_rmids", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_num_rmids_show, - .fflags = RFTYPE_MON_INFO, - }, - { - .name = "cbm_mask", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_default_ctrl_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "min_cbm_bits", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_min_cbm_bits_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "shareable_bits", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_shareable_bits_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "bit_usage", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_bit_usage_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "min_bandwidth", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_min_bw_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, - }, - { - .name = "bandwidth_gran", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_bw_gran_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, - }, - { - .name = "delay_linear", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_delay_linear_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, - }, - /* - * Platform specific which (if any) capabilities are provided by - * thread_throttle_mode. Defer "fflags" initialization to platform - * discovery. - */ - { - .name = "thread_throttle_mode", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_thread_throttle_mode_show, - }, - { - .name = "max_threshold_occupancy", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = max_threshold_occ_write, - .seq_show = max_threshold_occ_show, - .fflags = RFTYPE_MON_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "mbm_total_bytes_config", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = mbm_total_bytes_config_show, - .write = mbm_total_bytes_config_write, - }, - { - .name = "mbm_local_bytes_config", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = mbm_local_bytes_config_show, - .write = mbm_local_bytes_config_write, - }, - { - .name = "cpus", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = rdtgroup_cpus_write, - .seq_show = rdtgroup_cpus_show, - .fflags = RFTYPE_BASE, - }, - { - .name = "cpus_list", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = rdtgroup_cpus_write, - .seq_show = rdtgroup_cpus_show, - .flags = RFTYPE_FLAGS_CPUS_LIST, - .fflags = RFTYPE_BASE, - }, - { - .name = "tasks", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = rdtgroup_tasks_write, - .seq_show = rdtgroup_tasks_show, - .fflags = RFTYPE_BASE, - }, - { - .name = "mon_hw_id", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdtgroup_rmid_show, - .fflags = RFTYPE_MON_BASE | RFTYPE_DEBUG, - }, - { - .name = "schemata", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = rdtgroup_schemata_write, - .seq_show = rdtgroup_schemata_show, - .fflags = RFTYPE_CTRL_BASE, - }, - { - .name = "mba_MBps_event", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = rdtgroup_mba_mbps_event_write, - .seq_show = rdtgroup_mba_mbps_event_show, - }, - { - .name = "mode", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = rdtgroup_mode_write, - .seq_show = rdtgroup_mode_show, - .fflags = RFTYPE_CTRL_BASE, - }, - { - .name = "size", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdtgroup_size_show, - .fflags = RFTYPE_CTRL_BASE, - }, - { - .name = "sparse_masks", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_has_sparse_bitmasks_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "ctrl_hw_id", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdtgroup_closid_show, - .fflags = RFTYPE_CTRL_BASE | RFTYPE_DEBUG, - }, -}; - -static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags) -{ - struct rftype *rfts, *rft; - int ret, len; - - rfts = res_common_files; - len = ARRAY_SIZE(res_common_files); - - lockdep_assert_held(&rdtgroup_mutex); - - if (resctrl_debug) - fflags |= RFTYPE_DEBUG; - - for (rft = rfts; rft < rfts + len; rft++) { - if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) { - ret = rdtgroup_add_file(kn, rft); - if (ret) - goto error; - } - } - - return 0; -error: - pr_warn("Failed to add %s, err=%d\n", rft->name, ret); - while (--rft >= rfts) { - if ((fflags & rft->fflags) == rft->fflags) - kernfs_remove_by_name(kn, rft->name); - } - return ret; -} - -static struct rftype *rdtgroup_get_rftype_by_name(const char *name) -{ - struct rftype *rfts, *rft; - int len; - - rfts = res_common_files; - len = ARRAY_SIZE(res_common_files); - - for (rft = rfts; rft < rfts + len; rft++) { - if (!strcmp(rft->name, name)) - return rft; - } - - return NULL; -} - -static void thread_throttle_mode_init(void) -{ - enum membw_throttle_mode throttle_mode = THREAD_THROTTLE_UNDEFINED; - struct rdt_resource *r_mba, *r_smba; - - r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA); - if (r_mba->alloc_capable && - r_mba->membw.throttle_mode != THREAD_THROTTLE_UNDEFINED) - throttle_mode = r_mba->membw.throttle_mode; - - r_smba = resctrl_arch_get_resource(RDT_RESOURCE_SMBA); - if (r_smba->alloc_capable && - r_smba->membw.throttle_mode != THREAD_THROTTLE_UNDEFINED) - throttle_mode = r_smba->membw.throttle_mode; - - if (throttle_mode == THREAD_THROTTLE_UNDEFINED) - return; - - resctrl_file_fflags_init("thread_throttle_mode", - RFTYPE_CTRL_INFO | RFTYPE_RES_MB); -} - -void resctrl_file_fflags_init(const char *config, unsigned long fflags) -{ - struct rftype *rft; - - rft = rdtgroup_get_rftype_by_name(config); - if (rft) - rft->fflags = fflags; -} - -/** - * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file - * @r: The resource group with which the file is associated. - * @name: Name of the file - * - * The permissions of named resctrl file, directory, or link are modified - * to not allow read, write, or execute by any user. - * - * WARNING: This function is intended to communicate to the user that the - * resctrl file has been locked down - that it is not relevant to the - * particular state the system finds itself in. It should not be relied - * on to protect from user access because after the file's permissions - * are restricted the user can still change the permissions using chmod - * from the command line. - * - * Return: 0 on success, <0 on failure. - */ -int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name) -{ - struct iattr iattr = {.ia_valid = ATTR_MODE,}; - struct kernfs_node *kn; - int ret = 0; - - kn = kernfs_find_and_get_ns(r->kn, name, NULL); - if (!kn) - return -ENOENT; - - switch (kernfs_type(kn)) { - case KERNFS_DIR: - iattr.ia_mode = S_IFDIR; - break; - case KERNFS_FILE: - iattr.ia_mode = S_IFREG; - break; - case KERNFS_LINK: - iattr.ia_mode = S_IFLNK; - break; - } - - ret = kernfs_setattr(kn, &iattr); - kernfs_put(kn); - return ret; -} - -/** - * rdtgroup_kn_mode_restore - Restore user access to named resctrl file - * @r: The resource group with which the file is associated. - * @name: Name of the file - * @mask: Mask of permissions that should be restored - * - * Restore the permissions of the named file. If @name is a directory the - * permissions of its parent will be used. - * - * Return: 0 on success, <0 on failure. - */ -int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name, - umode_t mask) -{ - struct iattr iattr = {.ia_valid = ATTR_MODE,}; - struct kernfs_node *kn, *parent; - struct rftype *rfts, *rft; - int ret, len; - - rfts = res_common_files; - len = ARRAY_SIZE(res_common_files); - - for (rft = rfts; rft < rfts + len; rft++) { - if (!strcmp(rft->name, name)) - iattr.ia_mode = rft->mode & mask; - } - - kn = kernfs_find_and_get_ns(r->kn, name, NULL); - if (!kn) - return -ENOENT; - - switch (kernfs_type(kn)) { - case KERNFS_DIR: - parent = kernfs_get_parent(kn); - if (parent) { - iattr.ia_mode |= parent->mode; - kernfs_put(parent); - } - iattr.ia_mode |= S_IFDIR; - break; - case KERNFS_FILE: - iattr.ia_mode |= S_IFREG; - break; - case KERNFS_LINK: - iattr.ia_mode |= S_IFLNK; - break; - } - - ret = kernfs_setattr(kn, &iattr); - kernfs_put(kn); - return ret; -} - -static int rdtgroup_mkdir_info_resdir(void *priv, char *name, - unsigned long fflags) -{ - struct kernfs_node *kn_subdir; - int ret; - - kn_subdir = kernfs_create_dir(kn_info, name, - kn_info->mode, priv); - if (IS_ERR(kn_subdir)) - return PTR_ERR(kn_subdir); - - ret = rdtgroup_kn_set_ugid(kn_subdir); - if (ret) - return ret; - - ret = rdtgroup_add_files(kn_subdir, fflags); - if (!ret) - kernfs_activate(kn_subdir); - - return ret; -} - -static unsigned long fflags_from_resource(struct rdt_resource *r) -{ - switch (r->rid) { - case RDT_RESOURCE_L3: - case RDT_RESOURCE_L2: - return RFTYPE_RES_CACHE; - case RDT_RESOURCE_MBA: - case RDT_RESOURCE_SMBA: - return RFTYPE_RES_MB; - } - - return WARN_ON_ONCE(1); -} - -static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn) -{ - struct resctrl_schema *s; - struct rdt_resource *r; - unsigned long fflags; - char name[32]; - int ret; - - /* create the directory */ - kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL); - if (IS_ERR(kn_info)) - return PTR_ERR(kn_info); - - ret = rdtgroup_add_files(kn_info, RFTYPE_TOP_INFO); - if (ret) - goto out_destroy; - - /* loop over enabled controls, these are all alloc_capable */ - list_for_each_entry(s, &resctrl_schema_all, list) { - r = s->res; - fflags = fflags_from_resource(r) | RFTYPE_CTRL_INFO; - ret = rdtgroup_mkdir_info_resdir(s, s->name, fflags); - if (ret) - goto out_destroy; - } - - for_each_mon_capable_rdt_resource(r) { - fflags = fflags_from_resource(r) | RFTYPE_MON_INFO; - sprintf(name, "%s_MON", r->name); - ret = rdtgroup_mkdir_info_resdir(r, name, fflags); - if (ret) - goto out_destroy; - } - - ret = rdtgroup_kn_set_ugid(kn_info); - if (ret) - goto out_destroy; - - kernfs_activate(kn_info); - - return 0; - -out_destroy: - kernfs_remove(kn_info); - return ret; -} - -static int -mongroup_create_dir(struct kernfs_node *parent_kn, struct rdtgroup *prgrp, - char *name, struct kernfs_node **dest_kn) -{ - struct kernfs_node *kn; - int ret; - - /* create the directory */ - kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp); - if (IS_ERR(kn)) - return PTR_ERR(kn); - - if (dest_kn) - *dest_kn = kn; - - ret = rdtgroup_kn_set_ugid(kn); - if (ret) - goto out_destroy; - - kernfs_activate(kn); - - return 0; - -out_destroy: - kernfs_remove(kn); - return ret; -} - -static void l3_qos_cfg_update(void *arg) -{ - bool *enable = arg; - - wrmsrl(MSR_IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL); -} - -static void l2_qos_cfg_update(void *arg) -{ - bool *enable = arg; - - wrmsrl(MSR_IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL); -} - -static inline bool is_mba_linear(void) -{ - return resctrl_arch_get_resource(RDT_RESOURCE_MBA)->membw.delay_linear; -} - -static int set_cache_qos_cfg(int level, bool enable) -{ - void (*update)(void *arg); - struct rdt_ctrl_domain *d; - struct rdt_resource *r_l; - cpumask_var_t cpu_mask; - int cpu; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - if (level == RDT_RESOURCE_L3) - update = l3_qos_cfg_update; - else if (level == RDT_RESOURCE_L2) - update = l2_qos_cfg_update; - else - return -EINVAL; - - if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) - return -ENOMEM; - - r_l = &rdt_resources_all[level].r_resctrl; - list_for_each_entry(d, &r_l->ctrl_domains, hdr.list) { - if (r_l->cache.arch_has_per_cpu_cfg) - /* Pick all the CPUs in the domain instance */ - for_each_cpu(cpu, &d->hdr.cpu_mask) - cpumask_set_cpu(cpu, cpu_mask); - else - /* Pick one CPU from each domain instance to update MSR */ - cpumask_set_cpu(cpumask_any(&d->hdr.cpu_mask), cpu_mask); - } - - /* Update QOS_CFG MSR on all the CPUs in cpu_mask */ - on_each_cpu_mask(cpu_mask, update, &enable, 1); - - free_cpumask_var(cpu_mask); - - return 0; -} - -/* Restore the qos cfg state when a domain comes online */ -void rdt_domain_reconfigure_cdp(struct rdt_resource *r) -{ - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); - - if (!r->cdp_capable) - return; - - if (r->rid == RDT_RESOURCE_L2) - l2_qos_cfg_update(&hw_res->cdp_enabled); - - if (r->rid == RDT_RESOURCE_L3) - l3_qos_cfg_update(&hw_res->cdp_enabled); -} - -static int mba_sc_domain_allocate(struct rdt_resource *r, struct rdt_ctrl_domain *d) -{ - u32 num_closid = resctrl_arch_get_num_closid(r); - int cpu = cpumask_any(&d->hdr.cpu_mask); - int i; - - d->mbps_val = kcalloc_node(num_closid, sizeof(*d->mbps_val), - GFP_KERNEL, cpu_to_node(cpu)); - if (!d->mbps_val) - return -ENOMEM; - - for (i = 0; i < num_closid; i++) - d->mbps_val[i] = MBA_MAX_MBPS; - - return 0; -} - -static void mba_sc_domain_destroy(struct rdt_resource *r, - struct rdt_ctrl_domain *d) -{ - kfree(d->mbps_val); - d->mbps_val = NULL; -} - -/* - * MBA software controller is supported only if - * MBM is supported and MBA is in linear scale, - * and the MBM monitor scope is the same as MBA - * control scope. - */ -static bool supports_mba_mbps(void) -{ - struct rdt_resource *rmbm = resctrl_arch_get_resource(RDT_RESOURCE_L3); - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); - - return (resctrl_is_mbm_enabled() && - r->alloc_capable && is_mba_linear() && - r->ctrl_scope == rmbm->mon_scope); -} - -/* - * Enable or disable the MBA software controller - * which helps user specify bandwidth in MBps. - */ -static int set_mba_sc(bool mba_sc) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); - u32 num_closid = resctrl_arch_get_num_closid(r); - struct rdt_ctrl_domain *d; - unsigned long fflags; - int i; - - if (!supports_mba_mbps() || mba_sc == is_mba_sc(r)) - return -EINVAL; - - r->membw.mba_sc = mba_sc; - - rdtgroup_default.mba_mbps_event = mba_mbps_default_event; - - list_for_each_entry(d, &r->ctrl_domains, hdr.list) { - for (i = 0; i < num_closid; i++) - d->mbps_val[i] = MBA_MAX_MBPS; - } - - fflags = mba_sc ? RFTYPE_CTRL_BASE | RFTYPE_MON_BASE : 0; - resctrl_file_fflags_init("mba_MBps_event", fflags); - - return 0; -} - -static int cdp_enable(int level) -{ - struct rdt_resource *r_l = &rdt_resources_all[level].r_resctrl; - int ret; - - if (!r_l->alloc_capable) - return -EINVAL; - - ret = set_cache_qos_cfg(level, true); - if (!ret) - rdt_resources_all[level].cdp_enabled = true; - - return ret; -} - -static void cdp_disable(int level) -{ - struct rdt_hw_resource *r_hw = &rdt_resources_all[level]; - - if (r_hw->cdp_enabled) { - set_cache_qos_cfg(level, false); - r_hw->cdp_enabled = false; - } -} - -int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable) -{ - struct rdt_hw_resource *hw_res = &rdt_resources_all[l]; - - if (!hw_res->r_resctrl.cdp_capable) - return -EINVAL; - - if (enable) - return cdp_enable(l); - - cdp_disable(l); - - return 0; -} - -bool resctrl_arch_get_cdp_enabled(enum resctrl_res_level l) -{ - return rdt_resources_all[l].cdp_enabled; -} - -/* - * We don't allow rdtgroup directories to be created anywhere - * except the root directory. Thus when looking for the rdtgroup - * structure for a kernfs node we are either looking at a directory, - * in which case the rdtgroup structure is pointed at by the "priv" - * field, otherwise we have a file, and need only look to the parent - * to find the rdtgroup. - */ -static struct rdtgroup *kernfs_to_rdtgroup(struct kernfs_node *kn) -{ - if (kernfs_type(kn) == KERNFS_DIR) { - /* - * All the resource directories use "kn->priv" - * to point to the "struct rdtgroup" for the - * resource. "info" and its subdirectories don't - * have rdtgroup structures, so return NULL here. - */ - if (kn == kn_info || - rcu_access_pointer(kn->__parent) == kn_info) - return NULL; - else - return kn->priv; - } else { - return rdt_kn_parent_priv(kn); - } -} - -static void rdtgroup_kn_get(struct rdtgroup *rdtgrp, struct kernfs_node *kn) -{ - atomic_inc(&rdtgrp->waitcount); - kernfs_break_active_protection(kn); -} - -static void rdtgroup_kn_put(struct rdtgroup *rdtgrp, struct kernfs_node *kn) -{ - if (atomic_dec_and_test(&rdtgrp->waitcount) && - (rdtgrp->flags & RDT_DELETED)) { - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) - rdtgroup_pseudo_lock_remove(rdtgrp); - kernfs_unbreak_active_protection(kn); - rdtgroup_remove(rdtgrp); - } else { - kernfs_unbreak_active_protection(kn); - } -} - -struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn) -{ - struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn); - - if (!rdtgrp) - return NULL; - - rdtgroup_kn_get(rdtgrp, kn); - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - /* Was this group deleted while we waited? */ - if (rdtgrp->flags & RDT_DELETED) - return NULL; - - return rdtgrp; -} - -void rdtgroup_kn_unlock(struct kernfs_node *kn) -{ - struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn); - - if (!rdtgrp) - return; - - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - - rdtgroup_kn_put(rdtgrp, kn); -} - -static int mkdir_mondata_all(struct kernfs_node *parent_kn, - struct rdtgroup *prgrp, - struct kernfs_node **mon_data_kn); - -static void rdt_disable_ctx(void) -{ - resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false); - resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false); - set_mba_sc(false); - - resctrl_debug = false; -} - -static int rdt_enable_ctx(struct rdt_fs_context *ctx) -{ - int ret = 0; - - if (ctx->enable_cdpl2) { - ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, true); - if (ret) - goto out_done; - } - - if (ctx->enable_cdpl3) { - ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true); - if (ret) - goto out_cdpl2; - } - - if (ctx->enable_mba_mbps) { - ret = set_mba_sc(true); - if (ret) - goto out_cdpl3; - } - - if (ctx->enable_debug) - resctrl_debug = true; - - return 0; - -out_cdpl3: - resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false); -out_cdpl2: - resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false); -out_done: - return ret; -} - -static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type) -{ - struct resctrl_schema *s; - const char *suffix = ""; - int ret, cl; - - s = kzalloc(sizeof(*s), GFP_KERNEL); - if (!s) - return -ENOMEM; - - s->res = r; - s->num_closid = resctrl_arch_get_num_closid(r); - if (resctrl_arch_get_cdp_enabled(r->rid)) - s->num_closid /= 2; - - s->conf_type = type; - switch (type) { - case CDP_CODE: - suffix = "CODE"; - break; - case CDP_DATA: - suffix = "DATA"; - break; - case CDP_NONE: - suffix = ""; - break; - } - - ret = snprintf(s->name, sizeof(s->name), "%s%s", r->name, suffix); - if (ret >= sizeof(s->name)) { - kfree(s); - return -EINVAL; - } - - cl = strlen(s->name); - - /* - * If CDP is supported by this resource, but not enabled, - * include the suffix. This ensures the tabular format of the - * schemata file does not change between mounts of the filesystem. - */ - if (r->cdp_capable && !resctrl_arch_get_cdp_enabled(r->rid)) - cl += 4; - - if (cl > max_name_width) - max_name_width = cl; - - switch (r->schema_fmt) { - case RESCTRL_SCHEMA_BITMAP: - s->fmt_str = "%d=%x"; - break; - case RESCTRL_SCHEMA_RANGE: - s->fmt_str = "%d=%u"; - break; - } - - if (WARN_ON_ONCE(!s->fmt_str)) { - kfree(s); - return -EINVAL; - } - - INIT_LIST_HEAD(&s->list); - list_add(&s->list, &resctrl_schema_all); - - return 0; -} - -static int schemata_list_create(void) -{ - struct rdt_resource *r; - int ret = 0; - - for_each_alloc_capable_rdt_resource(r) { - if (resctrl_arch_get_cdp_enabled(r->rid)) { - ret = schemata_list_add(r, CDP_CODE); - if (ret) - break; - - ret = schemata_list_add(r, CDP_DATA); - } else { - ret = schemata_list_add(r, CDP_NONE); - } - - if (ret) - break; - } - - return ret; -} - -static void schemata_list_destroy(void) -{ - struct resctrl_schema *s, *tmp; - - list_for_each_entry_safe(s, tmp, &resctrl_schema_all, list) { - list_del(&s->list); - kfree(s); - } -} - -static int rdt_get_tree(struct fs_context *fc) -{ - struct rdt_fs_context *ctx = rdt_fc2context(fc); - unsigned long flags = RFTYPE_CTRL_BASE; - struct rdt_mon_domain *dom; - struct rdt_resource *r; - int ret; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - /* - * resctrl file system can only be mounted once. - */ - if (resctrl_mounted) { - ret = -EBUSY; - goto out; - } - - ret = rdtgroup_setup_root(ctx); - if (ret) - goto out; - - ret = rdt_enable_ctx(ctx); - if (ret) - goto out_root; - - ret = schemata_list_create(); - if (ret) { - schemata_list_destroy(); - goto out_ctx; - } - - ret = closid_init(); - if (ret) - goto out_schemata_free; - - if (resctrl_arch_mon_capable()) - flags |= RFTYPE_MON; - - ret = rdtgroup_add_files(rdtgroup_default.kn, flags); - if (ret) - goto out_closid_exit; - - kernfs_activate(rdtgroup_default.kn); - - ret = rdtgroup_create_info_dir(rdtgroup_default.kn); - if (ret < 0) - goto out_closid_exit; - - if (resctrl_arch_mon_capable()) { - ret = mongroup_create_dir(rdtgroup_default.kn, - &rdtgroup_default, "mon_groups", - &kn_mongrp); - if (ret < 0) - goto out_info; - - ret = mkdir_mondata_all(rdtgroup_default.kn, - &rdtgroup_default, &kn_mondata); - if (ret < 0) - goto out_mongrp; - rdtgroup_default.mon.mon_data_kn = kn_mondata; - } - - ret = rdt_pseudo_lock_init(); - if (ret) - goto out_mondata; - - ret = kernfs_get_tree(fc); - if (ret < 0) - goto out_psl; - - if (resctrl_arch_alloc_capable()) - resctrl_arch_enable_alloc(); - if (resctrl_arch_mon_capable()) - resctrl_arch_enable_mon(); - - if (resctrl_arch_alloc_capable() || resctrl_arch_mon_capable()) - resctrl_mounted = true; - - if (resctrl_is_mbm_enabled()) { - r = resctrl_arch_get_resource(RDT_RESOURCE_L3); - list_for_each_entry(dom, &r->mon_domains, hdr.list) - mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL, - RESCTRL_PICK_ANY_CPU); - } - - goto out; - -out_psl: - rdt_pseudo_lock_release(); -out_mondata: - if (resctrl_arch_mon_capable()) - kernfs_remove(kn_mondata); -out_mongrp: - if (resctrl_arch_mon_capable()) - kernfs_remove(kn_mongrp); -out_info: - kernfs_remove(kn_info); -out_closid_exit: - closid_exit(); -out_schemata_free: - schemata_list_destroy(); -out_ctx: - rdt_disable_ctx(); -out_root: - rdtgroup_destroy_root(); -out: - rdt_last_cmd_clear(); - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - return ret; -} - -enum rdt_param { - Opt_cdp, - Opt_cdpl2, - Opt_mba_mbps, - Opt_debug, - nr__rdt_params -}; - -static const struct fs_parameter_spec rdt_fs_parameters[] = { - fsparam_flag("cdp", Opt_cdp), - fsparam_flag("cdpl2", Opt_cdpl2), - fsparam_flag("mba_MBps", Opt_mba_mbps), - fsparam_flag("debug", Opt_debug), - {} -}; - -static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param) -{ - struct rdt_fs_context *ctx = rdt_fc2context(fc); - struct fs_parse_result result; - const char *msg; - int opt; - - opt = fs_parse(fc, rdt_fs_parameters, param, &result); - if (opt < 0) - return opt; - - switch (opt) { - case Opt_cdp: - ctx->enable_cdpl3 = true; - return 0; - case Opt_cdpl2: - ctx->enable_cdpl2 = true; - return 0; - case Opt_mba_mbps: - msg = "mba_MBps requires MBM and linear scale MBA at L3 scope"; - if (!supports_mba_mbps()) - return invalfc(fc, msg); - ctx->enable_mba_mbps = true; - return 0; - case Opt_debug: - ctx->enable_debug = true; - return 0; - } - - return -EINVAL; -} - -static void rdt_fs_context_free(struct fs_context *fc) -{ - struct rdt_fs_context *ctx = rdt_fc2context(fc); - - kernfs_free_fs_context(fc); - kfree(ctx); -} - -static const struct fs_context_operations rdt_fs_context_ops = { - .free = rdt_fs_context_free, - .parse_param = rdt_parse_param, - .get_tree = rdt_get_tree, -}; - -static int rdt_init_fs_context(struct fs_context *fc) -{ - struct rdt_fs_context *ctx; - - ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); - if (!ctx) - return -ENOMEM; - - ctx->kfc.magic = RDTGROUP_SUPER_MAGIC; - fc->fs_private = &ctx->kfc; - fc->ops = &rdt_fs_context_ops; - put_user_ns(fc->user_ns); - fc->user_ns = get_user_ns(&init_user_ns); - fc->global = true; - return 0; -} - -void resctrl_arch_reset_all_ctrls(struct rdt_resource *r) -{ - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); - struct rdt_hw_ctrl_domain *hw_dom; - struct msr_param msr_param; - struct rdt_ctrl_domain *d; - int i; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - msr_param.res = r; - msr_param.low = 0; - msr_param.high = hw_res->num_closid; - - /* - * Disable resource control for this resource by setting all - * CBMs in all ctrl_domains to the maximum mask value. Pick one CPU - * from each domain to update the MSRs below. - */ - list_for_each_entry(d, &r->ctrl_domains, hdr.list) { - hw_dom = resctrl_to_arch_ctrl_dom(d); - - for (i = 0; i < hw_res->num_closid; i++) - hw_dom->ctrl_val[i] = resctrl_get_default_ctrl(r); - msr_param.dom = d; - smp_call_function_any(&d->hdr.cpu_mask, rdt_ctrl_update, &msr_param, 1); - } - - return; -} - -/* - * Move tasks from one to the other group. If @from is NULL, then all tasks - * in the systems are moved unconditionally (used for teardown). - * - * If @mask is not NULL the cpus on which moved tasks are running are set - * in that mask so the update smp function call is restricted to affected - * cpus. - */ -static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to, - struct cpumask *mask) -{ - struct task_struct *p, *t; - - read_lock(&tasklist_lock); - for_each_process_thread(p, t) { - if (!from || is_closid_match(t, from) || - is_rmid_match(t, from)) { - resctrl_arch_set_closid_rmid(t, to->closid, - to->mon.rmid); - - /* - * Order the closid/rmid stores above before the loads - * in task_curr(). This pairs with the full barrier - * between the rq->curr update and - * resctrl_arch_sched_in() during context switch. - */ - smp_mb(); - - /* - * If the task is on a CPU, set the CPU in the mask. - * The detection is inaccurate as tasks might move or - * schedule before the smp function call takes place. - * In such a case the function call is pointless, but - * there is no other side effect. - */ - if (IS_ENABLED(CONFIG_SMP) && mask && task_curr(t)) - cpumask_set_cpu(task_cpu(t), mask); - } - } - read_unlock(&tasklist_lock); -} - -static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp) -{ - struct rdtgroup *sentry, *stmp; - struct list_head *head; - - head = &rdtgrp->mon.crdtgrp_list; - list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) { - free_rmid(sentry->closid, sentry->mon.rmid); - list_del(&sentry->mon.crdtgrp_list); - - if (atomic_read(&sentry->waitcount) != 0) - sentry->flags = RDT_DELETED; - else - rdtgroup_remove(sentry); - } -} - -/* - * Forcibly remove all of subdirectories under root. - */ -static void rmdir_all_sub(void) -{ - struct rdtgroup *rdtgrp, *tmp; - - /* Move all tasks to the default resource group */ - rdt_move_group_tasks(NULL, &rdtgroup_default, NULL); - - list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) { - /* Free any child rmids */ - free_all_child_rdtgrp(rdtgrp); - - /* Remove each rdtgroup other than root */ - if (rdtgrp == &rdtgroup_default) - continue; - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) - rdtgroup_pseudo_lock_remove(rdtgrp); - - /* - * Give any CPUs back to the default group. We cannot copy - * cpu_online_mask because a CPU might have executed the - * offline callback already, but is still marked online. - */ - cpumask_or(&rdtgroup_default.cpu_mask, - &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); - - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - - kernfs_remove(rdtgrp->kn); - list_del(&rdtgrp->rdtgroup_list); - - if (atomic_read(&rdtgrp->waitcount) != 0) - rdtgrp->flags = RDT_DELETED; - else - rdtgroup_remove(rdtgrp); - } - /* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */ - update_closid_rmid(cpu_online_mask, &rdtgroup_default); - - kernfs_remove(kn_info); - kernfs_remove(kn_mongrp); - kernfs_remove(kn_mondata); -} - -/** - * mon_get_kn_priv() - Get the mon_data priv data for this event. - * - * The same values are used across the mon_data directories of all control and - * monitor groups for the same event in the same domain. Keep a list of - * allocated structures and re-use an existing one with the same values for - * @rid, @domid, etc. - * - * @rid: The resource id for the event file being created. - * @domid: The domain id for the event file being created. - * @mevt: The type of event file being created. - * @do_sum: Whether SNC summing monitors are being created. - */ -static struct mon_data *mon_get_kn_priv(enum resctrl_res_level rid, int domid, - struct mon_evt *mevt, - bool do_sum) -{ - struct mon_data *priv; - - lockdep_assert_held(&rdtgroup_mutex); - - list_for_each_entry(priv, &mon_data_kn_priv_list, list) { - if (priv->rid == rid && priv->domid == domid && - priv->sum == do_sum && priv->evtid == mevt->evtid) - return priv; - } - - priv = kzalloc(sizeof(*priv), GFP_KERNEL); - if (!priv) - return NULL; - - priv->rid = rid; - priv->domid = domid; - priv->sum = do_sum; - priv->evtid = mevt->evtid; - list_add_tail(&priv->list, &mon_data_kn_priv_list); - - return priv; -} - -/** - * mon_put_kn_priv() - Free all allocated mon_data structures. - * - * Called when resctrl file system is unmounted. - */ -static void mon_put_kn_priv(void) -{ - struct mon_data *priv, *tmp; - - lockdep_assert_held(&rdtgroup_mutex); - - list_for_each_entry_safe(priv, tmp, &mon_data_kn_priv_list, list) { - list_del(&priv->list); - kfree(priv); - } -} - -static void resctrl_fs_teardown(void) -{ - lockdep_assert_held(&rdtgroup_mutex); - - /* Cleared by rdtgroup_destroy_root() */ - if (!rdtgroup_default.kn) - return; - - rmdir_all_sub(); - mon_put_kn_priv(); - rdt_pseudo_lock_release(); - rdtgroup_default.mode = RDT_MODE_SHAREABLE; - closid_exit(); - schemata_list_destroy(); - rdtgroup_destroy_root(); -} - -static void rdt_kill_sb(struct super_block *sb) -{ - struct rdt_resource *r; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - rdt_disable_ctx(); - - /* Put everything back to default values. */ - for_each_alloc_capable_rdt_resource(r) - resctrl_arch_reset_all_ctrls(r); - - resctrl_fs_teardown(); - if (resctrl_arch_alloc_capable()) - resctrl_arch_disable_alloc(); - if (resctrl_arch_mon_capable()) - resctrl_arch_disable_mon(); - resctrl_mounted = false; - kernfs_kill_sb(sb); - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); -} - -static struct file_system_type rdt_fs_type = { - .name = "resctrl", - .init_fs_context = rdt_init_fs_context, - .parameters = rdt_fs_parameters, - .kill_sb = rdt_kill_sb, -}; - -static int mon_addfile(struct kernfs_node *parent_kn, const char *name, - void *priv) -{ - struct kernfs_node *kn; - int ret = 0; - - kn = __kernfs_create_file(parent_kn, name, 0444, - GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0, - &kf_mondata_ops, priv, NULL, NULL); - if (IS_ERR(kn)) - return PTR_ERR(kn); - - ret = rdtgroup_kn_set_ugid(kn); - if (ret) { - kernfs_remove(kn); - return ret; - } - - return ret; -} - -static void mon_rmdir_one_subdir(struct kernfs_node *pkn, char *name, char *subname) -{ - struct kernfs_node *kn; - - kn = kernfs_find_and_get(pkn, name); - if (!kn) - return; - kernfs_put(kn); - - if (kn->dir.subdirs <= 1) - kernfs_remove(kn); - else - kernfs_remove_by_name(kn, subname); -} - -/* - * Remove all subdirectories of mon_data of ctrl_mon groups - * and monitor groups for the given domain. - * Remove files and directories containing "sum" of domain data - * when last domain being summed is removed. - */ -static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, - struct rdt_mon_domain *d) -{ - struct rdtgroup *prgrp, *crgrp; - char subname[32]; - bool snc_mode; - char name[32]; - - snc_mode = r->mon_scope == RESCTRL_L3_NODE; - sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id); - if (snc_mode) - sprintf(subname, "mon_sub_%s_%02d", r->name, d->hdr.id); - - list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { - mon_rmdir_one_subdir(prgrp->mon.mon_data_kn, name, subname); - - list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list) - mon_rmdir_one_subdir(crgrp->mon.mon_data_kn, name, subname); - } -} - -static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d, - struct rdt_resource *r, struct rdtgroup *prgrp, - bool do_sum) -{ - struct rmid_read rr = {0}; - struct mon_data *priv; - struct mon_evt *mevt; - int ret, domid; - - if (WARN_ON(list_empty(&r->evt_list))) - return -EPERM; - - list_for_each_entry(mevt, &r->evt_list, list) { - domid = do_sum ? d->ci->id : d->hdr.id; - priv = mon_get_kn_priv(r->rid, domid, mevt, do_sum); - if (WARN_ON_ONCE(!priv)) - return -EINVAL; - - ret = mon_addfile(kn, mevt->name, priv); - if (ret) - return ret; - - if (!do_sum && resctrl_is_mbm_event(mevt->evtid)) - mon_event_read(&rr, r, d, prgrp, &d->hdr.cpu_mask, mevt->evtid, true); - } - - return 0; -} - -static int mkdir_mondata_subdir(struct kernfs_node *parent_kn, - struct rdt_mon_domain *d, - struct rdt_resource *r, struct rdtgroup *prgrp) -{ - struct kernfs_node *kn, *ckn; - char name[32]; - bool snc_mode; - int ret = 0; - - lockdep_assert_held(&rdtgroup_mutex); - - snc_mode = r->mon_scope == RESCTRL_L3_NODE; - sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id); - kn = kernfs_find_and_get(parent_kn, name); - if (kn) { - /* - * rdtgroup_mutex will prevent this directory from being - * removed. No need to keep this hold. - */ - kernfs_put(kn); - } else { - kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp); - if (IS_ERR(kn)) - return PTR_ERR(kn); - - ret = rdtgroup_kn_set_ugid(kn); - if (ret) - goto out_destroy; - ret = mon_add_all_files(kn, d, r, prgrp, snc_mode); - if (ret) - goto out_destroy; - } - - if (snc_mode) { - sprintf(name, "mon_sub_%s_%02d", r->name, d->hdr.id); - ckn = kernfs_create_dir(kn, name, parent_kn->mode, prgrp); - if (IS_ERR(ckn)) { - ret = -EINVAL; - goto out_destroy; - } - - ret = rdtgroup_kn_set_ugid(ckn); - if (ret) - goto out_destroy; - - ret = mon_add_all_files(ckn, d, r, prgrp, false); - if (ret) - goto out_destroy; - } - - kernfs_activate(kn); - return 0; - -out_destroy: - kernfs_remove(kn); - return ret; -} - -/* - * Add all subdirectories of mon_data for "ctrl_mon" groups - * and "monitor" groups with given domain id. - */ -static void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, - struct rdt_mon_domain *d) -{ - struct kernfs_node *parent_kn; - struct rdtgroup *prgrp, *crgrp; - struct list_head *head; - - list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { - parent_kn = prgrp->mon.mon_data_kn; - mkdir_mondata_subdir(parent_kn, d, r, prgrp); - - head = &prgrp->mon.crdtgrp_list; - list_for_each_entry(crgrp, head, mon.crdtgrp_list) { - parent_kn = crgrp->mon.mon_data_kn; - mkdir_mondata_subdir(parent_kn, d, r, crgrp); - } - } -} - -static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn, - struct rdt_resource *r, - struct rdtgroup *prgrp) -{ - struct rdt_mon_domain *dom; - int ret; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - list_for_each_entry(dom, &r->mon_domains, hdr.list) { - ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp); - if (ret) - return ret; - } - - return 0; -} - -/* - * This creates a directory mon_data which contains the monitored data. - * - * mon_data has one directory for each domain which are named - * in the format mon__. For ex: A mon_data - * with L3 domain looks as below: - * ./mon_data: - * mon_L3_00 - * mon_L3_01 - * mon_L3_02 - * ... - * - * Each domain directory has one file per event: - * ./mon_L3_00/: - * llc_occupancy - * - */ -static int mkdir_mondata_all(struct kernfs_node *parent_kn, - struct rdtgroup *prgrp, - struct kernfs_node **dest_kn) -{ - struct rdt_resource *r; - struct kernfs_node *kn; - int ret; - - /* - * Create the mon_data directory first. - */ - ret = mongroup_create_dir(parent_kn, prgrp, "mon_data", &kn); - if (ret) - return ret; - - if (dest_kn) - *dest_kn = kn; - - /* - * Create the subdirectories for each domain. Note that all events - * in a domain like L3 are grouped into a resource whose domain is L3 - */ - for_each_mon_capable_rdt_resource(r) { - ret = mkdir_mondata_subdir_alldom(kn, r, prgrp); - if (ret) - goto out_destroy; - } - - return 0; - -out_destroy: - kernfs_remove(kn); - return ret; -} - -/** - * cbm_ensure_valid - Enforce validity on provided CBM - * @_val: Candidate CBM - * @r: RDT resource to which the CBM belongs - * - * The provided CBM represents all cache portions available for use. This - * may be represented by a bitmap that does not consist of contiguous ones - * and thus be an invalid CBM. - * Here the provided CBM is forced to be a valid CBM by only considering - * the first set of contiguous bits as valid and clearing all bits. - * The intention here is to provide a valid default CBM with which a new - * resource group is initialized. The user can follow this with a - * modification to the CBM if the default does not satisfy the - * requirements. - */ -static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r) -{ - unsigned int cbm_len = r->cache.cbm_len; - unsigned long first_bit, zero_bit; - unsigned long val = _val; - - if (!val) - return 0; - - first_bit = find_first_bit(&val, cbm_len); - zero_bit = find_next_zero_bit(&val, cbm_len, first_bit); - - /* Clear any remaining bits to ensure contiguous region */ - bitmap_clear(&val, zero_bit, cbm_len - zero_bit); - return (u32)val; -} - -/* - * Initialize cache resources per RDT domain - * - * Set the RDT domain up to start off with all usable allocations. That is, - * all shareable and unused bits. All-zero CBM is invalid. - */ -static int __init_one_rdt_domain(struct rdt_ctrl_domain *d, struct resctrl_schema *s, - u32 closid) -{ - enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type); - enum resctrl_conf_type t = s->conf_type; - struct resctrl_staged_config *cfg; - struct rdt_resource *r = s->res; - u32 used_b = 0, unused_b = 0; - unsigned long tmp_cbm; - enum rdtgrp_mode mode; - u32 peer_ctl, ctrl_val; - int i; - - cfg = &d->staged_config[t]; - cfg->have_new_ctrl = false; - cfg->new_ctrl = r->cache.shareable_bits; - used_b = r->cache.shareable_bits; - for (i = 0; i < closids_supported(); i++) { - if (closid_allocated(i) && i != closid) { - mode = rdtgroup_mode_by_closid(i); - if (mode == RDT_MODE_PSEUDO_LOCKSETUP) - /* - * ctrl values for locksetup aren't relevant - * until the schemata is written, and the mode - * becomes RDT_MODE_PSEUDO_LOCKED. - */ - continue; - /* - * If CDP is active include peer domain's - * usage to ensure there is no overlap - * with an exclusive group. - */ - if (resctrl_arch_get_cdp_enabled(r->rid)) - peer_ctl = resctrl_arch_get_config(r, d, i, - peer_type); - else - peer_ctl = 0; - ctrl_val = resctrl_arch_get_config(r, d, i, - s->conf_type); - used_b |= ctrl_val | peer_ctl; - if (mode == RDT_MODE_SHAREABLE) - cfg->new_ctrl |= ctrl_val | peer_ctl; - } - } - if (d->plr && d->plr->cbm > 0) - used_b |= d->plr->cbm; - unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1); - unused_b &= BIT_MASK(r->cache.cbm_len) - 1; - cfg->new_ctrl |= unused_b; - /* - * Force the initial CBM to be valid, user can - * modify the CBM based on system availability. - */ - cfg->new_ctrl = cbm_ensure_valid(cfg->new_ctrl, r); - /* - * Assign the u32 CBM to an unsigned long to ensure that - * bitmap_weight() does not access out-of-bound memory. - */ - tmp_cbm = cfg->new_ctrl; - if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) { - rdt_last_cmd_printf("No space on %s:%d\n", s->name, d->hdr.id); - return -ENOSPC; - } - cfg->have_new_ctrl = true; - - return 0; -} - -/* - * Initialize cache resources with default values. - * - * A new RDT group is being created on an allocation capable (CAT) - * supporting system. Set this group up to start off with all usable - * allocations. - * - * If there are no more shareable bits available on any domain then - * the entire allocation will fail. - */ -static int rdtgroup_init_cat(struct resctrl_schema *s, u32 closid) -{ - struct rdt_ctrl_domain *d; - int ret; - - list_for_each_entry(d, &s->res->ctrl_domains, hdr.list) { - ret = __init_one_rdt_domain(d, s, closid); - if (ret < 0) - return ret; - } - - return 0; -} - -/* Initialize MBA resource with default values. */ -static void rdtgroup_init_mba(struct rdt_resource *r, u32 closid) -{ - struct resctrl_staged_config *cfg; - struct rdt_ctrl_domain *d; - - list_for_each_entry(d, &r->ctrl_domains, hdr.list) { - if (is_mba_sc(r)) { - d->mbps_val[closid] = MBA_MAX_MBPS; - continue; - } - - cfg = &d->staged_config[CDP_NONE]; - cfg->new_ctrl = resctrl_get_default_ctrl(r); - cfg->have_new_ctrl = true; - } -} - -/* Initialize the RDT group's allocations. */ -static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) -{ - struct resctrl_schema *s; - struct rdt_resource *r; - int ret = 0; - - rdt_staged_configs_clear(); - - list_for_each_entry(s, &resctrl_schema_all, list) { - r = s->res; - if (r->rid == RDT_RESOURCE_MBA || - r->rid == RDT_RESOURCE_SMBA) { - rdtgroup_init_mba(r, rdtgrp->closid); - if (is_mba_sc(r)) - continue; - } else { - ret = rdtgroup_init_cat(s, rdtgrp->closid); - if (ret < 0) - goto out; - } - - ret = resctrl_arch_update_domains(r, rdtgrp->closid); - if (ret < 0) { - rdt_last_cmd_puts("Failed to initialize allocations\n"); - goto out; - } - } - - rdtgrp->mode = RDT_MODE_SHAREABLE; - -out: - rdt_staged_configs_clear(); - return ret; -} - -static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp) -{ - int ret; - - if (!resctrl_arch_mon_capable()) - return 0; - - ret = alloc_rmid(rdtgrp->closid); - if (ret < 0) { - rdt_last_cmd_puts("Out of RMIDs\n"); - return ret; - } - rdtgrp->mon.rmid = ret; - - ret = mkdir_mondata_all(rdtgrp->kn, rdtgrp, &rdtgrp->mon.mon_data_kn); - if (ret) { - rdt_last_cmd_puts("kernfs subdir error\n"); - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - return ret; - } - - return 0; -} - -static void mkdir_rdt_prepare_rmid_free(struct rdtgroup *rgrp) -{ - if (resctrl_arch_mon_capable()) - free_rmid(rgrp->closid, rgrp->mon.rmid); -} - -/* - * We allow creating mon groups only with in a directory called "mon_groups" - * which is present in every ctrl_mon group. Check if this is a valid - * "mon_groups" directory. - * - * 1. The directory should be named "mon_groups". - * 2. The mon group itself should "not" be named "mon_groups". - * This makes sure "mon_groups" directory always has a ctrl_mon group - * as parent. - */ -static bool is_mon_groups(struct kernfs_node *kn, const char *name) -{ - return (!strcmp(rdt_kn_name(kn), "mon_groups") && - strcmp(name, "mon_groups")); -} - -static int mkdir_rdt_prepare(struct kernfs_node *parent_kn, - const char *name, umode_t mode, - enum rdt_group_type rtype, struct rdtgroup **r) -{ - struct rdtgroup *prdtgrp, *rdtgrp; - unsigned long files = 0; - struct kernfs_node *kn; - int ret; - - prdtgrp = rdtgroup_kn_lock_live(parent_kn); - if (!prdtgrp) { - ret = -ENODEV; - goto out_unlock; - } - - /* - * Check that the parent directory for a monitor group is a "mon_groups" - * directory. - */ - if (rtype == RDTMON_GROUP && !is_mon_groups(parent_kn, name)) { - ret = -EPERM; - goto out_unlock; - } - - if (rtype == RDTMON_GROUP && - (prdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || - prdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)) { - ret = -EINVAL; - rdt_last_cmd_puts("Pseudo-locking in progress\n"); - goto out_unlock; - } - - /* allocate the rdtgroup. */ - rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL); - if (!rdtgrp) { - ret = -ENOSPC; - rdt_last_cmd_puts("Kernel out of memory\n"); - goto out_unlock; - } - *r = rdtgrp; - rdtgrp->mon.parent = prdtgrp; - rdtgrp->type = rtype; - INIT_LIST_HEAD(&rdtgrp->mon.crdtgrp_list); - - /* kernfs creates the directory for rdtgrp */ - kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp); - if (IS_ERR(kn)) { - ret = PTR_ERR(kn); - rdt_last_cmd_puts("kernfs create error\n"); - goto out_free_rgrp; - } - rdtgrp->kn = kn; - - /* - * kernfs_remove() will drop the reference count on "kn" which - * will free it. But we still need it to stick around for the - * rdtgroup_kn_unlock(kn) call. Take one extra reference here, - * which will be dropped by kernfs_put() in rdtgroup_remove(). - */ - kernfs_get(kn); - - ret = rdtgroup_kn_set_ugid(kn); - if (ret) { - rdt_last_cmd_puts("kernfs perm error\n"); - goto out_destroy; - } - - if (rtype == RDTCTRL_GROUP) { - files = RFTYPE_BASE | RFTYPE_CTRL; - if (resctrl_arch_mon_capable()) - files |= RFTYPE_MON; - } else { - files = RFTYPE_BASE | RFTYPE_MON; - } - - ret = rdtgroup_add_files(kn, files); - if (ret) { - rdt_last_cmd_puts("kernfs fill error\n"); - goto out_destroy; - } - - /* - * The caller unlocks the parent_kn upon success. - */ - return 0; - -out_destroy: - kernfs_put(rdtgrp->kn); - kernfs_remove(rdtgrp->kn); -out_free_rgrp: - kfree(rdtgrp); -out_unlock: - rdtgroup_kn_unlock(parent_kn); - return ret; -} - -static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp) -{ - kernfs_remove(rgrp->kn); - rdtgroup_remove(rgrp); -} - -/* - * Create a monitor group under "mon_groups" directory of a control - * and monitor group(ctrl_mon). This is a resource group - * to monitor a subset of tasks and cpus in its parent ctrl_mon group. - */ -static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn, - const char *name, umode_t mode) -{ - struct rdtgroup *rdtgrp, *prgrp; - int ret; - - ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTMON_GROUP, &rdtgrp); - if (ret) - return ret; - - prgrp = rdtgrp->mon.parent; - rdtgrp->closid = prgrp->closid; - - ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp); - if (ret) { - mkdir_rdt_prepare_clean(rdtgrp); - goto out_unlock; - } - - kernfs_activate(rdtgrp->kn); - - /* - * Add the rdtgrp to the list of rdtgrps the parent - * ctrl_mon group has to track. - */ - list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list); - -out_unlock: - rdtgroup_kn_unlock(parent_kn); - return ret; -} - -/* - * These are rdtgroups created under the root directory. Can be used - * to allocate and monitor resources. - */ -static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn, - const char *name, umode_t mode) -{ - struct rdtgroup *rdtgrp; - struct kernfs_node *kn; - u32 closid; - int ret; - - ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTCTRL_GROUP, &rdtgrp); - if (ret) - return ret; - - kn = rdtgrp->kn; - ret = closid_alloc(); - if (ret < 0) { - rdt_last_cmd_puts("Out of CLOSIDs\n"); - goto out_common_fail; - } - closid = ret; - ret = 0; - - rdtgrp->closid = closid; - - ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp); - if (ret) - goto out_closid_free; - - kernfs_activate(rdtgrp->kn); - - ret = rdtgroup_init_alloc(rdtgrp); - if (ret < 0) - goto out_rmid_free; - - list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups); - - if (resctrl_arch_mon_capable()) { - /* - * Create an empty mon_groups directory to hold the subset - * of tasks and cpus to monitor. - */ - ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL); - if (ret) { - rdt_last_cmd_puts("kernfs subdir error\n"); - goto out_del_list; - } - if (is_mba_sc(NULL)) - rdtgrp->mba_mbps_event = mba_mbps_default_event; - } - - goto out_unlock; - -out_del_list: - list_del(&rdtgrp->rdtgroup_list); -out_rmid_free: - mkdir_rdt_prepare_rmid_free(rdtgrp); -out_closid_free: - closid_free(closid); -out_common_fail: - mkdir_rdt_prepare_clean(rdtgrp); -out_unlock: - rdtgroup_kn_unlock(parent_kn); - return ret; -} - -static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name, - umode_t mode) -{ - /* Do not accept '\n' to avoid unparsable situation. */ - if (strchr(name, '\n')) - return -EINVAL; - - /* - * If the parent directory is the root directory and RDT - * allocation is supported, add a control and monitoring - * subdirectory - */ - if (resctrl_arch_alloc_capable() && parent_kn == rdtgroup_default.kn) - return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode); - - /* Else, attempt to add a monitoring subdirectory. */ - if (resctrl_arch_mon_capable()) - return rdtgroup_mkdir_mon(parent_kn, name, mode); - - return -EPERM; -} - -static int rdtgroup_rmdir_mon(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask) -{ - struct rdtgroup *prdtgrp = rdtgrp->mon.parent; - u32 closid, rmid; - int cpu; - - /* Give any tasks back to the parent group */ - rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask); - - /* - * Update per cpu closid/rmid of the moved CPUs first. - * Note: the closid will not change, but the arch code still needs it. - */ - closid = prdtgrp->closid; - rmid = prdtgrp->mon.rmid; - for_each_cpu(cpu, &rdtgrp->cpu_mask) - resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid); - - /* - * Update the MSR on moved CPUs and CPUs which have moved - * task running on them. - */ - cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask); - update_closid_rmid(tmpmask, NULL); - - rdtgrp->flags = RDT_DELETED; - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - - /* - * Remove the rdtgrp from the parent ctrl_mon group's list - */ - WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list)); - list_del(&rdtgrp->mon.crdtgrp_list); - - kernfs_remove(rdtgrp->kn); - - return 0; -} - -static int rdtgroup_ctrl_remove(struct rdtgroup *rdtgrp) -{ - rdtgrp->flags = RDT_DELETED; - list_del(&rdtgrp->rdtgroup_list); - - kernfs_remove(rdtgrp->kn); - return 0; -} - -static int rdtgroup_rmdir_ctrl(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask) -{ - u32 closid, rmid; - int cpu; - - /* Give any tasks back to the default group */ - rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask); - - /* Give any CPUs back to the default group */ - cpumask_or(&rdtgroup_default.cpu_mask, - &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); - - /* Update per cpu closid and rmid of the moved CPUs first */ - closid = rdtgroup_default.closid; - rmid = rdtgroup_default.mon.rmid; - for_each_cpu(cpu, &rdtgrp->cpu_mask) - resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid); - - /* - * Update the MSR on moved CPUs and CPUs which have moved - * task running on them. - */ - cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask); - update_closid_rmid(tmpmask, NULL); - - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - closid_free(rdtgrp->closid); - - rdtgroup_ctrl_remove(rdtgrp); - - /* - * Free all the child monitor group rmids. - */ - free_all_child_rdtgrp(rdtgrp); - - return 0; -} - -static struct kernfs_node *rdt_kn_parent(struct kernfs_node *kn) -{ - /* - * Valid within the RCU section it was obtained or while rdtgroup_mutex - * is held. - */ - return rcu_dereference_check(kn->__parent, lockdep_is_held(&rdtgroup_mutex)); -} - -static int rdtgroup_rmdir(struct kernfs_node *kn) -{ - struct kernfs_node *parent_kn; - struct rdtgroup *rdtgrp; - cpumask_var_t tmpmask; - int ret = 0; - - if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) - return -ENOMEM; - - rdtgrp = rdtgroup_kn_lock_live(kn); - if (!rdtgrp) { - ret = -EPERM; - goto out; - } - parent_kn = rdt_kn_parent(kn); - - /* - * If the rdtgroup is a ctrl_mon group and parent directory - * is the root directory, remove the ctrl_mon group. - * - * If the rdtgroup is a mon group and parent directory - * is a valid "mon_groups" directory, remove the mon group. - */ - if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn && - rdtgrp != &rdtgroup_default) { - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - ret = rdtgroup_ctrl_remove(rdtgrp); - } else { - ret = rdtgroup_rmdir_ctrl(rdtgrp, tmpmask); - } - } else if (rdtgrp->type == RDTMON_GROUP && - is_mon_groups(parent_kn, rdt_kn_name(kn))) { - ret = rdtgroup_rmdir_mon(rdtgrp, tmpmask); - } else { - ret = -EPERM; - } - -out: - rdtgroup_kn_unlock(kn); - free_cpumask_var(tmpmask); - return ret; -} - -/** - * mongrp_reparent() - replace parent CTRL_MON group of a MON group - * @rdtgrp: the MON group whose parent should be replaced - * @new_prdtgrp: replacement parent CTRL_MON group for @rdtgrp - * @cpus: cpumask provided by the caller for use during this call - * - * Replaces the parent CTRL_MON group for a MON group, resulting in all member - * tasks' CLOSID immediately changing to that of the new parent group. - * Monitoring data for the group is unaffected by this operation. - */ -static void mongrp_reparent(struct rdtgroup *rdtgrp, - struct rdtgroup *new_prdtgrp, - cpumask_var_t cpus) -{ - struct rdtgroup *prdtgrp = rdtgrp->mon.parent; - - WARN_ON(rdtgrp->type != RDTMON_GROUP); - WARN_ON(new_prdtgrp->type != RDTCTRL_GROUP); - - /* Nothing to do when simply renaming a MON group. */ - if (prdtgrp == new_prdtgrp) - return; - - WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list)); - list_move_tail(&rdtgrp->mon.crdtgrp_list, - &new_prdtgrp->mon.crdtgrp_list); - - rdtgrp->mon.parent = new_prdtgrp; - rdtgrp->closid = new_prdtgrp->closid; - - /* Propagate updated closid to all tasks in this group. */ - rdt_move_group_tasks(rdtgrp, rdtgrp, cpus); - - update_closid_rmid(cpus, NULL); -} - -static int rdtgroup_rename(struct kernfs_node *kn, - struct kernfs_node *new_parent, const char *new_name) -{ - struct kernfs_node *kn_parent; - struct rdtgroup *new_prdtgrp; - struct rdtgroup *rdtgrp; - cpumask_var_t tmpmask; - int ret; - - rdtgrp = kernfs_to_rdtgroup(kn); - new_prdtgrp = kernfs_to_rdtgroup(new_parent); - if (!rdtgrp || !new_prdtgrp) - return -ENOENT; - - /* Release both kernfs active_refs before obtaining rdtgroup mutex. */ - rdtgroup_kn_get(rdtgrp, kn); - rdtgroup_kn_get(new_prdtgrp, new_parent); - - mutex_lock(&rdtgroup_mutex); - - rdt_last_cmd_clear(); - - /* - * Don't allow kernfs_to_rdtgroup() to return a parent rdtgroup if - * either kernfs_node is a file. - */ - if (kernfs_type(kn) != KERNFS_DIR || - kernfs_type(new_parent) != KERNFS_DIR) { - rdt_last_cmd_puts("Source and destination must be directories"); - ret = -EPERM; - goto out; - } - - if ((rdtgrp->flags & RDT_DELETED) || (new_prdtgrp->flags & RDT_DELETED)) { - ret = -ENOENT; - goto out; - } - - kn_parent = rdt_kn_parent(kn); - if (rdtgrp->type != RDTMON_GROUP || !kn_parent || - !is_mon_groups(kn_parent, rdt_kn_name(kn))) { - rdt_last_cmd_puts("Source must be a MON group\n"); - ret = -EPERM; - goto out; - } - - if (!is_mon_groups(new_parent, new_name)) { - rdt_last_cmd_puts("Destination must be a mon_groups subdirectory\n"); - ret = -EPERM; - goto out; - } - - /* - * If the MON group is monitoring CPUs, the CPUs must be assigned to the - * current parent CTRL_MON group and therefore cannot be assigned to - * the new parent, making the move illegal. - */ - if (!cpumask_empty(&rdtgrp->cpu_mask) && - rdtgrp->mon.parent != new_prdtgrp) { - rdt_last_cmd_puts("Cannot move a MON group that monitors CPUs\n"); - ret = -EPERM; - goto out; - } - - /* - * Allocate the cpumask for use in mongrp_reparent() to avoid the - * possibility of failing to allocate it after kernfs_rename() has - * succeeded. - */ - if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) { - ret = -ENOMEM; - goto out; - } - - /* - * Perform all input validation and allocations needed to ensure - * mongrp_reparent() will succeed before calling kernfs_rename(), - * otherwise it would be necessary to revert this call if - * mongrp_reparent() failed. - */ - ret = kernfs_rename(kn, new_parent, new_name); - if (!ret) - mongrp_reparent(rdtgrp, new_prdtgrp, tmpmask); - - free_cpumask_var(tmpmask); - -out: - mutex_unlock(&rdtgroup_mutex); - rdtgroup_kn_put(rdtgrp, kn); - rdtgroup_kn_put(new_prdtgrp, new_parent); - return ret; -} - -static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf) -{ - if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3)) - seq_puts(seq, ",cdp"); - - if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2)) - seq_puts(seq, ",cdpl2"); - - if (is_mba_sc(resctrl_arch_get_resource(RDT_RESOURCE_MBA))) - seq_puts(seq, ",mba_MBps"); - - if (resctrl_debug) - seq_puts(seq, ",debug"); - - return 0; -} - -static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = { - .mkdir = rdtgroup_mkdir, - .rmdir = rdtgroup_rmdir, - .rename = rdtgroup_rename, - .show_options = rdtgroup_show_options, -}; - -static int rdtgroup_setup_root(struct rdt_fs_context *ctx) -{ - rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops, - KERNFS_ROOT_CREATE_DEACTIVATED | - KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK, - &rdtgroup_default); - if (IS_ERR(rdt_root)) - return PTR_ERR(rdt_root); - - ctx->kfc.root = rdt_root; - rdtgroup_default.kn = kernfs_root_to_node(rdt_root); - - return 0; -} - -static void rdtgroup_destroy_root(void) -{ - lockdep_assert_held(&rdtgroup_mutex); - - kernfs_destroy_root(rdt_root); - rdtgroup_default.kn = NULL; -} - -static void rdtgroup_setup_default(void) -{ - mutex_lock(&rdtgroup_mutex); - - rdtgroup_default.closid = RESCTRL_RESERVED_CLOSID; - rdtgroup_default.mon.rmid = RESCTRL_RESERVED_RMID; - rdtgroup_default.type = RDTCTRL_GROUP; - INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list); - - list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups); - - mutex_unlock(&rdtgroup_mutex); -} - -static void domain_destroy_mon_state(struct rdt_mon_domain *d) -{ - bitmap_free(d->rmid_busy_llc); - kfree(d->mbm_total); - kfree(d->mbm_local); -} - -void resctrl_offline_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d) -{ - mutex_lock(&rdtgroup_mutex); - - if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA) - mba_sc_domain_destroy(r, d); - - mutex_unlock(&rdtgroup_mutex); -} - -void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d) -{ - mutex_lock(&rdtgroup_mutex); - - /* - * If resctrl is mounted, remove all the - * per domain monitor data directories. - */ - if (resctrl_mounted && resctrl_arch_mon_capable()) - rmdir_mondata_subdir_allrdtgrp(r, d); - - if (resctrl_is_mbm_enabled()) - cancel_delayed_work(&d->mbm_over); - if (resctrl_arch_is_llc_occupancy_enabled() && has_busy_rmid(d)) { - /* - * When a package is going down, forcefully - * decrement rmid->ebusy. There is no way to know - * that the L3 was flushed and hence may lead to - * incorrect counts in rare scenarios, but leaving - * the RMID as busy creates RMID leaks if the - * package never comes back. - */ - __check_limbo(d, true); - cancel_delayed_work(&d->cqm_limbo); - } - - domain_destroy_mon_state(d); - - mutex_unlock(&rdtgroup_mutex); -} - -/** - * domain_setup_mon_state() - Initialise domain monitoring structures. - * @r: The resource for the newly online domain. - * @d: The newly online domain. - * - * Allocate monitor resources that belong to this domain. - * Called when the first CPU of a domain comes online, regardless of whether - * the filesystem is mounted. - * During boot this may be called before global allocations have been made by - * resctrl_mon_resource_init(). - * - * Returns 0 for success, or -ENOMEM. - */ -static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_mon_domain *d) -{ - u32 idx_limit = resctrl_arch_system_num_rmid_idx(); - size_t tsize; - - if (resctrl_arch_is_llc_occupancy_enabled()) { - d->rmid_busy_llc = bitmap_zalloc(idx_limit, GFP_KERNEL); - if (!d->rmid_busy_llc) - return -ENOMEM; - } - if (resctrl_arch_is_mbm_total_enabled()) { - tsize = sizeof(*d->mbm_total); - d->mbm_total = kcalloc(idx_limit, tsize, GFP_KERNEL); - if (!d->mbm_total) { - bitmap_free(d->rmid_busy_llc); - return -ENOMEM; - } - } - if (resctrl_arch_is_mbm_local_enabled()) { - tsize = sizeof(*d->mbm_local); - d->mbm_local = kcalloc(idx_limit, tsize, GFP_KERNEL); - if (!d->mbm_local) { - bitmap_free(d->rmid_busy_llc); - kfree(d->mbm_total); - return -ENOMEM; - } - } - - return 0; -} - -int resctrl_online_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d) -{ - int err = 0; - - mutex_lock(&rdtgroup_mutex); - - if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA) { - /* RDT_RESOURCE_MBA is never mon_capable */ - err = mba_sc_domain_allocate(r, d); - } - - mutex_unlock(&rdtgroup_mutex); - - return err; -} - -int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d) -{ - int err; - - mutex_lock(&rdtgroup_mutex); - - err = domain_setup_mon_state(r, d); - if (err) - goto out_unlock; - - if (resctrl_is_mbm_enabled()) { - INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow); - mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL, - RESCTRL_PICK_ANY_CPU); - } - - if (resctrl_arch_is_llc_occupancy_enabled()) - INIT_DELAYED_WORK(&d->cqm_limbo, cqm_handle_limbo); - - /* - * If the filesystem is not mounted then only the default resource group - * exists. Creation of its directories is deferred until mount time - * by rdt_get_tree() calling mkdir_mondata_all(). - * If resctrl is mounted, add per domain monitor data directories. - */ - if (resctrl_mounted && resctrl_arch_mon_capable()) - mkdir_mondata_subdir_allrdtgrp(r, d); - -out_unlock: - mutex_unlock(&rdtgroup_mutex); - - return err; -} - -void resctrl_online_cpu(unsigned int cpu) -{ - mutex_lock(&rdtgroup_mutex); - /* The CPU is set in default rdtgroup after online. */ - cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask); - mutex_unlock(&rdtgroup_mutex); -} - -static void clear_childcpus(struct rdtgroup *r, unsigned int cpu) -{ - struct rdtgroup *cr; - - list_for_each_entry(cr, &r->mon.crdtgrp_list, mon.crdtgrp_list) { - if (cpumask_test_and_clear_cpu(cpu, &cr->cpu_mask)) - break; - } -} - -static struct rdt_mon_domain *get_mon_domain_from_cpu(int cpu, - struct rdt_resource *r) -{ - struct rdt_mon_domain *d; - - lockdep_assert_cpus_held(); - - list_for_each_entry(d, &r->mon_domains, hdr.list) { - /* Find the domain that contains this CPU */ - if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask)) - return d; - } - - return NULL; -} - -void resctrl_offline_cpu(unsigned int cpu) -{ - struct rdt_resource *l3 = resctrl_arch_get_resource(RDT_RESOURCE_L3); - struct rdt_mon_domain *d; - struct rdtgroup *rdtgrp; - - mutex_lock(&rdtgroup_mutex); - list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { - if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask)) { - clear_childcpus(rdtgrp, cpu); - break; - } - } - - if (!l3->mon_capable) - goto out_unlock; - - d = get_mon_domain_from_cpu(cpu, l3); - if (d) { - if (resctrl_is_mbm_enabled() && cpu == d->mbm_work_cpu) { - cancel_delayed_work(&d->mbm_over); - mbm_setup_overflow_handler(d, 0, cpu); - } - if (resctrl_arch_is_llc_occupancy_enabled() && - cpu == d->cqm_work_cpu && has_busy_rmid(d)) { - cancel_delayed_work(&d->cqm_limbo); - cqm_setup_limbo_handler(d, 0, cpu); - } - } - -out_unlock: - mutex_unlock(&rdtgroup_mutex); -} - -/* - * resctrl_init - resctrl filesystem initialization - * - * Setup resctrl file system including set up root, create mount point, - * register resctrl filesystem, and initialize files under root directory. - * - * Return: 0 on success or -errno - */ -int resctrl_init(void) -{ - int ret = 0; - - seq_buf_init(&last_cmd_status, last_cmd_status_buf, - sizeof(last_cmd_status_buf)); - - rdtgroup_setup_default(); - - thread_throttle_mode_init(); - - ret = resctrl_mon_resource_init(); - if (ret) - return ret; - - ret = sysfs_create_mount_point(fs_kobj, "resctrl"); - if (ret) { - resctrl_mon_resource_exit(); - return ret; - } - - ret = register_filesystem(&rdt_fs_type); - if (ret) - goto cleanup_mountpoint; - - /* - * Adding the resctrl debugfs directory here may not be ideal since - * it would let the resctrl debugfs directory appear on the debugfs - * filesystem before the resctrl filesystem is mounted. - * It may also be ok since that would enable debugging of RDT before - * resctrl is mounted. - * The reason why the debugfs directory is created here and not in - * rdt_get_tree() is because rdt_get_tree() takes rdtgroup_mutex and - * during the debugfs directory creation also &sb->s_type->i_mutex_key - * (the lockdep class of inode->i_rwsem). Other filesystem - * interactions (eg. SyS_getdents) have the lock ordering: - * &sb->s_type->i_mutex_key --> &mm->mmap_lock - * During mmap(), called with &mm->mmap_lock, the rdtgroup_mutex - * is taken, thus creating dependency: - * &mm->mmap_lock --> rdtgroup_mutex for the latter that can cause - * issues considering the other two lock dependencies. - * By creating the debugfs directory here we avoid a dependency - * that may cause deadlock (even though file operations cannot - * occur until the filesystem is mounted, but I do not know how to - * tell lockdep that). - */ - debugfs_resctrl = debugfs_create_dir("resctrl", NULL); - - return 0; - -cleanup_mountpoint: - sysfs_remove_mount_point(fs_kobj, "resctrl"); - resctrl_mon_resource_exit(); - - return ret; -} - -static bool resctrl_online_domains_exist(void) -{ - struct rdt_resource *r; - - /* - * Only walk capable resources to allow resctrl_arch_get_resource() - * to return dummy 'not capable' resources. - */ - for_each_alloc_capable_rdt_resource(r) { - if (!list_empty(&r->ctrl_domains)) - return true; - } - - for_each_mon_capable_rdt_resource(r) { - if (!list_empty(&r->mon_domains)) - return true; - } - - return false; -} - -/** - * resctrl_exit() - Remove the resctrl filesystem and free resources. - * - * Called by the architecture code in response to a fatal error. - * Removes resctrl files and structures from kernfs to prevent further - * configuration. - * - * When called by the architecture code, all CPUs and resctrl domains must be - * offline. This ensures the limbo and overflow handlers are not scheduled to - * run, meaning the data structures they access can be freed by - * resctrl_mon_resource_exit(). - * - * After resctrl_exit() returns, the architecture code should return an - * error from all resctrl_arch_ functions that can do this. - * resctrl_arch_get_resource() must continue to return struct rdt_resources - * with the correct rid field to ensure the filesystem can be unmounted. - */ -void resctrl_exit(void) -{ - cpus_read_lock(); - WARN_ON_ONCE(resctrl_online_domains_exist()); - - mutex_lock(&rdtgroup_mutex); - resctrl_fs_teardown(); - mutex_unlock(&rdtgroup_mutex); - - cpus_read_unlock(); - - debugfs_remove_recursive(debugfs_resctrl); - debugfs_resctrl = NULL; - unregister_filesystem(&rdt_fs_type); - - /* - * Do not remove the sysfs mount point added by resctrl_init() so that - * it can be used to umount resctrl. - */ - - resctrl_mon_resource_exit(); + return; } diff --git a/fs/resctrl/Kconfig b/fs/resctrl/Kconfig index 478a8e2ad99f..21671301bd8a 100644 --- a/fs/resctrl/Kconfig +++ b/fs/resctrl/Kconfig @@ -21,7 +21,7 @@ config RESCTRL_FS On architectures where this can be disabled independently, it is safe to say N. - See for more information. + See for more information. config RESCTRL_FS_PSEUDO_LOCK bool diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c index e69de29bb2d1..6ed2dfd4dbbd 100644 --- a/fs/resctrl/ctrlmondata.c +++ b/fs/resctrl/ctrlmondata.c @@ -0,0 +1,661 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Resource Director Technology(RDT) + * - Cache Allocation code. + * + * Copyright (C) 2016 Intel Corporation + * + * Authors: + * Fenghua Yu + * Tony Luck + * + * More information about RDT be found in the Intel (R) x86 Architecture + * Software Developer Manual June 2016, volume 3, section 17.17. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include + +#include "internal.h" + +struct rdt_parse_data { + struct rdtgroup *rdtgrp; + char *buf; +}; + +typedef int (ctrlval_parser_t)(struct rdt_parse_data *data, + struct resctrl_schema *s, + struct rdt_ctrl_domain *d); + +/* + * Check whether MBA bandwidth percentage value is correct. The value is + * checked against the minimum and max bandwidth values specified by the + * hardware. The allocated bandwidth percentage is rounded to the next + * control step available on the hardware. + */ +static bool bw_validate(char *buf, u32 *data, struct rdt_resource *r) +{ + int ret; + u32 bw; + + /* + * Only linear delay values is supported for current Intel SKUs. + */ + if (!r->membw.delay_linear && r->membw.arch_needs_linear) { + rdt_last_cmd_puts("No support for non-linear MB domains\n"); + return false; + } + + ret = kstrtou32(buf, 10, &bw); + if (ret) { + rdt_last_cmd_printf("Invalid MB value %s\n", buf); + return false; + } + + /* Nothing else to do if software controller is enabled. */ + if (is_mba_sc(r)) { + *data = bw; + return true; + } + + if (bw < r->membw.min_bw || bw > r->membw.max_bw) { + rdt_last_cmd_printf("MB value %u out of range [%d,%d]\n", + bw, r->membw.min_bw, r->membw.max_bw); + return false; + } + + *data = roundup(bw, (unsigned long)r->membw.bw_gran); + return true; +} + +static int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s, + struct rdt_ctrl_domain *d) +{ + struct resctrl_staged_config *cfg; + u32 closid = data->rdtgrp->closid; + struct rdt_resource *r = s->res; + u32 bw_val; + + cfg = &d->staged_config[s->conf_type]; + if (cfg->have_new_ctrl) { + rdt_last_cmd_printf("Duplicate domain %d\n", d->hdr.id); + return -EINVAL; + } + + if (!bw_validate(data->buf, &bw_val, r)) + return -EINVAL; + + if (is_mba_sc(r)) { + d->mbps_val[closid] = bw_val; + return 0; + } + + cfg->new_ctrl = bw_val; + cfg->have_new_ctrl = true; + + return 0; +} + +/* + * Check whether a cache bit mask is valid. + * On Intel CPUs, non-contiguous 1s value support is indicated by CPUID: + * - CPUID.0x10.1:ECX[3]: L3 non-contiguous 1s value supported if 1 + * - CPUID.0x10.2:ECX[3]: L2 non-contiguous 1s value supported if 1 + * + * Haswell does not support a non-contiguous 1s value and additionally + * requires at least two bits set. + * AMD allows non-contiguous bitmasks. + */ +static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r) +{ + u32 supported_bits = BIT_MASK(r->cache.cbm_len) - 1; + unsigned int cbm_len = r->cache.cbm_len; + unsigned long first_bit, zero_bit, val; + int ret; + + ret = kstrtoul(buf, 16, &val); + if (ret) { + rdt_last_cmd_printf("Non-hex character in the mask %s\n", buf); + return false; + } + + if ((r->cache.min_cbm_bits > 0 && val == 0) || val > supported_bits) { + rdt_last_cmd_puts("Mask out of range\n"); + return false; + } + + first_bit = find_first_bit(&val, cbm_len); + zero_bit = find_next_zero_bit(&val, cbm_len, first_bit); + + /* Are non-contiguous bitmasks allowed? */ + if (!r->cache.arch_has_sparse_bitmasks && + (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)) { + rdt_last_cmd_printf("The mask %lx has non-consecutive 1-bits\n", val); + return false; + } + + if ((zero_bit - first_bit) < r->cache.min_cbm_bits) { + rdt_last_cmd_printf("Need at least %d bits in the mask\n", + r->cache.min_cbm_bits); + return false; + } + + *data = val; + return true; +} + +/* + * Read one cache bit mask (hex). Check that it is valid for the current + * resource type. + */ +static int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s, + struct rdt_ctrl_domain *d) +{ + struct rdtgroup *rdtgrp = data->rdtgrp; + struct resctrl_staged_config *cfg; + struct rdt_resource *r = s->res; + u32 cbm_val; + + cfg = &d->staged_config[s->conf_type]; + if (cfg->have_new_ctrl) { + rdt_last_cmd_printf("Duplicate domain %d\n", d->hdr.id); + return -EINVAL; + } + + /* + * Cannot set up more than one pseudo-locked region in a cache + * hierarchy. + */ + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP && + rdtgroup_pseudo_locked_in_hierarchy(d)) { + rdt_last_cmd_puts("Pseudo-locked region in hierarchy\n"); + return -EINVAL; + } + + if (!cbm_validate(data->buf, &cbm_val, r)) + return -EINVAL; + + if ((rdtgrp->mode == RDT_MODE_EXCLUSIVE || + rdtgrp->mode == RDT_MODE_SHAREABLE) && + rdtgroup_cbm_overlaps_pseudo_locked(d, cbm_val)) { + rdt_last_cmd_puts("CBM overlaps with pseudo-locked region\n"); + return -EINVAL; + } + + /* + * The CBM may not overlap with the CBM of another closid if + * either is exclusive. + */ + if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, true)) { + rdt_last_cmd_puts("Overlaps with exclusive group\n"); + return -EINVAL; + } + + if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, false)) { + if (rdtgrp->mode == RDT_MODE_EXCLUSIVE || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + rdt_last_cmd_puts("Overlaps with other group\n"); + return -EINVAL; + } + } + + cfg->new_ctrl = cbm_val; + cfg->have_new_ctrl = true; + + return 0; +} + +/* + * For each domain in this resource we expect to find a series of: + * id=mask + * separated by ";". The "id" is in decimal, and must match one of + * the "id"s for this resource. + */ +static int parse_line(char *line, struct resctrl_schema *s, + struct rdtgroup *rdtgrp) +{ + enum resctrl_conf_type t = s->conf_type; + ctrlval_parser_t *parse_ctrlval = NULL; + struct resctrl_staged_config *cfg; + struct rdt_resource *r = s->res; + struct rdt_parse_data data; + struct rdt_ctrl_domain *d; + char *dom = NULL, *id; + unsigned long dom_id; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + switch (r->schema_fmt) { + case RESCTRL_SCHEMA_BITMAP: + parse_ctrlval = &parse_cbm; + break; + case RESCTRL_SCHEMA_RANGE: + parse_ctrlval = &parse_bw; + break; + } + + if (WARN_ON_ONCE(!parse_ctrlval)) + return -EINVAL; + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP && + (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)) { + rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n"); + return -EINVAL; + } + +next: + if (!line || line[0] == '\0') + return 0; + dom = strsep(&line, ";"); + id = strsep(&dom, "="); + if (!dom || kstrtoul(id, 10, &dom_id)) { + rdt_last_cmd_puts("Missing '=' or non-numeric domain\n"); + return -EINVAL; + } + dom = strim(dom); + list_for_each_entry(d, &r->ctrl_domains, hdr.list) { + if (d->hdr.id == dom_id) { + data.buf = dom; + data.rdtgrp = rdtgrp; + if (parse_ctrlval(&data, s, d)) + return -EINVAL; + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + cfg = &d->staged_config[t]; + /* + * In pseudo-locking setup mode and just + * parsed a valid CBM that should be + * pseudo-locked. Only one locked region per + * resource group and domain so just do + * the required initialization for single + * region and return. + */ + rdtgrp->plr->s = s; + rdtgrp->plr->d = d; + rdtgrp->plr->cbm = cfg->new_ctrl; + d->plr = rdtgrp->plr; + return 0; + } + goto next; + } + } + return -EINVAL; +} + +static int rdtgroup_parse_resource(char *resname, char *tok, + struct rdtgroup *rdtgrp) +{ + struct resctrl_schema *s; + + list_for_each_entry(s, &resctrl_schema_all, list) { + if (!strcmp(resname, s->name) && rdtgrp->closid < s->num_closid) + return parse_line(tok, s, rdtgrp); + } + rdt_last_cmd_printf("Unknown or unsupported resource name '%s'\n", resname); + return -EINVAL; +} + +ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct resctrl_schema *s; + struct rdtgroup *rdtgrp; + struct rdt_resource *r; + char *tok, *resname; + int ret = 0; + + /* Valid input requires a trailing newline */ + if (nbytes == 0 || buf[nbytes - 1] != '\n') + return -EINVAL; + buf[nbytes - 1] = '\0'; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + rdtgroup_kn_unlock(of->kn); + return -ENOENT; + } + rdt_last_cmd_clear(); + + /* + * No changes to pseudo-locked region allowed. It has to be removed + * and re-created instead. + */ + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + ret = -EINVAL; + rdt_last_cmd_puts("Resource group is pseudo-locked\n"); + goto out; + } + + rdt_staged_configs_clear(); + + while ((tok = strsep(&buf, "\n")) != NULL) { + resname = strim(strsep(&tok, ":")); + if (!tok) { + rdt_last_cmd_puts("Missing ':'\n"); + ret = -EINVAL; + goto out; + } + if (tok[0] == '\0') { + rdt_last_cmd_printf("Missing '%s' value\n", resname); + ret = -EINVAL; + goto out; + } + ret = rdtgroup_parse_resource(resname, tok, rdtgrp); + if (ret) + goto out; + } + + list_for_each_entry(s, &resctrl_schema_all, list) { + r = s->res; + + /* + * Writes to mba_sc resources update the software controller, + * not the control MSR. + */ + if (is_mba_sc(r)) + continue; + + ret = resctrl_arch_update_domains(r, rdtgrp->closid); + if (ret) + goto out; + } + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + /* + * If pseudo-locking fails we keep the resource group in + * mode RDT_MODE_PSEUDO_LOCKSETUP with its class of service + * active and updated for just the domain the pseudo-locked + * region was requested for. + */ + ret = rdtgroup_pseudo_lock_create(rdtgrp); + } + +out: + rdt_staged_configs_clear(); + rdtgroup_kn_unlock(of->kn); + return ret ?: nbytes; +} + +static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid) +{ + struct rdt_resource *r = schema->res; + struct rdt_ctrl_domain *dom; + bool sep = false; + u32 ctrl_val; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + seq_printf(s, "%*s:", max_name_width, schema->name); + list_for_each_entry(dom, &r->ctrl_domains, hdr.list) { + if (sep) + seq_puts(s, ";"); + + if (is_mba_sc(r)) + ctrl_val = dom->mbps_val[closid]; + else + ctrl_val = resctrl_arch_get_config(r, dom, closid, + schema->conf_type); + + seq_printf(s, schema->fmt_str, dom->hdr.id, ctrl_val); + sep = true; + } + seq_puts(s, "\n"); +} + +int rdtgroup_schemata_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct resctrl_schema *schema; + struct rdtgroup *rdtgrp; + int ret = 0; + u32 closid; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (rdtgrp) { + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + list_for_each_entry(schema, &resctrl_schema_all, list) { + seq_printf(s, "%s:uninitialized\n", schema->name); + } + } else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + if (!rdtgrp->plr->d) { + rdt_last_cmd_clear(); + rdt_last_cmd_puts("Cache domain offline\n"); + ret = -ENODEV; + } else { + seq_printf(s, "%s:%d=%x\n", + rdtgrp->plr->s->res->name, + rdtgrp->plr->d->hdr.id, + rdtgrp->plr->cbm); + } + } else { + closid = rdtgrp->closid; + list_for_each_entry(schema, &resctrl_schema_all, list) { + if (closid < schema->num_closid) + show_doms(s, schema, closid); + } + } + } else { + ret = -ENOENT; + } + rdtgroup_kn_unlock(of->kn); + return ret; +} + +static int smp_mon_event_count(void *arg) +{ + mon_event_count(arg); + + return 0; +} + +ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct rdtgroup *rdtgrp; + int ret = 0; + + /* Valid input requires a trailing newline */ + if (nbytes == 0 || buf[nbytes - 1] != '\n') + return -EINVAL; + buf[nbytes - 1] = '\0'; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + rdtgroup_kn_unlock(of->kn); + return -ENOENT; + } + rdt_last_cmd_clear(); + + if (!strcmp(buf, "mbm_local_bytes")) { + if (resctrl_arch_is_mbm_local_enabled()) + rdtgrp->mba_mbps_event = QOS_L3_MBM_LOCAL_EVENT_ID; + else + ret = -EINVAL; + } else if (!strcmp(buf, "mbm_total_bytes")) { + if (resctrl_arch_is_mbm_total_enabled()) + rdtgrp->mba_mbps_event = QOS_L3_MBM_TOTAL_EVENT_ID; + else + ret = -EINVAL; + } else { + ret = -EINVAL; + } + + if (ret) + rdt_last_cmd_printf("Unsupported event id '%s'\n", buf); + + rdtgroup_kn_unlock(of->kn); + + return ret ?: nbytes; +} + +int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + + if (rdtgrp) { + switch (rdtgrp->mba_mbps_event) { + case QOS_L3_MBM_LOCAL_EVENT_ID: + seq_puts(s, "mbm_local_bytes\n"); + break; + case QOS_L3_MBM_TOTAL_EVENT_ID: + seq_puts(s, "mbm_total_bytes\n"); + break; + default: + pr_warn_once("Bad event %d\n", rdtgrp->mba_mbps_event); + ret = -EINVAL; + break; + } + } else { + ret = -ENOENT; + } + + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +struct rdt_domain_hdr *resctrl_find_domain(struct list_head *h, int id, + struct list_head **pos) +{ + struct rdt_domain_hdr *d; + struct list_head *l; + + list_for_each(l, h) { + d = list_entry(l, struct rdt_domain_hdr, list); + /* When id is found, return its domain. */ + if (id == d->id) + return d; + /* Stop searching when finding id's position in sorted list. */ + if (id < d->id) + break; + } + + if (pos) + *pos = l; + + return NULL; +} + +void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, + struct rdt_mon_domain *d, struct rdtgroup *rdtgrp, + cpumask_t *cpumask, int evtid, int first) +{ + int cpu; + + /* When picking a CPU from cpu_mask, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + /* + * Setup the parameters to pass to mon_event_count() to read the data. + */ + rr->rgrp = rdtgrp; + rr->evtid = evtid; + rr->r = r; + rr->d = d; + rr->first = first; + rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid); + if (IS_ERR(rr->arch_mon_ctx)) { + rr->err = -EINVAL; + return; + } + + cpu = cpumask_any_housekeeping(cpumask, RESCTRL_PICK_ANY_CPU); + + /* + * cpumask_any_housekeeping() prefers housekeeping CPUs, but + * are all the CPUs nohz_full? If yes, pick a CPU to IPI. + * MPAM's resctrl_arch_rmid_read() is unable to read the + * counters on some platforms if its called in IRQ context. + */ + if (tick_nohz_full_cpu(cpu)) + smp_call_function_any(cpumask, mon_event_count, rr, 1); + else + smp_call_on_cpu(cpu, smp_mon_event_count, rr, false); + + resctrl_arch_mon_ctx_free(r, evtid, rr->arch_mon_ctx); +} + +int rdtgroup_mondata_show(struct seq_file *m, void *arg) +{ + struct kernfs_open_file *of = m->private; + enum resctrl_res_level resid; + enum resctrl_event_id evtid; + struct rdt_domain_hdr *hdr; + struct rmid_read rr = {0}; + struct rdt_mon_domain *d; + struct rdtgroup *rdtgrp; + struct rdt_resource *r; + struct mon_data *md; + int domid, ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + ret = -ENOENT; + goto out; + } + + md = of->kn->priv; + if (WARN_ON_ONCE(!md)) { + ret = -EIO; + goto out; + } + + resid = md->rid; + domid = md->domid; + evtid = md->evtid; + r = resctrl_arch_get_resource(resid); + + if (md->sum) { + /* + * This file requires summing across all domains that share + * the L3 cache id that was provided in the "domid" field of the + * struct mon_data. Search all domains in the resource for + * one that matches this cache id. + */ + list_for_each_entry(d, &r->mon_domains, hdr.list) { + if (d->ci->id == domid) { + rr.ci = d->ci; + mon_event_read(&rr, r, NULL, rdtgrp, + &d->ci->shared_cpu_map, evtid, false); + goto checkresult; + } + } + ret = -ENOENT; + goto out; + } else { + /* + * This file provides data from a single domain. Search + * the resource to find the domain with "domid". + */ + hdr = resctrl_find_domain(&r->mon_domains, domid, NULL); + if (!hdr || WARN_ON_ONCE(hdr->type != RESCTRL_MON_DOMAIN)) { + ret = -ENOENT; + goto out; + } + d = container_of(hdr, struct rdt_mon_domain, hdr); + mon_event_read(&rr, r, d, rdtgrp, &d->hdr.cpu_mask, evtid, false); + } + +checkresult: + + if (rr.err == -EIO) + seq_puts(m, "Error\n"); + else if (rr.err == -EINVAL) + seq_puts(m, "Unavailable\n"); + else + seq_printf(m, "%llu\n", rr.val); + +out: + rdtgroup_kn_unlock(of->kn); + return ret; +} diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h index e69de29bb2d1..9a8cf6f11151 100644 --- a/fs/resctrl/internal.h +++ b/fs/resctrl/internal.h @@ -0,0 +1,426 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _FS_RESCTRL_INTERNAL_H +#define _FS_RESCTRL_INTERNAL_H + +#include +#include +#include +#include + +#define CQM_LIMBOCHECK_INTERVAL 1000 + +/** + * cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that + * aren't marked nohz_full + * @mask: The mask to pick a CPU from. + * @exclude_cpu:The CPU to avoid picking. + * + * Returns a CPU from @mask, but not @exclude_cpu. If there are housekeeping + * CPUs that don't use nohz_full, these are preferred. Pass + * RESCTRL_PICK_ANY_CPU to avoid excluding any CPUs. + * + * When a CPU is excluded, returns >= nr_cpu_ids if no CPUs are available. + */ +static inline unsigned int +cpumask_any_housekeeping(const struct cpumask *mask, int exclude_cpu) +{ + unsigned int cpu; + + /* Try to find a CPU that isn't nohz_full to use in preference */ + if (tick_nohz_full_enabled()) { + cpu = cpumask_any_andnot_but(mask, tick_nohz_full_mask, exclude_cpu); + if (cpu < nr_cpu_ids) + return cpu; + } + + return cpumask_any_but(mask, exclude_cpu); +} + +struct rdt_fs_context { + struct kernfs_fs_context kfc; + bool enable_cdpl2; + bool enable_cdpl3; + bool enable_mba_mbps; + bool enable_debug; +}; + +static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc) +{ + struct kernfs_fs_context *kfc = fc->fs_private; + + return container_of(kfc, struct rdt_fs_context, kfc); +} + +/** + * struct mon_evt - Entry in the event list of a resource + * @evtid: event id + * @name: name of the event + * @configurable: true if the event is configurable + * @list: entry in &rdt_resource->evt_list + */ +struct mon_evt { + enum resctrl_event_id evtid; + char *name; + bool configurable; + struct list_head list; +}; + +/** + * struct mon_data - Monitoring details for each event file. + * @list: Member of the global @mon_data_kn_priv_list list. + * @rid: Resource id associated with the event file. + * @evtid: Event id associated with the event file. + * @sum: Set when event must be summed across multiple + * domains. + * @domid: When @sum is zero this is the domain to which + * the event file belongs. When @sum is one this + * is the id of the L3 cache that all domains to be + * summed share. + * + * Pointed to by the kernfs kn->priv field of monitoring event files. + * Readers and writers must hold rdtgroup_mutex. + */ +struct mon_data { + struct list_head list; + enum resctrl_res_level rid; + enum resctrl_event_id evtid; + int domid; + bool sum; +}; + +/** + * struct rmid_read - Data passed across smp_call*() to read event count. + * @rgrp: Resource group for which the counter is being read. If it is a parent + * resource group then its event count is summed with the count from all + * its child resource groups. + * @r: Resource describing the properties of the event being read. + * @d: Domain that the counter should be read from. If NULL then sum all + * domains in @r sharing L3 @ci.id + * @evtid: Which monitor event to read. + * @first: Initialize MBM counter when true. + * @ci: Cacheinfo for L3. Only set when @d is NULL. Used when summing domains. + * @err: Error encountered when reading counter. + * @val: Returned value of event counter. If @rgrp is a parent resource group, + * @val includes the sum of event counts from its child resource groups. + * If @d is NULL, @val includes the sum of all domains in @r sharing @ci.id, + * (summed across child resource groups if @rgrp is a parent resource group). + * @arch_mon_ctx: Hardware monitor allocated for this read request (MPAM only). + */ +struct rmid_read { + struct rdtgroup *rgrp; + struct rdt_resource *r; + struct rdt_mon_domain *d; + enum resctrl_event_id evtid; + bool first; + struct cacheinfo *ci; + int err; + u64 val; + void *arch_mon_ctx; +}; + +extern struct list_head resctrl_schema_all; + +extern bool resctrl_mounted; + +enum rdt_group_type { + RDTCTRL_GROUP = 0, + RDTMON_GROUP, + RDT_NUM_GROUP, +}; + +/** + * enum rdtgrp_mode - Mode of a RDT resource group + * @RDT_MODE_SHAREABLE: This resource group allows sharing of its allocations + * @RDT_MODE_EXCLUSIVE: No sharing of this resource group's allocations allowed + * @RDT_MODE_PSEUDO_LOCKSETUP: Resource group will be used for Pseudo-Locking + * @RDT_MODE_PSEUDO_LOCKED: No sharing of this resource group's allocations + * allowed AND the allocations are Cache Pseudo-Locked + * @RDT_NUM_MODES: Total number of modes + * + * The mode of a resource group enables control over the allowed overlap + * between allocations associated with different resource groups (classes + * of service). User is able to modify the mode of a resource group by + * writing to the "mode" resctrl file associated with the resource group. + * + * The "shareable", "exclusive", and "pseudo-locksetup" modes are set by + * writing the appropriate text to the "mode" file. A resource group enters + * "pseudo-locked" mode after the schemata is written while the resource + * group is in "pseudo-locksetup" mode. + */ +enum rdtgrp_mode { + RDT_MODE_SHAREABLE = 0, + RDT_MODE_EXCLUSIVE, + RDT_MODE_PSEUDO_LOCKSETUP, + RDT_MODE_PSEUDO_LOCKED, + + /* Must be last */ + RDT_NUM_MODES, +}; + +/** + * struct mongroup - store mon group's data in resctrl fs. + * @mon_data_kn: kernfs node for the mon_data directory + * @parent: parent rdtgrp + * @crdtgrp_list: child rdtgroup node list + * @rmid: rmid for this rdtgroup + */ +struct mongroup { + struct kernfs_node *mon_data_kn; + struct rdtgroup *parent; + struct list_head crdtgrp_list; + u32 rmid; +}; + +/** + * struct rdtgroup - store rdtgroup's data in resctrl file system. + * @kn: kernfs node + * @rdtgroup_list: linked list for all rdtgroups + * @closid: closid for this rdtgroup + * @cpu_mask: CPUs assigned to this rdtgroup + * @flags: status bits + * @waitcount: how many cpus expect to find this + * group when they acquire rdtgroup_mutex + * @type: indicates type of this rdtgroup - either + * monitor only or ctrl_mon group + * @mon: mongroup related data + * @mode: mode of resource group + * @mba_mbps_event: input monitoring event id when mba_sc is enabled + * @plr: pseudo-locked region + */ +struct rdtgroup { + struct kernfs_node *kn; + struct list_head rdtgroup_list; + u32 closid; + struct cpumask cpu_mask; + int flags; + atomic_t waitcount; + enum rdt_group_type type; + struct mongroup mon; + enum rdtgrp_mode mode; + enum resctrl_event_id mba_mbps_event; + struct pseudo_lock_region *plr; +}; + +/* rdtgroup.flags */ +#define RDT_DELETED 1 + +/* rftype.flags */ +#define RFTYPE_FLAGS_CPUS_LIST 1 + +/* + * Define the file type flags for base and info directories. + */ +#define RFTYPE_INFO BIT(0) + +#define RFTYPE_BASE BIT(1) + +#define RFTYPE_CTRL BIT(4) + +#define RFTYPE_MON BIT(5) + +#define RFTYPE_TOP BIT(6) + +#define RFTYPE_RES_CACHE BIT(8) + +#define RFTYPE_RES_MB BIT(9) + +#define RFTYPE_DEBUG BIT(10) + +#define RFTYPE_CTRL_INFO (RFTYPE_INFO | RFTYPE_CTRL) + +#define RFTYPE_MON_INFO (RFTYPE_INFO | RFTYPE_MON) + +#define RFTYPE_TOP_INFO (RFTYPE_INFO | RFTYPE_TOP) + +#define RFTYPE_CTRL_BASE (RFTYPE_BASE | RFTYPE_CTRL) + +#define RFTYPE_MON_BASE (RFTYPE_BASE | RFTYPE_MON) + +/* List of all resource groups */ +extern struct list_head rdt_all_groups; + +extern int max_name_width; + +/** + * struct rftype - describe each file in the resctrl file system + * @name: File name + * @mode: Access mode + * @kf_ops: File operations + * @flags: File specific RFTYPE_FLAGS_* flags + * @fflags: File specific RFTYPE_* flags + * @seq_show: Show content of the file + * @write: Write to the file + */ +struct rftype { + char *name; + umode_t mode; + const struct kernfs_ops *kf_ops; + unsigned long flags; + unsigned long fflags; + + int (*seq_show)(struct kernfs_open_file *of, + struct seq_file *sf, void *v); + /* + * write() is the generic write callback which maps directly to + * kernfs write operation and overrides all other operations. + * Maximum write size is determined by ->max_write_len. + */ + ssize_t (*write)(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off); +}; + +/** + * struct mbm_state - status for each MBM counter in each domain + * @prev_bw_bytes: Previous bytes value read for bandwidth calculation + * @prev_bw: The most recent bandwidth in MBps + */ +struct mbm_state { + u64 prev_bw_bytes; + u32 prev_bw; +}; + +extern struct mutex rdtgroup_mutex; + +static inline const char *rdt_kn_name(const struct kernfs_node *kn) +{ + return rcu_dereference_check(kn->name, lockdep_is_held(&rdtgroup_mutex)); +} + +extern struct rdtgroup rdtgroup_default; + +extern struct dentry *debugfs_resctrl; + +extern enum resctrl_event_id mba_mbps_default_event; + +void rdt_last_cmd_clear(void); + +void rdt_last_cmd_puts(const char *s); + +__printf(1, 2) +void rdt_last_cmd_printf(const char *fmt, ...); + +struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn); + +void rdtgroup_kn_unlock(struct kernfs_node *kn); + +int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name); + +int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name, + umode_t mask); + +ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off); + +int rdtgroup_schemata_show(struct kernfs_open_file *of, + struct seq_file *s, void *v); + +ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off); + +int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of, + struct seq_file *s, void *v); + +bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d, + unsigned long cbm, int closid, bool exclusive); + +unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, struct rdt_ctrl_domain *d, + unsigned long cbm); + +enum rdtgrp_mode rdtgroup_mode_by_closid(int closid); + +int rdtgroup_tasks_assigned(struct rdtgroup *r); + +int closids_supported(void); + +void closid_free(int closid); + +int alloc_rmid(u32 closid); + +void free_rmid(u32 closid, u32 rmid); + +void resctrl_mon_resource_exit(void); + +void mon_event_count(void *info); + +int rdtgroup_mondata_show(struct seq_file *m, void *arg); + +void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, + struct rdt_mon_domain *d, struct rdtgroup *rdtgrp, + cpumask_t *cpumask, int evtid, int first); + +int resctrl_mon_resource_init(void); + +void mbm_setup_overflow_handler(struct rdt_mon_domain *dom, + unsigned long delay_ms, + int exclude_cpu); + +void mbm_handle_overflow(struct work_struct *work); + +bool is_mba_sc(struct rdt_resource *r); + +void cqm_setup_limbo_handler(struct rdt_mon_domain *dom, unsigned long delay_ms, + int exclude_cpu); + +void cqm_handle_limbo(struct work_struct *work); + +bool has_busy_rmid(struct rdt_mon_domain *d); + +void __check_limbo(struct rdt_mon_domain *d, bool force_free); + +void resctrl_file_fflags_init(const char *config, unsigned long fflags); + +void rdt_staged_configs_clear(void); + +bool closid_allocated(unsigned int closid); + +int resctrl_find_cleanest_closid(void); + +#ifdef CONFIG_RESCTRL_FS_PSEUDO_LOCK +int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp); + +int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp); + +bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm); + +bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d); + +int rdt_pseudo_lock_init(void); + +void rdt_pseudo_lock_release(void); + +int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp); + +void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp); + +#else +static inline int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp) +{ + return -EOPNOTSUPP; +} + +static inline int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp) +{ + return -EOPNOTSUPP; +} + +static inline bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm) +{ + return false; +} + +static inline bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d) +{ + return false; +} + +static inline int rdt_pseudo_lock_init(void) { return 0; } +static inline void rdt_pseudo_lock_release(void) { } +static inline int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp) +{ + return -EOPNOTSUPP; +} + +static inline void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp) { } +#endif /* CONFIG_RESCTRL_FS_PSEUDO_LOCK */ + +#endif /* _FS_RESCTRL_INTERNAL_H */ diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c index e69de29bb2d1..bde2801289d3 100644 --- a/fs/resctrl/monitor.c +++ b/fs/resctrl/monitor.c @@ -0,0 +1,929 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Resource Director Technology(RDT) + * - Monitoring code + * + * Copyright (C) 2017 Intel Corporation + * + * Author: + * Vikas Shivappa + * + * This replaces the cqm.c based on perf but we reuse a lot of + * code and datastructures originally from Peter Zijlstra and Matt Fleming. + * + * More information about RDT be found in the Intel (R) x86 Architecture + * Software Developer Manual June 2016, volume 3, section 17.17. + */ + +#define pr_fmt(fmt) "resctrl: " fmt + +#include +#include +#include +#include + +#include "internal.h" + +#define CREATE_TRACE_POINTS + +#include "monitor_trace.h" + +/** + * struct rmid_entry - dirty tracking for all RMID. + * @closid: The CLOSID for this entry. + * @rmid: The RMID for this entry. + * @busy: The number of domains with cached data using this RMID. + * @list: Member of the rmid_free_lru list when busy == 0. + * + * Depending on the architecture the correct monitor is accessed using + * both @closid and @rmid, or @rmid only. + * + * Take the rdtgroup_mutex when accessing. + */ +struct rmid_entry { + u32 closid; + u32 rmid; + int busy; + struct list_head list; +}; + +/* + * @rmid_free_lru - A least recently used list of free RMIDs + * These RMIDs are guaranteed to have an occupancy less than the + * threshold occupancy + */ +static LIST_HEAD(rmid_free_lru); + +/* + * @closid_num_dirty_rmid The number of dirty RMID each CLOSID has. + * Only allocated when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is defined. + * Indexed by CLOSID. Protected by rdtgroup_mutex. + */ +static u32 *closid_num_dirty_rmid; + +/* + * @rmid_limbo_count - count of currently unused but (potentially) + * dirty RMIDs. + * This counts RMIDs that no one is currently using but that + * may have a occupancy value > resctrl_rmid_realloc_threshold. User can + * change the threshold occupancy value. + */ +static unsigned int rmid_limbo_count; + +/* + * @rmid_entry - The entry in the limbo and free lists. + */ +static struct rmid_entry *rmid_ptrs; + +/* + * This is the threshold cache occupancy in bytes at which we will consider an + * RMID available for re-allocation. + */ +unsigned int resctrl_rmid_realloc_threshold; + +/* + * This is the maximum value for the reallocation threshold, in bytes. + */ +unsigned int resctrl_rmid_realloc_limit; + +/* + * x86 and arm64 differ in their handling of monitoring. + * x86's RMID are independent numbers, there is only one source of traffic + * with an RMID value of '1'. + * arm64's PMG extends the PARTID/CLOSID space, there are multiple sources of + * traffic with a PMG value of '1', one for each CLOSID, meaning the RMID + * value is no longer unique. + * To account for this, resctrl uses an index. On x86 this is just the RMID, + * on arm64 it encodes the CLOSID and RMID. This gives a unique number. + * + * The domain's rmid_busy_llc and rmid_ptrs[] are sized by index. The arch code + * must accept an attempt to read every index. + */ +static inline struct rmid_entry *__rmid_entry(u32 idx) +{ + struct rmid_entry *entry; + u32 closid, rmid; + + entry = &rmid_ptrs[idx]; + resctrl_arch_rmid_idx_decode(idx, &closid, &rmid); + + WARN_ON_ONCE(entry->closid != closid); + WARN_ON_ONCE(entry->rmid != rmid); + + return entry; +} + +static void limbo_release_entry(struct rmid_entry *entry) +{ + lockdep_assert_held(&rdtgroup_mutex); + + rmid_limbo_count--; + list_add_tail(&entry->list, &rmid_free_lru); + + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) + closid_num_dirty_rmid[entry->closid]--; +} + +/* + * Check the RMIDs that are marked as busy for this domain. If the + * reported LLC occupancy is below the threshold clear the busy bit and + * decrement the count. If the busy count gets to zero on an RMID, we + * free the RMID + */ +void __check_limbo(struct rdt_mon_domain *d, bool force_free) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + u32 idx_limit = resctrl_arch_system_num_rmid_idx(); + struct rmid_entry *entry; + u32 idx, cur_idx = 1; + void *arch_mon_ctx; + bool rmid_dirty; + u64 val = 0; + + arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID); + if (IS_ERR(arch_mon_ctx)) { + pr_warn_ratelimited("Failed to allocate monitor context: %ld", + PTR_ERR(arch_mon_ctx)); + return; + } + + /* + * Skip RMID 0 and start from RMID 1 and check all the RMIDs that + * are marked as busy for occupancy < threshold. If the occupancy + * is less than the threshold decrement the busy counter of the + * RMID and move it to the free list when the counter reaches 0. + */ + for (;;) { + idx = find_next_bit(d->rmid_busy_llc, idx_limit, cur_idx); + if (idx >= idx_limit) + break; + + entry = __rmid_entry(idx); + if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid, + QOS_L3_OCCUP_EVENT_ID, &val, + arch_mon_ctx)) { + rmid_dirty = true; + } else { + rmid_dirty = (val >= resctrl_rmid_realloc_threshold); + + /* + * x86's CLOSID and RMID are independent numbers, so the entry's + * CLOSID is an empty CLOSID (X86_RESCTRL_EMPTY_CLOSID). On Arm the + * RMID (PMG) extends the CLOSID (PARTID) space with bits that aren't + * used to select the configuration. It is thus necessary to track both + * CLOSID and RMID because there may be dependencies between them + * on some architectures. + */ + trace_mon_llc_occupancy_limbo(entry->closid, entry->rmid, d->hdr.id, val); + } + + if (force_free || !rmid_dirty) { + clear_bit(idx, d->rmid_busy_llc); + if (!