Loading...
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#include <linux/module.h>
16#include <linux/file.h>
17#include <linux/delay.h>
18#include <linux/bitops.h>
19#include <linux/genhd.h>
20#include <linux/device.h>
21#include <linux/bio.h>
22#include <linux/blkdev.h>
23#include <linux/swap.h>
24#include <linux/swapops.h>
25#include <linux/pm.h>
26#include <linux/slab.h>
27#include <linux/lzo.h>
28#include <linux/vmalloc.h>
29#include <linux/cpumask.h>
30#include <linux/atomic.h>
31#include <linux/kthread.h>
32#include <linux/crc32.h>
33
34#include "power.h"
35
36#define HIBERNATE_SIG "S1SUSPEND"
37
38/*
39 * The swap map is a data structure used for keeping track of each page
40 * written to a swap partition. It consists of many swap_map_page
41 * structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
42 * These structures are stored on the swap and linked together with the
43 * help of the .next_swap member.
44 *
45 * The swap map is created during suspend. The swap map pages are
46 * allocated and populated one at a time, so we only need one memory
47 * page to set up the entire structure.
48 *
49 * During resume we pick up all swap_map_page structures into a list.
50 */
51
52#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
53
54/*
55 * Number of free pages that are not high.
56 */
57static inline unsigned long low_free_pages(void)
58{
59 return nr_free_pages() - nr_free_highpages();
60}
61
62/*
63 * Number of pages required to be kept free while writing the image. Always
64 * half of all available low pages before the writing starts.
65 */
66static inline unsigned long reqd_free_pages(void)
67{
68 return low_free_pages() / 2;
69}
70
71struct swap_map_page {
72 sector_t entries[MAP_PAGE_ENTRIES];
73 sector_t next_swap;
74};
75
76struct swap_map_page_list {
77 struct swap_map_page *map;
78 struct swap_map_page_list *next;
79};
80
81/**
82 * The swap_map_handle structure is used for handling swap in
83 * a file-alike way
84 */
85
86struct swap_map_handle {
87 struct swap_map_page *cur;
88 struct swap_map_page_list *maps;
89 sector_t cur_swap;
90 sector_t first_sector;
91 unsigned int k;
92 unsigned long reqd_free_pages;
93 u32 crc32;
94};
95
96struct swsusp_header {
97 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
98 sizeof(u32)];
99 u32 crc32;
100 sector_t image;
101 unsigned int flags; /* Flags to pass to the "boot" kernel */
102 char orig_sig[10];
103 char sig[10];
104} __packed;
105
106static struct swsusp_header *swsusp_header;
107
108/**
109 * The following functions are used for tracing the allocated
110 * swap pages, so that they can be freed in case of an error.
111 */
112
113struct swsusp_extent {
114 struct rb_node node;
115 unsigned long start;
116 unsigned long end;
117};
118
119static struct rb_root swsusp_extents = RB_ROOT;
120
121static int swsusp_extents_insert(unsigned long swap_offset)
122{
123 struct rb_node **new = &(swsusp_extents.rb_node);
124 struct rb_node *parent = NULL;
125 struct swsusp_extent *ext;
126
127 /* Figure out where to put the new node */
128 while (*new) {
129 ext = rb_entry(*new, struct swsusp_extent, node);
130 parent = *new;
131 if (swap_offset < ext->start) {
132 /* Try to merge */
133 if (swap_offset == ext->start - 1) {
134 ext->start--;
135 return 0;
136 }
137 new = &((*new)->rb_left);
138 } else if (swap_offset > ext->end) {
139 /* Try to merge */
140 if (swap_offset == ext->end + 1) {
141 ext->end++;
142 return 0;
143 }
144 new = &((*new)->rb_right);
145 } else {
146 /* It already is in the tree */
147 return -EINVAL;
148 }
149 }
150 /* Add the new node and rebalance the tree. */
151 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
152 if (!ext)
153 return -ENOMEM;
154
155 ext->start = swap_offset;
156 ext->end = swap_offset;
157 rb_link_node(&ext->node, parent, new);
158 rb_insert_color(&ext->node, &swsusp_extents);
159 return 0;
160}
161
162/**
163 * alloc_swapdev_block - allocate a swap page and register that it has
164 * been allocated, so that it can be freed in case of an error.
165 */
166
167sector_t alloc_swapdev_block(int swap)
168{
169 unsigned long offset;
170
171 offset = swp_offset(get_swap_page_of_type(swap));
172 if (offset) {
173 if (swsusp_extents_insert(offset))
174 swap_free(swp_entry(swap, offset));
175 else
176 return swapdev_block(swap, offset);
177 }
178 return 0;
179}
180
181/**
182 * free_all_swap_pages - free swap pages allocated for saving image data.
183 * It also frees the extents used to register which swap entries had been
184 * allocated.
185 */
186
187void free_all_swap_pages(int swap)
188{
189 struct rb_node *node;
190
191 while ((node = swsusp_extents.rb_node)) {
192 struct swsusp_extent *ext;
193 unsigned long offset;
194
195 ext = container_of(node, struct swsusp_extent, node);
196 rb_erase(node, &swsusp_extents);
197 for (offset = ext->start; offset <= ext->end; offset++)
198 swap_free(swp_entry(swap, offset));
199
200 kfree(ext);
201 }
202}
203
204int swsusp_swap_in_use(void)
205{
206 return (swsusp_extents.rb_node != NULL);
207}
208
209/*
210 * General things
211 */
212
213static unsigned short root_swap = 0xffff;
214struct block_device *hib_resume_bdev;
215
216/*
217 * Saving part
218 */
219
220static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
221{
222 int error;
223
224 hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
225 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
226 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
227 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
228 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
229 swsusp_header->image = handle->first_sector;
230 swsusp_header->flags = flags;
231 if (flags & SF_CRC32_MODE)
232 swsusp_header->crc32 = handle->crc32;
233 error = hib_bio_write_page(swsusp_resume_block,
234 swsusp_header, NULL);
235 } else {
236 printk(KERN_ERR "PM: Swap header not found!\n");
237 error = -ENODEV;
238 }
239 return error;
240}
241
242/**
243 * swsusp_swap_check - check if the resume device is a swap device
244 * and get its index (if so)
245 *
246 * This is called before saving image
247 */
248static int swsusp_swap_check(void)
249{
250 int res;
251
252 res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
253 &hib_resume_bdev);
254 if (res < 0)
255 return res;
256
257 root_swap = res;
258 res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
259 if (res)
260 return res;
261
262 res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
263 if (res < 0)
264 blkdev_put(hib_resume_bdev, FMODE_WRITE);
265
266 return res;
267}
268
269/**
270 * write_page - Write one page to given swap location.
