xref: /linux/kernel/power/swap.c (revision 6a069876eb1402478900ee0eb7d7fe276bb1f4e3)
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 <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 
38 u32 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  */
45 static bool clean_pages_on_read;
46 static 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  */
66 static inline unsigned long low_free_pages(void)
67 {
68 	return nr_free_pages() - nr_free_highpages();
69 }
70 
71 /*
72  * Number of pages required to be kept free while writing the image. Always
73  * half of all available low pages before the writing starts.
74  */
75 static inline unsigned long reqd_free_pages(void)
76 {
77 	return low_free_pages() / 2;
78 }
79 
80 struct swap_map_page {
81 	sector_t entries[MAP_PAGE_ENTRIES];
82 	sector_t next_swap;
83 };
84 
85 struct swap_map_page_list {
86 	struct swap_map_page *map;
87 	struct swap_map_page_list *next;
88 };
89 
90 /*
91  * The swap_map_handle structure is used for handling swap in a file-alike way.
92  */
93 struct 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 
103 struct 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 
114 static 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  */
120 struct swsusp_extent {
121 	struct rb_node node;
122 	unsigned long start;
123 	unsigned long end;
124 };
125 
126 static struct rb_root swsusp_extents = RB_ROOT;
127 
128 static 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(sizeof(struct swsusp_extent), GFP_KERNEL);
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 
169 sector_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(get_swap_page_of_type(swap));
178 	if (offset) {
179 		if (swsusp_extents_insert(offset))
180 			swap_free(swp_entry(swap, offset));
181 		else
182 			return swapdev_block(swap, offset);
183 	}
184 	return 0;
185 }
186 
187 void free_all_swap_pages(int swap)
188 {
189 	struct rb_node *node;
190 
191 	/*
192 	 * Free swap pages allocated for saving image data.  It also frees the
193 	 * extents used to register which swap entries had been allocated.
194 	 */
195 	while ((node = swsusp_extents.rb_node)) {
196 		struct swsusp_extent *ext;
197 
198 		ext = rb_entry(node, struct swsusp_extent, node);
199 		rb_erase(node, &swsusp_extents);
200 		swap_free_nr(swp_entry(swap, ext->start),
201 			     ext->end - ext->start + 1);
202 
203 		kfree(ext);
204 	}
205 }
206 
207 int swsusp_swap_in_use(void)
208 {
209 	return (swsusp_extents.rb_node != NULL);
210 }
211 
212 /*
213  * General things
214  */
215 
216 static unsigned short root_swap = 0xffff;
217 static struct file *hib_resume_bdev_file;
218 
219 struct hib_bio_batch {
220 	atomic_t		count;
221 	wait_queue_head_t	wait;
222 	blk_status_t		error;
223 	struct blk_plug		plug;
224 };
225 
226 static void hib_init_batch(struct hib_bio_batch *hb)
227 {
228 	atomic_set(&hb->count, 0);
229 	init_waitqueue_head(&hb->wait);
230 	hb->error = BLK_STS_OK;
231 	blk_start_plug(&hb->plug);
232 }
233 
234 static void hib_finish_batch(struct hib_bio_batch *hb)
235 {
236 	blk_finish_plug(&hb->plug);
237 }
238 
239 static void hib_end_io(struct bio *bio)
240 {
241 	struct hib_bio_batch *hb = bio->bi_private;
242 	struct page *page = bio_first_page_all(bio);
243 
244 	if (bio->bi_status) {
245 		pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
246 			 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
247 			 (unsigned long long)bio->bi_iter.bi_sector);
248 	}
249 
250 	if (bio_data_dir(bio) == WRITE)
251 		put_page(page);
252 	else if (clean_pages_on_read)
253 		flush_icache_range((unsigned long)page_address(page),
254 				   (unsigned long)page_address(page) + PAGE_SIZE);
255 
256 	if (bio->bi_status && !hb->error)
257 		hb->error = bio->bi_status;
258 	if (atomic_dec_and_test(&hb->count))
259 		wake_up(&hb->wait);
260 
261 	bio_put(bio);
262 }
263 
264 static int hib_submit_io_sync(blk_opf_t opf, pgoff_t page_off, void *addr)
265 {
266 	return bdev_rw_virt(file_bdev(hib_resume_bdev_file),
267 			page_off * (PAGE_SIZE >> 9), addr, PAGE_SIZE, opf);
268 }
269 
270 static int hib_submit_io_async(blk_opf_t opf, pgoff_t page_off, void *addr,
271 			 struct hib_bio_batch *hb)
272 {
273 	struct bio *bio;
274 
275 	bio = bio_alloc(file_bdev(hib_resume_bdev_file), 1, opf,
276 			GFP_NOIO | __GFP_HIGH);
277 	bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
278 	bio_add_virt_nofail(bio, addr, PAGE_SIZE);
279 	bio->bi_end_io = hib_end_io;
280 	bio->bi_private = hb;
281 	atomic_inc(&hb->count);
282 	submit_bio(bio);
283 	return 0;
284 }
285 
286 static int hib_wait_io(struct hib_bio_batch *hb)
287 {
288 	/*
289 	 * We are relying on the behavior of blk_plug that a thread with
290 	 * a plug will flush the plug list before sleeping.
291 	 */
292 	wait_event(hb->wait, atomic_read(&hb->count) == 0);
293 	return blk_status_to_errno(hb->error);
294 }
295 
296 /*
297  * Saving part
298  */
299 
300 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
301 {
302 	int error;
303 
304 	hib_submit_io_sync(REQ_OP_READ, swsusp_resume_block, swsusp_header);
305 	if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
306 	    !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
307 		memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
308 		memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
309 		swsusp_header->image = handle->first_sector;
310 		if (swsusp_hardware_signature) {
311 			swsusp_header->hw_sig = swsusp_hardware_signature;
312 			flags |= SF_HW_SIG;
313 		}
314 		swsusp_header->flags = flags;
315 		if (flags & SF_CRC32_MODE)
316 			swsusp_header->crc32 = handle->crc32;
317 		error = hib_submit_io_sync(REQ_OP_WRITE | REQ_SYNC,
318 				      swsusp_resume_block, swsusp_header);
319 	} else {
320 		pr_err("Swap header not found!\n");
321 		error = -ENODEV;
322 	}
323 	return error;
324 }
325 
326 /*
327  * Hold the swsusp_header flag. This is used in software_resume() in
328  * 'kernel/power/hibernate' to check if the image is compressed and query
329  * for the compression algorithm support(if so).
330  */
331 unsigned int swsusp_header_flags;
332 
333 static int swsusp_swap_check(void)
334 {
335 	int res;
336 
337 	/*
338 	 * Check if the resume device is a swap device and get its index (if so).
339 	 * This is called before saving the image.
