int hibernation_snapshot(int platform_mode)
{
int error;
/* Free memory before shutting down devices. */
error = swsusp_shrink_memory();
if (error)
return error;
error = platform_begin(platform_mode);
if (error)
goto Close;
suspend_console();
error = device_suspend(PMSG_FREEZE);
if (error)
goto Recover_platform;
if (hibernation_test(TEST_DEVICES))
goto Recover_platform;
error = platform_pre_snapshot(platform_mode);
if (error || hibernation_test(TEST_PLATFORM))
goto Finish;
error = disable_nonboot_cpus();
if (!error) {
if (hibernation_test(TEST_CPUS))
goto Enable_cpus;
if (hibernation_testmode(HIBERNATION_TEST))
goto Enable_cpus;
error = create_image(platform_mode);
/* Control returns here after successful restore */
}
Enable_cpus:
enable_nonboot_cpus();
Finish:
platform_finish(platform_mode);
Resume_devices:
device_resume(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
resume_console();
Close:
platform_end(platform_mode);
return error;
Recover_platform:
platform_recover(platform_mode);
goto Resume_devices;
}
int hibernate(void)
{
int error;
mutex_lock(&pm_mutex);
/* The snapshot device should not be opened while we're running */
if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
error = -EBUSY;
goto Unlock;
}
pm_prepare_console();
error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
if (error)
goto Exit;
error = usermodehelper_disable();
if (error)
goto Exit;
/* Allocate memory management structures */
error = create_basic_memory_bitmaps();
if (error)
goto Exit;
printk(KERN_INFO "PM: Syncing filesystems ... ");
sys_sync();
printk("done.\n");
error = prepare_processes();
if (error)
goto Finish;
if (hibernation_test(TEST_FREEZER))
goto Thaw;
if (hibernation_testmode(HIBERNATION_TESTPROC))
goto Thaw;
error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
if (error)
goto Thaw;
if (in_suspend) {
unsigned int flags = 0;
if (hibernation_mode == HIBERNATION_PLATFORM)
flags |= SF_PLATFORM_MODE;
pr_debug("PM: writing image.\n");
error = swsusp_write(flags);
swsusp_free();
if (!error)
power_down();
} else {
pr_debug("PM: Image restored successfully.\n");
}
Thaw:
thaw_processes();
Finish:
free_basic_memory_bitmaps();
usermodehelper_enable();
Exit:
pm_notifier_call_chain(PM_POST_HIBERNATION);
pm_restore_console();
atomic_inc(&snapshot_device_available);
Unlock:
mutex_unlock(&pm_mutex);
return error;
}
static int create_image(int platform_mode)
{
int error;
error = arch_prepare_suspend();
if (error)
return error;
/* At this point, dpm_suspend_start() has been called, but *not*
* dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() 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 = dpm_suspend_noirq(PMSG_FREEZE);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down, "
"aborting hibernation\n");
return error;
}
error = platform_pre_snapshot(platform_mode);
if (error || hibernation_test(TEST_PLATFORM))
goto Platform_finish;
error = disable_nonboot_cpus();
if (error || hibernation_test(TEST_CPUS)
|| hibernation_testmode(HIBERNATION_TEST))
goto Enable_cpus;
local_irq_disable();
error = sysdev_suspend(PMSG_FREEZE);
if (error) {
printk(KERN_ERR "PM: Some system devices failed to power down, "
"aborting hibernation\n");
goto Enable_irqs;
}
if (hibernation_test(TEST_CORE) || !pm_check_wakeup_events())
goto Power_up;
in_suspend = 1;
save_processor_state();
error = swsusp_arch_suspend();
if (error)
printk(KERN_ERR "PM: Error %d creating hibernation image\n",
error);
/* Restore control flow magically appears here */
restore_processor_state();
if (!in_suspend) {
events_check_enabled = false;
platform_leave(platform_mode);
}
Power_up:
sysdev_resume();
/* NOTE: dpm_resume_noirq() is just a resume() for devices
* that suspended with irqs off ... no overall powerup.
*/
Enable_irqs:
local_irq_enable();
Enable_cpus:
enable_nonboot_cpus();
Platform_finish:
platform_finish(platform_mode);
dpm_resume_noirq(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
return error;
}
/**
* hibernation_snapshot - Quiesce devices and create a hibernation image.
* @platform_mode: If set, use platform driver to prepare for the transition.
*
* This routine must be called with pm_mutex held.
*/
int hibernation_snapshot(int platform_mode)
{
pm_message_t msg = PMSG_RECOVER;
int error;
error = platform_begin(platform_mode);
if (error)
goto Close;
/* Preallocate image memory before shutting down devices. */
error = hibernate_preallocate_memory();
if (error)
goto Close;
error = freeze_kernel_threads();
if (error)
goto Cleanup;
if (hibernation_test(TEST_FREEZER) ||
hibernation_testmode(HIBERNATION_TESTPROC)) {
/*
* Indicate to the caller that we are returning due to a
* successful freezer test.
*/
freezer_test_done = true;
goto Cleanup;
}
error = dpm_prepare(PMSG_FREEZE);
if (error) {
dpm_complete(msg);
goto Cleanup;
}
suspend_console();
ftrace_stop();
pm_restrict_gfp_mask();
error = dpm_suspend(PMSG_FREEZE);
if (error)
goto Recover_platform;
if (hibernation_test(TEST_DEVICES))
goto Recover_platform;
error = create_image(platform_mode);
/*
* Control returns here (1) after the image has been created or the
* image creation has failed and (2) after a successful restore.
*/
Resume_devices:
/* We may need to release the preallocated image pages here. */
if (error || !in_suspend)
swsusp_free();
msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
dpm_resume(msg);
if (error || !in_suspend)
pm_restore_gfp_mask();
ftrace_start();
resume_console();
dpm_complete(msg);
Close:
platform_end(platform_mode);
return error;
Recover_platform:
platform_recover(platform_mode);
goto Resume_devices;
Cleanup:
swsusp_free();
goto Close;
}
/**
* create_image - Create a hibernation image.
* @platform_mode: Whether or not to use the platform driver.
*
* Execute device drivers' .freeze_noirq() callbacks, create a hibernation image
* and execute the drivers' .thaw_noirq() callbacks.
*
* Control reappears in this routine after the subsequent restore.
*/
static int create_image(int platform_mode)
{
int error;
error = dpm_suspend_noirq(PMSG_FREEZE);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down, "
"aborting hibernation\n");
return error;
}
error = platform_pre_snapshot(platform_mode);
if (error || hibernation_test(TEST_PLATFORM))
goto Platform_finish;
error = disable_nonboot_cpus();
if (error || hibernation_test(TEST_CPUS)
|| hibernation_testmode(HIBERNATION_TEST))
goto Enable_cpus;
local_irq_disable();
error = syscore_suspend();
if (error) {
printk(KERN_ERR "PM: Some system devices failed to power down, "
"aborting hibernation\n");
goto Enable_irqs;
}
if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
goto Power_up;
in_suspend = 1;
save_processor_state();
error = swsusp_arch_suspend();
if (error)
printk(KERN_ERR "PM: Error %d creating hibernation image\n",
error);
/* Restore control flow magically appears here */
restore_processor_state();
if (!in_suspend) {
events_check_enabled = false;
platform_leave(platform_mode);
}
Power_up:
syscore_resume();
Enable_irqs:
local_irq_enable();
Enable_cpus:
enable_nonboot_cpus();
Platform_finish:
platform_finish(platform_mode);
dpm_resume_noirq(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
return error;
}