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         return res;
 352 }
 353
 354 /**
 355  *      write_page - Write one page to given swap location.
 356  *      @buf:           Address we're writing.
 357  *      @offset:        Offset of the swap page we're writing to.
 358  *      @hb:            bio completion batch
 359  */
 360
 361 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 362 {
 363         void *src;
 364         int ret;
 365
 366         if (!offset)
 367                 return -ENOSPC;
 368
 369         if (hb) {
 370                 src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN |
 371                                               __GFP_NORETRY);
 372                 if (src) {
 373                         copy_page(src, buf);
 374                 } else {
 375                         ret = hib_wait_io(hb); /* Free pages */
 376                         if (ret)
 377                                 return ret;
 378                         src = (void *)__get_free_page(__GFP_RECLAIM |
 379                                                       __GFP_NOWARN |
 380                                                       __GFP_NORETRY);
 381                         if (src) {
 382                                 copy_page(src, buf);
 383                         } else {
 384                                 WARN_ON_ONCE(1);
 385                                 hb = NULL;      /* Go synchronous */
 386                                 src = buf;
 387                         }
 388                 }
 389         } else {
 390                 src = buf;
 391         }
 392         return hib_submit_io(WRITE_SYNC, offset, src, hb);
 393 }
 394
 395 static void release_swap_writer(struct swap_map_handle *handle)
 396 {
 397         if (handle->cur)
 398                 free_page((unsigned long)handle->cur);
 399         handle->cur = NULL;
 400 }
 401
 402 static int get_swap_writer(struct swap_map_handle *handle)
 403 {
 404         int ret;
 405
 406         ret = swsusp_swap_check();
 407         if (ret) {
 408                 if (ret != -ENOSPC)
 409                         printk(KERN_ERR "PM: Cannot find swap device, try "
 410                                         "swapon -a.\n");
 411                 return ret;
 412         }
 413         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 414         if (!handle->cur) {
 415                 ret = -ENOMEM;
 416                 goto err_close;
 417         }
 418         handle->cur_swap = alloc_swapdev_block(root_swap);
 419         if (!handle->cur_swap) {
 420                 ret = -ENOSPC;
 421                 goto err_rel;
 422         }
 423         handle->k = 0;
 424         handle->reqd_free_pages = reqd_free_pages();
 425         handle->first_sector = handle->cur_swap;
 426         return 0;
 427 err_rel:
 428         release_swap_writer(handle);
 429 err_close:
 430         swsusp_close(FMODE_WRITE);
 431         return ret;
 432 }
 433
 434 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 435                 struct hib_bio_batch *hb)
 436 {
 437         int error = 0;
 438         sector_t offset;
 439
 440         if (!handle->cur)
 441                 return -EINVAL;
 442         offset = alloc_swapdev_block(root_swap);
 443         error = write_page(buf, offset, hb);
 444         if (error)
 445                 return error;
 446         handle->cur->entries[handle->k++] = offset;
 447         if (handle->k >= MAP_PAGE_ENTRIES) {
 448                 offset = alloc_swapdev_block(root_swap);
 449                 if (!offset)
 450                         return -ENOSPC;
 451                 handle->cur->next_swap = offset;
 452                 error = write_page(handle->cur, handle->cur_swap, hb);
 453                 if (error)
 454                         goto out;
 455                 clear_page(handle->cur);
 456                 handle->cur_swap = offset;
 457                 handle->k = 0;
 458
 459                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 460                         error = hib_wait_io(hb);
 461                         if (error)
 462                                 goto out;
 463                         /*
 464                          * Recalculate the number of required free pages, to
 465                          * make sure we never take more than half.
