kernel/power/hibernate.c

   1 /*
   2  * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
   3  *
   4  * Copyright (c) 2003 Patrick Mochel
   5  * Copyright (c) 2003 Open Source Development Lab
   6  * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
   7  * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
   8  * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
   9  *
  10  * This file is released under the GPLv2.
  11  */
  12
  13 #include <linux/export.h>
  14 #include <linux/suspend.h>
  15 #include <linux/syscalls.h>
  16 #include <linux/reboot.h>
  17 #include <linux/string.h>
  18 #include <linux/device.h>
  19 #include <linux/async.h>
  20 #include <linux/delay.h>
  21 #include <linux/fs.h>
  22 #include <linux/mount.h>
  23 #include <linux/pm.h>
  24 #include <linux/console.h>
  25 #include <linux/cpu.h>
  26 #include <linux/freezer.h>
  27 #include <linux/gfp.h>
  28 #include <linux/syscore_ops.h>
  29 #include <linux/ctype.h>
  30 #include <linux/genhd.h>
  31
  32 #include "power.h"
  33
  34
  35 static int nocompress;
  36 static int noresume;
  37 static int resume_wait;
  38 static unsigned int resume_delay;
  39 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
  40 dev_t swsusp_resume_device;
  41 sector_t swsusp_resume_block;
  42 __visible int in_suspend __nosavedata;
  43
  44 enum {
  45         HIBERNATION_INVALID,
  46         HIBERNATION_PLATFORM,
  47         HIBERNATION_SHUTDOWN,
  48         HIBERNATION_REBOOT,
  49 #ifdef CONFIG_SUSPEND
  50         HIBERNATION_SUSPEND,
  51 #endif
  52         /* keep last */
  53         __HIBERNATION_AFTER_LAST
  54 };
  55 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  56 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  57
  58 static int hibernation_mode = HIBERNATION_SHUTDOWN;
  59
  60 bool freezer_test_done;
  61
  62 static const struct platform_hibernation_ops *hibernation_ops;
  63
  64 /**
  65  * hibernation_set_ops - Set the global hibernate operations.
  66  * @ops: Hibernation operations to use in subsequent hibernation transitions.
  67  */
  68 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
  69 {
  70         if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  71             && ops->prepare && ops->finish && ops->enter && ops->pre_restore
  72             && ops->restore_cleanup && ops->leave)) {
  73                 WARN_ON(1);
  74                 return;
  75         }
  76         lock_system_sleep();
  77         hibernation_ops = ops;
  78         if (ops)
  79                 hibernation_mode = HIBERNATION_PLATFORM;
  80         else if (hibernation_mode == HIBERNATION_PLATFORM)
  81                 hibernation_mode = HIBERNATION_SHUTDOWN;
  82
  83         unlock_system_sleep();
  84 }
  85 EXPORT_SYMBOL_GPL(hibernation_set_ops);
  86
  87 static bool entering_platform_hibernation;
  88
  89 bool system_entering_hibernation(void)
  90 {
  91         return entering_platform_hibernation;
  92 }
  93 EXPORT_SYMBOL(system_entering_hibernation);
  94
  95 #ifdef CONFIG_PM_DEBUG
  96 static void hibernation_debug_sleep(void)
  97 {
  98         printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
  99         mdelay(5000);
 100 }
 101
 102 static int hibernation_test(int level)
 103 {
 104         if (pm_test_level == level) {
 105                 hibernation_debug_sleep();
 106                 return 1;
 107         }
 108         return 0;
 109 }
 110 #else /* !CONFIG_PM_DEBUG */
 111 static int hibernation_test(int level) { return 0; }
 112 #endif /* !CONFIG_PM_DEBUG */
 113
 114 /**
 115  * platform_begin - Call platform to start hibernation.
 116  * @platform_mode: Whether or not to use the platform driver.
 117  */
 118 static int platform_begin(int platform_mode)
 119 {
 120         return (platform_mode && hibernation_ops) ?
 121                 hibernation_ops->begin() : 0;
 122 }
 123
 124 /**
 125  * platform_end - Call platform to finish transition to the working state.
 126  * @platform_mode: Whether or not to use the platform driver.
 127  */
 128 static void platform_end(int platform_mode)
 129 {
 130         if (platform_mode && hibernation_ops)
 131                 hibernation_ops->end();
 132 }
 133
 134 /**
 135  * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 136  * @platform_mode: Whether or not to use the platform driver.
