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Commit | Line | Data |
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61159a31 RW |
1 | /* |
2 | * linux/kernel/power/swap.c | |
3 | * | |
4 | * This file provides functions for reading the suspend image from | |
5 | * and writing it to a swap partition. | |
6 | * | |
7 | * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz> | |
8 | * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> | |
9 | * | |
10 | * This file is released under the GPLv2. | |
11 | * | |
12 | */ | |
13 | ||
14 | #include <linux/module.h> | |
61159a31 | 15 | #include <linux/file.h> |
61159a31 RW |
16 | #include <linux/delay.h> |
17 | #include <linux/bitops.h> | |
18 | #include <linux/genhd.h> | |
19 | #include <linux/device.h> | |
20 | #include <linux/buffer_head.h> | |
21 | #include <linux/bio.h> | |
546e0d27 | 22 | #include <linux/blkdev.h> |
61159a31 RW |
23 | #include <linux/swap.h> |
24 | #include <linux/swapops.h> | |
25 | #include <linux/pm.h> | |
5a0e3ad6 | 26 | #include <linux/slab.h> |
61159a31 RW |
27 | |
28 | #include "power.h" | |
29 | ||
61159a31 RW |
30 | #define SWSUSP_SIG "S1SUSPEND" |
31 | ||
1b29c164 | 32 | struct swsusp_header { |
a634cc10 | 33 | char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int)]; |
3aef83e0 | 34 | sector_t image; |
a634cc10 | 35 | unsigned int flags; /* Flags to pass to the "boot" kernel */ |
61159a31 RW |
36 | char orig_sig[10]; |
37 | char sig[10]; | |
1b29c164 VG |
38 | } __attribute__((packed)); |
39 | ||
40 | static struct swsusp_header *swsusp_header; | |
61159a31 | 41 | |
0414f2ec NC |
42 | /** |
43 | * The following functions are used for tracing the allocated | |
44 | * swap pages, so that they can be freed in case of an error. | |
45 | */ | |
46 | ||
47 | struct swsusp_extent { | |
48 | struct rb_node node; | |
49 | unsigned long start; | |
50 | unsigned long end; | |
51 | }; | |
52 | ||
53 | static struct rb_root swsusp_extents = RB_ROOT; | |
54 | ||
55 | static int swsusp_extents_insert(unsigned long swap_offset) | |
56 | { | |
57 | struct rb_node **new = &(swsusp_extents.rb_node); | |
58 | struct rb_node *parent = NULL; | |
59 | struct swsusp_extent *ext; | |
60 | ||
61 | /* Figure out where to put the new node */ | |
62 | while (*new) { | |
63 | ext = container_of(*new, struct swsusp_extent, node); | |
64 | parent = *new; | |
65 | if (swap_offset < ext->start) { | |
66 | /* Try to merge */ | |
67 | if (swap_offset == ext->start - 1) { | |
68 | ext->start--; | |
69 | return 0; | |
70 | } | |
71 | new = &((*new)->rb_left); | |
72 | } else if (swap_offset > ext->end) { | |
73 | /* Try to merge */ | |
74 | if (swap_offset == ext->end + 1) { | |
75 | ext->end++; | |
76 | return 0; | |
77 | } | |
78 | new = &((*new)->rb_right); | |
79 | } else { | |
80 | /* It already is in the tree */ | |
81 | return -EINVAL; | |
82 | } | |
83 | } | |
84 | /* Add the new node and rebalance the tree. */ | |
85 | ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL); | |
86 | if (!ext) | |
87 | return -ENOMEM; | |
88 | ||
89 | ext->start = swap_offset; | |
90 | ext->end = swap_offset; | |
91 | rb_link_node(&ext->node, parent, new); | |
92 | rb_insert_color(&ext->node, &swsusp_extents); | |
93 | return 0; | |
94 | } | |
95 | ||
96 | /** | |
97 | * alloc_swapdev_block - allocate a swap page and register that it has | |
