perf pmus: Factor perf_pmus__find_by_attr out of evsel__find_pmu

Allow a PMU to be found by a perf_event_attr, useful when creating
evsels.

Reviewed-by: Thomas Falcon <thomas.falcon@intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250719030517.1990983-10-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Author: captain5050

tools/perf/util/pmus.c

@@ -814,24 +814,18 @@ bool perf_pmus__supports_extended_type(void)
 	return perf_pmus__do_support_extended_type;
 }
 
-struct perf_pmu *evsel__find_pmu(const struct evsel *evsel)
+struct perf_pmu *perf_pmus__find_by_attr(const struct perf_event_attr *attr)
 {
-	struct perf_pmu *pmu = evsel->pmu;
-	bool legacy_core_type;
-
-	if (pmu)
-		return pmu;
+	struct perf_pmu *pmu = perf_pmus__find_by_type(attr->type);
+	u32 type = attr->type;
+	bool legacy_core_type = type == PERF_TYPE_HARDWARE || type == PERF_TYPE_HW_CACHE;
 
-	pmu = perf_pmus__find_by_type(evsel->core.attr.type);
-	legacy_core_type =
-		evsel->core.attr.type == PERF_TYPE_HARDWARE ||
-		evsel->core.attr.type == PERF_TYPE_HW_CACHE;
 	if (!pmu && legacy_core_type && perf_pmus__supports_extended_type()) {
-		u32 type = evsel->core.attr.config >> PERF_PMU_TYPE_SHIFT;
+		type = attr->config >> PERF_PMU_TYPE_SHIFT;
 
 		pmu = perf_pmus__find_by_type(type);
 	}
-	if (!pmu && (legacy_core_type || evsel->core.attr.type == PERF_TYPE_RAW)) {
+	if (!pmu && (legacy_core_type || type == PERF_TYPE_RAW)) {
 		/*
 		 * For legacy events, if there was no extended type info then
 		 * assume the PMU is the first core PMU.
@@ -842,6 +836,17 @@ struct perf_pmu *evsel__find_pmu(const struct evsel *evsel)
 		 */
 		pmu = perf_pmus__find_core_pmu();
 	}
+	return pmu;
+}
+
+struct perf_pmu *evsel__find_pmu(const struct evsel *evsel)
+{
+	struct perf_pmu *pmu = evsel->pmu;
+
+	if (pmu)
+		return pmu;
+
+	pmu = perf_pmus__find_by_attr(&evsel->core.attr);
 	((struct evsel *)evsel)->pmu = pmu;
 	return pmu;
 }

tools/perf/util/pmus.h

@@ -5,6 +5,7 @@
 #include <stdbool.h>
 #include <stddef.h>
 
+struct perf_event_attr;
 struct perf_pmu;
 struct print_callbacks;
 
@@ -16,6 +17,7 @@ void perf_pmus__destroy(void);
 
 struct perf_pmu *perf_pmus__find(const char *name);
 struct perf_pmu *perf_pmus__find_by_type(unsigned int type);
+struct perf_pmu *perf_pmus__find_by_attr(const struct perf_event_attr *attr);
 
 struct perf_pmu *perf_pmus__scan(struct perf_pmu *pmu);
 struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu);