1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/kernel/power/swap.c
4 *
5 * This file provides functions for reading the suspend image from
6 * and writing it to a swap partition.
7 *
8 * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
9 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
10 * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
11 */
12
13 #define pr_fmt(fmt) "PM: " fmt
14
15 #include <linux/module.h>
16 #include <linux/file.h>
17 #include <linux/delay.h>
18 #include <linux/bitops.h>
19 #include <linux/device.h>
20 #include <linux/bio.h>
21 #include <linux/blkdev.h>
22 #include <linux/swap.h>
23 #include <linux/swapops.h>
24 #include <linux/pm.h>
25 #include <linux/slab.h>
26 #include <linux/vmalloc.h>
27 #include <linux/cpumask.h>
28 #include <linux/atomic.h>
29 #include <linux/kthread.h>
30 #include <linux/crc32.h>
31 #include <linux/ktime.h>
32
33 #include "power.h"
34
35 #define HIBERNATE_SIG "S1SUSPEND"
36
37 u32 swsusp_hardware_signature;
38
39 /*
40 * When reading an {un,}compressed image, we may restore pages in place,
41 * in which case some architectures need these pages cleaning before they
42 * can be executed. We don't know which pages these may be, so clean the lot.
43 */
44 static bool clean_pages_on_read;
45 static bool clean_pages_on_decompress;
46
47 /*
48 * The swap map is a data structure used for keeping track of each page
49 * written to a swap partition. It consists of many swap_map_page
50 * structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
51 * These structures are stored on the swap and linked together with the
52 * help of the .next_swap member.
53 *
54 * The swap map is created during suspend. The swap map pages are
55 * allocated and populated one at a time, so we only need one memory
56 * page to set up the entire structure.
57 *
58 * During resume we pick up all swap_map_page structures into a list.
59 */
60
61 #define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
62
63 /*
64 * Number of free pages that are not high.
65 */
66 static inline unsigned long low_free_pages(void)
67 {
68 return nr_free_pages() - nr_free_highpages();
69 }
70
71 /*
72 * Number of pages required to be kept free while writing the image. Always
73 * half of all available low pages before the writing starts.
74 */
75 static inline unsigned long reqd_free_pages(void)
76 {
77 return low_free_pages() / 2;
78 }
79
80 struct swap_map_page {
81 sector_t entries[MAP_PAGE_ENTRIES];
82 sector_t next_swap;
83 };
84
85 struct swap_map_page_list {
86 struct swap_map_page *map;
87 struct swap_map_page_list *next;
88 };
89
90 /*
91 * The swap_map_handle structure is used for handling swap in
92 * a file-alike way
93 */
94
95 struct swap_map_handle {
96 struct swap_map_page *cur;
97 struct swap_map_page_list *maps;
98 sector_t cur_swap;
99 sector_t first_sector;
100 unsigned int k;
101 unsigned long reqd_free_pages;
102 u32 crc32;
103 };
104
105 struct swsusp_header {
106 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
107 sizeof(u32) - sizeof(u32)];
108 u32 hw_sig;
109 u32 crc32;
110 sector_t image;
111 unsigned int flags; /* Flags to pass to the "boot" kernel */
112 char orig_sig[10];
113 char sig[10];
114 } __packed;
115
116 static struct swsusp_header *swsusp_header;
117
118 /*
119 * The following functions are used for tracing the allocated
120 * swap pages, so that they can be freed in case of an error.
121 */
122
123 struct swsusp_extent {
124 struct rb_node node;
125 unsigned long start;
126 unsigned long end;
127 };
128
129 static struct rb_root swsusp_extents = RB_ROOT;
130
131 static int swsusp_extents_insert(unsigned long swap_offset)
132 {
133 struct rb_node **new = &(swsusp_extents.rb_node);
134 struct rb_node *parent = NULL;
135 struct swsusp_extent *ext;
136
137 /* Figure out where to put the new node */
138 while (*new) {
139 ext = rb_entry(*new, struct swsusp_extent, node);
140 parent = *new;
141 if (swap_offset < ext->start) {
142 /* Try to merge */
143 if (swap_offset == ext->start - 1) {
144 ext->start--;
145 return 0;
146 }
147 new = &((*new)->rb_left);
148 } else if (swap_offset > ext->end) {
149 /* Try to merge */
150 if (swap_offset == ext->end + 1) {
151 ext->end++;
152 return 0;
153 }
154 new = &((*new)->rb_right);
155 } else {
156 /* It already is in the tree */
157 return -EINVAL;
158 }
159 }
160 /* Add the new node and rebalance the tree. */
161 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
162 if (!ext)
163 return -ENOMEM;
164
165 ext->start = swap_offset;
166 ext->end = swap_offset;
167 rb_link_node(&ext->node, parent, new);
168 rb_insert_color(&ext->node, &swsusp_extents);
169 return 0;
170 }
171
172 /*
173 * alloc_swapdev_block - allocate a swap page and register that it has
174 * been allocated, so that it can be freed in case of an error.
175 */
176
177 sector_t alloc_swapdev_block(int swap)
178 {
179 unsigned long offset;
180
181 offset = swp_offset(get_swap_page_of_type(swap));
182 if (offset) {
183 if (swsusp_extents_insert(offset))
184 swap_free(swp_entry(swap, offset));
185 else
186 return swapdev_block(swap, offset);
187 }
188 return 0;
189 }
190
191 /*
192 * free_all_swap_pages - free swap pages allocated for saving image data.
193 * It also frees the extents used to register which swap entries had been
194 * allocated.
