[mirror_ubuntu-bionic-kernel.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;
	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->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);
	if (data->frozen) {
		mutex_lock(&pm_mutex);
		thaw_processes();
		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 (hibernation_ops)
		error = hibernation_ops->prepare();

	return error;
}

static inline void platform_finish(void)
{
	if (hibernation_ops)
		hibernation_ops->finish();
}

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;
		}
		offset = alloc_swapdev_block(data->swap);
		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);
		break;

	case SNAPSHOT_SET_SWAP_FILE:
		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 (!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 (hibernation_ops) {
				data->platform_suspend = 1;
				error = 0;
			} else {
				error = -ENOSYS;
			}
			break;

		case PMOPS_ENTER:
			if (data->platform_suspend) {
				kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
				error = hibernation_ops->enter();
			}
			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 (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
	31	#define SNAPSHOT_MINOR 231
	32
	33	static struct snapshot_data {
	34	struct snapshot_handle handle;
	35	int swap;
6e1819d6 RW	36	int mode;
	37	char frozen;
	38	char ready;
2b5b09b3	39	char platform_suspend;
6e1819d6 RW	40	} snapshot_state;
6e1819d6 RW	41
0709db60	42	atomic_t snapshot_device_available = ATOMIC_INIT(1);
6e1819d6 RW	43
	44	static int snapshot_open(struct inode inode, struct file filp)
	45	{
	46	struct snapshot_data *data;
	47
0709db60	48	if (!atomic_add_unless(&snapshot_device_available, -1, 0))
6e1819d6 RW	49	return -EBUSY;
6e1819d6 RW	50
1525a2ad	51	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
0709db60	52	atomic_inc(&snapshot_device_available);
6e1819d6	53	return -ENOSYS;
1525a2ad RW	54	}
1525a2ad RW	55	if(create_basic_memory_bitmaps()) {
0709db60	56	atomic_inc(&snapshot_device_available);
74dfd666	57	return -ENOMEM;
1525a2ad	58	}
6e1819d6 RW	59	nonseekable_open(inode, filp);
	60	data = &snapshot_state;
	61	filp->private_data = data;
	62	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	63	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
915bae9e	64	data->swap = swsusp_resume_device ?
7bf23687	65	swap_type_of(swsusp_resume_device, 0, NULL) : -1;
6e1819d6 RW	66	data->mode = O_RDONLY;
	67	} else {
	68	data->swap = -1;
	69	data->mode = O_WRONLY;
	70	}
6e1819d6 RW	71	data->frozen = 0;
6e1819d6 RW	72	data->ready = 0;
2b5b09b3	73	data->platform_suspend = 0;
6e1819d6 RW	74
	75	return 0;
	76	}
	77
	78	static int snapshot_release(struct inode inode, struct file filp)
	79	{
	80	struct snapshot_data *data;
	81
	82	swsusp_free();
74dfd666	83	free_basic_memory_bitmaps();
6e1819d6	84	data = filp->private_data;
d1d241cc	85	free_all_swap_pages(data->swap);
6e1819d6	86	if (data->frozen) {
a6d70980	87	mutex_lock(&pm_mutex);
6e1819d6	88	thaw_processes();
a6d70980	89	mutex_unlock(&pm_mutex);
6e1819d6	90	}
0709db60	91	atomic_inc(&snapshot_device_available);
6e1819d6 RW	92	return 0;
	93	}
	94
