[mirror_ubuntu-bionic-kernel.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/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);
		if (freeze_processes()) {
			thaw_processes();
			error = -EBUSY;
		}
		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();
		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 (!pm_ops) {
			error = -ENOSYS;
			break;
		}

		if (!data->frozen) {
			error = -EPERM;
			break;
		}

		if (!mutex_trylock(&pm_mutex)) {
			error = -EBUSY;
			break;
		}

		if (pm_ops->prepare) {
			error = pm_ops->prepare(PM_SUSPEND_MEM);
			if (error)
				goto OutS3;
		}

		/* Put devices to sleep */
		suspend_console();
		error = device_suspend(PMSG_SUSPEND);
		if (error) {
			printk(KERN_ERR "Failed to suspend some devices.\n");
		} else {
			error = disable_nonboot_cpus();
			if (!error) {
				/* Enter S3, system is already frozen */
				suspend_enter(PM_SUSPEND_MEM);
				enable_nonboot_cpus();
			}
			/* Wake up devices */
			device_resume();
		}
		resume_console();
		if (pm_ops->finish)
			pm_ops->finish(PM_SUSPEND_MEM);

 OutS3:
		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 <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>
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);
25913052 RW	154	if (freeze_processes()) {
	155	thaw_processes();
	156	error = -EBUSY;
6e1819d6	157	}
a6d70980	158	mutex_unlock(&pm_mutex);
6e1819d6 RW	159	if (!error)
	160	data->frozen = 1;
	161	break;
	162
	163	case SNAPSHOT_UNFREEZE:
2f41dddb	164	if (!data->frozen \|\| data->ready)
6e1819d6	165	break;
a6d70980	166	mutex_lock(&pm_mutex);
6e1819d6	167	thaw_processes();
a6d70980	168	mutex_unlock(&pm_mutex);
6e1819d6 RW	169	data->frozen = 0;
	170	break;
	171
	172	case SNAPSHOT_ATOMIC_SNAPSHOT:
	173	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	174	error = -EPERM;
	175	break;
	176	}
7777fab9	177	error = hibernation_snapshot(data->platform_suspend);
6e1819d6 RW	178	if (!error)
	179	error = put_user(in_suspend, (unsigned int __user *)arg);
	180	if (!error)
	181	data->ready = 1;
	182	break;
	183
	184	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	185	snapshot_write_finalize(&data->handle);
6e1819d6 RW	186	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	187	!snapshot_image_loaded(&data->handle)) {
	188	error = -EPERM;
	189	break;
	190	}
a634cc10	191	error = hibernation_restore(data->platform_suspend);
6e1819d6 RW	192	break;
	193
	194	case SNAPSHOT_FREE:
	195	swsusp_free();
	196	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	197	data->ready = 0;
	198	break;
	199
	200	case SNAPSHOT_SET_IMAGE_SIZE:
	201	image_size = arg;
	202	break;
	203
	204	case SNAPSHOT_AVAIL_SWAP:
	205	avail = count_swap_pages(data->swap, 1);
	206	avail <<= PAGE_SHIFT;
	207	error = put_user(avail, (loff_t __user *)arg);
	208	break;
	209
	210	case SNAPSHOT_GET_SWAP_PAGE:
	211	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	212	error = -ENODEV;
	213	break;
	214	}
d1d241cc	215	offset = alloc_swapdev_block(data->swap);
6e1819d6 RW	216	if (offset) {
6e1819d6 RW	217	offset <<= PAGE_SHIFT;
3aef83e0	218	error = put_user(offset, (sector_t __user *)arg);
6e1819d6 RW	219	} else {
	220	error = -ENOSPC;
	221	}
	222	break;
	223
	224	case SNAPSHOT_FREE_SWAP_PAGES:
	225	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	226	error = -ENODEV;
	227	break;
	228	}
d1d241cc	229	free_all_swap_pages(data->swap);
6e1819d6 RW	230	break;
	231
	232	case SNAPSHOT_SET_SWAP_FILE:
d1d241cc	233	if (!swsusp_swap_in_use()) {
6e1819d6 RW	234	/*
