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 static int goldenimage;
  40 /*
  41  * When reading an {un,}compressed image, we may restore pages in place,
  42  * in which case some architectures need these pages cleaning before they
  43  * can be executed. We don't know which pages these may be, so clean the lot.
  44  */
  45 static bool clean_pages_on_read;
  46 static bool clean_pages_on_decompress;
  47
  48 /*
  49  * When reading an {un,}compressed image, we may restore pages in place,
  50  * in which case some architectures need these pages cleaning before they
  51  * can be executed. We don't know which pages these may be, so clean the lot.
  52  */
  53 static bool clean_pages_on_read;
  54 static bool clean_pages_on_decompress;
  55
  56 /*
  57  *      The swap map is a data structure used for keeping track of each page
  58  *      written to a swap partition.  It consists of many swap_map_page
  59  *      structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
  60  *      These structures are stored on the swap and linked together with the
  61  *      help of the .next_swap member.
  62  *
  63  *      The swap map is created during suspend.  The swap map pages are
  64  *      allocated and populated one at a time, so we only need one memory
  65  *      page to set up the entire structure.
  66  *
  67  *      During resume we pick up all swap_map_page structures into a list.
  68  */
  69
  70 #define MAP_PAGE_ENTRIES        (PAGE_SIZE / sizeof(sector_t) - 1)
  71
  72 /*
  73  * Number of free pages that are not high.
  74  */
  75 static inline unsigned long low_free_pages(void)
  76 {
  77         return nr_free_pages() - nr_free_highpages();
  78 }
  79
  80 /*
  81  * Number of pages required to be kept free while writing the image. Always
  82  * half of all available low pages before the writing starts.
  83  */
  84 static inline unsigned long reqd_free_pages(void)
  85 {
  86         return low_free_pages() / 2;
  87 }
  88
  89 struct swap_map_page {
  90         sector_t entries[MAP_PAGE_ENTRIES];
  91         sector_t next_swap;
  92 };
  93
  94 struct swap_map_page_list {
  95         struct swap_map_page *map;
  96         struct swap_map_page_list *next;
  97 };
  98
  99 /**
 100  *      The swap_map_handle structure is used for handling swap in
 101  *      a file-alike way
 102  */
 103
 104 struct swap_map_handle {
 105         struct swap_map_page *cur;
 106         struct swap_map_page_list *maps;
 107         sector_t cur_swap;
 108         sector_t first_sector;
 109         unsigned int k;
 110         unsigned long reqd_free_pages;
 111         u32 crc32;
 112 };
 113
 114 struct swsusp_header {
 115         char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
 116                       sizeof(u32)];
 117         u32     crc32;
 118         sector_t image;
 119         unsigned int flags;     /* Flags to pass to the "boot" kernel */
 120         char    orig_sig[10];
 121         char    sig[10];
 122 } __packed;
 123
 124 static struct swsusp_header *swsusp_header;
 125
 126 /**
 127  *      The following functions are used for tracing the allocated
 128  *      swap pages, so that they can be freed in case of an error.
 129  */
 130
 131 struct swsusp_extent {
 132         struct rb_node node;
 133         unsigned long start;
 134         unsigned long end;
 135 };
 136
 137 static struct rb_root swsusp_extents = RB_ROOT;
 138
 139 static int swsusp_extents_insert(unsigned long swap_offset)
 140 {
 141         struct rb_node **new = &(swsusp_extents.rb_node);
 142         struct rb_node *parent = NULL;
 143         struct swsusp_extent *ext;
 144
 145         /* Figure out where to put the new node */
 146         while (*new) {
 147                 ext = rb_entry(*new, struct swsusp_extent, node);
 148                 parent = *new;
 149                 if (swap_offset < ext->start) {
 150                         /* Try to merge */
 151                         if (swap_offset == ext->start - 1) {
 152                                 ext->start--;
 153                                 return 0;
 154                         }
 155                         new = &((*new)->rb_left);
 156                 } else if (swap_offset > ext->end) {
 157                         /* Try to merge */
 158                         if (swap_offset == ext->end + 1) {
 159                                 ext->end++;
 160                                 return 0;
 161                         }
 162                         new = &((*new)->rb_right);
 163                 } else {
 164                         /* It already is in the tree */
 165                         return -EINVAL;
 166                 }
 167         }
 168         /* Add the new node and rebalance the tree. */
 169         ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
 170         if (!ext)
 171                 return -ENOMEM;
 172
 173         ext->start = swap_offset;
 174         ext->end = swap_offset;
 175         rb_link_node(&ext->node, parent, new);
 176         rb_insert_color(&ext->node, &swsusp_extents);
 177         return 0;
 178 }
 179
 180 /**
 181  *      alloc_swapdev_block - allocate a swap page and register that it has
 182  *      been allocated, so that it can be freed in case of an error.
 183  */
 184
 185 sector_t alloc_swapdev_block(int swap)
 186 {
 187         unsigned long offset;
 188
 189         offset = swp_offset(get_swap_page_of_type(swap));
 190         if (offset) {
 191                 if (swsusp_extents_insert(offset))
 192                         swap_free(swp_entry(swap, offset));
 193                 else
 194                         return swapdev_block(swap, offset);
 195         }
 196         return 0;
 197 }
 198
 199 /**
 200  *      free_all_swap_pages - free swap pages allocated for saving image data.
 201  *      It also frees the extents used to register which swap entries had been
 202  *      allocated.
