[GitHub/mt8127/android_kernel_alcatel_ttab.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/export.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;
} snapshot_state;

atomic_t snapshot_device_available = ATOMIC_INIT(1);
EXPORT_SYMBOL_GPL(snapshot_device_available);

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;
	}
	if(create_basic_memory_bitmaps()) {
		atomic_inc(&snapshot_device_available);
		error = -ENOMEM;
		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)
			pm_notifier_call_chain(PM_POST_RESTORE);
	}
	if (error) {
		free_basic_memory_bitmaps();
		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();
	free_basic_memory_bitmaps();
	data = filp->private_data;
	free_all_swap_pages(data->swap);
	if (data->frozen) {
		pm_restore_gfp_mask();
		thaw_processes();
	}
	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;

	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)
			data->frozen = 1;
		break;

	case SNAPSHOT_UNFREEZE:
		if (!data->frozen || data->ready)
			break;
		pm_restore_gfp_mask();
		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;

	}

	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>
6fa3eb70	15	#include <linux/export.h>
6e1819d6 RW	16	#include <linux/string.h>
	17	#include <linux/device.h>
	18	#include <linux/miscdevice.h>
	19	#include <linux/mm.h>
	20	#include <linux/swap.h>
	21	#include <linux/swapops.h>
	22	#include <linux/pm.h>
	23	#include <linux/fs.h>
c336078b	24	#include <linux/compat.h>
97c7801c	25	#include <linux/console.h>
e3920fb4	26	#include <linux/cpu.h>
7dfb7103	27	#include <linux/freezer.h>
6e1819d6 RW	28
	29	#include <asm/uaccess.h>
	30
	31	#include "power.h"
	32
eb57c1cf	33
6e1819d6 RW	34	#define SNAPSHOT_MINOR 231
	35
	36	static struct snapshot_data {
	37	struct snapshot_handle handle;
	38	int swap;
6e1819d6 RW	39	int mode;
	40	char frozen;
	41	char ready;
eb57c1cf	42	char platform_support;
6e1819d6 RW	43	} snapshot_state;
6e1819d6 RW	44
0709db60	45	atomic_t snapshot_device_available = ATOMIC_INIT(1);
6fa3eb70	46	EXPORT_SYMBOL_GPL(snapshot_device_available);
6e1819d6 RW	47
	48	static int snapshot_open(struct inode inode, struct file filp)
	49	{
	50	struct snapshot_data *data;
c3e94d89	51	int error;
6e1819d6	52
bcda53fa	53	lock_system_sleep();
25f2f3da RW	54
	55	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
	56	error = -EBUSY;
	57	goto Unlock;
	58	}
6e1819d6	59
1525a2ad	60	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
0709db60	61	atomic_inc(&snapshot_device_available);
25f2f3da RW	62	error = -ENOSYS;
25f2f3da RW	63	goto Unlock;
1525a2ad RW	64	}
1525a2ad RW	65	if(create_basic_memory_bitmaps()) {
0709db60	66	atomic_inc(&snapshot_device_available);
25f2f3da RW	67	error = -ENOMEM;
25f2f3da RW	68	goto Unlock;
1525a2ad	69	}
6e1819d6 RW	70	nonseekable_open(inode, filp);
	71	data = &snapshot_state;
	72	filp->private_data = data;
	73	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	74	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
c7510859	75	/* Hibernating. The image device should be accessible. */
915bae9e	76	data->swap = swsusp_resume_device ?
7bf23687	77	swap_type_of(swsusp_resume_device, 0, NULL) : -1;
6e1819d6	78	data->mode = O_RDONLY;
ebae2604	79	error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
c3e94d89	80	if (error)
ebae2604	81	pm_notifier_call_chain(PM_POST_HIBERNATION);
6e1819d6	82	} else {
c7510859 RW	83	/*
	84	* Resuming. We may need to wait for the image device to
	85	* appear.
