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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 | 38 | int mode; |
7bc9b1cf RW |
39 | bool frozen; |
40 | bool ready; | |
41 | bool platform_support; | |
aab17289 | 42 | bool free_bitmaps; |
6e1819d6 RW |
43 | } snapshot_state; |
44 | ||
0709db60 | 45 | atomic_t snapshot_device_available = ATOMIC_INIT(1); |
6e1819d6 RW |
46 | |
47 | static int snapshot_open(struct inode *inode, struct file *filp) | |
48 | { | |
49 | struct snapshot_data *data; | |
c3e94d89 | 50 | int error; |
6e1819d6 | 51 | |
bcda53fa | 52 | lock_system_sleep(); |
25f2f3da RW |
53 | |
54 | if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { | |
55 | error = -EBUSY; | |
56 | goto Unlock; | |
57 | } | |
6e1819d6 | 58 | |
1525a2ad | 59 | if ((filp->f_flags & O_ACCMODE) == O_RDWR) { |
0709db60 | 60 | atomic_inc(&snapshot_device_available); |
25f2f3da RW |
61 | error = -ENOSYS; |
62 | goto Unlock; | |
1525a2ad | 63 | } |
6e1819d6 RW |
64 | nonseekable_open(inode, filp); |
65 | data = &snapshot_state; | |
66 | filp->private_data = data; | |
67 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
68 | if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { | |
c7510859 | 69 | /* Hibernating. The image device should be accessible. */ |
915bae9e | 70 | data->swap = swsusp_resume_device ? |
7bf23687 | 71 | swap_type_of(swsusp_resume_device, 0, NULL) : -1; |
6e1819d6 | 72 | data->mode = O_RDONLY; |
6a0c7cd3 | 73 | data->free_bitmaps = false; |
ebae2604 | 74 | error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE); |
c3e94d89 | 75 | if (error) |
ebae2604 | 76 | pm_notifier_call_chain(PM_POST_HIBERNATION); |
6e1819d6 | 77 | } else { |
c7510859 RW |
78 | /* |
79 | * Resuming. We may need to wait for the image device to | |
80 | * appear. | |
81 | */ | |
82 | wait_for_device_probe(); | |
c7510859 | 83 | |
6e1819d6 RW |
84 | data->swap = -1; |
85 | data->mode = O_WRONLY; | |
ebae2604 | 86 | error = pm_notifier_call_chain(PM_RESTORE_PREPARE); |
aab17289 RW |
87 | if (!error) { |
88 | error = create_basic_memory_bitmaps(); | |
89 | data->free_bitmaps = !error; | |
90 | } | |
c3e94d89 | 91 | if (error) |
ebae2604 | 92 | pm_notifier_call_chain(PM_POST_RESTORE); |
c3e94d89 | 93 | } |
8fd37a4c | 94 | if (error) |
c3e94d89 | 95 | atomic_inc(&snapshot_device_available); |
8fd37a4c | 96 | |
7bc9b1cf RW |
97 | data->frozen = false; |
98 | data->ready = false; | |
99 | data->platform_support = false; | |
6e1819d6 | 100 | |
25f2f3da | 101 | Unlock: |
bcda53fa | 102 | unlock_system_sleep(); |
25f2f3da RW |
103 | |
104 | return error; | |
6e1819d6 RW |
105 | } |
106 | ||
107 | static int snapshot_release(struct inode *inode, struct file *filp) | |
108 | { | |
109 | struct snapshot_data *data; | |
110 | ||
bcda53fa | 111 | lock_system_sleep(); |
25f2f3da | 112 | |
6e1819d6 RW |
113 | swsusp_free(); |
114 | data = filp->private_data; | |
d1d241cc | 115 | free_all_swap_pages(data->swap); |
