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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/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#include <linux/ktime.h>
34
35#include "power.h"
36
37#define HIBERNATE_SIG "S1SUSPEND"
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)];
108 u32 crc32;
109 sector_t image;
110 unsigned int flags; /* Flags to pass to the "boot" kernel */
111 char orig_sig[10];
112 char sig[10];
113} __packed;
114
115static struct swsusp_header *swsusp_header;
116
117/**
118 * The following functions are used for tracing the allocated
119 * swap pages, so that they can be freed in case of an error.
120 */
121
122struct swsusp_extent {
123 struct rb_node node;
124 unsigned long start;
125 unsigned long end;
126};
127
128static struct rb_root swsusp_extents = RB_ROOT;
129
130static int swsusp_extents_insert(unsigned long swap_offset)
131{
132 struct rb_node **new = &(swsusp_extents.rb_node);
133 struct rb_node *parent = NULL;
134 struct swsusp_extent *ext;
135
136 /* Figure out where to put the new node */
137 while (*new) {
138 ext = rb_entry(*new, struct swsusp_extent, node);
139 parent = *new;
140 if (swap_offset < ext->start) {
141 /* Try to merge */
142 if (swap_offset == ext->start - 1) {
143 ext->start--;
144 return 0;
145 }
146 new = &((*new)->rb_left);
147 } else if (swap_offset > ext->end) {
148 /* Try to merge */
149 if (swap_offset == ext->end + 1) {
150 ext->end++;
151 return 0;
152 }
153 new = &((*new)->rb_right);
154 } else {
155 /* It already is in the tree */
156 return -EINVAL;
157 }
158 }
159 /* Add the new node and rebalance the tree. */
160 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
161 if (!ext)
162 return -ENOMEM;
163
164 ext->start = swap_offset;
165 ext->end = swap_offset;
166 rb_link_node(&ext->node, parent, new);
167 rb_insert_color(&ext->node, &swsusp_extents);
168 return 0;
169}
170
171/**
172 * alloc_swapdev_block - allocate a swap page and register that it has
173 * been allocated, so that it can be freed in case of an error.
174 */
175
176sector_t alloc_swapdev_block(int swap)
177{
178 unsigned long offset;
179
180 offset = swp_offset(get_swap_page_of_type(swap));
181 if (offset) {
182 if (swsusp_extents_insert(offset))
183 swap_free(swp_entry(swap, offset));
184 else
185 return swapdev_block(swap, offset);
186 }
187 return 0;
188}
189
190/**
191 * free_all_swap_pages - free swap pages allocated for saving image data.
192 * It also frees the extents used to register which swap entries had been
193 * allocated.
194 */
195
196void free_all_swap_pages(int swap)
197{
198 struct rb_node *node;
199
200 while ((node = swsusp_extents.rb_node)) {
201 struct swsusp_extent *ext;
202 unsigned long offset;
203
204 ext = rb_entry(node, struct swsusp_extent, node);
205 rb_erase(node, &swsusp_extents);
206 for (offset = ext->start; offset <= ext->end; offset++)
207 swap_free(swp_entry(swap, offset));
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 block_device *hib_resume_bdev;
224
225struct hib_bio_batch {
226 atomic_t count;
227 wait_queue_head_t wait;
228 blk_status_t error;
229};
230
231static void hib_init_batch(struct hib_bio_batch *hb)
232{
233 atomic_set(&hb->count, 0);
234 init_waitqueue_head(&hb->wait);
235 hb->error = BLK_STS_OK;
236}
237
238static void hib_end_io(struct bio *bio)
239{
240 struct hib_bio_batch *hb = bio->bi_private;
241 struct page *page = bio_first_page_all(bio);
242
243 if (bio->bi_status) {
244 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
245 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
246 (unsigned long long)bio->bi_iter.bi_sector);
247 }
248
249 if (bio_data_dir(bio) == WRITE)
250 put_page(page);
251 else if (clean_pages_on_read)
252 flush_icache_range((unsigned long)page_address(page),
253 (unsigned long)page_address(page) + PAGE_SIZE);
254
255 if (bio->bi_status && !hb->error)
256 hb->error = bio->bi_status;
257 if (atomic_dec_and_test(&hb->count))
258 wake_up(&hb->wait);
259
260 bio_put(bio);
261}
262
263static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
264 struct hib_bio_batch *hb)
265{
266 struct page *page = virt_to_page(addr);
267 struct bio *bio;
268 int error = 0;
269
270 bio = bio_alloc(GFP_NOIO | __GFP_HIGH, 1);
271 bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
272 bio_set_dev(bio, hib_resume_bdev);
273 bio_set_op_attrs(bio, op, op_flags);
274
275 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
276 pr_err("Adding page to bio failed at %llu\n",
277 (unsigned long long)bio->bi_iter.bi_sector);
278 bio_put(bio);
279 return -EFAULT;
280 }
281
282 if (hb) {
283 bio->bi_end_io = hib_end_io;
284 bio->bi_private = hb;
285 atomic_inc(&hb->count);
286 submit_bio(bio);
287 } else {
288 error = submit_bio_wait(bio);
289 bio_put(bio);
290 }
291
292 return error;
293}
294
295static blk_status_t hib_wait_io(struct hib_bio_batch *hb)
296{
297 wait_event(hb->wait, atomic_read(&hb->count) == 0);
298 return blk_status_to_errno(hb->error);
299}
300
301/*
302 * Saving part
303 */
304
305static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
306{
307 int error;
308
309 hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
310 swsusp_header, NULL);
311 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
312 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
313 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
314 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
315 swsusp_header->image = handle->first_sector;
316 swsusp_header->flags = flags;
317 if (flags & SF_CRC32_MODE)
318 swsusp_header->crc32 = handle->crc32;
319 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
320 swsusp_resume_block, swsusp_header, NULL);
321 } else {
322 pr_err("Swap header not found!\n");
323 error = -ENODEV;
324 }
325 return error;
326}
327
328/**
329 * swsusp_swap_check - check if the resume device is a swap device
330 * and get its index (if so)
331 *
332 * This is called before saving image
333 */
334static int swsusp_swap_check(void)
335{
336 int res;
337
338 res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
339 &hib_resume_bdev);
340 if (res < 0)
341 return res;
342
343 root_swap = res;
344 res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
345 if (res)
346 return res;
347
348 res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
349 if (res < 0)
350 blkdev_put(hib_resume_bdev, FMODE_WRITE);
351
352 /*
353 * Update the resume device to the one actually used,
354 * so the test_resume mode can use it in case it is
355 * invoked from hibernate() to test the snapshot.
356 */
357 swsusp_resume_device = hib_resume_bdev->bd_dev;
358 return res;
359}
360
361/**
362 * write_page - Write one page to given swap location.
363 * @buf: Address we're writing.
364 * @offset: Offset of the swap page we're writing to.
365 * @hb: bio completion batch
366 */
367
368static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
369{
370 void *src;
371 int ret;
372
373 if (!offset)
374 return -ENOSPC;
375
376 if (hb) {
377 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
378 __GFP_NORETRY);
379 if (src) {
380 copy_page(src, buf);
381 } else {
382 ret = hib_wait_io(hb); /* Free pages */
383 if (ret)
384 return ret;
385 src = (void *)__get_free_page(GFP_NOIO |
386 __GFP_NOWARN |
387 __GFP_NORETRY);
388 if (src) {
389 copy_page(src, buf);
390 } else {
391 WARN_ON_ONCE(1);
392 hb = NULL; /* Go synchronous */
393 src = buf;
394 }
395 }
396 } else {
397 src = buf;
398 }
399 return hib_submit_io(REQ_OP_WRITE, REQ_SYNC, offset, src, hb);
400}
401
402static void release_swap_writer(struct swap_map_handle *handle)
403{
404 if (handle->cur)
405 free_page((unsigned long)handle->cur);
406 handle->cur = NULL;
407}
408
409static int get_swap_writer(struct swap_map_handle *handle)
410{
411 int ret;
412
413 ret = swsusp_swap_check();
414 if (ret) {
415 if (ret != -ENOSPC)
416 pr_err("Cannot find swap device, try swapon -a\n");
417 return ret;
418 }
419 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
420 if (!handle->cur) {
421 ret = -ENOMEM;
422 goto err_close;
423 }
424 handle->cur_swap = alloc_swapdev_block(root_swap);
425 if (!handle->cur_swap) {
426 ret = -ENOSPC;
427 goto err_rel;
428 }
429 handle->k = 0;
430 handle->reqd_free_pages = reqd_free_pages();
431 handle->first_sector = handle->cur_swap;
432 return 0;
433err_rel:
434 release_swap_writer(handle);
435err_close:
436 swsusp_close(FMODE_WRITE);
437 return ret;
438}
439
440static int swap_write_page(struct swap_map_handle *handle, void *buf,
441 struct hib_bio_batch *hb)
442{
443 int error = 0;
444 sector_t offset;
445
446 if (!handle->cur)
447 return -EINVAL;
448 offset = alloc_swapdev_block(root_swap);
449 error = write_page(buf, offset, hb);
450 if (error)
451 return error;
452 handle->cur->entries[handle->k++] = offset;
453 if (handle->k >= MAP_PAGE_ENTRIES) {
454 offset = alloc_swapdev_block(root_swap);
455 if (!offset)
456 return -ENOSPC;
457 handle->cur->next_swap = offset;
458 error = write_page(handle->cur, handle->cur_swap, hb);
459 if (error)
460 goto out;
461 clear_page(handle->cur);
462 handle->cur_swap = offset;
463 handle->k = 0;
464
465 if (hb && low_free_pages() <= handle->reqd_free_pages) {
466 error = hib_wait_io(hb);
467 if (error)
468 goto out;
469 /*
470 * Recalculate the number of required free pages, to
471 * make sure we never take more than half.
