[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 <[email protected]>
 *
 * 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/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_suspend;
} snapshot_state;

atomic_t snapshot_device_available = ATOMIC_INIT(1);

static int snapshot_open(struct inode *inode, struct file *filp)
{
	struct snapshot_data *data;

	if (!atomic_add_unless(&snapshot_device_available, -1, 0))
		return -EBUSY;

	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
		atomic_inc(&snapshot_device_available);
		return -ENOSYS;
	}
	if(create_basic_memory_bitmaps()) {
		atomic_inc(&snapshot_device_available);
		return -ENOMEM;
	}
	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) {
		data->swap = swsusp_resume_device ?
			swap_type_of(swsusp_resume_device, 0, NULL) : -1;
		data->mode = O_RDONLY;
	} else {
		data->swap = -1;
		data->mode = O_WRONLY;
	}
	data->frozen = 0;
	data->ready = 0;
	data->platform_suspend = 0;

	return 0;
}

static int snapshot_release(struct inode *inode, struct file *filp)
{
	struct snapshot_data *data;

	swsusp_free();
	free_basic_memory_bitmaps();
	data = filp->private_data;
	free_all_swap_pages(data->swap);
	if (data->frozen) {
		mutex_lock(&pm_mutex);
		thaw_processes();
		mutex_unlock(&pm_mutex);
	}
	atomic_inc(&snapshot_device_available);
	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;

	data = filp->private_data;
	if (!data->ready)
		return -ENODATA;
	res = snapshot_read_next(&data->handle, count);
	if (res > 0) {
		if (copy_to_user(buf, data_of(data->handle), res))
			res = -EFAULT;
		else
			*offp = data->handle.offset;
	}
	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;

	data = filp->private_data;
	res = snapshot_write_next(&data->handle, count);
	if (res > 0) {
		if (copy_from_user(data_of(data->handle), buf, res))
			res = -EFAULT;
		else
			*offp = data->handle.offset;
	}
	return res;
}

static int snapshot_ioctl(struct inode *inode, struct file *filp,
                          unsigned int cmd, unsigned long arg)
{
	int error = 0;
	struct snapshot_data *data;
	loff_t avail;
	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;

	data = filp->private_data;

	switch (cmd) {

	case SNAPSHOT_FREEZE:
		if (data->frozen)
			break;
		mutex_lock(&pm_mutex);
		error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
		if (!error) {
			error = freeze_processes();
			if (error)
				thaw_processes();
		}
		if (error)
			pm_notifier_call_chain(PM_POST_HIBERNATION);
		mutex_unlock(&pm_mutex);
		if (!error)
			data->frozen = 1;
		break;

	case SNAPSHOT_UNFREEZE:
		if (!data->frozen || data->ready)
			break;
		mutex_lock(&pm_mutex);
		thaw_processes();
		pm_notifier_call_chain(PM_POST_HIBERNATION);
		mutex_unlock(&pm_mutex);
		data->frozen = 0;
		break;

	case SNAPSHOT_ATOMIC_SNAPSHOT:
		if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
			error = -EPERM;
			break;
		}
		error = hibernation_snapshot(data->platform_suspend);
		if (!error)
			error = put_user(in_suspend, (unsigned int __user *)arg);
		if (!error)
			data->ready = 1;
		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_suspend);
		break;

	case SNAPSHOT_FREE:
		swsusp_free();
		memset(&data->handle, 0, sizeof(struct snapshot_handle));
		data->ready = 0;
		break;

	case SNAPSHOT_SET_IMAGE_SIZE:
		image_size = arg;
		break;

	case SNAPSHOT_AVAIL_SWAP:
		avail = count_swap_pages(data->swap, 1);
		avail <<= PAGE_SHIFT;
		error = put_user(avail, (loff_t __user *)arg);
		break;

	case SNAPSHOT_GET_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, (sector_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_SET_SWAP_FILE:
		if (!swsusp_swap_in_use()) {
			/*
			 * User space encodes device types as two-byte values,
			 * so we need to recode them
			 */
			if (old_decode_dev(arg)) {
				data->swap = swap_type_of(old_decode_dev(arg),
							0, NULL);
				if (data->swap < 0)
					error = -ENODEV;
			} else {
				data->swap = -1;
				error = -EINVAL;
			}
		} else {
			error = -EPERM;
		}
		break;

