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/genhd.h>
  20 #include <linux/device.h>
  21 #include <linux/bio.h>
  22 #include <linux/blkdev.h>
  23 #include <linux/swap.h>
  24 #include <linux/swapops.h>
  25 #include <linux/pm.h>
  26 #include <linux/slab.h>
  27 #include <linux/lzo.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/cpumask.h>
  30 #include <linux/atomic.h>
  31 #include <linux/kthread.h>
  32 #include <linux/crc32.h>
  33 #include <linux/ktime.h>
  34
  35 #include "power.h"
  36
  37 #define HIBERNATE_SIG   "S1SUSPEND"
  38
  39 u32 swsusp_hardware_signature;
  40
  41 /*
  42  * When reading an {un,}compressed image, we may restore pages in place,
  43  * in which case some architectures need these pages cleaning before they
  44  * can be executed. We don't know which pages these may be, so clean the lot.
  45  */
  46 static bool clean_pages_on_read;
  47 static bool clean_pages_on_decompress;
  48
  49 /*
  50  *      The swap map is a data structure used for keeping track of each page
  51  *      written to a swap partition.  It consists of many swap_map_page
  52  *      structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
  53  *      These structures are stored on the swap and linked together with the
  54  *      help of the .next_swap member.
  55  *
  56  *      The swap map is created during suspend.  The swap map pages are
  57  *      allocated and populated one at a time, so we only need one memory
  58  *      page to set up the entire structure.
  59  *
  60  *      During resume we pick up all swap_map_page structures into a list.
  61  */
  62
  63 #define MAP_PAGE_ENTRIES        (PAGE_SIZE / sizeof(sector_t) - 1)
  64
  65 /*
  66  * Number of free pages that are not high.
  67  */
  68 static inline unsigned long low_free_pages(void)
  69 {
  70         return nr_free_pages() - nr_free_highpages();
  71 }
  72
  73 /*
  74  * Number of pages required to be kept free while writing the image. Always
  75  * half of all available low pages before the writing starts.
  76  */
  77 static inline unsigned long reqd_free_pages(void)
  78 {
  79         return low_free_pages() / 2;
  80 }
  81
  82 struct swap_map_page {
  83         sector_t entries[MAP_PAGE_ENTRIES];
  84         sector_t next_swap;
  85 };
  86
  87 struct swap_map_page_list {
  88         struct swap_map_page *map;
  89         struct swap_map_page_list *next;
  90 };
  91
  92 /**
  93  *      The swap_map_handle structure is used for handling swap in
  94  *      a file-alike way
  95  */
  96
  97 struct swap_map_handle {
  98         struct swap_map_page *cur;
  99         struct swap_map_page_list *maps;
 100         sector_t cur_swap;
 101         sector_t first_sector;
 102         unsigned int k;
 103         unsigned long reqd_free_pages;
 104         u32 crc32;
 105 };
 106
 107 struct swsusp_header {
 108         char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
 109                       sizeof(u32) - sizeof(u32)];
 110         u32     hw_sig;
 111         u32     crc32;
 112         sector_t image;
 113         unsigned int flags;     /* Flags to pass to the "boot" kernel */
 114         char    orig_sig[10];
 115         char    sig[10];
 116 } __packed;
 117
 118 static struct swsusp_header *swsusp_header;
 119
 120 /**
 121  *      The following functions are used for tracing the allocated
 122  *      swap pages, so that they can be freed in case of an error.
 123  */
 124
 125 struct swsusp_extent {
 126         struct rb_node node;
 127         unsigned long start;
 128         unsigned long end;
 129 };
 130
 131 static struct rb_root swsusp_extents = RB_ROOT;
 132
 133 static int swsusp_extents_insert(unsigned long swap_offset)
 134 {
 135         struct rb_node **new = &(swsusp_extents.rb_node);
 136         struct rb_node *parent = NULL;
 137         struct swsusp_extent *ext;
 138
 139         /* Figure out where to put the new node */
 140         while (*new) {
 141                 ext = rb_entry(*new, struct swsusp_extent, node);
 142                 parent = *new;
 143                 if (swap_offset < ext->start) {
 144                         /* Try to merge */
 145                         if (swap_offset == ext->start - 1) {
 146                                 ext->start--;
 147                                 return 0;
 148                         }
 149                         new = &((*new)->rb_left);
 150                 } else if (swap_offset > ext->end) {
 151                         /* Try to merge */
 152                         if (swap_offset == ext->end + 1) {
 153                                 ext->end++;
 154                                 return 0;
 155                         }
 156                         new = &((*new)->rb_right);
 157                 } else {
 158                         /* It already is in the tree */
 159                         return -EINVAL;
 160                 }
 161         }
 162         /* Add the new node and rebalance the tree. */
 163         ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
 164         if (!ext)
 165                 return -ENOMEM;
 166
 167         ext->start = swap_offset;
 168         ext->end = swap_offset;
 169         rb_link_node(&ext->node, parent, new);
 170         rb_insert_color(&ext->node, &swsusp_extents);
 171         return 0;
 172 }
 173
 174 /**
 175  *      alloc_swapdev_block - allocate a swap page and register that it has
 176  *      been allocated, so that it can be freed in case of an error.
 177  */
 178
 179 sector_t alloc_swapdev_block(int swap)
 180 {
 181         unsigned long offset;
 182
 183         offset = swp_offset(get_swap_page_of_type(swap));
 184         if (offset) {
 185                 if (swsusp_extents_insert(offset))
 186                         swap_free(swp_entry(swap, offset));
 187                 else
 188                         return swapdev_block(swap, offset);
 189         }
 190         return 0;
 191 }
 192
 193 /**
 194  *      free_all_swap_pages - free swap pages allocated for saving image data.
 195  *      It also frees the extents used to register which swap entries had been
 196  *      allocated.
