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Commit | Line | Data |
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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> | |
c336078b | 23 | #include <linux/compat.h> |
97c7801c | 24 | #include <linux/console.h> |
e3920fb4 | 25 | #include <linux/cpu.h> |
7dfb7103 | 26 | #include <linux/freezer.h> |
6e1819d6 RW |
27 | |
28 | #include <asm/uaccess.h> | |
29 | ||
30 | #include "power.h" | |
31 | ||
eb57c1cf | 32 | |
6e1819d6 RW |
33 | #define SNAPSHOT_MINOR 231 |
34 | ||
35 | static struct snapshot_data { | |
36 | struct snapshot_handle handle; | |
37 | int swap; | |
6e1819d6 RW |
38 | int mode; |
39 | char frozen; | |
40 | char ready; | |
eb57c1cf | 41 | char platform_support; |
6e1819d6 RW |
42 | } snapshot_state; |
43 | ||
0709db60 | 44 | atomic_t snapshot_device_available = ATOMIC_INIT(1); |
6e1819d6 RW |
45 | |
46 | static int snapshot_open(struct inode *inode, struct file *filp) | |
47 | { | |
48 | struct snapshot_data *data; | |
c3e94d89 | 49 | int error; |
6e1819d6 | 50 | |
bcda53fa | 51 | lock_system_sleep(); |
25f2f3da RW |
52 | |
53 | if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { | |
54 | error = -EBUSY; | |
55 | goto Unlock; | |
56 | } | |
6e1819d6 | 57 | |
1525a2ad | 58 | if ((filp->f_flags & O_ACCMODE) == O_RDWR) { |
0709db60 | 59 | atomic_inc(&snapshot_device_available); |
25f2f3da RW |
60 | error = -ENOSYS; |
61 | goto Unlock; | |
1525a2ad | 62 | } |
6e1819d6 RW |
63 | nonseekable_open(inode, filp); |
64 | data = &snapshot_state; | |
65 | filp->private_data = data; | |
66 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
67 | if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { | |
c7510859 | 68 | /* Hibernating. The image device should be accessible. */ |
915bae9e | 69 | data->swap = swsusp_resume_device ? |
7bf23687 | 70 | swap_type_of(swsusp_resume_device, 0, NULL) : -1; |
6e1819d6 | 71 | data->mode = O_RDONLY; |
ebae2604 | 72 | error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE); |
c3e94d89 | 73 | if (error) |
ebae2604 | 74 | pm_notifier_call_chain(PM_POST_HIBERNATION); |
6e1819d6 | 75 | } else { |
c7510859 RW |
76 | /* |
77 | * Resuming. We may need to wait for the image device to | |
78 | * appear. | |
79 | */ | |
80 | wait_for_device_probe(); | |
c7510859 | 81 | |
6e1819d6 RW |
82 | data->swap = -1; |
83 | data->mode = O_WRONLY; | |
ebae2604 | 84 | error = pm_notifier_call_chain(PM_RESTORE_PREPARE); |
c3e94d89 | 85 | if (error) |
ebae2604 | 86 | pm_notifier_call_chain(PM_POST_RESTORE); |
c3e94d89 | 87 | } |
8fd37a4c | 88 | if (error) |
c3e94d89 | 89 | atomic_inc(&snapshot_device_available); |
8fd37a4c | 90 | |
6e1819d6 RW |
91 | data->frozen = 0; |
92 | data->ready = 0; | |
eb57c1cf | 93 | data->platform_support = 0; |
6e1819d6 | 94 | |
25f2f3da | 95 | Unlock: |
bcda53fa | 96 | unlock_system_sleep(); |
25f2f3da RW |
97 | |
98 | return error; | |
6e1819d6 RW |
99 | } |
100 | ||
