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-rw-r--r--arch/x86/kernel/cpu/Makefile2
-rw-r--r--arch/x86/kernel/cpu/intel_cacheinfo.c20
-rw-r--r--arch/x86/kernel/cpu/intel_rdt.c403
-rw-r--r--arch/x86/kernel/cpu/intel_rdt_rdtgroup.c1115
-rw-r--r--arch/x86/kernel/cpu/intel_rdt_schemata.c245
-rw-r--r--arch/x86/kernel/cpu/scattered.c11
-rw-r--r--arch/x86/kernel/process_32.c4
-rw-r--r--arch/x86/kernel/process_64.c4
8 files changed, 1800 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 33b63670bf09..52000010c62e 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -32,6 +32,8 @@ obj-$(CONFIG_CPU_SUP_CENTAUR) += centaur.o
obj-$(CONFIG_CPU_SUP_TRANSMETA_32) += transmeta.o
obj-$(CONFIG_CPU_SUP_UMC_32) += umc.o
+obj-$(CONFIG_INTEL_RDT_A) += intel_rdt.o intel_rdt_rdtgroup.o intel_rdt_schemata.o
+
obj-$(CONFIG_X86_MCE) += mcheck/
obj-$(CONFIG_MTRR) += mtrr/
obj-$(CONFIG_MICROCODE) += microcode/
diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
index be6337156502..0282b0df004a 100644
--- a/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -153,6 +153,7 @@ struct _cpuid4_info_regs {
union _cpuid4_leaf_eax eax;
union _cpuid4_leaf_ebx ebx;
union _cpuid4_leaf_ecx ecx;
+ unsigned int id;
unsigned long size;
struct amd_northbridge *nb;
};
@@ -894,6 +895,8 @@ static void __cache_cpumap_setup(unsigned int cpu, int index,
static void ci_leaf_init(struct cacheinfo *this_leaf,
struct _cpuid4_info_regs *base)
{
+ this_leaf->id = base->id;
+ this_leaf->attributes = CACHE_ID;
this_leaf->level = base->eax.split.level;
this_leaf->type = cache_type_map[base->eax.split.type];
this_leaf->coherency_line_size =
@@ -920,6 +923,22 @@ static int __init_cache_level(unsigned int cpu)
return 0;
}
+/*
+ * The max shared threads number comes from CPUID.4:EAX[25-14] with input
+ * ECX as cache index. Then right shift apicid by the number's order to get
+ * cache id for this cache node.
+ */
+static void get_cache_id(int cpu, struct _cpuid4_info_regs *id4_regs)
+{
+ struct cpuinfo_x86 *c = &cpu_data(cpu);
+ unsigned long num_threads_sharing;
+ int index_msb;
+
+ num_threads_sharing = 1 + id4_regs->eax.split.num_threads_sharing;
+ index_msb = get_count_order(num_threads_sharing);
+ id4_regs->id = c->apicid >> index_msb;
+}
+
static int __populate_cache_leaves(unsigned int cpu)
{
unsigned int idx, ret;
@@ -931,6 +950,7 @@ static int __populate_cache_leaves(unsigned int cpu)
ret = cpuid4_cache_lookup_regs(idx, &id4_regs);
if (ret)
return ret;
+ get_cache_id(cpu, &id4_regs);
ci_leaf_init(this_leaf++, &id4_regs);
__cache_cpumap_setup(cpu, idx, &id4_regs);
}
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
new file mode 100644
index 000000000000..5a533fefefa0
--- /dev/null
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -0,0 +1,403 @@
+/*
+ * Resource Director Technology(RDT)
+ * - Cache Allocation code.
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Authors:
+ * Fenghua Yu <fenghua.yu@intel.com>
+ * Tony Luck <tony.luck@intel.com>
+ * Vikas Shivappa <vikas.shivappa@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * 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 <linux/slab.h>
+#include <linux/err.h>
+#include <linux/cacheinfo.h>
+#include <linux/cpuhotplug.h>
+
+#include <asm/intel-family.h>
+#include <asm/intel_rdt.h>
+
+/* Mutex to protect rdtgroup access. */
+DEFINE_MUTEX(rdtgroup_mutex);
+
+DEFINE_PER_CPU_READ_MOSTLY(int, cpu_closid);
+
+#define domain_init(id) LIST_HEAD_INIT(rdt_resources_all[id].domains)
+
+struct rdt_resource rdt_resources_all[] = {
+ {
+ .name = "L3",
+ .domains = domain_init(RDT_RESOURCE_L3),
+ .msr_base = IA32_L3_CBM_BASE,
+ .min_cbm_bits = 1,
+ .cache_level = 3,
+ .cbm_idx_multi = 1,
+ .cbm_idx_offset = 0
+ },
+ {
+ .name = "L3DATA",
+ .domains = domain_init(RDT_RESOURCE_L3DATA),
+ .msr_base = IA32_L3_CBM_BASE,
+ .min_cbm_bits = 1,
+ .cache_level = 3,
+ .cbm_idx_multi = 2,
+ .cbm_idx_offset = 0
+ },
+ {
+ .name = "L3CODE",
+ .domains = domain_init(RDT_RESOURCE_L3CODE),
+ .msr_base = IA32_L3_CBM_BASE,
+ .min_cbm_bits = 1,
+ .cache_level = 3,
+ .cbm_idx_multi = 2,
+ .cbm_idx_offset = 1
+ },
+ {
+ .name = "L2",
+ .domains = domain_init(RDT_RESOURCE_L2),
+ .msr_base = IA32_L2_CBM_BASE,
+ .min_cbm_bits = 1,
+ .cache_level = 2,
+ .cbm_idx_multi = 1,
+ .cbm_idx_offset = 0
+ },
+};
+
+static int cbm_idx(struct rdt_resource *r, int closid)
+{
+ return closid * r->cbm_idx_multi + r->cbm_idx_offset;
+}
+
+/*
+ * cache_alloc_hsw_probe() - Have to probe for Intel haswell server CPUs
+ * as they do not have CPUID enumeration support for Cache allocation.
