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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@ucw.cz>
8 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
10 *
11 * This file is released under the GPLv2.
12 *
13 */
14
15#define pr_fmt(fmt) "PM: " fmt
16
17#include <linux/module.h>
18#include <linux/file.h>
19#include <linux/delay.h>
20#include <linux/bitops.h>
21#include <linux/genhd.h>
22#include <linux/device.h>
23#include <linux/bio.h>
24#include <linux/blkdev.h>
25#include <linux/swap.h>
26#include <linux/swapops.h>
27#include <linux/pm.h>
28#include <linux/slab.h>
29#include <linux/lzo.h>
30#include <linux/vmalloc.h>
31#include <linux/cpumask.h>
32#include <linux/atomic.h>
33#include <linux/kthread.h>
34#include <linux/crc32.h>
35#include <linux/ktime.h>
36
37#include "power.h"
38
39#define HIBERNATE_SIG "S1SUSPEND"
40
41/*
42 * When reading an {un,}compressed image, we may restore pages in place,
43 * in which case some architectures need these pages cleaning before they
44 * can be executed. We don't know which pages these may be, so clean the lot.
45 */
46static bool clean_pages_on_read;
47static bool clean_pages_on_decompress;
48
49/*
50 * The swap map is a data structure used for keeping track of each page
51 * written to a swap partition. It consists of many swap_map_page
52 * structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
53 * These structures are stored on the swap and linked together with the
54 * help of the .next_swap member.
55 *
56 * The swap map is created during suspend. The swap map pages are
57 * allocated and populated one at a time, so we only need one memory
58 * page to set up the entire structure.
59 *
60 * During resume we pick up all swap_map_page structures into a list.
61 */
62
63#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
64
65/*
66 * Number of free pages that are not high.
67 */
68static inline unsigned long low_free_pages(void)
69{
70 return nr_free_pages() - nr_free_highpages();
71}
72
73/*
74 * Number of pages required to be kept free while writing the image. Always
75 * half of all available low pages before the writing starts.
76 */
77static inline unsigned long reqd_free_pages(void)
78{
79 return low_free_pages() / 2;
80}
81
82struct swap_map_page {
83 sector_t entries[MAP_PAGE_ENTRIES];
84 sector_t next_swap;
85};
86
87struct swap_map_page_list {
88 struct swap_map_page *map;
89 struct swap_map_page_list *next;
90};
91
92/**
93 * The swap_map_handle structure is used for handling swap in
94 * a file-alike way
95 */
96
97struct swap_map_handle {
98 struct swap_map_page *cur;
99 struct swap_map_page_list *maps;
100 sector_t cur_swap;
101 sector_t first_sector;
102 unsigned int k;
103 unsigned long reqd_free_pages;
104 u32 crc32;
105};
106
107struct swsusp_header {
108 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
109 sizeof(u32)];
110 u32 crc32;
111 sector_t image;
112 unsigned int flags; /* Flags to pass to the "boot" kernel */
113 char orig_sig[10];
114 char sig[10];
115} __packed;
116
117static struct swsusp_header *swsusp_header;
118
119/**
120 * The following functions are used for tracing the allocated
121 * swap pages, so that they can be freed in case of an error.
122 */
123
124struct swsusp_extent {
125 struct rb_node node;
126 unsigned long start;
127 unsigned long end;
128};
129
130static struct rb_root swsusp_extents = RB_ROOT;
131
132static int swsusp_extents_insert(unsigned long swap_offset)
133{
134 struct rb_node **new = &(swsusp_extents.rb_node);
135 struct rb_node *parent = NULL;
136 struct swsusp_extent *ext;
137
138 /* Figure out where to put the new node */
139 while (*new) {
140 ext = rb_entry(*new, struct swsusp_extent, node);
141 parent = *new;
142 if (swap_offset < ext->start) {
143 /* Try to merge */
144 if (swap_offset == ext->start - 1) {
145 ext->start--;
146 return 0;
147 }
148 new = &((*new)->rb_left);
149 } else if (swap_offset > ext->end) {
150 /* Try to merge */
151 if (swap_offset == ext->end + 1) {
152 ext->end++;
153 return 0;
154 }
155 new = &((*new)->rb_right);
156 } else {
157 /* It already is in the tree */
158 return -EINVAL;
159 }
160 }
161 /* Add the new node and rebalance the tree. */
162 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
163 if (!ext)
164 return -ENOMEM;
165
166 ext->start = swap_offset;
167 ext->end = swap_offset;
168 rb_link_node(&ext->node, parent, new);
169 rb_insert_color(&ext->node, &swsusp_extents);
170 return 0;
171}
172
173/**
174 * alloc_swapdev_block - allocate a swap page and register that it has
175 * been allocated, so that it can be freed in case of an error.
176 */
177
178sector_t alloc_swapdev_block(int swap)
179{
180 unsigned long offset;
181
182 offset = swp_offset(get_swap_page_of_type(swap));
183 if (offset) {
184 if (swsusp_extents_insert(offset))
185 swap_free(swp_entry(swap, offset));
186 else
187 return swapdev_block(swap, offset);
188 }
189 return 0;
190}
191
192/**
193 * free_all_swap_pages - free swap pages allocated for saving image data.
194 * It also frees the extents used to register which swap entries had been
195 * allocated.
196 */
197
198void free_all_swap_pages(int swap)
199{
200 struct rb_node *node;
201
202 while ((node = swsusp_extents.rb_node)) {
203 struct swsusp_extent *ext;
204 unsigned long offset;
205
206 ext = rb_entry(node, struct swsusp_extent, node);
207 rb_erase(node, &swsusp_extents);
208 for (offset = ext->start; offset <= ext->end; offset++)
209 swap_free(swp_entry(swap, offset));
210
211 kfree(ext);
212 }
213}
214
215int swsusp_swap_in_use(void)
216{
217 return (swsusp_extents.rb_node != NULL);
218}
219
220/*
221 * General things
222 */
223
224static unsigned short root_swap = 0xffff;
225static struct block_device *hib_resume_bdev;
226
227struct hib_bio_batch {
228 atomic_t count;
229 wait_queue_head_t wait;
230 blk_status_t error;
231};
232
233static void hib_init_batch(struct hib_bio_batch *hb)
234{
235 atomic_set(&hb->count, 0);
236 init_waitqueue_head(&hb->wait);
237 hb->error = BLK_STS_OK;
238}
239
240static void hib_end_io(struct bio *bio)
241{
242 struct hib_bio_batch *hb = bio->bi_private;
243 struct page *page = bio_first_page_all(bio);
244
245 if (bio->bi_status) {
246 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
247 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
248 (unsigned long long)bio->bi_iter.bi_sector);
249 }
250
251 if (bio_data_dir(bio) == WRITE)
252 put_page(page);
253 else if (clean_pages_on_read)
254 flush_icache_range((unsigned long)page_address(page),
255 (unsigned long)page_address(page) + PAGE_SIZE);
256
257 if (bio->bi_status && !hb->error)
258 hb->error = bio->bi_status;
259 if (atomic_dec_and_test(&hb->count))
260 wake_up(&hb->wait);
261
262 bio_put(bio);
263}
264
265static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
266 struct hib_bio_batch *hb)
267{
268 struct page *page = virt_to_page(addr);
269 struct bio *bio;
270 int error = 0;
271
272 bio = bio_alloc(__GFP_RECLAIM | __GFP_HIGH, 1);
273 bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
274 bio_set_dev(bio, hib_resume_bdev);
275 bio_set_op_attrs(bio, op, op_flags);
276
277 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
278 pr_err("Adding page to bio failed at %llu\n",
279 (unsigned long long)bio->bi_iter.bi_sector);
280 bio_put(bio);
281 return -EFAULT;
282 }
283
284 if (hb) {
285 bio->bi_end_io = hib_end_io;
286 bio->bi_private = hb;
287 atomic_inc(&hb->count);
288 submit_bio(bio);
289 } else {
290 error = submit_bio_wait(bio);
291 bio_put(bio);
292 }
293
294 return error;
295}
296
297static blk_status_t hib_wait_io(struct hib_bio_batch *hb)
298{
299 wait_event(hb->wait, atomic_read(&hb->count) == 0);
300 return blk_status_to_errno(hb->error);
301}
302
303/*
304 * Saving part
305 */
306
307static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
308{
309 int error;
310
311 hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
312 swsusp_header, NULL);
313 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
314 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
315 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
316 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
317 swsusp_header->image = handle->first_sector;
318 swsusp_header->flags = flags;
319 if (flags & SF_CRC32_MODE)
320 swsusp_header->crc32 = handle->crc32;
321 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
322 swsusp_resume_block, swsusp_header, NULL);
323 } else {
324 pr_err("Swap header not found!\n");
325 error = -ENODEV;
326 }
327 return error;
328}
329
330/**
331 * swsusp_swap_check - check if the resume device is a swap device
332 * and get its index (if so)
333 *
334 * This is called before saving image
335 */
336static int swsusp_swap_check(void)
337{
338 int res;
339
340 res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
341 &hib_resume_bdev);
342 if (res < 0)
343 return res;
344
345 root_swap = res;
346 res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
347 if (res)
348 return res;
349
350 res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
351 if (res < 0)
352 blkdev_put(hib_resume_bdev, FMODE_WRITE);
353
354 /*
355 * Update the resume device to the one actually used,
356 * so the test_resume mode can use it in case it is
357 * invoked from hibernate() to test the snapshot.
358 */
359 swsusp_resume_device = hib_resume_bdev->bd_dev;
360 return res;
361}
362
363/**
364 * write_page - Write one page to given swap location.
365 * @buf: Address we're writing.
366 * @offset: Offset of the swap page we're writing to.
367 * @hb: bio completion batch
368 */
369
370static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
371{
372 void *src;
373 int ret;
374
375 if (!offset)
376 return -ENOSPC;
377
378 if (hb) {
379 src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN |
380 __GFP_NORETRY);
381 if (src) {
382 copy_page(src, buf);
383 } else {
384 ret = hib_wait_io(hb); /* Free pages */
385 if (ret)
386 return ret;
387 src = (void *)__get_free_page(__GFP_RECLAIM |
388 __GFP_NOWARN |
389 __GFP_NORETRY);
390 if (src) {
391 copy_page(src, buf);
392 } else {
393 WARN_ON_ONCE(1);
394 hb = NULL; /* Go synchronous */
395 src = buf;
396 }
397 }
398 } else {
399 src = buf;
400 }
401 return hib_submit_io(REQ_OP_WRITE, REQ_SYNC, offset, src, hb);
402}
403
404static void release_swap_writer(struct swap_map_handle *handle)
405{
406 if (handle->cur)
407 free_page((unsigned long)handle->cur);
408 handle->cur = NULL;
409}
410
411static int get_swap_writer(struct swap_map_handle *handle)
412{
413 int ret;
414
415 ret = swsusp_swap_check();
416 if (ret) {
417 if (ret != -ENOSPC)
418 pr_err("Cannot find swap device, try swapon -a\n");
419 return ret;
420 }
421 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
422 if (!handle->cur) {
423 ret = -ENOMEM;
424 goto err_close;
425 }
426 handle->cur_swap = alloc_swapdev_block(root_swap);
427 if (!handle->cur_swap) {
428 ret = -ENOSPC;
429 goto err_rel;
430 }
431 handle->k = 0;
432 handle->reqd_free_pages = reqd_free_pages();
433 handle->first_sector = handle->cur_swap;
434 return 0;
435err_rel:
436 release_swap_writer(handle);
437err_close:
438 swsusp_close(FMODE_WRITE);
439 return ret;
440}
441
442static int swap_write_page(struct swap_map_handle *handle, void *buf,
443 struct hib_bio_batch *hb)
444{
445 int error = 0;
446 sector_t offset;
447
448 if (!handle->cur)
449 return -EINVAL;
450 offset = alloc_swapdev_block(root_swap);
451 error = write_page(buf, offset, hb);
452 if (error)
453 return error;
454 handle->cur->entries[handle->k++] = offset;
455 if (handle->k >= MAP_PAGE_ENTRIES) {
456 offset = alloc_swapdev_block(root_swap);
457 if (!offset)
458 return -ENOSPC;
459 handle->cur->next_swap = offset;
460 error = write_page(handle->cur, handle->cur_swap, hb);
461 if (error)
462 goto out;
463 clear_page(handle->cur);
464 handle->cur_swap = offset;
465 handle->k = 0;
466
467 if (hb && low_free_pages() <= handle->reqd_free_pages) {
468 error = hib_wait_io(hb);
469 if (error)
470 goto out;
471 /*
472 * Recalculate the number of required free pages, to
473 * make sure we never take more than half.