340 	 */
341 	if (swsusp_resume_device)
342 		res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
343 	else
344 		res = find_first_swap(&swsusp_resume_device);
345 	if (res < 0)
346 		return res;
347 	root_swap = res;
348 
349 	hib_resume_bdev_file = bdev_file_open_by_dev(swsusp_resume_device,
350 			BLK_OPEN_WRITE, NULL, NULL);
351 	if (IS_ERR(hib_resume_bdev_file))
352 		return PTR_ERR(hib_resume_bdev_file);
353 
354 	return 0;
355 }
356 
357 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
358 {
359 	gfp_t gfp = GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY;
360 	void *src;
361 	int ret;
362 
363 	if (!offset)
364 		return -ENOSPC;
365 
366 	if (!hb)
367 		goto sync_io;
368 
369 	src = (void *)__get_free_page(gfp);
370 	if (!src) {
371 		ret = hib_wait_io(hb); /* Free pages */
372 		if (ret)
373 			return ret;
374 		src = (void *)__get_free_page(gfp);
375 		if (WARN_ON_ONCE(!src))
376 			goto sync_io;
377 	}
378 
379 	copy_page(src, buf);
380 	return hib_submit_io_async(REQ_OP_WRITE | REQ_SYNC, offset, src, hb);
381 sync_io:
382 	return hib_submit_io_sync(REQ_OP_WRITE | REQ_SYNC, offset, buf);
383 }
384 
385 static void release_swap_writer(struct swap_map_handle *handle)
386 {
387 	if (handle->cur)
388 		free_page((unsigned long)handle->cur);
389 	handle->cur = NULL;
390 }
391 
392 static int get_swap_writer(struct swap_map_handle *handle)
393 {
394 	int ret;
395 
396 	ret = swsusp_swap_check();
397 	if (ret) {
398 		if (ret != -ENOSPC)
399 			pr_err("Cannot find swap device, try swapon -a\n");
400 		return ret;
401 	}
402 	handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
403 	if (!handle->cur) {
404 		ret = -ENOMEM;
405 		goto err_close;
406 	}
407 	handle->cur_swap = alloc_swapdev_block(root_swap);
408 	if (!handle->cur_swap) {
409 		ret = -ENOSPC;
410 		goto err_rel;
411 	}
412 	handle->k = 0;
413 	handle->reqd_free_pages = reqd_free_pages();
414 	handle->first_sector = handle->cur_swap;
415 	return 0;
416 err_rel:
417 	release_swap_writer(handle);
418 err_close:
419 	swsusp_close();
420 	return ret;
421 }
422 
423 static int swap_write_page(struct swap_map_handle *handle, void *buf,
424 		struct hib_bio_batch *hb)
425 {
426 	int error;
427 	sector_t offset;
428 
429 	if (!handle->cur)
430 		return -EINVAL;
431 	offset = alloc_swapdev_block(root_swap);
432 	error = write_page(buf, offset, hb);
433 	if (error)
434 		return error;
435 	handle->cur->entries[handle->k++] = offset;
436 	if (handle->k >= MAP_PAGE_ENTRIES) {
437 		offset = alloc_swapdev_block(root_swap);
438 		if (!offset)
439 			return -ENOSPC;
440 		handle->cur->next_swap = offset;
441 		error = write_page(handle->cur, handle->cur_swap, hb);
442 		if (error)
443 			goto out;
444 		clear_page(handle->cur);
445 		handle->cur_swap = offset;
446 		handle->k = 0;
447 
448 		if (hb && low_free_pages() <= handle->reqd_free_pages) {
449 			error = hib_wait_io(hb);
450 			if (error)
451 				goto out;
452 			/*
453 			 * Recalculate the number of required free pages, to
454 			 * make sure we never take more than half.
455 			 */
456 			handle->reqd_free_pages = reqd_free_pages();
457 		}
458 	}
459  out:
460 	return error;
461 }
462 
463 static int flush_swap_writer(struct swap_map_handle *handle)
464 {
465 	if (handle->cur && handle->cur_swap)
466 		return write_page(handle->cur, handle->cur_swap, NULL);
467 	else
468 		return -EINVAL;
469 }
470 
471 static int swap_writer_finish(struct swap_map_handle *handle,
472 		unsigned int flags, int error)
473 {
474 	if (!error) {
475 		pr_info("S");
476 		error = mark_swapfiles(handle, flags);
477 		pr_cont("|\n");
478 		flush_swap_writer(handle);
479 	}
480 
481 	if (error)
482 		free_all_swap_pages(root_swap);
483 	release_swap_writer(handle);
484 	swsusp_close();
485 
486 	return error;
487 }
488 
489 /*
490  * Bytes we need for compressed data in worst case. We assume(limitation)
491  * this is the worst of all the compression algorithms.
492  */
493 #define bytes_worst_compress(x) ((x) + ((x) / 16) + 64 + 3 + 2)
494 
495 /* We need to remember how much compressed data we need to read. */
496 #define CMP_HEADER	sizeof(size_t)
497 
498 /* Number of pages/bytes we'll compress at one time. */
499 #define UNC_PAGES	32
500 #define UNC_SIZE	(UNC_PAGES * PAGE_SIZE)
501 
502 /* Number of pages we need for compressed data (worst case). */
503 #define CMP_PAGES	DIV_ROUND_UP(bytes_worst_compress(UNC_SIZE) + \
504 				CMP_HEADER, PAGE_SIZE)
505 #define CMP_SIZE	(CMP_PAGES * PAGE_SIZE)
506 
507 /* Default number of threads for compression/decompression. */
508 #define CMP_THREADS    3
509 static unsigned int hibernate_compression_threads = CMP_THREADS;
510 
511 /* Minimum/maximum number of pages for read buffering. */
512 #define CMP_MIN_RD_PAGES	1024
513 #define CMP_MAX_RD_PAGES	8192
514 
515 static int save_image(struct swap_map_handle *handle,
516                       struct snapshot_handle *snapshot,
517                       unsigned int nr_to_write)
518 {
519 	unsigned int m;
520 	int ret;
521 	int nr_pages;
522 	int err2;
523 	struct hib_bio_batch hb;
524 	ktime_t start;
525 	ktime_t stop;
526 
527 	hib_init_batch(&hb);
528 
529 	pr_info("Saving image data pages (%u pages)...\n",
530 		nr_to_write);
531 	m = nr_to_write / 10;
532 	if (!m)
533 		m = 1;
534 	nr_pages = 0;
535 	start = ktime_get();
536 	while (1) {
537 		ret = snapshot_read_next(snapshot);
538 		if (ret <= 0)
539 			break;
540 		ret = swap_write_page(handle, data_of(*snapshot), &hb);
541 		if (ret)
542 			break;
543 		if (!(nr_pages % m))
544 			pr_info("Image saving progress: %3d%%\n",
545 				nr_pages / m * 10);
546 		nr_pages++;
547 	}
548 	err2 = hib_wait_io(&hb);
549 	hib_finish_batch(&hb);
550 	stop = ktime_get();
551 	if (!ret)
552 		ret = err2;
553 	if (!ret)
554 		pr_info("Image saving done\n");
555 	swsusp_show_speed(start, stop, nr_to_write, "Wrote");
556 	return ret;
557 }
558 
559 /*
560  * Structure used for CRC32.
