diff options
| -rw-r--r-- | arch/arm/Kconfig | 8 | ||||
| -rw-r--r-- | arch/arm/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/perf_event.c | 1348 |
3 files changed, 1357 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 74d1e767f0b..9fb91ce106b 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1174,6 +1174,14 @@ config HIGHPTE depends on HIGHMEM depends on !OUTER_CACHE +config HW_PERF_EVENTS + bool "Enable hardware performance counter support for perf events" + depends on PERF_EVENTS && CPU_HAS_PMU && CPU_V6 + default y + help + Enable hardware performance counter support for perf events. If + disabled, perf events will use software events only. + source "mm/Kconfig" config LEDS diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 216890d804c..c76e6d2679b 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -47,6 +47,7 @@ obj-$(CONFIG_CPU_XSC3) += xscale-cp0.o obj-$(CONFIG_CPU_MOHAWK) += xscale-cp0.o obj-$(CONFIG_IWMMXT) += iwmmxt.o obj-$(CONFIG_CPU_HAS_PMU) += pmu.o +obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o AFLAGS_iwmmxt.o := -Wa,-mcpu=iwmmxt ifneq ($(CONFIG_ARCH_EBSA110),y) diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c new file mode 100644 index 00000000000..7b1022b9aa5 --- /dev/null +++ b/arch/arm/kernel/perf_event.c @@ -0,0 +1,1348 @@ +#undef DEBUG + +/* + * ARM performance counter support. + * + * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles + * + * This code is based on the sparc64 perf event code, which is in turn based + * on the x86 code. Callchain code is based on the ARM OProfile backtrace + * code. + */ +#define pr_fmt(fmt) "hw perfevents: " fmt + +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/perf_event.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> + +static const struct pmu_irqs *pmu_irqs; + +/* + * Hardware lock to serialize accesses to PMU registers. Needed for the + * read/modify/write sequences. + */ +DEFINE_SPINLOCK(pmu_lock); + +/* + * ARMv6 supports a maximum of 3 events, starting from index 1. If we add + * another platform that supports more, we need to increase this to be the + * largest of all platforms. + */ +#define ARMPMU_MAX_HWEVENTS 4 + +/* The events for a given CPU. */ +struct cpu_hw_events { + /* + * The events that are active on the CPU for the given index. Index 0 + * is reserved. + */ + struct perf_event *events[ARMPMU_MAX_HWEVENTS]; + + /* + * A 1 bit for an index indicates that the counter is being used for + * an event. A 0 means that the counter can be used. + */ + unsigned long used_mask[BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)]; + + /* + * A 1 bit for an index indicates that the counter is actively being + * used. + */ + unsigned long active_mask[BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)]; +}; +DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events); + +struct arm_pmu { + const char *name; + irqreturn_t (*handle_irq)(int irq_num, void *dev); + void (*enable)(struct hw_perf_event *evt, int idx); + void (*disable)(struct hw_perf_event *evt, int idx); + int (*event_map)(int evt); + u64 (*raw_event)(u64); + int (*get_event_idx)(struct cpu_hw_events *cpuc, + struct hw_perf_event *hwc); + u32 (*read_counter)(int idx); + void (*write_counter)(int idx, u32 val); + void (*start)(void); + void (*stop)(void); + int num_events; + u64 max_period; +}; + +/* Set at runtime when we know what CPU type we are. */ +static const struct arm_pmu *armpmu; + +#define HW_OP_UNSUPPORTED 0xFFFF + +#define C(_x) \ + PERF_COUNT_HW_CACHE_##_x + +#define CACHE_OP_UNSUPPORTED 0xFFFF + +static unsigned armpmu_perf_cache_map[PERF_COUNT_HW_CACHE_MAX] + [PERF_COUNT_HW_CACHE_OP_MAX] + [PERF_COUNT_HW_CACHE_RESULT_MAX]; + +static int +armpmu_map_cache_event(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)armpmu_perf_cache_map[cache_type][cache_op][cache_result]; + + if (ret == CACHE_OP_UNSUPPORTED) + return -ENOENT; + + return ret; +} + +static int +armpmu_event_set_period(struct perf_event *event, + struct hw_perf_event *hwc, + int