[net-next-2.6.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 <linux/smp_lock.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 long snapshot_ioctl(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;

	lock_kernel();

	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;

	}
	unlock_kernel();
	return error;
}

static const struct file_operations snapshot_fops = {
	.open = snapshot_open,
	.release = snapshot_release,
	.read = snapshot_read,
	.write = snapshot_write,
	.llseek = no_llseek,
	.unlocked_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>
52d11025	26	#include <linux/smp_lock.h>
6e1819d6 RW	27
	28	#include <asm/uaccess.h>
	29
	30	#include "power.h"
	31
eb57c1cf	32	/*
96f73749 RW	33	* NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and
	34	* will be removed in the future. They are only preserved here for
	35	* compatibility with existing userland utilities.
eb57c1cf	36	*/
96f73749	37	#define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
eb57c1cf RW	38	#define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
	39
	40	#define PMOPS_PREPARE 1
	41	#define PMOPS_ENTER 2
	42	#define PMOPS_FINISH 3
	43
cc5d207c RW	44	/*
	45	* NOTE: The following ioctl definitions are wrong and have been replaced with
	46	* correct ones. They are only preserved here for compatibility with existing
	47	* userland utilities and will be removed in the future.
	48	*/
	49	#define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
	50	#define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
	51	#define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
	52	#define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
	53
eb57c1cf	54
6e1819d6 RW	55	#define SNAPSHOT_MINOR 231
	56
	57	static struct snapshot_data {
	58	struct snapshot_handle handle;
	59	int swap;
6e1819d6 RW	60	int mode;
	61	char frozen;
	62	char ready;
eb57c1cf	63	char platform_support;
6e1819d6 RW	64	} snapshot_state;
6e1819d6 RW	65
0709db60	66	atomic_t snapshot_device_available = ATOMIC_INIT(1);
6e1819d6 RW	67
	68	static int snapshot_open(struct inode inode, struct file filp)
	69	{
	70	struct snapshot_data *data;
c3e94d89	71	int error;
6e1819d6	72
0709db60	73	if (!atomic_add_unless(&snapshot_device_available, -1, 0))
6e1819d6 RW	74	return -EBUSY;
6e1819d6 RW	75
1525a2ad	76	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
0709db60	77	atomic_inc(&snapshot_device_available);
6e1819d6	78	return -ENOSYS;
1525a2ad RW	79	}
1525a2ad RW	80	if(create_basic_memory_bitmaps()) {
0709db60	81	atomic_inc(&snapshot_device_available);
74dfd666	82	return -ENOMEM;
1525a2ad	83	}
6e1819d6 RW	84	nonseekable_open(inode, filp);
	85	data = &snapshot_state;
	86	filp->private_data = data;
	87	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	88	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
915bae9e	89	data->swap = swsusp_resume_device ?
7bf23687	90	swap_type_of(swsusp_resume_device, 0, NULL) : -1;
6e1819d6	91	data->mode = O_RDONLY;
c3e94d89 AS	92	error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
	93	if (error)
	94	pm_notifier_call_chain(PM_POST_RESTORE);
6e1819d6 RW	95	} else {
	96	data->swap = -1;
	97	data->mode = O_WRONLY;
c3e94d89 AS	98	error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
	99	if (error)
	100	pm_notifier_call_chain(PM_POST_HIBERNATION);
	101	}
	102	if (error) {
	103	atomic_inc(&snapshot_device_available);
	104	return error;
6e1819d6	105	}
6e1819d6 RW	106	data->frozen = 0;
6e1819d6 RW	107	data->ready = 0;
eb57c1cf	108	data->platform_support = 0;
6e1819d6 RW	109
	110	return 0;
	111	}
	112
	113	static int snapshot_release(struct inode inode, struct file filp)
	114	{
	115	struct snapshot_data *data;
	116
	117	swsusp_free();
74dfd666	118	free_basic_memory_bitmaps();
6e1819d6	119	data = filp->private_data;
d1d241cc	120	free_all_swap_pages(data->swap);
6e1819d6	121	if (data->frozen) {
a6d70980	122	mutex_lock(&pm_mutex);
6e1819d6	123	thaw_processes();
a6d70980	124	mutex_unlock(&pm_mutex);
6e1819d6	125	}
c3e94d89 AS	126	pm_notifier_call_chain(data->mode == O_WRONLY ?