 137  *
 138  * Use the platform driver to prepare the system for creating a hibernate image,
 139  * if so configured, and return an error code if that fails.
 140  */
 141
 142 static int platform_pre_snapshot(int platform_mode)
 143 {
 144         return (platform_mode && hibernation_ops) ?
 145                 hibernation_ops->pre_snapshot() : 0;
 146 }
 147
 148 /**
 149  * platform_leave - Call platform to prepare a transition to the working state.
 150  * @platform_mode: Whether or not to use the platform driver.
 151  *
 152  * Use the platform driver prepare to prepare the machine for switching to the
 153  * normal mode of operation.
 154  *
 155  * This routine is called on one CPU with interrupts disabled.
 156  */
 157 static void platform_leave(int platform_mode)
 158 {
 159         if (platform_mode && hibernation_ops)
 160                 hibernation_ops->leave();
 161 }
 162
 163 /**
 164  * platform_finish - Call platform to switch the system to the working state.
 165  * @platform_mode: Whether or not to use the platform driver.
 166  *
 167  * Use the platform driver to switch the machine to the normal mode of
 168  * operation.
 169  *
 170  * This routine must be called after platform_prepare().
 171  */
 172 static void platform_finish(int platform_mode)
 173 {
 174         if (platform_mode && hibernation_ops)
 175                 hibernation_ops->finish();
 176 }
 177
 178 /**
 179  * platform_pre_restore - Prepare for hibernate image restoration.
 180  * @platform_mode: Whether or not to use the platform driver.
 181  *
 182  * Use the platform driver to prepare the system for resume from a hibernation
 183  * image.
 184  *
 185  * If the restore fails after this function has been called,
 186  * platform_restore_cleanup() must be called.
 187  */
 188 static int platform_pre_restore(int platform_mode)
 189 {
 190         return (platform_mode && hibernation_ops) ?
 191                 hibernation_ops->pre_restore() : 0;
 192 }
 193
 194 /**
 195  * platform_restore_cleanup - Switch to the working state after failing restore.
 196  * @platform_mode: Whether or not to use the platform driver.
 197  *
 198  * Use the platform driver to switch the system to the normal mode of operation
 199  * after a failing restore.
 200  *
 201  * If platform_pre_restore() has been called before the failing restore, this
 202  * function must be called too, regardless of the result of
 203  * platform_pre_restore().
 204  */
 205 static void platform_restore_cleanup(int platform_mode)
 206 {
 207         if (platform_mode && hibernation_ops)
 208                 hibernation_ops->restore_cleanup();
 209 }
 210
 211 /**
 212  * platform_recover - Recover from a failure to suspend devices.
 213  * @platform_mode: Whether or not to use the platform driver.
 214  */
 215 static void platform_recover(int platform_mode)
 216 {
 217         if (platform_mode && hibernation_ops && hibernation_ops->recover)
 218                 hibernation_ops->recover();
 219 }
 220
 221 /**
 222  * swsusp_show_speed - Print time elapsed between two events during hibernation.
 223  * @start: Starting event.
 224  * @stop: Final event.
 225  * @nr_pages: Number of memory pages processed between @start and @stop.
 226  * @msg: Additional diagnostic message to print.
 227  */
 228 void swsusp_show_speed(struct timeval *start, struct timeval *stop,
 229                         unsigned nr_pages, char *msg)
 230 {
 231         u64 elapsed_centisecs64;
 232         unsigned int centisecs;
 233         unsigned int k;
 234         unsigned int kps;
 235
 236         elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
 237         /*
 238          * If "(s64)elapsed_centisecs64 < 0", it will print long elapsed time,
 239          * it is obvious enough for what went wrong.
 240          */
 241         do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
 242         centisecs = elapsed_centisecs64;
 243         if (centisecs == 0)
 244                 centisecs = 1;  /* avoid div-by-zero */
 245         k = nr_pages * (PAGE_SIZE / 1024);
 246         kps = (k * 100) / centisecs;
 247         printk(KERN_INFO "PM: %s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 248                         msg, k,
 249                         centisecs / 100, centisecs % 100,
 250                         kps / 1000, (kps % 1000) / 10);
 251 }
 252
 253 /**
 254  * create_image - Create a hibernation image.
 255  * @platform_mode: Whether or not to use the platform driver.
