1	// SPDX-License-Identifier: GPL-2.0-only
2	/*
3	* linux/kernel/power/swap.c
4	*
5	* This file provides functions for reading the suspend image from
6	* and writing it to a swap partition.
7	*
8	* Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
9	* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
10	* Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
11	*/
12
13	#define pr_fmt(fmt) "PM: " fmt
14
15	#include <crypto/acompress.h>
16	#include <linux/module.h>
17	#include <linux/file.h>
18	#include <linux/delay.h>
19	#include <linux/bitops.h>
20	#include <linux/device.h>
21	#include <linux/bio.h>
22	#include <linux/blkdev.h>
23	#include <linux/swap.h>
24	#include <linux/swapops.h>
25	#include <linux/pm.h>
26	#include <linux/slab.h>
27	#include <linux/vmalloc.h>
28	#include <linux/cpumask.h>
29	#include <linux/atomic.h>
30	#include <linux/kthread.h>
31	#include <linux/crc32.h>
32	#include <linux/ktime.h>
33
34	#include "power.h"
35
36	#define HIBERNATE_SIG "S1SUSPEND"
37
38	u32 swsusp_hardware_signature;
39
40	/*
41	* When reading an {un,}compressed image, we may restore pages in place,
42	* in which case some architectures need these pages cleaning before they
43	* can be executed. We don't know which pages these may be, so clean the lot.
44	*/
45	static bool clean_pages_on_read;
46	static bool clean_pages_on_decompress;
47
48	/*
49	* The swap map is a data structure used for keeping track of each page
50	* written to a swap partition. It consists of many swap_map_page structures
51	* that contain each an array of MAP_PAGE_ENTRIES swap entries. These
52	* structures are stored on the swap and linked together with the help of the
53	* .next_swap member.
54	*
55	* The swap map is created during suspend. The swap map pages are allocated and
56	* populated one at a time, so we only need one memory page to set up the entire
57	* structure.
58	*
59	* During resume we pick up all swap_map_page structures into a list.
60	*/
61	#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
62
63	/*
64	* Number of free pages that are not high.
65	*/
66	static inline unsigned long low_free_pages(void)
67	{
68	return nr_free_pages() - nr_free_highpages();
69	}
70
71	/*
72	* Number of pages required to be kept free while writing the image. Always
73	* half of all available low pages before the writing starts.
74	*/
75	static inline unsigned long reqd_free_pages(void)
76	{
77	return low_free_pages() / 2;
78	}
79
80	struct swap_map_page {
81	sector_t entries[MAP_PAGE_ENTRIES];
82	sector_t next_swap;
83	};
84
85	struct swap_map_page_list {
86	struct swap_map_page *map;
87	struct swap_map_page_list *next;
88	};
89
90	/*
91	* The swap_map_handle structure is used for handling swap in a file-alike way.
92	*/
93	struct swap_map_handle {
94	struct swap_map_page *cur;
95	struct swap_map_page_list *maps;
96	sector_t cur_swap;
97	sector_t first_sector;
98	unsigned int k;
99	unsigned long reqd_free_pages;
100	u32 crc32;
101	};
102
103	struct swsusp_header {
104	char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
105	sizeof(u32) - sizeof(u32)];
106	u32 hw_sig;
107	u32 crc32;
108	sector_t image;
109	unsigned int flags; /* Flags to pass to the "boot" kernel */
110	char orig_sig[10];
111	char sig[10];
112	} __packed;
113
114	static struct swsusp_header *swsusp_header;
115
116	/*
117	* The following functions are used for tracing the allocated swap pages, so
118	* that they can be freed in case of an error.
119	*/
120	struct swsusp_extent {
121	struct rb_node node;
122	unsigned long start;
123	unsigned long end;
124	};
125
126	static struct rb_root swsusp_extents = RB_ROOT;
127
128	static int swsusp_extents_insert(unsigned long swap_offset)
129	{
130	struct rb_node **new = &(swsusp_extents.rb_node);
131	struct rb_node *parent = NULL;
132	struct swsusp_extent *ext;
133
134	/* Figure out where to put the new node */
135	while (*new) {
136	ext = rb_entry(*new, struct swsusp_extent, node);
137	parent = *new;
138	if (swap_offset < ext->start) {
139	/* Try to merge */
140	if (swap_offset == ext->start - 1) {
141	ext->start--;
142	return 0;
143	}
144	new = &((*new)->rb_left);
145	} else if (swap_offset > ext->end) {
146	/* Try to merge */
147	if (swap_offset == ext->end + 1) {
148	ext->end++;
149	return 0;
150	}
151	new = &((*new)->rb_right);
152	} else {
153	/* It already is in the tree */
154	return -EINVAL;
155	}
156	}
157	/* Add the new node and rebalance the tree. */
158	ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
159	if (!ext)
160	return -ENOMEM;
161
162	ext->start = swap_offset;
163	ext->end = swap_offset;
164	rb_link_node(node: &ext->node, parent, rb_link: new);
165	rb_insert_color(&ext->node, &swsusp_extents);
166	return 0;
167	}
168
169	sector_t alloc_swapdev_block(int swap)
170	{
171	unsigned long offset;
172
173	/*
174	* Allocate a swap page and register that it has been allocated, so that
175	* it can be freed in case of an error.
176	*/
177	offset = swp_offset(entry: get_swap_page_of_type(swap));
178	if (offset) {
179	if (swsusp_extents_insert(swap_offset: offset))
180	swap_free(entry: swp_entry(type: swap, offset));
181	else
182	return swapdev_block(swap, offset);
183	}
184	return 0;
185	}
186
187	void free_all_swap_pages(int swap)
188	{
189	struct rb_node *node;
190
191	/*
192	* Free swap pages allocated for saving image data. It also frees the
193	* extents used to register which swap entries had been allocated.
