2 files changed, 62 insertions, 10 deletions

diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index 7c5ab70b9ef3..2a3e581b8dcd 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -53,6 +53,23 @@ static void pm_wakeup_timer_fn(unsigned long data);
 static LIST_HEAD(wakeup_sources);
 
 /**
+ * wakeup_source_prepare - Prepare a new wakeup source for initialization.
+ * @ws: Wakeup source to prepare.
+ * @name: Pointer to the name of the new wakeup source.
+ *
+ * Callers must ensure that the @name string won't be freed when @ws is still in
+ * use.
+ */
+void wakeup_source_prepare(struct wakeup_source *ws, const char *name)
+{
+        if (ws) {
+                memset(ws, 0, sizeof(*ws));
+                ws->name = name;
+        }
+}
+EXPORT_SYMBOL_GPL(wakeup_source_prepare);
+
+/**
  * wakeup_source_create - Create a struct wakeup_source object.
  * @name: Name of the new wakeup source.
  */
@@ -60,31 +77,44 @@ struct wakeup_source *wakeup_source_create(const char *name)
 {
         struct wakeup_source *ws;
 
-        ws = kzalloc(sizeof(*ws), GFP_KERNEL);
+        ws = kmalloc(sizeof(*ws), GFP_KERNEL);
         if (!ws)
                 return NULL;
 
-        if (name)
-                ws->name = kstrdup(name, GFP_KERNEL);
-
+        wakeup_source_prepare(ws, name ? kstrdup(name, GFP_KERNEL) : NULL);
         return ws;
 }
 EXPORT_SYMBOL_GPL(wakeup_source_create);
 
 /**
- * wakeup_source_destroy - Destroy a struct wakeup_source object.
- * @ws: Wakeup source to destroy.
+ * wakeup_source_drop - Prepare a struct wakeup_source object for destruction.
+ * @ws: Wakeup source to prepare for destruction.
  *
  * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never
  * be run in parallel with this function for the same wakeup source object.
  */
-void wakeup_source_destroy(struct wakeup_source *ws)
+void wakeup_source_drop(struct wakeup_source *ws)
 {
         if (!ws)
                 return;
 
         del_timer_sync(&ws->timer);
         __pm_relax(ws);
+}
+EXPORT_SYMBOL_GPL(wakeup_source_drop);
+
+/**
+ * wakeup_source_destroy - Destroy a struct wakeup_source object.
+ * @ws: Wakeup source to destroy.
+ *
+ * Use only for wakeup source objects created with wakeup_source_create().
+ */
+void wakeup_source_destroy(struct wakeup_source *ws)
+{
+        if (!ws)
+                return;
+
+        wakeup_source_drop(ws);
         kfree(ws->name);
         kfree(ws);
 }
@@ -147,8 +177,10 @@ EXPORT_SYMBOL_GPL(wakeup_source_register);
  */
 void wakeup_source_unregister(struct wakeup_source *ws)
 {
-        wakeup_source_remove(ws);
-        wakeup_source_destroy(ws);
+        if (ws) {
+                wakeup_source_remove(ws);
+                wakeup_source_destroy(ws);
+        }
 }
 EXPORT_SYMBOL_GPL(wakeup_source_unregister);
 
diff --git a/include/linux/pm_wakeup.h b/include/linux/pm_wakeup.h
index a32da962d693..d9f05113e5fb 100644
--- a/include/linux/pm_wakeup.h
+++ b/include/linux/pm_wakeup.h
@@ -41,7 +41,7 @@
  * @active: Status of the wakeup source.
  */
 struct wakeup_source {
-        char                    *name;
+        const char              *name;
         struct list_head        entry;
         spinlock_t              lock;
         struct timer_list       timer;
@@ -73,7 +73,9 @@ static inline bool device_may_wakeup(struct device *dev)
 }
 
 /* drivers/base/power/wakeup.c */
+extern void wakeup_source_prepare(struct wakeup_source *ws, const char *name);
 extern struct wakeup_source *wakeup_source_create(const char *name);
+extern void wakeup_source_drop(struct wakeup_source *ws);
 extern void wakeup_source_destroy(struct wakeup_source *ws);
 extern void wakeup_source_add(struct wakeup_source *ws);
 extern void wakeup_source_remove(struct wakeup_source *ws);
@@ -103,11 +105,16 @@ static inline bool device_can_wakeup(struct device *dev)
         return dev->power.can_wakeup;
 }
 
+static inline void wakeup_source_prepare(struct wakeup_source *ws,
+                                         const char *name) {}
+
 static inline struct wakeup_source *wakeup_source_create(const char *name)
 {
         return NULL;
 }
 
+static inline void wakeup_source_drop(struct wakeup_source *ws) {}
+
 static inline void wakeup_source_destroy(struct wakeup_source *ws) {}
 
 static inline void wakeup_source_add(struct wakeup_source *ws) {}
@@ -165,4 +172,17 @@ static inline void pm_wakeup_event(struct device *dev, unsigned int msec) {}
 
 #endif /* !CONFIG_PM_SLEEP */
 
+static inline void wakeup_source_init(struct wakeup_source *ws,
+                                      const char *name)
+{
+        wakeup_source_prepare(ws, name);
+        wakeup_source_add(ws);
+}
+
+static inline void wakeup_source_trash(struct wakeup_source *ws)
+{
+        wakeup_source_remove(ws);
+        wakeup_source_drop(ws);
+}
+
 #endif /* _LINUX_PM_WAKEUP_H */