 256  *
 257  * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 258  * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 259  *
 260  * Control reappears in this routine after the subsequent restore.
 261  */
 262 static int create_image(int platform_mode)
 263 {
 264         int error;
 265
 266         error = dpm_suspend_end(PMSG_FREEZE);
 267         if (error) {
 268                 printk(KERN_ERR "PM: Some devices failed to power down, "
 269                         "aborting hibernation\n");
 270                 return error;
 271         }
 272
 273         error = platform_pre_snapshot(platform_mode);
 274         if (error || hibernation_test(TEST_PLATFORM))
 275                 goto Platform_finish;
 276
 277         error = disable_nonboot_cpus();
 278         if (error || hibernation_test(TEST_CPUS))
 279                 goto Enable_cpus;
 280
 281         local_irq_disable();
 282
 283         error = syscore_suspend();
 284         if (error) {
 285                 printk(KERN_ERR "PM: Some system devices failed to power down, "
 286                         "aborting hibernation\n");
 287                 goto Enable_irqs;
 288         }
 289
 290         if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 291                 goto Power_up;
 292
 293         in_suspend = 1;
 294         save_processor_state();
 295         error = swsusp_arch_suspend();
 296         if (error)
 297                 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
 298                         error);
 299         /* Restore control flow magically appears here */
 300         restore_processor_state();
 301         if (!in_suspend)
 302                 events_check_enabled = false;
 303
 304         platform_leave(platform_mode);
 305
 306  Power_up:
 307         syscore_resume();
 308
 309  Enable_irqs:
 310         local_irq_enable();
 311
 312  Enable_cpus:
 313         enable_nonboot_cpus();
 314
 315  Platform_finish:
 316         platform_finish(platform_mode);
 317
 318         dpm_resume_start(in_suspend ?
 319                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 320
 321         return error;
 322 }
 323
 324 /**
 325  * hibernation_snapshot - Quiesce devices and create a hibernation image.
 326  * @platform_mode: If set, use platform driver to prepare for the transition.
 327  *
 328  * This routine must be called with pm_mutex held.
 329  */
 330 int hibernation_snapshot(int platform_mode)
 331 {
 332         pm_message_t msg;
 333         int error;
 334
 335         error = platform_begin(platform_mode);
 336         if (error)
 337                 goto Close;
 338
 339         /* Preallocate image memory before shutting down devices. */
 340         error = hibernate_preallocate_memory();
 341         if (error)
 342                 goto Close;
 343
 344         error = freeze_kernel_threads();
 345         if (error)
 346                 goto Cleanup;
 347
 348         if (hibernation_test(TEST_FREEZER)) {
 349
 350                 /*
 351                  * Indicate to the caller that we are returning due to a
 352                  * successful freezer test.
 353                  */
 354                 freezer_test_done = true;
 355                 goto Thaw;
 356         }
 357
 358         error = dpm_prepare(PMSG_FREEZE);
 359         if (error) {
 360                 dpm_complete(PMSG_RECOVER);
 361                 goto Thaw;
 362         }
 363
 364         suspend_console();
 365         ftrace_stop();
 366         pm_restrict_gfp_mask();
 367
 368         error = dpm_suspend(PMSG_FREEZE);
 369
 370         if (error || hibernation_test(TEST_DEVICES))
 371                 platform_recover(platform_mode);
 372         else
 373                 error = create_image(platform_mode);
 374
 375         /*
 376          * In the case that we call create_image() above, the control
 377          * returns here (1) after the image has been created or the
 378          * image creation has failed and (2) after a successful restore.
 379          */
 380
 381         /* We may need to release the preallocated image pages here. */
 382         if (error || !in_suspend)
 383                 swsusp_free();
 384
 385         msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 386         dpm_resume(msg);
 387
 388         if (error || !in_suspend)
 389                 pm_restore_gfp_mask();
 390
 391         ftrace_start();
 392         resume_console();
 393         dpm_complete(msg);
 394
 395  Close:
 396         platform_end(platform_mode);
 397         return error;
 398
 399  Thaw:
 400         thaw_kernel_threads();
 401  Cleanup:
 402         swsusp_free();
 403         goto Close;
 404 }
 405
 406 /**
 407  * resume_target_kernel - Restore system state from a hibernation image.
 408  * @platform_mode: Whether or not to use the platform driver.
