2 files changed, 43 insertions, 1 deletions

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 3e084280b23e..6a5898355a83 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -577,7 +577,8 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 		etm4x_relaxed_write32(csa, trcpdcr | TRCPDCR_PU, TRCPDCR);
 	}
 
-	rc = etm4_enable_trace_unit(drvdata);
+	if (!drvdata->paused)
+		rc = etm4_enable_trace_unit(drvdata);
 done:
 	etm4_cs_lock(drvdata, csa);
 
@@ -820,6 +821,9 @@ static int etm4_enable_perf(struct coresight_device *csdev,
 
 	drvdata->trcid = path->trace_id;
 
+	/* Populate pause state */
+	drvdata->paused = !!READ_ONCE(event->hw.aux_paused);
+
 	/* And enable it */
 	ret = etm4_enable_hw(drvdata);
 
@@ -846,6 +850,9 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa
 
 	drvdata->trcid = path->trace_id;
 
+	/* Tracer will never be paused in sysfs mode */
+	drvdata->paused = false;
+
 	/*
 	 * Executing etm4_enable_hw on the cpu whose ETM is being enabled
 	 * ensures that register writes occur when cpu is powered.
@@ -1080,10 +1087,43 @@ static void etm4_disable(struct coresight_device *csdev,
 		coresight_set_mode(csdev, CS_MODE_DISABLED);
 }
 
+static int etm4_resume_perf(struct coresight_device *csdev)
+{
+	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+	struct csdev_access *csa = &csdev->access;
+
+	if (coresight_get_mode(csdev) != CS_MODE_PERF)
+		return -EINVAL;
+
+	etm4_cs_unlock(drvdata, csa);
+	etm4_enable_trace_unit(drvdata);
+	etm4_cs_lock(drvdata, csa);
+
+	drvdata->paused = false;
+	return 0;
+}
+
+static void etm4_pause_perf(struct coresight_device *csdev)
+{
+	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+	struct csdev_access *csa = &csdev->access;
+
+	if (coresight_get_mode(csdev) != CS_MODE_PERF)
+		return;
+
+	etm4_cs_unlock(drvdata, csa);
+	etm4_disable_trace_unit(drvdata);
+	etm4_cs_lock(drvdata, csa);
+
+	drvdata->paused = true;
+}
+
 static const struct coresight_ops_source etm4_source_ops = {
 	.cpu_id		= etm4_cpu_id,
 	.enable		= etm4_enable,
 	.disable	= etm4_disable,
+	.resume_perf	= etm4_resume_perf,
+	.pause_perf	= etm4_pause_perf,
 };
 
 static const struct coresight_ops etm4_cs_ops = {
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index bd7db36ba197..ac649515054d 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -983,6 +983,7 @@ struct etmv4_save_state {
  * @state_needs_restore: True when there is context to restore after PM exit
  * @skip_power_up: Indicates if an implementation can skip powering up
  *		   the trace unit.
+ * @paused:	Indicates if the trace unit is paused.
  * @arch_features: Bitmap of arch features of etmv4 devices.
  */
 struct etmv4_drvdata {
@@ -1036,6 +1037,7 @@ struct etmv4_drvdata {
 	struct etmv4_save_state		*save_state;
 	bool				state_needs_restore;
 	bool				skip_power_up;
+	bool				paused;
 	DECLARE_BITMAP(arch_features, ETM4_IMPDEF_FEATURE_MAX);
 };