 203  */
 204
 205 void free_all_swap_pages(int swap)
 206 {
 207         struct rb_node *node;
 208
 209         while ((node = swsusp_extents.rb_node)) {
 210                 struct swsusp_extent *ext;
 211                 unsigned long offset;
 212
 213                 ext = container_of(node, struct swsusp_extent, node);
 214                 rb_erase(node, &swsusp_extents);
 215                 for (offset = ext->start; offset <= ext->end; offset++)
 216                         swap_free(swp_entry(swap, offset));
 217
 218                 kfree(ext);
 219         }
 220 }
 221
 222 int swsusp_swap_in_use(void)
 223 {
 224         return (swsusp_extents.rb_node != NULL);
 225 }
 226
 227 /*
 228  * General things
 229  */
 230
 231 static unsigned short root_swap = 0xffff;
 232 static struct block_device *hib_resume_bdev;
 233
 234 struct hib_bio_batch {
 235         atomic_t                count;
 236         wait_queue_head_t       wait;
 237         int                     error;
 238 };
 239
 240 static void hib_init_batch(struct hib_bio_batch *hb)
 241 {
 242         atomic_set(&hb->count, 0);
 243         init_waitqueue_head(&hb->wait);
 244         hb->error = 0;
 245 }
 246
 247 static void hib_end_io(struct bio *bio)
 248 {
 249         struct hib_bio_batch *hb = bio->bi_private;
 250         struct page *page = bio->bi_io_vec[0].bv_page;
 251
 252         if (bio->bi_error) {
 253                 printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
 254                                 imajor(bio->bi_bdev->bd_inode),
 255                                 iminor(bio->bi_bdev->bd_inode),
 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_error && !hb->error)
 266                 hb->error = bio->bi_error;
 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 rw, 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_RECLAIM | __GFP_HIGH, 1);
 281         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 282         bio->bi_bdev = hib_resume_bdev;
 283
 284         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 285                 printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
 286                         (unsigned long long)bio->bi_iter.bi_sector);
 287                 bio_put(bio);
 288                 return -EFAULT;
 289         }
 290
 291         if (hb) {
 292                 bio->bi_end_io = hib_end_io;
 293                 bio->bi_private = hb;
 294                 atomic_inc(&hb->count);
 295                 submit_bio(rw, bio);
 296         } else {
 297                 error = submit_bio_wait(rw, bio);
 298                 bio_put(bio);
 299         }
 300
 301         return error;
 302 }
 303
 304 static int hib_wait_io(struct hib_bio_batch *hb)
 305 {
 306         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 307         return hb->error;
 308 }
 309
 310 /*
 311  * Saving part
 312  */
 313
 314 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 315 {
 316         int error;
 317
 318         hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
 319         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 320             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 321                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 322                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 323                 swsusp_header->image = handle->first_sector;
 324                 swsusp_header->flags = flags;
 325                 if (flags & SF_CRC32_MODE)
 326                         swsusp_header->crc32 = handle->crc32;
 327                 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
 328                                         swsusp_header, NULL);
 329         } else {
 330                 printk(KERN_ERR "PM: Swap header not found!\n");
 331                 error = -ENODEV;
 332         }
 333         return error;
 334 }
 335
 336 /**
 337  *      swsusp_swap_check - check if the resume device is a swap device
 338  *      and get its index (if so)
 339  *
 340  *      This is called before saving image
 341  */
 342 static int swsusp_swap_check(void)
 343 {
 344         int res;
 345
 346         res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
 347                         &hib_resume_bdev);
 348         if (res < 0)
 349                 return res;
 350
 351         root_swap = res;
 352         res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
 353         if (res)
 354                 return res;
 355
 356         res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 357         if (res < 0)
 358                 blkdev_put(hib_resume_bdev, FMODE_WRITE);
 359
 360         return res;
 361 }
 362
 363 /**
 364  *      write_page - Write one page to given swap location.
 365  *      @buf:           Address we're writing.
 366  *      @offset:        Offset of the swap page we're writing to.
 367  *      @hb:            bio completion batch
 368  */
 369
 370 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 371 {
 372         void *src;
 373         int ret;
 374
 375         if (!offset)
 376                 return -ENOSPC;
 377
 378         if (hb) {
 379                 src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN |
 380                                               __GFP_NORETRY);
 381                 if (src) {
 382                         copy_page(src, buf);
 383                 } else {
 384                         ret = hib_wait_io(hb); /* Free pages */
 385                         if (ret)
 386                                 return ret;
 387                         src = (void *)__get_free_page(__GFP_RECLAIM |
 388                                                       __GFP_NOWARN |
 389                                                       __GFP_NORETRY);
 390                         if (src) {
 391                                 copy_page(src, buf);
 392                         } else {
 393                                 WARN_ON_ONCE(1);
 394                                 hb = NULL;      /* Go synchronous */
 395                                 src = buf;
 396                         }
 397                 }
 398         } else {
 399                 src = buf;
 400         }
 401         return hib_submit_io(WRITE_SYNC, offset, src, hb);
 402 }
 403
 404 static void release_swap_writer(struct swap_map_handle *handle)
 405 {
 406         if (handle->cur)
 407                 free_page((unsigned long)handle->cur);
 408         handle->cur = NULL;
 409 }
 410
 411 static int get_swap_writer(struct swap_map_handle *handle)
 412 {
 413         int ret;
 414
 415         ret = swsusp_swap_check();
 416         if (ret) {
 417                 if (ret != -ENOSPC)
 418                         printk(KERN_ERR "PM: Cannot find swap device, try "
 419                                         "swapon -a.\n");
 420                 return ret;
 421         }
 422         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 423         if (!handle->cur) {
 424                 ret = -ENOMEM;
 425                 goto err_close;
 426         }
 427         handle->cur_swap = alloc_swapdev_block(root_swap);
 428         if (!handle->cur_swap) {
 429                 ret = -ENOSPC;
 430                 goto err_rel;
 431         }
 432         handle->k = 0;
 433         handle->reqd_free_pages = reqd_free_pages();
 434         handle->first_sector = handle->cur_swap;
 435         return 0;
 436 err_rel:
 437         release_swap_writer(handle);
 438 err_close:
 439         swsusp_close(FMODE_WRITE);
 440         return ret;
 441 }
 442
 443 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 444                 struct hib_bio_batch *hb)
 445 {
 446         int error = 0;
 447         sector_t offset;
 448
 449         if (!handle->cur)
 450                 return -EINVAL;
 451         offset = alloc_swapdev_block(root_swap);
 452         error = write_page(buf, offset, hb);
 453         if (error)
 454                 return error;
 455         handle->cur->entries[handle->k++] = offset;
 456         if (handle->k >= MAP_PAGE_ENTRIES) {
 457                 offset = alloc_swapdev_block(root_swap);
 458                 if (!offset)
 459                         return -ENOSPC;
 460                 handle->cur->next_swap = offset;
 461                 error = write_page(handle->cur, handle->cur_swap, hb);
 462                 if (error)
 463                         goto out;
 464                 clear_page(handle->cur);
 465                 handle->cur_swap = offset;
 466                 handle->k = 0;
 467
 468                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 469                         error = hib_wait_io(hb);
 470                         if (error)
 471                                 goto out;
 472                         /*
 473                          * Recalculate the number of required free pages, to
 474                          * make sure we never take more than half.
