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1 /*
2  * linux/kernel/power/swap.c
3  *
4  * This file provides functions for reading the suspend image from
5  * and writing it to a swap partition.
6  *
7  * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
8  * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9  * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
10  *
11  * This file is released under the GPLv2.
12  *
13  */
14 
15 #include <linux/module.h>
16 #include <linux/file.h>
17 #include <linux/delay.h>
18 #include <linux/bitops.h>
19 #include <linux/genhd.h>
20 #include <linux/device.h>
21 #include <linux/bio.h>
22 #include <linux/blkdev.h>
23 #include <linux/swap.h>
24 #include <linux/swapops.h>
25 #include <linux/pm.h>
26 #include <linux/slab.h>
27 #include <linux/lzo.h>
28 #include <linux/vmalloc.h>
29 #include <linux/cpumask.h>
30 #include <linux/atomic.h>
31 #include <linux/kthread.h>
32 #include <linux/crc32.h>
33 #include <linux/ktime.h>
34 
35 #include "power.h"
36 
37 #define HIBERNATE_SIG	"S1SUSPEND"
38 
39 /*
40  * When reading an {un,}compressed image, we may restore pages in place,
41  * in which case some architectures need these pages cleaning before they
42  * can be executed. We don't know which pages these may be, so clean the lot.
43  */
44 static bool clean_pages_on_read;
45 static bool clean_pages_on_decompress;
46 
47 /*
48  *	The swap map is a data structure used for keeping track of each page
49  *	written to a swap partition.  It consists of many swap_map_page
50  *	structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
51  *	These structures are stored on the swap and linked together with the
52  *	help of the .next_swap member.
53  *
54  *	The swap map is created during suspend.  The swap map pages are
55  *	allocated and populated one at a time, so we only need one memory
56  *	page to set up the entire structure.
57  *
58  *	During resume we pick up all swap_map_page structures into a list.
59  */
60 
61 #define MAP_PAGE_ENTRIES	(PAGE_SIZE / sizeof(sector_t) - 1)
62 
63 /*
64  * Number of free pages that are not high.
65  */
low_free_pages(void)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  */
reqd_free_pages(void)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
92  *	a file-alike way
93  */
94 
95 struct swap_map_handle {
96 	struct swap_map_page *cur;
97 	struct swap_map_page_list *maps;
98 	sector_t cur_swap;
99 	sector_t first_sector;
100 	unsigned int k;
101 	unsigned long reqd_free_pages;
102 	u32 crc32;
103 };
104 
105 struct swsusp_header {
106 	char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
107 	              sizeof(u32)];
108 	u32	crc32;
109 	sector_t image;
110 	unsigned int flags;	/* Flags to pass to the "boot" kernel */
111 	char	orig_sig[10];
112 	char	sig[10];
113 } __packed;
114 
115 static struct swsusp_header *swsusp_header;
116 
117 /**
118  *	The following functions are used for tracing the allocated
119  *	swap pages, so that they can be freed in case of an error.
120  */
121 
122 struct swsusp_extent {
123 	struct rb_node node;
124 	unsigned long start;
125 	unsigned long end;
126 };
127 
128 static struct rb_root swsusp_extents = RB_ROOT;
129 
swsusp_extents_insert(unsigned long swap_offset)130 static int swsusp_extents_insert(unsigned long swap_offset)
131 {
132 	struct rb_node **new = &(swsusp_extents.rb_node);
133 	struct rb_node *parent = NULL;
134 	struct swsusp_extent *ext;
135 
136 	/* Figure out where to put the new node */
137 	while (*new) {
138 		ext = rb_entry(*new, struct swsusp_extent, node);
139 		parent = *new;
140 		if (swap_offset < ext->start) {
141 			/* Try to merge */
142 			if (swap_offset == ext->start - 1) {
143 				ext->start--;
144 				return 0;
145 			}
146 			new = &((*new)->rb_left);
147 		} else if (swap_offset > ext->end) {
148 			/* Try to merge */
149 			if (swap_offset == ext->end + 1) {
150 				ext->end++;
151 				return 0;
152 			}
153 			new = &((*new)->rb_right);
154 		} else {
155 			/* It already is in the tree */
156 			return -EINVAL;
157 		}
158 	}
159 	/* Add the new node and rebalance the tree. */
160 	ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
161 	if (!ext)
162 		return -ENOMEM;
163 
164 	ext->start = swap_offset;
165 	ext->end = swap_offset;
166 	rb_link_node(&ext->node, parent, new);
167 	rb_insert_color(&ext->node, &swsusp_extents);
168 	return 0;
169 }
170 
171 /**
172  *	alloc_swapdev_block - allocate a swap page and register that it has
173  *	been allocated, so that it can be freed in case of an error.
174  */
175 
alloc_swapdev_block(int swap)176 sector_t alloc_swapdev_block(int swap)
177 {
178 	unsigned long offset;
179 
180 	offset = swp_offset(get_swap_page_of_type(swap));
181 	if (offset) {
182 		if (swsusp_extents_insert(offset))
183 			swap_free(swp_entry(swap, offset));
184 		else
185 			return swapdev_block(swap, offset);
186 	}
187 	return 0;
188 }
189 
190 /**
191  *	free_all_swap_pages - free swap pages allocated for saving image data.
192  *	It also frees the extents used to register which swap entries had been
193  *	allocated.
