Merge remote-tracking branch 'coresight/next'

3 files changed, 44 insertions, 18 deletions

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 288a423c1b27..8f546f59a3fd 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -201,6 +201,7 @@ static void *etm_setup_aux(int event_cpu, void **pages,
 	event_data = alloc_event_data(event_cpu);
 	if (!event_data)
 		return NULL;
+	INIT_WORK(&event_data->work, free_event_data);
 
 	/*
 	 * In theory nothing prevent tracers in a trace session from being
@@ -217,8 +218,6 @@ static void *etm_setup_aux(int event_cpu, void **pages,
 	if (!sink)
 		goto err;
 
-	INIT_WORK(&event_data->work, free_event_data);
-
 	mask = &event_data->mask;
 
 	/* Setup the path for each CPU in a trace session */
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index aec61a6d5c63..e3b9fb82eb8d 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -166,9 +166,6 @@ out:
 	if (!used)
 		kfree(buf);
 
-	if (!ret)
-		dev_info(drvdata->dev, "TMC-ETB/ETF enabled\n");
-
 	return ret;
 }
 
@@ -204,15 +201,27 @@ out:
 
 static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
 {
+	int ret;
+	struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
 	switch (mode) {
 	case CS_MODE_SYSFS:
-		return tmc_enable_etf_sink_sysfs(csdev);
+		ret = tmc_enable_etf_sink_sysfs(csdev);
+		break;
 	case CS_MODE_PERF:
-		return tmc_enable_etf_sink_perf(csdev);
+		ret = tmc_enable_etf_sink_perf(csdev);
+		break;
+	/* We shouldn't be here */
+	default:
+		ret = -EINVAL;
+		break;
 	}
 
-	/* We shouldn't be here */
-	return -EINVAL;
+	if (ret)
+		return ret;
+
+	dev_info(drvdata->dev, "TMC-ETB/ETF enabled\n");
+	return 0;
 }
 
 static void tmc_disable_etf_sink(struct coresight_device *csdev)
@@ -273,7 +282,7 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
 	drvdata->mode = CS_MODE_DISABLED;
 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
-	dev_info(drvdata->dev, "TMC disabled\n");
+	dev_info(drvdata->dev, "TMC-ETF disabled\n");
 }
 
 static void *tmc_alloc_etf_buffer(struct coresight_device *csdev, int cpu,
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index 0c37356e417c..6a0202b7384f 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -253,14 +253,22 @@ static int coresight_enable_source(struct coresight_device *csdev, u32 mode)
 	return 0;
 }
 
-static void coresight_disable_source(struct coresight_device *csdev)
+/**
+ *  coresight_disable_source - Drop the reference count by 1 and disable
+ *  the device if there are no users left.
+ *
+ *  @csdev - The coresight device to disable
+ *
+ *  Returns true if the device has been disabled.
+ */
+static bool coresight_disable_source(struct coresight_device *csdev)
 {
 	if (atomic_dec_return(csdev->refcnt) == 0) {
-		if (source_ops(csdev)->disable) {
+		if (source_ops(csdev)->disable)
 			source_ops(csdev)->disable(csdev, NULL);
-			csdev->enable = false;
-		}
+		csdev->enable = false;
 	}
+	return !csdev->enable;
 }
 
 void coresight_disable_path(struct list_head *path)
@@ -550,6 +558,9 @@ int coresight_enable(struct coresight_device *csdev)
 	int cpu, ret = 0;
 	struct coresight_device *sink;
 	struct list_head *path;
+	enum coresight_dev_subtype_source subtype;
+
+	subtype = csdev->subtype.source_subtype;
 
 	mutex_lock(&coresight_mutex);
 
@@ -557,8 +568,16 @@ int coresight_enable(struct coresight_device *csdev)
 	if (ret)
 		goto out;
 
-	if (csdev->enable)
+	if (csdev->enable) {
+		/*
+		 * There could be multiple applications driving the software
+		 * source. So keep the refcount for each such user when the
+		 * source is already enabled.
+		 */
+		if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE)
+			atomic_inc(csdev->refcnt);
 		goto out;
+	}
 
 	/*
 	 * Search for a valid sink for this session but don't reset the
@@ -585,7 +604,7 @@ int coresight_enable(struct coresight_device *csdev)
 	if (ret)
 		goto err_source;
 
-	switch (csdev->subtype.source_subtype) {
+	switch (subtype) {
 	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
 		/*
 		 * When working from sysFS it is important to keep track
@@ -629,7 +648,7 @@ void coresight_disable(struct coresight_device *csdev)
 	if (ret)
 		goto out;
 
-	if (!csdev->enable)
+	if (!csdev->enable || !coresight_disable_source(csdev))
 		goto out;
 
 	switch (csdev->subtype.source_subtype) {
@@ -647,7 +666,6 @@ void coresight_disable(struct coresight_device *csdev)
 		break;
 	}
 
-	coresight_disable_source(csdev);
 	coresight_disable_path(path);
 	coresight_release_path(path);