diff options
| -rw-r--r-- | arch/metag/Kconfig | 1 | ||||
| -rw-r--r-- | arch/metag/include/asm/perf_event.h | 4 | ||||
| -rw-r--r-- | arch/metag/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/metag/kernel/perf/Makefile | 3 | ||||
| -rw-r--r-- | arch/metag/kernel/perf/perf_event.c | 861 | ||||
| -rw-r--r-- | arch/metag/kernel/perf/perf_event.h | 106 | ||||
| -rw-r--r-- | arch/metag/kernel/perf_callchain.c | 96 |
7 files changed, 1073 insertions, 0 deletions
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig index f786e6e0970..47972025818 100644 --- a/arch/metag/Kconfig +++ b/arch/metag/Kconfig @@ -22,6 +22,7 @@ config METAG select HAVE_MEMBLOCK select HAVE_MEMBLOCK_NODE_MAP select HAVE_MOD_ARCH_SPECIFIC + select HAVE_PERF_EVENTS select HAVE_SYSCALL_TRACEPOINTS select IRQ_DOMAIN select MODULES_USE_ELF_RELA diff --git a/arch/metag/include/asm/perf_event.h b/arch/metag/include/asm/perf_event.h new file mode 100644 index 00000000000..105bbff0149 --- /dev/null +++ b/arch/metag/include/asm/perf_event.h @@ -0,0 +1,4 @@ +#ifndef __ASM_METAG_PERF_EVENT_H +#define __ASM_METAG_PERF_EVENT_H + +#endif /* __ASM_METAG_PERF_EVENT_H */ diff --git a/arch/metag/kernel/Makefile b/arch/metag/kernel/Makefile index e985d0ca618..a5e4ba6fd20 100644 --- a/arch/metag/kernel/Makefile +++ b/arch/metag/kernel/Makefile @@ -25,6 +25,8 @@ obj-y += topology.o obj-y += traps.o obj-y += user_gateway.o +obj-$(CONFIG_PERF_EVENTS) += perf/ + obj-$(CONFIG_METAG_COREMEM) += coremem.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o obj-$(CONFIG_FUNCTION_TRACER) += ftrace_stub.o diff --git a/arch/metag/kernel/perf/Makefile b/arch/metag/kernel/perf/Makefile new file mode 100644 index 00000000000..b158cb27208 --- /dev/null +++ b/arch/metag/kernel/perf/Makefile @@ -0,0 +1,3 @@ +# Makefile for performance event core + +obj-y += perf_event.o diff --git a/arch/metag/kernel/perf/perf_event.c b/arch/metag/kernel/perf/perf_event.c new file mode 100644 index 00000000000..a876d5ff389 --- /dev/null +++ b/arch/metag/kernel/perf/perf_event.c @@ -0,0 +1,861 @@ +/* + * Meta performance counter support. + * Copyright (C) 2012 Imagination Technologies Ltd + * + * This code is based on the sh pmu code: + * Copyright (C) 2009 Paul Mundt + * + * and on the arm pmu code: + * Copyright (C) 2009 picoChip Designs, Ltd., James Iles + * Copyright (C) 2010 ARM Ltd., Will Deacon <will.deacon@arm.com> + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include <linux/atomic.h> +#include <linux/export.h> +#include <linux/init.h> +#include <linux/irqchip/metag.h> +#include <linux/perf_event.h> +#include <linux/slab.h> + +#include <asm/core_reg.h> +#include <asm/hwthread.h> +#include <asm/io.h> +#include <asm/irq.h> + +#include "perf_event.h" + +static int _hw_perf_event_init(struct perf_event *); +static void _hw_perf_event_destroy(struct perf_event *); + +/* Determines which core type we are */ +static struct metag_pmu *metag_pmu __read_mostly; + +/* Processor specific data */ +static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events); + +/* PMU admin */ +const char *perf_pmu_name(void) +{ + if (metag_pmu) + return metag_pmu->pmu.name; + + return NULL; +} +EXPORT_SYMBOL_GPL(perf_pmu_name); + +int perf_num_counters(void) +{ + if (metag_pmu) + return metag_pmu->max_events; + + return 0; +} +EXPORT_SYMBOL_GPL(perf_num_counters); + +static inline int metag_pmu_initialised(void) +{ + return !!metag_pmu; +} + +static void release_pmu_hardware(void) +{ + int irq; + unsigned int version = (metag_pmu->version & + (METAC_ID_MINOR_BITS | METAC_ID_REV_BITS)) >> + METAC_ID_REV_S; + + /* Early cores don't have overflow interrupts */ + if (version < 0x0104) + return; + + irq = internal_irq_map(17); + if (irq >= 0) + free_irq(irq, (void *)1); + + irq = internal_irq_map(16); + if (irq >= 0) + free_irq(irq, (void *)0); +} + +static int reserve_pmu_hardware(void) +{ + int err = 0, irq[2]; + unsigned int