[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;
	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 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(void)
{
	int error;

	mutex_lock(&pm_mutex);
	pm_prepare_console();
	suspend_console();
	error = device_suspend(PMSG_PRETHAW);
	if (error)
		goto Finish;

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

	enable_nonboot_cpus();
 Finish:
	device_resume();
	resume_console();
	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 || data->ready)
			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();
		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;
2f41dddb RW	102	if (!data->ready)
2f41dddb RW	103	return -ENODATA;
6e1819d6 RW	104	res = snapshot_read_next(&data->handle, count);
	105	if (res > 0) {
	106	if (copy_to_user(buf, data_of(data->handle), res))
	107	res = -EFAULT;
	108	else
	109	*offp = data->handle.offset;
	110	}
	111	return res;
	112	}
	113
	114	static ssize_t snapshot_write(struct file filp, const char __user buf,
	115	size_t count, loff_t *offp)
	116	{
	117	struct snapshot_data *data;
	118	ssize_t res;
	119
	120	data = filp->private_data;
	121	res = snapshot_write_next(&data->handle, count);
	122	if (res > 0) {
	123	if (copy_from_user(data_of(data->handle), buf, res))
	124	res = -EFAULT;
	125	else
	126	*offp = data->handle.offset;
	127	}
	128	return res;
	129	}
	130
2b5b09b3 RW	131	static inline int platform_prepare(void)
	132	{
	133	int error = 0;
	134
a3d25c27 RW	135	if (hibernation_ops)
a3d25c27 RW	136	error = hibernation_ops->prepare();
2b5b09b3 RW	137
	138	return error;
	139	}
	140
	141	static inline void platform_finish(void)
	142	{
a3d25c27 RW	143	if (hibernation_ops)
a3d25c27 RW	144	hibernation_ops->finish();
2b5b09b3 RW	145	}
	146
	147	static inline int snapshot_suspend(int platform_suspend)
25913052 RW	148	{
	149	int error;
	150
	151	mutex_lock(&pm_mutex);
	152	/* Free memory before shutting down devices. */
	153	error = swsusp_shrink_memory();
	154	if (error)
	155	goto Finish;
	156
2b5b09b3 RW	157	if (platform_suspend) {
	158	error = platform_prepare();
	159	if (error)
	160	goto Finish;
	161	}
25913052 RW	162	suspend_console();
	163	error = device_suspend(PMSG_FREEZE);
	164	if (error)
	165	goto Resume_devices;
	166
	167	error = disable_nonboot_cpus();
	168	if (!error) {
	169	in_suspend = 1;
	170	error = swsusp_suspend();
	171	}
	172	enable_nonboot_cpus();
	173	Resume_devices:
2b5b09b3 RW	174	if (platform_suspend)
	175	platform_finish();
	176
25913052 RW	177	device_resume();
	178	resume_console();
	179	Finish:
	180	mutex_unlock(&pm_mutex);
	181	return error;
	182	}
	183
127067a9	184	static inline int snapshot_restore(void)
25913052 RW	185	{
	186	int error;
	187
	188	mutex_lock(&pm_mutex);
	189	pm_prepare_console();
	190	suspend_console();
	191	error = device_suspend(PMSG_PRETHAW);
	192	if (error)
127067a9	193	goto Finish;
25913052 RW	194
	195	error = disable_nonboot_cpus();
	196	if (!error)
	197	error = swsusp_resume();
	198
	199	enable_nonboot_cpus();
127067a9	200	Finish:
25913052 RW	201	device_resume();
	202	resume_console();
	203	pm_restore_console();
	204	mutex_unlock(&pm_mutex);
	205	return error;
	206	}
	207
6e1819d6 RW	208	static int snapshot_ioctl(struct inode inode, struct file filp,
