diff options
Diffstat (limited to 'kernel/arch/arm/kernel/perf_event.c')
-rw-r--r-- | kernel/arch/arm/kernel/perf_event.c | 553 |
1 files changed, 0 insertions, 553 deletions
diff --git a/kernel/arch/arm/kernel/perf_event.c b/kernel/arch/arm/kernel/perf_event.c deleted file mode 100644 index 4a86a0133..000000000 --- a/kernel/arch/arm/kernel/perf_event.c +++ /dev/null @@ -1,553 +0,0 @@ -#undef DEBUG - -/* - * ARM performance counter support. - * - * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles - * Copyright (C) 2010 ARM Ltd., Will Deacon <will.deacon@arm.com> - * - * This code is based on the sparc64 perf event code, which is in turn based - * on the x86 code. - */ -#define pr_fmt(fmt) "hw perfevents: " fmt - -#include <linux/kernel.h> -#include <linux/platform_device.h> -#include <linux/pm_runtime.h> -#include <linux/irq.h> -#include <linux/irqdesc.h> - -#include <asm/irq_regs.h> -#include <asm/pmu.h> - -static int -armpmu_map_cache_event(const unsigned (*cache_map) - [PERF_COUNT_HW_CACHE_MAX] - [PERF_COUNT_HW_CACHE_OP_MAX] - [PERF_COUNT_HW_CACHE_RESULT_MAX], - u64 config) -{ - unsigned int cache_type, cache_op, cache_result, ret; - - 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; - - ret = (int)(*cache_map)[cache_type][cache_op][cache_result]; - - if (ret == CACHE_OP_UNSUPPORTED) - return -ENOENT; - - return ret; -} - -static int -armpmu_map_hw_event(const unsigned (*event_map)[PERF_COUNT_HW_MAX], u64 config) -{ - int mapping; - - if (config >= PERF_COUNT_HW_MAX) - return -EINVAL; - - mapping = (*event_map)[config]; - return mapping == HW_OP_UNSUPPORTED ? -ENOENT : mapping; -} - -static int -armpmu_map_raw_event(u32 raw_event_mask, u64 config) -{ - return (int)(config & raw_event_mask); -} - -int -armpmu_map_event(struct perf_event *event, - const unsigned (*event_map)[PERF_COUNT_HW_MAX], - const unsigned (*cache_map) - [PERF_COUNT_HW_CACHE_MAX] - [PERF_COUNT_HW_CACHE_OP_MAX] - [PERF_COUNT_HW_CACHE_RESULT_MAX], - u32 raw_event_mask) -{ - u64 config = event->attr.config; - int type = event->attr.type; - - if (type == event->pmu->type) - return armpmu_map_raw_event(raw_event_mask, config); - - switch (type) { - case PERF_TYPE_HARDWARE: - return armpmu_map_hw_event(event_map, config); - case PERF_TYPE_HW_CACHE: - return armpmu_map_cache_event(cache_map, config); - case PERF_TYPE_RAW: - return armpmu_map_raw_event(raw_event_mask, config); - } - - return -ENOENT; -} - -int armpmu_event_set_period(struct perf_event *event) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct hw_perf_event *hwc = &event->hw; - s64 left = local64_read(&hwc->period_left); - s64 period = hwc->sample_period; - int ret = 0; - - 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; - } - - /* - * Limit the maximum period to prevent the counter value - * from overtaking the one we are about to program. In - * effect we are reducing max_period to account for - * interrupt latency (and we are being very conservative). - */ - if (left > (armpmu->max_period >> 1)) - left = armpmu->max_period >> 1; - - local64_set(&hwc->prev_count, (u64)-left); - - armpmu->write_counter(event, (u64)(-left) & 0xffffffff); - - perf_event_update_userpage(event); - - return ret; -} - -u64 armpmu_event_update(struct perf_event *event) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct hw_perf_event *hwc = &event->hw; - u64 delta, prev_raw_count, new_raw_count; - -again: - prev_raw_count = local64_read(&hwc->prev_count); - new_raw_count = armpmu->read_counter(event); - - if (local64_cmpxchg(&hwc->prev_count, prev_raw_count, - new_raw_count) != prev_raw_count) - goto again; - - delta = (new_raw_count - prev_raw_count) & armpmu->max_period; - - local64_add(delta, &event->count); - local64_sub(delta, &hwc->period_left); - - return new_raw_count; -} - -static void -armpmu_read(struct perf_event *event) -{ - armpmu_event_update(event); -} - -static void -armpmu_stop(struct perf_event *event, int flags) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct hw_perf_event *hwc = &event->hw; - - /* - * ARM pmu always has to update the counter, so ignore - * PERF_EF_UPDATE, see comments in armpmu_start(). - */ - if (!