195 */
196
197 void free_all_swap_pages(int swap)
198 {
199 struct rb_node *node;
200
201 while ((node = swsusp_extents.rb_node)) {
202 struct swsusp_extent *ext;
203
204 ext = rb_entry(node, struct swsusp_extent, node);
205 rb_erase(node, &swsusp_extents);
206 swap_free_nr(swp_entry(swap, ext->start),
207 ext->end - ext->start + 1);
208
209 kfree(ext);
210 }
211 }
212
213 int swsusp_swap_in_use(void)
214 {
215 return (swsusp_extents.rb_node != NULL);
216 }
217
218 /*
219 * General things
220 */
221
222 static unsigned short root_swap = 0xffff;
223 static struct file *hib_resume_bdev_file;
224
225 struct hib_bio_batch {
226 atomic_t count;
227 wait_queue_head_t wait;
228 blk_status_t error;
229 struct blk_plug plug;
230 };
231
232 static void hib_init_batch(struct hib_bio_batch *hb)
233 {
234 atomic_set(&hb->count, 0);
235 init_waitqueue_head(&hb->wait);
236 hb->error = BLK_STS_OK;
237 blk_start_plug(&hb->plug);
238 }
239
240 static void hib_finish_batch(struct hib_bio_batch *hb)
241 {
242 blk_finish_plug(&hb->plug);
243 }
244
245 static void hib_end_io(struct bio *bio)
246 {
247 struct hib_bio_batch *hb = bio->bi_private;
248 struct page *page = bio_first_page_all(bio);
249
250 if (bio->bi_status) {
251 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
252 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
253 (unsigned long long)bio->bi_iter.bi_sector);
254 }
255
256 if (bio_data_dir(bio) == WRITE)
257 put_page(page);
258 else if (clean_pages_on_read)
259 flush_icache_range((unsigned long)page_address(page),
260 (unsigned long)page_address(page) + PAGE_SIZE);
261
262 if (bio->bi_status && !hb->error)
263 hb->error = bio->bi_status;
264 if (atomic_dec_and_test(&hb->count))
265 wake_up(&hb->wait);
266
267 bio_put(bio);
268 }
269
270 static int hib_submit_io(blk_opf_t opf, pgoff_t page_off, void *addr,
271 struct hib_bio_batch *hb)
272 {
273 struct page *page = virt_to_page(addr);
274 struct bio *bio;
275 int error = 0;
276
277 bio = bio_alloc(file_bdev(hib_resume_bdev_file), 1, opf,
278 GFP_NOIO | __GFP_HIGH);
279 bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
280
281 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
282 pr_err("Adding page to bio failed at %llu\n",
283 (unsigned long long)bio->bi_iter.bi_sector);
284 bio_put(bio);
285 return -EFAULT;
286 }
287
288 if (hb) {
289 bio->bi_end_io = hib_end_io;
290 bio->bi_private = hb;
291 atomic_inc(&hb->count);
292 submit_bio(bio);
293 } else {
294 error = submit_bio_wait(bio);
295 bio_put(bio);
296 }
297
298 return error;
299 }
300
301 static int hib_wait_io(struct hib_bio_batch *hb)
302 {
303 /*
304 * We are relying on the behavior of blk_plug that a thread with
305 * a plug will flush the plug list before sleeping.
306 */
307 wait_event(hb->wait, atomic_read(&hb->count) == 0);
308 return blk_status_to_errno(hb->error);
309 }
310
311 /*
312 * Saving part
313 */
314 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
315 {
316 int error;
317
318 hib_submit_io(REQ_OP_READ, swsusp_resume_block, swsusp_header, NULL);
319 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
320 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
321 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
322 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
323 swsusp_header->image = handle->first_sector;
324 if (swsusp_hardware_signature) {
325 swsusp_header->hw_sig = swsusp_hardware_signature;
326 flags |= SF_HW_SIG;
327 }
328 swsusp_header->flags = flags;
329 if (flags & SF_CRC32_MODE)
330 swsusp_header->crc32 = handle->crc32;
331 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
332 swsusp_resume_block, swsusp_header, NULL);
333 } else {
334 pr_err("Swap header not found!\n");
335 error = -ENODEV;
336 }
337 return error;
338 }
339
340 /*
341 * Hold the swsusp_header flag. This is used in software_resume() in
342 * 'kernel/power/hibernate' to check if the image is compressed and query
343 * for the compression algorithm support(if so).
344 */
345 unsigned int swsusp_header_flags;
346
347 /**
348 * swsusp_swap_check - check if the resume device is a swap device
349 * and get its index (if so)
350 *
351 * This is called before saving image
352 */
353 static int swsusp_swap_check(void)
354 {
355 int res;
356
357 if (swsusp_resume_device)
358 res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
359 else
360 res = find_first_swap(&swsusp_resume_device);
361 if (res < 0)
362 return res;
363 root_swap = res;
364
365 hib_resume_bdev_file = bdev_file_open_by_dev(swsusp_resume_device,
366 BLK_OPEN_WRITE, NULL, NULL);
367 if (IS_ERR(hib_resume_bdev_file))
368 return PTR_ERR(hib_resume_bdev_file);
369
370 return 0;
371 }
372
373 /**
374 * write_page - Write one page to given swap location.
375 * @buf: Address we're writing.
376 * @offset: Offset of the swap page we're writing to.
377 * @hb: bio completion batch
378 */
379
380 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
381 {
382 void *src;
383 int ret;
384
385 if (!offset)
386 return -ENOSPC;
387
388 if (hb) {
389 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
390 __GFP_NORETRY);
391 if (src) {
392 copy_page(src, buf);
393 } else {
394 ret = hib_wait_io(hb); /* Free pages */
395 if (ret)
396 return ret;
397 src = (void *)__get_free_page(GFP_NOIO |
398 __GFP_NOWARN |
399 __GFP_NORETRY);
400 if (src) {
401 copy_page(src, buf);
402 } else {
403 WARN_ON_ONCE(1);
404 hb = NULL; /* Go synchronous */
405 src = buf;
406 }
407 }
408 } else {
409 src = buf;
410 }
411 return hib_submit_io(REQ_OP_WRITE | REQ_SYNC, offset, src, hb);
412 }
413
414 static void release_swap_writer(struct swap_map_handle *handle)
415 {
416 if (handle->cur)
417 free_page((unsigned long)handle->cur);
418 handle->cur = NULL;
419 }
420
421 static int get_swap_writer(struct swap_map_handle *handle)
422 {
423 int ret;
424
425 ret = swsusp_swap_check();
426 if (ret) {
427 if (ret != -ENOSPC)
428 pr_err("Cannot find swap device, try swapon -a\n");
429 return ret;
430 }
431 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
432 if (!handle->cur) {
433 ret = -ENOMEM;
434 goto err_close;
435 }
436 handle->cur_swap = alloc_swapdev_block(root_swap);
437 if (!handle->cur_swap) {
438 ret = -ENOSPC;
439 goto err_rel;
440 }
441 handle->k = 0;
442 handle->reqd_free_pages = reqd_free_pages();
443 handle->first_sector = handle->cur_swap;
444 return 0;
445 err_rel:
446 release_swap_writer(handle);
447 err_close:
448 swsusp_close();
449 return ret;
450 }
451
452 static int swap_write_page(struct swap_map_handle *handle, void *buf,
453 struct hib_bio_batch *hb)
454 {
455 int error;
456 sector_t offset;
457
458 if (!handle->cur)
459 return -EINVAL;
460 offset = alloc_swapdev_block(root_swap);
461 error = write_page(buf, offset, hb);
462 if (error)
463 return error;
464 handle->cur->entries[handle->k++] = offset;
465 if (handle->k >= MAP_PAGE_ENTRIES) {
466 offset = alloc_swapdev_block(root_swap);
467 if (!offset)
468 return -ENOSPC;
469 handle->cur->next_swap = offset;
470 error = write_page(handle->cur, handle->cur_swap, hb);
471 if (error)
472 goto out;
473 clear_page(handle->cur);
474 handle->cur_swap = offset;
475 handle->k = 0;
476
477 if (hb && low_free_pages() <= handle->reqd_free_pages) {
478 error = hib_wait_io(hb);
479 if (error)
480 goto out;
481 /*
482 * Recalculate the number of required free pages, to
483 * make sure we never take more than half.
