2 * Performance events x86 architecture code
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2009 Jaswinder Singh Rajput
7 * Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
8 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
9 * Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com>
10 * Copyright (C) 2009 Google, Inc., Stephane Eranian
12 * For licencing details see kernel-base/COPYING
15 #include <linux/perf_event.h>
16 #include <linux/capability.h>
17 #include <linux/notifier.h>
18 #include <linux/hardirq.h>
19 #include <linux/kprobes.h>
20 #include <linux/module.h>
21 #include <linux/kdebug.h>
22 #include <linux/sched.h>
23 #include <linux/uaccess.h>
24 #include <linux/highmem.h>
25 #include <linux/cpu.h>
26 #include <linux/bitops.h>
29 #include <asm/stacktrace.h>
32 static u64 perf_event_mask __read_mostly;
34 /* The maximal number of PEBS events: */
35 #define MAX_PEBS_EVENTS 4
37 /* The size of a BTS record in bytes: */
38 #define BTS_RECORD_SIZE 24
40 /* The size of a per-cpu BTS buffer in bytes: */
41 #define BTS_BUFFER_SIZE (BTS_RECORD_SIZE * 2048)
43 /* The BTS overflow threshold in bytes from the end of the buffer: */
44 #define BTS_OVFL_TH (BTS_RECORD_SIZE * 128)
48 * Bits in the debugctlmsr controlling branch tracing.
50 #define X86_DEBUGCTL_TR (1 << 6)
51 #define X86_DEBUGCTL_BTS (1 << 7)
52 #define X86_DEBUGCTL_BTINT (1 << 8)
53 #define X86_DEBUGCTL_BTS_OFF_OS (1 << 9)
54 #define X86_DEBUGCTL_BTS_OFF_USR (1 << 10)
57 * A debug store configuration.
59 * We only support architectures that use 64bit fields.
64 u64 bts_absolute_maximum;
65 u64 bts_interrupt_threshold;
68 u64 pebs_absolute_maximum;
69 u64 pebs_interrupt_threshold;
70 u64 pebs_event_reset[MAX_PEBS_EVENTS];
73 struct event_constraint {
75 unsigned long idxmsk[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
84 int nb_id; /* NorthBridge id */
85 int refcnt; /* reference count */
86 struct perf_event *owners[X86_PMC_IDX_MAX];
87 struct event_constraint event_constraints[X86_PMC_IDX_MAX];
90 struct cpu_hw_events {
91 struct perf_event *events[X86_PMC_IDX_MAX]; /* in counter order */
92 unsigned long active_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
93 unsigned long interrupts;
95 struct debug_store *ds;
99 int assign[X86_PMC_IDX_MAX]; /* event to counter assignment */
100 u64 tags[X86_PMC_IDX_MAX];
101 struct perf_event *event_list[X86_PMC_IDX_MAX]; /* in enabled order */
102 struct amd_nb *amd_nb;
105 #define __EVENT_CONSTRAINT(c, n, m, w) {\
106 { .idxmsk64 = (n) }, \
112 #define EVENT_CONSTRAINT(c, n, m) \
113 __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n))
115 #define INTEL_EVENT_CONSTRAINT(c, n) \
116 EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVTSEL_MASK)
118 #define FIXED_EVENT_CONSTRAINT(c, n) \
119 EVENT_CONSTRAINT(c, (1ULL << (32+n)), INTEL_ARCH_FIXED_MASK)
121 #define EVENT_CONSTRAINT_END \
122 EVENT_CONSTRAINT(0, 0, 0)
124 #define for_each_event_constraint(e, c) \
125 for ((e) = (c); (e)->cmask; (e)++)
128 * struct x86_pmu - generic x86 pmu
133 int (*handle_irq)(struct pt_regs *);
134 void (*disable_all)(void);
135 void (*enable_all)(void);
136 void (*enable)(struct hw_perf_event *, int);
137 void (*disable)(struct hw_perf_event *, int);
140 u64 (*event_map)(int);
141 u64 (*raw_event)(u64);
144 int num_events_fixed;
150 void (*enable_bts)(u64 config);
151 void (*disable_bts)(void);
153 struct event_constraint *
154 (*get_event_constraints)(struct cpu_hw_events *cpuc,
155 struct perf_event *event);
157 void (*put_event_constraints)(struct cpu_hw_events *cpuc,
158 struct perf_event *event);
159 struct event_constraint *event_constraints;
162 static struct x86_pmu x86_pmu __read_mostly;
164 static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
168 static int x86_perf_event_set_period(struct perf_event *event,
169 struct hw_perf_event *hwc, int idx);
172 * Generalized hw caching related hw_event table, filled
173 * in on a per model basis. A value of 0 means
174 * 'not supported', -1 means 'hw_event makes no sense on
175 * this CPU', any other value means the raw hw_event
179 #define C(x) PERF_COUNT_HW_CACHE_##x
181 static u64 __read_mostly hw_cache_event_ids
182 [PERF_COUNT_HW_CACHE_MAX]
183 [PERF_COUNT_HW_CACHE_OP_MAX]
184 [PERF_COUNT_HW_CACHE_RESULT_MAX];
187 * Propagate event elapsed time into the generic event.