472 */
473 handle->reqd_free_pages = reqd_free_pages();
474 }
475 }
476 out:
477 return error;
478}
479
480static int flush_swap_writer(struct swap_map_handle *handle)
481{
482 if (handle->cur && handle->cur_swap)
483 return write_page(handle->cur, handle->cur_swap, NULL);
484 else
485 return -EINVAL;
486}
487
488static int swap_writer_finish(struct swap_map_handle *handle,
489 unsigned int flags, int error)
490{
491 if (!error) {
492 flush_swap_writer(handle);
493 pr_info("S");
494 error = mark_swapfiles(handle, flags);
495 pr_cont("|\n");
496 }
497
498 if (error)
499 free_all_swap_pages(root_swap);
500 release_swap_writer(handle);
501 swsusp_close(FMODE_WRITE);
502
503 return error;
504}
505
506/* We need to remember how much compressed data we need to read. */
507#define LZO_HEADER sizeof(size_t)
508
509/* Number of pages/bytes we'll compress at one time. */
510#define LZO_UNC_PAGES 32
511#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE)
512
513/* Number of pages/bytes we need for compressed data (worst case). */
514#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
515 LZO_HEADER, PAGE_SIZE)
516#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE)
517
518/* Maximum number of threads for compression/decompression. */
519#define LZO_THREADS 3
520
521/* Minimum/maximum number of pages for read buffering. */
522#define LZO_MIN_RD_PAGES 1024
523#define LZO_MAX_RD_PAGES 8192
524
525
526/**
527 * save_image - save the suspend image data
528 */
529
530static int save_image(struct swap_map_handle *handle,
531 struct snapshot_handle *snapshot,
532 unsigned int nr_to_write)
533{
534 unsigned int m;
535 int ret;
536 int nr_pages;
537 int err2;
538 struct hib_bio_batch hb;
539 ktime_t start;
540 ktime_t stop;
541
542 hib_init_batch(&hb);
543
544 pr_info("Saving image data pages (%u pages)...\n",
545 nr_to_write);
546 m = nr_to_write / 10;
547 if (!m)
548 m = 1;
549 nr_pages = 0;
550 start = ktime_get();
551 while (1) {
552 ret = snapshot_read_next(snapshot);
553 if (ret <= 0)
554 break;
555 ret = swap_write_page(handle, data_of(*snapshot), &hb);
556 if (ret)
557 break;
558 if (!(nr_pages % m))
559 pr_info("Image saving progress: %3d%%\n",
560 nr_pages / m * 10);
561 nr_pages++;
562 }
563 err2 = hib_wait_io(&hb);
564 stop = ktime_get();
565 if (!ret)
566 ret = err2;
567 if (!ret)
568 pr_info("Image saving done\n");
569 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
570 return ret;
571}
572
573/**
574 * Structure used for CRC32.
575 */
576struct crc_data {
577 struct task_struct *thr; /* thread */
578 atomic_t ready; /* ready to start flag */
579 atomic_t stop; /* ready to stop flag */
580 unsigned run_threads; /* nr current threads */
581 wait_queue_head_t go; /* start crc update */
582 wait_queue_head_t done; /* crc update done */
583 u32 *crc32; /* points to handle's crc32 */
584 size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */
585 unsigned char *unc[LZO_THREADS]; /* uncompressed data */
586};
587
588/**
589 * CRC32 update function that runs in its own thread.
590 */
591static int crc32_threadfn(void *data)
592{
593 struct crc_data *d = data;
594 unsigned i;
595
596 while (1) {
597 wait_event(d->go, atomic_read(&d->ready) ||
598 kthread_should_stop());
599 if (kthread_should_stop()) {
600 d->thr = NULL;
601 atomic_set(&d->stop, 1);
602 wake_up(&d->done);
603 break;
604 }
605 atomic_set(&d->ready, 0);
606
607 for (i = 0; i < d->run_threads; i++)
608 *d->crc32 = crc32_le(*d->crc32,
609 d->unc[i], *d->unc_len[i]);
610 atomic_set(&d->stop, 1);
611 wake_up(&d->done);
612 }
613 return 0;
614}
615/**
616 * Structure used for LZO data compression.
617 */
618struct cmp_data {
619 struct task_struct *thr; /* thread */
620 atomic_t ready; /* ready to start flag */
621 atomic_t stop; /* ready to stop flag */
622 int ret; /* return code */
623 wait_queue_head_t go; /* start compression */
624 wait_queue_head_t done; /* compression done */
625 size_t unc_len; /* uncompressed length */
626 size_t cmp_len; /* compressed length */
627 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
628 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
629 unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
630};
631
632/**
633 * Compression function that runs in its own thread.
634 */
635static int lzo_compress_threadfn(void *data)
636{
637 struct cmp_data *d = data;
638
639 while (1) {
640 wait_event(d->go, atomic_read(&d->ready) ||
641 kthread_should_stop());
642 if (kthread_should_stop()) {
643 d->thr = NULL;
644 d->ret = -1;
645 atomic_set(&d->stop, 1);
646 wake_up(&d->done);
647 break;
648 }
649 atomic_set(&d->ready, 0);
650
651 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
652 d->cmp + LZO_HEADER, &d->cmp_len,
653 d->wrk);
654 atomic_set(&d->stop, 1);
655 wake_up(&d->done);
656 }
657 return 0;
658}
659
660/**
661 * save_image_lzo - Save the suspend image data compressed with LZO.
662 * @handle: Swap map handle to use for saving the image.
663 * @snapshot: Image to read data from.
664 * @nr_to_write: Number of pages to save.
665 */
666static int save_image_lzo(struct swap_map_handle *handle,
667 struct snapshot_handle *snapshot,
668 unsigned int nr_to_write)
669{
670 unsigned int m;
671 int ret = 0;
672 int nr_pages;
673 int err2;
674 struct hib_bio_batch hb;
675 ktime_t start;
676 ktime_t stop;
677 size_t off;
678 unsigned thr, run_threads, nr_threads;
679 unsigned char *page = NULL;
680 struct cmp_data *data = NULL;
681 struct crc_data *crc = NULL;
682
683 hib_init_batch(&hb);
684
685 /*
686 * We'll limit the number of threads for compression to limit memory
687 * footprint.
688 */
689 nr_threads = num_online_cpus() - 1;
690 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
691
692 page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
693 if (!page) {
694 pr_err("Failed to allocate LZO page\n");
695 ret = -ENOMEM;
696 goto out_clean;
697 }
698
699 data = vmalloc(array_size(nr_threads, sizeof(*data)));
700 if (!data) {
701 pr_err("Failed to allocate LZO data\n");
702 ret = -ENOMEM;
703 goto out_clean;
704 }
705 for (thr = 0; thr < nr_threads; thr++)
706 memset(&data[thr], 0, offsetof(struct cmp_data, go));
707
708 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
709 if (!crc) {
710 pr_err("Failed to allocate crc\n");
711 ret = -ENOMEM;
712 goto out_clean;
713 }
714 memset(crc, 0, offsetof(struct crc_data, go));
715
716 /*
717 * Start the compression threads.
718 */
719 for (thr = 0; thr < nr_threads; thr++) {
720 init_waitqueue_head(&data[thr].go);
721 init_waitqueue_head(&data[thr].done);
722
723 data[thr].thr = kthread_run(lzo_compress_threadfn,
724 &data[thr],
725 "image_compress/%u", thr);
726 if (IS_ERR(data[thr].thr)) {
727 data[thr].thr = NULL;
728 pr_err("Cannot start compression threads\n");
729 ret = -ENOMEM;
730 goto out_clean;
731 }
732 }
733
734 /*
735 * Start the CRC32 thread.
736 */
737 init_waitqueue_head(&crc->go);
738 init_waitqueue_head(&crc->done);
739
740 handle->crc32 = 0;
741 crc->crc32 = &handle->crc32;
742 for (thr = 0; thr < nr_threads; thr++) {
743 crc->unc[thr] = data[thr].unc;
744 crc->unc_len[thr] = &data[thr].unc_len;
745 }
746
747 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
748 if (IS_ERR(crc->thr)) {
749 crc->thr = NULL;
750 pr_err("Cannot start CRC32 thread\n");
751 ret = -ENOMEM;
752 goto out_clean;
753 }
754
755 /*
756 * Adjust the number of required free pages after all allocations have
757 * been done. We don't want to run out of pages when writing.
758 */
759 handle->reqd_free_pages = reqd_free_pages();
760
761 pr_info("Using %u thread(s) for compression\n", nr_threads);
762 pr_info("Compressing and saving image data (%u pages)...\n",
763 nr_to_write);
764 m = nr_to_write / 10;
765 if (!m)
766 m = 1;
767 nr_pages = 0;
768 start = ktime_get();
769 for (;;) {
770 for (thr = 0; thr < nr_threads; thr++) {
771 for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
772 ret = snapshot_read_next(snapshot);
773 if (ret < 0)
774 goto out_finish;
775
776 if (!ret)
777 break;
778
779 memcpy(data[thr].unc + off,
780 data_of(*snapshot), PAGE_SIZE);
781
782 if (!(nr_pages % m))
783 pr_info("Image saving progress: %3d%%\n",
784 nr_pages / m * 10);
785 nr_pages++;
786 }
787 if (!off)
788 break;
789
790 data[thr].unc_len = off;
791
792 atomic_set(&data[thr].ready, 1);
793 wake_up(&data[thr].go);
794 }
795
796 if (!thr)
797 break;
798
799 crc->run_threads = thr;
800 atomic_set(&crc->ready, 1);
801 wake_up(&crc->go);
802
803 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
804 wait_event(data[thr].done,
805 atomic_read(&data[thr].stop));
806 atomic_set(&data[thr].stop, 0);
807
808 ret = data[thr].ret;
809
810 if (ret < 0) {
811 pr_err("LZO compression failed\n");
812 goto out_finish;
813 }
814
815 if (unlikely(!data[thr].cmp_len ||
816 data[thr].cmp_len >
817 lzo1x_worst_compress(data[thr].unc_len))) {
818 pr_err("Invalid LZO compressed length\n");
819 ret = -1;
820 goto out_finish;
821 }
822
823 *(size_t *)data[thr].cmp = data[thr].cmp_len;
824
825 /*
826 * Given we are writing one page at a time to disk, we
827 * copy that much from the buffer, although the last
828 * bit will likely be smaller than full page. This is
829 * OK - we saved the length of the compressed data, so
830 * any garbage at the end will be discarded when we
831 * read it.
832 */
833 for (off = 0;
834 off < LZO_HEADER + data[thr].cmp_len;
835 off += PAGE_SIZE) {
836 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
837
838 ret = swap_write_page(handle, page, &hb);
839 if (ret)
840 goto out_finish;
841 }
842 }
843
844 wait_event(crc->done, atomic_read(&crc->stop));
845 atomic_set(&crc->stop, 0);
846 }
847
848out_finish:
849 err2 = hib_wait_io(&hb);
850 stop = ktime_get();
851 if (!ret)
852 ret = err2;
853 if (!ret)
854 pr_info("Image saving done\n");
855 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
856out_clean:
857 if (crc) {
858 if (crc->thr)
859 kthread_stop(crc->thr);
860 kfree(crc);
861 }
862 if (data) {
863 for (thr = 0; thr < nr_threads; thr++)
864 if (data[thr].thr)
865 kthread_stop(data[thr].thr);
866 vfree(data);
867 }
868 if (page) free_page((unsigned long)page);
869
870 return ret;
871}
872
873/**
874 * enough_swap - Make sure we have enough swap to save the image.
875 *
876 * Returns TRUE or FALSE after checking the total amount of swap
877 * space avaiable from the resume partition.
878 */
879
880static int enough_swap(unsigned int nr_pages)
881{
882 unsigned int free_swap = count_swap_pages(root_swap, 1);
883 unsigned int required;
884
885 pr_debug("Free swap pages: %u\n", free_swap);
886
887 required = PAGES_FOR_IO + nr_pages;
888 return free_swap > required;
889}
890
891/**
892 * swsusp_write - Write entire image and metadata.
893 * @flags: flags to pass to the "boot" kernel in the image header
894 *
895 * It is important _NOT_ to umount filesystems at this point. We want
896 * them synced (in case something goes wrong) but we DO not want to mark
897 * filesystem clean: it is not. (And it does not matter, if we resume
898 * correctly, we'll mark system clean, anyway.)
