xref: /openbmc/linux/kernel/power/swap.c (revision 7692e29d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * linux/kernel/power/swap.c
4  *
5  * This file provides functions for reading the suspend image from
6  * and writing it to a swap partition.
7  *
8  * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
9  * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
10  * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
11  */
12 
13 #define pr_fmt(fmt) "PM: " fmt
14 
15 #include <linux/module.h>
16 #include <linux/file.h>
17 #include <linux/delay.h>
18 #include <linux/bitops.h>
19 #include <linux/device.h>
20 #include <linux/bio.h>
21 #include <linux/blkdev.h>
22 #include <linux/swap.h>
23 #include <linux/swapops.h>
24 #include <linux/pm.h>
25 #include <linux/slab.h>
26 #include <linux/lzo.h>
27 #include <linux/vmalloc.h>
28 #include <linux/cpumask.h>
29 #include <linux/atomic.h>
30 #include <linux/kthread.h>
31 #include <linux/crc32.h>
32 #include <linux/ktime.h>
33 
34 #include "power.h"
35 
36 #define HIBERNATE_SIG	"S1SUSPEND"
37 
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
51  *	structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
52  *	These structures are stored on the swap and linked together with the
53  *	help of the .next_swap member.
54  *
55  *	The swap map is created during suspend.  The swap map pages are
56  *	allocated and populated one at a time, so we only need one memory
57  *	page to set up the entire structure.
58  *
59  *	During resume we pick up all swap_map_page structures into a list.
60  */
61 
62 #define MAP_PAGE_ENTRIES	(PAGE_SIZE / sizeof(sector_t) - 1)
63 
64 /*
65  * Number of free pages that are not high.
66  */
low_free_pages(void)67 static inline unsigned long low_free_pages(void)
68 {
69 	return nr_free_pages() - nr_free_highpages();
70 }
71 
72 /*
73  * Number of pages required to be kept free while writing the image. Always
74  * half of all available low pages before the writing starts.
75  */
reqd_free_pages(void)76 static inline unsigned long reqd_free_pages(void)
77 {
78 	return low_free_pages() / 2;
79 }
80 
81 struct swap_map_page {
82 	sector_t entries[MAP_PAGE_ENTRIES];
83 	sector_t next_swap;
84 };
85 
86 struct swap_map_page_list {
87 	struct swap_map_page *map;
88 	struct swap_map_page_list *next;
89 };
90 
91 /*
92  *	The swap_map_handle structure is used for handling swap in
93  *	a file-alike way
94  */
95 
96 struct swap_map_handle {
97 	struct swap_map_page *cur;
98 	struct swap_map_page_list *maps;
99 	sector_t cur_swap;
100 	sector_t first_sector;
101 	unsigned int k;
102 	unsigned long reqd_free_pages;
103 	u32 crc32;
104 };
105 
106 struct swsusp_header {
107 	char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
108 	              sizeof(u32) - sizeof(u32)];
109 	u32	hw_sig;
110 	u32	crc32;
111 	sector_t image;
112 	unsigned int flags;	/* Flags to pass to the "boot" kernel */
113 	char	orig_sig[10];
114 	char	sig[10];
115 } __packed;
116 
117 static struct swsusp_header *swsusp_header;
118 
119 /*
120  *	The following functions are used for tracing the allocated
121  *	swap pages, so that they can be freed in case of an error.
122  */
123 
124 struct swsusp_extent {
125 	struct rb_node node;
126 	unsigned long start;
127 	unsigned long end;
128 };
129 
130 static struct rb_root swsusp_extents = RB_ROOT;
131 
swsusp_extents_insert(unsigned long swap_offset)132 static int swsusp_extents_insert(unsigned long swap_offset)
133 {
134 	struct rb_node **new = &(swsusp_extents.rb_node);
135 	struct rb_node *parent = NULL;
136 	struct swsusp_extent *ext;
137 
138 	/* Figure out where to put the new node */
139 	while (*new) {
140 		ext = rb_entry(*new, struct swsusp_extent, node);
141 		parent = *new;
142 		if (swap_offset < ext->start) {
143 			/* Try to merge */
144 			if (swap_offset == ext->start - 1) {
145 				ext->start--;
146 				return 0;
147 			}
148 			new = &((*new)->rb_left);
149 		} else if (swap_offset > ext->end) {
150 			/* Try to merge */
151 			if (swap_offset == ext->end + 1) {
152 				ext->end++;
153 				return 0;
154 			}
155 			new = &((*new)->rb_right);
156 		} else {
157 			/* It already is in the tree */
158 			return -EINVAL;
159 		}
160 	}
161 	/* Add the new node and rebalance the tree. */
162 	ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
163 	if (!ext)
164 		return -ENOMEM;
165 
166 	ext->start = swap_offset;
167 	ext->end = swap_offset;
168 	rb_link_node(&ext->node, parent, new);
169 	rb_insert_color(&ext->node, &swsusp_extents);
170 	return 0;
171 }
172 
173 /*
174  *	alloc_swapdev_block - allocate a swap page and register that it has
175  *	been allocated, so that it can be freed in case of an error.
176  */
177 
alloc_swapdev_block(int swap)178 sector_t alloc_swapdev_block(int swap)
179 {
180 	unsigned long offset;
181 
182 	offset = swp_offset(get_swap_page_of_type(swap));
183 	if (offset) {
184 		if (swsusp_extents_insert(offset))
185 			swap_free(swp_entry(swap, offset));
186 		else
187 			return swapdev_block(swap, offset);
188 	}
189 	return 0;
190 }
191 
192 /*
193  *	free_all_swap_pages - free swap pages allocated for saving image data.
194  *	It also frees the extents used to register which swap entries had been
195  *	allocated.
