[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/kmod.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 <scsi/scsi_scan.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();
		scsi_complete_async_scans();

		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 = usermodehelper_disable();
		if (error)
			break;

		error = freeze_processes();
		if (error)
			usermodehelper_enable();
		else
			data->frozen = 1;
		break;

	case SNAPSHOT_UNFREEZE:
		if (!data->frozen || data->ready)
			break;
		pm_restore_gfp_mask();
		thaw_processes();
		usermodehelper_enable();
		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) {
			thaw_kernel_threads();
		} else {
			error = put_user(in_suspend, (int __user *)arg);
			if (!error && !freezer_test_done)
				data->ready = 1;
			if (freezer_test_done) {
				freezer_test_done = false;
				thaw_kernel_threads();
			}
		}
		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>
74da1ff7	15	#include <linux/kmod.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>
c7510859	28	#include <scsi/scsi_scan.h>
6e1819d6 RW	29
	30	#include <asm/uaccess.h>
	31
	32	#include "power.h"
	33
eb57c1cf	34
6e1819d6 RW	35	#define SNAPSHOT_MINOR 231
	36
	37	static struct snapshot_data {
	38	struct snapshot_handle handle;
	39	int swap;
6e1819d6 RW	40	int mode;
	41	char frozen;
	42	char ready;
eb57c1cf	43	char platform_support;
6e1819d6 RW	44	} snapshot_state;
6e1819d6 RW	45
0709db60	46	atomic_t snapshot_device_available = ATOMIC_INIT(1);
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();
	88	scsi_complete_async_scans();
	89
6e1819d6 RW	90	data->swap = -1;
6e1819d6 RW	91	data->mode = O_WRONLY;
ebae2604	92	error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
c3e94d89	93	if (error)
ebae2604	94	pm_notifier_call_chain(PM_POST_RESTORE);
c3e94d89	95	}
8440f4b1 MK	96	if (error) {
8440f4b1 MK	97	free_basic_memory_bitmaps();
c3e94d89	98	atomic_inc(&snapshot_device_available);
8440f4b1	99	}
6e1819d6 RW	100	data->frozen = 0;
6e1819d6 RW	101	data->ready = 0;
eb57c1cf	102	data->platform_support = 0;
6e1819d6	103
25f2f3da	104	Unlock:
bcda53fa	105	unlock_system_sleep();
25f2f3da RW	106
25f2f3da RW	107	return error;
6e1819d6 RW	108	}
	109
	110	static int snapshot_release(struct inode inode, struct file filp)
	111	{
	112	struct snapshot_data *data;
	113
bcda53fa	114	lock_system_sleep();
25f2f3da	115
6e1819d6	116	swsusp_free();
74dfd666	117	free_basic_memory_bitmaps();
6e1819d6	118	data = filp->private_data;
d1d241cc	119	free_all_swap_pages(data->swap);
9744997a RW	120	if (data->frozen) {
9744997a RW	121	pm_restore_gfp_mask();
6e1819d6	122	thaw_processes();
9744997a	123	}
1497dd1d	124	pm_notifier_call_chain(data->mode == O_RDONLY ?
