| /* |
| * Performance events x86 architecture code |
| * |
| * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> |
| * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar |
| * Copyright (C) 2009 Jaswinder Singh Rajput |
| * Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter |
| * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> |
| * Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com> |
| * Copyright (C) 2009 Google, Inc., Stephane Eranian |
| * |
| * For licencing details see kernel-base/COPYING |
| */ |
| |
| #include <linux/perf_event.h> |
| #include <linux/capability.h> |
| #include <linux/notifier.h> |
| #include <linux/hardirq.h> |
| #include <linux/kprobes.h> |
| #include <linux/module.h> |
| #include <linux/kdebug.h> |
| #include <linux/sched.h> |
| #include <linux/uaccess.h> |
| #include <linux/slab.h> |
| #include <linux/highmem.h> |
| #include <linux/cpu.h> |
| #include <linux/bitops.h> |
| |
| #include <asm/apic.h> |
| #include <asm/stacktrace.h> |
| #include <asm/nmi.h> |
| #include <asm/compat.h> |
| |
| #if 0 |
| #undef wrmsrl |
| #define wrmsrl(msr, val) \ |
| do { \ |
| trace_printk("wrmsrl(%lx, %lx)\n", (unsigned long)(msr),\ |
| (unsigned long)(val)); \ |
| native_write_msr((msr), (u32)((u64)(val)), \ |
| (u32)((u64)(val) >> 32)); \ |
| } while (0) |
| #endif |
| |
| /* |
| * best effort, GUP based copy_from_user() that assumes IRQ or NMI context |
| */ |
| static unsigned long |
| copy_from_user_nmi(void *to, const void __user *from, unsigned long n) |
| { |
| unsigned long offset, addr = (unsigned long)from; |
| int type = in_nmi() ? KM_NMI : KM_IRQ0; |
| unsigned long size, len = 0; |
| struct page *page; |
| void *map; |
| int ret; |
| |
| do { |
| ret = __get_user_pages_fast(addr, 1, 0, &page); |
| if (!ret) |
| break; |
| |
| offset = addr & (PAGE_SIZE - 1); |
| size = min(PAGE_SIZE - offset, n - len); |
| |
| map = kmap_atomic(page, type); |
| memcpy(to, map+offset, size); |
| kunmap_atomic(map, type); |
| put_page(page); |
| |
| len += size; |
| to += size; |
| addr += size; |
| |
| } while (len < n); |
| |
| return len; |
| } |
| |
| struct event_constraint { |
| union { |
| unsigned long idxmsk[BITS_TO_LONGS(X86_PMC_IDX_MAX)]; |
| u64 idxmsk64; |
| }; |
| u64 code; |
| u64 cmask; |
| int weight; |
| }; |
| |
| struct amd_nb { |
| int nb_id; /* NorthBridge id */ |
| int refcnt; /* reference count */ |
| struct perf_event *owners[X86_PMC_IDX_MAX]; |
| struct event_constraint event_constraints[X86_PMC_IDX_MAX]; |
| }; |
| |
| #define MAX_LBR_ENTRIES 16 |
| |
| struct cpu_hw_events { |
| /* |
| * Generic x86 PMC bits |
| */ |
| struct perf_event *events[X86_PMC_IDX_MAX]; /* in counter order */ |
| unsigned long active_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)]; |
| int enabled; |
| |
| int n_events; |
| int n_added; |
| int assign[X86_PMC_IDX_MAX]; /* event to counter assignment */ |
| u64 tags[X86_PMC_IDX_MAX]; |
| struct perf_event *event_list[X86_PMC_IDX_MAX]; /* in enabled order */ |
| |
| unsigned int group_flag; |
| |
| /* |
| * Intel DebugStore bits |
| */ |
| struct debug_store *ds; |
| u64 pebs_enabled; |
| |
| /* |
| * Intel LBR bits |
| */ |
| int lbr_users; |
| void *lbr_context; |
| struct perf_branch_stack lbr_stack; |
| struct perf_branch_entry lbr_entries[MAX_LBR_ENTRIES]; |
| |
| /* |
| * AMD specific bits |
| */ |
| struct amd_nb *amd_nb; |
| }; |
| |
| #define __EVENT_CONSTRAINT(c, n, m, w) {\ |
| { .idxmsk64 = (n) }, \ |
| .code = (c), \ |
| .cmask = (m), \ |
| .weight = (w), \ |
| } |
| |
| #define EVENT_CONSTRAINT(c, n, m) \ |
| __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n)) |
| |
| /* |
| * Constraint on the Event code. |
| */ |
| #define INTEL_EVENT_CONSTRAINT(c, n) \ |
| EVENT_CONSTRAINT(c, n, ARCH_PERFMON_EVENTSEL_EVENT) |
| |
| /* |
| * Constraint on the Event code + UMask + fixed-mask |
| * |
| * filter mask to validate fixed counter events. |
| * the following filters disqualify for fixed counters: |
| * - inv |
| * - edge |
| * - cnt-mask |
| * The other filters are supported by fixed counters. |
| * The any-thread option is supported starting with v3. |
| */ |
| #define FIXED_EVENT_CONSTRAINT(c, n) \ |
| EVENT_CONSTRAINT(c, (1ULL << (32+n)), X86_RAW_EVENT_MASK) |
| |
| /* |
| * Constraint on the Event code + UMask |
| */ |
| #define PEBS_EVENT_CONSTRAINT(c, n) \ |
| EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVENT_MASK) |
| |
| #define EVENT_CONSTRAINT_END \ |
| EVENT_CONSTRAINT(0, 0, 0) |
| |
| #define for_each_event_constraint(e, c) \ |
| for ((e) = (c); (e)->weight; (e)++) |
| |
| union perf_capabilities { |
| struct { |
| u64 lbr_format : 6; |
| u64 pebs_trap : 1; |
| u64 pebs_arch_reg : 1; |
| u64 pebs_format : 4; |
| u64 smm_freeze : 1; |
| }; |
| u64 capabilities; |
| }; |
| |
| /* |
| * struct x86_pmu - generic x86 pmu |
| */ |
| struct x86_pmu { |
| /* |
| * Generic x86 PMC bits |
| */ |
| const char *name; |
| int version; |
| int (*handle_irq)(struct pt_regs *); |
| void (*disable_all)(void); |
| void (*enable_all)(int added); |
| void (*enable)(struct perf_event *); |
| void (*disable)(struct perf_event *); |
| int (*hw_config)(struct perf_event *event); |
| int (*schedule_events)(struct cpu_hw_events *cpuc, int n, int *assign); |
| unsigned eventsel; |
| unsigned perfctr; |
| u64 (*event_map)(int); |
| int max_events; |
| int num_counters; |
| int num_counters_fixed; |
