[mirror_ubuntu-eoan-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/compat.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_support;
	bool free_bitmaps;
} 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;

	lock_system_sleep();

	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
		error = -EBUSY;
		goto Unlock;
	}

	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
		atomic_inc(&snapshot_device_available);
		error = -ENOSYS;
		goto Unlock;
	}
	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) {
		/* Hibernating.  The image device should be accessible. */
		data->swap = swsusp_resume_device ?
			swap_type_of(swsusp_resume_device, 0, NULL) : -1;
		data->mode = O_RDONLY;
		error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
		if (error)
			pm_notifier_call_chain(PM_POST_HIBERNATION);
	} else {
		/*
		 * Resuming.  We may need to wait for the image device to
		 * appear.
		 */
		wait_for_device_probe();

		data->swap = -1;
		data->mode = O_WRONLY;
		error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
		if (!error) {
			error = create_basic_memory_bitmaps();
			data->free_bitmaps = !error;
		}
		if (error)
			pm_notifier_call_chain(PM_POST_RESTORE);
	}
	if (error)
		atomic_inc(&snapshot_device_available);

	data->frozen = 0;
	data->ready = 0;
	data->platform_support = 0;

 Unlock:
	unlock_system_sleep();

	return error;
}

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

	lock_system_sleep();

	swsusp_free();
	data = filp->private_data;
	free_all_swap_pages(data->swap);
	if (data->frozen) {
		pm_restore_gfp_mask();
		free_basic_memory_bitmaps();
		thaw_processes();
	} else if (data->free_bitmaps) {
		free_basic_memory_bitmaps();
	}
	pm_notifier_call_chain(data->mode == O_RDONLY ?
			PM_POST_HIBERNATION : PM_POST_RESTORE);
	atomic_inc(&snapshot_device_available);

	unlock_system_sleep();

	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;
	loff_t pg_offp = *offp & ~PAGE_MASK;

	lock_system_sleep();

	data = filp->private_data;
	if (!data->ready) {
		res = -ENODATA;
		goto Unlock;
	}
	if (!pg_offp) { /* on page boundary? */
		res = snapshot_read_next(&data->handle);
		if (res <= 0)
			goto Unlock;
	} else {
		res = PAGE_SIZE - pg_offp;
	}

	res = simple_read_from_buffer(buf, count, &pg_offp,
			data_of(data->handle), res);
	if (res > 0)
		*offp += res;

 Unlock:
	unlock_system_sleep();

	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;
	loff_t pg_offp = *offp & ~PAGE_MASK;

	lock_system_sleep();

	data = filp->private_data;

	if (!pg_offp) {
		res = snapshot_write_next(&data->handle);
		if (res <= 0)
			goto unlock;
	} else {
		res = PAGE_SIZE - pg_offp;
	}

	res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
			buf, count);
	if (res > 0)
		*offp += res;
unlock:
	unlock_system_sleep();

	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;

	if (!mutex_trylock(&pm_mutex))
		return -EBUSY;

	lock_device_hotplug();
	data = filp->private_data;

	switch (cmd) {

	case SNAPSHOT_FREEZE:
		if (data->frozen)
			break;

		printk("Syncing filesystems ... ");
		sys_sync();
		printk("done.\n");

		error = freeze_processes();
		if (error)
			break;

		error = create_basic_memory_bitmaps();
		if (error)
			thaw_processes();
		else
			data->frozen = 1;

		break;

	case SNAPSHOT_UNFREEZE:
		if (!data->frozen || data->ready)
			break;
		pm_restore_gfp_mask();
		free_basic_memory_bitmaps();
		data->free_bitmaps = false;
		thaw_processes();
		data->frozen = 0;
		break;

	case SNAPSHOT_CREATE_IMAGE:
		if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
			error = -EPERM;
			break;
		}
		pm_restore_gfp_mask();
		error = hibernation_snapshot(data->platform_support);
		if (!error) {
			error = put_user(in_suspend, (int __user *)arg);
			data->ready = !freezer_test_done && !error;
			freezer_test_done = false;
		}
		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;
		/*
		 * It is necessary to thaw kernel threads here, because
		 * SNAPSHOT_CREATE_IMAGE may be invoked directly after
		 * SNAPSHOT_FREE.  In that case, if kernel threads were not
		 * thawed, the preallocation of memory carried out by
		 * hibernation_snapshot() might run into problems (i.e. it
		 * might fail or even deadlock).
		 */
		thaw_kernel_threads();
		break;

