perf pmu: Use perf_pmu__open_file() and perf_pmu__scan_file()

Remove some code that duplicates existing methods. Copy strings where
const strings are required.

No functional changes.

Committer notes:

Add a stub for erf_pmu__scan_file() in tools/perf/util/python.c not to
drag tools/perf/util/pmu.c into the python binding.

This fixes 'perf test python' at this point in this patchset.

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: Tanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-3-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 8 deletions

diff --git a/tools/perf/util/cputopo.c b/tools/perf/util/cputopo.c
index 1a3ff6449158..e08797c3cdbc 100644
--- a/tools/perf/util/cputopo.c
+++ b/tools/perf/util/cputopo.c
@@ -422,8 +422,6 @@ void numa_topology__delete(struct numa_topology *tp)
 static int load_hybrid_node(struct hybrid_topology_node *node,
 			    struct perf_pmu *pmu)
 {
-	const char *sysfs;
-	char path[PATH_MAX];
 	char *buf = NULL, *p;
 	FILE *fp;
 	size_t len = 0;
@@ -432,12 +430,7 @@ static int load_hybrid_node(struct hybrid_topology_node *node,
 	if (!node->pmu_name)
 		return -1;
 
-	sysfs = sysfs__mountpoint();
-	if (!sysfs)
-		goto err;
-
-	snprintf(path, PATH_MAX, CPUS_TEMPLATE_CPU, sysfs, pmu->name);
-	fp = fopen(path, "r");
+	fp = perf_pmu__open_file(pmu, "cpus");
 	if (!fp)
 		goto err;