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/slab.h>
25 #include <linux/cpu.h>
26 #include <linux/bitops.h>
27 #include <linux/device.h>
30 #include <asm/stacktrace.h>
33 #include <asm/alternative.h>
34 #include <asm/mmu_context.h>
35 #include <asm/tlbflush.h>
36 #include <asm/timer.h>
40 #include "perf_event.h"
42 struct x86_pmu x86_pmu __read_mostly;
44 DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
48 struct static_key rdpmc_always_available = STATIC_KEY_INIT_FALSE;
50 u64 __read_mostly hw_cache_event_ids
51 [PERF_COUNT_HW_CACHE_MAX]
52 [PERF_COUNT_HW_CACHE_OP_MAX]
53 [PERF_COUNT_HW_CACHE_RESULT_MAX];
54 u64 __read_mostly hw_cache_extra_regs
55 [PERF_COUNT_HW_CACHE_MAX]
56 [PERF_COUNT_HW_CACHE_OP_MAX]
57 [PERF_COUNT_HW_CACHE_RESULT_MAX];
60 * Propagate event elapsed time into the generic event.
61 * Can only be executed on the CPU where the event is active.
62 * Returns the delta events processed.
64 u64 x86_perf_event_update(struct perf_event *event)
66 struct hw_perf_event *hwc = &event->hw;
67 int shift = 64 - x86_pmu.cntval_bits;
68 u64 prev_raw_count, new_raw_count;
72 if (idx == INTEL_PMC_IDX_FIXED_BTS)
76 * Careful: an NMI might modify the previous event value.
78 * Our tactic to handle this is to first atomically read and
79 * exchange a new raw count - then add that new-prev delta
80 * count to the generic event atomically:
83 prev_raw_count = local64_read(&hwc->prev_count);
84 rdpmcl(hwc->event_base_rdpmc, new_raw_count);
86 if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
87 new_raw_count) != prev_raw_count)
91 * Now we have the new raw value and have updated the prev
92 * timestamp already. We can now calculate the elapsed delta
93 * (event-)time and add that to the generic event.
95 * Careful, not all hw sign-extends above the physical width
98 delta = (new_raw_count << shift) - (prev_raw_count << shift);
101 local64_add(delta, &event->count);
102 local64_sub(delta, &hwc->period_left);
104 return new_raw_count;
108 * Find and validate any extra registers to set up.
110 static int x86_pmu_extra_regs(u64 config, struct perf_event *event)
112 struct hw_perf_event_extra *reg;
113 struct extra_reg *er;
115 reg = &event->hw.extra_reg;
117 if (!x86_pmu.extra_regs)
120 for (er = x86_pmu.extra_regs; er->msr; er++) {
121 if (er->event != (config & er->config_mask))
123 if (event->attr.config1 & ~er->valid_mask)
125 /* Check if the extra msrs can be safely accessed*/
126 if (!er->extra_msr_access)
130 reg->config = event->attr.config1;
137 static atomic_t active_events;
138 static atomic_t pmc_refcount;
139 static DEFINE_MUTEX(pmc_reserve_mutex);
141 #ifdef CONFIG_X86_LOCAL_APIC
143 static bool reserve_pmc_hardware(void)
147 for (i = 0; i < x86_pmu.num_counters; i++) {
148 if (!reserve_perfctr_nmi(x86_pmu_event_addr(i)))
152 for (i = 0; i < x86_pmu.num_counters; i++) {
153 if (!reserve_evntsel_nmi(x86_pmu_config_addr(i)))
160 for (i--; i >= 0; i--)
161 release_evntsel_nmi(x86_pmu_config_addr(i));
163 i = x86_pmu.num_counters;
166 for (i--; i >= 0; i--)
167 release_perfctr_nmi(x86_pmu_event_addr(i));
172 static void release_pmc_hardware(void)
176 for (i = 0; i < x86_pmu.num_counters; i++) {
177 release_perfctr_nmi(x86_pmu_event_addr(i));
178 release_evntsel_nmi(x86_pmu_config_addr(i));
184 static bool reserve_pmc_hardware(void) { return true; }
185 static void release_pmc_hardware(void) {}
189 static bool check_hw_exists(void)
191 u64 val, val_fail, val_new= ~0;
192 int i, reg, reg_fail, ret = 0;
197 * Check to see if the BIOS enabled any of the counters, if so
200 for (i = 0; i < x86_pmu.num_counters; i++) {
201 reg = x86_pmu_config_addr(i);
202 ret = rdmsrl_safe(reg, &val);
205 if (val & ARCH_PERFMON_EVENTSEL_ENABLE) {
214 if (x86_pmu.num_counters_fixed) {
215 reg = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
216 ret = rdmsrl_safe(reg, &val);
219 for (i = 0; i < x86_pmu.num_counters_fixed; i++) {
220 if (val & (0x03 << i*4)) {
229 * If all the counters are enabled, the below test will always
230 * fail. The tools will also become useless in this scenario.
231 * Just fail and disable the hardware counters.
234 if (reg_safe == -1) {
240 * Read the current value, change it and read it back to see if it
241 * matches, this is needed to detect certain hardware emulators
242 * (qemu/kvm) that don't trap on the MSR access and always return 0s.
244 reg = x86_pmu_event_addr(reg_safe);
245 if (rdmsrl_safe(reg, &val))
248 ret = wrmsrl_safe(reg, val);
249 ret |= rdmsrl_safe(reg, &val_new);
250 if (ret || val != val_new)
254 * We still allow the PMU driver to operate:
257 printk(KERN_CONT "Broken BIOS detected, complain to your hardware vendor.\n");
258 printk(KERN_ERR FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n", reg_fail, val_fail);
264 printk(KERN_CONT "Broken PMU hardware detected, using software events only.\n");
265 printk("%sFailed to access perfctr msr (MSR %x is %Lx)\n",
266 boot_cpu_has(X86_FEATURE_HYPERVISOR) ? KERN_INFO : KERN_ERR,
272 static void hw_perf_event_destroy(struct perf_event *event)
274 x86_release_hardware();
275 atomic_dec(&active_events);
278 void hw_perf_lbr_event_destroy(struct perf_event *event)
280 hw_perf_event_destroy(event);
282 /* undo the lbr/bts event accounting */
283 x86_del_exclusive(x86_lbr_exclusive_lbr);
286 static inline int x86_pmu_initialized(void)
288 return x86_pmu.handle_irq != NULL;
292 set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event *event)
294 struct perf_event_attr *attr = &event->attr;
295 unsigned int cache_type, cache_op, cache_result;
298 config = attr->config;
300 cache_type = (config >> 0) & 0xff;
301 if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
304 cache_op = (config >> 8) & 0xff;
305 if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
308 cache_result = (config >> 16) & 0xff;
309 if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
312 val = hw_cache_event_ids[cache_type][cache_op][cache_result];
321 attr->config1 = hw_cache_extra_regs[cache_type][cache_op][cache_result];
322 return x86_pmu_extra_regs(val, event);
325 int x86_reserve_hardware(void)
329 if (!atomic_inc_not_zero(&pmc_refcount)) {
330 mutex_lock(&pmc_reserve_mutex);
331 if (atomic_read(&pmc_refcount) == 0) {
332 if (!reserve_pmc_hardware())
335 reserve_ds_buffers();
338 atomic_inc(&pmc_refcount);
339 mutex_unlock(&pmc_reserve_mutex);
345 void x86_release_hardware(void)
