projects/linux·blob master · refs

1720 lines · 40.8 KiB

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 <[email protected]>
9 * Copyright (C) 2006 Rafael J. Wysocki <[email protected]>
10 * Copyright (C) 2010-2012 Bojan Smojver <[email protected]>
11 */
12
13#define pr_fmt(fmt) "PM: " fmt
14
15#include <crypto/acompress.h>
16#include <linux/module.h>
17#include <linux/file.h>
18#include <linux/delay.h>
19#include <linux/bitops.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/vmalloc.h>
28#include <linux/cpumask.h>
29#include <linux/atomic.h>
30#include <linux/kthread.h>
31#include <linux/crc32.h>
32#include <linux/ktime.h>
33
34#include "power.h"
35
36#define HIBERNATE_SIG "S1SUSPEND"
37
38u32 swsusp_hardware_signature;
39
40/*
41 * When reading an {un,}compressed image, we may restore pages in place,
42 * in which case some architectures need these pages cleaning before they
43 * can be executed. We don't know which pages these may be, so clean the lot.
44 */
45static bool clean_pages_on_read;
46static bool clean_pages_on_decompress;
47
48/*
49 * The swap map is a data structure used for keeping track of each page
50 * written to a swap partition. It consists of many swap_map_page structures
51 * that contain each an array of MAP_PAGE_ENTRIES swap entries. These
52 * structures are stored on the swap and linked together with the help of the
53 * .next_swap member.
54 *
55 * The swap map is created during suspend. The swap map pages are allocated and
56 * populated one at a time, so we only need one memory page to set up the entire
57 * structure.
58 *
59 * During resume we pick up all swap_map_page structures into a list.
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 a file-alike way.
92 */
93struct swap_map_handle {
94 struct swap_map_page *cur;
95 struct swap_map_page_list *maps;
96 sector_t cur_swap;
97 sector_t first_sector;
98 unsigned int k;
99 unsigned long reqd_free_pages;
100 u32 crc32;
101};
102
103struct swsusp_header {
104 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
105 sizeof(u32) - sizeof(u32)];
106 u32 hw_sig;
107 u32 crc32;
108 sector_t image;
109 unsigned int flags; /* Flags to pass to the "boot" kernel */
110 char orig_sig[10];
111 char sig[10];
112} __packed;
113
114static struct swsusp_header *swsusp_header;
115
116/*
117 * The following functions are used for tracing the allocated swap pages, so
118 * that they can be freed in case of an error.
119 */
120struct swsusp_extent {
121 struct rb_node node;
122 unsigned long start;
123 unsigned long end;
124};
125
126static struct rb_root swsusp_extents = RB_ROOT;
127
128static int swsusp_extents_insert(unsigned long swap_offset)
129{
130 struct rb_node **new = &(swsusp_extents.rb_node);
131 struct rb_node *parent = NULL;
132 struct swsusp_extent *ext;
133
134 /* Figure out where to put the new node */
135 while (*new) {
136 ext = rb_entry(*new, struct swsusp_extent, node);
137 parent = *new;
138 if (swap_offset < ext->start) {
139 /* Try to merge */
140 if (swap_offset == ext->start - 1) {
141 ext->start--;
142 return 0;
143 }
144 new = &((*new)->rb_left);
145 } else if (swap_offset > ext->end) {
146 /* Try to merge */
147 if (swap_offset == ext->end + 1) {
148 ext->end++;
149 return 0;
150 }
151 new = &((*new)->rb_right);
152 } else {
153 /* It already is in the tree */
154 return -EINVAL;
155 }
156 }
157 /* Add the new node and rebalance the tree. */
158 ext = kzalloc_obj(struct swsusp_extent);
159 if (!ext)
160 return -ENOMEM;
161
162 ext->start = swap_offset;
163 ext->end = swap_offset;
164 rb_link_node(&ext->node, parent, new);
165 rb_insert_color(&ext->node, &swsusp_extents);
166 return 0;
167}
168
169sector_t alloc_swapdev_block(int swap)
170{
171 unsigned long offset;
172
173 /*
174 * Allocate a swap page and register that it has been allocated, so that
175 * it can be freed in case of an error.
176 */
177 offset = swp_offset(swap_alloc_hibernation_slot(swap));
178 if (offset) {
179 if (swsusp_extents_insert(offset))
180 swap_free_hibernation_slot(swp_entry(swap, offset));
181 else
182 return swapdev_block(swap, offset);
183 }
184 return 0;
185}
186
187void free_all_swap_pages(int swap)
188{
189 unsigned long offset;
190 struct rb_node *node;
191
192 /*
193 * Free swap pages allocated for saving image data. It also frees the
194 * extents used to register which swap entries had been allocated.
195 */
196 while ((node = swsusp_extents.rb_node)) {
197 struct swsusp_extent *ext;
198
199 ext = rb_entry(node, struct swsusp_extent, node);
200 rb_erase(node, &swsusp_extents);
201
202 for (offset = ext->start; offset <= ext->end; offset++)
203 swap_free_hibernation_slot(swp_entry(swap, offset));
204
205 kfree(ext);
206 }
207}
208
209int swsusp_swap_in_use(void)
210{
211 return (swsusp_extents.rb_node != NULL);
212}
213
214/*
215 * General things
216 */
217
218static unsigned short root_swap = 0xffff;
219static struct file *hib_resume_bdev_file;
220
221struct hib_bio_batch {
222 atomic_t count;
223 wait_queue_head_t wait;
224 blk_status_t error;
225 struct blk_plug plug;
226};
227
228static void hib_init_batch(struct hib_bio_batch *hb)
229{
230 atomic_set(&hb->count, 0);
231 init_waitqueue_head(&hb->wait);
232 hb->error = BLK_STS_OK;
233 blk_start_plug(&hb->plug);
234}
235
236static void hib_finish_batch(struct hib_bio_batch *hb)
237{
238 blk_finish_plug(&hb->plug);
239}
240
241static void hib_end_io(struct bio *bio)
242{
243 struct hib_bio_batch *hb = bio->bi_private;
244 struct page *page = bio_first_page_all(bio);
245
246 if (bio->bi_status) {
247 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
248 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
249 (unsigned long long)bio->bi_iter.bi_sector);
250 }
251
252 if (bio_data_dir(bio) == WRITE)
253 put_page(page);
254 else if (clean_pages_on_read)
255 flush_icache_range((unsigned long)page_address(page),
256 (unsigned long)page_address(page) + PAGE_SIZE);
257
258 if (bio->bi_status && !hb->error)
259 hb->error = bio->bi_status;
260 if (atomic_dec_and_test(&hb->count))
261 wake_up(&hb->wait);
262
263 bio_put(bio);
264}
265
266static int hib_submit_io_sync(blk_opf_t opf, pgoff_t page_off, void *addr)
267{
268 return bdev_rw_virt(file_bdev(hib_resume_bdev_file),
269 page_off * (PAGE_SIZE >> 9), addr, PAGE_SIZE, opf);
270}
271
272static int hib_submit_io_async(blk_opf_t opf, pgoff_t page_off, void *addr,
273 struct hib_bio_batch *hb)
274{
275 struct bio *bio;
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 bio_add_virt_nofail(bio, addr, PAGE_SIZE);
281 bio->bi_end_io = hib_end_io;
282 bio->bi_private = hb;
283 atomic_inc(&hb->count);
284 submit_bio(bio);
285 return 0;
286}
287
288static int hib_wait_io(struct hib_bio_batch *hb)
289{
290 /*
291 * We are relying on the behavior of blk_plug that a thread with
292 * a plug will flush the plug list before sleeping.