 409  *
 410  * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 411  * contents of highmem that have not been restored yet from the image and run
 412  * the low-level code that will restore the remaining contents of memory and
 413  * switch to the just restored target kernel.
 414  */
 415 static int resume_target_kernel(bool platform_mode)
 416 {
 417         int error;
 418
 419         error = dpm_suspend_end(PMSG_QUIESCE);
 420         if (error) {
 421                 printk(KERN_ERR "PM: Some devices failed to power down, "
 422                         "aborting resume\n");
 423                 return error;
 424         }
 425
 426         error = platform_pre_restore(platform_mode);
 427         if (error)
 428                 goto Cleanup;
 429
 430         error = disable_nonboot_cpus();
 431         if (error)
 432                 goto Enable_cpus;
 433
 434         local_irq_disable();
 435
 436         error = syscore_suspend();
 437         if (error)
 438                 goto Enable_irqs;
 439
 440         save_processor_state();
 441         error = restore_highmem();
 442         if (!error) {
 443                 error = swsusp_arch_resume();
 444                 /*
 445                  * The code below is only ever reached in case of a failure.
 446                  * Otherwise, execution continues at the place where
 447                  * swsusp_arch_suspend() was called.
 448                  */
 449                 BUG_ON(!error);
 450                 /*
 451                  * This call to restore_highmem() reverts the changes made by
 452                  * the previous one.
 453                  */
 454                 restore_highmem();
 455         }
 456         /*
 457          * The only reason why swsusp_arch_resume() can fail is memory being
 458          * very tight, so we have to free it as soon as we can to avoid
 459          * subsequent failures.
 460          */
 461         swsusp_free();
 462         restore_processor_state();
 463         touch_softlockup_watchdog();
 464
 465         syscore_resume();
 466
 467  Enable_irqs:
 468         local_irq_enable();
 469
 470  Enable_cpus:
 471         enable_nonboot_cpus();
 472
 473  Cleanup:
 474         platform_restore_cleanup(platform_mode);
 475
 476         dpm_resume_start(PMSG_RECOVER);
 477
 478         return error;
 479 }
 480
 481 /**
 482  * hibernation_restore - Quiesce devices and restore from a hibernation image.
 483  * @platform_mode: If set, use platform driver to prepare for the transition.
 484  *
 485  * This routine must be called with pm_mutex held.  If it is successful, control
 486  * reappears in the restored target kernel in hibernation_snapshot().
 487  */
 488 int hibernation_restore(int platform_mode)
 489 {
 490         int error;
 491
 492         pm_prepare_console();
 493         suspend_console();
 494         ftrace_stop();
 495         pm_restrict_gfp_mask();
 496         error = dpm_suspend_start(PMSG_QUIESCE);
 497         if (!error) {
 498                 error = resume_target_kernel(platform_mode);
 499                 dpm_resume_end(PMSG_RECOVER);
 500         }
 501         pm_restore_gfp_mask();
 502         ftrace_start();
 503         resume_console();
 504         pm_restore_console();
 505         return error;
 506 }
 507
 508 /**
 509  * hibernation_platform_enter - Power off the system using the platform driver.
 510  */
 511 int hibernation_platform_enter(void)
 512 {
 513         int error;
 514
 515         if (!hibernation_ops)
 516                 return -ENOSYS;
 517
 518         /*
 519          * We have cancelled the power transition by running
 520          * hibernation_ops->finish() before saving the image, so we should let
 521          * the firmware know that we're going to enter the sleep state after all
 522          */
 523         error = hibernation_ops->begin();
 524         if (error)
 525                 goto Close;
 526
 527         entering_platform_hibernation = true;
 528         suspend_console();
 529         ftrace_stop();
 530         error = dpm_suspend_start(PMSG_HIBERNATE);
 531         if (error) {
 532                 if (hibernation_ops->recover)
 533                         hibernation_ops->recover();
 534                 goto Resume_devices;
 535         }
 536
 537         error = dpm_suspend_end(PMSG_HIBERNATE);
 538         if (error)
 539                 goto Resume_devices;
 540
 541         error = hibernation_ops->prepare();
 542         if (error)
 543                 goto Platform_finish;
 544
 545         error = disable_nonboot_cpus();
 546         if (error)
 547                 goto Platform_finish;
 548
 549         local_irq_disable();
 550         syscore_suspend();
 551         if (pm_wakeup_pending()) {
 552                 error = -EAGAIN;
 553                 goto Power_up;
 554         }
 555
 556         hibernation_ops->enter();
 557         /* We should never get here */
 558         while (1);
 559
 560  Power_up:
 561         syscore_resume();
 562         local_irq_enable();
 563         enable_nonboot_cpus();
 564
 565  Platform_finish:
 566         hibernation_ops->finish();
 567
 568         dpm_resume_start(PMSG_RESTORE);
 569
 570  Resume_devices:
 571         entering_platform_hibernation = false;
 572         dpm_resume_end(PMSG_RESTORE);
 573         ftrace_start();
 574         resume_console();
 575
 576  Close:
 577         hibernation_ops->end();
 578
 579         return error;
 580 }
 581
 582 /**
 583  * power_down - Shut the machine down for hibernation.
