kernel/power/hibernate.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
   4  *
   5  * Copyright (c) 2003 Patrick Mochel
   6  * Copyright (c) 2003 Open Source Development Lab
   7  * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
   8  * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
   9  * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
  10  */
  11
  12 #define pr_fmt(fmt) "PM: hibernation: " fmt
  13
  14 #include <linux/export.h>
  15 #include <linux/suspend.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/nmi.h>
  25 #include <linux/console.h>
  26 #include <linux/cpu.h>
  27 #include <linux/freezer.h>
  28 #include <linux/gfp.h>
  29 #include <linux/syscore_ops.h>
  30 #include <linux/ctype.h>
  31 #include <linux/genhd.h>
  32 #include <linux/ktime.h>
  33 #include <linux/security.h>
  34 #include <linux/secretmem.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 static atomic_t hibernate_atomic = ATOMIC_INIT(1);
  72
  73 bool hibernate_acquire(void)
  74 {
  75         return atomic_add_unless(&hibernate_atomic, -1, 0);
  76 }
  77
  78 void hibernate_release(void)
  79 {
  80         atomic_inc(&hibernate_atomic);
  81 }
  82
  83 bool hibernation_available(void)
  84 {
  85         return nohibernate == 0 &&
  86                 !security_locked_down(LOCKDOWN_HIBERNATION) &&
  87                 !secretmem_active();
  88 }
  89
  90 /**
  91  * hibernation_set_ops - Set the global hibernate operations.
  92  * @ops: Hibernation operations to use in subsequent hibernation transitions.
  93  */
  94 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
  95 {
  96         if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  97             && ops->prepare && ops->finish && ops->enter && ops->pre_restore
  98             && ops->restore_cleanup && ops->leave)) {
  99                 WARN_ON(1);
 100                 return;
 101         }
 102         lock_system_sleep();
 103         hibernation_ops = ops;
 104         if (ops)
 105                 hibernation_mode = HIBERNATION_PLATFORM;
 106         else if (hibernation_mode == HIBERNATION_PLATFORM)
 107                 hibernation_mode = HIBERNATION_SHUTDOWN;
 108
 109         unlock_system_sleep();
 110 }
 111 EXPORT_SYMBOL_GPL(hibernation_set_ops);
 112
 113 static bool entering_platform_hibernation;
 114
 115 bool system_entering_hibernation(void)
 116 {
 117         return entering_platform_hibernation;
 118 }
 119 EXPORT_SYMBOL(system_entering_hibernation);
 120
 121 #ifdef CONFIG_PM_DEBUG
 122 static void hibernation_debug_sleep(void)
 123 {
 124         pr_info("debug: Waiting for 5 seconds.\n");
 125         mdelay(5000);
 126 }
 127
 128 static int hibernation_test(int level)
 129 {
 130         if (pm_test_level == level) {
 131                 hibernation_debug_sleep();
 132                 return 1;
 133         }
 134         return 0;
 135 }
 136 #else /* !CONFIG_PM_DEBUG */
 137 static int hibernation_test(int level) { return 0; }
 138 #endif /* !CONFIG_PM_DEBUG */
 139
 140 /**
 141  * platform_begin - Call platform to start hibernation.
 142  * @platform_mode: Whether or not to use the platform driver.
 143  */
 144 static int platform_begin(int platform_mode)
 145 {
 146         return (platform_mode && hibernation_ops) ?
 147                 hibernation_ops->begin(PMSG_FREEZE) : 0;
 148 }
 149
 150 /**
 151  * platform_end - Call platform to finish transition to the working state.
 152  * @platform_mode: Whether or not to use the platform driver.
 153  */
 154 static void platform_end(int platform_mode)
 155 {
 156         if (platform_mode && hibernation_ops)
 157                 hibernation_ops->end();
 158 }
 159
 160 /**
 161  * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 162  * @platform_mode: Whether or not to use the platform driver.
 163  *
 164  * Use the platform driver to prepare the system for creating a hibernate image,
 165  * if so configured, and return an error code if that fails.
 166  */
 167
 168 static int platform_pre_snapshot(int platform_mode)
 169 {
 170         return (platform_mode && hibernation_ops) ?
 171                 hibernation_ops->pre_snapshot() : 0;
 172 }
 173
 174 /**
 175  * platform_leave - Call platform to prepare a transition to the working state.
 176  * @platform_mode: Whether or not to use the platform driver.
 177  *
 178  * Use the platform driver prepare to prepare the machine for switching to the
 179  * normal mode of operation.
 180  *
 181  * This routine is called on one CPU with interrupts disabled.
 182  */
 183 static void platform_leave(int platform_mode)
 184 {
 185         if (platform_mode && hibernation_ops)
 186                 hibernation_ops->leave();
 187 }
 188
 189 /**
 190  * platform_finish - Call platform to switch the system to the working state.
 191  * @platform_mode: Whether or not to use the platform driver.