196  */
197 
free_all_swap_pages(int swap)198 void free_all_swap_pages(int swap)
199 {
200 	struct rb_node *node;
201 
202 	while ((node = swsusp_extents.rb_node)) {
203 		struct swsusp_extent *ext;
204 		unsigned long offset;
205 
206 		ext = rb_entry(node, struct swsusp_extent, node);
207 		rb_erase(node, &swsusp_extents);
208 		for (offset = ext->start; offset <= ext->end; offset++)
209 			swap_free(swp_entry(swap, offset));
210 
211 		kfree(ext);
212 	}
213 }
214 
swsusp_swap_in_use(void)215 int swsusp_swap_in_use(void)
216 {
217 	return (swsusp_extents.rb_node != NULL);
218 }
219 
220 /*
221  * General things
222  */
223 
224 static unsigned short root_swap = 0xffff;
225 static struct block_device *hib_resume_bdev;
226 
227 struct hib_bio_batch {
228 	atomic_t		count;
229 	wait_queue_head_t	wait;
230 	blk_status_t		error;
231 	struct blk_plug		plug;
232 };
233 
hib_init_batch(struct hib_bio_batch * hb)234 static void hib_init_batch(struct hib_bio_batch *hb)
235 {
236 	atomic_set(&hb->count, 0);
237 	init_waitqueue_head(&hb->wait);
238 	hb->error = BLK_STS_OK;
239 	blk_start_plug(&hb->plug);
240 }
241 
hib_finish_batch(struct hib_bio_batch * hb)242 static void hib_finish_batch(struct hib_bio_batch *hb)
243 {
244 	blk_finish_plug(&hb->plug);
245 }
246 
hib_end_io(struct bio * bio)247 static void hib_end_io(struct bio *bio)
248 {
249 	struct hib_bio_batch *hb = bio->bi_private;
250 	struct page *page = bio_first_page_all(bio);
251 
252 	if (bio->bi_status) {
253 		pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
254 			 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
255 			 (unsigned long long)bio->bi_iter.bi_sector);
256 	}
257 
258 	if (bio_data_dir(bio) == WRITE)
259 		put_page(page);
260 	else if (clean_pages_on_read)
261 		flush_icache_range((unsigned long)page_address(page),
262 				   (unsigned long)page_address(page) + PAGE_SIZE);
263 
264 	if (bio->bi_status && !hb->error)
265 		hb->error = bio->bi_status;
266 	if (atomic_dec_and_test(&hb->count))
267 		wake_up(&hb->wait);
268 
269 	bio_put(bio);
270 }
271 
hib_submit_io(blk_opf_t opf,pgoff_t page_off,void * addr,struct hib_bio_batch * hb)272 static int hib_submit_io(blk_opf_t opf, pgoff_t page_off, void *addr,
273 			 struct hib_bio_batch *hb)
274 {
275 	struct page *page = virt_to_page(addr);
276 	struct bio *bio;
277 	int error = 0;
278 
279 	bio = bio_alloc(hib_resume_bdev, 1, opf, GFP_NOIO | __GFP_HIGH);
280 	bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
281 
282 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
283 		pr_err("Adding page to bio failed at %llu\n",
284 		       (unsigned long long)bio->bi_iter.bi_sector);
285 		bio_put(bio);
286 		return -EFAULT;
287 	}
288 
289 	if (hb) {
290 		bio->bi_end_io = hib_end_io;
291 		bio->bi_private = hb;
292 		atomic_inc(&hb->count);
293 		submit_bio(bio);
294 	} else {
295 		error = submit_bio_wait(bio);
296 		bio_put(bio);
297 	}
298 
299 	return error;
300 }
301 
hib_wait_io(struct hib_bio_batch * hb)302 static int hib_wait_io(struct hib_bio_batch *hb)
303 {
304 	/*
305 	 * We are relying on the behavior of blk_plug that a thread with
306 	 * a plug will flush the plug list before sleeping.
307 	 */
308 	wait_event(hb->wait, atomic_read(&hb->count) == 0);
309 	return blk_status_to_errno(hb->error);
310 }
311 
312 /*
313  * Saving part
314  */
mark_swapfiles(struct swap_map_handle * handle,unsigned int flags)315 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
316 {
317 	int error;
318 
319 	hib_submit_io(REQ_OP_READ, swsusp_resume_block, swsusp_header, NULL);
320 	if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
321 	    !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
322 		memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
323 		memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
324 		swsusp_header->image = handle->first_sector;
325 		if (swsusp_hardware_signature) {
326 			swsusp_header->hw_sig = swsusp_hardware_signature;
327 			flags |= SF_HW_SIG;
328 		}
329 		swsusp_header->flags = flags;
330 		if (flags & SF_CRC32_MODE)
331 			swsusp_header->crc32 = handle->crc32;
332 		error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
333 				      swsusp_resume_block, swsusp_header, NULL);
334 	} else {
335 		pr_err("Swap header not found!\n");
336 		error = -ENODEV;
337 	}
338 	return error;
339 }
340 
341 /**
342  *	swsusp_swap_check - check if the resume device is a swap device
343  *	and get its index (if so)
344  *
345  *	This is called before saving image
346  */
swsusp_swap_check(void)347 static int swsusp_swap_check(void)
348 {
349 	int res;
350 
351 	if (swsusp_resume_device)
352 		res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
353 	else
354 		res = find_first_swap(&swsusp_resume_device);
355 	if (res < 0)
356 		return res;
357 	root_swap = res;
358 
359 	hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
360 			BLK_OPEN_WRITE, NULL, NULL);
361 	if (IS_ERR(hib_resume_bdev))
362 		return PTR_ERR(hib_resume_bdev);
363 
364 	res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
365 	if (res < 0)
366 		blkdev_put(hib_resume_bdev, NULL);
367 
368 	return res;
369 }
370 
371 /**
372  *	write_page - Write one page to given swap location.
373  *	@buf:		Address we're writing.
374  *	@offset:	Offset of the swap page we're writing to.
375  *	@hb:		bio completion batch
376  */
377 
write_page(void * buf,sector_t offset,struct hib_bio_batch * hb)378 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
379 {
380 	void *src;
381 	int ret;
382 
383 	if (!offset)
384 		return -ENOSPC;
385 
386 	if (hb) {
387 		src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
388 		                              __GFP_NORETRY);
389 		if (src) {
390 			copy_page(src, buf);
391 		} else {
392 			ret = hib_wait_io(hb); /* Free pages */
393 			if (ret)
394 				return ret;
395 			src = (void *)__get_free_page(GFP_NOIO |
396 			                              __GFP_NOWARN |
397 			                              __GFP_NORETRY);
398 			if (src) {
399 				copy_page(src, buf);
400 			} else {
401 				WARN_ON_ONCE(1);
402 				hb = NULL;	/* Go synchronous */
403 				src = buf;
404 			}
405 		}
406 	} else {
407 		src = buf;
408 	}
409 	return hib_submit_io(REQ_OP_WRITE | REQ_SYNC, offset, src, hb);
410 }
411 
release_swap_writer(struct swap_map_handle * handle)412 static void release_swap_writer(struct swap_map_handle *handle)
413 {
414 	if (handle->cur)
415 		free_page((unsigned long)handle->cur);
416 	handle->cur = NULL;
417 }
418 
get_swap_writer(struct swap_map_handle * handle)419 static int get_swap_writer(struct swap_map_handle *handle)
420 {
421 	int ret;
422 
423 	ret = swsusp_swap_check();
424 	if (ret) {
425 		if (ret != -ENOSPC)
426 			pr_err("Cannot find swap device, try swapon -a\n");
427 		return ret;
428 	}
429 	handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
430 	if (!handle->cur) {
431 		ret = -ENOMEM;
432 		goto err_close;
433 	}
434 	handle->cur_swap = alloc_swapdev_block(root_swap);
435 	if (!handle->cur_swap) {
436 		ret = -ENOSPC;
437 		goto err_rel;
438 	}
439 	handle->k = 0;
440 	handle->reqd_free_pages = reqd_free_pages();
441 	handle->first_sector = handle->cur_swap;
442 	return 0;
443 err_rel:
444 	release_swap_writer(handle);
445 err_close:
446 	swsusp_close(false);
447 	return ret;
448 }
449 
swap_write_page(struct swap_map_handle * handle,void * buf,struct hib_bio_batch * hb)450 static int swap_write_page(struct swap_map_handle *handle, void *buf,
451 		struct hib_bio_batch *hb)
452 {
453 	int error = 0;
454 	sector_t offset;
455 
456 	if (!handle->cur)
457 		return -EINVAL;
458 	offset = alloc_swapdev_block(root_swap);
459 	error = write_page(buf, offset, hb);
460 	if (error)
461 		return error;
462 	handle->cur->entries[handle->k++] = offset;
463 	if (handle->k >= MAP_PAGE_ENTRIES) {
464 		offset = alloc_swapdev_block(root_swap);
465 		if (!offset)
466 			return -ENOSPC;
467 		handle->cur->next_swap = offset;
468 		error = write_page(handle->cur, handle->cur_swap, hb);
469 		if (error)
470 			goto out;
471 		clear_page(handle->cur);
472 		handle->cur_swap = offset;
473 		handle->k = 0;
474 
475 		if (hb && low_free_pages() <= handle->reqd_free_pages) {
476 			error = hib_wait_io(hb);
477 			if (error)
478 				goto out;
479 			/*
480 			 * Recalculate the number of required free pages, to
481 			 * make sure we never take more than half.