idx) +{ + s64 left = atomic64_read(&hwc->period_left); + s64 period = hwc->sample_period; + int ret = 0; + + if (unlikely(left <= -period)) { + left = period; + atomic64_set(&hwc->period_left, left); + hwc->last_period = period; + ret = 1; + } + + if (unlikely(left <= 0)) { + left += period; + atomic64_set(&hwc->period_left, left); + hwc->last_period = period; + ret = 1; + } + + if (left > (s64)armpmu->max_period) + left = armpmu->max_period; + + atomic64_set(&hwc->prev_count, (u64)-left); + + armpmu->write_counter(idx, (u64)(-left) & 0xffffffff); + + perf_event_update_userpage(event); + + return ret; +} + +static u64 +armpmu_event_update(struct perf_event *event, + struct hw_perf_event *hwc, + int idx) +{ + int shift = 64 - 32; + s64 prev_raw_count, new_raw_count; + s64 delta; + +again: + prev_raw_count = atomic64_read(&hwc->prev_count); + new_raw_count = armpmu->read_counter(idx); + + if (atomic64_cmpxchg(&hwc->prev_count, prev_raw_count, + new_raw_count) != prev_raw_count) + goto again; + + delta = (new_raw_count << shift) - (prev_raw_count << shift); + delta >>= shift; + + atomic64_add(delta, &event->count); + atomic64_sub(delta, &hwc->period_left); + + return new_raw_count; +} + +static void +armpmu_disable(struct perf_event *event) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct hw_perf_event *hwc = &event->hw; + int idx = hwc->idx; + + WARN_ON(idx < 0); + + clear_bit(idx, cpuc->active_mask); + armpmu->disable(hwc, idx); + + barrier(); + + armpmu_event_update(event, hwc, idx); + cpuc->events[idx] = NULL; + clear_bit(idx, cpuc->used_mask); + + perf_event_update_userpage(event); +} + +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_unthrottle(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + + /* + * Set the period again. Some counters can't be stopped, so when we + * were throttled 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 int +armpmu_enable(struct perf_event *event) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct hw_perf_event *hwc = &event->hw; + int idx; + int err = 0; + + /* If we don't have a space for the counter then finish early. */ + idx = armpmu->get_event_idx(cpuc, 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); + cpuc->events[idx] = event; + set_bit(idx, cpuc->active_mask); + + /* Set the period for the event. */ + armpmu_event_set_period(event, hwc, idx); + + /* Enable the event. */ + armpmu->enable(hwc, idx); + + /* Propagate our changes to the userspace mapping. */ + perf_event_update_userpage(event); + +out: + return err; +} + +static struct pmu pmu = { + .enable = armpmu_enable, + .disable = armpmu_disable, + .unthrottle = armpmu_unthrottle, + .read = armpmu_read, +}; + +static int +validate_event(struct cpu_hw_events *cpuc, + struct perf_event *event) +{ + struct hw_perf_event fake_event = event->hw; + + if (event->pmu && event->pmu != &pmu) + return 0; + + return armpmu->get_event_idx(cpuc, &fake_event) >= 0; +} + +static int +validate_group(struct perf_event *event) +{ + struct perf_event *sibling, *leader = event->group_leader; + struct cpu_hw_events fake_pmu; + + memset(&fake_pmu, 0, sizeof(fake_pmu)); + + if (!validate_event(&fake_pmu, leader)) + return -ENOSPC; + + list_for_each_entry(sibling, &leader->sibling_list, group_entry) { + if (!validate_event(&fake_pmu, sibling)) + return -ENOSPC; + } + + if (!validate_event(&fake_pmu, event)) + return -ENOSPC; + + return 0; +} + +static int +armpmu_reserve_hardware(void) +{ + int i; + int err; + + pmu_irqs = reserve_pmu(); + if (IS_ERR(pmu_irqs)) { + pr_warning("unable to reserve pmu\n"); + return PTR_ERR(pmu_irqs); + } + + init_pmu(); + + if (pmu_irqs->num_irqs < 1) { + pr_err("no irqs for PMUs defined\n"); + return -ENODEV; + } + + for (i = 0; i < pmu_irqs->num_irqs; ++i) { + err = request_irq(pmu_irqs->irqs[i], armpmu->handle_irq, + IRQF_DISABLED, "armpmu", NULL); + if (err) { + pr_warning("unable to request IRQ%d for ARM " + "perf counters\n", pmu_irqs->irqs[i]); + break; + } + } + + if (err) { + for (i = i - 1; i >= 