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authorWill Deacon <will.deacon@arm.com>2018-10-05 13:24:36 +0100
committerWill Deacon <will.deacon@arm.com>2018-10-12 15:25:17 +0100
commitca2b497253ad01c80061a1f3ee9eb91b5d54a849 (patch)
tree06b96eee97a7f40173136b35f8b3ff945ae5925f
parentd91680e687f47984ffd3200c8e5d587903e7bd11 (diff)
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: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
-rw-r--r--arch/arm64/kernel/perf_event.c7
-rw-r--r--drivers/perf/arm_pmu.c8
-rw-r--r--include/linux/perf/arm_pmu.h1
3 files changed, 15 insertions, 1 deletions
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 8e38d5267f22..e213f8e867f6 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -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;
}
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 7f01f6f60b87..d0b7dd8fb184 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -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,
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 10f92e1d8e7b..bf309ff6f244 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -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