194  */
195 
free_all_swap_pages(int swap)196 void free_all_swap_pages(int swap)
197 {
198 	struct rb_node *node;
199 
200 	while ((node = swsusp_extents.rb_node)) {
201 		struct swsusp_extent *ext;
202 		unsigned long offset;
203 
204 		ext = container_of(node, struct swsusp_extent, node);
205 		rb_erase(node, &swsusp_extents);
206 		for (offset = ext->start; offset <= ext->end; offset++)
207 			swap_free(swp_entry(swap, offset));
208 
209 		kfree(ext);
210 	}
211 }
212 
swsusp_swap_in_use(void)213 int swsusp_swap_in_use(void)
214 {
215 	return (swsusp_extents.rb_node != NULL);
216 }
217 
218 /*
219  * General things
220  */
221 
222 static unsigned short root_swap = 0xffff;
223 static struct block_device *hib_resume_bdev;
224 
225 struct hib_bio_batch {
226 	atomic_t		count;
227 	wait_queue_head_t	wait;
228 	int			error;
229 };
230 
hib_init_batch(struct hib_bio_batch * hb)231 static void hib_init_batch(struct hib_bio_batch *hb)
232 {
233 	atomic_set(&hb->count, 0);
234 	init_waitqueue_head(&hb->wait);
235 	hb->error = 0;
236 }
237 
hib_end_io(struct bio * bio)238 static void hib_end_io(struct bio *bio)
239 {
240 	struct hib_bio_batch *hb = bio->bi_private;
241 	struct page *page = bio->bi_io_vec[0].bv_page;
242 
243 	if (bio->bi_error) {
244 		printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
245 				imajor(bio->bi_bdev->bd_inode),
246 				iminor(bio->bi_bdev->bd_inode),
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_error && !hb->error)
257 		hb->error = bio->bi_error;
258 	if (atomic_dec_and_test(&hb->count))
259 		wake_up(&hb->wait);
260 
261 	bio_put(bio);
262 }
263 
hib_submit_io(int rw,pgoff_t page_off,void * addr,struct hib_bio_batch * hb)264 static int hib_submit_io(int rw, pgoff_t page_off, void *addr,
265 		struct hib_bio_batch *hb)
266 {
267 	struct page *page = virt_to_page(addr);
268 	struct bio *bio;
269 	int error = 0;
270 
271 	bio = bio_alloc(__GFP_RECLAIM | __GFP_HIGH, 1);
272 	bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
273 	bio->bi_bdev = hib_resume_bdev;
274 
275 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
276 		printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
277 			(unsigned long long)bio->bi_iter.bi_sector);
278 		bio_put(bio);
279 		return -EFAULT;
280 	}
281 
282 	if (hb) {
283 		bio->bi_end_io = hib_end_io;
284 		bio->bi_private = hb;
285 		atomic_inc(&hb->count);
286 		submit_bio(rw, bio);
287 	} else {
288 		error = submit_bio_wait(rw, bio);
289 		bio_put(bio);
290 	}
291 
292 	return error;
293 }
294 
hib_wait_io(struct hib_bio_batch * hb)295 static int hib_wait_io(struct hib_bio_batch *hb)
296 {
297 	wait_event(hb->wait, atomic_read(&hb->count) == 0);
298 	return hb->error;
299 }
300 
301 /*
302  * Saving part
303  */
304 
mark_swapfiles(struct swap_map_handle * handle,unsigned int flags)305 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
306 {
307 	int error;
308 
309 	hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
310 	if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
311 	    !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
312 		memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
313 		memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
314 		swsusp_header->image = handle->first_sector;
315 		swsusp_header->flags = flags;
316 		if (flags & SF_CRC32_MODE)
317 			swsusp_header->crc32 = handle->crc32;
318 		error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
319 					swsusp_header, NULL);
320 	} else {
321 		printk(KERN_ERR "PM: Swap header not found!\n");
322 		error = -ENODEV;
323 	}
324 	return error;
325 }
326 
327 /**
328  *	swsusp_swap_check - check if the resume device is a swap device
329  *	and get its index (if so)
330  *
331  *	This is called before saving image
332  */
swsusp_swap_check(void)333 static int swsusp_swap_check(void)
334 {
335 	int res;
336 
337 	res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
338 			&hib_resume_bdev);
339 	if (res < 0)
340 		return res;
341 
342 	root_swap = res;
343 	res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
344 	if (res)
345 		return res;
346 
347 	res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
348 	if (res < 0)
349 		blkdev_put(hib_resume_bdev, FMODE_WRITE);
350 
351 	return res;
352 }
353 
354 /**
355  *	write_page - Write one page to given swap location.
356  *	@buf:		Address we're writing.
357  *	@offset:	Offset of the swap page we're writing to.
358  *	@hb:		bio completion batch
359  */
360 
write_page(void * buf,sector_t offset,struct hib_bio_batch * hb)361 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
362 {
363 	void *src;
364 	int ret;
365 
366 	if (!offset)
367 		return -ENOSPC;
368 
369 	if (hb) {
370 		src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN |
371 		                              __GFP_NORETRY);
372 		if (src) {
373 			copy_page(src, buf);
374 		} else {
375 			ret = hib_wait_io(hb); /* Free pages */
376 			if (ret)
377 				return ret;
378 			src = (void *)__get_free_page(__GFP_RECLAIM |
379 			                              __GFP_NOWARN |
380 			                              __GFP_NORETRY);
381 			if (src) {
382 				copy_page(src, buf);
383 			} else {
384 				WARN_ON_ONCE(1);
385 				hb = NULL;	/* Go synchronous */
386 				src = buf;
387 			}
388 		}
389 	} else {
390 		src = buf;
391 	}
392 	return hib_submit_io(WRITE_SYNC, offset, src, hb);
393 }
394 
release_swap_writer(struct swap_map_handle * handle)395 static void release_swap_writer(struct swap_map_handle *handle)
396 {
397 	if (handle->cur)
398 		free_page((unsigned long)handle->cur);
399 	handle->cur = NULL;
400 }
401 
get_swap_writer(struct swap_map_handle * handle)402 static int get_swap_writer(struct swap_map_handle *handle)
403 {
404 	int ret;
405 
406 	ret = swsusp_swap_check();
407 	if (ret) {
408 		if (ret != -ENOSPC)
409 			printk(KERN_ERR "PM: Cannot find swap device, try "
410 					"swapon -a.\n");
411 		return ret;
412 	}
413 	handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
414 	if (!handle->cur) {
415 		ret = -ENOMEM;
416 		goto err_close;
417 	}
418 	handle->cur_swap = alloc_swapdev_block(root_swap);
419 	if (!handle->cur_swap) {
420 		ret = -ENOSPC;
421 		goto err_rel;
422 	}
423 	handle->k = 0;
424 	handle->reqd_free_pages = reqd_free_pages();
425 	handle->first_sector = handle->cur_swap;
426 	return 0;
427 err_rel:
428 	release_swap_writer(handle);
429 err_close:
430 	swsusp_close(FMODE_WRITE);
431 	return ret;
432 }
433 
swap_write_page(struct swap_map_handle * handle,void * buf,struct hib_bio_batch * hb)434 static int swap_write_page(struct swap_map_handle *handle, void *buf,
435 		struct hib_bio_batch *hb)
436 {
437 	int error = 0;
438 	sector_t offset;
439 
440 	if (!handle->cur)
441 		return -EINVAL;
442 	offset = alloc_swapdev_block(root_swap);
443 	error = write_page(buf, offset, hb);
444 	if (error)
445 		return error;
446 	handle->cur->entries[handle->k++] = offset;
447 	if (handle->k >= MAP_PAGE_ENTRIES) {
448 		offset = alloc_swapdev_block(root_swap);
449 		if (!offset)
450 			return -ENOSPC;
451 		handle->cur->next_swap = offset;
452 		error = write_page(handle->cur, handle->cur_swap, hb);
453 		if (error)
454 			goto out;
455 		clear_page(handle->cur);
456 		handle->cur_swap = offset;
457 		handle->k = 0;
458 
459 		if (hb && low_free_pages() <= handle->reqd_free_pages) {
460 			error = hib_wait_io(hb);
461 			if (error)
462 				goto out;
463 			/*
464 			 * Recalculate the number of required free pages, to
465 			 * make sure we never take more than half.