 192  *
 193  * Use the platform driver to switch the machine to the normal mode of
 194  * operation.
 195  *
 196  * This routine must be called after platform_prepare().
 197  */
 198 static void platform_finish(int platform_mode)
 199 {
 200         if (platform_mode && hibernation_ops)
 201                 hibernation_ops->finish();
 202 }
 203
 204 /**
 205  * platform_pre_restore - Prepare for hibernate image restoration.
 206  * @platform_mode: Whether or not to use the platform driver.
 207  *
 208  * Use the platform driver to prepare the system for resume from a hibernation
 209  * image.
 210  *
 211  * If the restore fails after this function has been called,
 212  * platform_restore_cleanup() must be called.
 213  */
 214 static int platform_pre_restore(int platform_mode)
 215 {
 216         return (platform_mode && hibernation_ops) ?
 217                 hibernation_ops->pre_restore() : 0;
 218 }
 219
 220 /**
 221  * platform_restore_cleanup - Switch to the working state after failing restore.
 222  * @platform_mode: Whether or not to use the platform driver.
 223  *
 224  * Use the platform driver to switch the system to the normal mode of operation
 225  * after a failing restore.
 226  *
 227  * If platform_pre_restore() has been called before the failing restore, this
 228  * function must be called too, regardless of the result of
 229  * platform_pre_restore().
 230  */
 231 static void platform_restore_cleanup(int platform_mode)
 232 {
 233         if (platform_mode && hibernation_ops)
 234                 hibernation_ops->restore_cleanup();
 235 }
 236
 237 /**
 238  * platform_recover - Recover from a failure to suspend devices.
 239  * @platform_mode: Whether or not to use the platform driver.
 240  */
 241 static void platform_recover(int platform_mode)
 242 {
 243         if (platform_mode && hibernation_ops && hibernation_ops->recover)
 244                 hibernation_ops->recover();
 245 }
 246
 247 /**
 248  * swsusp_show_speed - Print time elapsed between two events during hibernation.
 249  * @start: Starting event.
 250  * @stop: Final event.
 251  * @nr_pages: Number of memory pages processed between @start and @stop.
 252  * @msg: Additional diagnostic message to print.
 253  */
 254 void swsusp_show_speed(ktime_t start, ktime_t stop,
 255                       unsigned nr_pages, char *msg)
 256 {
 257         ktime_t diff;
 258         u64 elapsed_centisecs64;
 259         unsigned int centisecs;
 260         unsigned int k;
 261         unsigned int kps;
 262
 263         diff = ktime_sub(stop, start);
 264         elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 265         centisecs = elapsed_centisecs64;
 266         if (centisecs == 0)
 267                 centisecs = 1;  /* avoid div-by-zero */
 268         k = nr_pages * (PAGE_SIZE / 1024);
 269         kps = (k * 100) / centisecs;
 270         pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 271                 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 272                 (kps % 1000) / 10);
 273 }
 274
 275 __weak int arch_resume_nosmt(void)
 276 {
 277         return 0;
 278 }
 279
 280 /**
 281  * create_image - Create a hibernation image.
 282  * @platform_mode: Whether or not to use the platform driver.
 283  *
 284  * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 285  * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 286  *
 287  * Control reappears in this routine after the subsequent restore.
 288  */
 289 static int create_image(int platform_mode)
 290 {
 291         int error;
 292
 293         error = dpm_suspend_end(PMSG_FREEZE);
 294         if (error) {
 295                 pr_err("Some devices failed to power down, aborting\n");
 296                 return error;
 297         }
 298
 299         error = platform_pre_snapshot(platform_mode);
 300         if (error || hibernation_test(TEST_PLATFORM))
 301                 goto Platform_finish;
 302
 303         error = pm_sleep_disable_secondary_cpus();
 304         if (error || hibernation_test(TEST_CPUS))
 305                 goto Enable_cpus;
 306
 307         local_irq_disable();
 308
 309         system_state = SYSTEM_SUSPEND;
 310
 311         error = syscore_suspend();
 312         if (error) {
 313                 pr_err("Some system devices failed to power down, aborting\n");
 314                 goto Enable_irqs;
 315         }
 316
 317         if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 318                 goto Power_up;
 319
 320         in_suspend = 1;
 321         save_processor_state();
 322         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 323         error = swsusp_arch_suspend();
 324         /* Restore control flow magically appears here */
 325         restore_processor_state();
 326         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 327         if (error)
 328                 pr_err("Error %d creating image\n", error);
 329
 330         if (!in_suspend) {
 331                 events_check_enabled = false;
 332                 clear_or_poison_free_pages();
 333         }
 334
 335         platform_leave(platform_mode);
 336
 337  Power_up:
 338         syscore_resume();
 339
 340  Enable_irqs:
 341         system_state = SYSTEM_RUNNING;
 342         local_irq_enable();
 343
 344  Enable_cpus:
 345         pm_sleep_enable_secondary_cpus();
 346
 347         /* Allow architectures to do nosmt-specific post-resume dances */
 348         if (!in_suspend)
 349                 error = arch_resume_nosmt();
 350
 351  Platform_finish:
 352         platform_finish(platform_mode);
 353
 354         dpm_resume_start(in_suspend ?
