kernel/power/swap.c

   1 /*
   2  * linux/kernel/power/swap.c
   3  *
   4  * This file provides functions for reading the suspend image from
   5  * and writing it to a swap partition.
   6  *
   7  * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
   8  * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
   9  * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
  10  *
  11  * This file is released under the GPLv2.
  12  *
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/file.h>
  17 #include <linux/delay.h>
  18 #include <linux/bitops.h>
  19 #include <linux/genhd.h>
  20 #include <linux/device.h>
  21 #include <linux/bio.h>
  22 #include <linux/blkdev.h>
  23 #include <linux/swap.h>
  24 #include <linux/swapops.h>
  25 #include <linux/pm.h>
  26 #include <linux/slab.h>
  27 #include <linux/lzo.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/cpumask.h>
  30 #include <linux/atomic.h>
  31 #include <linux/kthread.h>
  32 #include <linux/crc32.h>
  33 #include <linux/ktime.h>
  34
  35 #include "power.h"
  36
  37 #define HIBERNATE_SIG   "S1SUSPEND"
  38
  39 /*
  40  * When reading an {un,}compressed image, we may restore pages in place,
  41  * in which case some architectures need these pages cleaning before they
  42  * can be executed. We don't know which pages these may be, so clean the lot.
  43  */
  44 static bool clean_pages_on_read;
  45 static bool clean_pages_on_decompress;
  46
  47 /*
  48  *      The swap map is a data structure used for keeping track of each page
  49  *      written to a swap partition.  It consists of many swap_map_page
  50  *      structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
  51  *      These structures are stored on the swap and linked together with the
  52  *      help of the .next_swap member.
  53  *
  54  *      The swap map is created during suspend.  The swap map pages are
  55  *      allocated and populated one at a time, so we only need one memory
  56  *      page to set up the entire structure.
  57  *
  58  *      During resume we pick up all swap_map_page structures into a list.
  59  */
  60
  61 #define MAP_PAGE_ENTRIES        (PAGE_SIZE / sizeof(sector_t) - 1)
  62
  63 /*
  64  * Number of free pages that are not high.
  65  */
  66 static inline unsigned long low_free_pages(void)
  67 {
  68         return nr_free_pages() - nr_free_highpages();
  69 }
  70
  71 /*
  72  * Number of pages required to be kept free while writing the image. Always
  73  * half of all available low pages before the writing starts.
  74  */
  75 static inline unsigned long reqd_free_pages(void)
  76 {
  77         return low_free_pages() / 2;
  78 }
  79
  80 struct swap_map_page {
  81         sector_t entries[MAP_PAGE_ENTRIES];
  82         sector_t next_swap;
  83 };
  84
  85 struct swap_map_page_list {
  86         struct swap_map_page *map;
  87         struct swap_map_page_list *next;
  88 };
  89
  90 /**
  91  *      The swap_map_handle structure is used for handling swap in
  92  *      a file-alike way
  93  */
  94
  95 struct swap_map_handle {
  96         struct swap_map_page *cur;
  97         struct swap_map_page_list *maps;
  98         sector_t cur_swap;
  99         sector_t first_sector;
 100         unsigned int k;
 101         unsigned long reqd_free_pages;
 102         u32 crc32;
 103 };
 104
 105 struct swsusp_header {
 106         char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
 107                       sizeof(u32)];
 108         u32     crc32;
 109         sector_t image;
 110         unsigned int flags;     /* Flags to pass to the "boot" kernel */
 111         char    orig_sig[10];
 112         char    sig[10];
 113 } __packed;
 114
 115 static struct swsusp_header *swsusp_header;
 116
 117 /**
 118  *      The following functions are used for tracing the allocated
 119  *      swap pages, so that they can be freed in case of an error.
 120  */
 121
 122 struct swsusp_extent {
 123         struct rb_node node;
 124         unsigned long start;
 125         unsigned long end;
 126 };
 127
 128 static struct rb_root swsusp_extents = RB_ROOT;
 129
 130 static int swsusp_extents_insert(unsigned long swap_offset)
 131 {
 132         struct rb_node **new = &(swsusp_extents.rb_node);
 133         struct rb_node *parent = NULL;
 134         struct swsusp_extent *ext;
 135
 136         /* Figure out where to put the new node */
 137         while (*new) {
 138                 ext = rb_entry(*new, struct swsusp_extent, node);
 139                 parent = *new;
 140                 if (swap_offset < ext->start) {
 141                         /* Try to merge */
 142                         if (swap_offset == ext->start - 1) {
 143                                 ext->start--;
 144                                 return 0;
 145                         }
 146                         new = &((*new)->rb_left);
 147                 } else if (swap_offset > ext->end) {
 148                         /* Try to merge */
 149                         if (swap_offset == ext->end + 1) {
 150                                 ext->end++;
 151                                 return 0;
 152                         }
 153                         new = &((*new)->rb_right);
 154                 } else {
 155                         /* It already is in the tree */
 156                         return -EINVAL;
 157                 }
 158         }
 159         /* Add the new node and rebalance the tree. */
 160         ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
 161         if (!ext)
 162                 return -ENOMEM;
 163
 164         ext->start = swap_offset;
 165         ext->end = swap_offset;
 166         rb_link_node(&ext->node, parent, new);
 167         rb_insert_color(&ext->node, &swsusp_extents);
 168         return 0;
 169 }
 170
 171 /**
 172  *      alloc_swapdev_block - allocate a swap page and register that it has
 173  *      been allocated, so that it can be freed in case of an error.
 174  */
 175
 176 sector_t alloc_swapdev_block(int swap)
 177 {
 178         unsigned long offset;
 179
 180         offset = swp_offset(get_swap_page_of_type(swap));
 181         if (offset) {
 182                 if (swsusp_extents_insert(offset))
 183                         swap_free(swp_entry(swap, offset));
 184                 else
 185                         return swapdev_block(swap, offset);
 186         }
 187         return 0;
 188 }
 189
 190 /**
 191  *      free_all_swap_pages - free swap pages allocated for saving image data.
 192  *      It also frees the extents used to register which swap entries had been
 193  *      allocated.
