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>
26 #include <scsi/scsi_scan.h>
28 #include <asm/uaccess.h>
33 * NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and
34 * will be removed in the future. They are only preserved here for
35 * compatibility with existing userland utilities.
37 #define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
38 #define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
40 #define PMOPS_PREPARE 1
42 #define PMOPS_FINISH 3
45 * NOTE: The following ioctl definitions are wrong and have been replaced with
46 * correct ones. They are only preserved here for compatibility with existing
47 * userland utilities and will be removed in the future.
49 #define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
50 #define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
51 #define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
52 #define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
55 #define SNAPSHOT_MINOR 231
57 static struct snapshot_data
{
58 struct snapshot_handle handle
;
63 char platform_support
;
66 atomic_t snapshot_device_available
= ATOMIC_INIT(1);
68 static int snapshot_open(struct inode
*inode
, struct file
*filp
)
70 struct snapshot_data
*data
;
73 mutex_lock(&pm_mutex
);
75 if (!atomic_add_unless(&snapshot_device_available
, -1, 0)) {
80 if ((filp
->f_flags
& O_ACCMODE
) == O_RDWR
) {
81 atomic_inc(&snapshot_device_available
);
85 if(create_basic_memory_bitmaps()) {
86 atomic_inc(&snapshot_device_available
);
90 nonseekable_open(inode
, filp
);
91 data
= &snapshot_state
;
92 filp
->private_data
= data
;
93 memset(&data
->handle
, 0, sizeof(struct snapshot_handle
));
94 if ((filp
->f_flags
& O_ACCMODE
) == O_RDONLY
) {
95 /* Hibernating. The image device should be accessible. */
96 data
->swap
= swsusp_resume_device
?
97 swap_type_of(swsusp_resume_device
, 0, NULL
) : -1;
98 data
->mode
= O_RDONLY
;
99 error
= pm_notifier_call_chain(PM_HIBERNATION_PREPARE
);
101 pm_notifier_call_chain(PM_POST_HIBERNATION
);
104 * Resuming. We may need to wait for the image device to
107 wait_for_device_probe();
108 scsi_complete_async_scans();
111 data
->mode
= O_WRONLY
;
112 error
= pm_notifier_call_chain(PM_RESTORE_PREPARE
);
114 pm_notifier_call_chain(PM_POST_RESTORE
);
117 atomic_inc(&snapshot_device_available
);
120 data
->platform_support
= 0;
123 mutex_unlock(&pm_mutex
);
128 static int snapshot_release(struct inode
*inode
, struct file
*filp
)
130 struct snapshot_data
*data
;
132 mutex_lock(&pm_mutex
);
135 free_basic_memory_bitmaps();
136 data
= filp
->private_data
;
137 free_all_swap_pages(data
->swap
);
140 pm_notifier_call_chain(data
->mode
== O_WRONLY
?
141 PM_POST_HIBERNATION
: PM_POST_RESTORE
);
142 atomic_inc(&snapshot_device_available
);
144 mutex_unlock(&pm_mutex
);
149 static ssize_t
snapshot_read(struct file
*filp
, char __user
*buf
,
150 size_t count
, loff_t
*offp
)
152 struct snapshot_data
*data
;
155 mutex_lock(&pm_mutex
);
157 data
= filp
->private_data
;
162 res
= snapshot_read_next(&data
->handle
, count
);
164 if (copy_to_user(buf
, data_of(data
->handle
), res
))
167 *offp
= data
->handle
.offset
;
171 mutex_unlock(&pm_mutex
);
176 static ssize_t
snapshot_write(struct file
*filp
, const char __user
*buf
,
177 size_t count
, loff_t
*offp
)
179 struct snapshot_data
*data
;
182 mutex_lock(&pm_mutex
);
184 data
= filp
->private_data
;
185 res
= snapshot_write_next(&data
->handle
, count
);
187 if (copy_from_user(data_of(data
->handle
), buf
, res
))
190 *offp
= data
->handle
.offset
;
193 mutex_unlock(&pm_mutex
);
198 static void snapshot_deprecated_ioctl(unsigned int cmd
)
200 if (printk_ratelimit())
201 printk(KERN_NOTICE
"%pf: ioctl '%.8x' is deprecated and will "
202 "be removed soon, update your suspend-to-disk "