 355                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 356
 357         return error;
 358 }
 359
 360 /**
 361  * hibernation_snapshot - Quiesce devices and create a hibernation image.
 362  * @platform_mode: If set, use platform driver to prepare for the transition.
 363  *
 364  * This routine must be called with system_transition_mutex held.
 365  */
 366 int hibernation_snapshot(int platform_mode)
 367 {
 368         pm_message_t msg;
 369         int error;
 370
 371         pm_suspend_clear_flags();
 372         error = platform_begin(platform_mode);
 373         if (error)
 374                 goto Close;
 375
 376         /* Preallocate image memory before shutting down devices. */
 377         error = hibernate_preallocate_memory();
 378         if (error)
 379                 goto Close;
 380
 381         error = freeze_kernel_threads();
 382         if (error)
 383                 goto Cleanup;
 384
 385         if (hibernation_test(TEST_FREEZER)) {
 386
 387                 /*
 388                  * Indicate to the caller that we are returning due to a
 389                  * successful freezer test.
 390                  */
 391                 freezer_test_done = true;
 392                 goto Thaw;
 393         }
 394
 395         error = dpm_prepare(PMSG_FREEZE);
 396         if (error) {
 397                 dpm_complete(PMSG_RECOVER);
 398                 goto Thaw;
 399         }
 400
 401         suspend_console();
 402         pm_restrict_gfp_mask();
 403
 404         error = dpm_suspend(PMSG_FREEZE);
 405
 406         if (error || hibernation_test(TEST_DEVICES))
 407                 platform_recover(platform_mode);
 408         else
 409                 error = create_image(platform_mode);
 410
 411         /*
 412          * In the case that we call create_image() above, the control
 413          * returns here (1) after the image has been created or the
 414          * image creation has failed and (2) after a successful restore.
 415          */
 416
 417         /* We may need to release the preallocated image pages here. */
 418         if (error || !in_suspend)
 419                 swsusp_free();
 420
 421         msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 422         dpm_resume(msg);
 423
 424         if (error || !in_suspend)
 425                 pm_restore_gfp_mask();
 426
 427         resume_console();
 428         dpm_complete(msg);
 429
 430  Close:
 431         platform_end(platform_mode);
 432         return error;
 433
 434  Thaw:
 435         thaw_kernel_threads();
 436  Cleanup:
 437         swsusp_free();
 438         goto Close;
 439 }
 440
 441 int __weak hibernate_resume_nonboot_cpu_disable(void)
 442 {
 443         return suspend_disable_secondary_cpus();
 444 }
 445
 446 /**
 447  * resume_target_kernel - Restore system state from a hibernation image.
 448  * @platform_mode: Whether or not to use the platform driver.
 449  *
 450  * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 451  * contents of highmem that have not been restored yet from the image and run
 452  * the low-level code that will restore the remaining contents of memory and
 453  * switch to the just restored target kernel.
 454  */
 455 static int resume_target_kernel(bool platform_mode)
 456 {
 457         int error;
 458
 459         error = dpm_suspend_end(PMSG_QUIESCE);
 460         if (error) {
 461                 pr_err("Some devices failed to power down, aborting resume\n");
 462                 return error;
 463         }
 464
 465         error = platform_pre_restore(platform_mode);
 466         if (error)
 467                 goto Cleanup;
 468
 469         cpuidle_pause();
 470
 471         error = hibernate_resume_nonboot_cpu_disable();
 472         if (error)
 473                 goto Enable_cpus;
 474
 475         local_irq_disable();
 476         system_state = SYSTEM_SUSPEND;
 477
 478         error = syscore_suspend();
 479         if (error)
 480                 goto Enable_irqs;
 481
 482         save_processor_state();
 483         error = restore_highmem();
 484         if (!error) {
 485                 error = swsusp_arch_resume();
 486                 /*
 487                  * The code below is only ever reached in case of a failure.
 488                  * Otherwise, execution continues at the place where
 489                  * swsusp_arch_suspend() was called.
 490                  */
 491                 BUG_ON(!error);
 492                 /*
 493                  * This call to restore_highmem() reverts the changes made by
 494                  * the previous one.
 495                  */
 496                 restore_highmem();
 497         }
 498         /*
 499          * The only reason why swsusp_arch_resume() can fail is memory being
 500          * very tight, so we have to free it as soon as we can to avoid
 501          * subsequent failures.