899 */
900
901int swsusp_write(unsigned int flags)
902{
903 struct swap_map_handle handle;
904 struct snapshot_handle snapshot;
905 struct swsusp_info *header;
906 unsigned long pages;
907 int error;
908
909 pages = snapshot_get_image_size();
910 error = get_swap_writer(&handle);
911 if (error) {
912 pr_err("Cannot get swap writer\n");
913 return error;
914 }
915 if (flags & SF_NOCOMPRESS_MODE) {
916 if (!enough_swap(pages)) {
917 pr_err("Not enough free swap\n");
918 error = -ENOSPC;
919 goto out_finish;
920 }
921 }
922 memset(&snapshot, 0, sizeof(struct snapshot_handle));
923 error = snapshot_read_next(&snapshot);
924 if (error < (int)PAGE_SIZE) {
925 if (error >= 0)
926 error = -EFAULT;
927
928 goto out_finish;
929 }
930 header = (struct swsusp_info *)data_of(snapshot);
931 error = swap_write_page(&handle, header, NULL);
932 if (!error) {
933 error = (flags & SF_NOCOMPRESS_MODE) ?
934 save_image(&handle, &snapshot, pages - 1) :
935 save_image_lzo(&handle, &snapshot, pages - 1);
936 }
937out_finish:
938 error = swap_writer_finish(&handle, flags, error);
939 return error;
940}
941
942/**
943 * The following functions allow us to read data using a swap map
944 * in a file-alike way
945 */
946
947static void release_swap_reader(struct swap_map_handle *handle)
948{
949 struct swap_map_page_list *tmp;
950
951 while (handle->maps) {
952 if (handle->maps->map)
953 free_page((unsigned long)handle->maps->map);
954 tmp = handle->maps;
955 handle->maps = handle->maps->next;
956 kfree(tmp);
957 }
958 handle->cur = NULL;
959}
960
961static int get_swap_reader(struct swap_map_handle *handle,
962 unsigned int *flags_p)
963{
964 int error;
965 struct swap_map_page_list *tmp, *last;
966 sector_t offset;
967
968 *flags_p = swsusp_header->flags;
969
970 if (!swsusp_header->image) /* how can this happen? */
971 return -EINVAL;
972
973 handle->cur = NULL;
974 last = handle->maps = NULL;
975 offset = swsusp_header->image;
976 while (offset) {
977 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
978 if (!tmp) {
979 release_swap_reader(handle);
980 return -ENOMEM;
981 }
982 if (!handle->maps)
983 handle->maps = tmp;
984 if (last)
985 last->next = tmp;
986 last = tmp;
987
988 tmp->map = (struct swap_map_page *)
989 __get_free_page(GFP_NOIO | __GFP_HIGH);
990 if (!tmp->map) {
991 release_swap_reader(handle);
992 return -ENOMEM;
993 }
994
995 error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL);
996 if (error) {
997 release_swap_reader(handle);
998 return error;
999 }
1000 offset = tmp->map->next_swap;
1001 }
1002 handle->k = 0;
1003 handle->cur = handle->maps->map;
1004 return 0;
1005}
1006
1007static int swap_read_page(struct swap_map_handle *handle, void *buf,
1008 struct hib_bio_batch *hb)
1009{
1010 sector_t offset;
1011 int error;
1012 struct swap_map_page_list *tmp;
1013
1014 if (!handle->cur)
1015 return -EINVAL;
1016 offset = handle->cur->entries[handle->k];
1017 if (!offset)
1018 return -EFAULT;
1019 error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb);
1020 if (error)
1021 return error;
1022 if (++handle->k >= MAP_PAGE_ENTRIES) {
1023 handle->k = 0;
1024 free_page((unsigned long)handle->maps->map);
1025 tmp = handle->maps;
1026 handle->maps = handle->maps->next;
1027 kfree(tmp);
1028 if (!handle->maps)
1029 release_swap_reader(handle);
1030 else
1031 handle->cur = handle->maps->map;
1032 }
1033 return error;
1034}
1035
1036static int swap_reader_finish(struct swap_map_handle *handle)
1037{
1038 release_swap_reader(handle);
1039
1040 return 0;
1041}
1042
1043/**
1044 * load_image - load the image using the swap map handle
1045 * @handle and the snapshot handle @snapshot
1046 * (assume there are @nr_pages pages to load)
1047 */
1048
1049static int load_image(struct swap_map_handle *handle,
1050 struct snapshot_handle *snapshot,
1051 unsigned int nr_to_read)
1052{
1053 unsigned int m;
1054 int ret = 0;
1055 ktime_t start;
1056 ktime_t stop;
1057 struct hib_bio_batch hb;
1058 int err2;
1059 unsigned nr_pages;
1060
1061 hib_init_batch(&hb);
1062
1063 clean_pages_on_read = true;
1064 pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1065 m = nr_to_read / 10;
1066 if (!m)
1067 m = 1;
1068 nr_pages = 0;
1069 start = ktime_get();
1070 for ( ; ; ) {
1071 ret = snapshot_write_next(snapshot);
1072 if (ret <= 0)
1073 break;
1074 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1075 if (ret)
1076 break;
1077 if (snapshot->sync_read)
1078 ret = hib_wait_io(&hb);
1079 if (ret)
1080 break;
1081 if (!(nr_pages % m))
1082 pr_info("Image loading progress: %3d%%\n",
1083 nr_pages / m * 10);
1084 nr_pages++;
1085 }
1086 err2 = hib_wait_io(&hb);
1087 stop = ktime_get();
1088 if (!ret)
1089 ret = err2;
1090 if (!ret) {
1091 pr_info("Image loading done\n");
1092 snapshot_write_finalize(snapshot);
1093 if (!snapshot_image_loaded(snapshot))
1094 ret = -ENODATA;
1095 }
1096 swsusp_show_speed(start, stop, nr_to_read, "Read");
1097 return ret;
1098}
1099
1100/**
1101 * Structure used for LZO data decompression.
1102 */
1103struct dec_data {
1104 struct task_struct *thr; /* thread */
1105 atomic_t ready; /* ready to start flag */
1106 atomic_t stop; /* ready to stop flag */
1107 int ret; /* return code */
1108 wait_queue_head_t go; /* start decompression */
1109 wait_queue_head_t done; /* decompression done */
1110 size_t unc_len; /* uncompressed length */
1111 size_t cmp_len; /* compressed length */
1112 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
1113 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
1114};
1115
1116/**
1117 * Deompression function that runs in its own thread.
1118 */
1119static int lzo_decompress_threadfn(void *data)
1120{
1121 struct dec_data *d = data;
1122
1123 while (1) {
1124 wait_event(d->go, atomic_read(&d->ready) ||
1125 kthread_should_stop());
1126 if (kthread_should_stop()) {
1127 d->thr = NULL;
1128 d->ret = -1;
1129 atomic_set(&d->stop, 1);
1130 wake_up(&d->done);
1131 break;
1132 }
1133 atomic_set(&d->ready, 0);
1134
1135 d->unc_len = LZO_UNC_SIZE;
1136 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1137 d->unc, &d->unc_len);
1138 if (clean_pages_on_decompress)
1139 flush_icache_range((unsigned long)d->unc,
1140 (unsigned long)d->unc + d->unc_len);
1141
1142 atomic_set(&d->stop, 1);
1143 wake_up(&d->done);
1144 }
1145 return 0;
1146}
1147
1148/**
1149 * load_image_lzo - Load compressed image data and decompress them with LZO.
1150 * @handle: Swap map handle to use for loading data.
1151 * @snapshot: Image to copy uncompressed data into.
1152 * @nr_to_read: Number of pages to load.
1153 */
1154static int load_image_lzo(struct swap_map_handle *handle,
1155 struct snapshot_handle *snapshot,
1156 unsigned int nr_to_read)
1157{
1158 unsigned int m;
1159 int ret = 0;
1160 int eof = 0;
1161 struct hib_bio_batch hb;
1162 ktime_t start;
1163 ktime_t stop;
1164 unsigned nr_pages;
1165 size_t off;
1166 unsigned i, thr, run_threads, nr_threads;
1167 unsigned ring = 0, pg = 0, ring_size = 0,
1168 have = 0, want, need, asked = 0;
1169 unsigned long read_pages = 0;
1170 unsigned char **page = NULL;
1171 struct dec_data *data = NULL;
1172 struct crc_data *crc = NULL;
1173
1174 hib_init_batch(&hb);
1175
1176 /*
1177 * We'll limit the number of threads for decompression to limit memory
1178 * footprint.
1179 */
1180 nr_threads = num_online_cpus() - 1;
1181 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1182
1183 page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
1184 if (!page) {
1185 pr_err("Failed to allocate LZO page\n");
1186 ret = -ENOMEM;
1187 goto out_clean;
1188 }
1189
1190 data = vmalloc(array_size(nr_threads, sizeof(*data)));
1191 if (!data) {
1192 pr_err("Failed to allocate LZO data\n");
1193 ret = -ENOMEM;
1194 goto out_clean;
1195 }
1196 for (thr = 0; thr < nr_threads; thr++)
1197 memset(&data[thr], 0, offsetof(struct dec_data, go));
1198
1199 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1200 if (!crc) {
1201 pr_err("Failed to allocate crc\n");
1202 ret = -ENOMEM;
1203 goto out_clean;
1204 }
1205 memset(crc, 0, offsetof(struct crc_data, go));
1206
1207 clean_pages_on_decompress = true;
1208
1209 /*
1210 * Start the decompression threads.
1211 */
1212 for (thr = 0; thr < nr_threads; thr++) {
1213 init_waitqueue_head(&data[thr].go);
1214 init_waitqueue_head(&data[thr].done);
1215
1216 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1217 &data[thr],
1218 "image_decompress/%u", thr);
1219 if (IS_ERR(data[thr].thr)) {
1220 data[thr].thr = NULL;
1221 pr_err("Cannot start decompression threads\n");
1222 ret = -ENOMEM;
1223 goto out_clean;
1224 }
1225 }
1226
1227 /*
1228 * Start the CRC32 thread.
1229 */
1230 init_waitqueue_head(&crc->go);
1231 init_waitqueue_head(&crc->done);
1232
1233 handle->crc32 = 0;
1234 crc->crc32 = &handle->crc32;
1235 for (thr = 0; thr < nr_threads; thr++) {
1236 crc->unc[thr] = data[thr].unc;
1237 crc->unc_len[thr] = &data[thr].unc_len;
1238 }
1239
1240 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1241 if (IS_ERR(crc->thr)) {
1242 crc->thr = NULL;
1243 pr_err("Cannot start CRC32 thread\n");
1244 ret = -ENOMEM;
1245 goto out_clean;
1246 }
1247
1248 /*
1249 * Set the number of pages for read buffering.
1250 * This is complete guesswork, because we'll only know the real
1251 * picture once prepare_image() is called, which is much later on
1252 * during the image load phase. We'll assume the worst case and
1253 * say that none of the image pages are from high memory.