484 */
485 handle->reqd_free_pages = reqd_free_pages();
486 }
487 }
488 out:
489 return error;
490 }
491
492 static int flush_swap_writer(struct swap_map_handle *handle)
493 {
494 if (handle->cur && handle->cur_swap)
495 return write_page(handle->cur, handle->cur_swap, NULL);
496 else
497 return -EINVAL;
498 }
499
500 static int swap_writer_finish(struct swap_map_handle *handle,
501 unsigned int flags, int error)
502 {
503 if (!error) {
504 pr_info("S");
505 error = mark_swapfiles(handle, flags);
506 pr_cont("|\n");
507 flush_swap_writer(handle);
508 }
509
510 if (error)
511 free_all_swap_pages(root_swap);
512 release_swap_writer(handle);
513 swsusp_close();
514
515 return error;
516 }
517
518 /*
519 * Bytes we need for compressed data in worst case. We assume(limitation)
520 * this is the worst of all the compression algorithms.
521 */
522 #define bytes_worst_compress(x) ((x) + ((x) / 16) + 64 + 3 + 2)
523
524 /* We need to remember how much compressed data we need to read. */
525 #define CMP_HEADER sizeof(size_t)
526
527 /* Number of pages/bytes we'll compress at one time. */
528 #define UNC_PAGES 32
529 #define UNC_SIZE (UNC_PAGES * PAGE_SIZE)
530
531 /* Number of pages we need for compressed data (worst case). */
532 #define CMP_PAGES DIV_ROUND_UP(bytes_worst_compress(UNC_SIZE) + \
533 CMP_HEADER, PAGE_SIZE)
534 #define CMP_SIZE (CMP_PAGES * PAGE_SIZE)
535
536 /* Maximum number of threads for compression/decompression. */
537 #define CMP_THREADS 3
538
539 /* Minimum/maximum number of pages for read buffering. */
540 #define CMP_MIN_RD_PAGES 1024
541 #define CMP_MAX_RD_PAGES 8192
542
543 /**
544 * save_image - save the suspend image data
545 */
546
547 static int save_image(struct swap_map_handle *handle,
548 struct snapshot_handle *snapshot,
549 unsigned int nr_to_write)
550 {
551 unsigned int m;
552 int ret;
553 int nr_pages;
554 int err2;
555 struct hib_bio_batch hb;
556 ktime_t start;
557 ktime_t stop;
558
559 hib_init_batch(&hb);
560
561 pr_info("Saving image data pages (%u pages)...\n",
562 nr_to_write);
563 m = nr_to_write / 10;
564 if (!m)
565 m = 1;
566 nr_pages = 0;
567 start = ktime_get();
568 while (1) {
569 ret = snapshot_read_next(snapshot);
570 if (ret <= 0)
571 break;
572 ret = swap_write_page(handle, data_of(*snapshot), &hb);
573 if (ret)
574 break;
575 if (!(nr_pages % m))
576 pr_info("Image saving progress: %3d%%\n",
577 nr_pages / m * 10);
578 nr_pages++;
579 }
580 err2 = hib_wait_io(&hb);
581 hib_finish_batch(&hb);
582 stop = ktime_get();
583 if (!ret)
584 ret = err2;
585 if (!ret)
586 pr_info("Image saving done\n");
587 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
588 return ret;
589 }
590
591 /*
592 * Structure used for CRC32.
593 */
594 struct crc_data {
595 struct task_struct *thr; /* thread */
596 atomic_t ready; /* ready to start flag */
597 atomic_t stop; /* ready to stop flag */
598 unsigned run_threads; /* nr current threads */
599 wait_queue_head_t go; /* start crc update */
600 wait_queue_head_t done; /* crc update done */
601 u32 *crc32; /* points to handle's crc32 */
602 size_t *unc_len[CMP_THREADS]; /* uncompressed lengths */
603 unsigned char *unc[CMP_THREADS]; /* uncompressed data */
604 };
605
606 /*
607 * CRC32 update function that runs in its own thread.
608 */
609 static int crc32_threadfn(void *data)
610 {
611 struct crc_data *d = data;
612 unsigned i;
613
614 while (1) {
615 wait_event(d->go, atomic_read_acquire(&d->ready) ||
616 kthread_should_stop());
617 if (kthread_should_stop()) {
618 d->thr = NULL;
619 atomic_set_release(&d->stop, 1);
620 wake_up(&d->done);
621 break;
622 }
623 atomic_set(&d->ready, 0);
624
625 for (i = 0; i < d->run_threads; i++)
626 *d->crc32 = crc32_le(*d->crc32,
627 d->unc[i], *d->unc_len[i]);
628 atomic_set_release(&d->stop, 1);
629 wake_up(&d->done);
630 }
631 return 0;
632 }
633 /*
634 * Structure used for data compression.
635 */
636 struct cmp_data {
637 struct task_struct *thr; /* thread */
638 struct crypto_comp *cc; /* crypto compressor stream */
639 atomic_t ready; /* ready to start flag */
640 atomic_t stop; /* ready to stop flag */
641 int ret; /* return code */
642 wait_queue_head_t go; /* start compression */
643 wait_queue_head_t done; /* compression done */
644 size_t unc_len; /* uncompressed length */
645 size_t cmp_len; /* compressed length */
646 unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
647 unsigned char cmp[CMP_SIZE]; /* compressed buffer */
648 };
649
650 /* Indicates the image size after compression */
651 static atomic_t compressed_size = ATOMIC_INIT(0);
652
653 /*
654 * Compression function that runs in its own thread.
