perf pmu: Save pmu name

On hybrid platform, one event is available on one pmu
(such as, available on cpu_core or on cpu_atom).

This patch saves the pmu name to the pmu field of struct perf_pmu_alias.
Then next we can know the pmu which the event can be enabled on.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210427070139.25256-5-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/pmu.c

@@ -283,6 +283,7 @@ void perf_pmu_free_alias(struct perf_pmu_alias *newalias)
 	zfree(&newalias->str);
 	zfree(&newalias->metric_expr);
 	zfree(&newalias->metric_name);
+	zfree(&newalias->pmu_name);
 	parse_events_terms__purge(&newalias->terms);
 	free(newalias);
 }
@@ -297,6 +298,10 @@ static bool perf_pmu_merge_alias(struct perf_pmu_alias *newalias,
 
 	list_for_each_entry(a, alist, list) {
 		if (!strcasecmp(newalias->name, a->name)) {
+			if (newalias->pmu_name && a->pmu_name &&
+			    !strcasecmp(newalias->pmu_name, a->pmu_name)) {
+				continue;
+			}
 			perf_pmu_update_alias(a, newalias);
 			perf_pmu_free_alias(newalias);
 			return true;
@@ -314,7 +319,8 @@ static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
 	int num;
 	char newval[256];
 	char *long_desc = NULL, *topic = NULL, *unit = NULL, *perpkg = NULL,
-	     *metric_expr = NULL, *metric_name = NULL, *deprecated = NULL;
+	     *metric_expr = NULL, *metric_name = NULL, *deprecated = NULL,
+	     *pmu_name = NULL;
 
 	if (pe) {
 		long_desc = (char *)pe->long_desc;
@@ -324,6 +330,7 @@ static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
 		metric_expr = (char *)pe->metric_expr;
 		metric_name = (char *)pe->metric_name;
 		deprecated = (char *)pe->deprecated;
+		pmu_name = (char *)pe->pmu;
 	}
 
 	alias = malloc(sizeof(*alias));
@@ -389,6 +396,7 @@ static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
 	}
 	alias->per_pkg = perpkg && sscanf(perpkg, "%d", &num) == 1 && num == 1;
 	alias->str = strdup(newval);
+	alias->pmu_name = pmu_name ? strdup(pmu_name) : NULL;
 
 	if (deprecated)
 		alias->deprecated = true;

tools/perf/util/pmu.h

@@ -72,6 +72,7 @@ struct perf_pmu_alias {
 	bool deprecated;
 	char *metric_expr;
 	char *metric_name;
+	char *pmu_name;
 };
 
 struct perf_pmu *perf_pmu__find(const char *name);