347 if (atomic_dec_and_mutex_lock(&pmc_refcount, &pmc_reserve_mutex)) {
348 release_pmc_hardware();
349 release_ds_buffers();
350 mutex_unlock(&pmc_reserve_mutex);
355 * Check if we can create event of a certain type (that no conflicting events
358 int x86_add_exclusive(unsigned int what)
362 if (!atomic_inc_not_zero(&x86_pmu.lbr_exclusive[what])) {
363 mutex_lock(&pmc_reserve_mutex);
364 for (i = 0; i < ARRAY_SIZE(x86_pmu.lbr_exclusive); i++) {
365 if (i != what && atomic_read(&x86_pmu.lbr_exclusive[i]))
368 atomic_inc(&x86_pmu.lbr_exclusive[what]);
369 mutex_unlock(&pmc_reserve_mutex);
372 atomic_inc(&active_events);
376 mutex_unlock(&pmc_reserve_mutex);
380 void x86_del_exclusive(unsigned int what)
382 atomic_dec(&x86_pmu.lbr_exclusive[what]);
383 atomic_dec(&active_events);
386 int x86_setup_perfctr(struct perf_event *event)
388 struct perf_event_attr *attr = &event->attr;
389 struct hw_perf_event *hwc = &event->hw;
392 if (!is_sampling_event(event)) {
393 hwc->sample_period = x86_pmu.max_period;
394 hwc->last_period = hwc->sample_period;
395 local64_set(&hwc->period_left, hwc->sample_period);
398 if (attr->type == PERF_TYPE_RAW)
399 return x86_pmu_extra_regs(event->attr.config, event);
401 if (attr->type == PERF_TYPE_HW_CACHE)
402 return set_ext_hw_attr(hwc, event);
404 if (attr->config >= x86_pmu.max_events)
410 config = x86_pmu.event_map(attr->config);
421 if (attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS &&
422 !attr->freq && hwc->sample_period == 1) {
423 /* BTS is not supported by this architecture. */
424 if (!x86_pmu.bts_active)
427 /* BTS is currently only allowed for user-mode. */
428 if (!attr->exclude_kernel)
431 /* disallow bts if conflicting events are present */
432 if (x86_add_exclusive(x86_lbr_exclusive_lbr))
435 event->destroy = hw_perf_lbr_event_destroy;
438 hwc->config |= config;
444 * check that branch_sample_type is compatible with
445 * settings needed for precise_ip > 1 which implies
446 * using the LBR to capture ALL taken branches at the
447 * priv levels of the measurement
449 static inline int precise_br_compat(struct perf_event *event)
451 u64 m = event->attr.branch_sample_type;
454 /* must capture all branches */
455 if (!(m & PERF_SAMPLE_BRANCH_ANY))
458 m &= PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_USER;
460 if (!event->attr.exclude_user)
461 b |= PERF_SAMPLE_BRANCH_USER;
463 if (!event->attr.exclude_kernel)
464 b |= PERF_SAMPLE_BRANCH_KERNEL;
467 * ignore PERF_SAMPLE_BRANCH_HV, not supported on x86
473 int x86_pmu_hw_config(struct perf_event *event)
475 if (event->attr.precise_ip) {
478 /* Support for constant skid */
479 if (x86_pmu.pebs_active && !x86_pmu.pebs_broken) {
482 /* Support for IP fixup */
483 if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2)
487 if (event->attr.precise_ip > precise)
491 * check that PEBS LBR correction does not conflict with
492 * whatever the user is asking with attr->branch_sample_type
494 if (event->attr.precise_ip > 1 && x86_pmu.intel_cap.pebs_format < 2) {
495 u64 *br_type = &event->attr.branch_sample_type;
497 if (has_branch_stack(event)) {
498 if (!precise_br_compat(event))
501 /* branch_sample_type is compatible */
505 * user did not specify branch_sample_type
507 * For PEBS fixups, we capture all
508 * the branches at the priv level of the
511 *br_type = PERF_SAMPLE_BRANCH_ANY;
513 if (!event->attr.exclude_user)
514 *br_type |= PERF_SAMPLE_BRANCH_USER;
516 if (!event->attr.exclude_kernel)
517 *br_type |= PERF_SAMPLE_BRANCH_KERNEL;
521 if (event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK)
522 event->attach_state |= PERF_ATTACH_TASK_DATA;
526 * (keep 'enabled' bit clear for now)
528 event->hw.config = ARCH_PERFMON_EVENTSEL_INT;
531 * Count user and OS events unless requested not to
533 if (!event->attr.exclude_user)
534 event->hw.config |= ARCH_PERFMON_EVENTSEL_USR;
535 if (!event->attr.exclude_kernel)
536 event->hw.config |= ARCH_PERFMON_EVENTSEL_OS;
538 if (event->attr.type == PERF_TYPE_RAW)
539 event->hw.config |= event->attr.config & X86_RAW_EVENT_MASK;
541 if (event->attr.sample_period && x86_pmu.limit_period) {
542 if (x86_pmu.limit_period(event, event->attr.sample_period) >
543 event->attr.sample_period)
547 return x86_setup_perfctr(event);
551 * Setup the hardware configuration for a given attr_type
553 static int __x86_pmu_event_init(struct perf_event *event)
557 if (!x86_pmu_initialized())
560 err = x86_reserve_hardware();
564 atomic_inc(&active_events);
565 event->destroy = hw_perf_event_destroy;
568 event->hw.last_cpu = -1;
569 event->hw.last_tag = ~0ULL;
572 event->hw.extra_reg.idx = EXTRA_REG_NONE;
573 event->hw.branch_reg.idx = EXTRA_REG_NONE;
575 return x86_pmu.hw_config(event);
578 void x86_pmu_disable_all(void)
580 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
583 for (idx = 0; idx < x86_pmu.num_counters; idx++) {
586 if (!test_bit(idx, cpuc->active_mask))
588 rdmsrl(x86_pmu_config_addr(idx), val);
589 if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE))
591 val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;
592 wrmsrl(x86_pmu_config_addr(idx), val);
596 static void x86_pmu_disable(struct pmu *pmu)
598 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
600 if (!x86_pmu_initialized())
610 x86_pmu.disable_all();
613 void x86_pmu_enable_all(int added)
615 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
618 for (idx = 0; idx < x86_pmu.num_counters; idx++) {
619 struct hw_perf_event *hwc = &cpuc->events[idx]->hw;
621 if (!test_bit(idx, cpuc->active_mask))
624 __x86_pmu_enable_event(hwc, ARCH_PERFMON_EVENTSEL_ENABLE);
628 static struct pmu pmu;
630 static inline int is_x86_event(struct perf_event *event)
632 return event->pmu == &pmu;
636 * Event scheduler state:
638 * Assign events iterating over all events and counters, beginning
639 * with events with least weights first. Keep the current iterator
640 * state in struct sched_state.
644 int event; /* event index */
645 int counter; /* counter index */
646 int unassigned; /* number of events to be assigned left */
647 int nr_gp; /* number of GP counters used */
648 unsigned long used[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
651 /* Total max is X86_PMC_IDX_MAX, but we are O(n!) limited */
652 #define SCHED_STATES_MAX 2
659 struct event_constraint **constraints;
660 struct sched_state state;
661 struct sched_state saved[SCHED_STATES_MAX];
665 * Initialize interator that runs through all events and counters.