655 */
656 static int compress_threadfn(void *data)
657 {
658 struct cmp_data *d = data;
659 unsigned int cmp_len = 0;
660
661 while (1) {
662 wait_event(d->go, atomic_read_acquire(&d->ready) ||
663 kthread_should_stop());
664 if (kthread_should_stop()) {
665 d->thr = NULL;
666 d->ret = -1;
667 atomic_set_release(&d->stop, 1);
668 wake_up(&d->done);
669 break;
670 }
671 atomic_set(&d->ready, 0);
672
673 cmp_len = CMP_SIZE - CMP_HEADER;
674 d->ret = crypto_comp_compress(d->cc, d->unc, d->unc_len,
675 d->cmp + CMP_HEADER,
676 &cmp_len);
677 d->cmp_len = cmp_len;
678
679 atomic_set(&compressed_size, atomic_read(&compressed_size) + d->cmp_len);
680 atomic_set_release(&d->stop, 1);
681 wake_up(&d->done);
682 }
683 return 0;
684 }
685
686 /**
687 * save_compressed_image - Save the suspend image data after compression.
688 * @handle: Swap map handle to use for saving the image.
689 * @snapshot: Image to read data from.
690 * @nr_to_write: Number of pages to save.
691 */
692 static int save_compressed_image(struct swap_map_handle *handle,
693 struct snapshot_handle *snapshot,
694 unsigned int nr_to_write)
695 {
696 unsigned int m;
697 int ret = 0;
698 int nr_pages;
699 int err2;
700 struct hib_bio_batch hb;
701 ktime_t start;
702 ktime_t stop;
703 size_t off;
704 unsigned thr, run_threads, nr_threads;
705 unsigned char *page = NULL;
706 struct cmp_data *data = NULL;
707 struct crc_data *crc = NULL;
708
709 hib_init_batch(&hb);
710
711 atomic_set(&compressed_size, 0);
712
713 /*
714 * We'll limit the number of threads for compression to limit memory
715 * footprint.
716 */
717 nr_threads = num_online_cpus() - 1;
718 nr_threads = clamp_val(nr_threads, 1, CMP_THREADS);
719
720 page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
721 if (!page) {
722 pr_err("Failed to allocate %s page\n", hib_comp_algo);
723 ret = -ENOMEM;
724 goto out_clean;
725 }
726
727 data = vzalloc(array_size(nr_threads, sizeof(*data)));
728 if (!data) {
729 pr_err("Failed to allocate %s data\n", hib_comp_algo);
730 ret = -ENOMEM;
731 goto out_clean;
732 }
733
734 crc = kzalloc(sizeof(*crc), GFP_KERNEL);
735 if (!crc) {
736 pr_err("Failed to allocate crc\n");
737 ret = -ENOMEM;
738 goto out_clean;
739 }
740
741 /*
742 * Start the compression threads.
743 */
744 for (thr = 0; thr < nr_threads; thr++) {
745 init_waitqueue_head(&data[thr].go);
746 init_waitqueue_head(&data[thr].done);
747
748 data[thr].cc = crypto_alloc_comp(hib_comp_algo, 0, 0);
749 if (IS_ERR_OR_NULL(data[thr].cc)) {
750 pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
751 ret = -EFAULT;
752 goto out_clean;
753 }
754
755 data[thr].thr = kthread_run(compress_threadfn,
756 &data[thr],
757 "image_compress/%u", thr);
758 if (IS_ERR(data[thr].thr)) {
759 data[thr].thr = NULL;
760 pr_err("Cannot start compression threads\n");
761 ret = -ENOMEM;
762 goto out_clean;
763 }
764 }
765
766 /*
767 * Start the CRC32 thread.
768 */
769 init_waitqueue_head(&crc->go);
770 init_waitqueue_head(&crc->done);
771
772 handle->crc32 = 0;
773 crc->crc32 = &handle->crc32;
774 for (thr = 0; thr < nr_threads; thr++) {
775 crc->unc[thr] = data[thr].unc;
776 crc->unc_len[thr] = &data[thr].unc_len;
777 }
778
779 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
780 if (IS_ERR(crc->thr)) {
781 crc->thr = NULL;
782 pr_err("Cannot start CRC32 thread\n");
783 ret = -ENOMEM;
784 goto out_clean;
785 }
786
787 /*
788 * Adjust the number of required free pages after all allocations have
789 * been done. We don't want to run out of pages when writing.
790 */
791 handle->reqd_free_pages = reqd_free_pages();
792
793 pr_info("Using %u thread(s) for %s compression\n", nr_threads, hib_comp_algo);
794 pr_info("Compressing and saving image data (%u pages)...\n",
795 nr_to_write);
796 m = nr_to_write / 10;
797 if (!m)
798 m = 1;
799 nr_pages = 0;
800 start = ktime_get();
801 for (;;) {
802 for (thr = 0; thr < nr_threads; thr++) {
803 for (off = 0; off < UNC_SIZE; off += PAGE_SIZE) {
804 ret = snapshot_read_next(snapshot);
805 if (ret < 0)
806 goto out_finish;
807
808 if (!ret)
809 break;
810
811 memcpy(data[thr].unc + off,
812 data_of(*snapshot), PAGE_SIZE);
813
814 if (!(nr_pages % m))
815 pr_info("Image saving progress: %3d%%\n",
816 nr_pages / m * 10);
817 nr_pages++;
818 }
819 if (!off)
820 break;
821
822 data[thr].unc_len = off;
823
824 atomic_set_release(&data[thr].ready, 1);
825 wake_up(&data[thr].go);
826 }
827
828 if (!thr)
829 break;
830
831 crc->run_threads = thr;
832 atomic_set_release(&crc->ready, 1);
833 wake_up(&crc->go);
834
835 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
836 wait_event(data[thr].done,
837 atomic_read_acquire(&data[thr].stop));
838 atomic_set(&data[thr].stop, 0);
839
840 ret = data[thr].ret;
841
842 if (ret < 0) {
843 pr_err("%s compression failed\n", hib_comp_algo);
844 goto out_finish;
845 }
846
847 if (unlikely(!data[thr].cmp_len ||
848 data[thr].cmp_len >
849 bytes_worst_compress(data[thr].unc_len))) {
850 pr_err("Invalid %s compressed length\n", hib_comp_algo);
851 ret = -1;
852 goto out_finish;
853 }
854
855 *(size_t *)data[thr].cmp = data[thr].cmp_len;
856
857 /*
858 * Given we are writing one page at a time to disk, we
859 * copy that much from the buffer, although the last
860 * bit will likely be smaller than full page. This is
861 * OK - we saved the length of the compressed data, so
862 * any garbage at the end will be discarded when we
863 * read it.
