From: Yicong Yang <yangyicong@hisilicon.com> driver inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICXCYF ---------------------------------------------------------------------- PMCCNTR_EL0 is preferred for counting CPU_CYCLES under certain conditions. Factor out the condition check to a separate function for further extension. Add documents for better understanding. No functional changes intended. Fixes: 81e15ca3e523 ("perf: arm_pmuv3: Avoid assigning fixed cycle counter with threshold") Reviewed-by: James Clark <james.clark@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Qizhi Zhang <zhangqizhi3@h-partners.com> --- drivers/perf/arm_pmuv3.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c index 52ccd3d4b883..63740d8ef5d6 100644 --- a/drivers/perf/arm_pmuv3.c +++ b/drivers/perf/arm_pmuv3.c @@ -1177,6 +1177,25 @@ static int armv8pmu_get_hw_metric_event_idx(struct pmu_hw_events *cpuc, return leader_idx - 1; } +static bool armv8pmu_can_use_pmccntr(struct pmu_hw_events *cpuc, + struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + unsigned long evtype = hwc->config_base & ARMV8_PMU_EVTYPE_EVENT; + + if (evtype != ARMV8_PMUV3_PERFCTR_CPU_CYCLES) + return false; + + /* + * A CPU_CYCLES event with threshold counting cannot use PMCCNTR_EL0 + * since it lacks threshold support. + */ + if (armv8pmu_event_get_threshold(&event->attr)) + return false; + + return true; +} + static int armv8pmu_get_event_idx(struct pmu_hw_events *cpuc, struct perf_event *event) { @@ -1191,8 +1210,7 @@ static int armv8pmu_get_event_idx(struct pmu_hw_events *cpuc, return -EINVAL; /* Always prefer to place a cycle counter into the cycle counter. */ - if ((evtype == ARMV8_PMUV3_PERFCTR_CPU_CYCLES) && - !armv8pmu_event_get_threshold(&event->attr)) { + if (armv8pmu_can_use_pmccntr(cpuc, event)) { if (!test_and_set_bit(ARMV8_IDX_CYCLE_COUNTER, cpuc->used_mask)) return ARMV8_IDX_CYCLE_COUNTER; else if (armv8pmu_event_is_64bit(event) && -- 2.33.0