diff options
Diffstat (limited to 'arch/arm64/kernel/perf_event.c')
| -rw-r--r-- | arch/arm64/kernel/perf_event.c | 1368 |
1 files changed, 1368 insertions, 0 deletions
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c new file mode 100644 index 000000000000..ecbf2d81ec5c --- /dev/null +++ b/arch/arm64/kernel/perf_event.c @@ -0,0 +1,1368 @@ +/* + * PMU support + * + * Copyright (C) 2012 ARM Limited + * Author: Will Deacon <will.deacon@arm.com> + * + * This code is based heavily on the ARMv7 perf event code. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#define pr_fmt(fmt) "hw perfevents: " fmt + +#include <linux/bitmap.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/perf_event.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/uaccess.h> + +#include <asm/cputype.h> +#include <asm/irq.h> +#include <asm/irq_regs.h> +#include <asm/pmu.h> +#include <asm/stacktrace.h> + +/* + * ARMv8 supports a maximum of 32 events. + * The cycle counter is included in this total. + */ +#define ARMPMU_MAX_HWEVENTS 32 + +static DEFINE_PER_CPU(struct perf_event * [ARMPMU_MAX_HWEVENTS], hw_events); +static DEFINE_PER_CPU(unsigned long [BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)], used_mask); +static DEFINE_PER_CPU(struct pmu_hw_events, cpu_hw_events); + +#define to_arm_pmu(p) (container_of(p, struct arm_pmu, pmu)) + +/* Set at runtime when we know what CPU type we are. */ +static struct arm_pmu *cpu_pmu; + +int +armpmu_get_max_events(void) +{ + int max_events = 0; + + if (cpu_pmu != NULL) + max_events = cpu_pmu->num_events; + + return max_events; +} +EXPORT_SYMBOL_GPL(armpmu_get_max_events); + +int perf_num_counters(void) +{ + return armpmu_get_max_events(); +} +EXPORT_SYMBOL_GPL(perf_num_counters); + +#define HW_OP_UNSUPPORTED 0xFFFF + +#define C(_x) \ + PERF_COUNT_HW_CACHE_##_x + +#define CACHE_OP_UNSUPPORTED 0xFFFF + +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_event(const unsigned (*event_map)[PERF_COUNT_HW_MAX], u64 config) +{ + int 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); +} + +static int map_cpu_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; + + switch (event->attr.type) { + case PERF_TYPE_HARDWARE: + return armpmu_map_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 hw_perf_event *hwc, + int idx) +{ + struct arm_pmu *armpmu = to_arm_pmu(event->pmu); + 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; + } + + if (left > (s64)armpmu->max_period) + left = armpmu->max_period; + + local64_set(&hwc->prev_count, (u64)-left); + + armpmu->write_counter(idx, (u64)(-left) & 0xffffffff); + + perf_event_update_userpage(event); + + return ret; +} + +u64 +armpmu_event_update(struct perf_event *event, + struct hw_perf_event *hwc, + int idx) +{ + struct arm_pmu *armpmu = to_arm_pmu(event->pmu); + u64 delta, prev_raw_count, new_raw_count; + +again: + prev_raw_count = local64_read(&hwc->prev_count); + new_raw_count = armpmu->read_counter(idx); + + 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) +{ + struct hw_perf_event *hwc = &event->hw; + + /* Don't read disabled counters! */ + if (hwc->idx < 0) + return; + + armpmu_event_update(event, hwc, hwc->idx); +} + +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(hwc, hwc->idx); + barrier(); /* why? */ + armpmu_event_update(event, hwc, hwc->idx); + 