474 */
475 handle->reqd_free_pages = reqd_free_pages();
476 }
477 }
478 out:
479 return error;
480}
481
482static int flush_swap_writer(struct swap_map_handle *handle)
483{
484 if (handle->cur && handle->cur_swap)
485 return write_page(handle->cur, handle->cur_swap, NULL);
486 else
487 return -EINVAL;
488}
489
490static int swap_writer_finish(struct swap_map_handle *handle,
491 unsigned int flags, int error)
492{
493 if (!error) {
494 flush_swap_writer(handle);
495 pr_info("S");
496 error = mark_swapfiles(handle, flags);
497 pr_cont("|\n");
498 }
499
500 if (error)
501 free_all_swap_pages(root_swap);
502 release_swap_writer(handle);
503 swsusp_close(FMODE_WRITE);
504
505 return error;
506}
507
508/* We need to remember how much compressed data we need to read. */
509#define LZO_HEADER sizeof(size_t)
510
511/* Number of pages/bytes we'll compress at one time. */
512#define LZO_UNC_PAGES 32
513#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE)
514
515/* Number of pages/bytes we need for compressed data (worst case). */
516#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
517 LZO_HEADER, PAGE_SIZE)
518#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE)
519
520/* Maximum number of threads for compression/decompression. */
521#define LZO_THREADS 3
522
523/* Minimum/maximum number of pages for read buffering. */
524#define LZO_MIN_RD_PAGES 1024
525#define LZO_MAX_RD_PAGES 8192
526
527
528/**
529 * save_image - save the suspend image data
530 */
531
532static int save_image(struct swap_map_handle *handle,
533 struct snapshot_handle *snapshot,
534 unsigned int nr_to_write)
535{
536 unsigned int m;
537 int ret;
538 int nr_pages;
539 int err2;
540 struct hib_bio_batch hb;
541 ktime_t start;
542 ktime_t stop;
543
544 hib_init_batch(&hb);
545
546 pr_info("Saving image data pages (%u pages)...\n",
547 nr_to_write);
548 m = nr_to_write / 10;
549 if (!m)
550 m = 1;
551 nr_pages = 0;
552 start = ktime_get();
553 while (1) {
554 ret = snapshot_read_next(snapshot);
555 if (ret <= 0)
556 break;
557 ret = swap_write_page(handle, data_of(*snapshot), &hb);
558 if (ret)
559 break;
560 if (!(nr_pages % m))
561 pr_info("Image saving progress: %3d%%\n",
562 nr_pages / m * 10);
563 nr_pages++;
564 }
565 err2 = hib_wait_io(&hb);
566 stop = ktime_get();
567 if (!ret)
568 ret = err2;
569 if (!ret)
570 pr_info("Image saving done\n");
571 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
572 return ret;
573}
574
575/**
576 * Structure used for CRC32.
577 */
578struct crc_data {
579 struct task_struct *thr; /* thread */
580 atomic_t ready; /* ready to start flag */
581 atomic_t stop; /* ready to stop flag */
582 unsigned run_threads; /* nr current threads */
583 wait_queue_head_t go; /* start crc update */
584 wait_queue_head_t done; /* crc update done */
585 u32 *crc32; /* points to handle's crc32 */
586 size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */
587 unsigned char *unc[LZO_THREADS]; /* uncompressed data */
588};
589
590/**
591 * CRC32 update function that runs in its own thread.
592 */
593static int crc32_threadfn(void *data)
594{
595 struct crc_data *d = data;
596 unsigned i;
597
598 while (1) {
599 wait_event(d->go, atomic_read(&d->ready) ||
600 kthread_should_stop());
601 if (kthread_should_stop()) {
602 d->thr = NULL;
603 atomic_set(&d->stop, 1);
604 wake_up(&d->done);
605 break;
606 }
607 atomic_set(&d->ready, 0);
608
609 for (i = 0; i < d->run_threads; i++)
610 *d->crc32 = crc32_le(*d->crc32,
611 d->unc[i], *d->unc_len[i]);
612 atomic_set(&d->stop, 1);
613 wake_up(&d->done);
614 }
615 return 0;
616}
617/**
618 * Structure used for LZO data compression.
619 */
620struct cmp_data {
621 struct task_struct *thr; /* thread */
622 atomic_t ready; /* ready to start flag */
623 atomic_t stop; /* ready to stop flag */
624 int ret; /* return code */
625 wait_queue_head_t go; /* start compression */
626 wait_queue_head_t done; /* compression done */
627 size_t unc_len; /* uncompressed length */
628 size_t cmp_len; /* compressed length */
629 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
630 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
631 unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
632};
633
634/**
635 * Compression function that runs in its own thread.
636 */
637static int lzo_compress_threadfn(void *data)
638{
639 struct cmp_data *d = data;
640
641 while (1) {
642 wait_event(d->go, atomic_read(&d->ready) ||
643 kthread_should_stop());
644 if (kthread_should_stop()) {
645 d->thr = NULL;
646 d->ret = -1;
647 atomic_set(&d->stop, 1);
648 wake_up(&d->done);
649 break;
650 }
651 atomic_set(&d->ready, 0);
652
653 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
654 d->cmp + LZO_HEADER, &d->cmp_len,
655 d->wrk);
656 atomic_set(&d->stop, 1);
657 wake_up(&d->done);
658 }
659 return 0;
660}
661
662/**
663 * save_image_lzo - Save the suspend image data compressed with LZO.
664 * @handle: Swap map handle to use for saving the image.
665 * @snapshot: Image to read data from.
666 * @nr_to_write: Number of pages to save.
667 */
668static int save_image_lzo(struct swap_map_handle *handle,
669 struct snapshot_handle *snapshot,
670 unsigned int nr_to_write)
671{
672 unsigned int m;
673 int ret = 0;
674 int nr_pages;
675 int err2;
676 struct hib_bio_batch hb;
677 ktime_t start;
678 ktime_t stop;
679 size_t off;
680 unsigned thr, run_threads, nr_threads;
681 unsigned char *page = NULL;
682 struct cmp_data *data = NULL;
683 struct crc_data *crc = NULL;
684
685 hib_init_batch(&hb);
686
687 /*
688 * We'll limit the number of threads for compression to limit memory
689 * footprint.
690 */
691 nr_threads = num_online_cpus() - 1;
692 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
693
694 page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH);
695 if (!page) {
696 pr_err("Failed to allocate LZO page\n");
697 ret = -ENOMEM;
698 goto out_clean;
699 }
700
701 data = vmalloc(sizeof(*data) * nr_threads);
702 if (!data) {
703 pr_err("Failed to allocate LZO data\n");
704 ret = -ENOMEM;
705 goto out_clean;
706 }
707 for (thr = 0; thr < nr_threads; thr++)
708 memset(&data[thr], 0, offsetof(struct cmp_data, go));
709
710 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
711 if (!crc) {
712 pr_err("Failed to allocate crc\n");
713 ret = -ENOMEM;
714 goto out_clean;
715 }
716 memset(crc, 0, offsetof(struct crc_data, go));
717
718 /*
719 * Start the compression threads.
720 */
721 for (thr = 0; thr < nr_threads; thr++) {
722 init_waitqueue_head(&data[thr].go);
723 init_waitqueue_head(&data[thr].done);
724
725 data[thr].thr = kthread_run(lzo_compress_threadfn,
726 &data[thr],
727 "image_compress/%u", thr);
728 if (IS_ERR(data[thr].thr)) {
729 data[thr].thr = NULL;
730 pr_err("Cannot start compression threads\n");
731 ret = -ENOMEM;
732 goto out_clean;
733 }
734 }
735
736 /*
737 * Start the CRC32 thread.
738 */
739 init_waitqueue_head(&crc->go);
740 init_waitqueue_head(&crc->done);
741
742 handle->crc32 = 0;
743 crc->crc32 = &handle->crc32;
744 for (thr = 0; thr < nr_threads; thr++) {
745 crc->unc[thr] = data[thr].unc;
746 crc->unc_len[thr] = &data[thr].unc_len;
747 }
748
749 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
750 if (IS_ERR(crc->thr)) {
751 crc->thr = NULL;
752 pr_err("Cannot start CRC32 thread\n");
753 ret = -ENOMEM;
754 goto out_clean;
755 }
756
757 /*
758 * Adjust the number of required free pages after all allocations have
759 * been done. We don't want to run out of pages when writing.
760 */
761 handle->reqd_free_pages = reqd_free_pages();
762
763 pr_info("Using %u thread(s) for compression\n", nr_threads);
764 pr_info("Compressing and saving image data (%u pages)...\n",
765 nr_to_write);
766 m = nr_to_write / 10;
767 if (!m)
768 m = 1;
769 nr_pages = 0;
770 start = ktime_get();
771 for (;;) {
772 for (thr = 0; thr < nr_threads; thr++) {
773 for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
774 ret = snapshot_read_next(snapshot);
775 if (ret < 0)
776 goto out_finish;
777
778 if (!ret)
779 break;
780
781 memcpy(data[thr].unc + off,
782 data_of(*snapshot), PAGE_SIZE);
783
784 if (!(nr_pages % m))
785 pr_info("Image saving progress: %3d%%\n",
786 nr_pages / m * 10);
787 nr_pages++;
788 }
789 if (!off)
790 break;
791
792 data[thr].unc_len = off;
793
794 atomic_set(&data[thr].ready, 1);
795 wake_up(&data[thr].go);
796 }
797
798 if (!thr)
799 break;
800
801 crc->run_threads = thr;
802 atomic_set(&crc->ready, 1);
803 wake_up(&crc->go);
804
805 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
806 wait_event(data[thr].done,
807 atomic_read(&data[thr].stop));
808 atomic_set(&data[thr].stop, 0);
809
810 ret = data[thr].ret;
811
812 if (ret < 0) {
813 pr_err("LZO compression failed\n");
814 goto out_finish;
815 }
816
817 if (unlikely(!data[thr].cmp_len ||
818 data[thr].cmp_len >
819 lzo1x_worst_compress(data[thr].unc_len))) {
820 pr_err("Invalid LZO compressed length\n");
821 ret = -1;
822 goto out_finish;
823 }
824
825 *(size_t *)data[thr].cmp = data[thr].cmp_len;
826
827 /*
828 * Given we are writing one page at a time to disk, we
829 * copy that much from the buffer, although the last
830 * bit will likely be smaller than full page. This is
831 * OK - we saved the length of the compressed data, so
832 * any garbage at the end will be discarded when we
833 * read it.