864 */
865 for (off = 0;
866 off < CMP_HEADER + data[thr].cmp_len;
867 off += PAGE_SIZE) {
868 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
869
870 ret = swap_write_page(handle, page, &hb);
871 if (ret)
872 goto out_finish;
873 }
874 }
875
876 wait_event(crc->done, atomic_read_acquire(&crc->stop));
877 atomic_set(&crc->stop, 0);
878 }
879
880 out_finish:
881 err2 = hib_wait_io(&hb);
882 stop = ktime_get();
883 if (!ret)
884 ret = err2;
885 if (!ret)
886 pr_info("Image saving done\n");
887 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
888 pr_info("Image size after compression: %d kbytes\n",
889 (atomic_read(&compressed_size) / 1024));
890
891 out_clean:
892 hib_finish_batch(&hb);
893 if (crc) {
894 if (crc->thr)
895 kthread_stop(crc->thr);
896 kfree(crc);
897 }
898 if (data) {
899 for (thr = 0; thr < nr_threads; thr++) {
900 if (data[thr].thr)
901 kthread_stop(data[thr].thr);
902 if (data[thr].cc)
903 crypto_free_comp(data[thr].cc);
904 }
905 vfree(data);
906 }
907 if (page) free_page((unsigned long)page);
908
909 return ret;
910 }
911
912 /**
913 * enough_swap - Make sure we have enough swap to save the image.
914 *
915 * Returns TRUE or FALSE after checking the total amount of swap
916 * space available from the resume partition.
917 */
918
919 static int enough_swap(unsigned int nr_pages)
920 {
921 unsigned int free_swap = count_swap_pages(root_swap, 1);
922 unsigned int required;
923
924 pr_debug("Free swap pages: %u\n", free_swap);
925
926 required = PAGES_FOR_IO + nr_pages;
927 return free_swap > required;
928 }
929
930 /**
931 * swsusp_write - Write entire image and metadata.
932 * @flags: flags to pass to the "boot" kernel in the image header
933 *
934 * It is important _NOT_ to umount filesystems at this point. We want
935 * them synced (in case something goes wrong) but we DO not want to mark
936 * filesystem clean: it is not. (And it does not matter, if we resume
937 * correctly, we'll mark system clean, anyway.)
938 */
939
940 int swsusp_write(unsigned int flags)
941 {
942 struct swap_map_handle handle;
943 struct snapshot_handle snapshot;
944 struct swsusp_info *header;
945 unsigned long pages;
946 int error;
947
948 pages = snapshot_get_image_size();
949 error = get_swap_writer(&handle);
950 if (error) {
951 pr_err("Cannot get swap writer\n");
952 return error;
953 }
954 if (flags & SF_NOCOMPRESS_MODE) {
955 if (!enough_swap(pages)) {
956 pr_err("Not enough free swap\n");
957 error = -ENOSPC;
958 goto out_finish;
959 }
960 }
961 memset(&snapshot, 0, sizeof(struct snapshot_handle));
962 error = snapshot_read_next(&snapshot);
963 if (error < (int)PAGE_SIZE) {
964 if (error >= 0)
965 error = -EFAULT;
966
967 goto out_finish;
968 }
969 header = (struct swsusp_info *)data_of(snapshot);
970 error = swap_write_page(&handle, header, NULL);
971 if (!error) {
972 error = (flags & SF_NOCOMPRESS_MODE) ?
973 save_image(&handle, &snapshot, pages - 1) :
974 save_compressed_image(&handle, &snapshot, pages - 1);
975 }
976 out_finish:
977 error = swap_writer_finish(&handle, flags, error);
978 return error;
979 }
980
981 /*
982 * The following functions allow us to read data using a swap map
983 * in a file-like way.
984 */
985
986 static void release_swap_reader(struct swap_map_handle *handle)
987 {
988 struct swap_map_page_list *tmp;
989
990 while (handle->maps) {
991 if (handle->maps->map)
992 free_page((unsigned long)handle->maps->map);
993 tmp = handle->maps;
994 handle->maps = handle->maps->next;
995 kfree(tmp);
996 }
997 handle->cur = NULL;
998 }
999
1000 static int get_swap_reader(struct swap_map_handle *handle,
1001 unsigned int *flags_p)
1002 {
1003 int error;
1004 struct swap_map_page_list *tmp, *last;
1005 sector_t offset;
1006
1007 *flags_p = swsusp_header->flags;
1008
1009 if (!swsusp_header->image) /* how can this happen? */
1010 return -EINVAL;
1011
1012 handle->cur = NULL;
1013 last = handle->maps = NULL;
1014 offset = swsusp_header->image;
1015 while (offset) {
1016 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
1017 if (!tmp) {
1018 release_swap_reader(handle);
1019 return -ENOMEM;
1020 }
1021 if (!handle->maps)
1022 handle->maps = tmp;
1023 if (last)
1024 last->next = tmp;
1025 last = tmp;
1026
1027 tmp->map = (struct swap_map_page *)
1028 __get_free_page(GFP_NOIO | __GFP_HIGH);
1029 if (!tmp->map) {
1030 release_swap_reader(handle);
1031 return -ENOMEM;
1032 }
1033
1034 error = hib_submit_io(REQ_OP_READ, offset, tmp->map, NULL);
1035 if (error) {
1036 release_swap_reader(handle);
1037 return error;
1038 }
1039 offset = tmp->map->next_swap;
1040 }
1041 handle->k = 0;
1042 handle->cur = handle->maps->map;
1043 return 0;
1044 }
1045
1046 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1047 struct hib_bio_batch *hb)
1048 {
1049 sector_t offset;
1050 int error;
1051 struct swap_map_page_list *tmp;
1052
1053 if (!handle->cur)
1054 return -EINVAL;
1055 offset = handle->cur->entries[handle->k];
1056 if (!offset)
1057 return -EFAULT;
1058 error = hib_submit_io(REQ_OP_READ, offset, buf, hb);
1059 if (error)
1060 return error;
1061 if (++handle->k >= MAP_PAGE_ENTRIES) {
1062 handle->k = 0;
