[linux-2.6-block.git] / kernel / power / disk.c

/*
 * kernel/power/disk.c - Suspend-to-disk support.
 *
 * Copyright (c) 2003 Patrick Mochel
 * Copyright (c) 2003 Open Source Development Lab
 * Copyright (c) 2004 Pavel Machek <pavel@suse.cz>
 *
 * 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/delay.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/pm.h>
#include <linux/console.h>
#include <linux/cpu.h>

#include "power.h"


static int noresume = 0;
char resume_file[256] = CONFIG_PM_STD_PARTITION;
dev_t swsusp_resume_device;
sector_t swsusp_resume_block;

/**
 *	power_down - Shut machine down for hibernate.
 *	@mode:		Suspend-to-disk mode
 *
 *	Use the platform driver, if configured so, and return gracefully if it
 *	fails.
 *	Otherwise, try to power off and reboot. If they fail, halt the machine,
 *	there ain't no turning back.
 */

static void power_down(suspend_disk_method_t mode)
{
	int error = 0;

	switch(mode) {
	case PM_DISK_PLATFORM:
		kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
		error = pm_ops->enter(PM_SUSPEND_DISK);
		break;
	case PM_DISK_SHUTDOWN:
		kernel_power_off();
		break;
	case PM_DISK_REBOOT:
		kernel_restart(NULL);
		break;
	}
	kernel_halt();
	/* Valid image is on the disk, if we continue we risk serious data corruption
	   after resume. */
	printk(KERN_CRIT "Please power me down manually\n");
	while(1);
}

static inline void platform_finish(void)
{
	if (pm_disk_mode == PM_DISK_PLATFORM) {
		if (pm_ops && pm_ops->finish)
			pm_ops->finish(PM_SUSPEND_DISK);
	}
}

static int prepare_processes(void)
{
	int error = 0;

	pm_prepare_console();

	error = disable_nonboot_cpus();
	if (error)
		goto enable_cpus;

	if (freeze_processes()) {
		error = -EBUSY;
		goto thaw;
	}

	if (pm_disk_mode == PM_DISK_TESTPROC) {
		printk("swsusp debug: Waiting for 5 seconds.\n");
		mdelay(5000);
		goto thaw;
	}

	/* Free memory before shutting down devices. */
	if (!(error = swsusp_shrink_memory()))
		return 0;
thaw:
	thaw_processes();
enable_cpus:
	enable_nonboot_cpus();
	pm_restore_console();
	return error;
}

static void unprepare_processes(void)
{
	platform_finish();
	thaw_processes();
	enable_nonboot_cpus();
	pm_restore_console();
}

/**
 *	pm_suspend_disk - The granpappy of hibernation power management.
 *
 *	If we're going through the firmware, then get it over with quickly.
 *
 *	If not, then call swsusp to do its thing, then figure out how
 *	to power down the system.
 */

int pm_suspend_disk(void)
{
	int error;

	error = prepare_processes();
	if (error)
		return error;

	if (pm_disk_mode == PM_DISK_TESTPROC)
		goto Thaw;

	suspend_console();
	error = device_suspend(PMSG_FREEZE);
	if (error) {
		resume_console();
		printk("Some devices failed to suspend\n");
		goto Thaw;
	}

	if (pm_disk_mode == PM_DISK_TEST) {
		printk("swsusp debug: Waiting for 5 seconds.\n");
		mdelay(5000);
		goto Done;
	}

	pr_debug("PM: snapshotting memory.\n");
	in_suspend = 1;
	if ((error = swsusp_suspend()))
		goto Done;

	if (in_suspend) {
		device_resume();
		resume_console();
		pr_debug("PM: writing image.\n");
		error = swsusp_write();
		if (!error)
			power_down(pm_disk_mode);
		else {
			swsusp_free();
			goto Thaw;
		}
	} else {
		pr_debug("PM: Image restored successfully.\n");
	}

	swsusp_free();
 Done:
	device_resume();
	resume_console();
 Thaw:
	unprepare_processes();
	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 pm_suspend_disk() ) if everything goes well.
 *	Otherwise, we fail gracefully and return to the normally
 *	scheduled program.
 *
 */

static int software_resume(void)
{
	int error;

	down(&pm_sem);
	if (!swsusp_resume_device) {
		if (!strlen(resume_file)) {
			up(&pm_sem);
			return -ENOENT;
		}
		swsusp_resume_device = name_to_dev_t(resume_file);
		pr_debug("swsusp: Resume From Partition %s\n", resume_file);
	} else {
		pr_debug("swsusp: Resume From Partition %d:%d\n",
			 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
	}