561  */
562 struct crc_data {
563 	struct task_struct *thr;                  /* thread */
564 	atomic_t ready;                           /* ready to start flag */
565 	atomic_t stop;                            /* ready to stop flag */
566 	unsigned run_threads;                     /* nr current threads */
567 	wait_queue_head_t go;                     /* start crc update */
568 	wait_queue_head_t done;                   /* crc update done */
569 	u32 *crc32;                               /* points to handle's crc32 */
570 	size_t **unc_len;			  /* uncompressed lengths */
571 	unsigned char **unc;			  /* uncompressed data */
572 };
573 
574 static struct crc_data *alloc_crc_data(int nr_threads)
575 {
576 	struct crc_data *crc;
577 
578 	crc = kzalloc(sizeof(*crc), GFP_KERNEL);
579 	if (!crc)
580 		return NULL;
581 
582 	crc->unc = kcalloc(nr_threads, sizeof(*crc->unc), GFP_KERNEL);
583 	if (!crc->unc)
584 		goto err_free_crc;
585 
586 	crc->unc_len = kcalloc(nr_threads, sizeof(*crc->unc_len), GFP_KERNEL);
587 	if (!crc->unc_len)
588 		goto err_free_unc;
589 
590 	return crc;
591 
592 err_free_unc:
593 	kfree(crc->unc);
594 err_free_crc:
595 	kfree(crc);
596 	return NULL;
597 }
598 
599 static void free_crc_data(struct crc_data *crc)
600 {
601 	if (!crc)
602 		return;
603 
604 	if (crc->thr)
605 		kthread_stop(crc->thr);
606 
607 	kfree(crc->unc_len);
608 	kfree(crc->unc);
609 	kfree(crc);
610 }
611 
612 static int crc32_threadfn(void *data)
613 {
614 	struct crc_data *d = data;
615 	unsigned i;
616 
617 	while (1) {
618 		wait_event(d->go, atomic_read_acquire(&d->ready) ||
619 		                  kthread_should_stop());
620 		if (kthread_should_stop()) {
621 			d->thr = NULL;
622 			atomic_set_release(&d->stop, 1);
623 			wake_up(&d->done);
624 			break;
625 		}
626 		atomic_set(&d->ready, 0);
627 
628 		for (i = 0; i < d->run_threads; i++)
629 			*d->crc32 = crc32_le(*d->crc32,
630 			                     d->unc[i], *d->unc_len[i]);
631 		atomic_set_release(&d->stop, 1);
632 		wake_up(&d->done);
633 	}
634 	return 0;
635 }
636 
637 /*
638  * Structure used for data compression.
639  */
640 struct cmp_data {
641 	struct task_struct *thr;                  /* thread */
642 	struct crypto_acomp *cc;		  /* crypto compressor */
643 	struct acomp_req *cr;			  /* crypto request */
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 */
656 static atomic64_t compressed_size = ATOMIC_INIT(0);
657 
658 static int compress_threadfn(void *data)
659 {
660 	struct cmp_data *d = data;
661 
662 	while (1) {
663 		wait_event(d->go, atomic_read_acquire(&d->ready) ||
664 		                  kthread_should_stop());
665 		if (kthread_should_stop()) {
666 			d->thr = NULL;
667 			d->ret = -1;
668 			atomic_set_release(&d->stop, 1);
669 			wake_up(&d->done);
670 			break;
671 		}
672 		atomic_set(&d->ready, 0);
673 
674 		acomp_request_set_callback(d->cr, CRYPTO_TFM_REQ_MAY_SLEEP,
675 					   NULL, NULL);
676 		acomp_request_set_src_nondma(d->cr, d->unc, d->unc_len);
677 		acomp_request_set_dst_nondma(d->cr, d->cmp + CMP_HEADER,
678 					     CMP_SIZE - CMP_HEADER);
679 		d->ret = crypto_acomp_compress(d->cr);
680 		d->cmp_len = d->cr->dlen;
681 
682 		atomic64_add(d->cmp_len, &compressed_size);
683 		atomic_set_release(&d->stop, 1);
684 		wake_up(&d->done);
685 	}
686 	return 0;
687 }
688 
689 static int save_compressed_image(struct swap_map_handle *handle,
690 				 struct snapshot_handle *snapshot,
691 				 unsigned int nr_to_write)
692 {
693 	unsigned int m;
694 	int ret = 0;
695 	int nr_pages;
696 	int err2;
697 	struct hib_bio_batch hb;
698 	ktime_t start;
699 	ktime_t stop;
700 	size_t off;
701 	unsigned int thr, run_threads, nr_threads;
702 	unsigned char *page = NULL;
703 	struct cmp_data *data = NULL;
704 	struct crc_data *crc = NULL;
705 
706 	hib_init_batch(&hb);
707 
708 	atomic64_set(&compressed_size, 0);
709 
710 	/*
711 	 * We'll limit the number of threads for compression to limit memory
712 	 * footprint.
713 	 */
714 	nr_threads = num_online_cpus() - 1;
715 	nr_threads = clamp_val(nr_threads, 1, hibernate_compression_threads);
716 
717 	page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
718 	if (!page) {
719 		pr_err("Failed to allocate %s page\n", hib_comp_algo);
720 		ret = -ENOMEM;
721 		goto out_clean;
722 	}
723 
724 	data = vcalloc(nr_threads, sizeof(*data));
725 	if (!data) {
726 		pr_err("Failed to allocate %s data\n", hib_comp_algo);
727 		ret = -ENOMEM;
728 		goto out_clean;
729 	}
730 
731 	crc = alloc_crc_data(nr_threads);
732 	if (!crc) {
733 		pr_err("Failed to allocate crc\n");
734 		ret = -ENOMEM;
735 		goto out_clean;
736 	}
737 
738 	/*
739 	 * Start the compression threads.
740 	 */
741 	for (thr = 0; thr < nr_threads; thr++) {
742 		init_waitqueue_head(&data[thr].go);
743 		init_waitqueue_head(&data[thr].done);
744 
745 		data[thr].cc = crypto_alloc_acomp(hib_comp_algo, 0, CRYPTO_ALG_ASYNC);
746 		if (IS_ERR_OR_NULL(data[thr].cc)) {
747 			pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
748 			ret = -EFAULT;
749 			goto out_clean;
750 		}
751 
752 		data[thr].cr = acomp_request_alloc(data[thr].cc);
753 		if (!data[thr].cr) {
754 			pr_err("Could not allocate comp request\n");
755 			ret = -ENOMEM;
756 			goto out_clean;
757 		}
758 
759 		data[thr].thr = kthread_run(compress_threadfn,
760 		                            &data[thr],
761 		                            "image_compress/%u", thr);
762 		if (IS_ERR(data[thr].thr)) {
763 			data[thr].thr = NULL;
764 			pr_err("Cannot start compression threads\n");
765 			ret = -ENOMEM;
766 			goto out_clean;
767 		}
768 	}
769 
770 	/*
771 	 * Start the CRC32 thread.