version = (metag_pmu->version & + (METAC_ID_MINOR_BITS | METAC_ID_REV_BITS)) >> + METAC_ID_REV_S; + + /* Early cores don't have overflow interrupts */ + if (version < 0x0104) + goto out; + + /* + * Bit 16 on HWSTATMETA is the interrupt for performance counter 0; + * similarly, 17 is the interrupt for performance counter 1. + * We can't (yet) interrupt on the cycle counter, because it's a + * register, however it holds a 32-bit value as opposed to 24-bit. + */ + irq[0] = internal_irq_map(16); + if (irq[0] < 0) { + pr_err("unable to map internal IRQ %d\n", 16); + goto out; + } + err = request_irq(irq[0], metag_pmu->handle_irq, IRQF_NOBALANCING, + "metagpmu0", (void *)0); + if (err) { + pr_err("unable to request IRQ%d for metag PMU counters\n", + irq[0]); + goto out; + } + + irq[1] = internal_irq_map(17); + if (irq[1] < 0) { + pr_err("unable to map internal IRQ %d\n", 17); + goto out_irq1; + } + err = request_irq(irq[1], metag_pmu->handle_irq, IRQF_NOBALANCING, + "metagpmu1", (void *)1); + if (err) { + pr_err("unable to request IRQ%d for metag PMU counters\n", + irq[1]); + goto out_irq1; + } + + return 0; + +out_irq1: + free_irq(irq[0], (void *)0); +out: + return err; +} + +/* PMU operations */ +static void metag_pmu_enable(struct pmu *pmu) +{ +} + +static void metag_pmu_disable(struct pmu *pmu) +{ +} + +static int metag_pmu_event_init(struct perf_event *event) +{ + int err = 0; + atomic_t *active_events = &metag_pmu->active_events; + + if (!metag_pmu_initialised()) { + err = -ENODEV; + goto out; + } + + if (has_branch_stack(event)) + return -EOPNOTSUPP; + + event->destroy = _hw_perf_event_destroy; + + if (!atomic_inc_not_zero(active_events)) { + mutex_lock(&metag_pmu->reserve_mutex); + if (atomic_read(active_events) == 0) + err = reserve_pmu_hardware(); + + if (!err) + atomic_inc(active_events); + + mutex_unlock(&metag_pmu->reserve_mutex); + } + + /* Hardware and caches counters */ + switch (event->attr.type) { + case PERF_TYPE_HARDWARE: + case PERF_TYPE_HW_CACHE: + err = _hw_perf_event_init(event); + break; + + default: + return -ENOENT; + } + + if (err) + event->destroy(event); + +out: + return err; +} + +void metag_pmu_event_update(struct perf_event *event, + struct hw_perf_event *hwc, int idx) +{ + u64 prev_raw_count, new_raw_count; + s64 delta; + + /* + * If this counter is chained, it may be that the previous counter + * value has been changed beneath us. + * + * To get around this, we read and exchange the new raw count, then + * add the delta (new - prev) to the generic counter atomically. + * + * Without interrupts, this is the simplest approach. + */ +again: + prev_raw_count = local64_read(&hwc->prev_count); + new_raw_count = metag_pmu->read(idx); + + if (local64_cmpxchg(&hwc->prev_count, prev_raw_count, + new_raw_count) != prev_raw_count) + goto again; + + /* + * Calculate the delta and add it to the counter. + */ + delta = new_raw_count - prev_raw_count; + + local64_add(delta, &event->count); +} + +int metag_pmu_event_set_period(struct perf_event *event, + struct hw_perf_event *hwc, int idx) +{ + 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)metag_pmu->max_period) + left = metag_pmu->max_period; + + if (metag_pmu->write) + metag_pmu->write(idx, (u64)(-left) & MAX_PERIOD); + + perf_event_update_userpage(event); + + return ret; +} + +static void metag_pmu_start(struct perf_event *event, int flags) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct hw_perf_event *hwc = &event->hw; + int idx = hwc->idx; + + if (WARN_ON_ONCE(idx == -1)) + return; + + /* + * We always have to reprogram the period, so ignore PERF_EF_RELOAD. + */ + if (flags & PERF_EF_RELOAD) + WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE)); + + hwc->state = 0; + + /* + * Reset the period. + * Some counters can't be stopped (i.e. are core global), so when the + * counter was 'stopped' we merely disabled the IRQ. If we don't reset + * the period, then