perf pmu: Save detected hybrid pmus to a global pmu list

We identify the cpu_core pmu and cpu_atom pmu by explicitly
checking following files:

For cpu_core, checks:
"/sys/bus/event_source/devices/cpu_core/cpus"

For cpu_atom, checks:
"/sys/bus/event_source/devices/cpu_atom/cpus"

If the 'cpus' file exists and it has data, the pmu exists.

But in order not to hardcode the "cpu_core" and "cpu_atom",
and make the code in a generic way.

So if the path "/sys/bus/event_source/devices/cpu_xxx/cpus" exists, the
hybrid pmu exists. All the detected hybrid pmus are linked to a global
list 'perf_pmu__hybrid_pmus' and then next we just need to iterate the
list to get all hybrid pmu by using perf_pmu__for_each_hybrid_pmu.

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/20210427070139.25256-6-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 4f100768c264..9a2f89eeab6f 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -5,6 +5,7 @@
 #include <linux/bitmap.h>
 #include <linux/compiler.h>
 #include <linux/perf_event.h>
+#include <linux/list.h>
 #include <stdbool.h>
 #include "parse-events.h"
 #include "pmu-events/pmu-events.h"
@@ -19,6 +20,7 @@ enum {
 
 #define PERF_PMU_FORMAT_BITS 64
 #define EVENT_SOURCE_DEVICE_PATH "/bus/event_source/devices/"
+#define CPUS_TEMPLATE_CPU	"%s/bus/event_source/devices/%s/cpus"
 
 struct perf_event_attr;
 
@@ -34,6 +36,7 @@ struct perf_pmu {
 	__u32 type;
 	bool selectable;
 	bool is_uncore;
+	bool is_hybrid;
 	bool auxtrace;
 	int max_precise;
 	struct perf_event_attr *default_config;
@@ -42,6 +45,7 @@ struct perf_pmu {
 	struct list_head aliases; /* HEAD struct perf_pmu_alias -> list */
 	struct list_head caps;    /* HEAD struct perf_pmu_caps -> list */
 	struct list_head list;    /* ELEM */
+	struct list_head hybrid_list;
 };
 
 extern struct perf_pmu perf_pmu__fake;