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/lzo.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/cpumask.h>
  29 #include <linux/atomic.h>
  30 #include <linux/kthread.h>
  31 #include <linux/crc32.h>
  32 #include <linux/ktime.h>
  33
  34 #include "power.h"
  35
  36 #define HIBERNATE_SIG   "S1SUSPEND"
  37
  38 u32 swsusp_hardware_signature;
  39
  40 /*
  41  * When reading an {un,}compressed image, we may restore pages in place,
  42  * in which case some architectures need these pages cleaning before they
  43  * can be executed. We don't know which pages these may be, so clean the lot.
  44  */
  45 static bool clean_pages_on_read;
  46 static bool clean_pages_on_decompress;
  47
  48 /*
  49  *      The swap map is a data structure used for keeping track of each page
  50  *      written to a swap partition.  It consists of many swap_map_page
  51  *      structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
  52  *      These structures are stored on the swap and linked together with the
  53  *      help of the .next_swap member.
  54  *
  55  *      The swap map is created during suspend.  The swap map pages are
  56  *      allocated and populated one at a time, so we only need one memory
  57  *      page to set up the entire structure.
  58  *
  59  *      During resume we pick up all swap_map_page structures into a list.
  60  */
  61
  62 #define MAP_PAGE_ENTRIES        (PAGE_SIZE / sizeof(sector_t) - 1)
  63
  64 /*
  65  * Number of free pages that are not high.
  66  */
  67 static inline unsigned long low_free_pages(void)
  68 {
  69         return nr_free_pages() - nr_free_highpages();
  70 }
  71
  72 /*
  73  * Number of pages required to be kept free while writing the image. Always
  74  * half of all available low pages before the writing starts.
  75  */
  76 static inline unsigned long reqd_free_pages(void)
  77 {
  78         return low_free_pages() / 2;
  79 }
  80
  81 struct swap_map_page {
  82         sector_t entries[MAP_PAGE_ENTRIES];
  83         sector_t next_swap;
  84 };
  85
  86 struct swap_map_page_list {
  87         struct swap_map_page *map;
  88         struct swap_map_page_list *next;
  89 };
  90
  91 /*
  92  *      The swap_map_handle structure is used for handling swap in
  93  *      a file-alike way
  94  */
  95
  96 struct swap_map_handle {
  97         struct swap_map_page *cur;
  98         struct swap_map_page_list *maps;
  99         sector_t cur_swap;
 100         sector_t first_sector;
 101         unsigned int k;
 102         unsigned long reqd_free_pages;
 103         u32 crc32;
 104 };
 105
 106 struct swsusp_header {
 107         char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
 108                       sizeof(u32) - sizeof(u32)];
 109         u32     hw_sig;
 110         u32     crc32;
 111         sector_t image;
 112         unsigned int flags;     /* Flags to pass to the "boot" kernel */
 113         char    orig_sig[10];
 114         char    sig[10];
 115 } __packed;
 116
 117 static struct swsusp_header *swsusp_header;
 118
 119 /*
 120  *      The following functions are used for tracing the allocated
 121  *      swap pages, so that they can be freed in case of an error.
 122  */
 123
 124 struct swsusp_extent {
 125         struct rb_node node;
 126         unsigned long start;
 127         unsigned long end;
 128 };
 129
 130 static struct rb_root swsusp_extents = RB_ROOT;
 131
 132 static int swsusp_extents_insert(unsigned long swap_offset)
 133 {
 134         struct rb_node **new = &(swsusp_extents.rb_node);
 135         struct rb_node *parent = NULL;
 136         struct swsusp_extent *ext;
 137
 138         /* Figure out where to put the new node */
 139         while (*new) {
 140                 ext = rb_entry(*new, struct swsusp_extent, node);
 141                 parent = *new;
 142                 if (swap_offset < ext->start) {
 143                         /* Try to merge */
 144                         if (swap_offset == ext->start - 1) {
 145                                 ext->start--;
 146                                 return 0;
 147                         }
 148                         new = &((*new)->rb_left);
 149                 } else if (swap_offset > ext->end) {
 150                         /* Try to merge */
 151                         if (swap_offset == ext->end + 1) {
 152                                 ext->end++;
 153                                 return 0;
 154                         }
 155                         new = &((*new)->rb_right);
 156                 } else {
 157                         /* It already is in the tree */
 158                         return -EINVAL;
 159                 }
 160         }
 161         /* Add the new node and rebalance the tree. */
 162         ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
 163         if (!ext)
 164                 return -ENOMEM;
 165
 166         ext->start = swap_offset;
 167         ext->end = swap_offset;
 168         rb_link_node(&ext->node, parent, new);
 169         rb_insert_color(&ext->node, &swsusp_extents);
 170         return 0;
 171 }
 172
 173 /*
 174  *      alloc_swapdev_block - allocate a swap page and register that it has
 175  *      been allocated, so that it can be freed in case of an error.
 176  */
 177
 178 sector_t alloc_swapdev_block(int swap)
 179 {
 180         unsigned long offset;
 181
 182         offset = swp_offset(get_swap_page_of_type(swap));
 183         if (offset) {
 184                 if (swsusp_extents_insert(offset))
 185                         swap_free(swp_entry(swap, offset));
 186                 else
 187                         return swapdev_block(swap, offset);
 188         }
 189         return 0;
 190 }
 191
 192 /*
 193  *      free_all_swap_pages - free swap pages allocated for saving image data.
 194  *      It also frees the extents used to register which swap entries had been
 195  *      allocated.