667 static void perf_sched_init(struct perf_sched *sched, struct event_constraint **constraints,
668 int num, int wmin, int wmax, int gpmax)
672 memset(sched, 0, sizeof(*sched));
673 sched->max_events = num;
674 sched->max_weight = wmax;
675 sched->max_gp = gpmax;
676 sched->constraints = constraints;
678 for (idx = 0; idx < num; idx++) {
679 if (constraints[idx]->weight == wmin)
683 sched->state.event = idx; /* start with min weight */
684 sched->state.weight = wmin;
685 sched->state.unassigned = num;
688 static void perf_sched_save_state(struct perf_sched *sched)
690 if (WARN_ON_ONCE(sched->saved_states >= SCHED_STATES_MAX))
693 sched->saved[sched->saved_states] = sched->state;
694 sched->saved_states++;
697 static bool perf_sched_restore_state(struct perf_sched *sched)
699 if (!sched->saved_states)
702 sched->saved_states--;
703 sched->state = sched->saved[sched->saved_states];
705 /* continue with next counter: */
706 clear_bit(sched->state.counter++, sched->state.used);
712 * Select a counter for the current event to schedule. Return true on
715 static bool __perf_sched_find_counter(struct perf_sched *sched)
717 struct event_constraint *c;
720 if (!sched->state.unassigned)
723 if (sched->state.event >= sched->max_events)
726 c = sched->constraints[sched->state.event];
727 /* Prefer fixed purpose counters */
728 if (c->idxmsk64 & (~0ULL << INTEL_PMC_IDX_FIXED)) {
729 idx = INTEL_PMC_IDX_FIXED;
730 for_each_set_bit_from(idx, c->idxmsk, X86_PMC_IDX_MAX) {
731 if (!__test_and_set_bit(idx, sched->state.used))
736 /* Grab the first unused counter starting with idx */
737 idx = sched->state.counter;
738 for_each_set_bit_from(idx, c->idxmsk, INTEL_PMC_IDX_FIXED) {
739 if (!__test_and_set_bit(idx, sched->state.used)) {
740 if (sched->state.nr_gp++ >= sched->max_gp)
750 sched->state.counter = idx;
753 perf_sched_save_state(sched);
758 static bool perf_sched_find_counter(struct perf_sched *sched)
760 while (!__perf_sched_find_counter(sched)) {
761 if (!perf_sched_restore_state(sched))
769 * Go through all unassigned events and find the next one to schedule.
770 * Take events with the least weight first. Return true on success.
772 static bool perf_sched_next_event(struct perf_sched *sched)
774 struct event_constraint *c;
776 if (!sched->state.unassigned || !--sched->state.unassigned)
781 sched->state.event++;
782 if (sched->state.event >= sched->max_events) {
784 sched->state.event = 0;
785 sched->state.weight++;
786 if (sched->state.weight > sched->max_weight)
789 c = sched->constraints[sched->state.event];
790 } while (c->weight != sched->state.weight);
792 sched->state.counter = 0; /* start with first counter */
798 * Assign a counter for each event.
800 int perf_assign_events(struct event_constraint **constraints, int n,
801 int wmin, int wmax, int gpmax, int *assign)
803 struct perf_sched sched;
805 perf_sched_init(&sched, constraints, n, wmin, wmax, gpmax);
808 if (!perf_sched_find_counter(&sched))
811 assign[sched.state.event] = sched.state.counter;
812 } while (perf_sched_next_event(&sched));
814 return sched.state.unassigned;
816 EXPORT_SYMBOL_GPL(perf_assign_events);
818 int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
820 struct event_constraint *c;
821 unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
822 struct perf_event *e;
823 int i, wmin, wmax, unsched = 0;
824 struct hw_perf_event *hwc;
826 bitmap_zero(used_mask, X86_PMC_IDX_MAX);
828 if (x86_pmu.start_scheduling)
829 x86_pmu.start_scheduling(cpuc);
831 for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) {
832 cpuc->event_constraint[i] = NULL;
833 c = x86_pmu.get_event_constraints(cpuc, i, cpuc->event_list[i]);
834 cpuc->event_constraint[i] = c;
836 wmin = min(wmin, c->weight);
837 wmax = max(wmax, c->weight);
841 * fastpath, try to reuse previous register
843 for (i = 0; i < n; i++) {
844 hwc = &cpuc->event_list[i]->hw;
845 c = cpuc->event_constraint[i];
851 /* constraint still honored */
852 if (!test_bit(hwc->idx, c->idxmsk))
855 /* not already used */
856 if (test_bit(hwc->idx, used_mask))
859 __set_bit(hwc->idx, used_mask);
861 assign[i] = hwc->idx;
866 int gpmax = x86_pmu.num_counters;
869 * Do not allow scheduling of more than half the available
872 * This helps avoid counter starvation of sibling thread by
873 * ensuring at most half the counters cannot be in exclusive
874 * mode. There is no designated counters for the limits. Any
875 * N/2 counters can be used. This helps with events with
876 * specific counter constraints.
878 if (is_ht_workaround_enabled() && !cpuc->is_fake &&
879 READ_ONCE(cpuc->excl_cntrs->exclusive_present))
882 unsched = perf_assign_events(cpuc->event_constraint, n, wmin,
883 wmax, gpmax, assign);
887 * In case of success (unsched = 0), mark events as committed,
888 * so we do not put_constraint() in case new events are added
889 * and fail to be scheduled
891 * We invoke the lower level commit callback to lock the resource
893 * We do not need to do all of this in case we are called to
894 * validate an event group (assign == NULL)
896 if (!unsched && assign) {
897 for (i = 0; i < n; i++) {
898 e = cpuc->event_list[i];
899 e->hw.flags |= PERF_X86_EVENT_COMMITTED;
900 if (x86_pmu.commit_scheduling)
901 x86_pmu.commit_scheduling(cpuc, i, assign[i]);
904 for (i = 0; i < n; i++) {
905 e = cpuc->event_list[i];
907 * do not put_constraint() on comitted events,
908 * because they are good to go
910 if ((e->hw.flags & PERF_X86_EVENT_COMMITTED))
914 * release events that failed scheduling
916 if (x86_pmu.put_event_constraints)
917 x86_pmu.put_event_constraints(cpuc, e);
921 if (x86_pmu.stop_scheduling)
922 x86_pmu.stop_scheduling(cpuc);
924 return unsched ? -EINVAL : 0;
928 * dogrp: true if must collect siblings events (group)
929 * returns total number of events and error code
931 static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp)
933 struct perf_event *event;
936 max_count = x86_pmu.num_counters + x86_pmu.num_counters_fixed;
938 /* current number of events already accepted */
941 if (is_x86_event(leader)) {
944 cpuc->event_list[n] = leader;
950 list_for_each_entry(event, &leader->sibling_list, group_entry) {
951 if (!is_x86_event(event) ||
952 event->state <= PERF_EVENT_STATE_OFF)
958 cpuc->event_list[n] = event;
964 static inline void x86_assign_hw_event(struct perf_event *event,
965 struct cpu_hw_events *cpuc, int i)
967 struct hw_perf_event *hwc = &event->hw;
969 hwc->idx = cpuc->assign[i];
970 hwc->last_cpu = smp_processor_id();
971 hwc->last_tag = ++cpuc->tags[i];
973 if (hwc->idx == INTEL_PMC_IDX_FIXED_BTS) {
974 hwc->config_base = 0;
976 } else if (hwc->idx >= INTEL_PMC_IDX_FIXED) {
977 hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
978 hwc->event_base = MSR_ARCH_PERFMON_FIXED_CTR0 + (hwc->idx - INTEL_PMC_IDX_FIXED);
979 hwc->event_base_rdpmc = (hwc->idx - INTEL_PMC_IDX_FIXED) | 1<<30;
981 hwc->config_base = x86_pmu_config_addr(hwc->idx);
982 hwc->event_base = x86_pmu_event_addr(hwc->idx);
983 hwc->event_base_rdpmc = x86_pmu_rdpmc_index(hwc->idx);
987 static inline int match_prev_assignment(struct hw_perf_event *hwc,
988 struct cpu_hw_events *cpuc,
991 return hwc->idx == cpuc->assign[i] &&
992 hwc->last_cpu == smp_processor_id() &&
993 hwc->last_tag == cpuc->tags[i];
996 static void x86_pmu_start(struct perf_event *event, int flags);
998 static void x86_pmu_enable(struct pmu *pmu)
1000 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1001 struct perf_event *event;
1002 struct hw_perf_event *hwc;
1003 int i, added = cpuc->n_added;
1005 if (!x86_pmu_initialized())
1011 if (cpuc->n_added) {
1012 int n_running = cpuc->n_events - cpuc->n_added;
1014 * apply assignment obtained either from
1015 * hw_perf_group_sched_in() or x86_pmu_enable()
1017 * step1: save events moving to new counters
1019 for (i = 0; i < n_running; i++) {
1020 event = cpuc->event_list[i];
1024 * we can avoid reprogramming counter if:
1025 * - assigned same counter as last time
1026 * - running on same CPU as last time
1027 * - no other event has used the counter since
1029 if (hwc->idx == -1 ||
1030 match_prev_assignment(hwc, cpuc, i))
1034 * Ensure we don't accidentally enable a stopped
1035 * counter simply because we rescheduled.