	95	static ssize_t snapshot_read(struct file filp, char __user buf,
	96	size_t count, loff_t *offp)
	97	{
	98	struct snapshot_data *data;
	99	ssize_t res;
	100
	101	data = filp->private_data;
	102	res = snapshot_read_next(&data->handle, count);
	103	if (res > 0) {
	104	if (copy_to_user(buf, data_of(data->handle), res))
	105	res = -EFAULT;
	106	else
	107	*offp = data->handle.offset;
	108	}
	109	return res;
	110	}
	111
	112	static ssize_t snapshot_write(struct file filp, const char __user buf,
	113	size_t count, loff_t *offp)
	114	{
	115	struct snapshot_data *data;
	116	ssize_t res;
	117
	118	data = filp->private_data;
	119	res = snapshot_write_next(&data->handle, count);
	120	if (res > 0) {
	121	if (copy_from_user(data_of(data->handle), buf, res))
	122	res = -EFAULT;
	123	else
	124	*offp = data->handle.offset;
	125	}
	126	return res;
	127	}
	128
2b5b09b3 RW	129	static inline int platform_prepare(void)
	130	{
	131	int error = 0;
	132
a3d25c27 RW	133	if (hibernation_ops)
a3d25c27 RW	134	error = hibernation_ops->prepare();
2b5b09b3 RW	135
	136	return error;
	137	}
	138
	139	static inline void platform_finish(void)
	140	{
a3d25c27 RW	141	if (hibernation_ops)
a3d25c27 RW	142	hibernation_ops->finish();
2b5b09b3 RW	143	}
	144
	145	static inline int snapshot_suspend(int platform_suspend)
25913052 RW	146	{
	147	int error;
	148
	149	mutex_lock(&pm_mutex);
	150	/* Free memory before shutting down devices. */
	151	error = swsusp_shrink_memory();
	152	if (error)
	153	goto Finish;
	154
2b5b09b3 RW	155	if (platform_suspend) {
	156	error = platform_prepare();
	157	if (error)
	158	goto Finish;
	159	}
25913052 RW	160	suspend_console();
	161	error = device_suspend(PMSG_FREEZE);
	162	if (error)
	163	goto Resume_devices;
	164
	165	error = disable_nonboot_cpus();
	166	if (!error) {
	167	in_suspend = 1;
	168	error = swsusp_suspend();
	169	}
	170	enable_nonboot_cpus();
	171	Resume_devices:
2b5b09b3 RW	172	if (platform_suspend)
	173	platform_finish();
	174
25913052 RW	175	device_resume();
	176	resume_console();
	177	Finish:
	178	mutex_unlock(&pm_mutex);
	179	return error;
	180	}
	181
2b5b09b3	182	static inline int snapshot_restore(int platform_suspend)
25913052 RW	183	{
	184	int error;
	185
	186	mutex_lock(&pm_mutex);
	187	pm_prepare_console();
2b5b09b3 RW	188	if (platform_suspend) {
	189	error = platform_prepare();
	190	if (error)
	191	goto Finish;
	192	}
25913052 RW	193	suspend_console();
	194	error = device_suspend(PMSG_PRETHAW);
	195	if (error)
	196	goto Resume_devices;
	197
	198	error = disable_nonboot_cpus();
	199	if (!error)
	200	error = swsusp_resume();
	201
	202	enable_nonboot_cpus();
	203	Resume_devices:
2b5b09b3 RW	204	if (platform_suspend)
	205	platform_finish();
	206
25913052 RW	207	device_resume();
25913052 RW	208	resume_console();
2b5b09b3	209	Finish:
25913052 RW	210	pm_restore_console();
	211	mutex_unlock(&pm_mutex);
	212	return error;
	213	}
	214
6e1819d6 RW	215	static int snapshot_ioctl(struct inode inode, struct file filp,
	216	unsigned int cmd, unsigned long arg)
	217	{
	218	int error = 0;
	219	struct snapshot_data *data;
3aef83e0 RW	220	loff_t avail;
3aef83e0 RW	221	sector_t offset;
6e1819d6 RW	222