+ * The check for Vendor/Family/Model is not enough to guarantee that
+ * the MSRs won't #GP fault because only the following SKUs support
+ * CAT:
+ * Intel(R) Xeon(R) CPU E5-2658 v3 @ 2.20GHz
+ * Intel(R) Xeon(R) CPU E5-2648L v3 @ 1.80GHz
+ * Intel(R) Xeon(R) CPU E5-2628L v3 @ 2.00GHz
+ * Intel(R) Xeon(R) CPU E5-2618L v3 @ 2.30GHz
+ * Intel(R) Xeon(R) CPU E5-2608L v3 @ 2.00GHz
+ * Intel(R) Xeon(R) CPU E5-2658A v3 @ 2.20GHz
+ *
+ * Probe by trying to write the first of the L3 cach mask registers
+ * and checking that the bits stick. Max CLOSids is always 4 and max cbm length
+ * is always 20 on hsw server parts. The minimum cache bitmask length
+ * allowed for HSW server is always 2 bits. Hardcode all of them.
+ */
+static inline bool cache_alloc_hsw_probe(void)
+{
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+ boot_cpu_data.x86 == 6 &&
+ boot_cpu_data.x86_model == INTEL_FAM6_HASWELL_X) {
+ struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3];
+ u32 l, h, max_cbm = BIT_MASK(20) - 1;
+
+ if (wrmsr_safe(IA32_L3_CBM_BASE, max_cbm, 0))
+ return false;
+ rdmsr(IA32_L3_CBM_BASE, l, h);
+
+ /* If all the bits were set in MSR, return success */
+ if (l != max_cbm)
+ return false;
+
+ r->num_closid = 4;
+ r->cbm_len = 20;
+ r->max_cbm = max_cbm;
+ r->min_cbm_bits = 2;
+ r->capable = true;
+ r->enabled = true;
+
+ return true;
+ }
+
+ return false;
+}
+
+static void rdt_get_config(int idx, struct rdt_resource *r)
+{
+ union cpuid_0x10_1_eax eax;
+ union cpuid_0x10_1_edx edx;
+ u32 ebx, ecx;
+
+ cpuid_count(0x00000010, idx, &eax.full, &ebx, &ecx, &edx.full);
+ r->num_closid = edx.split.cos_max + 1;
+ r->cbm_len = eax.split.cbm_len + 1;
+ r->max_cbm = BIT_MASK(eax.split.cbm_len + 1) - 1;
+ r->capable = true;
+ r->enabled = true;
+}
+
+static void rdt_get_cdp_l3_config(int type)
+{
+ struct rdt_resource *r_l3 = &rdt_resources_all[RDT_RESOURCE_L3];
+ struct rdt_resource *r = &rdt_resources_all[type];
+
+ r->num_closid = r_l3->num_closid / 2;
+ r->cbm_len = r_l3->cbm_len;
+ r->max_cbm = r_l3->max_cbm;
+ r->capable = true;
+ /*
+ * By default, CDP is disabled. CDP can be enabled by mount parameter
+ * "cdp" during resctrl file system mount time.
+ */
+ r->enabled = false;
+}
+
+static inline bool get_rdt_resources(void)
+{
+ bool ret = false;
+
+ if (cache_alloc_hsw_probe())
+ return true;
+
+ if (!boot_cpu_has(X86_FEATURE_RDT_A))
+ return false;
+
+ if (boot_cpu_has(X86_FEATURE_CAT_L3)) {
+ rdt_get_config(1, &rdt_resources_all[RDT_RESOURCE_L3]);
+ if (boot_cpu_has(X86_FEATURE_CDP_L3)) {
+ rdt_get_cdp_l3_config(RDT_RESOURCE_L3DATA);
+ rdt_get_cdp_l3_config(RDT_RESOURCE_L3CODE);
+ }
+ ret = true;
+ }
+ if (boot_cpu_has(X86_FEATURE_CAT_L2)) {
+ /* CPUID 0x10.2 fields are same format at 0x10.1 */
+ rdt_get_config(2, &rdt_resources_all[RDT_RESOURCE_L2]);
+ ret = true;
+ }
+
+ return ret;
+}
+
+static int get_cache_id(int cpu, int level)
+{
+ struct cpu_cacheinfo *ci = get_cpu_cacheinfo(cpu);
+ int i;
+
+ for (i = 0; i < ci->num_leaves; i++) {
+ if (ci->info_list[i].level == level)
+ return ci->info_list[i].id;
+ }
+
+ return -1;
+}
+
+void rdt_cbm_update(void *arg)
+{
+ struct msr_param *m = (struct msr_param *)arg;
+ struct rdt_resource *r = m->res;
+ int i, cpu = smp_processor_id();
+ struct rdt_domain *d;
+
+ list_for_each_entry(d, &r->domains, list) {
+ /* Find the domain that contains this CPU */
+ if (cpumask_test_cpu(cpu, &d->cpu_mask))
+ goto found;
+ }
+ pr_info_once("cpu %d not found in any domain for resource %s\n",
+ cpu, r->name);
+
+ return;
+
+found:
+ for (i = m->low; i < m->high; i++) {
+ int idx = cbm_idx(r, i);
+
+ wrmsrl(r->msr_base + idx, d->cbm[i]);
+ }
+}
+
+/*
+ * rdt_find_domain - Find a domain in a resource that matches input resource id
+ *
+ * Search resource r's domain list to find the resource id. If the resource
+ * id is found in a domain, return the domain. Otherwise, if requested by
+ * caller, return the first domain whose id is bigger than the input id.
+ * The domain list is sorted by id in ascending order.
+ */
+static struct rdt_domain *rdt_find_domain(struct rdt_resource *r, int id,
+ struct list_head **pos)
+{
+ struct rdt_domain *d;
+ struct list_head *l;
+
+ if (id < 0)
+ return ERR_PTR(id);
+
+ list_for_each(l, &r->domains) {
+ d = list_entry(l, struct rdt_domain, 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;
+}
+
+/*
+ * domain_add_cpu - Add a cpu to a resource's domain list.