188 * Can only be executed on the CPU where the event is active.
189 * Returns the delta events processed.
192 x86_perf_event_update(struct perf_event *event,
193 struct hw_perf_event *hwc, int idx)
195 int shift = 64 - x86_pmu.event_bits;
196 u64 prev_raw_count, new_raw_count;
199 if (idx == X86_PMC_IDX_FIXED_BTS)
203 * Careful: an NMI might modify the previous event value.
205 * Our tactic to handle this is to first atomically read and
206 * exchange a new raw count - then add that new-prev delta
207 * count to the generic event atomically:
210 prev_raw_count = atomic64_read(&hwc->prev_count);
211 rdmsrl(hwc->event_base + idx, new_raw_count);
213 if (atomic64_cmpxchg(&hwc->prev_count, prev_raw_count,
214 new_raw_count) != prev_raw_count)
218 * Now we have the new raw value and have updated the prev
219 * timestamp already. We can now calculate the elapsed delta
220 * (event-)time and add that to the generic event.
222 * Careful, not all hw sign-extends above the physical width
225 delta = (new_raw_count << shift) - (prev_raw_count << shift);
228 atomic64_add(delta, &event->count);
229 atomic64_sub(delta, &hwc->period_left);
231 return new_raw_count;
234 static atomic_t active_events;
235 static DEFINE_MUTEX(pmc_reserve_mutex);
237 static bool reserve_pmc_hardware(void)
239 #ifdef CONFIG_X86_LOCAL_APIC
242 if (nmi_watchdog == NMI_LOCAL_APIC)
243 disable_lapic_nmi_watchdog();
245 for (i = 0; i < x86_pmu.num_events; i++) {
246 if (!reserve_perfctr_nmi(x86_pmu.perfctr + i))
250 for (i = 0; i < x86_pmu.num_events; i++) {
251 if (!reserve_evntsel_nmi(x86_pmu.eventsel + i))
258 #ifdef CONFIG_X86_LOCAL_APIC
260 for (i--; i >= 0; i--)
261 release_evntsel_nmi(x86_pmu.eventsel + i);
263 i = x86_pmu.num_events;
266 for (i--; i >= 0; i--)
267 release_perfctr_nmi(x86_pmu.perfctr + i);
269 if (nmi_watchdog == NMI_LOCAL_APIC)
270 enable_lapic_nmi_watchdog();
276 static void release_pmc_hardware(void)
278 #ifdef CONFIG_X86_LOCAL_APIC
281 for (i = 0; i < x86_pmu.num_events; i++) {
282 release_perfctr_nmi(x86_pmu.perfctr + i);
283 release_evntsel_nmi(x86_pmu.eventsel + i);
286 if (nmi_watchdog == NMI_LOCAL_APIC)
287 enable_lapic_nmi_watchdog();
291 static inline bool bts_available(void)
293 return x86_pmu.enable_bts != NULL;
296 static inline void init_debug_store_on_cpu(int cpu)
298 struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
303 wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA,
304 (u32)((u64)(unsigned long)ds),
305 (u32)((u64)(unsigned long)ds >> 32));
308 static inline void fini_debug_store_on_cpu(int cpu)
310 if (!per_cpu(cpu_hw_events, cpu).ds)
313 wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0);
316 static void release_bts_hardware(void)
320 if (!bts_available())
325 for_each_online_cpu(cpu)
326 fini_debug_store_on_cpu(cpu);
328 for_each_possible_cpu(cpu) {
329 struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
334 per_cpu(cpu_hw_events, cpu).ds = NULL;
336 kfree((void *)(unsigned long)ds->bts_buffer_base);
343 static int reserve_bts_hardware(void)
347 if (!bts_available())
352 for_each_possible_cpu(cpu) {
353 struct debug_store *ds;
357 buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL);
358 if (unlikely(!buffer))
361 ds = kzalloc(sizeof(*ds), GFP_KERNEL);
367 ds->bts_buffer_base = (u64)(unsigned long)buffer;
368 ds->bts_index = ds->bts_buffer_base;
369 ds->bts_absolute_maximum =
370 ds->bts_buffer_base + BTS_BUFFER_SIZE;
371 ds->bts_interrupt_threshold =
372 ds->bts_absolute_maximum - BTS_OVFL_TH;
374 per_cpu(cpu_hw_events, cpu).ds = ds;
379 release_bts_hardware();
381 for_each_online_cpu(cpu)
382 init_debug_store_on_cpu(cpu);
390 static void hw_perf_event_destroy(struct perf_event *event)
392 if (atomic_dec_and_mutex_lock(&active_events, &pmc_reserve_mutex)) {
393 release_pmc_hardware();
394 release_bts_hardware();
395 mutex_unlock(&pmc_reserve_mutex);
399 static inline int x86_pmu_initialized(void)
401 return x86_pmu.handle_irq != NULL;
405 set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event_attr *attr)
407 unsigned int cache_type, cache_op, cache_result;
410 config = attr->config;
412 cache_type = (config >> 0) & 0xff;
413 if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
416 cache_op = (config >> 8) & 0xff;
417 if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
420 cache_result = (config >> 16) & 0xff;
421 if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
424 val = hw_cache_event_ids[cache_type][cache_op][cache_result];
438 * Setup the hardware configuration for a given attr_type
440 static int __hw_perf_event_init(struct perf_event *event)
442 struct perf_event_attr *attr = &event->attr;
443 struct hw_perf_event *hwc = &event->hw;
447 if (!x86_pmu_initialized())
451 if (!atomic_inc_not_zero(&active_events)) {
452 mutex_lock(&pmc_reserve_mutex);
453 if (atomic_read(&active_events) == 0) {
454 if (!reserve_pmc_hardware())
457 err = reserve_bts_hardware();
460 atomic_inc(&active_events);
461 mutex_unlock(&pmc_reserve_mutex);
466 event->destroy = hw_perf_event_destroy;
470 * (keep 'enabled' bit clear for now)
472 hwc->config = ARCH_PERFMON_EVENTSEL_INT;
476 hwc->last_tag = ~0ULL;
479 * Count user and OS events unless requested not to.
