PM/Hibernate: Rename disk.c to hibernate.c

Change the name of kernel/power/disk.c to kernel/power/hibernate.c
in analogy with the file names introduced by the changes that
separated the suspend to RAM and standby funtionality from the
common PM functions.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>

1 files changed, 955 insertions, 0 deletions

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
new file mode 100644
index 00000000000..81d2e746489
--- /dev/null
+++ b/kernel/power/hibernate.c
@@ -0,0 +1,955 @@
+/*
+ * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Lab
+ * Copyright (c) 2004 Pavel Machek <pavel@suse.cz>
+ * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/suspend.h>
+#include <linux/syscalls.h>
+#include <linux/reboot.h>
+#include <linux/string.h>
+#include <linux/device.h>
+#include <linux/kmod.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/pm.h>
+#include <linux/console.h>
+#include <linux/cpu.h>
+#include <linux/freezer.h>
+#include <scsi/scsi_scan.h>
+#include <asm/suspend.h>
+
+#include "power.h"
+
+
+static int noresume = 0;
+static char resume_file[256] = CONFIG_PM_STD_PARTITION;
+dev_t swsusp_resume_device;
+sector_t swsusp_resume_block;
+
+enum {
+	HIBERNATION_INVALID,
+	HIBERNATION_PLATFORM,
+	HIBERNATION_TEST,
+	HIBERNATION_TESTPROC,
+	HIBERNATION_SHUTDOWN,
+	HIBERNATION_REBOOT,
+	/* keep last */
+	__HIBERNATION_AFTER_LAST
+};
+#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
+#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
+
+static int hibernation_mode = HIBERNATION_SHUTDOWN;
+
+static struct platform_hibernation_ops *hibernation_ops;
+
+/**
+ * hibernation_set_ops - set the global hibernate operations
+ * @ops: the hibernation operations to use in subsequent hibernation transitions
+ */
+
+void hibernation_set_ops(struct platform_hibernation_ops *ops)
+{
+	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
+	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore
+	    && ops->restore_cleanup)) {
+		WARN_ON(1);
+		return;
+	}
+	mutex_lock(&pm_mutex);
+	hibernation_ops = ops;
+	if (ops)
+		hibernation_mode = HIBERNATION_PLATFORM;
+	else if (hibernation_mode == HIBERNATION_PLATFORM)
+		hibernation_mode = HIBERNATION_SHUTDOWN;
+
+	mutex_unlock(&pm_mutex);
+}
+
+static bool entering_platform_hibernation;
+
+bool system_entering_hibernation(void)
+{
+	return entering_platform_hibernation;
+}
+EXPORT_SYMBOL(system_entering_hibernation);
+
+#ifdef CONFIG_PM_DEBUG
+static void hibernation_debug_sleep(void)
+{
+	printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
+	mdelay(5000);
+}
+
+static int hibernation_testmode(int mode)
+{
+	if (hibernation_mode == mode) {
+		hibernation_debug_sleep();
+		return 1;
+	}
+	return 0;
+}
+
+static int hibernation_test(int level)
+{
+	if (pm_test_level == level) {
+		hibernation_debug_sleep();
+		return 1;
+	}
+	return 0;
+}
+#else /* !CONFIG_PM_DEBUG */
+static int hibernation_testmode(int mode) { return 0; }
+static int hibernation_test(int level) { return 0; }
+#endif /* !CONFIG_PM_DEBUG */
+
+/**
+ *	platform_begin - tell the platform driver that we're starting
+ *	hibernation
+ */
+
+static int platform_begin(int platform_mode)
+{
+	return (platform_mode && hibernation_ops) ?
