swsusp: remove code duplication between disk.c and user.c

Currently, much of the code in kernel/power/disk.c is duplicated in
kernel/power/user.c , mainly for historical reasons.  By eliminating this code
duplication we can reduce the size of user.c quite substantially and remove
the maintenance difficulty resulting from it.

[bunk@stusta.de: kernel/power/disk.c: make code static]
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>

3 files changed, 115 insertions, 170 deletions

diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index f445b9cd60fb..47882bfa610e 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -45,7 +45,7 @@ enum {
 
 static int hibernation_mode = HIBERNATION_SHUTDOWN;
 
-struct hibernation_ops *hibernation_ops;
+static struct hibernation_ops *hibernation_ops;
 
 /**
  * hibernation_set_ops - set the global hibernate operations
@@ -74,9 +74,9 @@ void hibernation_set_ops(struct hibernation_ops *ops)
  *      platform driver if so configured and return an error code if it fails
  */
 
-static int platform_prepare(void)
+static int platform_prepare(int platform_mode)
 {
-        return (hibernation_mode == HIBERNATION_PLATFORM && hibernation_ops) ?
+        return (platform_mode && hibernation_ops) ?
                 hibernation_ops->prepare() : 0;
 }
 
@@ -85,13 +85,104 @@ static int platform_prepare(void)
  *      using the platform driver (must be called after platform_prepare())
  */
 
-static void platform_finish(void)
+static void platform_finish(int platform_mode)
 {
-        if (hibernation_mode == HIBERNATION_PLATFORM && hibernation_ops)
+        if (platform_mode && hibernation_ops)
                 hibernation_ops->finish();
 }
 
 /**
+ *      hibernation_snapshot - quiesce devices and create the hibernation
+ *      snapshot image.
+ *      @platform_mode - if set, use the platform driver, if available, to
+ *                       prepare the platform frimware for the power transition.
+ *
+ *      Must be called with pm_mutex held
+ */
+
+int hibernation_snapshot(int platform_mode)
+{
+        int error;
+
+        /* Free memory before shutting down devices. */
+        error = swsusp_shrink_memory();
+        if (error)
+                goto Finish;
+
+        error = platform_prepare(platform_mode);
+        if (error)
+                goto Finish;
+
+        suspend_console();
+        error = device_suspend(PMSG_FREEZE);
+        if (error)
+                goto Resume_devices;
+
+        error = disable_nonboot_cpus();
+        if (!error) {
+                if (hibernation_mode != HIBERNATION_TEST) {
+                        in_suspend = 1;
+                        error = swsusp_suspend();
+                        /* Control returns here after successful restore */
+                } else {
+                        printk("swsusp debug: Waiting for 5 seconds.\n");
+                        mdelay(5000);
+                }
+        }
+        enable_nonboot_cpus();
+ Resume_devices:
+        platform_finish(platform_mode);
+        device_resume();
+        resume_console();
+ Finish:
+        return error;
+}
+
+/**
+ *      hibernation_restore - quiesce devices and restore the hibernation
+ *      snapshot image.  If successful, control returns in hibernation_snaphot()
+ *
+ *      Must be called with pm_mutex held
+ */
+
+int hibernation_restore(void)
+{
+        int error;
+
+        pm_prepare_console();
+        suspend_console();
+        error = device_suspend(PMSG_PRETHAW);
+        if (error)
+                goto Finish;
+
+        error = disable_nonboot_cpus();
+        if (!error)
+                error = swsusp_resume();
+
+        enable_nonboot_cpus();
+ Finish:
+        device_resume();
+        resume_console();
+        pm_restore_console();
+        return error;
+}
+
+/**
+ *      hibernation_platform_enter - enter the hibernation state using the
+ *      platform driver (if available)
+ */
+
+int hibernation_platform_enter(void)
+{
+        if (hibernation_ops) {
+                kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
+                return hibernation_ops->enter();
+        } else {
+                return -ENOSYS;
+        }
+}
+
+/**
  *      power_down - Shut the machine down for hibernation.
  *
  *      Use the platform driver, if configured so; otherwise try
@@ -111,11 +202,7 @@ static void power_down(void)
                 kernel_restart(NULL);
                 break;
         case HIBERNATION_PLATFORM:
-                if (hibernation_ops) {
-                        kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
-                        hibernation_ops->enter();
-                        break;
-                }
+                hibernation_platform_enter();
         }
         kernel_halt();
         /*
@@ -171,62 +258,17 @@ int hibernate(void)
                 mdelay(5000);
                 goto Thaw;
         }
-
-        /* Free memory before shutting down devices. */
-        error = swsusp_shrink_memory();
-        if (error)
-                goto Thaw;
-
-        error = platform_prepare();
-        if (error)
-                goto Thaw;
-
-        suspend_console();
-        error = device_suspend(PMSG_FREEZE);
-        if (error) {
-                printk(KERN_ERR "PM: Some devices failed to suspend\n");
-                goto Resume_devices;
-        }
-        error = disable_nonboot_cpus();
-        if (error)
-                goto Enable_cpus;
-
-        if (hibernation_mode == HIBERNATION_TEST) {
-                printk("swsusp debug: Waiting for 5 seconds.\n");
-                mdelay(5000);
-                goto Enable_cpus;
-        }
-
-        pr_debug("PM: snapshotting memory.\n");
-        in_suspend = 1;
-        error = swsusp_suspend();
-        if (error)
-                goto Enable_cpus;
-
-        if (in_suspend) {
-                enable_nonboot_cpus();
-                platform_finish();
-                device_resume();
-                resume_console();
+        error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
+        if (in_suspend && !error) {
                 pr_debug("PM: writing image.\n");
                 error = swsusp_write();
+                swsusp_free();
                 if (!error)
                         power_down();
-                else {
-                        swsusp_free();
-                        goto Thaw;
-                }
         } else {
                 pr_debug("PM: Image restored successfully.\n");
+                swsusp_free();
         }
-
-        swsusp_free();
- Enable_cpus:
-        enable_nonboot_cpus();
- Resume_devices:
-        platform_finish();
-        device_resume();
-        resume_console();
  Thaw:
         mutex_unlock(&pm_mutex);
         unprepare_processes();
@@ -301,29 +343,11 @@ static int software_resume(void)
         pr_debug("PM: Reading swsusp image.\n");
 