481 if (!attr->exclude_user)
482 hwc->config |= ARCH_PERFMON_EVENTSEL_USR;
483 if (!attr->exclude_kernel)
484 hwc->config |= ARCH_PERFMON_EVENTSEL_OS;
486 if (!hwc->sample_period) {
487 hwc->sample_period = x86_pmu.max_period;
488 hwc->last_period = hwc->sample_period;
489 atomic64_set(&hwc->period_left, hwc->sample_period);
492 * If we have a PMU initialized but no APIC
493 * interrupts, we cannot sample hardware
494 * events (user-space has to fall back and
495 * sample via a hrtimer based software event):
502 * Raw hw_event type provide the config in the hw_event structure
504 if (attr->type == PERF_TYPE_RAW) {
505 hwc->config |= x86_pmu.raw_event(attr->config);
506 if ((hwc->config & ARCH_PERFMON_EVENTSEL_ANY) &&
507 perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
512 if (attr->type == PERF_TYPE_HW_CACHE)
513 return set_ext_hw_attr(hwc, attr);
515 if (attr->config >= x86_pmu.max_events)
521 config = x86_pmu.event_map(attr->config);
532 if ((attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) &&
533 (hwc->sample_period == 1)) {
534 /* BTS is not supported by this architecture. */
535 if (!bts_available())
538 /* BTS is currently only allowed for user-mode. */
539 if (hwc->config & ARCH_PERFMON_EVENTSEL_OS)
543 hwc->config |= config;
548 static void x86_pmu_disable_all(void)
550 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
553 for (idx = 0; idx < x86_pmu.num_events; idx++) {
556 if (!test_bit(idx, cpuc->active_mask))
558 rdmsrl(x86_pmu.eventsel + idx, val);
559 if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE))
561 val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;
562 wrmsrl(x86_pmu.eventsel + idx, val);
566 void hw_perf_disable(void)
568 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
570 if (!x86_pmu_initialized())
580 x86_pmu.disable_all();
583 static void x86_pmu_enable_all(void)
585 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
588 for (idx = 0; idx < x86_pmu.num_events; idx++) {
589 struct perf_event *event = cpuc->events[idx];
592 if (!test_bit(idx, cpuc->active_mask))
595 val = event->hw.config;
596 val |= ARCH_PERFMON_EVENTSEL_ENABLE;
597 wrmsrl(x86_pmu.eventsel + idx, val);
601 static const struct pmu pmu;
603 static inline int is_x86_event(struct perf_event *event)
605 return event->pmu == &pmu;
608 static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
610 struct event_constraint *c, *constraints[X86_PMC_IDX_MAX];
611 unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
612 int i, j, w, wmax, num = 0;
613 struct hw_perf_event *hwc;
615 bitmap_zero(used_mask, X86_PMC_IDX_MAX);
617 for (i = 0; i < n; i++) {
618 c = x86_pmu.get_event_constraints(cpuc, cpuc->event_list[i]);
623 * fastpath, try to reuse previous register
625 for (i = 0; i < n; i++) {
626 hwc = &cpuc->event_list[i]->hw;
633 /* constraint still honored */
634 if (!test_bit(hwc->idx, c->idxmsk))
637 /* not already used */
638 if (test_bit(hwc->idx, used_mask))
641 set_bit(hwc->idx, used_mask);
643 assign[i] = hwc->idx;
652 bitmap_zero(used_mask, X86_PMC_IDX_MAX);
655 * weight = number of possible counters
657 * 1 = most constrained, only works on one counter
658 * wmax = least constrained, works on any counter
660 * assign events to counters starting with most
661 * constrained events.