9744997a RW |
116 | if (data->frozen) { |
117 | pm_restore_gfp_mask(); | |
8fd37a4c | 118 | free_basic_memory_bitmaps(); |
6e1819d6 | 119 | thaw_processes(); |
aab17289 RW |
120 | } else if (data->free_bitmaps) { |
121 | free_basic_memory_bitmaps(); | |
9744997a | 122 | } |
1497dd1d | 123 | pm_notifier_call_chain(data->mode == O_RDONLY ? |
c3e94d89 | 124 | PM_POST_HIBERNATION : PM_POST_RESTORE); |
0709db60 | 125 | atomic_inc(&snapshot_device_available); |
25f2f3da | 126 | |
bcda53fa | 127 | unlock_system_sleep(); |
25f2f3da | 128 | |
6e1819d6 RW |
129 | return 0; |
130 | } | |
131 | ||
132 | static ssize_t snapshot_read(struct file *filp, char __user *buf, | |
133 | size_t count, loff_t *offp) | |
134 | { | |
135 | struct snapshot_data *data; | |
136 | ssize_t res; | |
d3c1b24c | 137 | loff_t pg_offp = *offp & ~PAGE_MASK; |
6e1819d6 | 138 | |
bcda53fa | 139 | lock_system_sleep(); |
25f2f3da | 140 | |
6e1819d6 | 141 | data = filp->private_data; |
25f2f3da RW |
142 | if (!data->ready) { |
143 | res = -ENODATA; | |
144 | goto Unlock; | |
145 | } | |
d3c1b24c JS |
146 | if (!pg_offp) { /* on page boundary? */ |
147 | res = snapshot_read_next(&data->handle); | |
148 | if (res <= 0) | |
149 | goto Unlock; | |
150 | } else { | |
151 | res = PAGE_SIZE - pg_offp; | |
6e1819d6 | 152 | } |
25f2f3da | 153 | |
d3c1b24c JS |
154 | res = simple_read_from_buffer(buf, count, &pg_offp, |
155 | data_of(data->handle), res); | |
156 | if (res > 0) | |
157 | *offp += res; | |
158 | ||
25f2f3da | 159 | Unlock: |
bcda53fa | 160 | unlock_system_sleep(); |
25f2f3da | 161 | |
6e1819d6 RW |
162 | return res; |
163 | } | |
164 | ||
165 | static ssize_t snapshot_write(struct file *filp, const char __user *buf, | |
166 | size_t count, loff_t *offp) | |
167 | { | |
168 | struct snapshot_data *data; | |
169 | ssize_t res; | |
d3c1b24c | 170 | loff_t pg_offp = *offp & ~PAGE_MASK; |
6e1819d6 | 171 | |
bcda53fa | 172 | lock_system_sleep(); |
25f2f3da | 173 | |
6e1819d6 | 174 | data = filp->private_data; |
d3c1b24c JS |
175 | |
176 | if (!pg_offp) { | |
177 | res = snapshot_write_next(&data->handle); | |
178 | if (res <= 0) | |
179 | goto unlock; | |
180 | } else { | |
181 | res = PAGE_SIZE - pg_offp; | |
6e1819d6 | 182 | } |
25f2f3da | 183 | |
d3c1b24c JS |
184 | res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp, |
185 | buf, count); | |
186 | if (res > 0) | |
187 | *offp += res; | |
188 | unlock: | |
bcda53fa | 189 | unlock_system_sleep(); |
25f2f3da | 190 | |
6e1819d6 RW |
191 | return res; |
192 | } | |
193 | ||
52d11025 AC |
194 | static long snapshot_ioctl(struct file *filp, unsigned int cmd, |
195 | unsigned long arg) | |
6e1819d6 RW |
196 | { |
197 | int error = 0; | |
198 | struct snapshot_data *data; | |
af508b34 | 199 | loff_t size; |
3aef83e0 | 200 | sector_t offset; |
6e1819d6 RW |
201 | |
202 | if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) | |
203 | return -ENOTTY; | |