 196  */
 197
 198 void free_all_swap_pages(int swap)
 199 {
 200         struct rb_node *node;
 201
 202         while ((node = swsusp_extents.rb_node)) {
 203                 struct swsusp_extent *ext;
 204                 unsigned long offset;
 205
 206                 ext = rb_entry(node, struct swsusp_extent, node);
 207                 rb_erase(node, &swsusp_extents);
 208                 for (offset = ext->start; offset <= ext->end; offset++)
 209                         swap_free(swp_entry(swap, offset));
 210
 211                 kfree(ext);
 212         }
 213 }
 214
 215 int swsusp_swap_in_use(void)
 216 {
 217         return (swsusp_extents.rb_node != NULL);
 218 }
 219
 220 /*
 221  * General things
 222  */
 223
 224 static unsigned short root_swap = 0xffff;
 225 static struct block_device *hib_resume_bdev;
 226
 227 struct hib_bio_batch {
 228         atomic_t                count;
 229         wait_queue_head_t       wait;
 230         blk_status_t            error;
 231         struct blk_plug         plug;
 232 };
 233
 234 static void hib_init_batch(struct hib_bio_batch *hb)
 235 {
 236         atomic_set(&hb->count, 0);
 237         init_waitqueue_head(&hb->wait);
 238         hb->error = BLK_STS_OK;
 239         blk_start_plug(&hb->plug);
 240 }
 241
 242 static void hib_finish_batch(struct hib_bio_batch *hb)
 243 {
 244         blk_finish_plug(&hb->plug);
 245 }
 246
 247 static void hib_end_io(struct bio *bio)
 248 {
 249         struct hib_bio_batch *hb = bio->bi_private;
 250         struct page *page = bio_first_page_all(bio);
 251
 252         if (bio->bi_status) {
 253                 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
 254                          MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
 255                          (unsigned long long)bio->bi_iter.bi_sector);
 256         }
 257
 258         if (bio_data_dir(bio) == WRITE)
 259                 put_page(page);
 260         else if (clean_pages_on_read)
 261                 flush_icache_range((unsigned long)page_address(page),
 262                                    (unsigned long)page_address(page) + PAGE_SIZE);
 263
 264         if (bio->bi_status && !hb->error)
 265                 hb->error = bio->bi_status;
 266         if (atomic_dec_and_test(&hb->count))
 267                 wake_up(&hb->wait);
 268
 269         bio_put(bio);
 270 }
 271
 272 static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
 273                 struct hib_bio_batch *hb)
 274 {
 275         struct page *page = virt_to_page(addr);
 276         struct bio *bio;
 277         int error = 0;
 278
 279         bio = bio_alloc(hib_resume_bdev, 1, op | op_flags,
 280                         GFP_NOIO | __GFP_HIGH);
 281         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 282
 283         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 284                 pr_err("Adding page to bio failed at %llu\n",
 285                        (unsigned long long)bio->bi_iter.bi_sector);
 286                 bio_put(bio);
 287                 return -EFAULT;
 288         }
 289
 290         if (hb) {
 291                 bio->bi_end_io = hib_end_io;
 292                 bio->bi_private = hb;
 293                 atomic_inc(&hb->count);
 294                 submit_bio(bio);
 295         } else {
 296                 error = submit_bio_wait(bio);
 297                 bio_put(bio);
 298         }
 299
 300         return error;
 301 }
 302
 303 static int hib_wait_io(struct hib_bio_batch *hb)
 304 {
 305         /*
 306          * We are relying on the behavior of blk_plug that a thread with
 307          * a plug will flush the plug list before sleeping.
 308          */
 309         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 310         return blk_status_to_errno(hb->error);
 311 }
 312
 313 /*
 314  * Saving part
 315  */
 316 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 317 {
 318         int error;
 319
 320         hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
 321                       swsusp_header, NULL);
 322         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 323             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 324                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 325                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 326                 swsusp_header->image = handle->first_sector;
 327                 if (swsusp_hardware_signature) {
 328                         swsusp_header->hw_sig = swsusp_hardware_signature;
 329                         flags |= SF_HW_SIG;
 330                 }
 331                 swsusp_header->flags = flags;
 332                 if (flags & SF_CRC32_MODE)
 333                         swsusp_header->crc32 = handle->crc32;
 334                 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
 335                                       swsusp_resume_block, swsusp_header, NULL);
 336         } else {
 337                 pr_err("Swap header not found!\n");
 338                 error = -ENODEV;
 339         }
 340         return error;
 341 }
 342
 343 /**
 344  *      swsusp_swap_check - check if the resume device is a swap device
 345  *      and get its index (if so)
 346  *
 347  *      This is called before saving image
 348  */
 349 static int swsusp_swap_check(void)
 350 {
 351         int res;
 352
 353         if (swsusp_resume_device)
 354                 res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
 355         else
 356                 res = find_first_swap(&swsusp_resume_device);
 357         if (res < 0)
 358                 return res;
 359         root_swap = res;
 360
 361         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, FMODE_WRITE,
 362                         NULL);
 363         if (IS_ERR(hib_resume_bdev))
 364                 return PTR_ERR(hib_resume_bdev);
 365
 366         res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 367         if (res < 0)
 368                 blkdev_put(hib_resume_bdev, FMODE_WRITE);
 369
 370         return res;
 371 }
 372
 373 /**
 374  *      write_page - Write one page to given swap location.
 375  *      @buf:           Address we're writing.
 376  *      @offset:        Offset of the swap page we're writing to.
 377  *      @hb:            bio completion batch
 378  */
 379
 380 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 381 {
 382         void *src;
 383         int ret;
 384
 385         if (!offset)
 386                 return -ENOSPC;
 387
 388         if (hb) {
 389                 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
 390                                               __GFP_NORETRY);
 391                 if (src) {
 392                         copy_page(src, buf);
 393                 } else {
 394                         ret = hib_wait_io(hb); /* Free pages */
 395                         if (ret)
 396                                 return ret;
 397                         src = (void *)__get_free_page(GFP_NOIO |
 398                                                       __GFP_NOWARN |
 399                                                       __GFP_NORETRY);
 400                         if (src) {
 401                                 copy_page(src, buf);
 402                         } else {
 403                                 WARN_ON_ONCE(1);
 404                                 hb = NULL;      /* Go synchronous */
 405                                 src = buf;
 406                         }
 407                 }
 408         } else {
 409                 src = buf;
 410         }
 411         return hib_submit_io(REQ_OP_WRITE, REQ_SYNC, offset, src, hb);
 412 }
 413
 414 static void release_swap_writer(struct swap_map_handle *handle)
 415 {
 416         if (handle->cur)
 417                 free_page((unsigned long)handle->cur);
 418         handle->cur = NULL;
 419 }
 420
 421 static int get_swap_writer(struct swap_map_handle *handle)
 422 {
 423         int ret;
 424
 425         ret = swsusp_swap_check();
 426         if (ret) {
 427                 if (ret != -ENOSPC)
 428                         pr_err("Cannot find swap device, try swapon -a\n");
 429                 return ret;
 430         }
 431         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 432         if (!handle->cur) {
 433                 ret = -ENOMEM;
 434                 goto err_close;
 435         }
 436         handle->cur_swap = alloc_swapdev_block(root_swap);
 437         if (!handle->cur_swap) {
 438                 ret = -ENOSPC;
 439                 goto err_rel;
 440         }
 441         handle->k = 0;
 442         handle->reqd_free_pages = reqd_free_pages();
 443         handle->first_sector = handle->cur_swap;
 444         return 0;
 445 err_rel:
 446         release_swap_writer(handle);
 447 err_close:
 448         swsusp_close(FMODE_WRITE);
 449         return ret;
 450 }
 451
 452 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 453                 struct hib_bio_batch *hb)
 454 {
 455         int error = 0;
 456         sector_t offset;
 457
 458         if (!handle->cur)
 459                 return -EINVAL;
 460         offset = alloc_swapdev_block(root_swap);
 461         error = write_page(buf, offset, hb);
 462         if (error)
 463                 return error;
 464         handle->cur->entries[handle->k++] = offset;
 465         if (handle->k >= MAP_PAGE_ENTRIES) {
 466                 offset = alloc_swapdev_block(root_swap);
 467                 if (!offset)
 468                         return -ENOSPC;
 469                 handle->cur->next_swap = offset;
 470                 error = write_page(handle->cur, handle->cur_swap, hb);
 471                 if (error)
 472                         goto out;
 473                 clear_page(handle->cur);
 474                 handle->cur_swap = offset;
 475                 handle->k = 0;
 476
 477                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 478                         error = hib_wait_io(hb);
 479                         if (error)
 480                                 goto out;
 481                         /*
 482                          * Recalculate the number of required free pages, to
 483                          * make sure we never take more than half.