 475                          */
 476                         handle->reqd_free_pages = reqd_free_pages();
 477                 }
 478         }
 479  out:
 480         return error;
 481 }
 482
 483 static int flush_swap_writer(struct swap_map_handle *handle)
 484 {
 485         if (handle->cur && handle->cur_swap)
 486                 return write_page(handle->cur, handle->cur_swap, NULL);
 487         else
 488                 return -EINVAL;
 489 }
 490
 491 static int swap_writer_finish(struct swap_map_handle *handle,
 492                 unsigned int flags, int error)
 493 {
 494         if (!error) {
 495                 flush_swap_writer(handle);
 496                 printk(KERN_INFO "PM: S");
 497                 error = mark_swapfiles(handle, flags);
 498                 printk("|\n");
 499         }
 500
 501         if (error)
 502                 free_all_swap_pages(root_swap);
 503         release_swap_writer(handle);
 504         swsusp_close(FMODE_WRITE);
 505
 506         return error;
 507 }
 508
 509 /* We need to remember how much compressed data we need to read. */
 510 #define LZO_HEADER      sizeof(size_t)
 511
 512 /* Number of pages/bytes we'll compress at one time. */
 513 #define LZO_UNC_PAGES   32
 514 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 515
 516 /* Number of pages/bytes we need for compressed data (worst case). */
 517 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 518                                      LZO_HEADER, PAGE_SIZE)
 519 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 520
 521 /* Maximum number of threads for compression/decompression. */
 522 #define LZO_THREADS     3
 523
 524 /* Minimum/maximum number of pages for read buffering. */
 525 #define LZO_MIN_RD_PAGES        1024
 526 #define LZO_MAX_RD_PAGES        8192
 527
 528
 529 /**
 530  *      save_image - save the suspend image data
 531  */
 532
 533 static int save_image(struct swap_map_handle *handle,
 534                       struct snapshot_handle *snapshot,
 535                       unsigned int nr_to_write)
 536 {
 537         unsigned int m;
 538         int ret;
 539         int nr_pages;
 540         int err2;
 541         struct hib_bio_batch hb;
 542         ktime_t start;
 543         ktime_t stop;
 544
 545         hib_init_batch(&hb);
 546
 547         printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
 548                 nr_to_write);
 549         m = nr_to_write / 10;
 550         if (!m)
 551                 m = 1;
 552         nr_pages = 0;
 553         start = ktime_get();
 554         while (1) {
 555                 ret = snapshot_read_next(snapshot);
 556                 if (ret <= 0)
 557                         break;
 558                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 559                 if (ret)
 560                         break;
 561                 if (!(nr_pages % m))
 562                         printk(KERN_INFO "PM: Image saving progress: %3d%%\n",
 563                                nr_pages / m * 10);
 564                 nr_pages++;
 565         }
 566         err2 = hib_wait_io(&hb);
 567         stop = ktime_get();
 568         if (!ret)
 569                 ret = err2;
 570         if (!ret)
 571                 printk(KERN_INFO "PM: Image saving done.\n");
 572         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 573         return ret;
 574 }
 575
 576 /**
 577  * Structure used for CRC32.
 578  */
 579 struct crc_data {
 580         struct task_struct *thr;                  /* thread */
 581         atomic_t ready;                           /* ready to start flag */
 582         atomic_t stop;                            /* ready to stop flag */
 583         unsigned run_threads;                     /* nr current threads */
 584         wait_queue_head_t go;                     /* start crc update */
 585         wait_queue_head_t done;                   /* crc update done */
 586         u32 *crc32;                               /* points to handle's crc32 */
 587         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 588         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 589 };
 590
 591 /**
 592  * CRC32 update function that runs in its own thread.
 593  */
 594 static int crc32_threadfn(void *data)
 595 {
 596         struct crc_data *d = data;
 597         unsigned i;
 598
 599         while (1) {
 600                 wait_event(d->go, atomic_read(&d->ready) ||
 601                                   kthread_should_stop());
 602                 if (kthread_should_stop()) {
 603                         d->thr = NULL;
 604                         atomic_set(&d->stop, 1);
 605                         wake_up(&d->done);
 606                         break;
 607                 }
 608                 atomic_set(&d->ready, 0);
 609
 610                 for (i = 0; i < d->run_threads; i++)
 611                         *d->crc32 = crc32_le(*d->crc32,
 612                                              d->unc[i], *d->unc_len[i]);
 613                 atomic_set(&d->stop, 1);
 614                 wake_up(&d->done);
 615         }
 616         return 0;
 617 }
 618 /**
 619  * Structure used for LZO data compression.
 620  */
 621 struct cmp_data {
 622         struct task_struct *thr;                  /* thread */
 623         atomic_t ready;                           /* ready to start flag */
 624         atomic_t stop;                            /* ready to stop flag */
 625         int ret;                                  /* return code */
 626         wait_queue_head_t go;                     /* start compression */
 627         wait_queue_head_t done;                   /* compression done */
 628         size_t unc_len;                           /* uncompressed length */
 629         size_t cmp_len;                           /* compressed length */
 630         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 631         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 632         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 633 };
 634
 635 /**
 636  * Compression function that runs in its own thread.