| int cntval_bits; |
| u64 cntval_mask; |
| int apic; |
| u64 max_period; |
| struct event_constraint * |
| (*get_event_constraints)(struct cpu_hw_events *cpuc, |
| struct perf_event *event); |
| |
| void (*put_event_constraints)(struct cpu_hw_events *cpuc, |
| struct perf_event *event); |
| struct event_constraint *event_constraints; |
| void (*quirks)(void); |
| |
| int (*cpu_prepare)(int cpu); |
| void (*cpu_starting)(int cpu); |
| void (*cpu_dying)(int cpu); |
| void (*cpu_dead)(int cpu); |
| |
| /* |
| * Intel Arch Perfmon v2+ |
| */ |
| u64 intel_ctrl; |
| union perf_capabilities intel_cap; |
| |
| /* |
| * Intel DebugStore bits |
| */ |
| int bts, pebs; |
| int pebs_record_size; |
| void (*drain_pebs)(struct pt_regs *regs); |
| struct event_constraint *pebs_constraints; |
| |
| /* |
| * Intel LBR |
| */ |
| unsigned long lbr_tos, lbr_from, lbr_to; /* MSR base regs */ |
| int lbr_nr; /* hardware stack size */ |
| }; |
| |
| static struct x86_pmu x86_pmu __read_mostly; |
| |
| static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = { |
| .enabled = 1, |
| }; |
| |
| static int x86_perf_event_set_period(struct perf_event *event); |
| |
| /* |
| * Generalized hw caching related hw_event table, filled |
| * in on a per model basis. A value of 0 means |
| * 'not supported', -1 means 'hw_event makes no sense on |
| * this CPU', any other value means the raw hw_event |
| * ID. |
| */ |
| |
| #define C(x) PERF_COUNT_HW_CACHE_##x |
| |
| static u64 __read_mostly hw_cache_event_ids |
| [PERF_COUNT_HW_CACHE_MAX] |
| [PERF_COUNT_HW_CACHE_OP_MAX] |
| [PERF_COUNT_HW_CACHE_RESULT_MAX]; |
| |
| /* |
| * Propagate event elapsed time into the generic event. |
| * Can only be executed on the CPU where the event is active. |
| * Returns the delta events processed. |
| */ |
| static u64 |
| x86_perf_event_update(struct perf_event *event) |
| { |
| struct hw_perf_event *hwc = &event->hw; |
| int shift = 64 - x86_pmu.cntval_bits; |
| u64 prev_raw_count, new_raw_count; |
| int idx = hwc->idx; |
| s64 delta; |
| |
| if (idx == X86_PMC_IDX_FIXED_BTS) |
| return 0; |
| |
| /* |
| * Careful: an NMI might modify the previous event value. |
| * |
| * Our tactic to handle this is to first atomically read and |
| * exchange a new raw count - then add that new-prev delta |
| * count to the generic event atomically: |
| */ |
| again: |
| prev_raw_count = atomic64_read(&hwc->prev_count); |
| rdmsrl(hwc->event_base + idx, new_raw_count); |
| |
| if (atomic64_cmpxchg(&hwc->prev_count, prev_raw_count, |
| new_raw_count) != prev_raw_count) |
| goto again; |
| |
| /* |
| * Now we have the new raw value and have updated the prev |
| * timestamp already. We can now calculate the elapsed delta |
| * (event-)time and add that to the generic event. |
| * |
| * Careful, not all hw sign-extends above the physical width |
| * of the count. |
| */ |
| delta = (new_raw_count << shift) - (prev_raw_count << shift); |
| delta >>= shift; |
| |
| atomic64_add(delta, &event->count); |
| atomic64_sub(delta, &hwc->period_left); |
| |
| return new_raw_count; |
| } |
| |
| static atomic_t active_events; |
| static DEFINE_MUTEX(pmc_reserve_mutex); |
| |
| #ifdef CONFIG_X86_LOCAL_APIC |
| |
| static bool reserve_pmc_hardware(void) |
| { |
| int i; |
| |
| if (nmi_watchdog == NMI_LOCAL_APIC) |
| disable_lapic_nmi_watchdog(); |
| |
| for (i = 0; i < x86_pmu.num_counters; i++) { |
| if (!reserve_perfctr_nmi(x86_pmu.perfctr + i)) |
| goto perfctr_fail; |
| } |
| |
| for (i = 0; i < x86_pmu.num_counters; i++) { |
| if (!reserve_evntsel_nmi(x86_pmu.eventsel + i)) |
| goto eventsel_fail; |
| } |
| |
| return true; |
| |
| eventsel_fail: |
| for (i--; i >= 0; i--) |
| release_evntsel_nmi(x86_pmu.eventsel + i); |
| |
| i = x86_pmu.num_counters; |
| |
| perfctr_fail: |
| for (i--; i >= 0; i--) |
| release_perfctr_nmi(x86_pmu.perfctr + i); |
| |
| if (nmi_watchdog == NMI_LOCAL_APIC) |
| enable_lapic_nmi_watchdog(); |
| |
| return false; |
| } |
| |
| static void release_pmc_hardware(void) |
| { |
| int i; |
| |
| for (i = 0; i < x86_pmu.num_counters; i++) { |
| release_perfctr_nmi(x86_pmu.perfctr + i); |
| release_evntsel_nmi(x86_pmu.eventsel + i); |
| } |
| |
| if (nmi_watchdog == NMI_LOCAL_APIC) |
| enable_lapic_nmi_watchdog(); |
| } |
| |
| #else |
| |
| static bool reserve_pmc_hardware(void) { return true; } |
| static void release_pmc_hardware(void) {} |
| |
| #endif |
| |
| static int reserve_ds_buffers(void); |
| static void release_ds_buffers(void); |
| |
| static void hw_perf_event_destroy(struct perf_event *event) |
| { |
| if (atomic_dec_and_mutex_lock(&active_events, &pmc_reserve_mutex)) { |
| release_pmc_hardware(); |
| release_ds_buffers(); |
| mutex_unlock(&pmc_reserve_mutex); |
| } |
| } |
| |
| static inline int x86_pmu_initialized(void) |
| { |
| return x86_pmu.handle_irq != NULL; |
| } |
| |
| static inline int |
| set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event_attr *attr) |
| { |
| unsigned int cache_type, cache_op, cache_result; |
| u64 config, val; |
| |
| config = attr->config; |
| |
| cache_type = (config >> 0) & 0xff; |
| if (cache_type >= PERF_COUNT_HW_CACHE_MAX) |
| return -EINVAL; |
| |
| cache_op = (config >> 8) & 0xff; |
| if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX) |
| return -EINVAL; |
| |
| cache_result = (config >> 16) & 0xff; |
| if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX) |