293 */
294 wait_event(hb->wait, atomic_read(&hb->count) == 0);
295 return blk_status_to_errno(hb->error);
296}
297
298/*
299 * Saving part
300 */
301
302static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
303{
304 int error;
305
306 hib_submit_io_sync(REQ_OP_READ, swsusp_resume_block, swsusp_header);
307 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
308 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
309 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
310 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
311 swsusp_header->image = handle->first_sector;
312 if (swsusp_hardware_signature) {
313 swsusp_header->hw_sig = swsusp_hardware_signature;
314 flags |= SF_HW_SIG;
315 }
316 swsusp_header->flags = flags;
317 if (flags & SF_CRC32_MODE)
318 swsusp_header->crc32 = handle->crc32;
319 error = hib_submit_io_sync(REQ_OP_WRITE | REQ_SYNC,
320 swsusp_resume_block, swsusp_header);
321 } else {
322 pr_err("Swap header not found!\n");
323 error = -ENODEV;
324 }
325 return error;
326}
327
328/*
329 * Hold the swsusp_header flag. This is used in software_resume() in
330 * 'kernel/power/hibernate' to check if the image is compressed and query
331 * for the compression algorithm support(if so).
332 */
333unsigned int swsusp_header_flags;
334
335static int swsusp_swap_check(void)
336{
337 int res;
338
339 /*
340 * Check if the resume device is a swap device and get its index (if so).
341 * This is called before saving the image.
342 */
343 if (swsusp_resume_device)
344 res = find_hibernation_swap_type(swsusp_resume_device, swsusp_resume_block);
345 else
346 res = find_first_swap(&swsusp_resume_device);
347 if (res < 0)
348 return res;
349 root_swap = res;
350
351 hib_resume_bdev_file = bdev_file_open_by_dev(swsusp_resume_device,
352 BLK_OPEN_WRITE, NULL, NULL);
353 if (IS_ERR(hib_resume_bdev_file))
354 return PTR_ERR(hib_resume_bdev_file);
355
356 return 0;
357}
358
359static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
360{
361 gfp_t gfp = GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY;
362 void *src;
363 int ret;
364
365 if (!offset)
366 return -ENOSPC;
367
368 if (!hb)
369 goto sync_io;
370
371 src = (void *)__get_free_page(gfp);
372 if (!src) {
373 ret = hib_wait_io(hb); /* Free pages */
374 if (ret)
375 return ret;
376 src = (void *)__get_free_page(gfp);
377 if (WARN_ON_ONCE(!src))
378 goto sync_io;
379 }
380
381 copy_page(src, buf);
382 return hib_submit_io_async(REQ_OP_WRITE | REQ_SYNC, offset, src, hb);
383sync_io:
384 return hib_submit_io_sync(REQ_OP_WRITE | REQ_SYNC, offset, buf);
385}
386
387static void release_swap_writer(struct swap_map_handle *handle)
388{
389 if (handle->cur)
390 free_page((unsigned long)handle->cur);
391 handle->cur = NULL;
392}
393
394static int get_swap_writer(struct swap_map_handle *handle)
395{
396 int ret;
397
398 ret = swsusp_swap_check();
399 if (ret) {
400 if (ret != -ENOSPC)
401 pr_err("Cannot find swap device, try swapon -a\n");
402 return ret;
403 }
404 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
405 if (!handle->cur) {
406 ret = -ENOMEM;
407 goto err_close;
408 }
409 handle->cur_swap = alloc_swapdev_block(root_swap);
410 if (!handle->cur_swap) {
411 ret = -ENOSPC;
412 goto err_rel;
413 }
414 handle->k = 0;
415 handle->reqd_free_pages = reqd_free_pages();
416 handle->first_sector = handle->cur_swap;
417 return 0;
418err_rel:
419 release_swap_writer(handle);
420err_close:
421 swsusp_close();
422 return ret;
423}
424
425static int swap_write_page(struct swap_map_handle *handle, void *buf,
426 struct hib_bio_batch *hb)
427{
428 int error;
429 sector_t offset;
430
431 if (!handle->cur)
432 return -EINVAL;
433
434 /*
435 * If the current map page is full, allocate and link next one first.
436 * Delaying this until here avoids writing an empty swap map page when
437 * the image size is an exact MAP_PAGE_ENTRIES multiple.
438 */
439 if (handle->k >= MAP_PAGE_ENTRIES) {
440 offset = alloc_swapdev_block(root_swap);
441 if (!offset)
442 return -ENOSPC;
443
444 handle->cur->next_swap = offset;
445 error = write_page(handle->cur, handle->cur_swap, hb);
446 if (error)
447 return error;
448
449 clear_page(handle->cur);
450 handle->cur_swap = offset;
451 handle->k = 0;
452
453 if (hb && low_free_pages() <= handle->reqd_free_pages) {
454 error = hib_wait_io(hb);
455 if (error)
456 return error;
457 /*
458 * Recalculate the number of required free pages, to
459 * make sure we never take more than half.
