diff options
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_amd_ibs.c | 294 |
2 files changed, 295 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index 1044fd787db8..fe6eb197f848 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -36,7 +36,7 @@ endif obj-$(CONFIG_X86_MCE) += mcheck/ obj-$(CONFIG_MTRR) += mtrr/ -obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o +obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o perf_event_amd_ibs.o quiet_cmd_mkcapflags = MKCAP $@ cmd_mkcapflags = $(PERL) $(srctree)/$(src)/mkcapflags.pl $< $@ diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c new file mode 100644 index 000000000000..ab6343d21825 --- /dev/null +++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c @@ -0,0 +1,294 @@ +/* + * Performance events - AMD IBS + * + * Copyright (C) 2011 Advanced Micro Devices, Inc., Robert Richter + * + * For licencing details see kernel-base/COPYING + */ + +#include <linux/perf_event.h> +#include <linux/module.h> +#include <linux/pci.h> + +#include <asm/apic.h> + +static u32 ibs_caps; + +#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD) + +static struct pmu perf_ibs; + +static int perf_ibs_init(struct perf_event *event) +{ + if (perf_ibs.type != event->attr.type) + return -ENOENT; + return 0; +} + +static int perf_ibs_add(struct perf_event *event, int flags) +{ + return 0; +} + +static void perf_ibs_del(struct perf_event *event, int flags) +{ +} + +static struct pmu perf_ibs = { + .event_init= perf_ibs_init, + .add= perf_ibs_add, + .del= perf_ibs_del, +}; + +static __init int perf_event_ibs_init(void) +{ + if (!ibs_caps) + return -ENODEV; /* ibs not supported by the cpu */ + + perf_pmu_register(&perf_ibs, "ibs", -1); + printk(KERN_INFO "perf: AMD IBS detected (0x%08x)\n", ibs_caps); + + return 0; +} + +#else /* defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD) */ + +static __init int perf_event_ibs_init(void) { return 0; } + +#endif + +/* IBS - apic initialization, for perf and oprofile */ + +static __init u32 __get_ibs_caps(void) +{ + u32 caps; + unsigned int max_level; + + if (!boot_cpu_has(X86_FEATURE_IBS)) + return 0; + + /* check IBS cpuid feature flags */ + max_level = cpuid_eax(0x80000000); + if (max_level < IBS_CPUID_FEATURES) + return IBS_CAPS_DEFAULT; + + caps = cpuid_eax(IBS_CPUID_FEATURES); + if (!(caps & IBS_CAPS_AVAIL)) + /* cpuid flags not valid */ + return IBS_CAPS_DEFAULT; + + return caps; +} + +u32 get_ibs_caps(void) +{ + return ibs_caps; +} + +EXPORT_SYMBOL(get_ibs_caps); + +static inline int get_eilvt(int offset) +{ + return !setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 1); +} + +static inline int put_eilvt(int offset) +{ + return !setup_APIC_eilvt(offset, 0, 0, 1); +} + +/* + * Check and reserve APIC extended interrupt LVT offset for IBS if available. + */ +static inline int ibs_eilvt_valid(void) +{ + int offset; + u64 val; + int valid = 0; + + preempt_disable(); + + rdmsrl(MSR_AMD64_IBSCTL, val); + offset = val & IBSCTL_LVT_OFFSET_MASK; + + if (!