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, 18 insertions, 0 deletions

diff --git a/tools/perf/util/pmu-hybrid.h b/tools/perf/util/pmu-hybrid.h
new file mode 100644
index 000000000000..35bed3714438
--- /dev/null
+++ b/tools/perf/util/pmu-hybrid.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PMU_HYBRID_H
+#define __PMU_HYBRID_H
+
+#include <linux/perf_event.h>
+#include <linux/compiler.h>
+#include <linux/list.h>
+#include <stdbool.h>
+#include "pmu.h"
+
+extern struct list_head perf_pmu__hybrid_pmus;
+
+#define perf_pmu__for_each_hybrid_pmu(pmu)	\
+	list_for_each_entry(pmu, &perf_pmu__hybrid_pmus, hybrid_list)
+
+bool perf_pmu__hybrid_mounted(const char *name);
+
+#endif /* __PMU_HYBRID_H */