	223	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	224	return -ENOTTY;
	225	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	226	return -ENOTTY;
	227	if (!capable(CAP_SYS_ADMIN))
	228	return -EPERM;
	229
	230	data = filp->private_data;
	231
	232	switch (cmd) {
	233
	234	case SNAPSHOT_FREEZE:
	235	if (data->frozen)
	236	break;
a6d70980	237	mutex_lock(&pm_mutex);
25913052 RW	238	if (freeze_processes()) {
	239	thaw_processes();
	240	error = -EBUSY;
6e1819d6	241	}
a6d70980	242	mutex_unlock(&pm_mutex);
6e1819d6 RW	243	if (!error)
	244	data->frozen = 1;
	245	break;
	246
	247	case SNAPSHOT_UNFREEZE:
	248	if (!data->frozen)
	249	break;
a6d70980	250	mutex_lock(&pm_mutex);
6e1819d6	251	thaw_processes();
a6d70980	252	mutex_unlock(&pm_mutex);
6e1819d6 RW	253	data->frozen = 0;
	254	break;
	255
	256	case SNAPSHOT_ATOMIC_SNAPSHOT:
	257	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	258	error = -EPERM;
	259	break;
	260	}
2b5b09b3	261	error = snapshot_suspend(data->platform_suspend);
6e1819d6 RW	262	if (!error)
	263	error = put_user(in_suspend, (unsigned int __user *)arg);
	264	if (!error)
	265	data->ready = 1;
	266	break;
	267
	268	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	269	snapshot_write_finalize(&data->handle);
6e1819d6 RW	270	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	271	!snapshot_image_loaded(&data->handle)) {
	272	error = -EPERM;
	273	break;
	274	}
2b5b09b3	275	error = snapshot_restore(data->platform_suspend);
6e1819d6 RW	276	break;
	277
	278	case SNAPSHOT_FREE:
	279	swsusp_free();
	280	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	281	data->ready = 0;
	282	break;
	283
	284	case SNAPSHOT_SET_IMAGE_SIZE:
	285	image_size = arg;
	286	break;
	287
	288	case SNAPSHOT_AVAIL_SWAP:
	289	avail = count_swap_pages(data->swap, 1);
	290	avail <<= PAGE_SHIFT;
	291	error = put_user(avail, (loff_t __user *)arg);
	292	break;
	293
	294	case SNAPSHOT_GET_SWAP_PAGE:
	295	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	296	error = -ENODEV;
	297	break;
	298	}
d1d241cc	299	offset = alloc_swapdev_block(data->swap);
6e1819d6 RW	300	if (offset) {
6e1819d6 RW	301	offset <<= PAGE_SHIFT;
3aef83e0	302	error = put_user(offset, (sector_t __user *)arg);
6e1819d6 RW	303	} else {
	304	error = -ENOSPC;
	305	}
	306	break;
	307
	308	case SNAPSHOT_FREE_SWAP_PAGES:
	309	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	310	error = -ENODEV;
	311	break;
	312	}
d1d241cc	313	free_all_swap_pages(data->swap);
6e1819d6 RW	314	break;
	315
	316	case SNAPSHOT_SET_SWAP_FILE:
d1d241cc	317	if (!swsusp_swap_in_use()) {
6e1819d6 RW	318	/*
	319	* User space encodes device types as two-byte values,
	320	* so we need to recode them
	321	*/
	322	if (old_decode_dev(arg)) {
7bf23687 RW	323	data->swap = swap_type_of(old_decode_dev(arg),
7bf23687 RW	324	0, NULL);
6e1819d6 RW	325	if (data->swap < 0)
	326	error = -ENODEV;
	327	} else {
	328	data->swap = -1;
	329	error = -EINVAL;
	330	}
	331	} else {
	332	error = -EPERM;
	333	}
	334	break;
	335
9b238205	336	case SNAPSHOT_S2RAM:
2b5b09b3 RW	337	if (!pm_ops) {
	338	error = -ENOSYS;
	339	break;
	340	}
	341
9b238205 LT	342	if (!data->frozen) {