 194  */
 195
 196 void free_all_swap_pages(int swap)
 197 {
 198         struct rb_node *node;
 199
 200         while ((node = swsusp_extents.rb_node)) {
 201                 struct swsusp_extent *ext;
 202                 unsigned long offset;
 203
 204                 ext = container_of(node, struct swsusp_extent, node);
 205                 rb_erase(node, &swsusp_extents);
 206                 for (offset = ext->start; offset <= ext->end; offset++)
 207                         swap_free(swp_entry(swap, offset));
 208
 209                 kfree(ext);
 210         }
 211 }
 212
 213 int swsusp_swap_in_use(void)
 214 {
 215         return (swsusp_extents.rb_node != NULL);
 216 }
 217
 218 /*
 219  * General things
 220  */
 221
 222 static unsigned short root_swap = 0xffff;
 223 static struct block_device *hib_resume_bdev;
 224
 225 struct hib_bio_batch {
 226         atomic_t                count;
 227         wait_queue_head_t       wait;
 228         int                     error;
 229 };
 230
 231 static void hib_init_batch(struct hib_bio_batch *hb)
 232 {
 233         atomic_set(&hb->count, 0);
 234         init_waitqueue_head(&hb->wait);
 235         hb->error = 0;
 236 }
 237
 238 static void hib_end_io(struct bio *bio)
 239 {
 240         struct hib_bio_batch *hb = bio->bi_private;
 241         struct page *page = bio->bi_io_vec[0].bv_page;
 242
 243         if (bio->bi_error) {
 244                 printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
 245                                 imajor(bio->bi_bdev->bd_inode),
 246                                 iminor(bio->bi_bdev->bd_inode),
 247                                 (unsigned long long)bio->bi_iter.bi_sector);
 248         }
 249
 250         if (bio_data_dir(bio) == WRITE)
 251                 put_page(page);
 252         else if (clean_pages_on_read)
 253                 flush_icache_range((unsigned long)page_address(page),
 254                                    (unsigned long)page_address(page) + PAGE_SIZE);
 255
 256         if (bio->bi_error && !hb->error)
 257                 hb->error = bio->bi_error;
 258         if (atomic_dec_and_test(&hb->count))
 259                 wake_up(&hb->wait);
 260
 261         bio_put(bio);
 262 }
 263
 264 static int hib_submit_io(int rw, pgoff_t page_off, void *addr,
 265                 struct hib_bio_batch *hb)
 266 {
 267         struct page *page = virt_to_page(addr);
 268         struct bio *bio;
 269         int error = 0;
 270
 271         bio = bio_alloc(__GFP_RECLAIM | __GFP_HIGH, 1);
 272         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 273         bio->bi_bdev = hib_resume_bdev;
 274
 275         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 276                 printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
 277                         (unsigned long long)bio->bi_iter.bi_sector);
 278                 bio_put(bio);
 279                 return -EFAULT;
 280         }
 281
 282         if (hb) {
 283                 bio->bi_end_io = hib_end_io;
 284                 bio->bi_private = hb;
 285                 atomic_inc(&hb->count);
 286                 submit_bio(rw, bio);
 287         } else {
 288                 error = submit_bio_wait(rw, bio);
 289                 bio_put(bio);
 290         }
 291
 292         return error;
 293 }
 294
 295 static int hib_wait_io(struct hib_bio_batch *hb)
 296 {
 297         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 298         return hb->error;
 299 }
 300
 301 /*
 302  * Saving part
 303  */
 304
 305 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 306 {
 307         int error;
 308
 309         hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
 310         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 311             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 312                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 313                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 314                 swsusp_header->image = handle->first_sector;
 315                 swsusp_header->flags = flags;
 316                 if (flags & SF_CRC32_MODE)
 317                         swsusp_header->crc32 = handle->crc32;
 318                 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
 319                                         swsusp_header, NULL);
 320         } else {
 321                 printk(KERN_ERR "PM: Swap header not found!\n");
 322                 error = -ENODEV;
 323         }
 324         return error;
 325 }
 326
 327 /**
 328  *      swsusp_swap_check - check if the resume device is a swap device
 329  *      and get its index (if so)
 330  *
 331  *      This is called before saving image
 332  */
 333 static int swsusp_swap_check(void)
 334 {
 335         int res;
 336
 337         res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
 338                         &hib_resume_bdev);
 339         if (res < 0)
 340                 return res;
 341
 342         root_swap = res;
 343         res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
 344         if (res)
 345                 return res;
 346
 347         res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 348         if (res < 0)
 349                 blkdev_put(hib_resume_bdev, FMODE_WRITE);
 350
 351         /*
 352          * Update the resume device to the one actually used,
 353          * so the test_resume mode can use it in case it is
 354          * invoked from hibernate() to test the snapshot.
 355          */
 356         swsusp_resume_device = hib_resume_bdev->bd_dev;
 357         return res;
 358 }
 359
 360 /**
 361  *      write_page - Write one page to given swap location.
 362  *      @buf:           Address we're writing.
 363  *      @offset:        Offset of the swap page we're writing to.
