perf mem: Introduce weak function perf_mem_events__ptr()

Different architectures might use different event or different event
parameters for memory profiling, this patch introduces a weak
perf_mem_events__ptr() function which allows to return back a
architecture specific memory event.

Since the variable 'perf_mem_events' can be only accessed by the
perf_mem_events__ptr() function, mark the variable as 'static', this
allows the architectures to define its own memory event array.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20201106094853.21082-3-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/mem-events.h b/tools/perf/util/mem-events.h
index 904dad3..726a9c8 100644
--- a/tools/perf/util/mem-events.h
+++ b/tools/perf/util/mem-events.h
@@ -31,13 +31,13 @@ enum {
 	PERF_MEM_EVENTS__MAX,
 };
 
-extern struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX];
 extern unsigned int perf_mem_events__loads_ldlat;
 
 int perf_mem_events__parse(const char *str);
 int perf_mem_events__init(void);
 
 char *perf_mem_events__name(int i);
+struct perf_mem_event *perf_mem_events__ptr(int i);
 
 void perf_mem_events__list(void);