2 * Performance counter x86 architecture code
4 * Copyright(C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright(C) 2008 Red Hat, Inc., Ingo Molnar
6 * Copyright(C) 2009 Jaswinder Singh Rajput
7 * Copyright(C) 2009 Advanced Micro Devices, Inc., Robert Richter
9 * For licencing details see kernel-base/COPYING
12 #include <linux/perf_counter.h>
13 #include <linux/capability.h>
14 #include <linux/notifier.h>
15 #include <linux/hardirq.h>
16 #include <linux/kprobes.h>
17 #include <linux/module.h>
18 #include <linux/kdebug.h>
19 #include <linux/sched.h>
20 #include <linux/uaccess.h>
23 #include <asm/stacktrace.h>
26 static bool perf_counters_initialized __read_mostly;
27 static u64 perf_counter_mask __read_mostly;
29 struct cpu_hw_counters {
30 struct perf_counter *counters[X86_PMC_IDX_MAX];
31 unsigned long used[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
32 unsigned long active[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
33 unsigned long interrupts;
39 * struct x86_pmu - generic x86 pmu
44 int (*handle_irq)(struct pt_regs *, int);
45 u64 (*save_disable_all)(void);
46 void (*restore_all)(u64);
47 void (*enable)(int, u64);
48 void (*disable)(int, u64);
51 u64 (*event_map)(int);
52 u64 (*raw_event)(u64);
55 int num_counters_fixed;
60 static struct x86_pmu x86_pmu __read_mostly;
62 static DEFINE_PER_CPU(struct cpu_hw_counters, cpu_hw_counters) = {
67 * Intel PerfMon v3. Used on Core2 and later.
69 static const u64 intel_perfmon_event_map[] =
71 [PERF_COUNT_CPU_CYCLES] = 0x003c,
72 [PERF_COUNT_INSTRUCTIONS] = 0x00c0,
73 [PERF_COUNT_CACHE_REFERENCES] = 0x4f2e,
74 [PERF_COUNT_CACHE_MISSES] = 0x412e,
75 [PERF_COUNT_BRANCH_INSTRUCTIONS] = 0x00c4,
76 [PERF_COUNT_BRANCH_MISSES] = 0x00c5,
77 [PERF_COUNT_BUS_CYCLES] = 0x013c,
80 static u64 intel_pmu_event_map(int event)
82 return intel_perfmon_event_map[event];
85 static u64 intel_pmu_raw_event(u64 event)
87 #define CORE_EVNTSEL_EVENT_MASK 0x000000FFULL
88 #define CORE_EVNTSEL_UNIT_MASK 0x0000FF00ULL
89 #define CORE_EVNTSEL_COUNTER_MASK 0xFF000000ULL
91 #define CORE_EVNTSEL_MASK \
92 (CORE_EVNTSEL_EVENT_MASK | \
93 CORE_EVNTSEL_UNIT_MASK | \
94 CORE_EVNTSEL_COUNTER_MASK)
96 return event & CORE_EVNTSEL_MASK;
100 * AMD Performance Monitor K7 and later.
102 static const u64 amd_perfmon_event_map[] =
104 [PERF_COUNT_CPU_CYCLES] = 0x0076,
105 [PERF_COUNT_INSTRUCTIONS] = 0x00c0,
106 [PERF_COUNT_CACHE_REFERENCES] = 0x0080,
107 [PERF_COUNT_CACHE_MISSES] = 0x0081,
108 [PERF_COUNT_BRANCH_INSTRUCTIONS] = 0x00c4,
109 [PERF_COUNT_BRANCH_MISSES] = 0x00c5,
112 static u64 amd_pmu_event_map(int event)
114 return amd_perfmon_event_map[event];
117 static u64 amd_pmu_raw_event(u64 event)
119 #define K7_EVNTSEL_EVENT_MASK 0x7000000FFULL
120 #define K7_EVNTSEL_UNIT_MASK 0x00000FF00ULL
121 #define K7_EVNTSEL_COUNTER_MASK 0x0FF000000ULL
123 #define K7_EVNTSEL_MASK \
124 (K7_EVNTSEL_EVENT_MASK | \
125 K7_EVNTSEL_UNIT_MASK | \
126 K7_EVNTSEL_COUNTER_MASK)
128 return event & K7_EVNTSEL_MASK;
132 * Propagate counter elapsed time into the generic counter.