| return -EINVAL; |
| |
| val = hw_cache_event_ids[cache_type][cache_op][cache_result]; |
| |
| if (val == 0) |
| return -ENOENT; |
| |
| if (val == -1) |
| return -EINVAL; |
| |
| hwc->config |= val; |
| |
| return 0; |
| } |
| |
| static int x86_setup_perfctr(struct perf_event *event) |
| { |
| struct perf_event_attr *attr = &event->attr; |
| struct hw_perf_event *hwc = &event->hw; |
| u64 config; |
| |
| if (!hwc->sample_period) { |
| hwc->sample_period = x86_pmu.max_period; |
| hwc->last_period = hwc->sample_period; |
| atomic64_set(&hwc->period_left, hwc->sample_period); |
| } else { |
| /* |
| * If we have a PMU initialized but no APIC |
| * interrupts, we cannot sample hardware |
| * events (user-space has to fall back and |
| * sample via a hrtimer based software event): |
| */ |
| if (!x86_pmu.apic) |
| return -EOPNOTSUPP; |
| } |
| |
| if (attr->type == PERF_TYPE_RAW) |
| return 0; |
| |
| if (attr->type == PERF_TYPE_HW_CACHE) |
| return set_ext_hw_attr(hwc, attr); |
| |
| if (attr->config >= x86_pmu.max_events) |
| return -EINVAL; |
| |
| /* |
| * The generic map: |
| */ |
| config = x86_pmu.event_map(attr->config); |
| |
| if (config == 0) |
| return -ENOENT; |
| |
| if (config == -1LL) |
| return -EINVAL; |
| |
| /* |
| * Branch tracing: |
| */ |
| if ((attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) && |
| (hwc->sample_period == 1)) { |
| /* BTS is not supported by this architecture. */ |
| if (!x86_pmu.bts) |
| return -EOPNOTSUPP; |
| |
| /* BTS is currently only allowed for user-mode. */ |
| if (!attr->exclude_kernel) |
| return -EOPNOTSUPP; |
| } |
| |
| hwc->config |= config; |
| |
| return 0; |
| } |
| |
| static int x86_pmu_hw_config(struct perf_event *event) |
| { |
| if (event->attr.precise_ip) { |
| int precise = 0; |
| |
| /* Support for constant skid */ |
| if (x86_pmu.pebs) |
| precise++; |
| |
| /* Support for IP fixup */ |
| if (x86_pmu.lbr_nr) |
| precise++; |
| |
| if (event->attr.precise_ip > precise) |
| return -EOPNOTSUPP; |
| } |
| |
| /* |
| * Generate PMC IRQs: |
| * (keep 'enabled' bit clear for now) |
| */ |
| event->hw.config = ARCH_PERFMON_EVENTSEL_INT; |
| |
| /* |
| * Count user and OS events unless requested not to |
| */ |
| if (!event->attr.exclude_user) |
| event->hw.config |= ARCH_PERFMON_EVENTSEL_USR; |
| if (!event->attr.exclude_kernel) |
| event->hw.config |= ARCH_PERFMON_EVENTSEL_OS; |
| |
| if (event->attr.type == PERF_TYPE_RAW) |
| event->hw.config |= event->attr.config & X86_RAW_EVENT_MASK; |
| |
| return x86_setup_perfctr(event); |
| } |
| |
| /* |
| * Setup the hardware configuration for a given attr_type |
| */ |
| static int __hw_perf_event_init(struct perf_event *event) |
| { |
| int err; |
| |
| if (!x86_pmu_initialized()) |
| return -ENODEV; |
| |
| err = 0; |
| if (!atomic_inc_not_zero(&active_events)) { |
| mutex_lock(&pmc_reserve_mutex); |
| if (atomic_read(&active_events) == 0) { |
| if (!reserve_pmc_hardware()) |
| err = -EBUSY; |
| else { |
| err = reserve_ds_buffers(); |
| if (err) |
| release_pmc_hardware(); |
| } |
| } |
| if (!err) |
| atomic_inc(&active_events); |
| mutex_unlock(&pmc_reserve_mutex); |
| } |
| if (err) |
| return err; |
| |
| event->destroy = hw_perf_event_destroy; |
| |
| event->hw.idx = -1; |
| event->hw.last_cpu = -1; |
| event->hw.last_tag = ~0ULL; |
| |
| return x86_pmu.hw_config(event); |
| } |
| |
| static void x86_pmu_disable_all(void) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| int idx; |
| |
| for (idx = 0; idx < x86_pmu.num_counters; idx++) { |
| u64 val; |
| |
| if (!test_bit(idx, cpuc->active_mask)) |
| continue; |
| rdmsrl(x86_pmu.eventsel + idx, val); |
| if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE)) |
| continue; |
| val &= ~ARCH_PERFMON_EVENTSEL_ENABLE; |
| wrmsrl(x86_pmu.eventsel + idx, val); |
| } |
| } |
| |
| void hw_perf_disable(void) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| |
| if (!x86_pmu_initialized()) |
| return; |
| |
| if (!cpuc->enabled) |
| return; |
| |
| cpuc->n_added = 0; |
| cpuc->enabled = 0; |
| barrier(); |
| |
| x86_pmu.disable_all(); |
| } |
| |
| static void x86_pmu_enable_all(int added) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| int idx; |
| |
| for (idx = 0; idx < x86_pmu.num_counters; idx++) { |
| struct perf_event *event = cpuc->events[idx]; |
| u64 val; |
| |
| if (!test_bit(idx, cpuc->active_mask)) |
| continue; |
| |
| val = event->hw.config; |
| val |= ARCH_PERFMON_EVENTSEL_ENABLE; |
| wrmsrl(x86_pmu.eventsel + idx, val); |
| } |
| } |
| |
| static const struct pmu pmu; |
| |
| static inline int is_x86_event(struct perf_event *event) |
| { |
| return event->pmu == &pmu; |
| } |
| |
| static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign) |
| { |
| struct event_constraint *c, *constraints[X86_PMC_IDX_MAX]; |
| unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)]; |
| int i, j, w, wmax, num = 0; |
| struct hw_perf_event *hwc; |
| |
| bitmap_zero(used_mask, X86_PMC_IDX_MAX); |
| |
| for (i = 0; i < n; i++) { |
| c = x86_pmu.get_event_constraints(cpuc, cpuc->event_list[i]); |
| constraints[i] = c; |
| } |
| |
| /* |
| * fastpath, try to reuse previous register |
| */ |
| for (i = 0; i < n; i++) { |
| hwc = &cpuc->event_list[i]->hw; |
| c = constraints[i]; |
| |
| /* never assigned */ |
| if (hwc->idx == -1) |
| break; |
| |
| /* constraint still honored */ |
| if (!test_bit(hwc->idx, c->idxmsk)) |
