/* * Performance events x86 architecture code * * Copyright (C) 2008 Thomas Gleixner * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar * Copyright (C) 2009 Jaswinder Singh Rajput * Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra * Copyright (C) 2009 Intel Corporation, * Copyright (C) 2009 Google, Inc., Stephane Eranian * * For licencing details see kernel-base/COPYING */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static u64 perf_event_mask __read_mostly; /* The maximal number of PEBS events: */ #define MAX_PEBS_EVENTS 4 /* The size of a BTS record in bytes: */ #define BTS_RECORD_SIZE 24 /* The size of a per-cpu BTS buffer in bytes: */ #define BTS_BUFFER_SIZE (BTS_RECORD_SIZE * 2048) /* The BTS overflow threshold in bytes from the end of the buffer: */ #define BTS_OVFL_TH (BTS_RECORD_SIZE * 128) /* * Bits in the debugctlmsr controlling branch tracing. */ #define X86_DEBUGCTL_TR (1 << 6) #define X86_DEBUGCTL_BTS (1 << 7) #define X86_DEBUGCTL_BTINT (1 << 8) #define X86_DEBUGCTL_BTS_OFF_OS (1 << 9) #define X86_DEBUGCTL_BTS_OFF_USR (1 << 10) /* * A debug store configuration. * * We only support architectures that use 64bit fields. */ struct debug_store { u64 bts_buffer_base; u64 bts_index; u64 bts_absolute_maximum; u64 bts_interrupt_threshold; u64 pebs_buffer_base; u64 pebs_index; u64 pebs_absolute_maximum; u64 pebs_interrupt_threshold; u64 pebs_event_reset[MAX_PEBS_EVENTS]; }; struct event_constraint { union { unsigned long idxmsk[BITS_TO_LONGS(X86_PMC_IDX_MAX)]; u64 idxmsk64; }; u64 code; u64 cmask; int weight; }; struct amd_nb { int nb_id; /* NorthBridge id */ int refcnt; /* reference count */ struct perf_event *owners[X86_PMC_IDX_MAX]; struct event_constraint event_constraints[X86_PMC_IDX_MAX]; }; struct cpu_hw_events { struct perf_event *events[X86_PMC_IDX_MAX]; /* in counter order */ unsigned long active_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)]; unsigned long interrupts; int enabled; struct debug_store *ds; int n_events; int n_added; int assign[X86_PMC_IDX_MAX]; /* event to counter assignment */ u64 tags[X86_PMC_IDX_MAX]; struct perf_event *event_list[X86_PMC_IDX_MAX]; /* in enabled order */ struct amd_nb *amd_nb; }; #define __EVENT_CONSTRAINT(c, n, m, w) {\ { .idxmsk64 = (n) }, \ .code = (c), \ .cmask = (m), \ .weight = (w), \ } #define EVENT_CONSTRAINT(c, n, m) \ __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n)) #define INTEL_EVENT_CONSTRAINT(c, n) \ EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVTSEL_MASK) #define FIXED_EVENT_CONSTRAINT(c, n) \ EVENT_CONSTRAINT(c, (1ULL << (32+n)), INTEL_ARCH_FIXED_MASK) #define EVENT_CONSTRAINT_END \ EVENT_CONSTRAINT(0, 0, 0) #define for_each_event_constraint(e, c) \ for ((e) = (c); (e)->cmask; (e)++) /* * struct x86_pmu - generic x86 pmu */ struct x86_pmu { const char *name; int version; int (*handle_irq)(struct pt_regs *); void (*disable_all)(void); void (*enable_all)(void); void (*enable)(struct hw_perf_event *, int); void (*disable)(struct hw_perf_event *, int); unsigned eventsel; unsigned perfctr; u64 (*event_map)(int); u64 (*raw_event)(u64); int max_events; int num_events; int num_events_fixed; int event_bits; u64 event_mask; int apic; u64 max_period; u64 intel_ctrl; void (*enable_bts)(u64 config); void (*disable_bts)(void); struct event_constraint * (*get_event_constraints)(struct cpu_hw_events *cpuc, struct perf_event *event); void (*put_event_constraints)(struct cpu_hw_events *cpuc, struct perf_event *event); struct event_constraint *event_constraints; }; static struct x86_pmu x86_pmu __read_mostly; static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = { .enabled = 1, }; static int x86_perf_event_set_period(struct perf_event *event, struct hw_perf_event *hwc, int idx); /* * Generalized hw caching related hw_event table, filled * in on a per model basis. A value of 0 means * 'not supported', -1 means 'hw_event makes no sense on * this CPU', any other value means the raw hw_event * ID. */ #define C(x) PERF_COUNT_HW_CACHE_##x static u64 __read_mostly hw_cache_event_ids [PERF_COUNT_HW_CACHE_MAX] [PERF_COUNT_HW_CACHE_OP_MAX] [PERF_COUNT_HW_CACHE_RESULT_MAX]; /* * Propagate event elapsed time into the generic event. * Can only be executed on the CPU where the event is active. * Returns the delta events processed. */ static u64 x86_perf_event_update(struct perf_event *event, struct hw_perf_event *hwc, int idx) { int shift = 64 - x86_pmu.event_bits; u64 prev_raw_count, new_raw_count; s64 delta; if (idx == X86_PMC_IDX_FIXED_BTS) return 0; /* * Careful: an NMI might modify the previous event value. * * Our tactic to handle this is to first atomically read and * exchange a new raw count - then add that new-prev delta * count to the generic event atomically: */ again: prev_raw_count = atomic64_read(&hwc->prev_count); rdmsrl(hwc->event_base + idx, new_raw_count); if (atomic64_cmpxchg(&hwc->prev_count, prev_raw_count, new_raw_count) != prev_raw_count) goto again; /* * Now we have the new raw value and have updated the prev * timestamp already. We can now calculate the elapsed delta * (event-)time and add that to the generic event. * * Careful, not all hw sign-extends above the physical width * of the count. */ delta = (new_raw_count << shift) - (prev_raw_count << shift); delta >>= shift; atomic64_add(delta, &event->count); atomic64_sub(delta, &hwc->period_left); return new_raw_count; } static atomic_t active_events; static DEFINE_MUTEX(pmc_reserve_mutex); static bool reserve_pmc_hardware(void) { #ifdef CONFIG_X86_LOCAL_APIC int i; if (nmi_watchdog == NMI_LOCAL_APIC) disable_lapic_nmi_watchdog(); for (i = 0; i < x86_pmu.num_events; i++) { if (!reserve_perfctr_nmi(x86_pmu.perfctr + i)) goto perfctr_fail; } for (i = 0; i < x86_pmu.num_events; i++) { if (!reserve_evntsel_nmi(x86_pmu.eventsel + i)) goto eventsel_fail; } #endif return true; #ifdef CONFIG_X86_LOCAL_APIC eventsel_fail: for (i--; i >= 0; i--) release_evntsel_nmi(x86_pmu.eventsel + i); i = x86_pmu.num_events; perfctr_fail: for (i--; i >= 0; i--) release_perfctr_nmi(x86_pmu.perfctr + i); if (nmi_watchdog == NMI_LOCAL_APIC) enable_lapic_nmi_watchdog(); return false; #endif } static void release_pmc_hardware(void) { #ifdef CONFIG_X86_LOCAL_APIC int i; for (i = 0; i < x86_pmu.num_events; i++) { release_perfctr_nmi(x86_pmu.perfctr + i); release_evntsel_nmi(x86_pmu.eventsel + i); } if (nmi_watchdog == NMI_LOCAL_APIC) enable_lapic_nmi_watchdog(); #endif } static inline bool bts_available(void) { return x86_pmu.enable_bts != NULL; } static inline void init_debug_store_on_cpu(int cpu) { struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; if (!ds) return; wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, (u32)((u64)(unsigned long)ds), (u32)((u64)(unsigned long)ds >> 32)); } static inline void fini_debug_store_on_cpu(int cpu) { if (!per_cpu(cpu_hw_events, cpu).ds) return; wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0); } static void release_bts_hardware(void) { int cpu; if (!bts_available()) return; get_online_cpus(); for_each_online_cpu(cpu) fini_debug_store_on_cpu(cpu); for_each_possible_cpu(cpu) { struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; if (!ds) continue; per_cpu(cpu_hw_events, cpu).ds = NULL; kfree((void *)(unsigned long)ds->bts_buffer_base); kfree(ds); } put_online_cpus(); } static int reserve_bts_hardware(void) { int cpu, err = 0; if (!bts_available()) return 0; get_online_cpus(); for_each_possible_cpu(cpu) { struct debug_store *ds; void *buffer; err = -ENOMEM; buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL); if (unlikely(!buffer)) break; ds = kzalloc(sizeof(*ds), GFP_KERNEL); if (unlikely(!ds)) { kfree(buffer); break; } ds->bts_buffer_base = (u64)(unsigned long)buffer; ds->bts_index = ds->bts_buffer_base; ds->bts_absolute_maximum = ds->bts_buffer_base + BTS_BUFFER_SIZE; ds->bts_interrupt_threshold = ds->bts_absolute_maximum - BTS_OVFL_TH; per_cpu(cpu_hw_events, cpu).ds = ds; err = 0; } if (err) release_bts_hardware(); else { for_each_online_cpu(cpu) init_debug_store_on_cpu(cpu); } put_online_cpus(); return err; } static void hw_perf_event_destroy(struct perf_event *event) { if (atomic_dec_and_mutex_lock(&active_events, &pmc_reserve_mutex)) { release_pmc_hardware(); release_bts_hardware(); mutex_unlock(&pmc_reserve_mutex); } } static inline int x86_pmu_initialized(void) { return x86_pmu.handle_irq != NULL; } static inline int set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event_attr *attr) { unsigned int cache_type, cache_op, cache_result; u64 config, val; config = attr->config; cache_type = (config >> 0) & 0xff; if (cache_type >= PERF_COUNT_HW_CACHE_MAX) return -EINVAL; cache_op = (config >> 8) & 0xff; if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX) return -EINVAL; cache_result = (config >> 16) & 0xff; if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX) return -EINVAL; val = hw_cache_event_ids[cache_type][cache_op][cache_result]; if (val == 0) return -ENOENT; if (val == -1) return -EINVAL; hwc->config |= val; return 0; } /* * Setup the hardware configuration for a given attr_type */ static int __hw_perf_event_init(struct perf_event *event) { struct perf_event_attr *attr = &event->attr; struct hw_perf_event *hwc = &event->hw; u64 config; int err; if (!x86_pmu_initialized()) return -ENODEV; err = 0; if (!atomic_inc_not_zero(&active_events)) { mutex_lock(&pmc_reserve_mutex); if (atomic_read(&active_events) == 0) { if (!reserve_pmc_hardware()) err = -EBUSY; else err = reserve_bts_hardware(); } if (!err) atomic_inc(&active_events); mutex_unlock(&pmc_reserve_mutex); } if (err) return err; event->destroy = hw_perf_event_destroy; /* * Generate PMC IRQs: * (keep 'enabled' bit clear for now) */ hwc->config = ARCH_PERFMON_EVENTSEL_INT; hwc->idx = -1; hwc->last_cpu = -1; hwc->last_tag = ~0ULL; /* * Count user and OS events unless requested not to. */ if (!attr->exclude_user) hwc->config |= ARCH_PERFMON_EVENTSEL_USR; if (!attr->exclude_kernel) hwc->config |= ARCH_PERFMON_EVENTSEL_OS; if (!hwc->sample_period) { hwc->sample_period = x86_pmu.max_period; hwc->last_period = hwc->sample_period; atomic64_set(&hwc->period_left, hwc->sample_period); } else { /* * If we have a PMU initialized but no APIC * interrupts, we cannot sample hardware * events (user-space has to fall back and * sample via a hrtimer based software event): */ if (!x86_pmu.apic) return -EOPNOTSUPP; } /* * Raw hw_event type provide the config in the hw_event structure */ if (attr->type == PERF_TYPE_RAW) { hwc->config |= x86_pmu.raw_event(attr->config); if ((hwc->config & ARCH_PERFMON_EVENTSEL_ANY) && perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) return -EACCES; return 0; } if (attr->type == PERF_TYPE_HW_CACHE) return set_ext_hw_attr(hwc, attr); if (attr->config >= x86_pmu.max_events) return -EINVAL; /* * The generic map: */ config = x86_pmu.event_map(attr->config); if (config == 0) return -ENOENT; if (config == -1LL) return -EINVAL; /* * Branch tracing: */ if ((attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) && (hwc->sample_period == 1)) { /* BTS is not supported by this architecture. */ if (!bts_available()) return -EOPNOTSUPP; /* BTS is currently only allowed for user-mode. */ if (hwc->config & ARCH_PERFMON_EVENTSEL_OS) return -EOPNOTSUPP; } hwc->config |= config; return 0; } static void x86_pmu_disable_all(void) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); int idx; for (idx = 0; idx < x86_pmu.num_events; idx++) { u64 val; if (!test_bit(idx, cpuc->active_mask)) continue; rdmsrl(x86_pmu.eventsel + idx, val); if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE)) continue; val &= ~ARCH_PERFMON_EVENTSEL_ENABLE; wrmsrl(x86_pmu.eventsel + idx, val); } } void hw_perf_disable(void) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); if (!x86_pmu_initialized()) return; if (!cpuc->enabled) return; cpuc->n_added = 0; cpuc->enabled = 0; barrier(); x86_pmu.disable_all(); } static void x86_pmu_enable_all(void) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); int idx; for (idx = 0; idx < x86_pmu.num_events; idx++) { struct perf_event *event = cpuc->events[idx]; u64 val; if (!test_bit(idx, cpuc->active_mask)) continue; val = event->hw.config; val |= ARCH_PERFMON_EVENTSEL_ENABLE; wrmsrl(x86_pmu.eventsel + idx, val); } } static const struct pmu pmu; static inline int is_x86_event(struct perf_event *event) { return event->pmu == &pmu; } static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign) { struct event_constraint *c, *constraints[X86_PMC_IDX_MAX]; unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)]; int i, j, w, wmax, num = 0; struct hw_perf_event *hwc; bitmap_zero(used_mask, X86_PMC_IDX_MAX); for (i = 0; i < n; i++) { c = x86_pmu.get_event_constraints(cpuc, cpuc->event_list[i]); constraints[i] = c; } /* * fastpath, try to reuse previous register */ for (i = 0; i < n; i++) { hwc = &cpuc->event_list[i]->hw; c = constraints[i]; /* never assigned */ if (hwc->idx == -1) break; /* constraint still honored */ if (!test_bit(hwc->idx, c->idxmsk)) break; /* not already used */ if (test_bit(hwc->idx, used_mask)) break; set_bit(hwc->idx, used_mask); if (assign) assign[i] = hwc->idx; } if (i == n) goto done; /* * begin slow path */ bitmap_zero(used_mask, X86_PMC_IDX_MAX); /* * weight = number of possible counters * * 1 = most constrained, only works on one counter * wmax = least constrained, works on any counter * * assign events to counters starting with most * constrained events. */ wmax = x86_pmu.num_events; /* * when fixed event counters are present, * wmax is incremented by 1 to account * for one more choice */ if (x86_pmu.num_events_fixed) wmax++; for (w = 1, num = n; num && w <= wmax; w++) { /* for each event */ for (i = 0; num && i < n; i++) { c = constraints[i]; hwc = &cpuc->event_list[i]->hw; if (c->weight != w) continue; for_each_set_bit(j, c->idxmsk, X86_PMC_IDX_MAX) { if (!test_bit(j, used_mask)) break; } if (j == X86_PMC_IDX_MAX) break; set_bit(j, used_mask); if (assign) assign[i] = j; num--; } } done: /* * scheduling failed or is just a simulation, * free resources if necessary */ if (!assign || num) { for (i = 0; i < n; i++) { if (x86_pmu.put_event_constraints) x86_pmu.put_event_constraints(cpuc, cpuc->event_list[i]); } } return num ? -ENOSPC : 0; } /* * dogrp: true if must collect siblings events (group) * returns total number of events and error code */ static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp) { struct perf_event *event; int n, max_count; max_count = x86_pmu.num_events + x86_pmu.num_events_fixed; /* current number of events already accepted */ n = cpuc->n_events; if (is_x86_event(leader)) { if (n >= max_count) return -ENOSPC; cpuc->event_list[n] = leader; n++; } if (!dogrp) return n; list_for_each_entry(event, &leader->sibling_list, group_entry) { if (!is_x86_event(event) || event->state <= PERF_EVENT_STATE_OFF) continue; if (n >= max_count) return -ENOSPC; cpuc->event_list[n] = event; n++; } return n; } static inline void x86_assign_hw_event(struct perf_event *event, struct cpu_hw_events *cpuc, int i) { struct hw_perf_event *hwc = &event->hw; hwc->idx = cpuc->assign[i]; hwc->last_cpu = smp_processor_id(); hwc->last_tag = ++cpuc->tags[i]; if (hwc->idx == X86_PMC_IDX_FIXED_BTS) { hwc->config_base = 0; hwc->event_base = 0; } else if (hwc->idx >= X86_PMC_IDX_FIXED) { hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL; /* * We set it so that event_base + idx in wrmsr/rdmsr maps to * MSR_ARCH_PERFMON_FIXED_CTR0 ... CTR2: */ hwc->event_base = MSR_ARCH_PERFMON_FIXED_CTR0 - X86_PMC_IDX_FIXED; } else { hwc->config_base = x86_pmu.eventsel; hwc->event_base = x86_pmu.perfctr; } } static inline int match_prev_assignment(struct hw_perf_event *hwc, struct cpu_hw_events *cpuc, int i) { return hwc->idx == cpuc->assign[i] && hwc->last_cpu == smp_processor_id() && hwc->last_tag == cpuc->tags[i]; } static void x86_pmu_stop(struct perf_event *event); void hw_perf_enable(void) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); struct perf_event *event; struct hw_perf_event *hwc; int i; if (!x86_pmu_initialized()) return; if (cpuc->enabled) return; if (cpuc->n_added) { /* * apply assignment obtained either from * hw_perf_group_sched_in() or x86_pmu_enable() * * step1: save events moving to new counters * step2: reprogram moved events into new counters */ for (i = 0; i < cpuc->n_events; i++) { event = cpuc->event_list[i]; hwc = &event->hw; /* * we can avoid reprogramming counter if: * - assigned same counter as last time * - running on same CPU as last time * - no other event has used the counter since */ if (hwc->idx == -1 || match_prev_assignment(hwc, cpuc, i)) continue; x86_pmu_stop(event); hwc->idx = -1; } for (i = 0; i < cpuc->n_events; i++) { event = cpuc->event_list[i]; hwc = &event->hw; if (hwc->idx == -1) { x86_assign_hw_event(event, cpuc, i); x86_perf_event_set_period(event, hwc, hwc->idx); } /* * need to mark as active because x86_pmu_disable() * clear active_mask and events[] yet it preserves * idx */ set_bit(hwc->idx, cpuc->active_mask); cpuc->events[hwc->idx] = event; x86_pmu.enable(hwc, hwc->idx); perf_event_update_userpage(event); } cpuc->n_added = 0; perf_events_lapic_init(); } cpuc->enabled = 1; barrier(); x86_pmu.enable_all(); } static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc, int idx) { (void)checking_wrmsrl(hwc->config_base + idx, hwc->config | ARCH_PERFMON_EVENTSEL_ENABLE); } static inline void x86_pmu_disable_event(struct hw_perf_event *hwc, int idx) { (void)checking_wrmsrl(hwc->config_base + idx, hwc->config); } static DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left); /* * Set the next IRQ period, based on the hwc->period_left value. * To be called with the event disabled in hw: */ static int x86_perf_event_set_period(struct perf_event *event, struct hw_perf_event *hwc, int idx) { s64 left = atomic64_read(&hwc->period_left); s64 period = hwc->sample_period; int err, ret = 0; if (idx == X86_PMC_IDX_FIXED_BTS) return 0; /* * If we are way outside a reasonable range then just skip forward: */ if (unlikely(left <= -period)) { left = period; atomic64_set(&hwc->period_left, left); hwc->last_period = period; ret = 1; } if (unlikely(left <= 0)) { left += period; atomic64_set(&hwc->period_left, left); hwc->last_period = period; ret = 1; } /* * Quirk: certain CPUs dont like it if just 1 hw_event is left: */ if (unlikely(left < 2)) left = 2; if (left > x86_pmu.max_period) left = x86_pmu.max_period; per_cpu(pmc_prev_left[idx], smp_processor_id()) = left; /* * The hw event starts counting from this event offset, * mark it to be able to extra future deltas: */ atomic64_set(&hwc->prev_count, (u64)-left); err = checking_wrmsrl(hwc->event_base + idx, (u64)(-left) & x86_pmu.event_mask); perf_event_update_userpage(event); return ret; } static void x86_pmu_enable_event(struct hw_perf_event *hwc, int idx) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); if (cpuc->enabled) __x86_pmu_enable_event(hwc, idx); } /* * activate a single event * * The event is added to the group of enabled events * but only if it can be scehduled with existing events. * * Called with PMU disabled. If successful and return value 1, * then guaranteed to call perf_enable() and hw_perf_enable() */ static int x86_pmu_enable(struct perf_event *event) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); struct hw_perf_event *hwc; int assign[X86_PMC_IDX_MAX]; int n, n0, ret; hwc = &event->hw; n0 = cpuc->n_events; n = collect_events(cpuc, event, false); if (n < 0) return n; ret = x86_schedule_events(cpuc, n, assign); if (ret) return ret; /* * copy new assignment, now we know it is possible * will be used by hw_perf_enable() */ memcpy(cpuc->assign, assign, n*sizeof(int)); cpuc->n_events = n; cpuc->n_added = n - n0; return 0; } static int x86_pmu_start(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; if (hwc->idx == -1) return -EAGAIN; x86_perf_event_set_period(event, hwc, hwc->idx); x86_pmu.enable(hwc, hwc->idx); return 0; } static void x86_pmu_unthrottle(struct perf_event *event) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); struct hw_perf_event *hwc = &event->hw; if (WARN_ON_ONCE(hwc->idx >= X86_PMC_IDX_MAX || cpuc->events[hwc->idx] != event)) return; x86_pmu.enable(hwc, hwc->idx); } void perf_event_print_debug(void) { u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed; struct cpu_hw_events *cpuc; unsigned long flags; int cpu, idx; if (!x86_pmu.num_events) return; local_irq_save(flags); cpu = smp_processor_id(); cpuc = &per_cpu(cpu_hw_events, cpu); if (x86_pmu.version >= 2) { rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl); rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status); rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow); rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed); pr_info("\n"); pr_info("CPU#%d: ctrl: %016llx\n", cpu, ctrl); pr_info("CPU#%d: status: %016llx\n", cpu, status); pr_info("CPU#%d: overflow: %016llx\n", cpu, overflow); pr_info("CPU#%d: fixed: %016llx\n", cpu, fixed); } pr_info("CPU#%d: active: %016llx\n", cpu, *(u64 *)cpuc->active_mask); for (idx = 0; idx < x86_pmu.num_events; idx++) { rdmsrl(x86_pmu.eventsel + idx, pmc_ctrl); rdmsrl(x86_pmu.perfctr + idx, pmc_count); prev_left = per_cpu(pmc_prev_left[idx], cpu); pr_info("CPU#%d: gen-PMC%d ctrl: %016llx\n", cpu, idx, pmc_ctrl); pr_info("CPU#%d: gen-PMC%d count: %016llx\n", cpu, idx, pmc_count); pr_info("CPU#%d: gen-PMC%d left: %016llx\n", cpu, idx, prev_left); } for (idx = 0; idx < x86_pmu.num_events_fixed; idx++) { rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, pmc_count); pr_info("CPU#%d: fixed-PMC%d count: %016llx\n", cpu, idx, pmc_count); } local_irq_restore(flags); } static void x86_pmu_stop(struct perf_event *event) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); struct hw_perf_event *hwc = &event->hw; int idx = hwc->idx; /* * Must be done before we disable, otherwise the nmi handler * could reenable again: */ clear_bit(idx, cpuc->active_mask); x86_pmu.disable(hwc, idx); /* * Drain the remaining delta count out of a event * that we are disabling: */ x86_perf_event_update(event, hwc, idx); cpuc->events[idx] = NULL; } static void x86_pmu_disable(struct perf_event *event) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); int i; x86_pmu_stop(event); for (i = 0; i < cpuc->n_events; i++) { if (event == cpuc->event_list[i]) { if (x86_pmu.put_event_constraints) x86_pmu.put_event_constraints(cpuc, event); while (++i < cpuc->n_events) cpuc->event_list[i-1] = cpuc->event_list[i]; --cpuc->n_events; break; } } perf_event_update_userpage(event); } static int x86_pmu_handle_irq(struct pt_regs *regs) { struct perf_sample_data data; struct cpu_hw_events *cpuc; struct perf_event *event; struct hw_perf_event *hwc; int idx, handled = 0; u64 val; data.addr = 0; data.raw = NULL; cpuc = &__get_cpu_var(cpu_hw_events); for (idx = 0; idx < x86_pmu.num_events; idx++) { if (!test_bit(idx, cpuc->active_mask)) continue; event = cpuc->events[idx]; hwc = &event->hw; val = x86_perf_event_update(event, hwc, idx); if (val & (1ULL << (x86_pmu.event_bits - 1))) continue; /* * event overflow */ handled = 1; data.period = event->hw.last_period; if (!x86_perf_event_set_period(event, hwc, idx)) continue; if (perf_event_overflow(event, 1, &data, regs)) x86_pmu.disable(hwc, idx); } if (handled) inc_irq_stat(apic_perf_irqs); return handled; } void smp_perf_pending_interrupt(struct pt_regs *regs) { irq_enter(); ack_APIC_irq(); inc_irq_stat(apic_pending_irqs); perf_event_do_pending(); irq_exit(); } void set_perf_event_pending(void) { #ifdef CONFIG_X86_LOCAL_APIC if (!x86_pmu.apic || !x86_pmu_initialized()) return; apic->send_IPI_self(LOCAL_PENDING_VECTOR); #endif } void perf_events_lapic_init(void) { #ifdef CONFIG_X86_LOCAL_APIC if (!x86_pmu.apic || !x86_pmu_initialized()) return; /* * Always use NMI for PMU */ apic_write(APIC_LVTPC, APIC_DM_NMI); #endif } static int __kprobes perf_event_nmi_handler(struct notifier_block *self, unsigned long cmd, void *__args) { struct die_args *args = __args; struct pt_regs *regs; if (!atomic_read(&active_events)) return NOTIFY_DONE; switch (cmd) { case DIE_NMI: case DIE_NMI_IPI: break; default: return NOTIFY_DONE; } regs = args->regs; #ifdef CONFIG_X86_LOCAL_APIC apic_write(APIC_LVTPC, APIC_DM_NMI); #endif /* * Can't rely on the handled return value to say it was our NMI, two * events could trigger 'simultaneously' raising two back-to-back NMIs. * * If the first NMI handles both, the latter will be empty and daze * the CPU. */ x86_pmu.handle_irq(regs); return NOTIFY_STOP; } static __read_mostly struct notifier_block perf_event_nmi_notifier = { .notifier_call = perf_event_nmi_handler, .next = NULL, .priority = 1 }; static struct event_constraint unconstrained; static struct event_constraint emptyconstraint; static struct event_constraint * x86_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event) { struct event_constraint *c; if (x86_pmu.event_constraints) { for_each_event_constraint(c, x86_pmu.event_constraints) { if ((event->hw.config & c->cmask) == c->code) return c; } } return &unconstrained; } static int x86_event_sched_in(struct perf_event *event, struct perf_cpu_context *cpuctx) { int ret = 0; event->state = PERF_EVENT_STATE_ACTIVE; event->oncpu = smp_processor_id(); event->tstamp_running += event->ctx->time - event->tstamp_stopped; if (!is_x86_event(event)) ret = event->pmu->enable(event); if (!ret && !is_software_event(event)) cpuctx->active_oncpu++; if (!ret && event->attr.exclusive) cpuctx->exclusive = 1; return ret; } static void x86_event_sched_out(struct perf_event *event, struct perf_cpu_context *cpuctx) { event->state = PERF_EVENT_STATE_INACTIVE; event->oncpu = -1; if (!is_x86_event(event)) event->pmu->disable(event); event->tstamp_running -= event->ctx->time - event->tstamp_stopped; if (!is_software_event(event)) cpuctx->active_oncpu--; if (event->attr.exclusive || !cpuctx->active_oncpu) cpuctx->exclusive = 0; } /* * Called to enable a whole group of events. * Returns 1 if the group was enabled, or -EAGAIN if it could not be. * Assumes the caller has disabled interrupts and has * frozen the PMU with hw_perf_save_disable. * * called with PMU disabled. If successful and return value 1, * then guaranteed to call perf_enable() and