1037 if (hwc->state & PERF_HES_STOPPED)
1038 hwc->state |= PERF_HES_ARCH;
1040 x86_pmu_stop(event, PERF_EF_UPDATE);
1044 * step2: reprogram moved events into new counters
1046 for (i = 0; i < cpuc->n_events; i++) {
1047 event = cpuc->event_list[i];
1050 if (!match_prev_assignment(hwc, cpuc, i))
1051 x86_assign_hw_event(event, cpuc, i);
1052 else if (i < n_running)
1055 if (hwc->state & PERF_HES_ARCH)
1058 x86_pmu_start(event, PERF_EF_RELOAD);
1061 perf_events_lapic_init();
1067 x86_pmu.enable_all(added);
1070 static DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left);
1073 * Set the next IRQ period, based on the hwc->period_left value.
1074 * To be called with the event disabled in hw:
1076 int x86_perf_event_set_period(struct perf_event *event)
1078 struct hw_perf_event *hwc = &event->hw;
1079 s64 left = local64_read(&hwc->period_left);
1080 s64 period = hwc->sample_period;
1081 int ret = 0, idx = hwc->idx;
1083 if (idx == INTEL_PMC_IDX_FIXED_BTS)
1087 * If we are way outside a reasonable range then just skip forward:
1089 if (unlikely(left <= -period)) {
1091 local64_set(&hwc->period_left, left);
1092 hwc->last_period = period;
1096 if (unlikely(left <= 0)) {
1098 local64_set(&hwc->period_left, left);
1099 hwc->last_period = period;
1103 * Quirk: certain CPUs dont like it if just 1 hw_event is left:
1105 if (unlikely(left < 2))
1108 if (left > x86_pmu.max_period)
1109 left = x86_pmu.max_period;
1111 if (x86_pmu.limit_period)
1112 left = x86_pmu.limit_period(event, left);
1114 per_cpu(pmc_prev_left[idx], smp_processor_id()) = left;
1116 if (!(hwc->flags & PERF_X86_EVENT_AUTO_RELOAD) ||
1117 local64_read(&hwc->prev_count) != (u64)-left) {
1119 * The hw event starts counting from this event offset,
1120 * mark it to be able to extra future deltas:
1122 local64_set(&hwc->prev_count, (u64)-left);
1124 wrmsrl(hwc->event_base, (u64)(-left) & x86_pmu.cntval_mask);
1128 * Due to erratum on certan cpu we need
1129 * a second write to be sure the register
1130 * is updated properly
1132 if (x86_pmu.perfctr_second_write) {
1133 wrmsrl(hwc->event_base,
1134 (u64)(-left) & x86_pmu.cntval_mask);
1137 perf_event_update_userpage(event);
1142 void x86_pmu_enable_event(struct perf_event *event)
1144 if (__this_cpu_read(cpu_hw_events.enabled))
1145 __x86_pmu_enable_event(&event->hw,
1146 ARCH_PERFMON_EVENTSEL_ENABLE);
1150 * Add a single event to the PMU.
1152 * The event is added to the group of enabled events
1153 * but only if it can be scehduled with existing events.
1155 static int x86_pmu_add(struct perf_event *event, int flags)
1157 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1158 struct hw_perf_event *hwc;
1159 int assign[X86_PMC_IDX_MAX];
1164 n0 = cpuc->n_events;
1165 ret = n = collect_events(cpuc, event, false);
1169 hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
1170 if (!(flags & PERF_EF_START))
1171 hwc->state |= PERF_HES_ARCH;
1174 * If group events scheduling transaction was started,
1175 * skip the schedulability test here, it will be performed
1176 * at commit time (->commit_txn) as a whole.
1178 if (cpuc->group_flag & PERF_EVENT_TXN)
1181 ret = x86_pmu.schedule_events(cpuc, n, assign);
1185 * copy new assignment, now we know it is possible
1186 * will be used by hw_perf_enable()
1188 memcpy(cpuc->assign, assign, n*sizeof(int));
1192 * Commit the collect_events() state. See x86_pmu_del() and
1196 cpuc->n_added += n - n0;
1197 cpuc->n_txn += n - n0;
1204 static void x86_pmu_start(struct perf_event *event, int flags)
1206 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1207 int idx = event->hw.idx;
1209 if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
1212 if (WARN_ON_ONCE(idx == -1))
1215 if (flags & PERF_EF_RELOAD) {
1216 WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
1217 x86_perf_event_set_period(event);
1220 event->hw.state = 0;
1222 cpuc->events[idx] = event;
1223 __set_bit(idx, cpuc->active_mask);
1224 __set_bit(idx, cpuc->running);
1225 x86_pmu.enable(event);
1226 perf_event_update_userpage(event);
1229 void perf_event_print_debug(void)
1231 u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
1233 struct cpu_hw_events *cpuc;
1234 unsigned long flags;
1237 if (!x86_pmu.num_counters)
1240 local_irq_save(flags);
1242 cpu = smp_processor_id();
1243 cpuc = &per_cpu(cpu_hw_events, cpu);
1245 if (x86_pmu.version >= 2) {
1246 rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
1247 rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
1248 rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
1249 rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed);
1252 pr_info("CPU#%d: ctrl: %016llx\n", cpu, ctrl);
1253 pr_info("CPU#%d: status: %016llx\n", cpu, status);
1254 pr_info("CPU#%d: overflow: %016llx\n", cpu, overflow);
1255 pr_info("CPU#%d: fixed: %016llx\n", cpu, fixed);
1256 if (x86_pmu.pebs_constraints) {
1257 rdmsrl(MSR_IA32_PEBS_ENABLE, pebs);
1258 pr_info("CPU#%d: pebs: %016llx\n", cpu, pebs);
1260 if (x86_pmu.lbr_nr) {
1261 rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
1262 pr_info("CPU#%d: debugctl: %016llx\n", cpu, debugctl);
1265 pr_info("CPU#%d: active: %016llx\n", cpu, *(u64 *)cpuc->active_mask);
1267 for (idx = 0; idx < x86_pmu.num_counters; idx++) {
1268 rdmsrl(x86_pmu_config_addr(idx), pmc_ctrl);
1269 rdmsrl(x86_pmu_event_addr(idx), pmc_count);
1271 prev_left = per_cpu(pmc_prev_left[idx], cpu);
1273 pr_info("CPU#%d: gen-PMC%d ctrl: %016llx\n",
1274 cpu, idx, pmc_ctrl);
1275 pr_info("CPU#%d: gen-PMC%d count: %016llx\n",
1276 cpu, idx, pmc_count);
1277 pr_info("CPU#%d: gen-PMC%d left: %016llx\n",
1278 cpu, idx, prev_left);
1280 for (idx = 0; idx < x86_pmu.num_counters_fixed; idx++) {
1281 rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, pmc_count);
1283 pr_info("CPU#%d: fixed-PMC%d count: %016llx\n",
1284 cpu, idx, pmc_count);
1286 local_irq_restore(flags);
1289 void x86_pmu_stop(struct perf_event *event, int flags)
1291 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1292 struct hw_perf_event *hwc = &event->hw;
1294 if (__test_and_clear_bit(hwc->idx, cpuc->active_mask)) {
1295 x86_pmu.disable(event);
1296 cpuc->events[hwc->idx] = NULL;
1297 WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
1298 hwc->state |= PERF_HES_STOPPED;
1301 if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
1303 * Drain the remaining delta count out of a event
1304 * that we are disabling:
1306 x86_perf_event_update(event);
1307 hwc->state |= PERF_HES_UPTODATE;
1311 static void x86_pmu_del(struct perf_event *event, int flags)
1313 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1317 * event is descheduled
1319 event->hw.flags &= ~PERF_X86_EVENT_COMMITTED;
1322 * If we're called during a txn, we don't need to do anything.