482 			 */
483 			handle->reqd_free_pages = reqd_free_pages();
484 		}
485 	}
486  out:
487 	return error;
488 }
489 
flush_swap_writer(struct swap_map_handle * handle)490 static int flush_swap_writer(struct swap_map_handle *handle)
491 {
492 	if (handle->cur && handle->cur_swap)
493 		return write_page(handle->cur, handle->cur_swap, NULL);
494 	else
495 		return -EINVAL;
496 }
497 
swap_writer_finish(struct swap_map_handle * handle,unsigned int flags,int error)498 static int swap_writer_finish(struct swap_map_handle *handle,
499 		unsigned int flags, int error)
500 {
501 	if (!error) {
502 		pr_info("S");
503 		error = mark_swapfiles(handle, flags);
504 		pr_cont("|\n");
505 		flush_swap_writer(handle);
506 	}
507 
508 	if (error)
509 		free_all_swap_pages(root_swap);
510 	release_swap_writer(handle);
511 	swsusp_close(false);
512 
513 	return error;
514 }
515 
516 /* We need to remember how much compressed data we need to read. */
517 #define LZO_HEADER	sizeof(size_t)
518 
519 /* Number of pages/bytes we'll compress at one time. */
520 #define LZO_UNC_PAGES	32
521 #define LZO_UNC_SIZE	(LZO_UNC_PAGES * PAGE_SIZE)
522 
523 /* Number of pages/bytes we need for compressed data (worst case). */
524 #define LZO_CMP_PAGES	DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
525 			             LZO_HEADER, PAGE_SIZE)
526 #define LZO_CMP_SIZE	(LZO_CMP_PAGES * PAGE_SIZE)
527 
528 /* Maximum number of threads for compression/decompression. */
529 #define LZO_THREADS	3
530 
531 /* Minimum/maximum number of pages for read buffering. */
532 #define LZO_MIN_RD_PAGES	1024
533 #define LZO_MAX_RD_PAGES	8192
534 
535 
536 /**
537  *	save_image - save the suspend image data
538  */
539 
save_image(struct swap_map_handle * handle,struct snapshot_handle * snapshot,unsigned int nr_to_write)540 static int save_image(struct swap_map_handle *handle,
541                       struct snapshot_handle *snapshot,
542                       unsigned int nr_to_write)
543 {
544 	unsigned int m;
545 	int ret;
546 	int nr_pages;
547 	int err2;
548 	struct hib_bio_batch hb;
549 	ktime_t start;
550 	ktime_t stop;
551 
552 	hib_init_batch(&hb);
553 
554 	pr_info("Saving image data pages (%u pages)...\n",
555 		nr_to_write);
556 	m = nr_to_write / 10;
557 	if (!m)
558 		m = 1;
559 	nr_pages = 0;
560 	start = ktime_get();
561 	while (1) {
562 		ret = snapshot_read_next(snapshot);
563 		if (ret <= 0)
564 			break;
565 		ret = swap_write_page(handle, data_of(*snapshot), &hb);
566 		if (ret)
567 			break;
568 		if (!(nr_pages % m))
569 			pr_info("Image saving progress: %3d%%\n",
570 				nr_pages / m * 10);
571 		nr_pages++;
572 	}
573 	err2 = hib_wait_io(&hb);
574 	hib_finish_batch(&hb);
575 	stop = ktime_get();
576 	if (!ret)
577 		ret = err2;
578 	if (!ret)
579 		pr_info("Image saving done\n");
580 	swsusp_show_speed(start, stop, nr_to_write, "Wrote");
581 	return ret;
582 }
583 
584 /*
585  * Structure used for CRC32.
586  */
587 struct crc_data {
588 	struct task_struct *thr;                  /* thread */
589 	atomic_t ready;                           /* ready to start flag */
590 	atomic_t stop;                            /* ready to stop flag */
591 	unsigned run_threads;                     /* nr current threads */
592 	wait_queue_head_t go;                     /* start crc update */
593 	wait_queue_head_t done;                   /* crc update done */
594 	u32 *crc32;                               /* points to handle's crc32 */
595 	size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
596 	unsigned char *unc[LZO_THREADS];          /* uncompressed data */
597 };
598 
599 /*
600  * CRC32 update function that runs in its own thread.
601  */
crc32_threadfn(void * data)602 static int crc32_threadfn(void *data)
603 {
604 	struct crc_data *d = data;
605 	unsigned i;
606 
607 	while (1) {
608 		wait_event(d->go, atomic_read_acquire(&d->ready) ||
609 		                  kthread_should_stop());
610 		if (kthread_should_stop()) {
611 			d->thr = NULL;
612 			atomic_set_release(&d->stop, 1);
613 			wake_up(&d->done);
614 			break;
615 		}
616 		atomic_set(&d->ready, 0);
617 
618 		for (i = 0; i < d->run_threads; i++)
619 			*d->crc32 = crc32_le(*d->crc32,
620 			                     d->unc[i], *d->unc_len[i]);
621 		atomic_set_release(&d->stop, 1);
622 		wake_up(&d->done);
623 	}
624 	return 0;
625 }
626 /*
627  * Structure used for LZO data compression.