772 	 */
773 	init_waitqueue_head(&crc->go);
774 	init_waitqueue_head(&crc->done);
775 
776 	handle->crc32 = 0;
777 	crc->crc32 = &handle->crc32;
778 	for (thr = 0; thr < nr_threads; thr++) {
779 		crc->unc[thr] = data[thr].unc;
780 		crc->unc_len[thr] = &data[thr].unc_len;
781 	}
782 
783 	crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
784 	if (IS_ERR(crc->thr)) {
785 		crc->thr = NULL;
786 		pr_err("Cannot start CRC32 thread\n");
787 		ret = -ENOMEM;
788 		goto out_clean;
789 	}
790 
791 	/*
792 	 * Adjust the number of required free pages after all allocations have
793 	 * been done. We don't want to run out of pages when writing.
794 	 */
795 	handle->reqd_free_pages = reqd_free_pages();
796 
797 	pr_info("Using %u thread(s) for %s compression\n", nr_threads, hib_comp_algo);
798 	pr_info("Compressing and saving image data (%u pages)...\n",
799 		nr_to_write);
800 	m = nr_to_write / 10;
801 	if (!m)
802 		m = 1;
803 	nr_pages = 0;
804 	start = ktime_get();
805 	for (;;) {
806 		for (thr = 0; thr < nr_threads; thr++) {
807 			for (off = 0; off < UNC_SIZE; off += PAGE_SIZE) {
808 				ret = snapshot_read_next(snapshot);
809 				if (ret < 0)
810 					goto out_finish;
811 
812 				if (!ret)
813 					break;
814 
815 				memcpy(data[thr].unc + off,
816 				       data_of(*snapshot), PAGE_SIZE);
817 
818 				if (!(nr_pages % m))
819 					pr_info("Image saving progress: %3d%%\n",
820 						nr_pages / m * 10);
821 				nr_pages++;
822 			}
823 			if (!off)
824 				break;
825 
826 			data[thr].unc_len = off;
827 
828 			atomic_set_release(&data[thr].ready, 1);
829 			wake_up(&data[thr].go);
830 		}
831 
832 		if (!thr)
833 			break;
834 
835 		crc->run_threads = thr;
836 		atomic_set_release(&crc->ready, 1);
837 		wake_up(&crc->go);
838 
839 		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
840 			wait_event(data[thr].done,
841 				atomic_read_acquire(&data[thr].stop));
842 			atomic_set(&data[thr].stop, 0);
843 
844 			ret = data[thr].ret;
845 
846 			if (ret < 0) {
847 				pr_err("%s compression failed\n", hib_comp_algo);
848 				goto out_finish;
849 			}
850 
851 			if (unlikely(!data[thr].cmp_len ||
852 			             data[thr].cmp_len >
853 				     bytes_worst_compress(data[thr].unc_len))) {
854 				pr_err("Invalid %s compressed length\n", hib_comp_algo);
855 				ret = -1;
856 				goto out_finish;
857 			}
858 
859 			*(size_t *)data[thr].cmp = data[thr].cmp_len;
860 
861 			/*
862 			 * Given we are writing one page at a time to disk, we
863 			 * copy that much from the buffer, although the last
864 			 * bit will likely be smaller than full page. This is
865 			 * OK - we saved the length of the compressed data, so
866 			 * any garbage at the end will be discarded when we
867 			 * read it.
868 			 */
869 			for (off = 0;
870 			     off < CMP_HEADER + data[thr].cmp_len;
871 			     off += PAGE_SIZE) {
872 				memcpy(page, data[thr].cmp + off, PAGE_SIZE);
873 
874 				ret = swap_write_page(handle, page, &hb);
875 				if (ret)
876 					goto out_finish;
877 			}
878 		}
879 
880 		wait_event(crc->done, atomic_read_acquire(&crc->stop));
881 		atomic_set(&crc->stop, 0);
882 	}
883 
884 out_finish:
885 	err2 = hib_wait_io(&hb);
886 	stop = ktime_get();
887 	if (!ret)
888 		ret = err2;
889 	if (!ret) {
890 		swsusp_show_speed(start, stop, nr_to_write, "Wrote");
891 		pr_info("Image size after compression: %lld kbytes\n",
892 			(atomic64_read(&compressed_size) / 1024));
893 		pr_info("Image saving done\n");
894 	} else {
895 		pr_err("Image saving failed: %d\n", ret);
896 	}
897 
898 out_clean:
899 	hib_finish_batch(&hb);
900 	free_crc_data(crc);
901 	if (data) {
902 		for (thr = 0; thr < nr_threads; thr++) {
903 			if (data[thr].thr)
904 				kthread_stop(data[thr].thr);
905 			if (data[thr].cr)
906 				acomp_request_free(data[thr].cr);
907 
908 			if (!IS_ERR_OR_NULL(data[thr].cc))
909 				crypto_free_acomp(data[thr].cc);
910 		}
911 		vfree(data);
912 	}
913 	if (page)
914 		free_page((unsigned long)page);
915 
916 	return ret;
917 }
918 
919 static int enough_swap(unsigned int nr_pages)
920 {
921 	unsigned int free_swap = count_swap_pages(root_swap, 1);
922 	unsigned int required;
923 
924 	pr_debug("Free swap pages: %u\n", free_swap);
925 
926 	required = PAGES_FOR_IO + nr_pages;
927 	return free_swap > required;
928 }
929 
930 /**
931  * swsusp_write - Write entire image and metadata.
932  * @flags: flags to pass to the "boot" kernel in the image header
933  *
934  * It is important _NOT_ to umount filesystems at this point. We want them
935  * synced (in case something goes wrong) but we DO not want to mark filesystem
936  * clean: it is not. (And it does not matter, if we resume correctly, we'll mark
937  * system clean, anyway.)
938  *
939  * Return: 0 on success, negative error code on failure.