0; --i) + free_irq(pmu_irqs->irqs[i], NULL); + release_pmu(pmu_irqs); + pmu_irqs = NULL; + } + + return err; +} + +static void +armpmu_release_hardware(void) +{ + int i; + + for (i = pmu_irqs->num_irqs - 1; i >= 0; --i) + free_irq(pmu_irqs->irqs[i], NULL); + armpmu->stop(); + + release_pmu(pmu_irqs); + pmu_irqs = NULL; +} + +static atomic_t active_events = ATOMIC_INIT(0); +static DEFINE_MUTEX(pmu_reserve_mutex); + +static void +hw_perf_event_destroy(struct perf_event *event) +{ + if (atomic_dec_and_mutex_lock(&active_events, &pmu_reserve_mutex)) { + armpmu_release_hardware(); + mutex_unlock(&pmu_reserve_mutex); + } +} + +static int +__hw_perf_event_init(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + int mapping, err; + + /* Decode the generic type into an ARM event identifier. */ + if (PERF_TYPE_HARDWARE == event->attr.type) { + mapping = armpmu->event_map(event->attr.config); + } else if (PERF_TYPE_HW_CACHE == event->attr.type) { + mapping = armpmu_map_cache_event(event->attr.config); + } else if (PERF_TYPE_RAW == event->attr.type) { + mapping = armpmu->raw_event(event->attr.config); + } else { + pr_debug("event type %x not supported\n", event->attr.type); + return -EOPNOTSUPP; + } + + if (mapping < 0) { + pr_debug("event %x:%llx not supported\n", event->attr.type, + event->attr.config); + return mapping; + } + + /* + * Check whether we need to exclude the counter from certain modes. + * The ARM performance counters are on all of the time so if someone + * has asked us for some excludes then we have to fail. + */ + if (event->attr.exclude_kernel || event->attr.exclude_user || + event->attr.exclude_hv || event->attr.exclude_idle) { + pr_debug("ARM performance counters do not support " + "mode exclusion\n"); + return -EPERM; + } + + /* + * 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; + + /* + * Store the event encoding into the config_base field. config and + * event_base are unused as the only 2 things we need to know are + * the event mapping and the counter to use. The counter to use is + * also the indx and the config_base is the event type. + */ + hwc->config_base = (unsigned long)mapping; + hwc->config = 0; + hwc->event_base = 0; + + if (!hwc->sample_period) { + hwc->sample_period = armpmu->max_period; + hwc->last_period = hwc->sample_period; + atomic64_set(&hwc->period_left, hwc->sample_period); + } + + err = 0; + if (event->group_leader != event) { + err = validate_group(event); + if (err) + return -EINVAL; + } + + return err; +} + +const struct pmu * +hw_perf_event_init(struct perf_event *event) +{ + int err = 0; + + if (!armpmu) + return ERR_PTR(-ENODEV); + + event->destroy = hw_perf_event_destroy; + + if (!atomic_inc_not_zero(&active_events)) { + if (atomic_read(&active_events) > perf_max_events) { + atomic_dec(&active_events); + return ERR_PTR(-ENOSPC); + } + + mutex_lock(&pmu_reserve_mutex); + if (atomic_read(&active_events) == 0) { + err = armpmu_reserve_hardware(); + } + + if (!err) + atomic_inc(&active_events); + mutex_unlock(&pmu_reserve_mutex); + } + + if (err) + return ERR_PTR(err); + + err = __hw_perf_event_init(event); + if (err) + hw_perf_event_destroy(event); + + return err ? ERR_PTR(err) : &pmu; +} + +void +hw_perf_enable(void) +{ + /* Enable all of the perf events on hardware. */ + int idx; + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + + if (!armpmu) + return; + + for (idx = 0; idx <= armpmu->num_events; ++idx) { + struct perf_event *event = cpuc->events[idx]; + + if (!event) + continue; + + armpmu->enable(&event->hw, idx); + } + + armpmu->start(); +} + +void +hw_perf_disable(void) +{ + if (armpmu) + armpmu->stop(); +} + +/* + * ARMv6 Performance counter handling code. + * + * ARMv6 has 2 configurable performance counters and a single cycle counter. + * They all share a single reset bit but can be written to zero so we can use + * that for a reset. + * + * The counters can't be individually enabled or disabled so when we remove + * one event and replace it with another we could get spurious counts from