628  */
629 struct cmp_data {
630 	struct task_struct *thr;                  /* thread */
631 	atomic_t ready;                           /* ready to start flag */
632 	atomic_t stop;                            /* ready to stop flag */
633 	int ret;                                  /* return code */
634 	wait_queue_head_t go;                     /* start compression */
635 	wait_queue_head_t done;                   /* compression done */
636 	size_t unc_len;                           /* uncompressed length */
637 	size_t cmp_len;                           /* compressed length */
638 	unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
639 	unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
640 	unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
641 };
642 
643 /*
644  * Compression function that runs in its own thread.
645  */
lzo_compress_threadfn(void * data)646 static int lzo_compress_threadfn(void *data)
647 {
648 	struct cmp_data *d = data;
649 
650 	while (1) {
651 		wait_event(d->go, atomic_read_acquire(&d->ready) ||
652 		                  kthread_should_stop());
653 		if (kthread_should_stop()) {
654 			d->thr = NULL;
655 			d->ret = -1;
656 			atomic_set_release(&d->stop, 1);
657 			wake_up(&d->done);
658 			break;
659 		}
660 		atomic_set(&d->ready, 0);
661 
662 		d->ret = lzo1x_1_compress(d->unc, d->unc_len,
663 		                          d->cmp + LZO_HEADER, &d->cmp_len,
664 		                          d->wrk);
665 		atomic_set_release(&d->stop, 1);
666 		wake_up(&d->done);
667 	}
668 	return 0;
669 }
670 
671 /**
672  * save_image_lzo - Save the suspend image data compressed with LZO.
673  * @handle: Swap map handle to use for saving the image.
674  * @snapshot: Image to read data from.
675  * @nr_to_write: Number of pages to save.
676  */
save_image_lzo(struct swap_map_handle * handle,struct snapshot_handle * snapshot,unsigned int nr_to_write)677 static int save_image_lzo(struct swap_map_handle *handle,
678                           struct snapshot_handle *snapshot,
679                           unsigned int nr_to_write)
680 {
681 	unsigned int m;
682 	int ret = 0;
683 	int nr_pages;
684 	int err2;
685 	struct hib_bio_batch hb;
686 	ktime_t start;
687 	ktime_t stop;
688 	size_t off;
689 	unsigned thr, run_threads, nr_threads;
690 	unsigned char *page = NULL;
691 	struct cmp_data *data = NULL;
692 	struct crc_data *crc = NULL;
693 
694 	hib_init_batch(&hb);
695 
696 	/*
697 	 * We'll limit the number of threads for compression to limit memory
698 	 * footprint.
699 	 */
700 	nr_threads = num_online_cpus() - 1;
701 	nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
702 
703 	page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
704 	if (!page) {
705 		pr_err("Failed to allocate LZO page\n");
706 		ret = -ENOMEM;
707 		goto out_clean;
708 	}
709 
710 	data = vzalloc(array_size(nr_threads, sizeof(*data)));
711 	if (!data) {
712 		pr_err("Failed to allocate LZO data\n");
713 		ret = -ENOMEM;
714 		goto out_clean;
715 	}
716 
717 	crc = kzalloc(sizeof(*crc), GFP_KERNEL);
718 	if (!crc) {
719 		pr_err("Failed to allocate crc\n");
720 		ret = -ENOMEM;
721 		goto out_clean;
722 	}
723 
724 	/*
725 	 * Start the compression threads.
726 	 */
727 	for (thr = 0; thr < nr_threads; thr++) {
728 		init_waitqueue_head(&data[thr].go);
729 		init_waitqueue_head(&data[thr].done);
730 
731 		data[thr].thr = kthread_run(lzo_compress_threadfn,
732 		                            &data[thr],
733 		                            "image_compress/%u", thr);
734 		if (IS_ERR(data[thr].thr)) {
735 			data[thr].thr = NULL;
736 			pr_err("Cannot start compression threads\n");
737 			ret = -ENOMEM;
738 			goto out_clean;
739 		}
740 	}
741 
742 	/*
743 	 * Start the CRC32 thread.
744 	 */
745 	init_waitqueue_head(&crc->go);
746 	init_waitqueue_head(&crc->done);
747 
748 	handle->crc32 = 0;
749 	crc->crc32 = &handle->crc32;
750 	for (thr = 0; thr < nr_threads; thr++) {
751 		crc->unc[thr] = data[thr].unc;
752 		crc->unc_len[thr] = &data[thr].unc_len;
753 	}
754 
755 	crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
756 	if (IS_ERR(crc->thr)) {
757 		crc->thr = NULL;
758 		pr_err("Cannot start CRC32 thread\n");
759 		ret = -ENOMEM;
760 		goto out_clean;
761 	}
762 
763 	/*
764 	 * Adjust the number of required free pages after all allocations have
765 	 * been done. We don't want to run out of pages when writing.
766 	 */
767 	handle->reqd_free_pages = reqd_free_pages();
768 
769 	pr_info("Using %u thread(s) for compression\n", nr_threads);
770 	pr_info("Compressing and saving image data (%u pages)...\n",
771 		nr_to_write);
772 	m = nr_to_write / 10;
773 	if (!m)
774 		m = 1;
775 	nr_pages = 0;
776 	start = ktime_get();
777 	for (;;) {
778 		for (thr = 0; thr < nr_threads; thr++) {
779 			for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
780 				ret = snapshot_read_next(snapshot);
781 				if (ret < 0)
782 					goto out_finish;
783 
784 				if (!ret)
785 					break;
786 
787 				memcpy(data[thr].unc + off,
788 				       data_of(*snapshot), PAGE_SIZE);
789 
790 				if (!(nr_pages % m))
791 					pr_info("Image saving progress: %3d%%\n",
792 						nr_pages / m * 10);
793 				nr_pages++;
794 			}
795 			if (!off)
796 				break;
797 
798 			data[thr].unc_len = off;
799 
800 			atomic_set_release(&data[thr].ready, 1);
801 			wake_up(&data[thr].go);
802 		}
803 
804 		if (!thr)
805 			break;
806 
807 		crc->run_threads = thr;
808 		atomic_set_release(&crc->ready, 1);
809 		wake_up(&crc->go);
810 
811 		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
812 			wait_event(data[thr].done,
813 				atomic_read_acquire(&data[thr].stop));
814 			atomic_set(&data[thr].stop, 0);
815 
816 			ret = data[thr].ret;
817 
818 			if (ret < 0) {
819 				pr_err("LZO compression failed\n");
820 				goto out_finish;
821 			}
822 
823 			if (unlikely(!data[thr].cmp_len ||
824 			             data[thr].cmp_len >
825 			             lzo1x_worst_compress(data[thr].unc_len))) {
826 				pr_err("Invalid LZO compressed length\n");
827 				ret = -1;
828 				goto out_finish;
829 			}
830 
831 			*(size_t *)data[thr].cmp = data[thr].cmp_len;
832 
833 			/*
834 			 * Given we are writing one page at a time to disk, we
835 			 * copy that much from the buffer, although the last
836 			 * bit will likely be smaller than full page. This is
837 			 * OK - we saved the length of the compressed data, so
838 			 * any garbage at the end will be discarded when we
839 			 * read it.