98 | * been allocated, so that it can be freed in case of an error. | |
99 | */ | |
100 | ||
101 | sector_t alloc_swapdev_block(int swap) | |
102 | { | |
103 | unsigned long offset; | |
104 | ||
105 | offset = swp_offset(get_swap_page_of_type(swap)); | |
106 | if (offset) { | |
107 | if (swsusp_extents_insert(offset)) | |
108 | swap_free(swp_entry(swap, offset)); | |
109 | else | |
110 | return swapdev_block(swap, offset); | |
111 | } | |
112 | return 0; | |
113 | } | |
114 | ||
115 | /** | |
116 | * free_all_swap_pages - free swap pages allocated for saving image data. | |
117 | * It also frees the extents used to register which swap entres had been | |
118 | * allocated. | |
119 | */ | |
120 | ||
121 | void free_all_swap_pages(int swap) | |
122 | { | |
123 | struct rb_node *node; | |
124 | ||
125 | while ((node = swsusp_extents.rb_node)) { | |
126 | struct swsusp_extent *ext; | |
127 | unsigned long offset; | |
128 | ||
129 | ext = container_of(node, struct swsusp_extent, node); | |
130 | rb_erase(node, &swsusp_extents); | |
131 | for (offset = ext->start; offset <= ext->end; offset++) | |
132 | swap_free(swp_entry(swap, offset)); | |
133 | ||
134 | kfree(ext); | |
135 | } | |
136 | } | |
137 | ||
138 | int swsusp_swap_in_use(void) | |
139 | { | |
140 | return (swsusp_extents.rb_node != NULL); | |
141 | } | |
142 | ||
61159a31 | 143 | /* |
3fc6b34f | 144 | * General things |
61159a31 RW |
145 | */ |
146 | ||
147 | static unsigned short root_swap = 0xffff; | |
8a0d613f | 148 | struct block_device *hib_resume_bdev; |
3fc6b34f | 149 | |
3fc6b34f RW |
150 | /* |
151 | * Saving part | |
152 | */ | |
61159a31 | 153 | |
a634cc10 | 154 | static int mark_swapfiles(sector_t start, unsigned int flags) |
61159a31 RW |
155 | { |
156 | int error; | |
157 | ||
8a0d613f | 158 | hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL); |
1b29c164 VG |
159 | if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) || |
160 | !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) { | |
161 | memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10); | |
162 | memcpy(swsusp_header->sig,SWSUSP_SIG, 10); | |
163 | swsusp_header->image = start; | |
a634cc10 | 164 | swsusp_header->flags = flags; |
8a0d613f | 165 | error = hib_bio_write_page(swsusp_resume_block, |
1b29c164 | 166 | swsusp_header, NULL); |
61159a31 | 167 | } else { |
23976728 | 168 | printk(KERN_ERR "PM: Swap header not found!\n"); |
61159a31 RW |
169 | error = -ENODEV; |
170 | } | |
171 | return error; | |
172 | } | |
173 | ||
174 | /** | |
175 | * swsusp_swap_check - check if the resume device is a swap device | |
176 | * and get its index (if so) | |
177 | */ | |
178 | ||
179 | static int swsusp_swap_check(void) /* This is called before saving image */ | |
180 | { | |
3aef83e0 RW |
181 | int res; |
182 | ||
7bf23687 | 183 | res = swap_type_of(swsusp_resume_device, swsusp_resume_block, |
8a0d613f | 184 | &hib_resume_bdev); |
3aef83e0 RW |
185 | if (res < 0) |
186 | return res; | |
187 | ||
188 | root_swap = res; | |
8a0d613f | 189 | res = blkdev_get(hib_resume_bdev, FMODE_WRITE); |
7bf23687 RW |
190 | if (res) |
191 | return res; | |
3aef83e0 | 192 | |
8a0d613f | 193 | res = set_blocksize(hib_resume_bdev, PAGE_SIZE); |
3aef83e0 | 194 | if (res < 0) |
8a0d613f | 195 | blkdev_put(hib_resume_bdev, FMODE_WRITE); |