 197  */
 198
 199 void free_all_swap_pages(int swap)
 200 {
 201         struct rb_node *node;
 202
 203         while ((node = swsusp_extents.rb_node)) {
 204                 struct swsusp_extent *ext;
 205                 unsigned long offset;
 206
 207                 ext = rb_entry(node, struct swsusp_extent, node);
 208                 rb_erase(node, &swsusp_extents);
 209                 for (offset = ext->start; offset <= ext->end; offset++)
 210                         swap_free(swp_entry(swap, offset));
 211
 212                 kfree(ext);
 213         }
 214 }
 215
 216 int swsusp_swap_in_use(void)
 217 {
 218         return (swsusp_extents.rb_node != NULL);
 219 }
 220
 221 /*
 222  * General things
 223  */
 224
 225 static unsigned short root_swap = 0xffff;
 226 static struct block_device *hib_resume_bdev;
 227
 228 struct hib_bio_batch {
 229         atomic_t                count;
 230         wait_queue_head_t       wait;
 231         blk_status_t            error;
 232         struct blk_plug         plug;
 233 };
 234
 235 static void hib_init_batch(struct hib_bio_batch *hb)
 236 {
 237         atomic_set(&hb->count, 0);
 238         init_waitqueue_head(&hb->wait);
 239         hb->error = BLK_STS_OK;
 240         blk_start_plug(&hb->plug);
 241 }
 242
 243 static void hib_finish_batch(struct hib_bio_batch *hb)
 244 {
 245         blk_finish_plug(&hb->plug);
 246 }
 247
 248 static void hib_end_io(struct bio *bio)
 249 {
 250         struct hib_bio_batch *hb = bio->bi_private;
 251         struct page *page = bio_first_page_all(bio);
 252
 253         if (bio->bi_status) {
 254                 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
 255                          MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
 256                          (unsigned long long)bio->bi_iter.bi_sector);
 257         }
 258
 259         if (bio_data_dir(bio) == WRITE)
 260                 put_page(page);
 261         else if (clean_pages_on_read)
 262                 flush_icache_range((unsigned long)page_address(page),
 263                                    (unsigned long)page_address(page) + PAGE_SIZE);
 264
 265         if (bio->bi_status && !hb->error)
 266                 hb->error = bio->bi_status;
 267         if (atomic_dec_and_test(&hb->count))
 268                 wake_up(&hb->wait);
 269
 270         bio_put(bio);
 271 }
 272
 273 static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
 274                 struct hib_bio_batch *hb)
 275 {
 276         struct page *page = virt_to_page(addr);
 277         struct bio *bio;
 278         int error = 0;
 279
 280         bio = bio_alloc(GFP_NOIO | __GFP_HIGH, 1);
 281         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 282         bio_set_dev(bio, hib_resume_bdev);
 283         bio_set_op_attrs(bio, op, op_flags);
 284
 285         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 286                 pr_err("Adding page to bio failed at %llu\n",
 287                        (unsigned long long)bio->bi_iter.bi_sector);
 288                 bio_put(bio);
 289                 return -EFAULT;
 290         }
 291
 292         if (hb) {
 293                 bio->bi_end_io = hib_end_io;
 294                 bio->bi_private = hb;
 295                 atomic_inc(&hb->count);
 296                 submit_bio(bio);
 297         } else {
 298                 error = submit_bio_wait(bio);
 299                 bio_put(bio);
 300         }
 301
 302         return error;
 303 }
 304
 305 static int hib_wait_io(struct hib_bio_batch *hb)
 306 {
 307         /*
 308          * We are relying on the behavior of blk_plug that a thread with
 309          * a plug will flush the plug list before sleeping.
 310          */
 311         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 312         return blk_status_to_errno(hb->error);
 313 }
 314
 315 /*
 316  * Saving part
 317  */
 318 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 319 {
 320         int error;
 321
 322         hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
 323                       swsusp_header, NULL);
 324         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 325             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 326                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 327                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 328                 swsusp_header->image = handle->first_sector;
 329                 if (swsusp_hardware_signature) {
 330                         swsusp_header->hw_sig = swsusp_hardware_signature;
 331                         flags |= SF_HW_SIG;
 332                 }
 333                 swsusp_header->flags = flags;
 334                 if (flags & SF_CRC32_MODE)
 335                         swsusp_header->crc32 = handle->crc32;
 336                 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
 337                                       swsusp_resume_block, swsusp_header, NULL);
 338         } else {
 339                 pr_err("Swap header not found!\n");
 340                 error = -ENODEV;
 341         }
 342         return error;
 343 }
 344
 345 /**
 346  *      swsusp_swap_check - check if the resume device is a swap device
 347  *      and get its index (if so)
 348  *
 349  *      This is called before saving image
 350  */
 351 static int swsusp_swap_check(void)
 352 {
 353         int res;
 354
 355         if (swsusp_resume_device)
 356                 res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
 357         else
 358                 res = find_first_swap(&swsusp_resume_device);
 359         if (res < 0)
 360                 return res;
 361         root_swap = res;
 362
 363         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, FMODE_WRITE,
 364                         NULL);
 365         if (IS_ERR(hib_resume_bdev))
 366                 return PTR_ERR(hib_resume_bdev);
 367
 368         res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 369         if (res < 0)
 370                 blkdev_put(hib_resume_bdev, FMODE_WRITE);
 371
 372         return res;
 373 }
 374
 375 /**
 376  *      write_page - Write one page to given swap location.
 377  *      @buf:           Address we're writing.
 378  *      @offset:        Offset of the swap page we're writing to.