--entry->busy) + limbo_release_entry(entry); + } + cur_idx = idx + 1; + } + + resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx); +} + +bool has_busy_rmid(struct rdt_mon_domain *d) +{ + u32 idx_limit = resctrl_arch_system_num_rmid_idx(); + + return find_first_bit(d->rmid_busy_llc, idx_limit) != idx_limit; +} + +static struct rmid_entry *resctrl_find_free_rmid(u32 closid) +{ + struct rmid_entry *itr; + u32 itr_idx, cmp_idx; + + if (list_empty(&rmid_free_lru)) + return rmid_limbo_count ? ERR_PTR(-EBUSY) : ERR_PTR(-ENOSPC); + + list_for_each_entry(itr, &rmid_free_lru, list) { + /* + * Get the index of this free RMID, and the index it would need + * to be if it were used with this CLOSID. + * If the CLOSID is irrelevant on this architecture, the two + * index values are always the same on every entry and thus the + * very first entry will be returned. + */ + itr_idx = resctrl_arch_rmid_idx_encode(itr->closid, itr->rmid); + cmp_idx = resctrl_arch_rmid_idx_encode(closid, itr->rmid); + + if (itr_idx == cmp_idx) + return itr; + } + + return ERR_PTR(-ENOSPC); +} + +/** + * resctrl_find_cleanest_closid() - Find a CLOSID where all the associated + * RMID are clean, or the CLOSID that has + * the most clean RMID. + * + * MPAM's equivalent of RMID are per-CLOSID, meaning a freshly allocated CLOSID + * may not be able to allocate clean RMID. To avoid this the allocator will + * choose the CLOSID with the most clean RMID. + * + * When the CLOSID and RMID are independent numbers, the first free CLOSID will + * be returned. + */ +int resctrl_find_cleanest_closid(void) +{ + u32 cleanest_closid = ~0; + int i = 0; + + lockdep_assert_held(&rdtgroup_mutex); + + if (!IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) + return -EIO; + + for (i = 0; i < closids_supported(); i++) { + int num_dirty; + + if (closid_allocated(i)) + continue; + + num_dirty = closid_num_dirty_rmid[i]; + if (num_dirty == 0) + return i; + + if (cleanest_closid == ~0) + cleanest_closid = i; + + if (num_dirty < closid_num_dirty_rmid[cleanest_closid]) + cleanest_closid = i; + } + + if (cleanest_closid == ~0) + return -ENOSPC; + + return cleanest_closid; +} + +/* + * For MPAM the RMID value is not unique, and has to be considered with + * the CLOSID. The (CLOSID, RMID) pair is allocated on all domains, which + * allows all domains to be managed by a single free list. + * Each domain also has a rmid_busy_llc to reduce the work of the limbo handler. + */ +int alloc_rmid(u32 closid) +{ + struct rmid_entry *entry; + + lockdep_assert_held(&rdtgroup_mutex); + + entry = resctrl_find_free_rmid(closid); + if (IS_ERR(entry)) + return PTR_ERR(entry); + + list_del(&entry->list); + return entry->rmid; +} + +static void add_rmid_to_limbo(struct rmid_entry *entry) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + struct rdt_mon_domain *d; + u32 idx; + + lockdep_assert_held(&rdtgroup_mutex); + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + idx = resctrl_arch_rmid_idx_encode(entry->closid, entry->rmid); + + entry->busy = 0; + list_for_each_entry(d, &r->mon_domains, hdr.list) { + /* + * For the first limbo RMID in the domain, + * setup up the limbo worker. + */ + if (!has_busy_rmid(d)) + cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL, + RESCTRL_PICK_ANY_CPU); + set_bit(idx, d->rmid_busy_llc); + entry->busy++; + } + + rmid_limbo_count++; + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) + closid_num_dirty_rmid[entry->closid]++; +} + +void free_rmid(u32 closid, u32 rmid) +{ + u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); + struct rmid_entry *entry; + + lockdep_assert_held(&rdtgroup_mutex); + + /* + * Do not allow the default rmid to be free'd. Comparing by index + * allows architectures that ignore the closid parameter to avoid an + * unnecessary check. + */ + if (!resctrl_arch_mon_capable() || + idx == resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID, + RESCTRL_RESERVED_RMID)) + return; + + entry = __rmid_entry(idx); + + if (resctrl_arch_is_llc_occupancy_enabled()) + add_rmid_to_limbo(entry); + else + list_add_tail(&entry->list, &rmid_free_lru); +} + +static struct mbm_state *get_mbm_state(struct rdt_mon_domain *d, u32 closid, + u32 rmid, enum resctrl_event_id evtid) +{ + u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); + + switch (evtid) { + case QOS_L3_MBM_TOTAL_EVENT_ID: + return &d->mbm_total[idx]; + case QOS_L3_MBM_LOCAL_EVENT_ID: + return &d->mbm_local[idx]; + default: + return NULL; + } +} + +static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) +{ + int cpu = smp_processor_id(); + struct rdt_mon_domain *d; + struct mbm_state *m; + int err, ret; + u64 tval = 0; + + if (rr->first) { + resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid); + m = get_mbm_state(rr->d, closid, rmid, rr->evtid); + if (m) + memset(m, 0, sizeof(struct mbm_state)); + return 0; + } + + if (rr->d) { + /* Reading a single domain, must be on a CPU in that domain. */ + if (!cpumask_test_cpu(cpu, &rr->d->hdr.cpu_mask)) + return -EINVAL; + rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid, + rr->evtid, &tval, rr->arch_mon_ctx); + if (rr->err) + return rr->err; + + rr->val += tval; + + return 0; + } + + /* Summing domains that share a cache, must be on a CPU for that cache. */ + if (!cpumask_test_cpu(cpu, &rr->ci->shared_cpu_map)) + return -EINVAL; + + /* + * Legacy files must report the sum of an event across all + * domains that share the same L3 cache instance. + * Report success if a read from any domain succeeds, -EINVAL + * (translated to "Unavailable" for user space) if reading from + * all domains fail for any reason. + */ + ret = -EINVAL; + list_for_each_entry(d, &rr->r->mon_domains, hdr.list) { + if (d->ci->id != rr->ci->id) + continue; + err = resctrl_arch_rmid_read(rr->r, d, closid, rmid, + rr->evtid, &tval, rr->arch_mon_ctx); + if (!err) { + rr->val += tval; + ret = 0; + } + } + + if (ret) + rr->err = ret; + + return ret; +} + +/* + * mbm_bw_count() - Update bw count from values previously read by + * __mon_event_count(). + * @closid: The closid used to identify the cached mbm_state. + * @rmid: The rmid used to identify the cached mbm_state. + * @rr: The struct rmid_read populated by __mon_event_count(). + * + * Supporting function to calculate the memory bandwidth + * and delta bandwidth in MBps. The chunks value previously read by + * __mon_event_count() is compared with the chunks value from the previous + * invocation. This must be called once per second to maintain values in MBps. + */ +static void mbm_bw_count(u32 closid, u32 rmid, struct rmid_read *rr) +{ + u64 cur_bw, bytes, cur_bytes; + struct mbm_state *m; + + m = get_mbm_state(rr->d, closid, rmid, rr->evtid); + if (WARN_ON_ONCE(!m)) + return; + + cur_bytes = rr->val; + bytes = cur_bytes - m->prev_bw_bytes; + m->prev_bw_bytes = cur_bytes; + + cur_bw = bytes / SZ_1M; + + m->prev_bw = cur_bw; +} + +/* + * This is scheduled by mon_event_read() to read the CQM/MBM counters + * on a domain. + */ +void mon_event_count(void *info) +{ + struct rdtgroup *rdtgrp, *entry; + struct rmid_read *rr = info; + struct list_head *head; + int ret; + + rdtgrp = rr->rgrp; + + ret = __mon_event_count(rdtgrp->closid, rdtgrp->mon.rmid, rr); + + /* + * For Ctrl groups read data from child monitor groups and + * add them together. Count events which are read successfully. + * Discard the rmid_read's reporting errors. + */ + head = &rdtgrp->mon.crdtgrp_list; + + if (rdtgrp->type == RDTCTRL_GROUP) { + list_for_each_entry(entry, head, mon.crdtgrp_list) { + if (__mon_event_count(entry->closid, entry->mon.rmid, + rr) == 0) + ret = 0; + } + } + + /* + * __mon_event_count() calls for newly created monitor groups may + * report -EINVAL/Unavailable if the monitor hasn't seen any traffic. + * Discard error if any of the monitor event reads succeeded. + */ + if (ret == 0) + rr->err = 0; +} + +static struct rdt_ctrl_domain *get_ctrl_domain_from_cpu(int cpu, + struct rdt_resource *r) +{ + struct rdt_ctrl_domain *d; + + lockdep_assert_cpus_held(); + + list_for_each_entry(d, &r->ctrl_domains, hdr.list) { + /* Find the domain that contains this CPU */ + if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask)) + return d; + } + + return NULL; +} + +/* + * Feedback loop for MBA software controller (mba_sc) + * + * mba_sc is a feedback loop where we periodically read MBM counters and + * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so + * that: + * + * current bandwidth(cur_bw) < user specified bandwidth(user_bw) + * + * This uses the MBM counters to measure the bandwidth and MBA throttle + * MSRs to control the bandwidth for a particular rdtgrp. It builds on the + * fact that resctrl rdtgroups have both monitoring and control. + * + * The frequency of the checks is 1s and we just tag along the MBM overflow + * timer. Having 1s interval makes the calculation of bandwidth simpler. + * + * Although MBA's goal is to restrict the bandwidth to a maximum, there may + * be a need to increase the bandwidth to avoid unnecessarily restricting + * the L2 <-> L3 traffic. + * + * Since MBA controls the L2 external bandwidth where as MBM measures the + * L3 external bandwidth the following sequence could lead to such a + * situation. + * + * Consider an rdtgroup which had high L3 <-> memory traffic in initial + * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but + * after some time rdtgroup has mostly L2 <-> L3 traffic. + * + * In this case we may restrict the rdtgroup's L2 <-> L3 traffic as its + * throttle MSRs already have low percentage values. To avoid + * unnecessarily restricting such rdtgroups, we also increase the bandwidth. + */ +static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm) +{ + u32 closid, rmid, cur_msr_val, new_msr_val; + struct mbm_state *pmbm_data, *cmbm_data; + struct rdt_ctrl_domain *dom_mba; + enum resctrl_event_id evt_id; + struct rdt_resource *r_mba; + struct list_head *head; + struct rdtgroup *entry; + u32 cur_bw, user_bw; + + r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA); + evt_id = rgrp->mba_mbps_event; + + closid = rgrp->closid; + rmid = rgrp->mon.rmid; + pmbm_data = get_mbm_state(dom_mbm, closid, rmid, evt_id); + if (WARN_ON_ONCE(!pmbm_data)) + return; + + dom_mba = get_ctrl_domain_from_cpu(smp_processor_id(), r_mba); + if (!dom_mba) { + pr_warn_once("Failure to get domain for MBA update\n"); + return; + } + + cur_bw = pmbm_data->prev_bw; + user_bw = dom_mba->mbps_val[closid]; + + /* MBA resource doesn't support CDP */ + cur_msr_val = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE); + + /* + * For Ctrl groups read data from child monitor groups. + */ + head = &rgrp->mon.crdtgrp_list; + list_for_each_entry(entry, head, mon.crdtgrp_list) { + cmbm_data = get_mbm_state(dom_mbm, entry->closid, entry->mon.rmid, evt_id); + if (WARN_ON_ONCE(!cmbm_data)) + return; + cur_bw += cmbm_data->prev_bw; + } + + /* + * Scale up/down the bandwidth linearly for the ctrl group. The + * bandwidth step is the bandwidth granularity specified by the + * hardware. + * Always increase throttling if current bandwidth is above the + * target set by user. + * But avoid thrashing up and down on every poll by checking + * whether a decrease in throttling is likely to push the group + * back over target. E.g. if currently throttling to 30% of bandwidth + * on a system with 10% granularity steps, check whether moving to + * 40% would go past the limit by multiplying current bandwidth by + * "(30 + 10) / 30". + */ + if (cur_msr_val > r_mba->membw.min_bw && user_bw < cur_bw) { + new_msr_val = cur_msr_val - r_mba->membw.bw_gran; + } else if (cur_msr_val < MAX_MBA_BW && + (user_bw > (cur_bw * (cur_msr_val + r_mba->membw.min_bw) / cur_msr_val))) { + new_msr_val = cur_msr_val + r_mba->membw.bw_gran; + } else { + return; + } + + resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val); +} + +static void mbm_update_one_event(struct rdt_resource *r, struct rdt_mon_domain *d, + u32 closid, u32 rmid, enum resctrl_event_id evtid) +{ + struct rmid_read rr = {0}; + + rr.r = r; + rr.d = d; + rr.evtid = evtid; + rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid); + if (IS_ERR(rr.arch_mon_ctx)) { + pr_warn_ratelimited("Failed to allocate monitor context: %ld", + PTR_ERR(rr.arch_mon_ctx)); + return; + } + + __mon_event_count(closid, rmid, &rr); + + /* + * If the software controller is enabled, compute the + * bandwidth for this event id. + */ + if (is_mba_sc(NULL)) + mbm_bw_count(closid, rmid, &rr); + + resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx); +} + +static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d, + u32 closid, u32 rmid) +{ + /* + * This is protected from concurrent reads from user as both + * the user and overflow handler hold the global mutex. + */ + if (resctrl_arch_is_mbm_total_enabled()) + mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_TOTAL_EVENT_ID); + + if (resctrl_arch_is_mbm_local_enabled()) + mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_LOCAL_EVENT_ID); +} + +/* + * Handler to scan the limbo list and move the RMIDs + * to free list whose occupancy < threshold_occupancy. + */ +void cqm_handle_limbo(struct work_struct *work) +{ + unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL); + struct rdt_mon_domain *d; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + d = container_of(work, struct rdt_mon_domain, cqm_limbo.work); + + __check_limbo(d, false); + + if (has_busy_rmid(d)) { + d->cqm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask, + RESCTRL_PICK_ANY_CPU); + schedule_delayed_work_on(d->cqm_work_cpu, &d->cqm_limbo, + delay); + } + + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); +} + +/** + * cqm_setup_limbo_handler() - Schedule the limbo handler to run for this + * domain. + * @dom: The domain the limbo handler should run for. + * @delay_ms: How far in the future the handler should run. + * @exclude_cpu: Which CPU the handler should not run on, + * RESCTRL_PICK_ANY_CPU to pick any CPU. + */ +void cqm_setup_limbo_handler(struct rdt_mon_domain *dom, unsigned long delay_ms, + int exclude_cpu) +{ + unsigned long delay = msecs_to_jiffies(delay_ms); + int cpu; + + cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu); + dom->cqm_work_cpu = cpu; + + if (cpu < nr_cpu_ids) + schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay); +} + +void mbm_handle_overflow(struct work_struct *work) +{ + unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL); + struct rdtgroup *prgrp, *crgrp; + struct rdt_mon_domain *d; + struct list_head *head; + struct rdt_resource *r; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + /* + * If the filesystem has been unmounted this work no longer needs to + * run. + */ + if (!resctrl_mounted || !resctrl_arch_mon_capable()) + goto out_unlock; + + r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + d = container_of(work, struct rdt_mon_domain, mbm_over.work); + + list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { + mbm_update(r, d, prgrp->closid, prgrp->mon.rmid); + + head = &prgrp->mon.crdtgrp_list; + list_for_each_entry(crgrp, head, mon.crdtgrp_list) + mbm_update(r, d, crgrp->closid, crgrp->mon.rmid); + + if (is_mba_sc(NULL)) + update_mba_bw(prgrp, d); + } + + /* + * Re-check for housekeeping CPUs. This allows the overflow handler to + * move off a nohz_full CPU quickly. + */ + d->mbm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask, + RESCTRL_PICK_ANY_CPU); + schedule_delayed_work_on(d->mbm_work_cpu, &d->mbm_over, delay); + +out_unlock: + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); +} + +/** + * mbm_setup_overflow_handler() - Schedule the overflow handler to run for this + * domain. + * @dom: The domain the overflow handler should run for. + * @delay_ms: How far in the future the handler should run. + * @exclude_cpu: Which CPU the handler should not run on, + * RESCTRL_PICK_ANY_CPU to pick any CPU. + */ +void mbm_setup_overflow_handler(struct rdt_mon_domain *dom, unsigned long delay_ms, + int exclude_cpu) +{ + unsigned long delay = msecs_to_jiffies(delay_ms); + int cpu; + + /* + * When a domain comes online there is no guarantee the filesystem is + * mounted. If not, there is no need to catch counter overflow. + */ + if (!resctrl_mounted || !resctrl_arch_mon_capable()) + return; + cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu); + dom->mbm_work_cpu = cpu; + + if (cpu < nr_cpu_ids) + schedule_delayed_work_on(cpu, &dom->mbm_over, delay); +} + +static int dom_data_init(struct rdt_resource *r) +{ + u32 idx_limit = resctrl_arch_system_num_rmid_idx(); + u32 num_closid = resctrl_arch_get_num_closid(r); + struct rmid_entry *entry = NULL; + int err = 0, i; + u32 idx; + + mutex_lock(&rdtgroup_mutex); + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { + u32 *tmp; + + /* + * If the architecture hasn't provided a sanitised value here, + * this may result in larger arrays than necessary. Resctrl will + * use a smaller system wide value based on the resources in + * use. + */ + tmp = kcalloc(num_closid, sizeof(*tmp), GFP_KERNEL); + if (!tmp) { + err = -ENOMEM; + goto out_unlock; + } + + closid_num_dirty_rmid = tmp; + } + + rmid_ptrs = kcalloc(idx_limit, sizeof(struct rmid_entry), GFP_KERNEL); + if (!rmid_ptrs) { + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { + kfree(closid_num_dirty_rmid); + closid_num_dirty_rmid = NULL; + } + err = -ENOMEM; + goto out_unlock; + } + + for (i = 0; i < idx_limit; i++) { + entry = &rmid_ptrs[i]; + INIT_LIST_HEAD(&entry->list); + + resctrl_arch_rmid_idx_decode(i, &entry->closid, &entry->rmid); + list_add_tail(&entry->list, &rmid_free_lru); + } + + /* + * RESCTRL_RESERVED_CLOSID and RESCTRL_RESERVED_RMID are special and + * are always allocated. These are used for the rdtgroup_default + * control group, which will be setup later in resctrl_init(). + */ + idx = resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID, + RESCTRL_RESERVED_RMID); + entry = __rmid_entry(idx); + list_del(&entry->list); + +out_unlock: + mutex_unlock(&rdtgroup_mutex); + + return err; +} + +static void dom_data_exit(struct rdt_resource *r) +{ + mutex_lock(&rdtgroup_mutex); + + if (!r->mon_capable) + goto out_unlock; + + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { + kfree(closid_num_dirty_rmid); + closid_num_dirty_rmid = NULL; + } + + kfree(rmid_ptrs); + rmid_ptrs = NULL; + +out_unlock: + mutex_unlock(&rdtgroup_mutex); +} + +static struct mon_evt llc_occupancy_event = { + .name = "llc_occupancy", + .evtid = QOS_L3_OCCUP_EVENT_ID, +}; + +static struct mon_evt mbm_total_event = { + .name = "mbm_total_bytes", + .evtid = QOS_L3_MBM_TOTAL_EVENT_ID, +}; + +static struct mon_evt mbm_local_event = { + .name = "mbm_local_bytes", + .evtid = QOS_L3_MBM_LOCAL_EVENT_ID, +}; + +/* + * Initialize the event list for the resource. + * + * Note that MBM events are also part of RDT_RESOURCE_L3 resource + * because as per the SDM the total and local memory bandwidth + * are enumerated as part of L3 monitoring. + */ +static void l3_mon_evt_init(struct rdt_resource *r) +{ + INIT_LIST_HEAD(&r->evt_list); + + if (resctrl_arch_is_llc_occupancy_enabled()) + list_add_tail(&llc_occupancy_event.list, &r->evt_list); + if (resctrl_arch_is_mbm_total_enabled()) + list_add_tail(&mbm_total_event.list, &r->evt_list); + if (resctrl_arch_is_mbm_local_enabled()) + list_add_tail(&mbm_local_event.list, &r->evt_list); +} + +/** + * resctrl_mon_resource_init() - Initialise global monitoring structures. + * + * Allocate and initialise global monitor resources that do not belong to a + * specific domain. i.e. the rmid_ptrs[] used for the limbo and free lists. + * Called once during boot after the struct rdt_resource's have been configured + * but before the filesystem is mounted. + * Resctrl's cpuhp callbacks may be called before this point to bring a domain + * online. + * + * Returns 0 for success, or -ENOMEM. + */ +int resctrl_mon_resource_init(void) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + int ret; + + if (!r->mon_capable) + return 0; + + ret = dom_data_init(r); + if (ret) + return ret; + + l3_mon_evt_init(r); + + if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_TOTAL_EVENT_ID)) { + mbm_total_event.configurable = true; + resctrl_file_fflags_init("mbm_total_bytes_config", + RFTYPE_MON_INFO | RFTYPE_RES_CACHE); + } + if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_LOCAL_EVENT_ID)) { + mbm_local_event.configurable = true; + resctrl_file_fflags_init("mbm_local_bytes_config", + RFTYPE_MON_INFO | RFTYPE_RES_CACHE); + } + + if (resctrl_arch_is_mbm_local_enabled()) + mba_mbps_default_event = QOS_L3_MBM_LOCAL_EVENT_ID; + else if (resctrl_arch_is_mbm_total_enabled()) + mba_mbps_default_event = QOS_L3_MBM_TOTAL_EVENT_ID; + + return 0; +} + +void resctrl_mon_resource_exit(void) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + + dom_data_exit(r); +} diff --git a/fs/resctrl/monitor_trace.h b/fs/resctrl/monitor_trace.h index e69de29bb2d1..fdf49f22576a 100644 --- a/fs/resctrl/monitor_trace.h +++ b/fs/resctrl/monitor_trace.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM resctrl + +#if !defined(_FS_RESCTRL_MONITOR_TRACE_H) || defined(TRACE_HEADER_MULTI_READ) +#define _FS_RESCTRL_MONITOR_TRACE_H + +#include + +TRACE_EVENT(mon_llc_occupancy_limbo, + TP_PROTO(u32 ctrl_hw_id, u32 mon_hw_id, int domain_id, u64 llc_occupancy_bytes), + TP_ARGS(ctrl_hw_id, mon_hw_id, domain_id, llc_occupancy_bytes), + TP_STRUCT__entry(__field(u32, ctrl_hw_id) + __field(u32, mon_hw_id) + __field(int, domain_id) + __field(u64, llc_occupancy_bytes)), + TP_fast_assign(__entry->ctrl_hw_id = ctrl_hw_id; + __entry->mon_hw_id = mon_hw_id; + __entry->domain_id = domain_id; + __entry->llc_occupancy_bytes = llc_occupancy_bytes;), + TP_printk("ctrl_hw_id=%u mon_hw_id=%u domain_id=%d llc_occupancy_bytes=%llu", + __entry->ctrl_hw_id, __entry->mon_hw_id, __entry->domain_id, + __entry->llc_occupancy_bytes) + ); + +#endif /* _FS_RESCTRL_MONITOR_TRACE_H */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . + +#define TRACE_INCLUDE_FILE monitor_trace + +#include diff --git a/fs/resctrl/pseudo_lock.c b/fs/resctrl/pseudo_lock.c index e69de29bb2d1..ccc2f9213b4b 100644 --- a/fs/resctrl/pseudo_lock.c +++ b/fs/resctrl/pseudo_lock.c @@ -0,0 +1,1105 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Resource Director Technology (RDT) + * + * Pseudo-locking support built on top of Cache Allocation Technology (CAT) + * + * Copyright (C) 2018 Intel Corporation + * + * Author: Reinette Chatre + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "internal.h" + +/* + * Major number assigned to and shared by all devices exposing + * pseudo-locked regions. + */ +static unsigned int pseudo_lock_major; + +static unsigned long pseudo_lock_minor_avail = GENMASK(MINORBITS, 0); + +static char *pseudo_lock_devnode(const struct device *dev, umode_t *mode) +{ + const struct rdtgroup *rdtgrp; + + rdtgrp = dev_get_drvdata(dev); + if (mode) + *mode = 0600; + guard(mutex)(&rdtgroup_mutex); + return kasprintf(GFP_KERNEL, "pseudo_lock/%s", rdt_kn_name(rdtgrp->kn)); +} + +static const struct class pseudo_lock_class = { + .name = "pseudo_lock", + .devnode = pseudo_lock_devnode, +}; + +/** + * pseudo_lock_minor_get - Obtain available minor number + * @minor: Pointer to where new minor number will be stored + * + * A bitmask is used to track available minor numbers. Here the next free + * minor number is marked as unavailable and returned. + * + * Return: 0 on success, <0 on failure. + */ +static int pseudo_lock_minor_get(unsigned int *minor) +{ + unsigned long first_bit; + + first_bit = find_first_bit(&pseudo_lock_minor_avail, MINORBITS); + + if (first_bit == MINORBITS) + return -ENOSPC; + + __clear_bit(first_bit, &pseudo_lock_minor_avail); + *minor = first_bit; + + return 0; +} + +/** + * pseudo_lock_minor_release - Return minor number to available + * @minor: The minor number made available + */ +static void pseudo_lock_minor_release(unsigned int minor) +{ + __set_bit(minor, &pseudo_lock_minor_avail); +} + +/** + * region_find_by_minor - Locate a pseudo-lock region by inode minor number + * @minor: The minor number of the device representing pseudo-locked region + * + * When the character device is accessed we need to determine which + * pseudo-locked region it belongs to. This is done by matching the minor + * number of the device to the pseudo-locked region it belongs. + * + * Minor numbers are assigned at the time a pseudo-locked region is associated + * with a cache instance. + * + * Return: On success return pointer to resource group owning the pseudo-locked + * region, NULL on failure. + */ +static struct rdtgroup *region_find_by_minor(unsigned int minor) +{ + struct rdtgroup *rdtgrp, *rdtgrp_match = NULL; + + list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { + if (rdtgrp->plr && rdtgrp->plr->minor == minor) { + rdtgrp_match = rdtgrp; + break; + } + } + return rdtgrp_match; +} + +/** + * struct pseudo_lock_pm_req - A power management QoS request list entry + * @list: Entry within the @pm_reqs list for a pseudo-locked region + * @req: PM QoS request + */ +struct pseudo_lock_pm_req { + struct list_head list; + struct dev_pm_qos_request req; +}; + +static void pseudo_lock_cstates_relax(struct pseudo_lock_region *plr) +{ + struct pseudo_lock_pm_req *pm_req, *next; + + list_for_each_entry_safe(pm_req, next, &plr->pm_reqs, list) { + dev_pm_qos_remove_request(&pm_req->req); + list_del(&pm_req->list); + kfree(pm_req); + } +} + +/** + * pseudo_lock_cstates_constrain - Restrict cores from entering C6 + * @plr: Pseudo-locked region + * + * To prevent the cache from being affected by power management entering + * C6 has to be avoided. This is accomplished by requesting a latency + * requirement lower than lowest C6 exit latency of all supported + * platforms as found in the cpuidle state tables in the intel_idle driver. + * At this time it is possible to do so with a single latency requirement + * for all supported platforms. + * + * Since Goldmont is supported, which is affected by X86_BUG_MONITOR, + * the ACPI latencies need to be considered while keeping in mind that C2 + * may be set to map to deeper sleep states. In this case the latency + * requirement needs to prevent entering C2 also. + * + * Return: 0 on success, <0 on failure + */ +static int pseudo_lock_cstates_constrain(struct pseudo_lock_region *plr) +{ + struct pseudo_lock_pm_req *pm_req; + int cpu; + int ret; + + for_each_cpu(cpu, &plr->d->hdr.cpu_mask) { + pm_req = kzalloc(sizeof(*pm_req), GFP_KERNEL); + if (!pm_req) { + rdt_last_cmd_puts("Failure to allocate memory for PM QoS\n"); + ret = -ENOMEM; + goto out_err; + } + ret = dev_pm_qos_add_request(get_cpu_device(cpu), + &pm_req->req, + DEV_PM_QOS_RESUME_LATENCY, + 30); + if (ret < 0) { + rdt_last_cmd_printf("Failed to add latency req CPU%d\n", + cpu); + kfree(pm_req); + ret = -1; + goto out_err; + } + list_add(&pm_req->list, &plr->pm_reqs); + } + + return 0; + +out_err: + pseudo_lock_cstates_relax(plr); + return ret; +} + +/** + * pseudo_lock_region_clear - Reset pseudo-lock region data + * @plr: pseudo-lock region + * + * All content of the pseudo-locked region is reset - any memory allocated + * freed. + * + * Return: void + */ +static void pseudo_lock_region_clear(struct pseudo_lock_region *plr) +{ + plr->size = 0; + plr->line_size = 0; + kfree(plr->kmem); + plr->kmem = NULL; + plr->s = NULL; + if (plr->d) + plr->d->plr = NULL; + plr->d = NULL; + plr->cbm = 0; + plr->debugfs_dir = NULL; +} + +/** + * pseudo_lock_region_init - Initialize pseudo-lock region information + * @plr: pseudo-lock region + * + * Called after user provided a schemata to be pseudo-locked. From the + * schemata the &struct pseudo_lock_region is on entry already initialized + * with the resource, domain, and capacity bitmask. Here the information + * required for pseudo-locking is deduced from this data and &struct + * pseudo_lock_region initialized further. This information includes: + * - size in bytes of the region to be pseudo-locked + * - cache line size to know the stride with which data needs to be accessed + * to be pseudo-locked + * - a cpu associated with the cache instance on which the pseudo-locking + * flow can be executed + * + * Return: 0 on success, <0 on failure. Descriptive error will be written + * to last_cmd_status buffer. + */ +static int pseudo_lock_region_init(struct pseudo_lock_region *plr) +{ + enum resctrl_scope scope = plr->s->res->ctrl_scope; + struct cacheinfo *ci; + int ret; + + if (WARN_ON_ONCE(scope != RESCTRL_L2_CACHE && scope != RESCTRL_L3_CACHE)) + return -ENODEV; + + /* Pick the first cpu we find that is associated with the cache. */ + plr->cpu = cpumask_first(&plr->d->hdr.cpu_mask); + + if (!cpu_online(plr->cpu)) { + rdt_last_cmd_printf("CPU %u associated with cache not online\n", + plr->cpu); + ret = -ENODEV; + goto out_region; + } + + ci = get_cpu_cacheinfo_level(plr->cpu, scope); + if (ci) { + plr->line_size = ci->coherency_line_size; + plr->size = rdtgroup_cbm_to_size(plr->s->res, plr->d, plr->cbm); + return 0; + } + + ret = -1; + rdt_last_cmd_puts("Unable to determine cache line size\n"); +out_region: + pseudo_lock_region_clear(plr); + return ret; +} + +/** + * pseudo_lock_init - Initialize a pseudo-lock region + * @rdtgrp: resource group to which new pseudo-locked region will belong + * + * A pseudo-locked region is associated with a resource group. When this + * association is created the pseudo-locked region is initialized. The + * details of the pseudo-locked region are not known at this time so only + * allocation is done and association established. + * + * Return: 0 on success, <0 on failure + */ +static int pseudo_lock_init(struct rdtgroup *rdtgrp) +{ + struct pseudo_lock_region *plr; + + plr = kzalloc(sizeof(*plr), GFP_KERNEL); + if (!plr) + return -ENOMEM; + + init_waitqueue_head(&plr->lock_thread_wq); + INIT_LIST_HEAD(&plr->pm_reqs); + rdtgrp->plr = plr; + return 0; +} + +/** + * pseudo_lock_region_alloc - Allocate kernel memory that will be pseudo-locked + * @plr: pseudo-lock region + * + * Initialize