61159a31 | 196 | |
61159a31 RW |
197 | return res; |
198 | } | |
199 | ||
200 | /** | |
201 | * write_page - Write one page to given swap location. | |
202 | * @buf: Address we're writing. | |
203 | * @offset: Offset of the swap page we're writing to. | |
ab954160 | 204 | * @bio_chain: Link the next write BIO here |
61159a31 RW |
205 | */ |
206 | ||
3aef83e0 | 207 | static int write_page(void *buf, sector_t offset, struct bio **bio_chain) |
61159a31 | 208 | { |
3aef83e0 RW |
209 | void *src; |
210 | ||
211 | if (!offset) | |
212 | return -ENOSPC; | |
213 | ||
214 | if (bio_chain) { | |
85949121 | 215 | src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH); |
3aef83e0 RW |
216 | if (src) { |
217 | memcpy(src, buf, PAGE_SIZE); | |
218 | } else { | |
219 | WARN_ON_ONCE(1); | |
220 | bio_chain = NULL; /* Go synchronous */ | |
221 | src = buf; | |
ab954160 | 222 | } |
3aef83e0 RW |
223 | } else { |
224 | src = buf; | |
61159a31 | 225 | } |
8a0d613f | 226 | return hib_bio_write_page(offset, src, bio_chain); |
61159a31 RW |
227 | } |
228 | ||
229 | /* | |
230 | * The swap map is a data structure used for keeping track of each page | |
231 | * written to a swap partition. It consists of many swap_map_page | |
232 | * structures that contain each an array of MAP_PAGE_SIZE swap entries. | |
233 | * These structures are stored on the swap and linked together with the | |
234 | * help of the .next_swap member. | |
235 | * | |
236 | * The swap map is created during suspend. The swap map pages are | |
237 | * allocated and populated one at a time, so we only need one memory | |
238 | * page to set up the entire structure. | |
239 | * | |
240 | * During resume we also only need to use one swap_map_page structure | |
241 | * at a time. | |
242 | */ | |
243 | ||
3aef83e0 | 244 | #define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1) |
61159a31 RW |
245 | |
246 | struct swap_map_page { | |
3aef83e0 RW |
247 | sector_t entries[MAP_PAGE_ENTRIES]; |
248 | sector_t next_swap; | |
61159a31 RW |
249 | }; |
250 | ||
251 | /** | |
252 | * The swap_map_handle structure is used for handling swap in | |
253 | * a file-alike way | |
254 | */ | |
255 | ||
256 | struct swap_map_handle { | |
257 | struct swap_map_page *cur; | |
3aef83e0 | 258 | sector_t cur_swap; |
61159a31 RW |
259 | unsigned int k; |
260 | }; | |
261 | ||
262 | static void release_swap_writer(struct swap_map_handle *handle) | |
263 | { | |
264 | if (handle->cur) | |
265 | free_page((unsigned long)handle->cur); | |
266 | handle->cur = NULL; | |
61159a31 RW |
267 | } |
268 | ||
269 | static int get_swap_writer(struct swap_map_handle *handle) | |
270 | { | |
271 | handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); | |
272 | if (!handle->cur) | |
273 | return -ENOMEM; | |
d1d241cc | 274 | handle->cur_swap = alloc_swapdev_block(root_swap); |
61159a31 RW |
275 | if (!handle->cur_swap) { |
276 | release_swap_writer(handle); | |
277 | return -ENOSPC; | |
278 | } | |
279 | handle->k = 0; | |
280 | return 0; | |
281 | } | |
282 | ||
ab954160 AM |
283 | static int swap_write_page(struct swap_map_handle *handle, void *buf, |
284 | struct bio **bio_chain) | |
285 | { | |
286 | int error = 0; | |
3aef83e0 | 287 | sector_t offset; |
61159a31 RW |
288 | |
289 | if (!handle->cur) | |