663 wmax = x86_pmu.num_events;
666 * when fixed event counters are present,
667 * wmax is incremented by 1 to account
668 * for one more choice
670 if (x86_pmu.num_events_fixed)
673 for (w = 1, num = n; num && w <= wmax; w++) {
675 for (i = 0; num && i < n; i++) {
677 hwc = &cpuc->event_list[i]->hw;
682 for_each_set_bit(j, c->idxmsk, X86_PMC_IDX_MAX) {
683 if (!test_bit(j, used_mask))
687 if (j == X86_PMC_IDX_MAX)
690 set_bit(j, used_mask);
699 * scheduling failed or is just a simulation,
700 * free resources if necessary
702 if (!assign || num) {
703 for (i = 0; i < n; i++) {
704 if (x86_pmu.put_event_constraints)
705 x86_pmu.put_event_constraints(cpuc, cpuc->event_list[i]);
708 return num ? -ENOSPC : 0;
712 * dogrp: true if must collect siblings events (group)
713 * returns total number of events and error code
715 static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp)
717 struct perf_event *event;
720 max_count = x86_pmu.num_events + x86_pmu.num_events_fixed;
722 /* current number of events already accepted */
725 if (is_x86_event(leader)) {
728 cpuc->event_list[n] = leader;
734 list_for_each_entry(event, &leader->sibling_list, group_entry) {
735 if (!is_x86_event(event) ||
736 event->state <= PERF_EVENT_STATE_OFF)
742 cpuc->event_list[n] = event;
748 static inline void x86_assign_hw_event(struct perf_event *event,
749 struct cpu_hw_events *cpuc, int i)
751 struct hw_perf_event *hwc = &event->hw;
753 hwc->idx = cpuc->assign[i];
754 hwc->last_cpu = smp_processor_id();
755 hwc->last_tag = ++cpuc->tags[i];
757 if (hwc->idx == X86_PMC_IDX_FIXED_BTS) {
758 hwc->config_base = 0;
760 } else if (hwc->idx >= X86_PMC_IDX_FIXED) {
761 hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
763 * We set it so that event_base + idx in wrmsr/rdmsr maps to
764 * MSR_ARCH_PERFMON_FIXED_CTR0 ... CTR2:
767 MSR_ARCH_PERFMON_FIXED_CTR0 - X86_PMC_IDX_FIXED;
769 hwc->config_base = x86_pmu.eventsel;
770 hwc->event_base = x86_pmu.perfctr;
774 static inline int match_prev_assignment(struct hw_perf_event *hwc,
775 struct cpu_hw_events *cpuc,
778 return hwc->idx == cpuc->assign[i] &&
779 hwc->last_cpu == smp_processor_id() &&
780 hwc->last_tag == cpuc->tags[i];
783 static void x86_pmu_stop(struct perf_event *event);
785 void hw_perf_enable(void)
787 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
788 struct perf_event *event;
789 struct hw_perf_event *hwc;
792 if (!x86_pmu_initialized())
800 * apply assignment obtained either from
801 * hw_perf_group_sched_in() or x86_pmu_enable()
803 * step1: save events moving to new counters
804 * step2: reprogram moved events into new counters
806 for (i = 0; i < cpuc->n_events; i++) {
808 event = cpuc->event_list[i];
812 * we can avoid reprogramming counter if:
813 * - assigned same counter as last time
814 * - running on same CPU as last time
815 * - no other event has used the counter since
817 if (hwc->idx == -1 ||
818 match_prev_assignment(hwc, cpuc, i))
826 for (i = 0; i < cpuc->n_events; i++) {
828 event = cpuc->event_list[i];
831 if (hwc->idx == -1) {
832 x86_assign_hw_event(event, cpuc, i);
833 x86_perf_event_set_period(event, hwc, hwc->idx);
836 * need to mark as active because x86_pmu_disable()
837 * clear active_mask and events[] yet it preserves
840 set_bit(hwc->idx, cpuc->active_mask);
841 cpuc->events[hwc->idx] = event;
843 x86_pmu.enable(hwc, hwc->idx);
844 perf_event_update_userpage(event);
847 perf_events_lapic_init();
853 x86_pmu.enable_all();
856 static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc, int idx)
858 (void)checking_wrmsrl(hwc->config_base + idx,
859 hwc->config | ARCH_PERFMON_EVENTSEL_ENABLE);
862 static inline void x86_pmu_disable_event(struct hw_perf_event *hwc, int idx)
864 (void)checking_wrmsrl(hwc->config_base + idx, hwc->config);
867 static DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left);
870 * Set the next IRQ period, based on the hwc->period_left value.