460 */
461 handle->reqd_free_pages = reqd_free_pages();
462 }
463 }
464
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 return 0;
471}
472
473static int flush_swap_writer(struct swap_map_handle *handle)
474{
475 if (handle->cur && handle->cur_swap && handle->k)
476 return write_page(handle->cur, handle->cur_swap, NULL);
477 else if (handle->cur && handle->cur_swap)
478 return 0;
479 else
480 return -EINVAL;
481}
482
483static int swap_writer_finish(struct swap_map_handle *handle,
484 unsigned int flags, int error)
485{
486 if (!error) {
487 pr_info("S");
488 error = mark_swapfiles(handle, flags);
489 pr_cont("|\n");
490 flush_swap_writer(handle);
491 }
492
493 if (error)
494 free_all_swap_pages(root_swap);
495 release_swap_writer(handle);
496 swsusp_close();
497
498 return error;
499}
500
501/*
502 * Bytes we need for compressed data in worst case. We assume(limitation)
503 * this is the worst of all the compression algorithms.
504 */
505#define bytes_worst_compress(x) ((x) + ((x) / 16) + 64 + 3 + 2)
506
507/* We need to remember how much compressed data we need to read. */
508#define CMP_HEADER sizeof(size_t)
509
510/* Number of pages/bytes we'll compress at one time. */
511#define UNC_PAGES 32
512#define UNC_SIZE (UNC_PAGES * PAGE_SIZE)
513
514/* Number of pages we need for compressed data (worst case). */
515#define CMP_PAGES DIV_ROUND_UP(bytes_worst_compress(UNC_SIZE) + \
516 CMP_HEADER, PAGE_SIZE)
517#define CMP_SIZE (CMP_PAGES * PAGE_SIZE)
518
519/* Default number of threads for compression/decompression. */
520#define CMP_THREADS 3
521static unsigned int hibernate_compression_threads = CMP_THREADS;
522
523/* Minimum/maximum number of pages for read buffering. */
524#define CMP_MIN_RD_PAGES 1024
525#define CMP_MAX_RD_PAGES 8192
526
527static int save_image(struct swap_map_handle *handle,
528 struct snapshot_handle *snapshot,
529 unsigned int nr_to_write)
530{
531 unsigned int m;
532 int ret;
533 int nr_pages;
534 int err2;
535 struct hib_bio_batch hb;
536 ktime_t start;
537 ktime_t stop;
538
539 hib_init_batch(&hb);
540
541 pr_info("Saving image data pages (%u pages)...\n",
542 nr_to_write);
543 m = nr_to_write / 10;
544 if (!m)
545 m = 1;
546 nr_pages = 0;
547 start = ktime_get();
548 while (1) {
549 ret = snapshot_read_next(snapshot);
550 if (ret <= 0)
551 break;
552 ret = swap_write_page(handle, data_of(*snapshot), &hb);
553 if (ret)
554 break;
555 if (!(nr_pages % m))
556 pr_info("Image saving progress: %3d%%\n",
557 nr_pages / m * 10);
558 nr_pages++;
559 }
560 err2 = hib_wait_io(&hb);
561 hib_finish_batch(&hb);
562 stop = ktime_get();
563 if (!ret)
564 ret = err2;
565 if (!ret)
566 pr_info("Image saving done\n");
567 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
568 return ret;
569}
570
571/*
572 * Structure used for CRC32.
573 */
574struct crc_data {
575 struct task_struct *thr; /* thread */
576 atomic_t ready; /* ready to start flag */
577 atomic_t stop; /* ready to stop flag */
578 unsigned run_threads; /* nr current threads */
579 wait_queue_head_t go; /* start crc update */
580 wait_queue_head_t done; /* crc update done */
581 u32 *crc32; /* points to handle's crc32 */
582 size_t **unc_len; /* uncompressed lengths */
583 unsigned char *unc[]; /* uncompressed data */
584};
585
586static struct crc_data *alloc_crc_data(int nr_threads)
587{
588 struct crc_data *crc;
589
590 crc = kzalloc_flex(*crc, unc, nr_threads);
591 if (!crc)
592 return NULL;
593
594 crc->unc_len = kzalloc_objs(*crc->unc_len, nr_threads);
595 if (!crc->unc_len)
596 goto err_free_crc;
597
598 return crc;
599
600err_free_crc:
601 kfree(crc);
602 return NULL;
603}
604
605static void free_crc_data(struct crc_data *crc)
606{
607 if (!crc)
608 return;
609
610 if (crc->thr)
611 kthread_stop(crc->thr);
612
613 kfree(crc->unc_len);
614 kfree(crc);
615}
616
617static int crc32_threadfn(void *data)
618{
619 struct crc_data *d = data;
620 unsigned i;
621
622 while (1) {
623 wait_event(d->go, atomic_read_acquire(&d->ready) ||
624 kthread_should_stop());
625 if (kthread_should_stop()) {
626 d->thr = NULL;
627 atomic_set_release(&d->stop, 1);
628 wake_up(&d->done);
629 break;
630 }
631 atomic_set(&d->ready, 0);
632
633 for (i = 0; i < d->run_threads; i++)
634 *d->crc32 = crc32_le(*d->crc32,
635 d->unc[i], *d->unc_len[i]);
636 atomic_set_release(&d->stop, 1);
637 wake_up(&d->done);
638 }
639 return 0;
640}
641
642/*
643 * Structure used for data compression.
644 */
645struct cmp_data {
646 struct task_struct *thr; /* thread */
647 struct crypto_acomp *cc; /* crypto compressor */
648 struct acomp_req *cr; /* crypto request */
649 atomic_t ready; /* ready to start flag */
650 atomic_t stop; /* ready to stop flag */
651 int ret; /* return code */
652 wait_queue_head_t go; /* start compression */
653 wait_queue_head_t done; /* compression done */
654 size_t unc_len; /* uncompressed length */
655 size_t cmp_len; /* compressed length */
656 unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
657 unsigned char cmp[CMP_SIZE]; /* compressed buffer */
658};
659
660/* Indicates the image size after compression */
661static atomic64_t compressed_size = ATOMIC_INIT(0);
662
663static int compress_threadfn(void *data)
664{
665 struct cmp_data *d = data;
666
667 while (1) {
668 wait_event(d->go, atomic_read_acquire(&d->ready) ||
669 kthread_should_stop());
670 if (kthread_should_stop()) {
671 d->thr = NULL;
672 d->ret = -1;
673 atomic_set_release(&d->stop, 1);
674 wake_up(&d->done);
675 break;
676 }
677 atomic_set(&d->ready, 0);
678
679 acomp_request_set_callback(d->cr, CRYPTO_TFM_REQ_MAY_SLEEP,
680 NULL, NULL);
681 acomp_request_set_src_nondma(d->cr, d->unc, d->unc_len);
682 acomp_request_set_dst_nondma(d->cr, d->cmp + CMP_HEADER,
683 CMP_SIZE - CMP_HEADER);
684 d->ret = crypto_acomp_compress(d->cr);
685 d->cmp_len = d->cr->dlen;
686
687 atomic64_add(d->cmp_len, &compressed_size);
688 atomic_set_release(&d->stop, 1);
689 wake_up(&d->done);
690 }
691 return 0;
692}
693
694static int save_compressed_image(struct swap_map_handle *handle,
695 struct snapshot_handle *snapshot,
696 unsigned int nr_to_write)
697{
698 unsigned int m;
699 int ret = 0;
700 int nr_pages;
701 int err2;
702 struct hib_bio_batch hb;
703 ktime_t start;
704 ktime_t stop;
705 size_t off;
706 unsigned int thr, run_threads, nr_threads;
707 unsigned char *page = NULL;
708 struct cmp_data *data = NULL;
709 struct crc_data *crc = NULL;
710
711 hib_init_batch(&hb);
712
713 atomic64_set(&compressed_size, 0);
714
715 /*
716 * We'll limit the number of threads for compression to limit memory
717 * footprint.
