diff options
Diffstat (limited to 'arch/arm/kernel/perf_event.c')
| -rw-r--r-- | arch/arm/kernel/perf_event.c | 36 |
1 files changed, 27 insertions, 9 deletions
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 22e194eb8536..139e3c827369 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -79,6 +79,7 @@ struct arm_pmu { void (*write_counter)(int idx, u32 val); void (*start)(void); void (*stop)(void); + void (*reset)(void *); const unsigned (*cache_map)[PERF_COUNT_HW_CACHE_MAX] [PERF_COUNT_HW_CACHE_OP_MAX] [PERF_COUNT_HW_CACHE_RESULT_MAX]; @@ -204,11 +205,9 @@ armpmu_event_set_period(struct perf_event *event, static u64 armpmu_event_update(struct perf_event *event, struct hw_perf_event *hwc, - int idx) + int idx, int overflow) { - int shift = 64 - 32; - s64 prev_raw_count, new_raw_count; - u64 delta; + u64 delta, prev_raw_count, new_raw_count; again: prev_raw_count = local64_read(&hwc->prev_count); @@ -218,8 +217,13 @@ again: new_raw_count) != prev_raw_count) goto again; - delta = (new_raw_count << shift) - (prev_raw_count << shift); - delta >>= shift; + new_raw_count &= armpmu->max_period; + prev_raw_count &= armpmu->max_period; + + if (overflow) + delta = armpmu->max_period - prev_raw_count + new_raw_count + 1; + else + delta = new_raw_count - prev_raw_count; local64_add(delta, &event->count); local64_sub(delta, &hwc->period_left); @@ -236,7 +240,7 @@ armpmu_read(struct perf_event *event) if (hwc->idx < 0) return; - armpmu_event_update(event, hwc, hwc->idx); + armpmu_event_update(event, hwc, hwc->idx, 0); } static void @@ -254,7 +258,7 @@ armpmu_stop(struct perf_event *event, int flags) if (!(hwc->state & PERF_HES_STOPPED)) { armpmu->disable(hwc, hwc->idx); barrier(); /* why? */ - armpmu_event_update(event, hwc, hwc->idx); + armpmu_event_update(event, hwc, hwc->idx, 0); hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; } } @@ -624,6 +628,19 @@ static struct pmu pmu = { #include "perf_event_v6.c" #include "perf_event_v7.c" +/* + * Ensure the PMU has sane values out of reset. + * This requires SMP to be available, so exists as a separate initcall. + */ +static int __init +armpmu_reset(void) +{ + if (armpmu && armpmu->reset) + return on_each_cpu(armpmu->reset, NULL, 1); + return 0; +} +arch_initcall(armpmu_reset); + static int __init init_hw_perf_events(void) { @@ -729,7 +746,8 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs) tail = (struct frame_tail __user *)regs->ARM_fp - 1; - while (tail && !((unsigned long)tail & 0x3)) + while ((entry->nr < PERF_MAX_STACK_DEPTH) && + tail && !((unsigned long)tail & 0x3)) tail = user_backtrace(tail, entry); } |