[net-next-2.6.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 "power.h"


extern suspend_disk_method_t pm_disk_mode;
extern struct pm_ops * pm_ops;

extern int swsusp_suspend(void);
extern int swsusp_write(void);
extern int swsusp_check(void);
extern int swsusp_read(void);
extern void swsusp_close(void);
extern int swsusp_resume(void);
extern int swsusp_free(void);


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

/**
 *	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)
{
	unsigned long flags;
	int error = 0;

	local_irq_save(flags);
	switch(mode) {
	case PM_DISK_PLATFORM:
 		device_shutdown();
		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 int in_suspend __nosavedata = 0;


/**
 *	free_some_memory -  Try to free as much memory as possible
 *
 *	... but do not OOM-kill anyone
 *
 *	Notice: all userland should be stopped at this point, or
 *	livelock is possible.
 */

static void free_some_memory(void)
{
	unsigned int i = 0;
	unsigned int tmp;
	unsigned long pages = 0;
	char *p = "-\\|/";

	printk("Freeing memory...  ");
	while ((tmp = shrink_all_memory(10000))) {
		pages += tmp;
		printk("\b%c", p[i]);
		i++;
		if (i > 3)
			i = 0;
	}
	printk("\bdone (%li pages freed)\n", pages);
}


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 void finish(void)
{
	device_resume();
	platform_finish();
	thaw_processes();
	enable_nonboot_cpus();
	pm_restore_console();
}


static int prepare_processes(void)
{
	int error;

	pm_prepare_console();

	sys_sync();

	disable_nonboot_cpus();

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

	if (pm_disk_mode == PM_DISK_PLATFORM) {
		if (pm_ops && pm_ops->prepare) {
			if ((error = pm_ops->prepare(PM_SUSPEND_DISK)))
				goto thaw;
		}
	}

	/* Free memory before shutting down devices. */
	free_some_memory();
	return 0;
thaw:
	thaw_processes();
	enable_nonboot_cpus();
	pm_restore_console();
	return error;
}

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

static int prepare_devices(void)
{
	int error;

	if ((error = device_suspend(PMSG_FREEZE)))
		printk("Some devices failed to suspend\n");
	return error;
}

/**
 *	pm_suspend_disk - The granpappy of 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;
	error = prepare_devices();

	if (error) {
		unprepare_processes();
		return error;
	}

	pr_debug("PM: Attempting to suspend to disk.\n");
	if (pm_disk_mode == PM_DISK_FIRMWARE)
		return pm_ops->enter(PM_SUSPEND_DISK);

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

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

	if (!swsusp_resume_device) {
		if (!strlen(resume_file))
			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.
		 */
		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()))
		goto Cleanup;

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

	if ((error = prepare_devices()))
		goto Free;

	mb();

	pr_debug("PM: Restoring saved image.\n");
	swsusp_resume();
	pr_debug("PM: Restore failed, recovering.n");
	finish();
 Free:
	swsusp_free();
 Cleanup:
	unprepare_processes();
 Done:
	pr_debug("PM: Resume from disk failed.\n");
	return 0;
}

late_initcall(software_resume);


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

/**
 *	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)
			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)
{
	int len;
	char *p;
	unsigned int maj, min;
	int error = -EINVAL;
	dev_t res;

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

	if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
		res = MKDEV(maj,min);
		if (maj == MAJOR(res) && min == MINOR(res)) {
			swsusp_resume_device = res;
			printk("Attempting manual resume\n");
			noresume = 0;
			software_resume();
		}
	}

	return error >= 0 ? n : error;
}

power_attr(resume);

static struct attribute * g[] = {
	&disk_attr.attr,
	&resume_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 noresume_setup(char *str)
{
	noresume = 1;
	return 1;
}