871 * To be called with the event disabled in hw:
874 x86_perf_event_set_period(struct perf_event *event,
875 struct hw_perf_event *hwc, int idx)
877 s64 left = atomic64_read(&hwc->period_left);
878 s64 period = hwc->sample_period;
881 if (idx == X86_PMC_IDX_FIXED_BTS)
885 * If we are way outside a reasonable range then just skip forward:
887 if (unlikely(left <= -period)) {
889 atomic64_set(&hwc->period_left, left);
890 hwc->last_period = period;
894 if (unlikely(left <= 0)) {
896 atomic64_set(&hwc->period_left, left);
897 hwc->last_period = period;
901 * Quirk: certain CPUs dont like it if just 1 hw_event is left:
903 if (unlikely(left < 2))
906 if (left > x86_pmu.max_period)
907 left = x86_pmu.max_period;
909 per_cpu(pmc_prev_left[idx], smp_processor_id()) = left;
912 * The hw event starts counting from this event offset,
913 * mark it to be able to extra future deltas:
915 atomic64_set(&hwc->prev_count, (u64)-left);
917 err = checking_wrmsrl(hwc->event_base + idx,
918 (u64)(-left) & x86_pmu.event_mask);
920 perf_event_update_userpage(event);
925 static void x86_pmu_enable_event(struct hw_perf_event *hwc, int idx)
927 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
929 __x86_pmu_enable_event(hwc, idx);
933 * activate a single event
935 * The event is added to the group of enabled events
936 * but only if it can be scehduled with existing events.
938 * Called with PMU disabled. If successful and return value 1,
939 * then guaranteed to call perf_enable() and hw_perf_enable()
941 static int x86_pmu_enable(struct perf_event *event)
943 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
944 struct hw_perf_event *hwc;
945 int assign[X86_PMC_IDX_MAX];
951 n = collect_events(cpuc, event, false);
955 ret = x86_schedule_events(cpuc, n, assign);
959 * copy new assignment, now we know it is possible
960 * will be used by hw_perf_enable()
962 memcpy(cpuc->assign, assign, n*sizeof(int));
965 cpuc->n_added = n - n0;
970 static int x86_pmu_start(struct perf_event *event)
972 struct hw_perf_event *hwc = &event->hw;
977 x86_perf_event_set_period(event, hwc, hwc->idx);
978 x86_pmu.enable(hwc, hwc->idx);
983 static void x86_pmu_unthrottle(struct perf_event *event)
985 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
986 struct hw_perf_event *hwc = &event->hw;
988 if (WARN_ON_ONCE(hwc->idx >= X86_PMC_IDX_MAX ||
989 cpuc->events[hwc->idx] != event))
992 x86_pmu.enable(hwc, hwc->idx);
995 void perf_event_print_debug(void)
997 u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
998 struct cpu_hw_events *cpuc;
1002 if (!x86_pmu.num_events)
1005 local_irq_save(flags);
1007 cpu = smp_processor_id();
1008 cpuc = &per_cpu(cpu_hw_events, cpu);
1010 if (x86_pmu.version >= 2) {
1011 rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
1012 rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
1013 rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
1014 rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed);
1017 pr_info("CPU#%d: ctrl: %016llx\n", cpu, ctrl);
1018 pr_info("CPU#%d: status: %016llx\n", cpu, status);
1019 pr_info("CPU#%d: overflow: %016llx\n", cpu, overflow);
1020 pr_info("CPU#%d: fixed: %016llx\n", cpu, fixed);
1022 pr_info("CPU#%d: active: %016llx\n", cpu, *(u64 *)cpuc->active_mask);
1024 for (idx = 0; idx < x86_pmu.num_events; idx++) {
1025 rdmsrl(x86_pmu.eventsel + idx, pmc_ctrl);
1026 rdmsrl(x86_pmu.perfctr + idx, pmc_count);
1028 prev_left = per_cpu(pmc_prev_left[idx], cpu);
1030 pr_info("CPU#%d: gen-PMC%d ctrl: %016llx\n",
1031 cpu, idx, pmc_ctrl);
1032 pr_info("CPU#%d: gen-PMC%d count: %016llx\n",
1033 cpu, idx, pmc_count);
1034 pr_info("CPU#%d: gen-PMC%d left: %016llx\n",
1035 cpu, idx, prev_left);
1037 for (idx = 0; idx < x86_pmu.num_events_fixed; idx++) {
1038 rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, pmc_count);
1040 pr_info("CPU#%d: fixed-PMC%d count: %016llx\n",
1041 cpu, idx, pmc_count);
1043 local_irq_restore(flags);
1046 static void x86_pmu_stop(struct perf_event *event)
1048 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1049 struct hw_perf_event *hwc = &event->hw;
1053 * Must be done before we disable, otherwise the nmi handler