 466                          */
 467                         handle->reqd_free_pages = reqd_free_pages();
 468                 }
 469         }
 470  out:
 471         return error;
 472 }
 473
 474 static int flush_swap_writer(struct swap_map_handle *handle)
 475 {
 476         if (handle->cur && handle->cur_swap)
 477                 return write_page(handle->cur, handle->cur_swap, NULL);
 478         else
 479                 return -EINVAL;
 480 }
 481
 482 static int swap_writer_finish(struct swap_map_handle *handle,
 483                 unsigned int flags, int error)
 484 {
 485         if (!error) {
 486                 flush_swap_writer(handle);
 487                 printk(KERN_INFO "PM: S");
 488                 error = mark_swapfiles(handle, flags);
 489                 printk("|\n");
 490         }
 491
 492         if (error)
 493                 free_all_swap_pages(root_swap);
 494         release_swap_writer(handle);
 495         swsusp_close(FMODE_WRITE);
 496
 497         return error;
 498 }
 499
 500 /* We need to remember how much compressed data we need to read. */
 501 #define LZO_HEADER      sizeof(size_t)
 502
 503 /* Number of pages/bytes we'll compress at one time. */
 504 #define LZO_UNC_PAGES   32
 505 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 506
 507 /* Number of pages/bytes we need for compressed data (worst case). */
 508 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 509                                      LZO_HEADER, PAGE_SIZE)
 510 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 511
 512 /* Maximum number of threads for compression/decompression. */
 513 #define LZO_THREADS     3
 514
 515 /* Minimum/maximum number of pages for read buffering. */
 516 #define LZO_MIN_RD_PAGES        1024
 517 #define LZO_MAX_RD_PAGES        8192
 518
 519
 520 /**
 521  *      save_image - save the suspend image data
 522  */
 523
 524 static int save_image(struct swap_map_handle *handle,
 525                       struct snapshot_handle *snapshot,
 526                       unsigned int nr_to_write)
 527 {
 528         unsigned int m;
 529         int ret;
 530         int nr_pages;
 531         int err2;
 532         struct hib_bio_batch hb;
 533         ktime_t start;
 534         ktime_t stop;
 535
 536         hib_init_batch(&hb);
 537
 538         printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
 539                 nr_to_write);
 540         m = nr_to_write / 10;
 541         if (!m)
 542                 m = 1;
 543         nr_pages = 0;
 544         start = ktime_get();
 545         while (1) {
 546                 ret = snapshot_read_next(snapshot);
 547                 if (ret <= 0)
 548                         break;
 549                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 550                 if (ret)
 551                         break;
 552                 if (!(nr_pages % m))
 553                         printk(KERN_INFO "PM: Image saving progress: %3d%%\n",
 554                                nr_pages / m * 10);
 555                 nr_pages++;
 556         }
 557         err2 = hib_wait_io(&hb);
 558         stop = ktime_get();
 559         if (!ret)
 560                 ret = err2;
 561         if (!ret)
 562                 printk(KERN_INFO "PM: Image saving done.\n");
 563         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 564         return ret;
 565 }
 566
 567 /**
 568  * Structure used for CRC32.
 569  */
 570 struct crc_data {
 571         struct task_struct *thr;                  /* thread */
 572         atomic_t ready;                           /* ready to start flag */
 573         atomic_t stop;                            /* ready to stop flag */
 574         unsigned run_threads;                     /* nr current threads */
 575         wait_queue_head_t go;                     /* start crc update */
 576         wait_queue_head_t done;                   /* crc update done */
 577         u32 *crc32;                               /* points to handle's crc32 */
 578         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 579         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 580 };
 581
 582 /**
 583  * CRC32 update function that runs in its own thread.
 584  */
 585 static int crc32_threadfn(void *data)
 586 {
 587         struct crc_data *d = data;
 588         unsigned i;
 589
 590         while (1) {
 591                 wait_event(d->go, atomic_read(&d->ready) ||
 592                                   kthread_should_stop());
 593                 if (kthread_should_stop()) {
 594                         d->thr = NULL;
 595                         atomic_set(&d->stop, 1);
 596                         wake_up(&d->done);
 597                         break;
 598                 }
 599                 atomic_set(&d->ready, 0);
 600
 601                 for (i = 0; i < d->run_threads; i++)
 602                         *d->crc32 = crc32_le(*d->crc32,
 603                                              d->unc[i], *d->unc_len[i]);
 604                 atomic_set(&d->stop, 1);
 605                 wake_up(&d->done);
 606         }
 607         return 0;
 608 }
 609 /**
 610  * Structure used for LZO data compression.
 611  */
 612 struct cmp_data {
 613         struct task_struct *thr;                  /* thread */
 614         atomic_t ready;                           /* ready to start flag */
 615         atomic_t stop;                            /* ready to stop flag */
 616         int ret;                                  /* return code */
 617         wait_queue_head_t go;                     /* start compression */
 618         wait_queue_head_t done;                   /* compression done */
 619         size_t unc_len;                           /* uncompressed length */
 620         size_t cmp_len;                           /* compressed length */
 621         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 622         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 623         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 624 };
 625
 626 /**
 627  * Compression function that runs in its own thread.
 628  */
 629 static int lzo_compress_threadfn(void *data)
 630 {
 631         struct cmp_data *d = data;
 632
 633         while (1) {
 634                 wait_event(d->go, atomic_read(&d->ready) ||
 635                                   kthread_should_stop());
 636                 if (kthread_should_stop()) {
 637                         d->thr = NULL;
 638                         d->ret = -1;
 639                         atomic_set(&d->stop, 1);
 640                         wake_up(&d->done);
 641                         break;
 642                 }
 643                 atomic_set(&d->ready, 0);
 644
 645                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 646                                           d->cmp + LZO_HEADER, &d->cmp_len,
 647                                           d->wrk);
 648                 atomic_set(&d->stop, 1);
 649                 wake_up(&d->done);
 650         }
 651         return 0;
 652 }
 653
 654 /**
 655  * save_image_lzo - Save the suspend image data compressed with LZO.
 656  * @handle: Swap map handle to use for saving the image.
 657  * @snapshot: Image to read data from.
 658  * @nr_to_write: Number of pages to save.