718 */
719 nr_threads = num_online_cpus() - 1;
720 nr_threads = clamp_val(nr_threads, 1, hibernate_compression_threads);
721
722 page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
723 if (!page) {
724 pr_err("Failed to allocate %s page\n", hib_comp_algo);
725 ret = -ENOMEM;
726 goto out_clean;
727 }
728
729 data = vcalloc(nr_threads, sizeof(*data));
730 if (!data) {
731 pr_err("Failed to allocate %s data\n", hib_comp_algo);
732 ret = -ENOMEM;
733 goto out_clean;
734 }
735
736 crc = alloc_crc_data(nr_threads);
737 if (!crc) {
738 pr_err("Failed to allocate crc\n");
739 ret = -ENOMEM;
740 goto out_clean;
741 }
742
743 /*
744 * Start the compression threads.
745 */
746 for (thr = 0; thr < nr_threads; thr++) {
747 init_waitqueue_head(&data[thr].go);
748 init_waitqueue_head(&data[thr].done);
749
750 data[thr].cc = crypto_alloc_acomp(hib_comp_algo, 0, CRYPTO_ALG_ASYNC);
751 if (IS_ERR_OR_NULL(data[thr].cc)) {
752 pr_err("Could not allocate comp stream %pe\n", data[thr].cc);
753 ret = -EFAULT;
754 goto out_clean;
755 }
756
757 data[thr].cr = acomp_request_alloc(data[thr].cc);
758 if (!data[thr].cr) {
759 pr_err("Could not allocate comp request\n");
760 ret = -ENOMEM;
761 goto out_clean;
762 }
763
764 data[thr].thr = kthread_run(compress_threadfn,
765 &data[thr],
766 "image_compress/%u", thr);
767 if (IS_ERR(data[thr].thr)) {
768 data[thr].thr = NULL;
769 pr_err("Cannot start compression threads\n");
770 ret = -ENOMEM;
771 goto out_clean;
772 }
773 }
774
775 /*
776 * Start the CRC32 thread.
777 */
778 init_waitqueue_head(&crc->go);
779 init_waitqueue_head(&crc->done);
780
781 handle->crc32 = 0;
782 crc->crc32 = &handle->crc32;
783 for (thr = 0; thr < nr_threads; thr++) {
784 crc->unc[thr] = data[thr].unc;
785 crc->unc_len[thr] = &data[thr].unc_len;
786 }
787
788 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
789 if (IS_ERR(crc->thr)) {
790 crc->thr = NULL;
791 pr_err("Cannot start CRC32 thread\n");
792 ret = -ENOMEM;
793 goto out_clean;
794 }
795
796 /*
797 * Adjust the number of required free pages after all allocations have
798 * been done. We don't want to run out of pages when writing.
799 */
800 handle->reqd_free_pages = reqd_free_pages();
801
802 pr_info("Using %u thread(s) for %s compression\n", nr_threads, hib_comp_algo);
803 pr_info("Compressing and saving image data (%u pages)...\n",
804 nr_to_write);
805 m = nr_to_write / 10;
806 if (!m)
807 m = 1;
808 nr_pages = 0;
809 start = ktime_get();
810 for (;;) {
811 for (thr = 0; thr < nr_threads; thr++) {
812 for (off = 0; off < UNC_SIZE; off += PAGE_SIZE) {
813 ret = snapshot_read_next(snapshot);
814 if (ret < 0)
815 goto out_finish;
816
817 if (!ret)
818 break;
819
820 memcpy(data[thr].unc + off,
821 data_of(*snapshot), PAGE_SIZE);
822
823 if (!(nr_pages % m))
824 pr_info("Image saving progress: %3d%%\n",
825 nr_pages / m * 10);
826 nr_pages++;
827 }
828 if (!off)
829 break;
830
831 data[thr].unc_len = off;
832
833 atomic_set_release(&data[thr].ready, 1);
834 wake_up(&data[thr].go);
835 }
836
837 if (!thr)
838 break;
839
840 crc->run_threads = thr;
841 atomic_set_release(&crc->ready, 1);
842 wake_up(&crc->go);
843
844 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
845 wait_event(data[thr].done,
846 atomic_read_acquire(&data[thr].stop));
847 atomic_set(&data[thr].stop, 0);
848
849 ret = data[thr].ret;
850
851 if (ret < 0) {
852 pr_err("%s compression failed\n", hib_comp_algo);
853 goto out_finish;
854 }
855
856 if (unlikely(!data[thr].cmp_len ||
857 data[thr].cmp_len >
858 bytes_worst_compress(data[thr].unc_len))) {
859 pr_err("Invalid %s compressed length\n", hib_comp_algo);
860 ret = -1;
861 goto out_finish;
862 }
863
864 *(size_t *)data[thr].cmp = data[thr].cmp_len;
865
866 /*
867 * Given we are writing one page at a time to disk, we
868 * copy that much from the buffer, although the last
869 * bit will likely be smaller than full page. This is
870 * OK - we saved the length of the compressed data, so
871 * any garbage at the end will be discarded when we
872 * read it.