 364  *      @hb:            bio completion batch
 365  */
 366
 367 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 368 {
 369         void *src;
 370         int ret;
 371
 372         if (!offset)
 373                 return -ENOSPC;
 374
 375         if (hb) {
 376                 src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN |
 377                                               __GFP_NORETRY);
 378                 if (src) {
 379                         copy_page(src, buf);
 380                 } else {
 381                         ret = hib_wait_io(hb); /* Free pages */
 382                         if (ret)
 383                                 return ret;
 384                         src = (void *)__get_free_page(__GFP_RECLAIM |
 385                                                       __GFP_NOWARN |
 386                                                       __GFP_NORETRY);
 387                         if (src) {
 388                                 copy_page(src, buf);
 389                         } else {
 390                                 WARN_ON_ONCE(1);
 391                                 hb = NULL;      /* Go synchronous */
 392                                 src = buf;
 393                         }
 394                 }
 395         } else {
 396                 src = buf;
 397         }
 398         return hib_submit_io(WRITE_SYNC, offset, src, hb);
 399 }
 400
 401 static void release_swap_writer(struct swap_map_handle *handle)
 402 {
 403         if (handle->cur)
 404                 free_page((unsigned long)handle->cur);
 405         handle->cur = NULL;
 406 }
 407
 408 static int get_swap_writer(struct swap_map_handle *handle)
 409 {
 410         int ret;
 411
 412         ret = swsusp_swap_check();
 413         if (ret) {
 414                 if (ret != -ENOSPC)
 415                         printk(KERN_ERR "PM: Cannot find swap device, try "
 416                                         "swapon -a.\n");
 417                 return ret;
 418         }
 419         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 420         if (!handle->cur) {
 421                 ret = -ENOMEM;
 422                 goto err_close;
 423         }
 424         handle->cur_swap = alloc_swapdev_block(root_swap);
 425         if (!handle->cur_swap) {
 426                 ret = -ENOSPC;
 427                 goto err_rel;
 428         }
 429         handle->k = 0;
 430         handle->reqd_free_pages = reqd_free_pages();
 431         handle->first_sector = handle->cur_swap;
 432         return 0;
 433 err_rel:
 434         release_swap_writer(handle);
 435 err_close:
 436         swsusp_close(FMODE_WRITE);
 437         return ret;
 438 }
 439
 440 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 441                 struct hib_bio_batch *hb)
 442 {
 443         int error = 0;
 444         sector_t offset;
 445
 446         if (!handle->cur)
 447                 return -EINVAL;
 448         offset = alloc_swapdev_block(root_swap);
 449         error = write_page(buf, offset, hb);
 450         if (error)
 451                 return error;
 452         handle->cur->entries[handle->k++] = offset;
 453         if (handle->k >= MAP_PAGE_ENTRIES) {
 454                 offset = alloc_swapdev_block(root_swap);
 455                 if (!offset)
 456                         return -ENOSPC;
 457                 handle->cur->next_swap = offset;
 458                 error = write_page(handle->cur, handle->cur_swap, hb);
 459                 if (error)
 460                         goto out;
 461                 clear_page(handle->cur);
 462                 handle->cur_swap = offset;
 463                 handle->k = 0;
 464
 465                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 466                         error = hib_wait_io(hb);
 467                         if (error)
 468                                 goto out;
 469                         /*
 470                          * Recalculate the number of required free pages, to
 471                          * make sure we never take more than half.
 472                          */
 473                         handle->reqd_free_pages = reqd_free_pages();
 474                 }
 475         }
 476  out:
 477         return error;
 478 }
 479
 480 static int flush_swap_writer(struct swap_map_handle *handle)
 481 {
 482         if (handle->cur && handle->cur_swap)
 483                 return write_page(handle->cur, handle->cur_swap, NULL);
 484         else
 485                 return -EINVAL;
 486 }
 487
 488 static int swap_writer_finish(struct swap_map_handle *handle,
 489                 unsigned int flags, int error)
 490 {
 491         if (!error) {
 492                 flush_swap_writer(handle);
 493                 printk(KERN_INFO "PM: S");
 494                 error = mark_swapfiles(handle, flags);
 495                 printk("|\n");
 496         }
 497
 498         if (error)
 499                 free_all_swap_pages(root_swap);
 500         release_swap_writer(handle);
 501         swsusp_close(FMODE_WRITE);
 502
 503         return error;
 504 }
 505
 506 /* We need to remember how much compressed data we need to read. */
 507 #define LZO_HEADER      sizeof(size_t)
 508
 509 /* Number of pages/bytes we'll compress at one time. */
 510 #define LZO_UNC_PAGES   32
 511 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 512
 513 /* Number of pages/bytes we need for compressed data (worst case). */
 514 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 515                                      LZO_HEADER, PAGE_SIZE)
 516 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 517
 518 /* Maximum number of threads for compression/decompression. */
 519 #define LZO_THREADS     3
 520
 521 /* Minimum/maximum number of pages for read buffering. */
 522 #define LZO_MIN_RD_PAGES        1024
 523 #define LZO_MAX_RD_PAGES        8192
 524
 525
 526 /**
 527  *      save_image - save the suspend image data
 528  */
 529
 530 static int save_image(struct swap_map_handle *handle,
 531                       struct snapshot_handle *snapshot,
 532                       unsigned int nr_to_write)
 533 {
 534         unsigned int m;
 535         int ret;
 536         int nr_pages;
 537         int err2;
 538         struct hib_bio_batch hb;
 539         ktime_t start;
 540         ktime_t stop;
 541
 542         hib_init_batch(&hb);
 543
 544         printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
 545                 nr_to_write);
 546         m = nr_to_write / 10;
 547         if (!m)
 548                 m = 1;
 549         nr_pages = 0;
 550         start = ktime_get();
 551         while (1) {
 552                 ret = snapshot_read_next(snapshot);
 553                 if (ret <= 0)
 554                         break;
 555                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 556                 if (ret)
 557                         break;
 558                 if (!(nr_pages % m))
 559                         printk(KERN_INFO "PM: Image saving progress: %3d%%\n",
 560                                nr_pages / m * 10);
 561                 nr_pages++;
 562         }
 563         err2 = hib_wait_io(&hb);
 564         stop = ktime_get();
 565         if (!ret)
 566                 ret = err2;
 567         if (!ret)
 568                 printk(KERN_INFO "PM: Image saving done.\n");
 569         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 570         return ret;
 571 }
 572
 573 /**
 574  * Structure used for CRC32.
 575  */
 576 struct crc_data {
 577         struct task_struct *thr;                  /* thread */
 578         atomic_t ready;                           /* ready to start flag */
 579         atomic_t stop;                            /* ready to stop flag */
 580         unsigned run_threads;                     /* nr current threads */
 581         wait_queue_head_t go;                     /* start crc update */
 582         wait_queue_head_t done;                   /* crc update done */
 583         u32 *crc32;                               /* points to handle's crc32 */
 584         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 585         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 586 };
 587
 588 /**
 589  * CRC32 update function that runs in its own thread.
