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>
25 #include <linux/freezer.h>
27 #include <asm/uaccess.h>
31 #define SNAPSHOT_MINOR 231
33 static struct snapshot_data
{
34 struct snapshot_handle handle
;
36 struct bitmap_page
*bitmap
;
40 char platform_suspend
;
43 static atomic_t device_available
= ATOMIC_INIT(1);
45 static int snapshot_open(struct inode
*inode
, struct file
*filp
)
47 struct snapshot_data
*data
;
49 if (!atomic_add_unless(&device_available
, -1, 0))
52 if ((filp
->f_flags
& O_ACCMODE
) == O_RDWR
) {
53 atomic_inc(&device_available
);
56 if(create_basic_memory_bitmaps()) {
57 atomic_inc(&device_available
);
60 nonseekable_open(inode
, filp
);
61 data
= &snapshot_state
;
62 filp
->private_data
= data
;
63 memset(&data
->handle
, 0, sizeof(struct snapshot_handle
));
64 if ((filp
->f_flags
& O_ACCMODE
) == O_RDONLY
) {
65 data
->swap
= swsusp_resume_device
?
66 swap_type_of(swsusp_resume_device
, 0, NULL
) : -1;
67 data
->mode
= O_RDONLY
;
70 data
->mode
= O_WRONLY
;
75 data
->platform_suspend
= 0;
80 static int snapshot_release(struct inode
*inode
, struct file
*filp
)
82 struct snapshot_data
*data
;
85 free_basic_memory_bitmaps();
86 data
= filp
->private_data
;
87 free_all_swap_pages(data
->swap
, data
->bitmap
);
88 free_bitmap(data
->bitmap
);
90 mutex_lock(&pm_mutex
);
92 enable_nonboot_cpus();
93 mutex_unlock(&pm_mutex
);
95 atomic_inc(&device_available
);
99 static ssize_t
snapshot_read(struct file
*filp
, char __user
*buf
,
100 size_t count
, loff_t
*offp
)
102 struct snapshot_data
*data
;
105 data
= filp
->private_data
;
106 res
= snapshot_read_next(&data
->handle
, count
);
108 if (copy_to_user(buf
, data_of(data
->handle
), res
))
111 *offp
= data
->handle
.offset
;
116 static ssize_t
snapshot_write(struct file
*filp
, const char __user
*buf
,
117 size_t count
, loff_t
*offp
)
119 struct snapshot_data
*data
;
122 data
= filp
->private_data
;
123 res
= snapshot_write_next(&data
->handle
, count
);
125 if (copy_from_user(data_of(data
->handle
), buf
, res
))
128 *offp
= data
->handle
.offset
;
133 static inline int platform_prepare(void)
137 if (pm_ops
&& pm_ops
->prepare
)
138 error
= pm_ops
->prepare(PM_SUSPEND_DISK
);
143 static inline void platform_finish(void)
145 if (pm_ops
&& pm_ops
->finish
)
146 pm_ops
->finish(PM_SUSPEND_DISK
);
149 static inline int snapshot_suspend(int platform_suspend
)
153 mutex_lock(&pm_mutex
);
154 /* Free memory before shutting down devices. */
155 error
= swsusp_shrink_memory();
159 if (platform_suspend
) {
160 error
= platform_prepare();
165 error
= device_suspend(PMSG_FREEZE
);
169 error
= disable_nonboot_cpus();
172 error
= swsusp_suspend();
174 enable_nonboot_cpus();
176 if (platform_suspend
)
182 mutex_unlock(&pm_mutex
);
186 static inline int snapshot_restore(int platform_suspend
)
190 mutex_lock(&pm_mutex
);
191 pm_prepare_console();
192 if (platform_suspend
) {
193 error
= platform_prepare();
198 error
= device_suspend(PMSG_PRETHAW
);
202 error
= disable_nonboot_cpus();
204 error
= swsusp_resume();
206 enable_nonboot_cpus();
208 if (platform_suspend
)
214 pm_restore_console();
215 mutex_unlock(&pm_mutex
);
219 static int snapshot_ioctl(struct inode
*inode
, struct file
*filp
,
220 unsigned int cmd
, unsigned long arg
)
223 struct snapshot_data
*data
;
227 if (_IOC_TYPE(cmd
) != SNAPSHOT_IOC_MAGIC
)
229 if (_IOC_NR(cmd