+		hibernation_ops->begin() : 0;
+}
+
+/**
+ *	platform_end - tell the platform driver that we've entered the
+ *	working state
+ */
+
+static void platform_end(int platform_mode)
+{
+	if (platform_mode && hibernation_ops)
+		hibernation_ops->end();
+}
+
+/**
+ *	platform_pre_snapshot - prepare the machine for hibernation using the
+ *	platform driver if so configured and return an error code if it fails
+ */
+
+static int platform_pre_snapshot(int platform_mode)
+{
+	return (platform_mode && hibernation_ops) ?
+		hibernation_ops->pre_snapshot() : 0;
+}
+
+/**
+ *	platform_leave - prepare the machine for switching to the normal mode
+ *	of operation using the platform driver (called with interrupts disabled)
+ */
+
+static void platform_leave(int platform_mode)
+{
+	if (platform_mode && hibernation_ops)
+		hibernation_ops->leave();
+}
+
+/**
+ *	platform_finish - switch the machine to the normal mode of operation
+ *	using the platform driver (must be called after platform_prepare())
+ */
+
+static void platform_finish(int platform_mode)
+{
+	if (platform_mode && hibernation_ops)
+		hibernation_ops->finish();
+}
+
+/**
+ *	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();
+}
+
+/**
+ *	platform_recover - recover the platform from a failure to suspend
+ *	devices.
+ */
+
+static void platform_recover(int platform_mode)
+{
+	if (platform_mode && hibernation_ops && hibernation_ops->recover)
+		hibernation_ops->recover();
+}
+
+/**
+ *	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.
+ */
+
+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))
+		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)
+		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 the hibernation
+ *	snapshot image.
+ *	@platform_mode - if set, use the platform driver, if available, to
+ *			 prepare the platform firmware for the power transition.
+ *
+ *	Must be called with pm_mutex held
+ */
+
+int hibernation_snapshot(int platform_mode)
+{
+	int error;
+
+	error = platform_begin(platform_mode);
+	if (error)
+		return error;
+
+	/* Free memory before shutting down devices. */
+	error = swsusp_shrink_memory();
+	if (error)
+		goto Close;
+
+	suspend_console();
+	error = dpm_suspend_start(PMSG_FREEZE);
+	if (error)
+		goto Recover_platform;
+
+	if (hibernation_test(TEST_DEVICES))
+		goto Recover_platform;
+
+	error = create_image(platform_mode);
+	/* Control returns here after successful restore */
+
+ Resume_devices:
+	dpm_resume_end(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;
+}
+
+/**
+ *	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(bool platform_mode)
+{
+	int error;
+
+	error = dpm_suspend_noirq(PMSG_QUIESCE);
+	if (error) {
+		printk(KERN_ERR "PM: Some devices failed to power down, "
+			"aborting resume\n");
+		return error;
+	}
+
+	error = platform_pre_restore(platform_mode);
+	if (error)
+		goto Cleanup;
+
+	error = disable_nonboot_cpus();
+	if (error)
+		goto Enable_cpus;
+
+	local_irq_disable();
+
+	error = sysdev_suspend(PMSG_QUIESCE);
+	if (error)
+		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();
+
+	sysdev_resume();
+
+ Enable_irqs:
+	local_irq_enable();
+
+ Enable_cpus:
+	enable_nonboot_cpus();
+
+ Cleanup:
+	platform_restore_cleanup(platform_mode);
+
+	dpm_resume_noirq(PMSG_RECOVER);
+
+	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 firmware for the transition.