1323 * The events never got scheduled and ->cancel_txn will truncate
1326 * XXX assumes any ->del() called during a TXN will only be on
1327 * an event added during that same TXN.
1329 if (cpuc->group_flag & PERF_EVENT_TXN)
1333 * Not a TXN, therefore cleanup properly.
1335 x86_pmu_stop(event, PERF_EF_UPDATE);
1337 for (i = 0; i < cpuc->n_events; i++) {
1338 if (event == cpuc->event_list[i])
1342 if (WARN_ON_ONCE(i == cpuc->n_events)) /* called ->del() without ->add() ? */
1345 /* If we have a newly added event; make sure to decrease n_added. */
1346 if (i >= cpuc->n_events - cpuc->n_added)
1349 if (x86_pmu.put_event_constraints)
1350 x86_pmu.put_event_constraints(cpuc, event);
1352 /* Delete the array entry. */
1353 while (++i < cpuc->n_events) {
1354 cpuc->event_list[i-1] = cpuc->event_list[i];
1355 cpuc->event_constraint[i-1] = cpuc->event_constraint[i];
1359 perf_event_update_userpage(event);
1362 int x86_pmu_handle_irq(struct pt_regs *regs)
1364 struct perf_sample_data data;
1365 struct cpu_hw_events *cpuc;
1366 struct perf_event *event;
1367 int idx, handled = 0;
1370 cpuc = this_cpu_ptr(&cpu_hw_events);
1373 * Some chipsets need to unmask the LVTPC in a particular spot
1374 * inside the nmi handler. As a result, the unmasking was pushed
1375 * into all the nmi handlers.
1377 * This generic handler doesn't seem to have any issues where the
1378 * unmasking occurs so it was left at the top.
1380 apic_write(APIC_LVTPC, APIC_DM_NMI);
1382 for (idx = 0; idx < x86_pmu.num_counters; idx++) {
1383 if (!test_bit(idx, cpuc->active_mask)) {
1385 * Though we deactivated the counter some cpus
1386 * might still deliver spurious interrupts still
1387 * in flight. Catch them:
1389 if (__test_and_clear_bit(idx, cpuc->running))
1394 event = cpuc->events[idx];
1396 val = x86_perf_event_update(event);
1397 if (val & (1ULL << (x86_pmu.cntval_bits - 1)))
1404 perf_sample_data_init(&data, 0, event->hw.last_period);
1406 if (!x86_perf_event_set_period(event))
1409 if (perf_event_overflow(event, &data, regs))
1410 x86_pmu_stop(event, 0);
1414 inc_irq_stat(apic_perf_irqs);
1419 void perf_events_lapic_init(void)
1421 if (!x86_pmu.apic || !x86_pmu_initialized())
1425 * Always use NMI for PMU
1427 apic_write(APIC_LVTPC, APIC_DM_NMI);
1431 perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs)
1438 * All PMUs/events that share this PMI handler should make sure to
1439 * increment active_events for their events.
1441 if (!atomic_read(&active_events))
1444 start_clock = sched_clock();
1445 ret = x86_pmu.handle_irq(regs);
1446 finish_clock = sched_clock();
1448 perf_sample_event_took(finish_clock - start_clock);
1452 NOKPROBE_SYMBOL(perf_event_nmi_handler);
1454 struct event_constraint emptyconstraint;
1455 struct event_constraint unconstrained;
1458 x86_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
1460 unsigned int cpu = (long)hcpu;
1461 struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
1462 int i, ret = NOTIFY_OK;
1464 switch (action & ~CPU_TASKS_FROZEN) {
1465 case CPU_UP_PREPARE:
1466 for (i = 0 ; i < X86_PERF_KFREE_MAX; i++)
1467 cpuc->kfree_on_online[i] = NULL;
1468 if (x86_pmu.cpu_prepare)
1469 ret = x86_pmu.cpu_prepare(cpu);
1473 if (x86_pmu.cpu_starting)
1474 x86_pmu.cpu_starting(cpu);
1478 for (i = 0 ; i < X86_PERF_KFREE_MAX; i++) {
1479 kfree(cpuc->kfree_on_online[i]);
1480 cpuc->kfree_on_online[i] = NULL;
1485 if (x86_pmu.cpu_dying)
1486 x86_pmu.cpu_dying(cpu);
1489 case CPU_UP_CANCELED:
1491 if (x86_pmu.cpu_dead)
1492 x86_pmu.cpu_dead(cpu);
1502 static void __init pmu_check_apic(void)
1508 pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n");
1509 pr_info("no hardware sampling interrupt available.\n");
1512 * If we have a PMU initialized but no APIC
1513 * interrupts, we cannot sample hardware
1514 * events (user-space has to fall back and
1515 * sample via a hrtimer based software event):
1517 pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1521 static struct attribute_group x86_pmu_format_group = {
1527 * Remove all undefined events (x86_pmu.event_map(id) == 0)
1528 * out of events_attr attributes.
