[deliverable/linux.git] / kernel / power / user.c

/*
 * linux/kernel/power/user.c
 *
 * This file provides the user space interface for software suspend/resume.
 *
 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
 *
 * 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/miscdevice.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/pm.h>
#include <linux/fs.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/freezer.h>

#include <asm/uaccess.h>

#include "power.h"

#define SNAPSHOT_MINOR	231

static struct snapshot_data {
	struct snapshot_handle handle;
	int swap;
	struct bitmap_page *bitmap;
	int mode;
	char frozen;
	char ready;
	char platform_suspend;
} snapshot_state;

atomic_t snapshot_device_available = ATOMIC_INIT(1);

static int snapshot_open(struct inode *inode, struct file *filp)
{
	struct snapshot_data *data;

	if (!atomic_add_unless(&snapshot_device_available, -1, 0))
		return -EBUSY;

	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
		atomic_inc(&snapshot_device_available);
		return -ENOSYS;
	}
	if(create_basic_memory_bitmaps()) {
		atomic_inc(&snapshot_device_available);
		return -ENOMEM;
	}
	nonseekable_open(inode, filp);
	data = &snapshot_state;
	filp->private_data = data;
	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
		data->swap = swsusp_resume_device ?
			swap_type_of(swsusp_resume_device, 0, NULL) : -1;
		data->mode = O_RDONLY;
	} else {
		data->swap = -1;
		data->mode = O_WRONLY;
	}
	data->bitmap = NULL;
	data->frozen = 0;
	data->ready = 0;
	data->platform_suspend = 0;

	return 0;
}

static int snapshot_release(struct inode *inode, struct file *filp)
{
	struct snapshot_data *data;

	swsusp_free();
	free_basic_memory_bitmaps();
	data = filp->private_data;
	free_all_swap_pages(data->swap, data->bitmap);
	free_bitmap(data->bitmap);
	if (data->frozen) {
		mutex_lock(&pm_mutex);
		thaw_processes();
		enable_nonboot_cpus();
		mutex_unlock(&pm_mutex);
	}
	atomic_inc(&snapshot_device_available);
	return 0;
}

static ssize_t snapshot_read(struct file *filp, char __user *buf,
                             size_t count, loff_t *offp)
{
	struct snapshot_data *data;
	ssize_t res;

	data = filp->private_data;
	res = snapshot_read_next(&data->handle, count);
	if (res > 0) {
		if (copy_to_user(buf, data_of(data->handle), res))
			res = -EFAULT;
		else
			*offp = data->handle.offset;
	}
	return res;
}

static ssize_t snapshot_write(struct file *filp, const char __user *buf,
                              size_t count, loff_t *offp)
{
	struct snapshot_data *data;
	ssize_t res;

	data = filp->private_data;
	res = snapshot_write_next(&data->handle, count);
	if (res > 0) {
		if (copy_from_user(data_of(data->handle), buf, res))
			res = -EFAULT;
		else
			*offp = data->handle.offset;
	}
	return res;
}

static inline int platform_prepare(void)
{
	int error = 0;

	if (pm_ops && pm_ops->prepare)
		error = pm_ops->prepare(PM_SUSPEND_DISK);

	return error;
}

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

static inline int snapshot_suspend(int platform_suspend)
{
	int error;

	mutex_lock(&pm_mutex);
	/* Free memory before shutting down devices. */
	error = swsusp_shrink_memory();
	if (error)
		goto Finish;

	if (platform_suspend) {
		error = platform_prepare();
		if (error)
			goto Finish;
	}
	suspend_console();
	error = device_suspend(PMSG_FREEZE);
	if (error)
		goto Resume_devices;

	error = disable_nonboot_cpus();
	if (!error) {
		in_suspend = 1;
		error = swsusp_suspend();
	}
	enable_nonboot_cpus();
 Resume_devices:
	if (platform_suspend)
		platform_finish();

