[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/console.h>
#include <linux/cpu.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>
6e1819d6 RW	25
	26	#include <asm/uaccess.h>
	27
	28	#include "power.h"
	29
	30	#define SNAPSHOT_MINOR 231
	31
	32	static struct snapshot_data {
	33	struct snapshot_handle handle;
	34	int swap;
	35	struct bitmap_page *bitmap;
	36	int mode;
	37	char frozen;
	38	char ready;
	39	} snapshot_state;
	40
	41	static atomic_t device_available = ATOMIC_INIT(1);
	42
	43	static int snapshot_open(struct inode inode, struct file filp)
	44	{
	45	struct snapshot_data *data;
	46
	47	if (!atomic_add_unless(&device_available, -1, 0))
	48	return -EBUSY;
	49
	50	if ((filp->f_flags & O_ACCMODE) == O_RDWR)
	51	return -ENOSYS;
	52
	53	nonseekable_open(inode, filp);
	54	data = &snapshot_state;
	55	filp->private_data = data;
	56	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	57	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
915bae9e RW	58	data->swap = swsusp_resume_device ?
915bae9e RW	59	swap_type_of(swsusp_resume_device, 0) : -1;
6e1819d6 RW	60	data->mode = O_RDONLY;
	61	} else {
	62	data->swap = -1;
	63	data->mode = O_WRONLY;
	64	}
	65	data->bitmap = NULL;
	66	data->frozen = 0;
	67	data->ready = 0;
	68
	69	return 0;
	70	}
	71
	72	static int snapshot_release(struct inode inode, struct file filp)
	73	{
	74	struct snapshot_data *data;
	75
	76	swsusp_free();
	77	data = filp->private_data;
	78	free_all_swap_pages(data->swap, data->bitmap);
	79	free_bitmap(data->bitmap);
	80	if (data->frozen) {
	81	down(&pm_sem);
	82	thaw_processes();
	83	enable_nonboot_cpus();
	84	up(&pm_sem);
	85	}
	86	atomic_inc(&device_available);
	87	return 0;
	88	}
	89
	90	static ssize_t snapshot_read(struct file filp, char __user buf,
	91	size_t count, loff_t *offp)
	92	{
	93	struct snapshot_data *data;
	94	ssize_t res;
	95
	96	data = filp->private_data;
	97	res = snapshot_read_next(&data->handle, count);
	98	if (res > 0) {
	99	if (copy_to_user(buf, data_of(data->handle), res))
	100	res = -EFAULT;
	101	else
	102	*offp = data->handle.offset;
	103	}
	104	return res;
	105	}
	106
	107	static ssize_t snapshot_write(struct file filp, const char __user buf,
	108	size_t count, loff_t *offp)
	109	{
	110	struct snapshot_data *data;
	111	ssize_t res;
	112
	113	data = filp->private_data;
	114	res = snapshot_write_next(&data->handle, count);
	115	if (res > 0) {
	116	if (copy_from_user(data_of(data->handle), buf, res))
	117	res = -EFAULT;
	118	else
	119	*offp = data->handle.offset;
	120	}
	121	return res;
	122	}
	123
124	static int snapshot_ioctl(struct inode inode, struct file filp,
125	unsigned int cmd, unsigned long arg)
126	{
127	int error = 0;
128	struct snapshot_data *data;
3aef83e0 RW	129	loff_t avail;
3aef83e0 RW	130	sector_t offset;
6e1819d6 RW	131
	132	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
	133	return -ENOTTY;
	134	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
	135	return -ENOTTY;
	136	if (!capable(CAP_SYS_ADMIN))
	137	return -EPERM;
	138
	139	data = filp->private_data;
	140
	141	switch (cmd) {
	142
	143	case SNAPSHOT_FREEZE:
