kernel/power/swsusp.c

   1 /*
   2  * linux/kernel/power/swsusp.c
   3  *
   4  * This file is to realize architecture-independent
   5  * machine suspend feature using pretty near only high-level routines
   6  *
   7  * Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu>
   8  * Copyright (C) 1998,2001-2004 Pavel Machek <pavel@suse.cz>
   9  *
  10  * This file is released under the GPLv2.
  11  *
  12  * I'd like to thank the following people for their work:
  13  *
  14  * Pavel Machek <pavel@ucw.cz>:
  15  * Modifications, defectiveness pointing, being with me at the very beginning,
  16  * suspend to swap space, stop all tasks. Port to 2.4.18-ac and 2.5.17.
  17  *
  18  * Steve Doddi <dirk@loth.demon.co.uk>:
  19  * Support the possibility of hardware state restoring.
  20  *
  21  * Raph <grey.havens@earthling.net>:
  22  * Support for preserving states of network devices and virtual console
  23  * (including X and svgatextmode)
  24  *
  25  * Kurt Garloff <garloff@suse.de>:
  26  * Straightened the critical function in order to prevent compilers from
  27  * playing tricks with local variables.
  28  *
  29  * Andreas Mohr <a.mohr@mailto.de>
  30  *
  31  * Alex Badea <vampire@go.ro>:
  32  * Fixed runaway init
  33  *
  34  * Andreas Steinmetz <ast@domdv.de>:
  35  * Added encrypted suspend option
  36  *
  37  * More state savers are welcome. Especially for the scsi layer...
  38  *
  39  * For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
  40  */
  41
  42 #include <linux/module.h>
  43 #include <linux/mm.h>
  44 #include <linux/suspend.h>
  45 #include <linux/smp_lock.h>
  46 #include <linux/file.h>
  47 #include <linux/utsname.h>
  48 #include <linux/version.h>
  49 #include <linux/delay.h>
  50 #include <linux/reboot.h>
  51 #include <linux/bitops.h>
  52 #include <linux/vt_kern.h>
  53 #include <linux/kbd_kern.h>
  54 #include <linux/keyboard.h>
  55 #include <linux/spinlock.h>
  56 #include <linux/genhd.h>
  57 #include <linux/kernel.h>
  58 #include <linux/major.h>
  59 #include <linux/swap.h>
  60 #include <linux/pm.h>
  61 #include <linux/device.h>
  62 #include <linux/buffer_head.h>
  63 #include <linux/swapops.h>
  64 #include <linux/bootmem.h>
  65 #include <linux/syscalls.h>
  66 #include <linux/console.h>
  67 #include <linux/highmem.h>
  68 #include <linux/bio.h>
  69 #include <linux/mount.h>
  70
  71 #include <asm/uaccess.h>
  72 #include <asm/mmu_context.h>
  73 #include <asm/pgtable.h>
  74 #include <asm/tlbflush.h>
  75 #include <asm/io.h>
  76
  77 #include <linux/random.h>
  78 #include <linux/crypto.h>
  79 #include <asm/scatterlist.h>
  80
  81 #include "power.h"
  82
  83 #define CIPHER "aes"
  84 #define MAXKEY 32
  85 #define MAXIV  32
  86
  87 /* References to section boundaries */
  88 extern const void __nosave_begin, __nosave_end;
  89
  90 /* Variables to be preserved over suspend */
  91 static int nr_copy_pages_check;
  92
  93 extern char resume_file[];
  94
  95 /* Local variables that should not be affected by save */
  96 static unsigned int nr_copy_pages __nosavedata = 0;
  97
  98 /* Suspend pagedir is allocated before final copy, therefore it
  99    must be freed after resume
 100
 101    Warning: this is evil. There are actually two pagedirs at time of
 102    resume. One is "pagedir_save", which is empty frame allocated at
 103    time of suspend, that must be freed. Second is "pagedir_nosave",
 104    allocated at time of resume, that travels through memory not to
 105    collide with anything.
 106
 107    Warning: this is even more evil than it seems. Pagedirs this file
 108    talks about are completely different from page directories used by
 109    MMU hardware.
 110  */
 111 suspend_pagedir_t *pagedir_nosave __nosavedata = NULL;
 112 static suspend_pagedir_t *pagedir_save;
 113
 114 #define SWSUSP_SIG      "S1SUSPEND"
 115
 116 static struct swsusp_header {
 117         char reserved[PAGE_SIZE - 20 - MAXKEY - MAXIV - sizeof(swp_entry_t)];
 118         u8 key_iv[MAXKEY+MAXIV];
 119         swp_entry_t swsusp_info;
 120         char    orig_sig[10];
 121         char    sig[10];
 122 } __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
 123
 124 static struct swsusp_info swsusp_info;
 125
 126 /*
 127  * XXX: We try to keep some more pages free so that I/O operations succeed
 128  * without paging. Might this be more?
 129  */
 130 #define PAGES_FOR_IO    512
 131
 132 /*
 133  * Saving part...