(val & IBSCTL_LVT_OFFSET_VALID)) { + pr_err(FW_BUG "cpu %d, invalid IBS interrupt offset %d (MSR%08X=0x%016llx)\n", + smp_processor_id(), offset, MSR_AMD64_IBSCTL, val); + goto out; + } + + if (!get_eilvt(offset)) { + pr_err(FW_BUG "cpu %d, IBS interrupt offset %d not available (MSR%08X=0x%016llx)\n", + smp_processor_id(), offset, MSR_AMD64_IBSCTL, val); + goto out; + } + + valid = 1; +out: + preempt_enable(); + + return valid; +} + +static int setup_ibs_ctl(int ibs_eilvt_off) +{ + struct pci_dev *cpu_cfg; + int nodes; + u32 value = 0; + + nodes = 0; + cpu_cfg = NULL; + do { + cpu_cfg = pci_get_device(PCI_VENDOR_ID_AMD, + PCI_DEVICE_ID_AMD_10H_NB_MISC, + cpu_cfg); + if (!cpu_cfg) + break; + ++nodes; + pci_write_config_dword(cpu_cfg, IBSCTL, ibs_eilvt_off + | IBSCTL_LVT_OFFSET_VALID); + pci_read_config_dword(cpu_cfg, IBSCTL, &value); + if (value != (ibs_eilvt_off | IBSCTL_LVT_OFFSET_VALID)) { + pci_dev_put(cpu_cfg); + printk(KERN_DEBUG "Failed to setup IBS LVT offset, " + "IBSCTL = 0x%08x\n", value); + return -EINVAL; + } + } while (1); + + if (!nodes) { + printk(KERN_DEBUG "No CPU node configured for IBS\n"); + return -ENODEV; + } + + return 0; +} + +/* + * This runs only on the current cpu. We try to find an LVT offset and + * setup the local APIC. For this we must disable preemption. On + * success we initialize all nodes with this offset. This updates then + * the offset in the IBS_CTL per-node msr. The per-core APIC setup of + * the IBS interrupt vector is handled by perf_ibs_cpu_notifier that + * is using the new offset. + */ +static int force_ibs_eilvt_setup(void) +{ + int offset; + int ret; + + preempt_disable(); + /* find the next free available EILVT entry, skip offset 0 */ + for (offset = 1; offset < APIC_EILVT_NR_MAX; offset++) { + if (get_eilvt(offset)) + break; + } + preempt_enable(); + + if (offset == APIC_EILVT_NR_MAX) { + printk(KERN_DEBUG "No EILVT entry available\n"); + return -EBUSY; + } + + ret = setup_ibs_ctl(offset); + if (ret) + goto out; + + if (!ibs_eilvt_valid()) { + ret = -EFAULT; + goto out; + } + + pr_err(FW_BUG "using offset %d for IBS interrupts\n", offset); + pr_err(FW_BUG "workaround enabled for IBS LVT offset\n"); + + return 0; +out: + preempt_disable(); + put_eilvt(offset); + preempt_enable(); + return ret; +} + +static inline int get_ibs_lvt_offset(void) +{ + u64 val; + + rdmsrl(MSR_AMD64_IBSCTL, val); + if (!(val & IBSCTL_LVT_OFFSET_VALID)) + return -EINVAL; + + return val & IBSCTL_LVT_OFFSET_MASK; +} + +static void setup_APIC_ibs(void *dummy) +{ + int offset; + + offset = get_ibs_lvt_offset(); + if (offset < 0) + goto failed; + + if (!setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 0)) + return; +failed: + pr_warn("perf: IBS APIC setup failed on cpu #%d\n", + smp_processor_id()); +} + +static void clear_APIC_ibs(void *dummy) +{ + int offset; + + offset = get_ibs_lvt_offset(); + if (offset >= 0) + setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_FIX, 1); +} + +static int __cpuinit +perf_ibs_cpu_notifier(struct notifier_block *self, unsigned long action, void *hcpu) +{ + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_STARTING: + setup_APIC_ibs(NULL); + break; + case CPU_DYING: + clear_APIC_ibs(NULL); + break; + default: + break; + } + + return NOTIFY_OK; +} + +static __init int amd_ibs_init(void) +{ + u32 caps; + int ret; + + caps = __get_ibs_caps(); + if (!caps) + return -ENODEV; /* ibs not supported by the cpu */ + + if (!ibs_eilvt_valid()) { + ret = force_ibs_eilvt_setup(); + if (ret) { + pr_err("Failed to setup IBS, %d\n", ret); + return ret; + } + } + + get_online_cpus(); + ibs_caps = caps; + /* make ibs_caps visible to other cpus: */ + smp_mb(); + perf_cpu_notifier(perf_ibs_cpu_notifier); + smp_call_function(setup_APIC_ibs, NULL, 1); + put_online_cpus(); + + return perf_event_ibs_init(); +} + +/* Since we need the pci subsystem to init ibs we can't do this earlier: */ +device_initcall(amd_ibs_init); |