+ *
+ * If an existing domain in the resource r's domain list matches the cpu's
+ * resource id, add the cpu in the domain.
+ *
+ * Otherwise, a new domain is allocated and inserted into the right position
+ * in the domain list sorted by id in ascending order.
+ *
+ * The order in the domain list is visible to users when we print entries
+ * in the schemata file and schemata input is validated to have the same order
+ * as this list.
+ */
+static void domain_add_cpu(int cpu, struct rdt_resource *r)
+{
+ int i, id = get_cache_id(cpu, r->cache_level);
+ struct list_head *add_pos = NULL;
+ struct rdt_domain *d;
+
+ d = rdt_find_domain(r, id, &add_pos);
+ if (IS_ERR(d)) {
+ pr_warn("Could't find cache id for cpu %d\n", cpu);
+ return;
+ }
+
+ if (d) {
+ cpumask_set_cpu(cpu, &d->cpu_mask);
+ return;
+ }
+
+ d = kzalloc_node(sizeof(*d), GFP_KERNEL, cpu_to_node(cpu));
+ if (!d)
+ return;
+
+ d->id = id;
+
+ d->cbm = kmalloc_array(r->num_closid, sizeof(*d->cbm), GFP_KERNEL);
+ if (!d->cbm) {
+ kfree(d);
+ return;
+ }
+
+ for (i = 0; i < r->num_closid; i++) {
+ int idx = cbm_idx(r, i);
+
+ d->cbm[i] = r->max_cbm;
+ wrmsrl(r->msr_base + idx, d->cbm[i]);
+ }
+
+ cpumask_set_cpu(cpu, &d->cpu_mask);
+ list_add_tail(&d->list, add_pos);
+ r->num_domains++;
+}
+
+static void domain_remove_cpu(int cpu, struct rdt_resource *r)
+{
+ int id = get_cache_id(cpu, r->cache_level);
+ struct rdt_domain *d;
+
+ d = rdt_find_domain(r, id, NULL);
+ if (IS_ERR_OR_NULL(d)) {
+ pr_warn("Could't find cache id for cpu %d\n", cpu);
+ return;
+ }
+
+ cpumask_clear_cpu(cpu, &d->cpu_mask);
+ if (cpumask_empty(&d->cpu_mask)) {
+ r->num_domains--;
+ kfree(d->cbm);
+ list_del(&d->list);
+ kfree(d);
+ }
+}
+
+static void clear_closid(int cpu)
+{
+ struct intel_pqr_state *state = this_cpu_ptr(&pqr_state);
+
+ per_cpu(cpu_closid, cpu) = 0;
+ state->closid = 0;
+ wrmsr(MSR_IA32_PQR_ASSOC, state->rmid, 0);
+}
+
+static int intel_rdt_online_cpu(unsigned int cpu)
+{
+ struct rdt_resource *r;
+
+ mutex_lock(&rdtgroup_mutex);
+ for_each_capable_rdt_resource(r)
+ domain_add_cpu(cpu, r);
+ /* The cpu is set in default rdtgroup after online. */
+ cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask);
+ clear_closid(cpu);
+ mutex_unlock(&rdtgroup_mutex);
+
+ return 0;
+}
+
+static int intel_rdt_offline_cpu(unsigned int cpu)
+{
+ struct rdtgroup *rdtgrp;
+ struct rdt_resource *r;
+
+ mutex_lock(&rdtgroup_mutex);
+ for_each_capable_rdt_resource(r)
+ domain_remove_cpu(cpu, r);
+ list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
+ if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask))
+ break;
+ }
+ clear_closid(cpu);
+ mutex_unlock(&rdtgroup_mutex);
+
+ return 0;
+}
+
+static int __init intel_rdt_late_init(void)
+{
+ struct rdt_resource *r;
+ int state, ret;
+
+ if (!get_rdt_resources())
+ return -ENODEV;
+
+ state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+ "x86/rdt/cat:online:",
+ intel_rdt_online_cpu, intel_rdt_offline_cpu);
+ if (state < 0)
+ return state;
+
+ ret = rdtgroup_init();
+ if (ret) {
+ cpuhp_remove_state(state);
+ return ret;
+ }
+
+ for_each_capable_rdt_resource(r)
+ pr_info("Intel RDT %s allocation detected\n", r->name);
+
+ return 0;
+}
+
+late_initcall(intel_rdt_late_init);
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
new file mode 100644
index 000000000000..8af04afdfcb9
--- /dev/null
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -0,0 +1,1115 @@
+/*
+ * User interface for Resource Alloction in Resource Director Technology(RDT)
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Fenghua Yu <fenghua.yu@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * More information about RDT be found in the Intel (R) x86 Architecture
+ * Software Developer Manual.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cpu.h>
+#include <linux/fs.h>
+#include <linux/sysfs.h>
+#include <linux/kernfs.h>
+#include <linux/seq_file.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/task_work.h>
+
+#include <uapi/linux/magic.h>
+
+#include <asm/intel_rdt.h>
+#include <asm/intel_rdt_common.h>
+
+DEFINE_STATIC_KEY_FALSE(rdt_enable_key);
+struct kernfs_root *rdt_root;
+struct rdtgroup rdtgroup_default;
+LIST_HEAD(rdt_all_groups);
+
+/* Kernel fs node for "info" directory under root */
+static struct kernfs_node *kn_info;
+
+/*
+ * Trivial allocator for CLOSIDs. Since h/w only supports a small number,
+ * we can keep a bitmap of free CLOSIDs in a single integer.