101 | static int snapshot_release(struct inode *inode, struct file *filp) | |
102 | { | |
103 | struct snapshot_data *data; | |
104 | ||
bcda53fa | 105 | lock_system_sleep(); |
25f2f3da | 106 | |
6e1819d6 RW |
107 | swsusp_free(); |
108 | data = filp->private_data; | |
d1d241cc | 109 | free_all_swap_pages(data->swap); |
9744997a RW |
110 | if (data->frozen) { |
111 | pm_restore_gfp_mask(); | |
8fd37a4c | 112 | free_basic_memory_bitmaps(); |
6e1819d6 | 113 | thaw_processes(); |
9744997a | 114 | } |
1497dd1d | 115 | pm_notifier_call_chain(data->mode == O_RDONLY ? |
c3e94d89 | 116 | PM_POST_HIBERNATION : PM_POST_RESTORE); |
0709db60 | 117 | atomic_inc(&snapshot_device_available); |
25f2f3da | 118 | |
bcda53fa | 119 | unlock_system_sleep(); |
25f2f3da | 120 | |
6e1819d6 RW |
121 | return 0; |
122 | } | |
123 | ||
124 | static ssize_t snapshot_read(struct file *filp, char __user *buf, | |
125 | size_t count, loff_t *offp) | |
126 | { | |
127 | struct snapshot_data *data; | |
128 | ssize_t res; | |
d3c1b24c | 129 | loff_t pg_offp = *offp & ~PAGE_MASK; |
6e1819d6 | 130 | |
bcda53fa | 131 | lock_system_sleep(); |
25f2f3da | 132 | |
6e1819d6 | 133 | data = filp->private_data; |
25f2f3da RW |
134 | if (!data->ready) { |
135 | res = -ENODATA; | |
136 | goto Unlock; | |
137 | } | |
d3c1b24c JS |
138 | if (!pg_offp) { /* on page boundary? */ |
139 | res = snapshot_read_next(&data->handle); | |
140 | if (res <= 0) | |
141 | goto Unlock; | |
142 | } else { | |
143 | res = PAGE_SIZE - pg_offp; | |
6e1819d6 | 144 | } |
25f2f3da | 145 | |
d3c1b24c JS |
146 | res = simple_read_from_buffer(buf, count, &pg_offp, |
147 | data_of(data->handle), res); | |
148 | if (res > 0) | |
149 | *offp += res; | |
150 | ||
25f2f3da | 151 | Unlock: |
bcda53fa | 152 | unlock_system_sleep(); |
25f2f3da | 153 | |
6e1819d6 RW |
154 | return res; |
155 | } | |
156 | ||
157 | static ssize_t snapshot_write(struct file *filp, const char __user *buf, | |
158 | size_t count, loff_t *offp) | |
159 | { | |
160 | struct snapshot_data *data; | |
161 | ssize_t res; | |
d3c1b24c | 162 | loff_t pg_offp = *offp & ~PAGE_MASK; |
6e1819d6 | 163 | |
bcda53fa | 164 | lock_system_sleep(); |
25f2f3da | 165 | |
6e1819d6 | 166 | data = filp->private_data; |
d3c1b24c JS |
167 | |
168 | if (!pg_offp) { | |
169 | res = snapshot_write_next(&data->handle); | |
170 | if (res <= 0) | |
171 | goto unlock; | |
172 | } else { | |
173 | res = PAGE_SIZE - pg_offp; | |
6e1819d6 | 174 | } |
25f2f3da | 175 | |
d3c1b24c JS |
176 | res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp, |
177 | buf, count); | |
178 | if (res > 0) | |
179 | *offp += res; | |
180 | unlock: | |
bcda53fa | 181 | unlock_system_sleep(); |
25f2f3da | 182 | |
6e1819d6 RW |
183 | return res; |
184 | } | |
185 | ||
52d11025 AC |
186 | static long snapshot_ioctl(struct file *filp, unsigned int cmd, |
187 | unsigned long arg) | |
6e1819d6 RW |
188 | { |
189 | int error = 0; | |