840 			 */
841 			for (off = 0;
842 			     off < LZO_HEADER + data[thr].cmp_len;
843 			     off += PAGE_SIZE) {
844 				memcpy(page, data[thr].cmp + off, PAGE_SIZE);
845 
846 				ret = swap_write_page(handle, page, &hb);
847 				if (ret)
848 					goto out_finish;
849 			}
850 		}
851 
852 		wait_event(crc->done, atomic_read_acquire(&crc->stop));
853 		atomic_set(&crc->stop, 0);
854 	}
855 
856 out_finish:
857 	err2 = hib_wait_io(&hb);
858 	stop = ktime_get();
859 	if (!ret)
860 		ret = err2;
861 	if (!ret)
862 		pr_info("Image saving done\n");
863 	swsusp_show_speed(start, stop, nr_to_write, "Wrote");
864 out_clean:
865 	hib_finish_batch(&hb);
866 	if (crc) {
867 		if (crc->thr)
868 			kthread_stop(crc->thr);
869 		kfree(crc);
870 	}
871 	if (data) {
872 		for (thr = 0; thr < nr_threads; thr++)
873 			if (data[thr].thr)
874 				kthread_stop(data[thr].thr);
875 		vfree(data);
876 	}
877 	if (page) free_page((unsigned long)page);
878 
879 	return ret;
880 }
881 
882 /**
883  *	enough_swap - Make sure we have enough swap to save the image.
884  *
885  *	Returns TRUE or FALSE after checking the total amount of swap
886  *	space available from the resume partition.
887  */
888 
enough_swap(unsigned int nr_pages)889 static int enough_swap(unsigned int nr_pages)
890 {
891 	unsigned int free_swap = count_swap_pages(root_swap, 1);
892 	unsigned int required;
893 
894 	pr_debug("Free swap pages: %u\n", free_swap);
895 
896 	required = PAGES_FOR_IO + nr_pages;
897 	return free_swap > required;
898 }
899 
900 /**
901  *	swsusp_write - Write entire image and metadata.
902  *	@flags: flags to pass to the "boot" kernel in the image header
903  *
904  *	It is important _NOT_ to umount filesystems at this point. We want
905  *	them synced (in case something goes wrong) but we DO not want to mark
906  *	filesystem clean: it is not. (And it does not matter, if we resume
907  *	correctly, we'll mark system clean, anyway.)
908  */
909 
swsusp_write(unsigned int flags)910 int swsusp_write(unsigned int flags)
911 {
912 	struct swap_map_handle handle;
913 	struct snapshot_handle snapshot;
914 	struct swsusp_info *header;
915 	unsigned long pages;
916 	int error;
917 
918 	pages = snapshot_get_image_size();
919 	error = get_swap_writer(&handle);
920 	if (error) {
921 		pr_err("Cannot get swap writer\n");
922 		return error;
923 	}
924 	if (flags & SF_NOCOMPRESS_MODE) {
925 		if (!enough_swap(pages)) {
926 			pr_err("Not enough free swap\n");
927 			error = -ENOSPC;
928 			goto out_finish;
929 		}
930 	}
931 	memset(&snapshot, 0, sizeof(struct snapshot_handle));
932 	error = snapshot_read_next(&snapshot);
933 	if (error < (int)PAGE_SIZE) {
934 		if (error >= 0)
935 			error = -EFAULT;
936 
937 		goto out_finish;
938 	}
939 	header = (struct swsusp_info *)data_of(snapshot);
940 	error = swap_write_page(&handle, header, NULL);
941 	if (!error) {
942 		error = (flags & SF_NOCOMPRESS_MODE) ?
943 			save_image(&handle, &snapshot, pages - 1) :
944 			save_image_lzo(&handle, &snapshot, pages - 1);
945 	}
946 out_finish:
947 	error = swap_writer_finish(&handle, flags, error);
948 	return error;
949 }
950 
951 /*
952  *	The following functions allow us to read data using a swap map
953  *	in a file-like way.
954  */
955 
release_swap_reader(struct swap_map_handle * handle)956 static void release_swap_reader(struct swap_map_handle *handle)
957 {
958 	struct swap_map_page_list *tmp;
959 
960 	while (handle->maps) {
961 		if (handle->maps->map)
962 			free_page((unsigned long)handle->maps->map);
963 		tmp = handle->maps;
964 		handle->maps = handle->maps->next;
965 		kfree(tmp);
966 	}
967 	handle->cur = NULL;
968 }
969 
get_swap_reader(struct swap_map_handle * handle,unsigned int * flags_p)970 static int get_swap_reader(struct swap_map_handle *handle,
971 		unsigned int *flags_p)
972 {
973 	int error;
974 	struct swap_map_page_list *tmp, *last;
975 	sector_t offset;
976 
977 	*flags_p = swsusp_header->flags;
978 
979 	if (!swsusp_header->image) /* how can this happen? */
980 		return -EINVAL;
981 
982 	handle->cur = NULL;
983 	last = handle->maps = NULL;
984 	offset = swsusp_header->image;
985 	while (offset) {
986 		tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
987 		if (!tmp) {
988 			release_swap_reader(handle);
989 			return -ENOMEM;
990 		}
991 		if (!handle->maps)
992 			handle->maps = tmp;
993 		if (last)
994 			last->next = tmp;
995 		last = tmp;
996 
997 		tmp->map = (struct swap_map_page *)
998 			   __get_free_page(GFP_NOIO | __GFP_HIGH);
999 		if (!tmp->map) {
1000 			release_swap_reader(handle);
1001 			return -ENOMEM;
1002 		}
1003 
1004 		error = hib_submit_io(REQ_OP_READ, offset, tmp->map, NULL);
1005 		if (error) {
1006 			release_swap_reader(handle);
1007 			return error;
1008 		}
1009 		offset = tmp->map->next_swap;
1010 	}
1011 	handle->k = 0;
1012 	handle->cur = handle->maps->map;
1013 	return 0;
1014 }
1015 
swap_read_page(struct swap_map_handle * handle,void * buf,struct hib_bio_batch * hb)1016 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1017 		struct hib_bio_batch *hb)
1018 {
1019 	sector_t offset;
1020 	int error;
1021 	struct swap_map_page_list *tmp;
1022 
1023 	if (!handle->cur)
1024 		return -EINVAL;
1025 	offset = handle->cur->entries[handle->k];
1026 	if (!offset)
1027 		return -EFAULT;
1028 	error = hib_submit_io(REQ_OP_READ, offset, buf, hb);
1029 	if (error)
1030 		return error;
1031 	if (++handle->k >= MAP_PAGE_ENTRIES) {
1032 		handle->k = 0;
1033 		free_page((unsigned long)handle->maps->map);
1034 		tmp = handle->maps;
1035 		handle->maps = handle->maps->next;
1036 		kfree(tmp);
1037 		if (!handle->maps)