1063 free_page((unsigned long)handle->maps->map);
1064 tmp = handle->maps;
1065 handle->maps = handle->maps->next;
1066 kfree(tmp);
1067 if (!handle->maps)
1068 release_swap_reader(handle);
1069 else
1070 handle->cur = handle->maps->map;
1071 }
1072 return error;
1073 }
1074
1075 static int swap_reader_finish(struct swap_map_handle *handle)
1076 {
1077 release_swap_reader(handle);
1078
1079 return 0;
1080 }
1081
1082 /**
1083 * load_image - load the image using the swap map handle
1084 * @handle and the snapshot handle @snapshot
1085 * (assume there are @nr_pages pages to load)
1086 */
1087
1088 static int load_image(struct swap_map_handle *handle,
1089 struct snapshot_handle *snapshot,
1090 unsigned int nr_to_read)
1091 {
1092 unsigned int m;
1093 int ret = 0;
1094 ktime_t start;
1095 ktime_t stop;
1096 struct hib_bio_batch hb;
1097 int err2;
1098 unsigned nr_pages;
1099
1100 hib_init_batch(&hb);
1101
1102 clean_pages_on_read = true;
1103 pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1104 m = nr_to_read / 10;
1105 if (!m)
1106 m = 1;
1107 nr_pages = 0;
1108 start = ktime_get();
1109 for ( ; ; ) {
1110 ret = snapshot_write_next(snapshot);
1111 if (ret <= 0)
1112 break;
1113 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1114 if (ret)
1115 break;
1116 if (snapshot->sync_read)
1117 ret = hib_wait_io(&hb);
1118 if (ret)
1119 break;
1120 if (!(nr_pages % m))
1121 pr_info("Image loading progress: %3d%%\n",
1122 nr_pages / m * 10);
1123 nr_pages++;
1124 }
1125 err2 = hib_wait_io(&hb);
1126 hib_finish_batch(&hb);
1127 stop = ktime_get();
1128 if (!ret)
1129 ret = err2;
1130 if (!ret) {
1131 pr_info("Image loading done\n");
1132 ret = snapshot_write_finalize(snapshot);
1133 if (!ret && !snapshot_image_loaded(snapshot))
1134 ret = -ENODATA;
1135 }
1136 swsusp_show_speed(start, stop, nr_to_read, "Read");
1137 return ret;
1138 }
1139
1140 /*
1141 * Structure used for data decompression.
1142 */
1143 struct dec_data {
1144 struct task_struct *thr; /* thread */
1145 struct crypto_comp *cc; /* crypto compressor stream */
1146 atomic_t ready; /* ready to start flag */
1147 atomic_t stop; /* ready to stop flag */
1148 int ret; /* return code */
1149 wait_queue_head_t go; /* start decompression */
1150 wait_queue_head_t done; /* decompression done */
1151 size_t unc_len; /* uncompressed length */
1152 size_t cmp_len; /* compressed length */
1153 unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
1154 unsigned char cmp[CMP_SIZE]; /* compressed buffer */
1155 };
1156
1157 /*
1158 * Decompression function that runs in its own thread.
1159 */
1160 static int decompress_threadfn(void *data)
1161 {
1162 struct dec_data *d = data;
1163 unsigned int unc_len = 0;
1164
1165 while (1) {
1166 wait_event(d->go, atomic_read_acquire(&d->ready) ||
1167 kthread_should_stop());
1168 if (kthread_should_stop()) {
1169 d->thr = NULL;
1170 d->ret = -1;
1171 atomic_set_release(&d->stop, 1);
1172 wake_up(&d->done);
1173 break;
1174 }
1175 atomic_set(&d->ready, 0);
1176
1177 unc_len = UNC_SIZE;
1178 d->ret = crypto_comp_decompress(d->cc, d->cmp + CMP_HEADER, d->cmp_len,
1179 d->unc, &unc_len);
1180 d->unc_len = unc_len;
1181
1182 if (clean_pages_on_decompress)
1183 flush_icache_range((unsigned long)d->unc,
1184 (unsigned long)d->unc + d->unc_len);
1185
1186 atomic_set_release(&d->stop, 1);
1187 wake_up(&d->done);
1188 }
1189 return 0;
1190 }
1191
1192 /**
1193 * load_compressed_image - Load compressed image data and decompress it.
1194 * @handle: Swap map handle to use for loading data.
1195 * @snapshot: Image to copy uncompressed data into.
1196 * @nr_to_read: Number of pages to load.
1197 */
1198 static int load_compressed_image(struct swap_map_handle *handle,
1199 struct snapshot_handle *snapshot,
1200 unsigned int nr_to_read)
1201 {
1202 unsigned int m;
1203 int ret = 0;
1204 int eof = 0;
1205 struct hib_bio_batch hb;
1206 ktime_t start;
1207 ktime_t stop;
1208 unsigned nr_pages;
1209 size_t off;
1210 unsigned i, thr, run_threads, nr_threads;
1211 unsigned ring = 0, pg = 0, ring_size = 0,
1212 have = 0, want, need, asked = 0;
1213 unsigned long read_pages = 0;
1214 unsigned char **page = NULL;
1215 struct dec_data *data = NULL;
1216 struct crc_data *crc = NULL;
1217
1218 hib_init_batch(&hb);
1219
1220 /*
1221 * We'll limit the number of threads for decompression to limit memory
1222 * footprint.
1223 */
1224 nr_threads = num_online_cpus() - 1;
1225 nr_threads = clamp_val(nr_threads, 1, CMP_THREADS);
1226
1227 page = vmalloc(array_size(CMP_MAX_RD_PAGES, sizeof(*page)));
1228 if (!page) {
1229 pr_err("Failed to allocate %s page\n", hib_comp_algo);
1230 ret = -ENOMEM;
1231 goto out_clean;
1232 }
1233
1234 data = vzalloc(array_size(nr_threads, sizeof(*data)));
1235 if (!data) {
1236 pr_err("Failed to allocate %s data\n", hib_comp_algo);
1237 ret = -ENOMEM;
1238 goto out_clean;
1239 }
1240
1241 crc = kzalloc(sizeof(*crc), GFP_KERNEL);
1242 if (!crc) {
1243 pr_err("Failed to allocate crc\n");
1244 ret = -ENOMEM;
1245 goto out_clean;
1246 }
1247
1248 clean_pages_on_decompress = true;
1249
1250 /*
1251 * Start the decompression threads.