1530 static void __init filter_events(struct attribute **attrs)
1532 struct device_attribute *d;
1533 struct perf_pmu_events_attr *pmu_attr;
1536 for (i = 0; attrs[i]; i++) {
1537 d = (struct device_attribute *)attrs[i];
1538 pmu_attr = container_of(d, struct perf_pmu_events_attr, attr);
1540 if (pmu_attr->event_str)
1542 if (x86_pmu.event_map(i))
1545 for (j = i; attrs[j]; j++)
1546 attrs[j] = attrs[j + 1];
1548 /* Check the shifted attr. */
1553 /* Merge two pointer arrays */
1554 static __init struct attribute **merge_attr(struct attribute **a, struct attribute **b)
1556 struct attribute **new;
1559 for (j = 0; a[j]; j++)
1561 for (i = 0; b[i]; i++)
1565 new = kmalloc(sizeof(struct attribute *) * j, GFP_KERNEL);
1570 for (i = 0; a[i]; i++)
1572 for (i = 0; b[i]; i++)
1579 ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr,
1582 struct perf_pmu_events_attr *pmu_attr = \
1583 container_of(attr, struct perf_pmu_events_attr, attr);
1584 u64 config = x86_pmu.event_map(pmu_attr->id);
1586 /* string trumps id */
1587 if (pmu_attr->event_str)
1588 return sprintf(page, "%s", pmu_attr->event_str);
1590 return x86_pmu.events_sysfs_show(page, config);
1593 EVENT_ATTR(cpu-cycles, CPU_CYCLES );
1594 EVENT_ATTR(instructions, INSTRUCTIONS );
1595 EVENT_ATTR(cache-references, CACHE_REFERENCES );
1596 EVENT_ATTR(cache-misses, CACHE_MISSES );
1597 EVENT_ATTR(branch-instructions, BRANCH_INSTRUCTIONS );
1598 EVENT_ATTR(branch-misses, BRANCH_MISSES );
1599 EVENT_ATTR(bus-cycles, BUS_CYCLES );
1600 EVENT_ATTR(stalled-cycles-frontend, STALLED_CYCLES_FRONTEND );
1601 EVENT_ATTR(stalled-cycles-backend, STALLED_CYCLES_BACKEND );
1602 EVENT_ATTR(ref-cycles, REF_CPU_CYCLES );
1604 static struct attribute *empty_attrs;
1606 static struct attribute *events_attr[] = {
1607 EVENT_PTR(CPU_CYCLES),
1608 EVENT_PTR(INSTRUCTIONS),
1609 EVENT_PTR(CACHE_REFERENCES),
1610 EVENT_PTR(CACHE_MISSES),
1611 EVENT_PTR(BRANCH_INSTRUCTIONS),
1612 EVENT_PTR(BRANCH_MISSES),
1613 EVENT_PTR(BUS_CYCLES),
1614 EVENT_PTR(STALLED_CYCLES_FRONTEND),
1615 EVENT_PTR(STALLED_CYCLES_BACKEND),
1616 EVENT_PTR(REF_CPU_CYCLES),
1620 static struct attribute_group x86_pmu_events_group = {
1622 .attrs = events_attr,
1625 ssize_t x86_event_sysfs_show(char *page, u64 config, u64 event)
1627 u64 umask = (config & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
1628 u64 cmask = (config & ARCH_PERFMON_EVENTSEL_CMASK) >> 24;
1629 bool edge = (config & ARCH_PERFMON_EVENTSEL_EDGE);
1630 bool pc = (config & ARCH_PERFMON_EVENTSEL_PIN_CONTROL);
1631 bool any = (config & ARCH_PERFMON_EVENTSEL_ANY);
1632 bool inv = (config & ARCH_PERFMON_EVENTSEL_INV);
1636 * We have whole page size to spend and just little data
1637 * to write, so we can safely use sprintf.
1639 ret = sprintf(page, "event=0x%02llx", event);
1642 ret += sprintf(page + ret, ",umask=0x%02llx", umask);
1645 ret += sprintf(page + ret, ",edge");
1648 ret += sprintf(page + ret, ",pc");
1651 ret += sprintf(page + ret, ",any");
1654 ret += sprintf(page + ret, ",inv");
1657 ret += sprintf(page + ret, ",cmask=0x%02llx", cmask);
1659 ret += sprintf(page + ret, "\n");
1664 static int __init init_hw_perf_events(void)
1666 struct x86_pmu_quirk *quirk;
1669 pr_info("Performance Events: ");
1671 switch (boot_cpu_data.x86_vendor) {
1672 case X86_VENDOR_INTEL:
1673 err = intel_pmu_init();
1675 case X86_VENDOR_AMD:
1676 err = amd_pmu_init();
1682 pr_cont("no PMU driver, software events only.\n");
1688 /* sanity check that the hardware exists or is emulated */
1689 if (!check_hw_exists())
1692 pr_cont("%s PMU driver.\n", x86_pmu.name);
1694 x86_pmu.attr_rdpmc = 1; /* enable userspace RDPMC usage by default */
1696 for (quirk = x86_pmu.quirks; quirk; quirk = quirk->next)
1699 if (!x86_pmu.intel_ctrl)
1700 x86_pmu.intel_ctrl = (1 << x86_pmu.num_counters) - 1;
1702 perf_events_lapic_init();
1703 register_nmi_handler(NMI_LOCAL, perf_event_nmi_handler, 0, "PMI");
1705 unconstrained = (struct event_constraint)
1706 __EVENT_CONSTRAINT(0, (1ULL << x86_pmu.num_counters) - 1,
1707 0, x86_pmu.num_counters, 0, 0);
1709 x86_pmu_format_group.attrs = x86_pmu.format_attrs;
1711 if (x86_pmu.event_attrs)
1712 x86_pmu_events_group.attrs = x86_pmu.event_attrs;
1714 if (!x86_pmu.events_sysfs_show)
1715 x86_pmu_events_group.attrs = &empty_attrs;
1717 filter_events(x86_pmu_events_group.attrs);
1719 if (x86_pmu.cpu_events) {
1720 struct attribute **tmp;
1722 tmp = merge_attr(x86_pmu_events_group.attrs, x86_pmu.cpu_events);
1724 x86_pmu_events_group.attrs = tmp;
1727 pr_info("... version: %d\n", x86_pmu.version);
1728 pr_info("... bit width: %d\n", x86_pmu.cntval_bits);
1729 pr_info("... generic registers: %d\n", x86_pmu.num_counters);
1730 pr_info("... value mask: %016Lx\n", x86_pmu.cntval_mask);
1731 pr_info("... max period: %016Lx\n", x86_pmu.max_period);
1732 pr_info("... fixed-purpose events: %d\n", x86_pmu.num_counters_fixed);
1733 pr_info("... event mask: %016Lx\n", x86_pmu.intel_ctrl);
1735 perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
1736 perf_cpu_notifier(x86_pmu_notifier);
1740 early_initcall(init_hw_perf_events);
1742 static inline void x86_pmu_read(struct perf_event *event)
1744 x86_perf_event_update(event);
1748 * Start group events scheduling transaction
1749 * Set the flag to make pmu::enable() not perform the
1750 * schedulability test, it will be performed at commit time
1752 static void x86_pmu_start_txn(struct pmu *pmu)
1754 perf_pmu_disable(pmu);
1755 __this_cpu_or(cpu_hw_events.group_flag, PERF_EVENT_TXN);
1756 __this_cpu_write(cpu_hw_events.n_txn, 0);
1760 * Stop group events scheduling transaction
1761 * Clear the flag and pmu::enable() will perform the
1762 * schedulability test.
1764 static void x86_pmu_cancel_txn(struct pmu *pmu)
1766 __this_cpu_and(cpu_hw_events.group_flag, ~PERF_EVENT_TXN);
1768 * Truncate collected array by the number of events added in this
1769 * transaction. See x86_pmu_add() and x86_pmu_*_txn().
1771 __this_cpu_sub(cpu_hw_events.n_added, __this_cpu_read(cpu_hw_events.n_txn));
1772 __this_cpu_sub(cpu_hw_events.n_events, __this_cpu_read(cpu_hw_events.n_txn));
1773 perf_pmu_enable(pmu);
1777 * Commit group events scheduling transaction
1778 * Perform the group schedulability test as a whole
1779 * Return 0 if success
1781 * Does not cancel the transaction on failure; expects the caller to do this.
