2 * linux/kernel/power/user.c
4 * This file provides the user space interface for software suspend/resume.
6 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
8 * This file is released under the GPLv2.
12 #include <linux/suspend.h>
13 #include <linux/syscalls.h>
14 #include <linux/reboot.h>
15 #include <linux/string.h>
16 #include <linux/device.h>
17 #include <linux/miscdevice.h>
19 #include <linux/swap.h>
20 #include <linux/swapops.h>
23 #include <linux/console.h>
24 #include <linux/cpu.h>
26 #include <asm/uaccess.h>
30 #define SNAPSHOT_MINOR 231
32 static struct snapshot_data
{
33 struct snapshot_handle handle
;
35 struct bitmap_page
*bitmap
;
41 static atomic_t device_available
= ATOMIC_INIT(1);
43 static int snapshot_open(struct inode
*inode
, struct file
*filp
)
45 struct snapshot_data
*data
;
47 if (!atomic_add_unless(&device_available
, -1, 0))
50 if ((filp
->f_flags
& O_ACCMODE
) == O_RDWR
)
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
) {
58 data
->swap
= swsusp_resume_device
?
59 swap_type_of(swsusp_resume_device
, 0) : -1;
60 data
->mode
= O_RDONLY
;
63 data
->mode
= O_WRONLY
;
72 static int snapshot_release(struct inode
*inode
, struct file
*filp
)
74 struct snapshot_data
*data
;
77 data
= filp
->private_data
;
78 free_all_swap_pages(data
->swap
, data
->bitmap
);
79 free_bitmap(data
->bitmap
);
83 enable_nonboot_cpus();
86 atomic_inc(&device_available
);
90 static ssize_t
snapshot_read(struct file
*filp
, char __user
*buf
,
91 size_t count
, loff_t
*offp
)
93 struct snapshot_data
*data
;
96 data
= filp
->private_data
;
97 res
= snapshot_read_next(&data
->handle
, count
);
99 if (copy_to_user(buf
, data_of(data
->handle
), res
))
102 *offp
= data
->handle
.offset
;
107 static ssize_t
snapshot_write(struct file
*filp
, const char __user
*buf
,
108 size_t count
, loff_t
*offp
)
110 struct snapshot_data
*data
;
113 data
= filp
->private_data
;
114 res
= snapshot_write_next(&data
->handle
, count
);
116 if (copy_from_user(data_of(data
->handle
), buf
, res
))
119 *offp
= data
->handle
.offset
;
124 static int snapshot_ioctl(struct inode
*inode
, struct file
*filp
,
125 unsigned int cmd
, unsigned long arg
)
128 struct snapshot_data
*data
;
132 if (_IOC_TYPE(cmd
) != SNAPSHOT_IOC_MAGIC
)
134 if (_IOC_NR(cmd
) > SNAPSHOT_IOC_MAXNR
)
136 if (!capable(CAP_SYS_ADMIN
))
139 data
= filp
->private_data
;
143 case SNAPSHOT_FREEZE
:
147 error
= disable_nonboot_cpus();
149 error
= freeze_processes();
152 enable_nonboot_cpus();
161 case SNAPSHOT_UNFREEZE
:
166 enable_nonboot_cpus();
171 case SNAPSHOT_ATOMIC_SNAPSHOT
:
172 if (data
->mode
!= O_RDONLY
|| !data
->frozen
|| data
->ready
) {
177 /* Free memory before shutting down devices. */
178 error
= swsusp_shrink_memory();
181 error
= device_suspend(PMSG_FREEZE
);
184 error
= swsusp_suspend();
191 error
= put_user(in_suspend
, (unsigned int __user
*)arg
);
196 case SNAPSHOT_ATOMIC_RESTORE
:
197 if (data
->mode
!= O_WRONLY
|| !data
->frozen
||
198 !snapshot_image_loaded(&data
->handle
)) {
202 snapshot_free_unused_memory(&data
->handle
);
204 pm_prepare_console();
206 error
= device_suspend(PMSG_PRETHAW
);
208 error
= swsusp_resume();
212 pm_restore_console();
218 memset(&data
->handle
, 0, sizeof(struct snapshot_handle
));
222 case SNAPSHOT_SET_IMAGE_SIZE
:
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
);
232 case SNAPSHOT_GET_SWAP_PAGE
:
233 if (data
->swap
< 0 || data
->swap
>= MAX_SWAPFILES
) {
238 data
->bitmap
= alloc_bitmap(count_swap_pages(data
->swap
, 0));
244 offset
= alloc_swapdev_block(data
->swap
, data
->bitmap
);
246 offset
<<= PAGE_SHIFT
;
247 error
= put_user(offset
, (sector_t __user
*)arg
);
253 case SNAPSHOT_FREE_SWAP_PAGES
:
254 if (data
->swap
< 0 || data
->swap
>= MAX_SWAPFILES
) {
258 free_all_swap_pages(data
->swap
, data
->bitmap
);
259 free_bitmap(data
->bitmap
);
263 case SNAPSHOT_SET_SWAP_FILE
:
266 * User space encodes device types as two-byte values,
267 * so we need to recode them
269 if (old_decode_dev(arg
)) {
270 data
->swap
= swap_type_of(old_decode_dev(arg
), 0);
288 if (down_trylock(&pm_sem
)) {
293 if (pm_ops
->prepare
) {
294 error
= pm_ops
->prepare(PM_SUSPEND_MEM
);
299 /* Put devices to sleep */
301 error
= device_suspend(PMSG_SUSPEND
);
303 printk(KERN_ERR
"Failed to suspend some devices.\n");
305 /* Enter S3, system is already frozen */
306 suspend_enter(PM_SUSPEND_MEM
);
308 /* Wake up devices */
313 pm_ops
->finish(PM_SUSPEND_MEM
);
323 if (pm_ops
->prepare
) {
324 error
= pm_ops
->prepare(PM_SUSPEND_DISK
);
329 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK
);
330 error
= pm_ops
->enter(PM_SUSPEND_DISK
);
334 if (pm_ops
&& pm_ops
->finish
) {
335 pm_ops
->finish(PM_SUSPEND_DISK
);
340 printk(KERN_ERR
"SNAPSHOT_PMOPS: invalid argument %ld\n", arg
);
346 case SNAPSHOT_SET_SWAP_AREA
:
350 struct resume_swap_area swap_area
;
353 error
= copy_from_user(&swap_area
, (void __user
*)arg
,
354 sizeof(struct resume_swap_area
));
361 * User space encodes device types as two-byte values,
362 * so we need to recode them
364 swdev
= old_decode_dev(swap_area
.dev
);
366 offset
= swap_area
.offset
;
367 data
->swap
= swap_type_of(swdev
, offset
);
385 static struct file_operations snapshot_fops
= {
386 .open
= snapshot_open
,
387 .release
= snapshot_release
,
388 .read
= snapshot_read
,
389 .write
= snapshot_write
,
391 .ioctl
= snapshot_ioctl
,
394 static struct miscdevice snapshot_device
= {
395 .minor
= SNAPSHOT_MINOR
,
397 .fops
= &snapshot_fops
,
400 static int __init
snapshot_device_init(void)
402 return misc_register(&snapshot_device
);
405 device_initcall(snapshot_device_init
);