the details required to set up the pseudo-locked region and + * allocate the contiguous memory that will be pseudo-locked to the cache. + * + * Return: 0 on success, <0 on failure. Descriptive error will be written + * to last_cmd_status buffer. + */ +static int pseudo_lock_region_alloc(struct pseudo_lock_region *plr) +{ + int ret; + + ret = pseudo_lock_region_init(plr); + if (ret < 0) + return ret; + + /* + * We do not yet support contiguous regions larger than + * KMALLOC_MAX_SIZE. + */ + if (plr->size > KMALLOC_MAX_SIZE) { + rdt_last_cmd_puts("Requested region exceeds maximum size\n"); + ret = -E2BIG; + goto out_region; + } + + plr->kmem = kzalloc(plr->size, GFP_KERNEL); + if (!plr->kmem) { + rdt_last_cmd_puts("Unable to allocate memory\n"); + ret = -ENOMEM; + goto out_region; + } + + ret = 0; + goto out; +out_region: + pseudo_lock_region_clear(plr); +out: + return ret; +} + +/** + * pseudo_lock_free - Free a pseudo-locked region + * @rdtgrp: resource group to which pseudo-locked region belonged + * + * The pseudo-locked region's resources have already been released, or not + * yet created at this point. Now it can be freed and disassociated from the + * resource group. + * + * Return: void + */ +static void pseudo_lock_free(struct rdtgroup *rdtgrp) +{ + pseudo_lock_region_clear(rdtgrp->plr); + kfree(rdtgrp->plr); + rdtgrp->plr = NULL; +} + +/** + * rdtgroup_monitor_in_progress - Test if monitoring in progress + * @rdtgrp: resource group being queried + * + * Return: 1 if monitor groups have been created for this resource + * group, 0 otherwise. + */ +static int rdtgroup_monitor_in_progress(struct rdtgroup *rdtgrp) +{ + return !list_empty(&rdtgrp->mon.crdtgrp_list); +} + +/** + * rdtgroup_locksetup_user_restrict - Restrict user access to group + * @rdtgrp: resource group needing access restricted + * + * A resource group used for cache pseudo-locking cannot have cpus or tasks + * assigned to it. This is communicated to the user by restricting access + * to all the files that can be used to make such changes. + * + * Permissions restored with rdtgroup_locksetup_user_restore() + * + * Return: 0 on success, <0 on failure. If a failure occurs during the + * restriction of access an attempt will be made to restore permissions but + * the state of the mode of these files will be uncertain when a failure + * occurs. + */ +static int rdtgroup_locksetup_user_restrict(struct rdtgroup *rdtgrp) +{ + int ret; + + ret = rdtgroup_kn_mode_restrict(rdtgrp, "tasks"); + if (ret) + return ret; + + ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus"); + if (ret) + goto err_tasks; + + ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list"); + if (ret) + goto err_cpus; + + if (resctrl_arch_mon_capable()) { + ret = rdtgroup_kn_mode_restrict(rdtgrp, "mon_groups"); + if (ret) + goto err_cpus_list; + } + + ret = 0; + goto out; + +err_cpus_list: + rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777); +err_cpus: + rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777); +err_tasks: + rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777); +out: + return ret; +} + +/** + * rdtgroup_locksetup_user_restore - Restore user access to group + * @rdtgrp: resource group needing access restored + * + * Restore all file access previously removed using + * rdtgroup_locksetup_user_restrict() + * + * Return: 0 on success, <0 on failure. If a failure occurs during the + * restoration of access an attempt will be made to restrict permissions + * again but the state of the mode of these files will be uncertain when + * a failure occurs. + */ +static int rdtgroup_locksetup_user_restore(struct rdtgroup *rdtgrp) +{ + int ret; + + ret = rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777); + if (ret) + return ret; + + ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777); + if (ret) + goto err_tasks; + + ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777); + if (ret) + goto err_cpus; + + if (resctrl_arch_mon_capable()) { + ret = rdtgroup_kn_mode_restore(rdtgrp, "mon_groups", 0777); + if (ret) + goto err_cpus_list; + } + + ret = 0; + goto out; + +err_cpus_list: + rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list"); +err_cpus: + rdtgroup_kn_mode_restrict(rdtgrp, "cpus"); +err_tasks: + rdtgroup_kn_mode_restrict(rdtgrp, "tasks"); +out: + return ret; +} + +/** + * rdtgroup_locksetup_enter - Resource group enters locksetup mode + * @rdtgrp: resource group requested to enter locksetup mode + * + * A resource group enters locksetup mode to reflect that it would be used + * to represent a pseudo-locked region and is in the process of being set + * up to do so. A resource group used for a pseudo-locked region would + * lose the closid associated with it so we cannot allow it to have any + * tasks or cpus assigned nor permit tasks or cpus to be assigned in the + * future. Monitoring of a pseudo-locked region is not allowed either. + * + * The above and more restrictions on a pseudo-locked region are checked + * for and enforced before the resource group enters the locksetup mode. + * + * Returns: 0 if the resource group successfully entered locksetup mode, <0 + * on failure. On failure the last_cmd_status buffer is updated with text to + * communicate details of failure to the user. + */ +int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp) +{ + int ret; + + /* + * The default resource group can neither be removed nor lose the + * default closid associated with it. + */ + if (rdtgrp == &rdtgroup_default) { + rdt_last_cmd_puts("Cannot pseudo-lock default group\n"); + return -EINVAL; + } + + /* + * Cache Pseudo-locking not supported when CDP is enabled. + * + * Some things to consider if you would like to enable this + * support (using L3 CDP as example): + * - When CDP is enabled two separate resources are exposed, + * L3DATA and L3CODE, but they are actually on the same cache. + * The implication for pseudo-locking is that if a + * pseudo-locked region is created on a domain of one + * resource (eg. L3CODE), then a pseudo-locked region cannot + * be created on that same domain of the other resource + * (eg. L3DATA). This is because the creation of a + * pseudo-locked region involves a call to wbinvd that will + * affect all cache allocations on particular domain. + * - Considering the previous, it may be possible to only + * expose one of the CDP resources to pseudo-locking and + * hide the other. For example, we could consider to only + * expose L3DATA and since the L3 cache is unified it is + * still possible to place instructions there are execute it. + * - If only one region is exposed to pseudo-locking we should + * still keep in mind that availability of a portion of cache + * for pseudo-locking should take into account both resources. + * Similarly, if a pseudo-locked region is created in one + * resource, the portion of cache used by it should be made + * unavailable to all future allocations from both resources. + */ + if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3) || + resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2)) { + rdt_last_cmd_puts("CDP enabled\n"); + return -EINVAL; + } + + /* + * Not knowing the bits to disable prefetching implies that this + * platform does not support Cache Pseudo-Locking. + */ + if (resctrl_arch_get_prefetch_disable_bits() == 0) { + rdt_last_cmd_puts("Pseudo-locking not supported\n"); + return -EINVAL; + } + + if (rdtgroup_monitor_in_progress(rdtgrp)) { + rdt_last_cmd_puts("Monitoring in progress\n"); + return -EINVAL; + } + + if (rdtgroup_tasks_assigned(rdtgrp)) { + rdt_last_cmd_puts("Tasks assigned to resource group\n"); + return -EINVAL; + } + + if (!cpumask_empty(&rdtgrp->cpu_mask)) { + rdt_last_cmd_puts("CPUs assigned to resource group\n"); + return -EINVAL; + } + + if (rdtgroup_locksetup_user_restrict(rdtgrp)) { + rdt_last_cmd_puts("Unable to modify resctrl permissions\n"); + return -EIO; + } + + ret = pseudo_lock_init(rdtgrp); + if (ret) { + rdt_last_cmd_puts("Unable to init pseudo-lock region\n"); + goto out_release; + } + + /* + * If this system is capable of monitoring a rmid would have been + * allocated when the control group was created. This is not needed + * anymore when this group would be used for pseudo-locking. This + * is safe to call on platforms not capable of monitoring. + */ + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + + ret = 0; + goto out; + +out_release: + rdtgroup_locksetup_user_restore(rdtgrp); +out: + return ret; +} + +/** + * rdtgroup_locksetup_exit - resource group exist locksetup mode + * @rdtgrp: resource group + * + * When a resource group exits locksetup mode the earlier restrictions are + * lifted. + * + * Return: 0 on success, <0 on failure + */ +int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp) +{ + int ret; + + if (resctrl_arch_mon_capable()) { + ret = alloc_rmid(rdtgrp->closid); + if (ret < 0) { + rdt_last_cmd_puts("Out of RMIDs\n"); + return ret; + } + rdtgrp->mon.rmid = ret; + } + + ret = rdtgroup_locksetup_user_restore(rdtgrp); + if (ret) { + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + return ret; + } + + pseudo_lock_free(rdtgrp); + return 0; +} + +/** + * rdtgroup_cbm_overlaps_pseudo_locked - Test if CBM or portion is pseudo-locked + * @d: RDT domain + * @cbm: CBM to test + * + * @d represents a cache instance and @cbm a capacity bitmask that is + * considered for it. Determine if @cbm overlaps with any existing + * pseudo-locked region on @d. + * + * @cbm is unsigned long, even if only 32 bits are used, to make the + * bitmap functions work correctly. + * + * Return: true if @cbm overlaps with pseudo-locked region on @d, false + * otherwise. + */ +bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm) +{ + unsigned int cbm_len; + unsigned long cbm_b; + + if (d->plr) { + cbm_len = d->plr->s->res->cache.cbm_len; + cbm_b = d->plr->cbm; + if (bitmap_intersects(&cbm, &cbm_b, cbm_len)) + return true; + } + return false; +} + +/** + * rdtgroup_pseudo_locked_in_hierarchy - Pseudo-locked region in cache hierarchy + * @d: RDT domain under test + * + * The setup of a pseudo-locked region affects all cache instances within + * the hierarchy of the region. It is thus essential to know if any + * pseudo-locked regions exist within a cache hierarchy to prevent any + * attempts to create new pseudo-locked regions in the same hierarchy. + * + * Return: true if a pseudo-locked region exists in the hierarchy of @d or + * if it is not possible to test due to memory allocation issue, + * false otherwise. + */ +bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d) +{ + struct rdt_ctrl_domain *d_i; + cpumask_var_t cpu_with_psl; + struct rdt_resource *r; + bool ret = false; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + if (!zalloc_cpumask_var(&cpu_with_psl, GFP_KERNEL)) + return true; + + /* + * First determine which cpus have pseudo-locked regions + * associated with them. + */ + for_each_alloc_capable_rdt_resource(r) { + list_for_each_entry(d_i, &r->ctrl_domains, hdr.list) { + if (d_i->plr) + cpumask_or(cpu_with_psl, cpu_with_psl, + &d_i->hdr.cpu_mask); + } + } + + /* + * Next test if new pseudo-locked region would intersect with + * existing region. + */ + if (cpumask_intersects(&d->hdr.cpu_mask, cpu_with_psl)) + ret = true; + + free_cpumask_var(cpu_with_psl); + return ret; +} + +/** + * pseudo_lock_measure_cycles - Trigger latency measure to pseudo-locked region + * @rdtgrp: Resource group to which the pseudo-locked region belongs. + * @sel: Selector of which measurement to perform on a pseudo-locked region. + * + * The measurement of latency to access a pseudo-locked region should be + * done from a cpu that is associated with that pseudo-locked region. + * Determine which cpu is associated with this region and start a thread on + * that cpu to perform the measurement, wait for that thread to complete. + * + * Return: 0 on success, <0 on failure + */ +static int pseudo_lock_measure_cycles(struct rdtgroup *rdtgrp, int sel) +{ + struct pseudo_lock_region *plr = rdtgrp->plr; + struct task_struct *thread; + unsigned int cpu; + int ret = -1; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + if (rdtgrp->flags & RDT_DELETED) { + ret = -ENODEV; + goto out; + } + + if (!plr->d) { + ret = -ENODEV; + goto out; + } + + plr->thread_done = 0; + cpu = cpumask_first(&plr->d->hdr.cpu_mask); + if (!cpu_online(cpu)) { + ret = -ENODEV; + goto out; + } + + plr->cpu = cpu; + + if (sel == 1) + thread = kthread_run_on_cpu(resctrl_arch_measure_cycles_lat_fn, + plr, cpu, "pseudo_lock_measure/%u"); + else if (sel == 2) + thread = kthread_run_on_cpu(resctrl_arch_measure_l2_residency, + plr, cpu, "pseudo_lock_measure/%u"); + else if (sel == 3) + thread = kthread_run_on_cpu(resctrl_arch_measure_l3_residency, + plr, cpu, "pseudo_lock_measure/%u"); + else + goto out; + + if (IS_ERR(thread)) { + ret = PTR_ERR(thread); + goto out; + } + + ret = wait_event_interruptible(plr->lock_thread_wq, + plr->thread_done == 1); + if (ret < 0) + goto out; + + ret = 0; + +out: + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + return ret; +} + +static ssize_t pseudo_lock_measure_trigger(struct file *file, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct rdtgroup *rdtgrp = file->private_data; + size_t buf_size; + char buf[32]; + int ret; + int sel; + + buf_size = min(count, (sizeof(buf) - 1)); + if (copy_from_user(buf, user_buf, buf_size)) + return -EFAULT; + + buf[buf_size] = '\0'; + ret = kstrtoint(buf, 10, &sel); + if (ret == 0) { + if (sel != 1 && sel != 2 && sel != 3) + return -EINVAL; + ret = debugfs_file_get(file->f_path.dentry); + if (ret) + return ret; + ret = pseudo_lock_measure_cycles(rdtgrp, sel); + if (ret == 0) + ret = count; + debugfs_file_put(file->f_path.dentry); + } + + return ret; +} + +static const struct file_operations pseudo_measure_fops = { + .write = pseudo_lock_measure_trigger, + .open = simple_open, + .llseek = default_llseek, +}; + +/** + * rdtgroup_pseudo_lock_create - Create a pseudo-locked region + * @rdtgrp: resource group to which pseudo-lock region belongs + * + * Called when a resource group in the pseudo-locksetup mode receives a + * valid schemata that should be pseudo-locked. Since the resource group is + * in pseudo-locksetup mode the &struct pseudo_lock_region has already been + * allocated and initialized with the essential information. If a failure + * occurs the resource group remains in the pseudo-locksetup mode with the + * &struct pseudo_lock_region associated with it, but cleared from all + * information and ready for the user to re-attempt pseudo-locking by + * writing the schemata again. + * + * Return: 0 if the pseudo-locked region was successfully pseudo-locked, <0 + * on failure. Descriptive error will be written to last_cmd_status buffer. + */ +int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp) +{ + struct pseudo_lock_region *plr = rdtgrp->plr; + struct task_struct *thread; + unsigned int new_minor; + struct device *dev; + char *kn_name __free(kfree) = NULL; + int ret; + + ret = pseudo_lock_region_alloc(plr); + if (ret < 0) + return ret; + + ret = pseudo_lock_cstates_constrain(plr); + if (ret < 0) { + ret = -EINVAL; + goto out_region; + } + kn_name = kstrdup(rdt_kn_name(rdtgrp->kn), GFP_KERNEL); + if (!kn_name) { + ret = -ENOMEM; + goto out_cstates; + } + + plr->thread_done = 0; + + thread = kthread_run_on_cpu(resctrl_arch_pseudo_lock_fn, plr, + plr->cpu, "pseudo_lock/%u"); + if (IS_ERR(thread)) { + ret = PTR_ERR(thread); + rdt_last_cmd_printf("Locking thread returned error %d\n", ret); + goto out_cstates; + } + + ret = wait_event_interruptible(plr->lock_thread_wq, + plr->thread_done == 1); + if (ret < 0) { + /* + * If the thread does not get on the CPU for whatever + * reason and the process which sets up the region is + * interrupted then this will leave the thread in runnable + * state and once it gets on the CPU it will dereference + * the cleared, but not freed, plr struct resulting in an + * empty pseudo-locking loop. + */ + rdt_last_cmd_puts("Locking thread interrupted\n"); + goto out_cstates; + } + + ret = pseudo_lock_minor_get(&new_minor); + if (ret < 0) { + rdt_last_cmd_puts("Unable to obtain a new minor number\n"); + goto out_cstates; + } + + /* + * Unlock access but do not release the reference. The + * pseudo-locked region will still be here on return. + * + * The mutex has to be released temporarily to avoid a potential + * deadlock with the mm->mmap_lock which is obtained in the + * device_create() and debugfs_create_dir() callpath below as well as + * before the mmap() callback is called. + */ + mutex_unlock(&rdtgroup_mutex); + + if (!IS_ERR_OR_NULL(debugfs_resctrl)) { + plr->debugfs_dir = debugfs_create_dir(kn_name, debugfs_resctrl); + if (!IS_ERR_OR_NULL(plr->debugfs_dir)) + debugfs_create_file("pseudo_lock_measure", 0200, + plr->debugfs_dir, rdtgrp, + &pseudo_measure_fops); + } + + dev = device_create(&pseudo_lock_class, NULL, + MKDEV(pseudo_lock_major, new_minor), + rdtgrp, "%s", kn_name); + + mutex_lock(&rdtgroup_mutex); + + if (IS_ERR(dev)) { + ret = PTR_ERR(dev); + rdt_last_cmd_printf("Failed to create character device: %d\n", + ret); + goto out_debugfs; + } + + /* We released the mutex - check if group was removed while we did so */ + if (rdtgrp->flags & RDT_DELETED) { + ret = -ENODEV; + goto out_device; + } + + plr->minor = new_minor; + + rdtgrp->mode = RDT_MODE_PSEUDO_LOCKED; + closid_free(rdtgrp->closid); + rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0444); + rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0444); + + ret = 0; + goto out; + +out_device: + device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, new_minor)); +out_debugfs: + debugfs_remove_recursive(plr->debugfs_dir); + pseudo_lock_minor_release(new_minor); +out_cstates: + pseudo_lock_cstates_relax(plr); +out_region: + pseudo_lock_region_clear(plr); +out: + return ret; +} + +/** + * rdtgroup_pseudo_lock_remove - Remove a pseudo-locked region + * @rdtgrp: resource group to which the pseudo-locked region belongs + * + * The removal of a pseudo-locked region can be initiated when the resource + * group is removed from user space via a "rmdir" from userspace or the + * unmount of the resctrl filesystem. On removal the resource group does + * not go back to pseudo-locksetup mode before it is removed, instead it is + * removed directly. There is thus asymmetry with the creation where the + * &struct pseudo_lock_region is removed here while it was not created in + * rdtgroup_pseudo_lock_create(). + * + * Return: void + */ +void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp) +{ + struct pseudo_lock_region *plr = rdtgrp->plr; + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + /* + * Default group cannot be a pseudo-locked region so we can + * free closid here. + */ + closid_free(rdtgrp->closid); + goto free; + } + + pseudo_lock_cstates_relax(plr); + debugfs_remove_recursive(rdtgrp->plr->debugfs_dir); + device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, plr->minor)); + pseudo_lock_minor_release(plr->minor); + +free: + pseudo_lock_free(rdtgrp); +} + +static int pseudo_lock_dev_open(struct inode *inode, struct file *filp) +{ + struct rdtgroup *rdtgrp; + + mutex_lock(&rdtgroup_mutex); + + rdtgrp = region_find_by_minor(iminor(inode)); + if (!rdtgrp) { + mutex_unlock(&rdtgroup_mutex); + return -ENODEV; + } + + filp->private_data = rdtgrp; + atomic_inc(&rdtgrp->waitcount); + /* Perform a non-seekable open - llseek is not supported */ + filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); + + mutex_unlock(&rdtgroup_mutex); + + return 0; +} + +static int pseudo_lock_dev_release(struct inode *inode, struct file *filp) +{ + struct rdtgroup *rdtgrp; + + mutex_lock(&rdtgroup_mutex); + rdtgrp = filp->private_data; + WARN_ON(!rdtgrp); + if (!rdtgrp) { + mutex_unlock(&rdtgroup_mutex); + return -ENODEV; + } + filp->private_data = NULL; + atomic_dec(&rdtgrp->waitcount); + mutex_unlock(&rdtgroup_mutex); + return 0; +} + +static int pseudo_lock_dev_mremap(struct vm_area_struct *area) +{ + /* Not supported */ + return -EINVAL; +} + +static const struct vm_operations_struct pseudo_mmap_ops = { + .mremap = pseudo_lock_dev_mremap, +}; + +static int pseudo_lock_dev_mmap(struct file *filp, struct vm_area_struct *vma) +{ + unsigned long vsize = vma->vm_end - vma->vm_start; + unsigned long off = vma->vm_pgoff << PAGE_SHIFT; + struct pseudo_lock_region *plr; + struct rdtgroup *rdtgrp; + unsigned long physical; + unsigned long psize; + + mutex_lock(&rdtgroup_mutex); + + rdtgrp = filp->private_data; + WARN_ON(!rdtgrp); + if (!rdtgrp) { + mutex_unlock(&rdtgroup_mutex); + return -ENODEV; + } + + plr = rdtgrp->plr; + + if (!plr->d) { + mutex_unlock(&rdtgroup_mutex); + return -ENODEV; + } + + /* + * Task is required to run with affinity to the cpus associated + * with the pseudo-locked region. If this is not the case the task + * may be scheduled elsewhere and invalidate entries in the + * pseudo-locked region. + */ + if (!cpumask_subset(current->cpus_ptr, &plr->d->hdr.cpu_mask)) { + mutex_unlock(&rdtgroup_mutex); + return -EINVAL; + } + + physical = __pa(plr->kmem) >> PAGE_SHIFT; + psize = plr->size - off; + + if (off > plr->size) { + mutex_unlock(&rdtgroup_mutex); + return -ENOSPC; + } + + /* + * Ensure changes are carried directly to the memory being mapped, + * do not allow copy-on-write mapping. + */ + if (!(vma->vm_flags & VM_SHARED)) { + mutex_unlock(&rdtgroup_mutex); + return -EINVAL; + } + + if (vsize > psize) { + mutex_unlock(&rdtgroup_mutex); + return -ENOSPC; + } + + memset(plr->kmem + off, 0, vsize); + + if (remap_pfn_range(vma, vma->vm_start, physical + vma->vm_pgoff, + vsize, vma->vm_page_prot)) { + mutex_unlock(&rdtgroup_mutex); + return -EAGAIN; + } + vma->vm_ops = &pseudo_mmap_ops; + mutex_unlock(&rdtgroup_mutex); + return 0; +} + +static const struct file_operations pseudo_lock_dev_fops = { + .owner = THIS_MODULE, + .read = NULL, + .write = NULL, + .open = pseudo_lock_dev_open, + .release = pseudo_lock_dev_release, + .mmap = pseudo_lock_dev_mmap, +}; + +int rdt_pseudo_lock_init(void) +{ + int ret; + + ret = register_chrdev(0, "pseudo_lock", &pseudo_lock_dev_fops); + if (ret < 0) + return ret; + + pseudo_lock_major = ret; + + ret = class_register(&pseudo_lock_class); + if (ret) { + unregister_chrdev(pseudo_lock_major, "pseudo_lock"); + return ret; + } + + return 0; +} + +void rdt_pseudo_lock_release(void) +{ + class_unregister(&pseudo_lock_class); + unregister_chrdev(pseudo_lock_major, "pseudo_lock"); + pseudo_lock_major = 0; +} diff --git a/fs/resctrl/pseudo_lock_trace.h b/fs/resctrl/pseudo_lock_trace.h deleted file mode 100644 index e69de29bb2d1..000000000000 diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c index e69de29bb2d1..cc37f58b47dd 100644 --- a/fs/resctrl/rdtgroup.c +++ b/fs/resctrl/rdtgroup.c @@ -0,0 +1,4353 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * User interface for Resource Allocation in Resource Director Technology(RDT) + * + * Copyright (C) 2016 Intel Corporation + * + * Author: Fenghua Yu + * + * More information about RDT be found in the Intel (R) x86 Architecture + * Software Developer Manual. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "internal.h" + +/* Mutex to protect rdtgroup access. */ +DEFINE_MUTEX(rdtgroup_mutex); + +static struct kernfs_root *rdt_root; + +struct rdtgroup rdtgroup_default; + +LIST_HEAD(rdt_all_groups); + +/* list of entries for the schemata file */ +LIST_HEAD(resctrl_schema_all); + +/* + * List of struct mon_data containing private data of event files for use by + * rdtgroup_mondata_show(). Protected by rdtgroup_mutex. + */ +static LIST_HEAD(mon_data_kn_priv_list); + +/* The filesystem can only be mounted once. */ +bool resctrl_mounted; + +/* Kernel fs node for "info" directory under root */ +static struct kernfs_node *kn_info; + +/* Kernel fs node for "mon_groups" directory under root */ +static struct kernfs_node *kn_mongrp; + +/* Kernel fs node for "mon_data" directory under root */ +static struct kernfs_node *kn_mondata; + +/* + * Used to store the max resource name width to display the schemata names in + * a tabular format. + */ +int max_name_width; + +static struct seq_buf last_cmd_status; + +static char last_cmd_status_buf[512]; + +static int rdtgroup_setup_root(struct rdt_fs_context *ctx); + +static void rdtgroup_destroy_root(void); + +struct dentry *debugfs_resctrl; + +/* + * Memory bandwidth monitoring event to use for the default CTRL_MON group + * and each new CTRL_MON group created by the user. Only relevant when + * the filesystem is mounted with the "mba_MBps" option so it does not + * matter that it remains uninitialized on systems that do not support + * the "mba_MBps" option. + */ +enum resctrl_event_id mba_mbps_default_event; + +static bool resctrl_debug; + +void rdt_last_cmd_clear(void) +{ + lockdep_assert_held(&rdtgroup_mutex); + seq_buf_clear(&last_cmd_status); +} + +void rdt_last_cmd_puts(const char *s) +{ + lockdep_assert_held(&rdtgroup_mutex); + seq_buf_puts(&last_cmd_status, s); +} + +void rdt_last_cmd_printf(const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + lockdep_assert_held(&rdtgroup_mutex); + seq_buf_vprintf(&last_cmd_status, fmt, ap); + va_end(ap); +} + +void rdt_staged_configs_clear(void) +{ + struct rdt_ctrl_domain *dom; + struct rdt_resource *r; + + lockdep_assert_held(&rdtgroup_mutex); + + for_each_alloc_capable_rdt_resource(r) { + list_for_each_entry(dom, &r->ctrl_domains, hdr.list) + memset(dom->staged_config, 0, sizeof(dom->staged_config)); + } +} + +static bool resctrl_is_mbm_enabled(void) +{ + return (resctrl_arch_is_mbm_total_enabled() || + resctrl_arch_is_mbm_local_enabled()); +} + +static bool resctrl_is_mbm_event(int e) +{ + return (e >= QOS_L3_MBM_TOTAL_EVENT_ID && + e <= QOS_L3_MBM_LOCAL_EVENT_ID); +} + +/* + * Trivial allocator for CLOSIDs. Use BITMAP APIs to manipulate a bitmap + * of free CLOSIDs. + * + * Using a global CLOSID across all resources has some advantages and + * some drawbacks: + * + We can simply set current's closid to assign a task to a resource + * group. + * + Context switch code can avoid extra memory references deciding which + * CLOSID to load into the PQR_ASSOC MSR + * - We give up some options in configuring resource groups across multi-socket + * systems. + * - Our choices on how to configure each resource become progressively more + * limited as the number of resources grows. + */ +static unsigned long *closid_free_map; + +static int closid_free_map_len; + +int closids_supported(void) +{ + return closid_free_map_len; +} + +static int closid_init(void) +{ + struct resctrl_schema *s; + u32 rdt_min_closid = ~0; + + /* Monitor only platforms still call closid_init() */ + if (list_empty(&resctrl_schema_all)) + return 0; + + /* Compute rdt_min_closid across all resources */ + list_for_each_entry(s, &resctrl_schema_all, list) + rdt_min_closid = min(rdt_min_closid, s->num_closid); + + closid_free_map = bitmap_alloc(rdt_min_closid, GFP_KERNEL); + if (!closid_free_map) + return -ENOMEM; + bitmap_fill(closid_free_map, rdt_min_closid); + + /* RESCTRL_RESERVED_CLOSID is always reserved for the default group */ + __clear_bit(RESCTRL_RESERVED_CLOSID, closid_free_map); + closid_free_map_len = rdt_min_closid; + + return 0; +} + +static void closid_exit(void) +{ + bitmap_free(closid_free_map); + closid_free_map = NULL; +} + +static int closid_alloc(void) +{ + int cleanest_closid; + u32 closid; + + lockdep_assert_held(&rdtgroup_mutex); + + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID) && + resctrl_arch_is_llc_occupancy_enabled()) { + cleanest_closid = resctrl_find_cleanest_closid(); + if (cleanest_closid < 0) + return cleanest_closid; + closid = cleanest_closid; + } else { + closid = find_first_bit(closid_free_map, closid_free_map_len); + if (closid == closid_free_map_len) + return -ENOSPC; + } + __clear_bit(closid, closid_free_map); + + return closid; +} + +void closid_free(int closid) +{ + lockdep_assert_held(&rdtgroup_mutex); + + __set_bit(closid, closid_free_map); +} + +/** + * closid_allocated - test if provided closid is in use + * @closid: closid to be tested + * + * Return: true if @closid is currently associated with a resource group, + * false if @closid is free + */ +bool closid_allocated(unsigned int closid) +{ + lockdep_assert_held(&rdtgroup_mutex); + + return !test_bit(closid, closid_free_map); +} + +/** + * rdtgroup_mode_by_closid - Return mode of resource group with closid + * @closid: closid if the resource group + * + * Each resource group is associated with a @closid. Here the mode + * of a resource group can be queried by searching for it using its closid. + * + * Return: mode as &enum rdtgrp_mode of resource group with closid @closid + */ +enum rdtgrp_mode rdtgroup_mode_by_closid(int closid) +{ + struct rdtgroup *rdtgrp; + + list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { + if (rdtgrp->closid == closid) + return rdtgrp->mode; + } + + return RDT_NUM_MODES; +} + +static const char * const rdt_mode_str[] = { + [RDT_MODE_SHAREABLE] = "shareable", + [RDT_MODE_EXCLUSIVE] = "exclusive", + [RDT_MODE_PSEUDO_LOCKSETUP] = "pseudo-locksetup", + [RDT_MODE_PSEUDO_LOCKED] = "pseudo-locked", +}; + +/** + * rdtgroup_mode_str - Return the string representation of mode + * @mode: the resource group mode as &enum rdtgroup_mode + * + * Return: string representation of valid mode, "unknown" otherwise + */ +static const char *rdtgroup_mode_str(enum rdtgrp_mode mode) +{ + if (mode < RDT_MODE_SHAREABLE || mode >= RDT_NUM_MODES) + return "unknown"; + + return rdt_mode_str[mode]; +} + +/* set uid and gid of rdtgroup dirs and files to that of the creator */ +static int rdtgroup_kn_set_ugid(struct kernfs_node *kn) +{ + struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID, + .ia_uid = current_fsuid(), + .ia_gid = current_fsgid(), }; + + if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) && + gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID)) + return 0; + + return kernfs_setattr(kn, &iattr); +} + +static int rdtgroup_add_file(struct kernfs_node *parent_kn, struct rftype *rft) +{ + struct kernfs_node *kn; + int ret; + + kn = __kernfs_create_file(parent_kn, rft->name, rft->mode, + GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, + 0, rft->kf_ops, rft, NULL, NULL); + if (IS_ERR(kn)) + return PTR_ERR(kn); + + ret = rdtgroup_kn_set_ugid(kn); + if (ret) { + kernfs_remove(kn); + return ret; + } + + return 0; +} + +static int rdtgroup_seqfile_show(struct seq_file *m, void *arg) +{ + struct kernfs_open_file *of = m->private; + struct rftype *rft = of->kn->priv; + + if (rft->seq_show) + return rft->seq_show(of, m, arg); + return 0; +} + +static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf, + size_t nbytes, loff_t off) +{ + struct rftype *rft = of->kn->priv; + + if (rft->write) + return rft->write(of, buf, nbytes, off); + + return -EINVAL; +} + +static const struct kernfs_ops rdtgroup_kf_single_ops = { + .atomic_write_len = PAGE_SIZE, + .write = rdtgroup_file_write, + .seq_show = rdtgroup_seqfile_show, +}; + +static const struct kernfs_ops kf_mondata_ops = { + .atomic_write_len = PAGE_SIZE, + .seq_show = rdtgroup_mondata_show, +}; + +static bool is_cpu_list(struct kernfs_open_file *of) +{ + struct rftype *rft = of->kn->priv; + + return rft->flags & RFTYPE_FLAGS_CPUS_LIST; +} + +static int rdtgroup_cpus_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + struct cpumask *mask; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + + if (rdtgrp) { + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + if (!rdtgrp->plr->d) { + rdt_last_cmd_clear(); + rdt_last_cmd_puts("Cache domain offline\n"); + ret = -ENODEV; + } else { + mask = &rdtgrp->plr->d->hdr.cpu_mask; + seq_printf(s, is_cpu_list(of) ? + "%*pbl\n" : "%*pb\n", + cpumask_pr_args(mask)); + } + } else { + seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n", + cpumask_pr_args(&rdtgrp->cpu_mask)); + } + } else { + ret = -ENOENT; + } + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +/* + * Update the PGR_ASSOC MSR on all cpus in @cpu_mask, + * + * Per task closids/rmids must have been set up before calling this function. + * @r may be NULL. + */ +static void +update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r) +{ + struct resctrl_cpu_defaults defaults, *p = NULL; + + if (r) { + defaults.closid = r->closid; + defaults.rmid = r->mon.rmid; + p = &defaults; + } + + on_each_cpu_mask(cpu_mask, resctrl_arch_sync_cpu_closid_rmid, p, 