c3e94d89	125	PM_POST_HIBERNATION : PM_POST_RESTORE);
0709db60	126	atomic_inc(&snapshot_device_available);
25f2f3da	127
bcda53fa	128	unlock_system_sleep();
25f2f3da	129
6e1819d6 RW	130	return 0;
	131	}
	132
	133	static ssize_t snapshot_read(struct file filp, char __user buf,
	134	size_t count, loff_t *offp)
	135	{
	136	struct snapshot_data *data;
	137	ssize_t res;
d3c1b24c	138	loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6	139
bcda53fa	140	lock_system_sleep();
25f2f3da	141
6e1819d6	142	data = filp->private_data;
25f2f3da RW	143	if (!data->ready) {
	144	res = -ENODATA;
	145	goto Unlock;
	146	}
d3c1b24c JS	147	if (!pg_offp) { /* on page boundary? */
	148	res = snapshot_read_next(&data->handle);
	149	if (res <= 0)
	150	goto Unlock;
	151	} else {
	152	res = PAGE_SIZE - pg_offp;
6e1819d6	153	}
25f2f3da	154
d3c1b24c JS	155	res = simple_read_from_buffer(buf, count, &pg_offp,
	156	data_of(data->handle), res);
	157	if (res > 0)
	158	*offp += res;
	159
25f2f3da	160	Unlock:
bcda53fa	161	unlock_system_sleep();
25f2f3da	162
6e1819d6 RW	163	return res;
	164	}
	165
	166	static ssize_t snapshot_write(struct file filp, const char __user buf,
	167	size_t count, loff_t *offp)
	168	{
	169	struct snapshot_data *data;
	170	ssize_t res;
d3c1b24c	171	loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6	172
bcda53fa	173	lock_system_sleep();
25f2f3da	174
6e1819d6	175	data = filp->private_data;
d3c1b24c JS	176
	177	if (!pg_offp) {
	178	res = snapshot_write_next(&data->handle);
	179	if (res <= 0)
	180	goto unlock;
	181	} else {
	182	res = PAGE_SIZE - pg_offp;
6e1819d6	183	}
25f2f3da	184
d3c1b24c JS	185	res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
	186	buf, count);
	187	if (res > 0)
	188	*offp += res;
	189	unlock:
bcda53fa	190	unlock_system_sleep();
25f2f3da	191
6e1819d6 RW	192	return res;
	193	}
	194
52d11025 AC	195	static long snapshot_ioctl(struct file *filp, unsigned int cmd,
52d11025 AC	196	unsigned long arg)
6e1819d6 RW	197	{
	198	int error = 0;
	199	struct snapshot_data *data;
af508b34	200	loff_t size;
3aef83e0	201	sector_t offset;
6e1819d6 RW	202
	203	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	204	return -ENOTTY;
	205	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	206	return -ENOTTY;
	207	if (!capable(CAP_SYS_ADMIN))
	208	return -EPERM;
	209
25f2f3da RW	210	if (!mutex_trylock(&pm_mutex))
25f2f3da RW	211	return -EBUSY;
6e1819d6	212
25f2f3da	213	data = filp->private_data;
52d11025	214
6e1819d6 RW	215	switch (cmd) {
	216
	217	case SNAPSHOT_FREEZE:
	218	if (data->frozen)
	219	break;
1bfcf130	220
c3e94d89 AS	221	printk("Syncing filesystems ... ");
	222	sys_sync();
	223	printk("done.\n");
	224
1bfcf130	225	error = usermodehelper_disable();
b10d9117	226	if (error)
1bfcf130 RW	227	break;
	228
	229	error = freeze_processes();
03afed8b	230	if (error)
1bfcf130	231	usermodehelper_enable();
e5b16746	232	else
6e1819d6 RW	233	data->frozen = 1;
	234	break;
	235
	236	case SNAPSHOT_UNFREEZE:
2f41dddb	237	if (!data->frozen \|\| data->ready)
6e1819d6	238	break;
c9e664f1	239	pm_restore_gfp_mask();
6e1819d6	240	thaw_processes();
1bfcf130	241	usermodehelper_enable();
6e1819d6 RW	242	data->frozen = 0;
	243	break;
	244
b694e52e	245	case SNAPSHOT_CREATE_IMAGE:
6e1819d6 RW	246	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	247	error = -EPERM;
	248	break;
	249	}
c9e664f1	250	pm_restore_gfp_mask();
eb57c1cf	251	error = hibernation_snapshot(data->platform_support);
fe9161db SB	252	if (error) {
	253	thaw_kernel_threads();
	254	} else {
cc5d207c	255	error = put_user(in_suspend, (int __user *)arg);
97819a26 SB	256	if (!error && !freezer_test_done)
	257	data->ready = 1;
	258	if (freezer_test_done) {
	259	freezer_test_done = false;
fe9161db	260	thaw_kernel_threads();
97819a26 SB	261	}
97819a26 SB	262	}
6e1819d6 RW	263	break;
	264
	265	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	266	snapshot_write_finalize(&data->handle);
6e1819d6 RW	267	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	268	!snapshot_image_loaded(&data->handle)) {
	269	error = -EPERM;
	270	break;
	271	}
eb57c1cf	272	error = hibernation_restore(data->platform_support);
6e1819d6 RW	273	break;
	274
	275	case SNAPSHOT_FREE:
	276	swsusp_free();
	277	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	278	data->ready = 0;
181e9bde RW	279	/*
	280	* It is necessary to thaw kernel threads here, because
	281	* SNAPSHOT_CREATE_IMAGE may be invoked directly after
	282	* SNAPSHOT_FREE. In that case, if kernel threads were not
	283	* thawed, the preallocation of memory carried out by
	284	* hibernation_snapshot() might run into problems (i.e. it
	285	* might fail or even deadlock).