466 			 */
467 			handle->reqd_free_pages = reqd_free_pages();
468 		}
469 	}
470  out:
471 	return error;
472 }
473 
flush_swap_writer(struct swap_map_handle * handle)474 static int flush_swap_writer(struct swap_map_handle *handle)
475 {
476 	if (handle->cur && handle->cur_swap)
477 		return write_page(handle->cur, handle->cur_swap, NULL);
478 	else
479 		return -EINVAL;
480 }
481 
swap_writer_finish(struct swap_map_handle * handle,unsigned int flags,int error)482 static int swap_writer_finish(struct swap_map_handle *handle,
483 		unsigned int flags, int error)
484 {
485 	if (!error) {
486 		flush_swap_writer(handle);
487 		printk(KERN_INFO "PM: S");
488 		error = mark_swapfiles(handle, flags);
489 		printk("|\n");
490 	}
491 
492 	if (error)
493 		free_all_swap_pages(root_swap);
494 	release_swap_writer(handle);
495 	swsusp_close(FMODE_WRITE);
496 
497 	return error;
498 }
499 
500 /* We need to remember how much compressed data we need to read. */
501 #define LZO_HEADER	sizeof(size_t)
502 
503 /* Number of pages/bytes we'll compress at one time. */
504 #define LZO_UNC_PAGES	32
505 #define LZO_UNC_SIZE	(LZO_UNC_PAGES * PAGE_SIZE)
506 
507 /* Number of pages/bytes we need for compressed data (worst case). */
508 #define LZO_CMP_PAGES	DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
509 			             LZO_HEADER, PAGE_SIZE)
510 #define LZO_CMP_SIZE	(LZO_CMP_PAGES * PAGE_SIZE)
511 
512 /* Maximum number of threads for compression/decompression. */
513 #define LZO_THREADS	3
514 
515 /* Minimum/maximum number of pages for read buffering. */
516 #define LZO_MIN_RD_PAGES	1024
517 #define LZO_MAX_RD_PAGES	8192
518 
519 
520 /**
521  *	save_image - save the suspend image data
522  */
523 
save_image(struct swap_map_handle * handle,struct snapshot_handle * snapshot,unsigned int nr_to_write)524 static int save_image(struct swap_map_handle *handle,
525                       struct snapshot_handle *snapshot,
526                       unsigned int nr_to_write)
527 {
528 	unsigned int m;
529 	int ret;
530 	int nr_pages;
531 	int err2;
532 	struct hib_bio_batch hb;
533 	ktime_t start;
534 	ktime_t stop;
535 
536 	hib_init_batch(&hb);
537 
538 	printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
539 		nr_to_write);
540 	m = nr_to_write / 10;
541 	if (!m)
542 		m = 1;
543 	nr_pages = 0;
544 	start = ktime_get();
545 	while (1) {
546 		ret = snapshot_read_next(snapshot);
547 		if (ret <= 0)
548 			break;
549 		ret = swap_write_page(handle, data_of(*snapshot), &hb);
550 		if (ret)
551 			break;
552 		if (!(nr_pages % m))
553 			printk(KERN_INFO "PM: Image saving progress: %3d%%\n",
554 			       nr_pages / m * 10);
555 		nr_pages++;
556 	}
557 	err2 = hib_wait_io(&hb);
558 	stop = ktime_get();
559 	if (!ret)
560 		ret = err2;
561 	if (!ret)
562 		printk(KERN_INFO "PM: Image saving done.\n");
563 	swsusp_show_speed(start, stop, nr_to_write, "Wrote");
564 	return ret;
565 }
566 
567 /**
568  * Structure used for CRC32.
569  */
570 struct crc_data {
571 	struct task_struct *thr;                  /* thread */
572 	atomic_t ready;                           /* ready to start flag */
573 	atomic_t stop;                            /* ready to stop flag */
574 	unsigned run_threads;                     /* nr current threads */
575 	wait_queue_head_t go;                     /* start crc update */
576 	wait_queue_head_t done;                   /* crc update done */
577 	u32 *crc32;                               /* points to handle's crc32 */
578 	size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
579 	unsigned char *unc[LZO_THREADS];          /* uncompressed data */
580 };
581 
582 /**
583  * CRC32 update function that runs in its own thread.
584  */
crc32_threadfn(void * data)585 static int crc32_threadfn(void *data)
586 {
587 	struct crc_data *d = data;
588 	unsigned i;
589 
590 	while (1) {
591 		wait_event(d->go, atomic_read(&d->ready) ||
592 		                  kthread_should_stop());
593 		if (kthread_should_stop()) {
594 			d->thr = NULL;
595 			atomic_set(&d->stop, 1);
596 			wake_up(&d->done);
597 			break;
598 		}
599 		atomic_set(&d->ready, 0);
600 
601 		for (i = 0; i < d->run_threads; i++)
602 			*d->crc32 = crc32_le(*d->crc32,
603 			                     d->unc[i], *d->unc_len[i]);
604 		atomic_set(&d->stop, 1);
605 		wake_up(&d->done);
606 	}
607 	return 0;
608 }
609 /**
610  * Structure used for LZO data compression.
611  */
612 struct cmp_data {
613 	struct task_struct *thr;                  /* thread */
614 	atomic_t ready;                           /* ready to start flag */
615 	atomic_t stop;                            /* ready to stop flag */
616 	int ret;                                  /* return code */
617 	wait_queue_head_t go;                     /* start compression */
618 	wait_queue_head_t done;                   /* compression done */
619 	size_t unc_len;                           /* uncompressed length */
620 	size_t cmp_len;                           /* compressed length */
621 	unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
622 	unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
623 	unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
624 };
625 
626 /**
627  * Compression function that runs in its own thread.
628  */
lzo_compress_threadfn(void * data)629 static int lzo_compress_threadfn(void *data)
630 {
631 	struct cmp_data *d = data;
632 
633 	while (1) {
634 		wait_event(d->go, atomic_read(&d->ready) ||
635 		                  kthread_should_stop());
636 		if (kthread_should_stop()) {
637 			d->thr = NULL;
638 			d->ret = -1;
639 			atomic_set(&d->stop, 1);
640 			wake_up(&d->done);
641 			break;
642 		}
643 		atomic_set(&d->ready, 0);
644 
645 		d->ret = lzo1x_1_compress(d->unc, d->unc_len,
646 		                          d->cmp + LZO_HEADER, &d->cmp_len,
647 		                          d->wrk);
648 		atomic_set(&d->stop, 1);
649 		wake_up(&d->done);
650 	}
651 	return 0;
652 }
653 
654 /**
655  * save_image_lzo - Save the suspend image data compressed with LZO.