we'll either: a) get an overflow too soon; + * or b) too late if the overflow happened since disabling. + * Obviously, this has little bearing on cores without the overflow + * interrupt, as the performance counter resets to zero on write + * anyway. + */ + if (metag_pmu->max_period) + metag_pmu_event_set_period(event, hwc, hwc->idx); + cpuc->events[idx] = event; + metag_pmu->enable(hwc, idx); +} + +static void metag_pmu_stop(struct perf_event *event, int flags) +{ + struct hw_perf_event *hwc = &event->hw; + + /* + * We should always update the counter on stop; see comment above + * why. + */ + if (!(hwc->state & PERF_HES_STOPPED)) { + metag_pmu_event_update(event, hwc, hwc->idx); + metag_pmu->disable(hwc, hwc->idx); + hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; + } +} + +static int metag_pmu_add(struct perf_event *event, int flags) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct hw_perf_event *hwc = &event->hw; + int idx = 0, ret = 0; + + perf_pmu_disable(event->pmu); + + /* check whether we're counting instructions */ + if (hwc->config == 0x100) { + if (__test_and_set_bit(METAG_INST_COUNTER, + cpuc->used_mask)) { + ret = -EAGAIN; + goto out; + } + idx = METAG_INST_COUNTER; + } else { + /* Check whether we have a spare counter */ + idx = find_first_zero_bit(cpuc->used_mask, + atomic_read(&metag_pmu->active_events)); + if (idx >= METAG_INST_COUNTER) { + ret = -EAGAIN; + goto out; + } + + __set_bit(idx, cpuc->used_mask); + } + hwc->idx = idx; + + /* Make sure the counter is disabled */ + metag_pmu->disable(hwc, idx); + + hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE; + if (flags & PERF_EF_START) + metag_pmu_start(event, PERF_EF_RELOAD); + + perf_event_update_userpage(event); +out: + perf_pmu_enable(event->pmu); + return ret; +} + +static void metag_pmu_del(struct perf_event *event, int flags) +{ + 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); + metag_pmu_stop(event, PERF_EF_UPDATE); + cpuc->events[idx] = NULL; + __clear_bit(idx, cpuc->used_mask); + + perf_event_update_userpage(event); +} + +static void metag_pmu_read(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + + /* Don't read disabled counters! */ + if (hwc->idx < 0) + return; + + metag_pmu_event_update(event, hwc, hwc->idx); +} + +static struct pmu pmu = { + .pmu_enable = metag_pmu_enable, + .pmu_disable = metag_pmu_disable, + + .event_init = metag_pmu_event_init, + + .add = metag_pmu_add, + .del = metag_pmu_del, + .start = metag_pmu_start, + .stop = metag_pmu_stop, + .read = metag_pmu_read, +}; + +/* Core counter specific functions */ +static const int metag_general_events[] = { + [PERF_COUNT_HW_CPU_CYCLES] = 0x03, + [PERF_COUNT_HW_INSTRUCTIONS] = 0x100, + [PERF_COUNT_HW_CACHE_REFERENCES] = -1, + [PERF_COUNT_HW_CACHE_MISSES] = -1, + [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = -1, + [PERF_COUNT_HW_BRANCH_MISSES] = -1, + [PERF_COUNT_HW_BUS_CYCLES] = -1, + [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = -1, + [PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = -1, + [PERF_COUNT_HW_REF_CPU_CYCLES] = -1, +}; + +static const int metag_pmu_cache_events[C(MAX)][C(OP_MAX)][C(RESULT_MAX)] = { + [C(L1D)] = { + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = 0x08, + [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(L1I)] = { + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = 0x09, + [C(RESULT_MISS)] = 0x0a, + }, + [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)] = 0xd0, + [C(RESULT_MISS)] = 0xd2, + }, + [C(OP_WRITE)] = { + [C(RESULT_ACCESS)] = 0xd4, + [C(RESULT_MISS)] = 0xd5, + }, + [C(OP_PREFETCH)] = { + [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED, + [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED, + }, + }, + [C(ITLB)] = { + [C(OP_READ)] = { + [C(RESULT_ACCESS)] = 0xd1, + [C(RESULT_MISS)] = 0xd3, + }, + [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)] = 