290 | return -EINVAL; | |
d1d241cc | 291 | offset = alloc_swapdev_block(root_swap); |
ab954160 | 292 | error = write_page(buf, offset, bio_chain); |
61159a31 RW |
293 | if (error) |
294 | return error; | |
295 | handle->cur->entries[handle->k++] = offset; | |
296 | if (handle->k >= MAP_PAGE_ENTRIES) { | |
8a0d613f | 297 | error = hib_wait_on_bio_chain(bio_chain); |
ab954160 AM |
298 | if (error) |
299 | goto out; | |
d1d241cc | 300 | offset = alloc_swapdev_block(root_swap); |
61159a31 RW |
301 | if (!offset) |
302 | return -ENOSPC; | |
303 | handle->cur->next_swap = offset; | |
ab954160 | 304 | error = write_page(handle->cur, handle->cur_swap, NULL); |
61159a31 | 305 | if (error) |
ab954160 | 306 | goto out; |
61159a31 RW |
307 | memset(handle->cur, 0, PAGE_SIZE); |
308 | handle->cur_swap = offset; | |
309 | handle->k = 0; | |
310 | } | |
59a49335 | 311 | out: |
ab954160 | 312 | return error; |
61159a31 RW |
313 | } |
314 | ||
315 | static int flush_swap_writer(struct swap_map_handle *handle) | |
316 | { | |
317 | if (handle->cur && handle->cur_swap) | |
ab954160 | 318 | return write_page(handle->cur, handle->cur_swap, NULL); |
61159a31 RW |
319 | else |
320 | return -EINVAL; | |
321 | } | |
322 | ||
323 | /** | |
324 | * save_image - save the suspend image data | |
325 | */ | |
326 | ||
327 | static int save_image(struct swap_map_handle *handle, | |
328 | struct snapshot_handle *snapshot, | |
3a4f7577 | 329 | unsigned int nr_to_write) |
61159a31 RW |
330 | { |
331 | unsigned int m; | |
332 | int ret; | |
3a4f7577 | 333 | int nr_pages; |
ab954160 AM |
334 | int err2; |
335 | struct bio *bio; | |
3a4f7577 AM |
336 | struct timeval start; |
337 | struct timeval stop; | |
61159a31 | 338 | |
23976728 RW |
339 | printk(KERN_INFO "PM: Saving image data pages (%u pages) ... ", |
340 | nr_to_write); | |
3a4f7577 | 341 | m = nr_to_write / 100; |
61159a31 RW |
342 | if (!m) |
343 | m = 1; | |
344 | nr_pages = 0; | |
ab954160 | 345 | bio = NULL; |
3a4f7577 | 346 | do_gettimeofday(&start); |
4ff277f9 | 347 | while (1) { |
d3c1b24c | 348 | ret = snapshot_read_next(snapshot); |
4ff277f9 JS |
349 | if (ret <= 0) |
350 | break; | |
351 | ret = swap_write_page(handle, data_of(*snapshot), &bio); | |
352 | if (ret) | |
353 | break; | |
354 | if (!(nr_pages % m)) | |
66d0ae4d | 355 | printk(KERN_CONT "\b\b\b\b%3d%%", nr_pages / m); |
4ff277f9 JS |
356 | nr_pages++; |
357 | } | |
8a0d613f | 358 | err2 = hib_wait_on_bio_chain(&bio); |
3a4f7577 | 359 | do_gettimeofday(&stop); |
4ff277f9 JS |
360 | if (!ret) |
361 | ret = err2; | |
362 | if (!ret) | |
66d0ae4d | 363 | printk(KERN_CONT "\b\b\b\bdone\n"); |
4ff277f9 | 364 | else |
66d0ae4d | 365 | printk(KERN_CONT "\n"); |
0d3a9abe | 366 | swsusp_show_speed(&start, &stop, nr_to_write, "Wrote"); |
4ff277f9 | 367 | return ret; |
61159a31 RW |
368 | } |
369 | ||
370 | /** | |
371 | * enough_swap - Make sure we have enough swap to save the image. | |
372 | * | |
373 | * Returns TRUE or FALSE after checking the total amount of swap | |
374 | * space avaiable from the resume partition. | |
375 | */ | |
376 | ||
377 | static int enough_swap(unsigned int nr_pages) | |
378 | { | |
379 | unsigned int free_swap = count_swap_pages(root_swap, 1); | |
380 | ||
23976728 | 381 | pr_debug("PM: Free swap pages: %u\n", free_swap); |