	86	*/
	87	wait_for_device_probe();
c7510859	88
6e1819d6 RW	89	data->swap = -1;
6e1819d6 RW	90	data->mode = O_WRONLY;
ebae2604	91	error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
c3e94d89	92	if (error)
ebae2604	93	pm_notifier_call_chain(PM_POST_RESTORE);
c3e94d89	94	}
8440f4b1 MK	95	if (error) {
8440f4b1 MK	96	free_basic_memory_bitmaps();
c3e94d89	97	atomic_inc(&snapshot_device_available);
8440f4b1	98	}
6e1819d6 RW	99	data->frozen = 0;
6e1819d6 RW	100	data->ready = 0;
eb57c1cf	101	data->platform_support = 0;
6e1819d6	102
25f2f3da	103	Unlock:
bcda53fa	104	unlock_system_sleep();
25f2f3da RW	105
25f2f3da RW	106	return error;
6e1819d6 RW	107	}
	108
	109	static int snapshot_release(struct inode inode, struct file filp)
	110	{
	111	struct snapshot_data *data;
	112
bcda53fa	113	lock_system_sleep();
25f2f3da	114
6e1819d6	115	swsusp_free();
74dfd666	116	free_basic_memory_bitmaps();
6e1819d6	117	data = filp->private_data;
d1d241cc	118	free_all_swap_pages(data->swap);
9744997a RW	119	if (data->frozen) {
9744997a RW	120	pm_restore_gfp_mask();
6e1819d6	121	thaw_processes();
9744997a	122	}
1497dd1d	123	pm_notifier_call_chain(data->mode == O_RDONLY ?
c3e94d89	124	PM_POST_HIBERNATION : PM_POST_RESTORE);
0709db60	125	atomic_inc(&snapshot_device_available);
25f2f3da	126
bcda53fa	127	unlock_system_sleep();
25f2f3da	128
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;
d3c1b24c	137	loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6	138
bcda53fa	139	lock_system_sleep();
25f2f3da	140
6e1819d6	141	data = filp->private_data;
25f2f3da RW	142	if (!data->ready) {
	143	res = -ENODATA;
	144	goto Unlock;
	145	}
d3c1b24c JS	146	if (!pg_offp) { /* on page boundary? */
	147	res = snapshot_read_next(&data->handle);
	148	if (res <= 0)
	149	goto Unlock;
	150	} else {
	151	res = PAGE_SIZE - pg_offp;
6e1819d6	152	}
25f2f3da	153
d3c1b24c JS	154	res = simple_read_from_buffer(buf, count, &pg_offp,
	155	data_of(data->handle), res);
	156	if (res > 0)
	157	*offp += res;
	158
25f2f3da	159	Unlock:
bcda53fa	160	unlock_system_sleep();
25f2f3da	161
6e1819d6 RW	162	return res;
	163	}
	164
	165	static ssize_t snapshot_write(struct file filp, const char __user buf,
	166	size_t count, loff_t *offp)
	167	{
	168	struct snapshot_data *data;
	169	ssize_t res;
d3c1b24c	170	loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6	171
bcda53fa	172	lock_system_sleep();
25f2f3da	173
6e1819d6	174	data = filp->private_data;
d3c1b24c JS	175
	176	if (!pg_offp) {
	177	res = snapshot_write_next(&data->handle);
	178	if (res <= 0)
	179	goto unlock;
	180	} else {
	181	res = PAGE_SIZE - pg_offp;
6e1819d6	182	}
25f2f3da	183
d3c1b24c JS	184	res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
	185	buf, count);
	186	if (res > 0)
	187	*offp += res;
	188	unlock:
bcda53fa	189	unlock_system_sleep();
25f2f3da	190
6e1819d6 RW	191	return res;
	192	}
	193
52d11025 AC	194	static long snapshot_ioctl(struct file *filp, unsigned int cmd,
52d11025 AC	195	unsigned long arg)
6e1819d6 RW	196	{
	197	int error = 0;
	198	struct snapshot_data *data;
af508b34	199	loff_t size;
3aef83e0	200	sector_t offset;
6e1819d6 RW	201
	202	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	203	return -ENOTTY;
	204	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	205	return -ENOTTY;
	206	if (!capable(CAP_SYS_ADMIN))
	207	return -EPERM;
	208
25f2f3da RW	209	if (!mutex_trylock(&pm_mutex))
