arm64: perf: Allow standard PMUv3 events to be extended by the CPU type

Rather than continue adding CPU-specific event maps, instead look up by
default in the PMUv3 event map and only fallback to the CPU-specific maps
if either the event isn't described by PMUv3, or it is described but
the PMCEID registers say that it is unsupported by the current CPU.

Signed-off-by: Will Deacon <will.deacon@arm.com>

2 files changed, 32 insertions, 20 deletions

diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 372317667773..b83f986e7fbf 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -921,7 +921,13 @@ static void armv8pmu_reset(void *info)
 			    ARMV8_PMU_PMCR_LC);
 }
 
-static int armv8_pmuv3_map_event(struct perf_event *event)
+static int __armv8_pmuv3_map_event(struct perf_event *event,
+				   const unsigned (*extra_event_map)
+						  [PERF_COUNT_HW_MAX],
+				   const unsigned (*extra_cache_map)
+						  [PERF_COUNT_HW_CACHE_MAX]
+						  [PERF_COUNT_HW_CACHE_OP_MAX]
+						  [PERF_COUNT_HW_CACHE_RESULT_MAX])
 {
 	int hw_event_id;
 	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
@@ -929,44 +935,44 @@ static int armv8_pmuv3_map_event(struct perf_event *event)
 	hw_event_id = armpmu_map_event(event, &armv8_pmuv3_perf_map,
 				       &armv8_pmuv3_perf_cache_map,
 				       ARMV8_PMU_EVTYPE_EVENT);
-	if (hw_event_id < 0)
-		return hw_event_id;
 
-	/* disable micro/arch events not supported by this PMU */
-	if ((hw_event_id < ARMV8_PMUV3_MAX_COMMON_EVENTS) &&
-		!test_bit(hw_event_id, armpmu->pmceid_bitmap)) {
-			return -EOPNOTSUPP;
+	/* Onl expose micro/arch events supported by this PMU */
+	if ((hw_event_id > 0) && (hw_event_id < ARMV8_PMUV3_MAX_COMMON_EVENTS)
+	    && test_bit(hw_event_id, armpmu->pmceid_bitmap)) {
+		return hw_event_id;
 	}
 
-	return hw_event_id;
+	return armpmu_map_event(event, extra_event_map, extra_cache_map,
+				ARMV8_PMU_EVTYPE_EVENT);
+}
+
+static int armv8_pmuv3_map_event(struct perf_event *event)
+{
+	return __armv8_pmuv3_map_event(event, NULL, NULL);
 }
 
 static int armv8_a53_map_event(struct perf_event *event)
 {
-	return armpmu_map_event(event, &armv8_a53_perf_map,
-				&armv8_a53_perf_cache_map,
-				ARMV8_PMU_EVTYPE_EVENT);
+	return __armv8_pmuv3_map_event(event, &armv8_a53_perf_map,
+				       &armv8_a53_perf_cache_map);
 }
 
 static int armv8_a57_map_event(struct perf_event *event)
 {
-	return armpmu_map_event(event, &armv8_a57_perf_map,
-				&armv8_a57_perf_cache_map,
-				ARMV8_PMU_EVTYPE_EVENT);
+	return __armv8_pmuv3_map_event(event, &armv8_a57_perf_map,
+				       &armv8_a57_perf_cache_map);
 }
 
 static int armv8_thunder_map_event(struct perf_event *event)
 {
-	return armpmu_map_event(event, &armv8_thunder_perf_map,
-				&armv8_thunder_perf_cache_map,
-				ARMV8_PMU_EVTYPE_EVENT);
+	return __armv8_pmuv3_map_event(event, &armv8_thunder_perf_map,
+				       &armv8_thunder_perf_cache_map);
 }
 
 static int armv8_vulcan_map_event(struct perf_event *event)
 {
-	return armpmu_map_event(event, &armv8_vulcan_perf_map,
-				&armv8_vulcan_perf_cache_map,
-				ARMV8_PMU_EVTYPE_EVENT);
+	return __armv8_pmuv3_map_event(event, &armv8_vulcan_perf_map,
+				       &armv8_vulcan_perf_cache_map);
 }
 
 struct armv8pmu_probe_info {
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 1c5e0f333779..d14fc2e67f93 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -47,6 +47,9 @@ armpmu_map_cache_event(const unsigned (*cache_map)
 	if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
 		return -EINVAL;
 
+	if (!cache_map)
+		return -ENOENT;
+
 	ret = (int)(*cache_map)[cache_type][cache_op][cache_result];
 
 	if (ret == CACHE_OP_UNSUPPORTED)
@@ -63,6 +66,9 @@ armpmu_map_hw_event(const unsigned (*event_map)[PERF_COUNT_HW_MAX], u64 config)
 	if (config >= PERF_COUNT_HW_MAX)
 		return -EINVAL;
 
+	if (!event_map)
+		return -ENOENT;
+
 	mapping = (*event_map)[config];
 	return mapping == HW_OP_UNSUPPORTED ? -ENOENT : mapping;
 }