1254 */
1255 if (low_free_pages() > snapshot_get_image_size())
1256 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1257 read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1258
1259 for (i = 0; i < read_pages; i++) {
1260 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1261 GFP_NOIO | __GFP_HIGH :
1262 GFP_NOIO | __GFP_NOWARN |
1263 __GFP_NORETRY);
1264
1265 if (!page[i]) {
1266 if (i < LZO_CMP_PAGES) {
1267 ring_size = i;
1268 pr_err("Failed to allocate LZO pages\n");
1269 ret = -ENOMEM;
1270 goto out_clean;
1271 } else {
1272 break;
1273 }
1274 }
1275 }
1276 want = ring_size = i;
1277
1278 pr_info("Using %u thread(s) for decompression\n", nr_threads);
1279 pr_info("Loading and decompressing image data (%u pages)...\n",
1280 nr_to_read);
1281 m = nr_to_read / 10;
1282 if (!m)
1283 m = 1;
1284 nr_pages = 0;
1285 start = ktime_get();
1286
1287 ret = snapshot_write_next(snapshot);
1288 if (ret <= 0)
1289 goto out_finish;
1290
1291 for(;;) {
1292 for (i = 0; !eof && i < want; i++) {
1293 ret = swap_read_page(handle, page[ring], &hb);
1294 if (ret) {
1295 /*
1296 * On real read error, finish. On end of data,
1297 * set EOF flag and just exit the read loop.
1298 */
1299 if (handle->cur &&
1300 handle->cur->entries[handle->k]) {
1301 goto out_finish;
1302 } else {
1303 eof = 1;
1304 break;
1305 }
1306 }
1307 if (++ring >= ring_size)
1308 ring = 0;
1309 }
1310 asked += i;
1311 want -= i;
1312
1313 /*
1314 * We are out of data, wait for some more.
1315 */
1316 if (!have) {
1317 if (!asked)
1318 break;
1319
1320 ret = hib_wait_io(&hb);
1321 if (ret)
1322 goto out_finish;
1323 have += asked;
1324 asked = 0;
1325 if (eof)
1326 eof = 2;
1327 }
1328
1329 if (crc->run_threads) {
1330 wait_event(crc->done, atomic_read(&crc->stop));
1331 atomic_set(&crc->stop, 0);
1332 crc->run_threads = 0;
1333 }
1334
1335 for (thr = 0; have && thr < nr_threads; thr++) {
1336 data[thr].cmp_len = *(size_t *)page[pg];
1337 if (unlikely(!data[thr].cmp_len ||
1338 data[thr].cmp_len >
1339 lzo1x_worst_compress(LZO_UNC_SIZE))) {
1340 pr_err("Invalid LZO compressed length\n");
1341 ret = -1;
1342 goto out_finish;
1343 }
1344
1345 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1346 PAGE_SIZE);
1347 if (need > have) {
1348 if (eof > 1) {
1349 ret = -1;
1350 goto out_finish;
1351 }
1352 break;
1353 }
1354
1355 for (off = 0;
1356 off < LZO_HEADER + data[thr].cmp_len;
1357 off += PAGE_SIZE) {
1358 memcpy(data[thr].cmp + off,
1359 page[pg], PAGE_SIZE);
1360 have--;
1361 want++;
1362 if (++pg >= ring_size)
1363 pg = 0;
1364 }
1365
1366 atomic_set(&data[thr].ready, 1);
1367 wake_up(&data[thr].go);
1368 }
1369
1370 /*
1371 * Wait for more data while we are decompressing.
1372 */
1373 if (have < LZO_CMP_PAGES && asked) {
1374 ret = hib_wait_io(&hb);
1375 if (ret)
1376 goto out_finish;
1377 have += asked;
1378 asked = 0;
1379 if (eof)
1380 eof = 2;
1381 }
1382
1383 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1384 wait_event(data[thr].done,
1385 atomic_read(&data[thr].stop));
1386 atomic_set(&data[thr].stop, 0);
1387
1388 ret = data[thr].ret;
1389
1390 if (ret < 0) {
1391 pr_err("LZO decompression failed\n");
1392 goto out_finish;
1393 }
1394
1395 if (unlikely(!data[thr].unc_len ||
1396 data[thr].unc_len > LZO_UNC_SIZE ||
1397 data[thr].unc_len & (PAGE_SIZE - 1))) {
1398 pr_err("Invalid LZO uncompressed length\n");
1399 ret = -1;
1400 goto out_finish;
1401 }
1402
1403 for (off = 0;
1404 off < data[thr].unc_len; off += PAGE_SIZE) {
1405 memcpy(data_of(*snapshot),
1406 data[thr].unc + off, PAGE_SIZE);
1407
1408 if (!(nr_pages % m))
1409 pr_info("Image loading progress: %3d%%\n",
1410 nr_pages / m * 10);
1411 nr_pages++;
1412
1413 ret = snapshot_write_next(snapshot);
1414 if (ret <= 0) {
1415 crc->run_threads = thr + 1;
1416 atomic_set(&crc->ready, 1);
1417 wake_up(&crc->go);
1418 goto out_finish;
1419 }
1420 }
1421 }
1422
1423 crc->run_threads = thr;
1424 atomic_set(&crc->ready, 1);
1425 wake_up(&crc->go);
1426 }
1427
1428out_finish:
1429 if (crc->run_threads) {
1430 wait_event(crc->done, atomic_read(&crc->stop));
1431 atomic_set(&crc->stop, 0);
1432 }
1433 stop = ktime_get();
1434 if (!ret) {
1435 pr_info("Image loading done\n");
1436 snapshot_write_finalize(snapshot);
1437 if (!snapshot_image_loaded(snapshot))
1438 ret = -ENODATA;
1439 if (!ret) {
1440 if (swsusp_header->flags & SF_CRC32_MODE) {
1441 if(handle->crc32 != swsusp_header->crc32) {
1442 pr_err("Invalid image CRC32!\n");
1443 ret = -ENODATA;
1444 }
1445 }
1446 }
1447 }
1448 swsusp_show_speed(start, stop, nr_to_read, "Read");
1449out_clean:
1450 for (i = 0; i < ring_size; i++)
1451 free_page((unsigned long)page[i]);
1452 if (crc) {
1453 if (crc->thr)
1454 kthread_stop(crc->thr);
1455 kfree(crc);
1456 }
1457 if (data) {
1458 for (thr = 0; thr < nr_threads; thr++)
1459 if (data[thr].thr)
1460 kthread_stop(data[thr].thr);
1461 vfree(data);
1462 }
1463 vfree(page);
1464
1465 return ret;
1466}
1467
1468/**
1469 * swsusp_read - read the hibernation image.
1470 * @flags_p: flags passed by the "frozen" kernel in the image header should
1471 * be written into this memory location
1472 */
1473
1474int swsusp_read(unsigned int *flags_p)
1475{
1476 int error;
1477 struct swap_map_handle handle;
1478 struct snapshot_handle snapshot;
1479 struct swsusp_info *header;
1480
1481 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1482 error = snapshot_write_next(&snapshot);
1483 if (error < (int)PAGE_SIZE)
1484 return error < 0 ? error : -EFAULT;
1485 header = (struct swsusp_info *)data_of(snapshot);
1486 error = get_swap_reader(&handle, flags_p);
1487 if (error)
1488 goto end;
1489 if (!error)
1490 error = swap_read_page(&handle, header, NULL);
1491 if (!error) {
1492 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1493 load_image(&handle, &snapshot, header->pages - 1) :
1494 load_image_lzo(&handle, &snapshot, header->pages - 1);
1495 }
1496 swap_reader_finish(&handle);
1497end:
1498 if (!error)
1499 pr_debug("Image successfully loaded\n");
1500 else
1501 pr_debug("Error %d resuming\n", error);
1502 return error;
1503}
1504
1505/**
1506 * swsusp_check - Check for swsusp signature in the resume device
1507 */
1508
1509int swsusp_check(void)
1510{
1511 int error;
1512
1513 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1514 FMODE_READ, NULL);
1515 if (!IS_ERR(hib_resume_bdev)) {
1516 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1517 clear_page(swsusp_header);
1518 error = hib_submit_io(REQ_OP_READ, 0,
1519 swsusp_resume_block,
1520 swsusp_header, NULL);
1521 if (error)
1522 goto put;
1523
1524 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1525 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1526 /* Reset swap signature now */
1527 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1528 swsusp_resume_block,
1529 swsusp_header, NULL);
1530 } else {
1531 error = -EINVAL;
1532 }
1533
1534put:
1535 if (error)
1536 blkdev_put(hib_resume_bdev, FMODE_READ);
1537 else
1538 pr_debug("Image signature found, resuming\n");
1539 } else {
1540 error = PTR_ERR(hib_resume_bdev);
1541 }
1542
1543 if (error)
1544 pr_debug("Image not found (code %d)\n", error);
1545
1546 return error;
1547}
1548
1549/**
1550 * swsusp_close - close swap device.
1551 */
1552
1553void swsusp_close(fmode_t mode)
1554{
1555 if (IS_ERR(hib_resume_bdev)) {
1556 pr_debug("Image device not initialised\n");
1557 return;
1558 }
1559
1560 blkdev_put(hib_resume_bdev, mode);
1561}
1562
1563/**
1564 * swsusp_unmark - Unmark swsusp signature in the resume device
1565 */
1566
1567#ifdef CONFIG_SUSPEND
1568int swsusp_unmark(void)
1569{
1570 int error;
1571
1572 hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
1573 swsusp_header, NULL);
1574 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1575 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1576 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1577 swsusp_resume_block,
1578 swsusp_header, NULL);
1579 } else {
1580 pr_err("Cannot find swsusp signature!\n");
1581 error = -ENODEV;
1582 }
1583
1584 /*
1585 * We just returned from suspend, we don't need the image any more.
