perf pmu: Add pmu_events_map__find() function to find the common PMU map for the system

Add a function to find the common PMU map for the system.

For arm64, a special variant is added. This is because arm64 supports
heterogeneous CPU systems. As such, it cannot be guaranteed that the
cpumap is same for all CPUs. So in case of heterogeneous systems, don't
return a cpumap.

Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Paul A. Clarke <pc@us.ibm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: https://lore.kernel.org/r/1617791570-165223-4-git-send-email-john.garry@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/tools/perf/arch/arm64/util/pmu.c b/tools/perf/arch/arm64/util/pmu.c
new file mode 100644
index 000000000000..d3259d61ca75
--- /dev/null
+++ b/tools/perf/arch/arm64/util/pmu.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "../../util/cpumap.h"
+#include "../../util/pmu.h"
+
+struct pmu_events_map *pmu_events_map__find(void)
+{
+	struct perf_pmu *pmu = NULL;
+
+	while ((pmu = perf_pmu__scan(pmu))) {
+		if (!is_pmu_core(pmu->name))
+			continue;
+
+		/*
+		 * The cpumap should cover all CPUs. Otherwise, some CPUs may
+		 * not support some events or have different event IDs.
+		 */
+		if (pmu->cpus->nr != cpu__max_cpu())
+			return NULL;
+
+		return perf_pmu__find_map(pmu);
+	}
+
+	return NULL;
+}