	device_resume();
	resume_console();
 Finish:
	mutex_unlock(&pm_mutex);
	return error;
}

static inline int snapshot_restore(int platform_suspend)
{
	int error;

	mutex_lock(&pm_mutex);
	pm_prepare_console();
	if (platform_suspend) {
		error = platform_prepare();
		if (error)
			goto Finish;
	}
	suspend_console();
	error = device_suspend(PMSG_PRETHAW);
	if (error)
		goto Resume_devices;

	error = disable_nonboot_cpus();
	if (!error)
		error = swsusp_resume();

	enable_nonboot_cpus();
 Resume_devices:
	if (platform_suspend)
		platform_finish();

	device_resume();
	resume_console();
 Finish:
	pm_restore_console();
	mutex_unlock(&pm_mutex);
	return error;
}

static int snapshot_ioctl(struct inode *inode, struct file *filp,
                          unsigned int cmd, unsigned long arg)
{
	int error = 0;
	struct snapshot_data *data;
	loff_t avail;
	sector_t offset;

	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
		return -ENOTTY;
	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
		return -ENOTTY;
	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	data = filp->private_data;

	switch (cmd) {

	case SNAPSHOT_FREEZE:
		if (data->frozen)
			break;
		mutex_lock(&pm_mutex);
		if (freeze_processes()) {
			thaw_processes();
			error = -EBUSY;
		}
		mutex_unlock(&pm_mutex);
		if (!error)
			data->frozen = 1;
		break;

	case SNAPSHOT_UNFREEZE:
		if (!data->frozen)
			break;
		mutex_lock(&pm_mutex);
		thaw_processes();
		mutex_unlock(&pm_mutex);
		data->frozen = 0;
		break;

	case SNAPSHOT_ATOMIC_SNAPSHOT:
		if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
			error = -EPERM;
			break;
		}
		error = snapshot_suspend(data->platform_suspend);
		if (!error)
			error = put_user(in_suspend, (unsigned int __user *)arg);
		if (!error)
			data->ready = 1;
		break;

	case SNAPSHOT_ATOMIC_RESTORE:
		snapshot_write_finalize(&data->handle);
		if (data->mode != O_WRONLY || !data->frozen ||
		    !snapshot_image_loaded(&data->handle)) {
			error = -EPERM;
			break;
		}
		error = snapshot_restore(data->platform_suspend);
		break;

	case SNAPSHOT_FREE:
		swsusp_free();
		memset(&data->handle, 0, sizeof(struct snapshot_handle));
		data->ready = 0;
		break;

	case SNAPSHOT_SET_IMAGE_SIZE:
		image_size = arg;
		break;

	case SNAPSHOT_AVAIL_SWAP:
		avail = count_swap_pages(data->swap, 1);
		avail <<= PAGE_SHIFT;
		error = put_user(avail, (loff_t __user *)arg);
		break;

	case SNAPSHOT_GET_SWAP_PAGE:
		if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
			error = -ENODEV;
			break;
		}
		if (!data->bitmap) {
			data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0));
			if (!data->bitmap) {
				error = -ENOMEM;
				break;
			}
		}
		offset = alloc_swapdev_block(data->swap, data->bitmap);
		if (offset) {
			offset <<= PAGE_SHIFT;
			error = put_user(offset, (sector_t __user *)arg);
		} else {
			error = -ENOSPC;
		}
		break;

	case SNAPSHOT_FREE_SWAP_PAGES:
		if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
			error = -ENODEV;
			break;
		}
		free_all_swap_pages(data->swap, data->bitmap);
		free_bitmap(data->bitmap);
		data->bitmap = NULL;
		break;

	case SNAPSHOT_SET_SWAP_FILE:
		if (!data->bitmap) {
			/*
			 * User space encodes device types as two-byte values,
			 * so we need to recode them
			 */
			if (old_decode_dev(arg)) {
				data->swap = swap_type_of(old_decode_dev(arg),
							0, NULL);
				if (data->swap < 0)
					error = -ENODEV;
			} else {
				data->swap = -1;
				error = -EINVAL;
			}
		} else {
			error = -EPERM;
		}
		break;

