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>

1 files changed, 7 insertions, 1 deletions

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,