diff options
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event.c')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 2428 |
1 files changed, 0 insertions, 2428 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c deleted file mode 100644 index 1b443db2db50..000000000000 --- a/arch/x86/kernel/cpu/perf_event.c +++ /dev/null @@ -1,2428 +0,0 @@ -/* - * 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 - * 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/cpu.h> -#include <linux/bitops.h> -#include <linux/device.h> - -#include <asm/apic.h> -#include <asm/stacktrace.h> -#include <asm/nmi.h> -#include <asm/smp.h> -#include <asm/alternative.h> -#include <asm/mmu_context.h> -#include <asm/tlbflush.h> -#include <asm/timer.h> -#include <asm/desc.h> -#include <asm/ldt.h> - -#include "perf_event.h" - -struct x86_pmu x86_pmu __read_mostly; - -DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = { - .enabled = 1, -}; - -struct static_key rdpmc_always_available = STATIC_KEY_INIT_FALSE; - -u64 __read_mostly hw_cache_event_ids - [PERF_COUNT_HW_CACHE_MAX] - [PERF_COUNT_HW_CACHE_OP_MAX] - [PERF_COUNT_HW_CACHE_RESULT_MAX]; -u64 __read_mostly hw_cache_extra_regs - [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. - */ -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 == INTEL_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 = local64_read(&hwc->prev_count); - rdpmcl(hwc->event_base_rdpmc, new_raw_count); - - if (local64_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; - - local64_add(delta, &event->count); - local64_sub(delta, &hwc->period_left); - - return new_raw_count; -} - -/* - * Find and validate any extra registers to set up. - */ -static int x86_pmu_extra_regs(u64 config, struct perf_event *event) -{ - struct hw_perf_event_extra *reg; - struct extra_reg *er; - - reg = &event->hw.extra_reg; - - if (!x86_pmu.extra_regs) - return 0; - - for (er = x86_pmu.extra_regs; er->msr; er++) { - if (er->event != (config & er->config_mask)) - continue; - if (event->attr.config1 & ~er->valid_mask) - return -EINVAL; - /* Check if the extra msrs can be safely accessed*/ - if (!er->extra_msr_access) - return -ENXIO; - - reg->idx = er->idx; - reg->config = event->attr.config1; - reg->reg = er->msr; - break; - } - return 0; -} - -static atomic_t active_events; -static atomic_t pmc_refcount; -static DEFINE_MUTEX(pmc_reserve_mutex); - -#ifdef CONFIG_X86_LOCAL_APIC - -static bool reserve_pmc_hardware(void) -{ - int i; - - for (i = 0; i < x86_pmu.num_counters; i++) { - if (!reserve_perfctr_nmi(x86_pmu_event_addr(i))) - goto perfctr_fail; - } - - for (i = 0; i < x86_pmu.num_counters; i++) { - if (!reserve_evntsel_nmi(x86_pmu_config_addr(i))) - goto eventsel_fail; - } - - return true; - -eventsel_fail: - for (i--; i >= 0; i--) - release_evntsel_nmi(x86_pmu_config_addr(i)); - - i = x86_pmu.num_counters; - -perfctr_fail: - for (i--; i >= 0; i--) - release_perfctr_nmi(x86_pmu_event_addr(i)); - - return false; -} - -static void release_pmc_hardware(void) -{ - int i; - - for (i = 0; i < x86_pmu.num_counters; i++) { - release_perfctr_nmi(x86_pmu_event_addr(i)); - release_evntsel_nmi(x86_pmu_config_addr(i)); - } -} - -#else - -static bool reserve_pmc_hardware(void) { return true; } -static void release_pmc_hardware(void) {} - -#endif - -static bool check_hw_exists(void) -{ - u64 val, val_fail, val_new= ~0; - int i, reg, reg_fail, ret = 0; - int bios_fail = 0; - int reg_safe = -1; - - /* - * Check to see if the BIOS enabled any of the counters, if so - * complain and bail. - */ - for (i = 0; i < x86_pmu.num_counters; i++) { - reg = x86_pmu_config_addr(i); - ret = rdmsrl_safe(reg, &val); - if (ret) - goto msr_fail; - if (val & ARCH_PERFMON_EVENTSEL_ENABLE) { - bios_fail = 1; - val_fail = val; - reg_fail = reg; - } else { - reg_safe = i; - } - } - - if (x86_pmu.num_counters_fixed) { - reg = MSR_ARCH_PERFMON_FIXED_CTR_CTRL; - ret = rdmsrl_safe(reg, &val); - if (ret) - goto msr_fail; - for (i = 0; i < x86_pmu.num_counters_fixed; i++) { - if (val & (0x03 << i*4)) { - bios_fail = 1; - val_fail = val; - reg_fail = reg; - } - } - } - - /* - * If all the counters are enabled, the below test will always - * fail. The tools will also become useless in this scenario. - * Just fail and disable the hardware counters. - */ - - if (reg_safe == -1) { - reg = reg_safe; - goto msr_fail; - } - - /* - * Read the current value, change it and read it back to see if it - * matches, this is needed to detect certain hardware emulators - * (qemu/kvm) that don't trap on the MSR access and always return 0s. - */ - reg = x86_pmu_event_addr(reg_safe); - if (rdmsrl_safe(reg, &val)) - goto msr_fail; - val ^= 0xffffUL; - ret = wrmsrl_safe(reg, val); - ret |= rdmsrl_safe(reg, &val_new); - if (ret || val != val_new) - goto msr_fail; - - /* - * We still allow the PMU driver to operate: - */ - if (bios_fail) { - printk(KERN_CONT "Broken BIOS detected, complain to your hardware vendor.\n"); - printk(KERN_ERR FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n", reg_fail, val_fail); - } - - return true; - -msr_fail: - printk(KERN_CONT "Broken PMU hardware detected, using software events only.