[linux-2.6-block.git] / kernel / power / user.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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>
 */

#include <linux/suspend.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 <linux/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, nr_calls = 0;

	if (!hibernation_available())
		return -EPERM;

	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, -1, &nr_calls);
		if (error)
			__pm_notifier_call_chain(PM_POST_HIBERNATION, --nr_calls, NULL);
	} 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, -1, &nr_calls);
		if (!error) {
			error = create_basic_memory_bitmaps();
			data->free_bitmaps = !error;
		} else
			nr_calls--;

		if (error)
			__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
	}
	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;
	}

	if (!data_of(data->handle)) {
		res = -EINVAL;
		goto unlock;
	}

	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(&system_transition_mutex))
		return -EBUSY;

	lock_device_hotplug();
	data = filp->private_data;

	switch (cmd) {

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

		ksys_sync_helper();

		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(&system_transition_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
55716d26	1	// SPDX-License-Identifier: GPL-2.0-only
6e1819d6 RW	2	/*
	3	* linux/kernel/power/user.c
	4	*
	5	* This file provides the user space interface for software suspend/resume.
	6	*
	7	* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
6e1819d6 RW	8	*/
	9
	10	#include <linux/suspend.h>
3592695c	11	#include <linux/reboot.h>
6e1819d6 RW	12	#include <linux/string.h>
	13	#include <linux/device.h>
	14	#include <linux/miscdevice.h>
	15	#include <linux/mm.h>
	16	#include <linux/swap.h>
	17	#include <linux/swapops.h>
	18	#include <linux/pm.h>
	19	#include <linux/fs.h>
c336078b	20	#include <linux/compat.h>
97c7801c	21	#include <linux/console.h>
e3920fb4	22	#include <linux/cpu.h>
7dfb7103	23	#include <linux/freezer.h>
6e1819d6	24
7c0f6ba6	25	#include <linux/uaccess.h>
6e1819d6 RW	26
	27	#include "power.h"
	28
eb57c1cf	29
6e1819d6 RW	30	#define SNAPSHOT_MINOR 231
	31
	32	static struct snapshot_data {
	33	struct snapshot_handle handle;
	34	int swap;
6e1819d6	35	int mode;
7bc9b1cf RW	36	bool frozen;
	37	bool ready;
	38	bool platform_support;
aab17289	39	bool free_bitmaps;
6e1819d6 RW	40	} snapshot_state;
6e1819d6 RW	41
0709db60	42	atomic_t snapshot_device_available = ATOMIC_INIT(1);
6e1819d6 RW	43
	44	static int snapshot_open(struct inode inode, struct file filp)
	45	{
	46	struct snapshot_data *data;
ea00f4f4	47	int error, nr_calls = 0;
6e1819d6	48
a6e15a39 KC	49	if (!hibernation_available())
	50	return -EPERM;
	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;
ea00f4f4	74	error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
c3e94d89	75	if (error)
ea00f4f4	76	__pm_notifier_call_chain(PM_POST_HIBERNATION, --nr_calls, NULL);
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;
ea00f4f4	86	error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
aab17289 RW	87	if (!error) {
	88	error = create_basic_memory_bitmaps();
	89	data->free_bitmaps = !error;
ea00f4f4 LW	90	} else
	91	nr_calls--;
	92
c3e94d89	93	if (error)
ea00f4f4	94	__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
c3e94d89	95	}
8fd37a4c	96	if (error)
c3e94d89	97	atomic_inc(&snapshot_device_available);
8fd37a4c	98
7bc9b1cf RW	99	data->frozen = false;
