PM: Rework struct hibernation_ops

During hibernation we also need to tell the ACPI core that we're going to put
the system into the S4 sleep state.  For this reason, an additional method in
'struct hibernation_ops' is needed, playing the role of set_target() in
'struct platform_suspend_operations'.  Moreover, the role of the .prepare()
method is now different, so it's better to introduce another method, that in
general may be different from .prepare(), that will be used to prepare the
platform for creating the hibernation image (.prepare() is used anyway to
notify the platform that we're going to enter the low power state after the
image has been saved).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 21 insertions, 6 deletions

diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index eb72255b5c86..d17bb14bce7b 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -54,8 +54,9 @@ static struct hibernation_ops *hibernation_ops;
 
 void hibernation_set_ops(struct hibernation_ops *ops)
 {
-        if (ops && !(ops->prepare && ops->enter && ops->finish
-            && ops->pre_restore && ops->restore_cleanup)) {
+        if (ops && !(ops->start && ops->pre_snapshot && ops->finish
+            && ops->prepare && ops->enter && ops->pre_restore
+            && ops->restore_cleanup)) {
                 WARN_ON(1);
                 return;
         }
@@ -69,16 +70,26 @@ void hibernation_set_ops(struct hibernation_ops *ops)
         mutex_unlock(&pm_mutex);
 }
 
+/**
+ *      platform_start - tell the platform driver that we're starting
+ *      hibernation
+ */
+
+static int platform_start(int platform_mode)
+{
+        return (platform_mode && hibernation_ops) ?
+                hibernation_ops->start() : 0;
+}
 
 /**
- *      platform_prepare - prepare the machine for hibernation using the
+ *      platform_pre_snapshot - prepare the machine for hibernation using the
  *      platform driver if so configured and return an error code if it fails
  */
 
-static int platform_prepare(int platform_mode)
+static int platform_pre_snapshot(int platform_mode)
 {
         return (platform_mode && hibernation_ops) ?
-                hibernation_ops->prepare() : 0;
+                hibernation_ops->pre_snapshot() : 0;
 }
 
 /**
@@ -135,12 +146,16 @@ int hibernation_snapshot(int platform_mode)
         if (error)
                 return error;
 
+        error = platform_start(platform_mode);
+        if (error)
+                return error;
+
         suspend_console();
         error = device_suspend(PMSG_FREEZE);
         if (error)
                 goto Resume_console;
 
-        error = platform_prepare(platform_mode);
+        error = platform_pre_snapshot(platform_mode);
         if (error)
                 goto Resume_devices;