	144	if (data->frozen)
	145	break;
6e1819d6	146	down(&pm_sem);
e3920fb4 RW	147	error = disable_nonboot_cpus();
	148	if (!error) {
	149	error = freeze_processes();
	150	if (error) {
	151	thaw_processes();
5c339d45	152	enable_nonboot_cpus();
e3920fb4 RW	153	error = -EBUSY;
e3920fb4 RW	154	}
6e1819d6 RW	155	}
	156	up(&pm_sem);
	157	if (!error)
	158	data->frozen = 1;
	159	break;
	160
	161	case SNAPSHOT_UNFREEZE:
	162	if (!data->frozen)
	163	break;
	164	down(&pm_sem);
	165	thaw_processes();
	166	enable_nonboot_cpus();
6e1819d6 RW	167	up(&pm_sem);
	168	data->frozen = 0;
	169	break;
	170
	171	case SNAPSHOT_ATOMIC_SNAPSHOT:
	172	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	173	error = -EPERM;
	174	break;
	175	}
	176	down(&pm_sem);
	177	/* Free memory before shutting down devices. */
	178	error = swsusp_shrink_memory();
	179	if (!error) {
97c7801c	180	suspend_console();
6e1819d6 RW	181	error = device_suspend(PMSG_FREEZE);
	182	if (!error) {
	183	in_suspend = 1;
	184	error = swsusp_suspend();
	185	device_resume();
	186	}
97c7801c	187	resume_console();
6e1819d6 RW	188	}
	189	up(&pm_sem);
	190	if (!error)
	191	error = put_user(in_suspend, (unsigned int __user *)arg);
	192	if (!error)
	193	data->ready = 1;
	194	break;
	195
	196	case SNAPSHOT_ATOMIC_RESTORE:
8357376d	197	snapshot_write_finalize(&data->handle);
6e1819d6 RW	198	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	199	!snapshot_image_loaded(&data->handle)) {
	200	error = -EPERM;
	201	break;
	202	}
	203	down(&pm_sem);
	204	pm_prepare_console();
97c7801c	205	suspend_console();
f1cc0a89	206	error = device_suspend(PMSG_PRETHAW);
6e1819d6 RW	207	if (!error) {
	208	error = swsusp_resume();
	209	device_resume();
	210	}
97c7801c	211	resume_console();
6e1819d6 RW	212	pm_restore_console();
	213	up(&pm_sem);
	214	break;
	215
	216	case SNAPSHOT_FREE:
	217	swsusp_free();
	218	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	219	data->ready = 0;
	220	break;
	221
	222	case SNAPSHOT_SET_IMAGE_SIZE:
	223	image_size = arg;
	224	break;
	225
	226	case SNAPSHOT_AVAIL_SWAP:
	227	avail = count_swap_pages(data->swap, 1);
	228	avail <<= PAGE_SHIFT;
	229	error = put_user(avail, (loff_t __user *)arg);
	230	break;
	231
	232	case SNAPSHOT_GET_SWAP_PAGE:
	233	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	234	error = -ENODEV;
	235	break;
	236	}
	237	if (!data->bitmap) {
	238	data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0));
	239	if (!data->bitmap) {
	240	error = -ENOMEM;
	241	break;
	242	}
	243	}
3aef83e0	244	offset = alloc_swapdev_block(data->swap, data->bitmap);
6e1819d6 RW	245	if (offset) {
6e1819d6 RW	246	offset <<= PAGE_SHIFT;
3aef83e0	247	error = put_user(offset, (sector_t __user *)arg);
6e1819d6 RW	248	} else {
	249	error = -ENOSPC;
	250	}
	251	break;
	252
	253	case SNAPSHOT_FREE_SWAP_PAGES:
	254	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	255	error = -ENODEV;
	256	break;
	257	}
	258	free_all_swap_pages(data->swap, data->bitmap);
	259	free_bitmap(data->bitmap);
	260	data->bitmap = NULL;
	261	break;
	262
	263	case SNAPSHOT_SET_SWAP_FILE:
	264	if (!data->bitmap) {
	265	/*
