Merge "thermal-core: Use rcu for accessing sensor list"

drivers/thermal/thermal_core.c

@@ -212,29 +212,38 @@ static DEFINE_MUTEX(sensor_list_lock);
 
 static struct sensor_info *get_sensor(uint32_t sensor_id)
 {
-	struct sensor_info *pos, *var;
+	struct sensor_info *pos = NULL, *matching_sensor = NULL;
 
-	list_for_each_entry_safe(pos, var, &sensor_info_list, sensor_list) {
-		if (pos->sensor_id == sensor_id)
-			return pos;
+	rcu_read_lock();
+	list_for_each_entry_rcu(pos, &sensor_info_list, sensor_list) {
+		if (pos->sensor_id == sensor_id) {
+			matching_sensor = pos;
+			break;
+		}
 	}
+	rcu_read_unlock();
 
-	return NULL;
+	return matching_sensor;
 }
 
 int sensor_get_id(char *name)
 {
-	struct sensor_info *pos, *var;
+	struct sensor_info *pos = NULL;
+	int matching_id = -ENODEV;
 
 	if (!name)
-		return -ENODEV;
+		return matching_id;
 
-	list_for_each_entry_safe(pos, var, &sensor_info_list, sensor_list) {
-		if (!strcmp(pos->tz->type, name))
-			return pos->sensor_id;
+	rcu_read_lock();
+	list_for_each_entry_rcu(pos, &sensor_info_list, sensor_list) {
+		if (!strcmp(pos->tz->type, name)) {
+			matching_id = pos->sensor_id;
+			break;
+		}
 	}
+	rcu_read_unlock();
 
-	return -ENODEV;
+	return matching_id;
 }
 EXPORT_SYMBOL(sensor_get_id);
 
@@ -572,7 +581,7 @@ int sensor_init(struct thermal_zone_device *tz)
 	sensor->max_idx = -1;
 	sensor->min_idx = -1;
 	mutex_init(&sensor->lock);
-	INIT_LIST_HEAD(&sensor->sensor_list);
+	INIT_LIST_HEAD_RCU(&sensor->sensor_list);
 	INIT_LIST_HEAD_RCU(&sensor->threshold_list);
 	INIT_LIST_HEAD(&tz->tz_threshold[0].list);
 	INIT_LIST_HEAD(&tz->tz_threshold[1].list);
@@ -582,7 +591,7 @@ int sensor_init(struct thermal_zone_device *tz)
 	tz->tz_threshold[1].notify = tz_notify_trip;
 	tz->tz_threshold[1].data = tz;
 	tz->tz_threshold[1].trip = THERMAL_TRIP_CONFIGURABLE_LOW;
-	list_add(&sensor->sensor_list, &sensor_info_list);
+	list_add_rcu(&sensor->sensor_list, &sensor_info_list);
 	INIT_WORK(&sensor->work, sensor_update_work);
 	init_completion(&sensor->sysfs_notify_complete);
 	sensor->sysfs_notify_thread = kthread_run(sensor_sysfs_notify,
@@ -2378,7 +2387,7 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 	}
 
 	mutex_lock(&thermal_list_lock);
-	list_add_tail(&tz->node, &thermal_tz_list);
+	list_add_tail_rcu(&tz->node, &thermal_tz_list);
 	sensor_init(tz);
 	mutex_unlock(&thermal_list_lock);
 
@@ -2426,7 +2435,7 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 		mutex_unlock(&thermal_list_lock);
 		return;
 	}
-	list_del(&tz->node);
+	list_del_rcu(&tz->node);
 
 	/* Unbind all cdevs associated with 'this' thermal zone */
 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
@@ -2464,7 +2473,7 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 	flush_work(&tz->sensor.work);
 	kthread_stop(tz->sensor.sysfs_notify_thread);
 	mutex_lock(&thermal_list_lock);
-	list_del(&tz->sensor.sensor_list);
+	list_del_rcu(&tz->sensor.sensor_list);
 	mutex_unlock(&thermal_list_lock);
 	release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
 	idr_destroy(&tz->idr);
@@ -2492,13 +2501,13 @@ struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
 	if (!name)
 		goto exit;
 
-	mutex_lock(&thermal_list_lock);
-	list_for_each_entry(pos, &thermal_tz_list, node)
+	rcu_read_lock();
+	list_for_each_entry_rcu(pos, &thermal_tz_list, node)
 		if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
 			found++;
 			ref = pos;
 		}
-	mutex_unlock(&thermal_list_lock);
+	rcu_read_unlock();
 
 	/* nothing has been found, thus an error code for it */
 	if (found == 0)