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arm64: perf: Reject stand-alone CHAIN events for PMUv3

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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>
This commit is contained in:
Will Deacon 2018-10-05 13:24:36 +01:00
parent d91680e687
commit ca2b497253
3 changed files with 15 additions and 1 deletions
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7
arch/arm64/kernel/perf_event.c
View File

@ -966,6 +966,12 @@ static int armv8pmu_set_event_filter(struct hw_perf_event *event,
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;
@ -1114,6 +1120,7 @@ static int armv8_pmu_init(struct arm_pmu *cpu_pmu)
cpu_pmu->stop = armv8pmu_stop,
cpu_pmu->reset = armv8pmu_reset,
cpu_pmu->set_event_filter = armv8pmu_set_event_filter;
cpu_pmu->filter_match = armv8pmu_filter_match;
return 0;
}

8
drivers/perf/arm_pmu.c
View File

@ -485,7 +485,13 @@ static int armpmu_filter_match(struct perf_event *event)
{
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,

1
include/linux/perf/arm_pmu.h
View File

@ -99,6 +99,7 @@ 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;
bool secure_access; /* 32-bit ARM only */
#define ARMV8_PMUV3_MAX_COMMON_EVENTS 0x40