coresight: Introduce coresight_enable_source() helper

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>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260515-arm_coresight_path_power_management_improvement-v14-18-f88c4a3ecfe9@arm.com

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 61ae7b6c7a836caafaf87787af91a1f5326c16ec..f833b73ebc168b2b039e5f0900594d0bde5ff916 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -479,11 +479,25 @@ 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 89b99c3caedbc34da57f406797701425d36a1333..09b21a711a8764ea429d712890265c84648e889e 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -593,7 +593,7 @@ 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 808d1546f568278d62fe72d871b6af82eb830074..dddac946659fcc63799d4b009f1c7ccd9f1809b6 100644 (file)
--- 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 682500b7296c20453edd0290e1dc44124e0c3228..9ec112b457bbdc85f807eccc6944bf39e5e363e1 100644 (file)
--- 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;
        }