 484                          */
 485                         handle->reqd_free_pages = reqd_free_pages();
 486                 }
 487         }
 488  out:
 489         return error;
 490 }
 491
 492 static int flush_swap_writer(struct swap_map_handle *handle)
 493 {
 494         if (handle->cur && handle->cur_swap)
 495                 return write_page(handle->cur, handle->cur_swap, NULL);
 496         else
 497                 return -EINVAL;
 498 }
 499
 500 static int swap_writer_finish(struct swap_map_handle *handle,
 501                 unsigned int flags, int error)
 502 {
 503         if (!error) {
 504                 pr_info("S");
 505                 error = mark_swapfiles(handle, flags);
 506                 pr_cont("|\n");
 507                 flush_swap_writer(handle);
 508         }
 509
 510         if (error)
 511                 free_all_swap_pages(root_swap);
 512         release_swap_writer(handle);
 513         swsusp_close(FMODE_WRITE);
 514
 515         return error;
 516 }
 517
 518 /* We need to remember how much compressed data we need to read. */
 519 #define LZO_HEADER      sizeof(size_t)
 520
 521 /* Number of pages/bytes we'll compress at one time. */
 522 #define LZO_UNC_PAGES   32
 523 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 524
 525 /* Number of pages/bytes we need for compressed data (worst case). */
 526 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 527                                      LZO_HEADER, PAGE_SIZE)
 528 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 529
 530 /* Maximum number of threads for compression/decompression. */
 531 #define LZO_THREADS     3
 532
 533 /* Minimum/maximum number of pages for read buffering. */
 534 #define LZO_MIN_RD_PAGES        1024
 535 #define LZO_MAX_RD_PAGES        8192
 536
 537
 538 /**
 539  *      save_image - save the suspend image data
 540  */
 541
 542 static int save_image(struct swap_map_handle *handle,
 543                       struct snapshot_handle *snapshot,
 544                       unsigned int nr_to_write)
 545 {
 546         unsigned int m;
 547         int ret;
 548         int nr_pages;
 549         int err2;
 550         struct hib_bio_batch hb;
 551         ktime_t start;
 552         ktime_t stop;
 553
 554         hib_init_batch(&hb);
 555
 556         pr_info("Saving image data pages (%u pages)...\n",
 557                 nr_to_write);
 558         m = nr_to_write / 10;
 559         if (!m)
 560                 m = 1;
 561         nr_pages = 0;
 562         start = ktime_get();
 563         while (1) {
 564                 ret = snapshot_read_next(snapshot);
 565                 if (ret <= 0)
 566                         break;
 567                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 568                 if (ret)
 569                         break;
 570                 if (!(nr_pages % m))
 571                         pr_info("Image saving progress: %3d%%\n",
 572                                 nr_pages / m * 10);
 573                 nr_pages++;
 574         }
 575         err2 = hib_wait_io(&hb);
 576         hib_finish_batch(&hb);
 577         stop = ktime_get();
 578         if (!ret)
 579                 ret = err2;
 580         if (!ret)
 581                 pr_info("Image saving done\n");
 582         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 583         return ret;
 584 }
 585
 586 /**
 587  * Structure used for CRC32.
 588  */
 589 struct crc_data {
 590         struct task_struct *thr;                  /* thread */
 591         atomic_t ready;                           /* ready to start flag */
 592         atomic_t stop;                            /* ready to stop flag */
 593         unsigned run_threads;                     /* nr current threads */
 594         wait_queue_head_t go;                     /* start crc update */
 595         wait_queue_head_t done;                   /* crc update done */
 596         u32 *crc32;                               /* points to handle's crc32 */
 597         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 598         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 599 };
 600
 601 /**
 602  * CRC32 update function that runs in its own thread.
 603  */
 604 static int crc32_threadfn(void *data)
 605 {
 606         struct crc_data *d = data;
 607         unsigned i;
 608
 609         while (1) {
 610                 wait_event(d->go, atomic_read(&d->ready) ||
 611                                   kthread_should_stop());
 612                 if (kthread_should_stop()) {
 613                         d->thr = NULL;
 614                         atomic_set(&d->stop, 1);
 615                         wake_up(&d->done);
 616                         break;
 617                 }
 618                 atomic_set(&d->ready, 0);
 619
 620                 for (i = 0; i < d->run_threads; i++)
 621                         *d->crc32 = crc32_le(*d->crc32,
 622                                              d->unc[i], *d->unc_len[i]);
 623                 atomic_set(&d->stop, 1);
 624                 wake_up(&d->done);
 625         }
 626         return 0;
 627 }
 628 /**
 629  * Structure used for LZO data compression.