\n"); - printk("%sFailed to access perfctr msr (MSR %x is %Lx)\n", - boot_cpu_has(X86_FEATURE_HYPERVISOR) ? KERN_INFO : KERN_ERR, - reg, val_new); - - return false; -} - -static void hw_perf_event_destroy(struct perf_event *event) -{ - x86_release_hardware(); - atomic_dec(&active_events); -} - -void hw_perf_lbr_event_destroy(struct perf_event *event) -{ - hw_perf_event_destroy(event); - - /* undo the lbr/bts event accounting */ - x86_del_exclusive(x86_lbr_exclusive_lbr); -} - -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 *event) -{ - struct perf_event_attr *attr = &event->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; - attr->config1 = hw_cache_extra_regs[cache_type][cache_op][cache_result]; - return x86_pmu_extra_regs(val, event); -} - -int x86_reserve_hardware(void) -{ - int err = 0; - - if (!atomic_inc_not_zero(&pmc_refcount)) { - mutex_lock(&pmc_reserve_mutex); - if (atomic_read(&pmc_refcount) == 0) { - if (!reserve_pmc_hardware()) - err = -EBUSY; - else - reserve_ds_buffers(); - } - if (!err) - atomic_inc(&pmc_refcount); - mutex_unlock(&pmc_reserve_mutex); - } - - return err; -} - -void x86_release_hardware(void) -{ - if (atomic_dec_and_mutex_lock(&pmc_refcount, &pmc_reserve_mutex)) { - release_pmc_hardware(); - release_ds_buffers(); - mutex_unlock(&pmc_reserve_mutex); - } -} - -/* - * Check if we can create event of a certain type (that no conflicting events - * are present). - */ -int x86_add_exclusive(unsigned int what) -{ - int i; - - if (!atomic_inc_not_zero(&x86_pmu.lbr_exclusive[what])) { - mutex_lock(&pmc_reserve_mutex); - for (i = 0; i < ARRAY_SIZE(x86_pmu.lbr_exclusive); i++) { - if (i != what && atomic_read(&x86_pmu.lbr_exclusive[i])) - goto fail_unlock; - } - atomic_inc(&x86_pmu.lbr_exclusive[what]); - mutex_unlock(&pmc_reserve_mutex); - } - - atomic_inc(&active_events); - return 0; - -fail_unlock: - mutex_unlock(&pmc_reserve_mutex); - return -EBUSY; -} - -void x86_del_exclusive(unsigned int what) -{ - atomic_dec(&x86_pmu.lbr_exclusive[what]); - atomic_dec(&active_events); -} - -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 (!is_sampling_event(event)) { - hwc->sample_period = x86_pmu.max_period; - hwc->last_period = hwc->sample_period; - local64_set(&hwc->period_left, hwc->sample_period); - } - - if (attr->type == PERF_TYPE_RAW) - return x86_pmu_extra_regs(event->attr.config, event); - - if (attr->type == PERF_TYPE_HW_CACHE) - return set_ext_hw_attr(hwc, event); - - 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 && - !attr->freq && hwc->sample_period == 1) { - /* BTS is not supported by this architecture. */ - if (!x86_pmu.bts_active) - return -EOPNOTSUPP; - - /* BTS is currently only allowed for user-mode. */ - if (!attr->exclude_kernel) - return -EOPNOTSUPP; - - /* disallow bts if conflicting events are present */ - if (x86_add_exclusive(x86_lbr_exclusive_lbr)) - return -EBUSY; - - event->destroy = hw_perf_lbr_event_destroy; - } - - hwc->config |= config; - - return 0; -} - -/* - * check that branch_sample_type is compatible with - * settings needed for precise_ip > 1 which implies - * using the LBR to capture ALL taken branches at the - * priv levels of the measurement - */ -static inline int precise_br_compat(struct perf_event *event) -{ - u64 m = event->attr.branch_sample_type; - u64 b = 0; - - /* must capture all branches */ - if (!(m & PERF_SAMPLE_BRANCH_ANY)) - return 0; - - m &= PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_USER; - - if (!event->attr.exclude_user) - b |= PERF_SAMPLE_BRANCH_USER; - - if (!event->attr.exclude_kernel) - b |= PERF_SAMPLE_BRANCH_KERNEL; - - /* - * ignore PERF_SAMPLE_BRANCH_HV, not supported on x86 - */ - - return m == b; -} - -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_active && !x86_pmu.pebs_broken) { - precise++; - - /* Support for IP fixup */ - if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2) - precise++; - - if (x86_pmu.pebs_prec_dist) - precise++; - } - - if (event->attr.precise_ip > precise) - return -EOPNOTSUPP; - } - /* - * check that PEBS LBR correction does not conflict with - * whatever the user is asking with attr->branch_sample_type - */ - if (event->attr.precise_ip > 1 && x86_pmu.intel_cap.pebs_format < 2) { - u64 *br_type = &event->attr.branch_sample_type; - - if (has_branch_stack(event)) { - if (!precise_br_compat(event)) - return -EOPNOTSUPP; - - /* branch_sample_type is compatible */ - - } else { - /* - * user did not specify branch_sample_type - * - * For PEBS fixups, we capture all - * the branches at the priv level of the - * event. - */ - *br_type = PERF_SAMPLE_BRANCH_ANY; - - if (!event->attr.exclude_user) - *br_type |= PERF_SAMPLE_BRANCH_USER; - - if (!event->attr.exclude_kernel) - *br_type |= PERF_SAMPLE_BRANCH_KERNEL; - } - } - - if (event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK) - event->attach_state |= PERF_ATTACH_TASK_DATA; - - /* - * 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; - - if (event->attr.sample_period && x86_pmu.limit_period) { - if (x86_pmu.limit_period(event, event->attr.sample_period) > - event->attr.sample_period) - return -EINVAL; - } - - return x86_setup_perfctr(event); -} - -/* - * Setup the hardware configuration for a given attr_type - */ -static int __x86_pmu_event_init(struct perf_event *event) -{ - int err; - - if (!x86_pmu_initialized()) - return -ENODEV; - - err = x86_reserve_hardware(); - if (err) - return err; - - atomic_inc(&active_events); - event->destroy = hw_perf_event_destroy; - - event->hw.idx = -1; - event->hw.last_cpu = -1; - event->hw.last_tag = ~0ULL; - - /* mark unused */ - event->hw.extra_reg.idx = EXTRA_REG_NONE; - event->hw.branch_reg.idx = EXTRA_REG_NONE; - - return x86_pmu.hw_config(event); -} - -void x86_pmu_disable_all(void) -{ - struct cpu_hw_events *cpuc = this_cpu_ptr(&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_config_addr(idx), val); - if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE)) - continue; - val &= ~ARCH_PERFMON_EVENTSEL_ENABLE; - wrmsrl(x86_pmu_config_addr(idx), val); - } -} - -static void x86_pmu_disable(struct pmu *pmu) -{ - struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - - if (!x86_pmu_initialized()) - return; - - if (!cpuc->enabled) - return; - - cpuc->n_added = 0; - cpuc->enabled = 0; - barrier(); - - x86_pmu.disable_all(); -} - -void x86_pmu_enable_all(int added) -{ - struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - int idx; - - for (idx = 0; idx < x86_pmu.num_counters; idx++) { - struct hw_perf_event *hwc = &cpuc->events[idx]->hw; - - if (!test_bit(idx, cpuc->active_mask)) - continue; - - __x86_pmu_enable_event(hwc, ARCH_PERFMON_EVENTSEL_ENABLE); - } -} - -static struct pmu pmu; - -static inline int is_x86_event(struct perf_event *event) -{ - return event->pmu == &pmu; -} - -/* - * Event scheduler state: - * - * Assign events iterating over all events and counters, beginning - * with events with least weights first. Keep the