From 4c2efb230a76d9dcdf0e4c39d1116df08312e740 Mon Sep 17 00:00:00 2001
From: James Clark <james.clark@linaro.org>
Date: Wed, 14 Jan 2026 15:57:22 +0000
Subject: [PATCH] perf cs-etm: Make a helper to find the Coresight evsel

This pattern occurs a few times and we'll add another one later, so add
a helper function for it.

Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/arch/arm/util/cs-etm.c | 50 +++++++++++++++++--------------
 1 file changed, 27 insertions(+), 23 deletions(-)

diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index c28208361d91..a49753f0d20f 100644
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -302,6 +302,19 @@ static int cs_etm_set_sink_attr(struct perf_pmu *pmu,
 	return 0;
 }
 
+static struct evsel *cs_etm_get_evsel(struct evlist *evlist,
+				      struct perf_pmu *cs_etm_pmu)
+{
+	struct evsel *evsel;
+
+	evlist__for_each_entry(evlist, evsel) {
+		if (evsel->core.attr.type == cs_etm_pmu->type)
+			return evsel;
+	}
+
+	return NULL;
+}
+
 static int cs_etm_recording_options(struct auxtrace_record *itr,
 				    struct evlist *evlist,
 				    struct record_opts *opts)
@@ -473,29 +486,21 @@ out:
 
 static u64 cs_etm_get_config(struct auxtrace_record *itr)
 {
-	u64 config = 0;
 	struct cs_etm_recording *ptr =
 			container_of(itr, struct cs_etm_recording, itr);
 	struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
 	struct evlist *evlist = ptr->evlist;
-	struct evsel *evsel;
+	struct evsel *evsel = cs_etm_get_evsel(evlist, cs_etm_pmu);
 
-	evlist__for_each_entry(evlist, evsel) {
-		if (evsel->core.attr.type == cs_etm_pmu->type) {
-			/*
-			 * Variable perf_event_attr::config is assigned to
-			 * ETMv3/PTM.  The bit fields have been made to match
-			 * the ETMv3.5 ETRMCR register specification.  See the
-			 * PMU_FORMAT_ATTR() declarations in
-			 * drivers/hwtracing/coresight/coresight-perf.c for
-			 * details.
-			 */
-			config = evsel->core.attr.config;
-			break;
-		}
-	}
-
-	return config;
+	/*
+	 * Variable perf_event_attr::config is assigned to
+	 * ETMv3/PTM.  The bit fields have been made to match
+	 * the ETMv3.5 ETRMCR register specification.  See the
+	 * PMU_FORMAT_ATTR() declarations in
+	 * drivers/hwtracing/coresight/coresight-perf.c for
+	 * details.
+	 */
+	return evsel ? evsel->core.attr.config : 0;
 }
 
 #ifndef BIT
@@ -829,12 +834,11 @@ static int cs_etm_snapshot_start(struct auxtrace_record *itr)
 {
 	struct cs_etm_recording *ptr =
 			container_of(itr, struct cs_etm_recording, itr);
-	struct evsel *evsel;
+	struct evsel *evsel = cs_etm_get_evsel(ptr->evlist, ptr->cs_etm_pmu);
+
+	if (evsel)
+		return evsel__disable(evsel);
 
-	evlist__for_each_entry(ptr->evlist, evsel) {
-		if (evsel->core.attr.type == ptr->cs_etm_pmu->type)
-			return evsel__disable(evsel);
-	}
 	return -EINVAL;
 }
 
-- 
2.47.3