perf tools: Support pmu prefix for mem-store event

For enabling mem-store event, it doesn't need an auxiliary event.
So just build an event name string with the pmu prefix.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
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/20210527001610.10553-4-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/arch/x86/util/mem-events.c

@@ -5,6 +5,7 @@
 
 static char mem_loads_name[100];
 static bool mem_loads_name__init;
+static char mem_stores_name[100];
 
 #define MEM_LOADS_AUX		0x8203
 #define MEM_LOADS_AUX_NAME     "{%s/mem-loads-aux/,%s/mem-loads,ldlat=%u/}:P"
@@ -13,7 +14,7 @@ static bool mem_loads_name__init;
 
 static struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX] = {
 	E("ldlat-loads",	"%s/mem-loads,ldlat=%u/P",	"%s/events/mem-loads"),
-	E("ldlat-stores",	"cpu/mem-stores/P",		"cpu/events/mem-stores"),
+	E("ldlat-stores",	"%s/mem-stores/P",		"%s/events/mem-stores"),
 	E(NULL,			NULL,				NULL),
 };
 
@@ -66,5 +67,14 @@ char *perf_mem_events__name(int i, char *pmu_name)
 		return mem_loads_name;
 	}
 
+	if (i == PERF_MEM_EVENTS__STORE) {
+		if (!pmu_name)
+			pmu_name = (char *)"cpu";
+
+		scnprintf(mem_stores_name, sizeof(mem_stores_name),
+			  e->name, pmu_name);
+		return mem_stores_name;
+	}
+
 	return (char *)e->name;
 }