133 * Can only be executed on the CPU where the counter is active.
134 * Returns the delta events processed.
137 x86_perf_counter_update(struct perf_counter *counter,
138 struct hw_perf_counter *hwc, int idx)
140 u64 prev_raw_count, new_raw_count, delta;
143 * Careful: an NMI might modify the previous counter value.
145 * Our tactic to handle this is to first atomically read and
146 * exchange a new raw count - then add that new-prev delta
147 * count to the generic counter atomically:
150 prev_raw_count = atomic64_read(&hwc->prev_count);
151 rdmsrl(hwc->counter_base + idx, new_raw_count);
153 if (atomic64_cmpxchg(&hwc->prev_count, prev_raw_count,
154 new_raw_count) != prev_raw_count)
158 * Now we have the new raw value and have updated the prev
159 * timestamp already. We can now calculate the elapsed delta
160 * (counter-)time and add that to the generic counter.
162 * Careful, not all hw sign-extends above the physical width
163 * of the count, so we do that by clipping the delta to 32 bits:
165 delta = (u64)(u32)((s32)new_raw_count - (s32)prev_raw_count);
167 atomic64_add(delta, &counter->count);
168 atomic64_sub(delta, &hwc->period_left);
171 static atomic_t num_counters;
172 static DEFINE_MUTEX(pmc_reserve_mutex);
174 static bool reserve_pmc_hardware(void)
178 if (nmi_watchdog == NMI_LOCAL_APIC)
179 disable_lapic_nmi_watchdog();
181 for (i = 0; i < x86_pmu.num_counters; i++) {
182 if (!reserve_perfctr_nmi(x86_pmu.perfctr + i))
186 for (i = 0; i < x86_pmu.num_counters; i++) {
187 if (!reserve_evntsel_nmi(x86_pmu.eventsel + i))
194 for (i--; i >= 0; i--)
195 release_evntsel_nmi(x86_pmu.eventsel + i);
197 i = x86_pmu.num_counters;
200 for (i--; i >= 0; i--)
201 release_perfctr_nmi(x86_pmu.perfctr + i);
203 if (nmi_watchdog == NMI_LOCAL_APIC)
204 enable_lapic_nmi_watchdog();
209 static void release_pmc_hardware(void)
213 for (i = 0; i < x86_pmu.num_counters; i++) {
214 release_perfctr_nmi(x86_pmu.perfctr + i);
215 release_evntsel_nmi(x86_pmu.eventsel + i);
218 if (nmi_watchdog == NMI_LOCAL_APIC)
219 enable_lapic_nmi_watchdog();
222 static void hw_perf_counter_destroy(struct perf_counter *counter)
224 if (atomic_dec_and_mutex_lock(&num_counters, &pmc_reserve_mutex)) {
225 release_pmc_hardware();
226 mutex_unlock(&pmc_reserve_mutex);
231 * Setup the hardware configuration for a given hw_event_type
233 static int __hw_perf_counter_init(struct perf_counter *counter)
235 struct perf_counter_hw_event *hw_event = &counter->hw_event;
236 struct hw_perf_counter *hwc = &counter->hw;
239 /* disable temporarily */
240 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
243 if (unlikely(!perf_counters_initialized))
247 if (atomic_inc_not_zero(&num_counters)) {
248 mutex_lock(&pmc_reserve_mutex);
249 if (atomic_read(&num_counters) == 0 && !reserve_pmc_hardware())
252 atomic_inc(&num_counters);
253 mutex_unlock(&pmc_reserve_mutex);
260 * (keep 'enabled' bit clear for now)
262 hwc->config = ARCH_PERFMON_EVENTSEL_INT;
265 * Count user and OS events unless requested not to.