	100	data->ready = false;
	101	data->platform_support = false;
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 RW	115	swsusp_free();
6e1819d6 RW	116	data = filp->private_data;
d1d241cc	117	free_all_swap_pages(data->swap);
9744997a RW	118	if (data->frozen) {
9744997a RW	119	pm_restore_gfp_mask();
8fd37a4c	120	free_basic_memory_bitmaps();
6e1819d6	121	thaw_processes();
aab17289 RW	122	} else if (data->free_bitmaps) {
aab17289 RW	123	free_basic_memory_bitmaps();
9744997a	124	}
1497dd1d	125	pm_notifier_call_chain(data->mode == O_RDONLY ?
c3e94d89	126	PM_POST_HIBERNATION : PM_POST_RESTORE);
0709db60	127	atomic_inc(&snapshot_device_available);
25f2f3da	128
bcda53fa	129	unlock_system_sleep();
25f2f3da	130
6e1819d6 RW	131	return 0;
	132	}
	133
	134	static ssize_t snapshot_read(struct file filp, char __user buf,
	135	size_t count, loff_t *offp)
	136	{
	137	struct snapshot_data *data;
	138	ssize_t res;
d3c1b24c	139	loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6	140
bcda53fa	141	lock_system_sleep();
25f2f3da	142
6e1819d6	143	data = filp->private_data;
25f2f3da RW	144	if (!data->ready) {
	145	res = -ENODATA;
	146	goto Unlock;
	147	}
d3c1b24c JS	148	if (!pg_offp) { /* on page boundary? */
	149	res = snapshot_read_next(&data->handle);
	150	if (res <= 0)
	151	goto Unlock;
	152	} else {
	153	res = PAGE_SIZE - pg_offp;
6e1819d6	154	}
25f2f3da	155
d3c1b24c JS	156	res = simple_read_from_buffer(buf, count, &pg_offp,
	157	data_of(data->handle), res);
	158	if (res > 0)
	159	*offp += res;
	160
25f2f3da	161	Unlock:
bcda53fa	162	unlock_system_sleep();
25f2f3da	163
6e1819d6 RW	164	return res;
	165	}
	166
	167	static ssize_t snapshot_write(struct file filp, const char __user buf,
	168	size_t count, loff_t *offp)
	169	{
	170	struct snapshot_data *data;
	171	ssize_t res;
d3c1b24c	172	loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6	173
bcda53fa	174	lock_system_sleep();
25f2f3da	175
6e1819d6	176	data = filp->private_data;
d3c1b24c JS	177
	178	if (!pg_offp) {
	179	res = snapshot_write_next(&data->handle);
	180	if (res <= 0)
	181	goto unlock;
	182	} else {
	183	res = PAGE_SIZE - pg_offp;
6e1819d6	184	}
25f2f3da	185
fc14eebf TH	186	if (!data_of(data->handle)) {
	187	res = -EINVAL;
	188	goto unlock;
	189	}
	190
d3c1b24c JS	191	res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
	192	buf, count);
	193	if (res > 0)
	194	*offp += res;
	195	unlock:
bcda53fa	196	unlock_system_sleep();
25f2f3da	197
6e1819d6 RW	198	return res;
	199	}
	200
52d11025 AC	201	static long snapshot_ioctl(struct file *filp, unsigned int cmd,
52d11025 AC	202	unsigned long arg)
6e1819d6 RW	203	{
	204	int error = 0;
	205	struct snapshot_data *data;
af508b34	206	loff_t size;
3aef83e0	207	sector_t offset;
6e1819d6 RW	208
	209	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	210	return -ENOTTY;
	211	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	212	return -ENOTTY;
	213	if (!capable(CAP_SYS_ADMIN))
	214	return -EPERM;
	215
55f2503c	216	if (!mutex_trylock(&system_transition_mutex))
25f2f3da	217	return -EBUSY;
6e1819d6	218
942f4015	219	lock_device_hotplug();
25f2f3da	220	data = filp->private_data;
52d11025	221
6e1819d6 RW	222	switch (cmd) {
	223
	224	case SNAPSHOT_FREEZE:
	225	if (data->frozen)
	226	break;
1bfcf130	227
b5dee313	228	ksys_sync_helper();
c3e94d89	229
1bfcf130	230	error = freeze_processes();
8fd37a4c RW	231	if (error)
	232	break;
	233
	234	error = create_basic_memory_bitmaps();
	235	if (error)