	if (noresume) {
		/**
		 * FIXME: If noresume is specified, we need to find the partition
		 * and reset it back to normal swap space.
		 */
		up(&pm_sem);
		return 0;
	}

	pr_debug("PM: Checking swsusp image.\n");

	if ((error = swsusp_check()))
		goto Done;

	pr_debug("PM: Preparing processes for restore.\n");

	if ((error = prepare_processes())) {
		swsusp_close();
		goto Done;
	}

	pr_debug("PM: Reading swsusp image.\n");

	if ((error = swsusp_read())) {
		swsusp_free();
		goto Thaw;
	}

	pr_debug("PM: Preparing devices for restore.\n");

	suspend_console();
	if ((error = device_suspend(PMSG_PRETHAW))) {
		resume_console();
		printk("Some devices failed to suspend\n");
		swsusp_free();
		goto Thaw;
	}

	mb();

	pr_debug("PM: Restoring saved image.\n");
	swsusp_resume();
	pr_debug("PM: Restore failed, recovering.n");
	device_resume();
	resume_console();
 Thaw:
	unprepare_processes();
 Done:
	/* For success case, the suspend path will release the lock */
	up(&pm_sem);
	pr_debug("PM: Resume from disk failed.\n");
	return 0;
}

late_initcall(software_resume);


static const char * const pm_disk_modes[] = {
	[PM_DISK_FIRMWARE]	= "firmware",
	[PM_DISK_PLATFORM]	= "platform",
	[PM_DISK_SHUTDOWN]	= "shutdown",
	[PM_DISK_REBOOT]	= "reboot",
	[PM_DISK_TEST]		= "test",
	[PM_DISK_TESTPROC]	= "testproc",
};

/**
 *	disk - Control suspend-to-disk mode
 *
 *	Suspend-to-disk can be handled in several ways. The greatest
 *	distinction is who writes memory to disk - the firmware or the OS.
 *	If the firmware does it, we assume that it also handles suspending
 *	the system.
 *	If the OS does it, then we have three options for putting the system
 *	to sleep - using the platform driver (e.g. ACPI or other PM registers),
 *	powering off the system or rebooting the system (for testing).
 *
 *	The system will support either 'firmware' or 'platform', and that is
 *	known a priori (and encoded in pm_ops). But, the user may choose
 *	'shutdown' or 'reboot' as alternatives.
 *
 *	show() will display what the mode is currently set to.
 *	store() will accept one of
 *
 *	'firmware'
 *	'platform'
 *	'shutdown'
 *	'reboot'
 *
 *	It will only change to 'firmware' or 'platform' if the system
 *	supports it (as determined from pm_ops->pm_disk_mode).
 */

static ssize_t disk_show(struct subsystem * subsys, char * buf)
{
	return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
}


static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
{
	int error = 0;
	int i;
	int len;
	char *p;
	suspend_disk_method_t mode = 0;

	p = memchr(buf, '\n', n);
	len = p ? p - buf : n;

	down(&pm_sem);
	for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
		if (!strncmp(buf, pm_disk_modes[i], len)) {
			mode = i;
			break;
		}
	}
	if (mode) {
		if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT ||
		     mode == PM_DISK_TEST || mode == PM_DISK_TESTPROC) {
			pm_disk_mode = mode;
		} else {
			if (pm_ops && pm_ops->enter &&
			    (mode == pm_ops->pm_disk_mode))
				pm_disk_mode = mode;
			else
				error = -EINVAL;
		}
	} else {
		error = -EINVAL;
	}

	pr_debug("PM: suspend-to-disk mode set to '%s'\n",
		 pm_disk_modes[mode]);
	up(&pm_sem);
	return error ? error : n;
}

power_attr(disk);

static ssize_t resume_show(struct subsystem * subsys, char *buf)
{
	return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
		       MINOR(swsusp_resume_device));
}

static ssize_t resume_store(struct subsystem *subsys, 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;

	down(&pm_sem);
	swsusp_resume_device = res;
	up(&pm_sem);
	printk("Attempting manual resume\n");
	noresume = 0;
	software_resume();
	ret = n;
out:
	return ret;
}

power_attr(resume);

static ssize_t image_size_show(struct subsystem * subsys, char *buf)
{
	return sprintf(buf, "%lu\n", image_size);
}