+ *
+ *	Must be called with pm_mutex held
+ */
+
+int hibernation_restore(int platform_mode)
+{
+	int error;
+
+	pm_prepare_console();
+	suspend_console();
+	error = dpm_suspend_start(PMSG_QUIESCE);
+	if (!error) {
+		error = resume_target_kernel(platform_mode);
+		dpm_resume_end(PMSG_RECOVER);
+	}
+	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->begin();
+	if (error)
+		goto Close;
+
+	entering_platform_hibernation = true;
+	suspend_console();
+	error = dpm_suspend_start(PMSG_HIBERNATE);
+	if (error) {
+		if (hibernation_ops->recover)
+			hibernation_ops->recover();
+		goto Resume_devices;
+	}
+
+	error = dpm_suspend_noirq(PMSG_HIBERNATE);
+	if (error)
+		goto Resume_devices;
+
+	error = hibernation_ops->prepare();
+	if (error)
+		goto Platofrm_finish;
+
+	error = disable_nonboot_cpus();
+	if (error)
+		goto Platofrm_finish;
+
+	local_irq_disable();
+	sysdev_suspend(PMSG_HIBERNATE);
+	hibernation_ops->enter();
+	/* We should never get here */
+	while (1);
+
+	/*
+	 * We don't need to reenable the nonboot CPUs or resume consoles, since
+	 * the system is going to be halted anyway.
+	 */
+ Platofrm_finish:
+	hibernation_ops->finish();
+
+	dpm_suspend_noirq(PMSG_RESTORE);
+
+ Resume_devices:
+	entering_platform_hibernation = false;
+	dpm_resume_end(PMSG_RESTORE);
+	resume_console();
+
+ Close:
+	hibernation_ops->end();
+
+	return error;
+}
+
+/**
+ *	power_down - Shut the machine down for hibernation.
+ *
+ *	Use the platform driver, if configured so; otherwise try
+ *	to power off or reboot.
+ */
+
+static void power_down(void)
+{
+	switch (hibernation_mode) {
+	case HIBERNATION_TEST:
+	case HIBERNATION_TESTPROC:
+		break;
+	case HIBERNATION_REBOOT:
+		kernel_restart(NULL);
+		break;
+	case HIBERNATION_PLATFORM:
+		hibernation_platform_enter();
+	case HIBERNATION_SHUTDOWN:
+		kernel_power_off();
+		break;
+	}
+	kernel_halt();
+	/*
+	 * Valid image is on the disk, if we continue we risk serious data
+	 * corruption after resume.
+	 */
+	printk(KERN_CRIT "PM: Please power down manually\n");
+	while(1);
+}
+
+static int prepare_processes(void)
+{
+	int error = 0;
+
+	if (freeze_processes()) {
+		error = -EBUSY;
+		thaw_processes();
+	}
+	return error;
+}
+
+/**
+ *	hibernate - The granpappy of the built-in hibernation management
+ */
+
+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 (in_suspend && !error) {
+		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");
+		swsusp_free();
+	}
+ 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;
+}
+
+
+/**
+ *	software_resume - Resume from a saved image.
+ *
+ *	Called as a late_initcall (so all devices are discovered and
+ *	initialized), we call swsusp to see if we have a saved image or not.
+ *	If so, we quiesce devices, the restore the saved image. We will
+ *	return above (in hibernate() ) if everything goes well.
+ *	Otherwise, we fail gracefully and return to the normally
+ *	scheduled program.
+ *
+ */
+
+static int software_resume(void)
+{
+	int error;
+	unsigned int flags;
+
+	/*
+	 * If the user said "noresume".. bail out early.
+	 */
+	if (noresume)
+		return 0;
+
+	/*
+	 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
+	 * is configured into the kernel. Since the regular hibernate
+	 * trigger path is via sysfs which takes a buffer mutex before
+	 * calling hibernate functions (which take pm_mutex) this can
+	 * cause lockdep to complain about a possible ABBA deadlock
+	 * which cannot happen since we're in the boot code here and
+	 * sysfs can't be invoked yet. Therefore, we use a subclass
+	 * here to avoid lockdep complaining.
+	 */
+	mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
+
+	if (swsusp_resume_device)
+		goto Check_image;
+
+	if (!strlen(resume_file)) {
+		error = -ENOENT;
+		goto Unlock;
+	}
+
+	pr_debug("PM: Checking image partition %s\n", resume_file);
+
+	/* Check if the device is there */
+	swsusp_resume_device = name_to_dev_t(resume_file);
+	if (!swsusp_resume_device) {
+		/*
+		 * Some device discovery might still be in progress; we need
+		 * to wait for this to finish.