	286	*/
	287	thaw_kernel_threads();
6e1819d6 RW	288	break;
6e1819d6 RW	289
b694e52e	290	case SNAPSHOT_PREF_IMAGE_SIZE:
6e1819d6 RW	291	image_size = arg;
	292	break;
	293
af508b34 RW	294	case SNAPSHOT_GET_IMAGE_SIZE:
	295	if (!data->ready) {
	296	error = -ENODATA;
	297	break;
	298	}
	299	size = snapshot_get_image_size();
	300	size <<= PAGE_SHIFT;
	301	error = put_user(size, (loff_t __user *)arg);
	302	break;
	303
b694e52e	304	case SNAPSHOT_AVAIL_SWAP_SIZE:
af508b34 RW	305	size = count_swap_pages(data->swap, 1);
	306	size <<= PAGE_SHIFT;
	307	error = put_user(size, (loff_t __user *)arg);
6e1819d6 RW	308	break;
6e1819d6 RW	309
b694e52e	310	case SNAPSHOT_ALLOC_SWAP_PAGE:
6e1819d6 RW	311	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	312	error = -ENODEV;
	313	break;
	314	}
d1d241cc	315	offset = alloc_swapdev_block(data->swap);
6e1819d6 RW	316	if (offset) {
6e1819d6 RW	317	offset <<= PAGE_SHIFT;
cc5d207c	318	error = put_user(offset, (loff_t __user *)arg);
6e1819d6 RW	319	} else {
	320	error = -ENOSPC;
	321	}
	322	break;
	323
	324	case SNAPSHOT_FREE_SWAP_PAGES:
	325	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	326	error = -ENODEV;
	327	break;
	328	}
d1d241cc	329	free_all_swap_pages(data->swap);
6e1819d6 RW	330	break;
6e1819d6 RW	331
9b238205 LT	332	case SNAPSHOT_S2RAM:
	333	if (!data->frozen) {
	334	error = -EPERM;
	335	break;
	336	}
6c961dfb RW	337	/*
	338	* Tasks are frozen and the notifiers have been called with
	339	* PM_HIBERNATION_PREPARE
	340	*/
	341	error = suspend_devices_and_enter(PM_SUSPEND_MEM);
36cb7035	342	data->ready = 0;
9b238205 LT	343	break;
9b238205 LT	344
eb57c1cf RW	345	case SNAPSHOT_PLATFORM_SUPPORT:
	346	data->platform_support = !!arg;
	347	break;
	348
	349	case SNAPSHOT_POWER_OFF:
	350	if (data->platform_support)
	351	error = hibernation_platform_enter();
	352	break;
	353
37b2ba12	354	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	355	if (swsusp_swap_in_use()) {
37b2ba12 RW	356	error = -EPERM;
	357	} else {
	358	struct resume_swap_area swap_area;
	359	dev_t swdev;
	360
	361	error = copy_from_user(&swap_area, (void __user *)arg,
	362	sizeof(struct resume_swap_area));
	363	if (error) {
	364	error = -EFAULT;
	365	break;
	366	}
	367
	368	/*
	369	* User space encodes device types as two-byte values,
	370	* so we need to recode them
	371	*/
d88d4050	372	swdev = new_decode_dev(swap_area.dev);
37b2ba12 RW	373	if (swdev) {
37b2ba12 RW	374	offset = swap_area.offset;
7bf23687	375	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	376	if (data->swap < 0)