25f2f3da RW	210	return -EBUSY;
6e1819d6	211
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();
1e73203c	225	if (!error)
6e1819d6 RW	226	data->frozen = 1;
	227	break;
	228
	229	case SNAPSHOT_UNFREEZE:
2f41dddb	230	if (!data->frozen \|\| data->ready)
6e1819d6	231	break;
c9e664f1	232	pm_restore_gfp_mask();
6e1819d6	233	thaw_processes();
6e1819d6 RW	234	data->frozen = 0;
	235	break;
	236
b694e52e	237	case SNAPSHOT_CREATE_IMAGE:
6e1819d6 RW	238	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	239	error = -EPERM;
	240	break;
	241	}
c9e664f1	242	pm_restore_gfp_mask();
eb57c1cf	243	error = hibernation_snapshot(data->platform_support);
51d6ff7a	244	if (!error) {
cc5d207c	245	error = put_user(in_suspend, (int __user *)arg);
a556d5b5 SB	246	data->ready = !freezer_test_done && !error;
a556d5b5 SB	247	freezer_test_done = false;
97819a26	248	}
6e1819d6 RW	249	break;
	250
	251	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	252	snapshot_write_finalize(&data->handle);
6e1819d6 RW	253	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	254	!snapshot_image_loaded(&data->handle)) {
	255	error = -EPERM;
	256	break;
	257	}
eb57c1cf	258	error = hibernation_restore(data->platform_support);
6e1819d6 RW	259	break;
	260
	261	case SNAPSHOT_FREE:
	262	swsusp_free();
	263	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	264	data->ready = 0;
181e9bde RW	265	/*
	266	* It is necessary to thaw kernel threads here, because
	267	* SNAPSHOT_CREATE_IMAGE may be invoked directly after
	268	* SNAPSHOT_FREE. In that case, if kernel threads were not
	269	* thawed, the preallocation of memory carried out by
	270	* hibernation_snapshot() might run into problems (i.e. it
	271	* might fail or even deadlock).
	272	*/
	273	thaw_kernel_threads();
6e1819d6 RW	274	break;
6e1819d6 RW	275
b694e52e	276	case SNAPSHOT_PREF_IMAGE_SIZE:
6e1819d6 RW	277	image_size = arg;
	278	break;
	279
af508b34 RW	280	case SNAPSHOT_GET_IMAGE_SIZE:
	281	if (!data->ready) {
	282	error = -ENODATA;
	283	break;
	284	}
	285	size = snapshot_get_image_size();
	286	size <<= PAGE_SHIFT;
	287	error = put_user(size, (loff_t __user *)arg);
	288	break;
	289
b694e52e	290	case SNAPSHOT_AVAIL_SWAP_SIZE:
af508b34 RW	291	size = count_swap_pages(data->swap, 1);
	292	size <<= PAGE_SHIFT;
	293	error = put_user(size, (loff_t __user *)arg);
6e1819d6 RW	294	break;
6e1819d6 RW	295
b694e52e	296	case SNAPSHOT_ALLOC_SWAP_PAGE:
6e1819d6 RW	297	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	298	error = -ENODEV;
	299	break;
	300	}
d1d241cc	301	offset = alloc_swapdev_block(data->swap);
6e1819d6 RW	302	if (offset) {
6e1819d6 RW	303	offset <<= PAGE_SHIFT;
cc5d207c	304	error = put_user(offset, (loff_t __user *)arg);
6e1819d6 RW	305	} else {
	306	error = -ENOSPC;
	307	}
	308	break;
	309
	310	case SNAPSHOT_FREE_SWAP_PAGES:
	311	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	312	error = -ENODEV;
	313	break;
	314	}
d1d241cc	315	free_all_swap_pages(data->swap);
6e1819d6 RW	316	break;
6e1819d6 RW	317
9b238205 LT	318	case SNAPSHOT_S2RAM:
	319	if (!data->frozen) {
	320	error = -EPERM;
	321	break;
	322	}
6c961dfb RW	323	/*
	324	* Tasks are frozen and the notifiers have been called with
	325	* PM_HIBERNATION_PREPARE
	326	*/
	327	error = suspend_devices_and_enter(PM_SUSPEND_MEM);
36cb7035	328	data->ready = 0;
9b238205 LT	329	break;
9b238205 LT	330
eb57c1cf RW	331	case SNAPSHOT_PLATFORM_SUPPORT:
	332	data->platform_support = !!arg;
	333	break;
	334
	335	case SNAPSHOT_POWER_OFF:
	336	if (data->platform_support)
	337	error = hibernation_platform_enter();
	338	break;
	339
37b2ba12	340	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	341	if (swsusp_swap_in_use()) {
37b2ba12 RW	342	error = -EPERM;
	343	} else {
	344	struct resume_swap_area swap_area;
	345	dev_t swdev;
	346
	347	error = copy_from_user(&swap_area, (void __user *)arg,
	348	sizeof(struct resume_swap_area));
	349	if (error) {
	350	error = -EFAULT;
	351	break;
	352	}
	353
	354	/*
	355	* User space encodes device types as two-byte values,
	356	* so we need to recode them
	357	*/
d88d4050	358	swdev = new_decode_dev(swap_area.dev);
37b2ba12 RW	359	if (swdev) {
37b2ba12 RW	360	offset = swap_area.offset;
7bf23687	361	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	362	if (data->swap < 0)
	363	error = -ENODEV;
	364	} else {
	365	data->swap = -1;
	366	error = -EINVAL;
	367	}
	368	}
	369	break;
	370
6e1819d6 RW	371	default:
	372	error = -ENOTTY;
	373
	374	}
25f2f3da RW	375
	376	mutex_unlock(&pm_mutex);
	377
6e1819d6 RW	378	return error;
	379	}
	380
c336078b BH	381	#ifdef CONFIG_COMPAT
	382
	383	struct compat_resume_swap_area {
	384	compat_loff_t offset;
	385	u32 dev;
	386	} __packed;
	387
	388	static long
	389	snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	390	{
	391	BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
	392
	393	switch (cmd) {
	394	case SNAPSHOT_GET_IMAGE_SIZE:
	395	case SNAPSHOT_AVAIL_SWAP_SIZE:
	396	case SNAPSHOT_ALLOC_SWAP_PAGE: {
	397	compat_loff_t __user *uoffset = compat_ptr(arg);
	398	loff_t offset;
	399	mm_segment_t old_fs;
	400	int err;
	401
	402	old_fs = get_fs();
	403	set_fs(KERNEL_DS);
	404	err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
	405	set_fs(old_fs);
	406	if (!err && put_user(offset, uoffset))
	407	err = -EFAULT;
	408	return err;
	409	}
	410
	411	case SNAPSHOT_CREATE_IMAGE:
	412	return snapshot_ioctl(file, cmd,
	413	(unsigned long) compat_ptr(arg));
	414
	415	case SNAPSHOT_SET_SWAP_AREA: {
	416	struct compat_resume_swap_area __user *u_swap_area =
	417	compat_ptr(arg);
	418	struct resume_swap_area swap_area;
	419	mm_segment_t old_fs;
	420	int err;
	421
	422	err = get_user(swap_area.offset, &u_swap_area->offset);
	423	err \|= get_user(swap_area.dev, &u_swap_area->dev);
	424	if (err)
	425	return -EFAULT;
	426	old_fs = get_fs();
	427	set_fs(KERNEL_DS);
	428	err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
	429	(unsigned long) &swap_area);
	430	set_fs(old_fs);
	431	return err;
	432	}
	433
	434	default:
	435	return snapshot_ioctl(file, cmd, arg);
	436	}
	437	}
	438
	439	#endif /* CONFIG_COMPAT */
	440
15ad7cdc	441	static const struct file_operations snapshot_fops = {
6e1819d6 RW	442	.open = snapshot_open,
	443	.release = snapshot_release,
	444	.read = snapshot_read,
	445	.write = snapshot_write,
	446	.llseek = no_llseek,
52d11025	447	.unlocked_ioctl = snapshot_ioctl,
c336078b BH	448	#ifdef CONFIG_COMPAT
	449	.compat_ioctl = snapshot_compat_ioctl,
	450	#endif
6e1819d6 RW	451	};
	452
	453	static struct miscdevice snapshot_device = {
	454	.minor = SNAPSHOT_MINOR,
	455	.name = "snapshot",
	456	.fops = &snapshot_fops,
	457	};
	458
	459	static int __init snapshot_device_init(void)
	460	{
	461	return misc_register(&snapshot_device);
	462	};
	463
	464	device_initcall(snapshot_device_init);