656  * @handle: Swap map handle to use for saving the image.
657  * @snapshot: Image to read data from.
658  * @nr_to_write: Number of pages to save.
659  */
save_image_lzo(struct swap_map_handle * handle,struct snapshot_handle * snapshot,unsigned int nr_to_write)660 static int save_image_lzo(struct swap_map_handle *handle,
661                           struct snapshot_handle *snapshot,
662                           unsigned int nr_to_write)
663 {
664 	unsigned int m;
665 	int ret = 0;
666 	int nr_pages;
667 	int err2;
668 	struct hib_bio_batch hb;
669 	ktime_t start;
670 	ktime_t stop;
671 	size_t off;
672 	unsigned thr, run_threads, nr_threads;
673 	unsigned char *page = NULL;
674 	struct cmp_data *data = NULL;
675 	struct crc_data *crc = NULL;
676 
677 	hib_init_batch(&hb);
678 
679 	/*
680 	 * We'll limit the number of threads for compression to limit memory
681 	 * footprint.
682 	 */
683 	nr_threads = num_online_cpus() - 1;
684 	nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
685 
686 	page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH);
687 	if (!page) {
688 		printk(KERN_ERR "PM: Failed to allocate LZO page\n");
689 		ret = -ENOMEM;
690 		goto out_clean;
691 	}
692 
693 	data = vmalloc(sizeof(*data) * nr_threads);
694 	if (!data) {
695 		printk(KERN_ERR "PM: Failed to allocate LZO data\n");
696 		ret = -ENOMEM;
697 		goto out_clean;
698 	}
699 	for (thr = 0; thr < nr_threads; thr++)
700 		memset(&data[thr], 0, offsetof(struct cmp_data, go));
701 
702 	crc = kmalloc(sizeof(*crc), GFP_KERNEL);
703 	if (!crc) {
704 		printk(KERN_ERR "PM: Failed to allocate crc\n");
705 		ret = -ENOMEM;
706 		goto out_clean;
707 	}
708 	memset(crc, 0, offsetof(struct crc_data, go));
709 
710 	/*
711 	 * Start the compression threads.
712 	 */
713 	for (thr = 0; thr < nr_threads; thr++) {
714 		init_waitqueue_head(&data[thr].go);
715 		init_waitqueue_head(&data[thr].done);
716 
717 		data[thr].thr = kthread_run(lzo_compress_threadfn,
718 		                            &data[thr],
719 		                            "image_compress/%u", thr);
720 		if (IS_ERR(data[thr].thr)) {
721 			data[thr].thr = NULL;
722 			printk(KERN_ERR
723 			       "PM: Cannot start compression threads\n");
724 			ret = -ENOMEM;
725 			goto out_clean;
726 		}
727 	}
728 
729 	/*
730 	 * Start the CRC32 thread.
731 	 */
732 	init_waitqueue_head(&crc->go);
733 	init_waitqueue_head(&crc->done);
734 
735 	handle->crc32 = 0;
736 	crc->crc32 = &handle->crc32;
737 	for (thr = 0; thr < nr_threads; thr++) {
738 		crc->unc[thr] = data[thr].unc;
739 		crc->unc_len[thr] = &data[thr].unc_len;
740 	}
741 
742 	crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
743 	if (IS_ERR(crc->thr)) {
744 		crc->thr = NULL;
745 		printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
746 		ret = -ENOMEM;
747 		goto out_clean;
748 	}
749 
750 	/*
751 	 * Adjust the number of required free pages after all allocations have
752 	 * been done. We don't want to run out of pages when writing.
753 	 */
754 	handle->reqd_free_pages = reqd_free_pages();
755 
756 	printk(KERN_INFO
757 		"PM: Using %u thread(s) for compression.\n"
758 		"PM: Compressing and saving image data (%u pages)...\n",
759 		nr_threads, nr_to_write);
760 	m = nr_to_write / 10;
761 	if (!m)
762 		m = 1;
763 	nr_pages = 0;
764 	start = ktime_get();
765 	for (;;) {
766 		for (thr = 0; thr < nr_threads; thr++) {
767 			for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
768 				ret = snapshot_read_next(snapshot);
769 				if (ret < 0)
770 					goto out_finish;
771 
772 				if (!ret)
773 					break;
774 
775 				memcpy(data[thr].unc + off,
776 				       data_of(*snapshot), PAGE_SIZE);
777 
778 				if (!(nr_pages % m))
779 					printk(KERN_INFO
780 					       "PM: Image saving progress: "
781 					       "%3d%%\n",
782 				               nr_pages / m * 10);
783 				nr_pages++;
784 			}
785 			if (!off)
786 				break;
787 
788 			data[thr].unc_len = off;
789 
790 			atomic_set(&data[thr].ready, 1);
791 			wake_up(&data[thr].go);
792 		}
793 
794 		if (!thr)
795 			break;
796 
797 		crc->run_threads = thr;
798 		atomic_set(&crc->ready, 1);
799 		wake_up(&crc->go);
800 
801 		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
802 			wait_event(data[thr].done,
803 			           atomic_read(&data[thr].stop));
804 			atomic_set(&data[thr].stop, 0);
805 
806 			ret = data[thr].ret;
807 
808 			if (ret < 0) {
809 				printk(KERN_ERR "PM: LZO compression failed\n");
810 				goto out_finish;
811 			}
812 
813 			if (unlikely(!data[thr].cmp_len ||
814 			             data[thr].cmp_len >
815 			             lzo1x_worst_compress(data[thr].unc_len))) {
816 				printk(KERN_ERR
817 				       "PM: Invalid LZO compressed length\n");
818 				ret = -1;
819 				goto out_finish;
820 			}
821 
822 			*(size_t *)data[thr].cmp = data[thr].cmp_len;
823 
824 			/*
825 			 * Given we are writing one page at a time to disk, we
826 			 * copy that much from the buffer, although the last
827 			 * bit will likely be smaller than full page. This is
828 			 * OK - we saved the length of the compressed data, so
829 			 * any garbage at the end will be discarded when we
830 			 * read it.