834 */
835 for (off = 0;
836 off < LZO_HEADER + data[thr].cmp_len;
837 off += PAGE_SIZE) {
838 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
839
840 ret = swap_write_page(handle, page, &hb);
841 if (ret)
842 goto out_finish;
843 }
844 }
845
846 wait_event(crc->done, atomic_read(&crc->stop));
847 atomic_set(&crc->stop, 0);
848 }
849
850out_finish:
851 err2 = hib_wait_io(&hb);
852 stop = ktime_get();
853 if (!ret)
854 ret = err2;
855 if (!ret)
856 pr_info("Image saving done\n");
857 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
858out_clean:
859 if (crc) {
860 if (crc->thr)
861 kthread_stop(crc->thr);
862 kfree(crc);
863 }
864 if (data) {
865 for (thr = 0; thr < nr_threads; thr++)
866 if (data[thr].thr)
867 kthread_stop(data[thr].thr);
868 vfree(data);
869 }
870 if (page) free_page((unsigned long)page);
871
872 return ret;
873}
874
875/**
876 * enough_swap - Make sure we have enough swap to save the image.
877 *
878 * Returns TRUE or FALSE after checking the total amount of swap
879 * space avaiable from the resume partition.
880 */
881
882static int enough_swap(unsigned int nr_pages)
883{
884 unsigned int free_swap = count_swap_pages(root_swap, 1);
885 unsigned int required;
886
887 pr_debug("Free swap pages: %u\n", free_swap);
888
889 required = PAGES_FOR_IO + nr_pages;
890 return free_swap > required;
891}
892
893/**
894 * swsusp_write - Write entire image and metadata.
895 * @flags: flags to pass to the "boot" kernel in the image header
896 *
897 * It is important _NOT_ to umount filesystems at this point. We want
898 * them synced (in case something goes wrong) but we DO not want to mark
899 * filesystem clean: it is not. (And it does not matter, if we resume
900 * correctly, we'll mark system clean, anyway.)
901 */
902
903int swsusp_write(unsigned int flags)
904{
905 struct swap_map_handle handle;
906 struct snapshot_handle snapshot;
907 struct swsusp_info *header;
908 unsigned long pages;
909 int error;
910
911 pages = snapshot_get_image_size();
912 error = get_swap_writer(&handle);
913 if (error) {
914 pr_err("Cannot get swap writer\n");
915 return error;
916 }
917 if (flags & SF_NOCOMPRESS_MODE) {
918 if (!enough_swap(pages)) {
919 pr_err("Not enough free swap\n");
920 error = -ENOSPC;
921 goto out_finish;
922 }
923 }
924 memset(&snapshot, 0, sizeof(struct snapshot_handle));
925 error = snapshot_read_next(&snapshot);
926 if (error < PAGE_SIZE) {
927 if (error >= 0)
928 error = -EFAULT;
929
930 goto out_finish;
931 }
932 header = (struct swsusp_info *)data_of(snapshot);
933 error = swap_write_page(&handle, header, NULL);
934 if (!error) {
935 error = (flags & SF_NOCOMPRESS_MODE) ?
936 save_image(&handle, &snapshot, pages - 1) :
937 save_image_lzo(&handle, &snapshot, pages - 1);
938 }
939out_finish:
940 error = swap_writer_finish(&handle, flags, error);
941 return error;
942}
943
944/**
945 * The following functions allow us to read data using a swap map
946 * in a file-alike way
947 */
948
949static void release_swap_reader(struct swap_map_handle *handle)
950{
951 struct swap_map_page_list *tmp;
952
953 while (handle->maps) {
954 if (handle->maps->map)
955 free_page((unsigned long)handle->maps->map);
956 tmp = handle->maps;
957 handle->maps = handle->maps->next;
958 kfree(tmp);
959 }
960 handle->cur = NULL;
961}
962
963static int get_swap_reader(struct swap_map_handle *handle,
964 unsigned int *flags_p)
965{
966 int error;
967 struct swap_map_page_list *tmp, *last;
968 sector_t offset;
969
970 *flags_p = swsusp_header->flags;
971
972 if (!swsusp_header->image) /* how can this happen? */
973 return -EINVAL;
974
975 handle->cur = NULL;
976 last = handle->maps = NULL;
977 offset = swsusp_header->image;
978 while (offset) {
979 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
980 if (!tmp) {
981 release_swap_reader(handle);
982 return -ENOMEM;
983 }
984 memset(tmp, 0, sizeof(*tmp));
985 if (!handle->maps)
986 handle->maps = tmp;
987 if (last)
988 last->next = tmp;
989 last = tmp;
990
991 tmp->map = (struct swap_map_page *)
992 __get_free_page(__GFP_RECLAIM | __GFP_HIGH);
993 if (!tmp->map) {
994 release_swap_reader(handle);
995 return -ENOMEM;
996 }
997
998 error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL);
999 if (error) {
1000 release_swap_reader(handle);
1001 return error;
1002 }
1003 offset = tmp->map->next_swap;
1004 }
1005 handle->k = 0;
1006 handle->cur = handle->maps->map;
1007 return 0;
1008}
1009
1010static int swap_read_page(struct swap_map_handle *handle, void *buf,
1011 struct hib_bio_batch *hb)
1012{
1013 sector_t offset;
1014 int error;
1015 struct swap_map_page_list *tmp;
1016
1017 if (!handle->cur)
1018 return -EINVAL;
1019 offset = handle->cur->entries[handle->k];
1020 if (!offset)
1021 return -EFAULT;
1022 error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb);
1023 if (error)
1024 return error;
1025 if (++handle->k >= MAP_PAGE_ENTRIES) {
1026 handle->k = 0;
1027 free_page((unsigned long)handle->maps->map);
1028 tmp = handle->maps;
1029 handle->maps = handle->maps->next;
1030 kfree(tmp);
1031 if (!handle->maps)
1032 release_swap_reader(handle);
1033 else
1034 handle->cur = handle->maps->map;
1035 }
1036 return error;
1037}
1038
1039static int swap_reader_finish(struct swap_map_handle *handle)
1040{
1041 release_swap_reader(handle);
1042
1043 return 0;
1044}
1045
1046/**
1047 * load_image - load the image using the swap map handle
1048 * @handle and the snapshot handle @snapshot
1049 * (assume there are @nr_pages pages to load)
1050 */
1051
1052static int load_image(struct swap_map_handle *handle,
1053 struct snapshot_handle *snapshot,
1054 unsigned int nr_to_read)
1055{
1056 unsigned int m;
1057 int ret = 0;
1058 ktime_t start;
1059 ktime_t stop;
1060 struct hib_bio_batch hb;
1061 int err2;
1062 unsigned nr_pages;
1063
1064 hib_init_batch(&hb);
1065
1066 clean_pages_on_read = true;
1067 pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1068 m = nr_to_read / 10;
1069 if (!m)
1070 m = 1;
1071 nr_pages = 0;
1072 start = ktime_get();
1073 for ( ; ; ) {
1074 ret = snapshot_write_next(snapshot);
1075 if (ret <= 0)
1076 break;
1077 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1078 if (ret)
1079 break;
1080 if (snapshot->sync_read)
1081 ret = hib_wait_io(&hb);
1082 if (ret)
1083 break;
1084 if (!(nr_pages % m))
1085 pr_info("Image loading progress: %3d%%\n",
1086 nr_pages / m * 10);
1087 nr_pages++;
1088 }
1089 err2 = hib_wait_io(&hb);
1090 stop = ktime_get();
1091 if (!ret)
1092 ret = err2;
1093 if (!ret) {
1094 pr_info("Image loading done\n");
1095 snapshot_write_finalize(snapshot);
1096 if (!snapshot_image_loaded(snapshot))
1097 ret = -ENODATA;
1098 }
1099 swsusp_show_speed(start, stop, nr_to_read, "Read");
1100 return ret;
1101}
1102
1103/**
1104 * Structure used for LZO data decompression.
1105 */
1106struct dec_data {
1107 struct task_struct *thr; /* thread */
1108 atomic_t ready; /* ready to start flag */
1109 atomic_t stop; /* ready to stop flag */
1110 int ret; /* return code */
1111 wait_queue_head_t go; /* start decompression */
1112 wait_queue_head_t done; /* decompression done */
1113 size_t unc_len; /* uncompressed length */
1114 size_t cmp_len; /* compressed length */
1115 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
1116 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
1117};
1118
1119/**
1120 * Deompression function that runs in its own thread.
1121 */
1122static int lzo_decompress_threadfn(void *data)
1123{
1124 struct dec_data *d = data;
1125
1126 while (1) {
1127 wait_event(d->go, atomic_read(&d->ready) ||
1128 kthread_should_stop());
1129 if (kthread_should_stop()) {
1130 d->thr = NULL;
1131 d->ret = -1;
1132 atomic_set(&d->stop, 1);
1133 wake_up(&d->done);
1134 break;
1135 }
1136 atomic_set(&d->ready, 0);
1137
1138 d->unc_len = LZO_UNC_SIZE;
1139 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1140 d->unc, &d->unc_len);
1141 if (clean_pages_on_decompress)
1142 flush_icache_range((unsigned long)d->unc,
1143 (unsigned long)d->unc + d->unc_len);
1144
1145 atomic_set(&d->stop, 1);
1146 wake_up(&d->done);
1147 }
1148 return 0;
1149}
1150
1151/**
1152 * load_image_lzo - Load compressed image data and decompress them with LZO.
1153 * @handle: Swap map handle to use for loading data.
1154 * @snapshot: Image to copy uncompressed data into.
1155 * @nr_to_read: Number of pages to load.
1156 */
1157static int load_image_lzo(struct swap_map_handle *handle,
1158 struct snapshot_handle *snapshot,
1159 unsigned int nr_to_read)
1160{
1161 unsigned int m;
1162 int ret = 0;
1163 int eof = 0;
1164 struct hib_bio_batch hb;
1165 ktime_t start;
1166 ktime_t stop;
1167 unsigned nr_pages;
1168 size_t off;
1169 unsigned i, thr, run_threads, nr_threads;
1170 unsigned ring = 0, pg = 0, ring_size = 0,
1171 have = 0, want, need, asked = 0;
1172 unsigned long read_pages = 0;
1173 unsigned char **page = NULL;
1174 struct dec_data *data = NULL;
1175 struct crc_data *crc = NULL;
1176
1177 hib_init_batch(&hb);
1178
1179 /*
1180 * We'll limit the number of threads for decompression to limit memory
1181 * footprint.
1182 */
1183 nr_threads = num_online_cpus() - 1;
1184 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1185
1186 page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1187 if (!page) {
1188 pr_err("Failed to allocate LZO page\n");
1189 ret = -ENOMEM;
1190 goto out_clean;
1191 }
1192
1193 data = vmalloc(sizeof(*data) * nr_threads);
1194 if (!data) {
1195 pr_err("Failed to allocate LZO data\n");
1196 ret = -ENOMEM;
1197 goto out_clean;
1198 }
1199 for (thr = 0; thr < nr_threads; thr++)
1200 memset(&data[thr], 0, offsetof(struct dec_data, go));
1201
1202 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1203 if (!crc) {
1204 pr_err("Failed to allocate crc\n");
1205 ret = -ENOMEM;
1206 goto out_clean;
1207 }
1208 memset(crc, 0, offsetof(struct crc_data, go));
1209
1210 clean_pages_on_decompress = true;
1211
1212 /*
1213 * Start the decompression threads.
1214 */
1215 for (thr = 0; thr < nr_threads; thr++) {
1216 init_waitqueue_head(&data[thr].go);
1217 init_waitqueue_head(&data[thr].done);
1218
1219 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1220 &data[thr],
1221 "image_decompress/%u", thr);
1222 if (IS_ERR(data[thr].thr)) {
1223 data[thr].thr = NULL;
1224 pr_err("Cannot start decompression threads\n");
1225 ret = -ENOMEM;
1226 goto out_clean;
1227 }
1228 }
1229
1230 /*
1231 * Start the CRC32 thread.
