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Commit ca2b4972 authored by Will Deacon's avatar Will Deacon
Browse files

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



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: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent d91680e6

arch/arm64/kernel/perf_event.c

+7 −0
Original line number Original line Diff line number Diff line
@@ -966,6 +966,12 @@ static int armv8pmu_set_event_filter(struct hw_perf_event *event, 
	return 0;

	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)

static void armv8pmu_reset(void *info)

{

{

	struct arm_pmu *cpu_pmu = (struct arm_pmu *)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->stop			= armv8pmu_stop,

	cpu_pmu->reset			= armv8pmu_reset,

	cpu_pmu->reset			= armv8pmu_reset,

	cpu_pmu->set_event_filter	= armv8pmu_set_event_filter;

	cpu_pmu->set_event_filter	= armv8pmu_set_event_filter;

	cpu_pmu->filter_match		= armv8pmu_filter_match;





	return 0;

	return 0;

}

}

drivers/perf/arm_pmu.c

+7 −1
Original line number Original line Diff line number Diff line
@@ -485,7 +485,13 @@ static int armpmu_filter_match(struct perf_event *event) 
{

{

	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);

	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);

	unsigned int cpu = smp_processor_id();

	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,

static ssize_t armpmu_cpumask_show(struct device *dev,

include/linux/perf/arm_pmu.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -99,6 +99,7 @@ struct arm_pmu { 
	void		(*stop)(struct arm_pmu *);

	void		(*stop)(struct arm_pmu *);

	void		(*reset)(void *);

	void		(*reset)(void *);

	int		(*map_event)(struct perf_event *event);

	int		(*map_event)(struct perf_event *event);

	int		(*filter_match)(struct perf_event *event);

	int		num_events;

	int		num_events;

	bool		secure_access; /* 32-bit ARM only */

	bool		secure_access; /* 32-bit ARM only */

#define ARMV8_PMUV3_MAX_COMMON_EVENTS 0x40

#define ARMV8_PMUV3_MAX_COMMON_EVENTS 0x40