[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:
		printk("Powering off system\n");
		device_shutdown();
		machine_power_off();
		break;
	case PM_DISK_REBOOT:
		device_shutdown();
		machine_restart(NULL);
		break;
	}
	machine_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:
	62	printk("Powering off system\n");
	63	device_shutdown();
	64	machine_power_off();
	65	break;
	66	case PM_DISK_REBOOT:
	67	device_shutdown();
	68	machine_restart(NULL);
	69	break;
	70	}
	71	machine_halt();
	72	/* Valid image is on the disk, if we continue we risk serious data corruption
	73	after resume. */
	74	printk(KERN_CRIT "Please power me down manually\n");
	75	while(1);
	76	}
	77
	78
	79	static int in_suspend __nosavedata = 0;
	80
	81
	82	/**
	83	* free_some_memory - Try to free as much memory as possible
	84	*
85	* ... but do not OOM-kill anyone
86	*
87	* Notice: all userland should be stopped at this point, or
88	* livelock is possible.
89	*/
90
91	static void free_some_memory(void)
92	{
93	unsigned int i = 0;
94	unsigned int tmp;
95	unsigned long pages = 0;
96	char *p = "-\\\|/";
97
98	printk("Freeing memory... ");
99	while ((tmp = shrink_all_memory(10000))) {
100	pages += tmp;
101	printk("\b%c", p[i]);
102	i++;
103	if (i > 3)
104	i = 0;
105	}
106	printk("\bdone (%li pages freed)\n", pages);
107	}
108
109
110	static inline void platform_finish(void)
111	{
112	if (pm_disk_mode == PM_DISK_PLATFORM) {
113	if (pm_ops && pm_ops->finish)
114	pm_ops->finish(PM_SUSPEND_DISK);
115	}
116	}
117
118	static void finish(void)
119	{
120	device_resume();
121	platform_finish();
1da177e4	122	thaw_processes();
5a72e04d	123	enable_nonboot_cpus();
1da177e4 LT	124	pm_restore_console();
	125	}
	126
	127
	128	static int prepare_processes(void)
	129	{
	130	int error;
	131
	132	pm_prepare_console();
	133
	134	sys_sync();
	135
5a72e04d LS	136	disable_nonboot_cpus();
5a72e04d LS	137
1da177e4 LT	138	if (freeze_processes()) {
1da177e4 LT	139	error = -EBUSY;
5a72e04d	140	goto thaw;
1da177e4 LT	141	}
	142
	143	if (pm_disk_mode == PM_DISK_PLATFORM) {
	144	if (pm_ops && pm_ops->prepare) {
	145	if ((error = pm_ops->prepare(PM_SUSPEND_DISK)))
5a72e04d	146	goto thaw;
1da177e4 LT	147	}
	148	}
	149
	150	/* Free memory before shutting down devices. */
	151	free_some_memory();
1da177e4	152	return 0;
5a72e04d LS	153	thaw:
	154	thaw_processes();
	155	enable_nonboot_cpus();
	156	pm_restore_console();
	157	return error;
1da177e4 LT	158	}
	159
	160	static void unprepare_processes(void)
	161	{
5a72e04d	162	platform_finish();
1da177e4	163	thaw_processes();
5a72e04d	164	enable_nonboot_cpus();
1da177e4 LT	165	pm_restore_console();
	166	}
	167
	168	static int prepare_devices(void)
	169	{
	170	int error;
	171
5a72e04d	172	if ((error = device_suspend(PMSG_FREEZE)))
1da177e4	173	printk("Some devices failed to suspend\n");
5a72e04d	174	return error;
1da177e4 LT	175	}
	176
	177	/**
	178	* pm_suspend_disk - The granpappy of power management.
	179	*
	180	* If we're going through the firmware, then get it over with quickly.
	181	*
	182	* If not, then call swsusp to do its thing, then figure out how
	183	* to power down the system.
	184	*/
	185
	186	int pm_suspend_disk(void)
	187	{
	188	int error;
	189
	190	error = prepare_processes();
5a72e04d LS	191	if (error)
	192	return error;
	193	error = prepare_devices();
1da177e4 LT	194
	195	if (error) {
	196	unprepare_processes();
	197	return error;
	198	}
	199
	200	pr_debug("PM: Attempting to suspend to disk.\n");
	201	if (pm_disk_mode == PM_DISK_FIRMWARE)
	202	return pm_ops->enter(PM_SUSPEND_DISK);
	203
	204	pr_debug("PM: snapshotting memory.\n");
	205	in_suspend = 1;
	206	if ((error = swsusp_suspend()))
	207	goto Done;
	208
	209	if (in_suspend) {
	210	pr_debug("PM: writing image.\n");
	211	error = swsusp_write();
	212	if (!error)
	213	power_down(pm_disk_mode);
	214	} else
	215	pr_debug("PM: Image restored successfully.\n");
	216	swsusp_free();
	217	Done:
	218	finish();
	219	return error;
	220	}
	221
	222
	223	/**
	224	* software_resume - Resume from a saved image.
	225	*
	226	* Called as a late_initcall (so all devices are discovered and
	227	* initialized), we call swsusp to see if we have a saved image or not.
	228	* If so, we quiesce devices, the restore the saved image. We will
	229	* return above (in pm_suspend_disk() ) if everything goes well.
	230	* Otherwise, we fail gracefully and return to the normally
	231	* scheduled program.