873 */
874 for (off = 0;
875 off < CMP_HEADER + data[thr].cmp_len;
876 off += PAGE_SIZE) {
877 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
878
879 ret = swap_write_page(handle, page, &hb);
880 if (ret)
881 goto out_finish;
882 }
883 }
884
885 wait_event(crc->done, atomic_read_acquire(&crc->stop));
886 atomic_set(&crc->stop, 0);
887 }
888
889out_finish:
890 err2 = hib_wait_io(&hb);
891 stop = ktime_get();
892 if (!ret)
893 ret = err2;
894 if (!ret) {
895 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
896 pr_info("Image size after compression: %lld kbytes\n",
897 (atomic64_read(&compressed_size) / 1024));
898 pr_info("Image saving done\n");
899 } else {
900 pr_err("Image saving failed: %d\n", ret);
901 }
902
903out_clean:
904 hib_finish_batch(&hb);
905 free_crc_data(crc);
906 if (data) {
907 for (thr = 0; thr < nr_threads; thr++) {
908 if (data[thr].thr)
909 kthread_stop(data[thr].thr);
910
911 acomp_request_free(data[thr].cr);
912
913 if (!IS_ERR_OR_NULL(data[thr].cc))
914 crypto_free_acomp(data[thr].cc);
915 }
916 vfree(data);
917 }
918 if (page)
919 free_page((unsigned long)page);
920
921 return ret;
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 them
940 * synced (in case something goes wrong) but we DO not want to mark filesystem
941 * clean: it is not. (And it does not matter, if we resume correctly, we'll mark
942 * system clean, anyway.)
943 *
944 * Return: 0 on success, negative error code on failure.
945 */
946int swsusp_write(unsigned int flags)
947{
948 struct swap_map_handle handle;
949 struct snapshot_handle snapshot;
950 struct swsusp_info *header;
951 unsigned long pages;
952 int error;
953
954 pages = snapshot_get_image_size();
955 error = get_swap_writer(&handle);
956 if (error) {
957 pr_err("Cannot get swap writer\n");
958 return error;
959 }
960 if (flags & SF_NOCOMPRESS_MODE) {
961 if (!enough_swap(pages)) {
962 pr_err("Not enough free swap\n");
963 error = -ENOSPC;
964 goto out_finish;
965 }
966 }
967 memset(&snapshot, 0, sizeof(struct snapshot_handle));
968 error = snapshot_read_next(&snapshot);
969 if (error < (int)PAGE_SIZE) {
970 if (error >= 0)
971 error = -EFAULT;
972
973 goto out_finish;
974 }
975 header = (struct swsusp_info *)data_of(snapshot);
976 error = swap_write_page(&handle, header, NULL);
977 if (!error) {
978 error = (flags & SF_NOCOMPRESS_MODE) ?
979 save_image(&handle, &snapshot, pages - 1) :
980 save_compressed_image(&handle, &snapshot, pages - 1);
981 }
982out_finish:
983 error = swap_writer_finish(&handle, flags, error);
984 return error;
985}
986
987/*
988 * The following functions allow us to read data using a swap map in a file-like
989 * way.
990 */
991
992static void release_swap_reader(struct swap_map_handle *handle)
993{
994 struct swap_map_page_list *tmp;
995
996 while (handle->maps) {
997 if (handle->maps->map)
998 free_page((unsigned long)handle->maps->map);
999 tmp = handle->maps;
1000 handle->maps = handle->maps->next;
1001 kfree(tmp);
1002 }
1003 handle->cur = NULL;
1004}
1005
1006static int get_swap_reader(struct swap_map_handle *handle,
1007 unsigned int *flags_p)
1008{
1009 int error;
1010 struct swap_map_page_list *tmp, *last;
1011 sector_t offset;
1012
1013 *flags_p = swsusp_header->flags;
1014
1015 if (!swsusp_header->image) /* how can this happen? */
1016 return -EINVAL;
1017
1018 handle->cur = NULL;
1019 last = handle->maps = NULL;
1020 offset = swsusp_header->image;
1021 while (offset) {
1022 tmp = kzalloc_obj(*handle->maps);
1023 if (!tmp) {
1024 release_swap_reader(handle);
1025 return -ENOMEM;
1026 }
1027 if (!handle->maps)
1028 handle->maps = tmp;
1029 if (last)
1030 last->next = tmp;
1031 last = tmp;
1032
1033 tmp->map = (struct swap_map_page *)
1034 __get_free_page(GFP_NOIO | __GFP_HIGH);
1035 if (!tmp->map) {
1036 release_swap_reader(handle);
1037 return -ENOMEM;
1038 }
1039
1040 error = hib_submit_io_sync(REQ_OP_READ, offset, tmp->map);
1041 if (error) {
1042 release_swap_reader(handle);
1043 return error;
1044 }
1045 offset = tmp->map->next_swap;
1046 }
1047 handle->k = 0;
1048 handle->cur = handle->maps->map;
1049 return 0;
1050}
1051
1052static int swap_read_page(struct swap_map_handle *handle, void *buf,
1053 struct hib_bio_batch *hb)
1054{
1055 sector_t offset;
1056 int error;
1057 struct swap_map_page_list *tmp;
1058
1059 if (!handle->cur)
1060 return -EINVAL;
1061 offset = handle->cur->entries[handle->k];
1062 if (!offset)
1063 return -EFAULT;
1064 if (hb)
1065 error = hib_submit_io_async(REQ_OP_READ, offset, buf, hb);
1066 else
1067 error = hib_submit_io_sync(REQ_OP_READ, offset, buf);
1068 if (error)
1069 return error;
1070 if (++handle->k >= MAP_PAGE_ENTRIES) {
1071 handle->k = 0;
1072 free_page((unsigned long)handle->maps->map);
1073 tmp = handle->maps;
1074 handle->maps = handle->maps->next;
1075 kfree(tmp);
1076 if (!handle->maps)
1077 release_swap_reader(handle);
1078 else
1079 handle->cur = handle->maps->map;
1080 }
1081 return error;
1082}
1083
1084static int swap_reader_finish(struct swap_map_handle *handle)
1085{
1086 release_swap_reader(handle);
1087
1088 return 0;
1089}
1090
1091static int load_image(struct swap_map_handle *handle,
1092 struct snapshot_handle *snapshot,
1093 unsigned int nr_to_read)
1094{
1095 unsigned int m;
1096 int ret = 0;
1097 ktime_t start;
1098 ktime_t stop;
1099 struct hib_bio_batch hb;
1100 int err2;
1101 unsigned nr_pages;
1102
1103 hib_init_batch(&hb);
1104
1105 clean_pages_on_read = true;
1106 pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1107 m = nr_to_read / 10;
1108 if (!m)
1109 m = 1;
1110 nr_pages = 0;
1111 start = ktime_get();
1112 for ( ; ; ) {
1113 ret = snapshot_write_next(snapshot);
1114 if (ret <= 0)
1115 break;
1116 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1117 if (ret)
1118 break;
1119 if (snapshot->sync_read)
1120 ret = hib_wait_io(&hb);
1121 if (ret)
1122 break;
1123 if (!(nr_pages % m))
1124 pr_info("Image loading progress: %3d%%\n",
1125 nr_pages / m * 10);
1126 nr_pages++;
1127 }
1128 err2 = hib_wait_io(&hb);
1129 hib_finish_batch(&hb);
1130 stop = ktime_get();
1131 if (!ret)
1132 ret = err2;
1133 if (!ret) {
1134 pr_info("Image loading done\n");
1135 ret = snapshot_write_finalize(snapshot);
1136 if (!ret && !snapshot_image_loaded(snapshot))
1137 ret = -ENODATA;
1138 }
1139 swsusp_show_speed(start, stop, nr_to_read, "Read");
1140 return ret;
1141}
1142
1143/*
1144 * Structure used for data decompression.