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, hwc, hwc->idx); + armpmu->enable(hwc, hwc->idx); +} + +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 = armpmu->get_hw_events(); + struct hw_perf_event *hwc = &event->hw; + int idx = hwc->idx; + + WARN_ON(idx < 0); + + armpmu_stop(event, PERF_EF_UPDATE); + hw_events->events[idx] = NULL; + clear_bit(idx, hw_events->used_mask); + + 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 = armpmu->get_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, hwc); + 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(hwc, idx); + 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_hw_events *hw_events, + struct perf_event *event) +{ + struct arm_pmu *armpmu = to_arm_pmu(event->pmu); + struct hw_perf_event fake_event = event->hw; + struct pmu *leader_pmu = event->group_leader->pmu; + + if (event->pmu != leader_pmu || event->state <= PERF_EVENT_STATE_OFF) + return 1; + + return armpmu->get_event_idx(hw_events, &fake_event) >= 0; +} + +static int +validate_group(struct perf_event *event) +{ + struct perf_event *sibling, *leader = event->group_leader; + struct pmu_hw_events fake_pmu; + DECLARE_BITMAP(fake_used_mask, ARMPMU_MAX_HWEVENTS); + + /* + * Initialise the fake PMU. We only need to populate the + * used_mask for the purposes of validation. + */ + memset(fake_used_mask, 0, sizeof(fake_used_mask)); + fake_pmu.used_mask = fake_used_mask; + + if (!validate_event(&fake_pmu, leader)) + return -EINVAL; + + list_for_each_entry(sibling, &leader->sibling_list, group_entry) { + if (!validate_event(&fake_pmu, sibling)) + return -EINVAL; + } + + if (!validate_event(&fake_pmu, event)) + return -EINVAL; + + return 0; +} + +static void +armpmu_release_hardware(struct arm_pmu *armpmu) +{ + int i, irq, irqs; + struct platform_device *pmu_device = armpmu->plat_device; + + irqs = min(pmu_device->num_resources, num_possible_cpus()); + + for (i = 0; i < irqs; ++i) { + if (!cpumask_test_and_clear_cpu(i, &armpmu->active_irqs)) + continue; + irq = platform_get_irq(pmu_device, i); + if (irq >= 0) + free_irq(irq, armpmu); + } +} + +static int +armpmu_reserve_hardware(struct arm_pmu *armpmu) +{ + int i, err, irq, irqs; + struct platform_device *pmu_device = armpmu->plat_device; + + if (!pmu_device) { + pr_err("no PMU device registered\n"); + return -ENODEV; + } + + irqs = min(pmu_device->num_resources, num_possible_cpus()); + if (irqs < 1) { + pr_err("no irqs for PMUs defined\n"); + return -ENODEV; + } + + for (i = 0; i < irqs; ++i) { + err = 0; + irq = platform_get_irq(pmu_device, i); + if (irq < 0) + continue; + + /* + * If we have a single PMU interrupt that we can't shift, + * assume that we're running on a uniprocessor machine and + * continue. Otherwise, continue without this interrupt. + */ + if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) { + pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n", + irq, i); + continue; + } + + err = request_irq(irq, armpmu->handle_irq, + IRQF_NOBALANCING, + "arm-pmu", armpmu); + if (err) { + pr_err("unable to request IRQ%d for ARM PMU counters\n", + irq); + armpmu_release_hardware(armpmu); + return err; + } + + cpumask_set_cpu(i, &armpmu->active_irqs); + } + + 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, err; + + 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 -EPERM; + } + + /* + * Store the event encoding into the config_base field. + */ + hwc->config_base |= (unsigned long)mapping; + + if (!hwc->sample_period) { + /* + * 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); + } + + err = 0; + if (event->group_leader != event) { + err = validate_group(event); + if (err) + return -EINVAL; + } + + return err; +} + +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; + + 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 = armpmu->get_hw_events(); + int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events); + + if (enabled) + armpmu->start(); +} + +static void armpmu_disable(struct pmu *pmu) +{ + struct arm_pmu *armpmu = to_arm_pmu(pmu); + armpmu->stop(); +} + +static void __init 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 __init armpmu_register(struct arm_pmu *armpmu, char *name, int type) +{ + armpmu_init(armpmu); + return perf_pmu_register(&armpmu->pmu, name, type); +} + +/* + * ARMv8 PMUv3 Performance Events handling code. + * Common event types. + */ +enum armv8_pmuv3_perf_types { + /* Required events. */ + ARMV8_PMUV3_PERFCTR_PMNC_SW_INCR = 0x00, + ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL = 0x03, + ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS = 0x04, + ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED = 0x10, + ARMV8_PMUV3_PERFCTR_CLOCK_CYCLES = 0x11, + ARMV8_PMUV3_PERFCTR_PC_BRANCH_PRED = 0x12, + + /* At least one of the following is required. */ + ARMV8_PMUV3_PERFCTR_INSTR_EXECUTED = 0x08, + ARMV8_PMUV3_PERFCTR_OP_SPEC = 0x1B, + + /* Common architectural events. */ + ARMV8_PMUV3_PERFCTR_MEM_READ = 0x06, + ARMV8_PMUV3_PERFCTR_MEM_WRITE = 0x07, + ARMV8_PMUV3_PERFCTR_EXC_TAKEN = 0x09, + ARMV8_PMUV3_PERFCTR_EXC_EXECUTED = 0x0A, + ARMV8_PMUV3_PERFCTR_CID_WRITE = 0x0B, + ARMV8_PMUV3_PERFCTR_PC_WRITE = 0x0C, + ARMV8_PMUV3_PERFCTR_PC_IMM_BRANCH = 0x0D, + ARMV8_PMUV3_PERFCTR_PC_PROC_RETURN = 0x0E, + ARMV8_PMUV3_PERFCTR_MEM_UNALIGNED_ACCESS = 0x0F, + ARMV8_PMUV3_PERFCTR_TTBR_WRITE = 0x1C, + + /* Common microarchitectural events. */ + ARMV8_PMUV3_PERFCTR_L1_ICACHE_REFILL = 0x01, + ARMV8_PMUV3_PERFCTR_ITLB_REFILL = 0x02, + ARMV8_PMUV3_PERFCTR_DTLB_REFILL = 0x05, + ARMV8_PMUV3_PERFCTR_MEM_ACCESS = 0x13, + ARMV8_PMUV3_PERFCTR_L1_ICACHE_ACCESS = 0x14, + ARMV8_PMUV3_PERFCTR_L1_DCACHE_WB = 0x15, + ARMV8_PMUV3_PERFCTR_L2_CACHE_ACCESS = 0x16, + ARMV8_PMUV3_PERFCTR_L2_CACHE_REFILL = 0x17, + ARMV8_PMUV3_PERFCTR_L2_CACHE_WB = 0x18, + ARMV8_PMUV3_PERFCTR_BUS_ACCESS = 0x19, + ARMV8_PMUV3_PERFCTR_MEM_ERROR = 0x1A, + ARMV8_PMUV3_PERFCTR_BUS_CYCLES = 0x1D, + + /* + * This isn't an architected event. + * We detect this event number and use the cycle counter instead. + */ + ARMV8_PMUV3_PERFCTR_CPU_CYCLES = 0xFF, +}; + +/* PMUv3 HW events mapping. */ +static const unsigned armv8_pmuv3_perf_map[PERF_COUNT_HW_MAX] = { + [PERF_COUNT_HW_CPU_CYCLES] = ARMV8_PMUV3_PERFCTR_CPU_CYCLES, + [PERF_COUNT_HW_INSTRUCTIONS] = ARMV8_PMUV3_PERFCTR_INSTR_EXECUTED, + [PERF_COUNT_HW_CACHE_REFERENCES] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS, + [PERF_COUNT_HW_CACHE_MISSES] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL, + [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = HW_OP_UNSUPPORTED, + [PERF_COUNT_HW_BRANCH_MISSES] = ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED, + [PERF_COUNT_HW_BUS_CYCLES] = HW_OP_UNSUPPORTED, + [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = HW_OP_UNSUPPORTED, + [PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = HW_OP_UNSUPPORTED, +}; + +static