the + * wrong event. However, we can take advantage of the fact that the + * performance counters can export events to the event bus, and the event bus + * itself can be monitored. This requires that we *don't* export the events to + * the event bus. The procedure for disabling a configurable counter is: + * - change the counter to count the ETMEXTOUT[0] signal (0x20). This + * effectively stops the counter from counting. + * - disable the counter's interrupt generation (each counter has it's + * own interrupt enable bit). + * Once stopped, the counter value can be written as 0 to reset. + * + * To enable a counter: + * - enable the counter's interrupt generation. + * - set the new event type. + * + * Note: the dedicated cycle counter only counts cycles and can't be + * enabled/disabled independently of the others. When we want to disable the + * cycle counter, we have to just disable the interrupt reporting and start + * ignoring that counter. When re-enabling, we have to reset the value and + * enable the interrupt. + */ + +enum armv6_perf_types { + ARMV6_PERFCTR_ICACHE_MISS = 0x0, + ARMV6_PERFCTR_IBUF_STALL = 0x1, + ARMV6_PERFCTR_DDEP_STALL = 0x2, + ARMV6_PERFCTR_ITLB_MISS = 0x3, + ARMV6_PERFCTR_DTLB_MISS = 0x4, + ARMV6_PERFCTR_BR_EXEC = 0x5, + ARMV6_PERFCTR_BR_MISPREDICT = 0x6, + ARMV6_PERFCTR_INSTR_EXEC = 0x7, + ARMV6_PERFCTR_DCACHE_HIT = 0x9, + ARMV6_PERFCTR_DCACHE_ACCESS = 0xA, + ARMV6_PERFCTR_DCACHE_MISS = 0xB, + ARMV6_PERFCTR_DCACHE_WBACK = 0xC, + ARMV6_PERFCTR_SW_PC_CHANGE = 0xD, + ARMV6_PERFCTR_MAIN_TLB_MISS = 0xF, + ARMV6_PERFCTR_EXPL_D_ACCESS = 0x10, + ARMV6_PERFCTR_LSU_FULL_STALL = 0x11, + ARMV6_PERFCTR_WBUF_DRAINED = 0x12, + ARMV6_PERFCTR_CPU_CYCLES = 0xFF, + ARMV6_PERFCTR_NOP = 0x20, +}; + +enum armv6_counters { + ARMV6_CYCLE_COUNTER = 1, + ARMV6_COUNTER0, + ARMV6_COUNTER1, +}; + +/* + * The hardware events that we support. We do support cache operations but + * we have harvard caches and no way to combine instruction and data + * accesses/misses in hardware. + */ +static const unsigned armv6_perf_map[PERF_COUNT_HW_MAX] = { + [PERF_COUNT_HW_CPU_CYCLES] = ARMV6_PERFCTR_CPU_CYCLES, + [PERF_COUNT_HW_INSTRUCTIONS] = ARMV6_PERFCTR_INSTR_EXEC, + [PERF_COUNT_HW_CACHE_REFERENCES] = HW_OP_UNSUPPORTED, + [PERF_COUNT_HW_CACHE_MISSES] = HW_OP_UNSUPPORTED, + [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = ARMV6_PERFCTR_BR_EXEC, + [PERF_COUNT_HW_BRANCH_MISSES] = ARMV6_PERFCTR_BR_MISPREDICT, + [PERF_COUNT_HW_BUS_CYCLES] = HW_OP_UNSUPPORTED, +}; + +static const unsigned armv6_perf_cache_map[PERF_COUNT_HW_CACHE_MAX] + [PERF_COUNT_HW_CACHE_OP_MAX] + [PERF_COUNT_HW_CACHE_RESULT_MAX] = { + [C(L1D)] = { + /* + * The performance counters don't differentiate between read + * and write accesses/misses so this isn't strictly correct, + * but it's the best we can do. Writes and reads get + * combined. + */ + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = ARMV6_PERFCTR_DCACHE_ACCESS, + [C(RESULT_MISS)] = ARMV6_PERFCTR_DCACHE_MISS, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = ARMV6_PERFCTR_DCACHE_ACCESS, + [C(RESULT_MISS)] = ARMV6_PERFCTR_DCACHE_MISS, + }, + [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)] = ARMV6_PERFCTR_ICACHE_MISS, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = ARMV6_PERFCTR_ICACHE_MISS, + }, + [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)] = { + /* + * The ARM performance counters can count micro DTLB misses, + * micro ITLB misses and main TLB misses. There isn't an event + * for TLB misses, so use the micro misses here and if users + * want the main TLB misses they can use a raw counter. + */ + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = ARMV6_PERFCTR_DTLB_MISS, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = ARMV6_PERFCTR_DTLB_MISS, + }, + [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)] = ARMV6_PERFCTR_ITLB_MISS, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = ARMV6_PERFCTR_ITLB_MISS, + }, + [C(OP_PREFETCH)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + }, + [C(BPU)] = { + [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, + }, + }, +}; + +enum armv6mpcore_perf_types { + ARMV6MPCORE_PERFCTR_ICACHE_MISS = 0x0, + ARMV6MPCORE_PERFCTR_IBUF_STALL = 0x1, + ARMV6MPCORE_PERFCTR_DDEP_STALL = 0x2, + ARMV6MPCORE_PERFCTR_ITLB_MISS = 0x3, + ARMV6MPCORE_PERFCTR_DTLB_MISS = 0x4, + ARMV6MPCORE_PERFCTR_BR_EXEC = 0x5, + ARMV6MPCORE_PERFCTR_BR_NOTPREDICT = 0x6, + ARMV6MPCORE_PERFCTR_BR_MISPREDICT = 0x7, + ARMV6MPCORE_PERFCTR_INSTR_EXEC = 0x8, + ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS = 0xA, + ARMV6MPCORE_PERFCTR_DCACHE_RDMISS = 0xB, + ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS = 0xC, + ARMV6MPCORE_PERFCTR_DCACHE_WRMISS = 0xD, + ARMV6MPCORE_PERFCTR_DCACHE_EVICTION = 0xE, + ARMV6MPCORE_PERFCTR_SW_PC_CHANGE = 0xF, + ARMV6MPCORE_PERFCTR_MAIN_TLB_MISS = 0x10, + ARMV6MPCORE_PERFCTR_EXPL_MEM_ACCESS = 0x11, + ARMV6MPCORE_PERFCTR_LSU_FULL_STALL = 0x12, + ARMV6MPCORE_PERFCTR_WBUF_DRAINED = 0x13, + ARMV6MPCORE_PERFCTR_CPU_CYCLES = 0xFF, +}; + +/* + * The hardware events that we support. We do support cache operations but + * we have harvard caches and no way to combine instruction and data + * accesses/misses in hardware. + */ +static const unsigned armv6mpcore_perf_map[PERF_COUNT_HW_MAX] = { + [PERF_COUNT_HW_CPU_CYCLES] = ARMV6MPCORE_PERFCTR_CPU_CYCLES, + [PERF_COUNT_HW_INSTRUCTIONS] = ARMV6MPCORE_PERFCTR_INSTR_EXEC, + [PERF_COUNT_HW_CACHE_REFERENCES] = HW_OP_UNSUPPORTED, + [PERF_COUNT_HW_CACHE_MISSES] = HW_OP_UNSUPPORTED, + [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = ARMV6MPCORE_PERFCTR_BR_EXEC, + [PERF_COUNT_HW_BRANCH_MISSES] = ARMV6MPCORE_PERFCTR_BR_MISPREDICT, + [PERF_COUNT_HW_BUS_CYCLES] = HW_OP_UNSUPPORTED, +}; + +static const unsigned armv6mpcore_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)] = + ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS, + [C(RESULT_MISS)] = + ARMV6MPCORE_PERFCTR_DCACHE_RDMISS, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = + ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS, + [C(RESULT_MISS)] = + ARMV6MPCORE_PERFCTR_DCACHE_WRMISS, + }, + [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)] = ARMV6MPCORE_PERFCTR_ICACHE_MISS, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ICACHE_MISS, + }, + [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)] = { + /* + * The ARM performance counters can count micro DTLB misses, + * micro ITLB misses and main TLB misses. There isn't an event + * for TLB misses, so use the micro misses here and if users + * want the main TLB misses they can use a raw counter. + */ + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_DTLB_MISS, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_DTLB_MISS, + }, + [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)] = ARMV6MPCORE_PERFCTR_ITLB_MISS, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ITLB_MISS, + }, + [C(OP_PREFETCH)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + }, + [C(BPU)] = { + [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, + }, + }, +}; + +static inline unsigned long +armv6_pmcr_read(void) +{ + u32 val; + asm volatile("mrc p15, 0, %0, c15, c12, 0" : "=r"(val)); + return val; +} + +static inline void +armv6_pmcr_write(unsigned long val) +{ + asm volatile("mcr p15, 0, %0, c15, c12, 0" : : "r"(val)); +} + +#define ARMV6_PMCR_ENABLE (1 << 0) +#define ARMV6_PMCR_CTR01_RESET (1 << 1) +#define ARMV6_PMCR_CCOUNT_RESET (1 << 2) +#define ARMV6_PMCR_CCOUNT_DIV (1 << 3) +#define ARMV6_PMCR_COUNT0_IEN (1 << 4) +#define ARMV6_PMCR_COUNT1_IEN (1 << 5) +#define ARMV6_PMCR_CCOUNT_IEN (1 << 6) +#define ARMV6_PMCR_COUNT0_OVERFLOW (1 << 8) +#define ARMV6_PMCR_COUNT1_OVERFLOW (1 << 9) +#define ARMV6_PMCR_CCOUNT_OVERFLOW (1 << 10) +#define ARMV6_PMCR_EVT_COUNT0_SHIFT 20 +#define ARMV6_PMCR_EVT_COUNT0_MASK (0xFF << ARMV6_PMCR_EVT_COUNT0_SHIFT) +#define ARMV6_PMCR_EVT_COUNT1_SHIFT 12 +#define ARMV6_PMCR_EVT_COUNT1_MASK (0xFF << ARMV6_PMCR_EVT_COUNT1_SHIFT) + +#define ARMV6_PMCR_OVERFLOWED_MASK \ + (ARMV6_PMCR_COUNT0_OVERFLOW | ARMV6_PMCR_COUNT1_OVERFLOW | \ + ARMV6_PMCR_CCOUNT_OVERFLOW) + +static inline int +armv6_pmcr_has_overflowed(unsigned long pmcr) +{ + return (pmcr & ARMV6_PMCR_OVERFLOWED_MASK); +} + +static inline int +armv6_pmcr_counter_has_overflowed(unsigned long pmcr, + enum armv6_counters counter) +{ + int ret = 0; + + if (ARMV6_CYCLE_COUNTER == counter) + ret = pmcr & ARMV6_PMCR_CCOUNT_OVERFLOW; + else if (ARMV6_COUNTER0 == counter) + ret = pmcr & ARMV6_PMCR_COUNT0_OVERFLOW; + else if (ARMV6_COUNTER1 == counter) + ret = pmcr & ARMV6_PMCR_COUNT1_OVERFLOW; + else + WARN_ONCE(1, "invalid counter number (%d)\n", counter); + + return ret; +} + +static inline u32 +armv6pmu_read_counter(int counter) +{ + unsigned long value = 0; + + if (ARMV6_CYCLE_COUNTER == counter) + asm volatile("mrc p15, 0, %0, c15, c12, 1" : "=r"(value)); + else if (ARMV6_COUNTER0 == counter) + asm volatile("mrc p15, 0, %0, c15, c12, 2" : "=r"(value)); + else if (ARMV6_COUNTER1 == counter) + asm volatile("mrc p15, 0, %0, c15, c12, 3" : "=r"(value)); + else + WARN_ONCE(1, "invalid counter number (%d)\n", counter); + + return value; +} + +static inline void +armv6pmu_write_counter(int counter, + u32 value) +{ + if (ARMV6_CYCLE_COUNTER == counter) + asm volatile("mcr p15, 0, %0, c15, c12, 1" : : "r"(value)); + else if (ARMV6_COUNTER0 == counter) + asm volatile("mcr p15, 0, %0, c15, c12, 2" : : "r"(value)); + else if (ARMV6_COUNTER1 == counter) + asm volatile("mcr p15, 0, %0, c15, c12, 3" : : "r"(value)); + else + WARN_ONCE(1, "invalid counter number (%d)\n", counter); +} + +void +armv6pmu_enable_event(struct hw_perf_event *hwc, + int idx) +{ + unsigned long val, mask, evt, flags; + + if (ARMV6_CYCLE_COUNTER == idx) { + mask = 0; + evt = ARMV6_PMCR_CCOUNT_IEN; + } else if (ARMV6_COUNTER0 == idx) { + mask = ARMV6_PMCR_EVT_COUNT0_MASK; + evt = (hwc->config_base << ARMV6_PMCR_EVT_COUNT0_SHIFT) | + ARMV6_PMCR_COUNT0_IEN; + } else if (ARMV6_COUNTER1 == idx) { + mask = ARMV6_PMCR_EVT_COUNT1_MASK; + evt = (hwc->config_base << ARMV6_PMCR_EVT_COUNT1_SHIFT) | + ARMV6_PMCR_COUNT1_IEN; + } else { + WARN_ONCE(1, "invalid counter number (%d)\n", idx); + return; + } + + /* + * Mask out the current event and set the counter to count the event + * that we're interested in. + */ + spin_lock_irqsave(&pmu_lock, flags); + val = armv6_pmcr_read(); + val &= ~mask; + val |= evt; + armv6_pmcr_write(val); + spin_unlock_irqrestore(&pmu_lock, flags); +} + +static irqreturn_t +armv6pmu_handle_irq(int irq_num, + void *dev) +{ + unsigned long pmcr = armv6_pmcr_read(); + struct perf_sample_data data; + struct cpu_hw_events *cpuc; + struct pt_regs *regs; + int idx; + + if (!armv6_pmcr_has_overflowed(pmcr)) + return IRQ_NONE; + + regs = get_irq_regs(); + + /* + * The interrupts are cleared by writing the overflow flags back to + * the control register. All of the other bits don't have any effect + * if they are rewritten, so write the whole value back. + */ + armv6_pmcr_write(pmcr); + + data.addr = 0; + + cpuc = &__get_cpu_var(cpu_hw_events); + for (idx = 0; idx <= armpmu->num_events; ++idx) { + struct perf_event *event = cpuc->events[idx]; + struct hw_perf_event *hwc; + + if (!test_bit(idx, cpuc->active_mask)) + continue; + + /* + * We have a single interrupt for all counters. Check that + * each counter has overflowed before we process it. + */ + if (!armv6_pmcr_counter_has_overflowed(pmcr, idx)) + continue; + + hwc = &event->hw; + armpmu_event_update(event, hwc, idx); + data.period = event->hw.last_period; + if (!armpmu_event_set_period(event, hwc, idx)) + continue; + + if (perf_event_overflow(event, 0, &data, regs)) + armpmu->disable(hwc, idx); + } + + /* + * Handle the pending perf events. + * + * Note: this call *must* be run with interrupts enabled. For + * platforms that can have the PMU interrupts raised as a PMI, this + * will not work. + */ + perf_event_do_pending(); + + return IRQ_HANDLED; +} + +static void +armv6pmu_start(void) +{ + unsigned long flags, val; + + spin_lock_irqsave(&pmu_lock, flags); + val = armv6_pmcr_read(); + val |= ARMV6_PMCR_ENABLE; + armv6_pmcr_write(val); + spin_unlock_irqrestore(&pmu_lock, flags); +} + +void +armv6pmu_stop(void) +{ + unsigned long flags, val; + + spin_lock_irqsave(&pmu_lock, flags); + val = armv6_pmcr_read(); + val &= ~ARMV6_PMCR_ENABLE; + armv6_pmcr_write(val); + spin_unlock_irqrestore(&pmu_lock, flags); +} + +static inline int +armv6pmu_event_map(int config) +{ + int mapping = armv6_perf_map[config]; + if (HW_OP_UNSUPPORTED == mapping) + mapping = -EOPNOTSUPP; + return mapping; +} + +static inline int +armv6mpcore_pmu_event_map(int config) +{ + int mapping = armv6mpcore_perf_map[config]; + if (HW_OP_UNSUPPORTED == mapping) + mapping = -EOPNOTSUPP; + return mapping; +} + +static u64 +armv6pmu_raw_event(u64 config) +{ + return config & 0xff; +} + +static int +armv6pmu_get_event_idx(struct cpu_hw_events *cpuc, + struct hw_perf_event *event) +{ + /* Always place a cycle counter into the cycle counter. */ + if (ARMV6_PERFCTR_CPU_CYCLES == event->config_base) { + if (test_and_set_bit(ARMV6_CYCLE_COUNTER, cpuc->used_mask)) + return -EAGAIN; + + return ARMV6_CYCLE_COUNTER; + } else { + /* + * For anything other than a cycle counter, try and use + * counter0 and counter1. + */ + if (!test_and_set_bit(ARMV6_COUNTER1, cpuc->used_mask)) { + return ARMV6_COUNTER1; + } + + if (!test_and_set_bit(ARMV6_COUNTER0, cpuc->used_mask)) { + return ARMV6_COUNTER0; + } + + /* The counters are all in use. */ + return -EAGAIN; + } +} + +static void +armv6pmu_disable_event(struct hw_perf_event *hwc, + int idx) +{ + unsigned long val, mask, evt, flags; + + if (ARMV6_CYCLE_COUNTER == idx) { + mask = ARMV6_PMCR_CCOUNT_IEN; + evt = 0; + } else if (ARMV6_COUNTER0 == idx) { + mask = ARMV6_PMCR_COUNT0_IEN | ARMV6_PMCR_EVT_COUNT0_MASK; + evt = ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT0_SHIFT; + } else if (ARMV6_COUNTER1 == idx) { + mask = ARMV6_PMCR_COUNT1_IEN | ARMV6_PMCR_EVT_COUNT1_MASK; + evt = ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT1_SHIFT; + } else { + WARN_ONCE(1, "invalid counter number (%d)\n", idx); + return; + } + + /* + * Mask out the current event and set the counter to count the number + * of ETM bus signal assertion cycles. The external reporting should + * be disabled and so this should never increment. + */ + spin_lock_irqsave(&pmu_lock, flags); + val = armv6_pmcr_read(); + val &= ~mask; + val |= evt; + armv6_pmcr_write(val); + spin_unlock_irqrestore(&pmu_lock, flags); +} + +static void +armv6mpcore_pmu_disable_event(struct hw_perf_event *hwc, + int idx) +{ + unsigned long val, mask, flags, evt = 0; + + if (ARMV6_CYCLE_COUNTER == idx) { + mask = ARMV6_PMCR_CCOUNT_IEN; + } else if (ARMV6_COUNTER0 == idx) { + mask = ARMV6_PMCR_COUNT0_IEN; + } else if (ARMV6_COUNTER1 == idx) { + mask = ARMV6_PMCR_COUNT1_IEN; + } else { + WARN_ONCE(1, "invalid counter number (%d)\n", idx); + return; + } + + /* + * Unlike UP ARMv6, we don't have a way of stopping the counters. We + * simply disable the interrupt reporting. + */ + spin_lock_irqsave(&pmu_lock, flags); + val = armv6_pmcr_read(); + val &= ~mask; + val |= evt; + armv6_pmcr_write(val); + spin_unlock_irqrestore(&pmu_lock, flags); +} + +static const struct arm_pmu armv6pmu = { + .name = "v6", + .handle_irq = armv6pmu_handle_irq, + .enable = armv6pmu_enable_event, + .disable = armv6pmu_disable_event, + .event_map = armv6pmu_event_map, + .raw_event = armv6pmu_raw_event, + .read_counter = armv6pmu_read_counter, + .write_counter = armv6pmu_write_counter, + .get_event_idx = armv6pmu_get_event_idx, + .start = armv6pmu_start, + .stop = armv6pmu_stop, + .num_events = 3, + .max_period = (1LLU << 32) - 1, +}; + +/* + * ARMv6mpcore is almost identical to single core ARMv6 with the exception + * that some of the events have different enumerations and that there is no + * *hack* to stop the programmable counters. To stop the counters we simply + * disable the interrupt reporting and update the event. When unthrottling we + * reset the period and enable the interrupt reporting. + */ +static const struct arm_pmu armv6mpcore_pmu = { + .name = "v6mpcore", + .handle_irq = armv6pmu_handle_irq, + .enable = armv6pmu_enable_event, + .disable = armv6mpcore_pmu_disable_event, + .event_map = armv6mpcore_pmu_event_map, + .raw_event = armv6pmu_raw_event, + .read_counter = armv6pmu_read_counter, + .write_counter = armv6pmu_write_counter, + .get_event_idx = armv6pmu_get_event_idx, + .start = armv6pmu_start, + .stop = armv6pmu_stop, + .num_events = 3, + .max_period = (1LLU << 32) - 1, +}; + +static int __init +init_hw_perf_events(void) +{ + unsigned long cpuid = read_cpuid_id(); + unsigned long implementor = (cpuid & 0xFF000000) >> 24; + unsigned long part_number = (cpuid & 0xFFF0); + + /* We only support ARM CPUs implemented by ARM at the moment. */ + if (0x41 == implementor) { + switch (part_number) { + case 0xB360: /* ARM1136 */ + case 0xB560: /* ARM1156 */ + case 0xB760: /* ARM1176 */ + armpmu = &armv6pmu; + memcpy(armpmu_perf_cache_map, armv6_perf_cache_map, + sizeof(armv6_perf_cache_map)); + perf_max_events = armv6pmu.num_events; + break; + case 0xB020: /* ARM11mpcore */ + armpmu = &armv6mpcore_pmu; + memcpy(armpmu_perf_cache_map, + armv6mpcore_perf_cache_map, + sizeof(armv6mpcore_perf_cache_map)); + perf_max_events = armv6mpcore_pmu.num_events; + break; + default: + pr_info("no hardware support available\n"); + perf_max_events = -1; + } + } + + if (armpmu) + pr_info("enabled with %s PMU driver\n", + armpmu->name); + + return 0; +} +arch_initcall(init_hw_perf_events); + +/* + * Callchain handling code. + */ +static inline void +callchain_store(struct perf_callchain_entry *entry, + u64 ip) +{ + if (entry->nr < PERF_MAX_STACK_DEPTH) + entry->ip[entry->nr++] = ip; +} + +/* + * The registers we're interested in are at the end of the variable + * length saved register structure. The fp points at the end of this + * structure so the address of this struct is: + * (struct frame_tail *)(xxx->fp)-1 + * + * This code has been adapted from the ARM OProfile support. + */ +struct frame_tail { + struct frame_tail *fp; + unsigned long sp; + 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_backtrace(struct frame_tail *tail, + struct perf_callchain_entry *entry) +{ + struct frame_tail buftail; + + /* Also check accessibility of one struct frame_tail beyond */ + if (!access_ok(VERIFY_READ, tail, sizeof(buftail))) + return NULL; + if (__copy_from_user_inatomic(&buftail, tail, sizeof(buftail))) + return NULL; + + 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 - 1; +} + +static void +perf_callchain_user(struct pt_regs *regs, + struct perf_callchain_entry *entry) +{ + struct frame_tail *tail; + + callchain_store(entry, PERF_CONTEXT_USER); + + if (!user_mode(regs)) + regs = task_pt_regs(current); + + tail = (struct frame_tail *)regs->ARM_fp - 1; + + while (tail && !((unsigned long)tail & 0x3)) + 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 *fr, + void *data) +{ + struct perf_callchain_entry *entry = data; + callchain_store(entry, fr->pc); + return 0; +} + +static void +perf_callchain_kernel(struct pt_regs *regs, + struct perf_callchain_entry *entry) +{ + struct stackframe fr; + + callchain_store(entry, PERF_CONTEXT_KERNEL); + fr.fp = regs->ARM_fp; + fr.sp = regs->ARM_sp; + fr.lr = regs->ARM_lr; + fr.pc = regs->ARM_pc; + walk_stackframe(&fr, callchain_trace, entry); +} + +static void +perf_do_callchain(struct pt_regs *regs, + struct perf_callchain_entry *entry) +{ + int is_user; + + if (!regs) + return; + + is_user = user_mode(regs); + + if (!current || !current->pid) + return; + + if (is_user && current->state != TASK_RUNNING) + return; + + if (!is_user) + perf_callchain_kernel(regs, entry); + + if (current->mm) + perf_callchain_user(regs, entry); +} + +static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_irq_entry); + +struct perf_callchain_entry * +perf_callchain(struct pt_regs *regs) +{ + struct perf_callchain_entry *entry = &__get_cpu_var(pmc_irq_entry); + + entry->nr = 0; + perf_do_callchain(regs, entry); + return entry; +} |