	209	unsigned int cmd, unsigned long arg)
	210	{
	211	int error = 0;
	212	struct snapshot_data *data;
3aef83e0 RW	213	loff_t avail;
3aef83e0 RW	214	sector_t offset;
6e1819d6 RW	215
	216	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	217	return -ENOTTY;
	218	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	219	return -ENOTTY;
	220	if (!capable(CAP_SYS_ADMIN))
	221	return -EPERM;
	222
	223	data = filp->private_data;
	224
	225	switch (cmd) {
	226
	227	case SNAPSHOT_FREEZE:
	228	if (data->frozen)
	229	break;
a6d70980	230	mutex_lock(&pm_mutex);
25913052 RW	231	if (freeze_processes()) {
	232	thaw_processes();
	233	error = -EBUSY;
6e1819d6	234	}
a6d70980	235	mutex_unlock(&pm_mutex);
6e1819d6 RW	236	if (!error)
	237	data->frozen = 1;
	238	break;
	239
	240	case SNAPSHOT_UNFREEZE:
2f41dddb	241	if (!data->frozen \|\| data->ready)
6e1819d6	242	break;
a6d70980	243	mutex_lock(&pm_mutex);
6e1819d6	244	thaw_processes();
a6d70980	245	mutex_unlock(&pm_mutex);
6e1819d6 RW	246	data->frozen = 0;
	247	break;
	248
	249	case SNAPSHOT_ATOMIC_SNAPSHOT:
	250	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	251	error = -EPERM;
	252	break;
	253	}
2b5b09b3	254	error = snapshot_suspend(data->platform_suspend);
6e1819d6 RW	255	if (!error)
	256	error = put_user(in_suspend, (unsigned int __user *)arg);
	257	if (!error)
	258	data->ready = 1;
	259	break;
	260
	261	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	262	snapshot_write_finalize(&data->handle);
6e1819d6 RW	263	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	264	!snapshot_image_loaded(&data->handle)) {
	265	error = -EPERM;
	266	break;
	267	}
127067a9	268	error = snapshot_restore();
6e1819d6 RW	269	break;
	270
	271	case SNAPSHOT_FREE:
	272	swsusp_free();
	273	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	274	data->ready = 0;
	275	break;
	276
	277	case SNAPSHOT_SET_IMAGE_SIZE:
	278	image_size = arg;
	279	break;
	280
	281	case SNAPSHOT_AVAIL_SWAP:
	282	avail = count_swap_pages(data->swap, 1);
	283	avail <<= PAGE_SHIFT;
	284	error = put_user(avail, (loff_t __user *)arg);
	285	break;
	286
	287	case SNAPSHOT_GET_SWAP_PAGE:
	288	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	289	error = -ENODEV;
	290	break;
	291	}
d1d241cc	292	offset = alloc_swapdev_block(data->swap);
6e1819d6 RW	293	if (offset) {
6e1819d6 RW	294	offset <<= PAGE_SHIFT;
3aef83e0	295	error = put_user(offset, (sector_t __user *)arg);
6e1819d6 RW	296	} else {
	297	error = -ENOSPC;
	298	}
	299	break;
	300
	301	case SNAPSHOT_FREE_SWAP_PAGES:
	302	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	303	error = -ENODEV;
	304	break;
	305	}
d1d241cc	306	free_all_swap_pages(data->swap);
6e1819d6 RW	307	break;
	308
	309	case SNAPSHOT_SET_SWAP_FILE:
d1d241cc	310	if (!swsusp_swap_in_use()) {
6e1819d6 RW	311	/*
	312	* User space encodes device types as two-byte values,
	313	* so we need to recode them
	314	*/
	315	if (old_decode_dev(arg)) {
7bf23687 RW	316	data->swap = swap_type_of(old_decode_dev(arg),
7bf23687 RW	317	0, NULL);
6e1819d6 RW	318	if (data->swap < 0)
	319	error = -ENODEV;
	320	} else {
	321	data->swap = -1;
	322	error = -EINVAL;
	323	}
	324	} else {
	325	error = -EPERM;
	326	}
	327	break;
	328
9b238205	329	case SNAPSHOT_S2RAM:
2b5b09b3 RW	330	if (!pm_ops) {