1232 */
1233 init_waitqueue_head(&crc->go);
1234 init_waitqueue_head(&crc->done);
1235
1236 handle->crc32 = 0;
1237 crc->crc32 = &handle->crc32;
1238 for (thr = 0; thr < nr_threads; thr++) {
1239 crc->unc[thr] = data[thr].unc;
1240 crc->unc_len[thr] = &data[thr].unc_len;
1241 }
1242
1243 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1244 if (IS_ERR(crc->thr)) {
1245 crc->thr = NULL;
1246 pr_err("Cannot start CRC32 thread\n");
1247 ret = -ENOMEM;
1248 goto out_clean;
1249 }
1250
1251 /*
1252 * Set the number of pages for read buffering.
1253 * This is complete guesswork, because we'll only know the real
1254 * picture once prepare_image() is called, which is much later on
1255 * during the image load phase. We'll assume the worst case and
1256 * say that none of the image pages are from high memory.
1257 */
1258 if (low_free_pages() > snapshot_get_image_size())
1259 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1260 read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1261
1262 for (i = 0; i < read_pages; i++) {
1263 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1264 __GFP_RECLAIM | __GFP_HIGH :
1265 __GFP_RECLAIM | __GFP_NOWARN |
1266 __GFP_NORETRY);
1267
1268 if (!page[i]) {
1269 if (i < LZO_CMP_PAGES) {
1270 ring_size = i;
1271 pr_err("Failed to allocate LZO pages\n");
1272 ret = -ENOMEM;
1273 goto out_clean;
1274 } else {
1275 break;
1276 }
1277 }
1278 }
1279 want = ring_size = i;
1280
1281 pr_info("Using %u thread(s) for decompression\n", nr_threads);
1282 pr_info("Loading and decompressing image data (%u pages)...\n",
1283 nr_to_read);
1284 m = nr_to_read / 10;
1285 if (!m)
1286 m = 1;
1287 nr_pages = 0;
1288 start = ktime_get();
1289
1290 ret = snapshot_write_next(snapshot);
1291 if (ret <= 0)
1292 goto out_finish;
1293
1294 for(;;) {
1295 for (i = 0; !eof && i < want; i++) {
1296 ret = swap_read_page(handle, page[ring], &hb);
1297 if (ret) {
1298 /*
1299 * On real read error, finish. On end of data,
1300 * set EOF flag and just exit the read loop.
1301 */
1302 if (handle->cur &&
1303 handle->cur->entries[handle->k]) {
1304 goto out_finish;
1305 } else {
1306 eof = 1;
1307 break;
1308 }
1309 }
1310 if (++ring >= ring_size)
1311 ring = 0;
1312 }
1313 asked += i;
1314 want -= i;
1315
1316 /*
1317 * We are out of data, wait for some more.
1318 */
1319 if (!have) {
1320 if (!asked)
1321 break;
1322
1323 ret = hib_wait_io(&hb);
1324 if (ret)
1325 goto out_finish;
1326 have += asked;
1327 asked = 0;
1328 if (eof)
1329 eof = 2;
1330 }
1331
1332 if (crc->run_threads) {
1333 wait_event(crc->done, atomic_read(&crc->stop));
1334 atomic_set(&crc->stop, 0);
1335 crc->run_threads = 0;
1336 }
1337
1338 for (thr = 0; have && thr < nr_threads; thr++) {
1339 data[thr].cmp_len = *(size_t *)page[pg];
1340 if (unlikely(!data[thr].cmp_len ||
1341 data[thr].cmp_len >
1342 lzo1x_worst_compress(LZO_UNC_SIZE))) {
1343 pr_err("Invalid LZO compressed length\n");
1344 ret = -1;
1345 goto out_finish;
1346 }
1347
1348 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1349 PAGE_SIZE);
1350 if (need > have) {
1351 if (eof > 1) {
1352 ret = -1;
1353 goto out_finish;
1354 }
1355 break;
1356 }
1357
1358 for (off = 0;
1359 off < LZO_HEADER + data[thr].cmp_len;
1360 off += PAGE_SIZE) {
1361 memcpy(data[thr].cmp + off,
1362 page[pg], PAGE_SIZE);
1363 have--;
1364 want++;
1365 if (++pg >= ring_size)
1366 pg = 0;
1367 }
1368
1369 atomic_set(&data[thr].ready, 1);
1370 wake_up(&data[thr].go);
1371 }
1372
1373 /*
1374 * Wait for more data while we are decompressing.
1375 */
1376 if (have < LZO_CMP_PAGES && asked) {
1377 ret = hib_wait_io(&hb);
1378 if (ret)
1379 goto out_finish;
1380 have += asked;
1381 asked = 0;
1382 if (eof)
1383 eof = 2;
1384 }
1385
1386 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1387 wait_event(data[thr].done,
1388 atomic_read(&data[thr].stop));
1389 atomic_set(&data[thr].stop, 0);
1390
1391 ret = data[thr].ret;
1392
1393 if (ret < 0) {
1394 pr_err("LZO decompression failed\n");
1395 goto out_finish;
1396 }
1397
1398 if (unlikely(!data[thr].unc_len ||
1399 data[thr].unc_len > LZO_UNC_SIZE ||
1400 data[thr].unc_len & (PAGE_SIZE - 1))) {
1401 pr_err("Invalid LZO uncompressed length\n");
1402 ret = -1;
1403 goto out_finish;
1404 }
1405
1406 for (off = 0;
1407 off < data[thr].unc_len; off += PAGE_SIZE) {
1408 memcpy(data_of(*snapshot),
1409 data[thr].unc + off, PAGE_SIZE);
1410
1411 if (!(nr_pages % m))
1412 pr_info("Image loading progress: %3d%%\n",
1413 nr_pages / m * 10);
1414 nr_pages++;
1415
1416 ret = snapshot_write_next(snapshot);
1417 if (ret <= 0) {
1418 crc->run_threads = thr + 1;
1419 atomic_set(&crc->ready, 1);
1420 wake_up(&crc->go);
1421 goto out_finish;
1422 }
1423 }
1424 }
1425
1426 crc->run_threads = thr;
1427 atomic_set(&crc->ready, 1);
1428 wake_up(&crc->go);
1429 }
1430
1431out_finish:
1432 if (crc->run_threads) {
1433 wait_event(crc->done, atomic_read(&crc->stop));
1434 atomic_set(&crc->stop, 0);
1435 }
1436 stop = ktime_get();
1437 if (!ret) {
1438 pr_info("Image loading done\n");
1439 snapshot_write_finalize(snapshot);
1440 if (!snapshot_image_loaded(snapshot))
1441 ret = -ENODATA;
1442 if (!ret) {
1443 if (swsusp_header->flags & SF_CRC32_MODE) {
1444 if(handle->crc32 != swsusp_header->crc32) {
1445 pr_err("Invalid image CRC32!\n");
1446 ret = -ENODATA;
1447 }
1448 }
1449 }
1450 }
1451 swsusp_show_speed(start, stop, nr_to_read, "Read");
1452out_clean:
1453 for (i = 0; i < ring_size; i++)
1454 free_page((unsigned long)page[i]);
1455 if (crc) {
1456 if (crc->thr)
1457 kthread_stop(crc->thr);
1458 kfree(crc);
1459 }
1460 if (data) {
1461 for (thr = 0; thr < nr_threads; thr++)
1462 if (data[thr].thr)
1463 kthread_stop(data[thr].thr);
1464 vfree(data);
1465 }
1466 vfree(page);
1467
1468 return ret;
1469}
1470
1471/**
1472 * swsusp_read - read the hibernation image.
1473 * @flags_p: flags passed by the "frozen" kernel in the image header should
1474 * be written into this memory location
1475 */
1476
1477int swsusp_read(unsigned int *flags_p)
1478{
1479 int error;
1480 struct swap_map_handle handle;
1481 struct snapshot_handle snapshot;
1482 struct swsusp_info *header;
1483
1484 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1485 error = snapshot_write_next(&snapshot);
1486 if (error < PAGE_SIZE)
1487 return error < 0 ? error : -EFAULT;
1488 header = (struct swsusp_info *)data_of(snapshot);
1489 error = get_swap_reader(&handle, flags_p);
1490 if (error)
1491 goto end;
1492 if (!error)
1493 error = swap_read_page(&handle, header, NULL);
1494 if (!error) {
1495 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1496 load_image(&handle, &snapshot, header->pages - 1) :
1497 load_image_lzo(&handle, &snapshot, header->pages - 1);
1498 }
1499 swap_reader_finish(&handle);
1500end:
1501 if (!error)
1502 pr_debug("Image successfully loaded\n");
1503 else
1504 pr_debug("Error %d resuming\n", error);
1505 return error;
1506}
1507
1508/**
1509 * swsusp_check - Check for swsusp signature in the resume device
1510 */
1511
1512int swsusp_check(void)
1513{
1514 int error;
1515
1516 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1517 FMODE_READ, NULL);
1518 if (!IS_ERR(hib_resume_bdev)) {
1519 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1520 clear_page(swsusp_header);
1521 error = hib_submit_io(REQ_OP_READ, 0,
1522 swsusp_resume_block,
1523 swsusp_header, NULL);
1524 if (error)
1525 goto put;
1526
1527 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1528 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1529 /* Reset swap signature now */
1530 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1531 swsusp_resume_block,
1532 swsusp_header, NULL);
1533 } else {
1534 error = -EINVAL;
1535 }
1536
1537put:
1538 if (error)
1539 blkdev_put(hib_resume_bdev, FMODE_READ);
1540 else
1541 pr_debug("Image signature found, resuming\n");
1542 } else {
1543 error = PTR_ERR(hib_resume_bdev);
1544 }
1545
1546 if (error)
1547 pr_debug("Image not found (code %d)\n", error);
1548
1549 return error;
1550}
1551
1552/**
1553 * swsusp_close - close swap device.
1554 */
1555
1556void swsusp_close(fmode_t mode)
1557{
1558 if (IS_ERR(hib_resume_bdev)) {
1559 pr_debug("Image device not initialised\n");
1560 return;
1561 }
1562
1563 blkdev_put(hib_resume_bdev, mode);
1564}
1565
1566/**
1567 * swsusp_unmark - Unmark swsusp signature in the resume device
1568 */
1569
1570#ifdef CONFIG_SUSPEND
1571int swsusp_unmark(void)
1572{
1573 int error;
1574
1575 hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
1576 swsusp_header, NULL);
1577 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1578 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1579 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1580 swsusp_resume_block,
1581 swsusp_header, NULL);
1582 } else {
1583 pr_err("Cannot find swsusp signature!\n");
1584 error = -ENODEV;
1585 }
1586
1587 /*
1588 * We just returned from suspend, we don't need the image any more.
1589 */
1590 free_all_swap_pages(root_swap);
1591
1592 return error;
1593}
1594#endif
1595
1596static int swsusp_header_init(void)
1597{
1598 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1599 if (!swsusp_header)
1600 panic("Could not allocate memory for swsusp_header\n");
1601 return 0;
1602}
1603
1604core_initcall(swsusp_header_init);
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/lzo.h>
27#include <linux/vmalloc.h>
28#include <linux/cpumask.h>
29#include <linux/atomic.h>
30#include <linux/kthread.h>
31#include <linux/crc32.h>
32#include <linux/ktime.h>
33
34#include "power.h"
35
36#define HIBERNATE_SIG "S1SUSPEND"
37
38u32 swsusp_hardware_signature;
39
40/*
41 * When reading an {un,}compressed image, we may restore pages in place,
42 * in which case some architectures need these pages cleaning before they
43 * can be executed. We don't know which pages these may be, so clean the lot.