1586 */
1587 free_all_swap_pages(root_swap);
1588
1589 return error;
1590}
1591#endif
1592
1593static int __init swsusp_header_init(void)
1594{
1595 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1596 if (!swsusp_header)
1597 panic("Could not allocate memory for swsusp_header\n");
1598 return 0;
1599}
1600
1601core_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 unsigned long offset;
204
205 ext = rb_entry(node, struct swsusp_extent, node);
206 rb_erase(node, &swsusp_extents);
207 for (offset = ext->start; offset <= ext->end; offset++)
208 swap_free(swp_entry(swap, offset));
209
210 kfree(ext);
211 }
212}
213
214int swsusp_swap_in_use(void)
215{
216 return (swsusp_extents.rb_node != NULL);
217}
218
219/*
220 * General things
221 */
222
223static unsigned short root_swap = 0xffff;
224static struct file *hib_resume_bdev_file;
225
226struct hib_bio_batch {
227 atomic_t count;
228 wait_queue_head_t wait;
229 blk_status_t error;
230 struct blk_plug plug;
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 blk_start_plug(&hb->plug);
239}
240
241static void hib_finish_batch(struct hib_bio_batch *hb)
242{
243 blk_finish_plug(&hb->plug);
244}
245
246static void hib_end_io(struct bio *bio)
247{
248 struct hib_bio_batch *hb = bio->bi_private;
249 struct page *page = bio_first_page_all(bio);
250
251 if (bio->bi_status) {
252 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
253 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
254 (unsigned long long)bio->bi_iter.bi_sector);
255 }
256
257 if (bio_data_dir(bio) == WRITE)
258 put_page(page);
259 else if (clean_pages_on_read)
260 flush_icache_range((unsigned long)page_address(page),
261 (unsigned long)page_address(page) + PAGE_SIZE);
262
263 if (bio->bi_status && !hb->error)
264 hb->error = bio->bi_status;
265 if (atomic_dec_and_test(&hb->count))
266 wake_up(&hb->wait);
267
268 bio_put(bio);
269}
270
271static int hib_submit_io(blk_opf_t opf, pgoff_t page_off, void *addr,
272 struct hib_bio_batch *hb)
273{
274 struct page *page = virt_to_page(addr);
275 struct bio *bio;
276 int error = 0;
277
278 bio = bio_alloc(file_bdev(hib_resume_bdev_file), 1, opf,
279 GFP_NOIO | __GFP_HIGH);
280 bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
281
282 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
283 pr_err("Adding page to bio failed at %llu\n",
284 (unsigned long long)bio->bi_iter.bi_sector);
285 bio_put(bio);
286 return -EFAULT;
287 }
288
289 if (hb) {
290 bio->bi_end_io = hib_end_io;
291 bio->bi_private = hb;
292 atomic_inc(&hb->count);
293 submit_bio(bio);
294 } else {
295 error = submit_bio_wait(bio);
296 bio_put(bio);
297 }
298
299 return error;
300}
301
302static int hib_wait_io(struct hib_bio_batch *hb)
303{
304 /*
305 * We are relying on the behavior of blk_plug that a thread with
306 * a plug will flush the plug list before sleeping.
307 */
308 wait_event(hb->wait, atomic_read(&hb->count) == 0);
309 return blk_status_to_errno(hb->error);
310}
311
312/*
313 * Saving part
314 */
315static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
316{
317 int error;
318
319 hib_submit_io(REQ_OP_READ, swsusp_resume_block, swsusp_header, NULL);
320 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
321 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
322 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
323 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
324 swsusp_header->image = handle->first_sector;
325 if (swsusp_hardware_signature) {
326 swsusp_header->hw_sig = swsusp_hardware_signature;
327 flags |= SF_HW_SIG;
328 }
329 swsusp_header->flags = flags;
330 if (flags & SF_CRC32_MODE)
331 swsusp_header->crc32 = handle->crc32;
332 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
333 swsusp_resume_block, swsusp_header, NULL);
334 } else {
335 pr_err("Swap header not found!\n");
336 error = -ENODEV;
337 }
338 return error;
339}
340
341/*
342 * Hold the swsusp_header flag. This is used in software_resume() in
343 * 'kernel/power/hibernate' to check if the image is compressed and query
344 * for the compression algorithm support(if so).
345 */
346unsigned int swsusp_header_flags;
347
348/**
349 * swsusp_swap_check - check if the resume device is a swap device
350 * and get its index (if so)
351 *
352 * This is called before saving image
353 */
354static int swsusp_swap_check(void)
355{
356 int res;
357
358 if (swsusp_resume_device)
359 res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
360 else
361 res = find_first_swap(&swsusp_resume_device);
362 if (res < 0)
363 return res;
364 root_swap = res;
365
366 hib_resume_bdev_file = bdev_file_open_by_dev(swsusp_resume_device,
367 BLK_OPEN_WRITE, NULL, NULL);
368 if (IS_ERR(hib_resume_bdev_file))
369 return PTR_ERR(hib_resume_bdev_file);
370
371 res = set_blocksize(file_bdev(hib_resume_bdev_file), PAGE_SIZE);
372 if (res < 0)
373 fput(hib_resume_bdev_file);
374
375 return res;
376}
377
378/**
379 * write_page - Write one page to given swap location.
380 * @buf: Address we're writing.
381 * @offset: Offset of the swap page we're writing to.
382 * @hb: bio completion batch
383 */
384
385static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
386{
387 void *src;
388 int ret;
389
390 if (!offset)
391 return -ENOSPC;
392
393 if (hb) {
394 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
395 __GFP_NORETRY);
396 if (src) {
397 copy_page(src, buf);
398 } else {
399 ret = hib_wait_io(hb); /* Free pages */
400 if (ret)
401 return ret;
402 src = (void *)__get_free_page(GFP_NOIO |
403 __GFP_NOWARN |
404 __GFP_NORETRY);
405 if (src) {
406 copy_page(src, buf);
407 } else {
408 WARN_ON_ONCE(1);
409 hb = NULL; /* Go synchronous */
410 src = buf;
411 }
412 }
413 } else {
414 src = buf;
415 }
416 return hib_submit_io(REQ_OP_WRITE | REQ_SYNC, offset, src, hb);
417}
418
419static void release_swap_writer(struct swap_map_handle *handle)
420{
421 if (handle->cur)
422 free_page((unsigned long)handle->cur);
423 handle->cur = NULL;
424}
425
426static int get_swap_writer(struct swap_map_handle *handle)
427{
428 int ret;
429
430 ret = swsusp_swap_check();
431 if (ret) {
432 if (ret != -ENOSPC)
433 pr_err("Cannot find swap device, try swapon -a\n");
434 return ret;
435 }
436 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
437 if (!handle->cur) {
438 ret = -ENOMEM;
439 goto err_close;
440 }
441 handle->cur_swap = alloc_swapdev_block(root_swap);
442 if (!handle->cur_swap) {
443 ret = -ENOSPC;
444 goto err_rel;
445 }
446 handle->k = 0;
447 handle->reqd_free_pages = reqd_free_pages();
448 handle->first_sector = handle->cur_swap;
449 return 0;
450err_rel:
451 release_swap_writer(handle);
452err_close:
453 swsusp_close();
454 return ret;
455}
456
457static int swap_write_page(struct swap_map_handle *handle, void *buf,
458 struct hib_bio_batch *hb)
459{
460 int error;
461 sector_t offset;
462
463 if (!handle->cur)
464 return -EINVAL;
465 offset = alloc_swapdev_block(root_swap);
466 error = write_page(buf, offset, hb);
467 if (error)
468 return error;
469 handle->cur->entries[handle->k++] = offset;
470 if (handle->k >= MAP_PAGE_ENTRIES) {
471 offset = alloc_swapdev_block(root_swap);
472 if (!offset)
473 return -ENOSPC;
474 handle->cur->next_swap = offset;
475 error = write_page(handle->cur, handle->cur_swap, hb);
476 if (error)
477 goto out;
478 clear_page(handle->cur);
479 handle->cur_swap = offset;
480 handle->k = 0;
481
482 if (hb && low_free_pages() <= handle->reqd_free_pages) {
483 error = hib_wait_io(hb);
484 if (error)
485 goto out;
486 /*
487 * Recalculate the number of required free pages, to
488 * make sure we never take more than half.
489 */
490 handle->reqd_free_pages = reqd_free_pages();
491 }
492 }
493 out:
494 return error;
495}
496
497static int flush_swap_writer(struct swap_map_handle *handle)
498{
499 if (handle->cur && handle->cur_swap)
500 return write_page(handle->cur, handle->cur_swap, NULL);
501 else
502 return -EINVAL;
503}
504
505static int swap_writer_finish(struct swap_map_handle *handle,
506 unsigned int flags, int error)
507{
508 if (!error) {
509 pr_info("S");
510 error = mark_swapfiles(handle, flags);
511 pr_cont("|\n");
512 flush_swap_writer(handle);
513 }
514
515 if (error)
516 free_all_swap_pages(root_swap);
517 release_swap_writer(handle);
518 swsusp_close();
519
520 return error;
521}
522
523/*
524 * Bytes we need for compressed data in worst case. We assume(limitation)
525 * this is the worst of all the compression algorithms.
526 */
527#define bytes_worst_compress(x) ((x) + ((x) / 16) + 64 + 3 + 2)
528
529/* We need to remember how much compressed data we need to read. */
530#define CMP_HEADER sizeof(size_t)
531
532/* Number of pages/bytes we'll compress at one time. */
533#define UNC_PAGES 32
534#define UNC_SIZE (UNC_PAGES * PAGE_SIZE)
535
536/* Number of pages we need for compressed data (worst case). */
537#define CMP_PAGES DIV_ROUND_UP(bytes_worst_compress(UNC_SIZE) + \
538 CMP_HEADER, PAGE_SIZE)
539#define CMP_SIZE (CMP_PAGES * PAGE_SIZE)
540
541/* Maximum number of threads for compression/decompression. */
542#define CMP_THREADS 3
543
544/* Minimum/maximum number of pages for read buffering. */
545#define CMP_MIN_RD_PAGES 1024
546#define CMP_MAX_RD_PAGES 8192
547
548/**
549 * save_image - save the suspend image data
550 */
551
552static int save_image(struct swap_map_handle *handle,
553 struct snapshot_handle *snapshot,
554 unsigned int nr_to_write)
555{
556 unsigned int m;
557 int ret;
558 int nr_pages;
559 int err2;
560 struct hib_bio_batch hb;
561 ktime_t start;
562 ktime_t stop;
563
564 hib_init_batch(&hb);
565
566 pr_info("Saving image data pages (%u pages)...\n",
567 nr_to_write);
568 m = nr_to_write / 10;
569 if (!m)
570 m = 1;
571 nr_pages = 0;
572 start = ktime_get();
573 while (1) {
574 ret = snapshot_read_next(snapshot);
575 if (ret <= 0)
576 break;
577 ret = swap_write_page(handle, data_of(*snapshot), &hb);
578 if (ret)
579 break;
580 if (!(nr_pages % m))
581 pr_info("Image saving progress: %3d%%\n",
582 nr_pages / m * 10);
583 nr_pages++;
584 }
585 err2 = hib_wait_io(&hb);
586 hib_finish_batch(&hb);
587 stop = ktime_get();
588 if (!ret)
589 ret = err2;
590 if (!ret)
591 pr_info("Image saving done\n");
592 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
593 return ret;
594}
595
596/*
597 * Structure used for CRC32.
598 */
599struct crc_data {
600 struct task_struct *thr; /* thread */
601 atomic_t ready; /* ready to start flag */
602 atomic_t stop; /* ready to stop flag */
603 unsigned run_threads; /* nr current threads */
604 wait_queue_head_t go; /* start crc update */
605 wait_queue_head_t done; /* crc update done */
606 u32 *crc32; /* points to handle's crc32 */
607 size_t *unc_len[CMP_THREADS]; /* uncompressed lengths */
608 unsigned char *unc[CMP_THREADS]; /* uncompressed data */
609};
610
611/*
612 * CRC32 update function that runs in its own thread.
613 */
614static int crc32_threadfn(void *data)
615{
616 struct crc_data *d = data;
617 unsigned i;
618
619 while (1) {
620 wait_event(d->go, atomic_read_acquire(&d->ready) ||
621 kthread_should_stop());
622 if (kthread_should_stop()) {
623 d->thr = NULL;
624 atomic_set_release(&d->stop, 1);
625 wake_up(&d->done);
626 break;
627 }
628 atomic_set(&d->ready, 0);
629
630 for (i = 0; i < d->run_threads; i++)
631 *d->crc32 = crc32_le(*d->crc32,
632 d->unc[i], *d->unc_len[i]);
633 atomic_set_release(&d->stop, 1);
634 wake_up(&d->done);
635 }
636 return 0;
637}
638/*
639 * Structure used for data compression.