190 | struct snapshot_data *data; | |
af508b34 | 191 | loff_t size; |
3aef83e0 | 192 | sector_t offset; |
6e1819d6 RW |
193 | |
194 | if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) | |
195 | return -ENOTTY; | |
196 | if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) | |
197 | return -ENOTTY; | |
198 | if (!capable(CAP_SYS_ADMIN)) | |
199 | return -EPERM; | |
200 | ||
25f2f3da RW |
201 | if (!mutex_trylock(&pm_mutex)) |
202 | return -EBUSY; | |
6e1819d6 | 203 | |
25f2f3da | 204 | data = filp->private_data; |
52d11025 | 205 | |
6e1819d6 RW |
206 | switch (cmd) { |
207 | ||
208 | case SNAPSHOT_FREEZE: | |
209 | if (data->frozen) | |
210 | break; | |
1bfcf130 | 211 | |
c3e94d89 AS |
212 | printk("Syncing filesystems ... "); |
213 | sys_sync(); | |
214 | printk("done.\n"); | |
215 | ||
1bfcf130 | 216 | error = freeze_processes(); |
8fd37a4c RW |
217 | if (error) |
218 | break; | |
219 | ||
220 | error = create_basic_memory_bitmaps(); | |
221 | if (error) | |
222 | thaw_processes(); | |
223 | else | |
6e1819d6 | 224 | data->frozen = 1; |
8fd37a4c | 225 | |
6e1819d6 RW |
226 | break; |
227 | ||
228 | case SNAPSHOT_UNFREEZE: | |
2f41dddb | 229 | if (!data->frozen || data->ready) |
6e1819d6 | 230 | break; |
c9e664f1 | 231 | pm_restore_gfp_mask(); |
8fd37a4c | 232 | free_basic_memory_bitmaps(); |
6e1819d6 | 233 | thaw_processes(); |
6e1819d6 RW |
234 | data->frozen = 0; |
235 | break; | |
236 | ||
b694e52e | 237 | case SNAPSHOT_CREATE_IMAGE: |
6e1819d6 RW |
238 | if (data->mode != O_RDONLY || !data->frozen || data->ready) { |
239 | error = -EPERM; | |
240 | break; | |
241 | } | |
c9e664f1 | 242 | pm_restore_gfp_mask(); |
eb57c1cf | 243 | error = hibernation_snapshot(data->platform_support); |
51d6ff7a | 244 | if (!error) { |
cc5d207c | 245 | error = put_user(in_suspend, (int __user *)arg); |
a556d5b5 SB |
246 | data->ready = !freezer_test_done && !error; |
247 | freezer_test_done = false; | |
97819a26 | 248 | } |
6e1819d6 RW |
249 | break; |
250 | ||
251 | case SNAPSHOT_ATOMIC_RESTORE: | |
8357376d | 252 | snapshot_write_finalize(&data->handle); |
6e1819d6 RW |
253 | if (data->mode != O_WRONLY || !data->frozen || |
254 | !snapshot_image_loaded(&data->handle)) { | |
255 | error = -EPERM; | |
256 | break; | |
257 | } | |
eb57c1cf | 258 | error = hibernation_restore(data->platform_support); |
6e1819d6 RW |
259 | break; |
260 | ||
261 | case SNAPSHOT_FREE: | |
262 | swsusp_free(); | |
263 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
264 | data->ready = 0; | |
181e9bde RW |
265 | /* |
266 | * It is necessary to thaw kernel threads here, because | |
267 | * SNAPSHOT_CREATE_IMAGE may be invoked directly after | |
268 | * SNAPSHOT_FREE. In that case, if kernel threads were not | |
269 | * thawed, the preallocation of memory carried out by | |
270 | * hibernation_snapshot() might run into problems (i.e. it | |
271 | * might fail or even deadlock). | |
272 | */ | |
273 | thaw_kernel_threads(); | |