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

	case SNAPSHOT_ALLOC_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_S2RAM:
		if (!data->frozen) {
			error = -EPERM;
			break;
		}
		/*
		 * Tasks are frozen and the notifiers have been called with
		 * PM_HIBERNATION_PREPARE
		 */
		error = suspend_devices_and_enter(PM_SUSPEND_MEM);
		data->ready = 0;
		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_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 = new_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_device_hotplug();
	mutex_unlock(&pm_mutex);

	return error;
}

#ifdef CONFIG_COMPAT

struct compat_resume_swap_area {
	compat_loff_t offset;
	u32 dev;
} __packed;

static long
snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));

	switch (cmd) {
	case SNAPSHOT_GET_IMAGE_SIZE:
	case SNAPSHOT_AVAIL_SWAP_SIZE:
	case SNAPSHOT_ALLOC_SWAP_PAGE: {
		compat_loff_t __user *uoffset = compat_ptr(arg);
		loff_t offset;
		mm_segment_t old_fs;
		int err;

		old_fs = get_fs();
		set_fs(KERNEL_DS);
		err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
		set_fs(old_fs);
		if (!err && put_user(offset, uoffset))
			err = -EFAULT;
		return err;
	}

	case SNAPSHOT_CREATE_IMAGE:
		return snapshot_ioctl(file, cmd,
				      (unsigned long) compat_ptr(arg));

	case SNAPSHOT_SET_SWAP_AREA: {
		struct compat_resume_swap_area __user *u_swap_area =
			compat_ptr(arg);
		struct resume_swap_area swap_area;
		mm_segment_t old_fs;
		int err;

		err = get_user(swap_area.offset, &u_swap_area->offset);
		err |= get_user(swap_area.dev, &u_swap_area->dev);
		if (err)
			return -EFAULT;
		old_fs = get_fs();
		set_fs(KERNEL_DS);
		err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
				     (unsigned long) &swap_area);
		set_fs(old_fs);
		return err;
	}

	default:
		return snapshot_ioctl(file, cmd, arg);
	}
}

#endif /* CONFIG_COMPAT */

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,
#ifdef CONFIG_COMPAT
	.compat_ioctl = snapshot_compat_ioctl,
#endif
};