 134  */
 135
 136 /* We memorize in swapfile_used what swap devices are used for suspension */
 137 #define SWAPFILE_UNUSED    0
 138 #define SWAPFILE_SUSPEND   1    /* This is the suspending device */
 139 #define SWAPFILE_IGNORED   2    /* Those are other swap devices ignored for suspension */
 140
 141 static unsigned short swapfile_used[MAX_SWAPFILES];
 142 static unsigned short root_swap;
 143
 144 static int write_page(unsigned long addr, swp_entry_t * loc);
 145 static int bio_read_page(pgoff_t page_off, void * page);
 146
 147 static u8 key_iv[MAXKEY+MAXIV];
 148
 149 #ifdef CONFIG_SWSUSP_ENCRYPT
 150
 151 static int crypto_init(int mode, void **mem)
 152 {
 153         int error = 0;
 154         int len;
 155         char *modemsg;
 156         struct crypto_tfm *tfm;
 157
 158         modemsg = mode ? "suspend not possible" : "resume not possible";
 159
 160         tfm = crypto_alloc_tfm(CIPHER, CRYPTO_TFM_MODE_CBC);
 161         if(!tfm) {
 162                 printk(KERN_ERR "swsusp: no tfm, %s\n", modemsg);
 163                 error = -EINVAL;
 164                 goto out;
 165         }
 166
 167         if(MAXKEY < crypto_tfm_alg_min_keysize(tfm)) {
 168                 printk(KERN_ERR "swsusp: key buffer too small, %s\n", modemsg);
 169                 error = -ENOKEY;
 170                 goto fail;
 171         }
 172
 173         if (mode)
 174                 get_random_bytes(key_iv, MAXKEY+MAXIV);
 175
 176         len = crypto_tfm_alg_max_keysize(tfm);
 177         if (len > MAXKEY)
 178                 len = MAXKEY;
 179
 180         if (crypto_cipher_setkey(tfm, key_iv, len)) {
 181                 printk(KERN_ERR "swsusp: key setup failure, %s\n", modemsg);
 182                 error = -EKEYREJECTED;
 183                 goto fail;
 184         }
 185
 186         len = crypto_tfm_alg_ivsize(tfm);
 187
 188         if (MAXIV < len) {
 189                 printk(KERN_ERR "swsusp: iv buffer too small, %s\n", modemsg);
 190                 error = -EOVERFLOW;
 191                 goto fail;
 192         }
 193
 194         crypto_cipher_set_iv(tfm, key_iv+MAXKEY, len);
 195
 196         *mem=(void *)tfm;
 197
 198         goto out;
 199
 200 fail:   crypto_free_tfm(tfm);
 201 out:    return error;
 202 }
 203
 204 static __inline__ void crypto_exit(void *mem)
 205 {
 206         crypto_free_tfm((struct crypto_tfm *)mem);
 207 }
 208
 209 static __inline__ int crypto_write(struct pbe *p, void *mem)
 210 {
 211         int error = 0;
 212         struct scatterlist src, dst;
 213
 214         src.page   = virt_to_page(p->address);
 215         src.offset = 0;
 216         src.length = PAGE_SIZE;
 217         dst.page   = virt_to_page((void *)&swsusp_header);
 218         dst.offset = 0;
 219         dst.length = PAGE_SIZE;
 220
 221         error = crypto_cipher_encrypt((struct crypto_tfm *)mem, &dst, &src,
 222                                         PAGE_SIZE);
 223
 224         if (!error)
 225                 error = write_page((unsigned long)&swsusp_header,
 226                                 &(p->swap_address));
 227         return error;
 228 }
 229
 230 static __inline__ int crypto_read(struct pbe *p, void *mem)
 231 {
 232         int error = 0;
 233         struct scatterlist src, dst;
 234
 235         error = bio_read_page(swp_offset(p->swap_address), (void *)p->address);
 236         if (!error) {
 237                 src.offset = 0;
 238                 src.length = PAGE_SIZE;
 239                 dst.offset = 0;
 240                 dst.length = PAGE_SIZE;
 241                 src.page = dst.page = virt_to_page((void *)p->address);
 242
 243                 error = crypto_cipher_decrypt((struct crypto_tfm *)mem, &dst,
 244                                                 &src, PAGE_SIZE);
 245         }
 246         return error;
 247 }
 248 #else
 249 static __inline__ int crypto_init(int mode, void *mem)
 250 {
 251         return 0;
 252 }
 253
 254 static __inline__ void crypto_exit(void *mem)
 255 {
 256 }
 257
 258 static __inline__ int crypto_write(struct pbe *p, void *mem)
 259 {
 260         return write_page(p->address, &(p->swap_address));
 261 }
 262
 263 static __inline__ int crypto_read(struct pbe *p, void *mem)
 264 {
 265         return bio_read_page(swp_offset(p->swap_address), (void *)p->address);
 266 }
 267 #endif
 268
 269 static int mark_swapfiles(swp_entry_t prev)
 270 {
 271         int error;
 272
 273         rw_swap_page_sync(READ,
 274                           swp_entry(root_swap, 0),
 275                           virt_to_page((unsigned long)&swsusp_header));
 276         if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
 277             !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
 278                 memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
 279                 memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
 280                 memcpy(swsusp_header.key_iv, key_iv, MAXKEY+MAXIV);
 281                 swsusp_header.swsusp_info = prev;
 282                 error = rw_swap_page_sync(WRITE,
 283                                           swp_entry(root_swap, 0),
 284                                           virt_to_page((unsigned long)
 285                                                        &swsusp_header));
 286         } else {
 287                 pr_debug("swsusp: Partition is not swap space.\n");
 288                 error = -ENODEV;
 289         }
 290         return error;
 291 }
 292
 293 /*
 294  * Check whether the swap device is the specified resume
 295  * device, irrespective of whether they are specified by
 296  * identical names.
 297  *
 298  * (Thus, device inode aliasing is allowed.  You can say /dev/hda4
 299  * instead of /dev/ide/host0/bus0/target0/lun0/part4 [if using devfs]
 300  * and they'll be considered the same device.  This is *necessary* for
 301  * devfs, since the resume code can only recognize the form /dev/hda4,
 302  * but the suspend code would see the long name.)
 303  */
 304 static int is_resume_device(const struct swap_info_struct *swap_info)
 305 {
 306         struct file *file = swap_info->swap_file;
 307         struct inode *inode = file->f_dentry->d_inode;
 308
 309         return S_ISBLK(inode->i_mode) &&
 310                 swsusp_resume_device == MKDEV(imajor(inode), iminor(inode));
 311 }
 312
 313 static int swsusp_swap_check(void) /* This is called before saving image */
 314 {
 315         int i, len;
 316
 317         len=strlen(resume_file);
 318         root_swap = 0xFFFF;
 319
 320         spin_lock(&swap_lock);
 321         for (i=0; i<MAX_SWAPFILES; i++) {
 322                 if (!(swap_info[i].flags & SWP_WRITEOK)) {
 323                         swapfile_used[i]=SWAPFILE_UNUSED;
 324                 } else {
 325                         if (!len) {
 326                                 printk(KERN_WARNING "resume= option should be used to set suspend device" );
 327                                 if (root_swap == 0xFFFF) {
 328                                         swapfile_used[i] = SWAPFILE_SUSPEND;
 329                                         root_swap = i;
 330                                 } else
 331                                         swapfile_used[i] = SWAPFILE_IGNORED;
 332                         } else {
 333                                 /* we ignore all swap devices that are not the resume_file */
 334                                 if (is_resume_device(&swap_info[i])) {
 335                                         swapfile_used[i] = SWAPFILE_SUSPEND;
 336                                         root_swap = i;
 337                                 } else {
 338                                         swapfile_used[i] = SWAPFILE_IGNORED;
 339                                 }
 340                         }
 341                 }
 342         }
 343         spin_unlock(&swap_lock);
 344         return (root_swap != 0xffff) ? 0 : -ENODEV;
 345 }
 346
 347 /**
 348  * This is called after saving image so modification
 349  * will be lost after resume... and that's what we want.
 350  * we make the device unusable. A new call to
 351  * lock_swapdevices can unlock the devices.