+ *
+ * Using a global CLOSID across all resources has some advantages and
+ * some drawbacks:
+ * + We can simply set "current->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 int closid_free_map;
+
+static void closid_init(void)
+{
+ struct rdt_resource *r;
+ int rdt_min_closid = 32;
+
+ /* Compute rdt_min_closid across all resources */
+ for_each_enabled_rdt_resource(r)
+ rdt_min_closid = min(rdt_min_closid, r->num_closid);
+
+ closid_free_map = BIT_MASK(rdt_min_closid) - 1;
+
+ /* CLOSID 0 is always reserved for the default group */
+ closid_free_map &= ~1;
+}
+
+int closid_alloc(void)
+{
+ int closid = ffs(closid_free_map);
+
+ if (closid == 0)
+ return -ENOSPC;
+ closid--;
+ closid_free_map &= ~(1 << closid);
+
+ return closid;
+}
+
+static void closid_free(int closid)
+{
+ closid_free_map |= 1 << closid;
+}
+
+/* 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,
+ 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_add_files(struct kernfs_node *kn, struct rftype *rfts,
+ int len)
+{
+ struct rftype *rft;
+ int ret;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ for (rft = rfts; rft < rfts + len; rft++) {
+ 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)
+ kernfs_remove_by_name(kn, rft->name);
+ return ret;
+}
+
+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 struct kernfs_ops rdtgroup_kf_single_ops = {
+ .atomic_write_len = PAGE_SIZE,
+ .write = rdtgroup_file_write,
+ .seq_show = rdtgroup_seqfile_show,
+};
+
+static int rdtgroup_cpus_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, "%*pb\n", cpumask_pr_args(&rdtgrp->cpu_mask));
+ else
+ ret = -ENOENT;
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret;
+}
+
+/*
+ * This is safe against intel_rdt_sched_in() called from __switch_to()
+ * because __switch_to() is executed with interrupts disabled. A local call
+ * from rdt_update_closid() is proteced against __switch_to() because
+ * preemption is disabled.
+ */
+static void rdt_update_cpu_closid(void *closid)
+{
+ if (closid)
+ this_cpu_write(cpu_closid, *(int *)closid);
+ /*
+ * We cannot unconditionally write the MSR because the current
+ * executing task might have its own closid selected. Just reuse
+ * the context switch code.
+ */
+ intel_rdt_sched_in();
+}
+
+/*
+ * Update the PGR_ASSOC MSR on all cpus in @cpu_mask,
+ *
+ * Per task closids must have been set up before calling this function.
+ *
+ * The per cpu closids are updated with the smp function call, when @closid
+ * is not NULL. If @closid is NULL then all affected percpu closids must
+ * have been set up before calling this function.
+ */
+static void
+rdt_update_closid(const struct cpumask *cpu_mask, int *closid)
+{
+ int cpu = get_cpu();
+
+ if (cpumask_test_cpu(cpu, cpu_mask))
+ rdt_update_cpu_closid(closid);
+ smp_call_function_many(cpu_mask, rdt_update_cpu_closid, closid, 1);
+ put_cpu();
+}
+
+static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ cpumask_var_t tmpmask, newmask;
+ struct rdtgroup *rdtgrp, *r;
+ 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;
+ }
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ ret = -ENOENT;
+ goto unlock;
+ }
+
+ ret = cpumask_parse(buf, newmask);
+ if (ret)
+ goto unlock;
+
+ /* check that user didn't specify any offline cpus */
+ cpumask_andnot(tmpmask, newmask, cpu_online_mask);
+ if (cpumask_weight(tmpmask)) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ /* Check whether cpus are dropped from this group */
+ cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
+ if (cpumask_weight(tmpmask)) {
+ /* Can't drop from default group */
+ if (rdtgrp == &rdtgroup_default) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+ /* Give any dropped cpus to rdtgroup_default */
+ cpumask_or(&rdtgroup_default.cpu_mask,
+ &rdtgroup_default.cpu_mask, tmpmask);
+ rdt_update_closid(tmpmask, &rdtgroup_default.closid);
+ }
+
+ /*
+ * If we added cpus, remove them from previous group that owned them
+ * and update per-cpu closid
+ */
+ cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
+ if (cpumask_weight(tmpmask)) {
+ list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) {
+ if (r == rdtgrp)
+ continue;
+ cpumask_andnot(&r->cpu_mask, &r->cpu_mask, tmpmask);
+ }
+ rdt_update_closid(tmpmask, &rdtgrp->closid);
+ }
+
+ /* Done pushing/pulling - update this group with new mask */
+ cpumask_copy(&rdtgrp->cpu_mask, newmask);
+
+unlock:
+ rdtgroup_kn_unlock(of->kn);
+ free_cpumask_var(tmpmask);
+ free_cpumask_var(newmask);
+
+ return ret ?: nbytes;
+}
+
+struct task_move_callback {
+ struct callback_head work;
+ struct rdtgroup *rdtgrp;
+};
+
+static void move_myself(struct callback_head *head)
+{
+ struct task_move_callback *callback;
+ struct rdtgroup *rdtgrp;
+
+ callback = container_of(head, struct task_move_callback, work);
+ rdtgrp = callback->rdtgrp;
+
+ /*
+ * If resource group was deleted before this task work callback
+ * was invoked, then assign the task to root group and free the
+ * resource group.
+ */
+ if (atomic_dec_and_test(&rdtgrp->waitcount) &&
+ (rdtgrp->flags & RDT_DELETED)) {
+ current->closid = 0;
+ kfree(rdtgrp);
+ }
+
+ preempt_disable();
+ /* update PQR_ASSOC MSR to make resource group go into effect */
+ intel_rdt_sched_in();
+ preempt_enable();
+
+ kfree(callback);
+}
+
+static int __rdtgroup_move_task(struct task_struct *tsk,
+ struct rdtgroup *rdtgrp)
+{
+ struct task_move_callback *callback;
+ int ret;
+
+ callback = kzalloc(sizeof(*callback), GFP_KERNEL);
+ if (!callback)
+ return -ENOMEM;
+ callback->work.func = move_myself;
+ callback->rdtgrp = rdtgrp;
+
+ /*
+ * Take a refcount, so rdtgrp cannot be freed before the
+ * callback has been invoked.
+ */
+ atomic_inc(&rdtgrp->waitcount);
+ ret = task_work_add(tsk, &callback->work, true);
+ if (ret) {
+ /*
+ * Task is exiting. Drop the refcount and free the callback.
+ * No need to check the refcount as the group cannot be
+ * deleted before the write function unlocks rdtgroup_mutex.
