diff options
Diffstat (limited to 'arch/x86/events')
| -rw-r--r-- | arch/x86/events/Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/events/core.c | 2429 |
2 files changed, 2430 insertions, 0 deletions
diff --git a/arch/x86/events/Makefile b/arch/x86/events/Makefile new file mode 100644 index 000000000000..3fad3ce1bbab --- /dev/null +++ b/arch/x86/events/Makefile @@ -0,0 +1 @@ +obj-y += core.o diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c new file mode 100644 index 000000000000..90ca601b5d5c --- /dev/null +++ b/arch/x86/events/core.c @@ -0,0 +1,2429 @@ +/* + * 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 "../kernel/cpu/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) { + pr_cont("Broken BIOS detected, complain to your hardware vendor.\n"); + pr_err(FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n", + reg_fail, val_fail); + } + + return true; + +msr_fail: + pr_cont("Broken PMU hardware detected, using software events only.\n"); + pr_info("%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); |