[linux-2.6-block.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;
	struct bitmap_page *bitmap;
	int mode;
	char frozen;
	char ready;
} snapshot_state;

static atomic_t device_available = ATOMIC_INIT(1);

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

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

	if ((filp->f_flags & O_ACCMODE) == O_RDWR)
		return -ENOSYS;

	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) : -1;
		data->mode = O_RDONLY;
	} else {
		data->swap = -1;
		data->mode = O_WRONLY;
	}
	data->bitmap = NULL;
	data->frozen = 0;
	data->ready = 0;

	return 0;
}

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

	swsusp_free();
	data = filp->private_data;
	free_all_swap_pages(data->swap, data->bitmap);
	free_bitmap(data->bitmap);
	if (data->frozen) {
		down(&pm_sem);
		thaw_processes();
		enable_nonboot_cpus();
		up(&pm_sem);
	}
	atomic_inc(&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;
	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;
		down(&pm_sem);
		error = disable_nonboot_cpus();
		if (!error) {
			error = freeze_processes();
			if (error) {
				thaw_processes();
				enable_nonboot_cpus();
				error = -EBUSY;
			}
		}
		up(&pm_sem);
		if (!error)
			data->frozen = 1;
		break;

	case SNAPSHOT_UNFREEZE:
		if (!data->frozen)
			break;
		down(&pm_sem);
		thaw_processes();
		enable_nonboot_cpus();
		up(&pm_sem);
		data->frozen = 0;
		break;

	case SNAPSHOT_ATOMIC_SNAPSHOT:
		if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
			error = -EPERM;
			break;
		}
		down(&pm_sem);
		/* Free memory before shutting down devices. */
		error = swsusp_shrink_memory();
		if (!error) {
			suspend_console();
			error = device_suspend(PMSG_FREEZE);
			if (!error) {
				in_suspend = 1;
				error = swsusp_suspend();
				device_resume();
			}
			resume_console();
		}
		up(&pm_sem);
		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;
		}
		down(&pm_sem);
		pm_prepare_console();
		suspend_console();
		error = device_suspend(PMSG_PRETHAW);
		if (!error) {
			error = swsusp_resume();
			device_resume();
		}
		resume_console();
		pm_restore_console();
		up(&pm_sem);
		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;
		}
		if (!data->bitmap) {
			data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0));
			if (!data->bitmap) {
				error = -ENOMEM;
				break;
			}
		}
		offset = alloc_swapdev_block(data->swap, data->bitmap);
		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, data->bitmap);
		free_bitmap(data->bitmap);
		data->bitmap = NULL;
		break;

	case SNAPSHOT_SET_SWAP_FILE:
		if (!data->bitmap) {
			/*
			 * 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);
				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 (down_trylock(&pm_sem)) {
			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 {
			/* Enter S3, system is already frozen */
			suspend_enter(PM_SUSPEND_MEM);

			/* Wake up devices */
			device_resume();
		}
		resume_console();
		if (pm_ops->finish)
			pm_ops->finish(PM_SUSPEND_MEM);

OutS3:
		up(&pm_sem);
		break;

	case SNAPSHOT_PMOPS:
		switch (arg) {

		case PMOPS_PREPARE:
			if (pm_ops->prepare) {
				error = pm_ops->prepare(PM_SUSPEND_DISK);
			}
			break;

		case PMOPS_ENTER:
			kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
			error = pm_ops->enter(PM_SUSPEND_DISK);
			break;

		case PMOPS_FINISH:
			if (pm_ops && pm_ops->finish) {
				pm_ops->finish(PM_SUSPEND_DISK);
			}
			break;

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

		}
		break;

	case SNAPSHOT_SET_SWAP_AREA:
		if (data->bitmap) {
			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);
				if (data->swap < 0)
					error = -ENODEV;
			} else {
				data->swap = -1;
				error = -EINVAL;
			}
		}
		break;

	default:
		error = -ENOTTY;