 590  */
 591 static int crc32_threadfn(void *data)
 592 {
 593         struct crc_data *d = data;
 594         unsigned i;
 595
 596         while (1) {
 597                 wait_event(d->go, atomic_read(&d->ready) ||
 598                                   kthread_should_stop());
 599                 if (kthread_should_stop()) {
 600                         d->thr = NULL;
 601                         atomic_set(&d->stop, 1);
 602                         wake_up(&d->done);
 603                         break;
 604                 }
 605                 atomic_set(&d->ready, 0);
 606
 607                 for (i = 0; i < d->run_threads; i++)
 608                         *d->crc32 = crc32_le(*d->crc32,
 609                                              d->unc[i], *d->unc_len[i]);
 610                 atomic_set(&d->stop, 1);
 611                 wake_up(&d->done);
 612         }
 613         return 0;
 614 }
 615 /**
 616  * Structure used for LZO data compression.
 617  */
 618 struct cmp_data {
 619         struct task_struct *thr;                  /* thread */
 620         atomic_t ready;                           /* ready to start flag */
 621         atomic_t stop;                            /* ready to stop flag */
 622         int ret;                                  /* return code */
 623         wait_queue_head_t go;                     /* start compression */
 624         wait_queue_head_t done;                   /* compression done */
 625         size_t unc_len;                           /* uncompressed length */
 626         size_t cmp_len;                           /* compressed length */
 627         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 628         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 629         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 630 };
 631
 632 /**
 633  * Compression function that runs in its own thread.
 634  */
 635 static int lzo_compress_threadfn(void *data)
 636 {
 637         struct cmp_data *d = data;
 638
 639         while (1) {
 640                 wait_event(d->go, atomic_read(&d->ready) ||
 641                                   kthread_should_stop());
 642                 if (kthread_should_stop()) {
 643                         d->thr = NULL;
 644                         d->ret = -1;
 645                         atomic_set(&d->stop, 1);
 646                         wake_up(&d->done);
 647                         break;
 648                 }
 649                 atomic_set(&d->ready, 0);
 650
 651                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 652                                           d->cmp + LZO_HEADER, &d->cmp_len,
 653                                           d->wrk);
 654                 atomic_set(&d->stop, 1);
 655                 wake_up(&d->done);
 656         }
 657         return 0;
 658 }
 659
 660 /**
 661  * save_image_lzo - Save the suspend image data compressed with LZO.
 662  * @handle: Swap map handle to use for saving the image.
 663  * @snapshot: Image to read data from.
 664  * @nr_to_write: Number of pages to save.
 665  */
 666 static int save_image_lzo(struct swap_map_handle *handle,
 667                           struct snapshot_handle *snapshot,
 668                           unsigned int nr_to_write)
 669 {
 670         unsigned int m;
 671         int ret = 0;
 672         int nr_pages;
 673         int err2;
 674         struct hib_bio_batch hb;
 675         ktime_t start;
 676         ktime_t stop;
 677         size_t off;
 678         unsigned thr, run_threads, nr_threads;
 679         unsigned char *page = NULL;
 680         struct cmp_data *data = NULL;
 681         struct crc_data *crc = NULL;
 682
 683         hib_init_batch(&hb);
 684
 685         /*
 686          * We'll limit the number of threads for compression to limit memory
 687          * footprint.
 688          */
 689         nr_threads = num_online_cpus() - 1;
 690         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 691
 692         page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 693         if (!page) {
 694                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
 695                 ret = -ENOMEM;
 696                 goto out_clean;
 697         }
 698
 699         data = vmalloc(sizeof(*data) * nr_threads);
 700         if (!data) {
 701                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
 702                 ret = -ENOMEM;
 703                 goto out_clean;
 704         }
 705         for (thr = 0; thr < nr_threads; thr++)
 706                 memset(&data[thr], 0, offsetof(struct cmp_data, go));
 707
 708         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
 709         if (!crc) {
 710                 printk(KERN_ERR "PM: Failed to allocate crc\n");
 711                 ret = -ENOMEM;
 712                 goto out_clean;
 713         }
 714         memset(crc, 0, offsetof(struct crc_data, go));
 715
 716         /*
 717          * Start the compression threads.
 718          */
 719         for (thr = 0; thr < nr_threads; thr++) {
 720                 init_waitqueue_head(&data[thr].go);
 721                 init_waitqueue_head(&data[thr].done);
 722
 723                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 724                                             &data[thr],
 725                                             "image_compress/%u", thr);
 726                 if (IS_ERR(data[thr].thr)) {
 727                         data[thr].thr = NULL;
 728                         printk(KERN_ERR
 729                                "PM: Cannot start compression threads\n");
 730                         ret = -ENOMEM;
 731                         goto out_clean;
 732                 }
 733         }
 734
 735         /*
 736          * Start the CRC32 thread.
 737          */
 738         init_waitqueue_head(&crc->go);
 739         init_waitqueue_head(&crc->done);
 740
 741         handle->crc32 = 0;
 742         crc->crc32 = &handle->crc32;
 743         for (thr = 0; thr < nr_threads; thr++) {
 744                 crc->unc[thr] = data[thr].unc;
 745                 crc->unc_len[thr] = &data[thr].unc_len;
 746         }
 747
 748         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 749         if (IS_ERR(crc->thr)) {
 750                 crc->thr = NULL;
 751                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
 752                 ret = -ENOMEM;
 753                 goto out_clean;
 754         }
 755
 756         /*
 757          * Adjust the number of required free pages after all allocations have
 758          * been done. We don't want to run out of pages when writing.