 659  */
 660 static int save_image_lzo(struct swap_map_handle *handle,
 661                           struct snapshot_handle *snapshot,
 662                           unsigned int nr_to_write)
 663 {
 664         unsigned int m;
 665         int ret = 0;
 666         int nr_pages;
 667         int err2;
 668         struct hib_bio_batch hb;
 669         ktime_t start;
 670         ktime_t stop;
 671         size_t off;
 672         unsigned thr, run_threads, nr_threads;
 673         unsigned char *page = NULL;
 674         struct cmp_data *data = NULL;
 675         struct crc_data *crc = NULL;
 676
 677         hib_init_batch(&hb);
 678
 679         /*
 680          * We'll limit the number of threads for compression to limit memory
 681          * footprint.
 682          */
 683         nr_threads = num_online_cpus() - 1;
 684         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 685
 686         page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 687         if (!page) {
 688                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
 689                 ret = -ENOMEM;
 690                 goto out_clean;
 691         }
 692
 693         data = vmalloc(sizeof(*data) * nr_threads);
 694         if (!data) {
 695                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
 696                 ret = -ENOMEM;
 697                 goto out_clean;
 698         }
 699         for (thr = 0; thr < nr_threads; thr++)
 700                 memset(&data[thr], 0, offsetof(struct cmp_data, go));
 701
 702         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
 703         if (!crc) {
 704                 printk(KERN_ERR "PM: Failed to allocate crc\n");
 705                 ret = -ENOMEM;
 706                 goto out_clean;
 707         }
 708         memset(crc, 0, offsetof(struct crc_data, go));
 709
 710         /*
 711          * Start the compression threads.
 712          */
 713         for (thr = 0; thr < nr_threads; thr++) {
 714                 init_waitqueue_head(&data[thr].go);
 715                 init_waitqueue_head(&data[thr].done);
 716
 717                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 718                                             &data[thr],
 719                                             "image_compress/%u", thr);
 720                 if (IS_ERR(data[thr].thr)) {
 721                         data[thr].thr = NULL;
 722                         printk(KERN_ERR
 723                                "PM: Cannot start compression threads\n");
 724                         ret = -ENOMEM;
 725                         goto out_clean;
 726                 }
 727         }
 728
 729         /*
 730          * Start the CRC32 thread.
 731          */
 732         init_waitqueue_head(&crc->go);
 733         init_waitqueue_head(&crc->done);
 734
 735         handle->crc32 = 0;
 736         crc->crc32 = &handle->crc32;
 737         for (thr = 0; thr < nr_threads; thr++) {
 738                 crc->unc[thr] = data[thr].unc;
 739                 crc->unc_len[thr] = &data[thr].unc_len;
 740         }
 741
 742         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 743         if (IS_ERR(crc->thr)) {
 744                 crc->thr = NULL;
 745                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
 746                 ret = -ENOMEM;
 747                 goto out_clean;
 748         }
 749
 750         /*
 751          * Adjust the number of required free pages after all allocations have
 752          * been done. We don't want to run out of pages when writing.
 753          */
 754         handle->reqd_free_pages = reqd_free_pages();
 755
 756         printk(KERN_INFO
 757                 "PM: Using %u thread(s) for compression.\n"
 758                 "PM: Compressing and saving image data (%u pages)...\n",
 759                 nr_threads, nr_to_write);
 760         m = nr_to_write / 10;
 761         if (!m)
 762                 m = 1;
 763         nr_pages = 0;
 764         start = ktime_get();
 765         for (;;) {
 766                 for (thr = 0; thr < nr_threads; thr++) {
 767                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 768                                 ret = snapshot_read_next(snapshot);
 769                                 if (ret < 0)
 770                                         goto out_finish;
 771
 772                                 if (!ret)
 773                                         break;
 774
 775                                 memcpy(data[thr].unc + off,
 776                                        data_of(*snapshot), PAGE_SIZE);
 777
 778                                 if (!(nr_pages % m))
 779                                         printk(KERN_INFO
 780                                                "PM: Image saving progress: "
 781                                                "%3d%%\n",
 782                                                nr_pages / m * 10);
 783                                 nr_pages++;
 784                         }
 785                         if (!off)
 786                                 break;
 787
 788                         data[thr].unc_len = off;
 789
 790                         atomic_set(&data[thr].ready, 1);
 791                         wake_up(&data[thr].go);
 792                 }
 793
 794                 if (!thr)
 795                         break;
 796
 797                 crc->run_threads = thr;
 798                 atomic_set(&crc->ready, 1);
 799                 wake_up(&crc->go);
 800
 801                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 802                         wait_event(data[thr].done,
 803                                    atomic_read(&data[thr].stop));
 804                         atomic_set(&data[thr].stop, 0);
 805
 806                         ret = data[thr].ret;
 807
 808                         if (ret < 0) {
 809                                 printk(KERN_ERR "PM: LZO compression failed\n");
 810                                 goto out_finish;
 811                         }
 812
 813                         if (unlikely(!data[thr].cmp_len ||
 814                                      data[thr].cmp_len >
 815                                      lzo1x_worst_compress(data[thr].unc_len))) {
 816                                 printk(KERN_ERR
 817                                        "PM: Invalid LZO compressed length\n");
 818                                 ret = -1;
 819                                 goto out_finish;
 820                         }
 821
 822                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 823
 824                         /*
 825                          * Given we are writing one page at a time to disk, we
 826                          * copy that much from the buffer, although the last
 827                          * bit will likely be smaller than full page. This is
 828                          * OK - we saved the length of the compressed data, so
 829                          * any garbage at the end will be discarded when we
 830                          * read it.