| break; |
| |
| /* not already used */ |
| if (test_bit(hwc->idx, used_mask)) |
| break; |
| |
| __set_bit(hwc->idx, used_mask); |
| if (assign) |
| assign[i] = hwc->idx; |
| } |
| if (i == n) |
| goto done; |
| |
| /* |
| * begin slow path |
| */ |
| |
| bitmap_zero(used_mask, X86_PMC_IDX_MAX); |
| |
| /* |
| * weight = number of possible counters |
| * |
| * 1 = most constrained, only works on one counter |
| * wmax = least constrained, works on any counter |
| * |
| * assign events to counters starting with most |
| * constrained events. |
| */ |
| wmax = x86_pmu.num_counters; |
| |
| /* |
| * when fixed event counters are present, |
| * wmax is incremented by 1 to account |
| * for one more choice |
| */ |
| if (x86_pmu.num_counters_fixed) |
| wmax++; |
| |
| for (w = 1, num = n; num && w <= wmax; w++) { |
| /* for each event */ |
| for (i = 0; num && i < n; i++) { |
| c = constraints[i]; |
| hwc = &cpuc->event_list[i]->hw; |
| |
| if (c->weight != w) |
| continue; |
| |
| for_each_set_bit(j, c->idxmsk, X86_PMC_IDX_MAX) { |
| if (!test_bit(j, used_mask)) |
| break; |
| } |
| |
| if (j == X86_PMC_IDX_MAX) |
| break; |
| |
| __set_bit(j, used_mask); |
| |
| if (assign) |
| assign[i] = j; |
| num--; |
| } |
| } |
| done: |
| /* |
| * scheduling failed or is just a simulation, |
| * free resources if necessary |
| */ |
| if (!assign || num) { |
| for (i = 0; i < n; i++) { |
| if (x86_pmu.put_event_constraints) |
| x86_pmu.put_event_constraints(cpuc, cpuc->event_list[i]); |
| } |
| } |
| return num ? -ENOSPC : 0; |
| } |
| |
| /* |
| * dogrp: true if must collect siblings events (group) |
| * returns total number of events and error code |
| */ |
| static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp) |
| { |
| struct perf_event *event; |
| int n, max_count; |
| |
| max_count = x86_pmu.num_counters + x86_pmu.num_counters_fixed; |
| |
| /* current number of events already accepted */ |
| n = cpuc->n_events; |
| |
| if (is_x86_event(leader)) { |
| if (n >= max_count) |
| return -ENOSPC; |
| cpuc->event_list[n] = leader; |
| n++; |
| } |
| if (!dogrp) |
| return n; |
| |
| list_for_each_entry(event, &leader->sibling_list, group_entry) { |
| if (!is_x86_event(event) || |
| event->state <= PERF_EVENT_STATE_OFF) |
| continue; |
| |
| if (n >= max_count) |
| return -ENOSPC; |
| |
| cpuc->event_list[n] = event; |
| n++; |
| } |
| return n; |
| } |
| |
| static inline void x86_assign_hw_event(struct perf_event *event, |
| struct cpu_hw_events *cpuc, int i) |
| { |
| struct hw_perf_event *hwc = &event->hw; |
| |
| hwc->idx = cpuc->assign[i]; |
| hwc->last_cpu = smp_processor_id(); |
| hwc->last_tag = ++cpuc->tags[i]; |
| |
| if (hwc->idx == X86_PMC_IDX_FIXED_BTS) { |
| hwc->config_base = 0; |
| hwc->event_base = 0; |
| } else if (hwc->idx >= X86_PMC_IDX_FIXED) { |
| hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL; |
| /* |
| * We set it so that event_base + idx in wrmsr/rdmsr maps to |
| * MSR_ARCH_PERFMON_FIXED_CTR0 ... CTR2: |
| */ |
| hwc->event_base = |
| MSR_ARCH_PERFMON_FIXED_CTR0 - X86_PMC_IDX_FIXED; |
| } else { |
| hwc->config_base = x86_pmu.eventsel; |
| hwc->event_base = x86_pmu.perfctr; |
| } |
| } |
| |
| static inline int match_prev_assignment(struct hw_perf_event *hwc, |
| struct cpu_hw_events *cpuc, |
| int i) |
| { |
| return hwc->idx == cpuc->assign[i] && |
| hwc->last_cpu == smp_processor_id() && |
| hwc->last_tag == cpuc->tags[i]; |
| } |
| |
| static int x86_pmu_start(struct perf_event *event); |
| static void x86_pmu_stop(struct perf_event *event); |
| |
| void hw_perf_enable(void) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| struct perf_event *event; |
| struct hw_perf_event *hwc; |
| int i, added = cpuc->n_added; |
| |
| if (!x86_pmu_initialized()) |
| return; |
| |
| if (cpuc->enabled) |
| return; |
| |
| if (cpuc->n_added) { |
| int n_running = cpuc->n_events - cpuc->n_added; |
| /* |
| * apply assignment obtained either from |
| * hw_perf_group_sched_in() or x86_pmu_enable() |
| * |
| * step1: save events moving to new counters |
| * step2: reprogram moved events into new counters |
| */ |
| for (i = 0; i < n_running; i++) { |
| event = cpuc->event_list[i]; |
| hwc = &event->hw; |
| |
| /* |
| * we can avoid reprogramming counter if: |
| * - assigned same counter as last time |
| * - running on same CPU as last time |
| * - no other event has used the counter since |
| */ |
| if (hwc->idx == -1 || |
| match_prev_assignment(hwc, cpuc, i)) |
| continue; |
| |
| x86_pmu_stop(event); |
| } |
| |
| for (i = 0; i < cpuc->n_events; i++) { |
| event = cpuc->event_list[i]; |
| hwc = &event->hw; |
| |
| if (!match_prev_assignment(hwc, cpuc, i)) |
| x86_assign_hw_event(event, cpuc, i); |
| else if (i < n_running) |
| continue; |
| |
| x86_pmu_start(event); |
| } |
| cpuc->n_added = 0; |
| perf_events_lapic_init(); |
| } |
| |
| cpuc->enabled = 1; |
| barrier(); |
| |
| x86_pmu.enable_all(added); |
| } |
| |
| static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc, |
| u64 enable_mask) |
| { |
| wrmsrl(hwc->config_base + hwc->idx, hwc->config | enable_mask); |
| } |
| |
| static inline void x86_pmu_disable_event(struct perf_event *event) |
| { |
| struct hw_perf_event *hwc = &event->hw; |
| |
| wrmsrl(hwc->config_base + hwc->idx, hwc->config); |
| } |
| |
| static DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left); |
| |
| /* |