	236	thaw_processes();
	237	else
7bc9b1cf	238	data->frozen = true;
8fd37a4c	239
6e1819d6 RW	240	break;
	241
	242	case SNAPSHOT_UNFREEZE:
2f41dddb	243	if (!data->frozen \|\| data->ready)
6e1819d6	244	break;
c9e664f1	245	pm_restore_gfp_mask();
8fd37a4c	246	free_basic_memory_bitmaps();
aab17289	247	data->free_bitmaps = false;
6e1819d6	248	thaw_processes();
7bc9b1cf	249	data->frozen = false;
6e1819d6 RW	250	break;
6e1819d6 RW	251
b694e52e	252	case SNAPSHOT_CREATE_IMAGE:
6e1819d6 RW	253	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	254	error = -EPERM;
	255	break;
	256	}
c9e664f1	257	pm_restore_gfp_mask();
eb57c1cf	258	error = hibernation_snapshot(data->platform_support);
51d6ff7a	259	if (!error) {
cc5d207c	260	error = put_user(in_suspend, (int __user *)arg);
a556d5b5 SB	261	data->ready = !freezer_test_done && !error;
a556d5b5 SB	262	freezer_test_done = false;
97819a26	263	}
6e1819d6 RW	264	break;
	265
	266	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	267	snapshot_write_finalize(&data->handle);
6e1819d6 RW	268	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	269	!snapshot_image_loaded(&data->handle)) {
	270	error = -EPERM;
	271	break;
	272	}
eb57c1cf	273	error = hibernation_restore(data->platform_support);
6e1819d6 RW	274	break;
	275
	276	case SNAPSHOT_FREE:
	277	swsusp_free();
	278	memset(&data->handle, 0, sizeof(struct snapshot_handle));
7bc9b1cf	279	data->ready = false;
181e9bde RW	280	/*
	281	* It is necessary to thaw kernel threads here, because
	282	* SNAPSHOT_CREATE_IMAGE may be invoked directly after
	283	* SNAPSHOT_FREE. In that case, if kernel threads were not
	284	* thawed, the preallocation of memory carried out by
	285	* hibernation_snapshot() might run into problems (i.e. it
	286	* might fail or even deadlock).
	287	*/
	288	thaw_kernel_threads();
6e1819d6 RW	289	break;
6e1819d6 RW	290
b694e52e	291	case SNAPSHOT_PREF_IMAGE_SIZE:
6e1819d6 RW	292	image_size = arg;
	293	break;
	294
af508b34 RW	295	case SNAPSHOT_GET_IMAGE_SIZE:
	296	if (!data->ready) {
	297	error = -ENODATA;
	298	break;
	299	}
	300	size = snapshot_get_image_size();
	301	size <<= PAGE_SHIFT;
	302	error = put_user(size, (loff_t __user *)arg);
	303	break;
	304
b694e52e	305	case SNAPSHOT_AVAIL_SWAP_SIZE:
af508b34 RW	306	size = count_swap_pages(data->swap, 1);
	307	size <<= PAGE_SHIFT;
	308	error = put_user(size, (loff_t __user *)arg);
6e1819d6 RW	309	break;
6e1819d6 RW	310
b694e52e	311	case SNAPSHOT_ALLOC_SWAP_PAGE:
6e1819d6 RW	312	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	313	error = -ENODEV;
	314	break;
	315	}
d1d241cc	316	offset = alloc_swapdev_block(data->swap);
6e1819d6 RW	317	if (offset) {
6e1819d6 RW	318	offset <<= PAGE_SHIFT;
cc5d207c	319	error = put_user(offset, (loff_t __user *)arg);
6e1819d6 RW	320	} else {
	321	error = -ENOSPC;
	322	}
	323	break;
	324
	325	case SNAPSHOT_FREE_SWAP_PAGES:
	326	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	327	error = -ENODEV;
	328	break;
	329	}
d1d241cc	330	free_all_swap_pages(data->swap);
6e1819d6 RW	331	break;
6e1819d6 RW	332
9b238205 LT	333	case SNAPSHOT_S2RAM:
	334	if (!data->frozen) {
	335	error = -EPERM;
	336	break;
	337	}
6c961dfb RW	338	/*
	339	* Tasks are frozen and the notifiers have been called with
	340	* PM_HIBERNATION_PREPARE
	341	*/
	342	error = suspend_devices_and_enter(PM_SUSPEND_MEM);
7bc9b1cf	343	data->ready = false;
9b238205 LT	344	break;
9b238205 LT	345
eb57c1cf RW	346	case SNAPSHOT_PLATFORM_SUPPORT:
