4.18-stable review patch. If anyone has any objections, please let me know.
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From: Will Deacon will.deacon@arm.com
commit ca2b497253ad01c80061a1f3ee9eb91b5d54a849 upstream.
It doesn't make sense for a perf event to be configured as a CHAIN event in isolation, so extend the arm_pmu structure with a ->filter_match() function to allow the backend PMU implementation to reject CHAIN events early.
Cc: stable@vger.kernel.org Reviewed-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm64/kernel/perf_event.c | 7 +++++++ drivers/perf/arm_pmu.c | 8 +++++++- include/linux/perf/arm_pmu.h | 1 + 3 files changed, 15 insertions(+), 1 deletion(-)
--- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -823,6 +823,12 @@ static int armv8pmu_set_event_filter(str return 0; }
+static int armv8pmu_filter_match(struct perf_event *event) +{ + unsigned long evtype = event->hw.config_base & ARMV8_PMU_EVTYPE_EVENT; + return evtype != ARMV8_PMUV3_PERFCTR_CHAIN; +} + static void armv8pmu_reset(void *info) { struct arm_pmu *cpu_pmu = (struct arm_pmu *)info; @@ -968,6 +974,7 @@ static int armv8_pmu_init(struct arm_pmu cpu_pmu->reset = armv8pmu_reset, cpu_pmu->max_period = (1LLU << 32) - 1, cpu_pmu->set_event_filter = armv8pmu_set_event_filter; + cpu_pmu->filter_match = armv8pmu_filter_match;
return 0; } --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -474,7 +474,13 @@ static int armpmu_filter_match(struct pe { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); unsigned int cpu = smp_processor_id(); - return cpumask_test_cpu(cpu, &armpmu->supported_cpus); + int ret; + + ret = cpumask_test_cpu(cpu, &armpmu->supported_cpus); + if (ret && armpmu->filter_match) + return armpmu->filter_match(event); + + return ret; }
static ssize_t armpmu_cpumask_show(struct device *dev, --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -93,6 +93,7 @@ struct arm_pmu { void (*stop)(struct arm_pmu *); void (*reset)(void *); int (*map_event)(struct perf_event *event); + int (*filter_match)(struct perf_event *event); int num_events; u64 max_period; bool secure_access; /* 32-bit ARM only */