204 | if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) | |
205 | return -ENOTTY; | |
206 | if (!capable(CAP_SYS_ADMIN)) | |
207 | return -EPERM; | |
208 | ||
25f2f3da RW |
209 | if (!mutex_trylock(&pm_mutex)) |
210 | return -EBUSY; | |
6e1819d6 | 211 | |
942f4015 | 212 | lock_device_hotplug(); |
25f2f3da | 213 | data = filp->private_data; |
52d11025 | 214 | |
6e1819d6 RW |
215 | switch (cmd) { |
216 | ||
217 | case SNAPSHOT_FREEZE: | |
218 | if (data->frozen) | |
219 | break; | |
1bfcf130 | 220 | |
c3e94d89 AS |
221 | printk("Syncing filesystems ... "); |
222 | sys_sync(); | |
223 | printk("done.\n"); | |
224 | ||
1bfcf130 | 225 | error = freeze_processes(); |
8fd37a4c RW |
226 | if (error) |
227 | break; | |
228 | ||
229 | error = create_basic_memory_bitmaps(); | |
230 | if (error) | |
231 | thaw_processes(); | |
232 | else | |
7bc9b1cf | 233 | data->frozen = true; |
8fd37a4c | 234 | |
6e1819d6 RW |
235 | break; |
236 | ||
237 | case SNAPSHOT_UNFREEZE: | |
2f41dddb | 238 | if (!data->frozen || data->ready) |
6e1819d6 | 239 | break; |
c9e664f1 | 240 | pm_restore_gfp_mask(); |
8fd37a4c | 241 | free_basic_memory_bitmaps(); |
aab17289 | 242 | data->free_bitmaps = false; |
6e1819d6 | 243 | thaw_processes(); |
7bc9b1cf | 244 | data->frozen = false; |
6e1819d6 RW |
245 | break; |
246 | ||
b694e52e | 247 | case SNAPSHOT_CREATE_IMAGE: |
6e1819d6 RW |
248 | if (data->mode != O_RDONLY || !data->frozen || data->ready) { |
249 | error = -EPERM; | |
250 | break; | |
251 | } | |
c9e664f1 | 252 | pm_restore_gfp_mask(); |
eb57c1cf | 253 | error = hibernation_snapshot(data->platform_support); |
51d6ff7a | 254 | if (!error) { |
cc5d207c | 255 | error = put_user(in_suspend, (int __user *)arg); |
a556d5b5 SB |
256 | data->ready = !freezer_test_done && !error; |
257 | freezer_test_done = false; | |
97819a26 | 258 | } |
6e1819d6 RW |
259 | break; |
260 | ||
261 | case SNAPSHOT_ATOMIC_RESTORE: | |
8357376d | 262 | snapshot_write_finalize(&data->handle); |
6e1819d6 RW |
263 | if (data->mode != O_WRONLY || !data->frozen || |
264 | !snapshot_image_loaded(&data->handle)) { | |
265 | error = -EPERM; | |
266 | break; | |
267 | } | |
eb57c1cf | 268 | error = hibernation_restore(data->platform_support); |
6e1819d6 RW |
269 | break; |
270 | ||
271 | case SNAPSHOT_FREE: | |
272 | swsusp_free(); | |
273 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
7bc9b1cf | 274 | data->ready = false; |
181e9bde RW |
275 | /* |
276 | * It is necessary to thaw kernel threads here, because | |
277 | * SNAPSHOT_CREATE_IMAGE may be invoked directly after | |
278 | * SNAPSHOT_FREE. In that case, if kernel threads were not | |
279 | * thawed, the preallocation of memory carried out by | |
280 | * hibernation_snapshot() might run into problems (i.e. it | |
281 | * might fail or even deadlock). | |
282 | */ | |
283 | thaw_kernel_threads(); | |
6e1819d6 RW |
284 | break; |
285 | ||
b694e52e | 286 | case SNAPSHOT_PREF_IMAGE_SIZE: |