 352  */
 353 static void lock_swapdevices(void)
 354 {
 355         int i;
 356
 357         spin_lock(&swap_lock);
 358         for (i = 0; i< MAX_SWAPFILES; i++)
 359                 if (swapfile_used[i] == SWAPFILE_IGNORED) {
 360                         swap_info[i].flags ^= SWP_WRITEOK;
 361                 }
 362         spin_unlock(&swap_lock);
 363 }
 364
 365 /**
 366  *      write_page - Write one page to a fresh swap location.
 367  *      @addr:  Address we're writing.
 368  *      @loc:   Place to store the entry we used.
 369  *
 370  *      Allocate a new swap entry and 'sync' it. Note we discard -EIO
 371  *      errors. That is an artifact left over from swsusp. It did not
 372  *      check the return of rw_swap_page_sync() at all, since most pages
 373  *      written back to swap would return -EIO.
 374  *      This is a partial improvement, since we will at least return other
 375  *      errors, though we need to eventually fix the damn code.
 376  */
 377 static int write_page(unsigned long addr, swp_entry_t * loc)
 378 {
 379         swp_entry_t entry;
 380         int error = 0;
 381
 382         entry = get_swap_page();
 383         if (swp_offset(entry) &&
 384             swapfile_used[swp_type(entry)] == SWAPFILE_SUSPEND) {
 385                 error = rw_swap_page_sync(WRITE, entry,
 386                                           virt_to_page(addr));
 387                 if (error == -EIO)
 388                         error = 0;
 389                 if (!error)
 390                         *loc = entry;
 391         } else
 392                 error = -ENOSPC;
 393         return error;
 394 }
 395
 396 /**
 397  *      data_free - Free the swap entries used by the saved image.
 398  *
 399  *      Walk the list of used swap entries and free each one.
 400  *      This is only used for cleanup when suspend fails.
 401  */
 402 static void data_free(void)
 403 {
 404         swp_entry_t entry;
 405         struct pbe * p;
 406
 407         for_each_pbe(p, pagedir_nosave) {
 408                 entry = p->swap_address;
 409                 if (entry.val)
 410                         swap_free(entry);
 411                 else
 412                         break;
 413         }
 414 }
 415
 416 /**
 417  *      data_write - Write saved image to swap.
 418  *
 419  *      Walk the list of pages in the image and sync each one to swap.
 420  */
 421 static int data_write(void)
 422 {
 423         int error = 0, i = 0;
 424         unsigned int mod = nr_copy_pages / 100;
 425         struct pbe *p;
 426         void *tfm;
 427
 428         if ((error = crypto_init(1, &tfm)))
 429                 return error;
 430
 431         if (!mod)
 432                 mod = 1;
 433
 434         printk( "Writing data to swap (%d pages)...     ", nr_copy_pages );
 435         for_each_pbe (p, pagedir_nosave) {
 436                 if (!(i%mod))
 437                         printk( "\b\b\b\b%3d%%", i / mod );
 438                 if ((error = crypto_write(p, tfm))) {
 439                         crypto_exit(tfm);
 440                         return error;
 441                 }
 442                 i++;
 443         }
 444         printk("\b\b\b\bdone\n");
 445         crypto_exit(tfm);
 446         return error;
 447 }
 448
 449 static void dump_info(void)
 450 {
 451         pr_debug(" swsusp: Version: %u\n",swsusp_info.version_code);
 452         pr_debug(" swsusp: Num Pages: %ld\n",swsusp_info.num_physpages);
 453         pr_debug(" swsusp: UTS Sys: %s\n",swsusp_info.uts.sysname);
 454         pr_debug(" swsusp: UTS Node: %s\n",swsusp_info.uts.nodename);
 455         pr_debug(" swsusp: UTS Release: %s\n",swsusp_info.uts.release);
 456         pr_debug(" swsusp: UTS Version: %s\n",swsusp_info.uts.version);
 457         pr_debug(" swsusp: UTS Machine: %s\n",swsusp_info.uts.machine);
 458         pr_debug(" swsusp: UTS Domain: %s\n",swsusp_info.uts.domainname);
 459         pr_debug(" swsusp: CPUs: %d\n",swsusp_info.cpus);
 460         pr_debug(" swsusp: Image: %ld Pages\n",swsusp_info.image_pages);
 461         pr_debug(" swsusp: Pagedir: %ld Pages\n",swsusp_info.pagedir_pages);
 462 }
 463
 464 static void init_header(void)
 465 {
 466         memset(&swsusp_info, 0, sizeof(swsusp_info));
 467         swsusp_info.version_code = LINUX_VERSION_CODE;
 468         swsusp_info.num_physpages = num_physpages;
 469         memcpy(&swsusp_info.uts, &system_utsname, sizeof(system_utsname));
 470
 471         swsusp_info.suspend_pagedir = pagedir_nosave;
 472         swsusp_info.cpus = num_online_cpus();
 473         swsusp_info.image_pages = nr_copy_pages;
 474 }
 475
 476 static int close_swap(void)
 477 {
 478         swp_entry_t entry;
 479         int error;
 480
 481         dump_info();
 482         error = write_page((unsigned long)&swsusp_info, &entry);
 483         if (!error) {
 484                 printk( "S" );
 485                 error = mark_swapfiles(entry);
 486                 printk( "|\n" );
 487         }
 488         return error;
 489 }
 490
 491 /**
 492  *      free_pagedir_entries - Free pages used by the page directory.
 493  *
 494  *      This is used during suspend for error recovery.
 495  */
 496
 497 static void free_pagedir_entries(void)
 498 {
 499         int i;
 500
 501         for (i = 0; i < swsusp_info.pagedir_pages; i++)
 502                 swap_free(swsusp_info.pagedir[i]);
 503 }
 504
 505
 506 /**
 507  *      write_pagedir - Write the array of pages holding the page directory.
 508  *      @last:  Last swap entry we write (needed for header).
 509  */
 510
 511 static int write_pagedir(void)
 512 {
 513         int error = 0;
 514         unsigned n = 0;
 515         struct pbe * pbe;
 516
 517         printk( "Writing pagedir...");
 518         for_each_pb_page (pbe, pagedir_nosave) {
 519                 if ((error = write_page((unsigned long)pbe, &swsusp_info.pagedir[n++])))
 520                         return error;
 521         }
 522
 523         swsusp_info.pagedir_pages = n;
 524         printk("done (%u pages)\n", n);
 525         return error;
 526 }
 527
 528 /**
 529  *      write_suspend_image - Write entire image and metadata.