__setup("noresume", noresume_setup);
__setup("resume=", resume_setup);
Commit	Line	Data
1da177e4 LT	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>
d53d9f16 AM	19	#include <linux/mount.h>
d53d9f16 AM	20
1da177e4 LT	21	#include "power.h"
	22
	23
	24	extern suspend_disk_method_t pm_disk_mode;
	25	extern struct pm_ops * pm_ops;
	26
	27	extern int swsusp_suspend(void);
	28	extern int swsusp_write(void);
	29	extern int swsusp_check(void);
	30	extern int swsusp_read(void);
	31	extern void swsusp_close(void);
	32	extern int swsusp_resume(void);
	33	extern int swsusp_free(void);
	34
	35
	36	static int noresume = 0;
	37	char resume_file[256] = CONFIG_PM_STD_PARTITION;
	38	dev_t swsusp_resume_device;
	39
	40	/**
	41	* power_down - Shut machine down for hibernate.
	42	* @mode: Suspend-to-disk mode
	43	*
	44	* Use the platform driver, if configured so, and return gracefully if it
	45	* fails.
	46	* Otherwise, try to power off and reboot. If they fail, halt the machine,
	47	* there ain't no turning back.
	48	*/
	49
	50	static void power_down(suspend_disk_method_t mode)
	51	{
	52	unsigned long flags;
	53	int error = 0;
	54
	55	local_irq_save(flags);
	56	switch(mode) {
	57	case PM_DISK_PLATFORM:
	58	device_shutdown();
	59	error = pm_ops->enter(PM_SUSPEND_DISK);
	60	break;
	61	case PM_DISK_SHUTDOWN:
fdde86ac	62	kernel_power_off();
1da177e4 LT	63	break;
1da177e4 LT	64	case PM_DISK_REBOOT:
fdde86ac	65	kernel_restart(NULL);
1da177e4 LT	66	break;
1da177e4 LT	67	}
fdde86ac	68	kernel_halt();
1da177e4 LT	69	/* Valid image is on the disk, if we continue we risk serious data corruption
	70	after resume. */
	71	printk(KERN_CRIT "Please power me down manually\n");
	72	while(1);
	73	}
	74
	75
	76	static int in_suspend __nosavedata = 0;
	77
	78
	79	/**
	80	* free_some_memory - Try to free as much memory as possible
	81	*
	82	* ... but do not OOM-kill anyone
	83	*
	84	* Notice: all userland should be stopped at this point, or
	85	* livelock is possible.
	86	*/
	87
	88	static void free_some_memory(void)
	89	{
	90	unsigned int i = 0;
	91	unsigned int tmp;
	92	unsigned long pages = 0;
	93	char *p = "-\\\|/";
	94
	95	printk("Freeing memory... ");
	96	while ((tmp = shrink_all_memory(10000))) {
	97	pages += tmp;
	98	printk("\b%c", p[i]);
	99	i++;
	100	if (i > 3)
	101	i = 0;
	102	}
	103	printk("\bdone (%li pages freed)\n", pages);
	104	}
	105
	106
	107	static inline void platform_finish(void)
	108	{
	109	if (pm_disk_mode == PM_DISK_PLATFORM) {
	110	if (pm_ops && pm_ops->finish)
	111	pm_ops->finish(PM_SUSPEND_DISK);
	112	}
	113	}
	114
	115	static void finish(void)
	116	{
	117	device_resume();
	118	platform_finish();
1da177e4	119	thaw_processes();
5a72e04d	120	enable_nonboot_cpus();
1da177e4 LT	121	pm_restore_console();
	122	}
	123
	124
	125	static int prepare_processes(void)
	126	{
	127	int error;
	128
	129	pm_prepare_console();
	130
	131	sys_sync();
	132
5a72e04d LS	133	disable_nonboot_cpus();
5a72e04d LS	134
1da177e4 LT	135	if (freeze_processes()) {
1da177e4 LT	136	error = -EBUSY;
5a72e04d	137	goto thaw;
1da177e4 LT	138	}
	139
	140	if (pm_disk_mode == PM_DISK_PLATFORM) {
	141	if (pm_ops && pm_ops->prepare) {
	142	if ((error = pm_ops->prepare(PM_SUSPEND_DISK)))
5a72e04d	143	goto thaw;
1da177e4 LT	144	}
	145	}
	146
	147	/* Free memory before shutting down devices. */
	148	free_some_memory();
1da177e4	149	return 0;
5a72e04d LS	150	thaw:
	151	thaw_processes();
	152	enable_nonboot_cpus();
	153	pm_restore_console();
	154	return error;
1da177e4 LT	155	}
	156
	157	static void unprepare_processes(void)
	158	{