current iterator - * state in struct sched_state. - */ -struct sched_state { - int weight; - int event; /* event index */ - int counter; /* counter index */ - int unassigned; /* number of events to be assigned left */ - int nr_gp; /* number of GP counters used */ - unsigned long used[BITS_TO_LONGS(X86_PMC_IDX_MAX)]; -}; - -/* Total max is X86_PMC_IDX_MAX, but we are O(n!) limited */ -#define SCHED_STATES_MAX 2 - -struct perf_sched { - int max_weight; - int max_events; - int max_gp; - int saved_states; - struct event_constraint **constraints; - struct sched_state state; - struct sched_state saved[SCHED_STATES_MAX]; -}; - -/* - * Initialize interator that runs through all events and counters. - */ -static void perf_sched_init(struct perf_sched *sched, struct event_constraint **constraints, - int num, int wmin, int wmax, int gpmax) -{ - int idx; - - memset(sched, 0, sizeof(*sched)); - sched->max_events = num; - sched->max_weight = wmax; - sched->max_gp = gpmax; - sched->constraints = constraints; - - for (idx = 0; idx < num; idx++) { - if (constraints[idx]->weight == wmin) - break; - } - - sched->state.event = idx; /* start with min weight */ - sched->state.weight = wmin; - sched->state.unassigned = num; -} - -static void perf_sched_save_state(struct perf_sched *sched) -{ - if (WARN_ON_ONCE(sched->saved_states >= SCHED_STATES_MAX)) - return; - - sched->saved[sched->saved_states] = sched->state; - sched->saved_states++; -} - -static bool perf_sched_restore_state(struct perf_sched *sched) -{ - if (!sched->saved_states) - return false; - - sched->saved_states--; - sched->state = sched->saved[sched->saved_states]; - - /* continue with next counter: */ - clear_bit(sched->state.counter++, sched->state.used); - - return true; -} - -/* - * Select a counter for the current event to schedule. Return true on - * success. - */ -static bool __perf_sched_find_counter(struct perf_sched *sched) -{ - struct event_constraint *c; - int idx; - - if (!sched->state.unassigned) - return false; - - if (sched->state.event >= sched->max_events) - return false; - - c = sched->constraints[sched->state.event]; - /* Prefer fixed purpose counters */ - if (c->idxmsk64 & (~0ULL << INTEL_PMC_IDX_FIXED)) { - idx = INTEL_PMC_IDX_FIXED; - for_each_set_bit_from(idx, c->idxmsk, X86_PMC_IDX_MAX) { - if (!__test_and_set_bit(idx, sched->state.used)) - goto done; - } - } - - /* Grab the first unused counter starting with idx */ - idx = sched->state.counter; - for_each_set_bit_from(idx, c->idxmsk, INTEL_PMC_IDX_FIXED) { - if (!__test_and_set_bit(idx, sched->state.used)) { - if (sched->state.nr_gp++ >= sched->max_gp) - return false; - - goto done; - } - } - - return false; - -done: - sched->state.counter = idx; - - if (c->overlap) - perf_sched_save_state(sched); - - return true; -} - -static bool perf_sched_find_counter(struct perf_sched *sched) -{ - while (!__perf_sched_find_counter(sched)) { - if (!perf_sched_restore_state(sched)) - return false; - } - - return true; -} - -/* - * Go through all unassigned events and find the next one to schedule. - * Take events with the least weight first. Return true on success. - */ -static bool perf_sched_next_event(struct perf_sched *sched) -{ - struct event_constraint *c; - - if (!sched->state.unassigned || !--sched->state.unassigned) - return false; - - do { - /* next event */ - sched->state.event++; - if (sched->state.event >= sched->max_events) { - /* next weight */ - sched->state.event = 0; - sched->state.weight++; - if (sched->state.weight > sched->max_weight) - return false; - } - c = sched->constraints[sched->state.event]; - } while (c->weight != sched->state.weight); - - sched->state.counter = 0; /* start with first counter */ - - return true; -} - -/* - * Assign a counter for each event. - */ -int perf_assign_events(struct event_constraint **constraints, int n, - int wmin, int wmax, int gpmax, int *assign) -{ - struct perf_sched sched; - - perf_sched_init(&sched, constraints, n, wmin, wmax, gpmax); - - do { - if (!perf_sched_find_counter(&sched)) - break; /* failed */ - if (assign) - assign[sched.state.event] = sched.state.counter; - } while (perf_sched_next_event(&sched)); - - return sched.state.unassigned; -} -EXPORT_SYMBOL_GPL(perf_assign_events); - -int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign) -{ - struct event_constraint *c; - unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)]; - struct perf_event *e; - int i, wmin, wmax, unsched = 0; - struct hw_perf_event *hwc; - - bitmap_zero(used_mask, X86_PMC_IDX_MAX); - - if (x86_pmu.start_scheduling) - x86_pmu.start_scheduling(cpuc); - - for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) { - cpuc->event_constraint[i] = NULL; - c = x86_pmu.get_event_constraints(cpuc, i, cpuc->event_list[i]); - cpuc->event_constraint[i] = c; - - wmin = min(wmin, c->weight); - wmax = max(wmax, c->weight); - } - - /* - * fastpath, try to reuse previous register - */ - for (i = 0; i < n; i++) { - hwc = &cpuc->event_list[i]->hw; - c = cpuc->event_constraint[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; - } - - /* slow path */ - if (i != n) { - int gpmax = x86_pmu.num_counters; - - /* - * Do not allow scheduling of more than half the available - * generic counters. - * - * This helps avoid counter starvation of sibling thread by - * ensuring at most half the counters cannot be in exclusive - * mode. There is no designated counters for the limits. Any - * N/2 counters can be used. This helps with events with - * specific counter constraints. - */ - if (is_ht_workaround_enabled() && !cpuc->is_fake && - READ_ONCE(cpuc->excl_cntrs->exclusive_present)) - gpmax /= 2; - - unsched = perf_assign_events(cpuc->event_constraint, n, wmin, - wmax, gpmax, assign); - } - - /* - * In case of success (unsched = 0), mark events as committed, - * so we do not put_constraint() in case new events are added - * and fail to be scheduled - * - * We invoke the lower level commit callback to lock the resource - * - * We do not need to do all of this in case we are called to - * validate an