const unsigned armv8_pmuv3_perf_cache_map[PERF_COUNT_HW_CACHE_MAX] + [PERF_COUNT_HW_CACHE_OP_MAX] + [PERF_COUNT_HW_CACHE_RESULT_MAX] = { + [C(L1D)] = { + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS, + [C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS, + [C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL, + }, + [C(OP_PREFETCH)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + }, + [C(L1I)] = { + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + [C(OP_PREFETCH)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + }, + [C(LL)] = { + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + [C(OP_PREFETCH)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + }, + [C(DTLB)] = { + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + [C(OP_PREFETCH)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + }, + [C(ITLB)] = { + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + [C(OP_PREFETCH)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + }, + [C(BPU)] = { + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_PC_BRANCH_PRED, + [C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_PC_BRANCH_PRED, + [C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED, + }, + [C(OP_PREFETCH)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + }, + [C(NODE)] = { + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + [C(OP_PREFETCH)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + }, +}; + +/* + * Perf Events' indices + */ +#define ARMV8_IDX_CYCLE_COUNTER 0 +#define ARMV8_IDX_COUNTER0 1 +#define ARMV8_IDX_COUNTER_LAST (ARMV8_IDX_CYCLE_COUNTER + cpu_pmu->num_events - 1) + +#define ARMV8_MAX_COUNTERS 32 +#define ARMV8_COUNTER_MASK (ARMV8_MAX_COUNTERS - 1) + +/* + * ARMv8 low level PMU access + */ + +/* + * Perf Event to low level counters mapping + */ +#define ARMV8_IDX_TO_COUNTER(x) \ + (((x) - ARMV8_IDX_COUNTER0) & ARMV8_COUNTER_MASK) + +/* + * Per-CPU PMCR: config reg + */ +#define ARMV8_PMCR_E (1 << 0) /* Enable all counters */ +#define ARMV8_PMCR_P (1 << 1) /* Reset all counters */ +#define ARMV8_PMCR_C (1 << 2) /* Cycle counter reset */ +#define ARMV8_PMCR_D (1 << 3) /* CCNT counts every 64th cpu cycle */ +#define ARMV8_PMCR_X (1 << 4) /* Export to ETM */ +#define ARMV8_PMCR_DP (1 << 5) /* Disable CCNT if non-invasive debug*/ +#define ARMV8_PMCR_N_SHIFT 11 /* Number of counters supported */ +#define ARMV8_PMCR_N_MASK 0x1f +#define ARMV8_PMCR_MASK 0x3f /* Mask for writable bits */ + +/* + * PMOVSR: counters overflow flag status reg + */ +#define ARMV8_OVSR_MASK 0xffffffff /* Mask for writable bits */ +#define ARMV8_OVERFLOWED_MASK ARMV8_OVSR_MASK + +/* + * PMXEVTYPER: Event selection reg + */ +#define ARMV8_EVTYPE_MASK 0xc00000ff /* Mask for writable bits */ +#define ARMV8_EVTYPE_EVENT 0xff /* Mask for EVENT bits */ + +/* + * Event filters for PMUv3 + */ +#define ARMV8_EXCLUDE_EL1 (1 << 31) +#define ARMV8_EXCLUDE_EL0 (1 << 30) +#define ARMV8_INCLUDE_EL2 (1 << 27) + +static inline u32 armv8pmu_pmcr_read(void) +{ + u32 val; + asm volatile("mrs %0, pmcr_el0" : "=r" (val)); + return val; +} + +static inline void armv8pmu_pmcr_write(u32 val) +{ + val &= ARMV8_PMCR_MASK; + isb(); + asm volatile("msr pmcr_el0, %0" :: "r" (val)); +} + +static inline int armv8pmu_has_overflowed(u32 pmovsr) +{ + return pmovsr & ARMV8_OVERFLOWED_MASK; +} + +static inline int armv8pmu_counter_valid(int idx) +{ + return idx >= ARMV8_IDX_CYCLE_COUNTER && idx <= ARMV8_IDX_COUNTER_LAST; +} + +static inline int armv8pmu_counter_has_overflowed(u32 pmnc, int idx) +{ + int ret = 0; + u32 counter; + + if (!armv8pmu_counter_valid(idx)) { + pr_err("CPU%u checking wrong counter %d overflow status\n", + smp_processor_id(), idx); + } else { + counter = ARMV8_IDX_TO_COUNTER(idx); + ret = pmnc & BIT(counter); + } + + return ret; +} + +static inline int armv8pmu_select_counter(int idx) +{ + u32 counter; + + if (!armv8pmu_counter_valid(idx)) { + pr_err("CPU%u selecting wrong PMNC counter %d\n", + smp_processor_id(), idx); + return -EINVAL; + } + + counter = ARMV8_IDX_TO_COUNTER(idx); + asm volatile("msr pmselr_el0, %0" :: "r" (counter)); + isb(); + + return idx; +} + +static inline u32 armv8pmu_read_counter(int idx) +{ + u32 value = 0; + + if (!armv8pmu_counter_valid(idx)) + pr_err("CPU%u reading wrong counter %d\n", + smp_processor_id(), idx); + else if (idx == ARMV8_IDX_CYCLE_COUNTER) + asm volatile("mrs %0, pmccntr_el0" : "=r" (value)); + else if (armv8pmu_select_counter(idx) == idx) + asm volatile("mrs %0, pmxevcntr_el0" : "=r" (value)); + + return value; +} + +static inline void armv8pmu_write_counter(int idx, u32 value) +{ + if (!armv8pmu_counter_valid(idx)) + pr_err("CPU%u writing wrong counter %d\n", + smp_processor_id(), idx); + else if (idx == ARMV8_IDX_CYCLE_COUNTER) + asm volatile("msr pmccntr_el0, %0" :: "r" (value)); + else if (armv8pmu_select_counter(idx) == idx) + asm volatile("msr pmxevcntr_el0, %0" :: "r" (value)); +} + +static inline void armv8pmu_write_evtype(int idx, u32 val) +{ + if (armv8pmu_select_counter(idx) == idx) { + val &= ARMV8_EVTYPE_MASK; + asm volatile("msr pmxevtyper_el0, %0" :: "r" (val)); + } +} + +static inline int armv8pmu_enable_counter(int idx) +{ + u32 counter; + + if (!armv8pmu_counter_valid(idx)) { + pr_err("CPU%u enabling wrong PMNC counter %d\n", + smp_processor_id(), idx); + return -EINVAL; + } + + counter = ARMV8_IDX_TO_COUNTER(idx); + asm volatile("msr pmcntenset_el0, %0" :: "r" (BIT(counter))); + return idx; +} + +static inline int armv8pmu_disable_counter(int idx) +{ + u32 counter; + + if (!armv8pmu_counter_valid(idx)) { + pr_err("CPU%u disabling wrong PMNC counter %d\n", + smp_processor_id(), idx); + return -EINVAL; + } + + counter = ARMV8_IDX_TO_COUNTER(idx); + asm volatile("msr pmcntenclr_el0, %0" :: "r" (BIT(counter))); + return idx; +} + +static inline int armv8pmu_enable_intens(int idx) +{ + u32 counter; + + if (!armv8pmu_counter_valid(idx)) { + pr_err("CPU%u enabling wrong PMNC counter IRQ enable %d\n", + smp_processor_id(), idx); + return -EINVAL; + } + + counter = ARMV8_IDX_TO_COUNTER(idx); + asm volatile("msr pmintenset_el1, %0" :: "r" (BIT(counter))); + return idx; +} + +static inline int armv8pmu_disable_intens(int idx) +{ + u32 counter; + + if (!armv8pmu_counter_valid(idx)) { + pr_err("CPU%u disabling wrong PMNC counter IRQ enable %d\n", + smp_processor_id(), idx); + return -EINVAL; + } + + counter = ARMV8_IDX_TO_COUNTER(idx); + asm volatile("msr pmintenclr_el1, %0" :: "r" (BIT(counter))); + isb(); + /* Clear the overflow flag in case an interrupt is pending. */ + asm volatile("msr pmovsclr_el0, %0" :: "r" (BIT(counter))); + isb(); + return idx; +} + +static