5a72e04d	159	platform_finish();
1da177e4	160	thaw_processes();
5a72e04d	161	enable_nonboot_cpus();
1da177e4 LT	162	pm_restore_console();
	163	}
	164
	165	static int prepare_devices(void)
	166	{
	167	int error;
	168
5a72e04d	169	if ((error = device_suspend(PMSG_FREEZE)))
1da177e4	170	printk("Some devices failed to suspend\n");
5a72e04d	171	return error;
1da177e4 LT	172	}
	173
	174	/**
	175	* pm_suspend_disk - The granpappy of power management.
	176	*
	177	* If we're going through the firmware, then get it over with quickly.
	178	*
	179	* If not, then call swsusp to do its thing, then figure out how
	180	* to power down the system.
	181	*/
	182
	183	int pm_suspend_disk(void)
	184	{
	185	int error;
	186
	187	error = prepare_processes();
5a72e04d LS	188	if (error)
	189	return error;
	190	error = prepare_devices();
1da177e4 LT	191
	192	if (error) {
	193	unprepare_processes();
	194	return error;
	195	}
	196
	197	pr_debug("PM: Attempting to suspend to disk.\n");
	198	if (pm_disk_mode == PM_DISK_FIRMWARE)
	199	return pm_ops->enter(PM_SUSPEND_DISK);
	200
	201	pr_debug("PM: snapshotting memory.\n");
	202	in_suspend = 1;
	203	if ((error = swsusp_suspend()))
	204	goto Done;
	205
	206	if (in_suspend) {
	207	pr_debug("PM: writing image.\n");
	208	error = swsusp_write();
	209	if (!error)
	210	power_down(pm_disk_mode);
	211	} else
	212	pr_debug("PM: Image restored successfully.\n");
	213	swsusp_free();
	214	Done:
	215	finish();
	216	return error;
	217	}
	218
	219
	220	/**
	221	* software_resume - Resume from a saved image.
	222	*
	223	* Called as a late_initcall (so all devices are discovered and
	224	* initialized), we call swsusp to see if we have a saved image or not.
	225	* If so, we quiesce devices, the restore the saved image. We will
	226	* return above (in pm_suspend_disk() ) if everything goes well.
	227	* Otherwise, we fail gracefully and return to the normally
	228	* scheduled program.
	229	*
	230	*/
	231
	232	static int software_resume(void)
	233	{
	234	int error;
	235
3efa147a PM	236	if (!swsusp_resume_device) {
	237	if (!strlen(resume_file))
	238	return -ENOENT;
	239	swsusp_resume_device = name_to_dev_t(resume_file);
	240	pr_debug("swsusp: Resume From Partition %s\n", resume_file);
	241	} else {
	242	pr_debug("swsusp: Resume From Partition %d:%d\n",
	243	MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
	244	}
	245
1da177e4 LT	246	if (noresume) {
	247	/**
	248	* FIXME: If noresume is specified, we need to find the partition
	249	* and reset it back to normal swap space.
	250	*/
	251	return 0;
	252	}
	253
	254	pr_debug("PM: Checking swsusp image.\n");
	255
	256	if ((error = swsusp_check()))
	257	goto Done;
	258
	259	pr_debug("PM: Preparing processes for restore.\n");
	260
	261	if ((error = prepare_processes())) {
	262	swsusp_close();
5a72e04d	263	goto Done;
1da177e4 LT	264	}
	265
	266	pr_debug("PM: Reading swsusp image.\n");
	267
	268	if ((error = swsusp_read()))
	269	goto Cleanup;
	270
	271	pr_debug("PM: Preparing devices for restore.\n");
	272
	273	if ((error = prepare_devices()))
	274	goto Free;
	275
	276	mb();
	277
	278	pr_debug("PM: Restoring saved image.\n");
	279	swsusp_resume();
	280	pr_debug("PM: Restore failed, recovering.n");
	281	finish();
	282	Free:
	283	swsusp_free();
	284	Cleanup:
	285	unprepare_processes();
	286	Done:
	287	pr_debug("PM: Resume from disk failed.\n");
	288	return 0;
	289	}
	290
	291	late_initcall(software_resume);
	292
	293
	294	static char * pm_disk_modes[] = {
	295	[PM_DISK_FIRMWARE] = "firmware",
	296	[PM_DISK_PLATFORM] = "platform",
	297	[PM_DISK_SHUTDOWN] = "shutdown",