831 			 */
832 			for (off = 0;
833 			     off < LZO_HEADER + data[thr].cmp_len;
834 			     off += PAGE_SIZE) {
835 				memcpy(page, data[thr].cmp + off, PAGE_SIZE);
836 
837 				ret = swap_write_page(handle, page, &hb);
838 				if (ret)
839 					goto out_finish;
840 			}
841 		}
842 
843 		wait_event(crc->done, atomic_read(&crc->stop));
844 		atomic_set(&crc->stop, 0);
845 	}
846 
847 out_finish:
848 	err2 = hib_wait_io(&hb);
849 	stop = ktime_get();
850 	if (!ret)
851 		ret = err2;
852 	if (!ret)
853 		printk(KERN_INFO "PM: Image saving done.\n");
854 	swsusp_show_speed(start, stop, nr_to_write, "Wrote");
855 out_clean:
856 	if (crc) {
857 		if (crc->thr)
858 			kthread_stop(crc->thr);
859 		kfree(crc);
860 	}
861 	if (data) {
862 		for (thr = 0; thr < nr_threads; thr++)
863 			if (data[thr].thr)
864 				kthread_stop(data[thr].thr);
865 		vfree(data);
866 	}
867 	if (page) free_page((unsigned long)page);
868 
869 	return ret;
870 }
871 
872 /**
873  *	enough_swap - Make sure we have enough swap to save the image.
874  *
875  *	Returns TRUE or FALSE after checking the total amount of swap
876  *	space avaiable from the resume partition.
877  */
878 
enough_swap(unsigned int nr_pages,unsigned int flags)879 static int enough_swap(unsigned int nr_pages, unsigned int flags)
880 {
881 	unsigned int free_swap = count_swap_pages(root_swap, 1);
882 	unsigned int required;
883 
884 	pr_debug("PM: Free swap pages: %u\n", free_swap);
885 
886 	required = PAGES_FOR_IO + nr_pages;
887 	return free_swap > required;
888 }
889 
890 /**
891  *	swsusp_write - Write entire image and metadata.
892  *	@flags: flags to pass to the "boot" kernel in the image header
893  *
894  *	It is important _NOT_ to umount filesystems at this point. We want
895  *	them synced (in case something goes wrong) but we DO not want to mark
896  *	filesystem clean: it is not. (And it does not matter, if we resume
897  *	correctly, we'll mark system clean, anyway.)
898  */
899 
swsusp_write(unsigned int flags)900 int swsusp_write(unsigned int flags)
901 {
902 	struct swap_map_handle handle;
903 	struct snapshot_handle snapshot;
904 	struct swsusp_info *header;
905 	unsigned long pages;
906 	int error;
907 
908 	pages = snapshot_get_image_size();
909 	error = get_swap_writer(&handle);
910 	if (error) {
911 		printk(KERN_ERR "PM: Cannot get swap writer\n");
912 		return error;
913 	}
914 	if (flags & SF_NOCOMPRESS_MODE) {
915 		if (!enough_swap(pages, flags)) {
916 			printk(KERN_ERR "PM: Not enough free swap\n");
917 			error = -ENOSPC;
918 			goto out_finish;
919 		}
920 	}
921 	memset(&snapshot, 0, sizeof(struct snapshot_handle));
922 	error = snapshot_read_next(&snapshot);
923 	if (error < PAGE_SIZE) {
924 		if (error >= 0)
925 			error = -EFAULT;
926 
927 		goto out_finish;
928 	}
929 	header = (struct swsusp_info *)data_of(snapshot);
930 	error = swap_write_page(&handle, header, NULL);
931 	if (!error) {
932 		error = (flags & SF_NOCOMPRESS_MODE) ?
933 			save_image(&handle, &snapshot, pages - 1) :
934 			save_image_lzo(&handle, &snapshot, pages - 1);
935 	}
936 out_finish:
937 	error = swap_writer_finish(&handle, flags, error);
938 	return error;
939 }
940 
941 /**
942  *	The following functions allow us to read data using a swap map
943  *	in a file-alike way
944  */
945 
release_swap_reader(struct swap_map_handle * handle)946 static void release_swap_reader(struct swap_map_handle *handle)
947 {
948 	struct swap_map_page_list *tmp;
949 
950 	while (handle->maps) {
951 		if (handle->maps->map)
952 			free_page((unsigned long)handle->maps->map);
953 		tmp = handle->maps;
954 		handle->maps = handle->maps->next;
955 		kfree(tmp);
956 	}
957 	handle->cur = NULL;
958 }
959 
get_swap_reader(struct swap_map_handle * handle,unsigned int * flags_p)960 static int get_swap_reader(struct swap_map_handle *handle,
961 		unsigned int *flags_p)
962 {
963 	int error;
964 	struct swap_map_page_list *tmp, *last;
965 	sector_t offset;
966 
967 	*flags_p = swsusp_header->flags;
968 
969 	if (!swsusp_header->image) /* how can this happen? */
970 		return -EINVAL;
971 
972 	handle->cur = NULL;
973 	last = handle->maps = NULL;
974 	offset = swsusp_header->image;
975 	while (offset) {
976 		tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
977 		if (!tmp) {
978 			release_swap_reader(handle);
979 			return -ENOMEM;
980 		}
981 		memset(tmp, 0, sizeof(*tmp));
982 		if (!handle->maps)
983 			handle->maps = tmp;
984 		if (last)
985 			last->next = tmp;
986 		last = tmp;
987 
988 		tmp->map = (struct swap_map_page *)
989 			   __get_free_page(__GFP_RECLAIM | __GFP_HIGH);
990 		if (!tmp->map) {
991 			release_swap_reader(handle);
992 			return -ENOMEM;
993 		}
994 
995 		error = hib_submit_io(READ_SYNC, offset, tmp->map, NULL);
996 		if (error) {
997 			release_swap_reader(handle);
998 			return error;
999 		}
1000 		offset = tmp->map->next_swap;
1001 	}
1002 	handle->k = 0;
1003 	handle->cur = handle->maps->map;
1004 	return 0;
1005 }
1006 
swap_read_page(struct swap_map_handle * handle,void * buf,struct hib_bio_batch * hb)1007 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1008 		struct hib_bio_batch *hb)
1009 {
1010 	sector_t offset;
1011 	int error;
1012 	struct swap_map_page_list *tmp;
1013 
1014 	if (!handle->cur)
1015 		return -EINVAL;
1016 	offset = handle->cur->entries[handle->k];
1017 	if (!offset)
1018 		return -EFAULT;
1019 	error = hib_submit_io(READ_SYNC, offset, buf, hb);
1020 	if (error)
1021 		return error;
1022 	if (++handle->k >= MAP_PAGE_ENTRIES) {
1023 		handle->k = 0;
1024 		free_page((unsigned long)handle->maps->map);
1025 		tmp = handle->maps;
1026 		handle->maps = handle->maps->next;
1027 		kfree(tmp);
1028 		if (!handle->maps)
1029 			release_swap_reader(handle);
1030 		else
1031 			handle->cur = handle->maps->map;
