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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 RW |
62 | } |
63 | if(create_basic_memory_bitmaps()) { | |
0709db60 | 64 | atomic_inc(&snapshot_device_available); |
25f2f3da RW |
65 | error = -ENOMEM; |
66 | goto Unlock; | |
1525a2ad | 67 | } |
6e1819d6 RW |
68 | nonseekable_open(inode, filp); |
69 | data = &snapshot_state; | |
70 | filp->private_data = data; | |
71 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
72 | if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { | |
c7510859 | 73 | /* Hibernating. The image device should be accessible. */ |
915bae9e | 74 | data->swap = swsusp_resume_device ? |
7bf23687 | 75 | swap_type_of(swsusp_resume_device, 0, NULL) : -1; |
6e1819d6 | 76 | data->mode = O_RDONLY; |
ebae2604 | 77 | error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE); |
c3e94d89 | 78 | if (error) |
ebae2604 | 79 | pm_notifier_call_chain(PM_POST_HIBERNATION); |
6e1819d6 | 80 | } else { |
c7510859 RW |
81 | /* |
82 | * Resuming. We may need to wait for the image device to | |
83 | * appear. | |
84 | */ | |
85 | wait_for_device_probe(); | |
c7510859 | 86 | |
6e1819d6 RW |
87 | data->swap = -1; |
88 | data->mode = O_WRONLY; | |
ebae2604 | 89 | error = pm_notifier_call_chain(PM_RESTORE_PREPARE); |
c3e94d89 | 90 | if (error) |
ebae2604 | 91 | pm_notifier_call_chain(PM_POST_RESTORE); |
c3e94d89 | 92 | } |
8440f4b1 MK |
93 | if (error) { |
94 | free_basic_memory_bitmaps(); | |
c3e94d89 | 95 | atomic_inc(&snapshot_device_available); |
8440f4b1 | 96 | } |
6e1819d6 RW |
97 | data->frozen = 0; |
98 | data->ready = 0; | |
eb57c1cf | 99 | data->platform_support = 0; |
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 | 113 | swsusp_free(); |
74dfd666 | 114 | free_basic_memory_bitmaps(); |
6e1819d6 | 115 | data = filp->private_data; |
d1d241cc | 116 | free_all_swap_pages(data->swap); |
9744997a RW |
117 | if (data->frozen) { |
118 | pm_restore_gfp_mask(); | |
6e1819d6 | 119 | thaw_processes(); |
9744997a | 120 | } |
1497dd1d | 121 | pm_notifier_call_chain(data->mode == O_RDONLY ? |
c3e94d89 | 122 | PM_POST_HIBERNATION : PM_POST_RESTORE); |
0709db60 | 123 | atomic_inc(&snapshot_device_available); |
25f2f3da | 124 | |
bcda53fa | 125 | unlock_system_sleep(); |
25f2f3da | 126 | |
6e1819d6 RW |
127 | return 0; |
128 | } | |
129 | ||
130 | static ssize_t snapshot_read(struct file *filp, char __user *buf, | |
131 | size_t count, loff_t *offp) | |
132 | { | |
133 | struct snapshot_data *data; | |
134 | ssize_t res; | |
d3c1b24c | 135 | loff_t pg_offp = *offp & ~PAGE_MASK; |
6e1819d6 | 136 | |
bcda53fa | 137 | lock_system_sleep(); |
25f2f3da | 138 | |
6e1819d6 | 139 | data = filp->private_data; |
25f2f3da RW |
140 | if (!data->ready) { |
141 | res = -ENODATA; | |
142 | goto Unlock; | |
143 | } | |
d3c1b24c JS |
144 | if (!pg_offp) { /* on page boundary? */ |
145 | res = snapshot_read_next(&data->handle); | |
146 | if (res <= 0) | |
147 | goto Unlock; | |
148 | } else { | |
149 | res = PAGE_SIZE - pg_offp; | |
6e1819d6 | 150 | } |
25f2f3da | 151 | |
d3c1b24c JS |
152 | res = simple_read_from_buffer(buf, count, &pg_offp, |
153 | data_of(data->handle), res); | |
154 | if (res > 0) | |
155 | *offp += res; | |
156 | ||
25f2f3da | 157 | Unlock: |
bcda53fa | 158 | unlock_system_sleep(); |
25f2f3da | 159 | |
6e1819d6 RW |
160 | return res; |
161 | } | |
162 | ||
163 | static ssize_t snapshot_write(struct file *filp, const char __user *buf, | |
164 | size_t count, loff_t *offp) | |
165 | { | |
166 | struct snapshot_data *data; | |
167 | ssize_t res; | |
d3c1b24c | 168 | loff_t pg_offp = *offp & ~PAGE_MASK; |
6e1819d6 | 169 | |
bcda53fa | 170 | lock_system_sleep(); |
25f2f3da | 171 | |
6e1819d6 | 172 | data = filp->private_data; |
d3c1b24c JS |
173 | |
174 | if (!pg_offp) { | |
175 | res = snapshot_write_next(&data->handle); | |
176 | if (res <= 0) | |
177 | goto unlock; | |
178 | } else { | |
179 | res = PAGE_SIZE - pg_offp; | |
6e1819d6 | 180 | } |
25f2f3da | 181 | |
d3c1b24c JS |
182 | res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp, |
183 | buf, count); | |
184 | if (res > 0) | |
185 | *offp += res; | |
186 | unlock: | |
bcda53fa | 187 | unlock_system_sleep(); |
25f2f3da | 188 | |
6e1819d6 RW |
189 | return res; |
190 | } | |
191 | ||
52d11025 AC |
192 | static long snapshot_ioctl(struct file *filp, unsigned int cmd, |
193 | unsigned long arg) | |
6e1819d6 RW |
194 | { |
195 | int error = 0; | |
196 | struct snapshot_data *data; | |
af508b34 | 197 | loff_t size; |
3aef83e0 | 198 | sector_t offset; |
6e1819d6 RW |
199 | |
200 | if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) | |
201 | return -ENOTTY; | |
202 | if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) | |
203 | return -ENOTTY; | |
204 | if (!capable(CAP_SYS_ADMIN)) | |
205 | return -EPERM; | |
206 | ||
25f2f3da RW |
207 | if (!mutex_trylock(&pm_mutex)) |
208 | return -EBUSY; | |
6e1819d6 | 209 | |
25f2f3da | 210 | data = filp->private_data; |
52d11025 | 211 | |
6e1819d6 RW |
212 | switch (cmd) { |
213 | ||
214 | case SNAPSHOT_FREEZE: | |
215 | if (data->frozen) | |
216 | break; | |
1bfcf130 | 217 | |
c3e94d89 AS |
218 | printk("Syncing filesystems ... "); |
219 | sys_sync(); | |
220 | printk("done.\n"); | |
221 | ||
1bfcf130 | 222 | error = freeze_processes(); |
1e73203c | 223 | if (!error) |
6e1819d6 RW |
224 | data->frozen = 1; |
225 | break; | |
226 | ||
227 | case SNAPSHOT_UNFREEZE: | |
2f41dddb | 228 | if (!data->frozen || data->ready) |
6e1819d6 | 229 | break; |
c9e664f1 | 230 | pm_restore_gfp_mask(); |
6e1819d6 | 231 | thaw_processes(); |
6e1819d6 RW |
232 | data->frozen = 0; |
233 | break; | |
234 | ||
b694e52e | 235 | case SNAPSHOT_CREATE_IMAGE: |
6e1819d6 RW |
236 | if (data->mode != O_RDONLY || !data->frozen || data->ready) { |
237 | error = -EPERM; | |
238 | break; | |
239 | } | |
c9e664f1 | 240 | pm_restore_gfp_mask(); |
eb57c1cf | 241 | error = hibernation_snapshot(data->platform_support); |
51d6ff7a | 242 | if (!error) { |
cc5d207c | 243 | error = put_user(in_suspend, (int __user *)arg); |
a556d5b5 SB |
244 | data->ready = !freezer_test_done && !error; |
245 | freezer_test_done = false; | |
97819a26 | 246 | } |
6e1819d6 RW |
247 | break; |
248 | ||
249 | case SNAPSHOT_ATOMIC_RESTORE: | |
8357376d | 250 | snapshot_write_finalize(&data->handle); |
6e1819d6 RW |
251 | if (data->mode != O_WRONLY || !data->frozen || |
252 | !snapshot_image_loaded(&data->handle)) { | |
253 | error = -EPERM; | |
254 | break; | |
255 | } | |