(hwc->state & PERF_HES_STOPPED)) { - armpmu->disable(event); - armpmu_event_update(event); - hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; - } -} - -static void armpmu_start(struct perf_event *event, int flags) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct hw_perf_event *hwc = &event->hw; - - /* - * ARM pmu always has to reprogram the period, so ignore - * PERF_EF_RELOAD, see the comment below. - */ - if (flags & PERF_EF_RELOAD) - WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE)); - - hwc->state = 0; - /* - * Set the period again. Some counters can't be stopped, so when we - * were stopped we simply disabled the IRQ source and the counter - * may have been left counting. If we don't do this step then we may - * get an interrupt too soon or *way* too late if the overflow has - * happened since disabling. - */ - armpmu_event_set_period(event); - armpmu->enable(event); -} - -static void -armpmu_del(struct perf_event *event, int flags) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); - struct hw_perf_event *hwc = &event->hw; - int idx = hwc->idx; - - armpmu_stop(event, PERF_EF_UPDATE); - hw_events->events[idx] = NULL; - clear_bit(idx, hw_events->used_mask); - if (armpmu->clear_event_idx) - armpmu->clear_event_idx(hw_events, event); - - perf_event_update_userpage(event); -} - -static int -armpmu_add(struct perf_event *event, int flags) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); - struct hw_perf_event *hwc = &event->hw; - int idx; - int err = 0; - - perf_pmu_disable(event->pmu); - - /* If we don't have a space for the counter then finish early. */ - idx = armpmu->get_event_idx(hw_events, event); - if (idx < 0) { - err = idx; - goto out; - } - - /* - * If there is an event in the counter we are going to use then make - * sure it is disabled. - */ - event->hw.idx = idx; - armpmu->disable(event); - hw_events->events[idx] = event; - - hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE; - if (flags & PERF_EF_START) - armpmu_start(event, PERF_EF_RELOAD); - - /* Propagate our changes to the userspace mapping. */ - perf_event_update_userpage(event); - -out: - perf_pmu_enable(event->pmu); - return err; -} - -static int -validate_event(struct pmu *pmu, struct pmu_hw_events *hw_events, - struct perf_event *event) -{ - struct arm_pmu *armpmu; - - if (is_software_event(event)) - return 1; - - /* - * Reject groups spanning multiple HW PMUs (e.g. CPU + CCI). The - * core perf code won't check that the pmu->ctx == leader->ctx - * until after pmu->event_init(event). - */ - if (event->pmu != pmu) - return 0; - - if (event->state < PERF_EVENT_STATE_OFF) - return 1; - - if (event->state == PERF_EVENT_STATE_OFF && !event->attr.enable_on_exec) - return 1; - - armpmu = to_arm_pmu(event->pmu); - return armpmu->get_event_idx(hw_events, event) >= 0; -} - -static int -validate_group(struct perf_event *event) -{ - struct perf_event *sibling, *leader = event->group_leader; - struct pmu_hw_events fake_pmu; - - /* - * Initialise the fake PMU. We only need to populate the - * used_mask for the purposes of validation. - */ - memset(&fake_pmu.used_mask, 0, sizeof(fake_pmu.used_mask)); - - if (!validate_event(event->pmu, &fake_pmu, leader)) - return -EINVAL; - - list_for_each_entry(sibling, &leader->sibling_list, group_entry) { - if (!validate_event(event->pmu, &fake_pmu, sibling)) - return -EINVAL; - } - - if (!validate_event(event->pmu, &fake_pmu, event)) - return -EINVAL; - - return 0; -} - -static irqreturn_t armpmu_dispatch_irq(int irq, void *dev) -{ - struct arm_pmu *armpmu; - struct platform_device *plat_device; - struct arm_pmu_platdata *plat; - int ret; - u64 start_clock, finish_clock; - - /* - * we request the IRQ with a (possibly percpu) struct arm_pmu**, but - * the handlers expect a struct arm_pmu*. The percpu_irq framework will - * do any necessary shifting, we just need to perform the first - * dereference. - */ - armpmu = *(void **)dev; - plat_device = armpmu->plat_device; - plat = dev_get_platdata(&plat_device->dev); - - start_clock = sched_clock(); - if (plat && plat->handle_irq) - ret = plat->handle_irq(irq, armpmu, armpmu->handle_irq); - else - ret = armpmu->handle_irq(irq, armpmu); - finish_clock = sched_clock(); - - perf_sample_event_took(finish_clock - start_clock); - return ret; -} - -static void -armpmu_release_hardware(struct arm_pmu *armpmu) -{ - armpmu->free_irq(armpmu); - pm_runtime_put_sync(&armpmu->plat_device->dev); -} - -static int -armpmu_reserve_hardware(struct arm_pmu *armpmu) -{ - int err; - struct platform_device *pmu_device = armpmu->plat_device; - - if (!pmu_device) - return -ENODEV; - - pm_runtime_get_sync(&pmu_device->dev); - err = armpmu->request_irq(armpmu, armpmu_dispatch_irq); - if (err) { - armpmu_release_hardware(armpmu); - return err; - } - - return 0; -} - -static void -hw_perf_event_destroy(struct perf_event *event) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - atomic_t *active_events = &armpmu->active_events; - struct mutex *pmu_reserve_mutex = &armpmu->reserve_mutex; - - if (atomic_dec_and_mutex_lock(active_events, pmu_reserve_mutex)) { - armpmu_release_hardware(armpmu); - mutex_unlock(pmu_reserve_mutex); - } -} - -static int -event_requires_mode_exclusion(struct perf_event_attr *attr) -{ - return attr->exclude_idle || attr->exclude_user || - attr->exclude_kernel || attr->exclude_hv; -} - -static int -__hw_perf_event_init(struct perf_event *event) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct hw_perf_event *hwc = &event->hw; - int mapping; - - mapping = armpmu->map_event(event); - - if (mapping < 0) { - pr_debug("event %x:%llx not supported\n", event->attr.type, - event->attr.config); - return mapping; - } - - /* - * We don't assign an index until we actually place the event onto - * hardware. Use -1 to signify that we haven't decided where to put it - * yet. For SMP systems, each core has it's own PMU so we can't do any - * clever allocation or constraints checking at this point. - */ - hwc->idx = -1; - hwc->config_base = 0; - hwc->config = 0; - hwc->event_base = 0; - - /* - * Check whether we need to exclude the counter from certain modes. - */ - if ((!armpmu->set_event_filter || - armpmu->set_event_filter(hwc, &event->attr)) && - event_requires_mode_exclusion(&event->attr)) { - pr_debug("ARM performance counters do not support " - "mode exclusion\n"); - return -EOPNOTSUPP; - } - - /* - * Store the event encoding into the config_base field. - */ - hwc->config_base |= (unsigned long)mapping; - - if (!is_sampling_event(event)) { - /* - * For non-sampling runs, limit the sample_period to half - * of the counter width. That way, the new counter value - * is far less likely to overtake the previous one unless - * you have some serious IRQ latency issues. - */ - hwc->sample_period = armpmu->max_period >> 1; - hwc->last_period = hwc->sample_period; - local64_set(&hwc->period_left, hwc->sample_period); - } - - if (event->group_leader != event) { - if (validate_group(event) != 0) - return -EINVAL; - } - - return 0; -} - -static int armpmu_event_init(struct perf_event *event) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - int err = 0; - atomic_t *active_events = &armpmu->active_events; - - /* does not support taken branch sampling */ - if (has_branch_stack(event)) - return -EOPNOTSUPP; - - if (armpmu->map_event(event) == -ENOENT) - return -ENOENT; - - event->destroy = hw_perf_event_destroy; - - if (!atomic_inc_not_zero(active_events)) { - mutex_lock(&armpmu->reserve_mutex); - if (atomic_read(active_events) == 0) - err = armpmu_reserve_hardware(armpmu); - - if (!err) - atomic_inc(active_events); - mutex_unlock(&armpmu->reserve_mutex); - } - - if (err) - return err; - - err = __hw_perf_event_init(event); - if (err) - hw_perf_event_destroy(event); - - return err; -} - -static void armpmu_enable(struct pmu *pmu) -{ - struct arm_pmu *armpmu = to_arm_pmu(pmu); - struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); - int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events); - - if (enabled) - armpmu->start(armpmu); -} - -static void armpmu_disable(struct pmu *pmu) -{ - struct arm_pmu *armpmu = to_arm_pmu(pmu); - armpmu->stop(armpmu); -} - -#ifdef CONFIG_PM -static int armpmu_runtime_resume(struct device *dev) -{ - struct arm_pmu_platdata *plat = dev_get_platdata(dev); - - if (plat && plat->runtime_resume) - return plat->runtime_resume(dev); - - return 0; -} - -static int armpmu_runtime_suspend(struct device *dev) -{ - struct arm_pmu_platdata *plat = dev_get_platdata(dev); - - if (plat && plat->runtime_suspend) - return plat->runtime_suspend(dev); - - return 0; -} -#endif - -const struct dev_pm_ops armpmu_dev_pm_ops = { - SET_RUNTIME_PM_OPS(armpmu_runtime_suspend, armpmu_runtime_resume, NULL) -}; - -static void armpmu_init(struct arm_pmu *armpmu) -{ - atomic_set(&armpmu->active_events, 0); - mutex_init(&armpmu->reserve_mutex); - - armpmu->pmu = (struct pmu) { - .pmu_enable = armpmu_enable, - .pmu_disable = armpmu_disable, - .event_init = armpmu_event_init, - .add = armpmu_add, - .del = armpmu_del, - .start = armpmu_start, - .stop = armpmu_stop, - .read = armpmu_read, - }; -} - -int armpmu_register(struct arm_pmu *armpmu, int type) -{ - armpmu_init(armpmu); - pm_runtime_enable(&armpmu->plat_device->dev); - pr_info("enabled with %s PMU driver, %d counters available\n", - armpmu->name, armpmu->num_events); - return perf_pmu_register(&armpmu->pmu, armpmu->name, type); -} - |