1252 */
1253 for (thr = 0; thr < nr_threads; thr++) {
1254 init_waitqueue_head(&data[thr].go);
1255 init_waitqueue_head(&data[thr].done);
1256
1257 data[thr].cc = crypto_alloc_comp(hib_comp_algo, 0, 0);
1258 if (IS_ERR_OR_NULL(data[thr].cc)) {
1259 pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
1260 ret = -EFAULT;
1261 goto out_clean;
1262 }
1263
1264 data[thr].thr = kthread_run(decompress_threadfn,
1265 &data[thr],
1266 "image_decompress/%u", thr);
1267 if (IS_ERR(data[thr].thr)) {
1268 data[thr].thr = NULL;
1269 pr_err("Cannot start decompression threads\n");
1270 ret = -ENOMEM;
1271 goto out_clean;
1272 }
1273 }
1274
1275 /*
1276 * Start the CRC32 thread.
1277 */
1278 init_waitqueue_head(&crc->go);
1279 init_waitqueue_head(&crc->done);
1280
1281 handle->crc32 = 0;
1282 crc->crc32 = &handle->crc32;
1283 for (thr = 0; thr < nr_threads; thr++) {
1284 crc->unc[thr] = data[thr].unc;
1285 crc->unc_len[thr] = &data[thr].unc_len;
1286 }
1287
1288 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1289 if (IS_ERR(crc->thr)) {
1290 crc->thr = NULL;
1291 pr_err("Cannot start CRC32 thread\n");
1292 ret = -ENOMEM;
1293 goto out_clean;
1294 }
1295
1296 /*
1297 * Set the number of pages for read buffering.
1298 * This is complete guesswork, because we'll only know the real
1299 * picture once prepare_image() is called, which is much later on
1300 * during the image load phase. We'll assume the worst case and
1301 * say that none of the image pages are from high memory.
1302 */
1303 if (low_free_pages() > snapshot_get_image_size())
1304 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1305 read_pages = clamp_val(read_pages, CMP_MIN_RD_PAGES, CMP_MAX_RD_PAGES);
1306
1307 for (i = 0; i < read_pages; i++) {
1308 page[i] = (void *)__get_free_page(i < CMP_PAGES ?
1309 GFP_NOIO | __GFP_HIGH :
1310 GFP_NOIO | __GFP_NOWARN |
1311 __GFP_NORETRY);
1312
1313 if (!page[i]) {
1314 if (i < CMP_PAGES) {
1315 ring_size = i;
1316 pr_err("Failed to allocate %s pages\n", hib_comp_algo);
1317 ret = -ENOMEM;
1318 goto out_clean;
1319 } else {
1320 break;
1321 }
1322 }
1323 }
1324 want = ring_size = i;
1325
1326 pr_info("Using %u thread(s) for %s decompression\n", nr_threads, hib_comp_algo);
1327 pr_info("Loading and decompressing image data (%u pages)...\n",
1328 nr_to_read);
1329 m = nr_to_read / 10;
1330 if (!m)
1331 m = 1;
1332 nr_pages = 0;
1333 start = ktime_get();
1334
1335 ret = snapshot_write_next(snapshot);
1336 if (ret <= 0)
1337 goto out_finish;
1338
1339 for(;;) {
1340 for (i = 0; !eof && i < want; i++) {
1341 ret = swap_read_page(handle, page[ring], &hb);
1342 if (ret) {
1343 /*
1344 * On real read error, finish. On end of data,
1345 * set EOF flag and just exit the read loop.
1346 */
1347 if (handle->cur &&
1348 handle->cur->entries[handle->k]) {
1349 goto out_finish;
1350 } else {
1351 eof = 1;
1352 break;
1353 }
1354 }
1355 if (++ring >= ring_size)
1356 ring = 0;
1357 }
1358 asked += i;
1359 want -= i;
1360
1361 /*
1362 * We are out of data, wait for some more.
1363 */
1364 if (!have) {
1365 if (!asked)
1366 break;
1367
1368 ret = hib_wait_io(&hb);
1369 if (ret)
1370 goto out_finish;
1371 have += asked;
1372 asked = 0;
1373 if (eof)
1374 eof = 2;
1375 }
1376
1377 if (crc->run_threads) {
1378 wait_event(crc->done, atomic_read_acquire(&crc->stop));
1379 atomic_set(&crc->stop, 0);
1380 crc->run_threads = 0;
1381 }
1382
1383 for (thr = 0; have && thr < nr_threads; thr++) {
1384 data[thr].cmp_len = *(size_t *)page[pg];
1385 if (unlikely(!data[thr].cmp_len ||
1386 data[thr].cmp_len >
1387 bytes_worst_compress(UNC_SIZE))) {
1388 pr_err("Invalid %s compressed length\n", hib_comp_algo);
1389 ret = -1;
1390 goto out_finish;
1391 }
1392
1393 need = DIV_ROUND_UP(data[thr].cmp_len + CMP_HEADER,
1394 PAGE_SIZE);
1395 if (need > have) {
1396 if (eof > 1) {
1397 ret = -1;
1398 goto out_finish;
1399 }
1400 break;
1401 }
1402
1403 for (off = 0;
1404 off < CMP_HEADER + data[thr].cmp_len;
1405 off += PAGE_SIZE) {
1406 memcpy(data[thr].cmp + off,
1407 page[pg], PAGE_SIZE);
1408 have--;
1409 want++;
1410 if (++pg >= ring_size)
1411 pg = 0;
1412 }
1413
1414 atomic_set_release(&data[thr].ready, 1);
1415 wake_up(&data[thr].go);
1416 }
1417
1418 /*
1419 * Wait for more data while we are decompressing.
