[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"

/*
 * NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and
 * will be removed in the future.  They are only preserved here for
 * compatibility with existing userland utilities.
 */
#define SNAPSHOT_SET_SWAP_FILE	_IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
#define SNAPSHOT_PMOPS		_IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)

#define PMOPS_PREPARE	1
#define PMOPS_ENTER	2
#define PMOPS_FINISH	3

/*
 * NOTE: The following ioctl definitions are wrong and have been replaced with
 * correct ones.  They are only preserved here for compatibility with existing
 * userland utilities and will be removed in the future.
 */
#define SNAPSHOT_ATOMIC_SNAPSHOT	_IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
#define SNAPSHOT_SET_IMAGE_SIZE		_IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
#define SNAPSHOT_AVAIL_SWAP		_IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
#define SNAPSHOT_GET_SWAP_PAGE		_IOR(SNAPSHOT_IOC_MAGIC, 8, void *)


#define SNAPSHOT_MINOR	231

static struct snapshot_data {
	struct snapshot_handle handle;
	int swap;
	int mode;
	char frozen;
	char ready;
	char platform_support;
} snapshot_state;

atomic_t snapshot_device_available = ATOMIC_INIT(1);

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

	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;
		error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
		if (error)
			pm_notifier_call_chain(PM_POST_RESTORE);
	} else {
		data->swap = -1;
		data->mode = O_WRONLY;
		error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
		if (error)
			pm_notifier_call_chain(PM_POST_HIBERNATION);
	}
	if (error) {
		atomic_inc(&snapshot_device_available);
		return error;
	}
	data->frozen = 0;
	data->ready = 0;
	data->platform_support = 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);
	if (data->frozen) {
		mutex_lock(&pm_mutex);
		thaw_processes();
		mutex_unlock(&pm_mutex);
	}
	pm_notifier_call_chain(data->mode == O_WRONLY ?
			PM_POST_HIBERNATION : PM_POST_RESTORE);
	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;
	if (!data->ready)
		return -ENODATA;
	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 int snapshot_ioctl(struct inode *inode, struct file *filp,
                          unsigned int cmd, unsigned long arg)
{
	int error = 0;
	struct snapshot_data *data;
	loff_t size;
	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);
		printk("Syncing filesystems ... ");
		sys_sync();
		printk("done.\n");

		error = freeze_processes();
		if (error)
			thaw_processes();
		mutex_unlock(&pm_mutex);
		if (!error)
			data->frozen = 1;
		break;

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

	case SNAPSHOT_CREATE_IMAGE:
	case SNAPSHOT_ATOMIC_SNAPSHOT:
		if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
			error = -EPERM;
			break;
		}
		error = hibernation_snapshot(data->platform_support);
		if (!error)
			error = put_user(in_suspend, (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 = hibernation_restore(data->platform_support);
		break;

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

	case SNAPSHOT_PREF_IMAGE_SIZE:
	case SNAPSHOT_SET_IMAGE_SIZE:
		image_size = arg;
		break;

	case SNAPSHOT_GET_IMAGE_SIZE:
		if (!data->ready) {
			error = -ENODATA;
			break;
		}
		size = snapshot_get_image_size();
		size <<= PAGE_SHIFT;
		error = put_user(size, (loff_t __user *)arg);
		break;

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

	case SNAPSHOT_ALLOC_SWAP_PAGE:
	case SNAPSHOT_GET_SWAP_PAGE:
		if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
			error = -ENODEV;
			break;
		}
		offset = alloc_swapdev_block(data->swap);
		if (offset) {
			offset <<= PAGE_SHIFT;
			error = put_user(offset, (loff_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);
		break;

	case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
		if (!swsusp_swap_in_use()) {
			/*
			 * 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 (!data->frozen) {
			error = -EPERM;
			break;
		}
		if (!mutex_trylock(&pm_mutex)) {
			error = -EBUSY;
			break;
		}
		/*
		 * Tasks are frozen and the notifiers have been called with
		 * PM_HIBERNATION_PREPARE
		 */
		error = suspend_devices_and_enter(PM_SUSPEND_MEM);
		mutex_unlock(&pm_mutex);
		break;

	case SNAPSHOT_PLATFORM_SUPPORT:
		data->platform_support = !!arg;
		break;

	case SNAPSHOT_POWER_OFF:
		if (data->platform_support)
			error = hibernation_platform_enter();
		break;

	case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
		error = -EINVAL;

		switch (arg) {

		case PMOPS_PREPARE:
			data->platform_support = 1;
			error = 0;
			break;

		case PMOPS_ENTER:
			if (data->platform_support)
				error = hibernation_platform_enter();
			break;