	331	error = -ENOSYS;
	332	break;
	333	}
	334
9b238205 LT	335	if (!data->frozen) {
	336	error = -EPERM;
	337	break;
	338	}
	339
a6d70980	340	if (!mutex_trylock(&pm_mutex)) {
9b238205 LT	341	error = -EBUSY;
	342	break;
	343	}
	344
	345	if (pm_ops->prepare) {
	346	error = pm_ops->prepare(PM_SUSPEND_MEM);
	347	if (error)
	348	goto OutS3;
	349	}
	350
	351	/* Put devices to sleep */
97c7801c	352	suspend_console();
9b238205 LT	353	error = device_suspend(PMSG_SUSPEND);
	354	if (error) {
	355	printk(KERN_ERR "Failed to suspend some devices.\n");
	356	} else {
93c9a7ff RW	357	error = disable_nonboot_cpus();
	358	if (!error) {
	359	/* Enter S3, system is already frozen */
	360	suspend_enter(PM_SUSPEND_MEM);
	361	enable_nonboot_cpus();
	362	}
9b238205 LT	363	/* Wake up devices */
	364	device_resume();
	365	}
97c7801c	366	resume_console();
9b238205 LT	367	if (pm_ops->finish)
	368	pm_ops->finish(PM_SUSPEND_MEM);
	369
59a49335	370	OutS3:
a6d70980	371	mutex_unlock(&pm_mutex);
9b238205 LT	372	break;
9b238205 LT	373
3592695c	374	case SNAPSHOT_PMOPS:
2b5b09b3 RW	375	error = -EINVAL;
2b5b09b3 RW	376
3592695c SS	377	switch (arg) {
	378
	379	case PMOPS_PREPARE:
a3d25c27	380	if (hibernation_ops) {
2b5b09b3 RW	381	data->platform_suspend = 1;
	382	error = 0;
	383	} else {
	384	error = -ENOSYS;
3592695c SS	385	}
	386	break;
	387
	388	case PMOPS_ENTER:
2b5b09b3 RW	389	if (data->platform_suspend) {
2b5b09b3 RW	390	kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
a3d25c27	391	error = hibernation_ops->enter();
2b5b09b3	392	}
3592695c SS	393	break;
	394
	395	case PMOPS_FINISH:
2b5b09b3 RW	396	if (data->platform_suspend)
	397	error = 0;
	398
3592695c SS	399	break;
	400
	401	default:
	402	printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
3592695c SS	403
	404	}
	405	break;
	406
37b2ba12	407	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	408	if (swsusp_swap_in_use()) {
37b2ba12 RW	409	error = -EPERM;
	410	} else {
	411	struct resume_swap_area swap_area;
	412	dev_t swdev;
	413
	414	error = copy_from_user(&swap_area, (void __user *)arg,
	415	sizeof(struct resume_swap_area));
	416	if (error) {
	417	error = -EFAULT;
	418	break;
	419	}
	420
	421	/*
	422	* User space encodes device types as two-byte values,
	423	* so we need to recode them
	424	*/
	425	swdev = old_decode_dev(swap_area.dev);
	426	if (swdev) {
	427	offset = swap_area.offset;
7bf23687	428	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	429	if (data->swap < 0)
	430	error = -ENODEV;
	431	} else {
	432	data->swap = -1;
	433	error = -EINVAL;
	434	}
	435	}
	436	break;
	437
6e1819d6 RW	438	default:
	439	error = -ENOTTY;
	440
	441	}
	442
	443	return error;
	444	}
	445
15ad7cdc	446	static const struct file_operations snapshot_fops = {
6e1819d6 RW	447	.open = snapshot_open,
	448	.release = snapshot_release,
	449	.read = snapshot_read,
	450	.write = snapshot_write,
	451	.llseek = no_llseek,
	452	.ioctl = snapshot_ioctl,
	453	};
	454
	455	static struct miscdevice snapshot_device = {
	456	.minor = SNAPSHOT_MINOR,
	457	.name = "snapshot",
	458	.fops = &snapshot_fops,
	459	};
	460
	461	static int __init snapshot_device_init(void)
	462	{
	463	return misc_register(&snapshot_device);
	464	};
	465
	466	device_initcall(snapshot_device_init);