940  */
941 int swsusp_write(unsigned int flags)
942 {
943 	struct swap_map_handle handle;
944 	struct snapshot_handle snapshot;
945 	struct swsusp_info *header;
946 	unsigned long pages;
947 	int error;
948 
949 	pages = snapshot_get_image_size();
950 	error = get_swap_writer(&handle);
951 	if (error) {
952 		pr_err("Cannot get swap writer\n");
953 		return error;
954 	}
955 	if (flags & SF_NOCOMPRESS_MODE) {
956 		if (!enough_swap(pages)) {
957 			pr_err("Not enough free swap\n");
958 			error = -ENOSPC;
959 			goto out_finish;
960 		}
961 	}
962 	memset(&snapshot, 0, sizeof(struct snapshot_handle));
963 	error = snapshot_read_next(&snapshot);
964 	if (error < (int)PAGE_SIZE) {
965 		if (error >= 0)
966 			error = -EFAULT;
967 
968 		goto out_finish;
969 	}
970 	header = (struct swsusp_info *)data_of(snapshot);
971 	error = swap_write_page(&handle, header, NULL);
972 	if (!error) {
973 		error = (flags & SF_NOCOMPRESS_MODE) ?
974 			save_image(&handle, &snapshot, pages - 1) :
975 			save_compressed_image(&handle, &snapshot, pages - 1);
976 	}
977 out_finish:
978 	error = swap_writer_finish(&handle, flags, error);
979 	return error;
980 }
981 
982 /*
983  * The following functions allow us to read data using a swap map in a file-like
984  * way.
985  */
986 
987 static void release_swap_reader(struct swap_map_handle *handle)
988 {
989 	struct swap_map_page_list *tmp;
990 
991 	while (handle->maps) {
992 		if (handle->maps->map)
993 			free_page((unsigned long)handle->maps->map);
994 		tmp = handle->maps;
995 		handle->maps = handle->maps->next;
996 		kfree(tmp);
997 	}
998 	handle->cur = NULL;
999 }
1000 
1001 static int get_swap_reader(struct swap_map_handle *handle,
1002 		unsigned int *flags_p)
1003 {
1004 	int error;
1005 	struct swap_map_page_list *tmp, *last;
1006 	sector_t offset;
1007 
1008 	*flags_p = swsusp_header->flags;
1009 
1010 	if (!swsusp_header->image) /* how can this happen? */
1011 		return -EINVAL;
1012 
1013 	handle->cur = NULL;
1014 	last = handle->maps = NULL;
1015 	offset = swsusp_header->image;
1016 	while (offset) {
1017 		tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
1018 		if (!tmp) {
1019 			release_swap_reader(handle);
1020 			return -ENOMEM;
1021 		}
1022 		if (!handle->maps)
1023 			handle->maps = tmp;
1024 		if (last)
1025 			last->next = tmp;
1026 		last = tmp;
1027 
1028 		tmp->map = (struct swap_map_page *)
1029 			   __get_free_page(GFP_NOIO | __GFP_HIGH);
1030 		if (!tmp->map) {
1031 			release_swap_reader(handle);
1032 			return -ENOMEM;
1033 		}
1034 
1035 		error = hib_submit_io_sync(REQ_OP_READ, offset, tmp->map);
1036 		if (error) {
1037 			release_swap_reader(handle);
1038 			return error;
1039 		}
1040 		offset = tmp->map->next_swap;
1041 	}
1042 	handle->k = 0;
1043 	handle->cur = handle->maps->map;
1044 	return 0;
1045 }
1046 
1047 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1048 		struct hib_bio_batch *hb)
1049 {
1050 	sector_t offset;
1051 	int error;
1052 	struct swap_map_page_list *tmp;
1053 
1054 	if (!handle->cur)
1055 		return -EINVAL;
1056 	offset = handle->cur->entries[handle->k];
1057 	if (!offset)
1058 		return -EFAULT;
1059 	if (hb)
1060 		error = hib_submit_io_async(REQ_OP_READ, offset, buf, hb);
1061 	else
1062 		error = hib_submit_io_sync(REQ_OP_READ, offset, buf);
1063 	if (error)
1064 		return error;
1065 	if (++handle->k >= MAP_PAGE_ENTRIES) {
1066 		handle->k = 0;
1067 		free_page((unsigned long)handle->maps->map);
1068 		tmp = handle->maps;
1069 		handle->maps = handle->maps->next;
1070 		kfree(tmp);
1071 		if (!handle->maps)
1072 			release_swap_reader(handle);
1073 		else
1074 			handle->cur = handle->maps->map;
1075 	}
1076 	return error;
1077 }
1078 
1079 static int swap_reader_finish(struct swap_map_handle *handle)
1080 {
1081 	release_swap_reader(handle);
1082 
1083 	return 0;
1084 }
1085 
1086 static int load_image(struct swap_map_handle *handle,
1087                       struct snapshot_handle *snapshot,
1088                       unsigned int nr_to_read)
1089 {
1090 	unsigned int m;
1091 	int ret = 0;
1092 	ktime_t start;
1093 	ktime_t stop;
1094 	struct hib_bio_batch hb;
1095 	int err2;
1096 	unsigned nr_pages;
1097 
1098 	hib_init_batch(&hb);
1099 
1100 	clean_pages_on_read = true;
1101 	pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1102 	m = nr_to_read / 10;
1103 	if (!m)
1104 		m = 1;
1105 	nr_pages = 0;
1106 	start = ktime_get();
1107 	for ( ; ; ) {
1108 		ret = snapshot_write_next(snapshot);
1109 		if (ret <= 0)
1110 			break;
1111 		ret = swap_read_page(handle, data_of(*snapshot), &hb);
1112 		if (ret)
1113 			break;
1114 		if (snapshot->sync_read)
1115 			ret = hib_wait_io(&hb);
1116 		if (ret)
1117 			break;
1118 		if (!(nr_pages % m))
1119 			pr_info("Image loading progress: %3d%%\n",
1120 				nr_pages / m * 10);
1121 		nr_pages++;
1122 	}
1123 	err2 = hib_wait_io(&hb);
1124 	hib_finish_batch(&hb);
1125 	stop = ktime_get();
1126 	if (!ret)
1127 		ret = err2;
1128 	if (!ret) {
1129 		pr_info("Image loading done\n");
1130 		ret = snapshot_write_finalize(snapshot);
1131 		if (!ret && !snapshot_image_loaded(snapshot))
1132 			ret = -ENODATA;
1133 	}
1134 	swsusp_show_speed(start, stop, nr_to_read, "Read");
1135 	return ret;
1136 }
1137 
1138 /*
1139  * Structure used for data decompression.