204 __builtin_return_address(0), cmd
);
207 static long snapshot_ioctl(struct file
*filp
, unsigned int cmd
,
211 struct snapshot_data
*data
;
215 if (_IOC_TYPE(cmd
) != SNAPSHOT_IOC_MAGIC
)
217 if (_IOC_NR(cmd
) > SNAPSHOT_IOC_MAXNR
)
219 if (!capable(CAP_SYS_ADMIN
))
222 if (!mutex_trylock(&pm_mutex
))
225 data
= filp
->private_data
;
229 case SNAPSHOT_FREEZE
:
233 printk("Syncing filesystems ... ");
237 error
= usermodehelper_disable();
241 error
= freeze_processes();
244 usermodehelper_enable();
250 case SNAPSHOT_UNFREEZE
:
251 if (!data
->frozen
|| data
->ready
)
254 usermodehelper_enable();
258 case SNAPSHOT_ATOMIC_SNAPSHOT
:
259 snapshot_deprecated_ioctl(cmd
);
260 case SNAPSHOT_CREATE_IMAGE
:
261 if (data
->mode
!= O_RDONLY
|| !data
->frozen
|| data
->ready
) {
265 error
= hibernation_snapshot(data
->platform_support
);
267 error
= put_user(in_suspend
, (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
= hibernation_restore(data
->platform_support
);
284 memset(&data
->handle
, 0, sizeof(struct snapshot_handle
));
288 case SNAPSHOT_SET_IMAGE_SIZE
:
289 snapshot_deprecated_ioctl(cmd
);
290 case SNAPSHOT_PREF_IMAGE_SIZE
:
294 case SNAPSHOT_GET_IMAGE_SIZE
:
299 size
= snapshot_get_image_size();
301 error
= put_user(size
, (loff_t __user
*)arg
);
304 case SNAPSHOT_AVAIL_SWAP
:
305 snapshot_deprecated_ioctl(cmd
);
306 case SNAPSHOT_AVAIL_SWAP_SIZE
:
307 size
= count_swap_pages(data
->swap
, 1);
309 error
= put_user(size
, (loff_t __user
*)arg
);
312 case SNAPSHOT_GET_SWAP_PAGE
:
313 snapshot_deprecated_ioctl(cmd
);
314 case SNAPSHOT_ALLOC_SWAP_PAGE
:
315 if (data
->swap
< 0 || data
->swap
>= MAX_SWAPFILES
) {
319 offset
= alloc_swapdev_block(data
->swap
);
321 offset
<<= PAGE_SHIFT
;
322 error
= put_user(offset
, (loff_t __user
*)arg
);
328 case SNAPSHOT_FREE_SWAP_PAGES
:
329 if (data
->swap
< 0 || data
->swap
>= MAX_SWAPFILES
) {
333 free_all_swap_pages(data
->swap
);
336 case SNAPSHOT_SET_SWAP_FILE
: /* This ioctl is deprecated */
337 snapshot_deprecated_ioctl(cmd
);
338 if (!swsusp_swap_in_use()) {
340 * User space encodes device types as two-byte values,
341 * so we need to recode them
343 if (old_decode_dev(arg
)) {
344 data
->swap
= swap_type_of(old_decode_dev(arg
),
363 * Tasks are frozen and the notifiers have been called with
364 * PM_HIBERNATION_PREPARE
366 error
= suspend_devices_and_enter(PM_SUSPEND_MEM
);
369 case SNAPSHOT_PLATFORM_SUPPORT
:
370 data
->platform_support
= !!arg
;
373 case SNAPSHOT_POWER_OFF
:
374 if (data
->platform_support
)
375 error
= hibernation_platform_enter();
378 case SNAPSHOT_PMOPS
: /* This ioctl is deprecated */
379 snapshot_deprecated_ioctl(cmd
);
385 data
->platform_support
= 1;
390 if (data
->platform_support
)
391 error
= hibernation_platform_enter();
395 if (data
->platform_support
)
400 printk(KERN_ERR
"SNAPSHOT_PMOPS: invalid argument %ld\n", arg
);
405 case SNAPSHOT_SET_SWAP_AREA
:
406 if (swsusp_swap_in_use()) {
409 struct resume_swap_area swap_area
;
412 error
= copy_from_user(&swap_area
, (void __user
*)arg
,
413 sizeof(struct resume_swap_area
));
420 * User space encodes device types as two-byte values,
421 * so we need to recode them
423 swdev
= old_decode_dev(swap_area
.dev
);
425 offset
= swap_area
.offset
;
426 data
->swap
= swap_type_of(swdev
, offset
, NULL
);
441 mutex_unlock(&pm_mutex
);
446 static const struct file_operations snapshot_fops
= {
447 .open
= snapshot_open
,
448 .release
= snapshot_release
,
449 .read
= snapshot_read
,
450 .write
= snapshot_write
,
452 .unlocked_ioctl
= snapshot_ioctl
,
455 static struct miscdevice snapshot_device
= {
456 .minor
= SNAPSHOT_MINOR
,
458 .fops
= &snapshot_fops
,
461 static int __init
snapshot_device_init(void)
463 return misc_register(&snapshot_device
);
466 device_initcall(snapshot_device_init
);