6e1819d6 RW |
287 | image_size = arg; |
288 | break; | |
289 | ||
af508b34 RW |
290 | case SNAPSHOT_GET_IMAGE_SIZE: |
291 | if (!data->ready) { | |
292 | error = -ENODATA; | |
293 | break; | |
294 | } | |
295 | size = snapshot_get_image_size(); | |
296 | size <<= PAGE_SHIFT; | |
297 | error = put_user(size, (loff_t __user *)arg); | |
298 | break; | |
299 | ||
b694e52e | 300 | case SNAPSHOT_AVAIL_SWAP_SIZE: |
af508b34 RW |
301 | size = count_swap_pages(data->swap, 1); |
302 | size <<= PAGE_SHIFT; | |
303 | error = put_user(size, (loff_t __user *)arg); | |
6e1819d6 RW |
304 | break; |
305 | ||
b694e52e | 306 | case SNAPSHOT_ALLOC_SWAP_PAGE: |
6e1819d6 RW |
307 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { |
308 | error = -ENODEV; | |
309 | break; | |
310 | } | |
d1d241cc | 311 | offset = alloc_swapdev_block(data->swap); |
6e1819d6 RW |
312 | if (offset) { |
313 | offset <<= PAGE_SHIFT; | |
cc5d207c | 314 | error = put_user(offset, (loff_t __user *)arg); |
6e1819d6 RW |
315 | } else { |
316 | error = -ENOSPC; | |
317 | } | |
318 | break; | |
319 | ||
320 | case SNAPSHOT_FREE_SWAP_PAGES: | |
321 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
322 | error = -ENODEV; | |
323 | break; | |
324 | } | |
d1d241cc | 325 | free_all_swap_pages(data->swap); |
6e1819d6 RW |
326 | break; |
327 | ||
9b238205 LT |
328 | case SNAPSHOT_S2RAM: |
329 | if (!data->frozen) { | |
330 | error = -EPERM; | |
331 | break; | |
332 | } | |
6c961dfb RW |
333 | /* |
334 | * Tasks are frozen and the notifiers have been called with | |
335 | * PM_HIBERNATION_PREPARE | |
336 | */ | |
337 | error = suspend_devices_and_enter(PM_SUSPEND_MEM); | |
7bc9b1cf | 338 | data->ready = false; |
9b238205 LT |
339 | break; |
340 | ||
eb57c1cf RW |
341 | case SNAPSHOT_PLATFORM_SUPPORT: |
342 | data->platform_support = !!arg; | |
343 | break; | |
344 | ||
345 | case SNAPSHOT_POWER_OFF: | |
346 | if (data->platform_support) | |
347 | error = hibernation_platform_enter(); | |
348 | break; | |
349 | ||
37b2ba12 | 350 | case SNAPSHOT_SET_SWAP_AREA: |
d1d241cc | 351 | if (swsusp_swap_in_use()) { |
37b2ba12 RW |
352 | error = -EPERM; |
353 | } else { | |
354 | struct resume_swap_area swap_area; | |
355 | dev_t swdev; | |
356 | ||
357 | error = copy_from_user(&swap_area, (void __user *)arg, | |
358 | sizeof(struct resume_swap_area)); | |
359 | if (error) { | |
360 | error = -EFAULT; | |
361 | break; | |
362 | } | |
363 | ||
364 | /* | |
365 | * User space encodes device types as two-byte values, | |
366 | * so we need to recode them | |
367 | */ | |
d88d4050 | 368 | swdev = new_decode_dev(swap_area.dev); |
37b2ba12 RW |
369 | if (swdev) { |
370 | offset = swap_area.offset; | |
7bf23687 | 371 | data->swap = swap_type_of(swdev, offset, NULL); |
37b2ba12 RW |
372 | if (data->swap < 0) |
373 | error = -ENODEV; | |
374 | } else { | |
375 | data->swap = -1; | |
376 | error = -EINVAL; | |
377 | } | |
378 | } | |