 379  *      @hb:            bio completion batch
 380  */
 381
 382 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 383 {
 384         void *src;
 385         int ret;
 386
 387         if (!offset)
 388                 return -ENOSPC;
 389
 390         if (hb) {
 391                 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
 392                                               __GFP_NORETRY);
 393                 if (src) {
 394                         copy_page(src, buf);
 395                 } else {
 396                         ret = hib_wait_io(hb); /* Free pages */
 397                         if (ret)
 398                                 return ret;
 399                         src = (void *)__get_free_page(GFP_NOIO |
 400                                                       __GFP_NOWARN |
 401                                                       __GFP_NORETRY);
 402                         if (src) {
 403                                 copy_page(src, buf);
 404                         } else {
 405                                 WARN_ON_ONCE(1);
 406                                 hb = NULL;      /* Go synchronous */
 407                                 src = buf;
 408                         }
 409                 }
 410         } else {
 411                 src = buf;
 412         }
 413         return hib_submit_io(REQ_OP_WRITE, REQ_SYNC, offset, src, hb);
 414 }
 415
 416 static void release_swap_writer(struct swap_map_handle *handle)
 417 {
 418         if (handle->cur)
 419                 free_page((unsigned long)handle->cur);
 420         handle->cur = NULL;
 421 }
 422
 423 static int get_swap_writer(struct swap_map_handle *handle)
 424 {
 425         int ret;
 426
 427         ret = swsusp_swap_check();
 428         if (ret) {
 429                 if (ret != -ENOSPC)
 430                         pr_err("Cannot find swap device, try swapon -a\n");
 431                 return ret;
 432         }
 433         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 434         if (!handle->cur) {
 435                 ret = -ENOMEM;
 436                 goto err_close;
 437         }
 438         handle->cur_swap = alloc_swapdev_block(root_swap);
 439         if (!handle->cur_swap) {
 440                 ret = -ENOSPC;
 441                 goto err_rel;
 442         }
 443         handle->k = 0;
 444         handle->reqd_free_pages = reqd_free_pages();
 445         handle->first_sector = handle->cur_swap;
 446         return 0;
 447 err_rel:
 448         release_swap_writer(handle);
 449 err_close:
 450         swsusp_close(FMODE_WRITE);
 451         return ret;
 452 }
 453
 454 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 455                 struct hib_bio_batch *hb)
 456 {
 457         int error = 0;
 458         sector_t offset;
 459
 460         if (!handle->cur)
 461                 return -EINVAL;
 462         offset = alloc_swapdev_block(root_swap);
 463         error = write_page(buf, offset, hb);
 464         if (error)
 465                 return error;
 466         handle->cur->entries[handle->k++] = offset;
 467         if (handle->k >= MAP_PAGE_ENTRIES) {
 468                 offset = alloc_swapdev_block(root_swap);
 469                 if (!offset)
 470                         return -ENOSPC;
 471                 handle->cur->next_swap = offset;
 472                 error = write_page(handle->cur, handle->cur_swap, hb);
 473                 if (error)
 474                         goto out;
 475                 clear_page(handle->cur);
 476                 handle->cur_swap = offset;
 477                 handle->k = 0;
 478
 479                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 480                         error = hib_wait_io(hb);
 481                         if (error)
 482                                 goto out;
 483                         /*
 484                          * Recalculate the number of required free pages, to
 485                          * make sure we never take more than half.
 486                          */
 487                         handle->reqd_free_pages = reqd_free_pages();
 488                 }
 489         }
 490  out:
 491         return error;
 492 }
 493
 494 static int flush_swap_writer(struct swap_map_handle *handle)
 495 {
 496         if (handle->cur && handle->cur_swap)
 497                 return write_page(handle->cur, handle->cur_swap, NULL);
 498         else
 499                 return -EINVAL;
 500 }
 501
 502 static int swap_writer_finish(struct swap_map_handle *handle,
 503                 unsigned int flags, int error)
 504 {
 505         if (!error) {
 506                 pr_info("S");
 507                 error = mark_swapfiles(handle, flags);
 508                 pr_cont("|\n");
 509                 flush_swap_writer(handle);
 510         }
 511
 512         if (error)
 513                 free_all_swap_pages(root_swap);
 514         release_swap_writer(handle);
 515         swsusp_close(FMODE_WRITE);
 516
 517         return error;
 518 }
 519
 520 /* We need to remember how much compressed data we need to read. */
 521 #define LZO_HEADER      sizeof(size_t)
 522
 523 /* Number of pages/bytes we'll compress at one time. */
 524 #define LZO_UNC_PAGES   32
 525 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 526
 527 /* Number of pages/bytes we need for compressed data (worst case). */
 528 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 529                                      LZO_HEADER, PAGE_SIZE)
 530 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 531
 532 /* Maximum number of threads for compression/decompression. */
 533 #define LZO_THREADS     3
 534
 535 /* Minimum/maximum number of pages for read buffering. */
 536 #define LZO_MIN_RD_PAGES        1024
 537 #define LZO_MAX_RD_PAGES        8192
 538
 539
 540 /**
 541  *      save_image - save the suspend image data
 542  */
 543
 544 static int save_image(struct swap_map_handle *handle,
 545                       struct snapshot_handle *snapshot,
 546                       unsigned int nr_to_write)
 547 {
 548         unsigned int m;
 549         int ret;
 550         int nr_pages;
 551         int err2;
 552         struct hib_bio_batch hb;
 553         ktime_t start;
 554         ktime_t stop;
 555
 556         hib_init_batch(&hb);
 557
 558         pr_info("Saving image data pages (%u pages)...\n",
 559                 nr_to_write);
 560         m = nr_to_write / 10;
 561         if (!m)
 562                 m = 1;
 563         nr_pages = 0;
 564         start = ktime_get();
 565         while (1) {
 566                 ret = snapshot_read_next(snapshot);
 567                 if (ret <= 0)
 568                         break;
 569                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 570                 if (ret)
 571                         break;
 572                 if (!(nr_pages % m))
 573                         pr_info("Image saving progress: %3d%%\n",
 574                                 nr_pages / m * 10);
 575                 nr_pages++;
 576         }
 577         err2 = hib_wait_io(&hb);
 578         hib_finish_batch(&hb);
 579         stop = ktime_get();
 580         if (!ret)
 581                 ret = err2;
 582         if (!ret)
 583                 pr_info("Image saving done\n");
 584         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 585         return ret;
 586 }
 587
 588 /**
 589  * Structure used for CRC32.
 590  */
 591 struct crc_data {
 592         struct task_struct *thr;                  /* thread */
 593         atomic_t ready;                           /* ready to start flag */
 594         atomic_t stop;                            /* ready to stop flag */
 595         unsigned run_threads;                     /* nr current threads */
 596         wait_queue_head_t go;                     /* start crc update */
 597         wait_queue_head_t done;                   /* crc update done */
 598         u32 *crc32;                               /* points to handle's crc32 */
 599         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 600         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 601 };
 602
 603 /**
 604  * CRC32 update function that runs in its own thread.
 605  */
 606 static int crc32_threadfn(void *data)
 607 {
 608         struct crc_data *d = data;
 609         unsigned i;
 610
 611         while (1) {
 612                 wait_event(d->go, atomic_read(&d->ready) ||
 613                                   kthread_should_stop());
 614                 if (kthread_should_stop()) {
 615                         d->thr = NULL;
 616                         atomic_set(&d->stop, 1);
 617                         wake_up(&d->done);
 618                         break;
 619                 }
 620                 atomic_set(&d->ready, 0);
 621
 622                 for (i = 0; i < d->run_threads; i++)
 623                         *d->crc32 = crc32_le(*d->crc32,
 624                                              d->unc[i], *d->unc_len[i]);
 625                 atomic_set(&d->stop, 1);
 626                 wake_up(&d->done);
 627         }
 628         return 0;
 629 }
 630 /**
 631  * Structure used for LZO data compression.