271 * @buf: Address we're writing.
272 * @offset: Offset of the swap page we're writing to.
273 * @bio_chain: Link the next write BIO here
274 */
275
276static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
277{
278 void *src;
279 int ret;
280
281 if (!offset)
282 return -ENOSPC;
283
284 if (bio_chain) {
285 src = (void *)__get_free_page(__GFP_WAIT | __GFP_NOWARN |
286 __GFP_NORETRY);
287 if (src) {
288 copy_page(src, buf);
289 } else {
290 ret = hib_wait_on_bio_chain(bio_chain); /* Free pages */
291 if (ret)
292 return ret;
293 src = (void *)__get_free_page(__GFP_WAIT |
294 __GFP_NOWARN |
295 __GFP_NORETRY);
296 if (src) {
297 copy_page(src, buf);
298 } else {
299 WARN_ON_ONCE(1);
300 bio_chain = NULL; /* Go synchronous */
301 src = buf;
302 }
303 }
304 } else {
305 src = buf;
306 }
307 return hib_bio_write_page(offset, src, bio_chain);
308}
309
310static void release_swap_writer(struct swap_map_handle *handle)
311{
312 if (handle->cur)
313 free_page((unsigned long)handle->cur);
314 handle->cur = NULL;
315}
316
317static int get_swap_writer(struct swap_map_handle *handle)
318{
319 int ret;
320
321 ret = swsusp_swap_check();
322 if (ret) {
323 if (ret != -ENOSPC)
324 printk(KERN_ERR "PM: Cannot find swap device, try "
325 "swapon -a.\n");
326 return ret;
327 }
328 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
329 if (!handle->cur) {
330 ret = -ENOMEM;
331 goto err_close;
332 }
333 handle->cur_swap = alloc_swapdev_block(root_swap);
334 if (!handle->cur_swap) {
335 ret = -ENOSPC;
336 goto err_rel;
337 }
338 handle->k = 0;
339 handle->reqd_free_pages = reqd_free_pages();
340 handle->first_sector = handle->cur_swap;
341 return 0;
342err_rel:
343 release_swap_writer(handle);
344err_close:
345 swsusp_close(FMODE_WRITE);
346 return ret;
347}
348
349static int swap_write_page(struct swap_map_handle *handle, void *buf,
350 struct bio **bio_chain)
351{
352 int error = 0;
353 sector_t offset;
354
355 if (!handle->cur)
356 return -EINVAL;
357 offset = alloc_swapdev_block(root_swap);
358 error = write_page(buf, offset, bio_chain);
359 if (error)
360 return error;
361 handle->cur->entries[handle->k++] = offset;
362 if (handle->k >= MAP_PAGE_ENTRIES) {
363 offset = alloc_swapdev_block(root_swap);
364 if (!offset)
365 return -ENOSPC;
366 handle->cur->next_swap = offset;
367 error = write_page(handle->cur, handle->cur_swap, bio_chain);
368 if (error)
369 goto out;
370 clear_page(handle->cur);
371 handle->cur_swap = offset;
372 handle->k = 0;
373
374 if (bio_chain && low_free_pages() <= handle->reqd_free_pages) {
375 error = hib_wait_on_bio_chain(bio_chain);
376 if (error)
377 goto out;
378 /*
379 * Recalculate the number of required free pages, to
380 * make sure we never take more than half.
381 */
382 handle->reqd_free_pages = reqd_free_pages();
383 }
384 }
385 out:
386 return error;
387}
388
389static int flush_swap_writer(struct swap_map_handle *handle)
390{
391 if (handle->cur && handle->cur_swap)
392 return write_page(handle->cur, handle->cur_swap, NULL);
393 else
394 return -EINVAL;
395}
396
397static int swap_writer_finish(struct swap_map_handle *handle,
398 unsigned int flags, int error)
399{
400 if (!error) {
401 flush_swap_writer(handle);
402 printk(KERN_INFO "PM: S");
403 error = mark_swapfiles(handle, flags);
404 printk("|\n");
405 }
406
407 if (error)
408 free_all_swap_pages(root_swap);
409 release_swap_writer(handle);
410 swsusp_close(FMODE_WRITE);
411
412 return error;
413}
414
415/* We need to remember how much compressed data we need to read. */
416#define LZO_HEADER sizeof(size_t)
417
418/* Number of pages/bytes we'll compress at one time. */
419#define LZO_UNC_PAGES 32
420#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE)
421
422/* Number of pages/bytes we need for compressed data (worst case). */
423#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
424 LZO_HEADER, PAGE_SIZE)
425#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE)
426
427/* Maximum number of threads for compression/decompression. */
428#define LZO_THREADS 3
429
430/* Minimum/maximum number of pages for read buffering. */
431#define LZO_MIN_RD_PAGES 1024
432#define LZO_MAX_RD_PAGES 8192
433
434
435/**
436 * save_image - save the suspend image data
437 */
438
439static int save_image(struct swap_map_handle *handle,
440 struct snapshot_handle *snapshot,
441 unsigned int nr_to_write)
442{
443 unsigned int m;
444 int ret;
445 int nr_pages;
446 int err2;
447 struct bio *bio;
448 struct timeval start;
449 struct timeval stop;
450
451 printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
452 nr_to_write);
453 m = nr_to_write / 10;
454 if (!m)
455 m = 1;
456 nr_pages = 0;
457 bio = NULL;
458 do_gettimeofday(&start);
459 while (1) {
460 ret = snapshot_read_next(snapshot);
461 if (ret <= 0)
462 break;
463 ret = swap_write_page(handle, data_of(*snapshot), &bio);
464 if (ret)
465 break;
466 if (!(nr_pages % m))
467 printk(KERN_INFO "PM: Image saving progress: %3d%%\n",
468 nr_pages / m * 10);
469 nr_pages++;
470 }
471 err2 = hib_wait_on_bio_chain(&bio);
472 do_gettimeofday(&stop);
473 if (!ret)
474 ret = err2;
475 if (!ret)
476 printk(KERN_INFO "PM: Image saving done.\n");
477 swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
478 return ret;
479}
480
481/**
482 * Structure used for CRC32.