 759          */
 760         handle->reqd_free_pages = reqd_free_pages();
 761
 762         printk(KERN_INFO
 763                 "PM: Using %u thread(s) for compression.\n"
 764                 "PM: Compressing and saving image data (%u pages)...\n",
 765                 nr_threads, nr_to_write);
 766         m = nr_to_write / 10;
 767         if (!m)
 768                 m = 1;
 769         nr_pages = 0;
 770         start = ktime_get();
 771         for (;;) {
 772                 for (thr = 0; thr < nr_threads; thr++) {
 773                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 774                                 ret = snapshot_read_next(snapshot);
 775                                 if (ret < 0)
 776                                         goto out_finish;
 777
 778                                 if (!ret)
 779                                         break;
 780
 781                                 memcpy(data[thr].unc + off,
 782                                        data_of(*snapshot), PAGE_SIZE);
 783
 784                                 if (!(nr_pages % m))
 785                                         printk(KERN_INFO
 786                                                "PM: Image saving progress: "
 787                                                "%3d%%\n",
 788                                                nr_pages / m * 10);
 789                                 nr_pages++;
 790                         }
 791                         if (!off)
 792                                 break;
 793
 794                         data[thr].unc_len = off;
 795
 796                         atomic_set(&data[thr].ready, 1);
 797                         wake_up(&data[thr].go);
 798                 }
 799
 800                 if (!thr)
 801                         break;
 802
 803                 crc->run_threads = thr;
 804                 atomic_set(&crc->ready, 1);
 805                 wake_up(&crc->go);
 806
 807                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 808                         wait_event(data[thr].done,
 809                                    atomic_read(&data[thr].stop));
 810                         atomic_set(&data[thr].stop, 0);
 811
 812                         ret = data[thr].ret;
 813
 814                         if (ret < 0) {
 815                                 printk(KERN_ERR "PM: LZO compression failed\n");
 816                                 goto out_finish;
 817                         }
 818
 819                         if (unlikely(!data[thr].cmp_len ||
 820                                      data[thr].cmp_len >
 821                                      lzo1x_worst_compress(data[thr].unc_len))) {
 822                                 printk(KERN_ERR
 823                                        "PM: Invalid LZO compressed length\n");
 824                                 ret = -1;
 825                                 goto out_finish;
 826                         }
 827
 828                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 829
 830                         /*
 831                          * Given we are writing one page at a time to disk, we
 832                          * copy that much from the buffer, although the last
 833                          * bit will likely be smaller than full page. This is
 834                          * OK - we saved the length of the compressed data, so
 835                          * any garbage at the end will be discarded when we
 836                          * read it.
 837                          */
 838                         for (off = 0;
 839                              off < LZO_HEADER + data[thr].cmp_len;
 840                              off += PAGE_SIZE) {
 841                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 842
 843                                 ret = swap_write_page(handle, page, &hb);
 844                                 if (ret)
 845                                         goto out_finish;
 846                         }
 847                 }
 848
 849                 wait_event(crc->done, atomic_read(&crc->stop));
 850                 atomic_set(&crc->stop, 0);
 851         }
 852
 853 out_finish:
 854         err2 = hib_wait_io(&hb);
 855         stop = ktime_get();
 856         if (!ret)
 857                 ret = err2;
 858         if (!ret)
 859                 printk(KERN_INFO "PM: Image saving done.\n");
 860         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 861 out_clean:
 862         if (crc) {
 863                 if (crc->thr)
 864                         kthread_stop(crc->thr);
 865                 kfree(crc);
 866         }
 867         if (data) {
 868                 for (thr = 0; thr < nr_threads; thr++)
 869                         if (data[thr].thr)
 870                                 kthread_stop(data[thr].thr);
 871                 vfree(data);
 872         }
 873         if (page) free_page((unsigned long)page);
 874
 875         return ret;
 876 }
 877
 878 /**
 879  *      enough_swap - Make sure we have enough swap to save the image.
 880  *
 881  *      Returns TRUE or FALSE after checking the total amount of swap
 882  *      space avaiable from the resume partition.
 883  */
 884
 885 static int enough_swap(unsigned int nr_pages, unsigned int flags)
 886 {
 887         unsigned int free_swap = count_swap_pages(root_swap, 1);
 888         unsigned int required;
 889
 890         pr_debug("PM: Free swap pages: %u\n", free_swap);
 891
 892         required = PAGES_FOR_IO + nr_pages;
 893         return free_swap > required;
 894 }
 895
 896 /**
 897  *      swsusp_write - Write entire image and metadata.
 898  *      @flags: flags to pass to the "boot" kernel in the image header
 899  *
 900  *      It is important _NOT_ to umount filesystems at this point. We want
 901  *      them synced (in case something goes wrong) but we DO not want to mark
 902  *      filesystem clean: it is not. (And it does not matter, if we resume
 903  *      correctly, we'll mark system clean, anyway.)
 904  */
 905
 906 int swsusp_write(unsigned int flags)
 907 {
 908         struct swap_map_handle handle;
 909         struct snapshot_handle snapshot;
 910         struct swsusp_info *header;
 911         unsigned long pages;
 912         int error;
 913
 914         pages = snapshot_get_image_size();
 915         error = get_swap_writer(&handle);
 916         if (error) {
 917                 printk(KERN_ERR "PM: Cannot get swap writer\n");
 918                 return error;
 919         }
 920         if (flags & SF_NOCOMPRESS_MODE) {
 921                 if (!enough_swap(pages, flags)) {
 922                         printk(KERN_ERR "PM: Not enough free swap\n");
 923                         error = -ENOSPC;
 924                         goto out_finish;
 925                 }
 926         }
 927         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 928         error = snapshot_read_next(&snapshot);
 929         if (error < PAGE_SIZE) {
 930                 if (error >= 0)
 931                         error = -EFAULT;
 932
 933                 goto out_finish;
 934         }
 935         header = (struct swsusp_info *)data_of(snapshot);
 936         error = swap_write_page(&handle, header, NULL);
 937         if (!error) {
 938                 error = (flags & SF_NOCOMPRESS_MODE) ?