1054 * could reenable again:
1056 clear_bit(idx, cpuc->active_mask);
1057 x86_pmu.disable(hwc, idx);
1060 * Drain the remaining delta count out of a event
1061 * that we are disabling:
1063 x86_perf_event_update(event, hwc, idx);
1065 cpuc->events[idx] = NULL;
1068 static void x86_pmu_disable(struct perf_event *event)
1070 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1073 x86_pmu_stop(event);
1075 for (i = 0; i < cpuc->n_events; i++) {
1076 if (event == cpuc->event_list[i]) {
1078 if (x86_pmu.put_event_constraints)
1079 x86_pmu.put_event_constraints(cpuc, event);
1081 while (++i < cpuc->n_events)
1082 cpuc->event_list[i-1] = cpuc->event_list[i];
1088 perf_event_update_userpage(event);
1091 static int x86_pmu_handle_irq(struct pt_regs *regs)
1093 struct perf_sample_data data;
1094 struct cpu_hw_events *cpuc;
1095 struct perf_event *event;
1096 struct hw_perf_event *hwc;
1097 int idx, handled = 0;
1103 cpuc = &__get_cpu_var(cpu_hw_events);
1105 for (idx = 0; idx < x86_pmu.num_events; idx++) {
1106 if (!test_bit(idx, cpuc->active_mask))
1109 event = cpuc->events[idx];
1112 val = x86_perf_event_update(event, hwc, idx);
1113 if (val & (1ULL << (x86_pmu.event_bits - 1)))
1120 data.period = event->hw.last_period;
1122 if (!x86_perf_event_set_period(event, hwc, idx))
1125 if (perf_event_overflow(event, 1, &data, regs))
1126 x86_pmu.disable(hwc, idx);
1130 inc_irq_stat(apic_perf_irqs);
1135 void smp_perf_pending_interrupt(struct pt_regs *regs)
1139 inc_irq_stat(apic_pending_irqs);
1140 perf_event_do_pending();
1144 void set_perf_event_pending(void)
1146 #ifdef CONFIG_X86_LOCAL_APIC
1147 if (!x86_pmu.apic || !x86_pmu_initialized())
1150 apic->send_IPI_self(LOCAL_PENDING_VECTOR);
1154 void perf_events_lapic_init(void)
1156 #ifdef CONFIG_X86_LOCAL_APIC
1157 if (!x86_pmu.apic || !x86_pmu_initialized())
1161 * Always use NMI for PMU
1163 apic_write(APIC_LVTPC, APIC_DM_NMI);
1167 static int __kprobes
1168 perf_event_nmi_handler(struct notifier_block *self,
1169 unsigned long cmd, void *__args)
1171 struct die_args *args = __args;
1172 struct pt_regs *regs;
1174 if (!atomic_read(&active_events))
1188 #ifdef CONFIG_X86_LOCAL_APIC
1189 apic_write(APIC_LVTPC, APIC_DM_NMI);
1192 * Can't rely on the handled return value to say it was our NMI, two
1193 * events could trigger 'simultaneously' raising two back-to-back NMIs.
1195 * If the first NMI handles both, the latter will be empty and daze
1198 x86_pmu.handle_irq(regs);
1203 static __read_mostly struct notifier_block perf_event_nmi_notifier = {
1204 .notifier_call = perf_event_nmi_handler,
1209 static struct event_constraint unconstrained;
1210 static struct event_constraint emptyconstraint;
1212 static struct event_constraint *
1213 x86_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event)
1215 struct event_constraint *c;
1217 if (x86_pmu.event_constraints) {
1218 for_each_event_constraint(c, x86_pmu.event_constraints) {
1219 if ((event->hw.config & c->cmask) == c->code)
1224 return &unconstrained;
1227 static int x86_event_sched_in(struct perf_event *event,
1228 struct perf_cpu_context *cpuctx)
1232 event->state = PERF_EVENT_STATE_ACTIVE;
1233 event->oncpu = smp_processor_id();
1234 event->tstamp_running += event->ctx->time - event->tstamp_stopped;
1236 if (!is_x86_event(event))
1237 ret = event->pmu->enable(event);
1239 if (!ret && !is_software_event(event))
1240 cpuctx->active_oncpu++;
1242 if (!ret && event->attr.exclusive)
1243 cpuctx->exclusive = 1;
1248 static void x86_event_sched_out(struct perf_event *event,
1249 struct perf_cpu_context *cpuctx)
1251 event->state = PERF_EVENT_STATE_INACTIVE;
1254 if (!is_x86_event(event))
1255 event->pmu->disable(event);
1257 event->tstamp_running -= event->ctx->time - event->tstamp_stopped;
1259 if (!is_software_event(event))
1260 cpuctx->active_oncpu--;
1262 if (event->attr.exclusive || !cpuctx->active_oncpu)
1263 cpuctx->exclusive = 0;
1267 * Called to enable a whole group of events.
1268 * Returns 1 if the group was enabled, or -EAGAIN if it could not be.
1269 * Assumes the caller has disabled interrupts and has
1270 * frozen the PMU with hw_perf_save_disable.