483 */
484struct crc_data {
485 struct task_struct *thr; /* thread */
486 atomic_t ready; /* ready to start flag */
487 atomic_t stop; /* ready to stop flag */
488 unsigned run_threads; /* nr current threads */
489 wait_queue_head_t go; /* start crc update */
490 wait_queue_head_t done; /* crc update done */
491 u32 *crc32; /* points to handle's crc32 */
492 size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */
493 unsigned char *unc[LZO_THREADS]; /* uncompressed data */
494};
495
496/**
497 * CRC32 update function that runs in its own thread.
498 */
499static int crc32_threadfn(void *data)
500{
501 struct crc_data *d = data;
502 unsigned i;
503
504 while (1) {
505 wait_event(d->go, atomic_read(&d->ready) ||
506 kthread_should_stop());
507 if (kthread_should_stop()) {
508 d->thr = NULL;
509 atomic_set(&d->stop, 1);
510 wake_up(&d->done);
511 break;
512 }
513 atomic_set(&d->ready, 0);
514
515 for (i = 0; i < d->run_threads; i++)
516 *d->crc32 = crc32_le(*d->crc32,
517 d->unc[i], *d->unc_len[i]);
518 atomic_set(&d->stop, 1);
519 wake_up(&d->done);
520 }
521 return 0;
522}
523/**
524 * Structure used for LZO data compression.
525 */
526struct cmp_data {
527 struct task_struct *thr; /* thread */
528 atomic_t ready; /* ready to start flag */
529 atomic_t stop; /* ready to stop flag */
530 int ret; /* return code */
531 wait_queue_head_t go; /* start compression */
532 wait_queue_head_t done; /* compression done */
533 size_t unc_len; /* uncompressed length */
534 size_t cmp_len; /* compressed length */
535 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
536 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
537 unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
538};
539
540/**
541 * Compression function that runs in its own thread.
542 */
543static int lzo_compress_threadfn(void *data)
544{
545 struct cmp_data *d = data;
546
547 while (1) {
548 wait_event(d->go, atomic_read(&d->ready) ||
549 kthread_should_stop());
550 if (kthread_should_stop()) {
551 d->thr = NULL;
552 d->ret = -1;
553 atomic_set(&d->stop, 1);
554 wake_up(&d->done);
555 break;
556 }
557 atomic_set(&d->ready, 0);
558
559 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
560 d->cmp + LZO_HEADER, &d->cmp_len,
561 d->wrk);
562 atomic_set(&d->stop, 1);
563 wake_up(&d->done);
564 }
565 return 0;
566}
567
568/**
569 * save_image_lzo - Save the suspend image data compressed with LZO.
570 * @handle: Swap mam handle to use for saving the image.
571 * @snapshot: Image to read data from.
572 * @nr_to_write: Number of pages to save.
573 */
574static int save_image_lzo(struct swap_map_handle *handle,
575 struct snapshot_handle *snapshot,
576 unsigned int nr_to_write)
577{
578 unsigned int m;
579 int ret = 0;
580 int nr_pages;
581 int err2;
582 struct bio *bio;
583 struct timeval start;
584 struct timeval stop;
585 size_t off;
586 unsigned thr, run_threads, nr_threads;
587 unsigned char *page = NULL;
588 struct cmp_data *data = NULL;
589 struct crc_data *crc = NULL;
590
591 /*
592 * We'll limit the number of threads for compression to limit memory
593 * footprint.
594 */
595 nr_threads = num_online_cpus() - 1;
596 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
597
598 page = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
599 if (!page) {
600 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
601 ret = -ENOMEM;
602 goto out_clean;
603 }
604
605 data = vmalloc(sizeof(*data) * nr_threads);
606 if (!data) {
607 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
608 ret = -ENOMEM;
609 goto out_clean;
610 }
611 for (thr = 0; thr < nr_threads; thr++)
612 memset(&data[thr], 0, offsetof(struct cmp_data, go));
613
614 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
615 if (!crc) {
616 printk(KERN_ERR "PM: Failed to allocate crc\n");
617 ret = -ENOMEM;
618 goto out_clean;
619 }
620 memset(crc, 0, offsetof(struct crc_data, go));
621
622 /*
623 * Start the compression threads.