 831                          */
 832                         for (off = 0;
 833                              off < LZO_HEADER + data[thr].cmp_len;
 834                              off += PAGE_SIZE) {
 835                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 836
 837                                 ret = swap_write_page(handle, page, &hb);
 838                                 if (ret)
 839                                         goto out_finish;
 840                         }
 841                 }
 842
 843                 wait_event(crc->done, atomic_read(&crc->stop));
 844                 atomic_set(&crc->stop, 0);
 845         }
 846
 847 out_finish:
 848         err2 = hib_wait_io(&hb);
 849         stop = ktime_get();
 850         if (!ret)
 851                 ret = err2;
 852         if (!ret)
 853                 printk(KERN_INFO "PM: Image saving done.\n");
 854         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 855 out_clean:
 856         if (crc) {
 857                 if (crc->thr)
 858                         kthread_stop(crc->thr);
 859                 kfree(crc);
 860         }
 861         if (data) {
 862                 for (thr = 0; thr < nr_threads; thr++)
 863                         if (data[thr].thr)
 864                                 kthread_stop(data[thr].thr);
 865                 vfree(data);
 866         }
 867         if (page) free_page((unsigned long)page);
 868
 869         return ret;
 870 }
 871
 872 /**
 873  *      enough_swap - Make sure we have enough swap to save the image.
 874  *
 875  *      Returns TRUE or FALSE after checking the total amount of swap
 876  *      space avaiable from the resume partition.
 877  */
 878
 879 static int enough_swap(unsigned int nr_pages, unsigned int flags)
 880 {
 881         unsigned int free_swap = count_swap_pages(root_swap, 1);
 882         unsigned int required;
 883
 884         pr_debug("PM: Free swap pages: %u\n", free_swap);
 885
 886         required = PAGES_FOR_IO + nr_pages;
 887         return free_swap > required;
 888 }
 889
 890 /**
 891  *      swsusp_write - Write entire image and metadata.
 892  *      @flags: flags to pass to the "boot" kernel in the image header
 893  *
 894  *      It is important _NOT_ to umount filesystems at this point. We want
 895  *      them synced (in case something goes wrong) but we DO not want to mark
 896  *      filesystem clean: it is not. (And it does not matter, if we resume
 897  *      correctly, we'll mark system clean, anyway.)
 898  */
 899
 900 int swsusp_write(unsigned int flags)
 901 {
 902         struct swap_map_handle handle;
 903         struct snapshot_handle snapshot;
 904         struct swsusp_info *header;
 905         unsigned long pages;
 906         int error;
 907
 908         pages = snapshot_get_image_size();
 909         error = get_swap_writer(&handle);
 910         if (error) {
 911                 printk(KERN_ERR "PM: Cannot get swap writer\n");
 912                 return error;
 913         }
 914         if (flags & SF_NOCOMPRESS_MODE) {
 915                 if (!enough_swap(pages, flags)) {
 916                         printk(KERN_ERR "PM: Not enough free swap\n");
 917                         error = -ENOSPC;
 918                         goto out_finish;
 919                 }
 920         }
 921         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 922         error = snapshot_read_next(&snapshot);
 923         if (error < PAGE_SIZE) {
 924                 if (error >= 0)
 925                         error = -EFAULT;
 926
 927                 goto out_finish;
 928         }
 929         header = (struct swsusp_info *)data_of(snapshot);
 930         error = swap_write_page(&handle, header, NULL);
 931         if (!error) {
 932                 error = (flags & SF_NOCOMPRESS_MODE) ?