	298	[PM_DISK_REBOOT] = "reboot",
	299	};
	300
	301	/**
	302	* disk - Control suspend-to-disk mode
	303	*
	304	* Suspend-to-disk can be handled in several ways. The greatest
	305	* distinction is who writes memory to disk - the firmware or the OS.
	306	* If the firmware does it, we assume that it also handles suspending
	307	* the system.
	308	* If the OS does it, then we have three options for putting the system
	309	* to sleep - using the platform driver (e.g. ACPI or other PM registers),
	310	* powering off the system or rebooting the system (for testing).
	311	*
	312	* The system will support either 'firmware' or 'platform', and that is
	313	* known a priori (and encoded in pm_ops). But, the user may choose
	314	* 'shutdown' or 'reboot' as alternatives.
	315	*
	316	* show() will display what the mode is currently set to.
	317	* store() will accept one of
	318	*
	319	* 'firmware'
	320	* 'platform'
	321	* 'shutdown'
	322	* 'reboot'
	323	*
	324	* It will only change to 'firmware' or 'platform' if the system
	325	* supports it (as determined from pm_ops->pm_disk_mode).
	326	*/
	327
328	static ssize_t disk_show(struct subsystem * subsys, char * buf)
329	{
330	return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
331	}
332
333
334	static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
335	{
336	int error = 0;
337	int i;
338	int len;
339	char *p;
340	suspend_disk_method_t mode = 0;
341
342	p = memchr(buf, '\n', n);
343	len = p ? p - buf : n;
344
345	down(&pm_sem);
346	for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
347	if (!strncmp(buf, pm_disk_modes[i], len)) {
348	mode = i;
349	break;
350	}
351	}
352	if (mode) {
353	if (mode == PM_DISK_SHUTDOWN \|\| mode == PM_DISK_REBOOT)
354	pm_disk_mode = mode;
355	else {
356	if (pm_ops && pm_ops->enter &&
357	(mode == pm_ops->pm_disk_mode))
358	pm_disk_mode = mode;
359	else
360	error = -EINVAL;
361	}
362	} else
363	error = -EINVAL;
364
365	pr_debug("PM: suspend-to-disk mode set to '%s'\n",
366	pm_disk_modes[mode]);
367	up(&pm_sem);
368	return error ? error : n;
369	}
370
371	power_attr(disk);
372
373	static ssize_t resume_show(struct subsystem * subsys, char *buf)
374	{
375	return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
376	MINOR(swsusp_resume_device));
377	}
378
379	static ssize_t resume_store(struct subsystem * subsys, const char * buf, size_t n)
380	{
381	int len;
382	char *p;
383	unsigned int maj, min;
384	int error = -EINVAL;
385	dev_t res;
386
387	p = memchr(buf, '\n', n);
388	len = p ? p - buf : n;
389
390	if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
391	res = MKDEV(maj,min);
392	if (maj == MAJOR(res) && min == MINOR(res)) {
393	swsusp_resume_device = res;
394	printk("Attempting manual resume\n");
395	noresume = 0;
396	software_resume();
397	}
398	}
399
400	return error >= 0 ? n : error;
401	}
402
403	power_attr(resume);
404
405	static struct attribute * g[] = {
406	&disk_attr.attr,
407	&resume_attr.attr,
408	NULL,
409	};
410
411
412	static struct attribute_group attr_group = {
413	.attrs = g,
414	};
415
416
417	static int __init pm_disk_init(void)
418	{
419	return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
420	}
421
422	core_initcall(pm_disk_init);
423
424
425	static int __init resume_setup(char *str)
426	{
427	if (noresume)
428	return 1;
429
430	strncpy( resume_file, str, 255 );
431	return 1;
432	}
433
434	static int __init noresume_setup(char *str)
435	{
436	noresume = 1;
437	return 1;
438	}
439
440	__setup("noresume", noresume_setup);
441	__setup("resume=", resume_setup);