 637  */
 638 static int lzo_compress_threadfn(void *data)
 639 {
 640         struct cmp_data *d = data;
 641
 642         while (1) {
 643                 wait_event(d->go, atomic_read(&d->ready) ||
 644                                   kthread_should_stop());
 645                 if (kthread_should_stop()) {
 646                         d->thr = NULL;
 647                         d->ret = -1;
 648                         atomic_set(&d->stop, 1);
 649                         wake_up(&d->done);
 650                         break;
 651                 }
 652                 atomic_set(&d->ready, 0);
 653
 654                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 655                                           d->cmp + LZO_HEADER, &d->cmp_len,
 656                                           d->wrk);
 657                 atomic_set(&d->stop, 1);
 658                 wake_up(&d->done);
 659         }
 660         return 0;
 661 }
 662
 663 /**
 664  * save_image_lzo - Save the suspend image data compressed with LZO.
 665  * @handle: Swap map handle to use for saving the image.
 666  * @snapshot: Image to read data from.
 667  * @nr_to_write: Number of pages to save.
 668  */
 669 static int save_image_lzo(struct swap_map_handle *handle,
 670                           struct snapshot_handle *snapshot,
 671                           unsigned int nr_to_write)
 672 {
 673         unsigned int m;
 674         int ret = 0;
 675         int nr_pages;
 676         int err2;
 677         struct hib_bio_batch hb;
 678         ktime_t start;
 679         ktime_t stop;
 680         size_t off;
 681         unsigned thr, run_threads, nr_threads;
 682         unsigned char *page = NULL;
 683         struct cmp_data *data = NULL;
 684         struct crc_data *crc = NULL;
 685
 686         hib_init_batch(&hb);
 687
 688         /*
 689          * We'll limit the number of threads for compression to limit memory
 690          * footprint.
 691          */
 692         nr_threads = num_online_cpus() - 1;
 693         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 694
 695         page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 696         if (!page) {
 697                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
 698                 ret = -ENOMEM;
 699                 goto out_clean;
 700         }
 701
 702         data = vmalloc(sizeof(*data) * nr_threads);
 703         if (!data) {
 704                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
 705                 ret = -ENOMEM;
 706                 goto out_clean;
 707         }
 708         for (thr = 0; thr < nr_threads; thr++)
 709                 memset(&data[thr], 0, offsetof(struct cmp_data, go));
 710
 711         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
 712         if (!crc) {
 713                 printk(KERN_ERR "PM: Failed to allocate crc\n");
 714                 ret = -ENOMEM;
 715                 goto out_clean;
 716         }
 717         memset(crc, 0, offsetof(struct crc_data, go));
 718
 719         /*
 720          * Start the compression threads.
 721          */
 722         for (thr = 0; thr < nr_threads; thr++) {
 723                 init_waitqueue_head(&data[thr].go);
 724                 init_waitqueue_head(&data[thr].done);
 725
 726                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 727                                             &data[thr],
 728                                             "image_compress/%u", thr);
 729                 if (IS_ERR(data[thr].thr)) {
 730                         data[thr].thr = NULL;
 731                         printk(KERN_ERR
 732                                "PM: Cannot start compression threads\n");
 733                         ret = -ENOMEM;
 734                         goto out_clean;
 735                 }
 736         }
 737
 738         /*
 739          * Start the CRC32 thread.
 740          */
 741         init_waitqueue_head(&crc->go);
 742         init_waitqueue_head(&crc->done);
 743
 744         handle->crc32 = 0;
 745         crc->crc32 = &handle->crc32;
 746         for (thr = 0; thr < nr_threads; thr++) {
 747                 crc->unc[thr] = data[thr].unc;
 748                 crc->unc_len[thr] = &data[thr].unc_len;
 749         }
 750
 751         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 752         if (IS_ERR(crc->thr)) {
 753                 crc->thr = NULL;
 754                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
 755                 ret = -ENOMEM;
 756                 goto out_clean;
 757         }
 758
 759         /*
 760          * Adjust the number of required free pages after all allocations have
 761          * been done. We don't want to run out of pages when writing.
 762          */
 763         handle->reqd_free_pages = reqd_free_pages();
 764
 765         printk(KERN_INFO
 766                 "PM: Using %u thread(s) for compression.\n"
 767                 "PM: Compressing and saving image data (%u pages)...\n",
 768                 nr_threads, nr_to_write);
 769         m = nr_to_write / 10;
 770         if (!m)
 771                 m = 1;
 772         nr_pages = 0;
 773         start = ktime_get();
 774         for (;;) {
 775                 for (thr = 0; thr < nr_threads; thr++) {
 776                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 777                                 ret = snapshot_read_next(snapshot);
 778                                 if (ret < 0)
 779                                         goto out_finish;
 780
 781                                 if (!ret)
 782                                         break;
 783
 784                                 memcpy(data[thr].unc + off,
 785                                        data_of(*snapshot), PAGE_SIZE);
 786
 787                                 if (!(nr_pages % m))
 788                                         printk(KERN_INFO
 789                                                "PM: Image saving progress: "
 790                                                "%3d%%\n",
 791                                                nr_pages / m * 10);
 792                                 nr_pages++;
 793                         }
 794                         if (!off)
 795                                 break;
 796
 797                         data[thr].unc_len = off;
 798
 799                         atomic_set(&data[thr].ready, 1);
 800                         wake_up(&data[thr].go);
 801                 }
 802
 803                 if (!thr)
 804                         break;
 805
 806                 crc->run_threads = thr;
 807                 atomic_set(&crc->ready, 1);
 808                 wake_up(&crc->go);
 809
 810                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 811                         wait_event(data[thr].done,
 812                                    atomic_read(&data[thr].stop));
 813                         atomic_set(&data[thr].stop, 0);
 814
 815                         ret = data[thr].ret;
 816
 817                         if (ret < 0) {
 818                                 printk(KERN_ERR "PM: LZO compression failed\n");
 819                                 goto out_finish;
 820                         }
 821
 822                         if (unlikely(!data[thr].cmp_len ||
 823                                      data[thr].cmp_len >
 824                                      lzo1x_worst_compress(data[thr].unc_len))) {
 825                                 printk(KERN_ERR
 826                                        "PM: Invalid LZO compressed length\n");
 827                                 ret = -1;
 828                                 goto out_finish;
 829                         }
 830
 831                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 832
 833                         /*
 834                          * Given we are writing one page at a time to disk, we
 835                          * copy that much from the buffer, although the last
 836                          * bit will likely be smaller than full page. This is
 837                          * OK - we saved the length of the compressed data, so
 838                          * any garbage at the end will be discarded when we
 839                          * read it.