	case SNAPSHOT_S2RAM:
		if (!data->frozen) {
			error = -EPERM;
			break;
		}
		if (!mutex_trylock(&pm_mutex)) {
			error = -EBUSY;
			break;
		}
		/*
		 * Tasks are frozen and the notifiers have been called with
		 * PM_HIBERNATION_PREPARE
		 */
		error = suspend_devices_and_enter(PM_SUSPEND_MEM);
		mutex_unlock(&pm_mutex);
		break;

	case SNAPSHOT_PMOPS:
		error = -EINVAL;

		switch (arg) {

		case PMOPS_PREPARE:
			data->platform_suspend = 1;
			error = 0;
			break;

		case PMOPS_ENTER:
			if (data->platform_suspend)
				error = hibernation_platform_enter();

			break;

		case PMOPS_FINISH:
			if (data->platform_suspend)
				error = 0;

			break;

		default:
			printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);

		}
		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 = old_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;

	}

	return error;
}

static const struct file_operations snapshot_fops = {
	.open = snapshot_open,
	.release = snapshot_release,
	.read = snapshot_read,
	.write = snapshot_write,
	.llseek = no_llseek,
	.ioctl = snapshot_ioctl,
};

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 <[email protected]>
	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>
97c7801c	23	#include <linux/console.h>
e3920fb4	24	#include <linux/cpu.h>
7dfb7103	25	#include <linux/freezer.h>
6e1819d6 RW	26
	27	#include <asm/uaccess.h>
	28
	29	#include "power.h"
	30
	31	#define SNAPSHOT_MINOR 231
	32
	33	static struct snapshot_data {
	34	struct snapshot_handle handle;
	35	int swap;
6e1819d6 RW	36	int mode;
	37	char frozen;
	38	char ready;
2b5b09b3	39	char platform_suspend;
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;
	47
0709db60	48	if (!atomic_add_unless(&snapshot_device_available, -1, 0))
6e1819d6 RW	49	return -EBUSY;
6e1819d6 RW	50
1525a2ad	51	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
0709db60	52	atomic_inc(&snapshot_device_available);
6e1819d6	53	return -ENOSYS;
1525a2ad RW	54	}
1525a2ad RW	55	if(create_basic_memory_bitmaps()) {
0709db60	56	atomic_inc(&snapshot_device_available);
74dfd666	57	return -ENOMEM;
1525a2ad	58	}
6e1819d6 RW	59	nonseekable_open(inode, filp);
	60	data = &snapshot_state;
	61	filp->private_data = data;
	62	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	63	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
915bae9e	64	data->swap = swsusp_resume_device ?
7bf23687	65	swap_type_of(swsusp_resume_device, 0, NULL) : -1;
6e1819d6 RW	66	data->mode = O_RDONLY;
	67	} else {
	68	data->swap = -1;
	69	data->mode = O_WRONLY;
	70	}
6e1819d6 RW	71	data->frozen = 0;
6e1819d6 RW	72	data->ready = 0;
2b5b09b3	73	data->platform_suspend = 0;
6e1819d6 RW	74
	75	return 0;
	76	}
	77
	78	static int snapshot_release(struct inode inode, struct file filp)
	79	{
	80	struct snapshot_data *data;
	81
	82	swsusp_free();
74dfd666	83	free_basic_memory_bitmaps();
6e1819d6	84	data = filp->private_data;
d1d241cc	85	free_all_swap_pages(data->swap);
6e1819d6	86	if (data->frozen) {
a6d70980	87	mutex_lock(&pm_mutex);
6e1819d6	88	thaw_processes();
a6d70980	89	mutex_unlock(&pm_mutex);
6e1819d6	90	}
0709db60	91	atomic_inc(&snapshot_device_available);
6e1819d6 RW	92	return 0;
	93	}
	94
	95	static ssize_t snapshot_read(struct file filp, char __user buf,
	96	size_t count, loff_t *offp)
	97	{
	98	struct snapshot_data *data;
	99	ssize_t res;
	100
	101	data = filp->private_data;