 632  */
 633 struct cmp_data {
 634         struct task_struct *thr;                  /* thread */
 635         atomic_t ready;                           /* ready to start flag */
 636         atomic_t stop;                            /* ready to stop flag */
 637         int ret;                                  /* return code */
 638         wait_queue_head_t go;                     /* start compression */
 639         wait_queue_head_t done;                   /* compression done */
 640         size_t unc_len;                           /* uncompressed length */
 641         size_t cmp_len;                           /* compressed length */
 642         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 643         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 644         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 645 };
 646
 647 /**
 648  * Compression function that runs in its own thread.
 649  */
 650 static int lzo_compress_threadfn(void *data)
 651 {
 652         struct cmp_data *d = data;
 653
 654         while (1) {
 655                 wait_event(d->go, atomic_read(&d->ready) ||
 656                                   kthread_should_stop());
 657                 if (kthread_should_stop()) {
 658                         d->thr = NULL;
 659                         d->ret = -1;
 660                         atomic_set(&d->stop, 1);
 661                         wake_up(&d->done);
 662                         break;
 663                 }
 664                 atomic_set(&d->ready, 0);
 665
 666                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 667                                           d->cmp + LZO_HEADER, &d->cmp_len,
 668                                           d->wrk);
 669                 atomic_set(&d->stop, 1);
 670                 wake_up(&d->done);
 671         }
 672         return 0;
 673 }
 674
 675 /**
 676  * save_image_lzo - Save the suspend image data compressed with LZO.
 677  * @handle: Swap map handle to use for saving the image.
 678  * @snapshot: Image to read data from.
 679  * @nr_to_write: Number of pages to save.
 680  */
 681 static int save_image_lzo(struct swap_map_handle *handle,
 682                           struct snapshot_handle *snapshot,
 683                           unsigned int nr_to_write)
 684 {
 685         unsigned int m;
 686         int ret = 0;
 687         int nr_pages;
 688         int err2;
 689         struct hib_bio_batch hb;
 690         ktime_t start;
 691         ktime_t stop;
 692         size_t off;
 693         unsigned thr, run_threads, nr_threads;
 694         unsigned char *page = NULL;
 695         struct cmp_data *data = NULL;
 696         struct crc_data *crc = NULL;
 697
 698         hib_init_batch(&hb);
 699
 700         /*
 701          * We'll limit the number of threads for compression to limit memory
 702          * footprint.
 703          */
 704         nr_threads = num_online_cpus() - 1;
 705         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 706
 707         page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
 708         if (!page) {
 709                 pr_err("Failed to allocate LZO page\n");
 710                 ret = -ENOMEM;
 711                 goto out_clean;
 712         }
 713
 714         data = vzalloc(array_size(nr_threads, sizeof(*data)));
 715         if (!data) {
 716                 pr_err("Failed to allocate LZO data\n");
 717                 ret = -ENOMEM;
 718                 goto out_clean;
 719         }
 720
 721         crc = kzalloc(sizeof(*crc), GFP_KERNEL);
 722         if (!crc) {
 723                 pr_err("Failed to allocate crc\n");
 724                 ret = -ENOMEM;
 725                 goto out_clean;
 726         }
 727
 728         /*
 729          * Start the compression threads.
 730          */
 731         for (thr = 0; thr < nr_threads; thr++) {
 732                 init_waitqueue_head(&data[thr].go);
 733                 init_waitqueue_head(&data[thr].done);
 734
 735                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 736                                             &data[thr],
 737                                             "image_compress/%u", thr);
 738                 if (IS_ERR(data[thr].thr)) {
 739                         data[thr].thr = NULL;
 740                         pr_err("Cannot start compression threads\n");
 741                         ret = -ENOMEM;
 742                         goto out_clean;
 743                 }
 744         }
 745
 746         /*
 747          * Start the CRC32 thread.
 748          */
 749         init_waitqueue_head(&crc->go);
 750         init_waitqueue_head(&crc->done);
 751
 752         handle->crc32 = 0;
 753         crc->crc32 = &handle->crc32;
 754         for (thr = 0; thr < nr_threads; thr++) {
 755                 crc->unc[thr] = data[thr].unc;
 756                 crc->unc_len[thr] = &data[thr].unc_len;
 757         }
 758
 759         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 760         if (IS_ERR(crc->thr)) {
 761                 crc->thr = NULL;
 762                 pr_err("Cannot start CRC32 thread\n");
 763                 ret = -ENOMEM;
 764                 goto out_clean;
 765         }
 766
 767         /*
 768          * Adjust the number of required free pages after all allocations have
 769          * been done. We don't want to run out of pages when writing.
 770          */
 771         handle->reqd_free_pages = reqd_free_pages();
 772
 773         pr_info("Using %u thread(s) for compression\n", nr_threads);
 774         pr_info("Compressing and saving image data (%u pages)...\n",
 775                 nr_to_write);
 776         m = nr_to_write / 10;
 777         if (!m)
 778                 m = 1;
 779         nr_pages = 0;
 780         start = ktime_get();
 781         for (;;) {
 782                 for (thr = 0; thr < nr_threads; thr++) {
 783                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 784                                 ret = snapshot_read_next(snapshot);
 785                                 if (ret < 0)
 786                                         goto out_finish;
 787
 788                                 if (!ret)
 789                                         break;
 790
 791                                 memcpy(data[thr].unc + off,
 792                                        data_of(*snapshot), PAGE_SIZE);
 793
 794                                 if (!(nr_pages % m))
 795                                         pr_info("Image saving progress: %3d%%\n",
 796                                                 nr_pages / m * 10);
 797                                 nr_pages++;
 798                         }
 799                         if (!off)
 800                                 break;
 801
 802                         data[thr].unc_len = off;
 803
 804                         atomic_set(&data[thr].ready, 1);
 805                         wake_up(&data[thr].go);
 806                 }
 807
 808                 if (!thr)
 809                         break;
 810
 811                 crc->run_threads = thr;
 812                 atomic_set(&crc->ready, 1);
 813                 wake_up(&crc->go);
 814
 815                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 816                         wait_event(data[thr].done,
 817                                    atomic_read(&data[thr].stop));
 818                         atomic_set(&data[thr].stop, 0);
 819
 820                         ret = data[thr].ret;
 821
 822                         if (ret < 0) {
 823                                 pr_err("LZO compression failed\n");
 824                                 goto out_finish;
 825                         }
 826
 827                         if (unlikely(!data[thr].cmp_len ||
 828                                      data[thr].cmp_len >
 829                                      lzo1x_worst_compress(data[thr].unc_len))) {
 830                                 pr_err("Invalid LZO compressed length\n");
 831                                 ret = -1;
 832                                 goto out_finish;
 833                         }
 834
 835                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 836
 837                         /*
 838                          * Given we are writing one page at a time to disk, we
 839                          * copy that much from the buffer, although the last
 840                          * bit will likely be smaller than full page. This is
 841                          * OK - we saved the length of the compressed data, so
 842                          * any garbage at the end will be discarded when we
 843                          * read it.