1145 */
1146struct dec_data {
1147 struct task_struct *thr; /* thread */
1148 struct crypto_acomp *cc; /* crypto compressor */
1149 struct acomp_req *cr; /* crypto request */
1150 atomic_t ready; /* ready to start flag */
1151 atomic_t stop; /* ready to stop flag */
1152 int ret; /* return code */
1153 wait_queue_head_t go; /* start decompression */
1154 wait_queue_head_t done; /* decompression done */
1155 size_t unc_len; /* uncompressed length */
1156 size_t cmp_len; /* compressed length */
1157 unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
1158 unsigned char cmp[CMP_SIZE]; /* compressed buffer */
1159};
1160
1161static int decompress_threadfn(void *data)
1162{
1163 struct dec_data *d = data;
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 acomp_request_set_callback(d->cr, CRYPTO_TFM_REQ_MAY_SLEEP,
1178 NULL, NULL);
1179 acomp_request_set_src_nondma(d->cr, d->cmp + CMP_HEADER,
1180 d->cmp_len);
1181 acomp_request_set_dst_nondma(d->cr, d->unc, UNC_SIZE);
1182 d->ret = crypto_acomp_decompress(d->cr);
1183 d->unc_len = d->cr->dlen;
1184
1185 if (clean_pages_on_decompress)
1186 flush_icache_range((unsigned long)d->unc,
1187 (unsigned long)d->unc + d->unc_len);
1188
1189 atomic_set_release(&d->stop, 1);
1190 wake_up(&d->done);
1191 }
1192 return 0;
1193}
1194
1195static int load_compressed_image(struct swap_map_handle *handle,
1196 struct snapshot_handle *snapshot,
1197 unsigned int nr_to_read)
1198{
1199 unsigned int m;
1200 int ret = 0;
1201 int eof = 0;
1202 struct hib_bio_batch hb;
1203 ktime_t start;
1204 ktime_t stop;
1205 unsigned nr_pages;
1206 size_t off;
1207 unsigned i, thr, run_threads, nr_threads;
1208 unsigned ring = 0, pg = 0, ring_size = 0,
1209 have = 0, want, need, asked = 0;
1210 unsigned long read_pages = 0;
1211 unsigned char **page = NULL;
1212 struct dec_data *data = NULL;
1213 struct crc_data *crc = NULL;
1214
1215 hib_init_batch(&hb);
1216
1217 /*
1218 * We'll limit the number of threads for decompression to limit memory
1219 * footprint.
1220 */
1221 nr_threads = num_online_cpus() - 1;
1222 nr_threads = clamp_val(nr_threads, 1, hibernate_compression_threads);
1223
1224 page = vmalloc_array(CMP_MAX_RD_PAGES, sizeof(*page));
1225 if (!page) {
1226 pr_err("Failed to allocate %s page\n", hib_comp_algo);
1227 ret = -ENOMEM;
1228 goto out_clean;
1229 }
1230
1231 data = vcalloc(nr_threads, sizeof(*data));
1232 if (!data) {
1233 pr_err("Failed to allocate %s data\n", hib_comp_algo);
1234 ret = -ENOMEM;
1235 goto out_clean;
1236 }
1237
1238 crc = alloc_crc_data(nr_threads);
1239 if (!crc) {
1240 pr_err("Failed to allocate crc\n");
1241 ret = -ENOMEM;
1242 goto out_clean;
1243 }
1244
1245 clean_pages_on_decompress = true;
1246
1247 /*
1248 * Start the decompression threads.
1249 */
1250 for (thr = 0; thr < nr_threads; thr++) {
1251 init_waitqueue_head(&data[thr].go);
1252 init_waitqueue_head(&data[thr].done);
1253
1254 data[thr].cc = crypto_alloc_acomp(hib_comp_algo, 0, CRYPTO_ALG_ASYNC);
1255 if (IS_ERR_OR_NULL(data[thr].cc)) {
1256 pr_err("Could not allocate comp stream %pe\n", data[thr].cc);
1257 ret = -EFAULT;
1258 goto out_clean;
1259 }
1260
1261 data[thr].cr = acomp_request_alloc(data[thr].cc);
1262 if (!data[thr].cr) {
1263 pr_err("Could not allocate comp request\n");
1264 ret = -ENOMEM;
1265 goto out_clean;
1266 }
1267
1268 data[thr].thr = kthread_run(decompress_threadfn,
1269 &data[thr],
1270 "image_decompress/%u", thr);
1271 if (IS_ERR(data[thr].thr)) {
1272 data[thr].thr = NULL;
1273 pr_err("Cannot start decompression threads\n");
1274 ret = -ENOMEM;
1275 goto out_clean;
1276 }
1277 }
1278
1279 /*
1280 * Start the CRC32 thread.
1281 */
1282 init_waitqueue_head(&crc->go);
1283 init_waitqueue_head(&crc->done);
1284
1285 handle->crc32 = 0;
1286 crc->crc32 = &handle->crc32;
1287 for (thr = 0; thr < nr_threads; thr++) {
1288 crc->unc[thr] = data[thr].unc;
1289 crc->unc_len[thr] = &data[thr].unc_len;
1290 }
1291
1292 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1293 if (IS_ERR(crc->thr)) {
1294 crc->thr = NULL;
1295 pr_err("Cannot start CRC32 thread\n");
1296 ret = -ENOMEM;
1297 goto out_clean;
1298 }
1299
1300 /*
1301 * Set the number of pages for read buffering.
1302 * This is complete guesswork, because we'll only know the real
1303 * picture once prepare_image() is called, which is much later on
1304 * during the image load phase. We'll assume the worst case and
1305 * say that none of the image pages are from high memory.