1783 static int x86_pmu_commit_txn(struct pmu *pmu)
1785 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1786 int assign[X86_PMC_IDX_MAX];
1791 if (!x86_pmu_initialized())
1794 ret = x86_pmu.schedule_events(cpuc, n, assign);
1799 * copy new assignment, now we know it is possible
1800 * will be used by hw_perf_enable()
1802 memcpy(cpuc->assign, assign, n*sizeof(int));
1804 cpuc->group_flag &= ~PERF_EVENT_TXN;
1805 perf_pmu_enable(pmu);
1809 * a fake_cpuc is used to validate event groups. Due to
1810 * the extra reg logic, we need to also allocate a fake
1811 * per_core and per_cpu structure. Otherwise, group events
1812 * using extra reg may conflict without the kernel being
1813 * able to catch this when the last event gets added to
1816 static void free_fake_cpuc(struct cpu_hw_events *cpuc)
1818 kfree(cpuc->shared_regs);
1822 static struct cpu_hw_events *allocate_fake_cpuc(void)
1824 struct cpu_hw_events *cpuc;
1825 int cpu = raw_smp_processor_id();
1827 cpuc = kzalloc(sizeof(*cpuc), GFP_KERNEL);
1829 return ERR_PTR(-ENOMEM);
1831 /* only needed, if we have extra_regs */
1832 if (x86_pmu.extra_regs) {
1833 cpuc->shared_regs = allocate_shared_regs(cpu);
1834 if (!cpuc->shared_regs)
1840 free_fake_cpuc(cpuc);
1841 return ERR_PTR(-ENOMEM);
1845 * validate that we can schedule this event
1847 static int validate_event(struct perf_event *event)
1849 struct cpu_hw_events *fake_cpuc;
1850 struct event_constraint *c;
1853 fake_cpuc = allocate_fake_cpuc();
1854 if (IS_ERR(fake_cpuc))
1855 return PTR_ERR(fake_cpuc);
1857 c = x86_pmu.get_event_constraints(fake_cpuc, -1, event);
1859 if (!c || !c->weight)
1862 if (x86_pmu.put_event_constraints)
1863 x86_pmu.put_event_constraints(fake_cpuc, event);
1865 free_fake_cpuc(fake_cpuc);
1871 * validate a single event group
1873 * validation include:
1874 * - check events are compatible which each other
1875 * - events do not compete for the same counter
1876 * - number of events <= number of counters
1878 * validation ensures the group can be loaded onto the
1879 * PMU if it was the only group available.
1881 static int validate_group(struct perf_event *event)
1883 struct perf_event *leader = event->group_leader;
1884 struct cpu_hw_events *fake_cpuc;
1885 int ret = -EINVAL, n;
1887 fake_cpuc = allocate_fake_cpuc();
1888 if (IS_ERR(fake_cpuc))
1889 return PTR_ERR(fake_cpuc);
1891 * the event is not yet connected with its
1892 * siblings therefore we must first collect
1893 * existing siblings, then add the new event
1894 * before we can simulate the scheduling
1896 n = collect_events(fake_cpuc, leader, true);
1900 fake_cpuc->n_events = n;
1901 n = collect_events(fake_cpuc, event, false);
1905 fake_cpuc->n_events = n;
1907 ret = x86_pmu.schedule_events(fake_cpuc, n, NULL);
1910 free_fake_cpuc(fake_cpuc);
1914 static int x86_pmu_event_init(struct perf_event *event)
1919 switch (event->attr.type) {
1921 case PERF_TYPE_HARDWARE:
1922 case PERF_TYPE_HW_CACHE:
1929 err = __x86_pmu_event_init(event);
1932 * we temporarily connect event to its pmu
1933 * such that validate_group() can classify
1934 * it as an x86 event using is_x86_event()
1939 if (event->group_leader != event)
1940 err = validate_group(event);
1942 err = validate_event(event);
1948 event->destroy(event);
1951 if (ACCESS_ONCE(x86_pmu.attr_rdpmc))
1952 event->hw.flags |= PERF_X86_EVENT_RDPMC_ALLOWED;
1957 static void refresh_pce(void *ignored)
1960 load_mm_cr4(current->mm);
1963 static void x86_pmu_event_mapped(struct perf_event *event)
1965 if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
1968 if (atomic_inc_return(¤t->mm->context.perf_rdpmc_allowed) == 1)
1969 on_each_cpu_mask(mm_cpumask(current->mm), refresh_pce, NULL, 1);
1972 static void x86_pmu_event_unmapped(struct perf_event *event)
1977 if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
1980 if (atomic_dec_and_test(¤t->mm->context.perf_rdpmc_allowed))
1981 on_each_cpu_mask(mm_cpumask(current->mm), refresh_pce, NULL, 1);
1984 static int x86_pmu_event_idx(struct perf_event *event)
1986 int idx = event->hw.idx;
1988 if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
1991 if (x86_pmu.num_counters_fixed && idx >= INTEL_PMC_IDX_FIXED) {
1992 idx -= INTEL_PMC_IDX_FIXED;
1999 static ssize_t get_attr_rdpmc(struct device *cdev,
2000 struct device_attribute *attr,
2003 return snprintf(buf, 40, "%d\n", x86_pmu.attr_rdpmc);
2006 static ssize_t set_attr_rdpmc(struct device *cdev,
2007 struct device_attribute *attr,
2008 const char *buf, size_t count)
2013 ret = kstrtoul(buf, 0, &val);
2020 if (x86_pmu.attr_rdpmc_broken)
2023 if ((val == 2) != (x86_pmu.attr_rdpmc == 2)) {
2025 * Changing into or out of always available, aka
2026 * perf-event-bypassing mode. This path is extremely slow,
2027 * but only root can trigger it, so it's okay.
2030 static_key_slow_inc(&rdpmc_always_available);
2032 static_key_slow_dec(&rdpmc_always_available);
2033 on_each_cpu(refresh_pce, NULL, 1);
2036 x86_pmu.attr_rdpmc = val;
2041 static DEVICE_ATTR(rdpmc, S_IRUSR | S_IWUSR, get_attr_rdpmc, set_attr_rdpmc);
2043 static struct attribute *x86_pmu_attrs[] = {
2044 &dev_attr_rdpmc.attr,
2048 static struct attribute_group x86_pmu_attr_group = {
2049 .attrs = x86_pmu_attrs,
2052 static const struct attribute_group *x86_pmu_attr_groups[] = {
2053 &x86_pmu_attr_group,
2054 &x86_pmu_format_group,
2055 &x86_pmu_events_group,
2059 static void x86_pmu_sched_task(struct perf_event_context *ctx, bool sched_in)
2061 if (x86_pmu.sched_task)
2062 x86_pmu.sched_task(ctx, sched_in);
2065 void perf_check_microcode(void)
2067 if (x86_pmu.check_microcode)
2068 x86_pmu.check_microcode();
2070 EXPORT_SYMBOL_GPL(perf_check_microcode);
2072 static struct pmu pmu = {
2073 .pmu_enable = x86_pmu_enable,
2074 .pmu_disable = x86_pmu_disable,
2076 .attr_groups = x86_pmu_attr_groups,
2078 .event_init = x86_pmu_event_init,
2080 .event_mapped = x86_pmu_event_mapped,
2081 .event_unmapped = x86_pmu_event_unmapped,
2085 .start = x86_pmu_start,
2086 .stop = x86_pmu_stop,
2087 .read = x86_pmu_read,
2089 .start_txn = x86_pmu_start_txn,
2090 .cancel_txn = x86_pmu_cancel_txn,
2091 .commit_txn = x86_pmu_commit_txn,
2093 .event_idx = x86_pmu_event_idx,
2094 .sched_task = x86_pmu_sched_task,
2095 .task_ctx_size = sizeof(struct x86_perf_task_context),
2098 void arch_perf_update_userpage(struct perf_event *event,
2099 struct perf_event_mmap_page *userpg, u64 now)
2101 struct cyc2ns_data *data;
2103 userpg->cap_user_time = 0;
2104 userpg->cap_user_time_zero = 0;
2105 userpg->cap_user_rdpmc =
2106 !!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED);
2107 userpg->pmc_width = x86_pmu.cntval_bits;
2109 if (!sched_clock_stable())
2112 data = cyc2ns_read_begin();
2115 * Internal timekeeping for enabled/running/stopped times
2116 * is always in the local_clock domain.