6e1819d6 RW |
274 | break; |
275 | ||
b694e52e | 276 | case SNAPSHOT_PREF_IMAGE_SIZE: |
6e1819d6 RW |
277 | image_size = arg; |
278 | break; | |
279 | ||
af508b34 RW |
280 | case SNAPSHOT_GET_IMAGE_SIZE: |
281 | if (!data->ready) { | |
282 | error = -ENODATA; | |
283 | break; | |
284 | } | |
285 | size = snapshot_get_image_size(); | |
286 | size <<= PAGE_SHIFT; | |
287 | error = put_user(size, (loff_t __user *)arg); | |
288 | break; | |
289 | ||
b694e52e | 290 | case SNAPSHOT_AVAIL_SWAP_SIZE: |
af508b34 RW |
291 | size = count_swap_pages(data->swap, 1); |
292 | size <<= PAGE_SHIFT; | |
293 | error = put_user(size, (loff_t __user *)arg); | |
6e1819d6 RW |
294 | break; |
295 | ||
b694e52e | 296 | case SNAPSHOT_ALLOC_SWAP_PAGE: |
6e1819d6 RW |
297 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { |
298 | error = -ENODEV; | |
299 | break; | |
300 | } | |
d1d241cc | 301 | offset = alloc_swapdev_block(data->swap); |
6e1819d6 RW |
302 | if (offset) { |
303 | offset <<= PAGE_SHIFT; | |
cc5d207c | 304 | error = put_user(offset, (loff_t __user *)arg); |
6e1819d6 RW |
305 | } else { |
306 | error = -ENOSPC; | |
307 | } | |
308 | break; | |
309 | ||
310 | case SNAPSHOT_FREE_SWAP_PAGES: | |
311 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
312 | error = -ENODEV; | |
313 | break; | |
314 | } | |
d1d241cc | 315 | free_all_swap_pages(data->swap); |
6e1819d6 RW |
316 | break; |
317 | ||
9b238205 LT |
318 | case SNAPSHOT_S2RAM: |
319 | if (!data->frozen) { | |
320 | error = -EPERM; | |
321 | break; | |
322 | } | |
6c961dfb RW |
323 | /* |
324 | * Tasks are frozen and the notifiers have been called with | |
325 | * PM_HIBERNATION_PREPARE | |
326 | */ | |
327 | error = suspend_devices_and_enter(PM_SUSPEND_MEM); | |
36cb7035 | 328 | data->ready = 0; |
9b238205 LT |
329 | break; |
330 | ||
eb57c1cf RW |
331 | case SNAPSHOT_PLATFORM_SUPPORT: |
332 | data->platform_support = !!arg; | |
333 | break; | |
334 | ||
335 | case SNAPSHOT_POWER_OFF: | |
336 | if (data->platform_support) | |
337 | error = hibernation_platform_enter(); | |
338 | break; | |
339 | ||
37b2ba12 | 340 | case SNAPSHOT_SET_SWAP_AREA: |
d1d241cc | 341 | if (swsusp_swap_in_use()) { |
37b2ba12 RW |
342 | error = -EPERM; |
343 | } else { | |
344 | struct resume_swap_area swap_area; | |
345 | dev_t swdev; | |
346 | ||
347 | error = copy_from_user(&swap_area, (void __user *)arg, | |
348 | sizeof(struct resume_swap_area)); | |
349 | if (error) { | |
350 | error = -EFAULT; | |
351 | break; | |
352 | } | |
353 | ||
354 | /* | |
355 | * User space encodes device types as two-byte values, | |
356 | * so we need to recode them | |
357 | */ | |
d88d4050 | 358 | swdev = new_decode_dev(swap_area.dev); |
37b2ba12 RW |
359 | if (swdev) { |
360 | offset = swap_area.offset; | |
7bf23687 | 361 | data->swap = swap_type_of(swdev, offset, NULL); |
37b2ba12 RW |
362 | if (data->swap < 0) |
363 | error = -ENODEV; | |
364 | } else { | |
365 | data->swap = -1; | |
