[Power Mgmt] Merge pmdisk and swsusp write wrappers.

- Merge suspend_save_image() from both into one.
- Rename to swsusp_write(). 
- Remove pmdisk_write().
- Fixup call in kernel/power/disk.c and software_suspend().
- Mark lock_swapdevices() static again.

kernel/power/disk.c

@@ -24,7 +24,7 @@ extern u32 pm_disk_mode;
 extern struct pm_ops * pm_ops;
 
 extern int swsusp_suspend(void);
-extern int pmdisk_write(void);
+extern int swsusp_write(void);
 extern int swsusp_read(void);
 extern int swsusp_resume(void);
 extern int pmdisk_free(void);
@@ -173,7 +173,7 @@ int pm_suspend_disk(void)
 		mb();
 		barrier();
 
-		error = pmdisk_write();
+		error = swsusp_write();
 		if (!error) {
 			error = power_down(pm_disk_mode);
 			pr_debug("PM: Power down failed.\n");

kernel/power/pmdisk.c

@@ -42,49 +42,6 @@ extern suspend_pagedir_t *pagedir_save;
  */
 
 
-extern void swsusp_swap_lock(void);
-
-/**
- *	suspend_save_image - Prepare and write saved image to swap.
- *
- *	IRQs are re-enabled here so we can resume devices and safely write
- *	to the swap devices. We disable them again before we leave.
- *
- *	The second swsusp_swap_lock() will unlock ignored swap devices since
- *	writing is finished.
- *	It is important _NOT_ to umount filesystems at this point. We want
- *	them synced (in case something goes wrong) but we DO not want to mark
- *	filesystem clean: it is not. (And it does not matter, if we resume
- *	correctly, we'll mark system clean, anyway.)
- */
-
-static int suspend_save_image(void)
-{
-	extern int write_suspend_image(void);
-	int error;
-	device_resume();
-	swsusp_swap_lock();
-	error = write_suspend_image();
-	swsusp_swap_lock();
-	return error;
-}
-
-
-/**
- *	pmdisk_write - Write saved memory image to swap.
- *
- *	pmdisk_arch_suspend(0) returns after system is resumed.
- *
- *	pmdisk_arch_suspend() copies all "used" memory to "free" memory,
- *	then unsuspends all device drivers, and writes memory to disk
- *	using normal kernel mechanism.
- */
-
-int pmdisk_write(void)
-{
-	return suspend_save_image();
-}
-
 /**
  *	pmdisk_free - Free memory allocated to hold snapshot.
  */

kernel/power/swsusp.c

@@ -246,7 +246,7 @@ int swsusp_swap_check(void) /* This is called before saving image */
  * we make the device unusable. A new call to
  * lock_swapdevices can unlock the devices. 
  */
-void swsusp_swap_lock(void)
+static void lock_swapdevices(void)
 {
 	int i;
 
@@ -439,7 +439,7 @@ static int write_pagedir(void)
  *
  */
 
-int write_suspend_image(void)
+static int write_suspend_image(void)
 {
 	int error;
 
@@ -862,20 +862,22 @@ int suspend_prepare_image(void)
 	return 0;
 }
 
-static void suspend_save_image(void)
+
+/* It is important _NOT_ to umount filesystems at this point. We want
+ * them synced (in case something goes wrong) but we DO not want to mark
+ * filesystem clean: it is not. (And it does not matter, if we resume
+ * correctly, we'll mark system clean, anyway.)
+ */
+int swsusp_write(void)
 {
+	int error;
 	device_resume();
-
-	swsusp_swap_lock();
-	write_suspend_image();
+	lock_swapdevices();
+	error = write_suspend_image();
 	/* This will unlock ignored swap devices since writing is finished */
-	swsusp_swap_lock();
+	lock_swapdevices();
+	return error;
 
-	/* It is important _NOT_ to umount filesystems at this point. We want
-	 * them synced (in case something goes wrong) but we DO not want to mark
-	 * filesystem clean: it is not. (And it does not matter, if we resume
-	 * correctly, we'll mark system clean, anyway.)
-	 */
 }
 
 static void suspend_power_down(void)
@@ -1011,7 +1013,7 @@ int software_suspend(void)
 			res = swsusp_save();
 
 			if (!res && in_suspend) {
-				suspend_save_image();
+				swsusp_write();
 				suspend_power_down();
 			}
 			in_suspend = 0;