1038 			release_swap_reader(handle);
1039 		else
1040 			handle->cur = handle->maps->map;
1041 	}
1042 	return error;
1043 }
1044 
swap_reader_finish(struct swap_map_handle * handle)1045 static int swap_reader_finish(struct swap_map_handle *handle)
1046 {
1047 	release_swap_reader(handle);
1048 
1049 	return 0;
1050 }
1051 
1052 /**
1053  *	load_image - load the image using the swap map handle
1054  *	@handle and the snapshot handle @snapshot
1055  *	(assume there are @nr_pages pages to load)
1056  */
1057 
load_image(struct swap_map_handle * handle,struct snapshot_handle * snapshot,unsigned int nr_to_read)1058 static int load_image(struct swap_map_handle *handle,
1059                       struct snapshot_handle *snapshot,
1060                       unsigned int nr_to_read)
1061 {
1062 	unsigned int m;
1063 	int ret = 0;
1064 	ktime_t start;
1065 	ktime_t stop;
1066 	struct hib_bio_batch hb;
1067 	int err2;
1068 	unsigned nr_pages;
1069 
1070 	hib_init_batch(&hb);
1071 
1072 	clean_pages_on_read = true;
1073 	pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1074 	m = nr_to_read / 10;
1075 	if (!m)
1076 		m = 1;
1077 	nr_pages = 0;
1078 	start = ktime_get();
1079 	for ( ; ; ) {
1080 		ret = snapshot_write_next(snapshot);
1081 		if (ret <= 0)
1082 			break;
1083 		ret = swap_read_page(handle, data_of(*snapshot), &hb);
1084 		if (ret)
1085 			break;
1086 		if (snapshot->sync_read)
1087 			ret = hib_wait_io(&hb);
1088 		if (ret)
1089 			break;
1090 		if (!(nr_pages % m))
1091 			pr_info("Image loading progress: %3d%%\n",
1092 				nr_pages / m * 10);
1093 		nr_pages++;
1094 	}
1095 	err2 = hib_wait_io(&hb);
1096 	hib_finish_batch(&hb);
1097 	stop = ktime_get();
1098 	if (!ret)
1099 		ret = err2;
1100 	if (!ret) {
1101 		pr_info("Image loading done\n");
1102 		snapshot_write_finalize(snapshot);
1103 		if (!snapshot_image_loaded(snapshot))
1104 			ret = -ENODATA;
1105 	}
1106 	swsusp_show_speed(start, stop, nr_to_read, "Read");
1107 	return ret;
1108 }
1109 
1110 /*
1111  * Structure used for LZO data decompression.
1112  */
1113 struct dec_data {
1114 	struct task_struct *thr;                  /* thread */
1115 	atomic_t ready;                           /* ready to start flag */
1116 	atomic_t stop;                            /* ready to stop flag */
1117 	int ret;                                  /* return code */
1118 	wait_queue_head_t go;                     /* start decompression */
1119 	wait_queue_head_t done;                   /* decompression done */
1120 	size_t unc_len;                           /* uncompressed length */
1121 	size_t cmp_len;                           /* compressed length */
1122 	unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1123 	unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1124 };
1125 
1126 /*
1127  * Decompression function that runs in its own thread.
1128  */
lzo_decompress_threadfn(void * data)1129 static int lzo_decompress_threadfn(void *data)
1130 {
1131 	struct dec_data *d = data;
1132 
1133 	while (1) {
1134 		wait_event(d->go, atomic_read_acquire(&d->ready) ||
1135 		                  kthread_should_stop());
1136 		if (kthread_should_stop()) {
1137 			d->thr = NULL;
1138 			d->ret = -1;
1139 			atomic_set_release(&d->stop, 1);
1140 			wake_up(&d->done);
1141 			break;
1142 		}
1143 		atomic_set(&d->ready, 0);
1144 
1145 		d->unc_len = LZO_UNC_SIZE;
1146 		d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1147 		                               d->unc, &d->unc_len);
1148 		if (clean_pages_on_decompress)
1149 			flush_icache_range((unsigned long)d->unc,
1150 					   (unsigned long)d->unc + d->unc_len);
1151 
1152 		atomic_set_release(&d->stop, 1);
1153 		wake_up(&d->done);
1154 	}
1155 	return 0;
1156 }
1157 
1158 /**
1159  * load_image_lzo - Load compressed image data and decompress them with LZO.
1160  * @handle: Swap map handle to use for loading data.
1161  * @snapshot: Image to copy uncompressed data into.
1162  * @nr_to_read: Number of pages to load.
1163  */
load_image_lzo(struct swap_map_handle * handle,struct snapshot_handle * snapshot,unsigned int nr_to_read)1164 static int load_image_lzo(struct swap_map_handle *handle,
1165                           struct snapshot_handle *snapshot,
1166                           unsigned int nr_to_read)
1167 {
1168 	unsigned int m;
1169 	int ret = 0;
1170 	int eof = 0;
1171 	struct hib_bio_batch hb;
1172 	ktime_t start;
1173 	ktime_t stop;
1174 	unsigned nr_pages;
1175 	size_t off;
1176 	unsigned i, thr, run_threads, nr_threads;
1177 	unsigned ring = 0, pg = 0, ring_size = 0,
1178 	         have = 0, want, need, asked = 0;
1179 	unsigned long read_pages = 0;
1180 	unsigned char **page = NULL;
1181 	struct dec_data *data = NULL;
1182 	struct crc_data *crc = NULL;
1183 
1184 	hib_init_batch(&hb);
1185 
1186 	/*
1187 	 * We'll limit the number of threads for decompression to limit memory
1188 	 * footprint.
1189 	 */
1190 	nr_threads = num_online_cpus() - 1;
1191 	nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1192 
1193 	page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
1194 	if (!page) {
1195 		pr_err("Failed to allocate LZO page\n");
1196 		ret = -ENOMEM;
1197 		goto out_clean;
1198 	}
1199 
1200 	data = vzalloc(array_size(nr_threads, sizeof(*data)));
1201 	if (!data) {
1202 		pr_err("Failed to allocate LZO data\n");
1203 		ret = -ENOMEM;
1204 		goto out_clean;
1205 	}
1206 
1207 	crc = kzalloc(sizeof(*crc), GFP_KERNEL);
1208 	if (!crc) {
1209 		pr_err("Failed to allocate crc\n");
1210 		ret = -ENOMEM;
1211 		goto out_clean;
1212 	}
1213 
1214 	clean_pages_on_decompress = true;
1215 
1216 	/*
1217 	 * Start the decompression threads.