c3e94d89 AS	127	PM_POST_HIBERNATION : PM_POST_RESTORE);
0709db60	128	atomic_inc(&snapshot_device_available);
6e1819d6 RW	129	return 0;
	130	}
	131
	132	static ssize_t snapshot_read(struct file filp, char __user buf,
	133	size_t count, loff_t *offp)
	134	{
	135	struct snapshot_data *data;
	136	ssize_t res;
	137
	138	data = filp->private_data;
2f41dddb RW	139	if (!data->ready)
2f41dddb RW	140	return -ENODATA;
6e1819d6 RW	141	res = snapshot_read_next(&data->handle, count);
	142	if (res > 0) {
	143	if (copy_to_user(buf, data_of(data->handle), res))
	144	res = -EFAULT;
	145	else
	146	*offp = data->handle.offset;
	147	}
	148	return res;
	149	}
	150
	151	static ssize_t snapshot_write(struct file filp, const char __user buf,
	152	size_t count, loff_t *offp)
	153	{
	154	struct snapshot_data *data;
	155	ssize_t res;
	156
	157	data = filp->private_data;
	158	res = snapshot_write_next(&data->handle, count);
	159	if (res > 0) {
	160	if (copy_from_user(data_of(data->handle), buf, res))
	161	res = -EFAULT;
	162	else
	163	*offp = data->handle.offset;
	164	}
	165	return res;
	166	}
	167
52d11025 AC	168	static long snapshot_ioctl(struct file *filp, unsigned int cmd,
52d11025 AC	169	unsigned long arg)
6e1819d6 RW	170	{
	171	int error = 0;
	172	struct snapshot_data *data;
af508b34	173	loff_t size;
3aef83e0	174	sector_t offset;
6e1819d6 RW	175
	176	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	177	return -ENOTTY;
	178	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	179	return -ENOTTY;
	180	if (!capable(CAP_SYS_ADMIN))
	181	return -EPERM;
	182
	183	data = filp->private_data;
	184
52d11025 AC	185	lock_kernel();
52d11025 AC	186
6e1819d6 RW	187	switch (cmd) {
	188
	189	case SNAPSHOT_FREEZE:
	190	if (data->frozen)
	191	break;
a6d70980	192	mutex_lock(&pm_mutex);
c3e94d89 AS	193	printk("Syncing filesystems ... ");
	194	sys_sync();
	195	printk("done.\n");
	196
	197	error = freeze_processes();
b10d9117	198	if (error)
c3e94d89	199	thaw_processes();
a6d70980	200	mutex_unlock(&pm_mutex);
6e1819d6 RW	201	if (!error)
	202	data->frozen = 1;
	203	break;
	204
	205	case SNAPSHOT_UNFREEZE:
2f41dddb	206	if (!data->frozen \|\| data->ready)
6e1819d6	207	break;
a6d70980	208	mutex_lock(&pm_mutex);
6e1819d6	209	thaw_processes();
a6d70980	210	mutex_unlock(&pm_mutex);
6e1819d6 RW	211	data->frozen = 0;
	212	break;
	213
cc5d207c	214	case SNAPSHOT_CREATE_IMAGE:
6e1819d6 RW	215	case SNAPSHOT_ATOMIC_SNAPSHOT:
	216	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	217	error = -EPERM;
	218	break;
	219	}
eb57c1cf	220	error = hibernation_snapshot(data->platform_support);
6e1819d6	221	if (!error)
cc5d207c	222	error = put_user(in_suspend, (int __user *)arg);
6e1819d6 RW	223	if (!error)
	224	data->ready = 1;
	225	break;
	226
	227	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	228	snapshot_write_finalize(&data->handle);
6e1819d6 RW	229	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	230	!snapshot_image_loaded(&data->handle)) {
	231	error = -EPERM;
	232	break;
	233	}
eb57c1cf	234	error = hibernation_restore(data->platform_support);
6e1819d6 RW	235	break;
	236
	237	case SNAPSHOT_FREE:
	238	swsusp_free();
	239	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	240	data->ready = 0;
	241	break;
	242
cc5d207c	243	case SNAPSHOT_PREF_IMAGE_SIZE:
6e1819d6 RW	244	case SNAPSHOT_SET_IMAGE_SIZE:
	245	image_size = arg;
	246	break;
	247
af508b34 RW	248	case SNAPSHOT_GET_IMAGE_SIZE:
	249	if (!data->ready) {
	250	error = -ENODATA;
	251	break;
	252	}
	253	size = snapshot_get_image_size();
	254	size <<= PAGE_SHIFT;
	255	error = put_user(size, (loff_t __user *)arg);
	256	break;
	257
cc5d207c	258	case SNAPSHOT_AVAIL_SWAP_SIZE:
6e1819d6	259	case SNAPSHOT_AVAIL_SWAP:
af508b34 RW	260	size = count_swap_pages(data->swap, 1);
	261	size <<= PAGE_SHIFT;
	262	error = put_user(size, (loff_t __user *)arg);
6e1819d6 RW	263	break;
6e1819d6 RW	264
cc5d207c	265	case SNAPSHOT_ALLOC_SWAP_PAGE:
6e1819d6 RW	266	case SNAPSHOT_GET_SWAP_PAGE:
	267	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	268	error = -ENODEV;
	269	break;
	270	}
d1d241cc	271	offset = alloc_swapdev_block(data->swap);
6e1819d6 RW	272	if (offset) {
6e1819d6 RW	273	offset <<= PAGE_SHIFT;
cc5d207c	274	error = put_user(offset, (loff_t __user *)arg);
6e1819d6 RW	275	} else {
	276	error = -ENOSPC;
	277	}
	278	break;
	279
	280	case SNAPSHOT_FREE_SWAP_PAGES:
	281	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	282	error = -ENODEV;
	283	break;
	284	}
d1d241cc	285	free_all_swap_pages(data->swap);
6e1819d6 RW	286	break;
6e1819d6 RW	287
96f73749	288	case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
d1d241cc	289	if (!swsusp_swap_in_use()) {
6e1819d6 RW	290	/*
	291	* User space encodes device types as two-byte values,
	292	* so we need to recode them
	293	*/
	294	if (old_decode_dev(arg)) {
7bf23687 RW	295	data->swap = swap_type_of(old_decode_dev(arg),
7bf23687 RW	296	0, NULL);
6e1819d6 RW	297	if (data->swap < 0)
	298	error = -ENODEV;
	299	} else {
	300	data->swap = -1;
	301	error = -EINVAL;
	302	}
	303	} else {
	304	error = -EPERM;
	305	}
	306	break;
	307
9b238205 LT	308	case SNAPSHOT_S2RAM:
	309	if (!data->frozen) {
	310	error = -EPERM;
	311	break;
	312	}
a6d70980	313	if (!mutex_trylock(&pm_mutex)) {
9b238205 LT	314	error = -EBUSY;
	315	break;
	316	}
6c961dfb RW	317	/*
	318	* Tasks are frozen and the notifiers have been called with
	319	* PM_HIBERNATION_PREPARE
	320	*/
	321	error = suspend_devices_and_enter(PM_SUSPEND_MEM);
a6d70980	322	mutex_unlock(&pm_mutex);
9b238205 LT	323	break;
9b238205 LT	324
eb57c1cf RW	325	case SNAPSHOT_PLATFORM_SUPPORT:
	326	data->platform_support = !!arg;
	327	break;
	328
	329	case SNAPSHOT_POWER_OFF:
	330	if (data->platform_support)
	331	error = hibernation_platform_enter();
	332	break;
	333
	334	case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
2b5b09b3 RW	335	error = -EINVAL;
2b5b09b3 RW	336
3592695c SS	337	switch (arg) {
	338
	339	case PMOPS_PREPARE:
eb57c1cf	340	data->platform_support = 1;
7777fab9	341	error = 0;
3592695c SS	342	break;
	343
	344	case PMOPS_ENTER:
eb57c1cf	345	if (data->platform_support)
7777fab9	346	error = hibernation_platform_enter();
3592695c SS	347	break;
	348
	349	case PMOPS_FINISH:
eb57c1cf	350	if (data->platform_support)
2b5b09b3	351	error = 0;
3592695c SS	352	break;
	353
	354	default:
	355	printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
3592695c SS	356
	357	}
	358	break;
	359
37b2ba12	360	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	361	if (swsusp_swap_in_use()) {
37b2ba12 RW	362	error = -EPERM;
	363	} else {
	364	struct resume_swap_area swap_area;
	365	dev_t swdev;
	366
	367	error = copy_from_user(&swap_area, (void __user *)arg,
	368	sizeof(struct resume_swap_area));
	369	if (error) {
	370	error = -EFAULT;
	371	break;
	372	}
	373
	374	/*
	375	* User space encodes device types as two-byte values,
	376	* so we need to recode them
	377	*/
	378	swdev = old_decode_dev(swap_area.dev);
	379	if (swdev) {
	380	offset = swap_area.offset;
7bf23687	381	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	382	if (data->swap < 0)
	383	error = -ENODEV;
	384	} else {
	385	data->swap = -1;
	386	error = -EINVAL;
	387	}
	388	}
	389	break;
	390
6e1819d6 RW	391	default:
	392	error = -ENOTTY;
	393
	394	}
52d11025	395	unlock_kernel();
6e1819d6 RW	396	return error;
	397	}
	398
15ad7cdc	399	static const struct file_operations snapshot_fops = {
6e1819d6 RW	400	.open = snapshot_open,
	401	.release = snapshot_release,
	402	.read = snapshot_read,
	403	.write = snapshot_write,
	404	.llseek = no_llseek,
52d11025	405	.unlocked_ioctl = snapshot_ioctl,
6e1819d6 RW	406	};
	407
	408	static struct miscdevice snapshot_device = {
	409	.minor = SNAPSHOT_MINOR,
	410	.name = "snapshot",
	411	.fops = &snapshot_fops,
	412	};
	413
	414	static int __init snapshot_device_init(void)
	415	{
	416	return misc_register(&snapshot_device);
	417	};
	418
	419	device_initcall(snapshot_device_init);