 939                         save_image(&handle, &snapshot, pages - 1) :
 940                         save_image_lzo(&handle, &snapshot, pages - 1);
 941         }
 942 out_finish:
 943         error = swap_writer_finish(&handle, flags, error);
 944         return error;
 945 }
 946
 947 /**
 948  *      The following functions allow us to read data using a swap map
 949  *      in a file-alike way
 950  */
 951
 952 static void release_swap_reader(struct swap_map_handle *handle)
 953 {
 954         struct swap_map_page_list *tmp;
 955
 956         while (handle->maps) {
 957                 if (handle->maps->map)
 958                         free_page((unsigned long)handle->maps->map);
 959                 tmp = handle->maps;
 960                 handle->maps = handle->maps->next;
 961                 kfree(tmp);
 962         }
 963         handle->cur = NULL;
 964 }
 965
 966 static int get_swap_reader(struct swap_map_handle *handle,
 967                 unsigned int *flags_p)
 968 {
 969         int error;
 970         struct swap_map_page_list *tmp, *last;
 971         sector_t offset;
 972
 973         *flags_p = swsusp_header->flags;
 974
 975         if (!swsusp_header->image) /* how can this happen? */
 976                 return -EINVAL;
 977
 978         handle->cur = NULL;
 979         last = handle->maps = NULL;
 980         offset = swsusp_header->image;
 981         while (offset) {
 982                 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
 983                 if (!tmp) {
 984                         release_swap_reader(handle);
 985                         return -ENOMEM;
 986                 }
 987                 memset(tmp, 0, sizeof(*tmp));
 988                 if (!handle->maps)
 989                         handle->maps = tmp;
 990                 if (last)
 991                         last->next = tmp;
 992                 last = tmp;
 993
 994                 tmp->map = (struct swap_map_page *)
 995                            __get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 996                 if (!tmp->map) {
 997                         release_swap_reader(handle);
 998                         return -ENOMEM;
 999                 }
1000
1001                 error = hib_submit_io(READ_SYNC, offset, tmp->map, NULL);
1002                 if (error) {
1003                         release_swap_reader(handle);
1004                         return error;
1005                 }
1006                 offset = tmp->map->next_swap;
1007         }
1008         handle->k = 0;
1009         handle->cur = handle->maps->map;
1010         return 0;
1011 }
1012
1013 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1014                 struct hib_bio_batch *hb)
1015 {
1016         sector_t offset;
1017         int error;
1018         struct swap_map_page_list *tmp;
1019
1020         if (!handle->cur)
1021                 return -EINVAL;
1022         offset = handle->cur->entries[handle->k];
1023         if (!offset)
1024                 return -EFAULT;
1025         error = hib_submit_io(READ_SYNC, offset, buf, hb);
1026         if (error)
1027                 return error;
1028         if (++handle->k >= MAP_PAGE_ENTRIES) {
1029                 handle->k = 0;
1030                 free_page((unsigned long)handle->maps->map);
1031                 tmp = handle->maps;
1032                 handle->maps = handle->maps->next;
1033                 kfree(tmp);
1034                 if (!handle->maps)
1035                         release_swap_reader(handle);
1036                 else
1037                         handle->cur = handle->maps->map;
1038         }
1039         return error;
1040 }
1041
1042 static int swap_reader_finish(struct swap_map_handle *handle)
1043 {
1044         release_swap_reader(handle);
1045
1046         return 0;
1047 }
1048
1049 /**
1050  *      load_image - load the image using the swap map handle
1051  *      @handle and the snapshot handle @snapshot
1052  *      (assume there are @nr_pages pages to load)
1053  */
1054
1055 static int load_image(struct swap_map_handle *handle,
1056                       struct snapshot_handle *snapshot,
1057                       unsigned int nr_to_read)
1058 {
1059         unsigned int m;
1060         int ret = 0;
1061         ktime_t start;
1062         ktime_t stop;
1063         struct hib_bio_batch hb;
1064         int err2;
1065         unsigned nr_pages;
1066
1067         hib_init_batch(&hb);
1068
1069         clean_pages_on_read = true;
1070         printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
1071                 nr_to_read);
1072         m = nr_to_read / 10;
1073         if (!m)
1074                 m = 1;
1075         nr_pages = 0;
1076         start = ktime_get();
1077         for ( ; ; ) {
1078                 ret = snapshot_write_next(snapshot);
1079                 if (ret <= 0)
1080                         break;
1081                 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1082                 if (ret)
1083                         break;
1084                 if (snapshot->sync_read)
1085                         ret = hib_wait_io(&hb);
1086                 if (ret)
1087                         break;
1088                 if (!(nr_pages % m))
1089                         printk(KERN_INFO "PM: Image loading progress: %3d%%\n",
1090                                nr_pages / m * 10);
1091                 nr_pages++;
1092         }
1093         err2 = hib_wait_io(&hb);
1094         stop = ktime_get();
1095         if (!ret)
1096                 ret = err2;
1097         if (!ret) {
1098                 printk(KERN_INFO "PM: Image loading done.\n");
1099                 snapshot_write_finalize(snapshot);
1100                 if (!snapshot_image_loaded(snapshot))
1101                         ret = -ENODATA;
1102         }
1103         swsusp_show_speed(start, stop, nr_to_read, "Read");
1104         return ret;
1105 }
1106
1107 /**
1108  * Structure used for LZO data decompression.
1109  */
1110 struct dec_data {
1111         struct task_struct *thr;                  /* thread */
1112         atomic_t ready;                           /* ready to start flag */
1113         atomic_t stop;                            /* ready to stop flag */
1114         int ret;                                  /* return code */
1115         wait_queue_head_t go;                     /* start decompression */
1116         wait_queue_head_t done;                   /* decompression done */
1117         size_t unc_len;                           /* uncompressed length */
1118         size_t cmp_len;                           /* compressed length */
1119         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1120         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1121 };
1122
1123 /**
1124  * Deompression function that runs in its own thread.
1125  */
1126 static int lzo_decompress_threadfn(void *data)
1127 {
1128         struct dec_data *d = data;
1129
1130         while (1) {
1131                 wait_event(d->go, atomic_read(&d->ready) ||
1132                                   kthread_should_stop());
1133                 if (kthread_should_stop()) {
1134                         d->thr = NULL;
1135                         d->ret = -1;
1136                         atomic_set(&d->stop, 1);
1137                         wake_up(&d->done);
1138                         break;
1139                 }
1140                 atomic_set(&d->ready, 0);
1141
1142                 d->unc_len = LZO_UNC_SIZE;
1143                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1144                                                d->unc, &d->unc_len);
1145                 if (clean_pages_on_decompress)
1146                         flush_icache_range((unsigned long)d->unc,
1147                                            (unsigned long)d->unc + d->unc_len);
1148
1149                 atomic_set(&d->stop, 1);
1150                 wake_up(&d->done);
1151         }
1152         return 0;
1153 }
1154
1155 /**
1156  * load_image_lzo - Load compressed image data and decompress them with LZO.
1157  * @handle: Swap map handle to use for loading data.
1158  * @snapshot: Image to copy uncompressed data into.
1159  * @nr_to_read: Number of pages to load.