 502          */
 503         swsusp_free();
 504         restore_processor_state();
 505         touch_softlockup_watchdog();
 506
 507         syscore_resume();
 508
 509  Enable_irqs:
 510         system_state = SYSTEM_RUNNING;
 511         local_irq_enable();
 512
 513  Enable_cpus:
 514         pm_sleep_enable_secondary_cpus();
 515
 516  Cleanup:
 517         platform_restore_cleanup(platform_mode);
 518
 519         dpm_resume_start(PMSG_RECOVER);
 520
 521         return error;
 522 }
 523
 524 /**
 525  * hibernation_restore - Quiesce devices and restore from a hibernation image.
 526  * @platform_mode: If set, use platform driver to prepare for the transition.
 527  *
 528  * This routine must be called with system_transition_mutex held.  If it is
 529  * successful, control reappears in the restored target kernel in
 530  * hibernation_snapshot().
 531  */
 532 int hibernation_restore(int platform_mode)
 533 {
 534         int error;
 535
 536         pm_prepare_console();
 537         suspend_console();
 538         pm_restrict_gfp_mask();
 539         error = dpm_suspend_start(PMSG_QUIESCE);
 540         if (!error) {
 541                 error = resume_target_kernel(platform_mode);
 542                 /*
 543                  * The above should either succeed and jump to the new kernel,
 544                  * or return with an error. Otherwise things are just
 545                  * undefined, so let's be paranoid.
 546                  */
 547                 BUG_ON(!error);
 548         }
 549         dpm_resume_end(PMSG_RECOVER);
 550         pm_restore_gfp_mask();
 551         resume_console();
 552         pm_restore_console();
 553         return error;
 554 }
 555
 556 /**
 557  * hibernation_platform_enter - Power off the system using the platform driver.
 558  */
 559 int hibernation_platform_enter(void)
 560 {
 561         int error;
 562
 563         if (!hibernation_ops)
 564                 return -ENOSYS;
 565
 566         /*
 567          * We have cancelled the power transition by running
 568          * hibernation_ops->finish() before saving the image, so we should let
 569          * the firmware know that we're going to enter the sleep state after all
 570          */
 571         error = hibernation_ops->begin(PMSG_HIBERNATE);
 572         if (error)
 573                 goto Close;
 574
 575         entering_platform_hibernation = true;
 576         suspend_console();
 577         error = dpm_suspend_start(PMSG_HIBERNATE);
 578         if (error) {
 579                 if (hibernation_ops->recover)
 580                         hibernation_ops->recover();
 581                 goto Resume_devices;
 582         }
 583
 584         error = dpm_suspend_end(PMSG_HIBERNATE);
 585         if (error)
 586                 goto Resume_devices;
 587
 588         error = hibernation_ops->prepare();
 589         if (error)
 590                 goto Platform_finish;
 591
 592         error = pm_sleep_disable_secondary_cpus();
 593         if (error)
 594                 goto Enable_cpus;
 595
 596         local_irq_disable();
 597         system_state = SYSTEM_SUSPEND;
 598         syscore_suspend();
 599         if (pm_wakeup_pending()) {
 600                 error = -EAGAIN;
 601                 goto Power_up;
 602         }
 603
 604         hibernation_ops->enter();
 605         /* We should never get here */
 606         while (1);
 607
 608  Power_up:
 609         syscore_resume();
 610         system_state = SYSTEM_RUNNING;
 611         local_irq_enable();
 612
 613  Enable_cpus:
 614         pm_sleep_enable_secondary_cpus();
 615
 616  Platform_finish:
 617         hibernation_ops->finish();
 618
 619         dpm_resume_start(PMSG_RESTORE);
 620
 621  Resume_devices:
 622         entering_platform_hibernation = false;
 623         dpm_resume_end(PMSG_RESTORE);
 624         resume_console();
 625
 626  Close:
 627         hibernation_ops->end();
 628
 629         return error;
 630 }
 631
 632 /**
 633  * power_down - Shut the machine down for hibernation.
 634  *
 635  * Use the platform driver, if configured, to put the system into the sleep
 636  * state corresponding to hibernation, or try to power it off or reboot,
 637  * depending on the value of hibernation_mode.
 638  */
 639 static void power_down(void)
 640 {
 641 #ifdef CONFIG_SUSPEND
 642         int error;
 643
 644         if (hibernation_mode == HIBERNATION_SUSPEND) {
 645                 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
 646                 if (error) {
 647                         hibernation_mode = hibernation_ops ?
 648                                                 HIBERNATION_PLATFORM :
 649                                                 HIBERNATION_SHUTDOWN;
 650                 } else {
 651                         /* Restore swap signature. */
 652                         error = swsusp_unmark();
 653                         if (error)
 654                                 pr_err("Swap will be unusable! Try swapon -a.\n");
 655
 656                         return;
 657                 }
 658         }
 659 #endif
 660
 661         switch (hibernation_mode) {
 662         case HIBERNATION_REBOOT:
 663                 kernel_restart(NULL);
 664                 break;
 665         case HIBERNATION_PLATFORM:
 666                 hibernation_platform_enter();
 667                 fallthrough;
 668         case HIBERNATION_SHUTDOWN:
 669                 if (pm_power_off)
 670                         kernel_power_off();
 671                 break;
 672         }
 673         kernel_halt();
 674         /*
 675          * Valid image is on the disk, if we continue we risk serious data
 676          * corruption after resume.