940864dd | 382 | return free_swap > nr_pages + PAGES_FOR_IO; |
61159a31 RW |
383 | } |
384 | ||
385 | /** | |
386 | * swsusp_write - Write entire image and metadata. | |
a634cc10 | 387 | * @flags: flags to pass to the "boot" kernel in the image header |
61159a31 RW |
388 | * |
389 | * It is important _NOT_ to umount filesystems at this point. We want | |
390 | * them synced (in case something goes wrong) but we DO not want to mark | |
391 | * filesystem clean: it is not. (And it does not matter, if we resume | |
392 | * correctly, we'll mark system clean, anyway.) | |
393 | */ | |
394 | ||
a634cc10 | 395 | int swsusp_write(unsigned int flags) |
61159a31 RW |
396 | { |
397 | struct swap_map_handle handle; | |
398 | struct snapshot_handle snapshot; | |
399 | struct swsusp_info *header; | |
61159a31 RW |
400 | int error; |
401 | ||
3aef83e0 RW |
402 | error = swsusp_swap_check(); |
403 | if (error) { | |
23976728 | 404 | printk(KERN_ERR "PM: Cannot find swap device, try " |
546e0d27 | 405 | "swapon -a.\n"); |
61159a31 RW |
406 | return error; |
407 | } | |
408 | memset(&snapshot, 0, sizeof(struct snapshot_handle)); | |
d3c1b24c | 409 | error = snapshot_read_next(&snapshot); |
3aef83e0 RW |
410 | if (error < PAGE_SIZE) { |
411 | if (error >= 0) | |
412 | error = -EFAULT; | |
413 | ||
414 | goto out; | |
415 | } | |
61159a31 RW |
416 | header = (struct swsusp_info *)data_of(snapshot); |
417 | if (!enough_swap(header->pages)) { | |
23976728 | 418 | printk(KERN_ERR "PM: Not enough free swap\n"); |
3aef83e0 RW |
419 | error = -ENOSPC; |
420 | goto out; | |
61159a31 RW |
421 | } |
422 | error = get_swap_writer(&handle); | |
423 | if (!error) { | |
3aef83e0 RW |
424 | sector_t start = handle.cur_swap; |
425 | ||
ab954160 | 426 | error = swap_write_page(&handle, header, NULL); |
712f403a AM |
427 | if (!error) |
428 | error = save_image(&handle, &snapshot, | |
429 | header->pages - 1); | |
3aef83e0 | 430 | |
712f403a AM |
431 | if (!error) { |
432 | flush_swap_writer(&handle); | |
23976728 | 433 | printk(KERN_INFO "PM: S"); |
a634cc10 | 434 | error = mark_swapfiles(start, flags); |
712f403a AM |
435 | printk("|\n"); |
436 | } | |
61159a31 RW |
437 | } |
438 | if (error) | |
d1d241cc RW |
439 | free_all_swap_pages(root_swap); |
440 | ||
61159a31 | 441 | release_swap_writer(&handle); |
59a49335 | 442 | out: |
c2dd0dae | 443 | swsusp_close(FMODE_WRITE); |
61159a31 RW |
444 | return error; |
445 | } | |
446 | ||
61159a31 RW |
447 | /** |
448 | * The following functions allow us to read data using a swap map | |
449 | * in a file-alike way | |
450 | */ | |
451 | ||
452 | static void release_swap_reader(struct swap_map_handle *handle) | |
453 | { | |
454 | if (handle->cur) | |
455 | free_page((unsigned long)handle->cur); | |
456 | handle->cur = NULL; | |
457 | } | |
458 | ||
3aef83e0 | 459 | static int get_swap_reader(struct swap_map_handle *handle, sector_t start) |
61159a31 RW |
460 | { |
461 | int error; | |
462 | ||
3aef83e0 | 463 | if (!start) |
61159a31 | 464 | return -EINVAL; |
3aef83e0 | 465 | |
85949121 | 466 | handle->cur = (struct swap_map_page *)get_zeroed_page(__GFP_WAIT | __GFP_HIGH); |
61159a31 RW |
467 | if (!handle->cur) |
468 | return -ENOMEM; | |
3aef83e0 | 469 | |
8a0d613f | 470 | error = hib_bio_read_page(start, handle->cur, NULL); |
61159a31 RW |
471 | if (error) { |