 630  */
 631 struct cmp_data {
 632         struct task_struct *thr;                  /* thread */
 633         atomic_t ready;                           /* ready to start flag */
 634         atomic_t stop;                            /* ready to stop flag */
 635         int ret;                                  /* return code */
 636         wait_queue_head_t go;                     /* start compression */
 637         wait_queue_head_t done;                   /* compression done */
 638         size_t unc_len;                           /* uncompressed length */
 639         size_t cmp_len;                           /* compressed length */
 640         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 641         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 642         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 643 };
 644
 645 /**
 646  * Compression function that runs in its own thread.
 647  */
 648 static int lzo_compress_threadfn(void *data)
 649 {
 650         struct cmp_data *d = data;
 651
 652         while (1) {
 653                 wait_event(d->go, atomic_read(&d->ready) ||
 654                                   kthread_should_stop());
 655                 if (kthread_should_stop()) {
 656                         d->thr = NULL;
 657                         d->ret = -1;
 658                         atomic_set(&d->stop, 1);
 659                         wake_up(&d->done);
 660                         break;
 661                 }
 662                 atomic_set(&d->ready, 0);
 663
 664                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 665                                           d->cmp + LZO_HEADER, &d->cmp_len,
 666                                           d->wrk);
 667                 atomic_set(&d->stop, 1);
 668                 wake_up(&d->done);
 669         }
 670         return 0;
 671 }
 672
 673 /**
 674  * save_image_lzo - Save the suspend image data compressed with LZO.
 675  * @handle: Swap map handle to use for saving the image.
 676  * @snapshot: Image to read data from.
 677  * @nr_to_write: Number of pages to save.
 678  */
 679 static int save_image_lzo(struct swap_map_handle *handle,
 680                           struct snapshot_handle *snapshot,
 681                           unsigned int nr_to_write)
 682 {
 683         unsigned int m;
 684         int ret = 0;
 685         int nr_pages;
 686         int err2;
 687         struct hib_bio_batch hb;
 688         ktime_t start;
 689         ktime_t stop;
 690         size_t off;
 691         unsigned thr, run_threads, nr_threads;
 692         unsigned char *page = NULL;
 693         struct cmp_data *data = NULL;
 694         struct crc_data *crc = NULL;
 695
 696         hib_init_batch(&hb);
 697
 698         /*
 699          * We'll limit the number of threads for compression to limit memory
 700          * footprint.
 701          */
 702         nr_threads = num_online_cpus() - 1;
 703         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 704
 705         page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
 706         if (!page) {
 707                 pr_err("Failed to allocate LZO page\n");
 708                 ret = -ENOMEM;
 709                 goto out_clean;
 710         }
 711
 712         data = vzalloc(array_size(nr_threads, sizeof(*data)));
 713         if (!data) {
 714                 pr_err("Failed to allocate LZO data\n");
 715                 ret = -ENOMEM;
 716                 goto out_clean;
 717         }
 718
 719         crc = kzalloc(sizeof(*crc), GFP_KERNEL);
 720         if (!crc) {
 721                 pr_err("Failed to allocate crc\n");
 722                 ret = -ENOMEM;
 723                 goto out_clean;
 724         }
 725
 726         /*
 727          * Start the compression threads.
 728          */
 729         for (thr = 0; thr < nr_threads; thr++) {
 730                 init_waitqueue_head(&data[thr].go);
 731                 init_waitqueue_head(&data[thr].done);
 732
 733                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 734                                             &data[thr],
 735                                             "image_compress/%u", thr);
 736                 if (IS_ERR(data[thr].thr)) {
 737                         data[thr].thr = NULL;
 738                         pr_err("Cannot start compression threads\n");
 739                         ret = -ENOMEM;
 740                         goto out_clean;
 741                 }
 742         }
 743
 744         /*
 745          * Start the CRC32 thread.
 746          */
 747         init_waitqueue_head(&crc->go);
 748         init_waitqueue_head(&crc->done);
 749
 750         handle->crc32 = 0;
 751         crc->crc32 = &handle->crc32;
 752         for (thr = 0; thr < nr_threads; thr++) {
 753                 crc->unc[thr] = data[thr].unc;
 754                 crc->unc_len[thr] = &data[thr].unc_len;
 755         }
 756
 757         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 758         if (IS_ERR(crc->thr)) {
 759                 crc->thr = NULL;
 760                 pr_err("Cannot start CRC32 thread\n");
 761                 ret = -ENOMEM;
 762                 goto out_clean;
 763         }
 764
 765         /*
 766          * Adjust the number of required free pages after all allocations have
 767          * been done. We don't want to run out of pages when writing.
 768          */
 769         handle->reqd_free_pages = reqd_free_pages();
 770
 771         pr_info("Using %u thread(s) for compression\n", nr_threads);
 772         pr_info("Compressing and saving image data (%u pages)...\n",
 773                 nr_to_write);
 774         m = nr_to_write / 10;
 775         if (!m)
 776                 m = 1;
 777         nr_pages = 0;
 778         start = ktime_get();
 779         for (;;) {
 780                 for (thr = 0; thr < nr_threads; thr++) {
 781                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 782                                 ret = snapshot_read_next(snapshot);
 783                                 if (ret < 0)
 784                                         goto out_finish;
 785
 786                                 if (!ret)
 787                                         break;
 788
 789                                 memcpy(data[thr].unc + off,
 790                                        data_of(*snapshot), PAGE_SIZE);
 791
 792                                 if (!(nr_pages % m))
 793                                         pr_info("Image saving progress: %3d%%\n",
 794                                                 nr_pages / m * 10);
 795                                 nr_pages++;
 796                         }
 797                         if (!off)
 798                                 break;
 799
 800                         data[thr].unc_len = off;
 801
 802                         atomic_set(&data[thr].ready, 1);
 803                         wake_up(&data[thr].go);
 804                 }
 805
 806                 if (!thr)
 807                         break;
 808
 809                 crc->run_threads = thr;
 810                 atomic_set(&crc->ready, 1);
 811                 wake_up(&crc->go);
 812
 813                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 814                         wait_event(data[thr].done,
 815                                    atomic_read(&data[thr].stop));
 816                         atomic_set(&data[thr].stop, 0);
 817
 818                         ret = data[thr].ret;
 819
 820                         if (ret < 0) {
 821                                 pr_err("LZO compression failed\n");
 822                                 goto out_finish;
 823                         }
 824
 825                         if (unlikely(!data[thr].cmp_len ||
 826                                      data[thr].cmp_len >
 827                                      lzo1x_worst_compress(data[thr].unc_len))) {
 828                                 pr_err("Invalid LZO compressed length\n");
 829                                 ret = -1;
 830                                 goto out_finish;
 831                         }
 832
 833                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 834
 835                         /*
 836                          * Given we are writing one page at a time to disk, we
 837                          * copy that much from the buffer, although the last
 838                          * bit will likely be smaller than full page. This is
 839                          * OK - we saved the length of the compressed data, so
 840                          * any garbage at the end will be discarded when we
 841                          * read it.