 584  *
 585  * Use the platform driver, if configured, to put the system into the sleep
 586  * state corresponding to hibernation, or try to power it off or reboot,
 587  * depending on the value of hibernation_mode.
 588  */
 589 static void power_down(void)
 590 {
 591 #ifdef CONFIG_SUSPEND
 592         int error;
 593 #endif
 594
 595         switch (hibernation_mode) {
 596         case HIBERNATION_REBOOT:
 597                 kernel_restart(NULL);
 598                 break;
 599         case HIBERNATION_PLATFORM:
 600                 hibernation_platform_enter();
 601         case HIBERNATION_SHUTDOWN:
 602                 if (pm_power_off)
 603                         kernel_power_off();
 604                 break;
 605 #ifdef CONFIG_SUSPEND
 606         case HIBERNATION_SUSPEND:
 607                 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
 608                 if (error) {
 609                         if (hibernation_ops)
 610                                 hibernation_mode = HIBERNATION_PLATFORM;
 611                         else
 612                                 hibernation_mode = HIBERNATION_SHUTDOWN;
 613                         power_down();
 614                 }
 615                 /*
 616                  * Restore swap signature.
 617                  */
 618                 error = swsusp_unmark();
 619                 if (error)
 620                         printk(KERN_ERR "PM: Swap will be unusable! "
 621                                         "Try swapon -a.\n");
 622                 return;
 623 #endif
 624         }
 625         kernel_halt();
 626         /*
 627          * Valid image is on the disk, if we continue we risk serious data
 628          * corruption after resume.
 629          */
 630         printk(KERN_CRIT "PM: Please power down manually\n");
 631         while (1)
 632                 cpu_relax();
 633 }
 634
 635 /**
 636  * hibernate - Carry out system hibernation, including saving the image.
 637  */
 638 int hibernate(void)
 639 {
 640         int error;
 641
 642         lock_system_sleep();
 643         /* The snapshot device should not be opened while we're running */
 644         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 645                 error = -EBUSY;
 646                 goto Unlock;
 647         }
 648
 649         pm_prepare_console();
 650         error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
 651         if (error)
 652                 goto Exit;
 653
 654         printk(KERN_INFO "PM: Syncing filesystems ... ");
 655         sys_sync();
 656         printk("done.\n");
 657
 658         error = freeze_processes();
 659         if (error)
 660                 goto Exit;
 661
 662         lock_device_hotplug();
 663         /* Allocate memory management structures */
 664         error = create_basic_memory_bitmaps();
 665         if (error)
 666                 goto Thaw;
 667
 668         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 669         if (error || freezer_test_done)
 670                 goto Free_bitmaps;
 671
 672         if (in_suspend) {
 673                 unsigned int flags = 0;
 674
 675                 if (hibernation_mode == HIBERNATION_PLATFORM)
 676                         flags |= SF_PLATFORM_MODE;
 677                 if (nocompress)
 678                         flags |= SF_NOCOMPRESS_MODE;
 679                 else
 680                         flags |= SF_CRC32_MODE;
 681
 682                 pr_debug("PM: writing image.\n");
 683                 error = swsusp_write(flags);
 684                 swsusp_free();
 685                 if (!error)
 686                         power_down();
 687                 in_suspend = 0;
 688                 pm_restore_gfp_mask();
 689         } else {
 690                 pr_debug("PM: Image restored successfully.\n");
 691         }
 692
 693  Free_bitmaps:
 694         free_basic_memory_bitmaps();
 695  Thaw:
 696         unlock_device_hotplug();
 697         thaw_processes();
 698
 699         /* Don't bother checking whether freezer_test_done is true */
 700         freezer_test_done = false;
 701  Exit:
 702         pm_notifier_call_chain(PM_POST_HIBERNATION);
 703         pm_restore_console();
 704         atomic_inc(&snapshot_device_available);
 705  Unlock:
 706         unlock_system_sleep();
 707         return error;
 708 }
 709
 710
 711 /**
 712  * software_resume - Resume from a saved hibernation image.