267 if (!hw_event->exclude_user)
268 hwc->config |= ARCH_PERFMON_EVENTSEL_USR;
269 if (!hw_event->exclude_kernel)
270 hwc->config |= ARCH_PERFMON_EVENTSEL_OS;
273 * If privileged enough, allow NMI events:
276 if (capable(CAP_SYS_ADMIN) && hw_event->nmi)
279 hwc->irq_period = hw_event->irq_period;
281 * Intel PMCs cannot be accessed sanely above 32 bit width,
282 * so we install an artificial 1<<31 period regardless of
283 * the generic counter period:
285 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
286 if ((s64)hwc->irq_period <= 0 || hwc->irq_period > 0x7FFFFFFF)
287 hwc->irq_period = 0x7FFFFFFF;
289 atomic64_set(&hwc->period_left, hwc->irq_period);
292 * Raw event type provide the config in the event structure
294 if (perf_event_raw(hw_event)) {
295 hwc->config |= x86_pmu.raw_event(perf_event_config(hw_event));
297 if (perf_event_id(hw_event) >= x86_pmu.max_events)
302 hwc->config |= x86_pmu.event_map(perf_event_id(hw_event));
305 counter->destroy = hw_perf_counter_destroy;
310 static u64 intel_pmu_save_disable_all(void)
314 rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
315 wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0);
320 static u64 amd_pmu_save_disable_all(void)
322 struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
325 enabled = cpuc->enabled;
328 * ensure we write the disable before we start disabling the
329 * counters proper, so that amd_pmu_enable_counter() does the
334 for (idx = 0; idx < x86_pmu.num_counters; idx++) {
337 if (!test_bit(idx, cpuc->active))
339 rdmsrl(MSR_K7_EVNTSEL0 + idx, val);
340 if (!(val & ARCH_PERFMON_EVENTSEL0_ENABLE))
342 val &= ~ARCH_PERFMON_EVENTSEL0_ENABLE;
343 wrmsrl(MSR_K7_EVNTSEL0 + idx, val);
349 u64 hw_perf_save_disable(void)
351 if (unlikely(!perf_counters_initialized))
354 return x86_pmu.save_disable_all();
357 * Exported because of ACPI idle
359 EXPORT_SYMBOL_GPL(hw_perf_save_disable);
361 static void intel_pmu_restore_all(u64 ctrl)
363 wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
366 static void amd_pmu_restore_all(u64 ctrl)
368 struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
371 cpuc->enabled = ctrl;
376 for (idx = 0; idx < x86_pmu.num_counters; idx++) {
379 if (!test_bit(idx, cpuc->active))
381 rdmsrl(MSR_K7_EVNTSEL0 + idx, val);
382 if (val & ARCH_PERFMON_EVENTSEL0_ENABLE)
384 val |= ARCH_PERFMON_EVENTSEL0_ENABLE;
385 wrmsrl(MSR_K7_EVNTSEL0 + idx, val);
389 void hw_perf_restore(u64 ctrl)
391 if (unlikely(!perf_counters_initialized))
394 x86_pmu.restore_all(ctrl);
397 * Exported because of ACPI idle
399 EXPORT_SYMBOL_GPL(hw_perf_restore);
401 static inline u64 intel_pmu_get_status(u64 mask)
405 if (unlikely(!perf_counters_initialized))
407 rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
412 static inline void intel_pmu_ack_status(u64 ack)
414 wrmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, ack);
417 static void intel_pmu_enable_counter(int idx, u64 config)
419 wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + idx,
420 config | ARCH_PERFMON_EVENTSEL0_ENABLE);
423 static void amd_pmu_enable_counter(int idx, u64 config)
425 struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