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

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

		}
		break;

	case SNAPSHOT_SET_SWAP_AREA:
		if (swsusp_swap_in_use()) {
			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
eb57c1cf	31	/*
96f73749 RW	32	* NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and
	33	* will be removed in the future. They are only preserved here for
	34	* compatibility with existing userland utilities.
eb57c1cf	35	*/
96f73749	36	#define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
eb57c1cf RW	37	#define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
	38
	39	#define PMOPS_PREPARE 1
	40	#define PMOPS_ENTER 2
	41	#define PMOPS_FINISH 3
	42
cc5d207c RW	43	/*
	44	* NOTE: The following ioctl definitions are wrong and have been replaced with
	45	* correct ones. They are only preserved here for compatibility with existing
	46	* userland utilities and will be removed in the future.
	47	*/
	48	#define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
	49	#define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
	50	#define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
	51	#define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
	52
eb57c1cf	53
6e1819d6 RW	54	#define SNAPSHOT_MINOR 231
	55
	56	static struct snapshot_data {
	57	struct snapshot_handle handle;
	58	int swap;
6e1819d6 RW	59	int mode;
	60	char frozen;
	61	char ready;
eb57c1cf	62	char platform_support;
6e1819d6 RW	63	} snapshot_state;
6e1819d6 RW	64
0709db60	65	atomic_t snapshot_device_available = ATOMIC_INIT(1);
6e1819d6 RW	66
	67	static int snapshot_open(struct inode inode, struct file filp)
	68	{
	69	struct snapshot_data *data;
c3e94d89	70	int error;
6e1819d6	71
0709db60	72	if (!atomic_add_unless(&snapshot_device_available, -1, 0))
6e1819d6 RW	73	return -EBUSY;
6e1819d6 RW	74
1525a2ad	75	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
0709db60	76	atomic_inc(&snapshot_device_available);
6e1819d6	77	return -ENOSYS;
1525a2ad RW	78	}
1525a2ad RW	79	if(create_basic_memory_bitmaps()) {
0709db60	80	atomic_inc(&snapshot_device_available);
74dfd666	81	return -ENOMEM;
1525a2ad	82	}
6e1819d6 RW	83	nonseekable_open(inode, filp);
	84	data = &snapshot_state;
	85	filp->private_data = data;
	86	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	87	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
915bae9e	88	data->swap = swsusp_resume_device ?
7bf23687	89	swap_type_of(swsusp_resume_device, 0, NULL) : -1;
6e1819d6	90	data->mode = O_RDONLY;
c3e94d89 AS	91	error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
	92	if (error)
	93	pm_notifier_call_chain(PM_POST_RESTORE);
6e1819d6 RW	94	} else {
	95	data->swap = -1;
	96	data->mode = O_WRONLY;
c3e94d89 AS	97	error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
	98	if (error)
	99	pm_notifier_call_chain(PM_POST_HIBERNATION);
	100	}
	101	if (error) {
	102	atomic_inc(&snapshot_device_available);
	103	return error;
6e1819d6	104	}
6e1819d6 RW	105	data->frozen = 0;
6e1819d6 RW	106	data->ready = 0;
eb57c1cf	107	data->platform_support = 0;
6e1819d6 RW	108
	109	return 0;
	110	}
	111
	112	static int snapshot_release(struct inode inode, struct file filp)
	113	{
	114	struct snapshot_data *data;
	115
	116	swsusp_free();
74dfd666	117	free_basic_memory_bitmaps();
6e1819d6	118	data = filp->private_data;
d1d241cc	119	free_all_swap_pages(data->swap);
6e1819d6	120	if (data->frozen) {
a6d70980	121	mutex_lock(&pm_mutex);
6e1819d6	122	thaw_processes();
a6d70980	123	mutex_unlock(&pm_mutex);
6e1819d6	124	}
c3e94d89 AS	125	pm_notifier_call_chain(data->mode == O_WRONLY ?
c3e94d89 AS	126	PM_POST_HIBERNATION : PM_POST_RESTORE);
0709db60	127	atomic_inc(&snapshot_device_available);
6e1819d6 RW	128	return 0;
	129	}
	130
	131	static ssize_t snapshot_read(struct file filp, char __user buf,