) > SNAPSHOT_IOC_MAXNR
)
231 if (!capable(CAP_SYS_ADMIN
))
234 data
= filp
->private_data
;
238 case SNAPSHOT_FREEZE
:
241 mutex_lock(&pm_mutex
);
242 if (freeze_processes()) {
246 mutex_unlock(&pm_mutex
);
251 case SNAPSHOT_UNFREEZE
:
254 mutex_lock(&pm_mutex
);
256 mutex_unlock(&pm_mutex
);
260 case SNAPSHOT_ATOMIC_SNAPSHOT
:
261 if (data
->mode
!= O_RDONLY
|| !data
->frozen
|| data
->ready
) {
265 error
= snapshot_suspend(data
->platform_suspend
);
267 error
= put_user(in_suspend
, (unsigned int __user
*)arg
);
272 case SNAPSHOT_ATOMIC_RESTORE
:
273 snapshot_write_finalize(&data
->handle
);
274 if (data
->mode
!= O_WRONLY
|| !data
->frozen
||
275 !snapshot_image_loaded(&data
->handle
)) {
279 error
= snapshot_restore(data
->platform_suspend
);
284 memset(&data
->handle
, 0, sizeof(struct snapshot_handle
));
288 case SNAPSHOT_SET_IMAGE_SIZE
:
292 case SNAPSHOT_AVAIL_SWAP
:
293 avail
= count_swap_pages(data
->swap
, 1);
294 avail
<<= PAGE_SHIFT
;
295 error
= put_user(avail
, (loff_t __user
*)arg
);
298 case SNAPSHOT_GET_SWAP_PAGE
:
299 if (data
->swap
< 0 || data
->swap
>= MAX_SWAPFILES
) {
304 data
->bitmap
= alloc_bitmap(count_swap_pages(data
->swap
, 0));
310 offset
= alloc_swapdev_block(data
->swap
, data
->bitmap
);
312 offset
<<= PAGE_SHIFT
;
313 error
= put_user(offset
, (sector_t __user
*)arg
);
319 case SNAPSHOT_FREE_SWAP_PAGES
:
320 if (data
->swap
< 0 || data
->swap
>= MAX_SWAPFILES
) {
324 free_all_swap_pages(data
->swap
, data
->bitmap
);
325 free_bitmap(data
->bitmap
);
329 case SNAPSHOT_SET_SWAP_FILE
:
332 * User space encodes device types as two-byte values,
333 * so we need to recode them
335 if (old_decode_dev(arg
)) {
336 data
->swap
= swap_type_of(old_decode_dev(arg
),
360 if (!mutex_trylock(&pm_mutex
)) {
365 if (pm_ops
->prepare
) {
366 error
= pm_ops
->prepare(PM_SUSPEND_MEM
);
371 /* Put devices to sleep */
373 error
= device_suspend(PMSG_SUSPEND
);
375 printk(KERN_ERR
"Failed to suspend some devices.\n");
377 error
= disable_nonboot_cpus();
379 /* Enter S3, system is already frozen */
380 suspend_enter(PM_SUSPEND_MEM
);
381 enable_nonboot_cpus();
383 /* Wake up devices */
388 pm_ops
->finish(PM_SUSPEND_MEM
);
391 mutex_unlock(&pm_mutex
);
400 if (pm_ops
&& pm_ops
->enter
) {
401 data
->platform_suspend
= 1;
409 if (data
->platform_suspend
) {
410 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK
);
411 error
= pm_ops
->enter(PM_SUSPEND_DISK
);
417 if (data
->platform_suspend
)
423 printk(KERN_ERR
"SNAPSHOT_PMOPS: invalid argument %ld\n", arg
);
428 case SNAPSHOT_SET_SWAP_AREA
:
432 struct resume_swap_area swap_area
;
435 error
= copy_from_user(&swap_area
, (void __user
*)arg
,
436 sizeof(struct resume_swap_area
));
443 * User space encodes device types as two-byte values,
444 * so we need to recode them
446 swdev
= old_decode_dev(swap_area
.dev
);
448 offset
= swap_area
.offset
;
449 data
->swap
= swap_type_of(swdev
, offset
, NULL
);
467 static const struct file_operations snapshot_fops
= {
468 .open
= snapshot_open
,
469 .release
= snapshot_release
,
470 .read
= snapshot_read
,
471 .write
= snapshot_write
,
473 .ioctl
= snapshot_ioctl
,
476 static struct miscdevice snapshot_device
= {
477 .minor
= SNAPSHOT_MINOR
,
479 .fops
= &snapshot_fops
,
482 static int __init
snapshot_device_init(void)
484 return misc_register(&snapshot_device
);
487 device_initcall(snapshot_device_init
);