427 set_bit(idx, cpuc->active);
429 config |= ARCH_PERFMON_EVENTSEL0_ENABLE;
431 wrmsrl(MSR_K7_EVNTSEL0 + idx, config);
434 static void hw_perf_enable(int idx, u64 config)
436 if (unlikely(!perf_counters_initialized))
439 x86_pmu.enable(idx, config);
442 static void intel_pmu_disable_counter(int idx, u64 config)
444 wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + idx, config);
447 static void amd_pmu_disable_counter(int idx, u64 config)
449 struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
451 clear_bit(idx, cpuc->active);
452 wrmsrl(MSR_K7_EVNTSEL0 + idx, config);
456 static void hw_perf_disable(int idx, u64 config)
458 if (unlikely(!perf_counters_initialized))
461 x86_pmu.disable(idx, config);
465 __pmc_fixed_disable(struct perf_counter *counter,
466 struct hw_perf_counter *hwc, unsigned int __idx)
468 int idx = __idx - X86_PMC_IDX_FIXED;
472 mask = 0xfULL << (idx * 4);
474 rdmsrl(hwc->config_base, ctrl_val);
476 err = checking_wrmsrl(hwc->config_base, ctrl_val);
480 __x86_pmu_disable(struct perf_counter *counter,
481 struct hw_perf_counter *hwc, unsigned int idx)
483 if (unlikely(hwc->config_base == MSR_ARCH_PERFMON_FIXED_CTR_CTRL))
484 __pmc_fixed_disable(counter, hwc, idx);
486 hw_perf_disable(idx, hwc->config);
489 static DEFINE_PER_CPU(u64, prev_left[X86_PMC_IDX_MAX]);
492 * Set the next IRQ period, based on the hwc->period_left value.
493 * To be called with the counter disabled in hw:
496 x86_perf_counter_set_period(struct perf_counter *counter,
497 struct hw_perf_counter *hwc, int idx)
499 s64 left = atomic64_read(&hwc->period_left);
500 s64 period = hwc->irq_period;
504 * If we are way outside a reasoable range then just skip forward:
506 if (unlikely(left <= -period)) {
508 atomic64_set(&hwc->period_left, left);
511 if (unlikely(left <= 0)) {
513 atomic64_set(&hwc->period_left, left);
516 per_cpu(prev_left[idx], smp_processor_id()) = left;
519 * The hw counter starts counting from this counter offset,
520 * mark it to be able to extra future deltas:
522 atomic64_set(&hwc->prev_count, (u64)-left);
524 err = checking_wrmsrl(hwc->counter_base + idx,
525 (u64)(-left) & x86_pmu.counter_mask);
529 __pmc_fixed_enable(struct perf_counter *counter,
530 struct hw_perf_counter *hwc, unsigned int __idx)
532 int idx = __idx - X86_PMC_IDX_FIXED;
533 u64 ctrl_val, bits, mask;
537 * Enable IRQ generation (0x8),
538 * and enable ring-3 counting (0x2) and ring-0 counting (0x1)
542 if (hwc->config & ARCH_PERFMON_EVENTSEL_USR)
544 if (hwc->config & ARCH_PERFMON_EVENTSEL_OS)
547 mask = 0xfULL << (idx * 4);
549 rdmsrl(hwc->config_base, ctrl_val);
552 err = checking_wrmsrl(hwc->config_base, ctrl_val);
556 __x86_pmu_enable(struct perf_counter *counter,
557 struct hw_perf_counter *hwc, int idx)
559 if (unlikely(hwc->config_base == MSR_ARCH_PERFMON_FIXED_CTR_CTRL))
560 __pmc_fixed_enable(counter, hwc, idx);
562 hw_perf_enable(idx, hwc->config);
566 fixed_mode_idx(struct perf_counter *counter, struct hw_perf_counter *hwc)
570 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
573 if (unlikely(hwc->nmi))
576 event = hwc->config & ARCH_PERFMON_EVENT_MASK;
578 if (unlikely(event == x86_pmu.event_map(PERF_COUNT_INSTRUCTIONS)))