event group (assign == NULL) - */ - if (!unsched && assign) { - for (i = 0; i < n; i++) { - e = cpuc->event_list[i]; - e->hw.flags |= PERF_X86_EVENT_COMMITTED; - if (x86_pmu.commit_scheduling) - x86_pmu.commit_scheduling(cpuc, i, assign[i]); - } - } else { - for (i = 0; i < n; i++) { - e = cpuc->event_list[i]; - /* - * do not put_constraint() on comitted events, - * because they are good to go - */ - if ((e->hw.flags & PERF_X86_EVENT_COMMITTED)) - continue; - - /* - * release events that failed scheduling - */ - if (x86_pmu.put_event_constraints) - x86_pmu.put_event_constraints(cpuc, e); - } - } - - if (x86_pmu.stop_scheduling) - x86_pmu.stop_scheduling(cpuc); - - return unsched ? -EINVAL : 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 -EINVAL; - 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 -EINVAL; - - 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 == INTEL_PMC_IDX_FIXED_BTS) { - hwc->config_base = 0; - hwc->event_base = 0; - } else if (hwc->idx >= INTEL_PMC_IDX_FIXED) { - hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL; - hwc->event_base = MSR_ARCH_PERFMON_FIXED_CTR0 + (hwc->idx - INTEL_PMC_IDX_FIXED); - hwc->event_base_rdpmc = (hwc->idx - INTEL_PMC_IDX_FIXED) | 1<<30; - } else { - hwc->config_base = x86_pmu_config_addr(hwc->idx); - hwc->event_base = x86_pmu_event_addr(hwc->idx); - hwc->event_base_rdpmc = x86_pmu_rdpmc_index(hwc->idx); - } -} - -static inline int match_prev_assignment(struct hw_perf_event *hwc, - struct cpu_hw_events *cpuc, - int i) -{ - return hwc->idx == cpuc->assign[i] && - hwc->last_cpu == smp_processor_id() && - hwc->last_tag == cpuc->tags[i]; -} - -static void x86_pmu_start(struct perf_event *event, int flags); - -static void x86_pmu_enable(struct pmu *pmu) -{ - struct cpu_hw_events *cpuc = this_cpu_ptr(&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 - */ - 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; - - /* - * Ensure we don't accidentally enable a stopped - * counter simply because we rescheduled. - */ - if (hwc->state & PERF_HES_STOPPED) - hwc->state |= PERF_HES_ARCH; - - x86_pmu_stop(event, PERF_EF_UPDATE); - } - - /* - * step2: reprogram moved events into new counters - */ - 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; - - if (hwc->state & PERF_HES_ARCH) - continue; - - x86_pmu_start(event, PERF_EF_RELOAD); - } - cpuc->n_added = 0; - perf_events_lapic_init(); - } - - cpuc->enabled = 1; - barrier(); - - x86_pmu.enable_all(added); -} - -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: - */ -int x86_perf_event_set_period(struct perf_event *event) -{ - struct hw_perf_event *hwc = &event->hw; - s64 left = local64_read(&hwc->period_left); - s64 period = hwc->sample_period; - int ret = 0, idx = hwc->idx; - - if (idx == INTEL_PMC_IDX_FIXED_BTS) - return 0; - - /* - * If we are way outside a reasonable range then just skip forward: - */ - if (unlikely(left <= -period)) { - left = period; - local64_set(&hwc->period_left, left); - hwc->last_period = period; - ret = 1; - } - - if (unlikely(left <= 0)) { - left += period; - local64_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; - - if (x86_pmu.limit_period) - left = x86_pmu.limit_period(event, left); - - per_cpu(pmc_prev_left[idx], smp_processor_id()) = left; - - if (!(hwc->flags & PERF_X86_EVENT_AUTO_RELOAD) || - local64_read(&hwc->prev_count) != (u64)-left) { - /* - * The hw event starts counting from this event offset, - * mark it to be able to extra future deltas: - */ - local64_set(&hwc->prev_count, (u64)-left); - - wrmsrl(hwc->event_base, (u64)(-left) & x86_pmu.cntval_mask); - } - - /* - * Due to erratum on certan cpu we need - * a second write to be sure the register - * is updated properly - */ - if (x86_pmu.perfctr_second_write) { - wrmsrl(hwc->event_base, - (u64)(-left) & x86_pmu.cntval_mask); - } - - perf_event_update_userpage(event); - - return ret; -} - -void x86_pmu_enable_event(struct perf_event *event) -{ - if (__this_cpu_read(cpu_hw_events.enabled)) - __x86_pmu_enable_event(&event->hw, - ARCH_PERFMON_EVENTSEL_ENABLE); -} - -/* - * Add a single event to the PMU. - * - * The event is added to the group of enabled events - * but only if it can be scehduled with existing events. - */ -static int x86_pmu_add(struct perf_event *event, int flags) -{ - struct cpu_hw_events *cpuc = this_cpu_ptr(&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; - ret = n = collect_events(cpuc, event, false); - if (ret < 0) - goto out; - - hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED; - if (!(flags & PERF_EF_START)) - hwc->state |= PERF_HES_ARCH; - - /* - * If group events scheduling transaction was started, - * skip the schedulability test here, it will be performed - * at commit time (->commit_txn) as a whole. - */ - if (cpuc->txn_flags & PERF_PMU_TXN_ADD) - goto done_collect; - - ret = x86_pmu.schedule_events(cpuc, n, assign); - if (ret) - goto out; - /* - * copy new assignment, now we know it is possible - * will be used by hw_perf_enable() - */ - memcpy(cpuc->assign, assign, n*sizeof(int)); - -done_collect: - /* - * Commit the collect_events() state. See x86_pmu_del() and - * x86_pmu_*_txn(). - */ - cpuc->n_events = n; - cpuc->n_added += n - n0; - cpuc->n_txn += n - n0; - - ret = 0; -out: - return ret; -} - -static void x86_pmu_start(struct perf_event *event, int flags) -{ - struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - int idx = event->hw.idx; - - if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED))) - return; - - if (WARN_ON_ONCE(idx == -1)) - return; - - if (flags & PERF_EF_RELOAD) { - WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE)); - x86_perf_event_set_period(event); - } - - event->hw.state = 0; - - cpuc->events[idx] = event; - __set_bit(idx, cpuc->active_mask); - __set_bit(idx, cpuc->running); - x86_pmu.enable(event); - perf_event_update_userpage(event); -} - -void perf_event_print_debug(void) -{ - u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed; - u64 pebs, debugctl; - 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); - - 