 933                         save_image(&handle, &snapshot, pages - 1) :
 934                         save_image_lzo(&handle, &snapshot, pages - 1);
 935         }
 936 out_finish:
 937         error = swap_writer_finish(&handle, flags, error);
 938         return error;
 939 }
 940
 941 /**
 942  *      The following functions allow us to read data using a swap map
 943  *      in a file-alike way
 944  */
 945
 946 static void release_swap_reader(struct swap_map_handle *handle)
 947 {
 948         struct swap_map_page_list *tmp;
 949
 950         while (handle->maps) {
 951                 if (handle->maps->map)
 952                         free_page((unsigned long)handle->maps->map);
 953                 tmp = handle->maps;
 954                 handle->maps = handle->maps->next;
 955                 kfree(tmp);
 956         }
 957         handle->cur = NULL;
 958 }
 959
 960 static int get_swap_reader(struct swap_map_handle *handle,
 961                 unsigned int *flags_p)
 962 {
 963         int error;
 964         struct swap_map_page_list *tmp, *last;
 965         sector_t offset;
 966
 967         *flags_p = swsusp_header->flags;
 968
 969         if (!swsusp_header->image) /* how can this happen? */
 970                 return -EINVAL;
 971
 972         handle->cur = NULL;
 973         last = handle->maps = NULL;
 974         offset = swsusp_header->image;
 975         while (offset) {
 976                 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
 977                 if (!tmp) {
 978                         release_swap_reader(handle);
 979                         return -ENOMEM;
 980                 }
 981                 memset(tmp, 0, sizeof(*tmp));
 982                 if (!handle->maps)
 983                         handle->maps = tmp;
 984                 if (last)
 985                         last->next = tmp;
 986                 last = tmp;
 987
 988                 tmp->map = (struct swap_map_page *)
 989                            __get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 990                 if (!tmp->map) {
 991                         release_swap_reader(handle);
 992                         return -ENOMEM;
 993                 }
 994
 995                 error = hib_submit_io(READ_SYNC, offset, tmp->map, NULL);
 996                 if (error) {
 997                         release_swap_reader(handle);
 998                         return error;
 999                 }
1000                 offset = tmp->map->next_swap;
1001         }
1002         handle->k = 0;
1003         handle->cur = handle->maps->map;
1004         return 0;
1005 }
1006
1007 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1008                 struct hib_bio_batch *hb)
1009 {
1010         sector_t offset;
1011         int error;
1012         struct swap_map_page_list *tmp;
1013
1014         if (!handle->cur)
1015                 return -EINVAL;
1016         offset = handle->cur->entries[handle->k];
1017         if (!offset)
1018                 return -EFAULT;
1019         error = hib_submit_io(READ_SYNC, offset, buf, hb);
1020         if (error)
1021                 return error;
1022         if (++handle->k >= MAP_PAGE_ENTRIES) {
1023                 handle->k = 0;
1024                 free_page((unsigned long)handle->maps->map);
1025                 tmp = handle->maps;
1026                 handle->maps = handle->maps->next;
1027                 kfree(tmp);
1028                 if (!handle->maps)
1029                         release_swap_reader(handle);
1030                 else
1031                         handle->cur = handle->maps->map;
1032         }
1033         return error;
1034 }
1035
1036 static int swap_reader_finish(struct swap_map_handle *handle)
1037 {
1038         release_swap_reader(handle);
1039
1040         return 0;
1041 }
1042
1043 /**
1044  *      load_image - load the image using the swap map handle
1045  *      @handle and the snapshot handle @snapshot
1046  *      (assume there are @nr_pages pages to load)
1047  */
1048
1049 static int load_image(struct swap_map_handle *handle,
1050                       struct snapshot_handle *snapshot,
1051                       unsigned int nr_to_read)
1052 {
1053         unsigned int m;
1054         int ret = 0;
1055         ktime_t start;
1056         ktime_t stop;
1057         struct hib_bio_batch hb;
1058         int err2;
1059         unsigned nr_pages;
1060
1061         hib_init_batch(&hb);
1062
1063         clean_pages_on_read = true;
1064         printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
1065                 nr_to_read);
1066         m = nr_to_read / 10;
1067         if (!m)
1068                 m = 1;
1069         nr_pages = 0;
1070         start = ktime_get();
1071         for ( ; ; ) {
1072                 ret = snapshot_write_next(snapshot);
1073                 if (ret <= 0)
1074                         break;
1075                 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1076                 if (ret)
1077                         break;
1078                 if (snapshot->sync_read)
1079                         ret = hib_wait_io(&hb);
1080                 if (ret)
1081                         break;
1082                 if (!(nr_pages % m))
1083                         printk(KERN_INFO "PM: Image loading progress: %3d%%\n",
1084                                nr_pages / m * 10);
1085                 nr_pages++;
1086         }
1087         err2 = hib_wait_io(&hb);
1088         stop = ktime_get();
1089         if (!ret)
1090                 ret = err2;
1091         if (!ret) {
1092                 printk(KERN_INFO "PM: Image loading done.\n");
1093                 snapshot_write_finalize(snapshot);
1094                 if (!snapshot_image_loaded(snapshot))
1095                         ret = -ENODATA;
1096         }
1097         swsusp_show_speed(start, stop, nr_to_read, "Read");
1098         return ret;
1099 }
1100
1101 /**
1102  * Structure used for LZO data decompression.
1103  */
1104 struct dec_data {
1105         struct task_struct *thr;                  /* thread */
1106         atomic_t ready;                           /* ready to start flag */
1107         atomic_t stop;                            /* ready to stop flag */
1108         int ret;                                  /* return code */
1109         wait_queue_head_t go;                     /* start decompression */
1110         wait_queue_head_t done;                   /* decompression done */
1111         size_t unc_len;                           /* uncompressed length */
1112         size_t cmp_len;                           /* compressed length */
1113         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1114         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1115 };
1116
1117 /**
1118  * Deompression function that runs in its own thread.
