[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/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);

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>
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;
6e1819d6 RW	42	} snapshot_state;
6e1819d6 RW	43
0709db60	44	atomic_t snapshot_device_available = ATOMIC_INIT(1);
6e1819d6 RW	45
	46	static int snapshot_open(struct inode inode, struct file filp)
	47	{
	48	struct snapshot_data *data;
c3e94d89	49	int error;
6e1819d6	50
bcda53fa	51	lock_system_sleep();
25f2f3da RW	52
	53	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
	54	error = -EBUSY;
	55	goto Unlock;
	56	}
6e1819d6	57
1525a2ad	58	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
0709db60	59	atomic_inc(&snapshot_device_available);
25f2f3da RW	60	error = -ENOSYS;
25f2f3da RW	61	goto Unlock;
1525a2ad RW	62	}
1525a2ad RW	63	if(create_basic_memory_bitmaps()) {
0709db60	64	atomic_inc(&snapshot_device_available);
25f2f3da RW	65	error = -ENOMEM;
25f2f3da RW	66	goto Unlock;
1525a2ad	67	}
6e1819d6 RW	68	nonseekable_open(inode, filp);
	69	data = &snapshot_state;
	70	filp->private_data = data;
	71	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	72	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
c7510859	73	/* Hibernating. The image device should be accessible. */
915bae9e	74	data->swap = swsusp_resume_device ?
7bf23687	75	swap_type_of(swsusp_resume_device, 0, NULL) : -1;
6e1819d6	76	data->mode = O_RDONLY;
ebae2604	77	error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
c3e94d89	78	if (error)
ebae2604	79	pm_notifier_call_chain(PM_POST_HIBERNATION);
6e1819d6	80	} else {
c7510859 RW	81	/*
	82	* Resuming. We may need to wait for the image device to
	83	* appear.
	84	*/
	85	wait_for_device_probe();
c7510859	86
6e1819d6 RW	87	data->swap = -1;
6e1819d6 RW	88	data->mode = O_WRONLY;
ebae2604	89	error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
c3e94d89	90	if (error)
ebae2604	91	pm_notifier_call_chain(PM_POST_RESTORE);
c3e94d89	92	}
8440f4b1 MK	93	if (error) {
8440f4b1 MK	94	free_basic_memory_bitmaps();
c3e94d89	95	atomic_inc(&snapshot_device_available);
8440f4b1	96	}
6e1819d6 RW	97	data->frozen = 0;
6e1819d6 RW	98	data->ready = 0;
eb57c1cf	99	data->platform_support = 0;
6e1819d6	100
25f2f3da	101	Unlock:
bcda53fa	102	unlock_system_sleep();
25f2f3da RW	103
25f2f3da RW	104	return error;
6e1819d6 RW	105	}
	106
	107	static int snapshot_release(struct inode inode, struct file filp)
	108	{
	109	struct snapshot_data *data;
	110
bcda53fa	111	lock_system_sleep();
25f2f3da	112
6e1819d6	113	swsusp_free();
74dfd666	114	free_basic_memory_bitmaps();
6e1819d6	115	data = filp->private_data;
d1d241cc	116	free_all_swap_pages(data->swap);
9744997a RW	117	if (data->frozen) {
9744997a RW	118	pm_restore_gfp_mask();
6e1819d6	119	thaw_processes();
9744997a	120	}
1497dd1d	121	pm_notifier_call_chain(data->mode == O_RDONLY ?
c3e94d89	122	PM_POST_HIBERNATION : PM_POST_RESTORE);
0709db60	123	atomic_inc(&snapshot_device_available);
25f2f3da	124
bcda53fa	125	unlock_system_sleep();
25f2f3da	126
6e1819d6 RW	127	return 0;
	128	}
	129
	130	static ssize_t snapshot_read(struct file filp, char __user buf,
	131	size_t count, loff_t *offp)
	132	{
	133	struct snapshot_data *data;
	134	ssize_t res;
d3c1b24c	135	loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6	136
bcda53fa	137	lock_system_sleep();
25f2f3da	138
6e1819d6	139	data = filp->private_data;
25f2f3da RW	140	if (!data->ready) {
	141	res = -ENODATA;
	142	goto Unlock;
	143	}
d3c1b24c JS	144	if (!pg_offp) { /* on page boundary? */
	145	res = snapshot_read_next(&data->handle);