472 | release_swap_reader(handle); | |
473 | return error; | |
474 | } | |
475 | handle->k = 0; | |
476 | return 0; | |
477 | } | |
478 | ||
546e0d27 AM |
479 | static int swap_read_page(struct swap_map_handle *handle, void *buf, |
480 | struct bio **bio_chain) | |
61159a31 | 481 | { |
3aef83e0 | 482 | sector_t offset; |
61159a31 RW |
483 | int error; |
484 | ||
485 | if (!handle->cur) | |
486 | return -EINVAL; | |
487 | offset = handle->cur->entries[handle->k]; | |
488 | if (!offset) | |
489 | return -EFAULT; | |
8a0d613f | 490 | error = hib_bio_read_page(offset, buf, bio_chain); |
61159a31 RW |
491 | if (error) |
492 | return error; | |
493 | if (++handle->k >= MAP_PAGE_ENTRIES) { | |
8a0d613f | 494 | error = hib_wait_on_bio_chain(bio_chain); |
61159a31 RW |
495 | handle->k = 0; |
496 | offset = handle->cur->next_swap; | |
497 | if (!offset) | |
498 | release_swap_reader(handle); | |
546e0d27 | 499 | else if (!error) |
8a0d613f | 500 | error = hib_bio_read_page(offset, handle->cur, NULL); |
61159a31 RW |
501 | } |
502 | return error; | |
503 | } | |
504 | ||
505 | /** | |
506 | * load_image - load the image using the swap map handle | |
507 | * @handle and the snapshot handle @snapshot | |
508 | * (assume there are @nr_pages pages to load) | |
509 | */ | |
510 | ||
511 | static int load_image(struct swap_map_handle *handle, | |
512 | struct snapshot_handle *snapshot, | |
546e0d27 | 513 | unsigned int nr_to_read) |
61159a31 RW |
514 | { |
515 | unsigned int m; | |
61159a31 | 516 | int error = 0; |
8c002494 AM |
517 | struct timeval start; |
518 | struct timeval stop; | |
546e0d27 AM |
519 | struct bio *bio; |
520 | int err2; | |
521 | unsigned nr_pages; | |
61159a31 | 522 | |
23976728 RW |
523 | printk(KERN_INFO "PM: Loading image data pages (%u pages) ... ", |
524 | nr_to_read); | |
546e0d27 | 525 | m = nr_to_read / 100; |
61159a31 RW |
526 | if (!m) |
527 | m = 1; | |
528 | nr_pages = 0; | |
546e0d27 | 529 | bio = NULL; |
8c002494 | 530 | do_gettimeofday(&start); |
546e0d27 | 531 | for ( ; ; ) { |
d3c1b24c | 532 | error = snapshot_write_next(snapshot); |
546e0d27 AM |
533 | if (error <= 0) |
534 | break; | |
535 | error = swap_read_page(handle, data_of(*snapshot), &bio); | |
536 | if (error) | |
537 | break; | |
538 | if (snapshot->sync_read) | |
8a0d613f | 539 | error = hib_wait_on_bio_chain(&bio); |
546e0d27 AM |
540 | if (error) |
541 | break; | |
542 | if (!(nr_pages % m)) | |
543 | printk("\b\b\b\b%3d%%", nr_pages / m); | |
544 | nr_pages++; | |
545 | } | |
8a0d613f | 546 | err2 = hib_wait_on_bio_chain(&bio); |
8c002494 | 547 | do_gettimeofday(&stop); |
546e0d27 AM |
548 | if (!error) |
549 | error = err2; | |
e655a250 | 550 | if (!error) { |
61159a31 | 551 | printk("\b\b\b\bdone\n"); |
8357376d | 552 | snapshot_write_finalize(snapshot); |
e655a250 CK |
553 | if (!snapshot_image_loaded(snapshot)) |
554 | error = -ENODATA; | |
bf9fd67a JS |
555 | } else |
556 | printk("\n"); | |
0d3a9abe | 557 | swsusp_show_speed(&start, &stop, nr_to_read, "Read"); |
61159a31 RW |
558 | return error; |
559 | } | |
560 | ||
a634cc10 RW |
561 | /** |
562 | * swsusp_read - read the hibernation image. | |
563 | * @flags_p: flags passed by the "frozen" kernel in the image header should | |
564 | * be written into this memeory location | |
565 | */ | |
566 | ||
567 | int swsusp_read(unsigned int *flags_p) | |