 840                          */
 841                         for (off = 0;
 842                              off < LZO_HEADER + data[thr].cmp_len;
 843                              off += PAGE_SIZE) {
 844                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 845
 846                                 ret = swap_write_page(handle, page, &hb);
 847                                 if (ret)
 848                                         goto out_finish;
 849                         }
 850                 }
 851
 852                 wait_event(crc->done, atomic_read(&crc->stop));
 853                 atomic_set(&crc->stop, 0);
 854         }
 855
 856 out_finish:
 857         err2 = hib_wait_io(&hb);
 858         stop = ktime_get();
 859         if (!ret)
 860                 ret = err2;
 861         if (!ret)
 862                 printk(KERN_INFO "PM: Image saving done.\n");
 863         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 864 out_clean:
 865         if (crc) {
 866                 if (crc->thr)
 867                         kthread_stop(crc->thr);
 868                 kfree(crc);
 869         }
 870         if (data) {
 871                 for (thr = 0; thr < nr_threads; thr++)
 872                         if (data[thr].thr)
 873                                 kthread_stop(data[thr].thr);
 874                 vfree(data);
 875         }
 876         if (page) free_page((unsigned long)page);
 877
 878         return ret;
 879 }
 880
 881 /**
 882  *      enough_swap - Make sure we have enough swap to save the image.
 883  *
 884  *      Returns TRUE or FALSE after checking the total amount of swap
 885  *      space avaiable from the resume partition.
 886  */
 887
 888 static int enough_swap(unsigned int nr_pages, unsigned int flags)
 889 {
 890         unsigned int free_swap = count_swap_pages(root_swap, 1);
 891         unsigned int required;
 892
 893         pr_debug("PM: Free swap pages: %u\n", free_swap);
 894
 895         required = PAGES_FOR_IO + nr_pages;
 896         return free_swap > required;
 897 }
 898
 899 /**
 900  *      swsusp_write - Write entire image and metadata.
 901  *      @flags: flags to pass to the "boot" kernel in the image header
 902  *
 903  *      It is important _NOT_ to umount filesystems at this point. We want
 904  *      them synced (in case something goes wrong) but we DO not want to mark
 905  *      filesystem clean: it is not. (And it does not matter, if we resume
 906  *      correctly, we'll mark system clean, anyway.)
 907  */
 908
 909 int swsusp_write(unsigned int flags)
 910 {
 911         struct swap_map_handle handle;
 912         struct snapshot_handle snapshot;
 913         struct swsusp_info *header;
 914         unsigned long pages;
 915         int error;
 916
 917         pages = snapshot_get_image_size();
 918         error = get_swap_writer(&handle);
 919         if (error) {
 920                 printk(KERN_ERR "PM: Cannot get swap writer\n");
 921                 return error;
 922         }
 923         if (flags & SF_NOCOMPRESS_MODE) {
 924                 if (!enough_swap(pages, flags)) {
 925                         printk(KERN_ERR "PM: Not enough free swap\n");
 926                         error = -ENOSPC;
 927                         goto out_finish;
 928                 }
 929         }
 930         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 931         error = snapshot_read_next(&snapshot);
 932         if (error < PAGE_SIZE) {
 933                 if (error >= 0)
 934                         error = -EFAULT;
 935
 936                 goto out_finish;
 937         }
 938         header = (struct swsusp_info *)data_of(snapshot);
 939         error = swap_write_page(&handle, header, NULL);
 940         if (!error) {
 941                 error = (flags & SF_NOCOMPRESS_MODE) ?
 942                         save_image(&handle, &snapshot, pages - 1) :
 943                         save_image_lzo(&handle, &snapshot, pages - 1);
 944         }
 945 out_finish:
 946         error = swap_writer_finish(&handle, flags, error);
 947         return error;
 948 }
 949
 950 /**
 951  *      The following functions allow us to read data using a swap map
 952  *      in a file-alike way
 953  */
 954
 955 static void release_swap_reader(struct swap_map_handle *handle)
 956 {
 957         struct swap_map_page_list *tmp;
 958
 959         while (handle->maps) {
 960                 if (handle->maps->map)
 961                         free_page((unsigned long)handle->maps->map);
 962                 tmp = handle->maps;
 963                 handle->maps = handle->maps->next;
 964                 kfree(tmp);
 965         }
 966         handle->cur = NULL;
 967 }
 968
 969 static int get_swap_reader(struct swap_map_handle *handle,
 970                 unsigned int *flags_p)
 971 {
 972         int error;
 973         struct swap_map_page_list *tmp, *last;
 974         sector_t offset;
 975
 976         *flags_p = swsusp_header->flags;
 977
 978         if (!swsusp_header->image) /* how can this happen? */
 979                 return -EINVAL;
 980
 981         handle->cur = NULL;
 982         last = handle->maps = NULL;
 983         offset = swsusp_header->image;
 984         while (offset) {
 985                 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
 986                 if (!tmp) {
 987                         release_swap_reader(handle);
 988                         return -ENOMEM;
 989                 }
 990                 memset(tmp, 0, sizeof(*tmp));
 991                 if (!handle->maps)
 992                         handle->maps = tmp;
 993                 if (last)
 994                         last->next = tmp;
 995                 last = tmp;
 996
 997                 tmp->map = (struct swap_map_page *)
 998                            __get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 999                 if (!tmp->map) {
1000                         release_swap_reader(handle);
1001                         return -ENOMEM;
1002                 }
1003
1004                 error = hib_submit_io(READ_SYNC, offset, tmp->map, NULL);
1005                 if (error) {
1006                         release_swap_reader(handle);
1007                         return error;
1008                 }
1009                 offset = tmp->map->next_swap;
1010         }
1011         handle->k = 0;
1012         handle->cur = handle->maps->map;
1013         return 0;
1014 }
1015