+ */
+ atomic_dec(&rdtgrp->waitcount);
+ kfree(callback);
+ } else {
+ tsk->closid = rdtgrp->closid;
+ }
+ 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))
+ 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();
+ 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;
+ int ret = 0;
+ pid_t pid;
+
+ if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
+ return -EINVAL;
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+
+ if (rdtgrp)
+ ret = rdtgroup_move_task(pid, rdtgrp, of);
+ else
+ ret = -ENOENT;
+
+ 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;
+
+ rcu_read_lock();
+ for_each_process_thread(p, t) {
+ if (t->closid == r->closid)
+ seq_printf(s, "%d\n", t->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;
+}
+
+/* Files in each rdtgroup */
+static struct rftype rdtgroup_base_files[] = {
+ {
+ .name = "cpus",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_cpus_write,
+ .seq_show = rdtgroup_cpus_show,
+ },
+ {
+ .name = "tasks",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_tasks_write,
+ .seq_show = rdtgroup_tasks_show,
+ },
+ {
+ .name = "schemata",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_schemata_write,
+ .seq_show = rdtgroup_schemata_show,
+ },
+};
+
+static int rdt_num_closids_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+
+ seq_printf(seq, "%d\n", r->num_closid);
+
+ return 0;
+}
+
+static int rdt_cbm_mask_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+
+ seq_printf(seq, "%x\n", r->max_cbm);
+
+ return 0;
+}
+
+static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+
+ seq_printf(seq, "%d\n", r->min_cbm_bits);
+
+ return 0;
+}
+
+/* rdtgroup information files for one cache resource. */
+static struct rftype res_info_files[] = {
+ {
+ .name = "num_closids",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_num_closids_show,
+ },
+ {
+ .name = "cbm_mask",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_cbm_mask_show,
+ },
+ {
+ .name = "min_cbm_bits",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_min_cbm_bits_show,
+ },
+};
+
+static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
+{
+ struct kernfs_node *kn_subdir;
+ struct rdt_resource *r;
+ 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);
+ kernfs_get(kn_info);
+
+ for_each_enabled_rdt_resource(r) {
+ kn_subdir = kernfs_create_dir(kn_info, r->name,
+ kn_info->mode, r);
+ if (IS_ERR(kn_subdir)) {
+ ret = PTR_ERR(kn_subdir);
+ goto out_destroy;
+ }
+ kernfs_get(kn_subdir);
+ ret = rdtgroup_kn_set_ugid(kn_subdir);
+ if (ret)
+ goto out_destroy;
+ ret = rdtgroup_add_files(kn_subdir, res_info_files,
+ ARRAY_SIZE(res_info_files));
+ if (ret)
+ goto out_destroy;
+ kernfs_activate(kn_subdir);
+ }
+
+ /*
+ * This extra ref will be put in kernfs_remove() and guarantees
+ * that @rdtgrp->kn is always accessible.
+ */
+ kernfs_get(kn_info);
+
+ 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 void l3_qos_cfg_update(void *arg)
+{
+ bool *enable = arg;
+
+ wrmsrl(IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL);
+}
+
+static int set_l3_qos_cfg(struct rdt_resource *r, bool enable)
+{
+ cpumask_var_t cpu_mask;
+ struct rdt_domain *d;
+ int cpu;
+
+ if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ list_for_each_entry(d, &r->domains, list) {
+ /* Pick one CPU from each domain instance to update MSR */
+ cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
+ }
+ cpu = get_cpu();
+ /* Update QOS_CFG MSR on this cpu if it's in cpu_mask. */
+ if (cpumask_test_cpu(cpu, cpu_mask))
+ l3_qos_cfg_update(&enable);
+ /* Update QOS_CFG MSR on all other cpus in cpu_mask. */
+ smp_call_function_many(cpu_mask, l3_qos_cfg_update, &enable, 1);
+ put_cpu();
+
+ free_cpumask_var(cpu_mask);
+
+ return 0;
+}
+
+static int cdp_enable(void)
+{
+ struct rdt_resource *r_l3data = &rdt_resources_all[RDT_RESOURCE_L3DATA];
+ struct rdt_resource *r_l3code = &rdt_resources_all[RDT_RESOURCE_L3CODE];
+ struct rdt_resource *r_l3 = &rdt_resources_all[RDT_RESOURCE_L3];
+ int ret;
+
+ if (!r_l3->capable || !r_l3data->capable || !r_l3code->capable)
+ return -EINVAL;
+
+ ret = set_l3_qos_cfg(r_l3, true);
+ if (!ret) {
+ r_l3->enabled = false;
+ r_l3data->enabled = true;
+ r_l3code->enabled = true;
+ }
+ return ret;
+}
+
+static void cdp_disable(void)
+{
+ struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3];
+
+ r->enabled = r->capable;
+
+ if (rdt_resources_all[RDT_RESOURCE_L3DATA].enabled) {
+ rdt_resources_all[RDT_RESOURCE_L3DATA].enabled = false;
+ rdt_resources_all[RDT_RESOURCE_L3CODE].enabled = false;
+ set_l3_qos_cfg(r, false);
+ }
+}
+
+static int parse_rdtgroupfs_options(char *data)
+{
+ char *token, *o = data;
+ int ret = 0;
+
+ while ((token = strsep(&o, ",")) != NULL) {
+ if (!*token)
+ return -EINVAL;
+
+ if (!strcmp(token, "cdp"))
+ ret = cdp_enable();
+ }
+
+ return ret;
+}
+
+/*
+ * 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 || kn->parent == kn_info)
+ return NULL;
+ else
+ return kn->priv;
+ } else {
+ return kn->parent->priv;
+ }
+}
+
+struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn)
+{
+ struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
+
+ if (!rdtgrp)
+ return NULL;
+
+ atomic_inc(&rdtgrp->waitcount);
+ kernfs_break_active_protection(kn);
+
+ 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);
+
+ if (atomic_dec_and_test(&rdtgrp->waitcount) &&
+ (rdtgrp->flags & RDT_DELETED)) {
+ kernfs_unbreak_active_protection(kn);
+ kernfs_put(kn);
+ kfree(rdtgrp);
+ } else {
+ kernfs_unbreak_active_protection(kn);
+ }
+}
+
+static struct dentry *rdt_mount(struct file_system_type *fs_type,
+ int flags, const char *unused_dev_name,
+ void *data)
+{
+ struct dentry *dentry;
+ int ret;
+
+ mutex_lock(&rdtgroup_mutex);
+ /*
+ * resctrl file system can only be mounted once.
