Hibernation: Move low level resume to disk.c

Move the low level restore code to kernel/power/disk.c , since the
corresponding low level hibernation code is already there.

Make restore fail if device_power_down(PMSG_PRETHAW) returns an
error.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 48 insertions, 1 deletions

diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 0866b163c6bb..2a4bada184ed 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -275,6 +275,53 @@ int hibernation_snapshot(int platform_mode)
 }
 
 /**
+ *      resume_target_kernel - prepare devices that need to be suspended with
+ *      interrupts off, restore the contents of highmem that have not been
+ *      restored yet from the image and run the low level code that will restore
+ *      the remaining contents of memory and switch to the just restored target
+ *      kernel.
+ */
+
+static int resume_target_kernel(void)
+{
+        int error;
+
+        local_irq_disable();
+        error = device_power_down(PMSG_PRETHAW);
+        if (error) {
+                printk(KERN_ERR "Some devices failed to power down, "
+                        "aborting resume\n");
+                goto Enable_irqs;
+        }
+        /* We'll ignore saved state, but this gets preempt count (etc) right */
+        save_processor_state();
+        error = restore_highmem();
+        if (!error) {
+                error = swsusp_arch_resume();
+                /*
+                 * The code below is only ever reached in case of a failure.
+                 * Otherwise execution continues at place where
+                 * swsusp_arch_suspend() was called
+                 */
+                BUG_ON(!error);
+                /* This call to restore_highmem() undos the previous one */
+                restore_highmem();
+        }
+        /*
+         * The only reason why swsusp_arch_resume() can fail is memory being
+         * very tight, so we have to free it as soon as we can to avoid
+         * subsequent failures
+         */
+        swsusp_free();
+        restore_processor_state();
+        touch_softlockup_watchdog();
+        device_power_up();
+ Enable_irqs:
+        local_irq_enable();
+        return error;
+}
+
+/**
  *      hibernation_restore - quiesce devices and restore the hibernation
  *      snapshot image.  If successful, control returns in hibernation_snaphot()
  *      @platform_mode - if set, use the platform driver, if available, to
@@ -297,7 +344,7 @@ int hibernation_restore(int platform_mode)
         if (!error) {
                 error = disable_nonboot_cpus();
                 if (!error)
-                        error = swsusp_resume();
+                        error = resume_target_kernel();
                 enable_nonboot_cpus();
         }
         platform_restore_cleanup(platform_mode);