+		 */
+		wait_for_device_probe();
+		/*
+		 * We can't depend on SCSI devices being available after loading
+		 * one of their modules until scsi_complete_async_scans() is
+		 * called and the resume device usually is a SCSI one.
+		 */
+		scsi_complete_async_scans();
+
+		swsusp_resume_device = name_to_dev_t(resume_file);
+		if (!swsusp_resume_device) {
+			error = -ENODEV;
+			goto Unlock;
+		}
+	}
+
+ Check_image:
+	pr_debug("PM: Resume from partition %d:%d\n",
+		MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
+
+	pr_debug("PM: Checking hibernation image.\n");
+	error = swsusp_check();
+	if (error)
+		goto Unlock;
+
+	/* 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_RESTORE_PREPARE);
+	if (error)
+		goto Finish;
+
+	error = usermodehelper_disable();
+	if (error)
+		goto Finish;
+
+	error = create_basic_memory_bitmaps();
+	if (error)
+		goto Finish;
+
+	pr_debug("PM: Preparing processes for restore.\n");
+	error = prepare_processes();
+	if (error) {
+		swsusp_close(FMODE_READ);
+		goto Done;
+	}
+
+	pr_debug("PM: Reading hibernation image.\n");
+
+	error = swsusp_read(&flags);
+	if (!error)
+		hibernation_restore(flags & SF_PLATFORM_MODE);
+
+	printk(KERN_ERR "PM: Restore failed, recovering.\n");
+	swsusp_free();
+	thaw_processes();
+ Done:
+	free_basic_memory_bitmaps();
+	usermodehelper_enable();
+ Finish:
+	pm_notifier_call_chain(PM_POST_RESTORE);
+	pm_restore_console();
+	atomic_inc(&snapshot_device_available);
+	/* For success case, the suspend path will release the lock */
+ Unlock:
+	mutex_unlock(&pm_mutex);
+	pr_debug("PM: Resume from disk failed.\n");
+	return error;
+}
+
+late_initcall(software_resume);
+
+
+static const char * const hibernation_modes[] = {
+	[HIBERNATION_PLATFORM]	= "platform",
+	[HIBERNATION_SHUTDOWN]	= "shutdown",
+	[HIBERNATION_REBOOT]	= "reboot",
+	[HIBERNATION_TEST]	= "test",
+	[HIBERNATION_TESTPROC]	= "testproc",
+};
+
+/**
+ *	disk - Control hibernation mode
+ *
+ *	Suspend-to-disk can be handled in several ways. We have a few options
+ *	for putting the system to sleep - using the platform driver (e.g. ACPI
+ *	or other hibernation_ops), powering off the system or rebooting the
+ *	system (for testing) as well as the two test modes.
+ *
+ *	The system can support 'platform', and that is known a priori (and
+ *	encoded by the presence of hibernation_ops). However, the user may
+ *	choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
+ *	test modes, 'test' or 'testproc'.
+ *
+ *	show() will display what the mode is currently set to.
+ *	store() will accept one of
+ *
+ *	'platform'
+ *	'shutdown'
+ *	'reboot'
+ *	'test'
+ *	'testproc'
+ *
+ *	It will only change to 'platform' if the system
+ *	supports it (as determined by having hibernation_ops).