379 | break; | |
380 | ||
6e1819d6 RW |
381 | default: |
382 | error = -ENOTTY; | |
383 | ||
384 | } | |
25f2f3da | 385 | |
942f4015 | 386 | unlock_device_hotplug(); |
25f2f3da RW |
387 | mutex_unlock(&pm_mutex); |
388 | ||
6e1819d6 RW |
389 | return error; |
390 | } | |
391 | ||
c336078b BH |
392 | #ifdef CONFIG_COMPAT |
393 | ||
394 | struct compat_resume_swap_area { | |
395 | compat_loff_t offset; | |
396 | u32 dev; | |
397 | } __packed; | |
398 | ||
399 | static long | |
400 | snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
401 | { | |
402 | BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t)); | |
403 | ||
404 | switch (cmd) { | |
405 | case SNAPSHOT_GET_IMAGE_SIZE: | |
406 | case SNAPSHOT_AVAIL_SWAP_SIZE: | |
407 | case SNAPSHOT_ALLOC_SWAP_PAGE: { | |
408 | compat_loff_t __user *uoffset = compat_ptr(arg); | |
409 | loff_t offset; | |
410 | mm_segment_t old_fs; | |
411 | int err; | |
412 | ||
413 | old_fs = get_fs(); | |
414 | set_fs(KERNEL_DS); | |
415 | err = snapshot_ioctl(file, cmd, (unsigned long) &offset); | |
416 | set_fs(old_fs); | |
417 | if (!err && put_user(offset, uoffset)) | |
418 | err = -EFAULT; | |
419 | return err; | |
420 | } | |
421 | ||
422 | case SNAPSHOT_CREATE_IMAGE: | |
423 | return snapshot_ioctl(file, cmd, | |
424 | (unsigned long) compat_ptr(arg)); | |
425 | ||
426 | case SNAPSHOT_SET_SWAP_AREA: { | |
427 | struct compat_resume_swap_area __user *u_swap_area = | |
428 | compat_ptr(arg); | |
429 | struct resume_swap_area swap_area; | |
430 | mm_segment_t old_fs; | |
431 | int err; | |
432 | ||
433 | err = get_user(swap_area.offset, &u_swap_area->offset); | |
434 | err |= get_user(swap_area.dev, &u_swap_area->dev); | |
435 | if (err) | |
436 | return -EFAULT; | |
437 | old_fs = get_fs(); | |
438 | set_fs(KERNEL_DS); | |
439 | err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA, | |
440 | (unsigned long) &swap_area); | |
441 | set_fs(old_fs); | |
442 | return err; | |
443 | } | |
444 | ||
445 | default: | |
446 | return snapshot_ioctl(file, cmd, arg); | |
447 | } | |
448 | } | |
449 | ||
450 | #endif /* CONFIG_COMPAT */ | |
451 | ||
15ad7cdc | 452 | static const struct file_operations snapshot_fops = { |
6e1819d6 RW |
453 | .open = snapshot_open, |
454 | .release = snapshot_release, | |
455 | .read = snapshot_read, | |
456 | .write = snapshot_write, | |
457 | .llseek = no_llseek, | |
52d11025 | 458 | .unlocked_ioctl = snapshot_ioctl, |
c336078b BH |
459 | #ifdef CONFIG_COMPAT |
460 | .compat_ioctl = snapshot_compat_ioctl, | |
461 | #endif | |
6e1819d6 RW |
462 | }; |
463 | ||
464 | static struct miscdevice snapshot_device = { | |
465 | .minor = SNAPSHOT_MINOR, | |
466 | .name = "snapshot", | |
467 | .fops = &snapshot_fops, | |
468 | }; | |
469 | ||
470 | static int __init snapshot_device_init(void) | |
471 | { | |
472 | return misc_register(&snapshot_device); | |
473 | }; | |
474 | ||
475 | device_initcall(snapshot_device_init); |