1306 */
1307 if (low_free_pages() > snapshot_get_image_size())
1308 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1309 read_pages = clamp_val(read_pages, CMP_MIN_RD_PAGES, CMP_MAX_RD_PAGES);
1310
1311 for (i = 0; i < read_pages; i++) {
1312 page[i] = (void *)__get_free_page(i < CMP_PAGES ?
1313 GFP_NOIO | __GFP_HIGH :
1314 GFP_NOIO | __GFP_NOWARN |
1315 __GFP_NORETRY);
1316
1317 if (!page[i]) {
1318 if (i < CMP_PAGES) {
1319 ring_size = i;
1320 pr_err("Failed to allocate %s pages\n", hib_comp_algo);
1321 ret = -ENOMEM;
1322 goto out_clean;
1323 } else {
1324 break;
1325 }
1326 }
1327 }
1328 want = ring_size = i;
1329
1330 pr_info("Using %u thread(s) for %s decompression\n", nr_threads, hib_comp_algo);
1331 pr_info("Loading and decompressing image data (%u pages)...\n",
1332 nr_to_read);
1333 m = nr_to_read / 10;
1334 if (!m)
1335 m = 1;
1336 nr_pages = 0;
1337 start = ktime_get();
1338
1339 ret = snapshot_write_next(snapshot);
1340 if (ret <= 0)
1341 goto out_finish;
1342
1343 for(;;) {
1344 for (i = 0; !eof && i < want; i++) {
1345 ret = swap_read_page(handle, page[ring], &hb);
1346 if (ret) {
1347 /*
1348 * On real read error, finish. On end of data,
1349 * set EOF flag and just exit the read loop.
1350 */
1351 if (handle->cur &&
1352 handle->cur->entries[handle->k]) {
1353 goto out_finish;
1354 } else {
1355 eof = 1;
1356 break;
1357 }
1358 }
1359 if (++ring >= ring_size)
1360 ring = 0;
1361 }
1362 asked += i;
1363 want -= i;
1364
1365 /*
1366 * We are out of data, wait for some more.
1367 */
1368 if (!have) {
1369 if (!asked)
1370 break;
1371
1372 ret = hib_wait_io(&hb);
1373 if (ret)
1374 goto out_finish;
1375 have += asked;
1376 asked = 0;
1377 if (eof)
1378 eof = 2;
1379 }
1380
1381 if (crc->run_threads) {
1382 wait_event(crc->done, atomic_read_acquire(&crc->stop));
1383 atomic_set(&crc->stop, 0);
1384 crc->run_threads = 0;
1385 }
1386
1387 for (thr = 0; have && thr < nr_threads; thr++) {
1388 data[thr].cmp_len = *(size_t *)page[pg];
1389 if (unlikely(!data[thr].cmp_len ||
1390 data[thr].cmp_len >
1391 bytes_worst_compress(UNC_SIZE))) {
1392 pr_err("Invalid %s compressed length\n", hib_comp_algo);
1393 ret = -1;
1394 goto out_finish;
1395 }
1396
1397 need = DIV_ROUND_UP(data[thr].cmp_len + CMP_HEADER,
1398 PAGE_SIZE);
1399 if (need > have) {
1400 if (eof > 1) {
1401 ret = -1;
1402 goto out_finish;
1403 }
1404 break;
1405 }
1406
1407 for (off = 0;
1408 off < CMP_HEADER + data[thr].cmp_len;
1409 off += PAGE_SIZE) {
1410 memcpy(data[thr].cmp + off,
1411 page[pg], PAGE_SIZE);
1412 have--;
1413 want++;
1414 if (++pg >= ring_size)
1415 pg = 0;
1416 }
1417
1418 atomic_set_release(&data[thr].ready, 1);
1419 wake_up(&data[thr].go);
1420 }
1421
1422 /*
1423 * Wait for more data while we are decompressing.
1424 */
1425 if (have < CMP_PAGES && asked) {
1426 ret = hib_wait_io(&hb);
1427 if (ret)
1428 goto out_finish;
1429 have += asked;
1430 asked = 0;
1431 if (eof)
1432 eof = 2;
1433 }
1434
1435 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1436 wait_event(data[thr].done,
1437 atomic_read_acquire(&data[thr].stop));
1438 atomic_set(&data[thr].stop, 0);
1439
1440 ret = data[thr].ret;
1441
1442 if (ret < 0) {
1443 pr_err("%s decompression failed\n", hib_comp_algo);
1444 goto out_finish;
1445 }
1446
1447 if (unlikely(!data[thr].unc_len ||
1448 data[thr].unc_len > UNC_SIZE ||
1449 data[thr].unc_len & (PAGE_SIZE - 1))) {
1450 pr_err("Invalid %s uncompressed length\n", hib_comp_algo);
1451 ret = -1;
1452 goto out_finish;
1453 }
1454
1455 for (off = 0;
1456 off < data[thr].unc_len; off += PAGE_SIZE) {
1457 memcpy(data_of(*snapshot),
1458 data[thr].unc + off, PAGE_SIZE);
1459
1460 if (!(nr_pages % m))
1461 pr_info("Image loading progress: %3d%%\n",
1462 nr_pages / m * 10);
1463 nr_pages++;
1464
1465 ret = snapshot_write_next(snapshot);
1466 if (ret <= 0) {
1467 crc->run_threads = thr + 1;
1468 atomic_set_release(&crc->ready, 1);
1469 wake_up(&crc->go);
1470 goto out_finish;
1471 }
1472 }
1473 }
1474
1475 crc->run_threads = thr;
1476 atomic_set_release(&crc->ready, 1);
1477 wake_up(&crc->go);
1478 }
1479
1480out_finish:
1481 if (crc->run_threads) {
1482 wait_event(crc->done, atomic_read_acquire(&crc->stop));
1483 atomic_set(&crc->stop, 0);
1484 }
1485 stop = ktime_get();
1486 if (!ret) {
1487 pr_info("Image loading done\n");
1488 ret = snapshot_write_finalize(snapshot);
1489 if (!ret && !snapshot_image_loaded(snapshot))
1490 ret = -ENODATA;
1491 if (!ret) {
1492 if (swsusp_header->flags & SF_CRC32_MODE) {
1493 if(handle->crc32 != swsusp_header->crc32) {
1494 pr_err("Invalid image CRC32!\n");
1495 ret = -ENODATA;
1496 }
1497 }
1498 }
1499 }
1500 swsusp_show_speed(start, stop, nr_to_read, "Read");
1501out_clean:
1502 hib_finish_batch(&hb);
1503 for (i = 0; i < ring_size; i++)
1504 free_page((unsigned long)page[i]);
1505 free_crc_data(crc);
1506 if (data) {
1507 for (thr = 0; thr < nr_threads; thr++) {
1508 if (data[thr].thr)
1509 kthread_stop(data[thr].thr);
1510
1511 acomp_request_free(data[thr].cr);
1512
1513 if (!IS_ERR_OR_NULL(data[thr].cc))
1514 crypto_free_acomp(data[thr].cc);
1515 }
1516 vfree(data);
1517 }
1518 vfree(page);
1519
1520 return ret;
1521}
1522
1523/**
1524 * swsusp_read - read the hibernation image.