 844                          */
 845                         for (off = 0;
 846                              off < LZO_HEADER + data[thr].cmp_len;
 847                              off += PAGE_SIZE) {
 848                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 849
 850                                 ret = swap_write_page(handle, page, &hb);
 851                                 if (ret)
 852                                         goto out_finish;
 853                         }
 854                 }
 855
 856                 wait_event(crc->done, atomic_read(&crc->stop));
 857                 atomic_set(&crc->stop, 0);
 858         }
 859
 860 out_finish:
 861         err2 = hib_wait_io(&hb);
 862         stop = ktime_get();
 863         if (!ret)
 864                 ret = err2;
 865         if (!ret)
 866                 pr_info("Image saving done\n");
 867         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 868 out_clean:
 869         hib_finish_batch(&hb);
 870         if (crc) {
 871                 if (crc->thr)
 872                         kthread_stop(crc->thr);
 873                 kfree(crc);
 874         }
 875         if (data) {
 876                 for (thr = 0; thr < nr_threads; thr++)
 877                         if (data[thr].thr)
 878                                 kthread_stop(data[thr].thr);
 879                 vfree(data);
 880         }
 881         if (page) free_page((unsigned long)page);
 882
 883         return ret;
 884 }
 885
 886 /**
 887  *      enough_swap - Make sure we have enough swap to save the image.
 888  *
 889  *      Returns TRUE or FALSE after checking the total amount of swap
 890  *      space available from the resume partition.
 891  */
 892
 893 static int enough_swap(unsigned int nr_pages)
 894 {
 895         unsigned int free_swap = count_swap_pages(root_swap, 1);
 896         unsigned int required;
 897
 898         pr_debug("Free swap pages: %u\n", free_swap);
 899
 900         required = PAGES_FOR_IO + nr_pages;
 901         return free_swap > required;
 902 }
 903
 904 /**
 905  *      swsusp_write - Write entire image and metadata.
 906  *      @flags: flags to pass to the "boot" kernel in the image header
 907  *
 908  *      It is important _NOT_ to umount filesystems at this point. We want
 909  *      them synced (in case something goes wrong) but we DO not want to mark
 910  *      filesystem clean: it is not. (And it does not matter, if we resume
 911  *      correctly, we'll mark system clean, anyway.)
 912  */
 913
 914 int swsusp_write(unsigned int flags)
 915 {
 916         struct swap_map_handle handle;
 917         struct snapshot_handle snapshot;
 918         struct swsusp_info *header;
 919         unsigned long pages;
 920         int error;
 921
 922         pages = snapshot_get_image_size();
 923         error = get_swap_writer(&handle);
 924         if (error) {
 925                 pr_err("Cannot get swap writer\n");
 926                 return error;
 927         }
 928         if (flags & SF_NOCOMPRESS_MODE) {
 929                 if (!enough_swap(pages)) {
 930                         pr_err("Not enough free swap\n");
 931                         error = -ENOSPC;
 932                         goto out_finish;
 933                 }
 934         }
 935         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 936         error = snapshot_read_next(&snapshot);
 937         if (error < (int)PAGE_SIZE) {
 938                 if (error >= 0)
 939                         error = -EFAULT;
 940
 941                 goto out_finish;
 942         }
 943         header = (struct swsusp_info *)data_of(snapshot);
 944         error = swap_write_page(&handle, header, NULL);
 945         if (!error) {
 946                 error = (flags & SF_NOCOMPRESS_MODE) ?
 947                         save_image(&handle, &snapshot, pages - 1) :
 948                         save_image_lzo(&handle, &snapshot, pages - 1);
 949         }
 950 out_finish:
 951         error = swap_writer_finish(&handle, flags, error);
 952         return error;
 953 }
 954
 955 /**
 956  *      The following functions allow us to read data using a swap map
 957  *      in a file-alike way
 958  */
 959
 960 static void release_swap_reader(struct swap_map_handle *handle)
 961 {
 962         struct swap_map_page_list *tmp;
 963
 964         while (handle->maps) {
 965                 if (handle->maps->map)
 966                         free_page((unsigned long)handle->maps->map);
 967                 tmp = handle->maps;
 968                 handle->maps = handle->maps->next;
 969                 kfree(tmp);
 970         }
 971         handle->cur = NULL;
 972 }
 973
 974 static int get_swap_reader(struct swap_map_handle *handle,
 975                 unsigned int *flags_p)
 976 {
 977         int error;
 978         struct swap_map_page_list *tmp, *last;
 979         sector_t offset;
 980
 981         *flags_p = swsusp_header->flags;
 982
 983         if (!swsusp_header->image) /* how can this happen? */
 984                 return -EINVAL;
 985
 986         handle->cur = NULL;
 987         last = handle->maps = NULL;
 988         offset = swsusp_header->image;
 989         while (offset) {
 990                 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
 991                 if (!tmp) {
 992                         release_swap_reader(handle);
 993                         return -ENOMEM;
 994                 }
 995                 if (!handle->maps)
 996                         handle->maps = tmp;
 997                 if (last)
 998                         last->next = tmp;
 999                 last = tmp;
1000
1001                 tmp->map = (struct swap_map_page *)
1002                            __get_free_page(GFP_NOIO | __GFP_HIGH);
1003                 if (!tmp->map) {
1004                         release_swap_reader(handle);
1005                         return -ENOMEM;
1006                 }
1007
1008                 error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL);
1009                 if (error) {
1010                         release_swap_reader(handle);
1011                         return error;
1012                 }
1013                 offset = tmp->map->next_swap;
1014         }
1015         handle->k = 0;
1016         handle->cur = handle->maps->map;
1017         return 0;
1018 }
1019
1020 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1021                 struct hib_bio_batch *hb)
1022 {
1023         sector_t offset;
1024         int error;
1025         struct swap_map_page_list *tmp;
1026
1027         if (!handle->cur)
1028                 return -EINVAL;
1029         offset = handle->cur->entries[handle->k];
1030         if (!offset)
1031                 return -EFAULT;
1032         error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb);
1033         if (error)
1034                 return error;
1035         if (++handle->k >= MAP_PAGE_ENTRIES) {