	}

	return error;
}

static 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;
	36	struct bitmap_page *bitmap;
	37	int mode;
	38	char frozen;
	39	char ready;
	40	} snapshot_state;
	41
	42	static atomic_t device_available = ATOMIC_INIT(1);
	43
	44	static int snapshot_open(struct inode inode, struct file filp)
	45	{
	46	struct snapshot_data *data;
	47
	48	if (!atomic_add_unless(&device_available, -1, 0))
	49	return -EBUSY;
	50
	51	if ((filp->f_flags & O_ACCMODE) == O_RDWR)
	52	return -ENOSYS;
	53
	54	nonseekable_open(inode, filp);
	55	data = &snapshot_state;
	56	filp->private_data = data;
	57	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	58	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
915bae9e RW	59	data->swap = swsusp_resume_device ?
915bae9e RW	60	swap_type_of(swsusp_resume_device, 0) : -1;
6e1819d6 RW	61	data->mode = O_RDONLY;
	62	} else {
	63	data->swap = -1;
	64	data->mode = O_WRONLY;
	65	}
	66	data->bitmap = NULL;
	67	data->frozen = 0;
	68	data->ready = 0;
	69
	70	return 0;
	71	}
	72
	73	static int snapshot_release(struct inode inode, struct file filp)
	74	{
	75	struct snapshot_data *data;
	76
	77	swsusp_free();
	78	data = filp->private_data;
	79	free_all_swap_pages(data->swap, data->bitmap);
	80	free_bitmap(data->bitmap);
	81	if (data->frozen) {
	82	down(&pm_sem);
	83	thaw_processes();
	84	enable_nonboot_cpus();
	85	up(&pm_sem);
	86	}
	87	atomic_inc(&device_available);
	88	return 0;
	89	}
	90
	91	static ssize_t snapshot_read(struct file filp, char __user buf,
	92	size_t count, loff_t *offp)
	93	{
	94	struct snapshot_data *data;
	95	ssize_t res;
	96
	97	data = filp->private_data;
	98	res = snapshot_read_next(&data->handle, count);
	99	if (res > 0) {
	100	if (copy_to_user(buf, data_of(data->handle), res))
	101	res = -EFAULT;
	102	else
	103	*offp = data->handle.offset;
	104	}
	105	return res;
	106	}
	107
	108	static ssize_t snapshot_write(struct file filp, const char __user buf,
	109	size_t count, loff_t *offp)
	110	{
	111	struct snapshot_data *data;
	112	ssize_t res;
	113
	114	data = filp->private_data;
	115	res = snapshot_write_next(&data->handle, count);
	116	if (res > 0) {
	117	if (copy_from_user(data_of(data->handle), buf, res))
	118	res = -EFAULT;
	119	else
	120	*offp = data->handle.offset;
	121	}
	122	return res;
	123	}
	124
125	static int snapshot_ioctl(struct inode inode, struct file filp,
126	unsigned int cmd, unsigned long arg)
127	{
128	int error = 0;
129	struct snapshot_data *data;
3aef83e0 RW	130	loff_t avail;
3aef83e0 RW	131	sector_t offset;
6e1819d6 RW	132
	133	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	134	return -ENOTTY;
	135	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	136	return -ENOTTY;
	137	if (!capable(CAP_SYS_ADMIN))
	138	return -EPERM;
	139
	140	data = filp->private_data;
	141
	142	switch (cmd) {
	143
	144	case SNAPSHOT_FREEZE:
	145	if (data->frozen)
	146	break;
6e1819d6	147	down(&pm_sem);
e3920fb4 RW	148	error = disable_nonboot_cpus();
	149	if (!error) {
	150	error = freeze_processes();
	151	if (error) {
	152	thaw_processes();
5c339d45	153	enable_nonboot_cpus();
e3920fb4 RW	154	error = -EBUSY;
e3920fb4 RW	155	}
6e1819d6 RW	156	}
	157	up(&pm_sem);
	158	if (!error)
	159	data->frozen = 1;
	160	break;
	161
	162	case SNAPSHOT_UNFREEZE:
	163	if (!data->frozen)
	164	break;
	165	down(&pm_sem);
	166	thaw_processes();
	167	enable_nonboot_cpus();
6e1819d6 RW	168	up(&pm_sem);
	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	}
	177	down(&pm_sem);
	178	/* Free memory before shutting down devices. */
	179	error = swsusp_shrink_memory();
	180	if (!error) {
97c7801c	181	suspend_console();
6e1819d6 RW	182	error = device_suspend(PMSG_FREEZE);
	183	if (!error) {
	184	in_suspend = 1;
	185	error = swsusp_suspend();
	186	device_resume();
	187	}
97c7801c	188	resume_console();
6e1819d6 RW	189	}
	190	up(&pm_sem);
	191	if (!error)
	192	error = put_user(in_suspend, (unsigned int __user *)arg);
	193	if (!error)
	194	data->ready = 1;
	195	break;
	196
	197	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	198	snapshot_write_finalize(&data->handle);
6e1819d6 RW	199	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	200	!snapshot_image_loaded(&data->handle)) {
	201	error = -EPERM;
	202	break;
	203	}
	204	down(&pm_sem);
	205	pm_prepare_console();
97c7801c	206	suspend_console();
f1cc0a89	207	error = device_suspend(PMSG_PRETHAW);
6e1819d6 RW	208	if (!error) {
	209	error = swsusp_resume();
	210	device_resume();
	211	}
97c7801c	212	resume_console();