	235	* User space encodes device types as two-byte values,
	236	* so we need to recode them
	237	*/
	238	if (old_decode_dev(arg)) {
7bf23687 RW	239	data->swap = swap_type_of(old_decode_dev(arg),
7bf23687 RW	240	0, NULL);
6e1819d6 RW	241	if (data->swap < 0)
	242	error = -ENODEV;
	243	} else {
	244	data->swap = -1;
	245	error = -EINVAL;
	246	}
	247	} else {
	248	error = -EPERM;
	249	}
	250	break;
	251
9b238205	252	case SNAPSHOT_S2RAM:
2b5b09b3 RW	253	if (!pm_ops) {
	254	error = -ENOSYS;
	255	break;
	256	}
	257
9b238205 LT	258	if (!data->frozen) {
	259	error = -EPERM;
	260	break;
	261	}
	262
a6d70980	263	if (!mutex_trylock(&pm_mutex)) {
9b238205 LT	264	error = -EBUSY;
	265	break;
	266	}
	267
	268	if (pm_ops->prepare) {
	269	error = pm_ops->prepare(PM_SUSPEND_MEM);
	270	if (error)
	271	goto OutS3;
	272	}
	273
	274	/* Put devices to sleep */
97c7801c	275	suspend_console();
9b238205 LT	276	error = device_suspend(PMSG_SUSPEND);
	277	if (error) {
	278	printk(KERN_ERR "Failed to suspend some devices.\n");
	279	} else {
93c9a7ff RW	280	error = disable_nonboot_cpus();
	281	if (!error) {
	282	/* Enter S3, system is already frozen */
	283	suspend_enter(PM_SUSPEND_MEM);
	284	enable_nonboot_cpus();
	285	}
9b238205 LT	286	/* Wake up devices */
	287	device_resume();
	288	}
97c7801c	289	resume_console();
9b238205 LT	290	if (pm_ops->finish)
	291	pm_ops->finish(PM_SUSPEND_MEM);
	292
59a49335	293	OutS3:
a6d70980	294	mutex_unlock(&pm_mutex);
9b238205 LT	295	break;
9b238205 LT	296
3592695c	297	case SNAPSHOT_PMOPS:
2b5b09b3 RW	298	error = -EINVAL;
2b5b09b3 RW	299
3592695c SS	300	switch (arg) {
	301
	302	case PMOPS_PREPARE:
7777fab9 RW	303	data->platform_suspend = 1;
7777fab9 RW	304	error = 0;
3592695c SS	305	break;
	306
	307	case PMOPS_ENTER:
7777fab9 RW	308	if (data->platform_suspend)
	309	error = hibernation_platform_enter();
	310
3592695c SS	311	break;
	312
	313	case PMOPS_FINISH:
2b5b09b3 RW	314	if (data->platform_suspend)
	315	error = 0;
	316
3592695c SS	317	break;
	318
	319	default:
	320	printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
3592695c SS	321
	322	}
	323	break;
	324
37b2ba12	325	case SNAPSHOT_SET_SWAP_AREA:
d1d241cc	326	if (swsusp_swap_in_use()) {
37b2ba12 RW	327	error = -EPERM;
	328	} else {
	329	struct resume_swap_area swap_area;
	330	dev_t swdev;
	331
	332	error = copy_from_user(&swap_area, (void __user *)arg,
	333	sizeof(struct resume_swap_area));
	334	if (error) {
	335	error = -EFAULT;
	336	break;
	337	}
	338
	339	/*
	340	* User space encodes device types as two-byte values,
	341	* so we need to recode them
	342	*/
	343	swdev = old_decode_dev(swap_area.dev);
	344	if (swdev) {
	345	offset = swap_area.offset;
7bf23687	346	data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12 RW	347	if (data->swap < 0)
	348	error = -ENODEV;
	349	} else {
	350	data->swap = -1;
	351	error = -EINVAL;
	352	}
	353	}
	354	break;
	355
6e1819d6 RW	356	default:
	357	error = -ENOTTY;
	358
	359	}
	360
	361	return error;
	362	}
	363
15ad7cdc	364	static const struct file_operations snapshot_fops = {
6e1819d6 RW	365	.open = snapshot_open,
	366	.release = snapshot_release,
	367	.read = snapshot_read,
	368	.write = snapshot_write,
	369	.llseek = no_llseek,
	370	.ioctl = snapshot_ioctl,
	371	};
	372
	373	static struct miscdevice snapshot_device = {
	374	.minor = SNAPSHOT_MINOR,
	375	.name = "snapshot",
	376	.fops = &snapshot_fops,
	377	};
	378
	379	static int __init snapshot_device_init(void)
	380	{
	381	return misc_register(&snapshot_device);
	382	};
	383
	384	device_initcall(snapshot_device_init);