1036                 handle->k = 0;
1037                 free_page((unsigned long)handle->maps->map);
1038                 tmp = handle->maps;
1039                 handle->maps = handle->maps->next;
1040                 kfree(tmp);
1041                 if (!handle->maps)
1042                         release_swap_reader(handle);
1043                 else
1044                         handle->cur = handle->maps->map;
1045         }
1046         return error;
1047 }
1048
1049 static int swap_reader_finish(struct swap_map_handle *handle)
1050 {
1051         release_swap_reader(handle);
1052
1053         return 0;
1054 }
1055
1056 /**
1057  *      load_image - load the image using the swap map handle
1058  *      @handle and the snapshot handle @snapshot
1059  *      (assume there are @nr_pages pages to load)
1060  */
1061
1062 static int load_image(struct swap_map_handle *handle,
1063                       struct snapshot_handle *snapshot,
1064                       unsigned int nr_to_read)
1065 {
1066         unsigned int m;
1067         int ret = 0;
1068         ktime_t start;
1069         ktime_t stop;
1070         struct hib_bio_batch hb;
1071         int err2;
1072         unsigned nr_pages;
1073
1074         hib_init_batch(&hb);
1075
1076         clean_pages_on_read = true;
1077         pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1078         m = nr_to_read / 10;
1079         if (!m)
1080                 m = 1;
1081         nr_pages = 0;
1082         start = ktime_get();
1083         for ( ; ; ) {
1084                 ret = snapshot_write_next(snapshot);
1085                 if (ret <= 0)
1086                         break;
1087                 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1088                 if (ret)
1089                         break;
1090                 if (snapshot->sync_read)
1091                         ret = hib_wait_io(&hb);
1092                 if (ret)
1093                         break;
1094                 if (!(nr_pages % m))
1095                         pr_info("Image loading progress: %3d%%\n",
1096                                 nr_pages / m * 10);
1097                 nr_pages++;
1098         }
1099         err2 = hib_wait_io(&hb);
1100         hib_finish_batch(&hb);
1101         stop = ktime_get();
1102         if (!ret)
1103                 ret = err2;
1104         if (!ret) {
1105                 pr_info("Image loading done\n");
1106                 snapshot_write_finalize(snapshot);
1107                 if (!snapshot_image_loaded(snapshot))
1108                         ret = -ENODATA;
1109         }
1110         swsusp_show_speed(start, stop, nr_to_read, "Read");
1111         return ret;
1112 }
1113
1114 /**
1115  * Structure used for LZO data decompression.
1116  */
1117 struct dec_data {
1118         struct task_struct *thr;                  /* thread */
1119         atomic_t ready;                           /* ready to start flag */
1120         atomic_t stop;                            /* ready to stop flag */
1121         int ret;                                  /* return code */
1122         wait_queue_head_t go;                     /* start decompression */
1123         wait_queue_head_t done;                   /* decompression done */
1124         size_t unc_len;                           /* uncompressed length */
1125         size_t cmp_len;                           /* compressed length */
1126         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1127         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1128 };
1129
1130 /**
1131  * Decompression function that runs in its own thread.
1132  */
1133 static int lzo_decompress_threadfn(void *data)
1134 {
1135         struct dec_data *d = data;
1136
1137         while (1) {
1138                 wait_event(d->go, atomic_read(&d->ready) ||
1139                                   kthread_should_stop());
1140                 if (kthread_should_stop()) {
1141                         d->thr = NULL;
1142                         d->ret = -1;
1143                         atomic_set(&d->stop, 1);
1144                         wake_up(&d->done);
1145                         break;
1146                 }
1147                 atomic_set(&d->ready, 0);
1148
1149                 d->unc_len = LZO_UNC_SIZE;
1150                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1151                                                d->unc, &d->unc_len);
1152                 if (clean_pages_on_decompress)
1153                         flush_icache_range((unsigned long)d->unc,
1154                                            (unsigned long)d->unc + d->unc_len);
1155
1156                 atomic_set(&d->stop, 1);
1157                 wake_up(&d->done);
1158         }
1159         return 0;
1160 }
1161
1162 /**
1163  * load_image_lzo - Load compressed image data and decompress them with LZO.
1164  * @handle: Swap map handle to use for loading data.
1165  * @snapshot: Image to copy uncompressed data into.
1166  * @nr_to_read: Number of pages to load.
1167  */
1168 static int load_image_lzo(struct swap_map_handle *handle,
1169                           struct snapshot_handle *snapshot,
1170                           unsigned int nr_to_read)
1171 {
1172         unsigned int m;
1173         int ret = 0;
1174         int eof = 0;
1175         struct hib_bio_batch hb;
1176         ktime_t start;
1177         ktime_t stop;
1178         unsigned nr_pages;
1179         size_t off;
1180         unsigned i, thr, run_threads, nr_threads;
1181         unsigned ring = 0, pg = 0, ring_size = 0,
1182                  have = 0, want, need, asked = 0;
1183         unsigned long read_pages = 0;
1184         unsigned char **page = NULL;
1185         struct dec_data *data = NULL;
1186         struct crc_data *crc = NULL;
1187
1188         hib_init_batch(&hb);
1189
1190         /*
1191          * We'll limit the number of threads for decompression to limit memory
1192          * footprint.
1193          */
1194         nr_threads = num_online_cpus() - 1;
1195         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1196
1197         page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
1198         if (!page) {
1199                 pr_err("Failed to allocate LZO page\n");
1200                 ret = -ENOMEM;
1201                 goto out_clean;
1202         }
1203
1204         data = vzalloc(array_size(nr_threads, sizeof(*data)));
1205         if (!data) {
1206                 pr_err("Failed to allocate LZO data\n");
1207                 ret = -ENOMEM;
1208                 goto out_clean;
1209         }
1210
1211         crc = kzalloc(sizeof(*crc), GFP_KERNEL);
1212         if (!crc) {
1213                 pr_err("Failed to allocate crc\n");
1214                 ret = -ENOMEM;
1215                 goto out_clean;
1216         }
1217
1218         clean_pages_on_decompress = true;
1219
1220         /*
1221          * Start the decompression threads.