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(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, + }, + }, +}; + + +static void _hw_perf_event_destroy(struct perf_event *event) +{ + atomic_t *active_events = &metag_pmu->active_events; + struct mutex *pmu_mutex = &metag_pmu->reserve_mutex; + + if (atomic_dec_and_mutex_lock(active_events, pmu_mutex)) { + release_pmu_hardware(); + mutex_unlock(pmu_mutex); + } +} + +static int _hw_perf_cache_event(int config, int *evp) +{ + unsigned long type, op, result; + int ev; + + if (!metag_pmu->cache_events) + return -EINVAL; + + /* Unpack config */ + type = config & 0xff; + op = (config >> 8) & 0xff; + result = (config >> 16) & 0xff; + + if (type >= PERF_COUNT_HW_CACHE_MAX || + op >= PERF_COUNT_HW_CACHE_OP_MAX || + result >= PERF_COUNT_HW_CACHE_RESULT_MAX) + return -EINVAL; + + ev = (*metag_pmu->cache_events)[type][op][result]; + if (ev == 0) + return -EOPNOTSUPP; + if (ev == -1) + return -EINVAL; + *evp = ev; + return 0; +} + +static int _hw_perf_event_init(struct perf_event *event) +{ + struct perf_event_attr *attr = &event->attr; + struct hw_perf_event *hwc = &event->hw; + int mapping = 0, err; + + switch (attr->type) { + case PERF_TYPE_HARDWARE: + if (attr->config >= PERF_COUNT_HW_MAX) + return -EINVAL; + + mapping = metag_pmu->event_map(attr->config); + break; + + case PERF_TYPE_HW_CACHE: + err = _hw_perf_cache_event(attr->config, &mapping); + if (err) + return err; + break; + } + + /* Return early if the event is unsupported */ + if (mapping == -1) + return -EINVAL; + + /* + * Early cores have "limited" counters - they have no overflow + * interrupts - and so are unable to do sampling without extra work + * and timer assistance. + */ + if (metag_pmu->max_period == 0) { + if (hwc->sample_period) + return -EINVAL; + } + + /* + * Don't assign an index until the event is placed into the hardware. + * -1 signifies that we're still deciding where to put it. On SMP + * systems each core has its own set of counters, so we can't do any + * constraint checking yet. + */ + hwc->idx = -1; + + /* Store the event encoding */ + hwc->config |= (unsigned long)mapping; + + /* + * For non-sampling runs, limit the sample_period to half of the + * counter width. This way, the new counter value should be less + * likely to overtake the previous one (unless there are IRQ latency + * issues...) + */ + if (metag_pmu->max_period) { + if (!hwc->sample_period) { + hwc->sample_period = metag_pmu->max_period >> 1; + hwc->last_period = hwc->sample_period; + local64_set(&hwc->period_left, hwc->sample_period); + } + } + + return 0; +} + +static void metag_pmu_enable_counter(struct hw_perf_event *event, int idx) +{ + struct cpu_hw_events *events = &__get_cpu_var(cpu_hw_events); + unsigned int config = event->config; + unsigned int tmp = config & 0xf0; + unsigned long flags; + + raw_spin_lock_irqsave(&events->pmu_lock, flags); + + /* + * Check if we're enabling the instruction counter (index of + * MAX_HWEVENTS - 1) + */ + if (METAG_INST_COUNTER == idx) { + WARN_ONCE((config != 0x100), + "invalid configuration (%d) for counter (%d)\n", + config, idx); + + /* Reset the cycle count */ + __core_reg_set(TXTACTCYC, 0); + goto unlock; + } + + /* Check for a core internal or performance channel event. */ + if (tmp) { + void *perf_addr = (void *)PERF_COUNT(idx); + + /* + * Anything other than a cycle count will write the low- + * nibble to the correct counter register. + */ + switch (tmp) { + case 0xd0: + perf_addr = (void *)PERF_ICORE(idx); + break; + + case 0xf0: + perf_addr = (void *)PERF_CHAN(idx); + break; + } + + metag_out32((tmp & 0x0f), perf_addr); + + /* + * Now we use the high nibble as the performance event to + * to count. + */ + config = tmp >> 4; + } + + /* + * Enabled counters start from 0. Early cores clear the count on + * write but newer cores don't, so we make sure that the count is + * set to 0. + */ + tmp = ((config & 0xf) << 