1016 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1017                 struct hib_bio_batch *hb)
1018 {
1019         sector_t offset;
1020         int error;
1021         struct swap_map_page_list *tmp;
1022
1023         if (!handle->cur)
1024                 return -EINVAL;
1025         offset = handle->cur->entries[handle->k];
1026         if (!offset)
1027                 return -EFAULT;
1028         error = hib_submit_io(READ_SYNC, offset, buf, hb);
1029         if (error)
1030                 return error;
1031         if (++handle->k >= MAP_PAGE_ENTRIES) {
1032                 handle->k = 0;
1033                 free_page((unsigned long)handle->maps->map);
1034                 tmp = handle->maps;
1035                 handle->maps = handle->maps->next;
1036                 kfree(tmp);
1037                 if (!handle->maps)
1038                         release_swap_reader(handle);
1039                 else
1040                         handle->cur = handle->maps->map;
1041         }
1042         return error;
1043 }
1044
1045 static int swap_reader_finish(struct swap_map_handle *handle)
1046 {
1047         release_swap_reader(handle);
1048
1049         return 0;
1050 }
1051
1052 /**
1053  *      load_image - load the image using the swap map handle
1054  *      @handle and the snapshot handle @snapshot
1055  *      (assume there are @nr_pages pages to load)
1056  */
1057
1058 static int load_image(struct swap_map_handle *handle,
1059                       struct snapshot_handle *snapshot,
1060                       unsigned int nr_to_read)
1061 {
1062         unsigned int m;
1063         int ret = 0;
1064         ktime_t start;
1065         ktime_t stop;
1066         struct hib_bio_batch hb;
1067         int err2;
1068         unsigned nr_pages;
1069
1070         hib_init_batch(&hb);
1071
1072         clean_pages_on_read = true;
1073         printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
1074                 nr_to_read);
1075         m = nr_to_read / 10;
1076         if (!m)
1077                 m = 1;
1078         nr_pages = 0;
1079         start = ktime_get();
1080         for ( ; ; ) {
1081                 ret = snapshot_write_next(snapshot);
1082                 if (ret <= 0)
1083                         break;
1084                 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1085                 if (ret)
1086                         break;
1087                 if (snapshot->sync_read)
1088                         ret = hib_wait_io(&hb);
1089                 if (ret)
1090                         break;
1091                 if (!(nr_pages % m))
1092                         printk(KERN_INFO "PM: Image loading progress: %3d%%\n",
1093                                nr_pages / m * 10);
1094                 nr_pages++;
1095         }
1096         err2 = hib_wait_io(&hb);
1097         stop = ktime_get();
1098         if (!ret)
1099                 ret = err2;
1100         if (!ret) {
1101                 printk(KERN_INFO "PM: Image loading done.\n");
1102                 snapshot_write_finalize(snapshot);
1103                 if (!snapshot_image_loaded(snapshot))
1104                         ret = -ENODATA;
1105         }
1106         swsusp_show_speed(start, stop, nr_to_read, "Read");
1107         return ret;
1108 }
1109
1110 /**
1111  * Structure used for LZO data decompression.
1112  */
1113 struct dec_data {
1114         struct task_struct *thr;                  /* thread */
1115         atomic_t ready;                           /* ready to start flag */
1116         atomic_t stop;                            /* ready to stop flag */
1117         int ret;                                  /* return code */
1118         wait_queue_head_t go;                     /* start decompression */
1119         wait_queue_head_t done;                   /* decompression done */
1120         size_t unc_len;                           /* uncompressed length */
1121         size_t cmp_len;                           /* compressed length */
1122         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1123         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1124 };
1125
1126 /**
1127  * Deompression function that runs in its own thread.
1128  */
1129 static int lzo_decompress_threadfn(void *data)
1130 {
1131         struct dec_data *d = data;
1132
1133         while (1) {
1134                 wait_event(d->go, atomic_read(&d->ready) ||
1135                                   kthread_should_stop());
1136                 if (kthread_should_stop()) {
1137                         d->thr = NULL;
1138                         d->ret = -1;
1139                         atomic_set(&d->stop, 1);
1140                         wake_up(&d->done);
1141                         break;
1142                 }
1143                 atomic_set(&d->ready, 0);
1144
1145                 d->unc_len = LZO_UNC_SIZE;
1146                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1147                                                d->unc, &d->unc_len);
1148                 if (clean_pages_on_decompress)
1149                         flush_icache_range((unsigned long)d->unc,
1150                                            (unsigned long)d->unc + d->unc_len);
1151
1152                 atomic_set(&d->stop, 1);
1153                 wake_up(&d->done);
1154         }
1155         return 0;
1156 }
1157
1158 /**
1159  * load_image_lzo - Load compressed image data and decompress them with LZO.
1160  * @handle: Swap map handle to use for loading data.
1161  * @snapshot: Image to copy uncompressed data into.
1162  * @nr_to_read: Number of pages to load.
1163  */
1164 static int load_image_lzo(struct swap_map_handle *handle,
1165                           struct snapshot_handle *snapshot,
1166                           unsigned int nr_to_read)
1167 {
1168         unsigned int m;
1169         int ret = 0;
1170         int eof = 0;
1171         struct hib_bio_batch hb;
1172         ktime_t start;
1173         ktime_t stop;
1174         unsigned nr_pages;
1175         size_t off;
1176         unsigned i, thr, run_threads, nr_threads;
1177         unsigned ring = 0, pg = 0, ring_size = 0,
1178                  have = 0, want, need, asked = 0;
1179         unsigned long read_pages = 0;
1180         unsigned char **page = NULL;
1181         struct dec_data *data = NULL;
1182         struct crc_data *crc = NULL;
1183
1184         hib_init_batch(&hb);
1185
1186         /*
1187          * We'll limit the number of threads for decompression to limit memory
1188          * footprint.