1160  */
1161 static int load_image_lzo(struct swap_map_handle *handle,
1162                           struct snapshot_handle *snapshot,
1163                           unsigned int nr_to_read)
1164 {
1165         unsigned int m;
1166         int ret = 0;
1167         int eof = 0;
1168         struct hib_bio_batch hb;
1169         ktime_t start;
1170         ktime_t stop;
1171         unsigned nr_pages;
1172         size_t off;
1173         unsigned i, thr, run_threads, nr_threads;
1174         unsigned ring = 0, pg = 0, ring_size = 0,
1175                  have = 0, want, need, asked = 0;
1176         unsigned long read_pages = 0;
1177         unsigned char **page = NULL;
1178         struct dec_data *data = NULL;
1179         struct crc_data *crc = NULL;
1180
1181         hib_init_batch(&hb);
1182
1183         /*
1184          * We'll limit the number of threads for decompression to limit memory
1185          * footprint.
1186          */
1187         nr_threads = num_online_cpus() - 1;
1188         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1189
1190         page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1191         if (!page) {
1192                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1193                 ret = -ENOMEM;
1194                 goto out_clean;
1195         }
1196
1197         data = vmalloc(sizeof(*data) * nr_threads);
1198         if (!data) {
1199                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1200                 ret = -ENOMEM;
1201                 goto out_clean;
1202         }
1203         for (thr = 0; thr < nr_threads; thr++)
1204                 memset(&data[thr], 0, offsetof(struct dec_data, go));
1205
1206         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1207         if (!crc) {
1208                 printk(KERN_ERR "PM: Failed to allocate crc\n");
1209                 ret = -ENOMEM;
1210                 goto out_clean;
1211         }
1212         memset(crc, 0, offsetof(struct crc_data, go));
1213
1214         clean_pages_on_decompress = true;
1215
1216         /*
1217          * Start the decompression threads.
1218          */
1219         for (thr = 0; thr < nr_threads; thr++) {
1220                 init_waitqueue_head(&data[thr].go);
1221                 init_waitqueue_head(&data[thr].done);
1222
1223                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1224                                             &data[thr],
1225                                             "image_decompress/%u", thr);
1226                 if (IS_ERR(data[thr].thr)) {
1227                         data[thr].thr = NULL;
1228                         printk(KERN_ERR
1229                                "PM: Cannot start decompression threads\n");
1230                         ret = -ENOMEM;
1231                         goto out_clean;
1232                 }
1233         }
1234
1235         /*
1236          * Start the CRC32 thread.
1237          */
1238         init_waitqueue_head(&crc->go);
1239         init_waitqueue_head(&crc->done);
1240
1241         handle->crc32 = 0;
1242         crc->crc32 = &handle->crc32;
1243         for (thr = 0; thr < nr_threads; thr++) {
1244                 crc->unc[thr] = data[thr].unc;
1245                 crc->unc_len[thr] = &data[thr].unc_len;
1246         }
1247
1248         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1249         if (IS_ERR(crc->thr)) {
1250                 crc->thr = NULL;
1251                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
1252                 ret = -ENOMEM;
1253                 goto out_clean;
1254         }
1255
1256         /*
1257          * Set the number of pages for read buffering.
1258          * This is complete guesswork, because we'll only know the real
1259          * picture once prepare_image() is called, which is much later on
1260          * during the image load phase. We'll assume the worst case and
1261          * say that none of the image pages are from high memory.
1262          */
1263         if (low_free_pages() > snapshot_get_image_size())
1264                 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1265         read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1266
1267         for (i = 0; i < read_pages; i++) {
1268                 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1269                                                   __GFP_RECLAIM | __GFP_HIGH :
1270                                                   __GFP_RECLAIM | __GFP_NOWARN |
1271                                                   __GFP_NORETRY);
1272
1273                 if (!page[i]) {
1274                         if (i < LZO_CMP_PAGES) {
1275                                 ring_size = i;
1276                                 printk(KERN_ERR
1277                                        "PM: 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         printk(KERN_INFO
1288                 "PM: Using %u thread(s) for decompression.\n"
1289                 "PM: Loading and decompressing image data (%u pages)...\n",
1290                 nr_threads, nr_to_read);
1291         m = nr_to_read / 10;
1292         if (!m)
1293                 m = 1;
1294         nr_pages = 0;
1295         start = ktime_get();
1296
1297         ret = snapshot_write_next(snapshot);
1298         if (ret <= 0)
1299                 goto out_finish;
1300
1301         for(;;) {
1302                 for (i = 0; !eof && i < want; i++) {
1303                         ret = swap_read_page(handle, page[ring], &hb);
1304                         if (ret) {
1305                                 /*
1306                                  * On real read error, finish. On end of data,
1307                                  * set EOF flag and just exit the read loop.
1308                                  */
1309                                 if (handle->cur &&
1310                                     handle->cur->entries[handle->k]) {
1311                                         goto out_finish;
1312                                 } else {
1313                                         eof = 1;
1314                                         break;
1315                                 }
1316                         }
1317                         if (++ring >= ring_size)
1318                                 ring = 0;
1319                 }
1320                 asked += i;
1321                 want -= i;
1322
1323                 /*
1324                  * We are out of data, wait for some more.