579 return X86_PMC_IDX_FIXED_INSTRUCTIONS;
580 if (unlikely(event == x86_pmu.event_map(PERF_COUNT_CPU_CYCLES)))
581 return X86_PMC_IDX_FIXED_CPU_CYCLES;
582 if (unlikely(event == x86_pmu.event_map(PERF_COUNT_BUS_CYCLES)))
583 return X86_PMC_IDX_FIXED_BUS_CYCLES;
589 * Find a PMC slot for the freshly enabled / scheduled in counter:
591 static int x86_pmu_enable(struct perf_counter *counter)
593 struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
594 struct hw_perf_counter *hwc = &counter->hw;
597 idx = fixed_mode_idx(counter, hwc);
600 * Try to get the fixed counter, if that is already taken
601 * then try to get a generic counter:
603 if (test_and_set_bit(idx, cpuc->used))
606 hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
608 * We set it so that counter_base + idx in wrmsr/rdmsr maps to
609 * MSR_ARCH_PERFMON_FIXED_CTR0 ... CTR2:
612 MSR_ARCH_PERFMON_FIXED_CTR0 - X86_PMC_IDX_FIXED;
616 /* Try to get the previous generic counter again */
617 if (test_and_set_bit(idx, cpuc->used)) {
619 idx = find_first_zero_bit(cpuc->used,
620 x86_pmu.num_counters);
621 if (idx == x86_pmu.num_counters)
624 set_bit(idx, cpuc->used);
627 hwc->config_base = x86_pmu.eventsel;
628 hwc->counter_base = x86_pmu.perfctr;
631 perf_counters_lapic_init(hwc->nmi);
633 __x86_pmu_disable(counter, hwc, idx);
635 cpuc->counters[idx] = counter;
637 * Make it visible before enabling the hw:
641 x86_perf_counter_set_period(counter, hwc, idx);
642 __x86_pmu_enable(counter, hwc, idx);
647 void perf_counter_print_debug(void)
649 u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
650 struct cpu_hw_counters *cpuc;
653 if (!x86_pmu.num_counters)
658 cpu = smp_processor_id();
659 cpuc = &per_cpu(cpu_hw_counters, cpu);
661 if (x86_pmu.version >= 2) {
662 rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
663 rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
664 rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
665 rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed);
668 pr_info("CPU#%d: ctrl: %016llx\n", cpu, ctrl);
669 pr_info("CPU#%d: status: %016llx\n", cpu, status);
670 pr_info("CPU#%d: overflow: %016llx\n", cpu, overflow);
671 pr_info("CPU#%d: fixed: %016llx\n", cpu, fixed);
673 pr_info("CPU#%d: used: %016llx\n", cpu, *(u64 *)cpuc->used);
675 for (idx = 0; idx < x86_pmu.num_counters; idx++) {
676 rdmsrl(x86_pmu.eventsel + idx, pmc_ctrl);
677 rdmsrl(x86_pmu.perfctr + idx, pmc_count);
679 prev_left = per_cpu(prev_left[idx], cpu);
681 pr_info("CPU#%d: gen-PMC%d ctrl: %016llx\n",
683 pr_info("CPU#%d: gen-PMC%d count: %016llx\n",
684 cpu, idx, pmc_count);
685 pr_info("CPU#%d: gen-PMC%d left: %016llx\n",
686 cpu, idx, prev_left);
688 for (idx = 0; idx < x86_pmu.num_counters_fixed; idx++) {
689 rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, pmc_count);
691 pr_info("CPU#%d: fixed-PMC%d count: %016llx\n",
692 cpu, idx, pmc_count);
697 static void x86_pmu_disable(struct perf_counter *counter)
699 struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
700 struct hw_perf_counter *hwc = &counter->hw;
701 unsigned int idx = hwc->idx;
703 __x86_pmu_disable(counter, hwc, idx);
705 clear_bit(idx, cpuc->used);