inline u32 armv8pmu_getreset_flags(void) +{ + u32 value; + + /* Read */ + asm volatile("mrs %0, pmovsclr_el0" : "=r" (value)); + + /* Write to clear flags */ + value &= ARMV8_OVSR_MASK; + asm volatile("msr pmovsclr_el0, %0" :: "r" (value)); + + return value; +} + +static void armv8pmu_enable_event(struct hw_perf_event *hwc, int idx) +{ + unsigned long flags; + struct pmu_hw_events *events = cpu_pmu->get_hw_events(); + + /* + * Enable counter and interrupt, and set the counter to count + * the event that we're interested in. + */ + raw_spin_lock_irqsave(&events->pmu_lock, flags); + + /* + * Disable counter + */ + armv8pmu_disable_counter(idx); + + /* + * Set event (if destined for PMNx counters). + */ + armv8pmu_write_evtype(idx, hwc->config_base); + + /* + * Enable interrupt for this counter + */ + armv8pmu_enable_intens(idx); + + /* + * Enable counter + */ + armv8pmu_enable_counter(idx); + + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); +} + +static void armv8pmu_disable_event(struct hw_perf_event *hwc, int idx) +{ + unsigned long flags; + struct pmu_hw_events *events = cpu_pmu->get_hw_events(); + + /* + * Disable counter and interrupt + */ + raw_spin_lock_irqsave(&events->pmu_lock, flags); + + /* + * Disable counter + */ + armv8pmu_disable_counter(idx); + + /* + * Disable interrupt for this counter + */ + armv8pmu_disable_intens(idx); + + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); +} + +static irqreturn_t armv8pmu_handle_irq(int irq_num, void *dev) +{ + u32 pmovsr; + struct perf_sample_data data; + struct pmu_hw_events *cpuc; + struct pt_regs *regs; + int idx; + + /* + * Get and reset the IRQ flags + */ + pmovsr = armv8pmu_getreset_flags(); + + /* + * Did an overflow occur? + */ + if (!armv8pmu_has_overflowed(pmovsr)) + return IRQ_NONE; + + /* + * Handle the counter(s) overflow(s) + */ + regs = get_irq_regs(); + + cpuc = &__get_cpu_var(cpu_hw_events); + for (idx = 0; idx < cpu_pmu->num_events; ++idx) { + struct perf_event *event = cpuc->events[idx]; + struct hw_perf_event *hwc; + + /* Ignore if we don't have an event. */ + if (!event) + continue; + + /* + * We have a single interrupt for all counters. Check that + * each counter has overflowed before we process it. + */ + if (!armv8pmu_counter_has_overflowed(pmovsr, idx)) + continue; + + hwc = &event->hw; + armpmu_event_update(event, hwc, idx); + perf_sample_data_init(&data, 0, hwc->last_period); + if (!armpmu_event_set_period(event, hwc, idx)) + continue; + + if (perf_event_overflow(event, &data, regs)) + cpu_pmu->disable(hwc, idx); + } + + /* + * Handle the pending perf events. + * + * Note: this call *must* be run with interrupts disabled. For + * platforms that can have the PMU interrupts raised as an NMI, this + * will not work. + */ + irq_work_run(); + + return IRQ_HANDLED; +} + +static void armv8pmu_start(void) +{ + unsigned long flags; + struct pmu_hw_events *events = cpu_pmu->get_hw_events(); + + raw_spin_lock_irqsave(&events->pmu_lock, flags); + /* Enable all counters */ + armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMCR_E); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); +} + +static void armv8pmu_stop(void) +{ + unsigned long flags; + struct pmu_hw_events *events = cpu_pmu->get_hw_events(); + + raw_spin_lock_irqsave(&events->pmu_lock, flags); + /* Disable all counters */ + armv8pmu_pmcr_write(armv8pmu_pmcr_read() & ~ARMV8_PMCR_E); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); +} + +static int armv8pmu_get_event_idx(struct pmu_hw_events *cpuc, + struct hw_perf_event *event) +{ + int idx; + unsigned long evtype = event->config_base & ARMV8_EVTYPE_EVENT; + + /* Always place a cycle counter into the cycle counter. */ + if (evtype == ARMV8_PMUV3_PERFCTR_CPU_CYCLES) { + if (test_and_set_bit(ARMV8_IDX_CYCLE_COUNTER, cpuc->used_mask)) + return -EAGAIN; + + return ARMV8_IDX_CYCLE_COUNTER; + } + + /* + * For anything other than a cycle counter, try and use + * the events counters + */ + for (idx = ARMV8_IDX_COUNTER0; idx < cpu_pmu->num_events; ++idx) { + if (!test_and_set_bit(idx, cpuc->used_mask)) + return idx; + } + + /* The counters are all in use. */ + return -EAGAIN; +} + +/* + * Add an event filter to a given event. This will only work for PMUv2 PMUs. + */ +static int armv8pmu_set_event_filter(struct hw_perf_event *event, + struct perf_event_attr *attr) +{ + unsigned long config_base = 0; + + if (attr->exclude_idle) + return -EPERM; + if (attr->exclude_user) + config_base |= ARMV8_EXCLUDE_EL0; + if (attr->exclude_kernel) + config_base |= ARMV8_EXCLUDE_EL1; + if (!attr->exclude_hv) + config_base |= ARMV8_INCLUDE_EL2; + + /* + * Install the filter into config_base as this is used to + * construct the event type. + */ + event->config_base = config_base; + + return 0; +} + +static void armv8pmu_reset(void *info) +{ + u32 idx, nb_cnt = cpu_pmu->num_events; + + /* The counter and interrupt enable registers are unknown at reset. */ + for (idx = ARMV8_IDX_CYCLE_COUNTER; idx < nb_cnt; ++idx) + armv8pmu_disable_event(NULL, idx); + + /* Initialize & Reset PMNC: C and P bits. */ + armv8pmu_pmcr_write(ARMV8_PMCR_P | ARMV8_PMCR_C); + + /* Disable access from userspace. */ + asm volatile("msr pmuserenr_el0, %0" :: "r" (0)); +} + +static int armv8_pmuv3_map_event(struct perf_event *event) +{ + return map_cpu_event(event, &armv8_pmuv3_perf_map, + &armv8_pmuv3_perf_cache_map, 0xFF); +} + +static struct arm_pmu armv8pmu = { + .handle_irq = armv8pmu_handle_irq, + .enable = armv8pmu_enable_event, + .disable = armv8pmu_disable_event, + .read_counter = armv8pmu_read_counter, + .write_counter = armv8pmu_write_counter, + .get_event_idx = armv8pmu_get_event_idx, + .start = armv8pmu_start, + .stop = armv8pmu_stop, + .reset = armv8pmu_reset, + .max_period = (1LLU << 32) - 1, +}; + +static u32 __init armv8pmu_read_num_pmnc_events(void) +{ + u32 nb_cnt; + + /* Read the nb of CNTx counters supported from PMNC */ + nb_cnt = (armv8pmu_pmcr_read() >> ARMV8_PMCR_N_SHIFT) & ARMV8_PMCR_N_MASK; + + /* Add the CPU cycles counter and return */ + return nb_cnt + 1; +} + +static struct arm_pmu *__init armv8_pmuv3_pmu_init(void) +{ + armv8pmu.name = "arm/armv8-pmuv3"; + armv8pmu.map_event = armv8_pmuv3_map_event; + armv8pmu.num_events = armv8pmu_read_num_pmnc_events(); + armv8pmu.set_event_filter = armv8pmu_set_event_filter; + return &armv8pmu; +} + +/* + * Ensure the PMU has sane values out of reset. + * This requires SMP to be available, so exists as a separate initcall. + */ +static int __init +cpu_pmu_reset(void) +{ + if (cpu_pmu && cpu_pmu->reset) + return on_each_cpu(cpu_pmu->reset, NULL, 1); + return 0; +} +arch_initcall(cpu_pmu_reset); + +/* + * PMU platform driver and devicetree bindings. + */ +static struct