194	*/
195	while ((node = swsusp_extents.rb_node)) {
196	struct swsusp_extent *ext;
197
198	ext = rb_entry(node, struct swsusp_extent, node);
199	rb_erase(node, &swsusp_extents);
200	swap_free_nr(entry: swp_entry(type: swap, offset: ext->start),
201	nr_pages: ext->end - ext->start + 1);
202
203	kfree(objp: ext);
204	}
205	}
206
207	int swsusp_swap_in_use(void)
208	{
209	return (swsusp_extents.rb_node != NULL);
210	}
211
212	/*
213	* General things
214	*/
215
216	static unsigned short root_swap = 0xffff;
217	static struct file *hib_resume_bdev_file;
218
219	struct hib_bio_batch {
220	atomic_t count;
221	wait_queue_head_t wait;
222	blk_status_t error;
223	struct blk_plug plug;
224	};
225
226	static void hib_init_batch(struct hib_bio_batch *hb)
227	{
228	atomic_set(v: &hb->count, i: 0);
229	init_waitqueue_head(&hb->wait);
230	hb->error = BLK_STS_OK;
231	blk_start_plug(&hb->plug);
232	}
233
234	static void hib_finish_batch(struct hib_bio_batch *hb)
235	{
236	blk_finish_plug(&hb->plug);
237	}
238
239	static void hib_end_io(struct bio *bio)
240	{
241	struct hib_bio_batch *hb = bio->bi_private;
242	struct page *page = bio_first_page_all(bio);
243
244	if (bio->bi_status) {
245	pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
246	MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
247	(unsigned long long)bio->bi_iter.bi_sector);
248	}
249
250	if (bio_data_dir(bio) == WRITE)
251	put_page(page);
252	else if (clean_pages_on_read)
253	flush_icache_range(start: (unsigned long)page_address(page),
254	end: (unsigned long)page_address(page) + PAGE_SIZE);
255
256	if (bio->bi_status && !hb->error)
257	hb->error = bio->bi_status;
258	if (atomic_dec_and_test(v: &hb->count))
259	wake_up(&hb->wait);
260
261	bio_put(bio);
262	}
263
264	static int hib_submit_io_sync(blk_opf_t opf, pgoff_t page_off, void *addr)
265	{
266	return bdev_rw_virt(bdev: file_bdev(bdev_file: hib_resume_bdev_file),
267	sector: page_off * (PAGE_SIZE >> 9), data: addr, PAGE_SIZE, op: opf);
268	}
269
270	static int hib_submit_io_async(blk_opf_t opf, pgoff_t page_off, void *addr,
271	struct hib_bio_batch *hb)
272	{
273	struct bio *bio;
274
275	bio = bio_alloc(bdev: file_bdev(bdev_file: hib_resume_bdev_file), nr_vecs: 1, opf,
276	GFP_NOIO | __GFP_HIGH);
277	bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
278	bio_add_virt_nofail(bio, vaddr: addr, PAGE_SIZE);
279	bio->bi_end_io = hib_end_io;
280	bio->bi_private = hb;
281	atomic_inc(v: &hb->count);
282	submit_bio(bio);
283	return 0;
284	}
285
286	static int hib_wait_io(struct hib_bio_batch *hb)
287	{
288	/*
289	* We are relying on the behavior of blk_plug that a thread with
290	* a plug will flush the plug list before sleeping.
291	*/
292	wait_event(hb->wait, atomic_read(&hb->count) == 0);
293	return blk_status_to_errno(status: hb->error);
294	}
295
296	/*
297	* Saving part
298	*/
299
300	static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
301	{
302	int error;
303
304	hib_submit_io_sync(opf: REQ_OP_READ, page_off: swsusp_resume_block, addr: swsusp_header);
305	if (!memcmp(p: "SWAP-SPACE",q: swsusp_header->sig, size: 10) ||
306	!memcmp(p: "SWAPSPACE2",q: swsusp_header->sig, size: 10)) {
307	memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
308	memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
309	swsusp_header->image = handle->first_sector;
310	if (swsusp_hardware_signature) {
311	swsusp_header->hw_sig = swsusp_hardware_signature;
312	flags |= SF_HW_SIG;
313	}
314	swsusp_header->flags = flags;
315	if (flags & SF_CRC32_MODE)
316	swsusp_header->crc32 = handle->crc32;
317	error = hib_submit_io_sync(opf: REQ_OP_WRITE | REQ_SYNC,
318	page_off: swsusp_resume_block, addr: swsusp_header);
319	} else {
320	pr_err("Swap header not found!\n");
321	error = -ENODEV;
322	}
323	return error;
324	}
325
326	/*
327	* Hold the swsusp_header flag. This is used in software_resume() in
328	* 'kernel/power/hibernate' to check if the image is compressed and query
329	* for the compression algorithm support(if so).
330	*/
331	unsigned int swsusp_header_flags;
332
333	static int swsusp_swap_check(void)
334	{
335	int res;
336
337	/*
338	* Check if the resume device is a swap device and get its index (if so).
339	* This is called before saving the image.
340	*/
341	if (swsusp_resume_device)
342	res = swap_type_of(device: swsusp_resume_device, offset: swsusp_resume_block);
343	else
344	res = find_first_swap(device: &swsusp_resume_device);
345	if (res < 0)
346	return res;
347	root_swap = res;
348
349	hib_resume_bdev_file = bdev_file_open_by_dev(dev: swsusp_resume_device,
350	BLK_OPEN_WRITE, NULL, NULL);
351	if (IS_ERR(ptr: hib_resume_bdev_file))
352	return PTR_ERR(ptr: hib_resume_bdev_file);
353
354	return 0;
355	}
356
357	static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
358	{
359	gfp_t gfp = GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY;
360	void *src;
361	int ret;
362
363	if (!offset)
364	return -ENOSPC;
365
366	if (!hb)
367	goto sync_io;
368
369	src = (void *)__get_free_page(gfp);
370	if (!src) {
371	ret = hib_wait_io(hb); /* Free pages */
372	if (ret)
373	return ret;
374	src = (void *)__get_free_page(gfp);
375	if (WARN_ON_ONCE(!src))
376	goto sync_io;
377	}
378
379	copy_page(to: src, from: buf);
380	return hib_submit_io_async(opf: REQ_OP_WRITE | REQ_SYNC, page_off: offset, addr: src, hb);
381	sync_io:
382	return hib_submit_io_sync(opf: REQ_OP_WRITE | REQ_SYNC, page_off: offset, addr: buf);
383	}
384
385	static void release_swap_writer(struct swap_map_handle *handle)
386	{
387	if (handle->cur)
388	free_page((unsigned long)handle->cur);
389	handle->cur = NULL;
390	}
391
392	static int get_swap_writer(struct swap_map_handle *handle)
393	{
394	int ret;
395
396	ret = swsusp_swap_check();
397	if (ret) {
398	if (ret != -ENOSPC)
399	pr_err("Cannot find swap device, try swapon -a\n");
400	return ret;
401	}
402	handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
403	if (!handle->cur) {
404	ret = -ENOMEM;
405	goto err_close;
406	}
407	handle->cur_swap = alloc_swapdev_block(swap: root_swap);
408	if (!handle->cur_swap) {
409	ret = -ENOSPC;
410	goto err_rel;
411	}
412	handle->k = 0;
413	handle->reqd_free_pages = reqd_free_pages();
414	handle->first_sector = handle->cur_swap;
415	return 0;
416	err_rel:
417	release_swap_writer(handle);
418	err_close:
419	swsusp_close();
420	return ret;
421	}
422
423	static int swap_write_page(struct swap_map_handle *handle, void *buf,
424	struct hib_bio_batch *hb)
425	{
426	int error;
427	sector_t offset;
428
429	if (!handle->cur)
430	return -EINVAL;
431	offset = alloc_swapdev_block(swap: root_swap);
432	error = write_page(buf, offset, hb);
433	if (error)
434	return error;
435	handle->cur->entries[handle->k++] = offset;
436	if (handle->k >= MAP_PAGE_ENTRIES) {
437	offset = alloc_swapdev_block(swap: root_swap);
438	if (!offset)
439	return -ENOSPC;
440	handle->cur->next_swap = offset;
441	error = write_page(buf: handle->cur, offset: handle->cur_swap, hb);
442	if (error)
443	goto out;
444	clear_page(page: handle->cur);
445	handle->cur_swap = offset;
446	handle->k = 0;
447
448	if (hb && low_free_pages() <= handle->reqd_free_pages) {
449	error = hib_wait_io(hb);
450	if (error)
451	goto out;
452	/*
453	* Recalculate the number of required free pages, to
454	* make sure we never take more than half.