1189          */
1190         nr_threads = num_online_cpus() - 1;
1191         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1192
1193         page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1194         if (!page) {
1195                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1196                 ret = -ENOMEM;
1197                 goto out_clean;
1198         }
1199
1200         data = vmalloc(sizeof(*data) * nr_threads);
1201         if (!data) {
1202                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1203                 ret = -ENOMEM;
1204                 goto out_clean;
1205         }
1206         for (thr = 0; thr < nr_threads; thr++)
1207                 memset(&data[thr], 0, offsetof(struct dec_data, go));
1208
1209         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1210         if (!crc) {
1211                 printk(KERN_ERR "PM: Failed to allocate crc\n");
1212                 ret = -ENOMEM;
1213                 goto out_clean;
1214         }
1215         memset(crc, 0, offsetof(struct crc_data, go));
1216
1217         clean_pages_on_decompress = true;
1218
1219         /*
1220          * Start the decompression threads.
1221          */
1222         for (thr = 0; thr < nr_threads; thr++) {
1223                 init_waitqueue_head(&data[thr].go);
1224                 init_waitqueue_head(&data[thr].done);
1225
1226                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1227                                             &data[thr],
1228                                             "image_decompress/%u", thr);
1229                 if (IS_ERR(data[thr].thr)) {
1230                         data[thr].thr = NULL;
1231                         printk(KERN_ERR
1232                                "PM: 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                 printk(KERN_ERR "PM: 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_RECLAIM | __GFP_HIGH :
1273                                                   __GFP_RECLAIM | __GFP_NOWARN |
1274                                                   __GFP_NORETRY);
1275
1276                 if (!page[i]) {
1277                         if (i < LZO_CMP_PAGES) {
1278                                 ring_size = i;
1279                                 printk(KERN_ERR
1280                                        "PM: Failed to allocate LZO pages\n");
1281                                 ret = -ENOMEM;
1282                                 goto out_clean;
1283                         } else {
1284                                 break;
1285                         }
1286                 }
1287         }
1288         want = ring_size = i;
1289
1290         printk(KERN_INFO
1291                 "PM: Using %u thread(s) for decompression.\n"
1292                 "PM: Loading and decompressing image data (%u pages)...\n",
1293                 nr_threads, nr_to_read);
1294         m = nr_to_read / 10;
1295         if (!m)
1296                 m = 1;
1297         nr_pages = 0;
1298         start = ktime_get();
1299
1300         ret = snapshot_write_next(snapshot);
1301         if (ret <= 0)
1302                 goto out_finish;
1303
1304         for(;;) {
1305                 for (i = 0; !eof && i < want; i++) {
1306                         ret = swap_read_page(handle, page[ring], &hb);
1307                         if (ret) {
1308                                 /*
1309                                  * On real read error, finish. On end of data,
1310                                  * set EOF flag and just exit the read loop.
1311                                  */
1312                                 if (handle->cur &&
1313                                     handle->cur->entries[handle->k]) {
1314                                         goto out_finish;
1315                                 } else {
1316                                         eof = 1;
1317                                         break;
1318                                 }
1319                         }
1320                         if (++ring >= ring_size)
1321                                 ring = 0;
1322                 }
1323                 asked += i;
1324                 want -= i;
1325
1326                 /*
1327                  * We are out of data, wait for some more.
1328                  */
1329                 if (!have) {
1330                         if (!asked)
1331                                 break;
1332
1333                         ret = hib_wait_io(&hb);
1334                         if (ret)
1335                                 goto out_finish;
1336                         have += asked;
1337                         asked = 0;
1338                         if (eof)
1339                                 eof = 2;
1340                 }
1341
1342                 if (crc->run_threads) {
1343                         wait_event(crc->done, atomic_read(&crc->stop));
1344                         atomic_set(&crc->stop, 0);
1345                         crc->run_threads = 0;
1346                 }
1347
1348                 for (thr = 0; have && thr < nr_threads; thr++) {
1349                         data[thr].cmp_len = *(size_t *)page[pg];
1350                         if (unlikely(!data[thr].cmp_len ||
1351                                      data[thr].cmp_len >
1352                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1353                                 printk(KERN_ERR
1354                                        "PM: Invalid LZO compressed length\n");
1355                                 ret = -1;
1356                                 goto out_finish;
1357                         }
1358
1359                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1360                                             PAGE_SIZE);
1361                         if (need > have) {
1362                                 if (eof > 1) {
1363                                         ret = -1;
1364                                         goto out_finish;
1365                                 }
1366                                 break;
1367                         }
1368
1369                         for (off = 0;
1370                              off < LZO_HEADER + data[thr].cmp_len;
1371                              off += PAGE_SIZE) {
1372                                 memcpy(data[thr].cmp + off,
1373                                        page[pg], PAGE_SIZE);
1374                                 have--;
1375                                 want++;
1376                                 if (++pg >= ring_size)
1377                                         pg = 0;
1378                         }
1379
1380                         atomic_set(&data[thr].ready, 1);
1381                         wake_up(&data[thr].go);
1382                 }
1383
1384                 /*
1385                  * Wait for more data while we are decompressing.