640 */
641struct cmp_data {
642 struct task_struct *thr; /* thread */
643 struct crypto_comp *cc; /* crypto compressor stream */
644 atomic_t ready; /* ready to start flag */
645 atomic_t stop; /* ready to stop flag */
646 int ret; /* return code */
647 wait_queue_head_t go; /* start compression */
648 wait_queue_head_t done; /* compression done */
649 size_t unc_len; /* uncompressed length */
650 size_t cmp_len; /* compressed length */
651 unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
652 unsigned char cmp[CMP_SIZE]; /* compressed buffer */
653};
654
655/* Indicates the image size after compression */
656static atomic_t compressed_size = ATOMIC_INIT(0);
657
658/*
659 * Compression function that runs in its own thread.
660 */
661static int compress_threadfn(void *data)
662{
663 struct cmp_data *d = data;
664 unsigned int cmp_len = 0;
665
666 while (1) {
667 wait_event(d->go, atomic_read_acquire(&d->ready) ||
668 kthread_should_stop());
669 if (kthread_should_stop()) {
670 d->thr = NULL;
671 d->ret = -1;
672 atomic_set_release(&d->stop, 1);
673 wake_up(&d->done);
674 break;
675 }
676 atomic_set(&d->ready, 0);
677
678 cmp_len = CMP_SIZE - CMP_HEADER;
679 d->ret = crypto_comp_compress(d->cc, d->unc, d->unc_len,
680 d->cmp + CMP_HEADER,
681 &cmp_len);
682 d->cmp_len = cmp_len;
683
684 atomic_set(&compressed_size, atomic_read(&compressed_size) + d->cmp_len);
685 atomic_set_release(&d->stop, 1);
686 wake_up(&d->done);
687 }
688 return 0;
689}
690
691/**
692 * save_compressed_image - Save the suspend image data after compression.
693 * @handle: Swap map handle to use for saving the image.
694 * @snapshot: Image to read data from.
695 * @nr_to_write: Number of pages to save.
696 */
697static int save_compressed_image(struct swap_map_handle *handle,
698 struct snapshot_handle *snapshot,
699 unsigned int nr_to_write)
700{
701 unsigned int m;
702 int ret = 0;
703 int nr_pages;
704 int err2;
705 struct hib_bio_batch hb;
706 ktime_t start;
707 ktime_t stop;
708 size_t off;
709 unsigned thr, run_threads, nr_threads;
710 unsigned char *page = NULL;
711 struct cmp_data *data = NULL;
712 struct crc_data *crc = NULL;
713
714 hib_init_batch(&hb);
715
716 atomic_set(&compressed_size, 0);
717
718 /*
719 * We'll limit the number of threads for compression to limit memory
720 * footprint.
721 */
722 nr_threads = num_online_cpus() - 1;
723 nr_threads = clamp_val(nr_threads, 1, CMP_THREADS);
724
725 page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
726 if (!page) {
727 pr_err("Failed to allocate %s page\n", hib_comp_algo);
728 ret = -ENOMEM;
729 goto out_clean;
730 }
731
732 data = vzalloc(array_size(nr_threads, sizeof(*data)));
733 if (!data) {
734 pr_err("Failed to allocate %s data\n", hib_comp_algo);
735 ret = -ENOMEM;
736 goto out_clean;
737 }
738
739 crc = kzalloc(sizeof(*crc), GFP_KERNEL);
740 if (!crc) {
741 pr_err("Failed to allocate crc\n");
742 ret = -ENOMEM;
743 goto out_clean;
744 }
745
746 /*
747 * Start the compression threads.
748 */
749 for (thr = 0; thr < nr_threads; thr++) {
750 init_waitqueue_head(&data[thr].go);
751 init_waitqueue_head(&data[thr].done);
752
753 data[thr].cc = crypto_alloc_comp(hib_comp_algo, 0, 0);
754 if (IS_ERR_OR_NULL(data[thr].cc)) {
755 pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
756 ret = -EFAULT;
757 goto out_clean;
758 }
759
760 data[thr].thr = kthread_run(compress_threadfn,
761 &data[thr],
762 "image_compress/%u", thr);
763 if (IS_ERR(data[thr].thr)) {
764 data[thr].thr = NULL;
765 pr_err("Cannot start compression threads\n");
766 ret = -ENOMEM;
767 goto out_clean;
768 }
769 }
770
771 /*
772 * Start the CRC32 thread.
773 */
774 init_waitqueue_head(&crc->go);
775 init_waitqueue_head(&crc->done);
776
777 handle->crc32 = 0;
778 crc->crc32 = &handle->crc32;
779 for (thr = 0; thr < nr_threads; thr++) {
780 crc->unc[thr] = data[thr].unc;
781 crc->unc_len[thr] = &data[thr].unc_len;
782 }
783
784 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
785 if (IS_ERR(crc->thr)) {
786 crc->thr = NULL;
787 pr_err("Cannot start CRC32 thread\n");
788 ret = -ENOMEM;
789 goto out_clean;
790 }
791
792 /*
793 * Adjust the number of required free pages after all allocations have
794 * been done. We don't want to run out of pages when writing.
795 */
796 handle->reqd_free_pages = reqd_free_pages();
797
798 pr_info("Using %u thread(s) for %s compression\n", nr_threads, hib_comp_algo);
799 pr_info("Compressing and saving image data (%u pages)...\n",
800 nr_to_write);
801 m = nr_to_write / 10;
802 if (!m)
803 m = 1;
804 nr_pages = 0;
805 start = ktime_get();
806 for (;;) {
807 for (thr = 0; thr < nr_threads; thr++) {
808 for (off = 0; off < UNC_SIZE; off += PAGE_SIZE) {
809 ret = snapshot_read_next(snapshot);
810 if (ret < 0)
811 goto out_finish;
812
813 if (!ret)
814 break;
815
816 memcpy(data[thr].unc + off,
817 data_of(*snapshot), PAGE_SIZE);
818
819 if (!(nr_pages % m))
820 pr_info("Image saving progress: %3d%%\n",
821 nr_pages / m * 10);
822 nr_pages++;
823 }
824 if (!off)
825 break;
826
827 data[thr].unc_len = off;
828
829 atomic_set_release(&data[thr].ready, 1);
830 wake_up(&data[thr].go);
831 }
832
833 if (!thr)
834 break;
835
836 crc->run_threads = thr;
837 atomic_set_release(&crc->ready, 1);
838 wake_up(&crc->go);
839
840 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
841 wait_event(data[thr].done,
842 atomic_read_acquire(&data[thr].stop));
843 atomic_set(&data[thr].stop, 0);
844
845 ret = data[thr].ret;
846
847 if (ret < 0) {
848 pr_err("%s compression failed\n", hib_comp_algo);
849 goto out_finish;
850 }
851
852 if (unlikely(!data[thr].cmp_len ||
853 data[thr].cmp_len >
854 bytes_worst_compress(data[thr].unc_len))) {
855 pr_err("Invalid %s compressed length\n", hib_comp_algo);
856 ret = -1;
857 goto out_finish;
858 }
859
860 *(size_t *)data[thr].cmp = data[thr].cmp_len;
861
862 /*
863 * Given we are writing one page at a time to disk, we
864 * copy that much from the buffer, although the last
865 * bit will likely be smaller than full page. This is
866 * OK - we saved the length of the compressed data, so
867 * any garbage at the end will be discarded when we
868 * read it.
869 */
870 for (off = 0;
871 off < CMP_HEADER + data[thr].cmp_len;
872 off += PAGE_SIZE) {
873 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
874
875 ret = swap_write_page(handle, page, &hb);
876 if (ret)
877 goto out_finish;
878 }
879 }
880
881 wait_event(crc->done, atomic_read_acquire(&crc->stop));
882 atomic_set(&crc->stop, 0);
883 }
884
885out_finish:
886 err2 = hib_wait_io(&hb);
887 stop = ktime_get();
888 if (!ret)
889 ret = err2;
890 if (!ret)
891 pr_info("Image saving done\n");
892 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
893 pr_info("Image size after compression: %d kbytes\n",
894 (atomic_read(&compressed_size) / 1024));
895
896out_clean:
897 hib_finish_batch(&hb);
898 if (crc) {
899 if (crc->thr)
900 kthread_stop(crc->thr);
901 kfree(crc);
902 }
903 if (data) {
904 for (thr = 0; thr < nr_threads; thr++) {
905 if (data[thr].thr)
906 kthread_stop(data[thr].thr);
907 if (data[thr].cc)
908 crypto_free_comp(data[thr].cc);
909 }
910 vfree(data);
911 }
912 if (page) free_page((unsigned long)page);
913
914 return ret;
915}
916
917/**
918 * enough_swap - Make sure we have enough swap to save the image.
919 *
920 * Returns TRUE or FALSE after checking the total amount of swap
921 * space available from the resume partition.
922 */
923
924static int enough_swap(unsigned int nr_pages)
925{
926 unsigned int free_swap = count_swap_pages(root_swap, 1);
927 unsigned int required;
928
929 pr_debug("Free swap pages: %u\n", free_swap);
930
931 required = PAGES_FOR_IO + nr_pages;
932 return free_swap > required;
933}
934
935/**
936 * swsusp_write - Write entire image and metadata.
937 * @flags: flags to pass to the "boot" kernel in the image header
938 *
939 * It is important _NOT_ to umount filesystems at this point. We want
940 * them synced (in case something goes wrong) but we DO not want to mark
941 * filesystem clean: it is not. (And it does not matter, if we resume
942 * correctly, we'll mark system clean, anyway.)
943 */
944
945int swsusp_write(unsigned int flags)
946{
947 struct swap_map_handle handle;
948 struct snapshot_handle snapshot;
949 struct swsusp_info *header;
950 unsigned long pages;
951 int error;
952
953 pages = snapshot_get_image_size();
954 error = get_swap_writer(&handle);
955 if (error) {
956 pr_err("Cannot get swap writer\n");
957 return error;
958 }
959 if (flags & SF_NOCOMPRESS_MODE) {
960 if (!enough_swap(pages)) {
961 pr_err("Not enough free swap\n");
962 error = -ENOSPC;
963 goto out_finish;
964 }
965 }
966 memset(&snapshot, 0, sizeof(struct snapshot_handle));
967 error = snapshot_read_next(&snapshot);
968 if (error < (int)PAGE_SIZE) {
969 if (error >= 0)
970 error = -EFAULT;
971
972 goto out_finish;
973 }
974 header = (struct swsusp_info *)data_of(snapshot);
975 error = swap_write_page(&handle, header, NULL);
976 if (!error) {
977 error = (flags & SF_NOCOMPRESS_MODE) ?