 842                          */
 843                         for (off = 0;
 844                              off < LZO_HEADER + data[thr].cmp_len;
 845                              off += PAGE_SIZE) {
 846                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 847
 848                                 ret = swap_write_page(handle, page, &hb);
 849                                 if (ret)
 850                                         goto out_finish;
 851                         }
 852                 }
 853
 854                 wait_event(crc->done, atomic_read(&crc->stop));
 855                 atomic_set(&crc->stop, 0);
 856         }
 857
 858 out_finish:
 859         err2 = hib_wait_io(&hb);
 860         stop = ktime_get();
 861         if (!ret)
 862                 ret = err2;
 863         if (!ret)
 864                 pr_info("Image saving done\n");
 865         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 866 out_clean:
 867         hib_finish_batch(&hb);
 868         if (crc) {
 869                 if (crc->thr)
 870                         kthread_stop(crc->thr);
 871                 kfree(crc);
 872         }
 873         if (data) {
 874                 for (thr = 0; thr < nr_threads; thr++)
 875                         if (data[thr].thr)
 876                                 kthread_stop(data[thr].thr);
 877                 vfree(data);
 878         }
 879         if (page) free_page((unsigned long)page);
 880
 881         return ret;
 882 }
 883
 884 /**
 885  *      enough_swap - Make sure we have enough swap to save the image.
 886  *
 887  *      Returns TRUE or FALSE after checking the total amount of swap
 888  *      space available from the resume partition.
 889  */
 890
 891 static int enough_swap(unsigned int nr_pages)
 892 {
 893         unsigned int free_swap = count_swap_pages(root_swap, 1);
 894         unsigned int required;
 895
 896         pr_debug("Free swap pages: %u\n", free_swap);
 897
 898         required = PAGES_FOR_IO + nr_pages;
 899         return free_swap > required;
 900 }
 901
 902 /**
 903  *      swsusp_write - Write entire image and metadata.
 904  *      @flags: flags to pass to the "boot" kernel in the image header
 905  *
 906  *      It is important _NOT_ to umount filesystems at this point. We want
 907  *      them synced (in case something goes wrong) but we DO not want to mark
 908  *      filesystem clean: it is not. (And it does not matter, if we resume
 909  *      correctly, we'll mark system clean, anyway.)
 910  */
 911
 912 int swsusp_write(unsigned int flags)
 913 {
 914         struct swap_map_handle handle;
 915         struct snapshot_handle snapshot;
 916         struct swsusp_info *header;
 917         unsigned long pages;
 918         int error;
 919
 920         pages = snapshot_get_image_size();
 921         error = get_swap_writer(&handle);
 922         if (error) {
 923                 pr_err("Cannot get swap writer\n");
 924                 return error;
 925         }
 926         if (flags & SF_NOCOMPRESS_MODE) {
 927                 if (!enough_swap(pages)) {
 928                         pr_err("Not enough free swap\n");
 929                         error = -ENOSPC;
 930                         goto out_finish;
 931                 }
 932         }
 933         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 934         error = snapshot_read_next(&snapshot);
 935         if (error < (int)PAGE_SIZE) {
 936                 if (error >= 0)
 937                         error = -EFAULT;
 938
 939                 goto out_finish;
 940         }
 941         header = (struct swsusp_info *)data_of(snapshot);
 942         error = swap_write_page(&handle, header, NULL);
 943         if (!error) {
 944                 error = (flags & SF_NOCOMPRESS_MODE) ?
 945                         save_image(&handle, &snapshot, pages - 1) :
 946                         save_image_lzo(&handle, &snapshot, pages - 1);
 947         }
 948 out_finish:
 949         error = swap_writer_finish(&handle, flags, error);
 950         return error;
 951 }
 952
 953 /**
 954  *      The following functions allow us to read data using a swap map
 955  *      in a file-alike way
 956  */
 957
 958 static void release_swap_reader(struct swap_map_handle *handle)
 959 {
 960         struct swap_map_page_list *tmp;
 961
 962         while (handle->maps) {
 963                 if (handle->maps->map)
 964                         free_page((unsigned long)handle->maps->map);
 965                 tmp = handle->maps;
 966                 handle->maps = handle->maps->next;
 967                 kfree(tmp);
 968         }
 969         handle->cur = NULL;
 970 }
 971
 972 static int get_swap_reader(struct swap_map_handle *handle,
 973                 unsigned int *flags_p)
 974 {
 975         int error;
 976         struct swap_map_page_list *tmp, *last;
 977         sector_t offset;
 978
 979         *flags_p = swsusp_header->flags;
 980
 981         if (!swsusp_header->image) /* how can this happen? */
 982                 return -EINVAL;
 983
 984         handle->cur = NULL;
 985         last = handle->maps = NULL;
 986         offset = swsusp_header->image;
 987         while (offset) {
 988                 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
 989                 if (!tmp) {
 990                         release_swap_reader(handle);
 991                         return -ENOMEM;
 992                 }
 993                 if (!handle->maps)
 994                         handle->maps = tmp;
 995                 if (last)
 996                         last->next = tmp;
 997                 last = tmp;
 998
 999                 tmp->map = (struct swap_map_page *)
1000                            __get_free_page(GFP_NOIO | __GFP_HIGH);
1001                 if (!tmp->map) {
1002                         release_swap_reader(handle);
1003                         return -ENOMEM;
1004                 }
1005
1006                 error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL);
1007                 if (error) {
1008                         release_swap_reader(handle);
1009                         return error;
1010                 }
1011                 offset = tmp->map->next_swap;
1012         }
1013         handle->k = 0;
1014         handle->cur = handle->maps->map;
1015         return 0;
1016 }
1017
1018 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1019                 struct hib_bio_batch *hb)
1020 {
1021         sector_t offset;
1022         int error;
1023         struct swap_map_page_list *tmp;
1024
1025         if (!handle->cur)
1026                 return -EINVAL;
1027         offset = handle->cur->entries[handle->k];
1028         if (!offset)
1029                 return -EFAULT;
1030         error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb);
1031         if (error)
1032                 return error;
1033         if (++handle->k >= MAP_PAGE_ENTRIES) {
