[deliverable/linux.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;
	bool frozen;
	bool ready;
	bool 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;
		data->free_bitmaps = false;
		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 = false;
	data->ready = false;
	data->platform_support = false;

 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 = true;

		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 = false;
		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 = false;
		/*
		 * 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 = false;
		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	38	int mode;
7bc9b1cf RW	39	bool frozen;
	40	bool ready;
	41	bool 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;
6a0c7cd3	73	data->free_bitmaps = false;
ebae2604	74	error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
c3e94d89	75	if (error)
ebae2604	76	pm_notifier_call_chain(PM_POST_HIBERNATION);
6e1819d6	77	} else {
c7510859 RW	78	/*
	79	* Resuming. We may need to wait for the image device to
	80	* appear.
	81	*/
	82	wait_for_device_probe();
c7510859	83
6e1819d6 RW	84	data->swap = -1;
6e1819d6 RW	85	data->mode = O_WRONLY;
ebae2604	86	error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
aab17289 RW	87	if (!error) {
	88	error = create_basic_memory_bitmaps();
	89	data->free_bitmaps = !error;
	90	}
c3e94d89	91	if (error)
ebae2604	92	pm_notifier_call_chain(PM_POST_RESTORE);
c3e94d89	93	}
8fd37a4c	94	if (error)
c3e94d89	95	atomic_inc(&snapshot_device_available);
8fd37a4c	96
7bc9b1cf RW	97	data->frozen = false;
	98	data->ready = false;
	99	data->platform_support = false;
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 RW	113	swsusp_free();
6e1819d6 RW	114	data = filp->private_data;
d1d241cc	115	free_all_swap_pages(data->swap);
9744997a RW	116	if (data->frozen) {
9744997a RW	117	pm_restore_gfp_mask();
8fd37a4c	118	free_basic_memory_bitmaps();
6e1819d6	119	thaw_processes();
aab17289 RW	120	} else if (data->free_bitmaps) {
aab17289 RW	121	free_basic_memory_bitmaps();
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
942f4015	212	lock_device_hotplug();
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 = freeze_processes();
8fd37a4c RW	226	if (error)
	227	break;
	228
	229	error = create_basic_memory_bitmaps();
	230	if (error)
	231	thaw_processes();
	232	else
7bc9b1cf	233	data->frozen = true;
8fd37a4c	234
6e1819d6 RW	235	break;
	236
	237	case SNAPSHOT_UNFREEZE:
2f41dddb	238	if (!data->frozen \|\| data->ready)
6e1819d6	239	break;
c9e664f1	240	pm_restore_gfp_mask();
8fd37a4c	241	free_basic_memory_bitmaps();
aab17289	242	data->free_bitmaps = false;
6e1819d6	243	thaw_processes();
7bc9b1cf	244	data->frozen = false;
6e1819d6 RW	245	break;
6e1819d6 RW	246
b694e52e	247	case SNAPSHOT_CREATE_IMAGE:
6e1819d6 RW	248	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	249	error = -EPERM;
	250	break;
	251	}
c9e664f1	252	pm_restore_gfp_mask();
eb57c1cf	253	error = hibernation_snapshot(data->platform_support);
51d6ff7a	254	if (!error) {
cc5d207c	255	error = put_user(in_suspend, (int __user *)arg);
a556d5b5 SB	256	data->ready = !freezer_test_done && !error;
a556d5b5 SB	257	freezer_test_done = false;
97819a26	258	}
6e1819d6 RW	259	break;
	260
	261	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	262	snapshot_write_finalize(&data->handle);
6e1819d6 RW	263	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	264	!snapshot_image_loaded(&data->handle)) {
	265	error = -EPERM;
	266	break;
	267	}
eb57c1cf	268	error = hibernation_restore(data->platform_support);
6e1819d6 RW	269	break;
	270
	271	case SNAPSHOT_FREE:
	272	swsusp_free();
	273	memset(&data->handle, 0, sizeof(struct snapshot_handle));
7bc9b1cf	274	data->ready = false;
181e9bde RW	275	/*
	276	* It is necessary to thaw kernel threads here, because
	277	* SNAPSHOT_CREATE_IMAGE may be invoked directly after
	278	* SNAPSHOT_FREE. In that case, if kernel threads were not
	279	* thawed, the preallocation of memory carried out by
	280	* hibernation_snapshot() might run into problems (i.e. it
	281	* might fail or even deadlock).