2f41dddb RW	102	if (!data->ready)
2f41dddb RW	103	return -ENODATA;
6e1819d6 RW	104	res = snapshot_read_next(&data->handle, count);
	105	if (res > 0) {
	106	if (copy_to_user(buf, data_of(data->handle), res))
	107	res = -EFAULT;
	108	else
	109	*offp = data->handle.offset;
	110	}
	111	return res;
	112	}
	113
	114	static ssize_t snapshot_write(struct file filp, const char __user buf,
	115	size_t count, loff_t *offp)
	116	{
	117	struct snapshot_data *data;
	118	ssize_t res;
	119
	120	data = filp->private_data;
	121	res = snapshot_write_next(&data->handle, count);
	122	if (res > 0) {
	123	if (copy_from_user(data_of(data->handle), buf, res))
	124	res = -EFAULT;
	125	else
	126	*offp = data->handle.offset;
	127	}
	128	return res;
	129	}
	130
	131	static int snapshot_ioctl(struct inode inode, struct file filp,
	132	unsigned int cmd, unsigned long arg)
	133	{
	134	int error = 0;
	135	struct snapshot_data *data;
3aef83e0 RW	136	loff_t avail;
3aef83e0 RW	137	sector_t offset;
6e1819d6 RW	138
	139	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	140	return -ENOTTY;
	141	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	142	return -ENOTTY;
	143	if (!capable(CAP_SYS_ADMIN))
	144	return -EPERM;
	145
	146	data = filp->private_data;
	147
	148	switch (cmd) {
	149
	150	case SNAPSHOT_FREEZE:
	151	if (data->frozen)
	152	break;
a6d70980	153	mutex_lock(&pm_mutex);
b10d9117 RW	154	error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
	155	if (!error) {
	156	error = freeze_processes();
	157	if (error)
	158	thaw_processes();
6e1819d6	159	}
b10d9117 RW	160	if (error)
b10d9117 RW	161	pm_notifier_call_chain(PM_POST_HIBERNATION);
a6d70980	162	mutex_unlock(&pm_mutex);
6e1819d6 RW	163	if (!error)
	164	data->frozen = 1;
	165	break;
	166
	167	case SNAPSHOT_UNFREEZE:
2f41dddb	168	if (!data->frozen \|\| data->ready)
6e1819d6	169	break;
a6d70980	170	mutex_lock(&pm_mutex);
6e1819d6	171	thaw_processes();
b10d9117	172	pm_notifier_call_chain(PM_POST_HIBERNATION);
a6d70980	173	mutex_unlock(&pm_mutex);
6e1819d6 RW	174	data->frozen = 0;
	175	break;
	176
	177	case SNAPSHOT_ATOMIC_SNAPSHOT:
	178	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	179	error = -EPERM;
	180	break;
	181	}
7777fab9	182	error = hibernation_snapshot(data->platform_suspend);
6e1819d6 RW	183	if (!error)
	184	error = put_user(in_suspend, (unsigned int __user *)arg);
	185	if (!error)
	186	data->ready = 1;
	187	break;
	188
	189	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	190	snapshot_write_finalize(&data->handle);
6e1819d6 RW	191	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	192	!snapshot_image_loaded(&data->handle)) {
	193	error = -EPERM;
	194	break;
	195	}
a634cc10	196	error = hibernation_restore(data->platform_suspend);
6e1819d6 RW	197	break;
	198
	199	case SNAPSHOT_FREE:
	200	swsusp_free();
	201	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	202	data->ready = 0;
	203	break;
	204
	205	case SNAPSHOT_SET_IMAGE_SIZE:
	206	image_size = arg;
	207	break;
	208
	209	case SNAPSHOT_AVAIL_SWAP:
	210	avail = count_swap_pages(data->swap, 1);
	211	avail <<= PAGE_SHIFT;
	212	error = put_user(avail, (loff_t __user *)arg);
	213	break;
	214
	215	case SNAPSHOT_GET_SWAP_PAGE:
	216	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	217	error = -ENODEV;
	218	break;
	219	}
d1d241cc	220	offset = alloc_swapdev_block(data->swap);
6e1819d6 RW	221	if (offset) {
6e1819d6 RW	222	offset <<= PAGE_SHIFT;