455	*/
456	handle->reqd_free_pages = reqd_free_pages();
457	}
458	}
459	out:
460	return error;
461	}
462
463	static int flush_swap_writer(struct swap_map_handle *handle)
464	{
465	if (handle->cur && handle->cur_swap)
466	return write_page(buf: handle->cur, offset: handle->cur_swap, NULL);
467	else
468	return -EINVAL;
469	}
470
471	static int swap_writer_finish(struct swap_map_handle *handle,
472	unsigned int flags, int error)
473	{
474	if (!error) {
475	pr_info("S");
476	error = mark_swapfiles(handle, flags);
477	pr_cont("|\n");
478	flush_swap_writer(handle);
479	}
480
481	if (error)
482	free_all_swap_pages(swap: root_swap);
483	release_swap_writer(handle);
484	swsusp_close();
485
486	return error;
487	}
488
489	/*
490	* Bytes we need for compressed data in worst case. We assume(limitation)
491	* this is the worst of all the compression algorithms.
492	*/
493	#define bytes_worst_compress(x) ((x) + ((x) / 16) + 64 + 3 + 2)
494
495	/* We need to remember how much compressed data we need to read. */
496	#define CMP_HEADER sizeof(size_t)
497
498	/* Number of pages/bytes we'll compress at one time. */
499	#define UNC_PAGES 32
500	#define UNC_SIZE (UNC_PAGES * PAGE_SIZE)
501
502	/* Number of pages we need for compressed data (worst case). */
503	#define CMP_PAGES DIV_ROUND_UP(bytes_worst_compress(UNC_SIZE) + \
504	CMP_HEADER, PAGE_SIZE)
505	#define CMP_SIZE (CMP_PAGES * PAGE_SIZE)
506
507	/* Default number of threads for compression/decompression. */
508	#define CMP_THREADS 3
509	static unsigned int hibernate_compression_threads = CMP_THREADS;
510
511	/* Minimum/maximum number of pages for read buffering. */
512	#define CMP_MIN_RD_PAGES 1024
513	#define CMP_MAX_RD_PAGES 8192
514
515	static int save_image(struct swap_map_handle *handle,
516	struct snapshot_handle *snapshot,
517	unsigned int nr_to_write)
518	{
519	unsigned int m;
520	int ret;
521	int nr_pages;
522	int err2;
523	struct hib_bio_batch hb;
524	ktime_t start;
525	ktime_t stop;
526
527	hib_init_batch(hb: &hb);
528
529	pr_info("Saving image data pages (%u pages)...\n",
530	nr_to_write);
531	m = nr_to_write / 10;
532	if (!m)
533	m = 1;
534	nr_pages = 0;
535	start = ktime_get();
536	while (1) {
537	ret = snapshot_read_next(handle: snapshot);
538	if (ret <= 0)
539	break;
540	ret = swap_write_page(handle, data_of(*snapshot), hb: &hb);
541	if (ret)
542	break;
543	if (!(nr_pages % m))
544	pr_info("Image saving progress: %3d%%\n",
545	nr_pages / m * 10);
546	nr_pages++;
547	}
548	err2 = hib_wait_io(hb: &hb);
549	hib_finish_batch(hb: &hb);
550	stop = ktime_get();
551	if (!ret)
552	ret = err2;
553	if (!ret)
554	pr_info("Image saving done\n");
555	swsusp_show_speed(start, stop, nr_to_write, "Wrote");
556	return ret;
557	}
558
559	/*
560	* Structure used for CRC32.
561	*/
562	struct crc_data {
563	struct task_struct *thr; /* thread */
564	atomic_t ready; /* ready to start flag */
565	atomic_t stop; /* ready to stop flag */
566	unsigned run_threads; /* nr current threads */
567	wait_queue_head_t go; /* start crc update */
568	wait_queue_head_t done; /* crc update done */
569	u32 *crc32; /* points to handle's crc32 */
570	size_t **unc_len; /* uncompressed lengths */
571	unsigned char **unc; /* uncompressed data */
572	};
573
574	static struct crc_data *alloc_crc_data(int nr_threads)
575	{
576	struct crc_data *crc;
577
578	crc = kzalloc(sizeof(*crc), GFP_KERNEL);
579	if (!crc)
580	return NULL;
581
582	crc->unc = kcalloc(nr_threads, sizeof(*crc->unc), GFP_KERNEL);
583	if (!crc->unc)
584	goto err_free_crc;
585
586	crc->unc_len = kcalloc(nr_threads, sizeof(*crc->unc_len), GFP_KERNEL);
587	if (!crc->unc_len)
588	goto err_free_unc;
589
590	return crc;
591
592	err_free_unc:
593	kfree(objp: crc->unc);
594	err_free_crc:
595	kfree(objp: crc);
596	return NULL;
597	}
598
599	static void free_crc_data(struct crc_data *crc)
600	{
601	if (!crc)
602	return;
603
604	if (crc->thr)
605	kthread_stop(k: crc->thr);
606
607	kfree(objp: crc->unc_len);
608	kfree(objp: crc->unc);
609	kfree(objp: crc);
610	}
611
612	static int crc32_threadfn(void *data)
613	{
614	struct crc_data *d = data;
615	unsigned i;
616
617	while (1) {
618	wait_event(d->go, atomic_read_acquire(&d->ready) ||
619	kthread_should_stop());
620	if (kthread_should_stop()) {
621	d->thr = NULL;
622	atomic_set_release(v: &d->stop, i: 1);
623	wake_up(&d->done);
624	break;
625	}
626	atomic_set(v: &d->ready, i: 0);
627
628	for (i = 0; i < d->run_threads; i++)
629	*d->crc32 = crc32_le(crc: *d->crc32,
630	p: d->unc[i], len: *d->unc_len[i]);
631	atomic_set_release(v: &d->stop, i: 1);
632	wake_up(&d->done);
633	}
634	return 0;
635	}
636
637	/*
638	* Structure used for data compression.
