PM: introduce hibernation and suspend notifiers

Make it possible to register hibernation and suspend notifiers, so that
subsystems can perform hibernation-related or suspend-related operations that
should not be carried out by device drivers' .suspend() and .resume()
routines.

[akpm@linux-foundation.org: build fixes]
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/kernel/power/main.c b/kernel/power/main.c
index fc45ed22620f..4d26ad394fb3 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -23,6 +23,8 @@
 
 #include "power.h"
 
+BLOCKING_NOTIFIER_HEAD(pm_chain_head);
+
 /*This is just an arbitrary number */
 #define FREE_PAGE_NUMBER (100)
 
@@ -78,6 +80,10 @@ static int suspend_prepare(suspend_state_t state)
         if (!pm_ops || !pm_ops->enter)
                 return -EPERM;
 
+        error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
+        if (error)
+                goto Finish;
+
         pm_prepare_console();
 
         if (freeze_processes()) {
@@ -125,6 +131,8 @@ static int suspend_prepare(suspend_state_t state)
  Thaw:
         thaw_processes();
         pm_restore_console();
+ Finish:
+        pm_notifier_call_chain(PM_POST_SUSPEND);
         return error;
 }
 
@@ -176,6 +184,7 @@ static void suspend_finish(suspend_state_t state)
         resume_console();
         thaw_processes();
         pm_restore_console();
+        pm_notifier_call_chain(PM_POST_SUSPEND);
 }