1); +} + +static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask, + cpumask_var_t tmpmask) +{ + struct rdtgroup *prgrp = rdtgrp->mon.parent, *crgrp; + struct list_head *head; + + /* Check whether cpus belong to parent ctrl group */ + cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask); + if (!cpumask_empty(tmpmask)) { + rdt_last_cmd_puts("Can only add CPUs to mongroup that belong to parent\n"); + return -EINVAL; + } + + /* Check whether cpus are dropped from this group */ + cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask); + if (!cpumask_empty(tmpmask)) { + /* Give any dropped cpus to parent rdtgroup */ + cpumask_or(&prgrp->cpu_mask, &prgrp->cpu_mask, tmpmask); + update_closid_rmid(tmpmask, prgrp); + } + + /* + * If we added cpus, remove them from previous group that owned them + * and update per-cpu rmid + */ + cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask); + if (!cpumask_empty(tmpmask)) { + head = &prgrp->mon.crdtgrp_list; + list_for_each_entry(crgrp, head, mon.crdtgrp_list) { + if (crgrp == rdtgrp) + continue; + cpumask_andnot(&crgrp->cpu_mask, &crgrp->cpu_mask, + tmpmask); + } + update_closid_rmid(tmpmask, rdtgrp); + } + + /* Done pushing/pulling - update this group with new mask */ + cpumask_copy(&rdtgrp->cpu_mask, newmask); + + return 0; +} + +static void cpumask_rdtgrp_clear(struct rdtgroup *r, struct cpumask *m) +{ + struct rdtgroup *crgrp; + + cpumask_andnot(&r->cpu_mask, &r->cpu_mask, m); + /* update the child mon group masks as well*/ + list_for_each_entry(crgrp, &r->mon.crdtgrp_list, mon.crdtgrp_list) + cpumask_and(&crgrp->cpu_mask, &r->cpu_mask, &crgrp->cpu_mask); +} + +static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask, + cpumask_var_t tmpmask, cpumask_var_t tmpmask1) +{ + struct rdtgroup *r, *crgrp; + struct list_head *head; + + /* Check whether cpus are dropped from this group */ + cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask); + if (!cpumask_empty(tmpmask)) { + /* Can't drop from default group */ + if (rdtgrp == &rdtgroup_default) { + rdt_last_cmd_puts("Can't drop CPUs from default group\n"); + return -EINVAL; + } + + /* Give any dropped cpus to rdtgroup_default */ + cpumask_or(&rdtgroup_default.cpu_mask, + &rdtgroup_default.cpu_mask, tmpmask); + update_closid_rmid(tmpmask, &rdtgroup_default); + } + + /* + * If we added cpus, remove them from previous group and + * the prev group's child groups that owned them + * and update per-cpu closid/rmid. + */ + cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask); + if (!cpumask_empty(tmpmask)) { + list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) { + if (r == rdtgrp) + continue; + cpumask_and(tmpmask1, &r->cpu_mask, tmpmask); + if (!cpumask_empty(tmpmask1)) + cpumask_rdtgrp_clear(r, tmpmask1); + } + update_closid_rmid(tmpmask, rdtgrp); + } + + /* Done pushing/pulling - update this group with new mask */ + cpumask_copy(&rdtgrp->cpu_mask, newmask); + + /* + * Clear child mon group masks since there is a new parent mask + * now and update the rmid for the cpus the child lost. + */ + head = &rdtgrp->mon.crdtgrp_list; + list_for_each_entry(crgrp, head, mon.crdtgrp_list) { + cpumask_and(tmpmask, &rdtgrp->cpu_mask, &crgrp->cpu_mask); + update_closid_rmid(tmpmask, rdtgrp); + cpumask_clear(&crgrp->cpu_mask); + } + + return 0; +} + +static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + cpumask_var_t tmpmask, newmask, tmpmask1; + struct rdtgroup *rdtgrp; + int ret; + + if (!buf) + return -EINVAL; + + if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) + return -ENOMEM; + if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) { + free_cpumask_var(tmpmask); + return -ENOMEM; + } + if (!zalloc_cpumask_var(&tmpmask1, GFP_KERNEL)) { + free_cpumask_var(tmpmask); + free_cpumask_var(newmask); + return -ENOMEM; + } + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + ret = -ENOENT; + goto unlock; + } + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + ret = -EINVAL; + rdt_last_cmd_puts("Pseudo-locking in progress\n"); + goto unlock; + } + + if (is_cpu_list(of)) + ret = cpulist_parse(buf, newmask); + else + ret = cpumask_parse(buf, newmask); + + if (ret) { + rdt_last_cmd_puts("Bad CPU list/mask\n"); + goto unlock; + } + + /* check that user didn't specify any offline cpus */ + cpumask_andnot(tmpmask, newmask, cpu_online_mask); + if (!cpumask_empty(tmpmask)) { + ret = -EINVAL; + rdt_last_cmd_puts("Can only assign online CPUs\n"); + goto unlock; + } + + if (rdtgrp->type == RDTCTRL_GROUP) + ret = cpus_ctrl_write(rdtgrp, newmask, tmpmask, tmpmask1); + else if (rdtgrp->type == RDTMON_GROUP) + ret = cpus_mon_write(rdtgrp, newmask, tmpmask); + else + ret = -EINVAL; + +unlock: + rdtgroup_kn_unlock(of->kn); + free_cpumask_var(tmpmask); + free_cpumask_var(newmask); + free_cpumask_var(tmpmask1); + + return ret ?: nbytes; +} + +/** + * rdtgroup_remove - the helper to remove resource group safely + * @rdtgrp: resource group to remove + * + * On resource group creation via a mkdir, an extra kernfs_node reference is + * taken to ensure that the rdtgroup structure remains accessible for the + * rdtgroup_kn_unlock() calls where it is removed. + * + * Drop the extra reference here, then free the rdtgroup structure. + * + * Return: void + */ +static void rdtgroup_remove(struct rdtgroup *rdtgrp) +{ + kernfs_put(rdtgrp->kn); + kfree(rdtgrp); +} + +static void _update_task_closid_rmid(void *task) +{ + /* + * If the task is still current on this CPU, update PQR_ASSOC MSR. + * Otherwise, the MSR is updated when the task is scheduled in. + */ + if (task == current) + resctrl_arch_sched_in(task); +} + +static void update_task_closid_rmid(struct task_struct *t) +{ + if (IS_ENABLED(CONFIG_SMP) && task_curr(t)) + smp_call_function_single(task_cpu(t), _update_task_closid_rmid, t, 1); + else + _update_task_closid_rmid(t); +} + +static bool task_in_rdtgroup(struct task_struct *tsk, struct rdtgroup *rdtgrp) +{ + u32 closid, rmid = rdtgrp->mon.rmid; + + if (rdtgrp->type == RDTCTRL_GROUP) + closid = rdtgrp->closid; + else if (rdtgrp->type == RDTMON_GROUP) + closid = rdtgrp->mon.parent->closid; + else + return false; + + return resctrl_arch_match_closid(tsk, closid) && + resctrl_arch_match_rmid(tsk, closid, rmid); +} + +static int __rdtgroup_move_task(struct task_struct *tsk, + struct rdtgroup *rdtgrp) +{ + /* If the task is already in rdtgrp, no need to move the task. */ + if (task_in_rdtgroup(tsk, rdtgrp)) + return 0; + + /* + * Set the task's closid/rmid before the PQR_ASSOC MSR can be + * updated by them. + * + * For ctrl_mon groups, move both closid and rmid. + * For monitor groups, can move the tasks only from + * their parent CTRL group. + */ + if (rdtgrp->type == RDTMON_GROUP && + !resctrl_arch_match_closid(tsk, rdtgrp->mon.parent->closid)) { + rdt_last_cmd_puts("Can't move task to different control group\n"); + return -EINVAL; + } + + if (rdtgrp->type == RDTMON_GROUP) + resctrl_arch_set_closid_rmid(tsk, rdtgrp->mon.parent->closid, + rdtgrp->mon.rmid); + else + resctrl_arch_set_closid_rmid(tsk, rdtgrp->closid, + rdtgrp->mon.rmid); + + /* + * Ensure the task's closid and rmid are written before determining if + * the task is current that will decide if it will be interrupted. + * This pairs with the full barrier between the rq->curr update and + * resctrl_arch_sched_in() during context switch. + */ + smp_mb(); + + /* + * By now, the task's closid and rmid are set. If the task is current + * on a CPU, the PQR_ASSOC MSR needs to be updated to make the resource + * group go into effect. If the task is not current, the MSR will be + * updated when the task is scheduled in. + */ + update_task_closid_rmid(tsk); + + return 0; +} + +static bool is_closid_match(struct task_struct *t, struct rdtgroup *r) +{ + return (resctrl_arch_alloc_capable() && (r->type == RDTCTRL_GROUP) && + resctrl_arch_match_closid(t, r->closid)); +} + +static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r) +{ + return (resctrl_arch_mon_capable() && (r->type == RDTMON_GROUP) && + resctrl_arch_match_rmid(t, r->mon.parent->closid, + r->mon.rmid)); +} + +/** + * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group + * @r: Resource group + * + * Return: 1 if tasks have been assigned to @r, 0 otherwise + */ +int rdtgroup_tasks_assigned(struct rdtgroup *r) +{ + struct task_struct *p, *t; + int ret = 0; + + lockdep_assert_held(&rdtgroup_mutex); + + rcu_read_lock(); + for_each_process_thread(p, t) { + if (is_closid_match(t, r) || is_rmid_match(t, r)) { + ret = 1; + break; + } + } + rcu_read_unlock(); + + return ret; +} + +static int rdtgroup_task_write_permission(struct task_struct *task, + struct kernfs_open_file *of) +{ + const struct cred *tcred = get_task_cred(task); + const struct cred *cred = current_cred(); + int ret = 0; + + /* + * Even if we're attaching all tasks in the thread group, we only + * need to check permissions on one of them. + */ + if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) && + !uid_eq(cred->euid, tcred->uid) && + !uid_eq(cred->euid, tcred->suid)) { + rdt_last_cmd_printf("No permission to move task %d\n", task->pid); + ret = -EPERM; + } + + put_cred(tcred); + return ret; +} + +static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp, + struct kernfs_open_file *of) +{ + struct task_struct *tsk; + int ret; + + rcu_read_lock(); + if (pid) { + tsk = find_task_by_vpid(pid); + if (!tsk) { + rcu_read_unlock(); + rdt_last_cmd_printf("No task %d\n", pid); + return -ESRCH; + } + } else { + tsk = current; + } + + get_task_struct(tsk); + rcu_read_unlock(); + + ret = rdtgroup_task_write_permission(tsk, of); + if (!ret) + ret = __rdtgroup_move_task(tsk, rdtgrp); + + put_task_struct(tsk); + return ret; +} + +static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct rdtgroup *rdtgrp; + char *pid_str; + int ret = 0; + pid_t pid; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + rdtgroup_kn_unlock(of->kn); + return -ENOENT; + } + rdt_last_cmd_clear(); + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + ret = -EINVAL; + rdt_last_cmd_puts("Pseudo-locking in progress\n"); + goto unlock; + } + + while (buf && buf[0] != '\0' && buf[0] != '\n') { + pid_str = strim(strsep(&buf, ",")); + + if (kstrtoint(pid_str, 0, &pid)) { + rdt_last_cmd_printf("Task list parsing error pid %s\n", pid_str); + ret = -EINVAL; + break; + } + + if (pid < 0) { + rdt_last_cmd_printf("Invalid pid %d\n", pid); + ret = -EINVAL; + break; + } + + ret = rdtgroup_move_task(pid, rdtgrp, of); + if (ret) { + rdt_last_cmd_printf("Error while processing task %d\n", pid); + break; + } + } + +unlock: + rdtgroup_kn_unlock(of->kn); + + return ret ?: nbytes; +} + +static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s) +{ + struct task_struct *p, *t; + pid_t pid; + + rcu_read_lock(); + for_each_process_thread(p, t) { + if (is_closid_match(t, r) || is_rmid_match(t, r)) { + pid = task_pid_vnr(t); + if (pid) + seq_printf(s, "%d\n", pid); + } + } + rcu_read_unlock(); +} + +static int rdtgroup_tasks_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (rdtgrp) + show_rdt_tasks(rdtgrp, s); + else + ret = -ENOENT; + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +static int rdtgroup_closid_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (rdtgrp) + seq_printf(s, "%u\n", rdtgrp->closid); + else + ret = -ENOENT; + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +static int rdtgroup_rmid_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (rdtgrp) + seq_printf(s, "%u\n", rdtgrp->mon.rmid); + else + ret = -ENOENT; + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +#ifdef CONFIG_PROC_CPU_RESCTRL +/* + * A task can only be part of one resctrl control group and of one monitor + * group which is associated to that control group. + * + * 1) res: + * mon: + * + * resctrl is not available. + * + * 2) res:/ + * mon: + * + * Task is part of the root resctrl control group, and it is not associated + * to any monitor group. + * + * 3) res:/ + * mon:mon0 + * + * Task is part of the root resctrl control group and monitor group mon0. + * + * 4) res:group0 + * mon: + * + * Task is part of resctrl control group group0, and it is not associated + * to any monitor group. + * + * 5) res:group0 + * mon:mon1 + * + * Task is part of resctrl control group group0 and monitor group mon1. + */ +int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns, + struct pid *pid, struct task_struct *tsk) +{ + struct rdtgroup *rdtg; + int ret = 0; + + mutex_lock(&rdtgroup_mutex); + + /* Return empty if resctrl has not been mounted. */ + if (!resctrl_mounted) { + seq_puts(s, "res:\nmon:\n"); + goto unlock; + } + + list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) { + struct rdtgroup *crg; + + /* + * Task information is only relevant for shareable + * and exclusive groups. + */ + if (rdtg->mode != RDT_MODE_SHAREABLE && + rdtg->mode != RDT_MODE_EXCLUSIVE) + continue; + + if (!resctrl_arch_match_closid(tsk, rdtg->closid)) + continue; + + seq_printf(s, "res:%s%s\n", (rdtg == &rdtgroup_default) ? "/" : "", + rdt_kn_name(rdtg->kn)); + seq_puts(s, "mon:"); + list_for_each_entry(crg, &rdtg->mon.crdtgrp_list, + mon.crdtgrp_list) { + if (!resctrl_arch_match_rmid(tsk, crg->mon.parent->closid, + crg->mon.rmid)) + continue; + seq_printf(s, "%s", rdt_kn_name(crg->kn)); + break; + } + seq_putc(s, '\n'); + goto unlock; + } + /* + * The above search should succeed. Otherwise return + * with an error. + */ + ret = -ENOENT; +unlock: + mutex_unlock(&rdtgroup_mutex); + + return ret; +} +#endif + +static int rdt_last_cmd_status_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + int len; + + mutex_lock(&rdtgroup_mutex); + len = seq_buf_used(&last_cmd_status); + if (len) + seq_printf(seq, "%.*s", len, last_cmd_status_buf); + else + seq_puts(seq, "ok\n"); + mutex_unlock(&rdtgroup_mutex); + return 0; +} + +static void *rdt_kn_parent_priv(struct kernfs_node *kn) +{ + /* + * The parent pointer is only valid within RCU section since it can be + * replaced. + */ + guard(rcu)(); + return rcu_dereference(kn->__parent)->priv; +} + +static int rdt_num_closids_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); + + seq_printf(seq, "%u\n", s->num_closid); + return 0; +} + +static int rdt_default_ctrl_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); + struct rdt_resource *r = s->res; + + seq_printf(seq, "%x\n", resctrl_get_default_ctrl(r)); + return 0; +} + +static int rdt_min_cbm_bits_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); + struct rdt_resource *r = s->res; + + seq_printf(seq, "%u\n", r->cache.min_cbm_bits); + return 0; +} + +static int rdt_shareable_bits_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); + struct rdt_resource *r = s->res; + + seq_printf(seq, "%x\n", r->cache.shareable_bits); + return 0; +} + +/* + * rdt_bit_usage_show - Display current usage of resources + * + * A domain is a shared resource that can now be allocated differently. Here + * we display the current regions of the domain as an annotated bitmask. + * For each domain of this resource its allocation bitmask + * is annotated as below to indicate the current usage of the corresponding bit: + * 0 - currently unused + * X - currently available for sharing and used by software and hardware + * H - currently used by hardware only but available for software use + * S - currently used and shareable by software only + * E - currently used exclusively by one resource group + * P - currently pseudo-locked by one resource group + */ +static int rdt_bit_usage_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); + /* + * Use unsigned long even though only 32 bits are used to ensure + * test_bit() is used safely. + */ + unsigned long sw_shareable = 0, hw_shareable = 0; + unsigned long exclusive = 0, pseudo_locked = 0; + struct rdt_resource *r = s->res; + struct rdt_ctrl_domain *dom; + int i, hwb, swb, excl, psl; + enum rdtgrp_mode mode; + bool sep = false; + u32 ctrl_val; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + hw_shareable = r->cache.shareable_bits; + list_for_each_entry(dom, &r->ctrl_domains, hdr.list) { + if (sep) + seq_putc(seq, ';'); + sw_shareable = 0; + exclusive = 0; + seq_printf(seq, "%d=", dom->hdr.id); + for (i = 0; i < closids_supported(); i++) { + if (!closid_allocated(i)) + continue; + ctrl_val = resctrl_arch_get_config(r, dom, i, + s->conf_type); + mode = rdtgroup_mode_by_closid(i); + switch (mode) { + case RDT_MODE_SHAREABLE: + sw_shareable |= ctrl_val; + break; + case RDT_MODE_EXCLUSIVE: + exclusive |= ctrl_val; + break; + case RDT_MODE_PSEUDO_LOCKSETUP: + /* + * RDT_MODE_PSEUDO_LOCKSETUP is possible + * here but not included since the CBM + * associated with this CLOSID in this mode + * is not initialized and no task or cpu can be + * assigned this CLOSID. + */ + break; + case RDT_MODE_PSEUDO_LOCKED: + case RDT_NUM_MODES: + WARN(1, + "invalid mode for closid %d\n", i); + break; + } + } + for (i = r->cache.cbm_len - 1; i >= 0; i--) { + pseudo_locked = dom->plr ? dom->plr->cbm : 0; + hwb = test_bit(i, &hw_shareable); + swb = test_bit(i, &sw_shareable); + excl = test_bit(i, &exclusive); + psl = test_bit(i, &pseudo_locked); + if (hwb && swb) + seq_putc(seq, 'X'); + else if (hwb && !swb) + seq_putc(seq, 'H'); + else if (!hwb && swb) + seq_putc(seq, 'S'); + else if (excl) + seq_putc(seq, 'E'); + else if (psl) + seq_putc(seq, 'P'); + else /* Unused bits remain */ + seq_putc(seq, '0'); + } + sep = true; + } + seq_putc(seq, '\n'); + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + return 0; +} + +static int rdt_min_bw_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); + struct rdt_resource *r = s->res; + + seq_printf(seq, "%u\n", r->membw.min_bw); + return 0; +} + +static int rdt_num_rmids_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct rdt_resource *r = rdt_kn_parent_priv(of->kn); + + seq_printf(seq, "%d\n", r->num_rmid); + + return 0; +} + +static int rdt_mon_features_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct rdt_resource *r = rdt_kn_parent_priv(of->kn); + struct mon_evt *mevt; + + list_for_each_entry(mevt, &r->evt_list, list) { + seq_printf(seq, "%s\n", mevt->name); + if (mevt->configurable) + seq_printf(seq, "%s_config\n", mevt->name); + } + + return 0; +} + +static int rdt_bw_gran_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); + struct rdt_resource *r = s->res; + + seq_printf(seq, "%u\n", r->membw.bw_gran); + return 0; +} + +static int rdt_delay_linear_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); + struct rdt_resource *r = s->res; + + seq_printf(seq, "%u\n", r->membw.delay_linear); + return 0; +} + +static int max_threshold_occ_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + seq_printf(seq, "%u\n", resctrl_rmid_realloc_threshold); + + return 0; +} + +static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); + struct rdt_resource *r = s->res; + + switch (r->membw.throttle_mode) { + case THREAD_THROTTLE_PER_THREAD: + seq_puts(seq, "per-thread\n"); + return 0; + case THREAD_THROTTLE_MAX: + seq_puts(seq, "max\n"); + return 0; + case THREAD_THROTTLE_UNDEFINED: + seq_puts(seq, "undefined\n"); + return 0; + } + + WARN_ON_ONCE(1); + + return 0; +} + +static ssize_t max_threshold_occ_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + unsigned int bytes; + int ret; + + ret = kstrtouint(buf, 0, &bytes); + if (ret) + return ret; + + if (bytes > resctrl_rmid_realloc_limit) + return -EINVAL; + + resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(bytes); + + return nbytes; +} + +/* + * rdtgroup_mode_show - Display mode of this resource group + */ +static int rdtgroup_mode_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + rdtgroup_kn_unlock(of->kn); + return -ENOENT; + } + + seq_printf(s, "%s\n", rdtgroup_mode_str(rdtgrp->mode)); + + rdtgroup_kn_unlock(of->kn); + return 0; +} + +static enum resctrl_conf_type resctrl_peer_type(enum resctrl_conf_type my_type) +{ + switch (my_type) { + case CDP_CODE: + return CDP_DATA; + case CDP_DATA: + return CDP_CODE; + default: + case CDP_NONE: + return CDP_NONE; + } +} + +static int rdt_has_sparse_bitmasks_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = rdt_kn_parent_priv(of->kn); + struct rdt_resource *r = s->res; + + seq_printf(seq, "%u\n", r->cache.arch_has_sparse_bitmasks); + + return 0; +} + +/** + * __rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other + * @r: Resource to which domain instance @d belongs. + * @d: The domain instance for which @closid is being tested. + * @cbm: Capacity bitmask being tested. + * @closid: Intended closid for @cbm. + * @type: CDP type of @r. + * @exclusive: Only check if overlaps with exclusive resource groups + * + * Checks if provided @cbm intended to be used for @closid on domain + * @d overlaps with any other closids or other hardware usage associated + * with this domain. If @exclusive is true then only overlaps with + * resource groups in exclusive mode will be considered. If @exclusive + * is false then overlaps with any resource group or hardware entities + * will be considered. + * + * @cbm is unsigned long, even if only 32 bits are used, to make the + * bitmap functions work correctly. + * + * Return: false if CBM does not overlap, true if it does. + */ +static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_ctrl_domain *d, + unsigned long cbm, int closid, + enum resctrl_conf_type type, bool exclusive) +{ + enum rdtgrp_mode mode; + unsigned long ctrl_b; + int i; + + /* Check for any overlap with regions used by hardware directly */ + if (!exclusive) { + ctrl_b = r->cache.shareable_bits; + if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) + return true; + } + + /* Check for overlap with other resource groups */ + for (i = 0; i < closids_supported(); i++) { + ctrl_b = resctrl_arch_get_config(r, d, i, type); + mode = rdtgroup_mode_by_closid(i); + if (closid_allocated(i) && i != closid && + mode != RDT_MODE_PSEUDO_LOCKSETUP) { + if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) { + if (exclusive) { + if (mode == RDT_MODE_EXCLUSIVE) + return true; + continue; + } + return true; + } + } + } + + return false; +} + +/** + * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware + * @s: Schema for the resource to which domain instance @d belongs. + * @d: The domain instance for which @closid is being tested. + * @cbm: Capacity bitmask being tested. + * @closid: Intended closid for @cbm. + * @exclusive: Only check if overlaps with exclusive resource groups + * + * Resources that can be allocated using a CBM can use the CBM to control + * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test + * for overlap. Overlap test is not limited to the specific resource for + * which the CBM is intended though - when dealing with CDP resources that + * share the underlying hardware the overlap check should be performed on + * the CDP resource sharing the hardware also. + * + * Refer to description of __rdtgroup_cbm_overlaps() for the details of the + * overlap test. + * + * Return: true if CBM overlap detected, false if there is no overlap + */ +bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d, + unsigned long cbm, int closid, bool exclusive) +{ + enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type); + struct rdt_resource *r = s->res; + + if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, s->conf_type, + exclusive)) + return true; + + if (!resctrl_arch_get_cdp_enabled(r->rid)) + return false; + return __rdtgroup_cbm_overlaps(r, d, cbm, closid, peer_type, exclusive); +} + +/** + * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive + * @rdtgrp: Resource group identified through its closid. + * + * An exclusive resource group implies that there should be no sharing of + * its allocated resources. At the time this group is considered to be + * exclusive this test can determine if its current schemata supports this + * setting by testing for overlap with all other resource groups. + * + * Return: true if resource group can be exclusive, false if there is overlap + * with allocations of other resource groups and thus this resource group + * cannot be exclusive. + */ +static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp) +{ + int closid = rdtgrp->closid; + struct rdt_ctrl_domain *d; + struct resctrl_schema *s; + struct rdt_resource *r; + bool has_cache = false; + u32 ctrl; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + list_for_each_entry(s, &resctrl_schema_all, list) { + r = s->res; + if (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA) + continue; + has_cache = true; + list_for_each_entry(d, &r->ctrl_domains, hdr.list) { + ctrl = resctrl_arch_get_config(r, d, closid, + s->conf_type); + if (rdtgroup_cbm_overlaps(s, d, ctrl, closid, false)) { + rdt_last_cmd_puts("Schemata overlaps\n"); + return false; + } + } + } + + if (!has_cache) { + rdt_last_cmd_puts("Cannot be exclusive without CAT/CDP\n"); + return false; + } + + return true; +} + +/* + * rdtgroup_mode_write - Modify the resource group's mode + */ +static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct rdtgroup *rdtgrp; + enum rdtgrp_mode mode; + int ret = 0; + + /* Valid input requires a trailing newline */ + if (nbytes == 0 || buf[nbytes - 1] != '\n') + return -EINVAL; + buf[nbytes - 1] = '\0'; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + rdtgroup_kn_unlock(of->kn); + return -ENOENT; + } + + rdt_last_cmd_clear(); + + mode = rdtgrp->mode; + + if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) || + (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) || + (!strcmp(buf, "pseudo-locksetup") && + mode == RDT_MODE_PSEUDO_LOCKSETUP) || + (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED)) + goto out; + + if (mode == RDT_MODE_PSEUDO_LOCKED) { + rdt_last_cmd_puts("Cannot change pseudo-locked group\n"); + ret = -EINVAL; + goto out; + } + + if (!strcmp(buf, "shareable")) { + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + ret = rdtgroup_locksetup_exit(rdtgrp); + if (ret) + goto out; + } + rdtgrp->mode = RDT_MODE_SHAREABLE; + } else if (!strcmp(buf, "exclusive")) { + if (!rdtgroup_mode_test_exclusive(rdtgrp)) { + ret = -EINVAL; + goto out; + } + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + ret = rdtgroup_locksetup_exit(rdtgrp); + if (ret) + goto out; + } + rdtgrp->mode = RDT_MODE_EXCLUSIVE; + } else if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK) && + !strcmp(buf, "pseudo-locksetup")) { + ret = rdtgroup_locksetup_enter(rdtgrp); + if (ret) + goto out; + rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP; + } else { + rdt_last_cmd_puts("Unknown or unsupported mode\n"); + ret = -EINVAL; + } + +out: + rdtgroup_kn_unlock(of->kn); + return ret ?: nbytes; +} + +/** + * rdtgroup_cbm_to_size - Translate CBM to size in bytes + * @r: RDT resource to which @d belongs. + * @d: RDT domain instance. + * @cbm: bitmask for which the size should be computed. + * + * The bitmask provided associated with the RDT domain instance @d will be + * translated into how many bytes it represents. The size in bytes is + * computed by first dividing the total cache size by the CBM length to + * determine how many bytes each bit in the bitmask represents. The result + * is multiplied with the number of bits set in the bitmask. + * + * @cbm is unsigned long, even if only 32 bits are used to make the + * bitmap functions work correctly. + */ +unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, + struct rdt_ctrl_domain *d, unsigned long cbm) +{ + unsigned int size = 0; + struct cacheinfo *ci; + int num_b; + + if (WARN_ON_ONCE(r->ctrl_scope != RESCTRL_L2_CACHE && r->ctrl_scope != RESCTRL_L3_CACHE)) + return size; + + num_b = bitmap_weight(&cbm, r->cache.cbm_len); + ci = get_cpu_cacheinfo_level(cpumask_any(&d->hdr.cpu_mask), r->ctrl_scope); + if (ci) + size = ci->size / r->cache.cbm_len * num_b; + + return size; +} + +bool is_mba_sc(struct rdt_resource *r) +{ + if (!r) + r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); + + /* + * The software controller support is only applicable to MBA resource. + * Make sure to check for resource type. + */ + if (r->rid != RDT_RESOURCE_MBA) + return false; + + return r->membw.mba_sc; +} + +/* + * rdtgroup_size_show - Display size in bytes of allocated regions + * + * The "size" file mirrors the layout of the "schemata" file, printing the + * size in bytes of each region instead of the capacity bitmask. + */ +static int rdtgroup_size_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct resctrl_schema *schema; + enum resctrl_conf_type type; + struct rdt_ctrl_domain *d; + struct rdtgroup *rdtgrp; + struct rdt_resource *r; + unsigned int size; + int ret = 0; + u32 closid; + bool sep; + u32 ctrl; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + rdtgroup_kn_unlock(of->kn); + return -ENOENT; + } + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + if (!rdtgrp->plr->d) { + rdt_last_cmd_clear(); + rdt_last_cmd_puts("Cache domain offline\n"); + ret = -ENODEV; + } else { + seq_printf(s, "%*s:", max_name_width, + rdtgrp->plr->s->name); + size = rdtgroup_cbm_to_size(rdtgrp->plr->s->res, + rdtgrp->plr->d, + rdtgrp->plr->cbm); + seq_printf(s, "%d=%u\n", rdtgrp->plr->d->hdr.id, size); + } + goto out; + } + + closid = rdtgrp->closid; + + list_for_each_entry(schema, &resctrl_schema_all, list) { + r = schema->res; + type = schema->conf_type; + sep = false; + seq_printf(s, "%*s:", max_name_width, schema->name); + list_for_each_entry(d, &r->ctrl_domains, hdr.list) { + if (sep) + seq_putc(s, ';'); + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + size = 0; + } else { + if (is_mba_sc(r)) + ctrl = d->mbps_val[closid]; + else + ctrl = resctrl_arch_get_config(r, d, + closid, + type); + if (r->rid == RDT_RESOURCE_MBA || + r->rid == RDT_RESOURCE_SMBA) + size = ctrl; + else + size = rdtgroup_cbm_to_size(r, d, ctrl); + } + seq_printf(s, "%d=%u", d->hdr.id, size); + sep = true; + } + seq_putc(s, '\n'); + } + +out: + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +static void mondata_config_read(struct resctrl_mon_config_info *mon_info) +{ + smp_call_function_any(&mon_info->d->hdr.cpu_mask, + resctrl_arch_mon_event_config_read, mon_info, 1); +} + +static int mbm_config_show(struct seq_file *s, struct rdt_resource *r, u32 evtid) +{ + struct resctrl_mon_config_info mon_info; + struct rdt_mon_domain *dom; + bool sep = false; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + list_for_each_entry(dom, &r->mon_domains, hdr.list) { + if (sep) + seq_puts(s, ";"); + + memset(&mon_info, 0, sizeof(struct resctrl_mon_config_info)); + mon_info.r = r; + mon_info.d = dom; + mon_info.evtid = evtid; + mondata_config_read(&mon_info); + + seq_printf(s, "%d=0x%02x", dom->hdr.id, mon_info.mon_config); + sep = true; + } + seq_puts(s, "\n"); + + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + + return 0; +} + +static int mbm_total_bytes_config_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct rdt_resource *r = rdt_kn_parent_priv(of->kn); + + mbm_config_show(seq, r, QOS_L3_MBM_TOTAL_EVENT_ID); + + return 0; +} + +static int mbm_local_bytes_config_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct rdt_resource *r = rdt_kn_parent_priv(of->kn); + + mbm_config_show(seq, r, QOS_L3_MBM_LOCAL_EVENT_ID); + + return 0; +} + +static void mbm_config_write_domain(struct rdt_resource *r, + struct rdt_mon_domain *d, u32 evtid, u32 val) +{ + struct resctrl_mon_config_info mon_info = {0}; + + /* + * Read the current config value first. If both are the same then + * no need to write it again. + */ + mon_info.r = r; + mon_info.d = d; + mon_info.evtid = evtid; + mondata_config_read(&mon_info); + if (mon_info.mon_config == val) + return; + + mon_info.mon_config = val; + + /* + * Update MSR_IA32_EVT_CFG_BASE MSR on one of the CPUs in the + * domain. The MSRs offset from MSR MSR_IA32_EVT_CFG_BASE + * are scoped at the domain level. Writing any of these MSRs + * on one CPU is observed by all the CPUs in the domain. + */ + smp_call_function_any(&d->hdr.cpu_mask, resctrl_arch_mon_event_config_write, + &mon_info, 1); + + /* + * When an Event Configuration is changed, the bandwidth counters + * for all RMIDs and Events will be cleared by the hardware. The + * hardware also sets MSR_IA32_QM_CTR.Unavailable (bit 62) for + * every RMID on the next read to any event for every RMID. + * Subsequent reads will have MSR_IA32_QM_CTR.Unavailable (bit 62) + * cleared while it is tracked by the hardware. Clear the + * mbm_local and mbm_total counts for all the RMIDs. + */ + resctrl_arch_reset_rmid_all(r, d); +} + +static