	132	size_t count, loff_t *offp)
	133	{
	134	struct snapshot_data *data;
	135	ssize_t res;
	136
	137	data = filp->private_data;
2f41dddb RW	138	if (!data->ready)
2f41dddb RW	139	return -ENODATA;
6e1819d6 RW	140	res = snapshot_read_next(&data->handle, count);
	141	if (res > 0) {
	142	if (copy_to_user(buf, data_of(data->handle), res))
	143	res = -EFAULT;
	144	else
	145	*offp = data->handle.offset;
	146	}
	147	return res;
	148	}
	149
	150	static ssize_t snapshot_write(struct file filp, const char __user buf,
	151	size_t count, loff_t *offp)
	152	{
	153	struct snapshot_data *data;
	154	ssize_t res;
	155
	156	data = filp->private_data;
	157	res = snapshot_write_next(&data->handle, count);
	158	if (res > 0) {
	159	if (copy_from_user(data_of(data->handle), buf, res))
	160	res = -EFAULT;
	161	else
	162	*offp = data->handle.offset;
	163	}
	164	return res;
	165	}
	166
	167	static int snapshot_ioctl(struct inode inode, struct file filp,
	168	unsigned int cmd, unsigned long arg)
	169	{
	170	int error = 0;
	171	struct snapshot_data *data;
af508b34	172	loff_t size;
3aef83e0	173	sector_t offset;
6e1819d6 RW	174
	175	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	176	return -ENOTTY;
	177	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	178	return -ENOTTY;
	179	if (!capable(CAP_SYS_ADMIN))
	180	return -EPERM;
	181
	182	data = filp->private_data;
	183
	184	switch (cmd) {
	185
	186	case SNAPSHOT_FREEZE:
	187	if (data->frozen)
	188	break;
a6d70980	189	mutex_lock(&pm_mutex);
c3e94d89 AS	190	printk("Syncing filesystems ... ");
	191	sys_sync();
	192	printk("done.\n");
	193
	194	error = freeze_processes();
b10d9117	195	if (error)
c3e94d89	196	thaw_processes();
a6d70980	197	mutex_unlock(&pm_mutex);
6e1819d6 RW	198	if (!error)
	199	data->frozen = 1;
	200	break;
	201
	202	case SNAPSHOT_UNFREEZE:
2f41dddb	203	if (!data->frozen \|\| data->ready)
6e1819d6	204	break;
a6d70980	205	mutex_lock(&pm_mutex);
6e1819d6	206	thaw_processes();
a6d70980	207	mutex_unlock(&pm_mutex);
6e1819d6 RW	208	data->frozen = 0;
	209	break;
	210
cc5d207c	211	case SNAPSHOT_CREATE_IMAGE:
6e1819d6 RW	212	case SNAPSHOT_ATOMIC_SNAPSHOT:
	213	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	214	error = -EPERM;
	215	break;
	216	}
eb57c1cf	217	error = hibernation_snapshot(data->platform_support);
6e1819d6	218	if (!error)
cc5d207c	219	error = put_user(in_suspend, (int __user *)arg);
6e1819d6 RW	220	if (!error)
	221	data->ready = 1;
	222	break;
	223
	224	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	225	snapshot_write_finalize(&data->handle);
6e1819d6 RW	226	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	227	!snapshot_image_loaded(&data->handle)) {
	228	error = -EPERM;
	229	break;
	230	}
eb57c1cf	231	error = hibernation_restore(data->platform_support);
6e1819d6 RW	232	break;
	233
	234	case SNAPSHOT_FREE:
	235	swsusp_free();
	236	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	237	data->ready = 0;
	238	break;
	239
cc5d207c	240	case SNAPSHOT_PREF_IMAGE_SIZE:
6e1819d6 RW	241	case SNAPSHOT_SET_IMAGE_SIZE:
	242	image_size = arg;
	243	break;
	244
af508b34 RW	245	case SNAPSHOT_GET_IMAGE_SIZE:
	246	if (!data->ready) {
	247	error = -ENODATA;
	248	break;
	249	}
	250	size = snapshot_get_image_size();
	251	size <<= PAGE_SHIFT;
	252	error = put_user(size, (loff_t __user *)arg);
	253	break;
	254
cc5d207c	255	case SNAPSHOT_AVAIL_SWAP_SIZE:
6e1819d6	256	case SNAPSHOT_AVAIL_SWAP:
af508b34 RW	257	size = count_swap_pages(data->swap, 1);
	258	size <<= PAGE_SHIFT;
	259	error = put_user(size, (loff_t __user *)arg);
6e1819d6 RW	260	break;
6e1819d6 RW	261
cc5d207c	262	case SNAPSHOT_ALLOC_SWAP_PAGE:
6e1819d6 RW	263	case SNAPSHOT_GET_SWAP_PAGE:
	264	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	265	error = -ENODEV;
	266	break;