 713  *
 714  * This routine is called as a late initcall, when all devices have been
 715  * discovered and initialized already.
 716  *
 717  * The image reading code is called to see if there is a hibernation image
 718  * available for reading.  If that is the case, devices are quiesced and the
 719  * contents of memory is restored from the saved image.
 720  *
 721  * If this is successful, control reappears in the restored target kernel in
 722  * hibernation_snaphot() which returns to hibernate().  Otherwise, the routine
 723  * attempts to recover gracefully and make the kernel return to the normal mode
 724  * of operation.
 725  */
 726 static int software_resume(void)
 727 {
 728         int error;
 729         unsigned int flags;
 730
 731         /*
 732          * If the user said "noresume".. bail out early.
 733          */
 734         if (noresume)
 735                 return 0;
 736
 737         /*
 738          * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 739          * is configured into the kernel. Since the regular hibernate
 740          * trigger path is via sysfs which takes a buffer mutex before
 741          * calling hibernate functions (which take pm_mutex) this can
 742          * cause lockdep to complain about a possible ABBA deadlock
 743          * which cannot happen since we're in the boot code here and
 744          * sysfs can't be invoked yet. Therefore, we use a subclass
 745          * here to avoid lockdep complaining.
 746          */
 747         mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
 748
 749         if (swsusp_resume_device)
 750                 goto Check_image;
 751
 752         if (!strlen(resume_file)) {
 753                 error = -ENOENT;
 754                 goto Unlock;
 755         }
 756
 757         pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
 758
 759         if (resume_delay) {
 760                 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
 761                         resume_delay);
 762                 ssleep(resume_delay);
 763         }
 764
 765         /* Check if the device is there */
 766         swsusp_resume_device = name_to_dev_t(resume_file);
 767
 768         /*
 769          * name_to_dev_t is ineffective to verify parition if resume_file is in
 770          * integer format. (e.g. major:minor)
 771          */
 772         if (isdigit(resume_file[0]) && resume_wait) {
 773                 int partno;
 774                 while (!get_gendisk(swsusp_resume_device, &partno))
 775                         msleep(10);
 776         }
 777
 778         if (!swsusp_resume_device) {
 779                 /*
 780                  * Some device discovery might still be in progress; we need
 781                  * to wait for this to finish.
 782                  */
 783                 wait_for_device_probe();
 784
 785                 if (resume_wait) {
 786                         while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 787                                 msleep(10);
 788                         async_synchronize_full();
 789                 }
 790
 791                 swsusp_resume_device = name_to_dev_t(resume_file);
 792                 if (!swsusp_resume_device) {
 793                         error = -ENODEV;
 794                         goto Unlock;
 795                 }
 796         }
 797
 798  Check_image:
 799         pr_debug("PM: Hibernation image partition %d:%d present\n",
 800                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 801
 802         pr_debug("PM: Looking for hibernation image.\n");
 803         error = swsusp_check();
 804         if (error)
 805                 goto Unlock;
 806
 807         /* The snapshot device should not be opened while we're running */
 808         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 809                 error = -EBUSY;
 810                 swsusp_close(FMODE_READ);
 811                 goto Unlock;
 812         }
 813
 814         pm_prepare_console();
 815         error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
 816         if (error)
 817                 goto Close_Finish;
 818
 819         pr_debug("PM: Preparing processes for restore.\n");
 820         error = freeze_processes();
 821         if (error)
 822                 goto Close_Finish;
 823
 824         pr_debug("PM: Loading hibernation image.\n");
 825
 826         lock_device_hotplug();
 827         error = create_basic_memory_bitmaps();
 828         if (error)
 829                 goto Thaw;
 830
 831         error = swsusp_read(&flags);
 832         swsusp_close(FMODE_READ);
 833         if (!error)
 834                 hibernation_restore(flags & SF_PLATFORM_MODE);
 835
 836         printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
 837         swsusp_free();
 838         free_basic_memory_bitmaps();
 839  Thaw:
 840         unlock_device_hotplug();
 841         thaw_processes();
 842  Finish:
 843         pm_notifier_call_chain(PM_POST_RESTORE);
 844         pm_restore_console();
 845         atomic_inc(&snapshot_device_available);
 846         /* For success case, the suspend path will release the lock */
 847  Unlock:
 848         mutex_unlock(&pm_mutex);
 849         pr_debug("PM: Hibernation image not present or could not be loaded.\n");
 850         return error;
 851  Close_Finish:
 852         swsusp_close(FMODE_READ);
 853         goto Finish;
 854 }
 855
 856 late_initcall_sync(software_resume);
 857
 858
 859 static const char * const hibernation_modes[] = {
 860         [HIBERNATION_PLATFORM]  = "platform",
 861         [HIBERNATION_SHUTDOWN]  = "shutdown",
 862         [HIBERNATION_REBOOT]    = "reboot",
 863 #ifdef CONFIG_SUSPEND
 864         [HIBERNATION_SUSPEND]   = "suspend",
 865 #endif
 866 };
 867
 868 /*
 869  * /sys/power/disk - Control hibernation mode.