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>
c336078b	23	#include <linux/compat.h>
97c7801c	24	#include <linux/console.h>
e3920fb4	25	#include <linux/cpu.h>
7dfb7103	26	#include <linux/freezer.h>
6e1819d6 RW	27
	28	#include <asm/uaccess.h>
	29
	30	#include "power.h"
	31
eb57c1cf	32
6e1819d6 RW	33	#define SNAPSHOT_MINOR 231
	34
	35	static struct snapshot_data {
	36	struct snapshot_handle handle;
	37	int swap;
6e1819d6 RW	38	int mode;
	39	char frozen;
	40	char ready;
eb57c1cf	41	char platform_support;
aab17289	42	bool free_bitmaps;
6e1819d6 RW	43	} snapshot_state;
6e1819d6 RW	44
0709db60	45	atomic_t snapshot_device_available = ATOMIC_INIT(1);
6e1819d6 RW	46
	47	static int snapshot_open(struct inode inode, struct file filp)
	48	{
	49	struct snapshot_data *data;
c3e94d89	50	int error;
6e1819d6	51
bcda53fa	52	lock_system_sleep();
25f2f3da RW	53
	54	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
	55	error = -EBUSY;
	56	goto Unlock;
	57	}
6e1819d6	58
1525a2ad	59	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
0709db60	60	atomic_inc(&snapshot_device_available);
25f2f3da RW	61	error = -ENOSYS;
25f2f3da RW	62	goto Unlock;
1525a2ad	63	}
6e1819d6 RW	64	nonseekable_open(inode, filp);
	65	data = &snapshot_state;
	66	filp->private_data = data;
	67	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	68	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
c7510859	69	/* Hibernating. The image device should be accessible. */
915bae9e	70	data->swap = swsusp_resume_device ?
7bf23687	71	swap_type_of(swsusp_resume_device, 0, NULL) : -1;
6e1819d6	72	data->mode = O_RDONLY;
ebae2604	73	error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
c3e94d89	74	if (error)
ebae2604	75	pm_notifier_call_chain(PM_POST_HIBERNATION);
6e1819d6	76	} else {
c7510859 RW	77	/*
	78	* Resuming. We may need to wait for the image device to
	79	* appear.
	80	*/
	81	wait_for_device_probe();
c7510859	82
6e1819d6 RW	83	data->swap = -1;
6e1819d6 RW	84	data->mode = O_WRONLY;
ebae2604	85	error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
aab17289 RW	86	if (!error) {
	87	error = create_basic_memory_bitmaps();
	88	data->free_bitmaps = !error;
	89	}
c3e94d89	90	if (error)
ebae2604	91	pm_notifier_call_chain(PM_POST_RESTORE);
c3e94d89	92	}
8fd37a4c	93	if (error)
c3e94d89	94	atomic_inc(&snapshot_device_available);
8fd37a4c	95
6e1819d6 RW	96	data->frozen = 0;
6e1819d6 RW	97	data->ready = 0;
eb57c1cf	98	data->platform_support = 0;
6e1819d6	99
25f2f3da	100	Unlock:
bcda53fa	101	unlock_system_sleep();
25f2f3da RW	102
25f2f3da RW	103	return error;
6e1819d6 RW	104	}
	105
	106	static int snapshot_release(struct inode inode, struct file filp)
	107	{
	108	struct snapshot_data *data;
	109
bcda53fa	110	lock_system_sleep();
25f2f3da	111
6e1819d6 RW	112	swsusp_free();
6e1819d6 RW	113	data = filp->private_data;
d1d241cc	114	free_all_swap_pages(data->swap);
9744997a RW	115	if (data->frozen) {
9744997a RW	116	pm_restore_gfp_mask();
8fd37a4c	117	free_basic_memory_bitmaps();
6e1819d6	118	thaw_processes();
aab17289 RW	119	} else if (data->free_bitmaps) {
aab17289 RW	120	free_basic_memory_bitmaps();
9744997a	121	}
1497dd1d	122	pm_notifier_call_chain(data->mode == O_RDONLY ?
c3e94d89	123	PM_POST_HIBERNATION : PM_POST_RESTORE);
0709db60	124	atomic_inc(&snapshot_device_available);
25f2f3da	125
bcda53fa	126	unlock_system_sleep();
25f2f3da	127
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;
d3c1b24c	136	loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6	137
bcda53fa	138	lock_system_sleep();
25f2f3da	139
6e1819d6	140	data = filp->private_data;
25f2f3da RW	141	if (!data->ready) {
	142	res = -ENODATA;
	143	goto Unlock;
	144	}
d3c1b24c JS	145	if (!pg_offp) { /* on page boundary? */
	146	res = snapshot_read_next(&data->handle);
	147	if (res <= 0)
	148	goto Unlock;
	149	} else {
	150	res = PAGE_SIZE - pg_offp;
6e1819d6	151	}
25f2f3da	152
d3c1b24c JS	153	res = simple_read_from_buffer(buf, count, &pg_offp,
	154	data_of(data->handle), res);
	155	if (res > 0)
	156	*offp += res;
	157
25f2f3da	158	Unlock:
bcda53fa	159	unlock_system_sleep();
25f2f3da	160
6e1819d6 RW	161	return res;
	162	}
	163
	164	static ssize_t snapshot_write(struct file filp, const char __user buf,