1525 * @flags_p: flags passed by the "frozen" kernel in the image header should
1526 * be written into this memory location
1527 *
1528 * Return: 0 on success, negative error code on failure.
1529 */
1530int swsusp_read(unsigned int *flags_p)
1531{
1532 int error;
1533 struct swap_map_handle handle;
1534 struct snapshot_handle snapshot;
1535 struct swsusp_info *header;
1536
1537 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1538 error = snapshot_write_next(&snapshot);
1539 if (error < (int)PAGE_SIZE)
1540 return error < 0 ? error : -EFAULT;
1541 header = (struct swsusp_info *)data_of(snapshot);
1542 error = get_swap_reader(&handle, flags_p);
1543 if (error)
1544 goto end;
1545 if (!error)
1546 error = swap_read_page(&handle, header, NULL);
1547 if (!error) {
1548 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1549 load_image(&handle, &snapshot, header->pages - 1) :
1550 load_compressed_image(&handle, &snapshot, header->pages - 1);
1551 }
1552 swap_reader_finish(&handle);
1553end:
1554 if (!error)
1555 pr_debug("Image successfully loaded\n");
1556 else
1557 pr_debug("Error %d resuming\n", error);
1558 return error;
1559}
1560
1561static void *swsusp_holder;
1562
1563/**
1564 * swsusp_check - Open the resume device and check for the swsusp signature.
1565 * @exclusive: Open the resume device exclusively.
1566 *
1567 * Return: 0 if a valid image is found, negative error code otherwise.
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 clear_page(swsusp_header);
1578 error = hib_submit_io_sync(REQ_OP_READ, swsusp_resume_block,
1579 swsusp_header);
1580 if (error)
1581 goto put;
1582
1583 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1584 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1585 swsusp_header_flags = swsusp_header->flags;
1586 /* Reset swap signature now */
1587 error = hib_submit_io_sync(REQ_OP_WRITE | REQ_SYNC,
1588 swsusp_resume_block,
1589 swsusp_header);
1590 } else {
1591 error = -EINVAL;
1592 }
1593 if (!error && swsusp_header->flags & SF_HW_SIG &&
1594 swsusp_header->hw_sig != swsusp_hardware_signature) {
1595 pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
1596 swsusp_header->hw_sig, swsusp_hardware_signature);
1597 error = -EINVAL;
1598 }
1599
1600put:
1601 if (error)
1602 bdev_fput(hib_resume_bdev_file);
1603 else
1604 pr_debug("Image signature found, resuming\n");
1605 } else {
1606 error = PTR_ERR(hib_resume_bdev_file);
1607 }
1608
1609 if (error)
1610 pr_debug("Image not found (code %d)\n", error);
1611
1612 return error;
1613}
1614
1615/**
1616 * swsusp_close - close resume device.
1617 */
1618void swsusp_close(void)
1619{
1620 if (IS_ERR(hib_resume_bdev_file)) {
1621 pr_debug("Image device not initialised\n");
1622 return;
1623 }
1624
1625 fput(hib_resume_bdev_file);
1626}
1627
1628/**
1629 * swsusp_unmark - Unmark swsusp signature in the resume device
1630 *
1631 * Return: 0 on success, negative error code on failure.
1632 */
1633#ifdef CONFIG_SUSPEND
1634int swsusp_unmark(void)
1635{
1636 int error;
1637
1638 hib_submit_io_sync(REQ_OP_READ, swsusp_resume_block, swsusp_header);
1639 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1640 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1641 error = hib_submit_io_sync(REQ_OP_WRITE | REQ_SYNC,
1642 swsusp_resume_block,
1643 swsusp_header);
1644 } else {
1645 pr_err("Cannot find swsusp signature!\n");
1646 error = -ENODEV;
1647 }
1648
1649 /*
1650 * We just returned from suspend, we don't need the image any more.
1651 */
1652 free_all_swap_pages(root_swap);
1653
1654 return error;
1655}
1656#endif
1657
1658static ssize_t hibernate_compression_threads_show(struct kobject *kobj,
1659 struct kobj_attribute *attr, char *buf)
1660{
1661 return sysfs_emit(buf, "%d\n", hibernate_compression_threads);
1662}
1663
1664static ssize_t hibernate_compression_threads_store(struct kobject *kobj,
1665 struct kobj_attribute *attr,
1666 const char *buf, size_t n)
1667{
1668 unsigned long val;
1669
1670 if (kstrtoul(buf, 0, &val))
1671 return -EINVAL;
1672
1673 if (val < 1)
1674 return -EINVAL;
1675
1676 hibernate_compression_threads = val;
1677 return n;
1678}
1679power_attr(hibernate_compression_threads);
1680
1681static struct attribute *g[] = {
1682 &hibernate_compression_threads_attr.attr,
1683 NULL,
1684};
1685
1686static const struct attribute_group attr_group = {
1687 .attrs = g,
1688};
1689
1690static int __init swsusp_header_init(void)
1691{
1692 int error;
1693
1694 error = sysfs_create_group(power_kobj, &attr_group);
1695 if (error)
1696 return -ENOMEM;
1697
1698 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1699 if (!swsusp_header)
1700 panic("Could not allocate memory for swsusp_header\n");
1701 return 0;
1702}
1703
1704core_initcall(swsusp_header_init);
1705
1706static int __init hibernate_compression_threads_setup(char *str)
1707{
1708 int rc = kstrtouint(str, 0, &hibernate_compression_threads);
1709
1710 if (rc)
1711 return rc;
1712
1713 if (hibernate_compression_threads < 1)
1714 hibernate_compression_threads = CMP_THREADS;
1715
1716 return 1;
1717
1718}
1719
1720__setup("hibernate_compression_threads=", hibernate_compression_threads_setup);