perf: arm_cspmu: Support implementation specific validation

Some platforms may use e.g. different filtering mechanism and, thus,
may need different way to validate the events and group.
Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230913233941.9814-4-ilkka@os.amperecomputing.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/arm_cspmu/arm_cspmu.c

@@ -576,7 +576,7 @@ static void arm_cspmu_disable(struct pmu *pmu)
 static int arm_cspmu_get_event_idx(struct arm_cspmu_hw_events *hw_events,
 				struct perf_event *event)
 {
-	int idx;
+	int idx, ret;
 	struct arm_cspmu *cspmu = to_arm_cspmu(event->pmu);
 
 	if (supports_cycle_counter(cspmu)) {
@@ -610,6 +610,12 @@ static int arm_cspmu_get_event_idx(struct arm_cspmu_hw_events *hw_events,
 	if (idx >= cspmu->num_logical_ctrs)
 		return -EAGAIN;
 
+	if (cspmu->impl.ops.validate_event) {
+		ret = cspmu->impl.ops.validate_event(cspmu, event);
+		if (ret)
+			return ret;
+	}
+
 	set_bit(idx, hw_events->used_ctrs);
 
 	return idx;

drivers/perf/arm_cspmu/arm_cspmu.h

@@ -107,6 +107,9 @@ struct arm_cspmu_impl_ops {
 	/* Set event filter */
 	void (*set_ev_filter)(struct arm_cspmu *cspmu,
 			      struct hw_perf_event *hwc, u32 filter);
+	/* Implementation specific event validation */
+	int (*validate_event)(struct arm_cspmu *cspmu,
+			      struct perf_event *event);
 	/* Hide/show unsupported events */
 	umode_t (*event_attr_is_visible)(struct kobject *kobj,
 					 struct attribute *attr, int unused);