61159a31 RW |
568 | { |
569 | int error; | |
570 | struct swap_map_handle handle; | |
571 | struct snapshot_handle snapshot; | |
572 | struct swsusp_info *header; | |
573 | ||
a634cc10 | 574 | *flags_p = swsusp_header->flags; |
61159a31 RW |
575 | |
576 | memset(&snapshot, 0, sizeof(struct snapshot_handle)); | |
d3c1b24c | 577 | error = snapshot_write_next(&snapshot); |
61159a31 RW |
578 | if (error < PAGE_SIZE) |
579 | return error < 0 ? error : -EFAULT; | |
580 | header = (struct swsusp_info *)data_of(snapshot); | |
1b29c164 | 581 | error = get_swap_reader(&handle, swsusp_header->image); |
61159a31 | 582 | if (!error) |
546e0d27 | 583 | error = swap_read_page(&handle, header, NULL); |
61159a31 RW |
584 | if (!error) |
585 | error = load_image(&handle, &snapshot, header->pages - 1); | |
586 | release_swap_reader(&handle); | |
587 | ||
61159a31 | 588 | if (!error) |
23976728 | 589 | pr_debug("PM: Image successfully loaded\n"); |
61159a31 | 590 | else |
23976728 | 591 | pr_debug("PM: Error %d resuming\n", error); |
61159a31 RW |
592 | return error; |
593 | } | |
594 | ||
595 | /** | |
596 | * swsusp_check - Check for swsusp signature in the resume device | |
597 | */ | |
598 | ||
599 | int swsusp_check(void) | |
600 | { | |
601 | int error; | |
602 | ||
8a0d613f JS |
603 | hib_resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ); |
604 | if (!IS_ERR(hib_resume_bdev)) { | |
605 | set_blocksize(hib_resume_bdev, PAGE_SIZE); | |
6373da1f | 606 | memset(swsusp_header, 0, PAGE_SIZE); |
8a0d613f | 607 | error = hib_bio_read_page(swsusp_resume_block, |
1b29c164 | 608 | swsusp_header, NULL); |
9a154d9d | 609 | if (error) |
76b57e61 | 610 | goto put; |
9a154d9d | 611 | |
1b29c164 VG |
612 | if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) { |
613 | memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10); | |
61159a31 | 614 | /* Reset swap signature now */ |
8a0d613f | 615 | error = hib_bio_write_page(swsusp_resume_block, |
1b29c164 | 616 | swsusp_header, NULL); |
61159a31 | 617 | } else { |
76b57e61 | 618 | error = -EINVAL; |
61159a31 | 619 | } |
76b57e61 JS |
620 | |
621 | put: | |
61159a31 | 622 | if (error) |
8a0d613f | 623 | blkdev_put(hib_resume_bdev, FMODE_READ); |
61159a31 | 624 | else |
23976728 | 625 | pr_debug("PM: Signature found, resuming\n"); |
61159a31 | 626 | } else { |
8a0d613f | 627 | error = PTR_ERR(hib_resume_bdev); |
61159a31 RW |
628 | } |
629 | ||
630 | if (error) | |
23976728 | 631 | pr_debug("PM: Error %d checking image file\n", error); |
61159a31 RW |
632 | |
633 | return error; | |
634 | } | |
635 | ||
636 | /** | |
637 | * swsusp_close - close swap device. | |
638 | */ | |
639 | ||
c2dd0dae | 640 | void swsusp_close(fmode_t mode) |
61159a31 | 641 | { |
8a0d613f | 642 | if (IS_ERR(hib_resume_bdev)) { |
23976728 | 643 | pr_debug("PM: Image device not initialised\n"); |
61159a31 RW |
644 | return; |
645 | } | |
646 | ||
8a0d613f | 647 | blkdev_put(hib_resume_bdev, mode); |
61159a31 | 648 | } |
1b29c164 VG |
649 | |
650 | static int swsusp_header_init(void) | |
651 | { | |
652 | swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL); | |
653 | if (!swsusp_header) | |
654 | panic("Could not allocate memory for swsusp_header\n"); | |
655 | return 0; | |
656 | } | |
657 | ||
658 | core_initcall(swsusp_header_init); |