1386                  */
1387                 if (have < LZO_CMP_PAGES && asked) {
1388                         ret = hib_wait_io(&hb);
1389                         if (ret)
1390                                 goto out_finish;
1391                         have += asked;
1392                         asked = 0;
1393                         if (eof)
1394                                 eof = 2;
1395                 }
1396
1397                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1398                         wait_event(data[thr].done,
1399                                    atomic_read(&data[thr].stop));
1400                         atomic_set(&data[thr].stop, 0);
1401
1402                         ret = data[thr].ret;
1403
1404                         if (ret < 0) {
1405                                 printk(KERN_ERR
1406                                        "PM: LZO decompression failed\n");
1407                                 goto out_finish;
1408                         }
1409
1410                         if (unlikely(!data[thr].unc_len ||
1411                                      data[thr].unc_len > LZO_UNC_SIZE ||
1412                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1413                                 printk(KERN_ERR
1414                                        "PM: Invalid LZO uncompressed length\n");
1415                                 ret = -1;
1416                                 goto out_finish;
1417                         }
1418
1419                         for (off = 0;
1420                              off < data[thr].unc_len; off += PAGE_SIZE) {
1421                                 memcpy(data_of(*snapshot),
1422                                        data[thr].unc + off, PAGE_SIZE);
1423
1424                                 if (!(nr_pages % m))
1425                                         printk(KERN_INFO
1426                                                "PM: Image loading progress: "
1427                                                "%3d%%\n",
1428                                                nr_pages / m * 10);
1429                                 nr_pages++;
1430
1431                                 ret = snapshot_write_next(snapshot);
1432                                 if (ret <= 0) {
1433                                         crc->run_threads = thr + 1;
1434                                         atomic_set(&crc->ready, 1);
1435                                         wake_up(&crc->go);
1436                                         goto out_finish;
1437                                 }
1438                         }
1439                 }
1440
1441                 crc->run_threads = thr;
1442                 atomic_set(&crc->ready, 1);
1443                 wake_up(&crc->go);
1444         }
1445
1446 out_finish:
1447         if (crc->run_threads) {
1448                 wait_event(crc->done, atomic_read(&crc->stop));
1449                 atomic_set(&crc->stop, 0);
1450         }
1451         stop = ktime_get();
1452         if (!ret) {
1453                 printk(KERN_INFO "PM: Image loading done.\n");
1454                 snapshot_write_finalize(snapshot);
1455                 if (!snapshot_image_loaded(snapshot))
1456                         ret = -ENODATA;
1457                 if (!ret) {
1458                         if (swsusp_header->flags & SF_CRC32_MODE) {
1459                                 if(handle->crc32 != swsusp_header->crc32) {
1460                                         printk(KERN_ERR
1461                                                "PM: Invalid image CRC32!\n");
1462                                         ret = -ENODATA;
1463                                 }
1464                         }
1465                 }
1466         }
1467         swsusp_show_speed(start, stop, nr_to_read, "Read");
1468 out_clean:
1469         for (i = 0; i < ring_size; i++)
1470                 free_page((unsigned long)page[i]);
1471         if (crc) {
1472                 if (crc->thr)
1473                         kthread_stop(crc->thr);
1474                 kfree(crc);
1475         }
1476         if (data) {
1477                 for (thr = 0; thr < nr_threads; thr++)
1478                         if (data[thr].thr)
1479                                 kthread_stop(data[thr].thr);
1480                 vfree(data);
1481         }
1482         vfree(page);
1483
1484         return ret;
1485 }
1486
1487 /**
1488  *      swsusp_read - read the hibernation image.
1489  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1490  *                be written into this memory location
1491  */
1492
1493 int swsusp_read(unsigned int *flags_p)
1494 {
1495         int error;
1496         struct swap_map_handle handle;
1497         struct snapshot_handle snapshot;
1498         struct swsusp_info *header;
1499
1500         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1501         error = snapshot_write_next(&snapshot);
1502         if (error < PAGE_SIZE)
1503                 return error < 0 ? error : -EFAULT;
1504         header = (struct swsusp_info *)data_of(snapshot);
1505         error = get_swap_reader(&handle, flags_p);
1506         if (error)
1507                 goto end;
1508         if (!error)
1509                 error = swap_read_page(&handle, header, NULL);
1510         if (!error) {
1511                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1512                         load_image(&handle, &snapshot, header->pages - 1) :
1513                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1514         }
1515         swap_reader_finish(&handle);
1516 end:
1517         if (!error)
1518                 pr_debug("PM: Image successfully loaded\n");
1519         else
1520                 pr_debug("PM: Error %d resuming\n", error);
1521         return error;
1522 }
1523
1524 /**
1525  *      swsusp_check - Check for swsusp signature in the resume device
1526  */
1527
1528 int swsusp_check(void)
1529 {
1530         int error;
1531
1532         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1533                                             FMODE_READ, NULL);
1534         if (!IS_ERR(hib_resume_bdev)) {
1535                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1536                 clear_page(swsusp_header);
1537                 error = hib_submit_io(READ_SYNC, swsusp_resume_block,
1538                                         swsusp_header, NULL);
1539                 if (error)
1540                         goto put;
1541
1542                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1543                         if (!goldenimage) {
1544                                 pr_debug("PM: corrupt hibernate image header\n");
1545                                 memcpy(swsusp_header->sig,
1546                                         swsusp_header->orig_sig, 10);
1547                         } else {
1548                                 pr_debug("PM: Header corruption avoided\n");
1549                         }
1550                         /* Reset swap signature now */
1551                         error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1552                                                 swsusp_header, NULL);
1553                 } else {
1554                         error = -EINVAL;
1555                 }
1556
1557 put:
1558                 if (error)
1559                         blkdev_put(hib_resume_bdev, FMODE_READ);
1560                 else
1561                         pr_debug("PM: Image signature found, resuming\n");
1562         } else {
1563                 error = PTR_ERR(hib_resume_bdev);
1564         }
1565
1566         if (error)
1567                 pr_debug("PM: Image not found (code %d)\n", error);
1568
1569         return error;
1570 }
1571
1572 /**
1573  *      swsusp_close - close swap device.
1574  */
1575
1576 void swsusp_close(fmode_t mode)
1577 {
1578         if (IS_ERR(hib_resume_bdev)) {
1579                 pr_debug("PM: Image device not initialised\n");
1580                 return;
1581         }
1582
1583         blkdev_put(hib_resume_bdev, mode);
1584 }
1585
1586 /**
1587  *      swsusp_unmark - Unmark swsusp signature in the resume device
1588  */
1589
1590 #ifdef CONFIG_SUSPEND
1591 int swsusp_unmark(void)
1592 {
1593         int error;
1594
1595         hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
1596         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1597                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1598                 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1599                                         swsusp_header, NULL);
1600         } else {
1601                 printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
1602                 error = -ENODEV;
1603         }
1604
1605         /*
1606          * We just returned from suspend, we don't need the image any more.
1607          */
1608         free_all_swap_pages(root_swap);
1609
1610         return error;
1611 }
1612 #endif
1613
1614 static int swsusp_header_init(void)
1615 {
1616         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1617         if (!swsusp_header)
1618                 panic("Could not allocate memory for swsusp_header\n");
1619         return 0;
1620 }
1621
1622 core_initcall(swsusp_header_init);
1623
1624 static int __init golden_image_setup(char *str)
1625 {
1626         goldenimage = 1;
1627         return 1;
1628 }
1629 __setup("golden_image", golden_image_setup);