1032 	}
1033 	return error;
1034 }
1035 
swap_reader_finish(struct swap_map_handle * handle)1036 static int swap_reader_finish(struct swap_map_handle *handle)
1037 {
1038 	release_swap_reader(handle);
1039 
1040 	return 0;
1041 }
1042 
1043 /**
1044  *	load_image - load the image using the swap map handle
1045  *	@handle and the snapshot handle @snapshot
1046  *	(assume there are @nr_pages pages to load)
1047  */
1048 
load_image(struct swap_map_handle * handle,struct snapshot_handle * snapshot,unsigned int nr_to_read)1049 static int load_image(struct swap_map_handle *handle,
1050                       struct snapshot_handle *snapshot,
1051                       unsigned int nr_to_read)
1052 {
1053 	unsigned int m;
1054 	int ret = 0;
1055 	ktime_t start;
1056 	ktime_t stop;
1057 	struct hib_bio_batch hb;
1058 	int err2;
1059 	unsigned nr_pages;
1060 
1061 	hib_init_batch(&hb);
1062 
1063 	clean_pages_on_read = true;
1064 	printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
1065 		nr_to_read);
1066 	m = nr_to_read / 10;
1067 	if (!m)
1068 		m = 1;
1069 	nr_pages = 0;
1070 	start = ktime_get();
1071 	for ( ; ; ) {
1072 		ret = snapshot_write_next(snapshot);
1073 		if (ret <= 0)
1074 			break;
1075 		ret = swap_read_page(handle, data_of(*snapshot), &hb);
1076 		if (ret)
1077 			break;
1078 		if (snapshot->sync_read)
1079 			ret = hib_wait_io(&hb);
1080 		if (ret)
1081 			break;
1082 		if (!(nr_pages % m))
1083 			printk(KERN_INFO "PM: Image loading progress: %3d%%\n",
1084 			       nr_pages / m * 10);
1085 		nr_pages++;
1086 	}
1087 	err2 = hib_wait_io(&hb);
1088 	stop = ktime_get();
1089 	if (!ret)
1090 		ret = err2;
1091 	if (!ret) {
1092 		printk(KERN_INFO "PM: Image loading done.\n");
1093 		snapshot_write_finalize(snapshot);
1094 		if (!snapshot_image_loaded(snapshot))
1095 			ret = -ENODATA;
1096 	}
1097 	swsusp_show_speed(start, stop, nr_to_read, "Read");
1098 	return ret;
1099 }
1100 
1101 /**
1102  * Structure used for LZO data decompression.
1103  */
1104 struct dec_data {
1105 	struct task_struct *thr;                  /* thread */
1106 	atomic_t ready;                           /* ready to start flag */
1107 	atomic_t stop;                            /* ready to stop flag */
1108 	int ret;                                  /* return code */
1109 	wait_queue_head_t go;                     /* start decompression */
1110 	wait_queue_head_t done;                   /* decompression done */
1111 	size_t unc_len;                           /* uncompressed length */
1112 	size_t cmp_len;                           /* compressed length */
1113 	unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1114 	unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1115 };
1116 
1117 /**
1118  * Deompression function that runs in its own thread.
1119  */
lzo_decompress_threadfn(void * data)1120 static int lzo_decompress_threadfn(void *data)
1121 {
1122 	struct dec_data *d = data;
1123 
1124 	while (1) {
1125 		wait_event(d->go, atomic_read(&d->ready) ||
1126 		                  kthread_should_stop());
1127 		if (kthread_should_stop()) {
1128 			d->thr = NULL;
1129 			d->ret = -1;
1130 			atomic_set(&d->stop, 1);
1131 			wake_up(&d->done);
1132 			break;
1133 		}
1134 		atomic_set(&d->ready, 0);
1135 
1136 		d->unc_len = LZO_UNC_SIZE;
1137 		d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1138 		                               d->unc, &d->unc_len);
1139 		if (clean_pages_on_decompress)
1140 			flush_icache_range((unsigned long)d->unc,
1141 					   (unsigned long)d->unc + d->unc_len);
1142 
1143 		atomic_set(&d->stop, 1);
1144 		wake_up(&d->done);
1145 	}
1146 	return 0;
1147 }
1148 
1149 /**
1150  * load_image_lzo - Load compressed image data and decompress them with LZO.
1151  * @handle: Swap map handle to use for loading data.
1152  * @snapshot: Image to copy uncompressed data into.
1153  * @nr_to_read: Number of pages to load.
1154  */
load_image_lzo(struct swap_map_handle * handle,struct snapshot_handle * snapshot,unsigned int nr_to_read)1155 static int load_image_lzo(struct swap_map_handle *handle,
1156                           struct snapshot_handle *snapshot,
1157                           unsigned int nr_to_read)
1158 {
1159 	unsigned int m;
1160 	int ret = 0;
1161 	int eof = 0;
1162 	struct hib_bio_batch hb;
1163 	ktime_t start;
1164 	ktime_t stop;
1165 	unsigned nr_pages;
1166 	size_t off;
1167 	unsigned i, thr, run_threads, nr_threads;
1168 	unsigned ring = 0, pg = 0, ring_size = 0,
1169 	         have = 0, want, need, asked = 0;
1170 	unsigned long read_pages = 0;
1171 	unsigned char **page = NULL;
1172 	struct dec_data *data = NULL;
1173 	struct crc_data *crc = NULL;
1174 
1175 	hib_init_batch(&hb);
1176 
1177 	/*
1178 	 * We'll limit the number of threads for decompression to limit memory
1179 	 * footprint.
1180 	 */
1181 	nr_threads = num_online_cpus() - 1;
1182 	nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1183 
1184 	page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1185 	if (!page) {
1186 		printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1187 		ret = -ENOMEM;
1188 		goto out_clean;
1189 	}
1190 
1191 	data = vmalloc(sizeof(*data) * nr_threads);
1192 	if (!data) {
1193 		printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1194 		ret = -ENOMEM;
1195 		goto out_clean;
1196 	}
1197 	for (thr = 0; thr < nr_threads; thr++)
1198 		memset(&data[thr], 0, offsetof(struct dec_data, go));
1199 
1200 	crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1201 	if (!crc) {
1202 		printk(KERN_ERR "PM: Failed to allocate crc\n");
1203 		ret = -ENOMEM;
1204 		goto out_clean;
1205 	}
1206 	memset(crc, 0, offsetof(struct crc_data, go));
1207 
1208 	clean_pages_on_decompress = true;
1209 
1210 	/*
1211 	 * Start the decompression threads.