 530  *
 531  */
 532 static int write_suspend_image(void)
 533 {
 534         int error;
 535
 536         init_header();
 537         if ((error = data_write()))
 538                 goto FreeData;
 539
 540         if ((error = write_pagedir()))
 541                 goto FreePagedir;
 542
 543         if ((error = close_swap()))
 544                 goto FreePagedir;
 545  Done:
 546         memset(key_iv, 0, MAXKEY+MAXIV);
 547         return error;
 548  FreePagedir:
 549         free_pagedir_entries();
 550  FreeData:
 551         data_free();
 552         goto Done;
 553 }
 554
 555
 556 #ifdef CONFIG_HIGHMEM
 557 struct highmem_page {
 558         char *data;
 559         struct page *page;
 560         struct highmem_page *next;
 561 };
 562
 563 static struct highmem_page *highmem_copy;
 564
 565 static int save_highmem_zone(struct zone *zone)
 566 {
 567         unsigned long zone_pfn;
 568         mark_free_pages(zone);
 569         for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
 570                 struct page *page;
 571                 struct highmem_page *save;
 572                 void *kaddr;
 573                 unsigned long pfn = zone_pfn + zone->zone_start_pfn;
 574
 575                 if (!(pfn%1000))
 576                         printk(".");
 577                 if (!pfn_valid(pfn))
 578                         continue;
 579                 page = pfn_to_page(pfn);
 580                 /*
 581                  * PageReserved results from rvmalloc() sans vmalloc_32()
 582                  * and architectural memory reservations.
 583                  *
 584                  * rvmalloc should not cause this, because all implementations
 585                  * appear to always be using vmalloc_32 on architectures with
 586                  * highmem. This is a good thing, because we would like to save
 587                  * rvmalloc pages.
 588                  *
 589                  * It appears to be triggered by pages which do not point to
 590                  * valid memory (see arch/i386/mm/init.c:one_highpage_init(),
 591                  * which sets PageReserved if the page does not point to valid
 592                  * RAM.
 593                  *
 594                  * XXX: must remove usage of PageReserved!
 595                  */
 596                 if (PageReserved(page))
 597                         continue;
 598                 BUG_ON(PageNosave(page));
 599                 if (PageNosaveFree(page))
 600                         continue;
 601                 save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC);
 602                 if (!save)
 603                         return -ENOMEM;
 604                 save->next = highmem_copy;
 605                 save->page = page;
 606                 save->data = (void *) get_zeroed_page(GFP_ATOMIC);
 607                 if (!save->data) {
 608                         kfree(save);
 609                         return -ENOMEM;
 610                 }
 611                 kaddr = kmap_atomic(page, KM_USER0);
 612                 memcpy(save->data, kaddr, PAGE_SIZE);
 613                 kunmap_atomic(kaddr, KM_USER0);
 614                 highmem_copy = save;
 615         }
 616         return 0;
 617 }
 618 #endif /* CONFIG_HIGHMEM */
 619
 620
 621 static int save_highmem(void)
 622 {
 623 #ifdef CONFIG_HIGHMEM
 624         struct zone *zone;
 625         int res = 0;
 626
 627         pr_debug("swsusp: Saving Highmem\n");
 628         for_each_zone (zone) {
 629                 if (is_highmem(zone))
 630                         res = save_highmem_zone(zone);
 631                 if (res)
 632                         return res;
 633         }
 634 #endif
 635         return 0;
 636 }
 637
 638 static int restore_highmem(void)
 639 {
 640 #ifdef CONFIG_HIGHMEM
 641         printk("swsusp: Restoring Highmem\n");
 642         while (highmem_copy) {
 643                 struct highmem_page *save = highmem_copy;
 644                 void *kaddr;
 645                 highmem_copy = save->next;
 646
 647                 kaddr = kmap_atomic(save->page, KM_USER0);
 648                 memcpy(kaddr, save->data, PAGE_SIZE);
 649                 kunmap_atomic(kaddr, KM_USER0);
 650                 free_page((long) save->data);
 651                 kfree(save);
 652         }
 653 #endif
 654         return 0;
 655 }
 656
 657
 658 static int pfn_is_nosave(unsigned long pfn)
 659 {
 660         unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
 661         unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
 662         return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
 663 }
 664
 665 /**
 666  *      saveable - Determine whether a page should be cloned or not.
 667  *      @pfn:   The page
 668  *
 669  *      We save a page if it's Reserved, and not in the range of pages
 670  *      statically defined as 'unsaveable', or if it isn't reserved, and
 671  *      isn't part of a free chunk of pages.
 672  */
 673
 674 static int saveable(struct zone * zone, unsigned long * zone_pfn)
 675 {
 676         unsigned long pfn = *zone_pfn + zone->zone_start_pfn;
 677         struct page * page;
 678
 679         if (!pfn_valid(pfn))
 680                 return 0;
 681
 682         page = pfn_to_page(pfn);
 683         if (PageNosave(page))
 684                 return 0;
 685         if (pfn_is_nosave(pfn)) {
 686                 pr_debug("[nosave pfn 0x%lx]", pfn);
 687                 return 0;
 688         }
 689         if (PageNosaveFree(page))
 690                 return 0;
 691
 692         return 1;
 693 }
 694
 695 static void count_data_pages(void)
 696 {
 697         struct zone *zone;
 698         unsigned long zone_pfn;
 699
 700         nr_copy_pages = 0;
 701
 702         for_each_zone (zone) {
 703                 if (is_highmem(zone))
 704                         continue;
 705                 mark_free_pages(zone);
 706                 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
 707                         nr_copy_pages += saveable(zone, &zone_pfn);
 708         }
 709 }
 710
 711
 712 static void copy_data_pages(void)
 713 {
 714         struct zone *zone;
 715         unsigned long zone_pfn;
 716         struct pbe * pbe = pagedir_nosave;
 717
 718         pr_debug("copy_data_pages(): pages to copy: %d\n", nr_copy_pages);
 719         for_each_zone (zone) {
 720                 if (is_highmem(zone))
 721                         continue;
 722                 mark_free_pages(zone);
 723                 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
 724                         if (saveable(zone, &zone_pfn)) {
 725                                 struct page * page;
 726                                 page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
 727                                 BUG_ON(!pbe);
 728                                 pbe->orig_address = (long) page_address(page);
 729                                 /* copy_page is not usable for copying task structs. */
 730                                 memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE);
 731                                 pbe = pbe->next;
 732                         }
 733                 }
 734         }
 735         BUG_ON(pbe);
 736 }
 737
 738
 739 /**
 740  *      calc_nr - Determine the number of pages needed for a pbe list.