624 */
625 for (thr = 0; thr < nr_threads; thr++) {
626 init_waitqueue_head(&data[thr].go);
627 init_waitqueue_head(&data[thr].done);
628
629 data[thr].thr = kthread_run(lzo_compress_threadfn,
630 &data[thr],
631 "image_compress/%u", thr);
632 if (IS_ERR(data[thr].thr)) {
633 data[thr].thr = NULL;
634 printk(KERN_ERR
635 "PM: Cannot start compression threads\n");
636 ret = -ENOMEM;
637 goto out_clean;
638 }
639 }
640
641 /*
642 * Start the CRC32 thread.
643 */
644 init_waitqueue_head(&crc->go);
645 init_waitqueue_head(&crc->done);
646
647 handle->crc32 = 0;
648 crc->crc32 = &handle->crc32;
649 for (thr = 0; thr < nr_threads; thr++) {
650 crc->unc[thr] = data[thr].unc;
651 crc->unc_len[thr] = &data[thr].unc_len;
652 }
653
654 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
655 if (IS_ERR(crc->thr)) {
656 crc->thr = NULL;
657 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
658 ret = -ENOMEM;
659 goto out_clean;
660 }
661
662 /*
663 * Adjust the number of required free pages after all allocations have
664 * been done. We don't want to run out of pages when writing.
665 */
666 handle->reqd_free_pages = reqd_free_pages();
667
668 printk(KERN_INFO
669 "PM: Using %u thread(s) for compression.\n"
670 "PM: Compressing and saving image data (%u pages)...\n",
671 nr_threads, nr_to_write);
672 m = nr_to_write / 10;
673 if (!m)
674 m = 1;
675 nr_pages = 0;
676 bio = NULL;
677 do_gettimeofday(&start);
678 for (;;) {
679 for (thr = 0; thr < nr_threads; thr++) {
680 for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
681 ret = snapshot_read_next(snapshot);
682 if (ret < 0)
683 goto out_finish;
684
685 if (!ret)
686 break;
687
688 memcpy(data[thr].unc + off,
689 data_of(*snapshot), PAGE_SIZE);
690
691 if (!(nr_pages % m))
692 printk(KERN_INFO
693 "PM: Image saving progress: "
694 "%3d%%\n",
695 nr_pages / m * 10);
696 nr_pages++;
697 }
698 if (!off)
699 break;
700
701 data[thr].unc_len = off;
702
703 atomic_set(&data[thr].ready, 1);
704 wake_up(&data[thr].go);
705 }
706
707 if (!thr)
708 break;
709
710 crc->run_threads = thr;
711 atomic_set(&crc->ready, 1);
712 wake_up(&crc->go);
713
714 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
715 wait_event(data[thr].done,
716 atomic_read(&data[thr].stop));
717 atomic_set(&data[thr].stop, 0);
718
719 ret = data[thr].ret;
720
721 if (ret < 0) {
722 printk(KERN_ERR "PM: LZO compression failed\n");
723 goto out_finish;
724 }
725
726 if (unlikely(!data[thr].cmp_len ||
727 data[thr].cmp_len >
728 lzo1x_worst_compress(data[thr].unc_len))) {
729 printk(KERN_ERR
730 "PM: Invalid LZO compressed length\n");
731 ret = -1;
732 goto out_finish;
733 }
734
735 *(size_t *)data[thr].cmp = data[thr].cmp_len;
736
737 /*
738 * Given we are writing one page at a time to disk, we
739 * copy that much from the buffer, although the last
740 * bit will likely be smaller than full page. This is
741 * OK - we saved the length of the compressed data, so
742 * any garbage at the end will be discarded when we
743 * read it.
744 */
745 for (off = 0;
746 off < LZO_HEADER + data[thr].cmp_len;
747 off += PAGE_SIZE) {
748 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
749
750 ret = swap_write_page(handle, page, &bio);
751 if (ret)
752 goto out_finish;
753 }
754 }
755
756 wait_event(crc->done, atomic_read(&crc->stop));
757 atomic_set(&crc->stop, 0);
758 }
759
760out_finish:
761 err2 = hib_wait_on_bio_chain(&bio);
762 do_gettimeofday(&stop);
763 if (!ret)
764 ret = err2;
765 if (!ret)
766 printk(KERN_INFO "PM: Image saving done.\n");
767 swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
768out_clean:
769 if (crc) {
770 if (crc->thr)
771 kthread_stop(crc->thr);
772 kfree(crc);
773 }
774 if (data) {
775 for (thr = 0; thr < nr_threads; thr++)
776 if (data[thr].thr)
777 kthread_stop(data[thr].thr);
778 vfree(data);
779 }
780 if (page) free_page((unsigned long)page);
781
782 return ret;
783}
784
785/**
786 * enough_swap - Make sure we have enough swap to save the image.
787 *
788 * Returns TRUE or FALSE after checking the total amount of swap
789 * space avaiable from the resume partition.
790 */
791
792static int enough_swap(unsigned int nr_pages, unsigned int flags)
793{
794 unsigned int free_swap = count_swap_pages(root_swap, 1);
795 unsigned int required;
796
797 pr_debug("PM: Free swap pages: %u\n", free_swap);
798
799 required = PAGES_FOR_IO + nr_pages;
800 return free_swap > required;
801}
802
803/**
804 * swsusp_write - Write entire image and metadata.
805 * @flags: flags to pass to the "boot" kernel in the image header
806 *
807 * It is important _NOT_ to umount filesystems at this point. We want
808 * them synced (in case something goes wrong) but we DO not want to mark
809 * filesystem clean: it is not. (And it does not matter, if we resume
810 * correctly, we'll mark system clean, anyway.)