hw_perf_enable() */ int hw_perf_group_sched_in(struct perf_event *leader, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); struct perf_event *sub; int assign[X86_PMC_IDX_MAX]; int n0, n1, ret; /* n0 = total number of events */ n0 = collect_events(cpuc, leader, true); if (n0 < 0) return n0; ret = x86_schedule_events(cpuc, n0, assign); if (ret) return ret; ret = x86_event_sched_in(leader, cpuctx); if (ret) return ret; n1 = 1; list_for_each_entry(sub, &leader->sibling_list, group_entry) { if (sub->state > PERF_EVENT_STATE_OFF) { ret = x86_event_sched_in(sub, cpuctx); if (ret) goto undo; ++n1; } } /* * copy new assignment, now we know it is possible * will be used by hw_perf_enable() */ memcpy(cpuc->assign, assign, n0*sizeof(int)); cpuc->n_events = n0; cpuc->n_added = n1; ctx->nr_active += n1; /* * 1 means successful and events are active * This is not quite true because we defer * actual activation until hw_perf_enable() but * this way we* ensure caller won't try to enable * individual events */ return 1; undo: x86_event_sched_out(leader, cpuctx); n0 = 1; list_for_each_entry(sub, &leader->sibling_list, group_entry) { if (sub->state == PERF_EVENT_STATE_ACTIVE) { x86_event_sched_out(sub, cpuctx); if (++n0 == n1) break; } } return ret; } #include "perf_event_amd.c" #include "perf_event_p6.c" #include "perf_event_intel.c" static void __init pmu_check_apic(void) { if (cpu_has_apic) return; x86_pmu.apic = 0; pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n"); pr_info("no hardware sampling interrupt available.\n"); } void __init init_hw_perf_events(void) { struct event_constraint *c; int err; pr_info("Performance Events: "); switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_INTEL: err = intel_pmu_init(); break; case X86_VENDOR_AMD: err = amd_pmu_init(); break; default: return; } if (err != 0) { pr_cont("no PMU driver, software events only.\n"); return; } pmu_check_apic(); pr_cont("%s PMU driver.\n", x86_pmu.name); if (x86_pmu.num_events > X86_PMC_MAX_GENERIC) { WARN(1, KERN_ERR "hw perf events %d > max(%d), clipping!", x86_pmu.num_events, X86_PMC_MAX_GENERIC); x86_pmu.num_events = X86_PMC_MAX_GENERIC; } perf_event_mask = (1 << x86_pmu.num_events) - 1; perf_max_events = x86_pmu.num_events; if (x86_pmu.num_events_fixed > X86_PMC_MAX_FIXED) { WARN(1, KERN_ERR "hw perf events fixed %d > max(%d), clipping!", x86_pmu.num_events_fixed, X86_PMC_MAX_FIXED); x86_pmu.num_events_fixed = X86_PMC_MAX_FIXED; } perf_event_mask |= ((1LL << x86_pmu.num_events_fixed)-1) << X86_PMC_IDX_FIXED; x86_pmu.intel_ctrl = perf_event_mask; perf_events_lapic_init(); register_die_notifier(&perf_event_nmi_notifier); unconstrained = (struct event_constraint) __EVENT_CONSTRAINT(0, (1ULL << x86_pmu.num_events) - 1, 0, x86_pmu.num_events); if (x86_pmu.event_constraints) { for_each_event_constraint(c, x86_pmu.event_constraints) { if (c->cmask != INTEL_ARCH_FIXED_MASK) continue; c->idxmsk64 |= (1ULL << x86_pmu.num_events) - 1; c->weight += x86_pmu.num_events; } } pr_info("... version: %d\n", x86_pmu.version); pr_info("... bit width: %d\n", x86_pmu.event_bits); pr_info("... generic registers: %d\n", x86_pmu.num_events); pr_info("... value mask: %016Lx\n", x86_pmu.event_mask); pr_info("... max period: %016Lx\n", x86_pmu.max_period); pr_info("... fixed-purpose events: %d\n", x86_pmu.num_events_fixed); pr_info("... event mask: %016Lx\n", perf_event_mask); } static inline void x86_pmu_read(struct perf_event *event) { x86_perf_event_update(event, &event->hw, event->hw.idx); } static const struct pmu pmu = { .enable = x86_pmu_enable, .disable = x86_pmu_disable, .start = x86_pmu_start, .stop = x86_pmu_stop, .read = x86_pmu_read, .unthrottle = x86_pmu_unthrottle, }; /* * validate a single event group * * validation include: * - check events are compatible which each other * - events do not compete for the same counter * - number of events <= number of counters * * validation ensures the group can be loaded onto the * PMU if it was the only group available. */ static int validate_group(struct perf_event *event) { struct perf_event *leader = event->group_leader; struct cpu_hw_events *fake_cpuc; int ret, n; ret = -ENOMEM; fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO); if (!fake_cpuc) goto out; /* * the event is not yet connected with its * siblings therefore we must first collect * existing siblings, then add the