639	*/
640	struct cmp_data {
641	struct task_struct *thr; /* thread */
642	struct crypto_acomp *cc; /* crypto compressor */
643	struct acomp_req *cr; /* crypto request */
644	atomic_t ready; /* ready to start flag */
645	atomic_t stop; /* ready to stop flag */
646	int ret; /* return code */
647	wait_queue_head_t go; /* start compression */
648	wait_queue_head_t done; /* compression done */
649	size_t unc_len; /* uncompressed length */
650	size_t cmp_len; /* compressed length */
651	unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
652	unsigned char cmp[CMP_SIZE]; /* compressed buffer */
653	};
654
655	/* Indicates the image size after compression */
656	static atomic64_t compressed_size = ATOMIC_INIT(0);
657
658	static int compress_threadfn(void *data)
659	{
660	struct cmp_data *d = data;
661
662	while (1) {
663	wait_event(d->go, atomic_read_acquire(&d->ready) ||
664	kthread_should_stop());
665	if (kthread_should_stop()) {
666	d->thr = NULL;
667	d->ret = -1;
668	atomic_set_release(v: &d->stop, i: 1);
669	wake_up(&d->done);
670	break;
671	}
672	atomic_set(v: &d->ready, i: 0);
673
674	acomp_request_set_callback(req: d->cr, CRYPTO_TFM_REQ_MAY_SLEEP,
675	NULL, NULL);
676	acomp_request_set_src_nondma(req: d->cr, src: d->unc, slen: d->unc_len);
677	acomp_request_set_dst_nondma(req: d->cr, dst: d->cmp + CMP_HEADER,
678	CMP_SIZE - CMP_HEADER);
679	d->ret = crypto_acomp_compress(req: d->cr);
680	d->cmp_len = d->cr->dlen;
681
682	atomic64_add(i: d->cmp_len, v: &compressed_size);
683	atomic_set_release(v: &d->stop, i: 1);
684	wake_up(&d->done);
685	}
686	return 0;
687	}
688
689	static int save_compressed_image(struct swap_map_handle *handle,
690	struct snapshot_handle *snapshot,
691	unsigned int nr_to_write)
692	{
693	unsigned int m;
694	int ret = 0;
695	int nr_pages;
696	int err2;
697	struct hib_bio_batch hb;
698	ktime_t start;
699	ktime_t stop;
700	size_t off;
701	unsigned int thr, run_threads, nr_threads;
702	unsigned char *page = NULL;
703	struct cmp_data *data = NULL;
704	struct crc_data *crc = NULL;
705
706	hib_init_batch(hb: &hb);
707
708	atomic64_set(v: &compressed_size, i: 0);
709
710	/*
711	* We'll limit the number of threads for compression to limit memory
712	* footprint.
713	*/
714	nr_threads = num_online_cpus() - 1;
715	nr_threads = clamp_val(nr_threads, 1, hibernate_compression_threads);
716
717	page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
718	if (!page) {
719	pr_err("Failed to allocate %s page\n", hib_comp_algo);
720	ret = -ENOMEM;
721	goto out_clean;
722	}
723
724	data = vcalloc(nr_threads, sizeof(*data));
725	if (!data) {
726	pr_err("Failed to allocate %s data\n", hib_comp_algo);
727	ret = -ENOMEM;
728	goto out_clean;
729	}
730
731	crc = alloc_crc_data(nr_threads);
732	if (!crc) {
733	pr_err("Failed to allocate crc\n");
734	ret = -ENOMEM;
735	goto out_clean;
736	}
737
738	/*
739	* Start the compression threads.
740	*/
741	for (thr = 0; thr < nr_threads; thr++) {
742	init_waitqueue_head(&data[thr].go);
743	init_waitqueue_head(&data[thr].done);
744
745	data[thr].cc = crypto_alloc_acomp(alg_name: hib_comp_algo, type: 0, CRYPTO_ALG_ASYNC);
746	if (IS_ERR_OR_NULL(ptr: data[thr].cc)) {
747	pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
748	ret = -EFAULT;
749	goto out_clean;
750	}
751
752	data[thr].cr = acomp_request_alloc(data[thr].cc);
753	if (!data[thr].cr) {
754	pr_err("Could not allocate comp request\n");
755	ret = -ENOMEM;
756	goto out_clean;
757	}
758
759	data[thr].thr = kthread_run(compress_threadfn,
760	&data[thr],
761	"image_compress/%u", thr);
762	if (IS_ERR(ptr: data[thr].thr)) {
763	data[thr].thr = NULL;
764	pr_err("Cannot start compression threads\n");
765	ret = -ENOMEM;
766	goto out_clean;
767	}
768	}
769
770	/*
771	* Start the CRC32 thread.
772	*/
773	init_waitqueue_head(&crc->go);
774	init_waitqueue_head(&crc->done);
775
776	handle->crc32 = 0;
777	crc->crc32 = &handle->crc32;
778	for (thr = 0; thr < nr_threads; thr++) {
779	crc->unc[thr] = data[thr].unc;
780	crc->unc_len[thr] = &data[thr].unc_len;
781	}
782
783	crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
784	if (IS_ERR(ptr: crc->thr)) {
785	crc->thr = NULL;
786	pr_err("Cannot start CRC32 thread\n");
787	ret = -ENOMEM;
788	goto out_clean;
789	}
790
791	/*
792	* Adjust the number of required free pages after all allocations have
793	* been done. We don't want to run out of pages when writing.
794	*/
795	handle->reqd_free_pages = reqd_free_pages();
796
797	pr_info("Using %u thread(s) for %s compression\n", nr_threads, hib_comp_algo);
798	pr_info("Compressing and saving image data (%u pages)...\n",
799	nr_to_write);
800	m = nr_to_write / 10;
801	if (!m)
802	m = 1;
803	nr_pages = 0;
804	start = ktime_get();
805	for (;;) {
806	for (thr = 0; thr < nr_threads; thr++) {
807	for (off = 0; off < UNC_SIZE; off += PAGE_SIZE) {
808	ret = snapshot_read_next(handle: snapshot);
809	if (ret < 0)
810	goto out_finish;
811
812	if (!ret)
813	break;
814
815	memcpy(data[thr].unc + off,
816	data_of(*snapshot), PAGE_SIZE);
817
818	if (!(nr_pages % m))
819	pr_info("Image saving progress: %3d%%\n",
820	nr_pages / m * 10);
821	nr_pages++;
822	}
823	if (!off)
824	break;
825
826	data[thr].unc_len = off;
827
828	atomic_set_release(v: &data[thr].ready, i: 1);
829	wake_up(&data[thr].go);
830	}
831
832	if (!thr)
833	break;
834
835	crc->run_threads = thr;
836	atomic_set_release(v: &crc->ready, i: 1);
837	wake_up(&crc->go);
838
839	for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
840	wait_event(data[thr].done,
841	atomic_read_acquire(&data[thr].stop));
842	atomic_set(v: &data[thr].stop, i: 0);
843
844	ret = data[thr].ret;
845
846	if (ret < 0) {
847	pr_err("%s compression failed\n", hib_comp_algo);
848	goto out_finish;
849	}
850
851	if (unlikely(!data[thr].cmp_len ||
852	data[thr].cmp_len >
853	bytes_worst_compress(data[thr].unc_len))) {
854	pr_err("Invalid %s compressed length\n", hib_comp_algo);
855	ret = -1;
856	goto out_finish;
857	}
858
859	*(size_t *)data[thr].cmp = data[thr].cmp_len;
860
861	/*
862	* Given we are writing one page at a time to disk, we
863	* copy that much from the buffer, although the last
864	* bit will likely be smaller than full page. This is
865	* OK - we saved the length of the compressed data, so
866	* any garbage at the end will be discarded when we
867	* read it.