1212 	 */
1213 	for (thr = 0; thr < nr_threads; thr++) {
1214 		init_waitqueue_head(&data[thr].go);
1215 		init_waitqueue_head(&data[thr].done);
1216 
1217 		data[thr].thr = kthread_run(lzo_decompress_threadfn,
1218 		                            &data[thr],
1219 		                            "image_decompress/%u", thr);
1220 		if (IS_ERR(data[thr].thr)) {
1221 			data[thr].thr = NULL;
1222 			printk(KERN_ERR
1223 			       "PM: Cannot start decompression threads\n");
1224 			ret = -ENOMEM;
1225 			goto out_clean;
1226 		}
1227 	}
1228 
1229 	/*
1230 	 * Start the CRC32 thread.
1231 	 */
1232 	init_waitqueue_head(&crc->go);
1233 	init_waitqueue_head(&crc->done);
1234 
1235 	handle->crc32 = 0;
1236 	crc->crc32 = &handle->crc32;
1237 	for (thr = 0; thr < nr_threads; thr++) {
1238 		crc->unc[thr] = data[thr].unc;
1239 		crc->unc_len[thr] = &data[thr].unc_len;
1240 	}
1241 
1242 	crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1243 	if (IS_ERR(crc->thr)) {
1244 		crc->thr = NULL;
1245 		printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
1246 		ret = -ENOMEM;
1247 		goto out_clean;
1248 	}
1249 
1250 	/*
1251 	 * Set the number of pages for read buffering.
1252 	 * This is complete guesswork, because we'll only know the real
1253 	 * picture once prepare_image() is called, which is much later on
1254 	 * during the image load phase. We'll assume the worst case and
1255 	 * say that none of the image pages are from high memory.
1256 	 */
1257 	if (low_free_pages() > snapshot_get_image_size())
1258 		read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1259 	read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1260 
1261 	for (i = 0; i < read_pages; i++) {
1262 		page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1263 						  __GFP_RECLAIM | __GFP_HIGH :
1264 						  __GFP_RECLAIM | __GFP_NOWARN |
1265 						  __GFP_NORETRY);
1266 
1267 		if (!page[i]) {
1268 			if (i < LZO_CMP_PAGES) {
1269 				ring_size = i;
1270 				printk(KERN_ERR
1271 				       "PM: Failed to allocate LZO pages\n");
1272 				ret = -ENOMEM;
1273 				goto out_clean;
1274 			} else {
1275 				break;
1276 			}
1277 		}
1278 	}
1279 	want = ring_size = i;
1280 
1281 	printk(KERN_INFO
1282 		"PM: Using %u thread(s) for decompression.\n"
1283 		"PM: Loading and decompressing image data (%u pages)...\n",
1284 		nr_threads, nr_to_read);
1285 	m = nr_to_read / 10;
1286 	if (!m)
1287 		m = 1;
1288 	nr_pages = 0;
1289 	start = ktime_get();
1290 
1291 	ret = snapshot_write_next(snapshot);
1292 	if (ret <= 0)
1293 		goto out_finish;
1294 
1295 	for(;;) {
1296 		for (i = 0; !eof && i < want; i++) {
1297 			ret = swap_read_page(handle, page[ring], &hb);
1298 			if (ret) {
1299 				/*
1300 				 * On real read error, finish. On end of data,
1301 				 * set EOF flag and just exit the read loop.
1302 				 */
1303 				if (handle->cur &&
1304 				    handle->cur->entries[handle->k]) {
1305 					goto out_finish;
1306 				} else {
1307 					eof = 1;
1308 					break;
1309 				}
1310 			}
1311 			if (++ring >= ring_size)
1312 				ring = 0;
1313 		}
1314 		asked += i;
1315 		want -= i;
1316 
1317 		/*
1318 		 * We are out of data, wait for some more.
1319 		 */
1320 		if (!have) {
1321 			if (!asked)
1322 				break;
1323 
1324 			ret = hib_wait_io(&hb);
1325 			if (ret)
1326 				goto out_finish;
1327 			have += asked;
1328 			asked = 0;
1329 			if (eof)
1330 				eof = 2;
1331 		}
1332 
1333 		if (crc->run_threads) {
1334 			wait_event(crc->done, atomic_read(&crc->stop));
1335 			atomic_set(&crc->stop, 0);
1336 			crc->run_threads = 0;
1337 		}
1338 
1339 		for (thr = 0; have && thr < nr_threads; thr++) {
1340 			data[thr].cmp_len = *(size_t *)page[pg];
1341 			if (unlikely(!data[thr].cmp_len ||
1342 			             data[thr].cmp_len >
1343 			             lzo1x_worst_compress(LZO_UNC_SIZE))) {
1344 				printk(KERN_ERR
1345 				       "PM: Invalid LZO compressed length\n");
1346 				ret = -1;
1347 				goto out_finish;
1348 			}
1349 
1350 			need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1351 			                    PAGE_SIZE);
1352 			if (need > have) {
1353 				if (eof > 1) {
1354 					ret = -1;
1355 					goto out_finish;
1356 				}
1357 				break;
1358 			}
1359 
1360 			for (off = 0;
1361 			     off < LZO_HEADER + data[thr].cmp_len;
1362 			     off += PAGE_SIZE) {
1363 				memcpy(data[thr].cmp + off,
1364 				       page[pg], PAGE_SIZE);
1365 				have--;
1366 				want++;
1367 				if (++pg >= ring_size)
1368 					pg = 0;
1369 			}
1370 
1371 			atomic_set(&data[thr].ready, 1);
1372 			wake_up(&data[thr].go);
1373 		}
1374 
1375 		/*
1376 		 * Wait for more data while we are decompressing.