811 */
812
813int swsusp_write(unsigned int flags)
814{
815 struct swap_map_handle handle;
816 struct snapshot_handle snapshot;
817 struct swsusp_info *header;
818 unsigned long pages;
819 int error;
820
821 pages = snapshot_get_image_size();
822 error = get_swap_writer(&handle);
823 if (error) {
824 printk(KERN_ERR "PM: Cannot get swap writer\n");
825 return error;
826 }
827 if (flags & SF_NOCOMPRESS_MODE) {
828 if (!enough_swap(pages, flags)) {
829 printk(KERN_ERR "PM: Not enough free swap\n");
830 error = -ENOSPC;
831 goto out_finish;
832 }
833 }
834 memset(&snapshot, 0, sizeof(struct snapshot_handle));
835 error = snapshot_read_next(&snapshot);
836 if (error < PAGE_SIZE) {
837 if (error >= 0)
838 error = -EFAULT;
839
840 goto out_finish;
841 }
842 header = (struct swsusp_info *)data_of(snapshot);
843 error = swap_write_page(&handle, header, NULL);
844 if (!error) {
845 error = (flags & SF_NOCOMPRESS_MODE) ?
846 save_image(&handle, &snapshot, pages - 1) :
847 save_image_lzo(&handle, &snapshot, pages - 1);
848 }
849out_finish:
850 error = swap_writer_finish(&handle, flags, error);
851 return error;
852}
853
854/**
855 * The following functions allow us to read data using a swap map
856 * in a file-alike way
857 */
858
859static void release_swap_reader(struct swap_map_handle *handle)
860{
861 struct swap_map_page_list *tmp;
862
863 while (handle->maps) {
864 if (handle->maps->map)
865 free_page((unsigned long)handle->maps->map);
866 tmp = handle->maps;
867 handle->maps = handle->maps->next;
868 kfree(tmp);
869 }
870 handle->cur = NULL;
871}
872
873static int get_swap_reader(struct swap_map_handle *handle,
874 unsigned int *flags_p)
875{
876 int error;
877 struct swap_map_page_list *tmp, *last;
878 sector_t offset;
879
880 *flags_p = swsusp_header->flags;
881
882 if (!swsusp_header->image) /* how can this happen? */
883 return -EINVAL;
884
885 handle->cur = NULL;
886 last = handle->maps = NULL;
887 offset = swsusp_header->image;
888 while (offset) {
889 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
890 if (!tmp) {
891 release_swap_reader(handle);
892 return -ENOMEM;
893 }
894 memset(tmp, 0, sizeof(*tmp));
895 if (!handle->maps)
896 handle->maps = tmp;
897 if (last)
898 last->next = tmp;
899 last = tmp;
900
901 tmp->map = (struct swap_map_page *)
902 __get_free_page(__GFP_WAIT | __GFP_HIGH);
903 if (!tmp->map) {
904 release_swap_reader(handle);
905 return -ENOMEM;
906 }
907
908 error = hib_bio_read_page(offset, tmp->map, NULL);
909 if (error) {
910 release_swap_reader(handle);
911 return error;
912 }
913 offset = tmp->map->next_swap;
914 }
915 handle->k = 0;
916 handle->cur = handle->maps->map;
917 return 0;
918}
919
920static int swap_read_page(struct swap_map_handle *handle, void *buf,
921 struct bio **bio_chain)
922{
923 sector_t offset;
924 int error;
925 struct swap_map_page_list *tmp;
926
927 if (!handle->cur)
928 return -EINVAL;
929 offset = handle->cur->entries[handle->k];
930 if (!offset)
931 return -EFAULT;
932 error = hib_bio_read_page(offset, buf, bio_chain);
933 if (error)
934 return error;
935 if (++handle->k >= MAP_PAGE_ENTRIES) {
936 handle->k = 0;
937 free_page((unsigned long)handle->maps->map);
938 tmp = handle->maps;
939 handle->maps = handle->maps->next;
940 kfree(tmp);
941 if (!handle->maps)
942 release_swap_reader(handle);
943 else
944 handle->cur = handle->maps->map;
945 }
946 return error;
947}
948
949static int swap_reader_finish(struct swap_map_handle *handle)
950{
951 release_swap_reader(handle);
952
953 return 0;
954}
955
956/**
957 * load_image - load the image using the swap map handle
958 * @handle and the snapshot handle @snapshot
959 * (assume there are @nr_pages pages to load)
960 */
961
962static int load_image(struct swap_map_handle *handle,
963 struct snapshot_handle *snapshot,
964 unsigned int nr_to_read)
965{
966 unsigned int m;
967 int ret = 0;
968 struct timeval start;
969 struct timeval stop;
970 struct bio *bio;
971 int err2;
972 unsigned nr_pages;
973
974 printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
975 nr_to_read);
976 m = nr_to_read / 10;
977 if (!m)
978 m = 1;
979 nr_pages = 0;
980 bio = NULL;
981 do_gettimeofday(&start);
982 for ( ; ; ) {
983 ret = snapshot_write_next(snapshot);
984 if (ret <= 0)
985 break;
986 ret = swap_read_page(handle, data_of(*snapshot), &bio);
987 if (ret)
988 break;
989 if (snapshot->sync_read)
990 ret = hib_wait_on_bio_chain(&bio);
991 if (ret)
992 break;
993 if (!(nr_pages % m))
994 printk(KERN_INFO "PM: Image loading progress: %3d%%\n",
995 nr_pages / m * 10);
996 nr_pages++;
997 }
998 err2 = hib_wait_on_bio_chain(&bio);
999 do_gettimeofday(&stop);
1000 if (!ret)
1001 ret = err2;
1002 if (!ret) {
1003 printk(KERN_INFO "PM: Image loading done.\n");
1004 snapshot_write_finalize(snapshot);
1005 if (!snapshot_image_loaded(snapshot))
1006 ret = -ENODATA;
1007 }
1008 swsusp_show_speed(&start, &stop, nr_to_read, "Read");
1009 return ret;
1010}
1011
1012/**
1013 * Structure used for LZO data decompression.