int mon_config_write(struct rdt_resource *r, char *tok, u32 evtid) +{ + char *dom_str = NULL, *id_str; + unsigned long dom_id, val; + struct rdt_mon_domain *d; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + +next: + if (!tok || tok[0] == '\0') + return 0; + + /* Start processing the strings for each domain */ + dom_str = strim(strsep(&tok, ";")); + id_str = strsep(&dom_str, "="); + + if (!id_str || kstrtoul(id_str, 10, &dom_id)) { + rdt_last_cmd_puts("Missing '=' or non-numeric domain id\n"); + return -EINVAL; + } + + if (!dom_str || kstrtoul(dom_str, 16, &val)) { + rdt_last_cmd_puts("Non-numeric event configuration value\n"); + return -EINVAL; + } + + /* Value from user cannot be more than the supported set of events */ + if ((val & r->mbm_cfg_mask) != val) { + rdt_last_cmd_printf("Invalid event configuration: max valid mask is 0x%02x\n", + r->mbm_cfg_mask); + return -EINVAL; + } + + list_for_each_entry(d, &r->mon_domains, hdr.list) { + if (d->hdr.id == dom_id) { + mbm_config_write_domain(r, d, evtid, val); + goto next; + } + } + + return -EINVAL; +} + +static ssize_t mbm_total_bytes_config_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, + loff_t off) +{ + struct rdt_resource *r = rdt_kn_parent_priv(of->kn); + int ret; + + /* Valid input requires a trailing newline */ + if (nbytes == 0 || buf[nbytes - 1] != '\n') + return -EINVAL; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + rdt_last_cmd_clear(); + + buf[nbytes - 1] = '\0'; + + ret = mon_config_write(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID); + + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + + return ret ?: nbytes; +} + +static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, + loff_t off) +{ + struct rdt_resource *r = rdt_kn_parent_priv(of->kn); + int ret; + + /* Valid input requires a trailing newline */ + if (nbytes == 0 || buf[nbytes - 1] != '\n') + return -EINVAL; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + rdt_last_cmd_clear(); + + buf[nbytes - 1] = '\0'; + + ret = mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID); + + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + + return ret ?: nbytes; +} + +/* rdtgroup information files for one cache resource. */ +static struct rftype res_common_files[] = { + { + .name = "last_cmd_status", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_last_cmd_status_show, + .fflags = RFTYPE_TOP_INFO, + }, + { + .name = "num_closids", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_num_closids_show, + .fflags = RFTYPE_CTRL_INFO, + }, + { + .name = "mon_features", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_mon_features_show, + .fflags = RFTYPE_MON_INFO, + }, + { + .name = "num_rmids", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_num_rmids_show, + .fflags = RFTYPE_MON_INFO, + }, + { + .name = "cbm_mask", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_default_ctrl_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "min_cbm_bits", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_min_cbm_bits_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "shareable_bits", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_shareable_bits_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "bit_usage", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_bit_usage_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "min_bandwidth", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_min_bw_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, + }, + { + .name = "bandwidth_gran", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_bw_gran_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, + }, + { + .name = "delay_linear", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_delay_linear_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, + }, + /* + * Platform specific which (if any) capabilities are provided by + * thread_throttle_mode. Defer "fflags" initialization to platform + * discovery. + */ + { + .name = "thread_throttle_mode", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_thread_throttle_mode_show, + }, + { + .name = "max_threshold_occupancy", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = max_threshold_occ_write, + .seq_show = max_threshold_occ_show, + .fflags = RFTYPE_MON_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "mbm_total_bytes_config", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = mbm_total_bytes_config_show, + .write = mbm_total_bytes_config_write, + }, + { + .name = "mbm_local_bytes_config", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = mbm_local_bytes_config_show, + .write = mbm_local_bytes_config_write, + }, + { + .name = "cpus", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_cpus_write, + .seq_show = rdtgroup_cpus_show, + .fflags = RFTYPE_BASE, + }, + { + .name = "cpus_list", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_cpus_write, + .seq_show = rdtgroup_cpus_show, + .flags = RFTYPE_FLAGS_CPUS_LIST, + .fflags = RFTYPE_BASE, + }, + { + .name = "tasks", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_tasks_write, + .seq_show = rdtgroup_tasks_show, + .fflags = RFTYPE_BASE, + }, + { + .name = "mon_hw_id", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdtgroup_rmid_show, + .fflags = RFTYPE_MON_BASE | RFTYPE_DEBUG, + }, + { + .name = "schemata", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_schemata_write, + .seq_show = rdtgroup_schemata_show, + .fflags = RFTYPE_CTRL_BASE, + }, + { + .name = "mba_MBps_event", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_mba_mbps_event_write, + .seq_show = rdtgroup_mba_mbps_event_show, + }, + { + .name = "mode", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_mode_write, + .seq_show = rdtgroup_mode_show, + .fflags = RFTYPE_CTRL_BASE, + }, + { + .name = "size", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdtgroup_size_show, + .fflags = RFTYPE_CTRL_BASE, + }, + { + .name = "sparse_masks", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_has_sparse_bitmasks_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "ctrl_hw_id", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdtgroup_closid_show, + .fflags = RFTYPE_CTRL_BASE | RFTYPE_DEBUG, + }, +}; + +static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags) +{ + struct rftype *rfts, *rft; + int ret, len; + + rfts = res_common_files; + len = ARRAY_SIZE(res_common_files); + + lockdep_assert_held(&rdtgroup_mutex); + + if (resctrl_debug) + fflags |= RFTYPE_DEBUG; + + for (rft = rfts; rft < rfts + len; rft++) { + if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) { + ret = rdtgroup_add_file(kn, rft); + if (ret) + goto error; + } + } + + return 0; +error: + pr_warn("Failed to add %s, err=%d\n", rft->name, ret); + while (--rft >= rfts) { + if ((fflags & rft->fflags) == rft->fflags) + kernfs_remove_by_name(kn, rft->name); + } + return ret; +} + +static struct rftype *rdtgroup_get_rftype_by_name(const char *name) +{ + struct rftype *rfts, *rft; + int len; + + rfts = res_common_files; + len = ARRAY_SIZE(res_common_files); + + for (rft = rfts; rft < rfts + len; rft++) { + if (!strcmp(rft->name, name)) + return rft; + } + + return NULL; +} + +static void thread_throttle_mode_init(void) +{ + enum membw_throttle_mode throttle_mode = THREAD_THROTTLE_UNDEFINED; + struct rdt_resource *r_mba, *r_smba; + + r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA); + if (r_mba->alloc_capable && + r_mba->membw.throttle_mode != THREAD_THROTTLE_UNDEFINED) + throttle_mode = r_mba->membw.throttle_mode; + + r_smba = resctrl_arch_get_resource(RDT_RESOURCE_SMBA); + if (r_smba->alloc_capable && + r_smba->membw.throttle_mode != THREAD_THROTTLE_UNDEFINED) + throttle_mode = r_smba->membw.throttle_mode; + + if (throttle_mode == THREAD_THROTTLE_UNDEFINED) + return; + + resctrl_file_fflags_init("thread_throttle_mode", + RFTYPE_CTRL_INFO | RFTYPE_RES_MB); +} + +void resctrl_file_fflags_init(const char *config, unsigned long fflags) +{ + struct rftype *rft; + + rft = rdtgroup_get_rftype_by_name(config); + if (rft) + rft->fflags = fflags; +} + +/** + * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file + * @r: The resource group with which the file is associated. + * @name: Name of the file + * + * The permissions of named resctrl file, directory, or link are modified + * to not allow read, write, or execute by any user. + * + * WARNING: This function is intended to communicate to the user that the + * resctrl file has been locked down - that it is not relevant to the + * particular state the system finds itself in. It should not be relied + * on to protect from user access because after the file's permissions + * are restricted the user can still change the permissions using chmod + * from the command line. + * + * Return: 0 on success, <0 on failure. + */ +int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name) +{ + struct iattr iattr = {.ia_valid = ATTR_MODE,}; + struct kernfs_node *kn; + int ret = 0; + + kn = kernfs_find_and_get_ns(r->kn, name, NULL); + if (!kn) + return -ENOENT; + + switch (kernfs_type(kn)) { + case KERNFS_DIR: + iattr.ia_mode = S_IFDIR; + break; + case KERNFS_FILE: + iattr.ia_mode = S_IFREG; + break; + case KERNFS_LINK: + iattr.ia_mode = S_IFLNK; + break; + } + + ret = kernfs_setattr(kn, &iattr); + kernfs_put(kn); + return ret; +} + +/** + * rdtgroup_kn_mode_restore - Restore user access to named resctrl file + * @r: The resource group with which the file is associated. + * @name: Name of the file + * @mask: Mask of permissions that should be restored + * + * Restore the permissions of the named file. If @name is a directory the + * permissions of its parent will be used. + * + * Return: 0 on success, <0 on failure. + */ +int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name, + umode_t mask) +{ + struct iattr iattr = {.ia_valid = ATTR_MODE,}; + struct kernfs_node *kn, *parent; + struct rftype *rfts, *rft; + int ret, len; + + rfts = res_common_files; + len = ARRAY_SIZE(res_common_files); + + for (rft = rfts; rft < rfts + len; rft++) { + if (!strcmp(rft->name, name)) + iattr.ia_mode = rft->mode & mask; + } + + kn = kernfs_find_and_get_ns(r->kn, name, NULL); + if (!kn) + return -ENOENT; + + switch (kernfs_type(kn)) { + case KERNFS_DIR: + parent = kernfs_get_parent(kn); + if (parent) { + iattr.ia_mode |= parent->mode; + kernfs_put(parent); + } + iattr.ia_mode |= S_IFDIR; + break; + case KERNFS_FILE: + iattr.ia_mode |= S_IFREG; + break; + case KERNFS_LINK: + iattr.ia_mode |= S_IFLNK; + break; + } + + ret = kernfs_setattr(kn, &iattr); + kernfs_put(kn); + return ret; +} + +static int rdtgroup_mkdir_info_resdir(void *priv, char *name, + unsigned long fflags) +{ + struct kernfs_node *kn_subdir; + int ret; + + kn_subdir = kernfs_create_dir(kn_info, name, + kn_info->mode, priv); + if (IS_ERR(kn_subdir)) + return PTR_ERR(kn_subdir); + + ret = rdtgroup_kn_set_ugid(kn_subdir); + if (ret) + return ret; + + ret = rdtgroup_add_files(kn_subdir, fflags); + if (!ret) + kernfs_activate(kn_subdir); + + return ret; +} + +static unsigned long fflags_from_resource(struct rdt_resource *r) +{ + switch (r->rid) { + case RDT_RESOURCE_L3: + case RDT_RESOURCE_L2: + return RFTYPE_RES_CACHE; + case RDT_RESOURCE_MBA: + case RDT_RESOURCE_SMBA: + return RFTYPE_RES_MB; + } + + return WARN_ON_ONCE(1); +} + +static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn) +{ + struct resctrl_schema *s; + struct rdt_resource *r; + unsigned long fflags; + char name[32]; + int ret; + + /* create the directory */ + kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL); + if (IS_ERR(kn_info)) + return PTR_ERR(kn_info); + + ret = rdtgroup_add_files(kn_info, RFTYPE_TOP_INFO); + if (ret) + goto out_destroy; + + /* loop over enabled controls, these are all alloc_capable */ + list_for_each_entry(s, &resctrl_schema_all, list) { + r = s->res; + fflags = fflags_from_resource(r) | RFTYPE_CTRL_INFO; + ret = rdtgroup_mkdir_info_resdir(s, s->name, fflags); + if (ret) + goto out_destroy; + } + + for_each_mon_capable_rdt_resource(r) { + fflags = fflags_from_resource(r) | RFTYPE_MON_INFO; + sprintf(name, "%s_MON", r->name); + ret = rdtgroup_mkdir_info_resdir(r, name, fflags); + if (ret) + goto out_destroy; + } + + ret = rdtgroup_kn_set_ugid(kn_info); + if (ret) + goto out_destroy; + + kernfs_activate(kn_info); + + return 0; + +out_destroy: + kernfs_remove(kn_info); + return ret; +} + +static int +mongroup_create_dir(struct kernfs_node *parent_kn, struct rdtgroup *prgrp, + char *name, struct kernfs_node **dest_kn) +{ + struct kernfs_node *kn; + int ret; + + /* create the directory */ + kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp); + if (IS_ERR(kn)) + return PTR_ERR(kn); + + if (dest_kn) + *dest_kn = kn; + + ret = rdtgroup_kn_set_ugid(kn); + if (ret) + goto out_destroy; + + kernfs_activate(kn); + + return 0; + +out_destroy: + kernfs_remove(kn); + return ret; +} + +static inline bool is_mba_linear(void) +{ + return resctrl_arch_get_resource(RDT_RESOURCE_MBA)->membw.delay_linear; +} + +static int mba_sc_domain_allocate(struct rdt_resource *r, struct rdt_ctrl_domain *d) +{ + u32 num_closid = resctrl_arch_get_num_closid(r); + int cpu = cpumask_any(&d->hdr.cpu_mask); + int i; + + d->mbps_val = kcalloc_node(num_closid, sizeof(*d->mbps_val), + GFP_KERNEL, cpu_to_node(cpu)); + if (!d->mbps_val) + return -ENOMEM; + + for (i = 0; i < num_closid; i++) + d->mbps_val[i] = MBA_MAX_MBPS; + + return 0; +} + +static void mba_sc_domain_destroy(struct rdt_resource *r, + struct rdt_ctrl_domain *d) +{ + kfree(d->mbps_val); + d->mbps_val = NULL; +} + +/* + * MBA software controller is supported only if + * MBM is supported and MBA is in linear scale, + * and the MBM monitor scope is the same as MBA + * control scope. + */ +static bool supports_mba_mbps(void) +{ + struct rdt_resource *rmbm = resctrl_arch_get_resource(RDT_RESOURCE_L3); + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); + + return (resctrl_is_mbm_enabled() && + r->alloc_capable && is_mba_linear() && + r->ctrl_scope == rmbm->mon_scope); +} + +/* + * Enable or disable the MBA software controller + * which helps user specify bandwidth in MBps. + */ +static int set_mba_sc(bool mba_sc) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); + u32 num_closid = resctrl_arch_get_num_closid(r); + struct rdt_ctrl_domain *d; + unsigned long fflags; + int i; + + if (!supports_mba_mbps() || mba_sc == is_mba_sc(r)) + return -EINVAL; + + r->membw.mba_sc = mba_sc; + + rdtgroup_default.mba_mbps_event = mba_mbps_default_event; + + list_for_each_entry(d, &r->ctrl_domains, hdr.list) { + for (i = 0; i < num_closid; i++) + d->mbps_val[i] = MBA_MAX_MBPS; + } + + fflags = mba_sc ? RFTYPE_CTRL_BASE | RFTYPE_MON_BASE : 0; + resctrl_file_fflags_init("mba_MBps_event", fflags); + + return 0; +} + +/* + * We don't allow rdtgroup directories to be created anywhere + * except the root directory. Thus when looking for the rdtgroup + * structure for a kernfs node we are either looking at a directory, + * in which case the rdtgroup structure is pointed at by the "priv" + * field, otherwise we have a file, and need only look to the parent + * to find the rdtgroup. + */ +static struct rdtgroup *kernfs_to_rdtgroup(struct kernfs_node *kn) +{ + if (kernfs_type(kn) == KERNFS_DIR) { + /* + * All the resource directories use "kn->priv" + * to point to the "struct rdtgroup" for the + * resource. "info" and its subdirectories don't + * have rdtgroup structures, so return NULL here. + */ + if (kn == kn_info || + rcu_access_pointer(kn->__parent) == kn_info) + return NULL; + else + return kn->priv; + } else { + return rdt_kn_parent_priv(kn); + } +} + +static void rdtgroup_kn_get(struct rdtgroup *rdtgrp, struct kernfs_node *kn) +{ + atomic_inc(&rdtgrp->waitcount); + kernfs_break_active_protection(kn); +} + +static void rdtgroup_kn_put(struct rdtgroup *rdtgrp, struct kernfs_node *kn) +{ + if (atomic_dec_and_test(&rdtgrp->waitcount) && + (rdtgrp->flags & RDT_DELETED)) { + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) + rdtgroup_pseudo_lock_remove(rdtgrp); + kernfs_unbreak_active_protection(kn); + rdtgroup_remove(rdtgrp); + } else { + kernfs_unbreak_active_protection(kn); + } +} + +struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn) +{ + struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn); + + if (!rdtgrp) + return NULL; + + rdtgroup_kn_get(rdtgrp, kn); + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + /* Was this group deleted while we waited? */ + if (rdtgrp->flags & RDT_DELETED) + return NULL; + + return rdtgrp; +} + +void rdtgroup_kn_unlock(struct kernfs_node *kn) +{ + struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn); + + if (!rdtgrp) + return; + + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + + rdtgroup_kn_put(rdtgrp, kn); +} + +static int mkdir_mondata_all(struct kernfs_node *parent_kn, + struct rdtgroup *prgrp, + struct kernfs_node **mon_data_kn); + +static void rdt_disable_ctx(void) +{ + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false); + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false); + set_mba_sc(false); + + resctrl_debug = false; +} + +static int rdt_enable_ctx(struct rdt_fs_context *ctx) +{ + int ret = 0; + + if (ctx->enable_cdpl2) { + ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, true); + if (ret) + goto out_done; + } + + if (ctx->enable_cdpl3) { + ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true); + if (ret) + goto out_cdpl2; + } + + if (ctx->enable_mba_mbps) { + ret = set_mba_sc(true); + if (ret) + goto out_cdpl3; + } + + if (ctx->enable_debug) + resctrl_debug = true; + + return 0; + +out_cdpl3: + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false); +out_cdpl2: + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false); +out_done: + return ret; +} + +static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type) +{ + struct resctrl_schema *s; + const char *suffix = ""; + int ret, cl; + + s = kzalloc(sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + + s->res = r; + s->num_closid = resctrl_arch_get_num_closid(r); + if (resctrl_arch_get_cdp_enabled(r->rid)) + s->num_closid /= 2; + + s->conf_type = type; + switch (type) { + case CDP_CODE: + suffix = "CODE"; + break; + case CDP_DATA: + suffix = "DATA"; + break; + case CDP_NONE: + suffix = ""; + break; + } + + ret = snprintf(s->name, sizeof(s->name), "%s%s", r->name, suffix); + if (ret >= sizeof(s->name)) { + kfree(s); + return -EINVAL; + } + + cl = strlen(s->name); + + /* + * If CDP is supported by this resource, but not enabled, + * include the suffix. This ensures the tabular format of the + * schemata file does not change between mounts of the filesystem. + */ + if (r->cdp_capable && !resctrl_arch_get_cdp_enabled(r->rid)) + cl += 4; + + if (cl > max_name_width) + max_name_width = cl; + + switch (r->schema_fmt) { + case RESCTRL_SCHEMA_BITMAP: + s->fmt_str = "%d=%x"; + break; + case RESCTRL_SCHEMA_RANGE: + s->fmt_str = "%d=%u"; + break; + } + + if (WARN_ON_ONCE(!s->fmt_str)) { + kfree(s); + return -EINVAL; + } + + INIT_LIST_HEAD(&s->list); + list_add(&s->list, &resctrl_schema_all); + + return 0; +} + +static int schemata_list_create(void) +{ + struct rdt_resource *r; + int ret = 0; + + for_each_alloc_capable_rdt_resource(r) { + if (resctrl_arch_get_cdp_enabled(r->rid)) { + ret = schemata_list_add(r, CDP_CODE); + if (ret) + break; + + ret = schemata_list_add(r, CDP_DATA); + } else { + ret = schemata_list_add(r, CDP_NONE); + } + + if (ret) + break; + } + + return ret; +} + +static void schemata_list_destroy(void) +{ + struct resctrl_schema *s, *tmp; + + list_for_each_entry_safe(s, tmp, &resctrl_schema_all, list) { + list_del(&s->list); + kfree(s); + } +} + +static int rdt_get_tree(struct fs_context *fc) +{ + struct rdt_fs_context *ctx = rdt_fc2context(fc); + unsigned long flags = RFTYPE_CTRL_BASE; + struct rdt_mon_domain *dom; + struct rdt_resource *r; + int ret; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + /* + * resctrl file system can only be mounted once. + */ + if (resctrl_mounted) { + ret = -EBUSY; + goto out; + } + + ret = rdtgroup_setup_root(ctx); + if (ret) + goto out; + + ret = rdt_enable_ctx(ctx); + if (ret) + goto out_root; + + ret = schemata_list_create(); + if (ret) { + schemata_list_destroy(); + goto out_ctx; + } + + ret = closid_init(); + if (ret) + goto out_schemata_free; + + if (resctrl_arch_mon_capable()) + flags |= RFTYPE_MON; + + ret = rdtgroup_add_files(rdtgroup_default.kn, flags); + if (ret) + goto out_closid_exit; + + kernfs_activate(rdtgroup_default.kn); + + ret = rdtgroup_create_info_dir(rdtgroup_default.kn); + if (ret < 0) + goto out_closid_exit; + + if (resctrl_arch_mon_capable()) { + ret = mongroup_create_dir(rdtgroup_default.kn, + &rdtgroup_default, "mon_groups", + &kn_mongrp); + if (ret < 0) + goto out_info; + + ret = mkdir_mondata_all(rdtgroup_default.kn, + &rdtgroup_default, &kn_mondata); + if (ret < 0) + goto out_mongrp; + rdtgroup_default.mon.mon_data_kn = kn_mondata; + } + + ret = rdt_pseudo_lock_init(); + if (ret) + goto out_mondata; + + ret = kernfs_get_tree(fc); + if (ret < 0) + goto out_psl; + + if (resctrl_arch_alloc_capable()) + resctrl_arch_enable_alloc(); + if (resctrl_arch_mon_capable()) + resctrl_arch_enable_mon(); + + if (resctrl_arch_alloc_capable() || resctrl_arch_mon_capable()) + resctrl_mounted = true; + + if (resctrl_is_mbm_enabled()) { + r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + list_for_each_entry(dom, &r->mon_domains, hdr.list) + mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL, + RESCTRL_PICK_ANY_CPU); + } + + goto out; + +out_psl: + rdt_pseudo_lock_release(); +out_mondata: + if (resctrl_arch_mon_capable()) + kernfs_remove(kn_mondata); +out_mongrp: + if (resctrl_arch_mon_capable()) + kernfs_remove(kn_mongrp); +out_info: + kernfs_remove(kn_info); +out_closid_exit: + closid_exit(); +out_schemata_free: + schemata_list_destroy(); +out_ctx: + rdt_disable_ctx(); +out_root: + rdtgroup_destroy_root(); +out: + rdt_last_cmd_clear(); + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + return ret; +} + +enum rdt_param { + Opt_cdp, + Opt_cdpl2, + Opt_mba_mbps, + Opt_debug, + nr__rdt_params +}; + +static const struct fs_parameter_spec rdt_fs_parameters[] = { + fsparam_flag("cdp", Opt_cdp), + fsparam_flag("cdpl2", Opt_cdpl2), + fsparam_flag("mba_MBps", Opt_mba_mbps), + fsparam_flag("debug", Opt_debug), + {} +}; + +static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param) +{ + struct rdt_fs_context *ctx = rdt_fc2context(fc); + struct fs_parse_result result; + const char *msg; + int opt; + + opt = fs_parse(fc, rdt_fs_parameters, param, &result); + if (opt < 0) + return opt; + + switch (opt) { + case Opt_cdp: + ctx->enable_cdpl3 = true; + return 0; + case Opt_cdpl2: + ctx->enable_cdpl2 = true; + return 0; + case Opt_mba_mbps: + msg = "mba_MBps requires MBM and linear scale MBA at L3 scope"; + if (!supports_mba_mbps()) + return invalfc(fc, msg); + ctx->enable_mba_mbps = true; + return 0; + case Opt_debug: + ctx->enable_debug = true; + return 0; + } + + return -EINVAL; +} + +static void rdt_fs_context_free(struct fs_context *fc) +{ + struct rdt_fs_context *ctx = rdt_fc2context(fc); + + kernfs_free_fs_context(fc); + kfree(ctx); +} + +static const struct fs_context_operations rdt_fs_context_ops = { + .free = rdt_fs_context_free, + .parse_param = rdt_parse_param, + .get_tree = rdt_get_tree, +}; + +static int rdt_init_fs_context(struct fs_context *fc) +{ + struct rdt_fs_context *ctx; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + ctx->kfc.magic = RDTGROUP_SUPER_MAGIC; + fc->fs_private = &ctx->kfc; + fc->ops = &rdt_fs_context_ops; + put_user_ns(fc->user_ns); + fc->user_ns = get_user_ns(&init_user_ns); + fc->global = true; + return 0; +} + +/* + * Move tasks from one to the other group. If @from is NULL, then all tasks + * in the systems are moved unconditionally (used for teardown). + * + * If @mask is not NULL the cpus on which moved tasks are running are set + * in that mask so the update smp function call is restricted to affected + * cpus. + */ +static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to, + struct cpumask *mask) +{ + struct task_struct *p, *t; + + read_lock(&tasklist_lock); + for_each_process_thread(p, t) { + if (!from || is_closid_match(t, from) || + is_rmid_match(t, from)) { + resctrl_arch_set_closid_rmid(t, to->closid, + to->mon.rmid); + + /* + * Order the closid/rmid stores above before the loads + * in task_curr(). This pairs with the full barrier + * between the rq->curr update and + * resctrl_arch_sched_in() during context switch. + */ + smp_mb(); + + /* + * If the task is on a CPU, set the CPU in the mask. + * The detection is inaccurate as tasks might move or + * schedule before the smp function call takes place. + * In such a case the function call is pointless, but + * there is no other side effect. + */ + if (IS_ENABLED(CONFIG_SMP) && mask && task_curr(t)) + cpumask_set_cpu(task_cpu(t), mask); + } + } + read_unlock(&tasklist_lock); +} + +static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp) +{ + struct rdtgroup *sentry, *stmp; + struct list_head *head; + + head = &rdtgrp->mon.crdtgrp_list; + list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) { + free_rmid(sentry->closid, sentry->mon.rmid); + list_del(&sentry->mon.crdtgrp_list); + + if (atomic_read(&sentry->waitcount) != 0) + sentry->flags = RDT_DELETED; + else + rdtgroup_remove(sentry); + } +} + +/* + * Forcibly remove all of subdirectories under root. + */ +static void rmdir_all_sub(void) +{ + struct rdtgroup *rdtgrp, *tmp; + + /* Move all tasks to the default resource group */ + rdt_move_group_tasks(NULL, &rdtgroup_default, NULL); + + list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) { + /* Free any child rmids */ + free_all_child_rdtgrp(rdtgrp); + + /* Remove each rdtgroup other than root */ + if (rdtgrp == &rdtgroup_default) + continue; + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) + rdtgroup_pseudo_lock_remove(rdtgrp); + + /* + * Give any CPUs back to the default group. We cannot copy + * cpu_online_mask because a CPU might have executed the + * offline callback already, but is still marked online. + */ + cpumask_or(&rdtgroup_default.cpu_mask, + &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); + + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + + kernfs_remove(rdtgrp->kn); + list_del(&rdtgrp->rdtgroup_list); + + if (atomic_read(&rdtgrp->waitcount) != 0) + rdtgrp->flags = RDT_DELETED; + else + rdtgroup_remove(rdtgrp); + } + /* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */ + update_closid_rmid(cpu_online_mask, &rdtgroup_default); + + kernfs_remove(kn_info); + kernfs_remove(kn_mongrp); + kernfs_remove(kn_mondata); +} + +/** + * mon_get_kn_priv() - Get the mon_data priv data for this event. + * + * The same values are used across the mon_data directories of all control and + * monitor groups for the same event in the same domain. Keep a list of + * allocated structures and re-use an existing one with the same values for + * @rid, @domid, etc. + * + * @rid: The resource id for the event file being created. + * @domid: The domain id for the event file being created. + * @mevt: The type of event file being created. + * @do_sum: Whether SNC summing monitors are being created. + */ +static struct mon_data *mon_get_kn_priv(enum resctrl_res_level rid, int domid, + struct mon_evt *mevt, + bool do_sum) +{ + struct mon_data *priv; + + lockdep_assert_held(&rdtgroup_mutex); + + list_for_each_entry(priv, &mon_data_kn_priv_list, list) { + if (priv->rid == rid && priv->domid == domid && + priv->sum == do_sum && priv->evtid == mevt->evtid) + return priv; + } + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return NULL; + + priv->rid = rid; + priv->domid = domid; + priv->sum = do_sum; + priv->evtid = mevt->evtid; + list_add_tail(&priv->list, &mon_data_kn_priv_list); + + return priv; +} + +/** + * mon_put_kn_priv() - Free all allocated mon_data structures. + * + * Called when resctrl file system is unmounted. + */ +static void mon_put_kn_priv(void) +{ + struct mon_data *priv, *tmp; + + lockdep_assert_held(&rdtgroup_mutex); + + list_for_each_entry_safe(priv, tmp, &mon_data_kn_priv_list, list) { + list_del(&priv->list); + kfree(priv); + } +} + +static void resctrl_fs_teardown(void) +{ + lockdep_assert_held(&rdtgroup_mutex); + + /* Cleared by rdtgroup_destroy_root() */ + if (!rdtgroup_default.kn) + return; + + rmdir_all_sub(); + mon_put_kn_priv(); + rdt_pseudo_lock_release(); + rdtgroup_default.mode = RDT_MODE_SHAREABLE; + closid_exit(); + schemata_list_destroy(); + rdtgroup_destroy_root(); +} + +static void rdt_kill_sb(struct super_block *sb) +{ + struct rdt_resource *r; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + rdt_disable_ctx(); + + /* Put everything back to default values. */ + for_each_alloc_capable_rdt_resource(r) + resctrl_arch_reset_all_ctrls(r); + + resctrl_fs_teardown(); + if (resctrl_arch_alloc_capable()) + resctrl_arch_disable_alloc(); + if (resctrl_arch_mon_capable()) + resctrl_arch_disable_mon(); + resctrl_mounted = false; + kernfs_kill_sb(sb); + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); +} + +static struct file_system_type rdt_fs_type = { + .name = "resctrl", + .init_fs_context = rdt_init_fs_context, + .parameters = rdt_fs_parameters, + .kill_sb = rdt_kill_sb, +}; + +static int mon_addfile(struct kernfs_node *parent_kn, const char *name, + void *priv) +{ + struct kernfs_node *kn; + int ret = 0; + + kn = __kernfs_create_file(parent_kn, name, 0444, + GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0, + &kf_mondata_ops, priv, NULL, NULL); + if (IS_ERR(kn)) + return PTR_ERR(kn); + + ret = rdtgroup_kn_set_ugid(kn); + if (ret) { + kernfs_remove(kn); + return ret; + } + + return ret; +} + +static void mon_rmdir_one_subdir(struct kernfs_node *pkn, char *name, char *subname) +{ + struct kernfs_node *kn; + + kn = kernfs_find_and_get(pkn, name); + if (!kn) + return; + kernfs_put(kn); + + if (kn->dir.subdirs <= 1) + kernfs_remove(kn); + else + kernfs_remove_by_name(kn, subname); +} + +/* + * Remove all subdirectories of mon_data of ctrl_mon groups + * and monitor groups for the given domain. + * Remove files and directories containing "sum" of domain data + * when last domain being summed is removed. + */ +static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, + struct rdt_mon_domain *d) +{ + struct rdtgroup *prgrp, *crgrp; + char subname[32]; + bool snc_mode; + char name[32]; + + snc_mode = r->mon_scope == RESCTRL_L3_NODE; + sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id); + if (snc_mode) + sprintf(subname, "mon_sub_%s_%02d", r->name, d->hdr.id); + + list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { + mon_rmdir_one_subdir(prgrp->mon.mon_data_kn, name, subname); + + list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list) + mon_rmdir_one_subdir(crgrp->mon.mon_data_kn, name, subname); + } +} + +static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d, + struct rdt_resource *r, struct rdtgroup *prgrp, + bool do_sum) +{ + struct rmid_read rr = {0}; + struct mon_data *priv; + struct mon_evt *mevt; + int ret, domid; + + if (WARN_ON(list_empty(&r->evt_list))) + return -EPERM; + + list_for_each_entry(mevt, &r->evt_list, list) { + domid = do_sum ? d->ci->id : d->hdr.id; + priv = mon_get_kn_priv(r->rid, domid, mevt, do_sum); + if (WARN_ON_ONCE(!priv)) + return -EINVAL; + + ret = mon_addfile(kn, mevt->name, priv); + if (ret) + return ret; + + if (!do_sum && resctrl_is_mbm_event(mevt->evtid)) + mon_event_read(&rr, r, d, prgrp, &d->hdr.cpu_mask, mevt->evtid, true); + } + + return 0; +} + +static int mkdir_mondata_subdir(struct kernfs_node *parent_kn, + struct rdt_mon_domain *d, + struct rdt_resource *r, struct rdtgroup *prgrp) +{ + struct kernfs_node *kn, *ckn; + char name[32]; + bool snc_mode; + int ret = 0; + + lockdep_assert_held(&rdtgroup_mutex); + + snc_mode = r->mon_scope == RESCTRL_L3_NODE; + sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id); + kn = kernfs_find_and_get(parent_kn, name); + if (kn) { + /* + * rdtgroup_mutex will prevent this directory from being + * removed. No need to keep this hold. + */ + kernfs_put(kn); + } else { + kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp); + if (IS_ERR(kn)) + return PTR_ERR(kn); + + ret = rdtgroup_kn_set_ugid(kn); + if (ret) + goto out_destroy; + ret = mon_add_all_files(kn, d, r, prgrp, snc_mode); + if (ret) + goto out_destroy; + } + + if (snc_mode) { + sprintf(name, "mon_sub_%s_%02d", r->name, d->hdr.id); + ckn = kernfs_create_dir(kn, name, parent_kn->mode, prgrp); + if (IS_ERR(ckn)) { + ret = -EINVAL; + goto out_destroy; + } + + ret = rdtgroup_kn_set_ugid(ckn); + if (ret) + goto out_destroy; + + ret = mon_add_all_files(ckn, d, r, prgrp, false); + if (ret) + goto out_destroy; + } + + kernfs_activate(kn); + return 0; + +out_destroy: + kernfs_remove(kn); + return ret; +} + +/* + * Add all subdirectories of mon_data for "ctrl_mon" groups + * and "monitor" groups with given domain id. + */ +static void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, + struct rdt_mon_domain *d) +{ + struct kernfs_node *parent_kn; + struct rdtgroup *prgrp, *crgrp; + struct list_head *head; + + list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { + parent_kn = prgrp->mon.mon_data_kn; + mkdir_mondata_subdir(parent_kn, d, r, prgrp); + + head = &prgrp->mon.crdtgrp_list; + list_for_each_entry(crgrp, head, mon.crdtgrp_list) { + parent_kn = crgrp->mon.mon_data_kn; + mkdir_mondata_subdir(parent_kn, d, r, crgrp); + } + } +} + +static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn, + struct rdt_resource *r, + struct rdtgroup *prgrp) +{ + struct rdt_mon_domain *dom; + int ret; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + list_for_each_entry(dom, &r->mon_domains, hdr.list) { + ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp); + if (ret) + return ret; + } + + return 0; +} + +/* + * This creates a directory mon_data which contains the monitored data. + * + * mon_data has one directory for each domain which are named + * in the format mon__. For ex: A mon_data + * with L3 domain looks as below: + * ./mon_data: + * mon_L3_00 + * mon_L3_01 + * mon_L3_02 + * ... + * + * Each domain directory has one file per event: + * ./mon_L3_00/: + * llc_occupancy + * + */ +static int mkdir_mondata_all(struct kernfs_node *parent_kn, + struct rdtgroup *prgrp, + struct kernfs_node **dest_kn) +{ + struct rdt_resource *r; + struct kernfs_node *kn; + int ret; + + /* + * Create the mon_data directory first. + */ + ret = mongroup_create_dir(parent_kn, prgrp, "mon_data", &kn); + if (ret) + return ret; + + if (dest_kn) + *dest_kn = kn; + + /* + * Create the subdirectories for each domain. Note that all events + * in a domain like L3 are grouped into a resource whose domain is L3 + */ + for_each_mon_capable_rdt_resource(r) { + ret = mkdir_mondata_subdir_alldom(kn, r, prgrp); + if (ret) + goto out_destroy; + } + + return 0; + +out_destroy: + kernfs_remove(kn); + return ret; +} + +/** + * cbm_ensure_valid - Enforce validity on provided CBM + * @_val: Candidate CBM + * @r: RDT resource to which the CBM belongs + * + * The provided CBM represents all cache portions available for use. This + * may be represented by a bitmap that does not consist of contiguous ones + * and thus be an invalid CBM. + * Here the provided CBM is forced to be a valid CBM by only considering + * the first set of contiguous bits as valid and clearing all bits. + * The intention here is to provide a valid default CBM with which a new + * resource group is initialized. The user can follow this with a + * modification to the CBM if the default does not satisfy the + * requirements. + */ +static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r) +{ + unsigned int cbm_len = r->cache.cbm_len; + unsigned long first_bit, zero_bit; + unsigned long val = _val; + + if (!val) + return 0; + + first_bit = find_first_bit(&val, cbm_len); + zero_bit = find_next_zero_bit(&val, cbm_len, first_bit); + + /* Clear any remaining bits to ensure contiguous region */ + bitmap_clear(&val, zero_bit, cbm_len - zero_bit); + return (u32)val; +} + +/* + * Initialize cache resources per RDT domain + * + * Set the RDT domain up to start off with all usable allocations. That is, + * all shareable and unused bits. All-zero CBM is invalid. + */ +static int __init_one_rdt_domain(struct rdt_ctrl_domain *d, struct resctrl_schema *s, + u32 closid) +{ + enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type); + enum resctrl_conf_type t = s->conf_type; + struct resctrl_staged_config *cfg; + struct rdt_resource *r = s->res; + u32 used_b = 0, unused_b = 0; + unsigned long tmp_cbm; + enum rdtgrp_mode mode; + u32 peer_ctl, ctrl_val; + int i; + + cfg = &d->staged_config[t]; + cfg->have_new_ctrl = false; + cfg->new_ctrl = r->cache.shareable_bits; + used_b = r->cache.shareable_bits; + for (i = 0; i < closids_supported(); i++) { + if (closid_allocated(i) && i != closid) { + mode = rdtgroup_mode_by_closid(i); + if (mode == RDT_MODE_PSEUDO_LOCKSETUP) + /* + * ctrl values for locksetup aren't relevant + * until the schemata is written, and the mode + * becomes RDT_MODE_PSEUDO_LOCKED. + */ + continue; + /* + * If CDP is active include peer domain's + * usage to ensure there is no overlap + * with an exclusive group. + */ + if (resctrl_arch_get_cdp_enabled(r->rid)) + peer_ctl = resctrl_arch_get_config(r, d, i, + peer_type); + else + peer_ctl = 0; + ctrl_val = resctrl_arch_get_config(r, d, i, + s->conf_type); + used_b |= ctrl_val | peer_ctl; + if (mode == RDT_MODE_SHAREABLE) + cfg->new_ctrl |= ctrl_val | peer_ctl; + } + } + if (d->plr && d->plr->cbm > 0) + used_b |= d->plr->cbm; + unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1); + unused_b &= BIT_MASK(r->cache.cbm_len) - 1; + cfg->new_ctrl |= unused_b; + /* + * Force the initial CBM to be valid, user can + * modify the CBM based on system availability. + */ + cfg->new_ctrl = cbm_ensure_valid(cfg->new_ctrl, r); + /* + * Assign the u32 CBM to an unsigned long to ensure that + * bitmap_weight() does not access out-of-bound memory. + */ + tmp_cbm = cfg->new_ctrl; + if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) { + rdt_last_cmd_printf("No space on %s:%d\n", s->name, d->hdr.id); + return -ENOSPC; + } + cfg->have_new_ctrl = true; + + return 0; +} + +/* + * Initialize cache resources with default values. + * + * A new RDT group is being created on an allocation capable (CAT) + * supporting system. Set this group up to start off with all usable + * allocations. + * + * If there are no more shareable bits available on any domain then + * the entire allocation will fail. + */ +static int rdtgroup_init_cat(struct resctrl_schema *s, u32 closid) +{ + struct rdt_ctrl_domain *d; + int ret; + + list_for_each_entry(d, &s->res->ctrl_domains, hdr.list) { + ret = __init_one_rdt_domain(d, s, closid); + if (ret < 0) + return ret; + } + + return 0; +} + +/* Initialize MBA resource with default values. */ +static void rdtgroup_init_mba(struct rdt_resource *r, u32 closid) +{ + struct resctrl_staged_config *cfg; + struct rdt_ctrl_domain *d; + + list_for_each_entry(d, &r->ctrl_domains, hdr.list) { + if (is_mba_sc(r)) { + d->mbps_val[closid] = MBA_MAX_MBPS; + continue; + } + + cfg = &d->staged_config[CDP_NONE]; + cfg->new_ctrl = resctrl_get_default_ctrl(r); + cfg->have_new_ctrl = true; + } +} + +/* Initialize the RDT group's allocations. */ +static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) +{ + struct resctrl_schema *s; + struct rdt_resource *r; + int ret = 0; + + rdt_staged_configs_clear(); + + list_for_each_entry(s, &resctrl_schema_all, list) { + r = s->res; + if (r->rid == RDT_RESOURCE_MBA || + r->rid == RDT_RESOURCE_SMBA) { + rdtgroup_init_mba(r, rdtgrp->closid); + if (is_mba_sc(r)) + continue; + } else { + ret = rdtgroup_init_cat(s, rdtgrp->closid); + if (ret < 0) + goto out; + } + + ret = resctrl_arch_update_domains(r, rdtgrp->closid); + if (ret < 0) { + rdt_last_cmd_puts("Failed to initialize allocations\n"); + goto out; + } + } + + rdtgrp->mode = RDT_MODE_SHAREABLE; + +out: + rdt_staged_configs_clear(); + return ret; +} + +static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp) +{ + int ret; + + if (!resctrl_arch_mon_capable()) + return 0; + + ret = alloc_rmid(rdtgrp->closid); + if (ret < 0) { + rdt_last_cmd_puts("Out of RMIDs\n"); + return ret; + } + rdtgrp->mon.rmid = ret; + + ret = mkdir_mondata_all(rdtgrp->kn, rdtgrp, &rdtgrp->mon.mon_data_kn); + if (ret) { + rdt_last_cmd_puts("kernfs subdir error\n"); + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + return ret; + } + + return 0; +} + +static void mkdir_rdt_prepare_rmid_free(struct rdtgroup *rgrp) +{ + if (resctrl_arch_mon_capable()) + free_rmid(rgrp->closid, rgrp->mon.rmid); +} + +/* + * We allow creating mon groups only with in a directory called "mon_groups" + * which is present in every ctrl_mon group. Check if this is a valid + * "mon_groups" directory. + * + * 1. The directory should be named "mon_groups". + * 2. The mon group itself should "not" be named "mon_groups". + * This makes sure "mon_groups" directory always has a ctrl_mon group + * as parent. + */ +static bool is_mon_groups(struct kernfs_node *kn, const char *name) +{ + return (!strcmp(rdt_kn_name(kn), "mon_groups") && + strcmp(name, "mon_groups")); +} + +static int mkdir_rdt_prepare(struct kernfs_node *parent_kn, + const char *name, umode_t mode, + enum rdt_group_type rtype, struct rdtgroup **r) +{ + struct rdtgroup *prdtgrp, *rdtgrp; + unsigned long files = 0; + struct kernfs_node *kn; + int ret; + + prdtgrp = rdtgroup_kn_lock_live(parent_kn); + if (!prdtgrp) { + ret = -ENODEV; + goto out_unlock; + } + + /* + * Check that the parent directory for a monitor group is a "mon_groups" + * directory. + */ + if (rtype == RDTMON_GROUP && !is_mon_groups(parent_kn, name)) { + ret = -EPERM; + goto out_unlock; + } + + if (rtype == RDTMON_GROUP && + (prdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || + prdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)) { + ret = -EINVAL; + rdt_last_cmd_puts("Pseudo-locking in progress\n"); + goto out_unlock; + } + + /* allocate the rdtgroup. */ + rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL); + if (!rdtgrp) { + ret = -ENOSPC; + rdt_last_cmd_puts("Kernel out of memory\n"); + goto out_unlock; + } + *r = rdtgrp; + rdtgrp->mon.parent = prdtgrp; + rdtgrp->type = rtype; + INIT_LIST_HEAD(&rdtgrp->mon.crdtgrp_list); + + /* kernfs creates the directory for rdtgrp */ + kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp); + if (IS_ERR(kn)) { + ret = PTR_ERR(kn); + rdt_last_cmd_puts("kernfs create error\n"); + goto out_free_rgrp; + } + rdtgrp->kn = kn; + + /* + * kernfs_remove() will drop the reference count on "kn" which + * will free it. But we still need it to stick around for the + * rdtgroup_kn_unlock(kn) call. Take one extra reference here, + * which will be dropped by kernfs_put() in rdtgroup_remove(). + */ + kernfs_get(kn); + + ret = rdtgroup_kn_set_ugid(kn); + if (ret) { + rdt_last_cmd_puts("kernfs perm error\n"); + goto out_destroy; + } + + if (rtype == RDTCTRL_GROUP) { + files = RFTYPE_BASE | RFTYPE_CTRL; + if (resctrl_arch_mon_capable()) + files |= RFTYPE_MON; + } else { + files = RFTYPE_BASE | RFTYPE_MON; + } + + ret = rdtgroup_add_files(kn, files); + if (ret) { + rdt_last_cmd_puts("kernfs fill error\n"); + goto out_destroy; + } + + /* + * The caller unlocks the parent_kn upon success. + */ + return 0; + +out_destroy: + kernfs_put(rdtgrp->kn); + kernfs_remove(rdtgrp->kn); +out_free_rgrp: + kfree(rdtgrp); +out_unlock: + rdtgroup_kn_unlock(parent_kn); + return ret; +} + +static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp) +{ + kernfs_remove(rgrp->kn); + rdtgroup_remove(rgrp); +} + +/* + * Create a monitor group under "mon_groups" directory of a control + * and monitor group(ctrl_mon). This is a resource group + * to monitor a subset of tasks and cpus in its parent ctrl_mon group. + */ +static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn, + const char *name, umode_t mode) +{ + struct rdtgroup *rdtgrp, *prgrp; + int ret; + + ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTMON_GROUP, &rdtgrp); + if (ret) + return ret; + + prgrp = rdtgrp->mon.parent; + rdtgrp->closid = prgrp->closid; + + ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp); + if (ret) { + mkdir_rdt_prepare_clean(rdtgrp); + goto out_unlock; + } + + kernfs_activate(rdtgrp->kn); + + /* + * Add the rdtgrp to the list of rdtgrps the parent + * ctrl_mon group has to track. + */ + list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list); + +out_unlock: + rdtgroup_kn_unlock(parent_kn); + return ret; +} + +/* + * These are rdtgroups created under the root directory. Can be used + * to allocate and monitor resources. + */ +static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn, + const char *name, umode_t mode) +{ + struct rdtgroup *rdtgrp; + struct kernfs_node *kn; + u32 closid; + int ret; + + ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTCTRL_GROUP, &rdtgrp); + if (ret) + return ret; + + kn = rdtgrp->kn; + ret = closid_alloc(); + if (ret < 0) { + rdt_last_cmd_puts("Out of CLOSIDs\n"); + goto out_common_fail; + } + closid = ret; + ret = 0; + + rdtgrp->closid = closid; + + ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp); + if (ret) + goto out_closid_free; + + kernfs_activate(rdtgrp->kn); + + ret = rdtgroup_init_alloc(rdtgrp); + if (ret < 0) + goto out_rmid_free; + + list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups); + + if (resctrl_arch_mon_capable()) { + /* + * Create an empty mon_groups directory to hold the subset + * of tasks and cpus to monitor. + */ + ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL); + if (ret) { + rdt_last_cmd_puts("kernfs subdir error\n"); + goto out_del_list; + } + if (is_mba_sc(NULL)) + rdtgrp->mba_mbps_event = mba_mbps_default_event; + } + + goto out_unlock; + +out_del_list: + list_del(&rdtgrp->rdtgroup_list); +out_rmid_free: + mkdir_rdt_prepare_rmid_free(rdtgrp); +out_closid_free: + closid_free(closid); +out_common_fail: + mkdir_rdt_prepare_clean(rdtgrp); +out_unlock: + rdtgroup_kn_unlock(parent_kn); + return ret; +} + +static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name, + umode_t mode) +{ + /* Do not accept '\n' to avoid unparsable situation. */ + if (strchr(name, '\n')) + return -EINVAL; + + /* + * If the parent directory is the root directory and RDT + * allocation is supported, add a control and monitoring + * subdirectory + */ + if (resctrl_arch_alloc_capable() && parent_kn == rdtgroup_default.kn) + return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode); + + /* Else, attempt to add a monitoring subdirectory. */ + if (resctrl_arch_mon_capable()) + return rdtgroup_mkdir_mon(parent_kn, name, mode); + + return -EPERM; +} + +static int rdtgroup_rmdir_mon(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask) +{ + struct rdtgroup *prdtgrp = rdtgrp->mon.parent; + u32 closid, rmid; + int cpu; + + /* Give any tasks back to the parent group */ + rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask); + + /* + * Update per cpu closid/rmid of the moved CPUs first. + * Note: the closid will not change, but the arch code still needs it. + */ + closid = prdtgrp->closid; + rmid = prdtgrp->mon.rmid; + for_each_cpu(cpu, &rdtgrp->cpu_mask) + resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid); + + /* + * Update the MSR on moved CPUs and CPUs which have moved + * task running on them. + */ + cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask); + update_closid_rmid(tmpmask, NULL); + + rdtgrp->flags = RDT_DELETED; + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + + /* + * Remove the rdtgrp from the parent ctrl_mon group's list + */ + WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list)); + list_del(&rdtgrp->mon.crdtgrp_list); + + kernfs_remove(rdtgrp->kn); + + return 0; +} + +static int rdtgroup_ctrl_remove(struct rdtgroup *rdtgrp) +{ + rdtgrp->flags = RDT_DELETED; + list_del(&rdtgrp->rdtgroup_list); + + kernfs_remove(rdtgrp->kn); + return 0; +} + +static int rdtgroup_rmdir_ctrl(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask) +{ + u32 closid, rmid; + int cpu; + + /* Give any tasks back to the default group */ + rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask); + + /* Give any CPUs back to the default group */ + cpumask_or(&rdtgroup_default.cpu_mask, + &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); + + /* Update per cpu closid and rmid of the moved CPUs first */ + closid = rdtgroup_default.closid; + rmid = rdtgroup_default.mon.rmid; + for_each_cpu(cpu, &rdtgrp->cpu_mask) + resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid); + + /* + * Update the MSR on moved CPUs and CPUs which have moved + * task running on them. + */ + cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask); + update_closid_rmid(tmpmask, NULL); + + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + closid_free(rdtgrp->closid); + + rdtgroup_ctrl_remove(rdtgrp); + + /* + * Free all the child monitor group rmids. + */ + free_all_child_rdtgrp(rdtgrp); + + return 0; +} + +static struct kernfs_node *rdt_kn_parent(struct kernfs_node *kn) +{ + /* + * Valid within the RCU section it was obtained or while rdtgroup_mutex + * is held. + */ + return rcu_dereference_check(kn->__parent, lockdep_is_held(&rdtgroup_mutex)); +} + +static int rdtgroup_rmdir(struct kernfs_node *kn) +{ + struct kernfs_node *parent_kn; + struct rdtgroup *rdtgrp; + cpumask_var_t tmpmask; + int ret = 0; + + if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) + return -ENOMEM; + + rdtgrp = rdtgroup_kn_lock_live(kn); + if (!rdtgrp) { + ret = -EPERM; + goto out; + } + parent_kn = rdt_kn_parent(kn); + + /* + * If the rdtgroup is a ctrl_mon group and parent directory + * is the root directory, remove the ctrl_mon group. + * + * If the rdtgroup is a mon group and parent directory + * is a valid "mon_groups" directory, remove the mon group. + */ + if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn && + rdtgrp != &rdtgroup_default) { + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + ret = rdtgroup_ctrl_remove(rdtgrp); + } else { + ret = rdtgroup_rmdir_ctrl(rdtgrp, tmpmask); + } + } else if (rdtgrp->type == RDTMON_GROUP && + is_mon_groups(parent_kn, rdt_kn_name(kn))) { + ret = rdtgroup_rmdir_mon(rdtgrp, tmpmask); + } else { + ret = -EPERM; + } + +out: + rdtgroup_kn_unlock(kn); + free_cpumask_var(tmpmask); + return ret; +} + +/** + * mongrp_reparent() - replace parent CTRL_MON group of a MON group + * @rdtgrp: the MON group whose parent should be replaced + * @new_prdtgrp: replacement parent CTRL_MON group for @rdtgrp + * @cpus: cpumask provided by the caller for use during this call + * + * Replaces the parent CTRL_MON group for a MON group, resulting in all member + * tasks' CLOSID immediately changing to that of the new parent group. + * Monitoring data for the group is unaffected by this operation. + */ +static void mongrp_reparent(struct rdtgroup *rdtgrp, + struct rdtgroup *new_prdtgrp, + cpumask_var_t cpus) +{ + struct rdtgroup *prdtgrp = rdtgrp->mon.parent; + + WARN_ON(rdtgrp->type != RDTMON_GROUP); + WARN_ON(new_prdtgrp->type != RDTCTRL_GROUP); + + /* Nothing to do when simply renaming a MON group. */ + if (prdtgrp == new_prdtgrp) + return; + + WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list)); + list_move_tail(&rdtgrp->mon.crdtgrp_list, + &new_prdtgrp->mon.crdtgrp_list); + + rdtgrp->mon.parent = new_prdtgrp; + rdtgrp->closid = new_prdtgrp->closid; + + /* Propagate updated closid to all tasks in this group. */ + rdt_move_group_tasks(rdtgrp, rdtgrp, cpus); + + update_closid_rmid(cpus, NULL); +} + +static int rdtgroup_rename(struct kernfs_node *kn, + struct kernfs_node *new_parent, const char *new_name) +{ + struct kernfs_node *kn_parent; + struct rdtgroup *new_prdtgrp; + struct rdtgroup *rdtgrp; + cpumask_var_t tmpmask; + int ret; + + rdtgrp = kernfs_to_rdtgroup(kn); + new_prdtgrp = kernfs_to_rdtgroup(new_parent); + if (!rdtgrp || !new_prdtgrp) + return -ENOENT; + + /* Release both kernfs active_refs before obtaining rdtgroup mutex. */ + rdtgroup_kn_get(rdtgrp, kn); + rdtgroup_kn_get(new_prdtgrp, new_parent); + + mutex_lock(&rdtgroup_mutex); + + rdt_last_cmd_clear(); + + /* + * Don't allow kernfs_to_rdtgroup() to return a parent rdtgroup if + * either kernfs_node is a file. + */ + if (kernfs_type(kn) != KERNFS_DIR || + kernfs_type(new_parent) != KERNFS_DIR) { + rdt_last_cmd_puts("Source and destination must be directories"); + ret = -EPERM; + goto out; + } + + if ((rdtgrp->flags & RDT_DELETED) || (new_prdtgrp->flags & RDT_DELETED)) { + ret = -ENOENT; + goto out; + } + + kn_parent = rdt_kn_parent(kn); + if (rdtgrp->type != RDTMON_GROUP || !kn_parent || + !is_mon_groups(kn_parent, rdt_kn_name(kn))) { + rdt_last_cmd_puts("Source must be a MON group\n"); + ret = -EPERM; + goto out; + } + + if (!is_mon_groups(new_parent, new_name)) { + rdt_last_cmd_puts("Destination must be a mon_groups subdirectory\n"); + ret = -EPERM; + goto out; + } + + /* + * If the MON group is monitoring CPUs, the CPUs must be assigned to the + * current parent CTRL_MON group and therefore cannot be assigned to + * the new parent, making the move illegal. + */ + if (!cpumask_empty(&rdtgrp->cpu_mask) && + rdtgrp->mon.parent != new_prdtgrp) { + rdt_last_cmd_puts("Cannot move a MON group that monitors CPUs\n"); + ret = -EPERM; + goto out; + } + + /* + * Allocate the cpumask for use in mongrp_reparent() to avoid the + * possibility of failing to allocate it after kernfs_rename() has + * succeeded. + */ + if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) { + ret = -ENOMEM; + goto out; + } + + /* + * Perform all input validation and allocations needed to ensure + * mongrp_reparent() will succeed before calling kernfs_rename(), + * otherwise it would be necessary to revert this call if + * mongrp_reparent() failed. + */ + ret = kernfs_rename(kn, new_parent, new_name); + if (!ret) + mongrp_reparent(rdtgrp, new_prdtgrp, tmpmask); + + free_cpumask_var(tmpmask); + +out: + mutex_unlock(&rdtgroup_mutex); + rdtgroup_kn_put(rdtgrp, kn); + rdtgroup_kn_put(new_prdtgrp, new_parent); + return ret; +} + +static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf) +{ + if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3)) + seq_puts(seq, ",cdp"); + + if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2)) + seq_puts(seq, ",cdpl2"); + + if (is_mba_sc(resctrl_arch_get_resource(RDT_RESOURCE_MBA))) + seq_puts(seq, ",mba_MBps"); + + if (resctrl_debug) + seq_puts(seq, ",debug"); + + return 0; +} + +static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = { + .mkdir = rdtgroup_mkdir, + .rmdir = rdtgroup_rmdir, + .rename = rdtgroup_rename, + .show_options = rdtgroup_show_options, +}; + +static int rdtgroup_setup_root(struct rdt_fs_context *ctx) +{ + rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops, + KERNFS_ROOT_CREATE_DEACTIVATED | + KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK, + &rdtgroup_default); + if (IS_ERR(rdt_root)) + return PTR_ERR(rdt_root); + + ctx->kfc.root = rdt_root; + rdtgroup_default.kn = kernfs_root_to_node(rdt_root); + + return 0; +} + +static void rdtgroup_destroy_root(void) +{ + lockdep_assert_held(&rdtgroup_mutex); + + kernfs_destroy_root(rdt_root); + rdtgroup_default.kn = NULL; +} + +static void rdtgroup_setup_default(void) +{ + mutex_lock(&rdtgroup_mutex); + + rdtgroup_default.closid = RESCTRL_RESERVED_CLOSID; + rdtgroup_default.mon.rmid = RESCTRL_RESERVED_RMID; + rdtgroup_default.type = RDTCTRL_GROUP; + INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list); + + list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups); + + mutex_unlock(&rdtgroup_mutex); +} + +static void domain_destroy_mon_state(struct rdt_mon_domain *d) +{ + bitmap_free(d->rmid_busy_llc); + kfree(d->mbm_total); + kfree(d->mbm_local); +} + +void resctrl_offline_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d) +{ + mutex_lock(&rdtgroup_mutex); + + if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA) + mba_sc_domain_destroy(r, d); + + mutex_unlock(&rdtgroup_mutex); +} + +void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d) +{ + mutex_lock(&rdtgroup_mutex); + + /* + * If resctrl is mounted, remove all the + * per domain monitor data directories. + */ + if (resctrl_mounted && resctrl_arch_mon_capable()) + rmdir_mondata_subdir_allrdtgrp(r, d); + + if (resctrl_is_mbm_enabled()) + cancel_delayed_work(&d->mbm_over); + if (resctrl_arch_is_llc_occupancy_enabled() && has_busy_rmid(d)) { + /* + * When a package is going down, forcefully + * decrement rmid->ebusy. There is no way to know + * that the L3 was flushed and hence may lead to + * incorrect counts in rare scenarios, but leaving + * the RMID as busy creates RMID leaks if the + * package never comes back. + */ + __check_limbo(d, true); + cancel_delayed_work(&d->cqm_limbo); + } + + domain_destroy_mon_state(d); + + mutex_unlock(&rdtgroup_mutex); +} + +/** + * domain_setup_mon_state() - Initialise domain monitoring structures. + * @r: The resource for the newly online domain. + * @d: The newly online domain. + * + * Allocate monitor resources that belong to this domain. + * Called when the first CPU of a domain comes online, regardless of whether + * the filesystem is mounted. + * During boot this may be called before global allocations have been made by + * resctrl_mon_resource_init(). + * + * Returns 0 for success, or -ENOMEM. + */ +static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_mon_domain *d) +{ + u32 idx_limit = resctrl_arch_system_num_rmid_idx(); + size_t tsize; + + if (resctrl_arch_is_llc_occupancy_enabled()) { + d->rmid_busy_llc = bitmap_zalloc(idx_limit, GFP_KERNEL); + if (!d->rmid_busy_llc) + return -ENOMEM; + } + if (resctrl_arch_is_mbm_total_enabled()) { + tsize = sizeof(*d->mbm_total); + d->mbm_total = kcalloc(idx_limit, tsize, GFP_KERNEL); + if (!d->mbm_total) { + bitmap_free(d->rmid_busy_llc); + return -ENOMEM; + } + } + if (resctrl_arch_is_mbm_local_enabled()) { + tsize = sizeof(*d->mbm_local); + d->mbm_local = kcalloc(idx_limit, tsize, GFP_KERNEL); + if (!d->mbm_local) { + bitmap_free(d->rmid_busy_llc); + kfree(d->mbm_total); + return -ENOMEM; + } + } + + return 0; +} + +int resctrl_online_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d) +{ + int err = 0; + + mutex_lock(&rdtgroup_mutex); + + if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA) { + /* RDT_RESOURCE_MBA is never mon_capable */ + err = mba_sc_domain_allocate(r, d); + } + + mutex_unlock(&rdtgroup_mutex); + + return err; +} + +int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d) +{ + int err; + + mutex_lock(&rdtgroup_mutex); + + err = domain_setup_mon_state(r, d); + if (err) + goto out_unlock; + + if (resctrl_is_mbm_enabled()) { + INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow); + mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL, + RESCTRL_PICK_ANY_CPU); + } + + if (resctrl_arch_is_llc_occupancy_enabled()) + INIT_DELAYED_WORK(&d->cqm_limbo, cqm_handle_limbo); + + /* + * If the filesystem is not mounted then only the default resource group + * exists. Creation of its directories is deferred until mount time + * by rdt_get_tree() calling mkdir_mondata_all(). + * If resctrl is mounted, add per domain monitor data directories. + */ + if (resctrl_mounted && resctrl_arch_mon_capable()) + mkdir_mondata_subdir_allrdtgrp(r, d); + +out_unlock: + mutex_unlock(&rdtgroup_mutex); + + return err; +} + +void resctrl_online_cpu(unsigned int cpu) +{ + mutex_lock(&rdtgroup_mutex); + /* The CPU is set in default rdtgroup after online. */ + cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask); + mutex_unlock(&rdtgroup_mutex); +} + +static void clear_childcpus(struct rdtgroup *r, unsigned int cpu) +{ + struct rdtgroup *cr; + + list_for_each_entry(cr, &r->mon.crdtgrp_list, mon.crdtgrp_list) { + if (cpumask_test_and_clear_cpu(cpu, &cr->cpu_mask)) + break; + } +} + +static struct rdt_mon_domain *get_mon_domain_from_cpu(int cpu, + struct rdt_resource *r) +{ + struct rdt_mon_domain *d; + + lockdep_assert_cpus_held(); + + list_for_each_entry(d, &r->mon_domains, hdr.list) { + /* Find the domain that contains this CPU */ + if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask)) + return d; + } + + return NULL; +} + +void resctrl_offline_cpu(unsigned int cpu) +{ + struct rdt_resource *l3 = resctrl_arch_get_resource(RDT_RESOURCE_L3); + struct rdt_mon_domain *d; + struct rdtgroup *rdtgrp; + + mutex_lock(&rdtgroup_mutex); + list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { + if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask)) { + clear_childcpus(rdtgrp, cpu); + break; + } + } + + if (!l3->mon_capable) + goto out_unlock; + + d = get_mon_domain_from_cpu(cpu, l3); + if (d) { + if (resctrl_is_mbm_enabled() && cpu == d->mbm_work_cpu) { + cancel_delayed_work(&d->mbm_over); + mbm_setup_overflow_handler(d, 0, cpu); + } + if (resctrl_arch_is_llc_occupancy_enabled() && + cpu == d->cqm_work_cpu && has_busy_rmid(d)) { + cancel_delayed_work(&d->cqm_limbo); + cqm_setup_limbo_handler(d, 0, cpu); + } + } + +out_unlock: + mutex_unlock(&rdtgroup_mutex); +} + +/* + * resctrl_init - resctrl filesystem initialization + * + * Setup resctrl file system including set up root, create mount point, + * register resctrl filesystem, and initialize files under root directory. + * + * Return: 0 on success or -errno + */ +int resctrl_init(void) +{ + int ret = 0; + + seq_buf_init(&last_cmd_status, last_cmd_status_buf, + sizeof(last_cmd_status_buf)); + + rdtgroup_setup_default(); + + thread_throttle_mode_init(); + + ret = resctrl_mon_resource_init(); + if (ret) + return ret; + + ret = sysfs_create_mount_point(fs_kobj, "resctrl"); + if (ret) { + resctrl_mon_resource_exit(); + return ret; + } + + ret = register_filesystem(&rdt_fs_type); + if (ret) + goto cleanup_mountpoint; + + /* + * Adding the resctrl debugfs directory here may not be ideal since + * it would let the resctrl debugfs directory appear on the debugfs + * filesystem before the resctrl filesystem is mounted. + * It may also be ok since that would enable debugging of RDT before + * resctrl is mounted. + * The reason why the debugfs directory is created here and not in + * rdt_get_tree() is because rdt_get_tree() takes rdtgroup_mutex and + * during the debugfs directory creation also &sb->s_type->i_mutex_key + * (the lockdep class of inode->i_rwsem). Other filesystem + * interactions (eg. SyS_getdents) have the lock ordering: + * &sb->s_type->i_mutex_key --> &mm->mmap_lock + * During mmap(), called with &mm->mmap_lock, the rdtgroup_mutex + * is taken, thus creating dependency: + * &mm->mmap_lock --> rdtgroup_mutex for the latter that can cause + * issues considering the other two lock dependencies. + * By creating the debugfs directory here we avoid a dependency + * that may cause deadlock (even though file operations cannot + * occur until the filesystem is mounted, but I do not know how to + * tell lockdep that). + */ + debugfs_resctrl = debugfs_create_dir("resctrl", NULL); + + return 0; + +cleanup_mountpoint: + sysfs_remove_mount_point(fs_kobj, "resctrl"); + resctrl_mon_resource_exit(); + + return ret; +} + +static bool resctrl_online_domains_exist(void) +{ + struct rdt_resource *r; + + /* + * Only walk capable resources to allow resctrl_arch_get_resource() + * to return dummy 'not capable' resources. + */ + for_each_alloc_capable_rdt_resource(r) { + if (!list_empty(&r->ctrl_domains)) + return true; + } + + for_each_mon_capable_rdt_resource(r) { + if (!list_empty(&r->mon_domains)) + return true; + } + + return false; +} + +/** + * resctrl_exit() - Remove the resctrl filesystem and free resources. + * + * Called by the architecture code in response to a fatal error. + * Removes resctrl files and structures from kernfs to prevent further + * configuration. + * + * When called by the architecture code, all CPUs and resctrl domains must be + * offline. This ensures the limbo and overflow handlers are not scheduled to + * run, meaning the data structures they access can be freed by + * resctrl_mon_resource_exit(). + * + * After resctrl_exit() returns, the architecture code should return an + * error from all resctrl_arch_ functions that can do this. + * resctrl_arch_get_resource() must continue to return struct rdt_resources + * with the correct rid field to ensure the filesystem can be unmounted. + */ +void resctrl_exit(void) +{ + cpus_read_lock(); + WARN_ON_ONCE(resctrl_online_domains_exist()); + + mutex_lock(&rdtgroup_mutex); + resctrl_fs_teardown(); + mutex_unlock(&rdtgroup_mutex); + + cpus_read_unlock(); + + debugfs_remove_recursive(debugfs_resctrl); + debugfs_resctrl = NULL; + unregister_filesystem(&rdt_fs_type); + + /* + * Do not remove the sysfs mount point added by resctrl_init() so that + * it can be used to umount resctrl. + */ + + resctrl_mon_resource_exit(); +} -- cgit v1.2.3-59-g8ed1b