	267	}
d1d241cc	268	offset = alloc_swapdev_block(data->swap);
6e1819d6 RW	269	if (offset) {
6e1819d6 RW	270	offset <<= PAGE_SHIFT;
cc5d207c	271	error = put_user(offset, (loff_t __user *)arg);
6e1819d6 RW	272	} else {
	273	error = -ENOSPC;
	274	}
	275	break;
	276
	277	case SNAPSHOT_FREE_SWAP_PAGES:
	278	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	279	error = -ENODEV;
	280	break;
	281	}
d1d241cc	282	free_all_swap_pages(data->swap);
6e1819d6 RW	283	break;
6e1819d6 RW	284
96f73749	285	case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
d1d241cc	286	if (!swsusp_swap_in_use()) {
6e1819d6 RW	287	/*
	288	* User space encodes device types as two-byte values,
	289	* so we need to recode them
	290	*/
	291	if (old_decode_dev(arg)) {
7bf23687 RW	292	data->swap = swap_type_of(old_decode_dev(arg),
7bf23687 RW	293	0, NULL);
6e1819d6 RW	294	if (data->swap < 0)
	295	error = -ENODEV;
	296	} else {
	297	data->swap = -1;
	298	error = -EINVAL;
	299	}
	300	} else {
	301	error = -EPERM;
	302	}
	303	break;
	304
9b238205 LT	305	case SNAPSHOT_S2RAM:
	306	if (!data->frozen) {
	307	error = -EPERM;
	308	break;
	309	}
a6d70980	310	if (!mutex_trylock(&pm_mutex)) {
9b238205 LT	311	error = -EBUSY;
	312	break;
	313	}
6c961dfb RW	314	/*
	315	* Tasks are frozen and the notifiers have been called with
	316	* PM_HIBERNATION_PREPARE
	317	*/
	318	error = suspend_devices_and_enter(PM_SUSPEND_MEM);
a6d70980	319	mutex_unlock(&pm_mutex);
9b238205 LT	320	break;
9b238205 LT	321
eb57c1cf RW	322	case SNAPSHOT_PLATFORM_SUPPORT:
	323	data->platform_support = !!arg;
	324	break;
	325
	326	case SNAPSHOT_POWER_OFF:
	327	if (data->platform_support)
	328	error = hibernation_platform_enter();
	329	break;
	330
	331	case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
2b5b09b3 RW	332	error = -EINVAL;
2b5b09b3 RW	333
3592695c SS	334	switch (arg) {
	335
	336	case PMOPS_PREPARE:
eb57c1cf	337	data->platform_support = 1;
7777fab9	338	error = 0;
3592695c SS	339	break;
	340
	341	case PMOPS_ENTER:
eb57c1cf	342	if (data->platform_support)
7777fab9	343	error = hibernation_platform_enter();
3592695c SS	344	break;
	345
	346	case PMOPS_FINISH:
eb57c1cf	347	if (data->platform_support)
2b5b09b3	348	error = 0;
3592695c SS	349	break;
	350
	351	default:
	352	printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
3592695c SS	353
	354	}
	355	break;
	356
37b2ba12	357	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	358	if (swsusp_swap_in_use()) {
37b2ba12 RW	359	error = -EPERM;
	360	} else {
	361	struct resume_swap_area swap_area;
	362	dev_t swdev;
	363
	364	error = copy_from_user(&swap_area, (void __user *)arg,
	365	sizeof(struct resume_swap_area));
	366	if (error) {
	367	error = -EFAULT;
	368	break;
	369	}
	370
	371	/*
	372	* User space encodes device types as two-byte values,
	373	* so we need to recode them
	374	*/
	375	swdev = old_decode_dev(swap_area.dev);
	376	if (swdev) {
	377	offset = swap_area.offset;
7bf23687	378	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	379	if (data->swap < 0)
	380	error = -ENODEV;
	381	} else {
	382	data->swap = -1;
	383	error = -EINVAL;
	384	}
	385	}
	386	break;
	387
6e1819d6 RW	388	default:
	389	error = -ENOTTY;
	390
	391	}
	392
	393	return error;
	394	}
	395
15ad7cdc	396	static const struct file_operations snapshot_fops = {
6e1819d6 RW	397	.open = snapshot_open,
	398	.release = snapshot_release,
	399	.read = snapshot_read,
	400	.write = snapshot_write,
	401	.llseek = no_llseek,
	402	.ioctl = snapshot_ioctl,
	403	};
	404
	405	static struct miscdevice snapshot_device = {
	406	.minor = SNAPSHOT_MINOR,
	407	.name = "snapshot",
	408	.fops = &snapshot_fops,
	409	};
	410
	411	static int __init snapshot_device_init(void)
	412	{
	413	return misc_register(&snapshot_device);
	414	};
	415
	416	device_initcall(snapshot_device_init);