978 save_image(&handle, &snapshot, pages - 1) :
979 save_compressed_image(&handle, &snapshot, pages - 1);
980 }
981out_finish:
982 error = swap_writer_finish(&handle, flags, error);
983 return error;
984}
985
986/*
987 * The following functions allow us to read data using a swap map
988 * in a file-like way.
989 */
990
991static void release_swap_reader(struct swap_map_handle *handle)
992{
993 struct swap_map_page_list *tmp;
994
995 while (handle->maps) {
996 if (handle->maps->map)
997 free_page((unsigned long)handle->maps->map);
998 tmp = handle->maps;
999 handle->maps = handle->maps->next;
1000 kfree(tmp);
1001 }
1002 handle->cur = NULL;
1003}
1004
1005static int get_swap_reader(struct swap_map_handle *handle,
1006 unsigned int *flags_p)
1007{
1008 int error;
1009 struct swap_map_page_list *tmp, *last;
1010 sector_t offset;
1011
1012 *flags_p = swsusp_header->flags;
1013
1014 if (!swsusp_header->image) /* how can this happen? */
1015 return -EINVAL;
1016
1017 handle->cur = NULL;
1018 last = handle->maps = NULL;
1019 offset = swsusp_header->image;
1020 while (offset) {
1021 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
1022 if (!tmp) {
1023 release_swap_reader(handle);
1024 return -ENOMEM;
1025 }
1026 if (!handle->maps)
1027 handle->maps = tmp;
1028 if (last)
1029 last->next = tmp;
1030 last = tmp;
1031
1032 tmp->map = (struct swap_map_page *)
1033 __get_free_page(GFP_NOIO | __GFP_HIGH);
1034 if (!tmp->map) {
1035 release_swap_reader(handle);
1036 return -ENOMEM;
1037 }
1038
1039 error = hib_submit_io(REQ_OP_READ, offset, tmp->map, NULL);
1040 if (error) {
1041 release_swap_reader(handle);
1042 return error;
1043 }
1044 offset = tmp->map->next_swap;
1045 }
1046 handle->k = 0;
1047 handle->cur = handle->maps->map;
1048 return 0;
1049}
1050
1051static int swap_read_page(struct swap_map_handle *handle, void *buf,
1052 struct hib_bio_batch *hb)
1053{
1054 sector_t offset;
1055 int error;
1056 struct swap_map_page_list *tmp;
1057
1058 if (!handle->cur)
1059 return -EINVAL;
1060 offset = handle->cur->entries[handle->k];
1061 if (!offset)
1062 return -EFAULT;
1063 error = hib_submit_io(REQ_OP_READ, offset, buf, hb);
1064 if (error)
1065 return error;
1066 if (++handle->k >= MAP_PAGE_ENTRIES) {
1067 handle->k = 0;
1068 free_page((unsigned long)handle->maps->map);
1069 tmp = handle->maps;
1070 handle->maps = handle->maps->next;
1071 kfree(tmp);
1072 if (!handle->maps)
1073 release_swap_reader(handle);
1074 else
1075 handle->cur = handle->maps->map;
1076 }
1077 return error;
1078}
1079
1080static int swap_reader_finish(struct swap_map_handle *handle)
1081{
1082 release_swap_reader(handle);
1083
1084 return 0;
1085}
1086
1087/**
1088 * load_image - load the image using the swap map handle
1089 * @handle and the snapshot handle @snapshot
1090 * (assume there are @nr_pages pages to load)
1091 */
1092
1093static int load_image(struct swap_map_handle *handle,
1094 struct snapshot_handle *snapshot,
1095 unsigned int nr_to_read)
1096{
1097 unsigned int m;
1098 int ret = 0;
1099 ktime_t start;
1100 ktime_t stop;
1101 struct hib_bio_batch hb;
1102 int err2;
1103 unsigned nr_pages;
1104
1105 hib_init_batch(&hb);
1106
1107 clean_pages_on_read = true;
1108 pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1109 m = nr_to_read / 10;
1110 if (!m)
1111 m = 1;
1112 nr_pages = 0;
1113 start = ktime_get();
1114 for ( ; ; ) {
1115 ret = snapshot_write_next(snapshot);
1116 if (ret <= 0)
1117 break;
1118 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1119 if (ret)
1120 break;
1121 if (snapshot->sync_read)
1122 ret = hib_wait_io(&hb);
1123 if (ret)
1124 break;
1125 if (!(nr_pages % m))
1126 pr_info("Image loading progress: %3d%%\n",
1127 nr_pages / m * 10);
1128 nr_pages++;
1129 }
1130 err2 = hib_wait_io(&hb);
1131 hib_finish_batch(&hb);
1132 stop = ktime_get();
1133 if (!ret)
1134 ret = err2;
1135 if (!ret) {
1136 pr_info("Image loading done\n");
1137 ret = snapshot_write_finalize(snapshot);
1138 if (!ret && !snapshot_image_loaded(snapshot))
1139 ret = -ENODATA;
1140 }
1141 swsusp_show_speed(start, stop, nr_to_read, "Read");
1142 return ret;
1143}
1144
1145/*
1146 * Structure used for data decompression.
1147 */
1148struct dec_data {
1149 struct task_struct *thr; /* thread */
1150 struct crypto_comp *cc; /* crypto compressor stream */
1151 atomic_t ready; /* ready to start flag */
1152 atomic_t stop; /* ready to stop flag */
1153 int ret; /* return code */
1154 wait_queue_head_t go; /* start decompression */
1155 wait_queue_head_t done; /* decompression done */
1156 size_t unc_len; /* uncompressed length */
1157 size_t cmp_len; /* compressed length */
1158 unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
1159 unsigned char cmp[CMP_SIZE]; /* compressed buffer */
1160};
1161
1162/*
1163 * Decompression function that runs in its own thread.
1164 */
1165static int decompress_threadfn(void *data)
1166{
1167 struct dec_data *d = data;
1168 unsigned int unc_len = 0;
1169
1170 while (1) {
1171 wait_event(d->go, atomic_read_acquire(&d->ready) ||
1172 kthread_should_stop());
1173 if (kthread_should_stop()) {
1174 d->thr = NULL;
1175 d->ret = -1;
1176 atomic_set_release(&d->stop, 1);
1177 wake_up(&d->done);
1178 break;
1179 }
1180 atomic_set(&d->ready, 0);
1181
1182 unc_len = UNC_SIZE;
1183 d->ret = crypto_comp_decompress(d->cc, d->cmp + CMP_HEADER, d->cmp_len,
1184 d->unc, &unc_len);
1185 d->unc_len = unc_len;
1186
1187 if (clean_pages_on_decompress)
1188 flush_icache_range((unsigned long)d->unc,
1189 (unsigned long)d->unc + d->unc_len);
1190
1191 atomic_set_release(&d->stop, 1);
1192 wake_up(&d->done);
1193 }
1194 return 0;
1195}
1196
1197/**
1198 * load_compressed_image - Load compressed image data and decompress it.
1199 * @handle: Swap map handle to use for loading data.
1200 * @snapshot: Image to copy uncompressed data into.
1201 * @nr_to_read: Number of pages to load.
1202 */
1203static int load_compressed_image(struct swap_map_handle *handle,
1204 struct snapshot_handle *snapshot,
1205 unsigned int nr_to_read)
1206{
1207 unsigned int m;
1208 int ret = 0;
1209 int eof = 0;
1210 struct hib_bio_batch hb;
1211 ktime_t start;
1212 ktime_t stop;
1213 unsigned nr_pages;
1214 size_t off;
1215 unsigned i, thr, run_threads, nr_threads;
1216 unsigned ring = 0, pg = 0, ring_size = 0,
1217 have = 0, want, need, asked = 0;
1218 unsigned long read_pages = 0;
1219 unsigned char **page = NULL;
1220 struct dec_data *data = NULL;
1221 struct crc_data *crc = NULL;
1222
1223 hib_init_batch(&hb);
1224
1225 /*
1226 * We'll limit the number of threads for decompression to limit memory
1227 * footprint.
1228 */
1229 nr_threads = num_online_cpus() - 1;
1230 nr_threads = clamp_val(nr_threads, 1, CMP_THREADS);
1231
1232 page = vmalloc(array_size(CMP_MAX_RD_PAGES, sizeof(*page)));
1233 if (!page) {
1234 pr_err("Failed to allocate %s page\n", hib_comp_algo);
1235 ret = -ENOMEM;
1236 goto out_clean;
1237 }
1238
1239 data = vzalloc(array_size(nr_threads, sizeof(*data)));
1240 if (!data) {
1241 pr_err("Failed to allocate %s data\n", hib_comp_algo);
1242 ret = -ENOMEM;
1243 goto out_clean;
1244 }
1245
1246 crc = kzalloc(sizeof(*crc), GFP_KERNEL);
1247 if (!crc) {
1248 pr_err("Failed to allocate crc\n");
1249 ret = -ENOMEM;
1250 goto out_clean;
1251 }
1252
1253 clean_pages_on_decompress = true;
1254
1255 /*
1256 * Start the decompression threads.
1257 */
1258 for (thr = 0; thr < nr_threads; thr++) {
1259 init_waitqueue_head(&data[thr].go);
1260 init_waitqueue_head(&data[thr].done);
1261
1262 data[thr].cc = crypto_alloc_comp(hib_comp_algo, 0, 0);
1263 if (IS_ERR_OR_NULL(data[thr].cc)) {
1264 pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
1265 ret = -EFAULT;
1266 goto out_clean;
1267 }
1268
1269 data[thr].thr = kthread_run(decompress_threadfn,
1270 &data[thr],
1271 "image_decompress/%u", thr);
1272 if (IS_ERR(data[thr].thr)) {
1273 data[thr].thr = NULL;
1274 pr_err("Cannot start decompression threads\n");
1275 ret = -ENOMEM;
1276 goto out_clean;
1277 }
1278 }
1279
1280 /*
1281 * Start the CRC32 thread.
1282 */
1283 init_waitqueue_head(&crc->go);
1284 init_waitqueue_head(&crc->done);
1285
1286 handle->crc32 = 0;
1287 crc->crc32 = &handle->crc32;
1288 for (thr = 0; thr < nr_threads; thr++) {
1289 crc->unc[thr] = data[thr].unc;
1290 crc->unc_len[thr] = &data[thr].unc_len;
1291 }
1292
1293 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1294 if (IS_ERR(crc->thr)) {
1295 crc->thr = NULL;
1296 pr_err("Cannot start CRC32 thread\n");
1297 ret = -ENOMEM;
1298 goto out_clean;
1299 }
1300
1301 /*
1302 * Set the number of pages for read buffering.
1303 * This is complete guesswork, because we'll only know the real
1304 * picture once prepare_image() is called, which is much later on
1305 * during the image load phase. We'll assume the worst case and
1306 * say that none of the image pages are from high memory.
1307 */
1308 if (low_free_pages() > snapshot_get_image_size())
1309 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1310 read_pages = clamp_val(read_pages, CMP_MIN_RD_PAGES, CMP_MAX_RD_PAGES);
1311
1312 for (i = 0; i < read_pages; i++) {
1313 page[i] = (void *)__get_free_page(i < CMP_PAGES ?