1140  */
1141 struct dec_data {
1142 	struct task_struct *thr;                  /* thread */
1143 	struct crypto_acomp *cc;		  /* crypto compressor */
1144 	struct acomp_req *cr;			  /* crypto request */
1145 	atomic_t ready;                           /* ready to start flag */
1146 	atomic_t stop;                            /* ready to stop flag */
1147 	int ret;                                  /* return code */
1148 	wait_queue_head_t go;                     /* start decompression */
1149 	wait_queue_head_t done;                   /* decompression done */
1150 	size_t unc_len;                           /* uncompressed length */
1151 	size_t cmp_len;                           /* compressed length */
1152 	unsigned char unc[UNC_SIZE];              /* uncompressed buffer */
1153 	unsigned char cmp[CMP_SIZE];              /* compressed buffer */
1154 };
1155 
1156 static int decompress_threadfn(void *data)
1157 {
1158 	struct dec_data *d = data;
1159 
1160 	while (1) {
1161 		wait_event(d->go, atomic_read_acquire(&d->ready) ||
1162 		                  kthread_should_stop());
1163 		if (kthread_should_stop()) {
1164 			d->thr = NULL;
1165 			d->ret = -1;
1166 			atomic_set_release(&d->stop, 1);
1167 			wake_up(&d->done);
1168 			break;
1169 		}
1170 		atomic_set(&d->ready, 0);
1171 
1172 		acomp_request_set_callback(d->cr, CRYPTO_TFM_REQ_MAY_SLEEP,
1173 					   NULL, NULL);
1174 		acomp_request_set_src_nondma(d->cr, d->cmp + CMP_HEADER,
1175 					     d->cmp_len);
1176 		acomp_request_set_dst_nondma(d->cr, d->unc, UNC_SIZE);
1177 		d->ret = crypto_acomp_decompress(d->cr);
1178 		d->unc_len = d->cr->dlen;
1179 
1180 		if (clean_pages_on_decompress)
1181 			flush_icache_range((unsigned long)d->unc,
1182 					   (unsigned long)d->unc + d->unc_len);
1183 
1184 		atomic_set_release(&d->stop, 1);
1185 		wake_up(&d->done);
1186 	}
1187 	return 0;
1188 }
1189 
1190 static int load_compressed_image(struct swap_map_handle *handle,
1191 				 struct snapshot_handle *snapshot,
1192 				 unsigned int nr_to_read)
1193 {
1194 	unsigned int m;
1195 	int ret = 0;
1196 	int eof = 0;
1197 	struct hib_bio_batch hb;
1198 	ktime_t start;
1199 	ktime_t stop;
1200 	unsigned nr_pages;
1201 	size_t off;
1202 	unsigned i, thr, run_threads, nr_threads;
1203 	unsigned ring = 0, pg = 0, ring_size = 0,
1204 	         have = 0, want, need, asked = 0;
1205 	unsigned long read_pages = 0;
1206 	unsigned char **page = NULL;
1207 	struct dec_data *data = NULL;
1208 	struct crc_data *crc = NULL;
1209 
1210 	hib_init_batch(&hb);
1211 
1212 	/*
1213 	 * We'll limit the number of threads for decompression to limit memory
1214 	 * footprint.
1215 	 */
1216 	nr_threads = num_online_cpus() - 1;
1217 	nr_threads = clamp_val(nr_threads, 1, hibernate_compression_threads);
1218 
1219 	page = vmalloc_array(CMP_MAX_RD_PAGES, sizeof(*page));
1220 	if (!page) {
1221 		pr_err("Failed to allocate %s page\n", hib_comp_algo);
1222 		ret = -ENOMEM;
1223 		goto out_clean;
1224 	}
1225 
1226 	data = vcalloc(nr_threads, sizeof(*data));
1227 	if (!data) {
1228 		pr_err("Failed to allocate %s data\n", hib_comp_algo);
1229 		ret = -ENOMEM;
1230 		goto out_clean;
1231 	}
1232 
1233 	crc = alloc_crc_data(nr_threads);
1234 	if (!crc) {
1235 		pr_err("Failed to allocate crc\n");
1236 		ret = -ENOMEM;
1237 		goto out_clean;
1238 	}
1239 
1240 	clean_pages_on_decompress = true;
1241 
1242 	/*
1243 	 * Start the decompression threads.
1244 	 */
1245 	for (thr = 0; thr < nr_threads; thr++) {
1246 		init_waitqueue_head(&data[thr].go);
1247 		init_waitqueue_head(&data[thr].done);
1248 
1249 		data[thr].cc = crypto_alloc_acomp(hib_comp_algo, 0, CRYPTO_ALG_ASYNC);
1250 		if (IS_ERR_OR_NULL(data[thr].cc)) {
1251 			pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
1252 			ret = -EFAULT;
1253 			goto out_clean;
1254 		}
1255 
1256 		data[thr].cr = acomp_request_alloc(data[thr].cc);
1257 		if (!data[thr].cr) {
1258 			pr_err("Could not allocate comp request\n");
1259 			ret = -ENOMEM;
1260 			goto out_clean;
1261 		}
1262 
1263 		data[thr].thr = kthread_run(decompress_threadfn,
1264 		                            &data[thr],
1265 		                            "image_decompress/%u", thr);
1266 		if (IS_ERR(data[thr].thr)) {
1267 			data[thr].thr = NULL;
1268 			pr_err("Cannot start decompression threads\n");
1269 			ret = -ENOMEM;
1270 			goto out_clean;
1271 		}
1272 	}
1273 
1274 	/*
1275 	 * Start the CRC32 thread.
1276 	 */
1277 	init_waitqueue_head(&crc->go);
1278 	init_waitqueue_head(&crc->done);
1279 
1280 	handle->crc32 = 0;
1281 	crc->crc32 = &handle->crc32;
1282 	for (thr = 0; thr < nr_threads; thr++) {
1283 		crc->unc[thr] = data[thr].unc;
1284 		crc->unc_len[thr] = &data[thr].unc_len;
1285 	}
1286 
1287 	crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1288 	if (IS_ERR(crc->thr)) {
1289 		crc->thr = NULL;
1290 		pr_err("Cannot start CRC32 thread\n");
1291 		ret = -ENOMEM;
1292 		goto out_clean;
1293 	}
1294 
1295 	/*
1296 	 * Set the number of pages for read buffering.
1297 	 * This is complete guesswork, because we'll only know the real
1298 	 * picture once prepare_image() is called, which is much later on
1299 	 * during the image load phase. We'll assume the worst case and
1300 	 * say that none of the image pages are from high memory.
1301 	 */
1302 	if (low_free_pages() > snapshot_get_image_size())
1303 		read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1304 	read_pages = clamp_val(read_pages, CMP_MIN_RD_PAGES, CMP_MAX_RD_PAGES);
1305 
1306 	for (i = 0; i < read_pages; i++) {
1307 		page[i] = (void *)__get_free_page(i < CMP_PAGES ?