	case SNAPSHOT_S2RAM:
		if (!pm_ops) {
			error = -ENOSYS;
			break;
		}

		if (!data->frozen) {
			error = -EPERM;
			break;
		}

		if (!mutex_trylock(&pm_mutex)) {
			error = -EBUSY;
			break;
		}

		if (pm_ops->prepare) {
			error = pm_ops->prepare(PM_SUSPEND_MEM);
			if (error)
				goto OutS3;
		}

		/* Put devices to sleep */
		suspend_console();
		error = device_suspend(PMSG_SUSPEND);
		if (error) {
			printk(KERN_ERR "Failed to suspend some devices.\n");
		} else {
			error = disable_nonboot_cpus();
			if (!error) {
				/* Enter S3, system is already frozen */
				suspend_enter(PM_SUSPEND_MEM);
				enable_nonboot_cpus();
			}
			/* Wake up devices */
			device_resume();
		}
		resume_console();
		if (pm_ops->finish)
			pm_ops->finish(PM_SUSPEND_MEM);

 OutS3:
		mutex_unlock(&pm_mutex);
		break;

	case SNAPSHOT_PMOPS:
		error = -EINVAL;

		switch (arg) {

		case PMOPS_PREPARE:
			if (pm_ops && pm_ops->enter) {
				data->platform_suspend = 1;
				error = 0;
			} else {
				error = -ENOSYS;
			}
			break;

		case PMOPS_ENTER:
			if (data->platform_suspend) {
				kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
				error = pm_ops->enter(PM_SUSPEND_DISK);
				error = 0;
			}
			break;

		case PMOPS_FINISH:
			if (data->platform_suspend)
				error = 0;

			break;

		default:
			printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);

		}
		break;

	case SNAPSHOT_SET_SWAP_AREA:
		if (data->bitmap) {
			error = -EPERM;
		} else {
			struct resume_swap_area swap_area;
			dev_t swdev;

			error = copy_from_user(&swap_area, (void __user *)arg,
					sizeof(struct resume_swap_area));
			if (error) {
				error = -EFAULT;
				break;
			}

			/*
			 * User space encodes device types as two-byte values,
			 * so we need to recode them
			 */
			swdev = old_decode_dev(swap_area.dev);
			if (swdev) {
				offset = swap_area.offset;
				data->swap = swap_type_of(swdev, offset, NULL);
				if (data->swap < 0)
					error = -ENODEV;
			} else {
				data->swap = -1;
				error = -EINVAL;
			}
		}
		break;

	default:
		error = -ENOTTY;

	}

	return error;
}

static const struct file_operations snapshot_fops = {
	.open = snapshot_open,
	.release = snapshot_release,
	.read = snapshot_read,
	.write = snapshot_write,
	.llseek = no_llseek,
	.ioctl = snapshot_ioctl,
};

static struct miscdevice snapshot_device = {
	.minor = SNAPSHOT_MINOR,
	.name = "snapshot",
	.fops = &snapshot_fops,
};

static int __init snapshot_device_init(void)
{
	return misc_register(&snapshot_device);
};