	282	*/
	283	thaw_kernel_threads();
6e1819d6 RW	284	break;
6e1819d6 RW	285
b694e52e	286	case SNAPSHOT_PREF_IMAGE_SIZE:
6e1819d6 RW	287	image_size = arg;
	288	break;
	289
af508b34 RW	290	case SNAPSHOT_GET_IMAGE_SIZE:
	291	if (!data->ready) {
	292	error = -ENODATA;
	293	break;
	294	}
	295	size = snapshot_get_image_size();
	296	size <<= PAGE_SHIFT;
	297	error = put_user(size, (loff_t __user *)arg);
	298	break;
	299
b694e52e	300	case SNAPSHOT_AVAIL_SWAP_SIZE:
af508b34 RW	301	size = count_swap_pages(data->swap, 1);
	302	size <<= PAGE_SHIFT;
	303	error = put_user(size, (loff_t __user *)arg);
6e1819d6 RW	304	break;
6e1819d6 RW	305
b694e52e	306	case SNAPSHOT_ALLOC_SWAP_PAGE:
6e1819d6 RW	307	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	308	error = -ENODEV;
	309	break;
	310	}
d1d241cc	311	offset = alloc_swapdev_block(data->swap);
6e1819d6 RW	312	if (offset) {
6e1819d6 RW	313	offset <<= PAGE_SHIFT;
cc5d207c	314	error = put_user(offset, (loff_t __user *)arg);
6e1819d6 RW	315	} else {
	316	error = -ENOSPC;
	317	}
	318	break;
	319
	320	case SNAPSHOT_FREE_SWAP_PAGES:
	321	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	322	error = -ENODEV;
	323	break;
	324	}
d1d241cc	325	free_all_swap_pages(data->swap);
6e1819d6 RW	326	break;
6e1819d6 RW	327
9b238205 LT	328	case SNAPSHOT_S2RAM:
	329	if (!data->frozen) {
	330	error = -EPERM;
	331	break;
	332	}
6c961dfb RW	333	/*
	334	* Tasks are frozen and the notifiers have been called with
	335	* PM_HIBERNATION_PREPARE
	336	*/
	337	error = suspend_devices_and_enter(PM_SUSPEND_MEM);
7bc9b1cf	338	data->ready = false;
9b238205 LT	339	break;
9b238205 LT	340
eb57c1cf RW	341	case SNAPSHOT_PLATFORM_SUPPORT:
	342	data->platform_support = !!arg;
	343	break;
	344
	345	case SNAPSHOT_POWER_OFF:
	346	if (data->platform_support)
	347	error = hibernation_platform_enter();
	348	break;
	349
37b2ba12	350	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	351	if (swsusp_swap_in_use()) {
37b2ba12 RW	352	error = -EPERM;
	353	} else {
	354	struct resume_swap_area swap_area;
	355	dev_t swdev;
	356
	357	error = copy_from_user(&swap_area, (void __user *)arg,
	358	sizeof(struct resume_swap_area));
	359	if (error) {
	360	error = -EFAULT;
	361	break;
	362	}
	363
	364	/*
	365	* User space encodes device types as two-byte values,
	366	* so we need to recode them
	367	*/
d88d4050	368	swdev = new_decode_dev(swap_area.dev);
37b2ba12 RW	369	if (swdev) {
37b2ba12 RW	370	offset = swap_area.offset;
7bf23687	371	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	372	if (data->swap < 0)
	373	error = -ENODEV;
	374	} else {
	375	data->swap = -1;
	376	error = -EINVAL;
	377	}
	378	}
	379	break;
	380
6e1819d6 RW	381	default:
	382	error = -ENOTTY;
	383
	384	}
25f2f3da	385
942f4015	386	unlock_device_hotplug();
25f2f3da RW	387	mutex_unlock(&pm_mutex);
25f2f3da RW	388
6e1819d6 RW	389	return error;
	390	}
	391
c336078b BH	392	#ifdef CONFIG_COMPAT
	393
	394	struct compat_resume_swap_area {
	395	compat_loff_t offset;
	396	u32 dev;
	397	} __packed;
	398
	399	static long
	400	snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	401	{
	402	BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
	403
	404	switch (cmd) {
	405	case SNAPSHOT_GET_IMAGE_SIZE:
	406	case SNAPSHOT_AVAIL_SWAP_SIZE:
	407	case SNAPSHOT_ALLOC_SWAP_PAGE: {
	408	compat_loff_t __user *uoffset = compat_ptr(arg);
	409	loff_t offset;
	410	mm_segment_t old_fs;
	411	int err;
	412
	413	old_fs = get_fs();
	414	set_fs(KERNEL_DS);
	415	err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
	416	set_fs(old_fs);
	417	if (!err && put_user(offset, uoffset))
	418	err = -EFAULT;
	419	return err;
	420	}
	421
	422	case SNAPSHOT_CREATE_IMAGE:
	423	return snapshot_ioctl(file, cmd,
	424	(unsigned long) compat_ptr(arg));
	425
	426	case SNAPSHOT_SET_SWAP_AREA: {
	427	struct compat_resume_swap_area __user *u_swap_area =
	428	compat_ptr(arg);
	429	struct resume_swap_area swap_area;
	430	mm_segment_t old_fs;
	431	int err;
	432
	433	err = get_user(swap_area.offset, &u_swap_area->offset);
	434	err \|= get_user(swap_area.dev, &u_swap_area->dev);
	435	if (err)
	436	return -EFAULT;
	437	old_fs = get_fs();
	438	set_fs(KERNEL_DS);
	439	err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
	440	(unsigned long) &swap_area);
	441	set_fs(old_fs);
	442	return err;
	443	}
	444
	445	default:
	446	return snapshot_ioctl(file, cmd, arg);
	447	}
	448	}
	449
	450	#endif /* CONFIG_COMPAT */
	451
15ad7cdc	452	static const struct file_operations snapshot_fops = {
6e1819d6 RW	453	.open = snapshot_open,
	454	.release = snapshot_release,
	455	.read = snapshot_read,
	456	.write = snapshot_write,
	457	.llseek = no_llseek,
52d11025	458	.unlocked_ioctl = snapshot_ioctl,
c336078b BH	459	#ifdef CONFIG_COMPAT
	460	.compat_ioctl = snapshot_compat_ioctl,
	461	#endif
6e1819d6 RW	462	};
	463
	464	static struct miscdevice snapshot_device = {
	465	.minor = SNAPSHOT_MINOR,
	466	.name = "snapshot",
	467	.fops = &snapshot_fops,
	468	};
	469
	470	static int __init snapshot_device_init(void)
	471	{
	472	return misc_register(&snapshot_device);
	473	};
	474
	475	device_initcall(snapshot_device_init);