kernel/power/swap.c

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