device_initcall(snapshot_device_init);
Commit	Line	Data
6e1819d6 RW	1	/*
	2	* linux/kernel/power/user.c
	3	*
	4	* This file provides the user space interface for software suspend/resume.
	5	*
	6	* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
	7	*
	8	* This file is released under the GPLv2.
	9	*
	10	*/
	11
	12	#include <linux/suspend.h>
	13	#include <linux/syscalls.h>
3592695c	14	#include <linux/reboot.h>
6e1819d6 RW	15	#include <linux/string.h>
	16	#include <linux/device.h>
	17	#include <linux/miscdevice.h>
	18	#include <linux/mm.h>
	19	#include <linux/swap.h>
	20	#include <linux/swapops.h>
	21	#include <linux/pm.h>
	22	#include <linux/fs.h>
97c7801c	23	#include <linux/console.h>
e3920fb4	24	#include <linux/cpu.h>
7dfb7103	25	#include <linux/freezer.h>
6e1819d6 RW	26
	27	#include <asm/uaccess.h>
	28
	29	#include "power.h"
	30
	31	#define SNAPSHOT_MINOR 231
	32
	33	static struct snapshot_data {
	34	struct snapshot_handle handle;
	35	int swap;
	36	struct bitmap_page *bitmap;
	37	int mode;
	38	char frozen;
	39	char ready;
2b5b09b3	40	char platform_suspend;
6e1819d6 RW	41	} snapshot_state;
6e1819d6 RW	42
0709db60	43	atomic_t snapshot_device_available = ATOMIC_INIT(1);
6e1819d6 RW	44
	45	static int snapshot_open(struct inode inode, struct file filp)
	46	{
	47	struct snapshot_data *data;
	48
0709db60	49	if (!atomic_add_unless(&snapshot_device_available, -1, 0))
6e1819d6 RW	50	return -EBUSY;
6e1819d6 RW	51
1525a2ad	52	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
0709db60	53	atomic_inc(&snapshot_device_available);
6e1819d6	54	return -ENOSYS;
1525a2ad RW	55	}
1525a2ad RW	56	if(create_basic_memory_bitmaps()) {
0709db60	57	atomic_inc(&snapshot_device_available);
74dfd666	58	return -ENOMEM;
1525a2ad	59	}
6e1819d6 RW	60	nonseekable_open(inode, filp);
	61	data = &snapshot_state;
	62	filp->private_data = data;
	63	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	64	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
915bae9e	65	data->swap = swsusp_resume_device ?
7bf23687	66	swap_type_of(swsusp_resume_device, 0, NULL) : -1;
6e1819d6 RW	67	data->mode = O_RDONLY;
	68	} else {
	69	data->swap = -1;
	70	data->mode = O_WRONLY;
	71	}
	72	data->bitmap = NULL;
	73	data->frozen = 0;
	74	data->ready = 0;
2b5b09b3	75	data->platform_suspend = 0;
6e1819d6 RW	76
	77	return 0;
	78	}
	79
	80	static int snapshot_release(struct inode inode, struct file filp)
	81	{
	82	struct snapshot_data *data;
	83
	84	swsusp_free();
74dfd666	85	free_basic_memory_bitmaps();
6e1819d6 RW	86	data = filp->private_data;
	87	free_all_swap_pages(data->swap, data->bitmap);
	88	free_bitmap(data->bitmap);
	89	if (data->frozen) {
a6d70980	90	mutex_lock(&pm_mutex);
6e1819d6 RW	91	thaw_processes();
6e1819d6 RW	92	enable_nonboot_cpus();
a6d70980	93	mutex_unlock(&pm_mutex);
6e1819d6	94	}
0709db60	95	atomic_inc(&snapshot_device_available);
6e1819d6 RW	96	return 0;
	97	}
	98
	99	static ssize_t snapshot_read(struct file filp, char __user buf,
	100	size_t count, loff_t *offp)
	101	{
	102	struct snapshot_data *data;
	103	ssize_t res;
	104
	105	data = filp->private_data;
	106	res = snapshot_read_next(&data->handle, count);