1034                 handle->k = 0;
1035                 free_page((unsigned long)handle->maps->map);
1036                 tmp = handle->maps;
1037                 handle->maps = handle->maps->next;
1038                 kfree(tmp);
1039                 if (!handle->maps)
1040                         release_swap_reader(handle);
1041                 else
1042                         handle->cur = handle->maps->map;
1043         }
1044         return error;
1045 }
1046
1047 static int swap_reader_finish(struct swap_map_handle *handle)
1048 {
1049         release_swap_reader(handle);
1050
1051         return 0;
1052 }
1053
1054 /**
1055  *      load_image - load the image using the swap map handle
1056  *      @handle and the snapshot handle @snapshot
1057  *      (assume there are @nr_pages pages to load)
1058  */
1059
1060 static int load_image(struct swap_map_handle *handle,
1061                       struct snapshot_handle *snapshot,
1062                       unsigned int nr_to_read)
1063 {
1064         unsigned int m;
1065         int ret = 0;
1066         ktime_t start;
1067         ktime_t stop;
1068         struct hib_bio_batch hb;
1069         int err2;
1070         unsigned nr_pages;
1071
1072         hib_init_batch(&hb);
1073
1074         clean_pages_on_read = true;
1075         pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1076         m = nr_to_read / 10;
1077         if (!m)
1078                 m = 1;
1079         nr_pages = 0;
1080         start = ktime_get();
1081         for ( ; ; ) {
1082                 ret = snapshot_write_next(snapshot);
1083                 if (ret <= 0)
1084                         break;
1085                 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1086                 if (ret)
1087                         break;
1088                 if (snapshot->sync_read)
1089                         ret = hib_wait_io(&hb);
1090                 if (ret)
1091                         break;
1092                 if (!(nr_pages % m))
1093                         pr_info("Image loading progress: %3d%%\n",
1094                                 nr_pages / m * 10);
1095                 nr_pages++;
1096         }
1097         err2 = hib_wait_io(&hb);
1098         hib_finish_batch(&hb);
1099         stop = ktime_get();
1100         if (!ret)
1101                 ret = err2;
1102         if (!ret) {
1103                 pr_info("Image loading done\n");
1104                 snapshot_write_finalize(snapshot);
1105                 if (!snapshot_image_loaded(snapshot))
1106                         ret = -ENODATA;
1107         }
1108         swsusp_show_speed(start, stop, nr_to_read, "Read");
1109         return ret;
1110 }
1111
1112 /**
1113  * Structure used for LZO data decompression.
1114  */
1115 struct dec_data {
1116         struct task_struct *thr;                  /* thread */
1117         atomic_t ready;                           /* ready to start flag */
1118         atomic_t stop;                            /* ready to stop flag */
1119         int ret;                                  /* return code */
1120         wait_queue_head_t go;                     /* start decompression */
1121         wait_queue_head_t done;                   /* decompression done */
1122         size_t unc_len;                           /* uncompressed length */
1123         size_t cmp_len;                           /* compressed length */
1124         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1125         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1126 };
1127
1128 /**
1129  * Decompression function that runs in its own thread.
1130  */
1131 static int lzo_decompress_threadfn(void *data)
1132 {
1133         struct dec_data *d = data;
1134
1135         while (1) {
1136                 wait_event(d->go, atomic_read(&d->ready) ||
1137                                   kthread_should_stop());
1138                 if (kthread_should_stop()) {
1139                         d->thr = NULL;
1140                         d->ret = -1;
1141                         atomic_set(&d->stop, 1);
1142                         wake_up(&d->done);
1143                         break;
1144                 }
1145                 atomic_set(&d->ready, 0);
1146
1147                 d->unc_len = LZO_UNC_SIZE;
1148                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1149                                                d->unc, &d->unc_len);
1150                 if (clean_pages_on_decompress)
1151                         flush_icache_range((unsigned long)d->unc,
1152                                            (unsigned long)d->unc + d->unc_len);
1153
1154                 atomic_set(&d->stop, 1);
1155                 wake_up(&d->done);
1156         }
1157         return 0;
1158 }
1159
1160 /**
1161  * load_image_lzo - Load compressed image data and decompress them with LZO.
1162  * @handle: Swap map handle to use for loading data.
1163  * @snapshot: Image to copy uncompressed data into.
1164  * @nr_to_read: Number of pages to load.
1165  */
1166 static int load_image_lzo(struct swap_map_handle *handle,
1167                           struct snapshot_handle *snapshot,
1168                           unsigned int nr_to_read)
1169 {
1170         unsigned int m;
1171         int ret = 0;
1172         int eof = 0;
1173         struct hib_bio_batch hb;
1174         ktime_t start;
1175         ktime_t stop;
1176         unsigned nr_pages;
1177         size_t off;
1178         unsigned i, thr, run_threads, nr_threads;
1179         unsigned ring = 0, pg = 0, ring_size = 0,
1180                  have = 0, want, need, asked = 0;
1181         unsigned long read_pages = 0;
1182         unsigned char **page = NULL;
1183         struct dec_data *data = NULL;
1184         struct crc_data *crc = NULL;
1185
1186         hib_init_batch(&hb);
1187
1188         /*
1189          * We'll limit the number of threads for decompression to limit memory
1190          * footprint.
1191          */
1192         nr_threads = num_online_cpus() - 1;
1193         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1194
1195         page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
1196         if (!page) {
1197                 pr_err("Failed to allocate LZO page\n");
1198                 ret = -ENOMEM;
1199                 goto out_clean;
1200         }
1201
1202         data = vzalloc(array_size(nr_threads, sizeof(*data)));
1203         if (!data) {
1204                 pr_err("Failed to allocate LZO data\n");
1205                 ret = -ENOMEM;
1206                 goto out_clean;
1207         }
1208
1209         crc = kzalloc(sizeof(*crc), GFP_KERNEL);
1210         if (!crc) {
1211                 pr_err("Failed to allocate crc\n");
1212                 ret = -ENOMEM;
1213                 goto out_clean;
1214         }
1215
1216         clean_pages_on_decompress = true;
1217
1218         /*
1219          * Start the decompression threads.