| * Set the next IRQ period, based on the hwc->period_left value. |
| * To be called with the event disabled in hw: |
| */ |
| static int |
| x86_perf_event_set_period(struct perf_event *event) |
| { |
| struct hw_perf_event *hwc = &event->hw; |
| s64 left = atomic64_read(&hwc->period_left); |
| s64 period = hwc->sample_period; |
| int ret = 0, idx = hwc->idx; |
| |
| if (idx == X86_PMC_IDX_FIXED_BTS) |
| return 0; |
| |
| /* |
| * If we are way outside a reasonable range then just skip forward: |
| */ |
| if (unlikely(left <= -period)) { |
| left = period; |
| atomic64_set(&hwc->period_left, left); |
| hwc->last_period = period; |
| ret = 1; |
| } |
| |
| if (unlikely(left <= 0)) { |
| left += period; |
| atomic64_set(&hwc->period_left, left); |
| hwc->last_period = period; |
| ret = 1; |
| } |
| /* |
| * Quirk: certain CPUs dont like it if just 1 hw_event is left: |
| */ |
| if (unlikely(left < 2)) |
| left = 2; |
| |
| if (left > x86_pmu.max_period) |
| left = x86_pmu.max_period; |
| |
| per_cpu(pmc_prev_left[idx], smp_processor_id()) = left; |
| |
| /* |
| * The hw event starts counting from this event offset, |
| * mark it to be able to extra future deltas: |
| */ |
| atomic64_set(&hwc->prev_count, (u64)-left); |
| |
| wrmsrl(hwc->event_base + idx, |
| (u64)(-left) & x86_pmu.cntval_mask); |
| |
| perf_event_update_userpage(event); |
| |
| return ret; |
| } |
| |
| static void x86_pmu_enable_event(struct perf_event *event) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| if (cpuc->enabled) |
| __x86_pmu_enable_event(&event->hw, |
| ARCH_PERFMON_EVENTSEL_ENABLE); |
| } |
| |
| /* |
| * activate a single event |
| * |
| * The event is added to the group of enabled events |
| * but only if it can be scehduled with existing events. |
| * |
| * Called with PMU disabled. If successful and return value 1, |
| * then guaranteed to call perf_enable() and hw_perf_enable() |
| */ |
| static int x86_pmu_enable(struct perf_event *event) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| struct hw_perf_event *hwc; |
| int assign[X86_PMC_IDX_MAX]; |
| int n, n0, ret; |
| |
| hwc = &event->hw; |
| |
| n0 = cpuc->n_events; |
| n = collect_events(cpuc, event, false); |
| if (n < 0) |
| return n; |
| |
| /* |
| * If group events scheduling transaction was started, |
| * skip the schedulability test here, it will be peformed |
| * at commit time(->commit_txn) as a whole |
| */ |
| if (cpuc->group_flag & PERF_EVENT_TXN_STARTED) |
| goto out; |
| |
| ret = x86_pmu.schedule_events(cpuc, n, assign); |
| if (ret) |
| return ret; |
| /* |
| * copy new assignment, now we know it is possible |
| * will be used by hw_perf_enable() |
| */ |
| memcpy(cpuc->assign, assign, n*sizeof(int)); |
| |
| out: |
| cpuc->n_events = n; |
| cpuc->n_added += n - n0; |
| |
| return 0; |
| } |
| |
| static int x86_pmu_start(struct perf_event *event) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| int idx = event->hw.idx; |
| |
| if (idx == -1) |
| return -EAGAIN; |
| |
| x86_perf_event_set_period(event); |
| cpuc->events[idx] = event; |
| __set_bit(idx, cpuc->active_mask); |
| x86_pmu.enable(event); |
| perf_event_update_userpage(event); |
| |
| return 0; |
| } |
| |
| static void x86_pmu_unthrottle(struct perf_event *event) |
| { |
| int ret = x86_pmu_start(event); |
| WARN_ON_ONCE(ret); |
| } |
| |
| void perf_event_print_debug(void) |
| { |
| u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed; |
| u64 pebs; |
| struct cpu_hw_events *cpuc; |
| unsigned long flags; |
| int cpu, idx; |
| |
| if (!x86_pmu.num_counters) |
| return; |
| |
| local_irq_save(flags); |
| |
| cpu = smp_processor_id(); |
| cpuc = &per_cpu(cpu_hw_events, cpu); |
| |
| if (x86_pmu.version >= 2) { |
| rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl); |
| rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status); |
| rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow); |
| rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed); |
| rdmsrl(MSR_IA32_PEBS_ENABLE, pebs); |
| |
| pr_info("\n"); |
| pr_info("CPU#%d: ctrl: %016llx\n", cpu, ctrl); |
| pr_info("CPU#%d: status: %016llx\n", cpu, status); |
| pr_info("CPU#%d: overflow: %016llx\n", cpu, overflow); |
| pr_info("CPU#%d: fixed: %016llx\n", cpu, fixed); |
| pr_info("CPU#%d: pebs: %016llx\n", cpu, pebs); |
| } |
| pr_info("CPU#%d: active: %016llx\n", cpu, *(u64 *)cpuc->active_mask); |
| |
| for (idx = 0; idx < x86_pmu.num_counters; idx++) { |
| rdmsrl(x86_pmu.eventsel + idx, pmc_ctrl); |
| rdmsrl(x86_pmu.perfctr + idx, pmc_count); |
| |
| prev_left = per_cpu(pmc_prev_left[idx], cpu); |
| |
| pr_info("CPU#%d: gen-PMC%d ctrl: %016llx\n", |
| cpu, idx, pmc_ctrl); |
| pr_info("CPU#%d: gen-PMC%d count: %016llx\n", |
| cpu, idx, pmc_count); |
| pr_info("CPU#%d: gen-PMC%d left: %016llx\n", |
| cpu, idx, prev_left); |
| } |
| for (idx = 0; idx < x86_pmu.num_counters_fixed; idx++) { |
| rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, pmc_count); |
| |
| pr_info("CPU#%d: fixed-PMC%d count: %016llx\n", |
| cpu, idx, pmc_count); |
| } |
| local_irq_restore(flags); |
| } |
| |
| static void x86_pmu_stop(struct perf_event *event) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| struct hw_perf_event *hwc = &event->hw; |
| int idx = hwc->idx; |
| |
| if (!__test_and_clear_bit(idx, cpuc->active_mask)) |
| return; |
| |
| x86_pmu.disable(event); |
| |
| /* |
| * Drain the remaining delta count out of a event |