static ssize_t image_size_store(struct subsystem * subsys, 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_subsys.kset.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);
Commit	Line	Data
	1	/*
	2	* kernel/power/disk.c - Suspend-to-disk support.
	3	*
	4	* Copyright (c) 2003 Patrick Mochel
	5	* Copyright (c) 2003 Open Source Development Lab
	6	* Copyright (c) 2004 Pavel Machek <pavel@suse.cz>
	7	*
	8	* This file is released under the GPLv2.
	9	*
	10	*/
	11
	12	#include <linux/suspend.h>
	13	#include <linux/syscalls.h>
	14	#include <linux/reboot.h>
	15	#include <linux/string.h>
	16	#include <linux/device.h>
	17	#include <linux/delay.h>
	18	#include <linux/fs.h>
	19	#include <linux/mount.h>
	20	#include <linux/pm.h>
	21	#include <linux/console.h>
	22	#include <linux/cpu.h>
	23
	24	#include "power.h"
	25
	26
	27	static int noresume = 0;
	28	char resume_file[256] = CONFIG_PM_STD_PARTITION;
	29	dev_t swsusp_resume_device;
	30	sector_t swsusp_resume_block;
	31
	32	/**
	33	* power_down - Shut machine down for hibernate.
	34	* @mode: Suspend-to-disk mode
	35	*
	36	* Use the platform driver, if configured so, and return gracefully if it
	37	* fails.
	38	* Otherwise, try to power off and reboot. If they fail, halt the machine,
	39	* there ain't no turning back.
	40	*/
	41
	42	static void power_down(suspend_disk_method_t mode)
	43	{
	44	int error = 0;
	45
	46	switch(mode) {
	47	case PM_DISK_PLATFORM:
	48	kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
	49	error = pm_ops->enter(PM_SUSPEND_DISK);
	50	break;
	51	case PM_DISK_SHUTDOWN:
	52	kernel_power_off();
	53	break;
	54	case PM_DISK_REBOOT:
	55	kernel_restart(NULL);
	56	break;
	57	}
	58	kernel_halt();
	59	/* Valid image is on the disk, if we continue we risk serious data corruption
	60	after resume. */
	61	printk(KERN_CRIT "Please power me down manually\n");
	62	while(1);
	63	}
	64
	65	static inline void platform_finish(void)
	66	{
	67	if (pm_disk_mode == PM_DISK_PLATFORM) {
	68	if (pm_ops && pm_ops->finish)
	69	pm_ops->finish(PM_SUSPEND_DISK);
	70	}
	71	}
	72
	73	static int prepare_processes(void)
	74	{
	75	int error = 0;
	76
	77	pm_prepare_console();
	78
	79	error = disable_nonboot_cpus();
	80	if (error)
	81	goto enable_cpus;
	82
	83	if (freeze_processes()) {
	84	error = -EBUSY;
	85	goto thaw;
	86	}
	87
	88	if (pm_disk_mode == PM_DISK_TESTPROC) {
	89	printk("swsusp debug: Waiting for 5 seconds.\n");
	90	mdelay(5000);
	91	goto thaw;
	92	}
	93
	94	/* Free memory before shutting down devices. */
	95	if (!(error = swsusp_shrink_memory()))
	96	return 0;
	97	thaw:
	98	thaw_processes();
	99	enable_cpus:
	100	enable_nonboot_cpus();
	101	pm_restore_console();
	102	return error;
	103	}
	104
	105	static void unprepare_processes(void)
	106	{
	107	platform_finish();
	108	thaw_processes();
	109	enable_nonboot_cpus();
	110	pm_restore_console();
	111	}
	112
	113	/**
	114	* pm_suspend_disk - The granpappy of hibernation power management.
	115	*
	116	* If we're going through the firmware, then get it over with quickly.
	117	*
	118	* If not, then call swsusp to do its thing, then figure out how
	119	* to power down the system.
	120	*/
	121
	122	int pm_suspend_disk(void)
	123	{
	124	int error;
	125
	126	error = prepare_processes();
	127	if (error)
	128	return error;
	129
	130	if (pm_disk_mode == PM_DISK_TESTPROC)
	131	goto Thaw;
	132
	133	suspend_console();
	134	error = device_suspend(PMSG_FREEZE);
	135	if (error) {
	136	resume_console();
	137	printk("Some devices failed to suspend\n");
	138	goto Thaw;
	139	}
	140
	141	if (pm_disk_mode == PM_DISK_TEST) {
	142	printk("swsusp debug: Waiting for 5 seconds.\n");
	143	mdelay(5000);
	144	goto Done;
	145	}
	146
	147	pr_debug("PM: snapshotting memory.\n");