1420 */
1421 if (have < CMP_PAGES && asked) {
1422 ret = hib_wait_io(&hb);
1423 if (ret)
1424 goto out_finish;
1425 have += asked;
1426 asked = 0;
1427 if (eof)
1428 eof = 2;
1429 }
1430
1431 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1432 wait_event(data[thr].done,
1433 atomic_read_acquire(&data[thr].stop));
1434 atomic_set(&data[thr].stop, 0);
1435
1436 ret = data[thr].ret;
1437
1438 if (ret < 0) {
1439 pr_err("%s decompression failed\n", hib_comp_algo);
1440 goto out_finish;
1441 }
1442
1443 if (unlikely(!data[thr].unc_len ||
1444 data[thr].unc_len > UNC_SIZE ||
1445 data[thr].unc_len & (PAGE_SIZE - 1))) {
1446 pr_err("Invalid %s uncompressed length\n", hib_comp_algo);
1447 ret = -1;
1448 goto out_finish;
1449 }
1450
1451 for (off = 0;
1452 off < data[thr].unc_len; off += PAGE_SIZE) {
1453 memcpy(data_of(*snapshot),
1454 data[thr].unc + off, PAGE_SIZE);
1455
1456 if (!(nr_pages % m))
1457 pr_info("Image loading progress: %3d%%\n",
1458 nr_pages / m * 10);
1459 nr_pages++;
1460
1461 ret = snapshot_write_next(snapshot);
1462 if (ret <= 0) {
1463 crc->run_threads = thr + 1;
1464 atomic_set_release(&crc->ready, 1);
1465 wake_up(&crc->go);
1466 goto out_finish;
1467 }
1468 }
1469 }
1470
1471 crc->run_threads = thr;
1472 atomic_set_release(&crc->ready, 1);
1473 wake_up(&crc->go);
1474 }
1475
1476 out_finish:
1477 if (crc->run_threads) {
1478 wait_event(crc->done, atomic_read_acquire(&crc->stop));
1479 atomic_set(&crc->stop, 0);
1480 }
1481 stop = ktime_get();
1482 if (!ret) {
1483 pr_info("Image loading done\n");
1484 ret = snapshot_write_finalize(snapshot);
1485 if (!ret && !snapshot_image_loaded(snapshot))
1486 ret = -ENODATA;
1487 if (!ret) {
1488 if (swsusp_header->flags & SF_CRC32_MODE) {
1489 if(handle->crc32 != swsusp_header->crc32) {
1490 pr_err("Invalid image CRC32!\n");
1491 ret = -ENODATA;
1492 }
1493 }
1494 }
1495 }
1496 swsusp_show_speed(start, stop, nr_to_read, "Read");
1497 out_clean:
1498 hib_finish_batch(&hb);
1499 for (i = 0; i < ring_size; i++)
1500 free_page((unsigned long)page[i]);
1501 if (crc) {
1502 if (crc->thr)
1503 kthread_stop(crc->thr);
1504 kfree(crc);
1505 }
1506 if (data) {
1507 for (thr = 0; thr < nr_threads; thr++) {
1508 if (data[thr].thr)
1509 kthread_stop(data[thr].thr);
1510 if (data[thr].cc)
1511 crypto_free_comp(data[thr].cc);
1512 }
1513 vfree(data);
1514 }
1515 vfree(page);
1516
1517 return ret;
1518 }
1519
1520 /**
1521 * swsusp_read - read the hibernation image.
1522 * @flags_p: flags passed by the "frozen" kernel in the image header should
1523 * be written into this memory location
1524 */
1525
1526 int swsusp_read(unsigned int *flags_p)
1527 {
1528 int error;
1529 struct swap_map_handle handle;
1530 struct snapshot_handle snapshot;
1531 struct swsusp_info *header;
1532
1533 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1534 error = snapshot_write_next(&snapshot);
1535 if (error < (int)PAGE_SIZE)
1536 return error < 0 ? error : -EFAULT;
1537 header = (struct swsusp_info *)data_of(snapshot);
1538 error = get_swap_reader(&handle, flags_p);
1539 if (error)
1540 goto end;
1541 if (!error)
1542 error = swap_read_page(&handle, header, NULL);
1543 if (!error) {
1544 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1545 load_image(&handle, &snapshot, header->pages - 1) :
1546 load_compressed_image(&handle, &snapshot, header->pages - 1);
1547 }
1548 swap_reader_finish(&handle);
1549 end:
1550 if (!error)
1551 pr_debug("Image successfully loaded\n");
1552 else
1553 pr_debug("Error %d resuming\n", error);
1554 return error;
1555 }
1556
1557 static void *swsusp_holder;
1558
1559 /**
1560 * swsusp_check - Open the resume device and check for the swsusp signature.
1561 * @exclusive: Open the resume device exclusively.
1562 */
1563
1564 int swsusp_check(bool exclusive)
1565 {
1566 void *holder = exclusive ? &swsusp_holder : NULL;
1567 int error;
1568
1569 hib_resume_bdev_file = bdev_file_open_by_dev(swsusp_resume_device,
1570 BLK_OPEN_READ, holder, NULL);
1571 if (!IS_ERR(hib_resume_bdev_file)) {
1572 clear_page(swsusp_header);
1573 error = hib_submit_io(REQ_OP_READ, swsusp_resume_block,
1574 swsusp_header, NULL);
1575 if (error)
1576 goto put;
1577
1578 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1579 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1580 swsusp_header_flags = swsusp_header->flags;
1581 /* Reset swap signature now */
1582 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
1583 swsusp_resume_block,
1584 swsusp_header, NULL);
1585 } else {
1586 error = -EINVAL;
1587 }
1588 if (!error && swsusp_header->flags & SF_HW_SIG &&
1589 swsusp_header->hw_sig != swsusp_hardware_signature) {
1590 pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
1591 swsusp_header->hw_sig, swsusp_hardware_signature);
1592 error = -EINVAL;
1593 }
1594
1595 put:
1596 if (error)
1597 bdev_fput(hib_resume_bdev_file);
1598 else
1599 pr_debug("Image signature found, resuming\n");
1600 } else {
1601 error = PTR_ERR(hib_resume_bdev_file);
1602 }
1603
1604 if (error)
1605 pr_debug("Image not found (code %d)\n", error);
1606
1607 return error;
1608 }
1609
1610 /**
1611 * swsusp_close - close resume device.
1612 */
1613
1614 void swsusp_close(void)
1615 {
1616 if (IS_ERR(hib_resume_bdev_file)) {
1617 pr_debug("Image device not initialised\n");
1618 return;
1619 }
1620
1621 fput(hib_resume_bdev_file);
1622 }
1623
1624 /**
1625 * swsusp_unmark - Unmark swsusp signature in the resume device
1626 */
1627
1628 #ifdef CONFIG_SUSPEND
1629 int swsusp_unmark(void)
1630 {
1631 int error;
1632
1633 hib_submit_io(REQ_OP_READ, swsusp_resume_block,
1634 swsusp_header, NULL);
1635 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1636 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1637 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
1638 swsusp_resume_block,
1639 swsusp_header, NULL);
1640 } else {
1641 pr_err("Cannot find swsusp signature!\n");
1642 error = -ENODEV;
1643 }
1644
1645 /*
1646 * We just returned from suspend, we don't need the image any more.
1647 */
1648 free_all_swap_pages(root_swap);
1649
1650 return error;
1651 }
1652 #endif
1653
1654 static int __init swsusp_header_init(void)
1655 {
1656 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1657 if (!swsusp_header)
1658 panic("Could not allocate memory for swsusp_header\n");
1659 return 0;
1660 }
1661
1662 core_initcall(swsusp_header_init);
1663
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