	146	if (res <= 0)
	147	goto Unlock;
	148	} else {
	149	res = PAGE_SIZE - pg_offp;
6e1819d6	150	}
25f2f3da	151
d3c1b24c JS	152	res = simple_read_from_buffer(buf, count, &pg_offp,
	153	data_of(data->handle), res);
	154	if (res > 0)
	155	*offp += res;
	156
25f2f3da	157	Unlock:
bcda53fa	158	unlock_system_sleep();
25f2f3da	159
6e1819d6 RW	160	return res;
	161	}
	162
	163	static ssize_t snapshot_write(struct file filp, const char __user buf,
	164	size_t count, loff_t *offp)
	165	{
	166	struct snapshot_data *data;
	167	ssize_t res;
d3c1b24c	168	loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6	169
bcda53fa	170	lock_system_sleep();
25f2f3da	171
6e1819d6	172	data = filp->private_data;
d3c1b24c JS	173
	174	if (!pg_offp) {
	175	res = snapshot_write_next(&data->handle);
	176	if (res <= 0)
	177	goto unlock;
	178	} else {
	179	res = PAGE_SIZE - pg_offp;
6e1819d6	180	}
25f2f3da	181
d3c1b24c JS	182	res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
	183	buf, count);
	184	if (res > 0)
	185	*offp += res;
	186	unlock:
bcda53fa	187	unlock_system_sleep();
25f2f3da	188
6e1819d6 RW	189	return res;
	190	}
	191
52d11025 AC	192	static long snapshot_ioctl(struct file *filp, unsigned int cmd,
52d11025 AC	193	unsigned long arg)
6e1819d6 RW	194	{
	195	int error = 0;
	196	struct snapshot_data *data;
af508b34	197	loff_t size;
3aef83e0	198	sector_t offset;
6e1819d6 RW	199
	200	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	201	return -ENOTTY;
	202	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	203	return -ENOTTY;
	204	if (!capable(CAP_SYS_ADMIN))
	205	return -EPERM;
	206
25f2f3da RW	207	if (!mutex_trylock(&pm_mutex))
25f2f3da RW	208	return -EBUSY;
6e1819d6	209
25f2f3da	210	data = filp->private_data;
52d11025	211
6e1819d6 RW	212	switch (cmd) {
	213
	214	case SNAPSHOT_FREEZE:
	215	if (data->frozen)
	216	break;
1bfcf130	217
c3e94d89 AS	218	printk("Syncing filesystems ... ");
	219	sys_sync();
	220	printk("done.\n");
	221
1bfcf130	222	error = freeze_processes();
1e73203c	223	if (!error)
6e1819d6 RW	224	data->frozen = 1;
	225	break;
	226
	227	case SNAPSHOT_UNFREEZE:
2f41dddb	228	if (!data->frozen \|\| data->ready)
6e1819d6	229	break;
c9e664f1	230	pm_restore_gfp_mask();
6e1819d6	231	thaw_processes();
6e1819d6 RW	232	data->frozen = 0;
	233	break;
	234
b694e52e	235	case SNAPSHOT_CREATE_IMAGE:
6e1819d6 RW	236	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	237	error = -EPERM;
	238	break;
	239	}
c9e664f1	240	pm_restore_gfp_mask();
eb57c1cf	241	error = hibernation_snapshot(data->platform_support);
51d6ff7a	242	if (!error) {
cc5d207c	243	error = put_user(in_suspend, (int __user *)arg);
a556d5b5 SB	244	data->ready = !freezer_test_done && !error;
a556d5b5 SB	245	freezer_test_done = false;
97819a26	246	}
6e1819d6 RW	247	break;
	248
	249	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	250	snapshot_write_finalize(&data->handle);
6e1819d6 RW	251	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	252	!snapshot_image_loaded(&data->handle)) {
	253	error = -EPERM;
	254	break;
	255	}
eb57c1cf	256	error = hibernation_restore(data->platform_support);
6e1819d6 RW	257	break;
	258
	259	case SNAPSHOT_FREE:
	260	swsusp_free();
	261	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	262	data->ready = 0;
181e9bde RW	263	/*
	264	* It is necessary to thaw kernel threads here, because
	265	* SNAPSHOT_CREATE_IMAGE may be invoked directly after
	266	* SNAPSHOT_FREE. In that case, if kernel threads were not
	267	* thawed, the preallocation of memory carried out by
	268	* hibernation_snapshot() might run into problems (i.e. it
	269	* might fail or even deadlock).