706 cpuc->counters[idx] = NULL;
708 * Make sure the cleared pointer becomes visible before we
709 * (potentially) free the counter:
714 * Drain the remaining delta count out of a counter
715 * that we are disabling:
717 x86_perf_counter_update(counter, hwc, idx);
721 * Save and restart an expired counter. Called by NMI contexts,
722 * so it has to be careful about preempting normal counter ops:
724 static void intel_pmu_save_and_restart(struct perf_counter *counter)
726 struct hw_perf_counter *hwc = &counter->hw;
729 x86_perf_counter_update(counter, hwc, idx);
730 x86_perf_counter_set_period(counter, hwc, idx);
732 if (counter->state == PERF_COUNTER_STATE_ACTIVE)
733 __x86_pmu_enable(counter, hwc, idx);
737 * Maximum interrupt frequency of 100KHz per CPU
739 #define PERFMON_MAX_INTERRUPTS (100000/HZ)
742 * This handler is triggered by the local APIC, so the APIC IRQ handling
745 static int intel_pmu_handle_irq(struct pt_regs *regs, int nmi)
747 int bit, cpu = smp_processor_id();
749 struct cpu_hw_counters *cpuc = &per_cpu(cpu_hw_counters, cpu);
752 cpuc->throttle_ctrl = intel_pmu_save_disable_all();
754 status = intel_pmu_get_status(cpuc->throttle_ctrl);
760 inc_irq_stat(apic_perf_irqs);
762 for_each_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {
763 struct perf_counter *counter = cpuc->counters[bit];
765 clear_bit(bit, (unsigned long *) &status);
769 intel_pmu_save_and_restart(counter);
770 if (perf_counter_overflow(counter, nmi, regs, 0))
771 __x86_pmu_disable(counter, &counter->hw, bit);
774 intel_pmu_ack_status(ack);
777 * Repeat if there is more work to be done:
779 status = intel_pmu_get_status(cpuc->throttle_ctrl);
784 * Restore - do not reenable when global enable is off or throttled:
786 if (++cpuc->interrupts < PERFMON_MAX_INTERRUPTS)
787 intel_pmu_restore_all(cpuc->throttle_ctrl);
792 static int amd_pmu_handle_irq(struct pt_regs *regs, int nmi) { return 0; }
794 void perf_counter_unthrottle(void)
796 struct cpu_hw_counters *cpuc;
798 if (!cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
801 if (unlikely(!perf_counters_initialized))
804 cpuc = &__get_cpu_var(cpu_hw_counters);
805 if (cpuc->interrupts >= PERFMON_MAX_INTERRUPTS) {
806 if (printk_ratelimit())
807 printk(KERN_WARNING "PERFMON: max interrupts exceeded!\n");
808 hw_perf_restore(cpuc->throttle_ctrl);
810 cpuc->interrupts = 0;
813 void smp_perf_counter_interrupt(struct pt_regs *regs)
816 apic_write(APIC_LVTPC, LOCAL_PERF_VECTOR);
818 x86_pmu.handle_irq(regs, 0);
822 void smp_perf_pending_interrupt(struct pt_regs *regs)
826 inc_irq_stat(apic_pending_irqs);
827 perf_counter_do_pending();
831 void set_perf_counter_pending(void)
833 apic->send_IPI_self(LOCAL_PENDING_VECTOR);
836 void perf_counters_lapic_init(int nmi)
840 if (!perf_counters_initialized)
843 * Enable the performance counter vector in the APIC LVT:
845 apic_val = apic_read(APIC_LVTERR);
847 apic_write(APIC_LVTERR, apic_val | APIC_LVT_MASKED);
849 apic_write(APIC_LVTPC, APIC_DM_NMI);
851 apic_write(APIC_LVTPC, LOCAL_PERF_VECTOR);
852 apic_write(APIC_LVTERR, apic_val);
856 perf_counter_nmi_handler(struct notifier_block *self,
857 unsigned long cmd, void *__args)
859 struct die_args *args = __args;
