+/**
+ * platform_pre_restore - prepare the platform for the restoration from a
+ * hibernation image. If the restore fails after this function has been
+ * called, platform_restore_cleanup() must be called.
+ */
+
+static int platform_pre_restore(int platform_mode)
+{
+ return (platform_mode && hibernation_ops) ?
+ hibernation_ops->pre_restore() : 0;
+}
+
+/**
+ * platform_restore_cleanup - switch the platform to the normal mode of
+ * operation after a failing restore. If platform_pre_restore() has been
+ * called before the failing restore, this function must be called too,
+ * regardless of the result of platform_pre_restore().
+ */
+
+static void platform_restore_cleanup(int platform_mode)
+{
+ if (platform_mode && hibernation_ops)
+ hibernation_ops->restore_cleanup();
+}
+
+/**
+ * create_image - freeze devices that need to be frozen with interrupts
+ * off, create the hibernation image and thaw those devices. Control
+ * reappears in this routine after a restore.
+ */
+
+int create_image(int platform_mode)
+{
+ int error;
+
+ error = arch_prepare_suspend();
+ if (error)
+ return error;
+
+ local_irq_disable();
+ /* At this point, device_suspend() has been called, but *not*
+ * device_power_down(). We *must* call device_power_down() now.
+ * Otherwise, drivers for some devices (e.g. interrupt controllers)
+ * become desynchronized with the actual state of the hardware
+ * at resume time, and evil weirdness ensues.
+ */
+ error = device_power_down(PMSG_FREEZE);
+ if (error) {
+ printk(KERN_ERR "Some devices failed to power down, "
+ KERN_ERR "aborting suspend\n");
+ goto Enable_irqs;
+ }
+
+ save_processor_state();
+ error = swsusp_arch_suspend();
+ if (error)
+ printk(KERN_ERR "Error %d while creating the image\n", error);
+ /* Restore control flow magically appears here */
+ restore_processor_state();
+ if (!in_suspend)
+ platform_leave(platform_mode);
+ /* NOTE: device_power_up() is just a resume() for devices
+ * that suspended with irqs off ... no overall powerup.
+ */
+ device_power_up();
+ Enable_irqs:
+ local_irq_enable();
+ return error;
+}
+
+/**
+ * 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)
+ 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_pre_snapshot(platform_mode);
+ if (error)
+ goto Resume_devices;
+
+ error = disable_nonboot_cpus();
+ if (!error) {
+ if (hibernation_mode != HIBERNATION_TEST) {
+ in_suspend = 1;
+ error = create_image(platform_mode);
+ /* 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:
+ resume_console();
+ 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
+ * prepare the platform frimware for the transition.
+ *
+ * Must be called with pm_mutex held
+ */
+
+int hibernation_restore(int platform_mode)
+{
+ int error;
+
+ pm_prepare_console();
+ suspend_console();
+ error = device_suspend(PMSG_PRETHAW);
+ if (error)
+ goto Finish;
+
+ error = platform_pre_restore(platform_mode);
+ if (!error) {
+ error = disable_nonboot_cpus();
+ if (!error)
+ error = swsusp_resume();
+ enable_nonboot_cpus();
+ }
+ platform_restore_cleanup(platform_mode);
+ device_resume();
+ Finish:
+ 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)
+{
+ int error;
+
+ if (!hibernation_ops)
+ return -ENOSYS;
+
+ /*
+ * We have cancelled the power transition by running
+ * hibernation_ops->finish() before saving the image, so we should let
+ * the firmware know that we're going to enter the sleep state after all
+ */
+ error = hibernation_ops->start();
+ if (error)
+ return error;
+
+ suspend_console();
+ error = device_suspend(PMSG_SUSPEND);
+ if (error)
+ goto Resume_console;
+
+ error = hibernation_ops->prepare();
+ if (error)
+ goto Resume_devices;
+
+ error = disable_nonboot_cpus();
+ if (error)
+ goto Finish;
+
+ local_irq_disable();
+ error = device_power_down(PMSG_SUSPEND);
+ if (!error) {
+ hibernation_ops->enter();
+ /* We should never get here */
+ while (1);
+ }
+ local_irq_enable();
+
+ /*
+ * We don't need to reenable the nonboot CPUs or resume consoles, since
+ * the system is going to be halted anyway.
+ */
+ Finish:
+ hibernation_ops->finish();
+ Resume_devices:
+ device_resume();
+ Resume_console:
+ resume_console();
+ return error;
+}
+