	377	error = -ENODEV;
	378	} else {
	379	data->swap = -1;
	380	error = -EINVAL;
	381	}
	382	}
	383	break;
	384
6e1819d6 RW	385	default:
	386	error = -ENOTTY;
	387
	388	}
25f2f3da RW	389
	390	mutex_unlock(&pm_mutex);
	391
6e1819d6 RW	392	return error;
	393	}
	394
c336078b BH	395	#ifdef CONFIG_COMPAT
	396
	397	struct compat_resume_swap_area {
	398	compat_loff_t offset;
	399	u32 dev;
	400	} __packed;
	401
	402	static long
	403	snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	404	{
	405	BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
	406
	407	switch (cmd) {
	408	case SNAPSHOT_GET_IMAGE_SIZE:
	409	case SNAPSHOT_AVAIL_SWAP_SIZE:
	410	case SNAPSHOT_ALLOC_SWAP_PAGE: {
	411	compat_loff_t __user *uoffset = compat_ptr(arg);
	412	loff_t offset;
	413	mm_segment_t old_fs;
	414	int err;
	415
	416	old_fs = get_fs();
	417	set_fs(KERNEL_DS);
	418	err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
	419	set_fs(old_fs);
	420	if (!err && put_user(offset, uoffset))
	421	err = -EFAULT;
	422	return err;
	423	}
	424
	425	case SNAPSHOT_CREATE_IMAGE:
	426	return snapshot_ioctl(file, cmd,
	427	(unsigned long) compat_ptr(arg));
	428
	429	case SNAPSHOT_SET_SWAP_AREA: {
	430	struct compat_resume_swap_area __user *u_swap_area =
	431	compat_ptr(arg);
	432	struct resume_swap_area swap_area;
	433	mm_segment_t old_fs;
	434	int err;
	435
	436	err = get_user(swap_area.offset, &u_swap_area->offset);
	437	err \|= get_user(swap_area.dev, &u_swap_area->dev);
	438	if (err)
	439	return -EFAULT;
	440	old_fs = get_fs();
	441	set_fs(KERNEL_DS);
	442	err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
	443	(unsigned long) &swap_area);
	444	set_fs(old_fs);
	445	return err;
	446	}
	447
	448	default:
	449	return snapshot_ioctl(file, cmd, arg);
	450	}
	451	}
	452
	453	#endif /* CONFIG_COMPAT */
	454
15ad7cdc	455	static const struct file_operations snapshot_fops = {
6e1819d6 RW	456	.open = snapshot_open,
	457	.release = snapshot_release,
	458	.read = snapshot_read,
	459	.write = snapshot_write,
	460	.llseek = no_llseek,
52d11025	461	.unlocked_ioctl = snapshot_ioctl,
c336078b BH	462	#ifdef CONFIG_COMPAT
	463	.compat_ioctl = snapshot_compat_ioctl,
	464	#endif
6e1819d6 RW	465	};
	466
	467	static struct miscdevice snapshot_device = {
	468	.minor = SNAPSHOT_MINOR,
	469	.name = "snapshot",
	470	.fops = &snapshot_fops,
	471	};
	472
	473	static int __init snapshot_device_init(void)
	474	{
	475	return misc_register(&snapshot_device);
	476	};
	477
	478	device_initcall(snapshot_device_init);