new event * before we can simulate the scheduling */ ret = -ENOSPC; n = collect_events(fake_cpuc, leader, true); if (n < 0) goto out_free; fake_cpuc->n_events = n; n = collect_events(fake_cpuc, event, false); if (n < 0) goto out_free; fake_cpuc->n_events = n; ret = x86_schedule_events(fake_cpuc, n, NULL); out_free: kfree(fake_cpuc); out: return ret; } const struct pmu *hw_perf_event_init(struct perf_event *event) { const struct pmu *tmp; int err; err = __hw_perf_event_init(event); if (!err) { /* * we temporarily connect event to its pmu * such that validate_group() can classify * it as an x86 event using is_x86_event() */ tmp = event->pmu; event->pmu = &pmu; if (event->group_leader != event) err = validate_group(event); event->pmu = tmp; } if (err) { if (event->destroy) event->destroy(event); return ERR_PTR(err); } return &pmu; } /* * callchain support */ static inline void callchain_store(struct perf_callchain_entry *entry, u64 ip) { if (entry->nr < PERF_MAX_STACK_DEPTH) entry->ip[entry->nr++] = ip; } static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_irq_entry); static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_nmi_entry); static void backtrace_warning_symbol(void *data, char *msg, unsigned long symbol) { /* Ignore warnings */ } static void backtrace_warning(void *data, char *msg) { /* Ignore warnings */ } static int backtrace_stack(void *data, char *name) { return 0; } static void backtrace_address(void *data, unsigned long addr, int reliable) { struct perf_callchain_entry *entry = data; if (reliable) callchain_store(entry, addr); } static const struct stacktrace_ops backtrace_ops = { .warning = backtrace_warning, .warning_symbol = backtrace_warning_symbol, .stack = backtrace_stack, .address = backtrace_address, .walk_stack = print_context_stack_bp, }; #include "../dumpstack.h" static void perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry) { callchain_store(entry, PERF_CONTEXT_KERNEL); callchain_store(entry, regs->ip); dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry); } /* * best effort, GUP based copy_from_user() that assumes IRQ or NMI context */ static unsigned long copy_from_user_nmi(void *to, const void __user *from, unsigned long n) { unsigned long offset, addr = (unsigned long)from; int type = in_nmi() ? KM_NMI : KM_IRQ0; unsigned long size, len = 0; struct page *page; void *map; int ret; do { ret = __get_user_pages_fast(addr, 1, 0, &page); if (!ret) break; offset = addr & (PAGE_SIZE - 1); size = min(PAGE_SIZE - offset, n - len); map = kmap_atomic(page, type); memcpy(to, map+offset, size); kunmap_atomic(map, type); put_page(page); len += size; to += size; addr += size; } while (len < n); return len; } static int copy_stack_frame(const void __user *fp, struct stack_frame *frame) { unsigned long bytes; bytes = copy_from_user_nmi(frame, fp, sizeof(*frame)); return bytes == sizeof(*frame); } static void perf_callchain_user(struct pt_regs *regs, struct perf_callchain_entry *entry) { struct stack_frame frame; const void __user *fp; if (!user_mode(regs)) regs = task_pt_regs(current); fp = (void __user *)regs->bp; callchain_store(entry, PERF_CONTEXT_USER); callchain_store(entry, regs->ip); while (entry->nr < PERF_MAX_STACK_DEPTH) { frame.next_frame = NULL; frame.return_address = 0; if (!copy_stack_frame(fp, &frame)) break; if ((unsigned long)fp < regs->sp) break; callchain_store(entry, frame.return_address); fp = frame.next_frame; } } static void perf_do_callchain(struct pt_regs *regs, struct perf_callchain_entry *entry) { int is_user; if (!regs) return; is_user = user_mode(regs); if (is_user && current->state != TASK_RUNNING) return; if (!is_user) perf_callchain_kernel(regs, entry); if (current->mm) perf_callchain_user(regs, entry); } struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) { struct perf_callchain_entry *entry; if (in_nmi()) entry = &__get_cpu_var(pmc_nmi_entry); else entry = &__get_cpu_var(pmc_irq_entry); entry->nr = 0; perf_do_callchain(regs, entry); return entry; } void hw_perf_event_setup_online(int cpu) { init_debug_store_on_cpu(cpu); switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: amd_pmu_cpu_online(cpu); break; default: return; } } void hw_perf_event_setup_offline(int cpu) { init_debug_store_on_cpu(cpu); switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: amd_pmu_cpu_offline(cpu); break; default: return; } }