 741  */
 742
 743 static int calc_nr(int nr_copy)
 744 {
 745         return nr_copy + (nr_copy+PBES_PER_PAGE-2)/(PBES_PER_PAGE-1);
 746 }
 747
 748 /**
 749  *      free_pagedir - free pages allocated with alloc_pagedir()
 750  */
 751
 752 static inline void free_pagedir(struct pbe *pblist)
 753 {
 754         struct pbe *pbe;
 755
 756         while (pblist) {
 757                 pbe = (pblist + PB_PAGE_SKIP)->next;
 758                 free_page((unsigned long)pblist);
 759                 pblist = pbe;
 760         }
 761 }
 762
 763 /**
 764  *      fill_pb_page - Create a list of PBEs on a given memory page
 765  */
 766
 767 static inline void fill_pb_page(struct pbe *pbpage)
 768 {
 769         struct pbe *p;
 770
 771         p = pbpage;
 772         pbpage += PB_PAGE_SKIP;
 773         do
 774                 p->next = p + 1;
 775         while (++p < pbpage);
 776 }
 777
 778 /**
 779  *      create_pbe_list - Create a list of PBEs on top of a given chain
 780  *      of memory pages allocated with alloc_pagedir()
 781  */
 782
 783 static void create_pbe_list(struct pbe *pblist, unsigned nr_pages)
 784 {
 785         struct pbe *pbpage, *p;
 786         unsigned num = PBES_PER_PAGE;
 787
 788         for_each_pb_page (pbpage, pblist) {
 789                 if (num >= nr_pages)
 790                         break;
 791
 792                 fill_pb_page(pbpage);
 793                 num += PBES_PER_PAGE;
 794         }
 795         if (pbpage) {
 796                 for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++)
 797                         p->next = p + 1;
 798                 p->next = NULL;
 799         }
 800         pr_debug("create_pbe_list(): initialized %d PBEs\n", num);
 801 }
 802
 803 /**
 804  *      alloc_pagedir - Allocate the page directory.
 805  *
 806  *      First, determine exactly how many pages we need and
 807  *      allocate them.
 808  *
 809  *      We arrange the pages in a chain: each page is an array of PBES_PER_PAGE
 810  *      struct pbe elements (pbes) and the last element in the page points
 811  *      to the next page.
 812  *
 813  *      On each page we set up a list of struct_pbe elements.
 814  */
 815
 816 static struct pbe * alloc_pagedir(unsigned nr_pages)
 817 {
 818         unsigned num;
 819         struct pbe *pblist, *pbe;
 820
 821         if (!nr_pages)
 822                 return NULL;
 823
 824         pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);
 825         pblist = (struct pbe *)get_zeroed_page(GFP_ATOMIC | __GFP_COLD);
 826         for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages;
 827                         pbe = pbe->next, num += PBES_PER_PAGE) {
 828                 pbe += PB_PAGE_SKIP;
 829                 pbe->next = (struct pbe *)get_zeroed_page(GFP_ATOMIC | __GFP_COLD);
 830         }
 831         if (!pbe) { /* get_zeroed_page() failed */
 832                 free_pagedir(pblist);
 833                 pblist = NULL;
 834         }
 835         return pblist;
 836 }
 837
 838 /**
 839  *      free_image_pages - Free pages allocated for snapshot
 840  */
 841
 842 static void free_image_pages(void)
 843 {
 844         struct pbe * p;
 845
 846         for_each_pbe (p, pagedir_save) {
 847                 if (p->address) {
 848                         ClearPageNosave(virt_to_page(p->address));
 849                         free_page(p->address);
 850                         p->address = 0;
 851                 }
 852         }
 853 }
 854
 855 /**
 856  *      alloc_image_pages - Allocate pages for the snapshot.
 857  */
 858
 859 static int alloc_image_pages(void)
 860 {
 861         struct pbe * p;
 862
 863         for_each_pbe (p, pagedir_save) {
 864                 p->address = get_zeroed_page(GFP_ATOMIC | __GFP_COLD);
 865                 if (!p->address)
 866                         return -ENOMEM;
 867                 SetPageNosave(virt_to_page(p->address));
 868         }
 869         return 0;
 870 }
 871
 872 /* Free pages we allocated for suspend. Suspend pages are alocated
 873  * before atomic copy, so we need to free them after resume.
 874  */
 875 void swsusp_free(void)
 876 {
 877         BUG_ON(PageNosave(virt_to_page(pagedir_save)));
 878         BUG_ON(PageNosaveFree(virt_to_page(pagedir_save)));
 879         free_image_pages();
 880         free_pagedir(pagedir_save);
 881 }
 882
 883
 884 /**
 885  *      enough_free_mem - Make sure we enough free memory to snapshot.
 886  *
 887  *      Returns TRUE or FALSE after checking the number of available
 888  *      free pages.
 889  */
 890
 891 static int enough_free_mem(void)
 892 {
 893         if (nr_free_pages() < (nr_copy_pages + PAGES_FOR_IO)) {
 894                 pr_debug("swsusp: Not enough free pages: Have %d\n",
 895                          nr_free_pages());
 896                 return 0;
 897         }
 898         return 1;
 899 }
 900
 901
 902 /**
 903  *      enough_swap - Make sure we have enough swap to save the image.
 904  *
 905  *      Returns TRUE or FALSE after checking the total amount of swap
 906  *      space avaiable.
 907  *
 908  *      FIXME: si_swapinfo(&i) returns all swap devices information.
 909  *      We should only consider resume_device.
 910  */
 911
 912 static int enough_swap(void)
 913 {
 914         struct sysinfo i;
 915
 916         si_swapinfo(&i);
 917         if (i.freeswap < (nr_copy_pages + PAGES_FOR_IO))  {
 918                 pr_debug("swsusp: Not enough swap. Need %ld\n",i.freeswap);
 919                 return 0;
 920         }
 921         return 1;
 922 }
 923
 924 static int swsusp_alloc(void)
 925 {
 926         int error;
 927
 928         pagedir_nosave = NULL;
 929         nr_copy_pages = calc_nr(nr_copy_pages);
 930         nr_copy_pages_check = nr_copy_pages;
 931
 932         pr_debug("suspend: (pages needed: %d + %d free: %d)\n",
 933                  nr_copy_pages, PAGES_FOR_IO, nr_free_pages());
 934
 935         if (!enough_free_mem())
 936                 return -ENOMEM;
 937
 938         if (!enough_swap())
 939                 return -ENOSPC;
 940
 941         if (MAX_PBES < nr_copy_pages / PBES_PER_PAGE +
 942             !!(nr_copy_pages % PBES_PER_PAGE))
 943                 return -ENOSPC;
 944
 945         if (!(pagedir_save = alloc_pagedir(nr_copy_pages))) {
 946                 printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
 947                 return -ENOMEM;
 948         }
 949         create_pbe_list(pagedir_save, nr_copy_pages);
 950         pagedir_nosave = pagedir_save;
 951         if ((error = alloc_image_pages())) {
 952                 printk(KERN_ERR "suspend: Allocating image pages failed.\n");
 953                 swsusp_free();
 954                 return error;
 955         }
 956
 957         return 0;
 958 }
 959
 960 static int suspend_prepare_image(void)
 961 {
 962         int error;
 963
 964         pr_debug("swsusp: critical section: \n");
 965         if (save_highmem()) {
 966                 printk(KERN_CRIT "Suspend machine: Not enough free pages for highmem\n");
 967                 restore_highmem();
 968                 return -ENOMEM;
 969         }
 970
 971         drain_local_pages();
 972         count_data_pages();
 973         printk("swsusp: Need to copy %u pages\n", nr_copy_pages);
 974
 975         error = swsusp_alloc();
 976         if (error)
 977                 return error;
 978
 979         /* During allocating of suspend pagedir, new cold pages may appear.