868	*/
869	for (off = 0;
870	off < CMP_HEADER + data[thr].cmp_len;
871	off += PAGE_SIZE) {
872	memcpy(page, data[thr].cmp + off, PAGE_SIZE);
873
874	ret = swap_write_page(handle, buf: page, hb: &hb);
875	if (ret)
876	goto out_finish;
877	}
878	}
879
880	wait_event(crc->done, atomic_read_acquire(&crc->stop));
881	atomic_set(v: &crc->stop, i: 0);
882	}
883
884	out_finish:
885	err2 = hib_wait_io(hb: &hb);
886	stop = ktime_get();
887	if (!ret)
888	ret = err2;
889	if (!ret) {
890	swsusp_show_speed(start, stop, nr_to_write, "Wrote");
891	pr_info("Image size after compression: %lld kbytes\n",
892	(atomic64_read(&compressed_size) / 1024));
893	pr_info("Image saving done\n");
894	} else {
895	pr_err("Image saving failed: %d\n", ret);
896	}
897
898	out_clean:
899	hib_finish_batch(hb: &hb);
900	free_crc_data(crc);
901	if (data) {
902	for (thr = 0; thr < nr_threads; thr++) {
903	if (data[thr].thr)
904	kthread_stop(k: data[thr].thr);
905	if (data[thr].cr)
906	acomp_request_free(req: data[thr].cr);
907
908	if (!IS_ERR_OR_NULL(ptr: data[thr].cc))
909	crypto_free_acomp(tfm: data[thr].cc);
910	}
911	vfree(addr: data);
912	}
913	if (page)
914	free_page((unsigned long)page);
915
916	return ret;
917	}
918
919	static int enough_swap(unsigned int nr_pages)
920	{
921	unsigned int free_swap = count_swap_pages(root_swap, 1);
922	unsigned int required;
923
924	pr_debug("Free swap pages: %u\n", free_swap);
925
926	required = PAGES_FOR_IO + nr_pages;
927	return free_swap > required;
928	}
929
930	/**
931	* swsusp_write - Write entire image and metadata.
932	* @flags: flags to pass to the "boot" kernel in the image header
933	*
934	* It is important _NOT_ to umount filesystems at this point. We want them
935	* synced (in case something goes wrong) but we DO not want to mark filesystem
936	* clean: it is not. (And it does not matter, if we resume correctly, we'll mark
937	* system clean, anyway.)
938	*
939	* Return: 0 on success, negative error code on failure.
940	*/
941	int swsusp_write(unsigned int flags)
942	{
943	struct swap_map_handle handle;
944	struct snapshot_handle snapshot;
945	struct swsusp_info *header;
946	unsigned long pages;
947	int error;
948
949	pages = snapshot_get_image_size();
950	error = get_swap_writer(handle: &handle);
951	if (error) {
952	pr_err("Cannot get swap writer\n");
953	return error;
954	}
955	if (flags & SF_NOCOMPRESS_MODE) {
956	if (!enough_swap(nr_pages: pages)) {
957	pr_err("Not enough free swap\n");
958	error = -ENOSPC;
959	goto out_finish;
960	}
961	}
962	memset(&snapshot, 0, sizeof(struct snapshot_handle));
963	error = snapshot_read_next(handle: &snapshot);
964	if (error < (int)PAGE_SIZE) {
965	if (error >= 0)
966	error = -EFAULT;
967
968	goto out_finish;
969	}
970	header = (struct swsusp_info *)data_of(snapshot);
971	error = swap_write_page(handle: &handle, buf: header, NULL);
972	if (!error) {
973	error = (flags & SF_NOCOMPRESS_MODE) ?
974	save_image(handle: &handle, snapshot: &snapshot, nr_to_write: pages - 1) :
975	save_compressed_image(handle: &handle, snapshot: &snapshot, nr_to_write: pages - 1);
976	}
977	out_finish:
978	error = swap_writer_finish(handle: &handle, flags, error);
979	return error;
980	}
981
982	/*
983	* The following functions allow us to read data using a swap map in a file-like
984	* way.
985	*/
986
987	static void release_swap_reader(struct swap_map_handle *handle)
988	{
989	struct swap_map_page_list *tmp;
990
991	while (handle->maps) {
992	if (handle->maps->map)
993	free_page((unsigned long)handle->maps->map);
994	tmp = handle->maps;
995	handle->maps = handle->maps->next;
996	kfree(objp: tmp);
997	}
998	handle->cur = NULL;
999	}
1000
1001	static int get_swap_reader(struct swap_map_handle *handle,
1002	unsigned int *flags_p)
1003	{
1004	int error;
1005	struct swap_map_page_list *tmp, *last;
1006	sector_t offset;
1007
1008	*flags_p = swsusp_header->flags;
1009
1010	if (!swsusp_header->image) /* how can this happen? */
1011	return -EINVAL;
1012
1013	handle->cur = NULL;
1014	last = handle->maps = NULL;
1015	offset = swsusp_header->image;
1016	while (offset) {
1017	tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
1018	if (!tmp) {
1019	release_swap_reader(handle);
1020	return -ENOMEM;
1021	}
1022	if (!handle->maps)
1023	handle->maps = tmp;
1024	if (last)
1025	last->next = tmp;
1026	last = tmp;
1027
1028	tmp->map = (struct swap_map_page *)
1029	__get_free_page(GFP_NOIO | __GFP_HIGH);
1030	if (!tmp->map) {
1031	release_swap_reader(handle);
1032	return -ENOMEM;
1033	}
1034
1035	error = hib_submit_io_sync(opf: REQ_OP_READ, page_off: offset, addr: tmp->map);
1036	if (error) {
1037	release_swap_reader(handle);
1038	return error;
1039	}
1040	offset = tmp->map->next_swap;
1041	}
1042	handle->k = 0;
1043	handle->cur = handle->maps->map;
1044	return 0;
1045	}
1046
1047	static int swap_read_page(struct swap_map_handle *handle, void *buf,
1048	struct hib_bio_batch *hb)
1049	{
1050	sector_t offset;
1051	int error;
1052	struct swap_map_page_list *tmp;
1053
1054	if (!handle->cur)
1055	return -EINVAL;
1056	offset = handle->cur->entries[handle->k];
1057	if (!offset)
1058	return -EFAULT;
1059	if (hb)
1060	error = hib_submit_io_async(opf: REQ_OP_READ, page_off: offset, addr: buf, hb);
1061	else
1062	error = hib_submit_io_sync(opf: REQ_OP_READ, page_off: offset, addr: buf);
1063	if (error)
1064	return error;
1065	if (++handle->k >= MAP_PAGE_ENTRIES) {
1066	handle->k = 0;
1067	free_page((unsigned long)handle->maps->map);
1068	tmp = handle->maps;
1069	handle->maps = handle->maps->next;
1070	kfree(objp: tmp);
1071	if (!handle->maps)
1072	release_swap_reader(handle);
1073	else
1074	handle->cur = handle->maps->map;
1075	}
1076	return error;
1077	}
1078
1079	static int swap_reader_finish(struct swap_map_handle *handle)
1080	{
1081	release_swap_reader(handle);
1082
1083	return 0;
1084	}
1085
1086	static int load_image(struct swap_map_handle *handle,
1087	struct snapshot_handle *snapshot,
1088	unsigned int nr_to_read)
1089	{
1090	unsigned int m;
1091	int ret = 0;
1092	ktime_t start;
1093	ktime_t stop;
1094	struct hib_bio_batch hb;
1095	int err2;
1096	unsigned nr_pages;
1097
1098	hib_init_batch(hb: &hb);
1099
1100	clean_pages_on_read = true;
1101	pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1102	m = nr_to_read / 10;
1103	if (!m)
1104	m = 1;
1105	nr_pages = 0;
1106	start = ktime_get();
1107	for ( ; ; ) {
1108	ret = snapshot_write_next(handle: snapshot);
1109	if (ret <= 0)
1110	break;
1111	ret = swap_read_page(handle, data_of(*snapshot), hb: &hb);
1112	if (ret)
1113	break;
1114	if (snapshot->sync_read)
1115	ret = hib_wait_io(hb: &hb);
1116	if (ret)
1117	break;
1118	if (!(nr_pages % m))
1119	pr_info("Image loading progress: %3d%%\n",
1120	nr_pages / m * 10);
1121	nr_pages++;
1122	}
1123	err2 = hib_wait_io(hb: &hb);
1124	hib_finish_batch(hb: &hb);
1125	stop = ktime_get();
1126	if (!ret)
1127	ret = err2;
1128	if (!ret) {
1129	pr_info("Image loading done\n");
1130	ret = snapshot_write_finalize(handle: snapshot);
1131	if (!ret && !snapshot_image_loaded(handle: snapshot))
1132	ret = -ENODATA;
1133	}
1134	swsusp_show_speed(start, stop, nr_to_read, "Read");
1135	return ret;
1136	}
1137
1138	/*
1139	* Structure used for data decompression.