	347	data->platform_support = !!arg;
	348	break;
	349
	350	case SNAPSHOT_POWER_OFF:
	351	if (data->platform_support)
	352	error = hibernation_platform_enter();
	353	break;
	354
37b2ba12	355	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	356	if (swsusp_swap_in_use()) {
37b2ba12 RW	357	error = -EPERM;
	358	} else {
	359	struct resume_swap_area swap_area;
	360	dev_t swdev;
	361
	362	error = copy_from_user(&swap_area, (void __user *)arg,
	363	sizeof(struct resume_swap_area));
	364	if (error) {
	365	error = -EFAULT;
	366	break;
	367	}
	368
	369	/*
	370	* User space encodes device types as two-byte values,
	371	* so we need to recode them
	372	*/
d88d4050	373	swdev = new_decode_dev(swap_area.dev);
37b2ba12 RW	374	if (swdev) {
37b2ba12 RW	375	offset = swap_area.offset;
7bf23687	376	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	377	if (data->swap < 0)
	378	error = -ENODEV;
	379	} else {
	380	data->swap = -1;
	381	error = -EINVAL;
	382	}
	383	}
	384	break;
	385
6e1819d6 RW	386	default:
	387	error = -ENOTTY;
	388
	389	}
25f2f3da	390
942f4015	391	unlock_device_hotplug();
55f2503c	392	mutex_unlock(&system_transition_mutex);
25f2f3da	393
6e1819d6 RW	394	return error;
	395	}
	396
c336078b BH	397	#ifdef CONFIG_COMPAT
	398
	399	struct compat_resume_swap_area {
	400	compat_loff_t offset;
	401	u32 dev;
	402	} __packed;
	403
	404	static long
	405	snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	406	{
	407	BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
	408
	409	switch (cmd) {
	410	case SNAPSHOT_GET_IMAGE_SIZE:
	411	case SNAPSHOT_AVAIL_SWAP_SIZE:
	412	case SNAPSHOT_ALLOC_SWAP_PAGE: {
	413	compat_loff_t __user *uoffset = compat_ptr(arg);
	414	loff_t offset;
	415	mm_segment_t old_fs;
	416	int err;
	417
	418	old_fs = get_fs();
	419	set_fs(KERNEL_DS);
	420	err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
	421	set_fs(old_fs);
	422	if (!err && put_user(offset, uoffset))
	423	err = -EFAULT;
	424	return err;
	425	}
	426
	427	case SNAPSHOT_CREATE_IMAGE:
	428	return snapshot_ioctl(file, cmd,
	429	(unsigned long) compat_ptr(arg));
	430
	431	case SNAPSHOT_SET_SWAP_AREA: {
	432	struct compat_resume_swap_area __user *u_swap_area =
	433	compat_ptr(arg);
	434	struct resume_swap_area swap_area;
	435	mm_segment_t old_fs;
	436	int err;
	437
	438	err = get_user(swap_area.offset, &u_swap_area->offset);
	439	err \|= get_user(swap_area.dev, &u_swap_area->dev);
	440	if (err)
	441	return -EFAULT;
	442	old_fs = get_fs();
	443	set_fs(KERNEL_DS);
	444	err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
	445	(unsigned long) &swap_area);
	446	set_fs(old_fs);
	447	return err;
	448	}
	449
	450	default:
	451	return snapshot_ioctl(file, cmd, arg);
	452	}
	453	}
	454
	455	#endif /* CONFIG_COMPAT */
	456
15ad7cdc	457	static const struct file_operations snapshot_fops = {
6e1819d6 RW	458	.open = snapshot_open,
	459	.release = snapshot_release,
	460	.read = snapshot_read,
	461	.write = snapshot_write,
	462	.llseek = no_llseek,
52d11025	463	.unlocked_ioctl = snapshot_ioctl,
c336078b BH	464	#ifdef CONFIG_COMPAT
	465	.compat_ioctl = snapshot_compat_ioctl,
	466	#endif
6e1819d6 RW	467	};
	468
	469	static struct miscdevice snapshot_device = {
	470	.minor = SNAPSHOT_MINOR,
	471	.name = "snapshot",
	472	.fops = &snapshot_fops,
	473	};
	474
	475	static int __init snapshot_device_init(void)
	476	{
	477	return misc_register(&snapshot_device);
	478	};
	479
	480	device_initcall(snapshot_device_init);