PM: Convert PM notifiers to out-of-line code

This patch (as1008b) converts the PM notifier routines from inline
calls to out-of-line code.  It also prevents pm_chain_head from
being created when CONFIG_PM_SLEEP isn't enabled, and EXPORTs the
notifier registration and unregistration routines.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 30 insertions, 10 deletions

diff --git a/kernel/power/main.c b/kernel/power/main.c
index fc717b836828..0a9f269075ee 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -24,13 +24,37 @@
 
 #include "power.h"
 
-BLOCKING_NOTIFIER_HEAD(pm_chain_head);
-
 DEFINE_MUTEX(pm_mutex);
 
 unsigned int pm_flags;
 EXPORT_SYMBOL(pm_flags);
 
+#ifdef CONFIG_PM_SLEEP
+
+/* Routines for PM-transition notifications */
+
+static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
+
+int register_pm_notifier(struct notifier_block *nb)
+{
+        return blocking_notifier_chain_register(&pm_chain_head, nb);
+}
+EXPORT_SYMBOL_GPL(register_pm_notifier);
+
+int unregister_pm_notifier(struct notifier_block *nb)
+{
+        return blocking_notifier_chain_unregister(&pm_chain_head, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_pm_notifier);
+
+int pm_notifier_call_chain(unsigned long val)
+{
+        return (blocking_notifier_call_chain(&pm_chain_head, val, NULL)
+                        == NOTIFY_BAD) ? -EINVAL : 0;
+}
+
+#endif /* CONFIG_PM_SLEEP */
+
 #ifdef CONFIG_PM_DEBUG
 int pm_test_level = TEST_NONE;
 
diff --git a/kernel/power/power.h b/kernel/power/power.h
index f9f0d4d26c50..a9732fd12239 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -172,14 +172,10 @@ static inline int suspend_devices_and_enter(suspend_state_t state)
 }
 #endif /* !CONFIG_SUSPEND */
 
-/* kernel/power/common.c */
-extern struct blocking_notifier_head pm_chain_head;
-
-static inline int pm_notifier_call_chain(unsigned long val)
-{
-        return (blocking_notifier_call_chain(&pm_chain_head, val, NULL)
-                        == NOTIFY_BAD) ? -EINVAL : 0;
-}
+#ifdef CONFIG_PM_SLEEP
+/* kernel/power/main.c */
+extern int pm_notifier_call_chain(unsigned long val);
+#endif
 
 #ifdef CONFIG_HIGHMEM
 unsigned int count_highmem_pages(void);