1 files changed, 19 insertions, 6 deletions

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 1a3169e69bb1..c2c9b127d074 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -126,10 +126,10 @@ static void free_sink_buffer(struct etm_event_data *event_data)
 	cpumask_t *mask = &event_data->mask;
 	struct coresight_device *sink;
 
-	if (WARN_ON(cpumask_empty(mask)))
+	if (!event_data->snk_config)
 		return;
 
-	if (!event_data->snk_config)
+	if (WARN_ON(cpumask_empty(mask)))
 		return;
 
 	cpu = cpumask_first(mask);
@@ -222,8 +222,6 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
 	if (event->attr.config2) {
 		id = (u32)event->attr.config2;
 		sink = coresight_get_sink_by_id(id);
-	} else {
-		sink = coresight_get_enabled_sink(true);
 	}
 
 	mask = &event_data->mask;
@@ -321,6 +319,16 @@ static void etm_event_start(struct perf_event *event, int flags)
 	if (!event_data)
 		goto fail;
 
+	/*
+	 * Check if this ETM is allowed to trace, as decided
+	 * at etm_setup_aux(). This could be due to an unreachable
+	 * sink from this ETM. We can't do much in this case if
+	 * the sink was specified or hinted to the driver. For
+	 * now, simply don't record anything on this ETM.
+	 */
+	if (!cpumask_test_cpu(cpu, &event_data->mask))
+		goto fail_end_stop;
+
 	path = etm_event_cpu_path(event_data, cpu);
 	/* We need a sink, no need to continue without one */
 	sink = coresight_get_sink(path);
@@ -517,6 +525,7 @@ int etm_perf_symlink(struct coresight_device *csdev, bool link)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(etm_perf_symlink);
 
 static ssize_t etm_perf_sink_name_show(struct device *dev,
 				       struct device_attribute *dattr,
@@ -590,7 +599,7 @@ void etm_perf_del_symlink_sink(struct coresight_device *csdev)
 	csdev->ea = NULL;
 }
 
-static int __init etm_perf_init(void)
+int __init etm_perf_init(void)
 {
 	int ret;
 
@@ -617,4 +626,8 @@ static int __init etm_perf_init(void)
 
 	return ret;
 }
-device_initcall(etm_perf_init);
+
+void __exit etm_perf_exit(void)
+{
+	perf_pmu_unregister(&etm_pmu);
+}