6e1819d6 RW	213	pm_restore_console();
	214	up(&pm_sem);
	215	break;
	216
	217	case SNAPSHOT_FREE:
	218	swsusp_free();
	219	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	220	data->ready = 0;
	221	break;
	222
	223	case SNAPSHOT_SET_IMAGE_SIZE:
	224	image_size = arg;
	225	break;
	226
	227	case SNAPSHOT_AVAIL_SWAP:
	228	avail = count_swap_pages(data->swap, 1);
	229	avail <<= PAGE_SHIFT;
	230	error = put_user(avail, (loff_t __user *)arg);
	231	break;
	232
	233	case SNAPSHOT_GET_SWAP_PAGE:
	234	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	235	error = -ENODEV;
	236	break;
	237	}
	238	if (!data->bitmap) {
	239	data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0));
	240	if (!data->bitmap) {
	241	error = -ENOMEM;
	242	break;
	243	}
	244	}
3aef83e0	245	offset = alloc_swapdev_block(data->swap, data->bitmap);
6e1819d6 RW	246	if (offset) {
6e1819d6 RW	247	offset <<= PAGE_SHIFT;
3aef83e0	248	error = put_user(offset, (sector_t __user *)arg);
6e1819d6 RW	249	} else {
	250	error = -ENOSPC;
	251	}
	252	break;
	253
	254	case SNAPSHOT_FREE_SWAP_PAGES:
	255	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	256	error = -ENODEV;
	257	break;
	258	}
	259	free_all_swap_pages(data->swap, data->bitmap);
	260	free_bitmap(data->bitmap);
	261	data->bitmap = NULL;
	262	break;
	263
	264	case SNAPSHOT_SET_SWAP_FILE:
	265	if (!data->bitmap) {
	266	/*
	267	* User space encodes device types as two-byte values,
	268	* so we need to recode them
	269	*/
	270	if (old_decode_dev(arg)) {
915bae9e	271	data->swap = swap_type_of(old_decode_dev(arg), 0);
6e1819d6 RW	272	if (data->swap < 0)
	273	error = -ENODEV;
	274	} else {
	275	data->swap = -1;
	276	error = -EINVAL;
	277	}
	278	} else {
	279	error = -EPERM;
	280	}
	281	break;
	282
9b238205 LT	283	case SNAPSHOT_S2RAM:
	284	if (!data->frozen) {
	285	error = -EPERM;
	286	break;
	287	}
	288
	289	if (down_trylock(&pm_sem)) {
	290	error = -EBUSY;
	291	break;
	292	}
	293
	294	if (pm_ops->prepare) {
	295	error = pm_ops->prepare(PM_SUSPEND_MEM);
	296	if (error)
	297	goto OutS3;
	298	}
	299
	300	/* Put devices to sleep */
97c7801c	301	suspend_console();
9b238205 LT	302	error = device_suspend(PMSG_SUSPEND);
	303	if (error) {
	304	printk(KERN_ERR "Failed to suspend some devices.\n");
	305	} else {
	306	/* Enter S3, system is already frozen */
	307	suspend_enter(PM_SUSPEND_MEM);
	308
	309	/* Wake up devices */
	310	device_resume();
	311	}
97c7801c	312	resume_console();
9b238205 LT	313	if (pm_ops->finish)
	314	pm_ops->finish(PM_SUSPEND_MEM);
	315
	316	OutS3:
	317	up(&pm_sem);
	318	break;
	319
3592695c SS	320	case SNAPSHOT_PMOPS:
	321	switch (arg) {
	322
	323	case PMOPS_PREPARE:
	324	if (pm_ops->prepare) {
	325	error = pm_ops->prepare(PM_SUSPEND_DISK);
	326	}
	327	break;
	328
	329	case PMOPS_ENTER:
	330	kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
	331	error = pm_ops->enter(PM_SUSPEND_DISK);
	332	break;
	333
	334	case PMOPS_FINISH:
	335	if (pm_ops && pm_ops->finish) {
	336	pm_ops->finish(PM_SUSPEND_DISK);
	337	}
	338	break;
	339
	340	default:
	341	printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
	342	error = -EINVAL;
	343
	344	}
	345	break;
	346
37b2ba12 RW	347	case SNAPSHOT_SET_SWAP_AREA:
	348	if (data->bitmap) {
	349	error = -EPERM;
	350	} else {
	351	struct resume_swap_area swap_area;
	352	dev_t swdev;
	353
	354	error = copy_from_user(&swap_area, (void __user *)arg,
	355	sizeof(struct resume_swap_area));
	356	if (error) {
	357	error = -EFAULT;
	358	break;
	359	}
	360
	361	/*
	362	* User space encodes device types as two-byte values,
	363	* so we need to recode them
	364	*/
	365	swdev = old_decode_dev(swap_area.dev);
	366	if (swdev) {
	367	offset = swap_area.offset;
	368	data->swap = swap_type_of(swdev, offset);
	369	if (data->swap < 0)
	370	error = -ENODEV;
	371	} else {
	372	data->swap = -1;
	373	error = -EINVAL;
	374	}
	375	}
	376	break;
	377
6e1819d6 RW	378	default:
	379	error = -ENOTTY;
	380
	381	}
	382
	383	return error;
	384	}
	385
	386	static struct file_operations snapshot_fops = {
	387	.open = snapshot_open,
	388	.release = snapshot_release,
	389	.read = snapshot_read,
	390	.write = snapshot_write,
	391	.llseek = no_llseek,
	392	.ioctl = snapshot_ioctl,
	393	};
	394
	395	static struct miscdevice snapshot_device = {
	396	.minor = SNAPSHOT_MINOR,
	397	.name = "snapshot",
	398	.fops = &snapshot_fops,
	399	};
	400
	401	static int __init snapshot_device_init(void)
	402	{
	403	return misc_register(&snapshot_device);
	404	};
	405
	406	device_initcall(snapshot_device_init);