1325                  */
1326                 if (!have) {
1327                         if (!asked)
1328                                 break;
1329
1330                         ret = hib_wait_io(&hb);
1331                         if (ret)
1332                                 goto out_finish;
1333                         have += asked;
1334                         asked = 0;
1335                         if (eof)
1336                                 eof = 2;
1337                 }
1338
1339                 if (crc->run_threads) {
1340                         wait_event(crc->done, atomic_read(&crc->stop));
1341                         atomic_set(&crc->stop, 0);
1342                         crc->run_threads = 0;
1343                 }
1344
1345                 for (thr = 0; have && thr < nr_threads; thr++) {
1346                         data[thr].cmp_len = *(size_t *)page[pg];
1347                         if (unlikely(!data[thr].cmp_len ||
1348                                      data[thr].cmp_len >
1349                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1350                                 printk(KERN_ERR
1351                                        "PM: 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                                 printk(KERN_ERR
1403                                        "PM: LZO decompression failed\n");
1404                                 goto out_finish;
1405                         }
1406
1407                         if (unlikely(!data[thr].unc_len ||
1408                                      data[thr].unc_len > LZO_UNC_SIZE ||
1409                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1410                                 printk(KERN_ERR
1411                                        "PM: Invalid LZO uncompressed length\n");
1412                                 ret = -1;
1413                                 goto out_finish;
1414                         }
1415
1416                         for (off = 0;
1417                              off < data[thr].unc_len; off += PAGE_SIZE) {
1418                                 memcpy(data_of(*snapshot),
1419                                        data[thr].unc + off, PAGE_SIZE);
1420
1421                                 if (!(nr_pages % m))
1422                                         printk(KERN_INFO
1423                                                "PM: Image loading progress: "
1424                                                "%3d%%\n",
1425                                                nr_pages / m * 10);
1426                                 nr_pages++;
1427
1428                                 ret = snapshot_write_next(snapshot);
1429                                 if (ret <= 0) {
1430                                         crc->run_threads = thr + 1;
1431                                         atomic_set(&crc->ready, 1);
1432                                         wake_up(&crc->go);
1433                                         goto out_finish;
1434                                 }
1435                         }
1436                 }
1437
1438                 crc->run_threads = thr;
1439                 atomic_set(&crc->ready, 1);
1440                 wake_up(&crc->go);
1441         }
1442
1443 out_finish:
1444         if (crc->run_threads) {
1445                 wait_event(crc->done, atomic_read(&crc->stop));
1446                 atomic_set(&crc->stop, 0);
1447         }
1448         stop = ktime_get();
1449         if (!ret) {
1450                 printk(KERN_INFO "PM: Image loading done.\n");
1451                 snapshot_write_finalize(snapshot);
1452                 if (!snapshot_image_loaded(snapshot))
1453                         ret = -ENODATA;
1454                 if (!ret) {
1455                         if (swsusp_header->flags & SF_CRC32_MODE) {
1456                                 if(handle->crc32 != swsusp_header->crc32) {
1457                                         printk(KERN_ERR
1458                                                "PM: Invalid image CRC32!\n");
1459                                         ret = -ENODATA;
1460                                 }
1461                         }
1462                 }
1463         }
1464         swsusp_show_speed(start, stop, nr_to_read, "Read");
1465 out_clean:
1466         for (i = 0; i < ring_size; i++)
1467                 free_page((unsigned long)page[i]);
1468         if (crc) {
1469                 if (crc->thr)
1470                         kthread_stop(crc->thr);
1471                 kfree(crc);
1472         }
1473         if (data) {
1474                 for (thr = 0; thr < nr_threads; thr++)
1475                         if (data[thr].thr)
1476                                 kthread_stop(data[thr].thr);
1477                 vfree(data);
1478         }
1479         vfree(page);
1480
1481         return ret;
1482 }
1483
1484 /**
1485  *      swsusp_read - read the hibernation image.
1486  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1487  *                be written into this memory location
1488  */
1489
1490 int swsusp_read(unsigned int *flags_p)
1491 {
1492         int error;
1493         struct swap_map_handle handle;
1494         struct snapshot_handle snapshot;
1495         struct swsusp_info *header;
1496
1497         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1498         error = snapshot_write_next(&snapshot);
1499         if (error < PAGE_SIZE)
1500                 return error < 0 ? error : -EFAULT;
1501         header = (struct swsusp_info *)data_of(snapshot);
1502         error = get_swap_reader(&handle, flags_p);
1503         if (error)
1504                 goto end;
1505         if (!error)
1506                 error = swap_read_page(&handle, header, NULL);
1507         if (!error) {
1508                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1509                         load_image(&handle, &snapshot, header->pages - 1) :
1510                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1511         }
1512         swap_reader_finish(&handle);
1513 end:
1514         if (!error)
1515                 pr_debug("PM: Image successfully loaded\n");
1516         else
1517                 pr_debug("PM: Error %d resuming\n", error);
1518         return error;
1519 }
1520
1521 /**
1522  *      swsusp_check - Check for swsusp signature in the resume device
1523  */
1524
1525 int swsusp_check(void)
1526 {
1527         int error;
1528
1529         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1530                                             FMODE_READ, NULL);
1531         if (!IS_ERR(hib_resume_bdev)) {
1532                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1533                 clear_page(swsusp_header);
1534                 error = hib_submit_io(READ_SYNC, swsusp_resume_block,
1535                                         swsusp_header, NULL);
1536                 if (error)
1537                         goto put;
1538
1539                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1540                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1541                         /* Reset swap signature now */
1542                         error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1543                                                 swsusp_header, NULL);
1544                 } else {
1545                         error = -EINVAL;
1546                 }
1547
1548 put:
1549                 if (error)
1550                         blkdev_put(hib_resume_bdev, FMODE_READ);
1551                 else
1552                         pr_debug("PM: Image signature found, resuming\n");
1553         } else {
1554                 error = PTR_ERR(hib_resume_bdev);
1555         }
1556
1557         if (error)
1558                 pr_debug("PM: Image not found (code %d)\n", error);
1559
1560         return error;
1561 }
1562
1563 /**
1564  *      swsusp_close - close swap device.
1565  */
1566
1567 void swsusp_close(fmode_t mode)
1568 {
1569         if (IS_ERR(hib_resume_bdev)) {
1570                 pr_debug("PM: Image device not initialised\n");
1571                 return;
1572         }
1573
1574         blkdev_put(hib_resume_bdev, mode);
1575 }
1576
1577 /**
1578  *      swsusp_unmark - Unmark swsusp signature in the resume device
1579  */
1580
1581 #ifdef CONFIG_SUSPEND
1582 int swsusp_unmark(void)
1583 {
1584         int error;
1585
1586         hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
1587         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1588                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1589                 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1590                                         swsusp_header, NULL);
1591         } else {
1592                 printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
1593                 error = -ENODEV;
1594         }
1595
1596         /*
1597          * We just returned from suspend, we don't need the image any more.
1598          */
1599         free_all_swap_pages(root_swap);
1600
1601         return error;
1602 }
1603 #endif
1604
1605 static int swsusp_header_init(void)
1606 {
1607         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1608         if (!swsusp_header)
1609                 panic("Could not allocate memory for swsusp_header\n");
1610         return 0;
1611 }
1612
1613 core_initcall(swsusp_header_init);