1014 */
1015struct dec_data {
1016 struct task_struct *thr; /* thread */
1017 atomic_t ready; /* ready to start flag */
1018 atomic_t stop; /* ready to stop flag */
1019 int ret; /* return code */
1020 wait_queue_head_t go; /* start decompression */
1021 wait_queue_head_t done; /* decompression done */
1022 size_t unc_len; /* uncompressed length */
1023 size_t cmp_len; /* compressed length */
1024 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
1025 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
1026};
1027
1028/**
1029 * Deompression function that runs in its own thread.
1030 */
1031static int lzo_decompress_threadfn(void *data)
1032{
1033 struct dec_data *d = data;
1034
1035 while (1) {
1036 wait_event(d->go, atomic_read(&d->ready) ||
1037 kthread_should_stop());
1038 if (kthread_should_stop()) {
1039 d->thr = NULL;
1040 d->ret = -1;
1041 atomic_set(&d->stop, 1);
1042 wake_up(&d->done);
1043 break;
1044 }
1045 atomic_set(&d->ready, 0);
1046
1047 d->unc_len = LZO_UNC_SIZE;
1048 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1049 d->unc, &d->unc_len);
1050 atomic_set(&d->stop, 1);
1051 wake_up(&d->done);
1052 }
1053 return 0;
1054}
1055
1056/**
1057 * load_image_lzo - Load compressed image data and decompress them with LZO.
1058 * @handle: Swap map handle to use for loading data.
1059 * @snapshot: Image to copy uncompressed data into.
1060 * @nr_to_read: Number of pages to load.
1061 */
1062static int load_image_lzo(struct swap_map_handle *handle,
1063 struct snapshot_handle *snapshot,
1064 unsigned int nr_to_read)
1065{
1066 unsigned int m;
1067 int ret = 0;
1068 int eof = 0;
1069 struct bio *bio;
1070 struct timeval start;
1071 struct timeval stop;
1072 unsigned nr_pages;
1073 size_t off;
1074 unsigned i, thr, run_threads, nr_threads;
1075 unsigned ring = 0, pg = 0, ring_size = 0,
1076 have = 0, want, need, asked = 0;
1077 unsigned long read_pages = 0;
1078 unsigned char **page = NULL;
1079 struct dec_data *data = NULL;
1080 struct crc_data *crc = NULL;
1081
1082 /*
1083 * We'll limit the number of threads for decompression to limit memory
1084 * footprint.
1085 */
1086 nr_threads = num_online_cpus() - 1;
1087 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1088
1089 page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1090 if (!page) {
1091 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1092 ret = -ENOMEM;
1093 goto out_clean;
1094 }
1095
1096 data = vmalloc(sizeof(*data) * nr_threads);
1097 if (!data) {
1098 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1099 ret = -ENOMEM;
1100 goto out_clean;
1101 }
1102 for (thr = 0; thr < nr_threads; thr++)
1103 memset(&data[thr], 0, offsetof(struct dec_data, go));
1104
1105 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1106 if (!crc) {
1107 printk(KERN_ERR "PM: Failed to allocate crc\n");
1108 ret = -ENOMEM;
1109 goto out_clean;
1110 }
1111 memset(crc, 0, offsetof(struct crc_data, go));
1112
1113 /*
1114 * Start the decompression threads.
1115 */
1116 for (thr = 0; thr < nr_threads; thr++) {
1117 init_waitqueue_head(&data[thr].go);
1118 init_waitqueue_head(&data[thr].done);
1119
1120 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1121 &data[thr],
1122 "image_decompress/%u", thr);
1123 if (IS_ERR(data[thr].thr)) {
1124 data[thr].thr = NULL;
1125 printk(KERN_ERR
1126 "PM: Cannot start decompression threads\n");
1127 ret = -ENOMEM;
1128 goto out_clean;
1129 }
1130 }
1131
1132 /*
1133 * Start the CRC32 thread.
1134 */
1135 init_waitqueue_head(&crc->go);
1136 init_waitqueue_head(&crc->done);
1137
1138 handle->crc32 = 0;
1139 crc->crc32 = &handle->crc32;
1140 for (thr = 0; thr < nr_threads; thr++) {
1141 crc->unc[thr] = data[thr].unc;
1142 crc->unc_len[thr] = &data[thr].unc_len;
1143 }
1144
1145 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1146 if (IS_ERR(crc->thr)) {
1147 crc->thr = NULL;
1148 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
1149 ret = -ENOMEM;
1150 goto out_clean;
1151 }
1152
1153 /*
1154 * Set the number of pages for read buffering.
1155 * This is complete guesswork, because we'll only know the real
1156 * picture once prepare_image() is called, which is much later on
1157 * during the image load phase. We'll assume the worst case and
1158 * say that none of the image pages are from high memory.
1159 */
1160 if (low_free_pages() > snapshot_get_image_size())
1161 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1162 read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1163
1164 for (i = 0; i < read_pages; i++) {
1165 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1166 __GFP_WAIT | __GFP_HIGH :
1167 __GFP_WAIT | __GFP_NOWARN |
1168 __GFP_NORETRY);
1169
1170 if (!page[i]) {
1171 if (i < LZO_CMP_PAGES) {
1172 ring_size = i;
1173 printk(KERN_ERR
1174 "PM: Failed to allocate LZO pages\n");
1175 ret = -ENOMEM;
1176 goto out_clean;
1177 } else {
1178 break;
1179 }
1180 }
1181 }
1182 want = ring_size = i;
1183
1184 printk(KERN_INFO
1185 "PM: Using %u thread(s) for decompression.\n"
1186 "PM: Loading and decompressing image data (%u pages)...\n",
1187 nr_threads, nr_to_read);
1188 m = nr_to_read / 10;
1189 if (!m)
1190 m = 1;
1191 nr_pages = 0;
1192 bio = NULL;
1193 do_gettimeofday(&start);
1194
1195 ret = snapshot_write_next(snapshot);
1196 if (ret <= 0)
1197 goto out_finish;
1198
1199 for(;;) {
1200 for (i = 0; !eof && i < want; i++) {
1201 ret = swap_read_page(handle, page[ring], &bio);
1202 if (ret) {
1203 /*
1204 * On real read error, finish. On end of data,
1205 * set EOF flag and just exit the read loop.