28) | + ((1 << 24) << cpu_2_hwthread_id[get_cpu()]); + metag_out32(tmp, PERF_COUNT(idx)); +unlock: + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); +} + +static void metag_pmu_disable_counter(struct hw_perf_event *event, int idx) +{ + struct cpu_hw_events *events = &__get_cpu_var(cpu_hw_events); + unsigned int tmp = 0; + unsigned long flags; + + /* + * The cycle counter can't be disabled per se, as it's a hardware + * thread register which is always counting. We merely return if this + * is the counter we're attempting to disable. + */ + if (METAG_INST_COUNTER == idx) + return; + + /* + * The counter value _should_ have been read prior to disabling, + * as if we're running on an early core then the value gets reset to + * 0, and any read after that would be useless. On the newer cores, + * however, it's better to read-modify-update this for purposes of + * the overflow interrupt. + * Here we remove the thread id AND the event nibble (there are at + * least two events that count events that are core global and ignore + * the thread id mask). This only works because we don't mix thread + * performance counts, and event 0x00 requires a thread id mask! + */ + raw_spin_lock_irqsave(&events->pmu_lock, flags); + + tmp = metag_in32(PERF_COUNT(idx)); + tmp &= 0x00ffffff; + metag_out32(tmp, PERF_COUNT(idx)); + + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); +} + +static u64 metag_pmu_read_counter(int idx) +{ + u32 tmp = 0; + + /* The act of reading the cycle counter also clears it */ + if (METAG_INST_COUNTER == idx) { + __core_reg_swap(TXTACTCYC, tmp); + goto out; + } + + tmp = metag_in32(PERF_COUNT(idx)) & 0x00ffffff; +out: + return tmp; +} + +static void metag_pmu_write_counter(int idx, u32 val) +{ + struct cpu_hw_events *events = &__get_cpu_var(cpu_hw_events); + u32 tmp = 0; + unsigned long flags; + + /* + * This _shouldn't_ happen, but if it does, then we can just + * ignore the write, as the register is read-only and clear-on-write. + */ + if (METAG_INST_COUNTER == idx) + return; + + /* + * We'll keep the thread mask and event id, and just update the + * counter itself. Also , we should bound the value to 24-bits. + */ + raw_spin_lock_irqsave(&events->pmu_lock, flags); + + val &= 0x00ffffff; + tmp = metag_in32(PERF_COUNT(idx)) & 0xff000000; + val |= tmp; + metag_out32(val, PERF_COUNT(idx)); + + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); +} + +static int metag_pmu_event_map(int idx) +{ + return metag_general_events[idx]; +} + +static irqreturn_t metag_pmu_counter_overflow(int irq, void *dev) +{ + int idx = (int)dev; + struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); + struct perf_event *event = cpuhw->events[idx]; + struct hw_perf_event *hwc = &event->hw; + struct pt_regs *regs = get_irq_regs(); + struct perf_sample_data sampledata; + unsigned long flags; + u32 counter = 0; + + /* + * We need to stop the core temporarily from generating another + * interrupt while we disable this counter. However, we don't want + * to flag the counter as free + */ + __global_lock2(flags); + counter = metag_in32(PERF_COUNT(idx)); + metag_out32((counter & 0x00ffffff), PERF_COUNT(idx)); + __global_unlock2(flags); + + /* Update the counts and reset the sample period */ + metag_pmu_event_update(event, hwc, idx); + perf_sample_data_init(&sampledata, 0, hwc->last_period); + metag_pmu_event_set_period(event, hwc, idx); + + /* + * Enable the counter again once core overflow processing has + * completed. + */ + if (!perf_event_overflow(event, &sampledata, regs)) + metag_out32(counter, PERF_COUNT(idx)); + + return IRQ_HANDLED; +} + +static struct metag_pmu _metag_pmu = { + .handle_irq = metag_pmu_counter_overflow, + .enable = metag_pmu_enable_counter, + .disable = metag_pmu_disable_counter, + .read = metag_pmu_read_counter, + .write = metag_pmu_write_counter, + .event_map = metag_pmu_event_map, + .cache_events = &metag_pmu_cache_events, + .max_period = MAX_PERIOD, + .max_events = MAX_HWEVENTS, +}; + +/* PMU CPU hotplug notifier */ +static int __cpuinit metag_pmu_cpu_notify(struct notifier_block *b, + unsigned long action, void *hcpu) +{ + unsigned int cpu = (unsigned int)hcpu; + struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); + + if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING) + return NOTIFY_DONE; + + memset(cpuc, 0, sizeof(struct cpu_hw_events)); + raw_spin_lock_init(&cpuc->pmu_lock); + + return NOTIFY_OK; +} + +static struct notifier_block __cpuinitdata metag_pmu_notifier = { + .notifier_call = metag_pmu_cpu_notify, +}; + +/* PMU Initialisation */ +static int __init init_hw_perf_events(void) +{ + int ret = 0, cpu; + u32 version = *(u32 *)METAC_ID; + int major = (version & METAC_ID_MAJOR_BITS) >> METAC_ID_MAJOR_S; + int min_rev = (version & (METAC_ID_MINOR_BITS | METAC_ID_REV_BITS)) + >> METAC_ID_REV_S; + + /* Not a Meta 2 core, then not supported */ + if (0x02 > major) { + pr_info("no hardware counter support available\n"); + goto out; + } else if (0x02 == major) { + metag_pmu = &_metag_pmu; + + if (min_rev < 0x0104) { + /* + * A core without overflow interrupts, and clear-on- + * write counters. + */ + metag_pmu->handle_irq = NULL; + metag_pmu->write = NULL; + metag_pmu->max_period = 0; + } + + metag_pmu->name = "Meta 2"; + metag_pmu->version = version; + metag_pmu->pmu = pmu; + } + + pr_info("enabled with %s PMU driver, %d counters available\n", + metag_pmu->name, metag_pmu->max_events); + + /* Initialise the active events and reservation mutex */ + atomic_set(&metag_pmu->active_events, 0); + mutex_init(&metag_pmu->reserve_mutex); + + /* Clear the counters */ + metag_out32(0, PERF_COUNT(0)); + metag_out32(0, PERF_COUNT(1)); + + for_each_possible_cpu(cpu) { + struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); + + memset(cpuc, 0, sizeof(struct cpu_hw_events)); + raw_spin_lock_init(&cpuc->pmu_lock); + } + + register_cpu_notifier(&metag_pmu_notifier); + ret = perf_pmu_register(&pmu, (char *)metag_pmu->name, PERF_TYPE_RAW); +out: + return ret; +} +early_initcall(init_hw_perf_events); diff --git a/arch/metag/kernel/perf/perf_event.h b/arch/metag/kernel/perf/perf_event.h new file mode 100644 index 00000000000..fd10a1345b6 --- /dev/null +++ b/arch/metag/kernel/perf/perf_event.h @@ -0,0 +1,106 @@ +/* + * Meta performance counter support. + * Copyright (C) 2012 Imagination Technologies Ltd + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#ifndef METAG_PERF_EVENT_H_ +#define METAG_PERF_EVENT_H_ + +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/perf_event.h> + +/* For performance counter definitions */ +#include <asm/metag_mem.h> + +/* + * The Meta core has two performance counters, with 24-bit resolution. Newer + * cores generate an overflow interrupt on transition from 0xffffff to 0. + * + * Each counter consists of the counter id, hardware thread id, and the count + * itself; each counter can be assigned to multiple hardware threads at any + * one time, with the returned count being an aggregate of events. A small + * number of events are thread global, i.e. they count the aggregate of all + * threads' events, regardless of the thread selected. + * + * Newer cores can store an arbitrary 24-bit number in the counter, whereas + * older cores will clear the counter bits on write. + * + * We also have a pseudo-counter in the form of the thread active cycles + * counter (which, incidentally, is also bound to + */ + +#define MAX_HWEVENTS 3 +#define MAX_PERIOD ((1UL << 24) - 1) +#define METAG_INST_COUNTER (MAX_HWEVENTS - 1) + +/** + * struct cpu_hw_events - a processor core's performance events + * @events: an array of perf_events active for a given index. + * @used_mask: a bitmap of in-use counters. + * @pmu_lock: a perf counter lock + * + * This is a per-cpu/core structure that maintains a record of its + * performance counters' state. + */ +struct cpu_hw_events { + struct perf_event *events[MAX_HWEVENTS]; + unsigned long used_mask[BITS_TO_LONGS(MAX_HWEVENTS)]; + raw_spinlock_t pmu_lock; +}; + +/** + * struct metag_pmu - the Meta PMU structure + * @pmu: core pmu structure + * @name: pmu name + * @version: core version + * @handle_irq: overflow interrupt handler + * @enable: enable a counter + * @disable: disable a counter + * @read: read the value of a counter + * @write: write a value to a counter + * @event_map: kernel event to counter event id map + * @cache_events: kernel cache counter to core cache counter map + * @max_period: maximum value of the counter before overflow + * @max_events: maximum number of counters available at any one time + * @active_events: number of active counters + * @reserve_mutex: counter reservation mutex + * + * This describes the main functionality and data used by the performance + * event core. + */ +struct metag_pmu { + struct pmu pmu; + const char *name; + u32 version; + 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); + u64 (*read)(int idx); + void (*write)(int idx, u32 val); + int (*event_map)(int idx); + const int (*cache_events)[PERF_COUNT_HW_CACHE_MAX] + [PERF_COUNT_HW_CACHE_OP_MAX] + [PERF_COUNT_HW_CACHE_RESULT_MAX]; + u32 max_period; + int max_events; + atomic_t active_events; + struct mutex reserve_mutex; +}; + +/* Convenience macros for accessing the perf counters */ +/* Define some convenience accessors */ +#define PERF_COUNT(x) (PERF_COUNT0 + (sizeof(u64) * (x))) +#define PERF_ICORE(x) (PERF_ICORE0 + (sizeof(u64) * (x))) +#define PERF_CHAN(x) (PERF_CHAN0 + (sizeof(u64) * (x))) + +/* Cache index macros */ +#define C(x) PERF_COUNT_HW_CACHE_##x +#define CACHE_OP_UNSUPPORTED 0xfffe +#define CACHE_OP_NONSENSE 0xffff + +#endif diff --git a/arch/metag/kernel/perf_callchain.c b/arch/metag/kernel/perf_callchain.c new file mode 100644 index 00000000000..315633461a9 --- /dev/null +++ b/arch/metag/kernel/perf_callchain.c @@ -0,0 +1,96 @@ +/* + * Perf callchain handling code. + * + * Based on the ARM perf implementation. + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/perf_event.h> +#include <linux/uaccess.h> +#include <asm/ptrace.h> +#include <asm/stacktrace.h> + +static bool is_valid_call(unsigned long calladdr) +{ + unsigned int callinsn; + + /* Check the possible return address is aligned. */ + if (!(calladdr & 0x3)) { + if (!get_user(callinsn, (unsigned int *)calladdr)) { + /* Check for CALLR or SWAP PC,D1RtP. */ + if ((callinsn & 0xff000000) == 0xab000000 || + callinsn == 0xa3200aa0) + return true; + } + } + return false; +} + +static struct metag_frame __user * +user_backtrace(struct metag_frame __user *user_frame, + struct perf_callchain_entry *entry) +{ + struct metag_frame frame; + unsigned long calladdr; + + /* We cannot rely on having frame pointers in user code. */ + while (1) { + /* Also check accessibility of one struct frame beyond */ + if (!access_ok(VERIFY_READ, user_frame, sizeof(frame))) + return 0; + if (__copy_from_user_inatomic(&frame, user_frame, + sizeof(frame))) + return 0; + + --user_frame; + + calladdr = frame.lr - 4; + if (is_valid_call(calladdr)) { + perf_callchain_store(entry, calladdr); + return user_frame; + } + } + + return 0; +} + +void +perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs) +{ + unsigned long sp = regs->ctx.AX[0].U0; + struct metag_frame __user *frame; + + frame = (struct metag_frame __user *)sp; + + --frame; + + while ((entry->nr < PERF_MAX_STACK_DEPTH) && frame) + frame = user_backtrace(frame, 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; + perf_callchain_store(entry, fr->pc); + return 0; +} + +void +perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) +{ + struct stackframe fr; + + fr.fp = regs->ctx.AX[1].U0; + fr.sp = regs->ctx.AX[0].U0; + fr.lr = regs->ctx.DX[4].U1; + fr.pc = regs->ctx.CurrPC; + walk_stackframe(&fr, callchain_trace, entry); +} |