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); - if (x86_pmu.pebs_constraints) { - rdmsrl(MSR_IA32_PEBS_ENABLE, pebs); - pr_info("CPU#%d: pebs: %016llx\n", cpu, pebs); - } - if (x86_pmu.lbr_nr) { - rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); - pr_info("CPU#%d: debugctl: %016llx\n", cpu, debugctl); - } - } - pr_info("CPU#%d: active: %016llx\n", cpu, *(u64 *)cpuc->active_mask); - - for (idx = 0; idx < x86_pmu.num_counters; idx++) { - rdmsrl(x86_pmu_config_addr(idx), pmc_ctrl); - rdmsrl(x86_pmu_event_addr(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); -} - -void x86_pmu_stop(struct perf_event *event, int flags) -{ - struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - struct hw_perf_event *hwc = &event->hw; - - if (__test_and_clear_bit(hwc->idx, cpuc->active_mask)) { - x86_pmu.disable(event); - cpuc->events[hwc->idx] = NULL; - WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED); - hwc->state |= PERF_HES_STOPPED; - } - - if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) { - /* - * Drain the remaining delta count out of a event - * that we are disabling: - */ - x86_perf_event_update(event); - hwc->state |= PERF_HES_UPTODATE; - } -} - -static void x86_pmu_del(struct perf_event *event, int flags) -{ - struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - int i; - - /* - * event is descheduled - */ - event->hw.flags &= ~PERF_X86_EVENT_COMMITTED; - - /* - * If we're called during a txn, we don't need to do anything. - * The events never got scheduled and ->cancel_txn will truncate - * the event_list. - * - * XXX assumes any ->del() called during a TXN will only be on - * an event added during that same TXN. - */ - if (cpuc->txn_flags & PERF_PMU_TXN_ADD) - return; - - /* - * Not a TXN, therefore cleanup properly. - */ - x86_pmu_stop(event, PERF_EF_UPDATE); - - for (i = 0; i < cpuc->n_events; i++) { - if (event == cpuc->event_list[i]) - break; - } - - if (WARN_ON_ONCE(i == cpuc->n_events)) /* called ->del() without ->add() ? */ - return; - - /* If we have a newly added event; make sure to decrease n_added. */ - if (i >= cpuc->n_events - cpuc->n_added) - --cpuc->n_added; - - if (x86_pmu.put_event_constraints) - x86_pmu.put_event_constraints(cpuc, event); - - /* Delete the array entry. */ - while (++i < cpuc->n_events) { - cpuc->event_list[i-1] = cpuc->event_list[i]; - cpuc->event_constraint[i-1] = cpuc->event_constraint[i]; - } - --cpuc->n_events; - - perf_event_update_userpage(event); -} - -int x86_pmu_handle_irq(struct pt_regs *regs) -{ - struct perf_sample_data data; - struct cpu_hw_events *cpuc; - struct perf_event *event; - int idx, handled = 0; - u64 val; - - cpuc = this_cpu_ptr(&cpu_hw_events); - - /* - * Some chipsets need to unmask the LVTPC in a particular spot - * inside the nmi handler. As a result, the unmasking was pushed - * into all the nmi handlers. - * - * This generic handler doesn't seem to have any issues where the - * unmasking occurs so it was left at the top. - */ - apic_write(APIC_LVTPC, APIC_DM_NMI); - - for (idx = 0; idx < x86_pmu.num_counters; idx++) { - if (!test_bit(idx, cpuc->active_mask)) { - /* - * Though we deactivated the counter some cpus - * might still deliver spurious interrupts still - * in flight. Catch them: - */ - if (__test_and_clear_bit(idx, cpuc->running)) - handled++; - continue; - } - - event = cpuc->events[idx]; - - val = x86_perf_event_update(event); - if (val & (1ULL << (x86_pmu.cntval_bits - 1))) - continue; - - /* - * event overflow - */ - handled++; - perf_sample_data_init(&data, 0, event->hw.last_period); - - if (!x86_perf_event_set_period(event)) - continue; - - if (perf_event_overflow(event, &data, regs)) - x86_pmu_stop(event, 0); - } - - if (handled) - inc_irq_stat(apic_perf_irqs); - - return handled; -} - -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 -perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs) -{ - u64 start_clock; - u64 finish_clock; - int ret; - - /* - * All PMUs/events that share this PMI handler should make sure to - * increment active_events for their events. - */ - if (!atomic_read(&active_events)) - return NMI_DONE; - - start_clock = sched_clock(); - ret = x86_pmu.handle_irq(regs); - finish_clock = sched_clock(); - - perf_sample_event_took(finish_clock - start_clock); - - return ret; -} -NOKPROBE_SYMBOL(perf_event_nmi_handler); - -struct event_constraint emptyconstraint; -struct event_constraint unconstrained; - -static int -x86_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu) -{ - unsigned int cpu = (long)hcpu; - struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); - int i, ret = NOTIFY_OK; - - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_UP_PREPARE: - for (i = 0 ; i < X86_PERF_KFREE_MAX; i++) - cpuc->kfree_on_online[i] = NULL; - 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_ONLINE: - for (i = 0 ; i < X86_PERF_KFREE_MAX; i++) { - kfree(cpuc->kfree_on_online[i]); - cpuc->kfree_on_online[i] = NULL; - } - 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"); - - /* - * 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): - */ - pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT; - -} - -static struct attribute_group x86_pmu_format_group = { - .name = "format", - .attrs = NULL, -}; - -/* - * Remove all undefined events (x86_pmu.event_map(id) == 0) - * out of events_attr attributes. - */ -static void __init filter_events(struct attribute **attrs) -{ - struct device_attribute *d; - struct perf_pmu_events_attr *pmu_attr; - int offset = 0; - int i, j; - - for (i = 0; attrs[i]; i++) { - d = (struct device_attribute *)attrs[i]; - pmu_attr = container_of(d, struct perf_pmu_events_attr, attr); - /* str trumps id */ - if (pmu_attr->event_str) - continue; - if (x86_pmu.event_map(i + offset)) - continue; - - for (j = i; attrs[j]; j++) - attrs[j] = attrs[j + 1]; - - /* Check the shifted attr. */ - i--; - - /* - * event_map() is index based, the attrs array is organized - * by increasing event index. If we shift the events, then - * we need to compensate for the event_map(), otherwise - * we are looking up the wrong event in the map - */ - offset++; - } -} - -/* Merge two pointer arrays */ -__init struct attribute **merge_attr(struct attribute **a, struct attribute **b) -{ - struct attribute **new; - int j, i; - - for (j = 0; a[j]; j++) - ; - for (i = 0; b[i]; i++) - j++; - j++; - - new = kmalloc(sizeof(struct attribute *) * j, GFP_KERNEL); - if (!new) - return NULL; - - j = 0; - for (i = 0; a[i]; i++) - new[j++] = a[i]; - for (i = 0; b[i]; i++) - new[j++] = b[i]; - new[j] = NULL; - - return new; -} - -ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr, - char *page) -{ - struct perf_pmu_events_attr *pmu_attr = \ - container_of(attr, struct perf_pmu_events_attr, attr); - u64 config = x86_pmu.event_map(pmu_attr->id); - - /* string trumps id */ - if (pmu_attr->event_str) - return sprintf(page, "%s", pmu_attr->event_str); - - return x86_pmu.events_sysfs_show(page, config); -} - -EVENT_ATTR(cpu-cycles, CPU_CYCLES ); -EVENT_ATTR(instructions, INSTRUCTIONS ); -EVENT_ATTR(cache-references, CACHE_REFERENCES ); -EVENT_ATTR(cache-misses, CACHE_MISSES ); -EVENT_ATTR(branch-instructions, BRANCH_INSTRUCTIONS ); -EVENT_ATTR(branch-misses, BRANCH_MISSES ); -EVENT_ATTR(bus-cycles, BUS_CYCLES ); -EVENT_ATTR(stalled-cycles-frontend, STALLED_CYCLES_FRONTEND ); -EVENT_ATTR(stalled-cycles-backend, STALLED_CYCLES_BACKEND ); -EVENT_ATTR(ref-cycles, REF_CPU_CYCLES ); - -static struct attribute *empty_attrs; - -static struct attribute *events_attr[] = { - EVENT_PTR(CPU_CYCLES), - EVENT_PTR(INSTRUCTIONS), - EVENT_PTR(CACHE_REFERENCES), - EVENT_PTR(CACHE_MISSES), - EVENT_PTR(BRANCH_INSTRUCTIONS), - EVENT_PTR(BRANCH_MISSES), - EVENT_PTR(BUS_CYCLES), - EVENT_PTR(STALLED_CYCLES_FRONTEND), - EVENT_PTR(STALLED_CYCLES_BACKEND), - EVENT_PTR(REF_CPU_CYCLES), - NULL, -}; - -static struct attribute_group x86_pmu_events_group = { - .name = "events", - .attrs = events_attr, -}; - -ssize_t x86_event_sysfs_show(char *page, u64 config, u64 event) -{ - u64 umask = (config & ARCH_PERFMON_EVENTSEL_UMASK) >> 8; - u64 cmask = (config & ARCH_PERFMON_EVENTSEL_CMASK) >> 24; - bool edge = (config & ARCH_PERFMON_EVENTSEL_EDGE); - bool pc = (config & ARCH_PERFMON_EVENTSEL_PIN_CONTROL); - bool any = (config & ARCH_PERFMON_EVENTSEL_ANY); - bool inv = (config & ARCH_PERFMON_EVENTSEL_INV); - ssize_t ret; - - /* - * We have whole page size to spend and just little data - * to write, so we can safely use sprintf. - */ - ret = sprintf(page, "event=0x%02llx", event); - - if (umask) - ret += sprintf(page + ret, ",umask=0x%02llx", umask); - - if (edge) - ret += sprintf(page + ret, ",edge"); - - if (pc) - ret += sprintf(page + ret, ",pc"); - - if (any) - ret += sprintf(page + ret, ",any"); - - if (inv) - ret += sprintf(page + ret, ",inv"); - - if (cmask) - ret += sprintf(page + ret, ",cmask=0x%02llx", cmask); - - ret += sprintf(page + ret, "\n"); - - return ret; -} - -static int __init init_hw_perf_events(void) -{ - struct x86_pmu_quirk *quirk; - 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: - err = -ENOTSUPP; - } - if (err != 0) { - pr_cont("no PMU driver, software events only.\n"); - return 0; - } - - pmu_check_apic(); - - /* sanity check that the hardware exists or is emulated */ - if (!check_hw_exists()) - return 0; - - pr_cont("%s PMU driver.\n", x86_pmu.name); - - x86_pmu.attr_rdpmc = 1; /* enable userspace RDPMC usage by default */ - - for (quirk = x86_pmu.quirks; quirk; quirk = quirk->next) - quirk->func(); - - if (!x86_pmu.intel_ctrl) - x86_pmu.intel_ctrl = (1 << x86_pmu.num_counters) - 1; - - perf_events_lapic_init(); - register_nmi_handler(NMI_LOCAL, perf_event_nmi_handler, 0, "PMI"); - - unconstrained = (struct event_constraint) - __EVENT_CONSTRAINT(0, (1ULL << x86_pmu.num_counters) - 1, - 0, x86_pmu.num_counters, 0, 0); - - x86_pmu_format_group.attrs = x86_pmu.format_attrs; - - if (x86_pmu.event_attrs) - x86_pmu_events_group.attrs = x86_pmu.event_attrs; - - if (!x86_pmu.events_sysfs_show) - x86_pmu_events_group.attrs = &empty_attrs; - else - filter_events(x86_pmu_events_group.attrs); - - if (x86_pmu.cpu_events) { - struct attribute **tmp; - - tmp = merge_attr(x86_pmu_events_group.attrs, x86_pmu.cpu_events); - if (!WARN_ON(!tmp)) - x86_pmu_events_group.attrs = tmp; - } - - 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_pmu_register(&pmu, "cpu", PERF_TYPE_RAW); - perf_cpu_notifier(x86_pmu_notifier); - - return 0; -} -early_initcall(init_hw_perf_events); - -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 - * - * We only support PERF_PMU_TXN_ADD transactions. Save the - * transaction flags but otherwise ignore non-PERF_PMU_TXN_ADD - * transactions. - */ -static void x86_pmu_start_txn(struct pmu *pmu, unsigned int txn_flags) -{ - struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - - WARN_ON_ONCE(cpuc->txn_flags); /* txn already in flight */ - - cpuc->txn_flags = txn_flags; - if (txn_flags & ~PERF_PMU_TXN_ADD) - return; - - perf_pmu_disable(pmu); - __this_cpu_write(cpu_hw_events.n_txn, 0); -} - -/* - * Stop group events scheduling transaction - * Clear the flag and pmu::enable() will perform the - * schedulability test. - */ -static void x86_pmu_cancel_txn(struct pmu *pmu) -{ - unsigned int txn_flags; - struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - - WARN_ON_ONCE(!cpuc->txn_flags); /* no txn in flight */ - - txn_flags = cpuc->txn_flags; - cpuc->txn_flags = 0; - if (txn_flags & ~PERF_PMU_TXN_ADD) - return; - - /* - * Truncate collected array by the number of events added in this - * transaction. See x86_pmu_add() and x86_pmu_*_txn(). - */ - __this_cpu_sub(cpu_hw_events.n_added, __this_cpu_read(cpu_hw_events.n_txn)); - __this_cpu_sub(cpu_hw_events.n_events, __this_cpu_read(cpu_hw_events.n_txn)); - perf_pmu_enable(pmu); -} - -/* - * Commit group events scheduling transaction - * Perform the group schedulability test as a whole - * Return 0 if success - * - * Does not cancel the transaction on failure; expects the caller to do this. - */ -static int x86_pmu_commit_txn(struct pmu *pmu) -{ - struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - int assign[X86_PMC_IDX_MAX]; - int n, ret; - - WARN_ON_ONCE(!cpuc->txn_flags); /* no txn in flight */ - - if (cpuc->txn_flags & ~PERF_PMU_TXN_ADD) { - cpuc->txn_flags = 0; - return 0; - } - - 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)); - - cpuc->txn_flags = 0; - perf_pmu_enable(pmu); - return 0; -} -/* - * a fake_cpuc is used to validate event groups. Due to - * the extra reg logic, we need to also allocate a fake - * per_core and per_cpu structure. Otherwise, group events - * using extra reg may conflict without the kernel being - * able to catch this when the last event gets added to - * the group. - */ -static void free_fake_cpuc(struct cpu_hw_events *cpuc) -{ - kfree(cpuc->shared_regs); - kfree(cpuc); -} - -static struct cpu_hw_events *allocate_fake_cpuc(void) -{ - struct cpu_hw_events *cpuc; - int cpu = raw_smp_processor_id(); - - cpuc = kzalloc(sizeof(*cpuc), GFP_KERNEL); - if (!cpuc) - return ERR_PTR(-ENOMEM); - - /* only needed, if we have extra_regs */ - if (x86_pmu.extra_regs) { - cpuc->shared_regs = allocate_shared_regs(cpu); - if (!cpuc->shared_regs) - goto error; - } - cpuc->is_fake = 1; - return cpuc; -error: - free_fake_cpuc(cpuc); - return ERR_PTR(-ENOMEM); -} - -/* - * 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 = allocate_fake_cpuc(); - if (IS_ERR(fake_cpuc)) - return PTR_ERR(fake_cpuc); - - c = x86_pmu.get_event_constraints(fake_cpuc, -1, event); - - if (!c || !c->weight) - ret = -EINVAL; - - if (x86_pmu.put_event_constraints) - x86_pmu.put_event_constraints(fake_cpuc, event); - - free_fake_cpuc(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 = -EINVAL, n; - - fake_cpuc = allocate_fake_cpuc(); - if (IS_ERR(fake_cpuc)) - return PTR_ERR(fake_cpuc); - /* - * 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 - */ - n = collect_events(fake_cpuc, leader, true); - if (n < 0) - goto out; - - fake_cpuc->n_events = n; - n = collect_events(fake_cpuc, event, false); - if (n < 0) - goto out; - - fake_cpuc->n_events = n; - - ret = x86_pmu.schedule_events(fake_cpuc, n, NULL); - -out: - free_fake_cpuc(fake_cpuc); - return ret; -} - -static int x86_pmu_event_init(struct perf_event *event) -{ - struct pmu *tmp; - int err; - - switch (event->attr.type) { - case PERF_TYPE_RAW: - case PERF_TYPE_HARDWARE: - case PERF_TYPE_HW_CACHE: - break; - - default: - return -ENOENT; - } - - err = __x86_pmu_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); - } - - if (ACCESS_ONCE(x86_pmu.attr_rdpmc)) - event->hw.flags |= PERF_X86_EVENT_RDPMC_ALLOWED; - - return err; -} - -static void refresh_pce(void *ignored) -{ - if (current->mm) - load_mm_cr4(current->mm); -} - -static void x86_pmu_event_mapped(struct perf_event *event) -{ - if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED)) - return; - - if (atomic_inc_return(¤t->mm->context.perf_rdpmc_allowed) == 1) - on_each_cpu_mask(mm_cpumask(current->mm), refresh_pce, NULL, 1); -} - -static void x86_pmu_event_unmapped(struct perf_event *event) -{ - if (!current->mm) - return; - - if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED)) - return; - - if (atomic_dec_and_test(¤t->mm->context.perf_rdpmc_allowed)) - on_each_cpu_mask(mm_cpumask(current->mm), refresh_pce, NULL, 1); -} - -static int x86_pmu_event_idx(struct perf_event *event) -{ - int idx = event->hw.idx; - - if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED)) - return 0; - - if (x86_pmu.num_counters_fixed && idx >= INTEL_PMC_IDX_FIXED) { - idx -= INTEL_PMC_IDX_FIXED; - idx |= 1 << 30; - } - - return idx + 1; -} - -static ssize_t get_attr_rdpmc(struct device *cdev, - struct device_attribute *attr, - char *buf) -{ - return snprintf(buf, 40, "%d\n", x86_pmu.attr_rdpmc); -} - -static ssize_t set_attr_rdpmc(struct device *cdev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - unsigned long val; - ssize_t ret; - - ret = kstrtoul(buf, 0, &val); - if (ret) - return ret; - - if (val > 2) - return -EINVAL; - - if (x86_pmu.attr_rdpmc_broken) - return -ENOTSUPP; - - if ((val == 2) != (x86_pmu.attr_rdpmc == 2)) { - /* - * Changing into or out of always available, aka - * perf-event-bypassing mode. This path is extremely slow, - * but only root can trigger it, so it's okay. - */ - if (val == 2) - static_key_slow_inc(&rdpmc_always_available); - else - static_key_slow_dec(&rdpmc_always_available); - on_each_cpu(refresh_pce, NULL, 1); - } - - x86_pmu.attr_rdpmc = val; - - return count; -} - -static DEVICE_ATTR(rdpmc, S_IRUSR | S_IWUSR, get_attr_rdpmc, set_attr_rdpmc); - -static struct attribute *x86_pmu_attrs[] = { - &dev_attr_rdpmc.attr, - NULL, -}; - -static struct attribute_group x86_pmu_attr_group = { - .attrs = x86_pmu_attrs, -}; - -static const struct attribute_group *x86_pmu_attr_groups[] = { - &x86_pmu_attr_group, - &x86_pmu_format_group, - &x86_pmu_events_group, - NULL, -}; - -static void x86_pmu_sched_task(struct perf_event_context *ctx, bool sched_in) -{ - if (x86_pmu.sched_task) - x86_pmu.sched_task(ctx, sched_in); -} - -void perf_check_microcode(void) -{ - if (x86_pmu.check_microcode) - x86_pmu.check_microcode(); -} -EXPORT_SYMBOL_GPL(perf_check_microcode); - -static struct pmu pmu = { - .pmu_enable = x86_pmu_enable, - .pmu_disable = x86_pmu_disable, - - .attr_groups = x86_pmu_attr_groups, - - .event_init = x86_pmu_event_init, - - .event_mapped = x86_pmu_event_mapped, - .event_unmapped = x86_pmu_event_unmapped, - - .add = x86_pmu_add, - .del = x86_pmu_del, - .start = x86_pmu_start, - .stop = x86_pmu_stop, - .read = x86_pmu_read, - - .start_txn = x86_pmu_start_txn, - .cancel_txn = x86_pmu_cancel_txn, - .commit_txn = x86_pmu_commit_txn, - - .event_idx = x86_pmu_event_idx, - .sched_task = x86_pmu_sched_task, - .task_ctx_size = sizeof(struct x86_perf_task_context), -}; - -void arch_perf_update_userpage(struct perf_event *event, - struct perf_event_mmap_page *userpg, u64 now) -{ - struct cyc2ns_data *data; - - userpg->cap_user_time = 0; - userpg->cap_user_time_zero = 0; - userpg->cap_user_rdpmc = - !!