1206 */
1207 if (handle->cur &&
1208 handle->cur->entries[handle->k]) {
1209 goto out_finish;
1210 } else {
1211 eof = 1;
1212 break;
1213 }
1214 }
1215 if (++ring >= ring_size)
1216 ring = 0;
1217 }
1218 asked += i;
1219 want -= i;
1220
1221 /*
1222 * We are out of data, wait for some more.
1223 */
1224 if (!have) {
1225 if (!asked)
1226 break;
1227
1228 ret = hib_wait_on_bio_chain(&bio);
1229 if (ret)
1230 goto out_finish;
1231 have += asked;
1232 asked = 0;
1233 if (eof)
1234 eof = 2;
1235 }
1236
1237 if (crc->run_threads) {
1238 wait_event(crc->done, atomic_read(&crc->stop));
1239 atomic_set(&crc->stop, 0);
1240 crc->run_threads = 0;
1241 }
1242
1243 for (thr = 0; have && thr < nr_threads; thr++) {
1244 data[thr].cmp_len = *(size_t *)page[pg];
1245 if (unlikely(!data[thr].cmp_len ||
1246 data[thr].cmp_len >
1247 lzo1x_worst_compress(LZO_UNC_SIZE))) {
1248 printk(KERN_ERR
1249 "PM: Invalid LZO compressed length\n");
1250 ret = -1;
1251 goto out_finish;
1252 }
1253
1254 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1255 PAGE_SIZE);
1256 if (need > have) {
1257 if (eof > 1) {
1258 ret = -1;
1259 goto out_finish;
1260 }
1261 break;
1262 }
1263
1264 for (off = 0;
1265 off < LZO_HEADER + data[thr].cmp_len;
1266 off += PAGE_SIZE) {
1267 memcpy(data[thr].cmp + off,
1268 page[pg], PAGE_SIZE);
1269 have--;
1270 want++;
1271 if (++pg >= ring_size)
1272 pg = 0;
1273 }
1274
1275 atomic_set(&data[thr].ready, 1);
1276 wake_up(&data[thr].go);
1277 }
1278
1279 /*
1280 * Wait for more data while we are decompressing.
1281 */
1282 if (have < LZO_CMP_PAGES && asked) {
1283 ret = hib_wait_on_bio_chain(&bio);
1284 if (ret)
1285 goto out_finish;
1286 have += asked;
1287 asked = 0;
1288 if (eof)
1289 eof = 2;
1290 }
1291
1292 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1293 wait_event(data[thr].done,
1294 atomic_read(&data[thr].stop));
1295 atomic_set(&data[thr].stop, 0);
1296
1297 ret = data[thr].ret;
1298
1299 if (ret < 0) {
1300 printk(KERN_ERR
1301 "PM: LZO decompression failed\n");
1302 goto out_finish;
1303 }
1304
1305 if (unlikely(!data[thr].unc_len ||
1306 data[thr].unc_len > LZO_UNC_SIZE ||
1307 data[thr].unc_len & (PAGE_SIZE - 1))) {
1308 printk(KERN_ERR
1309 "PM: Invalid LZO uncompressed length\n");
1310 ret = -1;
1311 goto out_finish;
1312 }
1313
1314 for (off = 0;
1315 off < data[thr].unc_len; off += PAGE_SIZE) {
1316 memcpy(data_of(*snapshot),
1317 data[thr].unc + off, PAGE_SIZE);
1318
1319 if (!(nr_pages % m))
1320 printk(KERN_INFO
1321 "PM: Image loading progress: "
1322 "%3d%%\n",
1323 nr_pages / m * 10);
1324 nr_pages++;
1325
1326 ret = snapshot_write_next(snapshot);
1327 if (ret <= 0) {
1328 crc->run_threads = thr + 1;
1329 atomic_set(&crc->ready, 1);
1330 wake_up(&crc->go);
1331 goto out_finish;
1332 }
1333 }
1334 }
1335
1336 crc->run_threads = thr;
1337 atomic_set(&crc->ready, 1);
1338 wake_up(&crc->go);
1339 }
1340
1341out_finish:
1342 if (crc->run_threads) {
1343 wait_event(crc->done, atomic_read(&crc->stop));
1344 atomic_set(&crc->stop, 0);
1345 }
1346 do_gettimeofday(&stop);
1347 if (!ret) {
1348 printk(KERN_INFO "PM: Image loading done.\n");
1349 snapshot_write_finalize(snapshot);
1350 if (!snapshot_image_loaded(snapshot))
1351 ret = -ENODATA;
1352 if (!ret) {
1353 if (swsusp_header->flags & SF_CRC32_MODE) {
1354 if(handle->crc32 != swsusp_header->crc32) {
1355 printk(KERN_ERR
1356 "PM: Invalid image CRC32!\n");
1357 ret = -ENODATA;
1358 }
1359 }
1360 }
1361 }
1362 swsusp_show_speed(&start, &stop, nr_to_read, "Read");
1363out_clean:
1364 for (i = 0; i < ring_size; i++)
1365 free_page((unsigned long)page[i]);
1366 if (crc) {
1367 if (crc->thr)
1368 kthread_stop(crc->thr);
1369 kfree(crc);
1370 }
1371 if (data) {
1372 for (thr = 0; thr < nr_threads; thr++)
1373 if (data[thr].thr)
1374 kthread_stop(data[thr].thr);
1375 vfree(data);
1376 }
1377 if (page) vfree(page);
1378
1379 return ret;
1380}
1381
1382/**
1383 * swsusp_read - read the hibernation image.