 870  *
 871  * Hibernation can be handled in several ways.  There are a few different ways
 872  * to put the system into the sleep state: using the platform driver (e.g. ACPI
 873  * or other hibernation_ops), powering it off or rebooting it (for testing
 874  * mostly).
 875  *
 876  * The sysfs file /sys/power/disk provides an interface for selecting the
 877  * hibernation mode to use.  Reading from this file causes the available modes
 878  * to be printed.  There are 3 modes that can be supported:
 879  *
 880  *      'platform'
 881  *      'shutdown'
 882  *      'reboot'
 883  *
 884  * If a platform hibernation driver is in use, 'platform' will be supported
 885  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
 886  * The selected option (i.e. the one corresponding to the current value of
 887  * hibernation_mode) is enclosed by a square bracket.
 888  *
 889  * To select a given hibernation mode it is necessary to write the mode's
 890  * string representation (as returned by reading from /sys/power/disk) back
 891  * into /sys/power/disk.
 892  */
 893
 894 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 895                          char *buf)
 896 {
 897         int i;
 898         char *start = buf;
 899
 900         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 901                 if (!hibernation_modes[i])
 902                         continue;
 903                 switch (i) {
 904                 case HIBERNATION_SHUTDOWN:
 905                 case HIBERNATION_REBOOT:
 906 #ifdef CONFIG_SUSPEND
 907                 case HIBERNATION_SUSPEND:
 908 #endif
 909                         break;
 910                 case HIBERNATION_PLATFORM:
 911                         if (hibernation_ops)
 912                                 break;
 913                         /* not a valid mode, continue with loop */
 914                         continue;
 915                 }
 916                 if (i == hibernation_mode)
 917                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
 918                 else
 919                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
 920         }
 921         buf += sprintf(buf, "\n");
 922         return buf-start;
 923 }
 924
 925 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 926                           const char *buf, size_t n)
 927 {
 928         int error = 0;
 929         int i;
 930         int len;
 931         char *p;
 932         int mode = HIBERNATION_INVALID;
 933
 934         p = memchr(buf, '\n', n);
 935         len = p ? p - buf : n;
 936
 937         lock_system_sleep();
 938         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 939                 if (len == strlen(hibernation_modes[i])
 940                     && !strncmp(buf, hibernation_modes[i], len)) {
 941                         mode = i;
 942                         break;
 943                 }
 944         }
 945         if (mode != HIBERNATION_INVALID) {
 946                 switch (mode) {
 947                 case HIBERNATION_SHUTDOWN:
 948                 case HIBERNATION_REBOOT:
 949 #ifdef CONFIG_SUSPEND
 950                 case HIBERNATION_SUSPEND:
 951 #endif
 952                         hibernation_mode = mode;
 953                         break;
 954                 case HIBERNATION_PLATFORM:
 955                         if (hibernation_ops)
 956                                 hibernation_mode = mode;
 957                         else
 958                                 error = -EINVAL;
 959                 }
 960         } else
 961                 error = -EINVAL;
 962
 963         if (!error)
 964                 pr_debug("PM: Hibernation mode set to '%s'\n",
 965                          hibernation_modes[mode]);
 966         unlock_system_sleep();
 967         return error ? error : n;
 968 }
 969
 970 power_attr(disk);
 971
 972 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
 973                            char *buf)
 974 {
 975         return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