1140	*/
1141	struct dec_data {
1142	struct task_struct *thr; /* thread */
1143	struct crypto_acomp *cc; /* crypto compressor */
1144	struct acomp_req *cr; /* crypto request */
1145	atomic_t ready; /* ready to start flag */
1146	atomic_t stop; /* ready to stop flag */
1147	int ret; /* return code */
1148	wait_queue_head_t go; /* start decompression */
1149	wait_queue_head_t done; /* decompression done */
1150	size_t unc_len; /* uncompressed length */
1151	size_t cmp_len; /* compressed length */
1152	unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
1153	unsigned char cmp[CMP_SIZE]; /* compressed buffer */
1154	};
1155
1156	static int decompress_threadfn(void *data)
1157	{
1158	struct dec_data *d = data;
1159
1160	while (1) {
1161	wait_event(d->go, atomic_read_acquire(&d->ready) ||
1162	kthread_should_stop());
1163	if (kthread_should_stop()) {
1164	d->thr = NULL;
1165	d->ret = -1;
1166	atomic_set_release(v: &d->stop, i: 1);
1167	wake_up(&d->done);
1168	break;
1169	}
1170	atomic_set(v: &d->ready, i: 0);
1171
1172	acomp_request_set_callback(req: d->cr, CRYPTO_TFM_REQ_MAY_SLEEP,
1173	NULL, NULL);
1174	acomp_request_set_src_nondma(req: d->cr, src: d->cmp + CMP_HEADER,
1175	slen: d->cmp_len);
1176	acomp_request_set_dst_nondma(req: d->cr, dst: d->unc, UNC_SIZE);
1177	d->ret = crypto_acomp_decompress(req: d->cr);
1178	d->unc_len = d->cr->dlen;
1179
1180	if (clean_pages_on_decompress)
1181	flush_icache_range(start: (unsigned long)d->unc,
1182	end: (unsigned long)d->unc + d->unc_len);
1183
1184	atomic_set_release(v: &d->stop, i: 1);
1185	wake_up(&d->done);
1186	}
1187	return 0;
1188	}
1189
1190	static int load_compressed_image(struct swap_map_handle *handle,
1191	struct snapshot_handle *snapshot,
1192	unsigned int nr_to_read)
1193	{
1194	unsigned int m;
1195	int ret = 0;
1196	int eof = 0;
1197	struct hib_bio_batch hb;
1198	ktime_t start;
1199	ktime_t stop;
1200	unsigned nr_pages;
1201	size_t off;
1202	unsigned i, thr, run_threads, nr_threads;
1203	unsigned ring = 0, pg = 0, ring_size = 0,
1204	have = 0, want, need, asked = 0;
1205	unsigned long read_pages = 0;
1206	unsigned char **page = NULL;
1207	struct dec_data *data = NULL;
1208	struct crc_data *crc = NULL;
1209
1210	hib_init_batch(hb: &hb);
1211
1212	/*
1213	* We'll limit the number of threads for decompression to limit memory
1214	* footprint.
1215	*/
1216	nr_threads = num_online_cpus() - 1;
1217	nr_threads = clamp_val(nr_threads, 1, hibernate_compression_threads);
1218
1219	page = vmalloc_array(CMP_MAX_RD_PAGES, sizeof(*page));
1220	if (!page) {
1221	pr_err("Failed to allocate %s page\n", hib_comp_algo);
1222	ret = -ENOMEM;
1223	goto out_clean;
1224	}
1225
1226	data = vcalloc(nr_threads, sizeof(*data));
1227	if (!data) {
1228	pr_err("Failed to allocate %s data\n", hib_comp_algo);
1229	ret = -ENOMEM;
1230	goto out_clean;
1231	}
1232
1233	crc = alloc_crc_data(nr_threads);
1234	if (!crc) {
1235	pr_err("Failed to allocate crc\n");
1236	ret = -ENOMEM;
1237	goto out_clean;
1238	}
1239
1240	clean_pages_on_decompress = true;
1241
1242	/*
1243	* Start the decompression threads.
1244	*/
1245	for (thr = 0; thr < nr_threads; thr++) {
1246	init_waitqueue_head(&data[thr].go);
1247	init_waitqueue_head(&data[thr].done);
1248
1249	data[thr].cc = crypto_alloc_acomp(alg_name: hib_comp_algo, type: 0, CRYPTO_ALG_ASYNC);
1250	if (IS_ERR_OR_NULL(ptr: data[thr].cc)) {
1251	pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
1252	ret = -EFAULT;
1253	goto out_clean;
1254	}
1255
1256	data[thr].cr = acomp_request_alloc(data[thr].cc);
1257	if (!data[thr].cr) {
1258	pr_err("Could not allocate comp request\n");
1259	ret = -ENOMEM;
1260	goto out_clean;
1261	}
1262
1263	data[thr].thr = kthread_run(decompress_threadfn,
1264	&data[thr],
1265	"image_decompress/%u", thr);
1266	if (IS_ERR(ptr: data[thr].thr)) {
1267	data[thr].thr = NULL;
1268	pr_err("Cannot start decompression threads\n");
1269	ret = -ENOMEM;
1270	goto out_clean;
1271	}
1272	}
1273
1274	/*
1275	* Start the CRC32 thread.
1276	*/
1277	init_waitqueue_head(&crc->go);
1278	init_waitqueue_head(&crc->done);
1279
1280	handle->crc32 = 0;
1281	crc->crc32 = &handle->crc32;
1282	for (thr = 0; thr < nr_threads; thr++) {
1283	crc->unc[thr] = data[thr].unc;
1284	crc->unc_len[thr] = &data[thr].unc_len;
1285	}
1286
1287	crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1288	if (IS_ERR(ptr: crc->thr)) {
1289	crc->thr = NULL;
1290	pr_err("Cannot start CRC32 thread\n");
1291	ret = -ENOMEM;
1292	goto out_clean;
1293	}
1294
1295	/*
1296	* Set the number of pages for read buffering.