1308 						  GFP_NOIO | __GFP_HIGH :
1309 						  GFP_NOIO | __GFP_NOWARN |
1310 						  __GFP_NORETRY);
1311 
1312 		if (!page[i]) {
1313 			if (i < CMP_PAGES) {
1314 				ring_size = i;
1315 				pr_err("Failed to allocate %s pages\n", hib_comp_algo);
1316 				ret = -ENOMEM;
1317 				goto out_clean;
1318 			} else {
1319 				break;
1320 			}
1321 		}
1322 	}
1323 	want = ring_size = i;
1324 
1325 	pr_info("Using %u thread(s) for %s decompression\n", nr_threads, hib_comp_algo);
1326 	pr_info("Loading and decompressing image data (%u pages)...\n",
1327 		nr_to_read);
1328 	m = nr_to_read / 10;
1329 	if (!m)
1330 		m = 1;
1331 	nr_pages = 0;
1332 	start = ktime_get();
1333 
1334 	ret = snapshot_write_next(snapshot);
1335 	if (ret <= 0)
1336 		goto out_finish;
1337 
1338 	for(;;) {
1339 		for (i = 0; !eof && i < want; i++) {
1340 			ret = swap_read_page(handle, page[ring], &hb);
1341 			if (ret) {
1342 				/*
1343 				 * On real read error, finish. On end of data,
1344 				 * set EOF flag and just exit the read loop.
1345 				 */
1346 				if (handle->cur &&
1347 				    handle->cur->entries[handle->k]) {
1348 					goto out_finish;
1349 				} else {
1350 					eof = 1;
1351 					break;
1352 				}
1353 			}
1354 			if (++ring >= ring_size)
1355 				ring = 0;
1356 		}
1357 		asked += i;
1358 		want -= i;
1359 
1360 		/*
1361 		 * We are out of data, wait for some more.
1362 		 */
1363 		if (!have) {
1364 			if (!asked)
1365 				break;
1366 
1367 			ret = hib_wait_io(&hb);
1368 			if (ret)
1369 				goto out_finish;
1370 			have += asked;
1371 			asked = 0;
1372 			if (eof)
1373 				eof = 2;
1374 		}
1375 
1376 		if (crc->run_threads) {
1377 			wait_event(crc->done, atomic_read_acquire(&crc->stop));
1378 			atomic_set(&crc->stop, 0);
1379 			crc->run_threads = 0;
1380 		}
1381 
1382 		for (thr = 0; have && thr < nr_threads; thr++) {
1383 			data[thr].cmp_len = *(size_t *)page[pg];
1384 			if (unlikely(!data[thr].cmp_len ||
1385 			             data[thr].cmp_len >
1386 					bytes_worst_compress(UNC_SIZE))) {
1387 				pr_err("Invalid %s compressed length\n", hib_comp_algo);
1388 				ret = -1;
1389 				goto out_finish;
1390 			}
1391 
1392 			need = DIV_ROUND_UP(data[thr].cmp_len + CMP_HEADER,
1393 			                    PAGE_SIZE);
1394 			if (need > have) {
1395 				if (eof > 1) {
1396 					ret = -1;
1397 					goto out_finish;
1398 				}
1399 				break;
1400 			}
1401 
1402 			for (off = 0;
1403 			     off < CMP_HEADER + data[thr].cmp_len;
1404 			     off += PAGE_SIZE) {
1405 				memcpy(data[thr].cmp + off,
1406 				       page[pg], PAGE_SIZE);
1407 				have--;
1408 				want++;
1409 				if (++pg >= ring_size)
1410 					pg = 0;
1411 			}
1412 
1413 			atomic_set_release(&data[thr].ready, 1);
1414 			wake_up(&data[thr].go);
1415 		}
1416 
1417 		/*
1418 		 * Wait for more data while we are decompressing.
1419 		 */
1420 		if (have < CMP_PAGES && asked) {
1421 			ret = hib_wait_io(&hb);
1422 			if (ret)
1423 				goto out_finish;
1424 			have += asked;
1425 			asked = 0;
1426 			if (eof)
1427 				eof = 2;
1428 		}
1429 
1430 		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1431 			wait_event(data[thr].done,
1432 				atomic_read_acquire(&data[thr].stop));
1433 			atomic_set(&data[thr].stop, 0);
1434 
1435 			ret = data[thr].ret;
1436 
1437 			if (ret < 0) {
1438 				pr_err("%s decompression failed\n", hib_comp_algo);
1439 				goto out_finish;
1440 			}
1441 
1442 			if (unlikely(!data[thr].unc_len ||
1443 				data[thr].unc_len > UNC_SIZE ||
1444 				data[thr].unc_len & (PAGE_SIZE - 1))) {
1445 				pr_err("Invalid %s uncompressed length\n", hib_comp_algo);
1446 				ret = -1;
1447 				goto out_finish;
1448 			}
1449 
1450 			for (off = 0;
1451 			     off < data[thr].unc_len; off += PAGE_SIZE) {
1452 				memcpy(data_of(*snapshot),
1453 				       data[thr].unc + off, PAGE_SIZE);
1454 
1455 				if (!(nr_pages % m))
1456 					pr_info("Image loading progress: %3d%%\n",
1457 						nr_pages / m * 10);
1458 				nr_pages++;
1459 
1460 				ret = snapshot_write_next(snapshot);
1461 				if (ret <= 0) {
1462 					crc->run_threads = thr + 1;
1463 					atomic_set_release(&crc->ready, 1);
1464 					wake_up(&crc->go);
1465 					goto out_finish;
1466 				}
1467 			}
1468 		}
1469 
1470 		crc->run_threads = thr;
1471 		atomic_set_release(&crc->ready, 1);
1472 		wake_up(&crc->go);
1473 	}
1474 
1475 out_finish:
1476 	if (crc->run_threads) {
1477 		wait_event(crc->done, atomic_read_acquire(&crc->stop));
1478 		atomic_set(&crc->stop, 0);
1479 	}
1480 	stop = ktime_get();
1481 	if (!ret) {
1482 		pr_info("Image loading done\n");
1483 		ret = snapshot_write_finalize(snapshot);
1484 		if (!ret && !snapshot_image_loaded(snapshot))
1485 			ret = -ENODATA;
1486 		if (!ret) {
1487 			if (swsusp_header->flags & SF_CRC32_MODE) {
1488 				if(handle->crc32 != swsusp_header->crc32) {
1489 					pr_err("Invalid image CRC32!\n");
1490 					ret = -ENODATA;
1491 				}
1492 			}
1493 		}
1494 	}
1495 	swsusp_show_speed(start, stop, nr_to_read, "Read");
1496 out_clean:
1497 	hib_finish_batch(&hb);
1498 	for (i = 0; i < ring_size; i++)
1499 		free_page((unsigned long)page[i]);
1500 	free_crc_data(crc);
1501 	if (data) {
1502 		for (thr = 0; thr < nr_threads; thr++) {
1503 			if (data[thr].thr)
1504 				kthread_stop(data[thr].thr);
1505 			if (data[thr].cr)
1506 				acomp_request_free(data[thr].cr);
1507 
1508 			if (!IS_ERR_OR_NULL(data[thr].cc))
1509 				crypto_free_acomp(data[thr].cc);
1510 		}
1511 		vfree(data);
1512 	}
1513 	vfree(page);
1514 
1515 	return ret;
1516 }
1517 
1518 /**
1519  *	swsusp_read - read the hibernation image.