1119  */
1120 static int lzo_decompress_threadfn(void *data)
1121 {
1122         struct dec_data *d = data;
1123
1124         while (1) {
1125                 wait_event(d->go, atomic_read(&d->ready) ||
1126                                   kthread_should_stop());
1127                 if (kthread_should_stop()) {
1128                         d->thr = NULL;
1129                         d->ret = -1;
1130                         atomic_set(&d->stop, 1);
1131                         wake_up(&d->done);
1132                         break;
1133                 }
1134                 atomic_set(&d->ready, 0);
1135
1136                 d->unc_len = LZO_UNC_SIZE;
1137                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1138                                                d->unc, &d->unc_len);
1139                 if (clean_pages_on_decompress)
1140                         flush_icache_range((unsigned long)d->unc,
1141                                            (unsigned long)d->unc + d->unc_len);
1142
1143                 atomic_set(&d->stop, 1);
1144                 wake_up(&d->done);
1145         }
1146         return 0;
1147 }
1148
1149 /**
1150  * load_image_lzo - Load compressed image data and decompress them with LZO.
1151  * @handle: Swap map handle to use for loading data.
1152  * @snapshot: Image to copy uncompressed data into.
1153  * @nr_to_read: Number of pages to load.
1154  */
1155 static int load_image_lzo(struct swap_map_handle *handle,
1156                           struct snapshot_handle *snapshot,
1157                           unsigned int nr_to_read)
1158 {
1159         unsigned int m;
1160         int ret = 0;
1161         int eof = 0;
1162         struct hib_bio_batch hb;
1163         ktime_t start;
1164         ktime_t stop;
1165         unsigned nr_pages;
1166         size_t off;
1167         unsigned i, thr, run_threads, nr_threads;
1168         unsigned ring = 0, pg = 0, ring_size = 0,
1169                  have = 0, want, need, asked = 0;
1170         unsigned long read_pages = 0;
1171         unsigned char **page = NULL;
1172         struct dec_data *data = NULL;
1173         struct crc_data *crc = NULL;
1174
1175         hib_init_batch(&hb);
1176
1177         /*
1178          * We'll limit the number of threads for decompression to limit memory
1179          * footprint.
1180          */
1181         nr_threads = num_online_cpus() - 1;
1182         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1183
1184         page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1185         if (!page) {
1186                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1187                 ret = -ENOMEM;
1188                 goto out_clean;
1189         }
1190
1191         data = vmalloc(sizeof(*data) * nr_threads);
1192         if (!data) {
1193                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1194                 ret = -ENOMEM;
1195                 goto out_clean;
1196         }
1197         for (thr = 0; thr < nr_threads; thr++)
1198                 memset(&data[thr], 0, offsetof(struct dec_data, go));
1199
1200         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1201         if (!crc) {
1202                 printk(KERN_ERR "PM: Failed to allocate crc\n");
1203                 ret = -ENOMEM;
1204                 goto out_clean;
1205         }
1206         memset(crc, 0, offsetof(struct crc_data, go));
1207
1208         clean_pages_on_decompress = true;
1209
1210         /*
1211          * Start the decompression threads.
1212          */
1213         for (thr = 0; thr < nr_threads; thr++) {
1214                 init_waitqueue_head(&data[thr].go);
1215                 init_waitqueue_head(&data[thr].done);
1216
1217                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1218                                             &data[thr],
1219                                             "image_decompress/%u", thr);
1220                 if (IS_ERR(data[thr].thr)) {
1221                         data[thr].thr = NULL;
1222                         printk(KERN_ERR
1223                                "PM: Cannot start decompression threads\n");
1224                         ret = -ENOMEM;
1225                         goto out_clean;
1226                 }
1227         }
1228
1229         /*
1230          * Start the CRC32 thread.
1231          */
1232         init_waitqueue_head(&crc->go);
1233         init_waitqueue_head(&crc->done);
1234
1235         handle->crc32 = 0;
1236         crc->crc32 = &handle->crc32;
1237         for (thr = 0; thr < nr_threads; thr++) {
1238                 crc->unc[thr] = data[thr].unc;
1239                 crc->unc_len[thr] = &data[thr].unc_len;
1240         }
1241
1242         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1243         if (IS_ERR(crc->thr)) {
1244                 crc->thr = NULL;
1245                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
1246                 ret = -ENOMEM;
1247                 goto out_clean;
1248         }
1249
1250         /*
1251          * Set the number of pages for read buffering.
1252          * This is complete guesswork, because we'll only know the real
1253          * picture once prepare_image() is called, which is much later on
1254          * during the image load phase. We'll assume the worst case and
1255          * say that none of the image pages are from high memory.
1256          */
1257         if (low_free_pages() > snapshot_get_image_size())
1258                 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1259         read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1260
1261         for (i = 0; i < read_pages; i++) {
1262                 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1263                                                   __GFP_RECLAIM | __GFP_HIGH :
1264                                                   __GFP_RECLAIM | __GFP_NOWARN |
1265                                                   __GFP_NORETRY);
1266
1267                 if (!page[i]) {
1268                         if (i < LZO_CMP_PAGES) {
1269                                 ring_size = i;
1270                                 printk(KERN_ERR
1271                                        "PM: Failed to allocate LZO pages\n");
1272                                 ret = -ENOMEM;
1273                                 goto out_clean;
1274                         } else {
1275                                 break;
1276                         }
1277                 }
1278         }
1279         want = ring_size = i;
1280
1281         printk(KERN_INFO
1282                 "PM: Using %u thread(s) for decompression.\n"
1283                 "PM: Loading and decompressing image data (%u pages)...\n",
1284                 nr_threads, nr_to_read);
1285         m = nr_to_read / 10;
1286         if (!m)
1287                 m = 1;
1288         nr_pages = 0;
1289         start = ktime_get();
1290
1291         ret = snapshot_write_next(snapshot);
1292         if (ret <= 0)
1293                 goto out_finish;
1294
1295         for(;;) {
1296                 for (i = 0; !eof && i < want; i++) {
1297                         ret = swap_read_page(handle, page[ring], &hb);
1298                         if (ret) {
1299                                 /*
1300                                  * On real read error, finish. On end of data,
1301                                  * set EOF flag and just exit the read loop.