 980          * Kill them.
 981          */
 982         drain_local_pages();
 983         copy_data_pages();
 984
 985         /*
 986          * End of critical section. From now on, we can write to memory,
 987          * but we should not touch disk. This specially means we must _not_
 988          * touch swap space! Except we must write out our image of course.
 989          */
 990
 991         printk("swsusp: critical section/: done (%d pages copied)\n", nr_copy_pages );
 992         return 0;
 993 }
 994
 995
 996 /* It is important _NOT_ to umount filesystems at this point. We want
 997  * them synced (in case something goes wrong) but we DO not want to mark
 998  * filesystem clean: it is not. (And it does not matter, if we resume
 999  * correctly, we'll mark system clean, anyway.)
1000  */
1001 int swsusp_write(void)
1002 {
1003         int error;
1004         device_resume();
1005         lock_swapdevices();
1006         error = write_suspend_image();
1007         /* This will unlock ignored swap devices since writing is finished */
1008         lock_swapdevices();
1009         return error;
1010
1011 }
1012
1013
1014 extern asmlinkage int swsusp_arch_suspend(void);
1015 extern asmlinkage int swsusp_arch_resume(void);
1016
1017
1018 asmlinkage int swsusp_save(void)
1019 {
1020         return suspend_prepare_image();
1021 }
1022
1023 int swsusp_suspend(void)
1024 {
1025         int error;
1026         if ((error = arch_prepare_suspend()))
1027                 return error;
1028         local_irq_disable();
1029         /* At this point, device_suspend() has been called, but *not*
1030          * device_power_down(). We *must* device_power_down() now.
1031          * Otherwise, drivers for some devices (e.g. interrupt controllers)
1032          * become desynchronized with the actual state of the hardware
1033          * at resume time, and evil weirdness ensues.
1034          */
1035         if ((error = device_power_down(PMSG_FREEZE))) {
1036                 printk(KERN_ERR "Some devices failed to power down, aborting suspend\n");
1037                 local_irq_enable();
1038                 return error;
1039         }
1040
1041         if ((error = swsusp_swap_check())) {
1042                 printk(KERN_ERR "swsusp: cannot find swap device, try swapon -a.\n");
1043                 device_power_up();
1044                 local_irq_enable();
1045                 return error;
1046         }
1047
1048         save_processor_state();
1049         if ((error = swsusp_arch_suspend()))
1050                 printk(KERN_ERR "Error %d suspending\n", error);
1051         /* Restore control flow magically appears here */
1052         restore_processor_state();
1053         BUG_ON (nr_copy_pages_check != nr_copy_pages);
1054         restore_highmem();
1055         device_power_up();
1056         local_irq_enable();
1057         return error;
1058 }
1059
1060 int swsusp_resume(void)
1061 {
1062         int error;
1063         local_irq_disable();
1064         if (device_power_down(PMSG_FREEZE))
1065                 printk(KERN_ERR "Some devices failed to power down, very bad\n");
1066         /* We'll ignore saved state, but this gets preempt count (etc) right */
1067         save_processor_state();
1068         error = swsusp_arch_resume();
1069         /* Code below is only ever reached in case of failure. Otherwise
1070          * execution continues at place where swsusp_arch_suspend was called
1071          */
1072         BUG_ON(!error);
1073         restore_processor_state();
1074         restore_highmem();
1075         touch_softlockup_watchdog();
1076         device_power_up();
1077         local_irq_enable();
1078         return error;
1079 }
1080
1081 /**
1082  *      On resume, for storing the PBE list and the image,
1083  *      we can only use memory pages that do not conflict with the pages
1084  *      which had been used before suspend.
1085  *
1086  *      We don't know which pages are usable until we allocate them.
1087  *
1088  *      Allocated but unusable (ie eaten) memory pages are linked together
1089  *      to create a list, so that we can free them easily
1090  *
1091  *      We could have used a type other than (void *)
1092  *      for this purpose, but ...
1093  */
1094 static void **eaten_memory = NULL;
1095
1096 static inline void eat_page(void *page)
1097 {
1098         void **c;
1099
1100         c = eaten_memory;
1101         eaten_memory = page;
1102         *eaten_memory = c;
1103 }
1104
1105 unsigned long get_usable_page(gfp_t gfp_mask)
1106 {
1107         unsigned long m;
1108
1109         m = get_zeroed_page(gfp_mask);
1110         while (!PageNosaveFree(virt_to_page(m))) {
1111                 eat_page((void *)m);
1112                 m = get_zeroed_page(gfp_mask);
1113                 if (!m)
1114                         break;
1115         }
1116         return m;
1117 }
1118
1119 void free_eaten_memory(void)
1120 {
1121         unsigned long m;
1122         void **c;
1123         int i = 0;
1124
1125         c = eaten_memory;
1126         while (c) {
1127                 m = (unsigned long)c;
1128                 c = *c;
1129                 free_page(m);
1130                 i++;
1131         }
1132         eaten_memory = NULL;
1133         pr_debug("swsusp: %d unused pages freed\n", i);
1134 }
1135
1136 /**
1137  *      check_pagedir - We ensure here that pages that the PBEs point to
1138  *      won't collide with pages where we're going to restore from the loaded
1139  *      pages later
1140  */
1141
1142 static int check_pagedir(struct pbe *pblist)
1143 {
1144         struct pbe *p;
1145
1146         /* This is necessary, so that we can free allocated pages
1147          * in case of failure
1148          */
1149         for_each_pbe (p, pblist)
1150                 p->address = 0UL;
1151
1152         for_each_pbe (p, pblist) {
1153                 p->address = get_usable_page(GFP_ATOMIC);
1154                 if (!p->address)
1155                         return -ENOMEM;
1156         }
1157         return 0;
1158 }
1159
1160 /**
1161  *      swsusp_pagedir_relocate - It is possible, that some memory pages
1162  *      occupied by the list of PBEs collide with pages where we're going to
1163  *      restore from the loaded pages later.  We relocate them here.