+ */
+
+static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
+			 char *buf)
+{
+	int i;
+	char *start = buf;
+
+	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
+		if (!hibernation_modes[i])
+			continue;
+		switch (i) {
+		case HIBERNATION_SHUTDOWN:
+		case HIBERNATION_REBOOT:
+		case HIBERNATION_TEST:
+		case HIBERNATION_TESTPROC:
+			break;
+		case HIBERNATION_PLATFORM:
+			if (hibernation_ops)
+				break;
+			/* not a valid mode, continue with loop */
+			continue;
+		}
+		if (i == hibernation_mode)
+			buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
+		else
+			buf += sprintf(buf, "%s ", hibernation_modes[i]);
+	}
+	buf += sprintf(buf, "\n");
+	return buf-start;
+}
+
+
+static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
+			  const char *buf, size_t n)
+{
+	int error = 0;
+	int i;
+	int len;
+	char *p;
+	int mode = HIBERNATION_INVALID;
+
+	p = memchr(buf, '\n', n);
+	len = p ? p - buf : n;
+
+	mutex_lock(&pm_mutex);
+	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
+		if (len == strlen(hibernation_modes[i])
+		    && !strncmp(buf, hibernation_modes[i], len)) {
+			mode = i;
+			break;
+		}
+	}
+	if (mode != HIBERNATION_INVALID) {
+		switch (mode) {
+		case HIBERNATION_SHUTDOWN:
+		case HIBERNATION_REBOOT:
+		case HIBERNATION_TEST:
+		case HIBERNATION_TESTPROC:
+			hibernation_mode = mode;
+			break;
+		case HIBERNATION_PLATFORM:
+			if (hibernation_ops)
+				hibernation_mode = mode;
+			else
+				error = -EINVAL;
+		}
+	} else
+		error = -EINVAL;
+
+	if (!error)
+		pr_debug("PM: Hibernation mode set to '%s'\n",
+			 hibernation_modes[mode]);
+	mutex_unlock(&pm_mutex);
+	return error ? error : n;
+}
+
+power_attr(disk);
+
+static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
+			   char *buf)
+{
+	return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
+		       MINOR(swsusp_resume_device));
+}
+
+static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
+			    const char *buf, size_t n)
+{
+	unsigned int maj, min;
+	dev_t res;
+	int ret = -EINVAL;
+
+	if (sscanf(buf, "%u:%u", &maj, &min) != 2)
+		goto out;
+
+	res = MKDEV(maj,min);
+	if (maj != MAJOR(res) || min != MINOR(res))
+		goto out;
+
+	mutex_lock(&pm_mutex);
+	swsusp_resume_device = res;
+	mutex_unlock(&pm_mutex);
+	printk(KERN_INFO "PM: Starting manual resume from disk\n");
+	noresume = 0;
+	software_resume();
+	ret = n;
+ out:
+	return ret;
+}
+
+power_attr(resume);
+
+static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
+			       char *buf)
+{
+	return sprintf(buf, "%lu\n", image_size);
+}
+
+static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
+				const char *buf, size_t n)
+{
+	unsigned long size;
+
+	if (sscanf(buf, "%lu", &size) == 1) {
+		image_size = size;
+		return n;
+	}
+
+	return -EINVAL;
+}
+
+power_attr(image_size);
+
+static struct attribute * g[] = {
+	&disk_attr.attr,
+	&resume_attr.attr,
+	&image_size_attr.attr,
+	NULL,
+};
+
+
+static struct attribute_group attr_group = {
+	.attrs = g,
+};
+
+
+static int __init pm_disk_init(void)
+{
+	return sysfs_create_group(power_kobj, &attr_group);
+}
+
+core_initcall(pm_disk_init);
+
+
+static int __init resume_setup(char *str)
+{
+	if (noresume)
+		return 1;
+
+	strncpy( resume_file, str, 255 );
+	return 1;
+}
+
+static int __init resume_offset_setup(char *str)
+{
+	unsigned long long offset;
+
+	if (noresume)
+		return 1;
+
+	if (sscanf(str, "%llu", &offset) == 1)
+		swsusp_resume_block = offset;
+
+	return 1;
+}
+
+static int __init noresume_setup(char *str)
+{
+	noresume = 1;
+	return 1;
+}
+
+__setup("noresume", noresume_setup);
+__setup("resume_offset=", resume_offset_setup);
+__setup("resume=", resume_setup);