	107	if (res > 0) {
	108	if (copy_to_user(buf, data_of(data->handle), res))
	109	res = -EFAULT;
	110	else
	111	*offp = data->handle.offset;
	112	}
	113	return res;
	114	}
	115
	116	static ssize_t snapshot_write(struct file filp, const char __user buf,
	117	size_t count, loff_t *offp)
	118	{
	119	struct snapshot_data *data;
	120	ssize_t res;
	121
	122	data = filp->private_data;
	123	res = snapshot_write_next(&data->handle, count);
	124	if (res > 0) {
	125	if (copy_from_user(data_of(data->handle), buf, res))
	126	res = -EFAULT;
	127	else
	128	*offp = data->handle.offset;
	129	}
	130	return res;
	131	}
	132
2b5b09b3 RW	133	static inline int platform_prepare(void)
	134	{
	135	int error = 0;
	136
	137	if (pm_ops && pm_ops->prepare)
	138	error = pm_ops->prepare(PM_SUSPEND_DISK);
	139
	140	return error;
	141	}
	142
	143	static inline void platform_finish(void)
	144	{
	145	if (pm_ops && pm_ops->finish)
	146	pm_ops->finish(PM_SUSPEND_DISK);
	147	}
	148
	149	static inline int snapshot_suspend(int platform_suspend)
25913052 RW	150	{
	151	int error;
	152
	153	mutex_lock(&pm_mutex);
	154	/* Free memory before shutting down devices. */
	155	error = swsusp_shrink_memory();
	156	if (error)
	157	goto Finish;
	158
2b5b09b3 RW	159	if (platform_suspend) {
	160	error = platform_prepare();
	161	if (error)
	162	goto Finish;
	163	}
25913052 RW	164	suspend_console();
	165	error = device_suspend(PMSG_FREEZE);
	166	if (error)
	167	goto Resume_devices;
	168
	169	error = disable_nonboot_cpus();
	170	if (!error) {
	171	in_suspend = 1;
	172	error = swsusp_suspend();
	173	}
	174	enable_nonboot_cpus();
	175	Resume_devices:
2b5b09b3 RW	176	if (platform_suspend)
	177	platform_finish();
	178
25913052 RW	179	device_resume();
	180	resume_console();
	181	Finish:
	182	mutex_unlock(&pm_mutex);
	183	return error;
	184	}
	185
2b5b09b3	186	static inline int snapshot_restore(int platform_suspend)
25913052 RW	187	{
	188	int error;
	189
	190	mutex_lock(&pm_mutex);
	191	pm_prepare_console();
2b5b09b3 RW	192	if (platform_suspend) {
	193	error = platform_prepare();
	194	if (error)
	195	goto Finish;
	196	}
25913052 RW	197	suspend_console();
	198	error = device_suspend(PMSG_PRETHAW);
	199	if (error)
	200	goto Resume_devices;
	201
	202	error = disable_nonboot_cpus();
	203	if (!error)
	204	error = swsusp_resume();
	205
	206	enable_nonboot_cpus();
	207	Resume_devices:
2b5b09b3 RW	208	if (platform_suspend)
	209	platform_finish();
	210
25913052 RW	211	device_resume();
25913052 RW	212	resume_console();
2b5b09b3	213	Finish:
25913052 RW	214	pm_restore_console();
	215	mutex_unlock(&pm_mutex);
	216	return error;
	217	}
	218
6e1819d6 RW	219	static int snapshot_ioctl(struct inode inode, struct file filp,
	220	unsigned int cmd, unsigned long arg)
	221	{
	222	int error = 0;
	223	struct snapshot_data *data;
3aef83e0 RW	224	loff_t avail;
3aef83e0 RW	225	sector_t offset;
6e1819d6 RW	226
	227	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	228	return -ENOTTY;
	229	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	230	return -ENOTTY;
	231	if (!capable(CAP_SYS_ADMIN))
	232	return -EPERM;
	233