44 */
45static bool clean_pages_on_read;
46static bool clean_pages_on_decompress;
47
48/*
49 * The swap map is a data structure used for keeping track of each page
50 * written to a swap partition. It consists of many swap_map_page
51 * structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
52 * These structures are stored on the swap and linked together with the
53 * help of the .next_swap member.
54 *
55 * The swap map is created during suspend. The swap map pages are
56 * allocated and populated one at a time, so we only need one memory
57 * page to set up the entire structure.
58 *
59 * During resume we pick up all swap_map_page structures into a list.
60 */
61
62#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
63
64/*
65 * Number of free pages that are not high.
66 */
67static inline unsigned long low_free_pages(void)
68{
69 return nr_free_pages() - nr_free_highpages();
70}
71
72/*
73 * Number of pages required to be kept free while writing the image. Always
74 * half of all available low pages before the writing starts.
75 */
76static inline unsigned long reqd_free_pages(void)
77{
78 return low_free_pages() / 2;
79}
80
81struct swap_map_page {
82 sector_t entries[MAP_PAGE_ENTRIES];
83 sector_t next_swap;
84};
85
86struct swap_map_page_list {
87 struct swap_map_page *map;
88 struct swap_map_page_list *next;
89};
90
91/*
92 * The swap_map_handle structure is used for handling swap in
93 * a file-alike way
94 */
95
96struct swap_map_handle {
97 struct swap_map_page *cur;
98 struct swap_map_page_list *maps;
99 sector_t cur_swap;
100 sector_t first_sector;
101 unsigned int k;
102 unsigned long reqd_free_pages;
103 u32 crc32;
104};
105
106struct swsusp_header {
107 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
108 sizeof(u32) - sizeof(u32)];
109 u32 hw_sig;
110 u32 crc32;
111 sector_t image;
112 unsigned int flags; /* Flags to pass to the "boot" kernel */
113 char orig_sig[10];
114 char sig[10];
115} __packed;
116
117static struct swsusp_header *swsusp_header;
118
119/*
120 * The following functions are used for tracing the allocated
121 * swap pages, so that they can be freed in case of an error.
122 */
123
124struct swsusp_extent {
125 struct rb_node node;
126 unsigned long start;
127 unsigned long end;
128};
129
130static struct rb_root swsusp_extents = RB_ROOT;
131
132static int swsusp_extents_insert(unsigned long swap_offset)
133{
134 struct rb_node **new = &(swsusp_extents.rb_node);
135 struct rb_node *parent = NULL;
136 struct swsusp_extent *ext;
137
138 /* Figure out where to put the new node */
139 while (*new) {
140 ext = rb_entry(*new, struct swsusp_extent, node);
141 parent = *new;
142 if (swap_offset < ext->start) {
143 /* Try to merge */
144 if (swap_offset == ext->start - 1) {
145 ext->start--;
146 return 0;
147 }
148 new = &((*new)->rb_left);
149 } else if (swap_offset > ext->end) {
150 /* Try to merge */
151 if (swap_offset == ext->end + 1) {
152 ext->end++;
153 return 0;
154 }
155 new = &((*new)->rb_right);
156 } else {
157 /* It already is in the tree */
158 return -EINVAL;
159 }
160 }
161 /* Add the new node and rebalance the tree. */
162 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
163 if (!ext)
164 return -ENOMEM;
165
166 ext->start = swap_offset;
167 ext->end = swap_offset;
168 rb_link_node(&ext->node, parent, new);
169 rb_insert_color(&ext->node, &swsusp_extents);
170 return 0;
171}
172
173/*
174 * alloc_swapdev_block - allocate a swap page and register that it has
175 * been allocated, so that it can be freed in case of an error.
176 */
177
178sector_t alloc_swapdev_block(int swap)
179{
180 unsigned long offset;
181
182 offset = swp_offset(get_swap_page_of_type(swap));
183 if (offset) {
184 if (swsusp_extents_insert(offset))
185 swap_free(swp_entry(swap, offset));
186 else
187 return swapdev_block(swap, offset);
188 }
189 return 0;
190}
191
192/*
193 * free_all_swap_pages - free swap pages allocated for saving image data.
194 * It also frees the extents used to register which swap entries had been
195 * allocated.
196 */
197
198void free_all_swap_pages(int swap)
199{
200 struct rb_node *node;
201
202 while ((node = swsusp_extents.rb_node)) {
203 struct swsusp_extent *ext;
204 unsigned long offset;
205
206 ext = rb_entry(node, struct swsusp_extent, node);
207 rb_erase(node, &swsusp_extents);
208 for (offset = ext->start; offset <= ext->end; offset++)
209 swap_free(swp_entry(swap, offset));
210
211 kfree(ext);
212 }
213}
214
215int swsusp_swap_in_use(void)
216{
217 return (swsusp_extents.rb_node != NULL);
218}
219
220/*
221 * General things
222 */
223
224static unsigned short root_swap = 0xffff;
225static struct bdev_handle *hib_resume_bdev_handle;
226
227struct hib_bio_batch {
228 atomic_t count;
229 wait_queue_head_t wait;
230 blk_status_t error;
231 struct blk_plug plug;
232};
233
234static void hib_init_batch(struct hib_bio_batch *hb)
235{
236 atomic_set(&hb->count, 0);
237 init_waitqueue_head(&hb->wait);
238 hb->error = BLK_STS_OK;
239 blk_start_plug(&hb->plug);
240}
241
242static void hib_finish_batch(struct hib_bio_batch *hb)
243{
244 blk_finish_plug(&hb->plug);
245}
246
247static void hib_end_io(struct bio *bio)
248{
249 struct hib_bio_batch *hb = bio->bi_private;
250 struct page *page = bio_first_page_all(bio);
251
252 if (bio->bi_status) {
253 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
254 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
255 (unsigned long long)bio->bi_iter.bi_sector);
256 }
257
258 if (bio_data_dir(bio) == WRITE)
259 put_page(page);
260 else if (clean_pages_on_read)
261 flush_icache_range((unsigned long)page_address(page),
262 (unsigned long)page_address(page) + PAGE_SIZE);
263
264 if (bio->bi_status && !hb->error)
265 hb->error = bio->bi_status;
266 if (atomic_dec_and_test(&hb->count))
267 wake_up(&hb->wait);
268
269 bio_put(bio);
270}
271
272static int hib_submit_io(blk_opf_t opf, pgoff_t page_off, void *addr,
273 struct hib_bio_batch *hb)
274{
275 struct page *page = virt_to_page(addr);
276 struct bio *bio;
277 int error = 0;
278
279 bio = bio_alloc(hib_resume_bdev_handle->bdev, 1, opf,
280 GFP_NOIO | __GFP_HIGH);
281 bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
282
283 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
284 pr_err("Adding page to bio failed at %llu\n",
285 (unsigned long long)bio->bi_iter.bi_sector);
286 bio_put(bio);
287 return -EFAULT;
288 }
289
290 if (hb) {
291 bio->bi_end_io = hib_end_io;
292 bio->bi_private = hb;
293 atomic_inc(&hb->count);
294 submit_bio(bio);
295 } else {
296 error = submit_bio_wait(bio);
297 bio_put(bio);
298 }
299
300 return error;
301}
302
303static int hib_wait_io(struct hib_bio_batch *hb)
304{
305 /*
306 * We are relying on the behavior of blk_plug that a thread with
307 * a plug will flush the plug list before sleeping.
308 */
309 wait_event(hb->wait, atomic_read(&hb->count) == 0);
310 return blk_status_to_errno(hb->error);
311}
312
313/*
314 * Saving part
315 */
316static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
317{
318 int error;
319
320 hib_submit_io(REQ_OP_READ, swsusp_resume_block, swsusp_header, NULL);
321 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
322 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
323 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
324 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
325 swsusp_header->image = handle->first_sector;
326 if (swsusp_hardware_signature) {
327 swsusp_header->hw_sig = swsusp_hardware_signature;
328 flags |= SF_HW_SIG;
329 }
330 swsusp_header->flags = flags;
331 if (flags & SF_CRC32_MODE)
332 swsusp_header->crc32 = handle->crc32;
333 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
334 swsusp_resume_block, swsusp_header, NULL);
335 } else {
336 pr_err("Swap header not found!\n");
337 error = -ENODEV;
338 }
339 return error;
340}
341
342/**
343 * swsusp_swap_check - check if the resume device is a swap device
344 * and get its index (if so)
345 *
346 * This is called before saving image
347 */
348static int swsusp_swap_check(void)
349{
350 int res;
351
352 if (swsusp_resume_device)
353 res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
354 else
355 res = find_first_swap(&swsusp_resume_device);
356 if (res < 0)
357 return res;
358 root_swap = res;
359
360 hib_resume_bdev_handle = bdev_open_by_dev(swsusp_resume_device,
361 BLK_OPEN_WRITE, NULL, NULL);
362 if (IS_ERR(hib_resume_bdev_handle))
363 return PTR_ERR(hib_resume_bdev_handle);
364
365 res = set_blocksize(hib_resume_bdev_handle->bdev, PAGE_SIZE);
366 if (res < 0)
367 bdev_release(hib_resume_bdev_handle);
368
369 return res;
370}
371
372/**
373 * write_page - Write one page to given swap location.
374 * @buf: Address we're writing.
375 * @offset: Offset of the swap page we're writing to.
376 * @hb: bio completion batch
377 */
378
379static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
380{
381 void *src;
382 int ret;
383
384 if (!offset)
385 return -ENOSPC;
386
387 if (hb) {
388 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
389 __GFP_NORETRY);
390 if (src) {
391 copy_page(src, buf);
392 } else {
393 ret = hib_wait_io(hb); /* Free pages */
394 if (ret)
395 return ret;
396 src = (void *)__get_free_page(GFP_NOIO |
397 __GFP_NOWARN |
398 __GFP_NORETRY);
399 if (src) {
400 copy_page(src, buf);
401 } else {
402 WARN_ON_ONCE(1);
403 hb = NULL; /* Go synchronous */
404 src = buf;
405 }
406 }
407 } else {
408 src = buf;
409 }
410 return hib_submit_io(REQ_OP_WRITE | REQ_SYNC, offset, src, hb);
411}
412
413static void release_swap_writer(struct swap_map_handle *handle)
414{
415 if (handle->cur)
416 free_page((unsigned long)handle->cur);
417 handle->cur = NULL;
418}
419
420static int get_swap_writer(struct swap_map_handle *handle)
421{
422 int ret;
423
424 ret = swsusp_swap_check();
425 if (ret) {
426 if (ret != -ENOSPC)
427 pr_err("Cannot find swap device, try swapon -a\n");
428 return ret;
429 }
430 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
431 if (!handle->cur) {
432 ret = -ENOMEM;
433 goto err_close;
434 }
435 handle->cur_swap = alloc_swapdev_block(root_swap);
436 if (!handle->cur_swap) {
437 ret = -ENOSPC;
438 goto err_rel;
439 }
440 handle->k = 0;
441 handle->reqd_free_pages = reqd_free_pages();
442 handle->first_sector = handle->cur_swap;
443 return 0;
444err_rel:
445 release_swap_writer(handle);
446err_close:
447 swsusp_close();
448 return ret;
449}
450
451static int swap_write_page(struct swap_map_handle *handle, void *buf,
452 struct hib_bio_batch *hb)
453{
454 int error;
455 sector_t offset;
456
457 if (!handle->cur)
458 return -EINVAL;
459 offset = alloc_swapdev_block(root_swap);
460 error = write_page(buf, offset, hb);
461 if (error)
462 return error;
463 handle->cur->entries[handle->k++] = offset;
464 if (handle->k >= MAP_PAGE_ENTRIES) {
465 offset = alloc_swapdev_block(root_swap);
466 if (!offset)
467 return -ENOSPC;
468 handle->cur->next_swap = offset;
469 error = write_page(handle->cur, handle->cur_swap, hb);
470 if (error)
471 goto out;
472 clear_page(handle->cur);
473 handle->cur_swap = offset;
474 handle->k = 0;
475
476 if (hb && low_free_pages() <= handle->reqd_free_pages) {
477 error = hib_wait_io(hb);
478 if (error)
479 goto out;
480 /*
481 * Recalculate the number of required free pages, to
482 * make sure we never take more than half.