| * that we are disabling: |
| */ |
| x86_perf_event_update(event); |
| |
| cpuc->events[idx] = NULL; |
| } |
| |
| static void x86_pmu_disable(struct perf_event *event) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| int i; |
| |
| x86_pmu_stop(event); |
| |
| for (i = 0; i < cpuc->n_events; i++) { |
| if (event == cpuc->event_list[i]) { |
| |
| if (x86_pmu.put_event_constraints) |
| x86_pmu.put_event_constraints(cpuc, event); |
| |
| while (++i < cpuc->n_events) |
| cpuc->event_list[i-1] = cpuc->event_list[i]; |
| |
| --cpuc->n_events; |
| break; |
| } |
| } |
| perf_event_update_userpage(event); |
| } |
| |
| static int x86_pmu_handle_irq(struct pt_regs *regs) |
| { |
| struct perf_sample_data data; |
| struct cpu_hw_events *cpuc; |
| struct perf_event *event; |
| struct hw_perf_event *hwc; |
| int idx, handled = 0; |
| u64 val; |
| |
| perf_sample_data_init(&data, 0); |
| |
| cpuc = &__get_cpu_var(cpu_hw_events); |
| |
| for (idx = 0; idx < x86_pmu.num_counters; idx++) { |
| if (!test_bit(idx, cpuc->active_mask)) |
| continue; |
| |
| event = cpuc->events[idx]; |
| hwc = &event->hw; |
| |
| val = x86_perf_event_update(event); |
| if (val & (1ULL << (x86_pmu.cntval_bits - 1))) |
| continue; |
| |
| /* |
| * event overflow |
| */ |
| handled = 1; |
| data.period = event->hw.last_period; |
| |
| if (!x86_perf_event_set_period(event)) |
| continue; |
| |
| if (perf_event_overflow(event, 1, &data, regs)) |
| x86_pmu_stop(event); |
| } |
| |
| if (handled) |
| inc_irq_stat(apic_perf_irqs); |
| |
| return handled; |
| } |
| |
| void smp_perf_pending_interrupt(struct pt_regs *regs) |
| { |
| irq_enter(); |
| ack_APIC_irq(); |
| inc_irq_stat(apic_pending_irqs); |
| perf_event_do_pending(); |
| irq_exit(); |
| } |
| |
| void set_perf_event_pending(void) |
| { |
| #ifdef CONFIG_X86_LOCAL_APIC |
| if (!x86_pmu.apic || !x86_pmu_initialized()) |
| return; |
| |
| apic->send_IPI_self(LOCAL_PENDING_VECTOR); |
| #endif |
| } |
| |
| void perf_events_lapic_init(void) |
| { |
| if (!x86_pmu.apic || !x86_pmu_initialized()) |
| return; |
| |
| /* |
| * Always use NMI for PMU |
| */ |
| apic_write(APIC_LVTPC, APIC_DM_NMI); |
| } |
| |
| static int __kprobes |
| perf_event_nmi_handler(struct notifier_block *self, |
| unsigned long cmd, void *__args) |
| { |
| struct die_args *args = __args; |
| struct pt_regs *regs; |
| |
| if (!atomic_read(&active_events)) |
| return NOTIFY_DONE; |
| |
| switch (cmd) { |
| case DIE_NMI: |
| case DIE_NMI_IPI: |
| break; |
| |
| default: |
| return NOTIFY_DONE; |
| } |
| |
| regs = args->regs; |
| |
| apic_write(APIC_LVTPC, APIC_DM_NMI); |
| /* |
| * Can't rely on the handled return value to say it was our NMI, two |
| * events could trigger 'simultaneously' raising two back-to-back NMIs. |
| * |
| * If the first NMI handles both, the latter will be empty and daze |
| * the CPU. |
| */ |
| x86_pmu.handle_irq(regs); |
| |
| return NOTIFY_STOP; |
| } |
| |
| static __read_mostly struct notifier_block perf_event_nmi_notifier = { |
| .notifier_call = perf_event_nmi_handler, |
| .next = NULL, |
| .priority = 1 |
| }; |
| |
| static struct event_constraint unconstrained; |
| static struct event_constraint emptyconstraint; |
| |
| static struct event_constraint * |
| x86_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event) |
| { |
| struct event_constraint *c; |
| |
| if (x86_pmu.event_constraints) { |
| for_each_event_constraint(c, x86_pmu.event_constraints) { |
| if ((event->hw.config & c->cmask) == c->code) |
| return c; |
| } |
| } |
| |
| return &unconstrained; |
| } |
| |
| #include "perf_event_amd.c" |
| #include "perf_event_p6.c" |
| #include "perf_event_p4.c" |
| #include "perf_event_intel_lbr.c" |
| #include "perf_event_intel_ds.c" |
| #include "perf_event_intel.c" |
| |
| static int __cpuinit |
| x86_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu) |
| { |
| unsigned int cpu = (long)hcpu; |
| int ret = NOTIFY_OK; |
| |
| switch (action & ~CPU_TASKS_FROZEN) { |
| case CPU_UP_PREPARE: |
| if (x86_pmu.cpu_prepare) |
| ret = x86_pmu.cpu_prepare(cpu); |
| break; |
| |
| case CPU_STARTING: |
| if (x86_pmu.cpu_starting) |
| x86_pmu.cpu_starting(cpu); |
| break; |
| |
| case CPU_DYING: |
| if (x86_pmu.cpu_dying) |
| x86_pmu.cpu_dying(cpu); |
| break; |
| |
| case CPU_UP_CANCELED: |
| case CPU_DEAD: |
| if (x86_pmu.cpu_dead) |
| x86_pmu.cpu_dead(cpu); |
| break; |
| |
| default: |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static void __init pmu_check_apic(void) |
| { |
| if (cpu_has_apic) |
| return; |
| |
| x86_pmu.apic = 0; |
| pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n"); |
| pr_info("no hardware sampling interrupt available.\n"); |
| } |
| |
| void __init init_hw_perf_events(void) |
| { |
| struct event_constraint *c; |
| int err; |
| |
| pr_info("Performance Events: "); |
| |
| switch (boot_cpu_data.x86_vendor) { |
| case X86_VENDOR_INTEL: |
| err = intel_pmu_init(); |
| break; |
| case X86_VENDOR_AMD: |
| err = amd_pmu_init(); |
| break; |
| default: |
| return; |
| } |
| if (err != 0) { |
| pr_cont("no PMU driver, software events only.\n"); |
| return; |
| } |
| |
| pmu_check_apic(); |
| |
| pr_cont("%s PMU driver.\n", x86_pmu.name); |
| |
| if (x86_pmu.quirks) |
| x86_pmu.quirks(); |
| |
| if (x86_pmu.num_counters > X86_PMC_MAX_GENERIC) { |
| WARN(1, KERN_ERR "hw perf events %d > max(%d), clipping!", |