	234	data = filp->private_data;
	235
	236	switch (cmd) {
	237
	238	case SNAPSHOT_FREEZE:
	239	if (data->frozen)
	240	break;
a6d70980	241	mutex_lock(&pm_mutex);
25913052 RW	242	if (freeze_processes()) {
	243	thaw_processes();
	244	error = -EBUSY;
6e1819d6	245	}
a6d70980	246	mutex_unlock(&pm_mutex);
6e1819d6 RW	247	if (!error)
	248	data->frozen = 1;
	249	break;
	250
	251	case SNAPSHOT_UNFREEZE:
	252	if (!data->frozen)
	253	break;
a6d70980	254	mutex_lock(&pm_mutex);
6e1819d6	255	thaw_processes();
a6d70980	256	mutex_unlock(&pm_mutex);
6e1819d6 RW	257	data->frozen = 0;
	258	break;
	259
	260	case SNAPSHOT_ATOMIC_SNAPSHOT:
	261	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	262	error = -EPERM;
	263	break;
	264	}
2b5b09b3	265	error = snapshot_suspend(data->platform_suspend);
6e1819d6 RW	266	if (!error)
	267	error = put_user(in_suspend, (unsigned int __user *)arg);
	268	if (!error)
	269	data->ready = 1;
	270	break;
	271
	272	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	273	snapshot_write_finalize(&data->handle);
6e1819d6 RW	274	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	275	!snapshot_image_loaded(&data->handle)) {
	276	error = -EPERM;
	277	break;
	278	}
2b5b09b3	279	error = snapshot_restore(data->platform_suspend);
6e1819d6 RW	280	break;
	281
	282	case SNAPSHOT_FREE:
	283	swsusp_free();
	284	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	285	data->ready = 0;
	286	break;
	287
	288	case SNAPSHOT_SET_IMAGE_SIZE:
	289	image_size = arg;
	290	break;
	291
	292	case SNAPSHOT_AVAIL_SWAP:
	293	avail = count_swap_pages(data->swap, 1);
	294	avail <<= PAGE_SHIFT;
	295	error = put_user(avail, (loff_t __user *)arg);
	296	break;
	297
	298	case SNAPSHOT_GET_SWAP_PAGE:
	299	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	300	error = -ENODEV;
	301	break;
	302	}
	303	if (!data->bitmap) {
	304	data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0));
	305	if (!data->bitmap) {
	306	error = -ENOMEM;
	307	break;
	308	}
	309	}
3aef83e0	310	offset = alloc_swapdev_block(data->swap, data->bitmap);
6e1819d6 RW	311	if (offset) {
6e1819d6 RW	312	offset <<= PAGE_SHIFT;
3aef83e0	313	error = put_user(offset, (sector_t __user *)arg);
6e1819d6 RW	314	} else {
	315	error = -ENOSPC;
	316	}
	317	break;
	318
	319	case SNAPSHOT_FREE_SWAP_PAGES:
	320	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	321	error = -ENODEV;
	322	break;
	323	}
	324	free_all_swap_pages(data->swap, data->bitmap);
	325	free_bitmap(data->bitmap);
	326	data->bitmap = NULL;
	327	break;
	328
	329	case SNAPSHOT_SET_SWAP_FILE:
	330	if (!data->bitmap) {
	331	/*
	332	* User space encodes device types as two-byte values,
	333	* so we need to recode them
	334	*/
	335	if (old_decode_dev(arg)) {
7bf23687 RW	336	data->swap = swap_type_of(old_decode_dev(arg),
7bf23687 RW	337	0, NULL);
6e1819d6 RW	338	if (data->swap < 0)
	339	error = -ENODEV;
	340	} else {
	341	data->swap = -1;
	342	error = -EINVAL;
	343	}
	344	} else {
	345	error = -EPERM;
	346	}
	347	break;
	348
9b238205	349	case SNAPSHOT_S2RAM:
2b5b09b3 RW	350	if (!pm_ops) {
	351	error = -ENOSYS;
	352	break;
	353	}
	354
9b238205 LT	355	if (!data->frozen) {