483 */
484 handle->reqd_free_pages = reqd_free_pages();
485 }
486 }
487 out:
488 return error;
489}
490
491static int flush_swap_writer(struct swap_map_handle *handle)
492{
493 if (handle->cur && handle->cur_swap)
494 return write_page(handle->cur, handle->cur_swap, NULL);
495 else
496 return -EINVAL;
497}
498
499static int swap_writer_finish(struct swap_map_handle *handle,
500 unsigned int flags, int error)
501{
502 if (!error) {
503 pr_info("S");
504 error = mark_swapfiles(handle, flags);
505 pr_cont("|\n");
506 flush_swap_writer(handle);
507 }
508
509 if (error)
510 free_all_swap_pages(root_swap);
511 release_swap_writer(handle);
512 swsusp_close();
513
514 return error;
515}
516
517/* We need to remember how much compressed data we need to read. */
518#define LZO_HEADER sizeof(size_t)
519
520/* Number of pages/bytes we'll compress at one time. */
521#define LZO_UNC_PAGES 32
522#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE)
523
524/* Number of pages/bytes we need for compressed data (worst case). */
525#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
526 LZO_HEADER, PAGE_SIZE)
527#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE)
528
529/* Maximum number of threads for compression/decompression. */
530#define LZO_THREADS 3
531
532/* Minimum/maximum number of pages for read buffering. */
533#define LZO_MIN_RD_PAGES 1024
534#define LZO_MAX_RD_PAGES 8192
535
536
537/**
538 * save_image - save the suspend image data
539 */
540
541static int save_image(struct swap_map_handle *handle,
542 struct snapshot_handle *snapshot,
543 unsigned int nr_to_write)
544{
545 unsigned int m;
546 int ret;
547 int nr_pages;
548 int err2;
549 struct hib_bio_batch hb;
550 ktime_t start;
551 ktime_t stop;
552
553 hib_init_batch(&hb);
554
555 pr_info("Saving image data pages (%u pages)...\n",
556 nr_to_write);
557 m = nr_to_write / 10;
558 if (!m)
559 m = 1;
560 nr_pages = 0;
561 start = ktime_get();
562 while (1) {
563 ret = snapshot_read_next(snapshot);
564 if (ret <= 0)
565 break;
566 ret = swap_write_page(handle, data_of(*snapshot), &hb);
567 if (ret)
568 break;
569 if (!(nr_pages % m))
570 pr_info("Image saving progress: %3d%%\n",
571 nr_pages / m * 10);
572 nr_pages++;
573 }
574 err2 = hib_wait_io(&hb);
575 hib_finish_batch(&hb);
576 stop = ktime_get();
577 if (!ret)
578 ret = err2;
579 if (!ret)
580 pr_info("Image saving done\n");
581 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
582 return ret;
583}
584
585/*
586 * Structure used for CRC32.
587 */
588struct crc_data {
589 struct task_struct *thr; /* thread */
590 atomic_t ready; /* ready to start flag */
591 atomic_t stop; /* ready to stop flag */
592 unsigned run_threads; /* nr current threads */
593 wait_queue_head_t go; /* start crc update */
594 wait_queue_head_t done; /* crc update done */
595 u32 *crc32; /* points to handle's crc32 */
596 size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */
597 unsigned char *unc[LZO_THREADS]; /* uncompressed data */
598};
599
600/*
601 * CRC32 update function that runs in its own thread.
602 */
603static int crc32_threadfn(void *data)
604{
605 struct crc_data *d = data;
606 unsigned i;
607
608 while (1) {
609 wait_event(d->go, atomic_read_acquire(&d->ready) ||
610 kthread_should_stop());
611 if (kthread_should_stop()) {
612 d->thr = NULL;
613 atomic_set_release(&d->stop, 1);
614 wake_up(&d->done);
615 break;
616 }
617 atomic_set(&d->ready, 0);
618
619 for (i = 0; i < d->run_threads; i++)
620 *d->crc32 = crc32_le(*d->crc32,
621 d->unc[i], *d->unc_len[i]);
622 atomic_set_release(&d->stop, 1);
623 wake_up(&d->done);
624 }
625 return 0;
626}
627/*
628 * Structure used for LZO data compression.
629 */
630struct cmp_data {
631 struct task_struct *thr; /* thread */
632 atomic_t ready; /* ready to start flag */
633 atomic_t stop; /* ready to stop flag */
634 int ret; /* return code */
635 wait_queue_head_t go; /* start compression */
636 wait_queue_head_t done; /* compression done */
637 size_t unc_len; /* uncompressed length */
638 size_t cmp_len; /* compressed length */
639 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
640 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
641 unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
642};
643
644/*
645 * Compression function that runs in its own thread.
646 */
647static int lzo_compress_threadfn(void *data)
648{
649 struct cmp_data *d = data;
650
651 while (1) {
652 wait_event(d->go, atomic_read_acquire(&d->ready) ||
653 kthread_should_stop());
654 if (kthread_should_stop()) {
655 d->thr = NULL;
656 d->ret = -1;
657 atomic_set_release(&d->stop, 1);
658 wake_up(&d->done);
659 break;
660 }
661 atomic_set(&d->ready, 0);
662
663 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
664 d->cmp + LZO_HEADER, &d->cmp_len,
665 d->wrk);
666 atomic_set_release(&d->stop, 1);
667 wake_up(&d->done);
668 }
669 return 0;
670}
671
672/**
673 * save_image_lzo - Save the suspend image data compressed with LZO.
674 * @handle: Swap map handle to use for saving the image.
675 * @snapshot: Image to read data from.
676 * @nr_to_write: Number of pages to save.
677 */
678static int save_image_lzo(struct swap_map_handle *handle,
679 struct snapshot_handle *snapshot,
680 unsigned int nr_to_write)
681{
682 unsigned int m;
683 int ret = 0;
684 int nr_pages;
685 int err2;
686 struct hib_bio_batch hb;
687 ktime_t start;
688 ktime_t stop;
689 size_t off;
690 unsigned thr, run_threads, nr_threads;
691 unsigned char *page = NULL;
692 struct cmp_data *data = NULL;
693 struct crc_data *crc = NULL;
694
695 hib_init_batch(&hb);
696
697 /*
698 * We'll limit the number of threads for compression to limit memory
699 * footprint.
700 */
701 nr_threads = num_online_cpus() - 1;
702 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
703
704 page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
705 if (!page) {
706 pr_err("Failed to allocate LZO page\n");
707 ret = -ENOMEM;
708 goto out_clean;
709 }
710
711 data = vzalloc(array_size(nr_threads, sizeof(*data)));
712 if (!data) {
713 pr_err("Failed to allocate LZO data\n");
714 ret = -ENOMEM;
715 goto out_clean;
716 }
717
718 crc = kzalloc(sizeof(*crc), GFP_KERNEL);
719 if (!crc) {
720 pr_err("Failed to allocate crc\n");
721 ret = -ENOMEM;
722 goto out_clean;
723 }
724
725 /*
726 * Start the compression threads.
727 */
728 for (thr = 0; thr < nr_threads; thr++) {
729 init_waitqueue_head(&data[thr].go);
730 init_waitqueue_head(&data[thr].done);
731
732 data[thr].thr = kthread_run(lzo_compress_threadfn,
733 &data[thr],
734 "image_compress/%u", thr);
735 if (IS_ERR(data[thr].thr)) {
736 data[thr].thr = NULL;
737 pr_err("Cannot start compression threads\n");
738 ret = -ENOMEM;
739 goto out_clean;
740 }
741 }
742
743 /*
744 * Start the CRC32 thread.
745 */
746 init_waitqueue_head(&crc->go);
747 init_waitqueue_head(&crc->done);
748
749 handle->crc32 = 0;
750 crc->crc32 = &handle->crc32;
751 for (thr = 0; thr < nr_threads; thr++) {
752 crc->unc[thr] = data[thr].unc;
753 crc->unc_len[thr] = &data[thr].unc_len;
754 }
755
756 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
757 if (IS_ERR(crc->thr)) {
758 crc->thr = NULL;
759 pr_err("Cannot start CRC32 thread\n");
760 ret = -ENOMEM;
761 goto out_clean;
762 }
763
764 /*
765 * Adjust the number of required free pages after all allocations have
766 * been done. We don't want to run out of pages when writing.
767 */
768 handle->reqd_free_pages = reqd_free_pages();
769
770 pr_info("Using %u thread(s) for compression\n", nr_threads);
771 pr_info("Compressing and saving image data (%u pages)...\n",
772 nr_to_write);
773 m = nr_to_write / 10;
774 if (!m)
775 m = 1;
776 nr_pages = 0;
777 start = ktime_get();
778 for (;;) {
779 for (thr = 0; thr < nr_threads; thr++) {
780 for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
781 ret = snapshot_read_next(snapshot);
782 if (ret < 0)
783 goto out_finish;
784
785 if (!ret)
786 break;
787
788 memcpy(data[thr].unc + off,
789 data_of(*snapshot), PAGE_SIZE);
790
791 if (!(nr_pages % m))
792 pr_info("Image saving progress: %3d%%\n",
793 nr_pages / m * 10);
794 nr_pages++;
795 }
796 if (!off)
797 break;
798
799 data[thr].unc_len = off;
800
801 atomic_set_release(&data[thr].ready, 1);
802 wake_up(&data[thr].go);
803 }
804
805 if (!thr)
806 break;
807
808 crc->run_threads = thr;
809 atomic_set_release(&crc->ready, 1);
810 wake_up(&crc->go);
811
812 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
813 wait_event(data[thr].done,
814 atomic_read_acquire(&data[thr].stop));
815 atomic_set(&data[thr].stop, 0);
816
817 ret = data[thr].ret;
818
819 if (ret < 0) {
820 pr_err("LZO compression failed\n");
821 goto out_finish;
822 }
823
824 if (unlikely(!data[thr].cmp_len ||
825 data[thr].cmp_len >
826 lzo1x_worst_compress(data[thr].unc_len))) {
827 pr_err("Invalid LZO compressed length\n");
828 ret = -1;
829 goto out_finish;
830 }
831
832 *(size_t *)data[thr].cmp = data[thr].cmp_len;
833
834 /*
835 * Given we are writing one page at a time to disk, we
836 * copy that much from the buffer, although the last
837 * bit will likely be smaller than full page. This is
838 * OK - we saved the length of the compressed data, so
839 * any garbage at the end will be discarded when we
840 * read it.
841 */
842 for (off = 0;
843 off < LZO_HEADER + data[thr].cmp_len;
844 off += PAGE_SIZE) {
845 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
846
847 ret = swap_write_page(handle, page, &hb);
848 if (ret)
849 goto out_finish;
850 }
851 }
852
853 wait_event(crc->done, atomic_read_acquire(&crc->stop));
854 atomic_set(&crc->stop, 0);
855 }
856
857out_finish:
858 err2 = hib_wait_io(&hb);
859 stop = ktime_get();
860 if (!ret)
861 ret = err2;
862 if (!ret)
863 pr_info("Image saving done\n");
864 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
865out_clean:
866 hib_finish_batch(&hb);
867 if (crc) {
868 if (crc->thr)
869 kthread_stop(crc->thr);
870 kfree(crc);
871 }
872 if (data) {
873 for (thr = 0; thr < nr_threads; thr++)
874 if (data[thr].thr)
875 kthread_stop(data[thr].thr);
876 vfree(data);
877 }
878 if (page) free_page((unsigned long)page);
879
880 return ret;
881}
882
883/**
884 * enough_swap - Make sure we have enough swap to save the image.