 677          */
 678         pr_crit("Power down manually\n");
 679         while (1)
 680                 cpu_relax();
 681 }
 682
 683 static int load_image_and_restore(void)
 684 {
 685         int error;
 686         unsigned int flags;
 687
 688         pm_pr_dbg("Loading hibernation image.\n");
 689
 690         lock_device_hotplug();
 691         error = create_basic_memory_bitmaps();
 692         if (error)
 693                 goto Unlock;
 694
 695         error = swsusp_read(&flags);
 696         swsusp_close(FMODE_READ);
 697         if (!error)
 698                 error = hibernation_restore(flags & SF_PLATFORM_MODE);
 699
 700         pr_err("Failed to load image, recovering.\n");
 701         swsusp_free();
 702         free_basic_memory_bitmaps();
 703  Unlock:
 704         unlock_device_hotplug();
 705
 706         return error;
 707 }
 708
 709 /**
 710  * hibernate - Carry out system hibernation, including saving the image.
 711  */
 712 int hibernate(void)
 713 {
 714         bool snapshot_test = false;
 715         int error;
 716
 717         if (!hibernation_available()) {
 718                 pm_pr_dbg("Hibernation not available.\n");
 719                 return -EPERM;
 720         }
 721
 722         lock_system_sleep();
 723         /* The snapshot device should not be opened while we're running */
 724         if (!hibernate_acquire()) {
 725                 error = -EBUSY;
 726                 goto Unlock;
 727         }
 728
 729         pr_info("hibernation entry\n");
 730         pm_prepare_console();
 731         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 732         if (error)
 733                 goto Restore;
 734
 735         ksys_sync_helper();
 736
 737         error = freeze_processes();
 738         if (error)
 739                 goto Exit;
 740
 741         lock_device_hotplug();
 742         /* Allocate memory management structures */
 743         error = create_basic_memory_bitmaps();
 744         if (error)
 745                 goto Thaw;
 746
 747         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 748         if (error || freezer_test_done)
 749                 goto Free_bitmaps;
 750
 751         if (in_suspend) {
 752                 unsigned int flags = 0;
 753
 754                 if (hibernation_mode == HIBERNATION_PLATFORM)
 755                         flags |= SF_PLATFORM_MODE;
 756                 if (nocompress)
 757                         flags |= SF_NOCOMPRESS_MODE;
 758                 else
 759                         flags |= SF_CRC32_MODE;
 760
 761                 pm_pr_dbg("Writing hibernation image.\n");
 762                 error = swsusp_write(flags);
 763                 swsusp_free();
 764                 if (!error) {
 765                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
 766                                 snapshot_test = true;
 767                         else
 768                                 power_down();
 769                 }
 770                 in_suspend = 0;
 771                 pm_restore_gfp_mask();
 772         } else {
 773                 pm_pr_dbg("Hibernation image restored successfully.\n");
 774         }
 775
 776  Free_bitmaps:
 777         free_basic_memory_bitmaps();
 778  Thaw:
 779         unlock_device_hotplug();
 780         if (snapshot_test) {
 781                 pm_pr_dbg("Checking hibernation image\n");
 782                 error = swsusp_check();
 783                 if (!error)
 784                         error = load_image_and_restore();
 785         }
 786         thaw_processes();
 787
 788         /* Don't bother checking whether freezer_test_done is true */
 789         freezer_test_done = false;
 790  Exit:
 791         pm_notifier_call_chain(PM_POST_HIBERNATION);
 792  Restore:
 793         pm_restore_console();
 794         hibernate_release();
 795  Unlock:
 796         unlock_system_sleep();
 797         pr_info("hibernation exit\n");
 798
 799         return error;
 800 }
 801
 802 /**
 803  * hibernate_quiet_exec - Execute a function with all devices frozen.
 804  * @func: Function to execute.
 805  * @data: Data pointer to pass to @func.
 806  *
 807  * Return the @func return value or an error code if it cannot be executed.
 808  */
 809 int hibernate_quiet_exec(int (*func)(void *data), void *data)
 810 {
 811         int error;
 812
 813         lock_system_sleep();
 814
 815         if (!hibernate_acquire()) {
 816                 error = -EBUSY;
 817                 goto unlock;
 818         }
 819
 820         pm_prepare_console();
 821
 822         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 823         if (error)
 824                 goto restore;
 825
 826         error = freeze_processes();
 827         if (error)
 828                 goto exit;
 829
 830         lock_device_hotplug();
 831
 832         pm_suspend_clear_flags();
 833
 834         error = platform_begin(true);
 835         if (error)
 836                 goto thaw;
 837
 838         error = freeze_kernel_threads();
 839         if (error)
 840                 goto thaw;
 841
 842         error = dpm_prepare(PMSG_FREEZE);
 843         if (error)
 844                 goto dpm_complete;
 845
 846         suspend_console();
 847
 848         error = dpm_suspend(PMSG_FREEZE);
 849         if (error)
 850                 goto dpm_resume;
 851
 852         error = dpm_suspend_end(PMSG_FREEZE);
 853         if (error)
 854                 goto dpm_resume;
 855
 856         error = platform_pre_snapshot(true);
 857         if (error)
 858                 goto skip;
 859
 860         error = func(data);
 861
 862 skip:
 863         platform_finish(true);
 864
 865         dpm_resume_start(PMSG_THAW);
 866
 867 dpm_resume:
 868         dpm_resume(PMSG_THAW);
 869
 870         resume_console();
 871
 872 dpm_complete:
 873         dpm_complete(PMSG_THAW);
 874
 875         thaw_kernel_threads();
 876
 877 thaw:
 878         platform_end(true);
 879
 880         unlock_device_hotplug();
 881
 882         thaw_processes();
 883
 884 exit:
 885         pm_notifier_call_chain(PM_POST_HIBERNATION);
 886
 887 restore:
 888         pm_restore_console();
 889
 890         hibernate_release();
 891
 892 unlock:
 893         unlock_system_sleep();
 894
 895         return error;
 896 }
 897 EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 898
 899 /**
 900  * software_resume - Resume from a saved hibernation image.
 901  *
 902  * This routine is called as a late initcall, when all devices have been
 903  * discovered and initialized already.
 904  *
 905  * The image reading code is called to see if there is a hibernation image
 906  * available for reading.  If that is the case, devices are quiesced and the
 907  * contents of memory is restored from the saved image.
 908  *
 909  * If this is successful, control reappears in the restored target kernel in
 910  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 911  * attempts to recover gracefully and make the kernel return to the normal mode
 912  * of operation.
 913  */
 914 static int software_resume(void)
 915 {
 916         int error;
 917
 918         /*
 919          * If the user said "noresume".. bail out early.
 920          */
 921         if (noresume || !hibernation_available())
 922                 return 0;
 923
 924         /*
 925          * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 926          * is configured into the kernel. Since the regular hibernate
 927          * trigger path is via sysfs which takes a buffer mutex before
 928          * calling hibernate functions (which take system_transition_mutex)
 929          * this can cause lockdep to complain about a possible ABBA deadlock
 930          * which cannot happen since we're in the boot code here and
 931          * sysfs can't be invoked yet. Therefore, we use a subclass
 932          * here to avoid lockdep complaining.
 933          */
 934         mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
 935
 936         if (swsusp_resume_device)
 937                 goto Check_image;
 938
 939         if (!strlen(resume_file)) {
 940                 error = -ENOENT;
 941                 goto Unlock;
 942         }
 943
 944         pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 945
 946         if (resume_delay) {
 947                 pr_info("Waiting %dsec before reading resume device ...\n",
 948                         resume_delay);
 949                 ssleep(resume_delay);
 950         }
 951
 952         /* Check if the device is there */
 953         swsusp_resume_device = name_to_dev_t(resume_file);
 954         if (!swsusp_resume_device) {
 955                 /*
 956                  * Some device discovery might still be in progress; we need
 957                  * to wait for this to finish.
 958                  */
 959                 wait_for_device_probe();
 960
 961                 if (resume_wait) {
 962                         while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 963                                 msleep(10);
 964                         async_synchronize_full();
 965                 }
 966
 967                 swsusp_resume_device = name_to_dev_t(resume_file);
 968                 if (!swsusp_resume_device) {
 969                         error = -ENODEV;
 970                         goto Unlock;
 971                 }
 972         }
 973
 974  Check_image:
 975         pm_pr_dbg("Hibernation image partition %d:%d present\n",
 976                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 977
 978         pm_pr_dbg("Looking for hibernation image.\n");
 979         error = swsusp_check();
 980         if (error)
 981                 goto Unlock;
 982
 983         /* The snapshot device should not be opened while we're running */
 984         if (!hibernate_acquire()) {
 985                 error = -EBUSY;
 986                 swsusp_close(FMODE_READ);
 987                 goto Unlock;
 988         }
 989
 990         pr_info("resume from hibernation\n");
 991         pm_prepare_console();
 992         error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
 993         if (error)
 994                 goto Restore;
 995
 996         pm_pr_dbg("Preparing processes for hibernation restore.\n");
 997         error = freeze_processes();
 998         if (error)
 999                 goto Close_Finish;
1000
1001         error = freeze_kernel_threads();
1002         if (error) {
1003                 thaw_processes();
1004                 goto Close_Finish;
1005         }
1006
1007         error = load_image_and_restore();
1008         thaw_processes();
1009  Finish:
1010         pm_notifier_call_chain(PM_POST_RESTORE);
1011  Restore:
1012         pm_restore_console();
1013         pr_info("resume failed (%d)\n", error);
1014         hibernate_release();
1015         /* For success case, the suspend path will release the lock */
1016  Unlock:
1017         mutex_unlock(&system_transition_mutex);
1018         pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1019         return error;
1020  Close_Finish:
1021         swsusp_close(FMODE_READ);
1022         goto Finish;
1023 }
1024
1025 late_initcall_sync(software_resume);
1026
1027
1028 static const char * const hibernation_modes[] = {
1029         [HIBERNATION_PLATFORM]  = "platform",
1030         [HIBERNATION_SHUTDOWN]  = "shutdown",
1031         [HIBERNATION_REBOOT]    = "reboot",
1032 #ifdef CONFIG_SUSPEND
1033         [HIBERNATION_SUSPEND]   = "suspend",
1034 #endif
1035         [HIBERNATION_TEST_RESUME]       = "test_resume",
1036 };
1037
1038 /*
1039  * /sys/power/disk - Control hibernation mode.
1040  *
1041  * Hibernation can be handled in several ways.  There are a few different ways
1042  * to put the system into the sleep state: using the platform driver (e.g. ACPI
1043  * or other hibernation_ops), powering it off or rebooting it (for testing
1044  * mostly).
1045  *
1046  * The sysfs file /sys/power/disk provides an interface for selecting the
1047  * hibernation mode to use.  Reading from this file causes the available modes
1048  * to be printed.  There are 3 modes that can be supported:
1049  *
1050  *      'platform'
1051  *      'shutdown'
1052  *      'reboot'
1053  *
1054  * If a platform hibernation driver is in use, 'platform' will be supported
1055  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1056  * The selected option (i.e. the one corresponding to the current value of
1057  * hibernation_mode) is enclosed by a square bracket.
1058  *
1059  * To select a given hibernation mode it is necessary to write the mode's
1060  * string representation (as returned by reading from /sys/power/disk) back
1061  * into /sys/power/disk.
1062  */
1063
1064 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1065                          char *buf)
1066 {
1067         int i;
1068         char *start = buf;
1069
1070         if (!hibernation_available())
1071                 return sprintf(buf, "[disabled]\n");
1072
1073         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1074                 if (!hibernation_modes[i])
1075                         continue;
1076                 switch (i) {
1077                 case HIBERNATION_SHUTDOWN:
1078                 case HIBERNATION_REBOOT:
1079 #ifdef CONFIG_SUSPEND
1080                 case HIBERNATION_SUSPEND:
1081 #endif
1082                 case HIBERNATION_TEST_RESUME:
1083                         break;
1084                 case HIBERNATION_PLATFORM:
1085                         if (hibernation_ops)
1086                                 break;
1087                         /* not a valid mode, continue with loop */
1088                         continue;
1089                 }
1090                 if (i == hibernation_mode)
1091                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1092                 else
1093                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
1094         }
1095         buf += sprintf(buf, "\n");
1096         return buf-start;
1097 }
1098
1099 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1100                           const char *buf, size_t n)
1101 {
1102         int error = 0;
1103         int i;
1104         int len;
1105         char *p;
1106         int mode = HIBERNATION_INVALID;
1107
1108         if (!hibernation_available())
1109                 return -EPERM;
1110
1111         p = memchr(buf, '\n', n);
1112         len = p ? p - buf : n;
1113
1114         lock_system_sleep();
1115         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1116                 if (len == strlen(hibernation_modes[i])
1117                     && !strncmp(buf, hibernation_modes[i], len)) {
1118                         mode = i;
1119                         break;
1120                 }
1121         }
1122         if (mode != HIBERNATION_INVALID) {
1123                 switch (mode) {
1124                 case HIBERNATION_SHUTDOWN:
1125                 case HIBERNATION_REBOOT:
1126 #ifdef CONFIG_SUSPEND
1127                 case HIBERNATION_SUSPEND:
1128 #endif
1129                 case HIBERNATION_TEST_RESUME:
1130                         hibernation_mode = mode;
1131                         break;
1132                 case HIBERNATION_PLATFORM:
1133                         if (hibernation_ops)
1134                                 hibernation_mode = mode;
1135                         else
1136                                 error = -EINVAL;
1137                 }
1138         } else
1139                 error = -EINVAL;
1140
1141         if (!error)
1142                 pm_pr_dbg("Hibernation mode set to '%s'\n",
1143                                hibernation_modes[mode]);
1144         unlock_system_sleep();
1145         return error ? error : n;
1146 }
1147
1148 power_attr(disk);
1149
1150 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1151                            char *buf)
1152 {
1153         return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1154                        MINOR(swsusp_resume_device));
1155 }
1156
1157 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1158                             const char *buf, size_t n)
1159 {
1160         dev_t res;
1161         int len = n;
1162         char *name;
1163
1164         if (len && buf[len-1] == '\n')
1165                 len--;
1166         name = kstrndup(buf, len, GFP_KERNEL);
1167         if (!name)
1168                 return -ENOMEM;
1169
1170         res = name_to_dev_t(name);
1171         kfree(name);
1172         if (!res)
1173                 return -EINVAL;
1174
1175         lock_system_sleep();
1176         swsusp_resume_device = res;
1177         unlock_system_sleep();
1178         pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1179                   swsusp_resume_device);
1180         noresume = 0;
1181         software_resume();
1182         return n;
1183 }
1184
1185 power_attr(resume);
1186
1187 static ssize_t resume_offset_show(struct kobject *kobj,
1188                                   struct kobj_attribute *attr, char *buf)
1189 {
1190         return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1191 }
1192
1193 static ssize_t resume_offset_store(struct kobject *kobj,
1194                                    struct kobj_attribute *attr, const char *buf,
1195                                    size_t n)
1196 {
1197         unsigned long long offset;
1198         int rc;
1199
1200         rc = kstrtoull(buf, 0, &offset);
1201         if (rc)
1202                 return rc;
1203         swsusp_resume_block = offset;
1204
1205         return n;
1206 }
1207
1208 power_attr(resume_offset);
1209
1210 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1211                                char *buf)
1212 {
1213         return sprintf(buf, "%lu\n", image_size);
1214 }
1215
1216 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1217                                 const char *buf, size_t n)
1218 {
1219         unsigned long size;
1220
1221         if (sscanf(buf, "%lu", &size) == 1) {
1222                 image_size = size;
1223                 return n;
1224         }
1225
1226         return -EINVAL;
1227 }
1228
1229 power_attr(image_size);
1230
1231 static ssize_t reserved_size_show(struct kobject *kobj,
1232                                   struct kobj_attribute *attr, char *buf)
1233 {
1234         return sprintf(buf, "%lu\n", reserved_size);
1235 }
1236
1237 static ssize_t reserved_size_store(struct kobject *kobj,
1238                                    struct kobj_attribute *attr,
1239                                    const char *buf, size_t n)
1240 {
1241         unsigned long size;
1242
1243         if (sscanf(buf, "%lu", &size) == 1) {
1244                 reserved_size = size;
1245                 return n;
1246         }
1247
1248         return -EINVAL;
1249 }
1250
1251 power_attr(reserved_size);
1252
1253 static struct attribute *g[] = {
1254         &disk_attr.attr,
1255         &resume_offset_attr.attr,
1256         &resume_attr.attr,
1257         &image_size_attr.attr,
1258         &reserved_size_attr.attr,
1259         NULL,
1260 };
1261
1262
1263 static const struct attribute_group attr_group = {
1264         .attrs = g,
1265 };
1266
1267
1268 static int __init pm_disk_init(void)
1269 {
1270         return sysfs_create_group(power_kobj, &attr_group);
1271 }
1272
1273 core_initcall(pm_disk_init);
1274
1275
1276 static int __init resume_setup(char *str)
1277 {
1278         if (noresume)
1279                 return 1;
1280
1281         strncpy(resume_file, str, 255);
1282         return 1;
1283 }
1284
1285 static int __init resume_offset_setup(char *str)
1286 {
1287         unsigned long long offset;
1288
1289         if (noresume)
1290                 return 1;
1291
1292         if (sscanf(str, "%llu", &offset) == 1)
1293                 swsusp_resume_block = offset;
1294
1295         return 1;
1296 }
1297
1298 static int __init hibernate_setup(char *str)
1299 {
1300         if (!strncmp(str, "noresume", 8)) {
1301                 noresume = 1;
1302         } else if (!strncmp(str, "nocompress", 10)) {
1303                 nocompress = 1;
1304         } else if (!strncmp(str, "no", 2)) {
1305                 noresume = 1;
1306                 nohibernate = 1;
1307         } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1308                    && !strncmp(str, "protect_image", 13)) {
1309                 enable_restore_image_protection();
1310         }
1311         return 1;
1312 }
1313
1314 static int __init noresume_setup(char *str)
1315 {
1316         noresume = 1;
1317         return 1;
1318 }
1319
1320 static int __init resumewait_setup(char *str)
1321 {
1322         resume_wait = 1;
1323         return 1;
1324 }
1325
1326 static int __init resumedelay_setup(char *str)
1327 {
1328         int rc = kstrtouint(str, 0, &resume_delay);
1329
1330         if (rc)
1331                 return rc;
1332         return 1;
1333 }
1334
1335 static int __init nohibernate_setup(char *str)
1336 {
1337         noresume = 1;
1338         nohibernate = 1;
1339         return 1;
1340 }
1341
1342 __setup("noresume", noresume_setup);
1343 __setup("resume_offset=", resume_offset_setup);
1344 __setup("resume=", resume_setup);
1345 __setup("hibernate=", hibernate_setup);
1346 __setup("resumewait", resumewait_setup);
1347 __setup("resumedelay=", resumedelay_setup);
1348 __setup("nohibernate", nohibernate_setup);