1297	* This is complete guesswork, because we'll only know the real
1298	* picture once prepare_image() is called, which is much later on
1299	* during the image load phase. We'll assume the worst case and
1300	* say that none of the image pages are from high memory.
1301	*/
1302	if (low_free_pages() > snapshot_get_image_size())
1303	read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1304	read_pages = clamp_val(read_pages, CMP_MIN_RD_PAGES, CMP_MAX_RD_PAGES);
1305
1306	for (i = 0; i < read_pages; i++) {
1307	page[i] = (void *)__get_free_page(i < CMP_PAGES ?
1308	GFP_NOIO | __GFP_HIGH :
1309	GFP_NOIO | __GFP_NOWARN |
1310	__GFP_NORETRY);
1311
1312	if (!page[i]) {
1313	if (i < CMP_PAGES) {
1314	ring_size = i;
1315	pr_err("Failed to allocate %s pages\n", hib_comp_algo);
1316	ret = -ENOMEM;
1317	goto out_clean;
1318	} else {
1319	break;
1320	}
1321	}
1322	}
1323	want = ring_size = i;
1324
1325	pr_info("Using %u thread(s) for %s decompression\n", nr_threads, hib_comp_algo);
1326	pr_info("Loading and decompressing image data (%u pages)...\n",
1327	nr_to_read);
1328	m = nr_to_read / 10;
1329	if (!m)
1330	m = 1;
1331	nr_pages = 0;
1332	start = ktime_get();
1333
1334	ret = snapshot_write_next(handle: snapshot);
1335	if (ret <= 0)
1336	goto out_finish;
1337
1338	for(;;) {
1339	for (i = 0; !eof && i < want; i++) {
1340	ret = swap_read_page(handle, buf: page[ring], hb: &hb);
1341	if (ret) {
1342	/*
1343	* On real read error, finish. On end of data,
1344	* set EOF flag and just exit the read loop.
1345	*/
1346	if (handle->cur &&
1347	handle->cur->entries[handle->k]) {
1348	goto out_finish;
1349	} else {
1350	eof = 1;
1351	break;
1352	}
1353	}
1354	if (++ring >= ring_size)
1355	ring = 0;
1356	}
1357	asked += i;
1358	want -= i;
1359
1360	/*
1361	* We are out of data, wait for some more.
1362	*/
1363	if (!have) {
1364	if (!asked)
1365	break;
1366
1367	ret = hib_wait_io(hb: &hb);
1368	if (ret)
1369	goto out_finish;
1370	have += asked;
1371	asked = 0;
1372	if (eof)
1373	eof = 2;
1374	}
1375
1376	if (crc->run_threads) {
1377	wait_event(crc->done, atomic_read_acquire(&crc->stop));
1378	atomic_set(v: &crc->stop, i: 0);
1379	crc->run_threads = 0;
1380	}
1381
1382	for (thr = 0; have && thr < nr_threads; thr++) {
1383	data[thr].cmp_len = *(size_t *)page[pg];
1384	if (unlikely(!data[thr].cmp_len ||
1385	data[thr].cmp_len >
1386	bytes_worst_compress(UNC_SIZE))) {
1387	pr_err("Invalid %s compressed length\n", hib_comp_algo);
1388	ret = -1;
1389	goto out_finish;
1390	}
1391
1392	need = DIV_ROUND_UP(data[thr].cmp_len + CMP_HEADER,
1393	PAGE_SIZE);
1394	if (need > have) {
1395	if (eof > 1) {
1396	ret = -1;
1397	goto out_finish;
1398	}
1399	break;
1400	}
1401
1402	for (off = 0;
1403	off < CMP_HEADER + data[thr].cmp_len;
1404	off += PAGE_SIZE) {
1405	memcpy(data[thr].cmp + off,
1406	page[pg], PAGE_SIZE);
1407	have--;
1408	want++;
1409	if (++pg >= ring_size)
1410	pg = 0;
1411	}
1412
1413	atomic_set_release(v: &data[thr].ready, i: 1);
1414	wake_up(&data[thr].go);
1415	}
1416
1417	/*
1418	* Wait for more data while we are decompressing.
1419	*/
1420	if (have < CMP_PAGES && asked) {
1421	ret = hib_wait_io(hb: &hb);
1422	if (ret)
1423	goto out_finish;
1424	have += asked;
1425	asked = 0;
1426	if (eof)
1427	eof = 2;
1428	}
1429
1430	for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1431	wait_event(data[thr].done,
1432	atomic_read_acquire(&data[thr].stop));
1433	atomic_set(v: &data[thr].stop, i: 0);
1434
1435	ret = data[thr].ret;
1436
1437	if (ret < 0) {
1438	pr_err("%s decompression failed\n", hib_comp_algo);
1439	goto out_finish;
1440	}
1441
1442	if (unlikely(!data[thr].unc_len ||
1443	data[thr].unc_len > UNC_SIZE ||
1444	data[thr].unc_len & (PAGE_SIZE - 1))) {
1445	pr_err("Invalid %s uncompressed length\n", hib_comp_algo);
1446	ret = -1;
1447	goto out_finish;
1448	}
1449
1450	for (off = 0;
1451	off < data[thr].unc_len; off += PAGE_SIZE) {
1452	memcpy(data_of(*snapshot),
1453	data[thr].unc + off, PAGE_SIZE);
1454
1455	if (!(nr_pages % m))
1456	pr_info("Image loading progress: %3d%%\n",
1457	nr_pages / m * 10);
1458	nr_pages++;
1459
1460	ret = snapshot_write_next(handle: snapshot);
1461	if (ret <= 0) {
1462	crc->run_threads = thr + 1;
1463	atomic_set_release(v: &crc->ready, i: 1);
1464	wake_up(&crc->go);
1465	goto out_finish;
1466	}
1467	}
1468	}
1469
1470	crc->run_threads = thr;
1471	atomic_set_release(v: &crc->ready, i: 1);
1472	wake_up(&crc->go);
1473	}
1474
1475	out_finish:
1476	if (crc->run_threads) {
1477	wait_event(crc->done, atomic_read_acquire(&crc->stop));
1478	atomic_set(v: &crc->stop, i: 0);
1479	}
1480	stop = ktime_get();
1481	if (!ret) {
1482	pr_info("Image loading done\n");
1483	ret = snapshot_write_finalize(handle: snapshot);
1484	if (!ret && !snapshot_image_loaded(handle: snapshot))
1485	ret = -ENODATA;
1486	if (!ret) {
1487	if (swsusp_header->flags & SF_CRC32_MODE) {
1488	if(handle->crc32 != swsusp_header->crc32) {
1489	pr_err("Invalid image CRC32!\n");
1490	ret = -ENODATA;
1491	}
1492	}
1493	}
1494	}
1495	swsusp_show_speed(start, stop, nr_to_read, "Read");
1496	out_clean:
1497	hib_finish_batch(hb: &hb);
1498	for (i = 0; i < ring_size; i++)
1499	free_page((unsigned long)page[i]);
1500	free_crc_data(crc);
1501	if (data) {
1502	for (thr = 0; thr < nr_threads; thr++) {
1503	if (data[thr].thr)
1504	kthread_stop(k: data[thr].thr);
1505	if (data[thr].cr)
1506	acomp_request_free(req: data[thr].cr);
1507
1508	if (!IS_ERR_OR_NULL(ptr: data[thr].cc))
1509	crypto_free_acomp(tfm: data[thr].cc);
1510	}
1511	vfree(addr: data);
1512	}
1513	vfree(addr: page);
1514
1515	return ret;
1516	}
1517
1518	/**
1519	* swsusp_read - read the hibernation image.
