From 50be342829053d6d4a3c66eacc0e778f6611a37a Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti Date: Wed, 2 Aug 2023 10:03:24 +0200 Subject: drivers: perf: Implement perf event mmap support in the legacy backend Implement the needed callbacks in the legacy driver so that we can directly access the counters through perf in userspace. Signed-off-by: Alexandre Ghiti Reviewed-by: Andrew Jones Reviewed-by: Atish Patra --- drivers/perf/riscv_pmu_legacy.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'drivers/perf') diff --git a/drivers/perf/riscv_pmu_legacy.c b/drivers/perf/riscv_pmu_legacy.c index 6a000abc28bb..79fdd667922e 100644 --- a/drivers/perf/riscv_pmu_legacy.c +++ b/drivers/perf/riscv_pmu_legacy.c @@ -71,6 +71,29 @@ static void pmu_legacy_ctr_start(struct perf_event *event, u64 ival) local64_set(&hwc->prev_count, initial_val); } +static uint8_t pmu_legacy_csr_index(struct perf_event *event) +{ + return event->hw.idx; +} + +static void pmu_legacy_event_mapped(struct perf_event *event, struct mm_struct *mm) +{ + if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES && + event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) + return; + + event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT; +} + +static void pmu_legacy_event_unmapped(struct perf_event *event, struct mm_struct *mm) +{ + if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES && + event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) + return; + + event->hw.flags &= ~PERF_EVENT_FLAG_USER_READ_CNT; +} + /* * This is just a simple implementation to allow legacy implementations * compatible with new RISC-V PMU driver framework. @@ -91,6 +114,9 @@ static void pmu_legacy_init(struct riscv_pmu *pmu) pmu->ctr_get_width = NULL; pmu->ctr_clear_idx = NULL; pmu->ctr_read = pmu_legacy_read_ctr; + pmu->event_mapped = pmu_legacy_event_mapped; + pmu->event_unmapped = pmu_legacy_event_unmapped; + pmu->csr_index = pmu_legacy_csr_index; perf_pmu_register(&pmu->pmu, "cpu", PERF_TYPE_RAW); } -- cgit v1.2.3