| x86_pmu.num_counters, X86_PMC_MAX_GENERIC); |
| x86_pmu.num_counters = X86_PMC_MAX_GENERIC; |
| } |
| x86_pmu.intel_ctrl = (1 << x86_pmu.num_counters) - 1; |
| perf_max_events = x86_pmu.num_counters; |
| |
| if (x86_pmu.num_counters_fixed > X86_PMC_MAX_FIXED) { |
| WARN(1, KERN_ERR "hw perf events fixed %d > max(%d), clipping!", |
| x86_pmu.num_counters_fixed, X86_PMC_MAX_FIXED); |
| x86_pmu.num_counters_fixed = X86_PMC_MAX_FIXED; |
| } |
| |
| x86_pmu.intel_ctrl |= |
| ((1LL << x86_pmu.num_counters_fixed)-1) << X86_PMC_IDX_FIXED; |
| |
| perf_events_lapic_init(); |
| register_die_notifier(&perf_event_nmi_notifier); |
| |
| unconstrained = (struct event_constraint) |
| __EVENT_CONSTRAINT(0, (1ULL << x86_pmu.num_counters) - 1, |
| 0, x86_pmu.num_counters); |
| |
| if (x86_pmu.event_constraints) { |
| for_each_event_constraint(c, x86_pmu.event_constraints) { |
| if (c->cmask != X86_RAW_EVENT_MASK) |
| continue; |
| |
| c->idxmsk64 |= (1ULL << x86_pmu.num_counters) - 1; |
| c->weight += x86_pmu.num_counters; |
| } |
| } |
| |
| pr_info("... version: %d\n", x86_pmu.version); |
| pr_info("... bit width: %d\n", x86_pmu.cntval_bits); |
| pr_info("... generic registers: %d\n", x86_pmu.num_counters); |
| pr_info("... value mask: %016Lx\n", x86_pmu.cntval_mask); |
| pr_info("... max period: %016Lx\n", x86_pmu.max_period); |
| pr_info("... fixed-purpose events: %d\n", x86_pmu.num_counters_fixed); |
| pr_info("... event mask: %016Lx\n", x86_pmu.intel_ctrl); |
| |
| perf_cpu_notifier(x86_pmu_notifier); |
| } |
| |
| static inline void x86_pmu_read(struct perf_event *event) |
| { |
| x86_perf_event_update(event); |
| } |
| |
| /* |
| * Start group events scheduling transaction |
| * Set the flag to make pmu::enable() not perform the |
| * schedulability test, it will be performed at commit time |
| */ |
| static void x86_pmu_start_txn(const struct pmu *pmu) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| |
| cpuc->group_flag |= PERF_EVENT_TXN_STARTED; |
| } |
| |
| /* |
| * Stop group events scheduling transaction |
| * Clear the flag and pmu::enable() will perform the |
| * schedulability test. |
| */ |
| static void x86_pmu_cancel_txn(const struct pmu *pmu) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| |
| cpuc->group_flag &= ~PERF_EVENT_TXN_STARTED; |
| } |
| |
| /* |
| * Commit group events scheduling transaction |
| * Perform the group schedulability test as a whole |
| * Return 0 if success |
| */ |
| static int x86_pmu_commit_txn(const struct pmu *pmu) |
| { |
| struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); |
| int assign[X86_PMC_IDX_MAX]; |
| int n, ret; |
| |
| n = cpuc->n_events; |
| |
| if (!x86_pmu_initialized()) |
| return -EAGAIN; |
| |
| ret = x86_pmu.schedule_events(cpuc, n, assign); |
| if (ret) |
| return ret; |
| |
| /* |
| * copy new assignment, now we know it is possible |
| * will be used by hw_perf_enable() |
| */ |
| memcpy(cpuc->assign, assign, n*sizeof(int)); |
| |
| return 0; |
| } |
| |
| static const struct pmu pmu = { |
| .enable = x86_pmu_enable, |
| .disable = x86_pmu_disable, |
| .start = x86_pmu_start, |
| .stop = x86_pmu_stop, |
| .read = x86_pmu_read, |
| .unthrottle = x86_pmu_unthrottle, |
| .start_txn = x86_pmu_start_txn, |
| .cancel_txn = x86_pmu_cancel_txn, |
| .commit_txn = x86_pmu_commit_txn, |
| }; |
| |
| /* |
| * validate that we can schedule this event |
| */ |
| static int validate_event(struct perf_event *event) |
| { |
| struct cpu_hw_events *fake_cpuc; |
| struct event_constraint *c; |
| int ret = 0; |
| |
| fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO); |
| if (!fake_cpuc) |
| return -ENOMEM; |
| |
| c = x86_pmu.get_event_constraints(fake_cpuc, event); |
| |
| if (!c || !c->weight) |
| ret = -ENOSPC; |
| |
| if (x86_pmu.put_event_constraints) |
| x86_pmu.put_event_constraints(fake_cpuc, event); |
| |
| kfree(fake_cpuc); |
| |
| return ret; |
| } |
| |
| /* |
| * validate a single event group |
| * |
| * validation include: |
| * - check events are compatible which each other |
| * - events do not compete for the same counter |
| * - number of events <= number of counters |
| * |
| * validation ensures the group can be loaded onto the |
| * PMU if it was the only group available. |
| */ |
| static int validate_group(struct perf_event *event) |
| { |
| struct perf_event *leader = event->group_leader; |
| struct cpu_hw_events *fake_cpuc; |
| int ret, n; |
| |
| ret = -ENOMEM; |
| fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO); |
| if (!fake_cpuc) |
| goto out; |
| |
| /* |
| * the event is not yet connected with its |
| * siblings therefore we must first collect |
| * existing siblings, then add the new event |
| * before we can simulate the scheduling |
| */ |
| ret = -ENOSPC; |
| n = collect_events(fake_cpuc, leader, true); |
| if (n < 0) |
| goto out_free; |
| |
| fake_cpuc->n_events = n; |
| n = collect_events(fake_cpuc, event, false); |
| if (n < 0) |
| goto out_free; |
| |
| fake_cpuc->n_events = n; |
| |
| ret = x86_pmu.schedule_events(fake_cpuc, n, NULL); |
| |
| out_free: |
| kfree(fake_cpuc); |
| out: |
| return ret; |
| } |
| |
| const struct pmu *hw_perf_event_init(struct perf_event *event) |
| { |
| const struct pmu *tmp; |
| int err; |
| |
| err = __hw_perf_event_init(event); |
| if (!err) { |
| /* |
| * we temporarily connect event to its pmu |
| * such that validate_group() can classify |