+ */
+ if (static_branch_unlikely(&rdt_enable_key)) {
+ dentry = ERR_PTR(-EBUSY);
+ goto out;
+ }
+
+ ret = parse_rdtgroupfs_options(data);
+ if (ret) {
+ dentry = ERR_PTR(ret);
+ goto out_cdp;
+ }
+
+ closid_init();
+
+ ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
+ if (ret) {
+ dentry = ERR_PTR(ret);
+ goto out_cdp;
+ }
+
+ dentry = kernfs_mount(fs_type, flags, rdt_root,
+ RDTGROUP_SUPER_MAGIC, NULL);
+ if (IS_ERR(dentry))
+ goto out_cdp;
+
+ static_branch_enable(&rdt_enable_key);
+ goto out;
+
+out_cdp:
+ cdp_disable();
+out:
+ mutex_unlock(&rdtgroup_mutex);
+
+ return dentry;
+}
+
+static int reset_all_cbms(struct rdt_resource *r)
+{
+ struct msr_param msr_param;
+ cpumask_var_t cpu_mask;
+ struct rdt_domain *d;
+ int i, cpu;
+
+ if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ msr_param.res = r;
+ msr_param.low = 0;
+ msr_param.high = r->num_closid;
+
+ /*
+ * Disable resource control for this resource by setting all
+ * CBMs in all domains to the maximum mask value. Pick one CPU
+ * from each domain to update the MSRs below.
+ */
+ list_for_each_entry(d, &r->domains, list) {
+ cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
+
+ for (i = 0; i < r->num_closid; i++)
+ d->cbm[i] = r->max_cbm;
+ }
+ cpu = get_cpu();
+ /* Update CBM on this cpu if it's in cpu_mask. */
+ if (cpumask_test_cpu(cpu, cpu_mask))
+ rdt_cbm_update(&msr_param);
+ /* Update CBM on all other cpus in cpu_mask. */
+ smp_call_function_many(cpu_mask, rdt_cbm_update, &msr_param, 1);
+ put_cpu();
+
+ free_cpumask_var(cpu_mask);
+
+ 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 || t->closid == from->closid) {
+ t->closid = to->closid;
+#ifdef CONFIG_SMP
+ /*
+ * This is safe on x86 w/o barriers as the ordering
+ * of writing to task_cpu() and t->on_cpu is
+ * reverse to the reading here. 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 (mask && t->on_cpu)
+ cpumask_set_cpu(task_cpu(t), mask);
+#endif
+ }
+ }
+ read_unlock(&tasklist_lock);
+}
+
+/*
+ * 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) {
+ /* Remove each rdtgroup other than root */
+ if (rdtgrp == &rdtgroup_default)
+ continue;
+
+ /*
+ * 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);
+
+ kernfs_remove(rdtgrp->kn);
+ list_del(&rdtgrp->rdtgroup_list);
+ kfree(rdtgrp);
+ }
+ /* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
+ get_online_cpus();
+ rdt_update_closid(cpu_online_mask, &rdtgroup_default.closid);
+ put_online_cpus();
+
+ kernfs_remove(kn_info);
+}
+
+static void rdt_kill_sb(struct super_block *sb)
+{
+ struct rdt_resource *r;
+
+ mutex_lock(&rdtgroup_mutex);
+
+ /*Put everything back to default values. */
+ for_each_enabled_rdt_resource(r)
+ reset_all_cbms(r);
+ cdp_disable();
+ rmdir_all_sub();
+ static_branch_disable(&rdt_enable_key);
+ kernfs_kill_sb(sb);
+ mutex_unlock(&rdtgroup_mutex);
+}
+
+static struct file_system_type rdt_fs_type = {
+ .name = "resctrl",
+ .mount = rdt_mount,
+ .kill_sb = rdt_kill_sb,
+};
+
+static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
+ umode_t mode)
+{
+ struct rdtgroup *parent, *rdtgrp;
+ struct kernfs_node *kn;
+ int ret, closid;
+
+ /* Only allow mkdir in the root directory */
+ if (parent_kn != rdtgroup_default.kn)
+ return -EPERM;
+
+ /* Do not accept '\n' to avoid unparsable situation. */
+ if (strchr(name, '\n'))
+ return -EINVAL;
+
+ parent = rdtgroup_kn_lock_live(parent_kn);
+ if (!parent) {
+ ret = -ENODEV;
+ goto out_unlock;
+ }
+
+ ret = closid_alloc();
+ if (ret < 0)
+ goto out_unlock;
+ closid = ret;
+
+ /* allocate the rdtgroup. */
+ rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL);
+ if (!rdtgrp) {
+ ret = -ENOSPC;
+ goto out_closid_free;
+ }
+ rdtgrp->closid = closid;
+ list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups);
+
+ /* kernfs creates the directory for rdtgrp */
+ kn = kernfs_create_dir(parent->kn, name, mode, rdtgrp);
+ if (IS_ERR(kn)) {
+ ret = PTR_ERR(kn);
+ goto out_cancel_ref;
+ }
+ 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 below. Take one extra reference
+ * here, which will be dropped inside rdtgroup_kn_unlock().