         error = swsusp_read();
-        if (error) {
-                swsusp_free();
-                goto Thaw;
-        }
-
-        pr_debug("PM: Preparing devices for restore.\n");
-
-        suspend_console();
-        error = device_suspend(PMSG_PRETHAW);
-        if (error)
-                goto Free;
-
-        error = disable_nonboot_cpus();
         if (!error)
-                swsusp_resume();
+                hibernation_restore();
 
-        enable_nonboot_cpus();
- Free:
-        swsusp_free();
-        device_resume();
-        resume_console();
- Thaw:
         printk(KERN_ERR "PM: Restore failed, recovering.\n");
+        swsusp_free();
         unprepare_processes();
  Done:
         free_basic_memory_bitmaps();
@@ -333,7 +357,7 @@ static int software_resume(void)
  Unlock:
         mutex_unlock(&pm_mutex);
         pr_debug("PM: Resume from disk failed.\n");
-        return 0;
+        return error;
 }
 
 late_initcall(software_resume);
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 51381487103f..70c378b3f85a 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -25,7 +25,10 @@ struct swsusp_info {
  */
 #define SPARE_PAGES     ((1024 * 1024) >> PAGE_SHIFT)
 
-extern struct hibernation_ops *hibernation_ops;
+/* kernel/power/disk.c */
+extern int hibernation_snapshot(int platform_mode);
+extern int hibernation_restore(void);
+extern int hibernation_platform_enter(void);
 #endif
 
 extern int pfn_is_nosave(unsigned long);
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 09468ec61124..bfed3b924093 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -128,83 +128,6 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf,
         return res;
 }
 
-static inline int platform_prepare(void)
-{
-        int error = 0;
-
-        if (hibernation_ops)
-                error = hibernation_ops->prepare();
-
-        return error;
-}
-
-static inline void platform_finish(void)
-{
-        if (hibernation_ops)
-                hibernation_ops->finish();
-}
-
-static inline int snapshot_suspend(int platform_suspend)
-{
-        int error;
-
-        mutex_lock(&pm_mutex);
-        /* Free memory before shutting down devices. */
-        error = swsusp_shrink_memory();
-        if (error)
-                goto Finish;
-
-        if (platform_suspend) {
-                error = platform_prepare();
-                if (error)
-                        goto Finish;
-        }
-        suspend_console();
-        error = device_suspend(PMSG_FREEZE);
-        if (error)
-                goto Resume_devices;
-
-        error = disable_nonboot_cpus();
-        if (!error) {
-                in_suspend = 1;
-                error = swsusp_suspend();
-        }
-        enable_nonboot_cpus();
- Resume_devices:
-        if (platform_suspend)
-                platform_finish();
-
-        device_resume();
-        resume_console();
- Finish:
-        mutex_unlock(&pm_mutex);
-        return error;
-}
-
-static inline int snapshot_restore(void)
-{
-        int error;
-
-        mutex_lock(&pm_mutex);
-        pm_prepare_console();
-        suspend_console();
-        error = device_suspend(PMSG_PRETHAW);
-        if (error)
-                goto Finish;
-
-        error = disable_nonboot_cpus();
-        if (!error)
-                error = swsusp_resume();
-
-        enable_nonboot_cpus();
- Finish:
-        device_resume();
-        resume_console();
-        pm_restore_console();
-        mutex_unlock(&pm_mutex);
-        return error;
-}
-
 static int snapshot_ioctl(struct inode *inode, struct file *filp,
                           unsigned int cmd, unsigned long arg)
 {
@@ -251,7 +174,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
                         error = -EPERM;
                         break;
                 }
-                error = snapshot_suspend(data->platform_suspend);
+                error = hibernation_snapshot(data->platform_suspend);
                 if (!error)
                         error = put_user(in_suspend, (unsigned int __user *)arg);
                 if (!error)
@@ -265,7 +188,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
                         error = -EPERM;
                         break;
                 }
-                error = snapshot_restore();
+                error = hibernation_restore();
                 break;
 
         case SNAPSHOT_FREE:
@@ -377,19 +300,14 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
                 switch (arg) {
 
                 case PMOPS_PREPARE:
-                        if (hibernation_ops) {
-                                data->platform_suspend = 1;
-                                error = 0;
-                        } else {
-                                error = -ENOSYS;
-                        }
+                        data->platform_suspend = 1;
+                        error = 0;
                         break;
 
                 case PMOPS_ENTER:
-                        if (data->platform_suspend) {
-                                kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
-                                error = hibernation_ops->enter();
-                        }
+                        if (data->platform_suspend)
+                                error = hibernation_platform_enter();
+
                         break;
 
                 case PMOPS_FINISH: