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 #define pr_fmt(fmt) "PM: " fmt
  14
  15 #include <linux/export.h>
  16 #include <linux/suspend.h>
  17 #include <linux/syscalls.h>
  18 #include <linux/reboot.h>
  19 #include <linux/string.h>
  20 #include <linux/device.h>
  21 #include <linux/async.h>
  22 #include <linux/delay.h>
  23 #include <linux/fs.h>
  24 #include <linux/mount.h>
  25 #include <linux/pm.h>
  26 #include <linux/nmi.h>
  27 #include <linux/console.h>
  28 #include <linux/cpu.h>
  29 #include <linux/freezer.h>
  30 #include <linux/gfp.h>
  31 #include <linux/syscore_ops.h>
  32 #include <linux/ctype.h>
  33 #include <linux/genhd.h>
  34 #include <linux/ktime.h>
  35 #include <trace/events/power.h>
  36
  37 #include "power.h"
  38
  39
  40 static int nocompress;
  41 static int noresume;
  42 static int nohibernate;
  43 static int resume_wait;
  44 static unsigned int resume_delay;
  45 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
  46 dev_t swsusp_resume_device;
  47 sector_t swsusp_resume_block;
  48 __visible int in_suspend __nosavedata;
  49
  50 enum {
  51         HIBERNATION_INVALID,
  52         HIBERNATION_PLATFORM,
  53         HIBERNATION_SHUTDOWN,
  54         HIBERNATION_REBOOT,
  55 #ifdef CONFIG_SUSPEND
  56         HIBERNATION_SUSPEND,
  57 #endif
  58         HIBERNATION_TEST_RESUME,
  59         /* keep last */
  60         __HIBERNATION_AFTER_LAST
  61 };
  62 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  63 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  64
  65 static int hibernation_mode = HIBERNATION_SHUTDOWN;
  66
  67 bool freezer_test_done;
  68
  69 static const struct platform_hibernation_ops *hibernation_ops;
  70
  71 bool hibernation_available(void)
  72 {
  73         return (nohibernate == 0);
  74 }
  75
  76 /**
  77  * hibernation_set_ops - Set the global hibernate operations.
  78  * @ops: Hibernation operations to use in subsequent hibernation transitions.
  79  */
  80 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
  81 {
  82         if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  83             && ops->prepare && ops->finish && ops->enter && ops->pre_restore
  84             && ops->restore_cleanup && ops->leave)) {
  85                 WARN_ON(1);
  86                 return;
  87         }
  88         lock_system_sleep();
  89         hibernation_ops = ops;
  90         if (ops)
  91                 hibernation_mode = HIBERNATION_PLATFORM;
  92         else if (hibernation_mode == HIBERNATION_PLATFORM)
  93                 hibernation_mode = HIBERNATION_SHUTDOWN;
  94
  95         unlock_system_sleep();
  96 }
  97 EXPORT_SYMBOL_GPL(hibernation_set_ops);
  98
  99 static bool entering_platform_hibernation;
 100
 101 bool system_entering_hibernation(void)
 102 {
 103         return entering_platform_hibernation;
 104 }
 105 EXPORT_SYMBOL(system_entering_hibernation);
 106
 107 #ifdef CONFIG_PM_DEBUG
 108 static void hibernation_debug_sleep(void)
 109 {
 110         pr_info("hibernation debug: Waiting for 5 seconds.\n");
 111         mdelay(5000);
 112 }
 113
 114 static int hibernation_test(int level)
 115 {
 116         if (pm_test_level == level) {
 117                 hibernation_debug_sleep();
 118                 return 1;
 119         }
 120         return 0;
 121 }
 122 #else /* !CONFIG_PM_DEBUG */
 123 static int hibernation_test(int level) { return 0; }
 124 #endif /* !CONFIG_PM_DEBUG */
 125
 126 /**
 127  * platform_begin - Call platform to start hibernation.
 128  * @platform_mode: Whether or not to use the platform driver.
 129  */
 130 static int platform_begin(int platform_mode)
 131 {
 132         return (platform_mode && hibernation_ops) ?
 133                 hibernation_ops->begin() : 0;
 134 }
 135
 136 /**
 137  * platform_end - Call platform to finish transition to the working state.
 138  * @platform_mode: Whether or not to use the platform driver.
 139  */
 140 static void platform_end(int platform_mode)
 141 {
 142         if (platform_mode && hibernation_ops)
 143                 hibernation_ops->end();
 144 }
 145
 146 /**
 147  * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 148  * @platform_mode: Whether or not to use the platform driver.
 149  *
 150  * Use the platform driver to prepare the system for creating a hibernate image,
 151  * if so configured, and return an error code if that fails.
 152  */
 153
 154 static int platform_pre_snapshot(int platform_mode)
 155 {
 156         return (platform_mode && hibernation_ops) ?
 157                 hibernation_ops->pre_snapshot() : 0;
 158 }
 159
 160 /**
 161  * platform_leave - Call platform to prepare a transition to the working state.
 162  * @platform_mode: Whether or not to use the platform driver.
 163  *
 164  * Use the platform driver prepare to prepare the machine for switching to the
 165  * normal mode of operation.
 166  *
 167  * This routine is called on one CPU with interrupts disabled.
 168  */
 169 static void platform_leave(int platform_mode)
 170 {
 171         if (platform_mode && hibernation_ops)
 172                 hibernation_ops->leave();
 173 }
 174
 175 /**
 176  * platform_finish - Call platform to switch the system to the working state.
 177  * @platform_mode: Whether or not to use the platform driver.
 178  *
 179  * Use the platform driver to switch the machine to the normal mode of
 180  * operation.
 181  *
 182  * This routine must be called after platform_prepare().
 183  */
 184 static void platform_finish(int platform_mode)
 185 {
 186         if (platform_mode && hibernation_ops)
 187                 hibernation_ops->finish();
 188 }
 189
 190 /**
 191  * platform_pre_restore - Prepare for hibernate image restoration.
 192  * @platform_mode: Whether or not to use the platform driver.
 193  *
 194  * Use the platform driver to prepare the system for resume from a hibernation
 195  * image.
 196  *
 197  * If the restore fails after this function has been called,
 198  * platform_restore_cleanup() must be called.
 199  */
 200 static int platform_pre_restore(int platform_mode)
 201 {
 202         return (platform_mode && hibernation_ops) ?
 203                 hibernation_ops->pre_restore() : 0;
 204 }
 205
 206 /**
 207  * platform_restore_cleanup - Switch to the working state after failing restore.
 208  * @platform_mode: Whether or not to use the platform driver.
 209  *
 210  * Use the platform driver to switch the system to the normal mode of operation
 211  * after a failing restore.
 212  *
 213  * If platform_pre_restore() has been called before the failing restore, this
 214  * function must be called too, regardless of the result of
 215  * platform_pre_restore().
 216  */
 217 static void platform_restore_cleanup(int platform_mode)
 218 {
 219         if (platform_mode && hibernation_ops)
 220                 hibernation_ops->restore_cleanup();
 221 }
 222
 223 /**
 224  * platform_recover - Recover from a failure to suspend devices.
 225  * @platform_mode: Whether or not to use the platform driver.
 226  */
 227 static void platform_recover(int platform_mode)
 228 {
 229         if (platform_mode && hibernation_ops && hibernation_ops->recover)
 230                 hibernation_ops->recover();
 231 }
 232
 233 /**
 234  * swsusp_show_speed - Print time elapsed between two events during hibernation.
 235  * @start: Starting event.
 236  * @stop: Final event.
 237  * @nr_pages: Number of memory pages processed between @start and @stop.
 238  * @msg: Additional diagnostic message to print.
 239  */
 240 void swsusp_show_speed(ktime_t start, ktime_t stop,
 241                       unsigned nr_pages, char *msg)
 242 {
 243         ktime_t diff;
 244         u64 elapsed_centisecs64;
 245         unsigned int centisecs;
 246         unsigned int k;
 247         unsigned int kps;
 248
 249         diff = ktime_sub(stop, start);
 250         elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 251         centisecs = elapsed_centisecs64;
 252         if (centisecs == 0)
 253                 centisecs = 1;  /* avoid div-by-zero */
 254         k = nr_pages * (PAGE_SIZE / 1024);
 255         kps = (k * 100) / centisecs;
 256         pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 257                 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 258                 (kps % 1000) / 10);
 259 }
 260
 261 __weak int arch_resume_nosmt(void)
 262 {
 263         return 0;
 264 }
 265
 266 /**
 267  * create_image - Create a hibernation image.
 268  * @platform_mode: Whether or not to use the platform driver.
 269  *
 270  * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 271  * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 272  *
 273  * Control reappears in this routine after the subsequent restore.
 274  */
 275 static int create_image(int platform_mode)
 276 {
 277         int error;
 278
 279         error = dpm_suspend_end(PMSG_FREEZE);
 280         if (error) {
 281                 pr_err("Some devices failed to power down, aborting hibernation\n");
 282                 return error;
 283         }
 284
 285         error = platform_pre_snapshot(platform_mode);
 286         if (error || hibernation_test(TEST_PLATFORM))
 287                 goto Platform_finish;
 288
 289         error = disable_nonboot_cpus();
 290         if (error || hibernation_test(TEST_CPUS))
 291                 goto Enable_cpus;
 292
 293         local_irq_disable();
 294
 295         system_state = SYSTEM_SUSPEND;
 296
 297         error = syscore_suspend();
 298         if (error) {
 299                 pr_err("Some system devices failed to power down, aborting hibernation\n");
 300                 goto Enable_irqs;
 301         }
 302
 303         if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 304                 goto Power_up;
 305
 306         in_suspend = 1;
 307         save_processor_state();
 308         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 309         error = swsusp_arch_suspend();
 310         /* Restore control flow magically appears here */
 311         restore_processor_state();
 312         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 313         if (error)
 314                 pr_err("Error %d creating hibernation image\n", error);
 315
 316         if (!in_suspend) {
 317                 events_check_enabled = false;
 318                 clear_free_pages();
 319         }
 320
 321         platform_leave(platform_mode);
 322
 323  Power_up:
 324         syscore_resume();
 325
 326  Enable_irqs:
 327         system_state = SYSTEM_RUNNING;
 328         local_irq_enable();
 329
 330  Enable_cpus:
 331         enable_nonboot_cpus();
 332
 333         /* Allow architectures to do nosmt-specific post-resume dances */
 334         if (!in_suspend)
 335                 error = arch_resume_nosmt();
 336
 337  Platform_finish:
 338         platform_finish(platform_mode);
 339
 340         dpm_resume_start(in_suspend ?
 341                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 342
 343         return error;
 344 }
 345
 346 /**
 347  * hibernation_snapshot - Quiesce devices and create a hibernation image.
 348  * @platform_mode: If set, use platform driver to prepare for the transition.
 349  *
 350  * This routine must be called with system_transition_mutex held.
 351  */
 352 int hibernation_snapshot(int platform_mode)
 353 {
 354         pm_message_t msg;
 355         int error;
 356
 357         pm_suspend_clear_flags();
 358         error = platform_begin(platform_mode);
 359         if (error)
 360                 goto Close;
 361
 362         /* Preallocate image memory before shutting down devices. */
 363         error = hibernate_preallocate_memory();
 364         if (error)
 365                 goto Close;
 366
 367         error = freeze_kernel_threads();
 368         if (error)
 369                 goto Cleanup;
 370
 371         if (hibernation_test(TEST_FREEZER)) {
 372
 373                 /*
 374                  * Indicate to the caller that we are returning due to a
 375                  * successful freezer test.
 376                  */
 377                 freezer_test_done = true;
 378                 goto Thaw;
 379         }
 380
 381         error = dpm_prepare(PMSG_FREEZE);
 382         if (error) {
 383                 dpm_complete(PMSG_RECOVER);
 384                 goto Thaw;
 385         }
 386
 387         suspend_console();
 388         pm_restrict_gfp_mask();
 389
 390         error = dpm_suspend(PMSG_FREEZE);
 391
 392         if (error || hibernation_test(TEST_DEVICES))
 393                 platform_recover(platform_mode);
 394         else
 395                 error = create_image(platform_mode);
 396
 397         /*
 398          * In the case that we call create_image() above, the control
 399          * returns here (1) after the image has been created or the
 400          * image creation has failed and (2) after a successful restore.
 401          */
 402
 403         /* We may need to release the preallocated image pages here. */
 404         if (error || !in_suspend)
 405                 swsusp_free();
 406
 407         msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 408         dpm_resume(msg);
 409
 410         if (error || !in_suspend)
 411                 pm_restore_gfp_mask();
 412
 413         resume_console();
 414         dpm_complete(msg);
 415
 416  Close:
 417         platform_end(platform_mode);
 418         return error;
 419
 420  Thaw:
 421         thaw_kernel_threads();
 422  Cleanup:
 423         swsusp_free();
 424         goto Close;
 425 }
 426
 427 int __weak hibernate_resume_nonboot_cpu_disable(void)
 428 {
 429         return disable_nonboot_cpus();
 430 }
 431
 432 /**
 433  * resume_target_kernel - Restore system state from a hibernation image.
 434  * @platform_mode: Whether or not to use the platform driver.
 435  *
 436  * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 437  * contents of highmem that have not been restored yet from the image and run
 438  * the low-level code that will restore the remaining contents of memory and
 439  * switch to the just restored target kernel.
 440  */
 441 static int resume_target_kernel(bool platform_mode)
 442 {
 443         int error;
 444
 445         error = dpm_suspend_end(PMSG_QUIESCE);
 446         if (error) {
 447                 pr_err("Some devices failed to power down, aborting resume\n");
 448                 return error;
 449         }
 450
 451         error = platform_pre_restore(platform_mode);
 452         if (error)
 453                 goto Cleanup;
 454
 455         error = hibernate_resume_nonboot_cpu_disable();
 456         if (error)
 457                 goto Enable_cpus;
 458
 459         local_irq_disable();
 460         system_state = SYSTEM_SUSPEND;
 461
 462         error = syscore_suspend();
 463         if (error)
 464                 goto Enable_irqs;
 465
 466         save_processor_state();
 467         error = restore_highmem();
 468         if (!error) {
 469                 error = swsusp_arch_resume();
 470                 /*
 471                  * The code below is only ever reached in case of a failure.
 472                  * Otherwise, execution continues at the place where
 473                  * swsusp_arch_suspend() was called.
 474                  */
 475                 BUG_ON(!error);
 476                 /*
 477                  * This call to restore_highmem() reverts the changes made by
 478                  * the previous one.
 479                  */
 480                 restore_highmem();
 481         }
 482         /*
 483          * The only reason why swsusp_arch_resume() can fail is memory being
 484          * very tight, so we have to free it as soon as we can to avoid
 485          * subsequent failures.
 486          */
 487         swsusp_free();
 488         restore_processor_state();
 489         touch_softlockup_watchdog();
 490
 491         syscore_resume();
 492
 493  Enable_irqs:
 494         system_state = SYSTEM_RUNNING;
 495         local_irq_enable();
 496
 497  Enable_cpus:
 498         enable_nonboot_cpus();
 499
 500  Cleanup:
 501         platform_restore_cleanup(platform_mode);
 502
 503         dpm_resume_start(PMSG_RECOVER);
 504
 505         return error;
 506 }
 507
 508 /**
 509  * hibernation_restore - Quiesce devices and restore from a hibernation image.
 510  * @platform_mode: If set, use platform driver to prepare for the transition.
 511  *
 512  * This routine must be called with system_transition_mutex held.  If it is
 513  * successful, control reappears in the restored target kernel in
 514  * hibernation_snapshot().
 515  */
 516 int hibernation_restore(int platform_mode)
 517 {
 518         int error;
 519
 520         pm_prepare_console();
 521         suspend_console();
 522         pm_restrict_gfp_mask();
 523         error = dpm_suspend_start(PMSG_QUIESCE);
 524         if (!error) {
 525                 error = resume_target_kernel(platform_mode);
 526                 /*
 527                  * The above should either succeed and jump to the new kernel,
 528                  * or return with an error. Otherwise things are just
 529                  * undefined, so let's be paranoid.
 530                  */
 531                 BUG_ON(!error);
 532         }
 533         dpm_resume_end(PMSG_RECOVER);
 534         pm_restore_gfp_mask();
 535         resume_console();
 536         pm_restore_console();
 537         return error;
 538 }
 539
 540 /**
 541  * hibernation_platform_enter - Power off the system using the platform driver.
 542  */
 543 int hibernation_platform_enter(void)
 544 {
 545         int error;
 546
 547         if (!hibernation_ops)
 548                 return -ENOSYS;
 549
 550         /*
 551          * We have cancelled the power transition by running
 552          * hibernation_ops->finish() before saving the image, so we should let
 553          * the firmware know that we're going to enter the sleep state after all
 554          */
 555         error = hibernation_ops->begin();
 556         if (error)
 557                 goto Close;
 558
 559         entering_platform_hibernation = true;
 560         suspend_console();
 561         error = dpm_suspend_start(PMSG_HIBERNATE);
 562         if (error) {
 563                 if (hibernation_ops->recover)
 564                         hibernation_ops->recover();
 565                 goto Resume_devices;
 566         }
 567
 568         error = dpm_suspend_end(PMSG_HIBERNATE);
 569         if (error)
 570                 goto Resume_devices;
 571
 572         error = hibernation_ops->prepare();
 573         if (error)
 574                 goto Platform_finish;
 575
 576         error = disable_nonboot_cpus();
 577         if (error)
 578                 goto Enable_cpus;
 579
 580         local_irq_disable();
 581         system_state = SYSTEM_SUSPEND;
 582         syscore_suspend();
 583         if (pm_wakeup_pending()) {
 584                 error = -EAGAIN;
 585                 goto Power_up;
 586         }
 587
 588         hibernation_ops->enter();
 589         /* We should never get here */
 590         while (1);
 591
 592  Power_up:
 593         syscore_resume();
 594         system_state = SYSTEM_RUNNING;
 595         local_irq_enable();
 596
 597  Enable_cpus:
 598         enable_nonboot_cpus();
 599
 600  Platform_finish:
 601         hibernation_ops->finish();
 602
 603         dpm_resume_start(PMSG_RESTORE);
 604
 605  Resume_devices:
 606         entering_platform_hibernation = false;
 607         dpm_resume_end(PMSG_RESTORE);
 608         resume_console();
 609
 610  Close:
 611         hibernation_ops->end();
 612
 613         return error;
 614 }
 615
 616 /**
 617  * power_down - Shut the machine down for hibernation.
 618  *
 619  * Use the platform driver, if configured, to put the system into the sleep
 620  * state corresponding to hibernation, or try to power it off or reboot,
 621  * depending on the value of hibernation_mode.
 622  */
 623 static void power_down(void)
 624 {
 625 #ifdef CONFIG_SUSPEND
 626         int error;
 627
 628         if (hibernation_mode == HIBERNATION_SUSPEND) {
 629                 error = suspend_devices_and_enter(mem_sleep_current);
 630                 if (error) {
 631                         hibernation_mode = hibernation_ops ?
 632                                                 HIBERNATION_PLATFORM :
 633                                                 HIBERNATION_SHUTDOWN;
 634                 } else {
 635                         /* Restore swap signature. */
 636                         error = swsusp_unmark();
 637                         if (error)
 638                                 pr_err("Swap will be unusable! Try swapon -a.\n");
 639
 640                         return;
 641                 }
 642         }
 643 #endif
 644
 645         switch (hibernation_mode) {
 646         case HIBERNATION_REBOOT:
 647                 kernel_restart(NULL);
 648                 break;
 649         case HIBERNATION_PLATFORM:
 650                 hibernation_platform_enter();
 651                 /* Fall through */
 652         case HIBERNATION_SHUTDOWN:
 653                 if (pm_power_off)
 654                         kernel_power_off();
 655                 break;
 656         }
 657         kernel_halt();
 658         /*
 659          * Valid image is on the disk, if we continue we risk serious data
 660          * corruption after resume.
 661          */
 662         pr_crit("Power down manually\n");
 663         while (1)
 664                 cpu_relax();
 665 }
 666
 667 static int load_image_and_restore(void)
 668 {
 669         int error;
 670         unsigned int flags;
 671
 672         pm_pr_dbg("Loading hibernation image.\n");
 673
 674         lock_device_hotplug();
 675         error = create_basic_memory_bitmaps();
 676         if (error)
 677                 goto Unlock;
 678
 679         error = swsusp_read(&flags);
 680         swsusp_close(FMODE_READ | FMODE_EXCL);
 681         if (!error)
 682                 hibernation_restore(flags & SF_PLATFORM_MODE);
 683
 684         pr_err("Failed to load hibernation image, recovering.\n");
 685         swsusp_free();
 686         free_basic_memory_bitmaps();
 687  Unlock:
 688         unlock_device_hotplug();
 689
 690         return error;
 691 }
 692
 693 /**
 694  * hibernate - Carry out system hibernation, including saving the image.
 695  */
 696 int hibernate(void)
 697 {
 698         int error, nr_calls = 0;
 699         bool snapshot_test = false;
 700
 701         if (!hibernation_available()) {
 702                 pm_pr_dbg("Hibernation not available.\n");
 703                 return -EPERM;
 704         }
 705
 706         lock_system_sleep();
 707         /* The snapshot device should not be opened while we're running */
 708         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 709                 error = -EBUSY;
 710                 goto Unlock;
 711         }
 712
 713         pr_info("hibernation entry\n");
 714         pm_prepare_console();
 715         error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
 716         if (error) {
 717                 nr_calls--;
 718                 goto Exit;
 719         }
 720
 721         pr_info("Syncing filesystems ... \n");
 722         ksys_sync();
 723         pr_info("done.\n");
 724
 725         error = freeze_processes();
 726         if (error)
 727                 goto Exit;
 728
 729         lock_device_hotplug();
 730         /* Allocate memory management structures */
 731         error = create_basic_memory_bitmaps();
 732         if (error)
 733                 goto Thaw;
 734
 735         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 736         if (error || freezer_test_done)
 737                 goto Free_bitmaps;
 738
 739         if (in_suspend) {
 740                 unsigned int flags = 0;
 741
 742                 if (hibernation_mode == HIBERNATION_PLATFORM)
 743                         flags |= SF_PLATFORM_MODE;
 744                 if (nocompress)
 745                         flags |= SF_NOCOMPRESS_MODE;
 746                 else
 747                         flags |= SF_CRC32_MODE;
 748
 749                 pm_pr_dbg("Writing image.\n");
 750                 error = swsusp_write(flags);
 751                 swsusp_free();
 752                 if (!error) {
 753                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
 754                                 snapshot_test = true;
 755                         else
 756                                 power_down();
 757                 }
 758                 in_suspend = 0;
 759                 pm_restore_gfp_mask();
 760         } else {
 761                 pm_pr_dbg("Image restored successfully.\n");
 762         }
 763
 764  Free_bitmaps:
 765         free_basic_memory_bitmaps();
 766  Thaw:
 767         unlock_device_hotplug();
 768         if (snapshot_test) {
 769                 pm_pr_dbg("Checking hibernation image\n");
 770                 error = swsusp_check();
 771                 if (!error)
 772                         error = load_image_and_restore();
 773         }
 774         thaw_processes();
 775
 776         /* Don't bother checking whether freezer_test_done is true */
 777         freezer_test_done = false;
 778  Exit:
 779         __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
 780         pm_restore_console();
 781         atomic_inc(&snapshot_device_available);
 782  Unlock:
 783         unlock_system_sleep();
 784         pr_info("hibernation exit\n");
 785
 786         return error;
 787 }
 788
 789
 790 /**
 791  * software_resume - Resume from a saved hibernation image.
 792  *
 793  * This routine is called as a late initcall, when all devices have been
 794  * discovered and initialized already.
 795  *
 796  * The image reading code is called to see if there is a hibernation image
 797  * available for reading.  If that is the case, devices are quiesced and the
 798  * contents of memory is restored from the saved image.
 799  *
 800  * If this is successful, control reappears in the restored target kernel in
 801  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 802  * attempts to recover gracefully and make the kernel return to the normal mode
 803  * of operation.
 804  */
 805 static int software_resume(void)
 806 {
 807         int error, nr_calls = 0;
 808
 809         /*
 810          * If the user said "noresume".. bail out early.
 811          */
 812         if (noresume || !hibernation_available())
 813                 return 0;
 814
 815         /*
 816          * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 817          * is configured into the kernel. Since the regular hibernate
 818          * trigger path is via sysfs which takes a buffer mutex before
 819          * calling hibernate functions (which take system_transition_mutex)
 820          * this can cause lockdep to complain about a possible ABBA deadlock
 821          * which cannot happen since we're in the boot code here and
 822          * sysfs can't be invoked yet. Therefore, we use a subclass
 823          * here to avoid lockdep complaining.
 824          */
 825         mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
 826
 827         if (swsusp_resume_device)
 828                 goto Check_image;
 829
 830         if (!strlen(resume_file)) {
 831                 error = -ENOENT;
 832                 goto Unlock;
 833         }
 834
 835         pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 836
 837         if (resume_delay) {
 838                 pr_info("Waiting %dsec before reading resume device ...\n",
 839                         resume_delay);
 840                 ssleep(resume_delay);
 841         }
 842
 843         /* Check if the device is there */
 844         swsusp_resume_device = name_to_dev_t(resume_file);
 845         if (!swsusp_resume_device) {
 846                 /*
 847                  * Some device discovery might still be in progress; we need
 848                  * to wait for this to finish.
 849                  */
 850                 wait_for_device_probe();
 851
 852                 if (resume_wait) {
 853                         while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 854                                 msleep(10);
 855                         async_synchronize_full();
 856                 }
 857
 858                 swsusp_resume_device = name_to_dev_t(resume_file);
 859                 if (!swsusp_resume_device) {
 860                         error = -ENODEV;
 861                         goto Unlock;
 862                 }
 863         }
 864
 865  Check_image:
 866         pm_pr_dbg("Hibernation image partition %d:%d present\n",
 867                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 868
 869         pm_pr_dbg("Looking for hibernation image.\n");
 870         error = swsusp_check();
 871         if (error)
 872                 goto Unlock;
 873
 874         /* The snapshot device should not be opened while we're running */
 875         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 876                 error = -EBUSY;
 877                 swsusp_close(FMODE_READ | FMODE_EXCL);
 878                 goto Unlock;
 879         }
 880
 881         pr_info("resume from hibernation\n");
 882         pm_prepare_console();
 883         error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
 884         if (error) {
 885                 nr_calls--;
 886                 goto Close_Finish;
 887         }
 888
 889         pm_pr_dbg("Preparing processes for restore.\n");
 890         error = freeze_processes();
 891         if (error)
 892                 goto Close_Finish;
 893
 894         error = freeze_kernel_threads();
 895         if (error) {
 896                 thaw_processes();
 897                 goto Close_Finish;
 898         }
 899
 900         error = load_image_and_restore();
 901         thaw_processes();
 902  Finish:
 903         __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
 904         pm_restore_console();
 905         pr_info("resume from hibernation failed (%d)\n", error);
 906         atomic_inc(&snapshot_device_available);
 907         /* For success case, the suspend path will release the lock */
 908  Unlock:
 909         mutex_unlock(&system_transition_mutex);
 910         pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
 911         return error;
 912  Close_Finish:
 913         swsusp_close(FMODE_READ | FMODE_EXCL);
 914         goto Finish;
 915 }
 916
 917 late_initcall_sync(software_resume);
 918
 919
 920 static const char * const hibernation_modes[] = {
 921         [HIBERNATION_PLATFORM]  = "platform",
 922         [HIBERNATION_SHUTDOWN]  = "shutdown",
 923         [HIBERNATION_REBOOT]    = "reboot",
 924 #ifdef CONFIG_SUSPEND
 925         [HIBERNATION_SUSPEND]   = "suspend",
 926 #endif
 927         [HIBERNATION_TEST_RESUME]       = "test_resume",
 928 };
 929
 930 /*
 931  * /sys/power/disk - Control hibernation mode.
 932  *
 933  * Hibernation can be handled in several ways.  There are a few different ways
 934  * to put the system into the sleep state: using the platform driver (e.g. ACPI
 935  * or other hibernation_ops), powering it off or rebooting it (for testing
 936  * mostly).
 937  *
 938  * The sysfs file /sys/power/disk provides an interface for selecting the
 939  * hibernation mode to use.  Reading from this file causes the available modes
 940  * to be printed.  There are 3 modes that can be supported:
 941  *
 942  *      'platform'
 943  *      'shutdown'
 944  *      'reboot'
 945  *
 946  * If a platform hibernation driver is in use, 'platform' will be supported
 947  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
 948  * The selected option (i.e. the one corresponding to the current value of
 949  * hibernation_mode) is enclosed by a square bracket.
 950  *
 951  * To select a given hibernation mode it is necessary to write the mode's
 952  * string representation (as returned by reading from /sys/power/disk) back
 953  * into /sys/power/disk.
 954  */
 955
 956 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 957                          char *buf)
 958 {
 959         int i;
 960         char *start = buf;
 961
 962         if (!hibernation_available())
 963                 return sprintf(buf, "[disabled]\n");
 964
 965         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 966                 if (!hibernation_modes[i])
 967                         continue;
 968                 switch (i) {
 969                 case HIBERNATION_SHUTDOWN:
 970                 case HIBERNATION_REBOOT:
 971 #ifdef CONFIG_SUSPEND
 972                 case HIBERNATION_SUSPEND:
 973 #endif
 974                 case HIBERNATION_TEST_RESUME:
 975                         break;
 976                 case HIBERNATION_PLATFORM:
 977                         if (hibernation_ops)
 978                                 break;
 979                         /* not a valid mode, continue with loop */
 980                         continue;
 981                 }
 982                 if (i == hibernation_mode)
 983                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
 984                 else
 985                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
 986         }
 987         buf += sprintf(buf, "\n");
 988         return buf-start;
 989 }
 990
 991 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 992                           const char *buf, size_t n)
 993 {
 994         int error = 0;
 995         int i;
 996         int len;
 997         char *p;
 998         int mode = HIBERNATION_INVALID;
 999
1000         if (!hibernation_available())
1001                 return -EPERM;
1002
1003         p = memchr(buf, '\n', n);
1004         len = p ? p - buf : n;
1005
1006         lock_system_sleep();
1007         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1008                 if (len == strlen(hibernation_modes[i])
1009                     && !strncmp(buf, hibernation_modes[i], len)) {
1010                         mode = i;
1011                         break;
1012                 }
1013         }
1014         if (mode != HIBERNATION_INVALID) {
1015                 switch (mode) {
1016                 case HIBERNATION_SHUTDOWN:
1017                 case HIBERNATION_REBOOT:
1018 #ifdef CONFIG_SUSPEND
1019                 case HIBERNATION_SUSPEND:
1020 #endif
1021                 case HIBERNATION_TEST_RESUME:
1022                         hibernation_mode = mode;
1023                         break;
1024                 case HIBERNATION_PLATFORM:
1025                         if (hibernation_ops)
1026                                 hibernation_mode = mode;
1027                         else
1028                                 error = -EINVAL;
1029                 }
1030         } else
1031                 error = -EINVAL;
1032
1033         if (!error)
1034                 pm_pr_dbg("Hibernation mode set to '%s'\n",
1035                                hibernation_modes[mode]);
1036         unlock_system_sleep();
1037         return error ? error : n;
1038 }
1039
1040 power_attr(disk);
1041
1042 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1043                            char *buf)
1044 {
1045         return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
1046                        MINOR(swsusp_resume_device));
1047 }
1048
1049 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1050                             const char *buf, size_t n)
1051 {
1052         dev_t res;
1053         int len = n;
1054         char *name;
1055
1056         if (len && buf[len-1] == '\n')
1057                 len--;
1058         name = kstrndup(buf, len, GFP_KERNEL);
1059         if (!name)
1060                 return -ENOMEM;
1061
1062         res = name_to_dev_t(name);
1063         kfree(name);
1064         if (!res)
1065                 return -EINVAL;
1066
1067         lock_system_sleep();
1068         swsusp_resume_device = res;
1069         unlock_system_sleep();
1070         pm_pr_dbg("Configured resume from disk to %u\n", swsusp_resume_device);
1071         noresume = 0;
1072         software_resume();
1073         return n;
1074 }
1075
1076 power_attr(resume);
1077
1078 static ssize_t resume_offset_show(struct kobject *kobj,
1079                                   struct kobj_attribute *attr, char *buf)
1080 {
1081         return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1082 }
1083
1084 static ssize_t resume_offset_store(struct kobject *kobj,
1085                                    struct kobj_attribute *attr, const char *buf,
1086                                    size_t n)
1087 {
1088         unsigned long long offset;
1089         int rc;
1090
1091         rc = kstrtoull(buf, 0, &offset);
1092         if (rc)
1093                 return rc;
1094         swsusp_resume_block = offset;
1095
1096         return n;
1097 }
1098
1099 power_attr(resume_offset);
1100
1101 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1102                                char *buf)
1103 {
1104         return sprintf(buf, "%lu\n", image_size);
1105 }
1106
1107 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1108                                 const char *buf, size_t n)
1109 {
1110         unsigned long size;
1111
1112         if (sscanf(buf, "%lu", &size) == 1) {
1113                 image_size = size;
1114                 return n;
1115         }
1116
1117         return -EINVAL;
1118 }
1119
1120 power_attr(image_size);
1121
1122 static ssize_t reserved_size_show(struct kobject *kobj,
1123                                   struct kobj_attribute *attr, char *buf)
1124 {
1125         return sprintf(buf, "%lu\n", reserved_size);
1126 }
1127
1128 static ssize_t reserved_size_store(struct kobject *kobj,
1129                                    struct kobj_attribute *attr,
1130                                    const char *buf, size_t n)
1131 {
1132         unsigned long size;
1133
1134         if (sscanf(buf, "%lu", &size) == 1) {
1135                 reserved_size = size;
1136                 return n;
1137         }
1138
1139         return -EINVAL;
1140 }
1141
1142 power_attr(reserved_size);
1143
1144 static struct attribute * g[] = {
1145         &disk_attr.attr,
1146         &resume_offset_attr.attr,
1147         &resume_attr.attr,
1148         &image_size_attr.attr,
1149         &reserved_size_attr.attr,
1150         NULL,
1151 };
1152
1153
1154 static const struct attribute_group attr_group = {
1155         .attrs = g,
1156 };
1157
1158
1159 static int __init pm_disk_init(void)
1160 {
1161         return sysfs_create_group(power_kobj, &attr_group);
1162 }
1163
1164 core_initcall(pm_disk_init);
1165
1166
1167 static int __init resume_setup(char *str)
1168 {
1169         if (noresume)
1170                 return 1;
1171
1172         strncpy( resume_file, str, 255 );
1173         return 1;
1174 }
1175
1176 static int __init resume_offset_setup(char *str)
1177 {
1178         unsigned long long offset;
1179
1180         if (noresume)
1181                 return 1;
1182
1183         if (sscanf(str, "%llu", &offset) == 1)
1184                 swsusp_resume_block = offset;
1185
1186         return 1;
1187 }
1188
1189 static int __init hibernate_setup(char *str)
1190 {
1191         if (!strncmp(str, "noresume", 8)) {
1192                 noresume = 1;
1193         } else if (!strncmp(str, "nocompress", 10)) {
1194                 nocompress = 1;
1195         } else if (!strncmp(str, "no", 2)) {
1196                 noresume = 1;
1197                 nohibernate = 1;
1198         } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1199                    && !strncmp(str, "protect_image", 13)) {
1200                 enable_restore_image_protection();
1201         }
1202         return 1;
1203 }
1204
1205 static int __init noresume_setup(char *str)
1206 {
1207         noresume = 1;
1208         return 1;
1209 }
1210
1211 static int __init resumewait_setup(char *str)
1212 {
1213         resume_wait = 1;
1214         return 1;
1215 }
1216
1217 static int __init resumedelay_setup(char *str)
1218 {
1219         int rc = kstrtouint(str, 0, &resume_delay);
1220
1221         if (rc)
1222                 pr_warn("resumedelay: bad option string '%s'\n", str);
1223         return 1;
1224 }
1225
1226 static int __init nohibernate_setup(char *str)
1227 {
1228         noresume = 1;
1229         nohibernate = 1;
1230         return 1;
1231 }
1232
1233 __setup("noresume", noresume_setup);
1234 __setup("resume_offset=", resume_offset_setup);
1235 __setup("resume=", resume_setup);
1236 __setup("hibernate=", hibernate_setup);
1237 __setup("resumewait", resumewait_setup);
1238 __setup("resumedelay=", resumedelay_setup);
1239 __setup("nohibernate", nohibernate_setup);