885 *
886 * Returns TRUE or FALSE after checking the total amount of swap
887 * space available from the resume partition.
888 */
889
890static int enough_swap(unsigned int nr_pages)
891{
892 unsigned int free_swap = count_swap_pages(root_swap, 1);
893 unsigned int required;
894
895 pr_debug("Free swap pages: %u\n", free_swap);
896
897 required = PAGES_FOR_IO + nr_pages;
898 return free_swap > required;
899}
900
901/**
902 * swsusp_write - Write entire image and metadata.
903 * @flags: flags to pass to the "boot" kernel in the image header
904 *
905 * It is important _NOT_ to umount filesystems at this point. We want
906 * them synced (in case something goes wrong) but we DO not want to mark
907 * filesystem clean: it is not. (And it does not matter, if we resume
908 * correctly, we'll mark system clean, anyway.)
909 */
910
911int swsusp_write(unsigned int flags)
912{
913 struct swap_map_handle handle;
914 struct snapshot_handle snapshot;
915 struct swsusp_info *header;
916 unsigned long pages;
917 int error;
918
919 pages = snapshot_get_image_size();
920 error = get_swap_writer(&handle);
921 if (error) {
922 pr_err("Cannot get swap writer\n");
923 return error;
924 }
925 if (flags & SF_NOCOMPRESS_MODE) {
926 if (!enough_swap(pages)) {
927 pr_err("Not enough free swap\n");
928 error = -ENOSPC;
929 goto out_finish;
930 }
931 }
932 memset(&snapshot, 0, sizeof(struct snapshot_handle));
933 error = snapshot_read_next(&snapshot);
934 if (error < (int)PAGE_SIZE) {
935 if (error >= 0)
936 error = -EFAULT;
937
938 goto out_finish;
939 }
940 header = (struct swsusp_info *)data_of(snapshot);
941 error = swap_write_page(&handle, header, NULL);
942 if (!error) {
943 error = (flags & SF_NOCOMPRESS_MODE) ?
944 save_image(&handle, &snapshot, pages - 1) :
945 save_image_lzo(&handle, &snapshot, pages - 1);
946 }
947out_finish:
948 error = swap_writer_finish(&handle, flags, error);
949 return error;
950}
951
952/*
953 * The following functions allow us to read data using a swap map
954 * in a file-like way.
955 */
956
957static void release_swap_reader(struct swap_map_handle *handle)
958{
959 struct swap_map_page_list *tmp;
960
961 while (handle->maps) {
962 if (handle->maps->map)
963 free_page((unsigned long)handle->maps->map);
964 tmp = handle->maps;
965 handle->maps = handle->maps->next;
966 kfree(tmp);
967 }
968 handle->cur = NULL;
969}
970
971static int get_swap_reader(struct swap_map_handle *handle,
972 unsigned int *flags_p)
973{
974 int error;
975 struct swap_map_page_list *tmp, *last;
976 sector_t offset;
977
978 *flags_p = swsusp_header->flags;
979
980 if (!swsusp_header->image) /* how can this happen? */
981 return -EINVAL;
982
983 handle->cur = NULL;
984 last = handle->maps = NULL;
985 offset = swsusp_header->image;
986 while (offset) {
987 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
988 if (!tmp) {
989 release_swap_reader(handle);
990 return -ENOMEM;
991 }
992 if (!handle->maps)
993 handle->maps = tmp;
994 if (last)
995 last->next = tmp;
996 last = tmp;
997
998 tmp->map = (struct swap_map_page *)
999 __get_free_page(GFP_NOIO | __GFP_HIGH);
1000 if (!tmp->map) {
1001 release_swap_reader(handle);
1002 return -ENOMEM;
1003 }
1004
1005 error = hib_submit_io(REQ_OP_READ, offset, tmp->map, NULL);
1006 if (error) {
1007 release_swap_reader(handle);
1008 return error;
1009 }
1010 offset = tmp->map->next_swap;
1011 }
1012 handle->k = 0;
1013 handle->cur = handle->maps->map;
1014 return 0;
1015}
1016
1017static int swap_read_page(struct swap_map_handle *handle, void *buf,
1018 struct hib_bio_batch *hb)
1019{
1020 sector_t offset;
1021 int error;
1022 struct swap_map_page_list *tmp;
1023
1024 if (!handle->cur)
1025 return -EINVAL;
1026 offset = handle->cur->entries[handle->k];
1027 if (!offset)
1028 return -EFAULT;
1029 error = hib_submit_io(REQ_OP_READ, offset, buf, hb);
1030 if (error)
1031 return error;
1032 if (++handle->k >= MAP_PAGE_ENTRIES) {
1033 handle->k = 0;
1034 free_page((unsigned long)handle->maps->map);
1035 tmp = handle->maps;
1036 handle->maps = handle->maps->next;
1037 kfree(tmp);
1038 if (!handle->maps)
1039 release_swap_reader(handle);
1040 else
1041 handle->cur = handle->maps->map;
1042 }
1043 return error;
1044}
1045
1046static int swap_reader_finish(struct swap_map_handle *handle)
1047{
1048 release_swap_reader(handle);
1049
1050 return 0;
1051}
1052
1053/**
1054 * load_image - load the image using the swap map handle
1055 * @handle and the snapshot handle @snapshot
1056 * (assume there are @nr_pages pages to load)
1057 */
1058
1059static int load_image(struct swap_map_handle *handle,
1060 struct snapshot_handle *snapshot,
1061 unsigned int nr_to_read)
1062{
1063 unsigned int m;
1064 int ret = 0;
1065 ktime_t start;
1066 ktime_t stop;
1067 struct hib_bio_batch hb;
1068 int err2;
1069 unsigned nr_pages;
1070
1071 hib_init_batch(&hb);
1072
1073 clean_pages_on_read = true;
1074 pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1075 m = nr_to_read / 10;
1076 if (!m)
1077 m = 1;
1078 nr_pages = 0;
1079 start = ktime_get();
1080 for ( ; ; ) {
1081 ret = snapshot_write_next(snapshot);
1082 if (ret <= 0)
1083 break;
1084 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1085 if (ret)
1086 break;
1087 if (snapshot->sync_read)
1088 ret = hib_wait_io(&hb);
1089 if (ret)
1090 break;
1091 if (!(nr_pages % m))
1092 pr_info("Image loading progress: %3d%%\n",
1093 nr_pages / m * 10);
1094 nr_pages++;
1095 }
1096 err2 = hib_wait_io(&hb);
1097 hib_finish_batch(&hb);
1098 stop = ktime_get();
1099 if (!ret)
1100 ret = err2;
1101 if (!ret) {
1102 pr_info("Image loading done\n");
1103 snapshot_write_finalize(snapshot);
1104 if (!snapshot_image_loaded(snapshot))
1105 ret = -ENODATA;
1106 }
1107 swsusp_show_speed(start, stop, nr_to_read, "Read");
1108 return ret;
1109}
1110
1111/*
1112 * Structure used for LZO data decompression.
1113 */
1114struct dec_data {
1115 struct task_struct *thr; /* thread */
1116 atomic_t ready; /* ready to start flag */
1117 atomic_t stop; /* ready to stop flag */
1118 int ret; /* return code */
1119 wait_queue_head_t go; /* start decompression */
1120 wait_queue_head_t done; /* decompression done */
1121 size_t unc_len; /* uncompressed length */
1122 size_t cmp_len; /* compressed length */
1123 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
1124 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
1125};
1126
1127/*
1128 * Decompression function that runs in its own thread.
1129 */
1130static int lzo_decompress_threadfn(void *data)
1131{
1132 struct dec_data *d = data;
1133
1134 while (1) {
1135 wait_event(d->go, atomic_read_acquire(&d->ready) ||
1136 kthread_should_stop());
1137 if (kthread_should_stop()) {
1138 d->thr = NULL;
1139 d->ret = -1;
1140 atomic_set_release(&d->stop, 1);
1141 wake_up(&d->done);
1142 break;
1143 }
1144 atomic_set(&d->ready, 0);
1145
1146 d->unc_len = LZO_UNC_SIZE;
1147 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1148 d->unc, &d->unc_len);
1149 if (clean_pages_on_decompress)
1150 flush_icache_range((unsigned long)d->unc,
1151 (unsigned long)d->unc + d->unc_len);
1152
1153 atomic_set_release(&d->stop, 1);
1154 wake_up(&d->done);
1155 }
1156 return 0;
1157}
1158
1159/**
1160 * load_image_lzo - Load compressed image data and decompress them with LZO.
1161 * @handle: Swap map handle to use for loading data.
1162 * @snapshot: Image to copy uncompressed data into.
1163 * @nr_to_read: Number of pages to load.
1164 */
1165static int load_image_lzo(struct swap_map_handle *handle,
1166 struct snapshot_handle *snapshot,
1167 unsigned int nr_to_read)
1168{
1169 unsigned int m;
1170 int ret = 0;
1171 int eof = 0;
1172 struct hib_bio_batch hb;
1173 ktime_t start;
1174 ktime_t stop;
1175 unsigned nr_pages;
1176 size_t off;
1177 unsigned i, thr, run_threads, nr_threads;
1178 unsigned ring = 0, pg = 0, ring_size = 0,
1179 have = 0, want, need, asked = 0;
1180 unsigned long read_pages = 0;
1181 unsigned char **page = NULL;
1182 struct dec_data *data = NULL;
1183 struct crc_data *crc = NULL;
1184
1185 hib_init_batch(&hb);
1186
1187 /*
1188 * We'll limit the number of threads for decompression to limit memory
1189 * footprint.
1190 */
1191 nr_threads = num_online_cpus() - 1;
1192 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1193
1194 page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
1195 if (!page) {
1196 pr_err("Failed to allocate LZO page\n");
1197 ret = -ENOMEM;
1198 goto out_clean;
1199 }
1200
1201 data = vzalloc(array_size(nr_threads, sizeof(*data)));
1202 if (!data) {
1203 pr_err("Failed to allocate LZO data\n");
1204 ret = -ENOMEM;
1205 goto out_clean;
1206 }
1207
1208 crc = kzalloc(sizeof(*crc), GFP_KERNEL);
1209 if (!crc) {
1210 pr_err("Failed to allocate crc\n");
1211 ret = -ENOMEM;
1212 goto out_clean;
1213 }
1214
1215 clean_pages_on_decompress = true;
1216
1217 /*
1218 * Start the decompression threads.
1219 */
1220 for (thr = 0; thr < nr_threads; thr++) {
1221 init_waitqueue_head(&data[thr].go);
1222 init_waitqueue_head(&data[thr].done);
1223
1224 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1225 &data[thr],
1226 "image_decompress/%u", thr);
1227 if (IS_ERR(data[thr].thr)) {
1228 data[thr].thr = NULL;
1229 pr_err("Cannot start decompression threads\n");
1230 ret = -ENOMEM;
1231 goto out_clean;
1232 }
1233 }
1234
1235 /*
1236 * Start the CRC32 thread.