860 struct pt_regs *regs;
874 apic_write(APIC_LVTPC, APIC_DM_NMI);
875 ret = x86_pmu.handle_irq(regs, 1);
877 return ret ? NOTIFY_STOP : NOTIFY_OK;
880 static __read_mostly struct notifier_block perf_counter_nmi_notifier = {
881 .notifier_call = perf_counter_nmi_handler,
886 static struct x86_pmu intel_pmu = {
888 .handle_irq = intel_pmu_handle_irq,
889 .save_disable_all = intel_pmu_save_disable_all,
890 .restore_all = intel_pmu_restore_all,
891 .enable = intel_pmu_enable_counter,
892 .disable = intel_pmu_disable_counter,
893 .eventsel = MSR_ARCH_PERFMON_EVENTSEL0,
894 .perfctr = MSR_ARCH_PERFMON_PERFCTR0,
895 .event_map = intel_pmu_event_map,
896 .raw_event = intel_pmu_raw_event,
897 .max_events = ARRAY_SIZE(intel_perfmon_event_map),
900 static struct x86_pmu amd_pmu = {
902 .handle_irq = amd_pmu_handle_irq,
903 .save_disable_all = amd_pmu_save_disable_all,
904 .restore_all = amd_pmu_restore_all,
905 .enable = amd_pmu_enable_counter,
906 .disable = amd_pmu_disable_counter,
907 .eventsel = MSR_K7_EVNTSEL0,
908 .perfctr = MSR_K7_PERFCTR0,
909 .event_map = amd_pmu_event_map,
910 .raw_event = amd_pmu_raw_event,
911 .max_events = ARRAY_SIZE(amd_perfmon_event_map),
914 .counter_mask = (1ULL << 48) - 1,
917 static int intel_pmu_init(void)
919 union cpuid10_edx edx;
920 union cpuid10_eax eax;
925 if (!cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
929 * Check whether the Architectural PerfMon supports
930 * Branch Misses Retired Event or not.
932 cpuid(10, &eax.full, &ebx, &unused, &edx.full);
933 if (eax.split.mask_length <= ARCH_PERFMON_BRANCH_MISSES_RETIRED)
936 version = eax.split.version_id;
941 x86_pmu.version = version;
942 x86_pmu.num_counters = eax.split.num_counters;
943 x86_pmu.num_counters_fixed = edx.split.num_counters_fixed;
944 x86_pmu.counter_bits = eax.split.bit_width;
945 x86_pmu.counter_mask = (1ULL << eax.split.bit_width) - 1;
950 static int amd_pmu_init(void)
956 void __init init_hw_perf_counters(void)
960 switch (boot_cpu_data.x86_vendor) {
961 case X86_VENDOR_INTEL:
962 err = intel_pmu_init();
965 err = amd_pmu_init();
973 pr_info("%s Performance Monitoring support detected.\n", x86_pmu.name);
974 pr_info("... version: %d\n", x86_pmu.version);
975 pr_info("... bit width: %d\n", x86_pmu.counter_bits);
977 pr_info("... num counters: %d\n", x86_pmu.num_counters);
978 if (x86_pmu.num_counters > X86_PMC_MAX_GENERIC) {
979 x86_pmu.num_counters = X86_PMC_MAX_GENERIC;
980 WARN(1, KERN_ERR "hw perf counters %d > max(%d), clipping!",
981 x86_pmu.num_counters, X86_PMC_MAX_GENERIC);
983 perf_counter_mask = (1 << x86_pmu.num_counters) - 1;
984 perf_max_counters = x86_pmu.num_counters;
986 pr_info("... value mask: %016Lx\n", x86_pmu.counter_mask);
988 if (x86_pmu.num_counters_fixed > X86_PMC_MAX_FIXED) {
989 x86_pmu.num_counters_fixed = X86_PMC_MAX_FIXED;
990 WARN(1, KERN_ERR "hw perf counters fixed %d > max(%d), clipping!",
991 x86_pmu.num_counters_fixed, X86_PMC_MAX_FIXED);
993 pr_info("... fixed counters: %d\n", x86_pmu.num_counters_fixed);
996 ((1LL << x86_pmu.num_counters_fixed)-1) << X86_PMC_IDX_FIXED;
998 pr_info("... counter mask: %016Lx\n", perf_counter_mask);
999 perf_counters_initialized = true;