1218 	 */
1219 	for (thr = 0; thr < nr_threads; thr++) {
1220 		init_waitqueue_head(&data[thr].go);
1221 		init_waitqueue_head(&data[thr].done);
1222 
1223 		data[thr].thr = kthread_run(lzo_decompress_threadfn,
1224 		                            &data[thr],
1225 		                            "image_decompress/%u", thr);
1226 		if (IS_ERR(data[thr].thr)) {
1227 			data[thr].thr = NULL;
1228 			pr_err("Cannot start decompression threads\n");
1229 			ret = -ENOMEM;
1230 			goto out_clean;
1231 		}
1232 	}
1233 
1234 	/*
1235 	 * Start the CRC32 thread.
1236 	 */
1237 	init_waitqueue_head(&crc->go);
1238 	init_waitqueue_head(&crc->done);
1239 
1240 	handle->crc32 = 0;
1241 	crc->crc32 = &handle->crc32;
1242 	for (thr = 0; thr < nr_threads; thr++) {
1243 		crc->unc[thr] = data[thr].unc;
1244 		crc->unc_len[thr] = &data[thr].unc_len;
1245 	}
1246 
1247 	crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1248 	if (IS_ERR(crc->thr)) {
1249 		crc->thr = NULL;
1250 		pr_err("Cannot start CRC32 thread\n");
1251 		ret = -ENOMEM;
1252 		goto out_clean;
1253 	}
1254 
1255 	/*
1256 	 * Set the number of pages for read buffering.
1257 	 * This is complete guesswork, because we'll only know the real
1258 	 * picture once prepare_image() is called, which is much later on
1259 	 * during the image load phase. We'll assume the worst case and
1260 	 * say that none of the image pages are from high memory.
1261 	 */
1262 	if (low_free_pages() > snapshot_get_image_size())
1263 		read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1264 	read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1265 
1266 	for (i = 0; i < read_pages; i++) {
1267 		page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1268 						  GFP_NOIO | __GFP_HIGH :
1269 						  GFP_NOIO | __GFP_NOWARN |
1270 						  __GFP_NORETRY);
1271 
1272 		if (!page[i]) {
1273 			if (i < LZO_CMP_PAGES) {
1274 				ring_size = i;
1275 				pr_err("Failed to allocate LZO pages\n");
1276 				ret = -ENOMEM;
1277 				goto out_clean;
1278 			} else {
1279 				break;
1280 			}
1281 		}
1282 	}
1283 	want = ring_size = i;
1284 
1285 	pr_info("Using %u thread(s) for decompression\n", nr_threads);
1286 	pr_info("Loading and decompressing image data (%u pages)...\n",
1287 		nr_to_read);
1288 	m = nr_to_read / 10;
1289 	if (!m)
1290 		m = 1;
1291 	nr_pages = 0;
1292 	start = ktime_get();
1293 
1294 	ret = snapshot_write_next(snapshot);
1295 	if (ret <= 0)
1296 		goto out_finish;
1297 
1298 	for(;;) {
1299 		for (i = 0; !eof && i < want; i++) {
1300 			ret = swap_read_page(handle, page[ring], &hb);
1301 			if (ret) {
1302 				/*
1303 				 * On real read error, finish. On end of data,
1304 				 * set EOF flag and just exit the read loop.
1305 				 */
1306 				if (handle->cur &&
1307 				    handle->cur->entries[handle->k]) {
1308 					goto out_finish;
1309 				} else {
1310 					eof = 1;
1311 					break;
1312 				}
1313 			}
1314 			if (++ring >= ring_size)
1315 				ring = 0;
1316 		}
1317 		asked += i;
1318 		want -= i;
1319 
1320 		/*
1321 		 * We are out of data, wait for some more.
1322 		 */
1323 		if (!have) {
1324 			if (!asked)
1325 				break;
1326 
1327 			ret = hib_wait_io(&hb);
1328 			if (ret)
1329 				goto out_finish;
1330 			have += asked;
1331 			asked = 0;
1332 			if (eof)
1333 				eof = 2;
1334 		}
1335 
1336 		if (crc->run_threads) {
1337 			wait_event(crc->done, atomic_read_acquire(&crc->stop));
1338 			atomic_set(&crc->stop, 0);
1339 			crc->run_threads = 0;
1340 		}
1341 
1342 		for (thr = 0; have && thr < nr_threads; thr++) {
1343 			data[thr].cmp_len = *(size_t *)page[pg];
1344 			if (unlikely(!data[thr].cmp_len ||
1345 			             data[thr].cmp_len >
1346 			             lzo1x_worst_compress(LZO_UNC_SIZE))) {
1347 				pr_err("Invalid LZO compressed length\n");
1348 				ret = -1;
1349 				goto out_finish;
1350 			}
1351 
1352 			need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1353 			                    PAGE_SIZE);
1354 			if (need > have) {
1355 				if (eof > 1) {
1356 					ret = -1;
1357 					goto out_finish;
1358 				}
1359 				break;
1360 			}
1361 
1362 			for (off = 0;
1363 			     off < LZO_HEADER + data[thr].cmp_len;
1364 			     off += PAGE_SIZE) {
1365 				memcpy(data[thr].cmp + off,
1366 				       page[pg], PAGE_SIZE);
1367 				have--;
1368 				want++;
1369 				if (++pg >= ring_size)
1370 					pg = 0;
1371 			}
1372 
1373 			atomic_set_release(&data[thr].ready, 1);
1374 			wake_up(&data[thr].go);
1375 		}
1376 
1377 		/*
1378 		 * Wait for more data while we are decompressing.