1237 */
1238 init_waitqueue_head(&crc->go);
1239 init_waitqueue_head(&crc->done);
1240
1241 handle->crc32 = 0;
1242 crc->crc32 = &handle->crc32;
1243 for (thr = 0; thr < nr_threads; thr++) {
1244 crc->unc[thr] = data[thr].unc;
1245 crc->unc_len[thr] = &data[thr].unc_len;
1246 }
1247
1248 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1249 if (IS_ERR(crc->thr)) {
1250 crc->thr = NULL;
1251 pr_err("Cannot start CRC32 thread\n");
1252 ret = -ENOMEM;
1253 goto out_clean;
1254 }
1255
1256 /*
1257 * Set the number of pages for read buffering.
1258 * This is complete guesswork, because we'll only know the real
1259 * picture once prepare_image() is called, which is much later on
1260 * during the image load phase. We'll assume the worst case and
1261 * say that none of the image pages are from high memory.
1262 */
1263 if (low_free_pages() > snapshot_get_image_size())
1264 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1265 read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1266
1267 for (i = 0; i < read_pages; i++) {
1268 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1269 GFP_NOIO | __GFP_HIGH :
1270 GFP_NOIO | __GFP_NOWARN |
1271 __GFP_NORETRY);
1272
1273 if (!page[i]) {
1274 if (i < LZO_CMP_PAGES) {
1275 ring_size = i;
1276 pr_err("Failed to allocate LZO pages\n");
1277 ret = -ENOMEM;
1278 goto out_clean;
1279 } else {
1280 break;
1281 }
1282 }
1283 }
1284 want = ring_size = i;
1285
1286 pr_info("Using %u thread(s) for decompression\n", nr_threads);
1287 pr_info("Loading and decompressing image data (%u pages)...\n",
1288 nr_to_read);
1289 m = nr_to_read / 10;
1290 if (!m)
1291 m = 1;
1292 nr_pages = 0;
1293 start = ktime_get();
1294
1295 ret = snapshot_write_next(snapshot);
1296 if (ret <= 0)
1297 goto out_finish;
1298
1299 for(;;) {
1300 for (i = 0; !eof && i < want; i++) {
1301 ret = swap_read_page(handle, page[ring], &hb);
1302 if (ret) {
1303 /*
1304 * On real read error, finish. On end of data,
1305 * set EOF flag and just exit the read loop.
1306 */
1307 if (handle->cur &&
1308 handle->cur->entries[handle->k]) {
1309 goto out_finish;
1310 } else {
1311 eof = 1;
1312 break;
1313 }
1314 }
1315 if (++ring >= ring_size)
1316 ring = 0;
1317 }
1318 asked += i;
1319 want -= i;
1320
1321 /*
1322 * We are out of data, wait for some more.
1323 */
1324 if (!have) {
1325 if (!asked)
1326 break;
1327
1328 ret = hib_wait_io(&hb);
1329 if (ret)
1330 goto out_finish;
1331 have += asked;
1332 asked = 0;
1333 if (eof)
1334 eof = 2;
1335 }
1336
1337 if (crc->run_threads) {
1338 wait_event(crc->done, atomic_read_acquire(&crc->stop));
1339 atomic_set(&crc->stop, 0);
1340 crc->run_threads = 0;
1341 }
1342
1343 for (thr = 0; have && thr < nr_threads; thr++) {
1344 data[thr].cmp_len = *(size_t *)page[pg];
1345 if (unlikely(!data[thr].cmp_len ||
1346 data[thr].cmp_len >
1347 lzo1x_worst_compress(LZO_UNC_SIZE))) {
1348 pr_err("Invalid LZO compressed length\n");
1349 ret = -1;
1350 goto out_finish;
1351 }
1352
1353 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1354 PAGE_SIZE);
1355 if (need > have) {
1356 if (eof > 1) {
1357 ret = -1;
1358 goto out_finish;
1359 }
1360 break;
1361 }
1362
1363 for (off = 0;
1364 off < LZO_HEADER + data[thr].cmp_len;
1365 off += PAGE_SIZE) {
1366 memcpy(data[thr].cmp + off,
1367 page[pg], PAGE_SIZE);
1368 have--;
1369 want++;
1370 if (++pg >= ring_size)
1371 pg = 0;
1372 }
1373
1374 atomic_set_release(&data[thr].ready, 1);
1375 wake_up(&data[thr].go);
1376 }
1377
1378 /*
1379 * Wait for more data while we are decompressing.
1380 */
1381 if (have < LZO_CMP_PAGES && asked) {
1382 ret = hib_wait_io(&hb);
1383 if (ret)
1384 goto out_finish;
1385 have += asked;
1386 asked = 0;
1387 if (eof)
1388 eof = 2;
1389 }
1390
1391 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1392 wait_event(data[thr].done,
1393 atomic_read_acquire(&data[thr].stop));
1394 atomic_set(&data[thr].stop, 0);
1395
1396 ret = data[thr].ret;
1397
1398 if (ret < 0) {
1399 pr_err("LZO decompression failed\n");
1400 goto out_finish;
1401 }
1402
1403 if (unlikely(!data[thr].unc_len ||
1404 data[thr].unc_len > LZO_UNC_SIZE ||
1405 data[thr].unc_len & (PAGE_SIZE - 1))) {
1406 pr_err("Invalid LZO uncompressed length\n");
1407 ret = -1;
1408 goto out_finish;
1409 }
1410
1411 for (off = 0;
1412 off < data[thr].unc_len; off += PAGE_SIZE) {
1413 memcpy(data_of(*snapshot),
1414 data[thr].unc + off, PAGE_SIZE);
1415
1416 if (!(nr_pages % m))
1417 pr_info("Image loading progress: %3d%%\n",
1418 nr_pages / m * 10);
1419 nr_pages++;
1420
1421 ret = snapshot_write_next(snapshot);
1422 if (ret <= 0) {
1423 crc->run_threads = thr + 1;
1424 atomic_set_release(&crc->ready, 1);
1425 wake_up(&crc->go);
1426 goto out_finish;
1427 }
1428 }
1429 }
1430
1431 crc->run_threads = thr;
1432 atomic_set_release(&crc->ready, 1);
1433 wake_up(&crc->go);
1434 }
1435
1436out_finish:
1437 if (crc->run_threads) {
1438 wait_event(crc->done, atomic_read_acquire(&crc->stop));
1439 atomic_set(&crc->stop, 0);
1440 }
1441 stop = ktime_get();
1442 if (!ret) {
1443 pr_info("Image loading done\n");
1444 snapshot_write_finalize(snapshot);
1445 if (!snapshot_image_loaded(snapshot))
1446 ret = -ENODATA;
1447 if (!ret) {
1448 if (swsusp_header->flags & SF_CRC32_MODE) {
1449 if(handle->crc32 != swsusp_header->crc32) {
1450 pr_err("Invalid image CRC32!\n");
1451 ret = -ENODATA;
1452 }
1453 }
1454 }
1455 }
1456 swsusp_show_speed(start, stop, nr_to_read, "Read");
1457out_clean:
1458 hib_finish_batch(&hb);
1459 for (i = 0; i < ring_size; i++)
1460 free_page((unsigned long)page[i]);
1461 if (crc) {
1462 if (crc->thr)
1463 kthread_stop(crc->thr);
1464 kfree(crc);
1465 }
1466 if (data) {
1467 for (thr = 0; thr < nr_threads; thr++)
1468 if (data[thr].thr)
1469 kthread_stop(data[thr].thr);
1470 vfree(data);
1471 }
1472 vfree(page);
1473
1474 return ret;
1475}
1476
1477/**
1478 * swsusp_read - read the hibernation image.
1479 * @flags_p: flags passed by the "frozen" kernel in the image header should
1480 * be written into this memory location
1481 */
1482
1483int swsusp_read(unsigned int *flags_p)
1484{
1485 int error;
1486 struct swap_map_handle handle;
1487 struct snapshot_handle snapshot;
1488 struct swsusp_info *header;
1489
1490 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1491 error = snapshot_write_next(&snapshot);
1492 if (error < (int)PAGE_SIZE)
1493 return error < 0 ? error : -EFAULT;
1494 header = (struct swsusp_info *)data_of(snapshot);
1495 error = get_swap_reader(&handle, flags_p);
1496 if (error)
1497 goto end;
1498 if (!error)
1499 error = swap_read_page(&handle, header, NULL);
1500 if (!error) {
1501 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1502 load_image(&handle, &snapshot, header->pages - 1) :
1503 load_image_lzo(&handle, &snapshot, header->pages - 1);
1504 }
1505 swap_reader_finish(&handle);
1506end:
1507 if (!error)
1508 pr_debug("Image successfully loaded\n");
1509 else
1510 pr_debug("Error %d resuming\n", error);
1511 return error;
1512}
1513
1514static void *swsusp_holder;
1515
1516/**
1517 * swsusp_check - Open the resume device and check for the swsusp signature.
1518 * @exclusive: Open the resume device exclusively.
1519 */
1520
1521int swsusp_check(bool exclusive)
1522{
1523 void *holder = exclusive ? &swsusp_holder : NULL;
1524 int error;
1525
1526 hib_resume_bdev_handle = bdev_open_by_dev(swsusp_resume_device,
1527 BLK_OPEN_READ, holder, NULL);
1528 if (!IS_ERR(hib_resume_bdev_handle)) {
1529 set_blocksize(hib_resume_bdev_handle->bdev, PAGE_SIZE);
1530 clear_page(swsusp_header);
1531 error = hib_submit_io(REQ_OP_READ, swsusp_resume_block,
1532 swsusp_header, NULL);
1533 if (error)
1534 goto put;
1535
1536 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1537 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1538 /* Reset swap signature now */
1539 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
1540 swsusp_resume_block,
1541 swsusp_header, NULL);
1542 } else {
1543 error = -EINVAL;
1544 }
1545 if (!error && swsusp_header->flags & SF_HW_SIG &&
1546 swsusp_header->hw_sig != swsusp_hardware_signature) {
1547 pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
1548 swsusp_header->hw_sig, swsusp_hardware_signature);
1549 error = -EINVAL;
1550 }
1551
1552put:
1553 if (error)
1554 bdev_release(hib_resume_bdev_handle);
1555 else
1556 pr_debug("Image signature found, resuming\n");
1557 } else {
1558 error = PTR_ERR(hib_resume_bdev_handle);
1559 }
1560
1561 if (error)
1562 pr_debug("Image not found (code %d)\n", error);
1563
1564 return error;
1565}
1566
1567/**
1568 * swsusp_close - close resume device.
1569 */
1570
1571void swsusp_close(void)
1572{
1573 if (IS_ERR(hib_resume_bdev_handle)) {
1574 pr_debug("Image device not initialised\n");
1575 return;
1576 }
1577
1578 bdev_release(hib_resume_bdev_handle);
1579}
1580
1581/**
1582 * swsusp_unmark - Unmark swsusp signature in the resume device
1583 */
1584
1585#ifdef CONFIG_SUSPEND
1586int swsusp_unmark(void)
1587{
1588 int error;
1589
1590 hib_submit_io(REQ_OP_READ, swsusp_resume_block,
1591 swsusp_header, NULL);
1592 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1593 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1594 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
1595 swsusp_resume_block,
1596 swsusp_header, NULL);
1597 } else {
1598 pr_err("Cannot find swsusp signature!\n");
1599 error = -ENODEV;
1600 }
1601
1602 /*
1603 * We just returned from suspend, we don't need the image any more.
1604 */
1605 free_all_swap_pages(root_swap);
1606
1607 return error;
1608}
1609#endif
1610
1611static int __init swsusp_header_init(void)
1612{
1613 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1614 if (!swsusp_header)
1615 panic("Could not allocate memory for swsusp_header\n");
1616 return 0;
1617}
1618
1619core_initcall(swsusp_header_init);