1164  */
1165
1166 static struct pbe * swsusp_pagedir_relocate(struct pbe *pblist)
1167 {
1168         struct zone *zone;
1169         unsigned long zone_pfn;
1170         struct pbe *pbpage, *tail, *p;
1171         void *m;
1172         int rel = 0, error = 0;
1173
1174         if (!pblist) /* a sanity check */
1175                 return NULL;
1176
1177         pr_debug("swsusp: Relocating pagedir (%lu pages to check)\n",
1178                         swsusp_info.pagedir_pages);
1179
1180         /* Set page flags */
1181
1182         for_each_zone (zone) {
1183                 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
1184                         SetPageNosaveFree(pfn_to_page(zone_pfn +
1185                                         zone->zone_start_pfn));
1186         }
1187
1188         /* Clear orig addresses */
1189
1190         for_each_pbe (p, pblist)
1191                 ClearPageNosaveFree(virt_to_page(p->orig_address));
1192
1193         tail = pblist + PB_PAGE_SKIP;
1194
1195         /* Relocate colliding pages */
1196
1197         for_each_pb_page (pbpage, pblist) {
1198                 if (!PageNosaveFree(virt_to_page((unsigned long)pbpage))) {
1199                         m = (void *)get_usable_page(GFP_ATOMIC | __GFP_COLD);
1200                         if (!m) {
1201                                 error = -ENOMEM;
1202                                 break;
1203                         }
1204                         memcpy(m, (void *)pbpage, PAGE_SIZE);
1205                         if (pbpage == pblist)
1206                                 pblist = (struct pbe *)m;
1207                         else
1208                                 tail->next = (struct pbe *)m;
1209
1210                         eat_page((void *)pbpage);
1211                         pbpage = (struct pbe *)m;
1212
1213                         /* We have to link the PBEs again */
1214
1215                         for (p = pbpage; p < pbpage + PB_PAGE_SKIP; p++)
1216                                 if (p->next) /* needed to save the end */
1217                                         p->next = p + 1;
1218
1219                         rel++;
1220                 }
1221                 tail = pbpage + PB_PAGE_SKIP;
1222         }
1223
1224         if (error) {
1225                 printk("\nswsusp: Out of memory\n\n");
1226                 free_pagedir(pblist);
1227                 free_eaten_memory();
1228                 pblist = NULL;
1229                 /* Is this even worth handling? It should never ever happen, and we
1230                    have just lost user's state, anyway... */
1231         } else
1232                 printk("swsusp: Relocated %d pages\n", rel);
1233
1234         return pblist;
1235 }
1236
1237 /*
1238  *      Using bio to read from swap.
1239  *      This code requires a bit more work than just using buffer heads
1240  *      but, it is the recommended way for 2.5/2.6.
1241  *      The following are to signal the beginning and end of I/O. Bios
1242  *      finish asynchronously, while we want them to happen synchronously.
1243  *      A simple atomic_t, and a wait loop take care of this problem.
1244  */
1245
1246 static atomic_t io_done = ATOMIC_INIT(0);
1247
1248 static int end_io(struct bio * bio, unsigned int num, int err)
1249 {
1250         if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
1251                 panic("I/O error reading memory image");
1252         atomic_set(&io_done, 0);
1253         return 0;
1254 }
1255
1256 static struct block_device * resume_bdev;
1257
1258 /**
1259  *      submit - submit BIO request.
1260  *      @rw:    READ or WRITE.
1261  *      @off    physical offset of page.
1262  *      @page:  page we're reading or writing.
1263  *
1264  *      Straight from the textbook - allocate and initialize the bio.
1265  *      If we're writing, make sure the page is marked as dirty.
1266  *      Then submit it and wait.
1267  */
1268
1269 static int submit(int rw, pgoff_t page_off, void * page)
1270 {
1271         int error = 0;
1272         struct bio * bio;
1273
1274         bio = bio_alloc(GFP_ATOMIC, 1);
1275         if (!bio)
1276                 return -ENOMEM;
1277         bio->bi_sector = page_off * (PAGE_SIZE >> 9);
1278         bio_get(bio);
1279         bio->bi_bdev = resume_bdev;
1280         bio->bi_end_io = end_io;
1281
1282         if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) {
1283                 printk("swsusp: ERROR: adding page to bio at %ld\n",page_off);
1284                 error = -EFAULT;
1285                 goto Done;
1286         }
1287
1288         if (rw == WRITE)
1289                 bio_set_pages_dirty(bio);
1290
1291         atomic_set(&io_done, 1);
1292         submit_bio(rw | (1 << BIO_RW_SYNC), bio);
1293         while (atomic_read(&io_done))
1294                 yield();
1295
1296  Done:
1297         bio_put(bio);
1298         return error;
1299 }
1300
1301 static int bio_read_page(pgoff_t page_off, void * page)
1302 {
1303         return submit(READ, page_off, page);
1304 }
1305
1306 static int bio_write_page(pgoff_t page_off, void * page)
1307 {
1308         return submit(WRITE, page_off, page);
1309 }
1310
1311 /*
1312  * Sanity check if this image makes sense with this kernel/swap context
1313  * I really don't think that it's foolproof but more than nothing..
1314  */
1315
1316 static const char * sanity_check(void)
1317 {
1318         dump_info();
1319         if (swsusp_info.version_code != LINUX_VERSION_CODE)
1320                 return "kernel version";
1321         if (swsusp_info.num_physpages != num_physpages)
1322                 return "memory size";
1323         if (strcmp(swsusp_info.uts.sysname,system_utsname.sysname))
1324                 return "system type";
1325         if (strcmp(swsusp_info.uts.release,system_utsname.release))
1326                 return "kernel release";
1327         if (strcmp(swsusp_info.uts.version,system_utsname.version))
1328                 return "version";
1329         if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
1330                 return "machine";
1331 #if 0
1332         /* We can't use number of online CPUs when we use hotplug to remove them ;-))) */
1333         if (swsusp_info.cpus != num_possible_cpus())
1334                 return "number of cpus";
1335 #endif
1336         return NULL;
1337 }
1338
1339
1340 static int check_header(void)
1341 {
1342         const char * reason = NULL;
1343         int error;
1344
1345         if ((error = bio_read_page(swp_offset(swsusp_header.swsusp_info), &swsusp_info)))
1346                 return error;
1347
1348         /* Is this same machine? */
1349         if ((reason = sanity_check())) {
1350                 printk(KERN_ERR "swsusp: Resume mismatch: %s\n",reason);
1351                 return -EPERM;
1352         }
1353         nr_copy_pages = swsusp_info.image_pages;
1354         return error;
1355 }
1356
1357 static int check_sig(void)
1358 {
1359         int error;
1360
1361         memset(&swsusp_header, 0, sizeof(swsusp_header));
1362         if ((error = bio_read_page(0, &swsusp_header)))
1363                 return error;
1364         if (!memcmp(SWSUSP_SIG, swsusp_header.sig, 10)) {
1365                 memcpy(swsusp_header.sig, swsusp_header.orig_sig, 10);
1366                 memcpy(key_iv, swsusp_header.key_iv, MAXKEY+MAXIV);
1367                 memset(swsusp_header.key_iv, 0, MAXKEY+MAXIV);
1368
1369                 /*
1370                  * Reset swap signature now.