of_device_id armpmu_of_device_ids[] = { + {.compatible = "arm,armv8-pmuv3"}, + {}, +}; + +static int __devinit armpmu_device_probe(struct platform_device *pdev) +{ + if (!cpu_pmu) + return -ENODEV; + + cpu_pmu->plat_device = pdev; + return 0; +} + +static struct platform_driver armpmu_driver = { + .driver = { + .name = "arm-pmu", + .of_match_table = armpmu_of_device_ids, + }, + .probe = armpmu_device_probe, +}; + +static int __init register_pmu_driver(void) +{ + return platform_driver_register(&armpmu_driver); +} +device_initcall(register_pmu_driver); + +static struct pmu_hw_events *armpmu_get_cpu_events(void) +{ + return &__get_cpu_var(cpu_hw_events); +} + +static void __init cpu_pmu_init(struct arm_pmu *armpmu) +{ + int cpu; + for_each_possible_cpu(cpu) { + struct pmu_hw_events *events = &per_cpu(cpu_hw_events, cpu); + events->events = per_cpu(hw_events, cpu); + events->used_mask = per_cpu(used_mask, cpu); + raw_spin_lock_init(&events->pmu_lock); + } + armpmu->get_hw_events = armpmu_get_cpu_events; +} + +static int __init init_hw_perf_events(void) +{ + u64 dfr = read_cpuid(ID_AA64DFR0_EL1); + + switch ((dfr >> 8) & 0xf) { + case 0x1: /* PMUv3 */ + cpu_pmu = armv8_pmuv3_pmu_init(); + break; + } + + if (cpu_pmu) { + pr_info("enabled with %s PMU driver, %d counters available\n", + cpu_pmu->name, cpu_pmu->num_events); + cpu_pmu_init(cpu_pmu); + armpmu_register(cpu_pmu, "cpu", PERF_TYPE_RAW); + } else { + pr_info("no hardware support available\n"); + } + + return 0; +} +early_initcall(init_hw_perf_events); + +/* + * Callchain handling code. + */ +struct frame_tail { + struct frame_tail __user *fp; + unsigned long lr; +} __attribute__((packed)); + +/* + * Get the return address for a single stackframe and return a pointer to the + * next frame tail. + */ +static struct frame_tail __user * +user_backtrace(struct frame_tail __user *tail, + struct perf_callchain_entry *entry) +{ + struct frame_tail buftail; + unsigned long err; + + /* Also check accessibility of one struct frame_tail beyond */ + if (!access_ok(VERIFY_READ, tail, sizeof(buftail))) + return NULL; + + pagefault_disable(); + err = __copy_from_user_inatomic(&buftail, tail, sizeof(buftail)); + pagefault_enable(); + + if (err) + return NULL; + + perf_callchain_store(entry, buftail.lr); + + /* + * Frame pointers should strictly progress back up the stack + * (towards higher addresses). + */ + if (tail >= buftail.fp) + return NULL; + + return buftail.fp; +} + +void perf_callchain_user(struct perf_callchain_entry *entry, + struct pt_regs *regs) +{ + struct frame_tail __user *tail; + + tail = (struct frame_tail __user *)regs->regs[29]; + + while (entry->nr < PERF_MAX_STACK_DEPTH && + tail && !((unsigned long)tail & 0xf)) + tail = user_backtrace(tail, entry); +} + +/* + * Gets called by walk_stackframe() for every stackframe. This will be called + * whist unwinding the stackframe and is like a subroutine return so we use + * the PC. + */ +static int callchain_trace(struct stackframe *frame, void *data) +{ + struct perf_callchain_entry *entry = data; + perf_callchain_store(entry, frame->pc); + return 0; +} + +void perf_callchain_kernel(struct perf_callchain_entry *entry, + struct pt_regs *regs) +{ + struct stackframe frame; + + frame.fp = regs->regs[29]; + frame.sp = regs->sp; + frame.pc = regs->pc; + walk_stackframe(&frame, callchain_trace, entry); +} |