eb57c1cf | 256 | error = hibernation_restore(data->platform_support); |
6e1819d6 RW |
257 | break; |
258 | ||
259 | case SNAPSHOT_FREE: | |
260 | swsusp_free(); | |
261 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
262 | data->ready = 0; | |
181e9bde RW |
263 | /* |
264 | * It is necessary to thaw kernel threads here, because | |
265 | * SNAPSHOT_CREATE_IMAGE may be invoked directly after | |
266 | * SNAPSHOT_FREE. In that case, if kernel threads were not | |
267 | * thawed, the preallocation of memory carried out by | |
268 | * hibernation_snapshot() might run into problems (i.e. it | |
269 | * might fail or even deadlock). | |
270 | */ | |
271 | thaw_kernel_threads(); | |
6e1819d6 RW |
272 | break; |
273 | ||
b694e52e | 274 | case SNAPSHOT_PREF_IMAGE_SIZE: |
6e1819d6 RW |
275 | image_size = arg; |
276 | break; | |
277 | ||
af508b34 RW |
278 | case SNAPSHOT_GET_IMAGE_SIZE: |
279 | if (!data->ready) { | |
280 | error = -ENODATA; | |
281 | break; | |
282 | } | |
283 | size = snapshot_get_image_size(); | |
284 | size <<= PAGE_SHIFT; | |
285 | error = put_user(size, (loff_t __user *)arg); | |
286 | break; | |
287 | ||
b694e52e | 288 | case SNAPSHOT_AVAIL_SWAP_SIZE: |
af508b34 RW |
289 | size = count_swap_pages(data->swap, 1); |
290 | size <<= PAGE_SHIFT; | |
291 | error = put_user(size, (loff_t __user *)arg); | |
6e1819d6 RW |
292 | break; |
293 | ||
b694e52e | 294 | case SNAPSHOT_ALLOC_SWAP_PAGE: |
6e1819d6 RW |
295 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { |
296 | error = -ENODEV; | |
297 | break; | |
298 | } | |
d1d241cc | 299 | offset = alloc_swapdev_block(data->swap); |
6e1819d6 RW |
300 | if (offset) { |
301 | offset <<= PAGE_SHIFT; | |
cc5d207c | 302 | error = put_user(offset, (loff_t __user *)arg); |
6e1819d6 RW |
303 | } else { |
304 | error = -ENOSPC; | |
305 | } | |
306 | break; | |
307 | ||
308 | case SNAPSHOT_FREE_SWAP_PAGES: | |
309 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
310 | error = -ENODEV; | |
311 | break; | |
312 | } | |
d1d241cc | 313 | free_all_swap_pages(data->swap); |
6e1819d6 RW |
314 | break; |
315 | ||
9b238205 LT |
316 | case SNAPSHOT_S2RAM: |
317 | if (!data->frozen) { | |
318 | error = -EPERM; | |
319 | break; | |
320 | } | |
6c961dfb RW |
321 | /* |
322 | * Tasks are frozen and the notifiers have been called with | |
323 | * PM_HIBERNATION_PREPARE | |
324 | */ | |
325 | error = suspend_devices_and_enter(PM_SUSPEND_MEM); | |
36cb7035 | 326 | data->ready = 0; |
9b238205 LT |
327 | break; |
328 | ||
eb57c1cf RW |
329 | case SNAPSHOT_PLATFORM_SUPPORT: |
330 | data->platform_support = !!arg; | |
331 | break; | |
332 | ||
333 | case SNAPSHOT_POWER_OFF: | |
334 | if (data->platform_support) | |
335 | error = hibernation_platform_enter(); | |
336 | break; | |
337 | ||
37b2ba12 | 338 | case SNAPSHOT_SET_SWAP_AREA: |
d1d241cc | 339 | if (swsusp_swap_in_use()) { |
37b2ba12 RW |
340 | error = -EPERM; |
341 | } else { | |
342 | struct resume_swap_area swap_area; | |
343 | dev_t swdev; | |
344 | ||
345 | error = copy_from_user(&swap_area, (void __user *)arg, | |
346 | sizeof(struct resume_swap_area)); | |
347 | if (error) { | |
348 | error = -EFAULT; | |
349 | break; | |
350 | } | |
351 | ||
352 | /* | |
353 | * User space encodes device types as two-byte values, | |
354 | * so we need to recode them | |