| * it as an x86 event using is_x86_event() |
| */ |
| tmp = event->pmu; |
| event->pmu = &pmu; |
| |
| if (event->group_leader != event) |
| err = validate_group(event); |
| else |
| err = validate_event(event); |
| |
| event->pmu = tmp; |
| } |
| if (err) { |
| if (event->destroy) |
| event->destroy(event); |
| return ERR_PTR(err); |
| } |
| |
| return &pmu; |
| } |
| |
| /* |
| * callchain support |
| */ |
| |
| static inline |
| void callchain_store(struct perf_callchain_entry *entry, u64 ip) |
| { |
| if (entry->nr < PERF_MAX_STACK_DEPTH) |
| entry->ip[entry->nr++] = ip; |
| } |
| |
| static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_irq_entry); |
| static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_nmi_entry); |
| |
| |
| static void |
| backtrace_warning_symbol(void *data, char *msg, unsigned long symbol) |
| { |
| /* Ignore warnings */ |
| } |
| |
| static void backtrace_warning(void *data, char *msg) |
| { |
| /* Ignore warnings */ |
| } |
| |
| static int backtrace_stack(void *data, char *name) |
| { |
| return 0; |
| } |
| |
| static void backtrace_address(void *data, unsigned long addr, int reliable) |
| { |
| struct perf_callchain_entry *entry = data; |
| |
| callchain_store(entry, addr); |
| } |
| |
| static const struct stacktrace_ops backtrace_ops = { |
| .warning = backtrace_warning, |
| .warning_symbol = backtrace_warning_symbol, |
| .stack = backtrace_stack, |
| .address = backtrace_address, |
| .walk_stack = print_context_stack_bp, |
| }; |
| |
| #include "../dumpstack.h" |
| |
| static void |
| perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry) |
| { |
| callchain_store(entry, PERF_CONTEXT_KERNEL); |
| callchain_store(entry, regs->ip); |
| |
| dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry); |
| } |
| |
| #ifdef CONFIG_COMPAT |
| static inline int |
| perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry) |
| { |
| /* 32-bit process in 64-bit kernel. */ |
| struct stack_frame_ia32 frame; |
| const void __user *fp; |
| |
| if (!test_thread_flag(TIF_IA32)) |
| return 0; |
| |
| fp = compat_ptr(regs->bp); |
| while (entry->nr < PERF_MAX_STACK_DEPTH) { |
| unsigned long bytes; |
| frame.next_frame = 0; |
| frame.return_address = 0; |
| |
| bytes = copy_from_user_nmi(&frame, fp, sizeof(frame)); |
| if (bytes != sizeof(frame)) |
| break; |
| |
| if (fp < compat_ptr(regs->sp)) |
| break; |
| |
| callchain_store(entry, frame.return_address); |
| fp = compat_ptr(frame.next_frame); |
| } |
| return 1; |
| } |
| #else |
| static inline int |
| perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry) |
| { |
| return 0; |
| } |
| #endif |
| |
| static void |
| perf_callchain_user(struct pt_regs *regs, struct perf_callchain_entry *entry) |
| { |
| struct stack_frame frame; |
| const void __user *fp; |
| |
| if (!user_mode(regs)) |
| regs = task_pt_regs(current); |
| |
| fp = (void __user *)regs->bp; |
| |
| callchain_store(entry, PERF_CONTEXT_USER); |
| callchain_store(entry, regs->ip); |
| |
| if (perf_callchain_user32(regs, entry)) |
| return; |
| |
| while (entry->nr < PERF_MAX_STACK_DEPTH) { |
| unsigned long bytes; |
| frame.next_frame = NULL; |
| frame.return_address = 0; |
| |
| bytes = copy_from_user_nmi(&frame, fp, sizeof(frame)); |
| if (bytes != sizeof(frame)) |
| break; |
| |
| if ((unsigned long)fp < regs->sp) |
| break; |
| |
| callchain_store(entry, frame.return_address); |
| fp = frame.next_frame; |
| } |
| } |
| |
| static void |
| perf_do_callchain(struct pt_regs *regs, struct perf_callchain_entry *entry) |
| { |
| int is_user; |
| |
| if (!regs) |
| return; |
| |
| is_user = user_mode(regs); |
| |
| if (is_user && current->state != TASK_RUNNING) |
| return; |
| |
| if (!is_user) |
| perf_callchain_kernel(regs, entry); |
| |
| if (current->mm) |
| perf_callchain_user(regs, entry); |
| } |
| |
| struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) |
| { |
| struct perf_callchain_entry *entry; |
| |
| if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { |
| /* TODO: We don't support guest os callchain now */ |
| return NULL; |
| } |
| |
| if (in_nmi()) |
| entry = &__get_cpu_var(pmc_nmi_entry); |
| else |
| entry = &__get_cpu_var(pmc_irq_entry); |
| |
| entry->nr = 0; |
| |
| perf_do_callchain(regs, entry); |
| |
| return entry; |
| } |
| |
| void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip) |
| { |
| regs->ip = ip; |
| /* |
| * perf_arch_fetch_caller_regs adds another call, we need to increment |
| * the skip level |
| */ |
| regs->bp = rewind_frame_pointer(skip + 1); |
| regs->cs = __KERNEL_CS; |
| local_save_flags(regs->flags); |
| } |
| |
| unsigned long perf_instruction_pointer(struct pt_regs *regs) |
| { |
| unsigned long ip; |
| |
| if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) |
| ip = perf_guest_cbs->get_guest_ip(); |
| else |
| ip = instruction_pointer(regs); |
| |
| return ip; |
| } |
| |
| unsigned long perf_misc_flags(struct pt_regs *regs) |
| { |
| int misc = 0; |
| |
| if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { |
| if (perf_guest_cbs->is_user_mode()) |
| misc |= PERF_RECORD_MISC_GUEST_USER; |
| else |
| misc |= PERF_RECORD_MISC_GUEST_KERNEL; |
| } else { |
| if (user_mode(regs)) |
| misc |= PERF_RECORD_MISC_USER; |
| else |
| misc |= PERF_RECORD_MISC_KERNEL; |
| } |
| |
| if (regs->flags & PERF_EFLAGS_EXACT) |
| misc |= PERF_RECORD_MISC_EXACT_IP; |
| |
| return misc; |
| } |