1302                                  */
1303                                 if (handle->cur &&
1304                                     handle->cur->entries[handle->k]) {
1305                                         goto out_finish;
1306                                 } else {
1307                                         eof = 1;
1308                                         break;
1309                                 }
1310                         }
1311                         if (++ring >= ring_size)
1312                                 ring = 0;
1313                 }
1314                 asked += i;
1315                 want -= i;
1316
1317                 /*
1318                  * We are out of data, wait for some more.
1319                  */
1320                 if (!have) {
1321                         if (!asked)
1322                                 break;
1323
1324                         ret = hib_wait_io(&hb);
1325                         if (ret)
1326                                 goto out_finish;
1327                         have += asked;
1328                         asked = 0;
1329                         if (eof)
1330                                 eof = 2;
1331                 }
1332
1333                 if (crc->run_threads) {
1334                         wait_event(crc->done, atomic_read(&crc->stop));
1335                         atomic_set(&crc->stop, 0);
1336                         crc->run_threads = 0;
1337                 }
1338
1339                 for (thr = 0; have && thr < nr_threads; thr++) {
1340                         data[thr].cmp_len = *(size_t *)page[pg];
1341                         if (unlikely(!data[thr].cmp_len ||
1342                                      data[thr].cmp_len >
1343                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1344                                 printk(KERN_ERR
1345                                        "PM: Invalid LZO compressed length\n");
1346                                 ret = -1;
1347                                 goto out_finish;
1348                         }
1349
1350                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1351                                             PAGE_SIZE);
1352                         if (need > have) {
1353                                 if (eof > 1) {
1354                                         ret = -1;
1355                                         goto out_finish;
1356                                 }
1357                                 break;
1358                         }
1359
1360                         for (off = 0;
1361                              off < LZO_HEADER + data[thr].cmp_len;
1362                              off += PAGE_SIZE) {
1363                                 memcpy(data[thr].cmp + off,
1364                                        page[pg], PAGE_SIZE);
1365                                 have--;
1366                                 want++;
1367                                 if (++pg >= ring_size)
1368                                         pg = 0;
1369                         }
1370
1371                         atomic_set(&data[thr].ready, 1);
1372                         wake_up(&data[thr].go);
1373                 }
1374
1375                 /*
1376                  * Wait for more data while we are decompressing.
1377                  */
1378                 if (have < LZO_CMP_PAGES && asked) {
1379                         ret = hib_wait_io(&hb);
1380                         if (ret)
1381                                 goto out_finish;
1382                         have += asked;
1383                         asked = 0;
1384                         if (eof)
1385                                 eof = 2;
1386                 }
1387
1388                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1389                         wait_event(data[thr].done,
1390                                    atomic_read(&data[thr].stop));
1391                         atomic_set(&data[thr].stop, 0);
1392
1393                         ret = data[thr].ret;
1394
1395                         if (ret < 0) {
1396                                 printk(KERN_ERR
1397                                        "PM: LZO decompression failed\n");
1398                                 goto out_finish;
1399                         }
1400
1401                         if (unlikely(!data[thr].unc_len ||
1402                                      data[thr].unc_len > LZO_UNC_SIZE ||
1403                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1404                                 printk(KERN_ERR
1405                                        "PM: Invalid LZO uncompressed length\n");
1406                                 ret = -1;
1407                                 goto out_finish;
1408                         }
1409
1410                         for (off = 0;
1411                              off < data[thr].unc_len; off += PAGE_SIZE) {
1412                                 memcpy(data_of(*snapshot),
1413                                        data[thr].unc + off, PAGE_SIZE);
1414
1415                                 if (!(nr_pages % m))
1416                                         printk(KERN_INFO
1417                                                "PM: Image loading progress: "
1418                                                "%3d%%\n",
1419                                                nr_pages / m * 10);
1420                                 nr_pages++;
1421
1422                                 ret = snapshot_write_next(snapshot);
1423                                 if (ret <= 0) {
1424                                         crc->run_threads = thr + 1;
1425                                         atomic_set(&crc->ready, 1);
1426                                         wake_up(&crc->go);
1427                                         goto out_finish;
1428                                 }
1429                         }
1430                 }
1431
1432                 crc->run_threads = thr;
1433                 atomic_set(&crc->ready, 1);
1434                 wake_up(&crc->go);
1435         }
1436
1437 out_finish:
1438         if (crc->run_threads) {
1439                 wait_event(crc->done, atomic_read(&crc->stop));
1440                 atomic_set(&crc->stop, 0);
1441         }
1442         stop = ktime_get();
1443         if (!ret) {
1444                 printk(KERN_INFO "PM: Image loading done.\n");
1445                 snapshot_write_finalize(snapshot);
1446                 if (!snapshot_image_loaded(snapshot))
1447                         ret = -ENODATA;
1448                 if (!ret) {
1449                         if (swsusp_header->flags & SF_CRC32_MODE) {
1450                                 if(handle->crc32 != swsusp_header->crc32) {
1451                                         printk(KERN_ERR
1452                                                "PM: Invalid image CRC32!\n");
1453                                         ret = -ENODATA;
1454                                 }
1455                         }
1456                 }
1457         }
1458         swsusp_show_speed(start, stop, nr_to_read, "Read");
1459 out_clean:
1460         for (i = 0; i < ring_size; i++)
1461                 free_page((unsigned long)page[i]);
1462         if (crc) {
1463                 if (crc->thr)
1464                         kthread_stop(crc->thr);
1465                 kfree(crc);
1466         }
1467         if (data) {
1468                 for (thr = 0; thr < nr_threads; thr++)
1469                         if (data[thr].thr)
1470                                 kthread_stop(data[thr].thr);
1471                 vfree(data);
1472         }
1473         vfree(page);
1474
1475         return ret;
1476 }
1477
1478 /**
1479  *      swsusp_read - read the hibernation image.
1480  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1481  *                be written into this memory location
1482  */
1483
1484 int swsusp_read(unsigned int *flags_p)
1485 {
1486         int error;
1487         struct swap_map_handle handle;
1488         struct snapshot_handle snapshot;
1489         struct swsusp_info *header;
1490
1491         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1492         error = snapshot_write_next(&snapshot);
1493         if (error < PAGE_SIZE)
1494                 return error < 0 ? error : -EFAULT;
1495         header = (struct swsusp_info *)data_of(snapshot);
1496         error = get_swap_reader(&handle, flags_p);
1497         if (error)
1498                 goto end;
1499         if (!error)
1500                 error = swap_read_page(&handle, header, NULL);
1501         if (!error) {
1502                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1503                         load_image(&handle, &snapshot, header->pages - 1) :
1504                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1505         }
1506         swap_reader_finish(&handle);
1507 end:
1508         if (!error)
1509                 pr_debug("PM: Image successfully loaded\n");
1510         else
1511                 pr_debug("PM: Error %d resuming\n", error);
1512         return error;
1513 }
1514
1515 /**
1516  *      swsusp_check - Check for swsusp signature in the resume device
1517  */
1518
1519 int swsusp_check(void)
1520 {
1521         int error;
1522
1523         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1524                                             FMODE_READ, NULL);
1525         if (!IS_ERR(hib_resume_bdev)) {
1526                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1527                 clear_page(swsusp_header);
1528                 error = hib_submit_io(READ_SYNC, swsusp_resume_block,
1529                                         swsusp_header, NULL);
1530                 if (error)
1531                         goto put;
1532
1533                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1534                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1535                         /* Reset swap signature now */
1536                         error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1537                                                 swsusp_header, NULL);
1538                 } else {
1539                         error = -EINVAL;
1540                 }
1541
1542 put:
1543                 if (error)
1544                         blkdev_put(hib_resume_bdev, FMODE_READ);
1545                 else
1546                         pr_debug("PM: Image signature found, resuming\n");
1547         } else {
1548                 error = PTR_ERR(hib_resume_bdev);
1549         }
1550
1551         if (error)
1552                 pr_debug("PM: Image not found (code %d)\n", error);
1553
1554         return error;
1555 }
1556
1557 /**
1558  *      swsusp_close - close swap device.
1559  */
1560
1561 void swsusp_close(fmode_t mode)
1562 {
1563         if (IS_ERR(hib_resume_bdev)) {
1564                 pr_debug("PM: Image device not initialised\n");
1565                 return;
1566         }
1567
1568         blkdev_put(hib_resume_bdev, mode);
1569 }
1570
1571 /**
1572  *      swsusp_unmark - Unmark swsusp signature in the resume device
1573  */
1574
1575 #ifdef CONFIG_SUSPEND
1576 int swsusp_unmark(void)
1577 {
1578         int error;
1579
1580         hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
1581         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1582                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1583                 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1584                                         swsusp_header, NULL);
1585         } else {
1586                 printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
1587                 error = -ENODEV;
1588         }
1589
1590         /*
1591          * We just returned from suspend, we don't need the image any more.
1592          */
1593         free_all_swap_pages(root_swap);
1594
1595         return error;
1596 }
1597 #endif
1598
1599 static int swsusp_header_init(void)
1600 {
1601         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1602         if (!swsusp_header)
1603                 panic("Could not allocate memory for swsusp_header\n");
1604         return 0;
1605 }
1606
1607 core_initcall(swsusp_header_init);