	343	error = -EPERM;
	344	break;
	345	}
	346
a6d70980	347	if (!mutex_trylock(&pm_mutex)) {
9b238205 LT	348	error = -EBUSY;
	349	break;
	350	}
	351
	352	if (pm_ops->prepare) {
	353	error = pm_ops->prepare(PM_SUSPEND_MEM);
	354	if (error)
	355	goto OutS3;
	356	}
	357
	358	/* Put devices to sleep */
97c7801c	359	suspend_console();
9b238205 LT	360	error = device_suspend(PMSG_SUSPEND);
	361	if (error) {
	362	printk(KERN_ERR "Failed to suspend some devices.\n");
	363	} else {
93c9a7ff RW	364	error = disable_nonboot_cpus();
	365	if (!error) {
	366	/* Enter S3, system is already frozen */
	367	suspend_enter(PM_SUSPEND_MEM);
	368	enable_nonboot_cpus();
	369	}
9b238205 LT	370	/* Wake up devices */
	371	device_resume();
	372	}
97c7801c	373	resume_console();
9b238205 LT	374	if (pm_ops->finish)
	375	pm_ops->finish(PM_SUSPEND_MEM);
	376
59a49335	377	OutS3:
a6d70980	378	mutex_unlock(&pm_mutex);
9b238205 LT	379	break;
9b238205 LT	380
3592695c	381	case SNAPSHOT_PMOPS:
2b5b09b3 RW	382	error = -EINVAL;
2b5b09b3 RW	383
3592695c SS	384	switch (arg) {
	385
	386	case PMOPS_PREPARE:
a3d25c27	387	if (hibernation_ops) {
2b5b09b3 RW	388	data->platform_suspend = 1;
	389	error = 0;
	390	} else {
	391	error = -ENOSYS;
3592695c SS	392	}
	393	break;
	394
	395	case PMOPS_ENTER:
2b5b09b3 RW	396	if (data->platform_suspend) {
2b5b09b3 RW	397	kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
a3d25c27	398	error = hibernation_ops->enter();
2b5b09b3	399	}
3592695c SS	400	break;
	401
	402	case PMOPS_FINISH:
2b5b09b3 RW	403	if (data->platform_suspend)
	404	error = 0;
	405
3592695c SS	406	break;
	407
	408	default:
	409	printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
3592695c SS	410
	411	}
	412	break;
	413
37b2ba12	414	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	415	if (swsusp_swap_in_use()) {
37b2ba12 RW	416	error = -EPERM;
	417	} else {
	418	struct resume_swap_area swap_area;
	419	dev_t swdev;
	420
	421	error = copy_from_user(&swap_area, (void __user *)arg,
	422	sizeof(struct resume_swap_area));
	423	if (error) {
	424	error = -EFAULT;
	425	break;
	426	}
	427
	428	/*
	429	* User space encodes device types as two-byte values,
	430	* so we need to recode them
	431	*/
	432	swdev = old_decode_dev(swap_area.dev);
	433	if (swdev) {
	434	offset = swap_area.offset;
7bf23687	435	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	436	if (data->swap < 0)
	437	error = -ENODEV;
	438	} else {
	439	data->swap = -1;
	440	error = -EINVAL;
	441	}
	442	}
	443	break;
	444
6e1819d6 RW	445	default:
	446	error = -ENOTTY;
	447
	448	}
	449
	450	return error;
	451	}
	452
15ad7cdc	453	static const struct file_operations snapshot_fops = {
6e1819d6 RW	454	.open = snapshot_open,
	455	.release = snapshot_release,
	456	.read = snapshot_read,
	457	.write = snapshot_write,
	458	.llseek = no_llseek,
	459	.ioctl = snapshot_ioctl,
	460	};
	461
	462	static struct miscdevice snapshot_device = {
	463	.minor = SNAPSHOT_MINOR,
	464	.name = "snapshot",
	465	.fops = &snapshot_fops,
	466	};
	467
	468	static int __init snapshot_device_init(void)
	469	{
	470	return misc_register(&snapshot_device);
	471	};
	472
	473	device_initcall(snapshot_device_init);