1377 		 */
1378 		if (have < LZO_CMP_PAGES && asked) {
1379 			ret = hib_wait_io(&hb);
1380 			if (ret)
1381 				goto out_finish;
1382 			have += asked;
1383 			asked = 0;
1384 			if (eof)
1385 				eof = 2;
1386 		}
1387 
1388 		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1389 			wait_event(data[thr].done,
1390 			           atomic_read(&data[thr].stop));
1391 			atomic_set(&data[thr].stop, 0);
1392 
1393 			ret = data[thr].ret;
1394 
1395 			if (ret < 0) {
1396 				printk(KERN_ERR
1397 				       "PM: LZO decompression failed\n");
1398 				goto out_finish;
1399 			}
1400 
1401 			if (unlikely(!data[thr].unc_len ||
1402 			             data[thr].unc_len > LZO_UNC_SIZE ||
1403 			             data[thr].unc_len & (PAGE_SIZE - 1))) {
1404 				printk(KERN_ERR
1405 				       "PM: 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 					printk(KERN_INFO
1417 					       "PM: Image loading progress: "
1418 					       "%3d%%\n",
1419 					       nr_pages / m * 10);
1420 				nr_pages++;
1421 
1422 				ret = snapshot_write_next(snapshot);
1423 				if (ret <= 0) {
1424 					crc->run_threads = thr + 1;
1425 					atomic_set(&crc->ready, 1);
1426 					wake_up(&crc->go);
1427 					goto out_finish;
1428 				}
1429 			}
1430 		}
1431 
1432 		crc->run_threads = thr;
1433 		atomic_set(&crc->ready, 1);
1434 		wake_up(&crc->go);
1435 	}
1436 
1437 out_finish:
1438 	if (crc->run_threads) {
1439 		wait_event(crc->done, atomic_read(&crc->stop));
1440 		atomic_set(&crc->stop, 0);
1441 	}
1442 	stop = ktime_get();
1443 	if (!ret) {
1444 		printk(KERN_INFO "PM: Image loading done.\n");
1445 		snapshot_write_finalize(snapshot);
1446 		if (!snapshot_image_loaded(snapshot))
1447 			ret = -ENODATA;
1448 		if (!ret) {
1449 			if (swsusp_header->flags & SF_CRC32_MODE) {
1450 				if(handle->crc32 != swsusp_header->crc32) {
1451 					printk(KERN_ERR
1452 					       "PM: Invalid image CRC32!\n");
1453 					ret = -ENODATA;
1454 				}
1455 			}
1456 		}
1457 	}
1458 	swsusp_show_speed(start, stop, nr_to_read, "Read");
1459 out_clean:
1460 	for (i = 0; i < ring_size; i++)
1461 		free_page((unsigned long)page[i]);
1462 	if (crc) {
1463 		if (crc->thr)
1464 			kthread_stop(crc->thr);
1465 		kfree(crc);
1466 	}
1467 	if (data) {
1468 		for (thr = 0; thr < nr_threads; thr++)
1469 			if (data[thr].thr)
1470 				kthread_stop(data[thr].thr);
1471 		vfree(data);
1472 	}
1473 	vfree(page);
1474 
1475 	return ret;
1476 }
1477 
1478 /**
1479  *	swsusp_read - read the hibernation image.
1480  *	@flags_p: flags passed by the "frozen" kernel in the image header should
1481  *		  be written into this memory location
1482  */
1483 
swsusp_read(unsigned int * flags_p)1484 int swsusp_read(unsigned int *flags_p)
1485 {
1486 	int error;
1487 	struct swap_map_handle handle;
1488 	struct snapshot_handle snapshot;
1489 	struct swsusp_info *header;
1490 
1491 	memset(&snapshot, 0, sizeof(struct snapshot_handle));
1492 	error = snapshot_write_next(&snapshot);
1493 	if (error < PAGE_SIZE)
1494 		return error < 0 ? error : -EFAULT;
1495 	header = (struct swsusp_info *)data_of(snapshot);
1496 	error = get_swap_reader(&handle, flags_p);
1497 	if (error)
1498 		goto end;
1499 	if (!error)
1500 		error = swap_read_page(&handle, header, NULL);
1501 	if (!error) {
1502 		error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1503 			load_image(&handle, &snapshot, header->pages - 1) :
1504 			load_image_lzo(&handle, &snapshot, header->pages - 1);
1505 	}
1506 	swap_reader_finish(&handle);
1507 end:
1508 	if (!error)
1509 		pr_debug("PM: Image successfully loaded\n");
1510 	else
1511 		pr_debug("PM: Error %d resuming\n", error);
1512 	return error;
1513 }
1514 
1515 /**
1516  *      swsusp_check - Check for swsusp signature in the resume device
1517  */
1518 
swsusp_check(void)1519 int swsusp_check(void)
1520 {
1521 	int error;
1522 	void *holder;
1523 
1524 	hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1525 					    FMODE_READ | FMODE_EXCL, &holder);
1526 	if (!IS_ERR(hib_resume_bdev)) {
1527 		set_blocksize(hib_resume_bdev, PAGE_SIZE);
1528 		clear_page(swsusp_header);
1529 		error = hib_submit_io(READ_SYNC, swsusp_resume_block,
1530 					swsusp_header, NULL);
1531 		if (error)
1532 			goto put;
1533 
1534 		if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1535 			memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1536 			/* Reset swap signature now */
1537 			error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1538 						swsusp_header, NULL);
1539 		} else {
1540 			error = -EINVAL;
1541 		}
1542 
1543 put:
1544 		if (error)
1545 			blkdev_put(hib_resume_bdev, FMODE_READ | FMODE_EXCL);
1546 		else
1547 			pr_debug("PM: Image signature found, resuming\n");
1548 	} else {
1549 		error = PTR_ERR(hib_resume_bdev);
1550 	}
1551 
1552 	if (error)
1553 		pr_debug("PM: Image not found (code %d)\n", error);
1554 
1555 	return error;
1556 }
1557 
1558 /**
1559  *	swsusp_close - close swap device.
1560  */
1561 
swsusp_close(fmode_t mode)1562 void swsusp_close(fmode_t mode)
1563 {
1564 	if (IS_ERR(hib_resume_bdev)) {
1565 		pr_debug("PM: Image device not initialised\n");
1566 		return;
1567 	}
1568 
1569 	blkdev_put(hib_resume_bdev, mode);
1570 }
1571 
1572 /**
1573  *      swsusp_unmark - Unmark swsusp signature in the resume device
1574  */
1575 
1576 #ifdef CONFIG_SUSPEND
swsusp_unmark(void)1577 int swsusp_unmark(void)
1578 {
1579 	int error;
1580 
1581 	hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
1582 	if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1583 		memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1584 		error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1585 					swsusp_header, NULL);
1586 	} else {
1587 		printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
1588 		error = -ENODEV;
1589 	}
1590 
1591 	/*
1592 	 * We just returned from suspend, we don't need the image any more.
1593 	 */
1594 	free_all_swap_pages(root_swap);
1595 
1596 	return error;
1597 }
1598 #endif
1599 
swsusp_header_init(void)1600 static int swsusp_header_init(void)
1601 {
1602 	swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1603 	if (!swsusp_header)
1604 		panic("Could not allocate memory for swsusp_header\n");
1605 	return 0;
1606 }
1607 
1608 core_initcall(swsusp_header_init);
1609