3aef83e0	223	error = put_user(offset, (sector_t __user *)arg);
6e1819d6 RW	224	} else {
	225	error = -ENOSPC;
	226	}
	227	break;
	228
	229	case SNAPSHOT_FREE_SWAP_PAGES:
	230	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	231	error = -ENODEV;
	232	break;
	233	}
d1d241cc	234	free_all_swap_pages(data->swap);
6e1819d6 RW	235	break;
	236
	237	case SNAPSHOT_SET_SWAP_FILE:
d1d241cc	238	if (!swsusp_swap_in_use()) {
6e1819d6 RW	239	/*
	240	* User space encodes device types as two-byte values,
	241	* so we need to recode them
	242	*/
	243	if (old_decode_dev(arg)) {
7bf23687 RW	244	data->swap = swap_type_of(old_decode_dev(arg),
7bf23687 RW	245	0, NULL);
6e1819d6 RW	246	if (data->swap < 0)
	247	error = -ENODEV;
	248	} else {
	249	data->swap = -1;
	250	error = -EINVAL;
	251	}
	252	} else {
	253	error = -EPERM;
	254	}
	255	break;
	256
9b238205 LT	257	case SNAPSHOT_S2RAM:
	258	if (!data->frozen) {
	259	error = -EPERM;
	260	break;
	261	}
a6d70980	262	if (!mutex_trylock(&pm_mutex)) {
9b238205 LT	263	error = -EBUSY;
	264	break;
	265	}
6c961dfb RW	266	/*
	267	* Tasks are frozen and the notifiers have been called with
	268	* PM_HIBERNATION_PREPARE
	269	*/
	270	error = suspend_devices_and_enter(PM_SUSPEND_MEM);
a6d70980	271	mutex_unlock(&pm_mutex);
9b238205 LT	272	break;
9b238205 LT	273
3592695c	274	case SNAPSHOT_PMOPS:
2b5b09b3 RW	275	error = -EINVAL;
2b5b09b3 RW	276
3592695c SS	277	switch (arg) {
	278
	279	case PMOPS_PREPARE:
7777fab9 RW	280	data->platform_suspend = 1;
7777fab9 RW	281	error = 0;
3592695c SS	282	break;
	283
	284	case PMOPS_ENTER:
7777fab9 RW	285	if (data->platform_suspend)
	286	error = hibernation_platform_enter();
	287
3592695c SS	288	break;
	289
	290	case PMOPS_FINISH:
2b5b09b3 RW	291	if (data->platform_suspend)
	292	error = 0;
	293
3592695c SS	294	break;
	295
	296	default:
	297	printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
3592695c SS	298
	299	}
	300	break;
	301
37b2ba12	302	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	303	if (swsusp_swap_in_use()) {
37b2ba12 RW	304	error = -EPERM;
	305	} else {
	306	struct resume_swap_area swap_area;
	307	dev_t swdev;
	308
	309	error = copy_from_user(&swap_area, (void __user *)arg,
	310	sizeof(struct resume_swap_area));
	311	if (error) {
	312	error = -EFAULT;
	313	break;
	314	}
	315
	316	/*
	317	* User space encodes device types as two-byte values,
	318	* so we need to recode them
	319	*/
	320	swdev = old_decode_dev(swap_area.dev);
	321	if (swdev) {
	322	offset = swap_area.offset;
7bf23687	323	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	324	if (data->swap < 0)
	325	error = -ENODEV;
	326	} else {
	327	data->swap = -1;
	328	error = -EINVAL;
	329	}
	330	}
	331	break;
	332
6e1819d6 RW	333	default:
	334	error = -ENOTTY;
	335
	336	}
	337
	338	return error;
	339	}
	340
15ad7cdc	341	static const struct file_operations snapshot_fops = {
6e1819d6 RW	342	.open = snapshot_open,
	343	.release = snapshot_release,
	344	.read = snapshot_read,
	345	.write = snapshot_write,
	346	.llseek = no_llseek,
	347	.ioctl = snapshot_ioctl,
	348	};
	349
	350	static struct miscdevice snapshot_device = {
	351	.minor = SNAPSHOT_MINOR,
	352	.name = "snapshot",
	353	.fops = &snapshot_fops,
	354	};
	355
	356	static int __init snapshot_device_init(void)
	357	{
	358	return misc_register(&snapshot_device);
	359	};
	360
	361	device_initcall(snapshot_device_init);