1384 * @flags_p: flags passed by the "frozen" kernel in the image header should
1385 * be written into this memory location
1386 */
1387
1388int swsusp_read(unsigned int *flags_p)
1389{
1390 int error;
1391 struct swap_map_handle handle;
1392 struct snapshot_handle snapshot;
1393 struct swsusp_info *header;
1394
1395 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1396 error = snapshot_write_next(&snapshot);
1397 if (error < PAGE_SIZE)
1398 return error < 0 ? error : -EFAULT;
1399 header = (struct swsusp_info *)data_of(snapshot);
1400 error = get_swap_reader(&handle, flags_p);
1401 if (error)
1402 goto end;
1403 if (!error)
1404 error = swap_read_page(&handle, header, NULL);
1405 if (!error) {
1406 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1407 load_image(&handle, &snapshot, header->pages - 1) :
1408 load_image_lzo(&handle, &snapshot, header->pages - 1);
1409 }
1410 swap_reader_finish(&handle);
1411end:
1412 if (!error)
1413 pr_debug("PM: Image successfully loaded\n");
1414 else
1415 pr_debug("PM: Error %d resuming\n", error);
1416 return error;
1417}
1418
1419/**
1420 * swsusp_check - Check for swsusp signature in the resume device
1421 */
1422
1423int swsusp_check(void)
1424{
1425 int error;
1426
1427 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1428 FMODE_READ, NULL);
1429 if (!IS_ERR(hib_resume_bdev)) {
1430 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1431 clear_page(swsusp_header);
1432 error = hib_bio_read_page(swsusp_resume_block,
1433 swsusp_header, NULL);
1434 if (error)
1435 goto put;
1436
1437 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1438 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1439 /* Reset swap signature now */
1440 error = hib_bio_write_page(swsusp_resume_block,
1441 swsusp_header, NULL);
1442 } else {
1443 error = -EINVAL;
1444 }
1445
1446put:
1447 if (error)
1448 blkdev_put(hib_resume_bdev, FMODE_READ);
1449 else
1450 pr_debug("PM: Image signature found, resuming\n");
1451 } else {
1452 error = PTR_ERR(hib_resume_bdev);
1453 }
1454
1455 if (error)
1456 pr_debug("PM: Image not found (code %d)\n", error);
1457
1458 return error;
1459}
1460
1461/**
1462 * swsusp_close - close swap device.
1463 */
1464
1465void swsusp_close(fmode_t mode)
1466{
1467 if (IS_ERR(hib_resume_bdev)) {
1468 pr_debug("PM: Image device not initialised\n");
1469 return;
1470 }
1471
1472 blkdev_put(hib_resume_bdev, mode);
1473}
1474
1475/**
1476 * swsusp_unmark - Unmark swsusp signature in the resume device
1477 */
1478
1479#ifdef CONFIG_SUSPEND
1480int swsusp_unmark(void)
1481{
1482 int error;
1483
1484 hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
1485 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1486 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1487 error = hib_bio_write_page(swsusp_resume_block,
1488 swsusp_header, NULL);
1489 } else {
1490 printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
1491 error = -ENODEV;
1492 }
1493
1494 /*
1495 * We just returned from suspend, we don't need the image any more.
1496 */
1497 free_all_swap_pages(root_swap);
1498
1499 return error;
1500}
1501#endif
1502
1503static int swsusp_header_init(void)
1504{
1505 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1506 if (!swsusp_header)
1507 panic("Could not allocate memory for swsusp_header\n");
1508 return 0;
1509}
1510
1511core_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/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
37u32 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 */
44static bool clean_pages_on_read;
45static 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 */
66static 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 */
75static inline unsigned long reqd_free_pages(void)
76{
77 return low_free_pages() / 2;
78}
79
80struct swap_map_page {
81 sector_t entries[MAP_PAGE_ENTRIES];
82 sector_t next_swap;
83};
84
85struct 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
95struct 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
105struct 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
116static 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
123struct swsusp_extent {
124 struct rb_node node;
125 unsigned long start;
126 unsigned long end;
127};
128
129static struct rb_root swsusp_extents = RB_ROOT;
130
131static 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
177sector_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
197void 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
213int swsusp_swap_in_use(void)
214{
215 return (swsusp_extents.rb_node != NULL);
216}
217
218/*
219 * General things
220 */
221
222static unsigned short root_swap = 0xffff;
223static struct file *hib_resume_bdev_file;
224
225struct 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
232static 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
240static void hib_finish_batch(struct hib_bio_batch *hb)
241{
242 blk_finish_plug(&hb->plug);
243}
244
245static 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
270static 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
301static 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 */
314static 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 */
345unsigned 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 */
353static 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
380static 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
414static 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
421static 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;
445err_rel:
446 release_swap_writer(handle);
447err_close:
448 swsusp_close();
449 return ret;
450}
451
452static 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
492static 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
500static 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
547static 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 */
594struct 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 */
609static 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 */
636struct 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 */
651static atomic_t compressed_size = ATOMIC_INIT(0);
652
653/*
654 * Compression function that runs in its own thread.
655 */
656static 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 */
692static 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
880out_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
891out_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
919static 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
940int 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 }
976out_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
986static 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
1000static 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
1046static 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
1075static 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
1088static 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 */
1143struct 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 */
1160static 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 */
1198static 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
1476out_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");
1497out_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
1526int 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);
1549end:
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
1557static 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
1564int 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
1595put:
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
1614void 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
1629int 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
1654static 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
1662core_initcall(swsusp_header_init);