	266	* User space encodes device types as two-byte values,
	267	* so we need to recode them
	268	*/
	269	if (old_decode_dev(arg)) {
915bae9e	270	data->swap = swap_type_of(old_decode_dev(arg), 0);
6e1819d6 RW	271	if (data->swap < 0)
	272	error = -ENODEV;
	273	} else {
	274	data->swap = -1;
	275	error = -EINVAL;
	276	}
	277	} else {
	278	error = -EPERM;
	279	}
	280	break;
	281
9b238205 LT	282	case SNAPSHOT_S2RAM:
	283	if (!data->frozen) {
	284	error = -EPERM;
	285	break;
	286	}
	287
	288	if (down_trylock(&pm_sem)) {
	289	error = -EBUSY;
	290	break;
	291	}
	292
	293	if (pm_ops->prepare) {
	294	error = pm_ops->prepare(PM_SUSPEND_MEM);
	295	if (error)
	296	goto OutS3;
	297	}
	298
	299	/* Put devices to sleep */
97c7801c	300	suspend_console();
9b238205 LT	301	error = device_suspend(PMSG_SUSPEND);
	302	if (error) {
	303	printk(KERN_ERR "Failed to suspend some devices.\n");
	304	} else {
	305	/* Enter S3, system is already frozen */
	306	suspend_enter(PM_SUSPEND_MEM);
	307
	308	/* Wake up devices */
	309	device_resume();
	310	}
97c7801c	311	resume_console();
9b238205 LT	312	if (pm_ops->finish)
	313	pm_ops->finish(PM_SUSPEND_MEM);
	314
	315	OutS3:
	316	up(&pm_sem);
	317	break;
	318
3592695c SS	319	case SNAPSHOT_PMOPS:
	320	switch (arg) {
	321
	322	case PMOPS_PREPARE:
	323	if (pm_ops->prepare) {
	324	error = pm_ops->prepare(PM_SUSPEND_DISK);
	325	}
	326	break;
	327
	328	case PMOPS_ENTER:
	329	kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
	330	error = pm_ops->enter(PM_SUSPEND_DISK);
	331	break;
	332
	333	case PMOPS_FINISH:
	334	if (pm_ops && pm_ops->finish) {
	335	pm_ops->finish(PM_SUSPEND_DISK);
	336	}
	337	break;
	338
	339	default:
	340	printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
	341	error = -EINVAL;
	342
	343	}
	344	break;
	345
37b2ba12 RW	346	case SNAPSHOT_SET_SWAP_AREA:
	347	if (data->bitmap) {
	348	error = -EPERM;
	349	} else {
	350	struct resume_swap_area swap_area;
	351	dev_t swdev;
	352
	353	error = copy_from_user(&swap_area, (void __user *)arg,
	354	sizeof(struct resume_swap_area));
	355	if (error) {
	356	error = -EFAULT;
	357	break;
	358	}
	359
	360	/*
	361	* User space encodes device types as two-byte values,
	362	* so we need to recode them
	363	*/
	364	swdev = old_decode_dev(swap_area.dev);
	365	if (swdev) {
	366	offset = swap_area.offset;
	367	data->swap = swap_type_of(swdev, offset);
	368	if (data->swap < 0)
	369	error = -ENODEV;
	370	} else {
	371	data->swap = -1;
	372	error = -EINVAL;
	373	}
	374	}
	375	break;
	376
6e1819d6 RW	377	default:
	378	error = -ENOTTY;
	379
	380	}
	381
	382	return error;
	383	}
	384
	385	static struct file_operations snapshot_fops = {
	386	.open = snapshot_open,
	387	.release = snapshot_release,
	388	.read = snapshot_read,
	389	.write = snapshot_write,
	390	.llseek = no_llseek,
	391	.ioctl = snapshot_ioctl,
	392	};
	393
	394	static struct miscdevice snapshot_device = {
	395	.minor = SNAPSHOT_MINOR,
	396	.name = "snapshot",
	397	.fops = &snapshot_fops,
	398	};
	399
	400	static int __init snapshot_device_init(void)
	401	{
	402	return misc_register(&snapshot_device);
	403	};
	404
	405	device_initcall(snapshot_device_init);