366 | error = -EINVAL; | |
367 | } | |
368 | } | |
369 | break; | |
370 | ||
6e1819d6 RW |
371 | default: |
372 | error = -ENOTTY; | |
373 | ||
374 | } | |
25f2f3da RW |
375 | |
376 | mutex_unlock(&pm_mutex); | |
377 | ||
6e1819d6 RW |
378 | return error; |
379 | } | |
380 | ||
c336078b BH |
381 | #ifdef CONFIG_COMPAT |
382 | ||
383 | struct compat_resume_swap_area { | |
384 | compat_loff_t offset; | |
385 | u32 dev; | |
386 | } __packed; | |
387 | ||
388 | static long | |
389 | snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
390 | { | |
391 | BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t)); | |
392 | ||
393 | switch (cmd) { | |
394 | case SNAPSHOT_GET_IMAGE_SIZE: | |
395 | case SNAPSHOT_AVAIL_SWAP_SIZE: | |
396 | case SNAPSHOT_ALLOC_SWAP_PAGE: { | |
397 | compat_loff_t __user *uoffset = compat_ptr(arg); | |
398 | loff_t offset; | |
399 | mm_segment_t old_fs; | |
400 | int err; | |
401 | ||
402 | old_fs = get_fs(); | |
403 | set_fs(KERNEL_DS); | |
404 | err = snapshot_ioctl(file, cmd, (unsigned long) &offset); | |
405 | set_fs(old_fs); | |
406 | if (!err && put_user(offset, uoffset)) | |
407 | err = -EFAULT; | |
408 | return err; | |
409 | } | |
410 | ||
411 | case SNAPSHOT_CREATE_IMAGE: | |
412 | return snapshot_ioctl(file, cmd, | |
413 | (unsigned long) compat_ptr(arg)); | |
414 | ||
415 | case SNAPSHOT_SET_SWAP_AREA: { | |
416 | struct compat_resume_swap_area __user *u_swap_area = | |
417 | compat_ptr(arg); | |
418 | struct resume_swap_area swap_area; | |
419 | mm_segment_t old_fs; | |
420 | int err; | |
421 | ||
422 | err = get_user(swap_area.offset, &u_swap_area->offset); | |
423 | err |= get_user(swap_area.dev, &u_swap_area->dev); | |
424 | if (err) | |
425 | return -EFAULT; | |
426 | old_fs = get_fs(); | |
427 | set_fs(KERNEL_DS); | |
428 | err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA, | |
429 | (unsigned long) &swap_area); | |
430 | set_fs(old_fs); | |
431 | return err; | |
432 | } | |
433 | ||
434 | default: | |
435 | return snapshot_ioctl(file, cmd, arg); | |
436 | } | |
437 | } | |
438 | ||
439 | #endif /* CONFIG_COMPAT */ | |
440 | ||
15ad7cdc | 441 | static const struct file_operations snapshot_fops = { |
6e1819d6 RW |
442 | .open = snapshot_open, |
443 | .release = snapshot_release, | |
444 | .read = snapshot_read, | |
445 | .write = snapshot_write, | |
446 | .llseek = no_llseek, | |
52d11025 | 447 | .unlocked_ioctl = snapshot_ioctl, |
c336078b BH |
448 | #ifdef CONFIG_COMPAT |
449 | .compat_ioctl = snapshot_compat_ioctl, | |
450 | #endif | |
6e1819d6 RW |
451 | }; |
452 | ||
453 | static struct miscdevice snapshot_device = { | |
454 | .minor = SNAPSHOT_MINOR, | |
455 | .name = "snapshot", | |
456 | .fops = &snapshot_fops, | |
457 | }; | |
458 | ||
459 | static int __init snapshot_device_init(void) | |
460 | { | |
461 | return misc_register(&snapshot_device); | |
462 | }; | |
463 | ||
464 | device_initcall(snapshot_device_init); |