	148	in_suspend = 1;
	149	if ((error = swsusp_suspend()))
	150	goto Done;
	151
	152	if (in_suspend) {
	153	device_resume();
	154	resume_console();
	155	pr_debug("PM: writing image.\n");
	156	error = swsusp_write();
	157	if (!error)
	158	power_down(pm_disk_mode);
	159	else {
	160	swsusp_free();
	161	goto Thaw;
	162	}
	163	} else {
	164	pr_debug("PM: Image restored successfully.\n");
	165	}
	166
	167	swsusp_free();
	168	Done:
	169	device_resume();
	170	resume_console();
	171	Thaw:
	172	unprepare_processes();
	173	return error;
	174	}
	175
	176
	177	/**
	178	* software_resume - Resume from a saved image.
	179	*
	180	* Called as a late_initcall (so all devices are discovered and
	181	* initialized), we call swsusp to see if we have a saved image or not.
	182	* If so, we quiesce devices, the restore the saved image. We will
	183	* return above (in pm_suspend_disk() ) if everything goes well.
	184	* Otherwise, we fail gracefully and return to the normally
	185	* scheduled program.
	186	*
	187	*/
	188
	189	static int software_resume(void)
	190	{
	191	int error;
	192
	193	down(&pm_sem);
	194	if (!swsusp_resume_device) {
	195	if (!strlen(resume_file)) {
	196	up(&pm_sem);
	197	return -ENOENT;
	198	}
	199	swsusp_resume_device = name_to_dev_t(resume_file);
	200	pr_debug("swsusp: Resume From Partition %s\n", resume_file);
	201	} else {
	202	pr_debug("swsusp: Resume From Partition %d:%d\n",
	203	MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
	204	}
	205
	206	if (noresume) {
	207	/**
	208	* FIXME: If noresume is specified, we need to find the partition
	209	* and reset it back to normal swap space.
	210	*/
	211	up(&pm_sem);
	212	return 0;
	213	}
	214
	215	pr_debug("PM: Checking swsusp image.\n");
	216
	217	if ((error = swsusp_check()))
	218	goto Done;
	219
	220	pr_debug("PM: Preparing processes for restore.\n");
	221
	222	if ((error = prepare_processes())) {
	223	swsusp_close();
	224	goto Done;
	225	}
	226
	227	pr_debug("PM: Reading swsusp image.\n");
	228
	229	if ((error = swsusp_read())) {
	230	swsusp_free();
	231	goto Thaw;
	232	}
	233
	234	pr_debug("PM: Preparing devices for restore.\n");
	235
	236	suspend_console();
	237	if ((error = device_suspend(PMSG_PRETHAW))) {
	238	resume_console();
	239	printk("Some devices failed to suspend\n");
	240	swsusp_free();
	241	goto Thaw;
	242	}
	243
	244	mb();
	245
	246	pr_debug("PM: Restoring saved image.\n");
	247	swsusp_resume();
	248	pr_debug("PM: Restore failed, recovering.n");
	249	device_resume();
	250	resume_console();
	251	Thaw:
	252	unprepare_processes();
	253	Done:
	254	/* For success case, the suspend path will release the lock */
	255	up(&pm_sem);
	256	pr_debug("PM: Resume from disk failed.\n");
	257	return 0;
	258	}
	259
	260	late_initcall(software_resume);
	261
	262
	263	static const char * const pm_disk_modes[] = {
	264	[PM_DISK_FIRMWARE] = "firmware",
	265	[PM_DISK_PLATFORM] = "platform",
	266	[PM_DISK_SHUTDOWN] = "shutdown",
	267	[PM_DISK_REBOOT] = "reboot",
	268	[PM_DISK_TEST] = "test",
	269	[PM_DISK_TESTPROC] = "testproc",
	270	};
	271
	272	/**
	273	* disk - Control suspend-to-disk mode
	274	*
	275	* Suspend-to-disk can be handled in several ways. The greatest
	276	* distinction is who writes memory to disk - the firmware or the OS.
	277	* If the firmware does it, we assume that it also handles suspending
	278	* the system.
	279	* If the OS does it, then we have three options for putting the system
	280	* to sleep - using the platform driver (e.g. ACPI or other PM registers),
	281	* powering off the system or rebooting the system (for testing).
	282	*
	283	* The system will support either 'firmware' or 'platform', and that is
	284	* known a priori (and encoded in pm_ops). But, the user may choose