+ */
+ kernfs_get(kn);
+
+ ret = rdtgroup_kn_set_ugid(kn);
+ if (ret)
+ goto out_destroy;
+
+ ret = rdtgroup_add_files(kn, rdtgroup_base_files,
+ ARRAY_SIZE(rdtgroup_base_files));
+ if (ret)
+ goto out_destroy;
+
+ kernfs_activate(kn);
+
+ ret = 0;
+ goto out_unlock;
+
+out_destroy:
+ kernfs_remove(rdtgrp->kn);
+out_cancel_ref:
+ list_del(&rdtgrp->rdtgroup_list);
+ kfree(rdtgrp);
+out_closid_free:
+ closid_free(closid);
+out_unlock:
+ rdtgroup_kn_unlock(parent_kn);
+ return ret;
+}
+
+static int rdtgroup_rmdir(struct kernfs_node *kn)
+{
+ int ret, cpu, closid = rdtgroup_default.closid;
+ struct rdtgroup *rdtgrp;
+ cpumask_var_t tmpmask;
+
+ if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
+ return -ENOMEM;
+
+ rdtgrp = rdtgroup_kn_lock_live(kn);
+ if (!rdtgrp) {
+ ret = -EPERM;
+ goto out;
+ }
+
+ /* 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 of the moved CPUs first */
+ for_each_cpu(cpu, &rdtgrp->cpu_mask)
+ per_cpu(cpu_closid, cpu) = closid;
+ /*
+ * Update the MSR on moved CPUs and CPUs which have moved
+ * task running on them.
+ */
+ cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
+ rdt_update_closid(tmpmask, NULL);
+
+ rdtgrp->flags = RDT_DELETED;
+ closid_free(rdtgrp->closid);
+ list_del(&rdtgrp->rdtgroup_list);
+
+ /*
+ * one extra hold on this, will drop when we kfree(rdtgrp)
+ * in rdtgroup_kn_unlock()
+ */
+ kernfs_get(kn);
+ kernfs_remove(rdtgrp->kn);
+ ret = 0;
+out:
+ rdtgroup_kn_unlock(kn);
+ free_cpumask_var(tmpmask);
+ return ret;
+}
+
+static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf)
+{
+ if (rdt_resources_all[RDT_RESOURCE_L3DATA].enabled)
+ seq_puts(seq, ",cdp");
+ return 0;
+}
+
+static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
+ .mkdir = rdtgroup_mkdir,
+ .rmdir = rdtgroup_rmdir,
+ .show_options = rdtgroup_show_options,
+};
+
+static int __init rdtgroup_setup_root(void)
+{
+ int ret;
+
+ rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops,
+ KERNFS_ROOT_CREATE_DEACTIVATED,
+ &rdtgroup_default);
+ if (IS_ERR(rdt_root))
+ return PTR_ERR(rdt_root);
+
+ mutex_lock(&rdtgroup_mutex);
+
+ rdtgroup_default.closid = 0;
+ list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
+
+ ret = rdtgroup_add_files(rdt_root->kn, rdtgroup_base_files,
+ ARRAY_SIZE(rdtgroup_base_files));
+ if (ret) {
+ kernfs_destroy_root(rdt_root);
+ goto out;
+ }
+
+ rdtgroup_default.kn = rdt_root->kn;
+ kernfs_activate(rdtgroup_default.kn);
+
+out:
+ mutex_unlock(&rdtgroup_mutex);
+
+ return ret;
+}
+
+/*
+ * rdtgroup_init - rdtgroup initialization
+ *
+ * Setup resctrl file system including set up root, create mount point,
+ * register rdtgroup filesystem, and initialize files under root directory.
+ *
+ * Return: 0 on success or -errno
+ */
+int __init rdtgroup_init(void)
+{
+ int ret = 0;
+
+ ret = rdtgroup_setup_root();
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_mount_point(fs_kobj, "resctrl");
+ if (ret)
+ goto cleanup_root;
+
+ ret = register_filesystem(&rdt_fs_type);
+ if (ret)
+ goto cleanup_mountpoint;
+
+ return 0;
+
+cleanup_mountpoint:
+ sysfs_remove_mount_point(fs_kobj, "resctrl");
+cleanup_root:
+ kernfs_destroy_root(rdt_root);
+
+ return ret;
+}
diff --git a/arch/x86/kernel/cpu/intel_rdt_schemata.c b/arch/x86/kernel/cpu/intel_rdt_schemata.c
new file mode 100644
index 000000000000..f369cb8db0d5
--- /dev/null
+++ b/arch/x86/kernel/cpu/intel_rdt_schemata.c
@@ -0,0 +1,245 @@
+/*
+ * Resource Director Technology(RDT)
+ * - Cache Allocation code.
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Authors:
+ * Fenghua Yu <fenghua.yu@intel.com>
+ * Tony Luck <tony.luck@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * 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 <linux/kernfs.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <asm/intel_rdt.h>
+
+/*
+ * Check whether a cache bit mask is valid. The SDM says:
+ * Please note that all (and only) contiguous '1' combinations
+ * are allowed (e.g. FFFFH, 0FF0H, 003CH, etc.).
+ * Additionally Haswell requires at least two bits set.
+ */
+static bool cbm_validate(unsigned long var, struct rdt_resource *r)
+{
+ unsigned long first_bit, zero_bit;
+
+ if (var == 0 || var > r->max_cbm)
+ return false;
+
+ first_bit = find_first_bit(&var, r->cbm_len);
+ zero_bit = find_next_zero_bit(&var, r->cbm_len, first_bit);
+
+ if (find_next_bit(&var, r->cbm_len, zero_bit) < r->cbm_len)
+ return false;
+
+ if ((zero_bit - first_bit) < r->min_cbm_bits)
+ return false;
+ return true;
+}
+
+/*
+ * Read one cache bit mask (hex). Check that it is valid for the current
+ * resource type.
+ */
+static int parse_cbm(char *buf, struct rdt_resource *r)
+{
+ unsigned long data;
+ int ret;
+
+ ret = kstrtoul(buf, 16, &data);
+ if (ret)
+ return ret;
+ if (!cbm_validate(data, r))
+ return -EINVAL;
+ r->tmp_cbms[r->num_tmp_cbms++] = data;
+
+ 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 appear in the
+ * right order.