1520  *	@flags_p: flags passed by the "frozen" kernel in the image header should
1521  *		  be written into this memory location
1522  *
1523  *	Return: 0 on success, negative error code on failure.
1524  */
1525 int swsusp_read(unsigned int *flags_p)
1526 {
1527 	int error;
1528 	struct swap_map_handle handle;
1529 	struct snapshot_handle snapshot;
1530 	struct swsusp_info *header;
1531 
1532 	memset(&snapshot, 0, sizeof(struct snapshot_handle));
1533 	error = snapshot_write_next(&snapshot);
1534 	if (error < (int)PAGE_SIZE)
1535 		return error < 0 ? error : -EFAULT;
1536 	header = (struct swsusp_info *)data_of(snapshot);
1537 	error = get_swap_reader(&handle, flags_p);
1538 	if (error)
1539 		goto end;
1540 	if (!error)
1541 		error = swap_read_page(&handle, header, NULL);
1542 	if (!error) {
1543 		error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1544 			load_image(&handle, &snapshot, header->pages - 1) :
1545 			load_compressed_image(&handle, &snapshot, header->pages - 1);
1546 	}
1547 	swap_reader_finish(&handle);
1548 end:
1549 	if (!error)
1550 		pr_debug("Image successfully loaded\n");
1551 	else
1552 		pr_debug("Error %d resuming\n", error);
1553 	return error;
1554 }
1555 
1556 static void *swsusp_holder;
1557 
1558 /**
1559  * swsusp_check - Open the resume device and check for the swsusp signature.
1560  * @exclusive: Open the resume device exclusively.
1561  *
1562  * Return: 0 if a valid image is found, negative error code otherwise.
1563  */
1564 int swsusp_check(bool exclusive)
1565 {
1566 	void *holder = exclusive ? &swsusp_holder : NULL;
1567 	int error;
1568 
1569 	hib_resume_bdev_file = bdev_file_open_by_dev(swsusp_resume_device,
1570 				BLK_OPEN_READ, holder, NULL);
1571 	if (!IS_ERR(hib_resume_bdev_file)) {
1572 		clear_page(swsusp_header);
1573 		error = hib_submit_io_sync(REQ_OP_READ, swsusp_resume_block,
1574 					swsusp_header);
1575 		if (error)
1576 			goto put;
1577 
1578 		if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1579 			memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1580 			swsusp_header_flags = swsusp_header->flags;
1581 			/* Reset swap signature now */
1582 			error = hib_submit_io_sync(REQ_OP_WRITE | REQ_SYNC,
1583 						swsusp_resume_block,
1584 						swsusp_header);
1585 		} else {
1586 			error = -EINVAL;
1587 		}
1588 		if (!error && swsusp_header->flags & SF_HW_SIG &&
1589 		    swsusp_header->hw_sig != swsusp_hardware_signature) {
1590 			pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
1591 				swsusp_header->hw_sig, swsusp_hardware_signature);
1592 			error = -EINVAL;
1593 		}
1594 
1595 put:
1596 		if (error)
1597 			bdev_fput(hib_resume_bdev_file);
1598 		else
1599 			pr_debug("Image signature found, resuming\n");
1600 	} else {
1601 		error = PTR_ERR(hib_resume_bdev_file);
1602 	}
1603 
1604 	if (error)
1605 		pr_debug("Image not found (code %d)\n", error);
1606 
1607 	return error;
1608 }
1609 
1610 /**
1611  * swsusp_close - close resume device.
1612  */
1613 void swsusp_close(void)
1614 {
1615 	if (IS_ERR(hib_resume_bdev_file)) {
1616 		pr_debug("Image device not initialised\n");
1617 		return;
1618 	}
1619 
1620 	fput(hib_resume_bdev_file);
1621 }
1622 
1623 /**
1624  * swsusp_unmark - Unmark swsusp signature in the resume device
1625  *
1626  * Return: 0 on success, negative error code on failure.
1627  */
1628 #ifdef CONFIG_SUSPEND
1629 int swsusp_unmark(void)
1630 {
1631 	int error;
1632 
1633 	hib_submit_io_sync(REQ_OP_READ, swsusp_resume_block, swsusp_header);
1634 	if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1635 		memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1636 		error = hib_submit_io_sync(REQ_OP_WRITE | REQ_SYNC,
1637 					swsusp_resume_block,
1638 					swsusp_header);
1639 	} else {
1640 		pr_err("Cannot find swsusp signature!\n");
1641 		error = -ENODEV;
1642 	}
1643 
1644 	/*
1645 	 * We just returned from suspend, we don't need the image any more.
1646 	 */
1647 	free_all_swap_pages(root_swap);
1648 
1649 	return error;
1650 }
1651 #endif
1652 
1653 static ssize_t hibernate_compression_threads_show(struct kobject *kobj,
1654 				struct kobj_attribute *attr, char *buf)
1655 {
1656 	return sysfs_emit(buf, "%d\n", hibernate_compression_threads);
1657 }
1658 
1659 static ssize_t hibernate_compression_threads_store(struct kobject *kobj,
1660 				struct kobj_attribute *attr,
1661 				const char *buf, size_t n)
1662 {
1663 	unsigned long val;
1664 
1665 	if (kstrtoul(buf, 0, &val))
1666 		return -EINVAL;
1667 
1668 	if (val < 1)
1669 		return -EINVAL;
1670 
1671 	hibernate_compression_threads = val;
1672 	return n;
1673 }
1674 power_attr(hibernate_compression_threads);
1675 
1676 static struct attribute *g[] = {
1677 	&hibernate_compression_threads_attr.attr,
1678 	NULL,
1679 };
1680 
1681 static const struct attribute_group attr_group = {
1682 	.attrs = g,
1683 };
1684 
1685 static int __init swsusp_header_init(void)
1686 {
1687 	int error;
1688 
1689 	error = sysfs_create_group(power_kobj, &attr_group);
1690 	if (error)
1691 		return -ENOMEM;
1692 
1693 	swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1694 	if (!swsusp_header)
1695 		panic("Could not allocate memory for swsusp_header\n");
1696 	return 0;
1697 }
1698 
1699 core_initcall(swsusp_header_init);
1700 
1701 static int __init hibernate_compression_threads_setup(char *str)
1702 {
1703 	int rc = kstrtouint(str, 0, &hibernate_compression_threads);
1704 
1705 	if (rc)
1706 		return rc;
1707 
1708 	if (hibernate_compression_threads < 1)
1709 		hibernate_compression_threads = CMP_THREADS;
1710 
1711 	return 1;
1712 
1713 }
1714 
1715 __setup("hibernate_compression_threads=", hibernate_compression_threads_setup);
1716