	165	size_t count, loff_t *offp)
	166	{
	167	struct snapshot_data *data;
	168	ssize_t res;
d3c1b24c	169	loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6	170
bcda53fa	171	lock_system_sleep();
25f2f3da	172
6e1819d6	173	data = filp->private_data;
d3c1b24c JS	174
	175	if (!pg_offp) {
	176	res = snapshot_write_next(&data->handle);
	177	if (res <= 0)
	178	goto unlock;
	179	} else {
	180	res = PAGE_SIZE - pg_offp;
6e1819d6	181	}
25f2f3da	182
d3c1b24c JS	183	res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
	184	buf, count);
	185	if (res > 0)
	186	*offp += res;
	187	unlock:
bcda53fa	188	unlock_system_sleep();
25f2f3da	189
6e1819d6 RW	190	return res;
	191	}
	192
52d11025 AC	193	static long snapshot_ioctl(struct file *filp, unsigned int cmd,
52d11025 AC	194	unsigned long arg)
6e1819d6 RW	195	{
	196	int error = 0;
	197	struct snapshot_data *data;
af508b34	198	loff_t size;
3aef83e0	199	sector_t offset;
6e1819d6 RW	200
	201	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	202	return -ENOTTY;
	203	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	204	return -ENOTTY;
	205	if (!capable(CAP_SYS_ADMIN))
	206	return -EPERM;
	207
25f2f3da RW	208	if (!mutex_trylock(&pm_mutex))
25f2f3da RW	209	return -EBUSY;
6e1819d6	210
942f4015	211	lock_device_hotplug();
25f2f3da	212	data = filp->private_data;
52d11025	213
6e1819d6 RW	214	switch (cmd) {
	215
	216	case SNAPSHOT_FREEZE:
	217	if (data->frozen)
	218	break;
1bfcf130	219
c3e94d89 AS	220	printk("Syncing filesystems ... ");
	221	sys_sync();
	222	printk("done.\n");
	223
1bfcf130	224	error = freeze_processes();
8fd37a4c RW	225	if (error)
	226	break;
	227
	228	error = create_basic_memory_bitmaps();
	229	if (error)
	230	thaw_processes();
	231	else
6e1819d6	232	data->frozen = 1;
8fd37a4c	233
6e1819d6 RW	234	break;
	235
	236	case SNAPSHOT_UNFREEZE:
2f41dddb	237	if (!data->frozen \|\| data->ready)
6e1819d6	238	break;
c9e664f1	239	pm_restore_gfp_mask();
8fd37a4c	240	free_basic_memory_bitmaps();
aab17289	241	data->free_bitmaps = false;
6e1819d6	242	thaw_processes();
6e1819d6 RW	243	data->frozen = 0;
	244	break;
	245
b694e52e	246	case SNAPSHOT_CREATE_IMAGE:
6e1819d6 RW	247	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	248	error = -EPERM;
	249	break;
	250	}
c9e664f1	251	pm_restore_gfp_mask();
eb57c1cf	252	error = hibernation_snapshot(data->platform_support);
51d6ff7a	253	if (!error) {
cc5d207c	254	error = put_user(in_suspend, (int __user *)arg);
a556d5b5 SB	255	data->ready = !freezer_test_done && !error;
a556d5b5 SB	256	freezer_test_done = false;
97819a26	257	}
6e1819d6 RW	258	break;
	259
	260	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	261	snapshot_write_finalize(&data->handle);
6e1819d6 RW	262	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	263	!snapshot_image_loaded(&data->handle)) {
	264	error = -EPERM;
	265	break;
	266	}
eb57c1cf	267	error = hibernation_restore(data->platform_support);
6e1819d6 RW	268	break;
	269
	270	case SNAPSHOT_FREE:
	271	swsusp_free();
	272	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	273	data->ready = 0;
181e9bde RW	274	/*
	275	* It is necessary to thaw kernel threads here, because
	276	* SNAPSHOT_CREATE_IMAGE may be invoked directly after
	277	* SNAPSHOT_FREE. In that case, if kernel threads were not
	278	* thawed, the preallocation of memory carried out by
	279	* hibernation_snapshot() might run into problems (i.e. it
	280	* might fail or even deadlock).
	281	*/
	282	thaw_kernel_threads();
6e1819d6 RW	283	break;
6e1819d6 RW	284
b694e52e	285	case SNAPSHOT_PREF_IMAGE_SIZE:
6e1819d6 RW	286	image_size = arg;
	287	break;
	288
af508b34 RW	289	case SNAPSHOT_GET_IMAGE_SIZE:
	290	if (!data->ready) {
	291	error = -ENODATA;
	292	break;
	293	}
	294	size = snapshot_get_image_size();
	295	size <<= PAGE_SHIFT;
	296	error = put_user(size, (loff_t __user *)arg);
	297	break;
	298
b694e52e	299	case SNAPSHOT_AVAIL_SWAP_SIZE:
af508b34 RW	300	size = count_swap_pages(data->swap, 1);
	301	size <<= PAGE_SHIFT;
	302	error = put_user(size, (loff_t __user *)arg);
6e1819d6 RW	303	break;
6e1819d6 RW	304
b694e52e	305	case SNAPSHOT_ALLOC_SWAP_PAGE:
6e1819d6 RW	306	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	307	error = -ENODEV;