+ */
+static int parse_line(char *line, struct rdt_resource *r)
+{
+ char *dom = NULL, *id;
+ struct rdt_domain *d;
+ unsigned long dom_id;
+
+ list_for_each_entry(d, &r->domains, list) {
+ dom = strsep(&line, ";");
+ if (!dom)
+ return -EINVAL;
+ id = strsep(&dom, "=");
+ if (kstrtoul(id, 10, &dom_id) || dom_id != d->id)
+ return -EINVAL;
+ if (parse_cbm(dom, r))
+ return -EINVAL;
+ }
+
+ /* Any garbage at the end of the line? */
+ if (line && line[0])
+ return -EINVAL;
+ return 0;
+}
+
+static int update_domains(struct rdt_resource *r, int closid)
+{
+ struct msr_param msr_param;
+ cpumask_var_t cpu_mask;
+ struct rdt_domain *d;
+ int cpu, idx = 0;
+
+ if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ msr_param.low = closid;
+ msr_param.high = msr_param.low + 1;
+ msr_param.res = r;
+
+ list_for_each_entry(d, &r->domains, list) {
+ cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
+ d->cbm[msr_param.low] = r->tmp_cbms[idx++];
+ }
+ cpu = get_cpu();
+ /* Update CBM on this cpu if it's in cpu_mask. */
+ if (cpumask_test_cpu(cpu, cpu_mask))
+ rdt_cbm_update(&msr_param);
+ /* Update CBM on other cpus. */
+ smp_call_function_many(cpu_mask, rdt_cbm_update, &msr_param, 1);
+ put_cpu();
+
+ free_cpumask_var(cpu_mask);
+
+ return 0;
+}
+
+ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct rdtgroup *rdtgrp;
+ struct rdt_resource *r;
+ char *tok, *resname;
+ int closid, ret = 0;
+ u32 *l3_cbms = NULL;
+
+ /* 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;
+ }
+
+ closid = rdtgrp->closid;
+
+ /* get scratch space to save all the masks while we validate input */
+ for_each_enabled_rdt_resource(r) {
+ r->tmp_cbms = kcalloc(r->num_domains, sizeof(*l3_cbms),
+ GFP_KERNEL);
+ if (!r->tmp_cbms) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ r->num_tmp_cbms = 0;
+ }
+
+ while ((tok = strsep(&buf, "\n")) != NULL) {
+ resname = strsep(&tok, ":");
+ if (!tok) {
+ ret = -EINVAL;
+ goto out;
+ }
+ for_each_enabled_rdt_resource(r) {
+ if (!strcmp(resname, r->name) &&
+ closid < r->num_closid) {
+ ret = parse_line(tok, r);
+ if (ret)
+ goto out;
+ break;
+ }
+ }
+ if (!r->name) {
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ /* Did the parser find all the masks we need? */
+ for_each_enabled_rdt_resource(r) {
+ if (r->num_tmp_cbms != r->num_domains) {
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ for_each_enabled_rdt_resource(r) {
+ ret = update_domains(r, closid);
+ if (ret)
+ goto out;
+ }
+
+out:
+ rdtgroup_kn_unlock(of->kn);
+ for_each_enabled_rdt_resource(r) {
+ kfree(r->tmp_cbms);
+ r->tmp_cbms = NULL;
+ }
+ return ret ?: nbytes;
+}
+
+static void show_doms(struct seq_file *s, struct rdt_resource *r, int closid)
+{
+ struct rdt_domain *dom;
+ bool sep = false;
+
+ seq_printf(s, "%s:", r->name);
+ list_for_each_entry(dom, &r->domains, list) {
+ if (sep)
+ seq_puts(s, ";");
+ seq_printf(s, "%d=%x", dom->id, dom->cbm[closid]);
+ sep = true;
+ }
+ seq_puts(s, "\n");
+}
+
+int rdtgroup_schemata_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdtgroup *rdtgrp;
+ struct rdt_resource *r;
+ int closid, ret = 0;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (rdtgrp) {
+ closid = rdtgrp->closid;
+ for_each_enabled_rdt_resource(r) {
+ if (closid < r->num_closid)
+ show_doms(s, r, closid);
+ }
+ } else {
+ ret = -ENOENT;
+ }
+ rdtgroup_kn_unlock(of->kn);
+ return ret;
+}
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index d1316f9c8329..d9794060fe22 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -20,12 +20,15 @@ struct cpuid_bit {
/* Please keep the leaf sorted by cpuid_bit.level for faster search. */
static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 },
- { X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 },
- { X86_FEATURE_INTEL_PT, CPUID_EBX, 25, 0x00000007, 0 },
+ { X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 },
+ { X86_FEATURE_INTEL_PT, CPUID_EBX, 25, 0x00000007, 0 },
{ X86_FEATURE_AVX512_4VNNIW, CPUID_EDX, 2, 0x00000007, 0 },
{ X86_FEATURE_AVX512_4FMAPS, CPUID_EDX, 3, 0x00000007, 0 },
- { X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 },
- { X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
+ { X86_FEATURE_CAT_L3, CPUID_EBX, 1, 0x00000010, 0 },
+ { X86_FEATURE_CAT_L2, CPUID_EBX, 2, 0x00000010, 0 },
+ { X86_FEATURE_CDP_L3, CPUID_ECX, 2, 0x00000010, 1 },
+ { X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 },
+ { X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
{ X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
{ 0, 0, 0, 0, 0 }
};
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index d0d744108594..a0ac3e81518a 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -53,6 +53,7 @@
#include <asm/debugreg.h>
#include <asm/switch_to.h>
#include <asm/vm86.h>
+#include <asm/intel_rdt.h>
void __show_regs(struct pt_regs *regs, int all)
{
@@ -296,5 +297,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
this_cpu_write(current_task, next_p);
+ /* Load the Intel cache allocation PQR MSR. */
+ intel_rdt_sched_in();
+
return prev_p;
}
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index a76b65e3e615..a61e141b6891 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -49,6 +49,7 @@
#include <asm/switch_to.h>
#include <asm/xen/hypervisor.h>
#include <asm/vdso.h>
+#include <asm/intel_rdt.h>
__visible DEFINE_PER_CPU(unsigned long, rsp_scratch);
@@ -476,6 +477,9 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
loadsegment(ss, __KERNEL_DS);
}
+ /* Load the Intel cache allocation PQR MSR. */
+ intel_rdt_sched_in();
+
return prev_p;
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.