1520	* @flags_p: flags passed by the "frozen" kernel in the image header should
1521	* be written into this memory location
1522	*
1523	* Return: 0 on success, negative error code on failure.
1524	*/
1525	int swsusp_read(unsigned int *flags_p)
1526	{
1527	int error;
1528	struct swap_map_handle handle;
1529	struct snapshot_handle snapshot;
1530	struct swsusp_info *header;
1531
1532	memset(&snapshot, 0, sizeof(struct snapshot_handle));
1533	error = snapshot_write_next(handle: &snapshot);
1534	if (error < (int)PAGE_SIZE)
1535	return error < 0 ? error : -EFAULT;
1536	header = (struct swsusp_info *)data_of(snapshot);
1537	error = get_swap_reader(handle: &handle, flags_p);
1538	if (error)
1539	goto end;
1540	if (!error)
1541	error = swap_read_page(handle: &handle, buf: header, NULL);
1542	if (!error) {
1543	error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1544	load_image(handle: &handle, snapshot: &snapshot, nr_to_read: header->pages - 1) :
1545	load_compressed_image(handle: &handle, snapshot: &snapshot, nr_to_read: header->pages - 1);
1546	}
1547	swap_reader_finish(handle: &handle);
1548	end:
1549	if (!error)
1550	pr_debug("Image successfully loaded\n");
1551	else
1552	pr_debug("Error %d resuming\n", error);
1553	return error;
1554	}
1555
1556	static void *swsusp_holder;
1557
1558	/**
1559	* swsusp_check - Open the resume device and check for the swsusp signature.
1560	* @exclusive: Open the resume device exclusively.
1561	*
1562	* Return: 0 if a valid image is found, negative error code otherwise.
1563	*/
1564	int swsusp_check(bool exclusive)
1565	{
1566	void *holder = exclusive ? &swsusp_holder : NULL;
1567	int error;
1568
1569	hib_resume_bdev_file = bdev_file_open_by_dev(dev: swsusp_resume_device,
1570	BLK_OPEN_READ, holder, NULL);
1571	if (!IS_ERR(ptr: hib_resume_bdev_file)) {
1572	clear_page(page: swsusp_header);
1573	error = hib_submit_io_sync(opf: REQ_OP_READ, page_off: swsusp_resume_block,
1574	addr: swsusp_header);
1575	if (error)
1576	goto put;
1577
1578	if (!memcmp(HIBERNATE_SIG, q: swsusp_header->sig, size: 10)) {
1579	memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1580	swsusp_header_flags = swsusp_header->flags;
1581	/* Reset swap signature now */
1582	error = hib_submit_io_sync(opf: REQ_OP_WRITE | REQ_SYNC,
1583	page_off: swsusp_resume_block,
1584	addr: swsusp_header);
1585	} else {
1586	error = -EINVAL;
1587	}
1588	if (!error && swsusp_header->flags & SF_HW_SIG &&
1589	swsusp_header->hw_sig != swsusp_hardware_signature) {
1590	pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
1591	swsusp_header->hw_sig, swsusp_hardware_signature);
1592	error = -EINVAL;
1593	}
1594
1595	put:
1596	if (error)
1597	bdev_fput(bdev_file: hib_resume_bdev_file);
1598	else
1599	pr_debug("Image signature found, resuming\n");
1600	} else {
1601	error = PTR_ERR(ptr: hib_resume_bdev_file);
1602	}
1603
1604	if (error)
1605	pr_debug("Image not found (code %d)\n", error);
1606
1607	return error;
1608	}
1609
1610	/**
1611	* swsusp_close - close resume device.
1612	*/
1613	void swsusp_close(void)
1614	{
1615	if (IS_ERR(ptr: hib_resume_bdev_file)) {
1616	pr_debug("Image device not initialised\n");
1617	return;
1618	}
1619
1620	fput(hib_resume_bdev_file);
1621	}
1622
1623	/**
1624	* swsusp_unmark - Unmark swsusp signature in the resume device
1625	*
1626	* Return: 0 on success, negative error code on failure.
1627	*/
1628	#ifdef CONFIG_SUSPEND
1629	int swsusp_unmark(void)
1630	{
1631	int error;
1632
1633	hib_submit_io_sync(opf: REQ_OP_READ, page_off: swsusp_resume_block, addr: swsusp_header);
1634	if (!memcmp(HIBERNATE_SIG,q: swsusp_header->sig, size: 10)) {
1635	memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1636	error = hib_submit_io_sync(opf: REQ_OP_WRITE | REQ_SYNC,
1637	page_off: swsusp_resume_block,
1638	addr: swsusp_header);
1639	} else {
1640	pr_err("Cannot find swsusp signature!\n");
1641	error = -ENODEV;
1642	}
1643
1644	/*
1645	* We just returned from suspend, we don't need the image any more.
1646	*/
1647	free_all_swap_pages(swap: root_swap);
1648
1649	return error;
1650	}
1651	#endif
1652
1653	static ssize_t hibernate_compression_threads_show(struct kobject *kobj,
1654	struct kobj_attribute *attr, char *buf)
1655	{
1656	return sysfs_emit(buf, fmt: "%d\n", hibernate_compression_threads);
1657	}
1658
1659	static ssize_t hibernate_compression_threads_store(struct kobject *kobj,
1660	struct kobj_attribute *attr,
1661	const char *buf, size_t n)
1662	{
1663	unsigned long val;
1664
1665	if (kstrtoul(s: buf, base: 0, res: &val))
1666	return -EINVAL;
1667
1668	if (val < 1)
1669	return -EINVAL;
1670
1671	hibernate_compression_threads = val;
1672	return n;
1673	}
1674	power_attr(hibernate_compression_threads);
1675
1676	static struct attribute *g[] = {
1677	&hibernate_compression_threads_attr.attr,
1678	NULL,
1679	};
1680
1681	static const struct attribute_group attr_group = {
1682	.attrs = g,
1683	};
1684
1685	static int __init swsusp_header_init(void)
1686	{
1687	int error;
1688
1689	error = sysfs_create_group(kobj: power_kobj, grp: &attr_group);
1690	if (error)
1691	return -ENOMEM;
1692
1693	swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1694	if (!swsusp_header)
1695	panic(fmt: "Could not allocate memory for swsusp_header\n");
1696	return 0;
1697	}
1698
1699	core_initcall(swsusp_header_init);
1700
1701	static int __init hibernate_compression_threads_setup(char *str)
1702	{
1703	int rc = kstrtouint(s: str, base: 0, res: &hibernate_compression_threads);
1704
1705	if (rc)
1706	return rc;
1707
1708	if (hibernate_compression_threads < 1)
1709	hibernate_compression_threads = CMP_THREADS;
1710
1711	return 1;
1712
1713	}
1714
1715	__setup("hibernate_compression_threads=", hibernate_compression_threads_setup);
1716