1379 		 */
1380 		if (have < LZO_CMP_PAGES && asked) {
1381 			ret = hib_wait_io(&hb);
1382 			if (ret)
1383 				goto out_finish;
1384 			have += asked;
1385 			asked = 0;
1386 			if (eof)
1387 				eof = 2;
1388 		}
1389 
1390 		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1391 			wait_event(data[thr].done,
1392 				atomic_read_acquire(&data[thr].stop));
1393 			atomic_set(&data[thr].stop, 0);
1394 
1395 			ret = data[thr].ret;
1396 
1397 			if (ret < 0) {
1398 				pr_err("LZO decompression failed\n");
1399 				goto out_finish;
1400 			}
1401 
1402 			if (unlikely(!data[thr].unc_len ||
1403 			             data[thr].unc_len > LZO_UNC_SIZE ||
1404 			             data[thr].unc_len & (PAGE_SIZE - 1))) {
1405 				pr_err("Invalid LZO uncompressed length\n");
1406 				ret = -1;
1407 				goto out_finish;
1408 			}
1409 
1410 			for (off = 0;
1411 			     off < data[thr].unc_len; off += PAGE_SIZE) {
1412 				memcpy(data_of(*snapshot),
1413 				       data[thr].unc + off, PAGE_SIZE);
1414 
1415 				if (!(nr_pages % m))
1416 					pr_info("Image loading progress: %3d%%\n",
1417 						nr_pages / m * 10);
1418 				nr_pages++;
1419 
1420 				ret = snapshot_write_next(snapshot);
1421 				if (ret <= 0) {
1422 					crc->run_threads = thr + 1;
1423 					atomic_set_release(&crc->ready, 1);
1424 					wake_up(&crc->go);
1425 					goto out_finish;
1426 				}
1427 			}
1428 		}
1429 
1430 		crc->run_threads = thr;
1431 		atomic_set_release(&crc->ready, 1);
1432 		wake_up(&crc->go);
1433 	}
1434 
1435 out_finish:
1436 	if (crc->run_threads) {
1437 		wait_event(crc->done, atomic_read_acquire(&crc->stop));
1438 		atomic_set(&crc->stop, 0);
1439 	}
1440 	stop = ktime_get();
1441 	if (!ret) {
1442 		pr_info("Image loading done\n");
1443 		snapshot_write_finalize(snapshot);
1444 		if (!snapshot_image_loaded(snapshot))
1445 			ret = -ENODATA;
1446 		if (!ret) {
1447 			if (swsusp_header->flags & SF_CRC32_MODE) {
1448 				if(handle->crc32 != swsusp_header->crc32) {
1449 					pr_err("Invalid image CRC32!\n");
1450 					ret = -ENODATA;
1451 				}
1452 			}
1453 		}
1454 	}
1455 	swsusp_show_speed(start, stop, nr_to_read, "Read");
1456 out_clean:
1457 	hib_finish_batch(&hb);
1458 	for (i = 0; i < ring_size; i++)
1459 		free_page((unsigned long)page[i]);
1460 	if (crc) {
1461 		if (crc->thr)
1462 			kthread_stop(crc->thr);
1463 		kfree(crc);
1464 	}
1465 	if (data) {
1466 		for (thr = 0; thr < nr_threads; thr++)
1467 			if (data[thr].thr)
1468 				kthread_stop(data[thr].thr);
1469 		vfree(data);
1470 	}
1471 	vfree(page);
1472 
1473 	return ret;
1474 }
1475 
1476 /**
1477  *	swsusp_read - read the hibernation image.
1478  *	@flags_p: flags passed by the "frozen" kernel in the image header should
1479  *		  be written into this memory location
1480  */
1481 
swsusp_read(unsigned int * flags_p)1482 int swsusp_read(unsigned int *flags_p)
1483 {
1484 	int error;
1485 	struct swap_map_handle handle;
1486 	struct snapshot_handle snapshot;
1487 	struct swsusp_info *header;
1488 
1489 	memset(&snapshot, 0, sizeof(struct snapshot_handle));
1490 	error = snapshot_write_next(&snapshot);
1491 	if (error < (int)PAGE_SIZE)
1492 		return error < 0 ? error : -EFAULT;
1493 	header = (struct swsusp_info *)data_of(snapshot);
1494 	error = get_swap_reader(&handle, flags_p);
1495 	if (error)
1496 		goto end;
1497 	if (!error)
1498 		error = swap_read_page(&handle, header, NULL);
1499 	if (!error) {
1500 		error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1501 			load_image(&handle, &snapshot, header->pages - 1) :
1502 			load_image_lzo(&handle, &snapshot, header->pages - 1);
1503 	}
1504 	swap_reader_finish(&handle);
1505 end:
1506 	if (!error)
1507 		pr_debug("Image successfully loaded\n");
1508 	else
1509 		pr_debug("Error %d resuming\n", error);
1510 	return error;
1511 }
1512 
1513 static void *swsusp_holder;
1514 
1515 /**
1516  * swsusp_check - Check for swsusp signature in the resume device
1517  * @exclusive: Open the resume device exclusively.
1518  */
1519 
swsusp_check(bool exclusive)1520 int swsusp_check(bool exclusive)
1521 {
1522 	void *holder = exclusive ? &swsusp_holder : NULL;
1523 	int error;
1524 
1525 	hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, BLK_OPEN_READ,
1526 					    holder, NULL);
1527 	if (!IS_ERR(hib_resume_bdev)) {
1528 		set_blocksize(hib_resume_bdev, PAGE_SIZE);
1529 		clear_page(swsusp_header);
1530 		error = hib_submit_io(REQ_OP_READ, swsusp_resume_block,
1531 					swsusp_header, NULL);
1532 		if (error)
1533 			goto put;
1534 
1535 		if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1536 			memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1537 			/* Reset swap signature now */
1538 			error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
1539 						swsusp_resume_block,
1540 						swsusp_header, NULL);
1541 		} else {
1542 			error = -EINVAL;
1543 		}
1544 		if (!error && swsusp_header->flags & SF_HW_SIG &&
1545 		    swsusp_header->hw_sig != swsusp_hardware_signature) {
1546 			pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
1547 				swsusp_header->hw_sig, swsusp_hardware_signature);
1548 			error = -EINVAL;
1549 		}
1550 
1551 put:
1552 		if (error)
1553 			blkdev_put(hib_resume_bdev, holder);
1554 		else
1555 			pr_debug("Image signature found, resuming\n");
1556 	} else {
1557 		error = PTR_ERR(hib_resume_bdev);
1558 	}
1559 
1560 	if (error)
1561 		pr_debug("Image not found (code %d)\n", error);
1562 
1563 	return error;
1564 }
1565 
1566 /**
1567  * swsusp_close - close swap device.
1568  * @exclusive: Close the resume device which is exclusively opened.
1569  */
1570 
swsusp_close(bool exclusive)1571 void swsusp_close(bool exclusive)
1572 {
1573 	if (IS_ERR(hib_resume_bdev)) {
1574 		pr_debug("Image device not initialised\n");
1575 		return;
1576 	}
1577 
1578 	blkdev_put(hib_resume_bdev, exclusive ? &swsusp_holder : NULL);
1579 }
1580 
1581 /**
1582  *      swsusp_unmark - Unmark swsusp signature in the resume device
1583  */
1584 
1585 #ifdef CONFIG_SUSPEND
swsusp_unmark(void)1586 int swsusp_unmark(void)
1587 {
1588 	int error;
1589 
1590 	hib_submit_io(REQ_OP_READ, swsusp_resume_block,
1591 			swsusp_header, NULL);
1592 	if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1593 		memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1594 		error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
1595 					swsusp_resume_block,
1596 					swsusp_header, NULL);
1597 	} else {
1598 		pr_err("Cannot find swsusp signature!\n");
1599 		error = -ENODEV;
1600 	}
1601 
1602 	/*
1603 	 * We just returned from suspend, we don't need the image any more.
1604 	 */
1605 	free_all_swap_pages(root_swap);
1606 
1607 	return error;
1608 }
1609 #endif
1610 
swsusp_header_init(void)1611 static int __init swsusp_header_init(void)
1612 {
1613 	swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1614 	if (!swsusp_header)
1615 		panic("Could not allocate memory for swsusp_header\n");
1616 	return 0;
1617 }
1618 
1619 core_initcall(swsusp_header_init);
1620