1314 GFP_NOIO | __GFP_HIGH :
1315 GFP_NOIO | __GFP_NOWARN |
1316 __GFP_NORETRY);
1317
1318 if (!page[i]) {
1319 if (i < CMP_PAGES) {
1320 ring_size = i;
1321 pr_err("Failed to allocate %s pages\n", hib_comp_algo);
1322 ret = -ENOMEM;
1323 goto out_clean;
1324 } else {
1325 break;
1326 }
1327 }
1328 }
1329 want = ring_size = i;
1330
1331 pr_info("Using %u thread(s) for %s decompression\n", nr_threads, hib_comp_algo);
1332 pr_info("Loading and decompressing image data (%u pages)...\n",
1333 nr_to_read);
1334 m = nr_to_read / 10;
1335 if (!m)
1336 m = 1;
1337 nr_pages = 0;
1338 start = ktime_get();
1339
1340 ret = snapshot_write_next(snapshot);
1341 if (ret <= 0)
1342 goto out_finish;
1343
1344 for(;;) {
1345 for (i = 0; !eof && i < want; i++) {
1346 ret = swap_read_page(handle, page[ring], &hb);
1347 if (ret) {
1348 /*
1349 * On real read error, finish. On end of data,
1350 * set EOF flag and just exit the read loop.
1351 */
1352 if (handle->cur &&
1353 handle->cur->entries[handle->k]) {
1354 goto out_finish;
1355 } else {
1356 eof = 1;
1357 break;
1358 }
1359 }
1360 if (++ring >= ring_size)
1361 ring = 0;
1362 }
1363 asked += i;
1364 want -= i;
1365
1366 /*
1367 * We are out of data, wait for some more.
1368 */
1369 if (!have) {
1370 if (!asked)
1371 break;
1372
1373 ret = hib_wait_io(&hb);
1374 if (ret)
1375 goto out_finish;
1376 have += asked;
1377 asked = 0;
1378 if (eof)
1379 eof = 2;
1380 }
1381
1382 if (crc->run_threads) {
1383 wait_event(crc->done, atomic_read_acquire(&crc->stop));
1384 atomic_set(&crc->stop, 0);
1385 crc->run_threads = 0;
1386 }
1387
1388 for (thr = 0; have && thr < nr_threads; thr++) {
1389 data[thr].cmp_len = *(size_t *)page[pg];
1390 if (unlikely(!data[thr].cmp_len ||
1391 data[thr].cmp_len >
1392 bytes_worst_compress(UNC_SIZE))) {
1393 pr_err("Invalid %s compressed length\n", hib_comp_algo);
1394 ret = -1;
1395 goto out_finish;
1396 }
1397
1398 need = DIV_ROUND_UP(data[thr].cmp_len + CMP_HEADER,
1399 PAGE_SIZE);
1400 if (need > have) {
1401 if (eof > 1) {
1402 ret = -1;
1403 goto out_finish;
1404 }
1405 break;
1406 }
1407
1408 for (off = 0;
1409 off < CMP_HEADER + data[thr].cmp_len;
1410 off += PAGE_SIZE) {
1411 memcpy(data[thr].cmp + off,
1412 page[pg], PAGE_SIZE);
1413 have--;
1414 want++;
1415 if (++pg >= ring_size)
1416 pg = 0;
1417 }
1418
1419 atomic_set_release(&data[thr].ready, 1);
1420 wake_up(&data[thr].go);
1421 }
1422
1423 /*
1424 * Wait for more data while we are decompressing.
1425 */
1426 if (have < CMP_PAGES && asked) {
1427 ret = hib_wait_io(&hb);
1428 if (ret)
1429 goto out_finish;
1430 have += asked;
1431 asked = 0;
1432 if (eof)
1433 eof = 2;
1434 }
1435
1436 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1437 wait_event(data[thr].done,
1438 atomic_read_acquire(&data[thr].stop));
1439 atomic_set(&data[thr].stop, 0);
1440
1441 ret = data[thr].ret;
1442
1443 if (ret < 0) {
1444 pr_err("%s decompression failed\n", hib_comp_algo);
1445 goto out_finish;
1446 }
1447
1448 if (unlikely(!data[thr].unc_len ||
1449 data[thr].unc_len > UNC_SIZE ||
1450 data[thr].unc_len & (PAGE_SIZE - 1))) {
1451 pr_err("Invalid %s uncompressed length\n", hib_comp_algo);
1452 ret = -1;
1453 goto out_finish;
1454 }
1455
1456 for (off = 0;
1457 off < data[thr].unc_len; off += PAGE_SIZE) {
1458 memcpy(data_of(*snapshot),
1459 data[thr].unc + off, PAGE_SIZE);
1460
1461 if (!(nr_pages % m))
1462 pr_info("Image loading progress: %3d%%\n",
1463 nr_pages / m * 10);
1464 nr_pages++;
1465
1466 ret = snapshot_write_next(snapshot);
1467 if (ret <= 0) {
1468 crc->run_threads = thr + 1;
1469 atomic_set_release(&crc->ready, 1);
1470 wake_up(&crc->go);
1471 goto out_finish;
1472 }
1473 }
1474 }
1475
1476 crc->run_threads = thr;
1477 atomic_set_release(&crc->ready, 1);
1478 wake_up(&crc->go);
1479 }
1480
1481out_finish:
1482 if (crc->run_threads) {
1483 wait_event(crc->done, atomic_read_acquire(&crc->stop));
1484 atomic_set(&crc->stop, 0);
1485 }
1486 stop = ktime_get();
1487 if (!ret) {
1488 pr_info("Image loading done\n");
1489 ret = snapshot_write_finalize(snapshot);
1490 if (!ret && !snapshot_image_loaded(snapshot))
1491 ret = -ENODATA;
1492 if (!ret) {
1493 if (swsusp_header->flags & SF_CRC32_MODE) {
1494 if(handle->crc32 != swsusp_header->crc32) {
1495 pr_err("Invalid image CRC32!\n");
1496 ret = -ENODATA;
1497 }
1498 }
1499 }
1500 }
1501 swsusp_show_speed(start, stop, nr_to_read, "Read");
1502out_clean:
1503 hib_finish_batch(&hb);
1504 for (i = 0; i < ring_size; i++)
1505 free_page((unsigned long)page[i]);
1506 if (crc) {
1507 if (crc->thr)
1508 kthread_stop(crc->thr);
1509 kfree(crc);
1510 }
1511 if (data) {
1512 for (thr = 0; thr < nr_threads; thr++) {
1513 if (data[thr].thr)
1514 kthread_stop(data[thr].thr);
1515 if (data[thr].cc)
1516 crypto_free_comp(data[thr].cc);
1517 }
1518 vfree(data);
1519 }
1520 vfree(page);
1521
1522 return ret;
1523}
1524
1525/**
1526 * swsusp_read - read the hibernation image.
1527 * @flags_p: flags passed by the "frozen" kernel in the image header should
1528 * be written into this memory location
1529 */
1530
1531int swsusp_read(unsigned int *flags_p)
1532{
1533 int error;
1534 struct swap_map_handle handle;
1535 struct snapshot_handle snapshot;
1536 struct swsusp_info *header;
1537
1538 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1539 error = snapshot_write_next(&snapshot);
1540 if (error < (int)PAGE_SIZE)
1541 return error < 0 ? error : -EFAULT;
1542 header = (struct swsusp_info *)data_of(snapshot);
1543 error = get_swap_reader(&handle, flags_p);
1544 if (error)
1545 goto end;
1546 if (!error)
1547 error = swap_read_page(&handle, header, NULL);
1548 if (!error) {
1549 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1550 load_image(&handle, &snapshot, header->pages - 1) :
1551 load_compressed_image(&handle, &snapshot, header->pages - 1);
1552 }
1553 swap_reader_finish(&handle);
1554end:
1555 if (!error)
1556 pr_debug("Image successfully loaded\n");
1557 else
1558 pr_debug("Error %d resuming\n", error);
1559 return error;
1560}
1561
1562static void *swsusp_holder;
1563
1564/**
1565 * swsusp_check - Open the resume device and check for the swsusp signature.
1566 * @exclusive: Open the resume device exclusively.
1567 */
1568
1569int swsusp_check(bool exclusive)
1570{
1571 void *holder = exclusive ? &swsusp_holder : NULL;
1572 int error;
1573
1574 hib_resume_bdev_file = bdev_file_open_by_dev(swsusp_resume_device,
1575 BLK_OPEN_READ, holder, NULL);
1576 if (!IS_ERR(hib_resume_bdev_file)) {
1577 set_blocksize(file_bdev(hib_resume_bdev_file), PAGE_SIZE);
1578 clear_page(swsusp_header);
1579 error = hib_submit_io(REQ_OP_READ, swsusp_resume_block,
1580 swsusp_header, NULL);
1581 if (error)
1582 goto put;
1583
1584 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1585 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1586 swsusp_header_flags = swsusp_header->flags;
1587 /* Reset swap signature now */
1588 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
1589 swsusp_resume_block,
1590 swsusp_header, NULL);
1591 } else {
1592 error = -EINVAL;
1593 }
1594 if (!error && swsusp_header->flags & SF_HW_SIG &&
1595 swsusp_header->hw_sig != swsusp_hardware_signature) {
1596 pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
1597 swsusp_header->hw_sig, swsusp_hardware_signature);
1598 error = -EINVAL;
1599 }
1600
1601put:
1602 if (error)
1603 fput(hib_resume_bdev_file);
1604 else
1605 pr_debug("Image signature found, resuming\n");
1606 } else {
1607 error = PTR_ERR(hib_resume_bdev_file);
1608 }
1609
1610 if (error)
1611 pr_debug("Image not found (code %d)\n", error);
1612
1613 return error;
1614}
1615
1616/**
1617 * swsusp_close - close resume device.
1618 */
1619
1620void swsusp_close(void)
1621{
1622 if (IS_ERR(hib_resume_bdev_file)) {
1623 pr_debug("Image device not initialised\n");
1624 return;
1625 }
1626
1627 fput(hib_resume_bdev_file);
1628}
1629
1630/**
1631 * swsusp_unmark - Unmark swsusp signature in the resume device
1632 */
1633
1634#ifdef CONFIG_SUSPEND
1635int swsusp_unmark(void)
1636{
1637 int error;
1638
1639 hib_submit_io(REQ_OP_READ, swsusp_resume_block,
1640 swsusp_header, NULL);
1641 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1642 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1643 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
1644 swsusp_resume_block,
1645 swsusp_header, NULL);
1646 } else {
1647 pr_err("Cannot find swsusp signature!\n");
1648 error = -ENODEV;
1649 }
1650
1651 /*
1652 * We just returned from suspend, we don't need the image any more.
1653 */
1654 free_all_swap_pages(root_swap);
1655
1656 return error;
1657}
1658#endif
1659
1660static int __init swsusp_header_init(void)
1661{
1662 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1663 if (!swsusp_header)
1664 panic("Could not allocate memory for swsusp_header\n");
1665 return 0;
1666}
1667
1668core_initcall(swsusp_header_init);