 976                        MINOR(swsusp_resume_device));
 977 }
 978
 979 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
 980                             const char *buf, size_t n)
 981 {
 982         dev_t res;
 983         int len = n;
 984         char *name;
 985
 986         if (len && buf[len-1] == '\n')
 987                 len--;
 988         name = kstrndup(buf, len, GFP_KERNEL);
 989         if (!name)
 990                 return -ENOMEM;
 991
 992         res = name_to_dev_t(name);
 993         kfree(name);
 994         if (!res)
 995                 return -EINVAL;
 996
 997         lock_system_sleep();
 998         swsusp_resume_device = res;
 999         unlock_system_sleep();
1000         printk(KERN_INFO "PM: Starting manual resume from disk\n");
1001         noresume = 0;
1002         software_resume();
1003         return n;
1004 }
1005
1006 power_attr(resume);
1007
1008 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1009                                char *buf)
1010 {
1011         return sprintf(buf, "%lu\n", image_size);
1012 }
1013
1014 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1015                                 const char *buf, size_t n)
1016 {
1017         unsigned long size;
1018
1019         if (sscanf(buf, "%lu", &size) == 1) {
1020                 image_size = size;
1021                 return n;
1022         }
1023
1024         return -EINVAL;
1025 }
1026
1027 power_attr(image_size);
1028
1029 static ssize_t reserved_size_show(struct kobject *kobj,
1030                                   struct kobj_attribute *attr, char *buf)
1031 {
1032         return sprintf(buf, "%lu\n", reserved_size);
1033 }
1034
1035 static ssize_t reserved_size_store(struct kobject *kobj,
1036                                    struct kobj_attribute *attr,
1037                                    const char *buf, size_t n)
1038 {
1039         unsigned long size;
1040
1041         if (sscanf(buf, "%lu", &size) == 1) {
1042                 reserved_size = size;
1043                 return n;
1044         }
1045
1046         return -EINVAL;
1047 }
1048
1049 power_attr(reserved_size);
1050
1051 static struct attribute * g[] = {
1052         &disk_attr.attr,
1053         &resume_attr.attr,
1054         &image_size_attr.attr,
1055         &reserved_size_attr.attr,
1056         NULL,
1057 };
1058
1059
1060 static struct attribute_group attr_group = {
1061         .attrs = g,
1062 };
1063
1064
1065 static int __init pm_disk_init(void)
1066 {
1067         return sysfs_create_group(power_kobj, &attr_group);
1068 }
1069
1070 core_initcall(pm_disk_init);
1071
1072
1073 static int __init resume_setup(char *str)
1074 {
1075         if (noresume)
1076                 return 1;
1077
1078         strncpy( resume_file, str, 255 );
1079         return 1;
1080 }
1081
1082 static int __init resume_offset_setup(char *str)
1083 {
1084         unsigned long long offset;
1085
1086         if (noresume)
1087                 return 1;
1088
1089         if (sscanf(str, "%llu", &offset) == 1)
1090                 swsusp_resume_block = offset;
1091
1092         return 1;
1093 }
1094
1095 static int __init hibernate_setup(char *str)
1096 {
1097         if (!strncmp(str, "noresume", 8))
1098                 noresume = 1;
1099         else if (!strncmp(str, "nocompress", 10))
1100                 nocompress = 1;
1101         return 1;
1102 }
1103
1104 static int __init noresume_setup(char *str)
1105 {
1106         noresume = 1;
1107         return 1;
1108 }
1109
1110 static int __init resumewait_setup(char *str)
1111 {
1112         resume_wait = 1;
1113         return 1;
1114 }
1115
1116 static int __init resumedelay_setup(char *str)
1117 {
1118         int rc = kstrtouint(str, 0, &resume_delay);
1119
1120         if (rc)
1121                 return rc;
1122         return 1;
1123 }
1124
1125 __setup("noresume", noresume_setup);
1126 __setup("resume_offset=", resume_offset_setup);
1127 __setup("resume=", resume_setup);
1128 __setup("hibernate=", hibernate_setup);
1129 __setup("resumewait", resumewait_setup);
1130 __setup("resumedelay=", resumedelay_setup);