	270	*/
	271	thaw_kernel_threads();
6e1819d6 RW	272	break;
6e1819d6 RW	273
b694e52e	274	case SNAPSHOT_PREF_IMAGE_SIZE:
6e1819d6 RW	275	image_size = arg;
	276	break;
	277
af508b34 RW	278	case SNAPSHOT_GET_IMAGE_SIZE:
	279	if (!data->ready) {
	280	error = -ENODATA;
	281	break;
	282	}
	283	size = snapshot_get_image_size();
	284	size <<= PAGE_SHIFT;
	285	error = put_user(size, (loff_t __user *)arg);
	286	break;
	287
b694e52e	288	case SNAPSHOT_AVAIL_SWAP_SIZE:
af508b34 RW	289	size = count_swap_pages(data->swap, 1);
	290	size <<= PAGE_SHIFT;
	291	error = put_user(size, (loff_t __user *)arg);
6e1819d6 RW	292	break;
6e1819d6 RW	293
b694e52e	294	case SNAPSHOT_ALLOC_SWAP_PAGE:
6e1819d6 RW	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;
cc5d207c	302	error = put_user(offset, (loff_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;
6e1819d6 RW	315
9b238205 LT	316	case SNAPSHOT_S2RAM:
	317	if (!data->frozen) {
	318	error = -EPERM;
	319	break;
	320	}
6c961dfb RW	321	/*
	322	* Tasks are frozen and the notifiers have been called with
	323	* PM_HIBERNATION_PREPARE
	324	*/
	325	error = suspend_devices_and_enter(PM_SUSPEND_MEM);
36cb7035	326	data->ready = 0;
9b238205 LT	327	break;
9b238205 LT	328
eb57c1cf RW	329	case SNAPSHOT_PLATFORM_SUPPORT:
	330	data->platform_support = !!arg;
	331	break;
	332
	333	case SNAPSHOT_POWER_OFF:
	334	if (data->platform_support)
	335	error = hibernation_platform_enter();
	336	break;
	337
37b2ba12	338	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	339	if (swsusp_swap_in_use()) {
37b2ba12 RW	340	error = -EPERM;
	341	} else {
	342	struct resume_swap_area swap_area;
	343	dev_t swdev;
	344
	345	error = copy_from_user(&swap_area, (void __user *)arg,
	346	sizeof(struct resume_swap_area));
	347	if (error) {
	348	error = -EFAULT;
	349	break;
	350	}
	351
	352	/*
	353	* User space encodes device types as two-byte values,
	354	* so we need to recode them
	355	*/
d88d4050	356	swdev = new_decode_dev(swap_area.dev);
37b2ba12 RW	357	if (swdev) {
37b2ba12 RW	358	offset = swap_area.offset;
7bf23687	359	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	360	if (data->swap < 0)
	361	error = -ENODEV;
	362	} else {
	363	data->swap = -1;
	364	error = -EINVAL;
	365	}
	366	}
	367	break;
	368
6e1819d6 RW	369	default:
	370	error = -ENOTTY;
	371
	372	}
25f2f3da RW	373
	374	mutex_unlock(&pm_mutex);
	375
6e1819d6 RW	376	return error;
	377	}
	378
c336078b BH	379	#ifdef CONFIG_COMPAT
	380
	381	struct compat_resume_swap_area {
	382	compat_loff_t offset;
	383	u32 dev;
	384	} __packed;
	385
	386	static long
	387	snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	388	{
	389	BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
	390
	391	switch (cmd) {
	392	case SNAPSHOT_GET_IMAGE_SIZE:
	393	case SNAPSHOT_AVAIL_SWAP_SIZE:
	394	case SNAPSHOT_ALLOC_SWAP_PAGE: {
	395	compat_loff_t __user *uoffset = compat_ptr(arg);
	396	loff_t offset;
	397	mm_segment_t old_fs;
	398	int err;
	399
	400	old_fs = get_fs();
	401	set_fs(KERNEL_DS);
	402	err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
	403	set_fs(old_fs);
	404	if (!err && put_user(offset, uoffset))
	405	err = -EFAULT;
	406	return err;
	407	}
	408
	409	case SNAPSHOT_CREATE_IMAGE:
	410	return snapshot_ioctl(file, cmd,
	411	(unsigned long) compat_ptr(arg));
	412
	413	case SNAPSHOT_SET_SWAP_AREA: {
	414	struct compat_resume_swap_area __user *u_swap_area =
	415	compat_ptr(arg);
	416	struct resume_swap_area swap_area;
	417	mm_segment_t old_fs;
	418	int err;
	419
	420	err = get_user(swap_area.offset, &u_swap_area->offset);
	421	err \|= get_user(swap_area.dev, &u_swap_area->dev);
	422	if (err)
	423	return -EFAULT;
	424	old_fs = get_fs();
	425	set_fs(KERNEL_DS);
	426	err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
	427	(unsigned long) &swap_area);
	428	set_fs(old_fs);
	429	return err;
	430	}
	431
	432	default:
	433	return snapshot_ioctl(file, cmd, arg);
	434	}
	435	}
	436
	437	#endif /* CONFIG_COMPAT */
	438
15ad7cdc	439	static const struct file_operations snapshot_fops = {
6e1819d6 RW	440	.open = snapshot_open,
	441	.release = snapshot_release,
	442	.read = snapshot_read,
	443	.write = snapshot_write,
	444	.llseek = no_llseek,
52d11025	445	.unlocked_ioctl = snapshot_ioctl,
c336078b BH	446	#ifdef CONFIG_COMPAT
	447	.compat_ioctl = snapshot_compat_ioctl,
	448	#endif
6e1819d6 RW	449	};
	450
	451	static struct miscdevice snapshot_device = {
	452	.minor = SNAPSHOT_MINOR,
	453	.name = "snapshot",
	454	.fops = &snapshot_fops,
	455	};
	456
	457	static int __init snapshot_device_init(void)
	458	{
	459	return misc_register(&snapshot_device);
	460	};
	461
	462	device_initcall(snapshot_device_init);