355 | */ | |
d88d4050 | 356 | swdev = new_decode_dev(swap_area.dev); |
37b2ba12 RW |
357 | if (swdev) { |
358 | offset = swap_area.offset; | |
7bf23687 | 359 | data->swap = swap_type_of(swdev, offset, NULL); |
37b2ba12 RW |
360 | if (data->swap < 0) |
361 | error = -ENODEV; | |
362 | } else { | |
363 | data->swap = -1; | |
364 | error = -EINVAL; | |
365 | } | |
366 | } | |
367 | break; | |
368 | ||
6e1819d6 RW |
369 | default: |
370 | error = -ENOTTY; | |
371 | ||
372 | } | |
25f2f3da RW |
373 | |
374 | mutex_unlock(&pm_mutex); | |
375 | ||
6e1819d6 RW |
376 | return error; |
377 | } | |
378 | ||
c336078b BH |
379 | #ifdef CONFIG_COMPAT |
380 | ||
381 | struct compat_resume_swap_area { | |
382 | compat_loff_t offset; | |
383 | u32 dev; | |
384 | } __packed; | |
385 | ||
386 | static long | |
387 | snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
388 | { | |
389 | BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t)); | |
390 | ||
391 | switch (cmd) { | |
392 | case SNAPSHOT_GET_IMAGE_SIZE: | |
393 | case SNAPSHOT_AVAIL_SWAP_SIZE: | |
394 | case SNAPSHOT_ALLOC_SWAP_PAGE: { | |
395 | compat_loff_t __user *uoffset = compat_ptr(arg); | |
396 | loff_t offset; | |
397 | mm_segment_t old_fs; | |
398 | int err; | |
399 | ||
400 | old_fs = get_fs(); | |
401 | set_fs(KERNEL_DS); | |
402 | err = snapshot_ioctl(file, cmd, (unsigned long) &offset); | |
403 | set_fs(old_fs); | |
404 | if (!err && put_user(offset, uoffset)) | |
405 | err = -EFAULT; | |
406 | return err; | |
407 | } | |
408 | ||
409 | case SNAPSHOT_CREATE_IMAGE: | |
410 | return snapshot_ioctl(file, cmd, | |
411 | (unsigned long) compat_ptr(arg)); | |
412 | ||
413 | case SNAPSHOT_SET_SWAP_AREA: { | |
414 | struct compat_resume_swap_area __user *u_swap_area = | |
415 | compat_ptr(arg); | |
416 | struct resume_swap_area swap_area; | |
417 | mm_segment_t old_fs; | |
418 | int err; | |
419 | ||
420 | err = get_user(swap_area.offset, &u_swap_area->offset); | |
421 | err |= get_user(swap_area.dev, &u_swap_area->dev); | |
422 | if (err) | |
423 | return -EFAULT; | |
424 | old_fs = get_fs(); | |
425 | set_fs(KERNEL_DS); | |
426 | err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA, | |
427 | (unsigned long) &swap_area); | |
428 | set_fs(old_fs); | |
429 | return err; | |
430 | } | |
431 | ||
432 | default: | |
433 | return snapshot_ioctl(file, cmd, arg); | |
434 | } | |
435 | } | |
436 | ||
437 | #endif /* CONFIG_COMPAT */ | |
438 | ||
15ad7cdc | 439 | static const struct file_operations snapshot_fops = { |
6e1819d6 RW |
440 | .open = snapshot_open, |
441 | .release = snapshot_release, | |
442 | .read = snapshot_read, | |
443 | .write = snapshot_write, | |
444 | .llseek = no_llseek, | |
52d11025 | 445 | .unlocked_ioctl = snapshot_ioctl, |
c336078b BH |
446 | #ifdef CONFIG_COMPAT |
447 | .compat_ioctl = snapshot_compat_ioctl, | |
448 | #endif | |
6e1819d6 RW |
449 | }; |
450 | ||
451 | static struct miscdevice snapshot_device = { | |
452 | .minor = SNAPSHOT_MINOR, | |
453 | .name = "snapshot", | |
454 | .fops = &snapshot_fops, | |
455 | }; | |
456 | ||
457 | static int __init snapshot_device_init(void) | |
458 | { | |
459 | return misc_register(&snapshot_device); | |
460 | }; | |
461 | ||
462 | device_initcall(snapshot_device_init); |