1001 perf_counters_lapic_init(0);
1002 register_die_notifier(&perf_counter_nmi_notifier);
1005 static inline void x86_pmu_read(struct perf_counter *counter)
1007 x86_perf_counter_update(counter, &counter->hw, counter->hw.idx);
1010 static const struct pmu pmu = {
1011 .enable = x86_pmu_enable,
1012 .disable = x86_pmu_disable,
1013 .read = x86_pmu_read,
1016 const struct pmu *hw_perf_counter_init(struct perf_counter *counter)
1020 err = __hw_perf_counter_init(counter);
1022 return ERR_PTR(err);
1032 void callchain_store(struct perf_callchain_entry *entry, unsigned long ip)
1034 if (entry->nr < MAX_STACK_DEPTH)
1035 entry->ip[entry->nr++] = ip;
1038 static DEFINE_PER_CPU(struct perf_callchain_entry, irq_entry);
1039 static DEFINE_PER_CPU(struct perf_callchain_entry, nmi_entry);
1043 backtrace_warning_symbol(void *data, char *msg, unsigned long symbol)
1045 /* Ignore warnings */
1048 static void backtrace_warning(void *data, char *msg)
1050 /* Ignore warnings */
1053 static int backtrace_stack(void *data, char *name)
1055 /* Don't bother with IRQ stacks for now */
1059 static void backtrace_address(void *data, unsigned long addr, int reliable)
1061 struct perf_callchain_entry *entry = data;
1064 callchain_store(entry, addr);
1067 static const struct stacktrace_ops backtrace_ops = {
1068 .warning = backtrace_warning,
1069 .warning_symbol = backtrace_warning_symbol,
1070 .stack = backtrace_stack,
1071 .address = backtrace_address,
1075 perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry)
1081 callchain_store(entry, instruction_pointer(regs));
1083 stack = ((char *)regs + sizeof(struct pt_regs));
1084 #ifdef CONFIG_FRAME_POINTER
1085 bp = frame_pointer(regs);
1090 dump_trace(NULL, regs, (void *)stack, bp, &backtrace_ops, entry);
1092 entry->kernel = entry->nr - nr;
1096 struct stack_frame {
1097 const void __user *next_fp;
1098 unsigned long return_address;
1101 static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
1105 if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))
1109 pagefault_disable();
1110 if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
1118 perf_callchain_user(struct pt_regs *regs, struct perf_callchain_entry *entry)
1120 struct stack_frame frame;
1121 const void __user *fp;
1124 regs = (struct pt_regs *)current->thread.sp0 - 1;
1125 fp = (void __user *)regs->bp;
1127 callchain_store(entry, regs->ip);
1129 while (entry->nr < MAX_STACK_DEPTH) {
1130 frame.next_fp = NULL;
1131 frame.return_address = 0;
1133 if (!copy_stack_frame(fp, &frame))
1136 if ((unsigned long)fp < user_stack_pointer(regs))
1139 callchain_store(entry, frame.return_address);
1143 entry->user = entry->nr - nr;
1147 perf_do_callchain(struct pt_regs *regs, struct perf_callchain_entry *entry)
1154 is_user = user_mode(regs);
1156 if (!current || current->pid == 0)
1159 if (is_user && current->state != TASK_RUNNING)
1163 perf_callchain_kernel(regs, entry);
1166 perf_callchain_user(regs, entry);
1169 struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
1171 struct perf_callchain_entry *entry;
1174 entry = &__get_cpu_var(nmi_entry);
1176 entry = &__get_cpu_var(irq_entry);
1183 perf_do_callchain(regs, entry);