	285	* 'shutdown' or 'reboot' as alternatives.
	286	*
	287	* show() will display what the mode is currently set to.
	288	* store() will accept one of
	289	*
	290	* 'firmware'
	291	* 'platform'
	292	* 'shutdown'
	293	* 'reboot'
	294	*
	295	* It will only change to 'firmware' or 'platform' if the system
	296	* supports it (as determined from pm_ops->pm_disk_mode).
	297	*/
	298
	299	static ssize_t disk_show(struct subsystem * subsys, char * buf)
	300	{
	301	return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
	302	}
	303
	304
	305	static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
	306	{
	307	int error = 0;
	308	int i;
	309	int len;
	310	char *p;
	311	suspend_disk_method_t mode = 0;
	312
	313	p = memchr(buf, '\n', n);
	314	len = p ? p - buf : n;
	315
	316	down(&pm_sem);
	317	for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
	318	if (!strncmp(buf, pm_disk_modes[i], len)) {
	319	mode = i;
	320	break;
	321	}
	322	}
	323	if (mode) {
	324	if (mode == PM_DISK_SHUTDOWN \|\| mode == PM_DISK_REBOOT \|\|
	325	mode == PM_DISK_TEST \|\| mode == PM_DISK_TESTPROC) {
	326	pm_disk_mode = mode;
	327	} else {
	328	if (pm_ops && pm_ops->enter &&
	329	(mode == pm_ops->pm_disk_mode))
	330	pm_disk_mode = mode;
	331	else
	332	error = -EINVAL;
	333	}
	334	} else {
	335	error = -EINVAL;
	336	}
	337
	338	pr_debug("PM: suspend-to-disk mode set to '%s'\n",
	339	pm_disk_modes[mode]);
	340	up(&pm_sem);
	341	return error ? error : n;
	342	}
	343
	344	power_attr(disk);
	345
	346	static ssize_t resume_show(struct subsystem * subsys, char *buf)
	347	{
	348	return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
	349	MINOR(swsusp_resume_device));
	350	}
	351
	352	static ssize_t resume_store(struct subsystem subsys, const char buf, size_t n)
	353	{
	354	unsigned int maj, min;
	355	dev_t res;
	356	int ret = -EINVAL;
	357
	358	if (sscanf(buf, "%u:%u", &maj, &min) != 2)
	359	goto out;
	360
	361	res = MKDEV(maj,min);
	362	if (maj != MAJOR(res) \|\| min != MINOR(res))
	363	goto out;
	364
	365	down(&pm_sem);
	366	swsusp_resume_device = res;
	367	up(&pm_sem);
	368	printk("Attempting manual resume\n");
	369	noresume = 0;
	370	software_resume();
	371	ret = n;
	372	out:
	373	return ret;
	374	}
	375
	376	power_attr(resume);
	377
	378	static ssize_t image_size_show(struct subsystem * subsys, char *buf)
	379	{
	380	return sprintf(buf, "%lu\n", image_size);
	381	}
	382
	383	static ssize_t image_size_store(struct subsystem * subsys, const char * buf, size_t n)
	384	{
	385	unsigned long size;
	386
	387	if (sscanf(buf, "%lu", &size) == 1) {
	388	image_size = size;
	389	return n;
	390	}
	391
	392	return -EINVAL;
	393	}
	394
	395	power_attr(image_size);
	396
	397	static struct attribute * g[] = {
	398	&disk_attr.attr,
	399	&resume_attr.attr,
	400	&image_size_attr.attr,
	401	NULL,
	402	};
	403
	404
	405	static struct attribute_group attr_group = {
	406	.attrs = g,
	407	};
	408
	409
	410	static int __init pm_disk_init(void)
	411	{
	412	return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
	413	}
	414
	415	core_initcall(pm_disk_init);
	416
	417
	418	static int __init resume_setup(char *str)
	419	{
	420	if (noresume)
	421	return 1;
	422
	423	strncpy( resume_file, str, 255 );
	424	return 1;
	425	}
	426
	427	static int __init resume_offset_setup(char *str)
	428	{
	429	unsigned long long offset;
	430
	431	if (noresume)
	432	return 1;
	433
	434	if (sscanf(str, "%llu", &offset) == 1)
	435	swsusp_resume_block = offset;
	436
	437	return 1;
	438	}
	439
	440	static int __init noresume_setup(char *str)
	441	{
	442	noresume = 1;
	443	return 1;
	444	}
	445
	446	__setup("noresume", noresume_setup);
	447	__setup("resume_offset=", resume_offset_setup);
	448	__setup("resume=", resume_setup);