	232	*
	233	*/
	234
	235	static int software_resume(void)
	236	{
	237	int error;
	238
3efa147a PM	239	if (!swsusp_resume_device) {
	240	if (!strlen(resume_file))
	241	return -ENOENT;
	242	swsusp_resume_device = name_to_dev_t(resume_file);
	243	pr_debug("swsusp: Resume From Partition %s\n", resume_file);
	244	} else {
	245	pr_debug("swsusp: Resume From Partition %d:%d\n",
	246	MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
	247	}
	248
1da177e4 LT	249	if (noresume) {
	250	/**
	251	* FIXME: If noresume is specified, we need to find the partition
	252	* and reset it back to normal swap space.
	253	*/
	254	return 0;
	255	}
	256
	257	pr_debug("PM: Checking swsusp image.\n");
	258
	259	if ((error = swsusp_check()))
	260	goto Done;
	261
	262	pr_debug("PM: Preparing processes for restore.\n");
	263
	264	if ((error = prepare_processes())) {
	265	swsusp_close();
5a72e04d	266	goto Done;
1da177e4 LT	267	}
	268
	269	pr_debug("PM: Reading swsusp image.\n");
	270
	271	if ((error = swsusp_read()))
	272	goto Cleanup;
	273
	274	pr_debug("PM: Preparing devices for restore.\n");
	275
	276	if ((error = prepare_devices()))
	277	goto Free;
	278
	279	mb();
	280
	281	pr_debug("PM: Restoring saved image.\n");
	282	swsusp_resume();
	283	pr_debug("PM: Restore failed, recovering.n");
	284	finish();
	285	Free:
	286	swsusp_free();
	287	Cleanup:
	288	unprepare_processes();
	289	Done:
	290	pr_debug("PM: Resume from disk failed.\n");
	291	return 0;
	292	}
	293
	294	late_initcall(software_resume);
	295
	296
	297	static char * pm_disk_modes[] = {
	298	[PM_DISK_FIRMWARE] = "firmware",
	299	[PM_DISK_PLATFORM] = "platform",
	300	[PM_DISK_SHUTDOWN] = "shutdown",
	301	[PM_DISK_REBOOT] = "reboot",
	302	};
	303
	304	/**
	305	* disk - Control suspend-to-disk mode
	306	*
	307	* Suspend-to-disk can be handled in several ways. The greatest
	308	* distinction is who writes memory to disk - the firmware or the OS.
	309	* If the firmware does it, we assume that it also handles suspending
	310	* the system.
	311	* If the OS does it, then we have three options for putting the system
	312	* to sleep - using the platform driver (e.g. ACPI or other PM registers),
	313	* powering off the system or rebooting the system (for testing).
	314	*
	315	* The system will support either 'firmware' or 'platform', and that is
	316	* known a priori (and encoded in pm_ops). But, the user may choose
	317	* 'shutdown' or 'reboot' as alternatives.
	318	*
	319	* show() will display what the mode is currently set to.
	320	* store() will accept one of
	321	*
	322	* 'firmware'
	323	* 'platform'
	324	* 'shutdown'
	325	* 'reboot'
	326	*
	327	* It will only change to 'firmware' or 'platform' if the system
	328	* supports it (as determined from pm_ops->pm_disk_mode).
	329	*/
	330
331	static ssize_t disk_show(struct subsystem * subsys, char * buf)
332	{
333	return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
334	}
335
336
337	static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
338	{
339	int error = 0;
340	int i;
341	int len;
342	char *p;
343	suspend_disk_method_t mode = 0;
344
345	p = memchr(buf, '\n', n);
346	len = p ? p - buf : n;
347
348	down(&pm_sem);
349	for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
350	if (!strncmp(buf, pm_disk_modes[i], len)) {
351	mode = i;
352	break;
353	}
354	}
355	if (mode) {
356	if (mode == PM_DISK_SHUTDOWN \|\| mode == PM_DISK_REBOOT)
357	pm_disk_mode = mode;
358	else {
359	if (pm_ops && pm_ops->enter &&
360	(mode == pm_ops->pm_disk_mode))
361	pm_disk_mode = mode;
362	else
363	error = -EINVAL;
364	}
365	} else
366	error = -EINVAL;
367
368	pr_debug("PM: suspend-to-disk mode set to '%s'\n",
369	pm_disk_modes[mode]);
370	up(&pm_sem);
371	return error ? error : n;
372	}
373
374	power_attr(disk);
375
376	static ssize_t resume_show(struct subsystem * subsys, char *buf)
377	{
378	return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
379	MINOR(swsusp_resume_device));
380	}
381
382	static ssize_t resume_store(struct subsystem * subsys, const char * buf, size_t n)
383	{
384	int len;
385	char *p;
386	unsigned int maj, min;
387	int error = -EINVAL;
388	dev_t res;
389
390	p = memchr(buf, '\n', n);
391	len = p ? p - buf : n;
392
393	if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
394	res = MKDEV(maj,min);
395	if (maj == MAJOR(res) && min == MINOR(res)) {
396	swsusp_resume_device = res;
397	printk("Attempting manual resume\n");
398	noresume = 0;
399	software_resume();
400	}
401	}
402
403	return error >= 0 ? n : error;
404	}
405
406	power_attr(resume);
407
408	static struct attribute * g[] = {
409	&disk_attr.attr,
410	&resume_attr.attr,
411	NULL,
412	};
413
414
415	static struct attribute_group attr_group = {
416	.attrs = g,
417	};
418
419
420	static int __init pm_disk_init(void)
421	{
422	return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
423	}
424
425	core_initcall(pm_disk_init);
426
427
428	static int __init resume_setup(char *str)
429	{
430	if (noresume)
431	return 1;
432
433	strncpy( resume_file, str, 255 );
434	return 1;
435	}
436
437	static int __init noresume_setup(char *str)
438	{
439	noresume = 1;
440	return 1;
441	}
442
443	__setup("noresume", noresume_setup);
444	__setup("resume=", resume_setup);