1220          */
1221         for (thr = 0; thr < nr_threads; thr++) {
1222                 init_waitqueue_head(&data[thr].go);
1223                 init_waitqueue_head(&data[thr].done);
1224
1225                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1226                                             &data[thr],
1227                                             "image_decompress/%u", thr);
1228                 if (IS_ERR(data[thr].thr)) {
1229                         data[thr].thr = NULL;
1230                         pr_err("Cannot start decompression threads\n");
1231                         ret = -ENOMEM;
1232                         goto out_clean;
1233                 }
1234         }
1235
1236         /*
1237          * Start the CRC32 thread.
1238          */
1239         init_waitqueue_head(&crc->go);
1240         init_waitqueue_head(&crc->done);
1241
1242         handle->crc32 = 0;
1243         crc->crc32 = &handle->crc32;
1244         for (thr = 0; thr < nr_threads; thr++) {
1245                 crc->unc[thr] = data[thr].unc;
1246                 crc->unc_len[thr] = &data[thr].unc_len;
1247         }
1248
1249         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1250         if (IS_ERR(crc->thr)) {
1251                 crc->thr = NULL;
1252                 pr_err("Cannot start CRC32 thread\n");
1253                 ret = -ENOMEM;
1254                 goto out_clean;
1255         }
1256
1257         /*
1258          * Set the number of pages for read buffering.
1259          * This is complete guesswork, because we'll only know the real
1260          * picture once prepare_image() is called, which is much later on
1261          * during the image load phase. We'll assume the worst case and
1262          * say that none of the image pages are from high memory.
1263          */
1264         if (low_free_pages() > snapshot_get_image_size())
1265                 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1266         read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1267
1268         for (i = 0; i < read_pages; i++) {
1269                 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1270                                                   GFP_NOIO | __GFP_HIGH :
1271                                                   GFP_NOIO | __GFP_NOWARN |
1272                                                   __GFP_NORETRY);
1273
1274                 if (!page[i]) {
1275                         if (i < LZO_CMP_PAGES) {
1276                                 ring_size = i;
1277                                 pr_err("Failed to allocate LZO pages\n");
1278                                 ret = -ENOMEM;
1279                                 goto out_clean;
1280                         } else {
1281                                 break;
1282                         }
1283                 }
1284         }
1285         want = ring_size = i;
1286
1287         pr_info("Using %u thread(s) for decompression\n", nr_threads);
1288         pr_info("Loading and decompressing image data (%u pages)...\n",
1289                 nr_to_read);
1290         m = nr_to_read / 10;
1291         if (!m)
1292                 m = 1;
1293         nr_pages = 0;
1294         start = ktime_get();
1295
1296         ret = snapshot_write_next(snapshot);
1297         if (ret <= 0)
1298                 goto out_finish;
1299
1300         for(;;) {
1301                 for (i = 0; !eof && i < want; i++) {
1302                         ret = swap_read_page(handle, page[ring], &hb);
1303                         if (ret) {
1304                                 /*
1305                                  * On real read error, finish. On end of data,
1306                                  * set EOF flag and just exit the read loop.
1307                                  */
1308                                 if (handle->cur &&
1309                                     handle->cur->entries[handle->k]) {
1310                                         goto out_finish;
1311                                 } else {
1312                                         eof = 1;
1313                                         break;
1314                                 }
1315                         }
1316                         if (++ring >= ring_size)
1317                                 ring = 0;
1318                 }
1319                 asked += i;
1320                 want -= i;
1321
1322                 /*
1323                  * We are out of data, wait for some more.
1324                  */
1325                 if (!have) {
1326                         if (!asked)
1327                                 break;
1328
1329                         ret = hib_wait_io(&hb);
1330                         if (ret)
1331                                 goto out_finish;
1332                         have += asked;
1333                         asked = 0;
1334                         if (eof)
1335                                 eof = 2;
1336                 }
1337
1338                 if (crc->run_threads) {
1339                         wait_event(crc->done, atomic_read(&crc->stop));
1340                         atomic_set(&crc->stop, 0);
1341                         crc->run_threads = 0;
1342                 }
1343
1344                 for (thr = 0; have && thr < nr_threads; thr++) {
1345                         data[thr].cmp_len = *(size_t *)page[pg];
1346                         if (unlikely(!data[thr].cmp_len ||
1347                                      data[thr].cmp_len >
1348                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1349                                 pr_err("Invalid LZO compressed length\n");
1350                                 ret = -1;
1351                                 goto out_finish;
1352                         }
1353
1354                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1355                                             PAGE_SIZE);
1356                         if (need > have) {
1357                                 if (eof > 1) {
1358                                         ret = -1;
1359                                         goto out_finish;
1360                                 }
1361                                 break;
1362                         }
1363
1364                         for (off = 0;
1365                              off < LZO_HEADER + data[thr].cmp_len;
1366                              off += PAGE_SIZE) {
1367                                 memcpy(data[thr].cmp + off,
1368                                        page[pg], PAGE_SIZE);
1369                                 have--;
1370                                 want++;
1371                                 if (++pg >= ring_size)
1372                                         pg = 0;
1373                         }
1374
1375                         atomic_set(&data[thr].ready, 1);
1376                         wake_up(&data[thr].go);
1377                 }
1378
1379                 /*
1380                  * Wait for more data while we are decompressing.