	308	break;
	309	}
d1d241cc	310	offset = alloc_swapdev_block(data->swap);
6e1819d6 RW	311	if (offset) {
6e1819d6 RW	312	offset <<= PAGE_SHIFT;
cc5d207c	313	error = put_user(offset, (loff_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	}
d1d241cc	324	free_all_swap_pages(data->swap);
6e1819d6 RW	325	break;
6e1819d6 RW	326
9b238205 LT	327	case SNAPSHOT_S2RAM:
	328	if (!data->frozen) {
	329	error = -EPERM;
	330	break;
	331	}
6c961dfb RW	332	/*
	333	* Tasks are frozen and the notifiers have been called with
	334	* PM_HIBERNATION_PREPARE
	335	*/
	336	error = suspend_devices_and_enter(PM_SUSPEND_MEM);
36cb7035	337	data->ready = 0;
9b238205 LT	338	break;
9b238205 LT	339
eb57c1cf RW	340	case SNAPSHOT_PLATFORM_SUPPORT:
	341	data->platform_support = !!arg;
	342	break;
	343
	344	case SNAPSHOT_POWER_OFF:
	345	if (data->platform_support)
	346	error = hibernation_platform_enter();
	347	break;
	348
37b2ba12	349	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	350	if (swsusp_swap_in_use()) {
37b2ba12 RW	351	error = -EPERM;
	352	} else {
	353	struct resume_swap_area swap_area;
	354	dev_t swdev;
	355
	356	error = copy_from_user(&swap_area, (void __user *)arg,
	357	sizeof(struct resume_swap_area));
	358	if (error) {
	359	error = -EFAULT;
	360	break;
	361	}
	362
	363	/*
	364	* User space encodes device types as two-byte values,
	365	* so we need to recode them
	366	*/
d88d4050	367	swdev = new_decode_dev(swap_area.dev);
37b2ba12 RW	368	if (swdev) {
37b2ba12 RW	369	offset = swap_area.offset;
7bf23687	370	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	371	if (data->swap < 0)
	372	error = -ENODEV;
	373	} else {
	374	data->swap = -1;
	375	error = -EINVAL;
	376	}
	377	}
	378	break;
	379
6e1819d6 RW	380	default:
	381	error = -ENOTTY;
	382
	383	}
25f2f3da	384
942f4015	385	unlock_device_hotplug();
25f2f3da RW	386	mutex_unlock(&pm_mutex);
25f2f3da RW	387
6e1819d6 RW	388	return error;
	389	}
	390
c336078b BH	391	#ifdef CONFIG_COMPAT
	392
	393	struct compat_resume_swap_area {
	394	compat_loff_t offset;
	395	u32 dev;
	396	} __packed;
	397
	398	static long
	399	snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	400	{
	401	BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
	402
	403	switch (cmd) {
	404	case SNAPSHOT_GET_IMAGE_SIZE:
	405	case SNAPSHOT_AVAIL_SWAP_SIZE:
	406	case SNAPSHOT_ALLOC_SWAP_PAGE: {
	407	compat_loff_t __user *uoffset = compat_ptr(arg);
	408	loff_t offset;
	409	mm_segment_t old_fs;
	410	int err;
	411
	412	old_fs = get_fs();
	413	set_fs(KERNEL_DS);
	414	err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
	415	set_fs(old_fs);
	416	if (!err && put_user(offset, uoffset))
	417	err = -EFAULT;
	418	return err;
	419	}
	420
	421	case SNAPSHOT_CREATE_IMAGE:
	422	return snapshot_ioctl(file, cmd,
	423	(unsigned long) compat_ptr(arg));
	424
	425	case SNAPSHOT_SET_SWAP_AREA: {
	426	struct compat_resume_swap_area __user *u_swap_area =
	427	compat_ptr(arg);
	428	struct resume_swap_area swap_area;
	429	mm_segment_t old_fs;
	430	int err;
	431
	432	err = get_user(swap_area.offset, &u_swap_area->offset);
	433	err \|= get_user(swap_area.dev, &u_swap_area->dev);
	434	if (err)
	435	return -EFAULT;
	436	old_fs = get_fs();
	437	set_fs(KERNEL_DS);
	438	err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
	439	(unsigned long) &swap_area);
	440	set_fs(old_fs);
	441	return err;
	442	}
	443
	444	default:
	445	return snapshot_ioctl(file, cmd, arg);
	446	}
	447	}
	448
	449	#endif /* CONFIG_COMPAT */
	450
15ad7cdc	451	static const struct file_operations snapshot_fops = {
6e1819d6 RW	452	.open = snapshot_open,
	453	.release = snapshot_release,
	454	.read = snapshot_read,
	455	.write = snapshot_write,
	456	.llseek = no_llseek,
52d11025	457	.unlocked_ioctl = snapshot_ioctl,
c336078b BH	458	#ifdef CONFIG_COMPAT
	459	.compat_ioctl = snapshot_compat_ioctl,
	460	#endif
6e1819d6 RW	461	};
	462
	463	static struct miscdevice snapshot_device = {
	464	.minor = SNAPSHOT_MINOR,
	465	.name = "snapshot",
	466	.fops = &snapshot_fops,
	467	};
	468
	469	static int __init snapshot_device_init(void)
	470	{
	471	return misc_register(&snapshot_device);
	472	};
	473
	474	device_initcall(snapshot_device_init);