1222          */
1223         for (thr = 0; thr < nr_threads; thr++) {
1224                 init_waitqueue_head(&data[thr].go);
1225                 init_waitqueue_head(&data[thr].done);
1226
1227                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1228                                             &data[thr],
1229                                             "image_decompress/%u", thr);
1230                 if (IS_ERR(data[thr].thr)) {
1231                         data[thr].thr = NULL;
1232                         pr_err("Cannot start decompression threads\n");
1233                         ret = -ENOMEM;
1234                         goto out_clean;
1235                 }
1236         }
1237
1238         /*
1239          * Start the CRC32 thread.
1240          */
1241         init_waitqueue_head(&crc->go);
1242         init_waitqueue_head(&crc->done);
1243
1244         handle->crc32 = 0;
1245         crc->crc32 = &handle->crc32;
1246         for (thr = 0; thr < nr_threads; thr++) {
1247                 crc->unc[thr] = data[thr].unc;
1248                 crc->unc_len[thr] = &data[thr].unc_len;
1249         }
1250
1251         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1252         if (IS_ERR(crc->thr)) {
1253                 crc->thr = NULL;
1254                 pr_err("Cannot start CRC32 thread\n");
1255                 ret = -ENOMEM;
1256                 goto out_clean;
1257         }
1258
1259         /*
1260          * Set the number of pages for read buffering.
1261          * This is complete guesswork, because we'll only know the real
1262          * picture once prepare_image() is called, which is much later on
1263          * during the image load phase. We'll assume the worst case and
1264          * say that none of the image pages are from high memory.
1265          */
1266         if (low_free_pages() > snapshot_get_image_size())
1267                 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1268         read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1269
1270         for (i = 0; i < read_pages; i++) {
1271                 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1272                                                   GFP_NOIO | __GFP_HIGH :
1273                                                   GFP_NOIO | __GFP_NOWARN |
1274                                                   __GFP_NORETRY);
1275
1276                 if (!page[i]) {
1277                         if (i < LZO_CMP_PAGES) {
1278                                 ring_size = i;
1279                                 pr_err("Failed to allocate LZO pages\n");
1280                                 ret = -ENOMEM;
1281                                 goto out_clean;
1282                         } else {
1283                                 break;
1284                         }
1285                 }
1286         }
1287         want = ring_size = i;
1288
1289         pr_info("Using %u thread(s) for decompression\n", nr_threads);
1290         pr_info("Loading and decompressing image data (%u pages)...\n",
1291                 nr_to_read);
1292         m = nr_to_read / 10;
1293         if (!m)
1294                 m = 1;
1295         nr_pages = 0;
1296         start = ktime_get();
1297
1298         ret = snapshot_write_next(snapshot);
1299         if (ret <= 0)
1300                 goto out_finish;
1301
1302         for(;;) {
1303                 for (i = 0; !eof && i < want; i++) {
1304                         ret = swap_read_page(handle, page[ring], &hb);
1305                         if (ret) {
1306                                 /*
1307                                  * On real read error, finish. On end of data,
1308                                  * set EOF flag and just exit the read loop.
1309                                  */
1310                                 if (handle->cur &&
1311                                     handle->cur->entries[handle->k]) {
1312                                         goto out_finish;
1313                                 } else {
1314                                         eof = 1;
1315                                         break;
1316                                 }
1317                         }
1318                         if (++ring >= ring_size)
1319                                 ring = 0;
1320                 }
1321                 asked += i;
1322                 want -= i;
1323
1324                 /*
1325                  * We are out of data, wait for some more.
1326                  */
1327                 if (!have) {
1328                         if (!asked)
1329                                 break;
1330
1331                         ret = hib_wait_io(&hb);
1332                         if (ret)
1333                                 goto out_finish;
1334                         have += asked;
1335                         asked = 0;
1336                         if (eof)
1337                                 eof = 2;
1338                 }
1339
1340                 if (crc->run_threads) {
1341                         wait_event(crc->done, atomic_read(&crc->stop));
1342                         atomic_set(&crc->stop, 0);
1343                         crc->run_threads = 0;
1344                 }
1345
1346                 for (thr = 0; have && thr < nr_threads; thr++) {
1347                         data[thr].cmp_len = *(size_t *)page[pg];
1348                         if (unlikely(!data[thr].cmp_len ||
1349                                      data[thr].cmp_len >
1350                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1351                                 pr_err("Invalid LZO compressed length\n");
1352                                 ret = -1;
1353                                 goto out_finish;
1354                         }
1355
1356                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1357                                             PAGE_SIZE);
1358                         if (need > have) {
1359                                 if (eof > 1) {
1360                                         ret = -1;
1361                                         goto out_finish;
1362                                 }
1363                                 break;
1364                         }
1365
1366                         for (off = 0;
1367                              off < LZO_HEADER + data[thr].cmp_len;
1368                              off += PAGE_SIZE) {
1369                                 memcpy(data[thr].cmp + off,
1370                                        page[pg], PAGE_SIZE);
1371                                 have--;
1372                                 want++;
1373                                 if (++pg >= ring_size)
1374                                         pg = 0;
1375                         }
1376
1377                         atomic_set(&data[thr].ready, 1);
1378                         wake_up(&data[thr].go);
1379                 }
1380
1381                 /*
1382                  * Wait for more data while we are decompressing.