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED); - userpg->pmc_width = x86_pmu.cntval_bits; - - if (!sched_clock_stable()) - return; - - data = cyc2ns_read_begin(); - - /* - * Internal timekeeping for enabled/running/stopped times - * is always in the local_clock domain. - */ - userpg->cap_user_time = 1; - userpg->time_mult = data->cyc2ns_mul; - userpg->time_shift = data->cyc2ns_shift; - userpg->time_offset = data->cyc2ns_offset - now; - - /* - * cap_user_time_zero doesn't make sense when we're using a different - * time base for the records. - */ - if (event->clock == &local_clock) { - userpg->cap_user_time_zero = 1; - userpg->time_zero = data->cyc2ns_offset; - } - - cyc2ns_read_end(data); -} - -/* - * callchain support - */ - -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; - - perf_callchain_store(entry, addr); -} - -static const struct stacktrace_ops backtrace_ops = { - .stack = backtrace_stack, - .address = backtrace_address, - .walk_stack = print_context_stack_bp, -}; - -void -perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) -{ - if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { - /* TODO: We don't support guest os callchain now */ - return; - } - - perf_callchain_store(entry, regs->ip); - - dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry); -} - -static inline int -valid_user_frame(const void __user *fp, unsigned long size) -{ - return (__range_not_ok(fp, size, TASK_SIZE) == 0); -} - -static unsigned long get_segment_base(unsigned int segment) -{ - struct desc_struct *desc; - int idx = segment >> 3; - - if ((segment & SEGMENT_TI_MASK) == SEGMENT_LDT) { -#ifdef CONFIG_MODIFY_LDT_SYSCALL - struct ldt_struct *ldt; - - if (idx > LDT_ENTRIES) - return 0; - - /* IRQs are off, so this synchronizes with smp_store_release */ - ldt = lockless_dereference(current->active_mm->context.ldt); - if (!ldt || idx > ldt->size) - return 0; - - desc = &ldt->entries[idx]; -#else - return 0; -#endif - } else { - if (idx > GDT_ENTRIES) - return 0; - - desc = raw_cpu_ptr(gdt_page.gdt) + idx; - } - - return get_desc_base(desc); -} - -#ifdef CONFIG_IA32_EMULATION - -#include <asm/compat.h> - -static inline int -perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry) -{ - /* 32-bit process in 64-bit kernel. */ - unsigned long ss_base, cs_base; - struct stack_frame_ia32 frame; - const void __user *fp; - - if (!test_thread_flag(TIF_IA32)) - return 0; - - cs_base = get_segment_base(regs->cs); - ss_base = get_segment_base(regs->ss); - - fp = compat_ptr(ss_base + regs->bp); - pagefault_disable(); - while (entry->nr < PERF_MAX_STACK_DEPTH) { - unsigned long bytes; - frame.next_frame = 0; - frame.return_address = 0; - - if (!access_ok(VERIFY_READ, fp, 8)) - break; - - bytes = __copy_from_user_nmi(&frame.next_frame, fp, 4); - if (bytes != 0) - break; - bytes = __copy_from_user_nmi(&frame.return_address, fp+4, 4); - if (bytes != 0) - break; - - if (!valid_user_frame(fp, sizeof(frame))) - break; - - perf_callchain_store(entry, cs_base + frame.return_address); - fp = compat_ptr(ss_base + frame.next_frame); - } - pagefault_enable(); - return 1; -} -#else -static inline int -perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry) -{ - return 0; -} -#endif - -void -perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs) -{ - struct stack_frame frame; - const void __user *fp; - - if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { - /* TODO: We don't support guest os callchain now */ - return; - } - - /* - * We don't know what to do with VM86 stacks.. ignore them for now. - */ - if (regs->flags & (X86_VM_MASK | PERF_EFLAGS_VM)) - return; - - fp = (void __user *)regs->bp; - - perf_callchain_store(entry, regs->ip); - - if (!current->mm) - return; - - if (perf_callchain_user32(regs, entry)) - return; - - pagefault_disable(); - while (entry->nr < PERF_MAX_STACK_DEPTH) { - unsigned long bytes; - frame.next_frame = NULL; - frame.return_address = 0; - - if (!access_ok(VERIFY_READ, fp, 16)) - break; - - bytes = __copy_from_user_nmi(&frame.next_frame, fp, 8); - if (bytes != 0) - break; - bytes = __copy_from_user_nmi(&frame.return_address, fp+8, 8); - if (bytes != 0) - break; - - if (!valid_user_frame(fp, sizeof(frame))) - break; - - perf_callchain_store(entry, frame.return_address); - fp = (void __user *)frame.next_frame; - } - pagefault_enable(); -} - -/* - * Deal with code segment offsets for the various execution modes: - * - * VM86 - the good olde 16 bit days, where the linear address is - * 20 bits and we use regs->ip + 0x10 * regs->cs. - * - * IA32 - Where we need to look at GDT/LDT segment descriptor tables - * to figure out what the 32bit base address is. - * - * X32 - has TIF_X32 set, but is running in x86_64 - * - * X86_64 - CS,DS,SS,ES are all zero based. - */ -static unsigned long code_segment_base(struct pt_regs *regs) -{ - /* - * For IA32 we look at the GDT/LDT segment base to convert the - * effective IP to a linear address. - */ - -#ifdef CONFIG_X86_32 - /* - * If we are in VM86 mode, add the segment offset to convert to a - * linear address. - */ - if (regs->flags & X86_VM_MASK) - return 0x10 * regs->cs; - - if (user_mode(regs) && regs->cs != __USER_CS) - return get_segment_base(regs->cs); -#else - if (user_mode(regs) && !user_64bit_mode(regs) && - regs->cs != __USER32_CS) - return get_segment_base(regs->cs); -#endif - return 0; -} - -unsigned long perf_instruction_pointer(struct pt_regs *regs) -{ - if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) - return perf_guest_cbs->get_guest_ip(); - - return regs->ip + code_segment_base(regs); -} - -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; -} - -void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap) -{ - cap->version = x86_pmu.version; - cap->num_counters_gp = x86_pmu.num_counters; - cap->num_counters_fixed = x86_pmu.num_counters_fixed; - cap->bit_width_gp = x86_pmu.cntval_bits; - cap->bit_width_fixed = x86_pmu.cntval_bits; - cap->events_mask = (unsigned int)x86_pmu.events_maskl; - cap->events_mask_len = x86_pmu.events_mask_len; -} -EXPORT_SYMBOL_GPL(perf_get_x86_pmu_capability); |