1272 * called with PMU disabled. If successful and return value 1,
1273 * then guaranteed to call perf_enable() and hw_perf_enable()
1275 int hw_perf_group_sched_in(struct perf_event *leader,
1276 struct perf_cpu_context *cpuctx,
1277 struct perf_event_context *ctx)
1279 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1280 struct perf_event *sub;
1281 int assign[X86_PMC_IDX_MAX];
1284 /* n0 = total number of events */
1285 n0 = collect_events(cpuc, leader, true);
1289 ret = x86_schedule_events(cpuc, n0, assign);
1293 ret = x86_event_sched_in(leader, cpuctx);
1298 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
1299 if (sub->state > PERF_EVENT_STATE_OFF) {
1300 ret = x86_event_sched_in(sub, cpuctx);
1307 * copy new assignment, now we know it is possible
1308 * will be used by hw_perf_enable()
1310 memcpy(cpuc->assign, assign, n0*sizeof(int));
1312 cpuc->n_events = n0;
1314 ctx->nr_active += n1;
1317 * 1 means successful and events are active
1318 * This is not quite true because we defer
1319 * actual activation until hw_perf_enable() but
1320 * this way we* ensure caller won't try to enable
1325 x86_event_sched_out(leader, cpuctx);
1327 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
1328 if (sub->state == PERF_EVENT_STATE_ACTIVE) {
1329 x86_event_sched_out(sub, cpuctx);
1337 #include "perf_event_amd.c"
1338 #include "perf_event_p6.c"
1339 #include "perf_event_intel.c"
1341 static void __init pmu_check_apic(void)
1347 pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n");
1348 pr_info("no hardware sampling interrupt available.\n");
1351 void __init init_hw_perf_events(void)
1353 struct event_constraint *c;
1356 pr_info("Performance Events: ");
1358 switch (boot_cpu_data.x86_vendor) {
1359 case X86_VENDOR_INTEL:
1360 err = intel_pmu_init();
1362 case X86_VENDOR_AMD:
1363 err = amd_pmu_init();
1369 pr_cont("no PMU driver, software events only.\n");
1375 pr_cont("%s PMU driver.\n", x86_pmu.name);
1377 if (x86_pmu.num_events > X86_PMC_MAX_GENERIC) {
1378 WARN(1, KERN_ERR "hw perf events %d > max(%d), clipping!",
1379 x86_pmu.num_events, X86_PMC_MAX_GENERIC);
1380 x86_pmu.num_events = X86_PMC_MAX_GENERIC;
1382 perf_event_mask = (1 << x86_pmu.num_events) - 1;
1383 perf_max_events = x86_pmu.num_events;
1385 if (x86_pmu.num_events_fixed > X86_PMC_MAX_FIXED) {
1386 WARN(1, KERN_ERR "hw perf events fixed %d > max(%d), clipping!",
1387 x86_pmu.num_events_fixed, X86_PMC_MAX_FIXED);
1388 x86_pmu.num_events_fixed = X86_PMC_MAX_FIXED;
1392 ((1LL << x86_pmu.num_events_fixed)-1) << X86_PMC_IDX_FIXED;
1393 x86_pmu.intel_ctrl = perf_event_mask;
1395 perf_events_lapic_init();
1396 register_die_notifier(&perf_event_nmi_notifier);
1398 unconstrained = (struct event_constraint)
1399 __EVENT_CONSTRAINT(0, (1ULL << x86_pmu.num_events) - 1,
1400 0, x86_pmu.num_events);
1402 if (x86_pmu.event_constraints) {
1403 for_each_event_constraint(c, x86_pmu.event_constraints) {
1404 if (c->cmask != INTEL_ARCH_FIXED_MASK)
1407 c->idxmsk64 |= (1ULL << x86_pmu.num_events) - 1;
1408 c->weight += x86_pmu.num_events;
1412 pr_info("... version: %d\n", x86_pmu.version);
1413 pr_info("... bit width: %d\n", x86_pmu.event_bits);
1414 pr_info("... generic registers: %d\n", x86_pmu.num_events);
1415 pr_info("... value mask: %016Lx\n", x86_pmu.event_mask);
1416 pr_info("... max period: %016Lx\n", x86_pmu.max_period);
1417 pr_info("... fixed-purpose events: %d\n", x86_pmu.num_events_fixed);
1418 pr_info("... event mask: %016Lx\n", perf_event_mask);
1421 static inline void x86_pmu_read(struct perf_event *event)
1423 x86_perf_event_update(event, &event->hw, event->hw.idx);
1426 static const struct pmu pmu = {
1427 .enable = x86_pmu_enable,
1428 .disable = x86_pmu_disable,
1429 .start = x86_pmu_start,
1430 .stop = x86_pmu_stop,
1431 .read = x86_pmu_read,
1432 .unthrottle = x86_pmu_unthrottle,
1436 * validate a single event group
1438 * validation include:
1439 * - check events are compatible which each other
1440 * - events do not compete for the same counter
1441 * - number of events <= number of counters
1443 * validation ensures the group can be loaded onto the
1444 * PMU if it was the only group available.
1446 static int validate_group(struct perf_event *event)
1448 struct perf_event *leader = event->group_leader;
1449 struct cpu_hw_events *fake_cpuc;
1453 fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO);
1458 * the event is not yet connected with its
1459 * siblings therefore we must first collect
1460 * existing siblings, then add the new event
1461 * before we can simulate the scheduling
1464 n = collect_events(fake_cpuc, leader, true);
1468 fake_cpuc->n_events = n;
1469 n = collect_events(fake_cpuc, event, false);
1473 fake_cpuc->n_events = n;
1475 ret = x86_schedule_events(fake_cpuc, n, NULL);
1483 const struct pmu *hw_perf_event_init(struct perf_event *event)
1485 const struct pmu *tmp;
1488 err = __hw_perf_event_init(event);
1491 * we temporarily connect event to its pmu
1492 * such that validate_group() can classify
1493 * it as an x86 event using is_x86_event()
1498 if (event->group_leader != event)
1499 err = validate_group(event);
1505 event->destroy(event);
1506 return ERR_PTR(err);
1517 void callchain_store(struct perf_callchain_entry *entry, u64 ip)
1519 if (entry->nr < PERF_MAX_STACK_DEPTH)
1520 entry->ip[entry->nr++] = ip;
1523 static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_irq_entry);
1524 static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_nmi_entry);
1528 backtrace_warning_symbol(void *data, char *msg, unsigned long symbol)
1530 /* Ignore warnings */
1533 static void backtrace_warning(void *data, char *msg)
1535 /* Ignore warnings */
1538 static int backtrace_stack(void *data, char *name)
1543 static void backtrace_address(void *data, unsigned long addr, int reliable)
1545 struct perf_callchain_entry *entry = data;
1548 callchain_store(entry, addr);
1551 static const struct stacktrace_ops backtrace_ops = {
1552 .warning = backtrace_warning,
1553 .warning_symbol = backtrace_warning_symbol,
1554 .stack = backtrace_stack,
1555 .address = backtrace_address,
1556 .walk_stack = print_context_stack_bp,
1559 #include "../dumpstack.h"
1562 perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry)
1564 callchain_store(entry, PERF_CONTEXT_KERNEL);
1565 callchain_store(entry, regs->ip);
1567 dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry);
1571 * best effort, GUP based copy_from_user() that assumes IRQ or NMI context
1573 static unsigned long
1574 copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
1576 unsigned long offset, addr = (unsigned long)from;
1577 int type = in_nmi() ? KM_NMI : KM_IRQ0;
1578 unsigned long size, len = 0;
1584 ret = __get_user_pages_fast(addr, 1, 0, &page);
1588 offset = addr & (PAGE_SIZE - 1);
1589 size = min(PAGE_SIZE - offset, n - len);
1591 map = kmap_atomic(page, type);
1592 memcpy(to, map+offset, size);
1593 kunmap_atomic(map, type);
1605 static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
1607 unsigned long bytes;
1609 bytes = copy_from_user_nmi(frame, fp, sizeof(*frame));
1611 return bytes == sizeof(*frame);
1615 perf_callchain_user(struct pt_regs *regs, struct perf_callchain_entry *entry)
1617 struct stack_frame frame;
1618 const void __user *fp;
1620 if (!user_mode(regs))
1621 regs = task_pt_regs(current);
1623 fp = (void __user *)regs->bp;
1625 callchain_store(entry, PERF_CONTEXT_USER);
1626 callchain_store(entry, regs->ip);
1628 while (entry->nr < PERF_MAX_STACK_DEPTH) {
1629 frame.next_frame = NULL;
1630 frame.return_address = 0;
1632 if (!copy_stack_frame(fp, &frame))
1635 if ((unsigned long)fp < regs->sp)
1638 callchain_store(entry, frame.return_address);
1639 fp = frame.next_frame;
1644 perf_do_callchain(struct pt_regs *regs, struct perf_callchain_entry *entry)
1651 is_user = user_mode(regs);
1653 if (is_user && current->state != TASK_RUNNING)
1657 perf_callchain_kernel(regs, entry);
1660 perf_callchain_user(regs, entry);
1663 struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
1665 struct perf_callchain_entry *entry;
1668 entry = &__get_cpu_var(pmc_nmi_entry);
1670 entry = &__get_cpu_var(pmc_irq_entry);
1674 perf_do_callchain(regs, entry);
1679 void hw_perf_event_setup_online(int cpu)
1681 init_debug_store_on_cpu(cpu);
1683 switch (boot_cpu_data.x86_vendor) {
1684 case X86_VENDOR_AMD:
1685 amd_pmu_cpu_online(cpu);
1692 void hw_perf_event_setup_offline(int cpu)
1694 init_debug_store_on_cpu(cpu);
1696 switch (boot_cpu_data.x86_vendor) {
1697 case X86_VENDOR_AMD:
1698 amd_pmu_cpu_offline(cpu);