1371                  */
1372                 error = bio_write_page(0, &swsusp_header);
1373         } else {
1374                 return -EINVAL;
1375         }
1376         if (!error)
1377                 pr_debug("swsusp: Signature found, resuming\n");
1378         return error;
1379 }
1380
1381 /**
1382  *      data_read - Read image pages from swap.
1383  *
1384  *      You do not need to check for overlaps, check_pagedir()
1385  *      already did that.
1386  */
1387
1388 static int data_read(struct pbe *pblist)
1389 {
1390         struct pbe * p;
1391         int error = 0;
1392         int i = 0;
1393         int mod = swsusp_info.image_pages / 100;
1394         void *tfm;
1395
1396         if ((error = crypto_init(0, &tfm)))
1397                 return error;
1398
1399         if (!mod)
1400                 mod = 1;
1401
1402         printk("swsusp: Reading image data (%lu pages):     ",
1403                         swsusp_info.image_pages);
1404
1405         for_each_pbe (p, pblist) {
1406                 if (!(i % mod))
1407                         printk("\b\b\b\b%3d%%", i / mod);
1408
1409                 if ((error = crypto_read(p, tfm))) {
1410                         crypto_exit(tfm);
1411                         return error;
1412                 }
1413
1414                 i++;
1415         }
1416         printk("\b\b\b\bdone\n");
1417         crypto_exit(tfm);
1418         return error;
1419 }
1420
1421 /**
1422  *      read_pagedir - Read page backup list pages from swap
1423  */
1424
1425 static int read_pagedir(struct pbe *pblist)
1426 {
1427         struct pbe *pbpage, *p;
1428         unsigned i = 0;
1429         int error;
1430
1431         if (!pblist)
1432                 return -EFAULT;
1433
1434         printk("swsusp: Reading pagedir (%lu pages)\n",
1435                         swsusp_info.pagedir_pages);
1436
1437         for_each_pb_page (pbpage, pblist) {
1438                 unsigned long offset = swp_offset(swsusp_info.pagedir[i++]);
1439
1440                 error = -EFAULT;
1441                 if (offset) {
1442                         p = (pbpage + PB_PAGE_SKIP)->next;
1443                         error = bio_read_page(offset, (void *)pbpage);
1444                         (pbpage + PB_PAGE_SKIP)->next = p;
1445                 }
1446                 if (error)
1447                         break;
1448         }
1449
1450         if (error)
1451                 free_pagedir(pblist);
1452         else
1453                 BUG_ON(i != swsusp_info.pagedir_pages);
1454
1455         return error;
1456 }
1457
1458
1459 static int check_suspend_image(void)
1460 {
1461         int error = 0;
1462
1463         if ((error = check_sig()))
1464                 return error;
1465
1466         if ((error = check_header()))
1467                 return error;
1468
1469         return 0;
1470 }
1471
1472 static int read_suspend_image(void)
1473 {
1474         int error = 0;
1475         struct pbe *p;
1476
1477         if (!(p = alloc_pagedir(nr_copy_pages)))
1478                 return -ENOMEM;
1479
1480         if ((error = read_pagedir(p)))
1481                 return error;
1482
1483         create_pbe_list(p, nr_copy_pages);
1484
1485         if (!(pagedir_nosave = swsusp_pagedir_relocate(p)))
1486                 return -ENOMEM;
1487
1488         /* Allocate memory for the image and read the data from swap */
1489
1490         error = check_pagedir(pagedir_nosave);
1491
1492         if (!error)
1493                 error = data_read(pagedir_nosave);
1494
1495         if (error) { /* We fail cleanly */
1496                 free_eaten_memory();
1497                 for_each_pbe (p, pagedir_nosave)
1498                         if (p->address) {
1499                                 free_page(p->address);
1500                                 p->address = 0UL;
1501                         }
1502                 free_pagedir(pagedir_nosave);
1503         }
1504         return error;
1505 }
1506
1507 /**
1508  *      swsusp_check - Check for saved image in swap
1509  */
1510
1511 int swsusp_check(void)
1512 {
1513         int error;
1514
1515         resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
1516         if (!IS_ERR(resume_bdev)) {
1517                 set_blocksize(resume_bdev, PAGE_SIZE);
1518                 error = check_suspend_image();
1519                 if (error)
1520                     blkdev_put(resume_bdev);
1521         } else
1522                 error = PTR_ERR(resume_bdev);
1523
1524         if (!error)
1525                 pr_debug("swsusp: resume file found\n");
1526         else
1527                 pr_debug("swsusp: Error %d check for resume file\n", error);
1528         return error;
1529 }
1530
1531 /**
1532  *      swsusp_read - Read saved image from swap.
1533  */
1534
1535 int swsusp_read(void)
1536 {
1537         int error;
1538
1539         if (IS_ERR(resume_bdev)) {
1540                 pr_debug("swsusp: block device not initialised\n");
1541                 return PTR_ERR(resume_bdev);
1542         }
1543
1544         error = read_suspend_image();
1545         blkdev_put(resume_bdev);
1546         memset(key_iv, 0, MAXKEY+MAXIV);
1547
1548         if (!error)
1549                 pr_debug("swsusp: Reading resume file was successful\n");
1550         else
1551                 pr_debug("swsusp: Error %d resuming\n", error);
1552         return error;
1553 }
1554
1555 /**
1556  *      swsusp_close - close swap device.
1557  */
1558
1559 void swsusp_close(void)
1560 {
1561         if (IS_ERR(resume_bdev)) {
1562                 pr_debug("swsusp: block device not initialised\n");
1563                 return;
1564         }
1565
1566         blkdev_put(resume_bdev);
1567 }