1383                  */
1384                 if (have < LZO_CMP_PAGES && asked) {
1385                         ret = hib_wait_io(&hb);
1386                         if (ret)
1387                                 goto out_finish;
1388                         have += asked;
1389                         asked = 0;
1390                         if (eof)
1391                                 eof = 2;
1392                 }
1393
1394                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1395                         wait_event(data[thr].done,
1396                                    atomic_read(&data[thr].stop));
1397                         atomic_set(&data[thr].stop, 0);
1398
1399                         ret = data[thr].ret;
1400
1401                         if (ret < 0) {
1402                                 pr_err("LZO decompression failed\n");
1403                                 goto out_finish;
1404                         }
1405
1406                         if (unlikely(!data[thr].unc_len ||
1407                                      data[thr].unc_len > LZO_UNC_SIZE ||
1408                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1409                                 pr_err("Invalid LZO uncompressed length\n");
1410                                 ret = -1;
1411                                 goto out_finish;
1412                         }
1413
1414                         for (off = 0;
1415                              off < data[thr].unc_len; off += PAGE_SIZE) {
1416                                 memcpy(data_of(*snapshot),
1417                                        data[thr].unc + off, PAGE_SIZE);
1418
1419                                 if (!(nr_pages % m))
1420                                         pr_info("Image loading progress: %3d%%\n",
1421                                                 nr_pages / m * 10);
1422                                 nr_pages++;
1423
1424                                 ret = snapshot_write_next(snapshot);
1425                                 if (ret <= 0) {
1426                                         crc->run_threads = thr + 1;
1427                                         atomic_set(&crc->ready, 1);
1428                                         wake_up(&crc->go);
1429                                         goto out_finish;
1430                                 }
1431                         }
1432                 }
1433
1434                 crc->run_threads = thr;
1435                 atomic_set(&crc->ready, 1);
1436                 wake_up(&crc->go);
1437         }
1438
1439 out_finish:
1440         if (crc->run_threads) {
1441                 wait_event(crc->done, atomic_read(&crc->stop));
1442                 atomic_set(&crc->stop, 0);
1443         }
1444         stop = ktime_get();
1445         if (!ret) {
1446                 pr_info("Image loading done\n");
1447                 snapshot_write_finalize(snapshot);
1448                 if (!snapshot_image_loaded(snapshot))
1449                         ret = -ENODATA;
1450                 if (!ret) {
1451                         if (swsusp_header->flags & SF_CRC32_MODE) {
1452                                 if(handle->crc32 != swsusp_header->crc32) {
1453                                         pr_err("Invalid image CRC32!\n");
1454                                         ret = -ENODATA;
1455                                 }
1456                         }
1457                 }
1458         }
1459         swsusp_show_speed(start, stop, nr_to_read, "Read");
1460 out_clean:
1461         hib_finish_batch(&hb);
1462         for (i = 0; i < ring_size; i++)
1463                 free_page((unsigned long)page[i]);
1464         if (crc) {
1465                 if (crc->thr)
1466                         kthread_stop(crc->thr);
1467                 kfree(crc);
1468         }
1469         if (data) {
1470                 for (thr = 0; thr < nr_threads; thr++)
1471                         if (data[thr].thr)
1472                                 kthread_stop(data[thr].thr);
1473                 vfree(data);
1474         }
1475         vfree(page);
1476
1477         return ret;
1478 }
1479
1480 /**
1481  *      swsusp_read - read the hibernation image.
1482  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1483  *                be written into this memory location
1484  */
1485
1486 int swsusp_read(unsigned int *flags_p)
1487 {
1488         int error;
1489         struct swap_map_handle handle;
1490         struct snapshot_handle snapshot;
1491         struct swsusp_info *header;
1492
1493         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1494         error = snapshot_write_next(&snapshot);
1495         if (error < (int)PAGE_SIZE)
1496                 return error < 0 ? error : -EFAULT;
1497         header = (struct swsusp_info *)data_of(snapshot);
1498         error = get_swap_reader(&handle, flags_p);
1499         if (error)
1500                 goto end;
1501         if (!error)
1502                 error = swap_read_page(&handle, header, NULL);
1503         if (!error) {
1504                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1505                         load_image(&handle, &snapshot, header->pages - 1) :
1506                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1507         }
1508         swap_reader_finish(&handle);
1509 end:
1510         if (!error)
1511                 pr_debug("Image successfully loaded\n");
1512         else
1513                 pr_debug("Error %d resuming\n", error);
1514         return error;
1515 }
1516
1517 /**
1518  *      swsusp_check - Check for swsusp signature in the resume device
1519  */
1520
1521 int swsusp_check(void)
1522 {
1523         int error;
1524         void *holder;
1525
1526         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1527                                             FMODE_READ | FMODE_EXCL, &holder);
1528         if (!IS_ERR(hib_resume_bdev)) {
1529                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1530                 clear_page(swsusp_header);
1531                 error = hib_submit_io(REQ_OP_READ, 0,
1532                                         swsusp_resume_block,
1533                                         swsusp_header, NULL);
1534                 if (error)
1535                         goto put;
1536
1537                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1538                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1539                         /* Reset swap signature now */
1540                         error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1541                                                 swsusp_resume_block,
1542                                                 swsusp_header, NULL);
1543                 } else {
1544                         error = -EINVAL;
1545                 }
1546                 if (!error && swsusp_header->flags & SF_HW_SIG &&
1547                     swsusp_header->hw_sig != swsusp_hardware_signature) {
1548                         pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
1549                                 swsusp_header->hw_sig, swsusp_hardware_signature);
1550                         error = -EINVAL;
1551                 }
1552
1553 put:
1554                 if (error)
1555                         blkdev_put(hib_resume_bdev, FMODE_READ | FMODE_EXCL);
1556                 else
1557                         pr_debug("Image signature found, resuming\n");
1558         } else {
1559                 error = PTR_ERR(hib_resume_bdev);
1560         }
1561
1562         if (error)
1563                 pr_debug("Image not found (code %d)\n", error);
1564
1565         return error;
1566 }
1567
1568 /**
1569  *      swsusp_close - close swap device.
1570  */
1571
1572 void swsusp_close(fmode_t mode)
1573 {
1574         if (IS_ERR(hib_resume_bdev)) {
1575                 pr_debug("Image device not initialised\n");
1576                 return;
1577         }
1578
1579         blkdev_put(hib_resume_bdev, mode);
1580 }
1581
1582 /**
1583  *      swsusp_unmark - Unmark swsusp signature in the resume device
1584  */
1585
1586 #ifdef CONFIG_SUSPEND
1587 int swsusp_unmark(void)
1588 {
1589         int error;
1590
1591         hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
1592                       swsusp_header, NULL);
1593         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1594                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1595                 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1596                                         swsusp_resume_block,
1597                                         swsusp_header, NULL);
1598         } else {
1599                 pr_err("Cannot find swsusp signature!\n");
1600                 error = -ENODEV;
1601         }
1602
1603         /*
1604          * We just returned from suspend, we don't need the image any more.
1605          */
1606         free_all_swap_pages(root_swap);
1607
1608         return error;
1609 }
1610 #endif
1611
1612 static int __init swsusp_header_init(void)
1613 {
1614         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1615         if (!swsusp_header)
1616                 panic("Could not allocate memory for swsusp_header\n");
1617         return 0;
1618 }
1619
1620 core_initcall(swsusp_header_init);