[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/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 <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) : -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 offset, avail;

	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);
		disable_nonboot_cpus();
		if (freeze_processes()) {
			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) {
			error = device_suspend(PMSG_FREEZE);
			if (!error) {
				in_suspend = 1;
				error = swsusp_suspend();
				device_resume();
			}
		}
		up(&pm_sem);
		if (!error)
			error = put_user(in_suspend, (unsigned int __user *)arg);
		if (!error)
			data->ready = 1;
		break;

	case SNAPSHOT_ATOMIC_RESTORE:
		if (data->mode != O_WRONLY || !data->frozen ||
		    !snapshot_image_loaded(&data->handle)) {
			error = -EPERM;
			break;
		}
		down(&pm_sem);
		pm_prepare_console();
		error = device_suspend(PMSG_FREEZE);
		if (!error) {
			error = swsusp_resume();
			device_resume();
		}
		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_swap_page(data->swap, data->bitmap);
		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, 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));
				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 */
		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();
		}

		if (pm_ops->finish)
			pm_ops->finish(PM_SUSPEND_MEM);

OutS3:
		up(&pm_sem);
		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>
	14	#include <linux/string.h>
	15	#include <linux/device.h>
	16	#include <linux/miscdevice.h>
	17	#include <linux/mm.h>
	18	#include <linux/swap.h>
	19	#include <linux/swapops.h>
	20	#include <linux/pm.h>
	21	#include <linux/fs.h>
	22
	23	#include <asm/uaccess.h>
	24
	25	#include "power.h"
	26
	27	#define SNAPSHOT_MINOR 231
	28
	29	static struct snapshot_data {
	30	struct snapshot_handle handle;
	31	int swap;
	32	struct bitmap_page *bitmap;
	33	int mode;
	34	char frozen;
	35	char ready;
	36	} snapshot_state;
	37
	38	static atomic_t device_available = ATOMIC_INIT(1);
	39
	40	static int snapshot_open(struct inode inode, struct file filp)
	41	{
	42	struct snapshot_data *data;
	43
	44	if (!atomic_add_unless(&device_available, -1, 0))
	45	return -EBUSY;
	46
	47	if ((filp->f_flags & O_ACCMODE) == O_RDWR)
	48	return -ENOSYS;
	49
	50	nonseekable_open(inode, filp);
	51	data = &snapshot_state;
	52	filp->private_data = data;
	53	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	54	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
	55	data->swap = swsusp_resume_device ? swap_type_of(swsusp_resume_device) : -1;
	56	data->mode = O_RDONLY;
	57	} else {
	58	data->swap = -1;
	59	data->mode = O_WRONLY;
	60	}
	61	data->bitmap = NULL;
	62	data->frozen = 0;
	63	data->ready = 0;
	64
65	return 0;
66	}
67
68	static int snapshot_release(struct inode inode, struct file filp)
69	{
70	struct snapshot_data *data;
71
72	swsusp_free();
73	data = filp->private_data;
74	free_all_swap_pages(data->swap, data->bitmap);
75	free_bitmap(data->bitmap);
76	if (data->frozen) {
77	down(&pm_sem);
78	thaw_processes();
79	enable_nonboot_cpus();
80	up(&pm_sem);
81	}
82	atomic_inc(&device_available);
83	return 0;
84	}
85
86	static ssize_t snapshot_read(struct file filp, char __user buf,
87	size_t count, loff_t *offp)
88	{
89	struct snapshot_data *data;
90	ssize_t res;
91
92	data = filp->private_data;
93	res = snapshot_read_next(&data->handle, count);
94	if (res > 0) {
95	if (copy_to_user(buf, data_of(data->handle), res))
96	res = -EFAULT;
97	else
98	*offp = data->handle.offset;
99	}
100	return res;
101	}
102
103	static ssize_t snapshot_write(struct file filp, const char __user buf,
104	size_t count, loff_t *offp)
105	{
106	struct snapshot_data *data;
107	ssize_t res;
108
109	data = filp->private_data;
110	res = snapshot_write_next(&data->handle, count);
111	if (res > 0) {
112	if (copy_from_user(data_of(data->handle), buf, res))
113	res = -EFAULT;
114	else
115	*offp = data->handle.offset;
116	}
117	return res;
118	}
119
120	static int snapshot_ioctl(struct inode inode, struct file filp,
121	unsigned int cmd, unsigned long arg)
122	{
123	int error = 0;
124	struct snapshot_data *data;
125	loff_t offset, avail;
126
127	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
128	return -ENOTTY;
129	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
130	return -ENOTTY;
131	if (!capable(CAP_SYS_ADMIN))
132	return -EPERM;
133
134	data = filp->private_data;
135
136	switch (cmd) {