	356	error = -EPERM;
	357	break;
	358	}
	359
a6d70980	360	if (!mutex_trylock(&pm_mutex)) {
9b238205 LT	361	error = -EBUSY;
	362	break;
	363	}
	364
	365	if (pm_ops->prepare) {
	366	error = pm_ops->prepare(PM_SUSPEND_MEM);
	367	if (error)
	368	goto OutS3;
	369	}
	370
	371	/* Put devices to sleep */
97c7801c	372	suspend_console();
9b238205 LT	373	error = device_suspend(PMSG_SUSPEND);
	374	if (error) {
	375	printk(KERN_ERR "Failed to suspend some devices.\n");
	376	} else {
93c9a7ff RW	377	error = disable_nonboot_cpus();
	378	if (!error) {
	379	/* Enter S3, system is already frozen */
	380	suspend_enter(PM_SUSPEND_MEM);
	381	enable_nonboot_cpus();
	382	}
9b238205 LT	383	/* Wake up devices */
	384	device_resume();
	385	}
97c7801c	386	resume_console();
9b238205 LT	387	if (pm_ops->finish)
	388	pm_ops->finish(PM_SUSPEND_MEM);
	389
59a49335	390	OutS3:
a6d70980	391	mutex_unlock(&pm_mutex);
9b238205 LT	392	break;
9b238205 LT	393
3592695c	394	case SNAPSHOT_PMOPS:
2b5b09b3 RW	395	error = -EINVAL;
2b5b09b3 RW	396
3592695c SS	397	switch (arg) {
	398
	399	case PMOPS_PREPARE:
2b5b09b3 RW	400	if (pm_ops && pm_ops->enter) {
	401	data->platform_suspend = 1;
	402	error = 0;
	403	} else {
	404	error = -ENOSYS;
3592695c SS	405	}
	406	break;
	407
	408	case PMOPS_ENTER:
2b5b09b3 RW	409	if (data->platform_suspend) {
	410	kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
	411	error = pm_ops->enter(PM_SUSPEND_DISK);
436ce716	412	error = 0;
2b5b09b3	413	}
3592695c SS	414	break;
	415
	416	case PMOPS_FINISH:
2b5b09b3 RW	417	if (data->platform_suspend)
	418	error = 0;
	419
3592695c SS	420	break;
	421
	422	default:
	423	printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
3592695c SS	424
	425	}
	426	break;
	427
37b2ba12 RW	428	case SNAPSHOT_SET_SWAP_AREA:
	429	if (data->bitmap) {
	430	error = -EPERM;
	431	} else {
	432	struct resume_swap_area swap_area;
	433	dev_t swdev;
	434
	435	error = copy_from_user(&swap_area, (void __user *)arg,
	436	sizeof(struct resume_swap_area));
	437	if (error) {
	438	error = -EFAULT;
	439	break;
	440	}
	441
	442	/*
	443	* User space encodes device types as two-byte values,
	444	* so we need to recode them
	445	*/
	446	swdev = old_decode_dev(swap_area.dev);
	447	if (swdev) {
	448	offset = swap_area.offset;
7bf23687	449	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	450	if (data->swap < 0)
	451	error = -ENODEV;
	452	} else {
	453	data->swap = -1;
	454	error = -EINVAL;
	455	}
	456	}
	457	break;
	458
6e1819d6 RW	459	default:
	460	error = -ENOTTY;
	461
	462	}
	463
	464	return error;
	465	}
	466
15ad7cdc	467	static const struct file_operations snapshot_fops = {
6e1819d6 RW	468	.open = snapshot_open,
	469	.release = snapshot_release,
	470	.read = snapshot_read,
	471	.write = snapshot_write,
	472	.llseek = no_llseek,
	473	.ioctl = snapshot_ioctl,
	474	};
	475
	476	static struct miscdevice snapshot_device = {
	477	.minor = SNAPSHOT_MINOR,
	478	.name = "snapshot",
	479	.fops = &snapshot_fops,
	480	};
	481
	482	static int __init snapshot_device_init(void)
	483	{
	484	return misc_register(&snapshot_device);
	485	};
	486
	487	device_initcall(snapshot_device_init);