2118 userpg->cap_user_time = 1;
2119 userpg->time_mult = data->cyc2ns_mul;
2120 userpg->time_shift = data->cyc2ns_shift;
2121 userpg->time_offset = data->cyc2ns_offset - now;
2124 * cap_user_time_zero doesn't make sense when we're using a different
2125 * time base for the records.
2127 if (event->clock == &local_clock) {
2128 userpg->cap_user_time_zero = 1;
2129 userpg->time_zero = data->cyc2ns_offset;
2132 cyc2ns_read_end(data);
2139 static int backtrace_stack(void *data, char *name)
2144 static void backtrace_address(void *data, unsigned long addr, int reliable)
2146 struct perf_callchain_entry *entry = data;
2148 perf_callchain_store(entry, addr);
2151 static const struct stacktrace_ops backtrace_ops = {
2152 .stack = backtrace_stack,
2153 .address = backtrace_address,
2154 .walk_stack = print_context_stack_bp,
2158 perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
2160 if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
2161 /* TODO: We don't support guest os callchain now */
2165 perf_callchain_store(entry, regs->ip);
2167 dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry);
2171 valid_user_frame(const void __user *fp, unsigned long size)
2173 return (__range_not_ok(fp, size, TASK_SIZE) == 0);
2176 static unsigned long get_segment_base(unsigned int segment)
2178 struct desc_struct *desc;
2179 int idx = segment >> 3;
2181 if ((segment & SEGMENT_TI_MASK) == SEGMENT_LDT) {
2182 struct ldt_struct *ldt;
2184 if (idx > LDT_ENTRIES)
2187 /* IRQs are off, so this synchronizes with smp_store_release */
2188 ldt = lockless_dereference(current->active_mm->context.ldt);
2189 if (!ldt || idx > ldt->size)
2192 desc = &ldt->entries[idx];
2194 if (idx > GDT_ENTRIES)
2197 desc = raw_cpu_ptr(gdt_page.gdt) + idx;
2200 return get_desc_base(desc);
2203 #ifdef CONFIG_COMPAT
2205 #include <asm/compat.h>
2208 perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
2210 /* 32-bit process in 64-bit kernel. */
2211 unsigned long ss_base, cs_base;
2212 struct stack_frame_ia32 frame;
2213 const void __user *fp;
2215 if (!test_thread_flag(TIF_IA32))
2218 cs_base = get_segment_base(regs->cs);
2219 ss_base = get_segment_base(regs->ss);
2221 fp = compat_ptr(ss_base + regs->bp);
2222 while (entry->nr < PERF_MAX_STACK_DEPTH) {
2223 unsigned long bytes;
2224 frame.next_frame = 0;
2225 frame.return_address = 0;
2227 bytes = copy_from_user_nmi(&frame, fp, sizeof(frame));
2231 if (!valid_user_frame(fp, sizeof(frame)))
2234 perf_callchain_store(entry, cs_base + frame.return_address);
2235 fp = compat_ptr(ss_base + frame.next_frame);
2241 perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
2248 perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
2250 struct stack_frame frame;
2251 const void __user *fp;
2253 if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
2254 /* TODO: We don't support guest os callchain now */
2259 * We don't know what to do with VM86 stacks.. ignore them for now.
2261 if (regs->flags & (X86_VM_MASK | PERF_EFLAGS_VM))
2264 fp = (void __user *)regs->bp;
2266 perf_callchain_store(entry, regs->ip);
2271 if (perf_callchain_user32(regs, entry))
2274 while (entry->nr < PERF_MAX_STACK_DEPTH) {
2275 unsigned long bytes;
2276 frame.next_frame = NULL;
2277 frame.return_address = 0;
2279 bytes = copy_from_user_nmi(&frame, fp, sizeof(frame));
2283 if (!valid_user_frame(fp, sizeof(frame)))
2286 perf_callchain_store(entry, frame.return_address);
2287 fp = frame.next_frame;
2292 * Deal with code segment offsets for the various execution modes:
2294 * VM86 - the good olde 16 bit days, where the linear address is
2295 * 20 bits and we use regs->ip + 0x10 * regs->cs.
2297 * IA32 - Where we need to look at GDT/LDT segment descriptor tables
2298 * to figure out what the 32bit base address is.
2300 * X32 - has TIF_X32 set, but is running in x86_64
2302 * X86_64 - CS,DS,SS,ES are all zero based.
2304 static unsigned long code_segment_base(struct pt_regs *regs)
2307 * For IA32 we look at the GDT/LDT segment base to convert the
2308 * effective IP to a linear address.
2311 #ifdef CONFIG_X86_32
2313 * If we are in VM86 mode, add the segment offset to convert to a
2316 if (regs->flags & X86_VM_MASK)
2317 return 0x10 * regs->cs;
2319 if (user_mode(regs) && regs->cs != __USER_CS)
2320 return get_segment_base(regs->cs);
2322 if (user_mode(regs) && !user_64bit_mode(regs) &&
2323 regs->cs != __USER32_CS)
2324 return get_segment_base(regs->cs);
2329 unsigned long perf_instruction_pointer(struct pt_regs *regs)
2331 if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
2332 return perf_guest_cbs->get_guest_ip();
2334 return regs->ip + code_segment_base(regs);
2337 unsigned long perf_misc_flags(struct pt_regs *regs)
2341 if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
2342 if (perf_guest_cbs->is_user_mode())
2343 misc |= PERF_RECORD_MISC_GUEST_USER;
2345 misc |= PERF_RECORD_MISC_GUEST_KERNEL;
2347 if (user_mode(regs))
2348 misc |= PERF_RECORD_MISC_USER;
2350 misc |= PERF_RECORD_MISC_KERNEL;
2353 if (regs->flags & PERF_EFLAGS_EXACT)
2354 misc |= PERF_RECORD_MISC_EXACT_IP;
2359 void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
2361 cap->version = x86_pmu.version;
2362 cap->num_counters_gp = x86_pmu.num_counters;
2363 cap->num_counters_fixed = x86_pmu.num_counters_fixed;
2364 cap->bit_width_gp = x86_pmu.cntval_bits;
2365 cap->bit_width_fixed = x86_pmu.cntval_bits;
2366 cap->events_mask = (unsigned int)x86_pmu.events_maskl;
2367 cap->events_mask_len = x86_pmu.events_mask_len;
2369 EXPORT_SYMBOL_GPL(perf_get_x86_pmu_capability);