[PATCH v11 17/27] coresight: Introduce coresight_enable_source() helper

Leo Yan
2026-05-01T16:49:08Z

Introduce the coresight_enable_source() helper for enabling source
device.

Add validation to ensure the device is a source before proceeding with
further operations.

Reviewed-by: James Clark <james.clark@linaro.org>
Tested-by: James Clark <james.clark@linaro.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Tested-by: Jie Gan <jie.gan@oss.qualcomm.com>
Signed-off-by: Leo Yan <leo.yan@arm.com>
---
drivers/hwtracing/coresight/coresight-core.c | 18 ++++++++++++++++--
drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +-
drivers/hwtracing/coresight/coresight-priv.h | 3 +++
drivers/hwtracing/coresight/coresight-sysfs.c | 2 +-
4 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 7ca142b77186143aeaf5b9903475e21559b7b2fa..308282d2d4611997834bd39dc2de271bfa568ee0 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -470,11 +470,25 @@ static void coresight_disable_helpers(struct coresight_device *csdev,
}

/*
- * coresight_disable_source() only disables the source, but do nothing for
- * the associated helpers, which are controlled as part of the path.
+ * coresight_enable_source() and coresight_disable_source() only enable and
+ * disable the source, but do nothing for the associated helpers, which are
+ * controlled as part of the path.
*/
+int coresight_enable_source(struct coresight_device *csdev,
+ struct perf_event *event, enum cs_mode mode,
+ struct coresight_path *path)
+{
+ if (!coresight_is_device_source(csdev))
+ return -EINVAL;
+
+ return source_ops(csdev)->enable(csdev, event, mode, path);
+}
+
void coresight_disable_source(struct coresight_device *csdev, void *data)
{
+ if (!coresight_is_device_source(csdev))
+ return;
+
source_ops(csdev)->disable(csdev, data);
}
EXPORT_SYMBOL_GPL(coresight_disable_source);
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 9950ad481f29eed3bfac8fe4ae3a593b53830617..87e3245fbbe9c73df6e5bb3d24a912cbd1dc1e57 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -588,7 +588,7 @@ static void etm_event_start(struct perf_event *event, int flags)
goto fail_end_stop;

/* Finally enable the tracer */
- if (source_ops(source)->enable(source, event, CS_MODE_PERF, path))
+ if (coresight_enable_source(source, event, CS_MODE_PERF, path))
goto fail_disable_path;

/*
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index a1aab67e23db7fdea5139100312b3eb7cd31df51..456c53ba5d4c87bf33490383eb59b6a1710bbdf7 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -251,6 +251,9 @@ struct coresight_device *coresight_get_percpu_sink(int cpu);
struct coresight_device *coresight_get_source(struct coresight_path *path);
struct coresight_device *coresight_get_percpu_source_ref(int cpu);
void coresight_put_percpu_source_ref(struct coresight_device *csdev);
+int coresight_enable_source(struct coresight_device *csdev,
+ struct perf_event *event, enum cs_mode mode,
+ struct coresight_path *path);
void coresight_disable_source(struct coresight_device *csdev, void *data);
void coresight_pause_source(struct coresight_device *csdev);
int coresight_resume_source(struct coresight_device *csdev);
diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
index f398dbfbcb8de0c5a873837c19b3fdcf97b64abe..9449de66ba3941614928924086100866f3c88a54 100644
--- a/drivers/hwtracing/coresight/coresight-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-sysfs.c
@@ -66,7 +66,7 @@ static int coresight_enable_source_sysfs(struct coresight_device *csdev,
*/
lockdep_assert_held(&coresight_mutex);
if (coresight_get_mode(csdev) != CS_MODE_SYSFS) {
- ret = source_ops(csdev)->enable(csdev, NULL, mode, path);
+ ret = coresight_enable_source(csdev, NULL, mode, path);
if (ret)
return ret;
}

--
2.34.1