137
138	case SNAPSHOT_FREEZE:
139	if (data->frozen)
140	break;
6e1819d6	141	down(&pm_sem);
6e1819d6 RW	142	disable_nonboot_cpus();
	143	if (freeze_processes()) {
	144	thaw_processes();
	145	enable_nonboot_cpus();
6e1819d6 RW	146	error = -EBUSY;
	147	}
	148	up(&pm_sem);
	149	if (!error)
	150	data->frozen = 1;
	151	break;
	152
	153	case SNAPSHOT_UNFREEZE:
	154	if (!data->frozen)
	155	break;
	156	down(&pm_sem);
	157	thaw_processes();
	158	enable_nonboot_cpus();
6e1819d6 RW	159	up(&pm_sem);
	160	data->frozen = 0;
	161	break;
	162
	163	case SNAPSHOT_ATOMIC_SNAPSHOT:
	164	if (data->mode != O_RDONLY \|\| !data->frozen \|\| data->ready) {
	165	error = -EPERM;
	166	break;
	167	}
	168	down(&pm_sem);
	169	/* Free memory before shutting down devices. */
	170	error = swsusp_shrink_memory();
	171	if (!error) {
	172	error = device_suspend(PMSG_FREEZE);
	173	if (!error) {
	174	in_suspend = 1;
	175	error = swsusp_suspend();
	176	device_resume();
	177	}
	178	}
	179	up(&pm_sem);
	180	if (!error)
	181	error = put_user(in_suspend, (unsigned int __user *)arg);
	182	if (!error)
	183	data->ready = 1;
	184	break;
	185
	186	case SNAPSHOT_ATOMIC_RESTORE:
	187	if (data->mode != O_WRONLY \|\| !data->frozen \|\|
	188	!snapshot_image_loaded(&data->handle)) {
	189	error = -EPERM;
	190	break;
	191	}
	192	down(&pm_sem);
	193	pm_prepare_console();
	194	error = device_suspend(PMSG_FREEZE);
	195	if (!error) {
	196	error = swsusp_resume();
	197	device_resume();
	198	}
	199	pm_restore_console();
	200	up(&pm_sem);
	201	break;
	202
	203	case SNAPSHOT_FREE:
	204	swsusp_free();
	205	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	206	data->ready = 0;
	207	break;
	208
	209	case SNAPSHOT_SET_IMAGE_SIZE:
	210	image_size = arg;
	211	break;
	212
	213	case SNAPSHOT_AVAIL_SWAP:
	214	avail = count_swap_pages(data->swap, 1);
	215	avail <<= PAGE_SHIFT;
	216	error = put_user(avail, (loff_t __user *)arg);
	217	break;
	218
	219	case SNAPSHOT_GET_SWAP_PAGE:
	220	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
	221	error = -ENODEV;
	222	break;
223	}
224	if (!data->bitmap) {
225	data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0));
226	if (!data->bitmap) {
227	error = -ENOMEM;
228	break;
229	}
230	}
231	offset = alloc_swap_page(data->swap, data->bitmap);
232	if (offset) {
233	offset <<= PAGE_SHIFT;
234	error = put_user(offset, (loff_t __user *)arg);
235	} else {
236	error = -ENOSPC;
237	}
238	break;
239
240	case SNAPSHOT_FREE_SWAP_PAGES:
241	if (data->swap < 0 \|\| data->swap >= MAX_SWAPFILES) {
242	error = -ENODEV;
243	break;
244	}
245	free_all_swap_pages(data->swap, data->bitmap);
246	free_bitmap(data->bitmap);
247	data->bitmap = NULL;
248	break;
249
250	case SNAPSHOT_SET_SWAP_FILE:
251	if (!data->bitmap) {
252	/*
253	* User space encodes device types as two-byte values,
254	* so we need to recode them
255	*/
256	if (old_decode_dev(arg)) {
257	data->swap = swap_type_of(old_decode_dev(arg));
258	if (data->swap < 0)
259	error = -ENODEV;
260	} else {
261	data->swap = -1;
262	error = -EINVAL;
263	}
264	} else {
265	error = -EPERM;
266	}
267	break;
268
9b238205 LT	269	case SNAPSHOT_S2RAM:
	270	if (!data->frozen) {
	271	error = -EPERM;
	272	break;
	273	}
	274
	275	if (down_trylock(&pm_sem)) {
	276	error = -EBUSY;
	277	break;
	278	}
	279
	280	if (pm_ops->prepare) {
	281	error = pm_ops->prepare(PM_SUSPEND_MEM);
	282	if (error)
	283	goto OutS3;
	284	}
	285
	286	/* Put devices to sleep */
	287	error = device_suspend(PMSG_SUSPEND);
	288	if (error) {
	289	printk(KERN_ERR "Failed to suspend some devices.\n");
	290	} else {
	291	/* Enter S3, system is already frozen */
	292	suspend_enter(PM_SUSPEND_MEM);
	293
	294	/* Wake up devices */
	295	device_resume();
	296	}
	297
	298	if (pm_ops->finish)
	299	pm_ops->finish(PM_SUSPEND_MEM);
	300
	301	OutS3:
	302	up(&pm_sem);
	303	break;
	304
6e1819d6 RW	305	default:
	306	error = -ENOTTY;
	307
	308	}
	309
	310	return error;
	311	}
	312
	313	static struct file_operations snapshot_fops = {
	314	.open = snapshot_open,
	315	.release = snapshot_release,
	316	.read = snapshot_read,
	317	.write = snapshot_write,
	318	.llseek = no_llseek,
	319	.ioctl = snapshot_ioctl,
	320	};
	321
	322	static struct miscdevice snapshot_device = {
	323	.minor = SNAPSHOT_MINOR,
	324	.name = "snapshot",
	325	.fops = &snapshot_fops,
	326	};
	327
	328	static int __init snapshot_device_init(void)
	329	{
	330	return misc_register(&snapshot_device);
	331	};
	332
	333	device_initcall(snapshot_device_init);