1381                  */
1382                 if (have < LZO_CMP_PAGES && asked) {
1383                         ret = hib_wait_io(&hb);
1384                         if (ret)
1385                                 goto out_finish;
1386                         have += asked;
1387                         asked = 0;
1388                         if (eof)
1389                                 eof = 2;
1390                 }
1391
1392                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1393                         wait_event(data[thr].done,
1394                                    atomic_read(&data[thr].stop));
1395                         atomic_set(&data[thr].stop, 0);
1396
1397                         ret = data[thr].ret;
1398
1399                         if (ret < 0) {
1400                                 pr_err("LZO decompression failed\n");
1401                                 goto out_finish;
1402                         }
1403
1404                         if (unlikely(!data[thr].unc_len ||
1405                                      data[thr].unc_len > LZO_UNC_SIZE ||
1406                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1407                                 pr_err("Invalid LZO uncompressed length\n");
1408                                 ret = -1;
1409                                 goto out_finish;
1410                         }
1411
1412                         for (off = 0;
1413                              off < data[thr].unc_len; off += PAGE_SIZE) {
1414                                 memcpy(data_of(*snapshot),
1415                                        data[thr].unc + off, PAGE_SIZE);
1416
1417                                 if (!(nr_pages % m))
1418                                         pr_info("Image loading progress: %3d%%\n",
1419                                                 nr_pages / m * 10);
1420                                 nr_pages++;
1421
1422                                 ret = snapshot_write_next(snapshot);
1423                                 if (ret <= 0) {
1424                                         crc->run_threads = thr + 1;
1425                                         atomic_set(&crc->ready, 1);
1426                                         wake_up(&crc->go);
1427                                         goto out_finish;
1428                                 }
1429                         }
1430                 }
1431
1432                 crc->run_threads = thr;
1433                 atomic_set(&crc->ready, 1);
1434                 wake_up(&crc->go);
1435         }
1436
1437 out_finish:
1438         if (crc->run_threads) {
1439                 wait_event(crc->done, atomic_read(&crc->stop));
1440                 atomic_set(&crc->stop, 0);
1441         }
1442         stop = ktime_get();
1443         if (!ret) {
1444                 pr_info("Image loading done\n");
1445                 snapshot_write_finalize(snapshot);
1446                 if (!snapshot_image_loaded(snapshot))
1447                         ret = -ENODATA;
1448                 if (!ret) {
1449                         if (swsusp_header->flags & SF_CRC32_MODE) {
1450                                 if(handle->crc32 != swsusp_header->crc32) {
1451                                         pr_err("Invalid image CRC32!\n");
1452                                         ret = -ENODATA;
1453                                 }
1454                         }
1455                 }
1456         }
1457         swsusp_show_speed(start, stop, nr_to_read, "Read");
1458 out_clean:
1459         hib_finish_batch(&hb);
1460         for (i = 0; i < ring_size; i++)
1461                 free_page((unsigned long)page[i]);
1462         if (crc) {
1463                 if (crc->thr)
1464                         kthread_stop(crc->thr);
1465                 kfree(crc);
1466         }
1467         if (data) {
1468                 for (thr = 0; thr < nr_threads; thr++)
1469                         if (data[thr].thr)
1470                                 kthread_stop(data[thr].thr);
1471                 vfree(data);
1472         }
1473         vfree(page);
1474
1475         return ret;
1476 }
1477
1478 /**
1479  *      swsusp_read - read the hibernation image.
1480  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1481  *                be written into this memory location
1482  */
1483
1484 int swsusp_read(unsigned int *flags_p)
1485 {
1486         int error;
1487         struct swap_map_handle handle;
1488         struct snapshot_handle snapshot;
1489         struct swsusp_info *header;
1490
1491         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1492         error = snapshot_write_next(&snapshot);
1493         if (error < (int)PAGE_SIZE)
1494                 return error < 0 ? error : -EFAULT;
1495         header = (struct swsusp_info *)data_of(snapshot);
1496         error = get_swap_reader(&handle, flags_p);
1497         if (error)
1498                 goto end;
1499         if (!error)
1500                 error = swap_read_page(&handle, header, NULL);
1501         if (!error) {
1502                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1503                         load_image(&handle, &snapshot, header->pages - 1) :
1504                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1505         }
1506         swap_reader_finish(&handle);
1507 end:
1508         if (!error)
1509                 pr_debug("Image successfully loaded\n");
1510         else
1511                 pr_debug("Error %d resuming\n", error);
1512         return error;
1513 }
1514
1515 /**
1516  *      swsusp_check - Check for swsusp signature in the resume device
1517  */
1518
1519 int swsusp_check(void)
1520 {
1521         int error;
1522         void *holder;
1523
1524         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1525                                             FMODE_READ | FMODE_EXCL, &holder);
1526         if (!IS_ERR(hib_resume_bdev)) {
1527                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1528                 clear_page(swsusp_header);
1529                 error = hib_submit_io(REQ_OP_READ, 0,
1530                                         swsusp_resume_block,
1531                                         swsusp_header, NULL);
1532                 if (error)
1533                         goto put;
1534
1535                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1536                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1537                         /* Reset swap signature now */
1538                         error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1539                                                 swsusp_resume_block,
1540                                                 swsusp_header, NULL);
1541                 } else {
1542                         error = -EINVAL;
1543                 }
1544                 if (!error && swsusp_header->flags & SF_HW_SIG &&
1545                     swsusp_header->hw_sig != swsusp_hardware_signature) {
1546                         pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
1547                                 swsusp_header->hw_sig, swsusp_hardware_signature);
1548                         error = -EINVAL;
1549                 }
1550
1551 put:
1552                 if (error)
1553                         blkdev_put(hib_resume_bdev, FMODE_READ | FMODE_EXCL);
1554                 else
1555                         pr_debug("Image signature found, resuming\n");
1556         } else {
1557                 error = PTR_ERR(hib_resume_bdev);
1558         }
1559
1560         if (error)
1561                 pr_debug("Image not found (code %d)\n", error);
1562
1563         return error;
1564 }
1565
1566 /**
1567  *      swsusp_close - close swap device.
1568  */
1569
1570 void swsusp_close(fmode_t mode)
1571 {
1572         if (IS_ERR(hib_resume_bdev)) {
1573                 pr_debug("Image device not initialised\n");
1574                 return;
1575         }
1576
1577         blkdev_put(hib_resume_bdev, mode);
1578 }
1579
1580 /**
1581  *      swsusp_unmark - Unmark swsusp signature in the resume device
1582  */
1583
1584 #ifdef CONFIG_SUSPEND
1585 int swsusp_unmark(void)
1586 {
1587         int error;
1588
1589         hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
1590                       swsusp_header, NULL);
1591         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1592                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1593                 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1594                                         swsusp_resume_block,
1595                                         swsusp_header, NULL);
1596         } else {
1597                 pr_err("Cannot find swsusp signature!\n");
1598                 error = -ENODEV;
1599         }
1600
1601         /*
1602          * We just returned from suspend, we don't need the image any more.
1603          */
1604         free_all_swap_pages(root_swap);
1605
1606         return error;
1607 }
1608 #endif
1609
1610 static int __init swsusp_header_init(void)
1611 {
1612         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1613         if (!swsusp_header)
1614                 panic("Could not allocate memory for swsusp_header\n");
1615         return 0;
1616 }
1617
1618 core_initcall(swsusp_header_init);