PM / wakeup: Use wakeup_source_register() in wakelock.c

kernel/power/wakelock.c duplicates wakeup source creation and
registration code from drivers/base/power/wakeup.c.

Change struct wakelock's wakeup source to a pointer and use
wakeup_source_register() function to create and register said wakeup
source. Use wakeup_source_unregister() on cleanup path.
Signed-off-by: Tri Vo <trong@android.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/power/wakelock.c

@@ -27,7 +27,7 @@ static DEFINE_MUTEX(wakelocks_lock);
 struct wakelock {
 	char			*name;
 	struct rb_node		node;
-	struct wakeup_source	ws;
+	struct wakeup_source	*ws;
 #ifdef CONFIG_PM_WAKELOCKS_GC
 	struct list_head	lru;
 #endif
@@ -46,7 +46,7 @@ ssize_t pm_show_wakelocks(char *buf, bool show_active)
 
 	for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) {
 		wl = rb_entry(node, struct wakelock, node);
-		if (wl->ws.active == show_active)
+		if (wl->ws->active == show_active)
 			str += scnprintf(str, end - str, "%s ", wl->name);
 	}
 	if (str > buf)
@@ -112,16 +112,16 @@ static void __wakelocks_gc(struct work_struct *work)
 		u64 idle_time_ns;
 		bool active;
 
-		spin_lock_irq(&wl->ws.lock);
-		idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws.last_time));
-		active = wl->ws.active;
-		spin_unlock_irq(&wl->ws.lock);
+		spin_lock_irq(&wl->ws->lock);
+		idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws->last_time));
+		active = wl->ws->active;
+		spin_unlock_irq(&wl->ws->lock);
 
 		if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC))
 			break;
 
 		if (!active) {
-			wakeup_source_remove(&wl->ws);
+			wakeup_source_unregister(wl->ws);
 			rb_erase(&wl->node, &wakelocks_tree);
 			list_del(&wl->lru);
 			kfree(wl->name);
@@ -187,9 +187,15 @@ static struct wakelock *wakelock_lookup_add(const char *name, size_t len,
 		kfree(wl);
 		return ERR_PTR(-ENOMEM);
 	}
-	wl->ws.name = wl->name;
-	wl->ws.last_time = ktime_get();
-	wakeup_source_add(&wl->ws);
+
+	wl->ws = wakeup_source_register(wl->name);
+	if (!wl->ws) {
+		kfree(wl->name);
+		kfree(wl);
+		return ERR_PTR(-ENOMEM);
+	}
+	wl->ws->last_time = ktime_get();
+
 	rb_link_node(&wl->node, parent, node);
 	rb_insert_color(&wl->node, &wakelocks_tree);
 	wakelocks_lru_add(wl);
@@ -233,9 +239,9 @@ int pm_wake_lock(const char *buf)
 		u64 timeout_ms = timeout_ns + NSEC_PER_MSEC - 1;
 
 		do_div(timeout_ms, NSEC_PER_MSEC);
-		__pm_wakeup_event(&wl->ws, timeout_ms);
+		__pm_wakeup_event(wl->ws, timeout_ms);
 	} else {
-		__pm_stay_awake(&wl->ws);
+		__pm_stay_awake(wl->ws);
 	}
 
 	wakelocks_lru_most_recent(wl);
@@ -271,7 +277,7 @@ int pm_wake_unlock(const char *buf)
 		ret = PTR_ERR(wl);
 		goto out;
 	}
-	__pm_relax(&wl->ws);
+	__pm_relax(wl->ws);
 
 	wakelocks_lru_most_recent(wl);
 	wakelocks_gc();