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/ktime.h>
  32 #include <linux/security.h>
  33 #include <linux/secretmem.h>
  34 #include <trace/events/power.h>
  35
  36 #include "power.h"
  37
  38
  39 static int nocompress;
  40 static int noresume;
  41 static int nohibernate;
  42 static int resume_wait;
  43 static unsigned int resume_delay;
  44 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
  45 dev_t swsusp_resume_device;
  46 sector_t swsusp_resume_block;
  47 __visible int in_suspend __nosavedata;
  48
  49 enum {
  50         HIBERNATION_INVALID,
  51         HIBERNATION_PLATFORM,
  52         HIBERNATION_SHUTDOWN,
  53         HIBERNATION_REBOOT,
  54 #ifdef CONFIG_SUSPEND
  55         HIBERNATION_SUSPEND,
  56 #endif
  57         HIBERNATION_TEST_RESUME,
  58         /* keep last */
  59         __HIBERNATION_AFTER_LAST
  60 };
  61 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  62 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  63
  64 static int hibernation_mode = HIBERNATION_SHUTDOWN;
  65
  66 bool freezer_test_done;
  67
  68 static const struct platform_hibernation_ops *hibernation_ops;
  69
  70 static atomic_t hibernate_atomic = ATOMIC_INIT(1);
  71
  72 bool hibernate_acquire(void)
  73 {
  74         return atomic_add_unless(&hibernate_atomic, -1, 0);
  75 }
  76
  77 void hibernate_release(void)
  78 {
  79         atomic_inc(&hibernate_atomic);
  80 }
  81
  82 bool hibernation_available(void)
  83 {
  84         return nohibernate == 0 &&
  85                 !security_locked_down(LOCKDOWN_HIBERNATION) &&
  86                 !secretmem_active() && !cxl_mem_active();
  87 }
  88
  89 /**
  90  * hibernation_set_ops - Set the global hibernate operations.
  91  * @ops: Hibernation operations to use in subsequent hibernation transitions.
  92  */
  93 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
  94 {
  95         if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  96             && ops->prepare && ops->finish && ops->enter && ops->pre_restore
  97             && ops->restore_cleanup && ops->leave)) {
  98                 WARN_ON(1);
  99                 return;
 100         }
 101         lock_system_sleep();
 102         hibernation_ops = ops;
 103         if (ops)
 104                 hibernation_mode = HIBERNATION_PLATFORM;
 105         else if (hibernation_mode == HIBERNATION_PLATFORM)
 106                 hibernation_mode = HIBERNATION_SHUTDOWN;
 107
 108         unlock_system_sleep();
 109 }
 110 EXPORT_SYMBOL_GPL(hibernation_set_ops);
 111
 112 static bool entering_platform_hibernation;
 113
 114 bool system_entering_hibernation(void)
 115 {
 116         return entering_platform_hibernation;
 117 }
 118 EXPORT_SYMBOL(system_entering_hibernation);
 119
 120 #ifdef CONFIG_PM_DEBUG
 121 static void hibernation_debug_sleep(void)
 122 {
 123         pr_info("debug: Waiting for 5 seconds.\n");
 124         mdelay(5000);
 125 }
 126
 127 static int hibernation_test(int level)
 128 {
 129         if (pm_test_level == level) {
 130                 hibernation_debug_sleep();
 131                 return 1;
 132         }
 133         return 0;
 134 }
 135 #else /* !CONFIG_PM_DEBUG */
 136 static int hibernation_test(int level) { return 0; }
 137 #endif /* !CONFIG_PM_DEBUG */
 138
 139 /**
 140  * platform_begin - Call platform to start hibernation.
 141  * @platform_mode: Whether or not to use the platform driver.
 142  */
 143 static int platform_begin(int platform_mode)
 144 {
 145         return (platform_mode && hibernation_ops) ?
 146                 hibernation_ops->begin(PMSG_FREEZE) : 0;
 147 }
 148
 149 /**
 150  * platform_end - Call platform to finish transition to the working state.
 151  * @platform_mode: Whether or not to use the platform driver.
 152  */
 153 static void platform_end(int platform_mode)
 154 {
 155         if (platform_mode && hibernation_ops)
 156                 hibernation_ops->end();
 157 }
 158
 159 /**
 160  * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 161  * @platform_mode: Whether or not to use the platform driver.
 162  *
 163  * Use the platform driver to prepare the system for creating a hibernate image,
 164  * if so configured, and return an error code if that fails.
 165  */
 166
 167 static int platform_pre_snapshot(int platform_mode)
 168 {
 169         return (platform_mode && hibernation_ops) ?
 170                 hibernation_ops->pre_snapshot() : 0;
 171 }
 172
 173 /**
 174  * platform_leave - Call platform to prepare a transition to the working state.
 175  * @platform_mode: Whether or not to use the platform driver.
 176  *
 177  * Use the platform driver prepare to prepare the machine for switching to the
 178  * normal mode of operation.
 179  *
 180  * This routine is called on one CPU with interrupts disabled.
 181  */
 182 static void platform_leave(int platform_mode)
 183 {
 184         if (platform_mode && hibernation_ops)
 185                 hibernation_ops->leave();
 186 }
 187
 188 /**
 189  * platform_finish - Call platform to switch the system to the working state.
 190  * @platform_mode: Whether or not to use the platform driver.
 191  *
 192  * Use the platform driver to switch the machine to the normal mode of
 193  * operation.
 194  *
 195  * This routine must be called after platform_prepare().
 196  */
 197 static void platform_finish(int platform_mode)
 198 {
 199         if (platform_mode && hibernation_ops)
 200                 hibernation_ops->finish();
 201 }
 202
 203 /**
 204  * platform_pre_restore - Prepare for hibernate image restoration.
 205  * @platform_mode: Whether or not to use the platform driver.
 206  *
 207  * Use the platform driver to prepare the system for resume from a hibernation
 208  * image.
 209  *
 210  * If the restore fails after this function has been called,
 211  * platform_restore_cleanup() must be called.
 212  */
 213 static int platform_pre_restore(int platform_mode)
 214 {
 215         return (platform_mode && hibernation_ops) ?
 216                 hibernation_ops->pre_restore() : 0;
 217 }
 218
 219 /**
 220  * platform_restore_cleanup - Switch to the working state after failing restore.
 221  * @platform_mode: Whether or not to use the platform driver.
 222  *
 223  * Use the platform driver to switch the system to the normal mode of operation
 224  * after a failing restore.
 225  *
 226  * If platform_pre_restore() has been called before the failing restore, this
 227  * function must be called too, regardless of the result of
 228  * platform_pre_restore().
 229  */
 230 static void platform_restore_cleanup(int platform_mode)
 231 {
 232         if (platform_mode && hibernation_ops)
 233                 hibernation_ops->restore_cleanup();
 234 }
 235
 236 /**
 237  * platform_recover - Recover from a failure to suspend devices.
 238  * @platform_mode: Whether or not to use the platform driver.
 239  */
 240 static void platform_recover(int platform_mode)
 241 {
 242         if (platform_mode && hibernation_ops && hibernation_ops->recover)
 243                 hibernation_ops->recover();
 244 }
 245
 246 /**
 247  * swsusp_show_speed - Print time elapsed between two events during hibernation.
 248  * @start: Starting event.
 249  * @stop: Final event.
 250  * @nr_pages: Number of memory pages processed between @start and @stop.
 251  * @msg: Additional diagnostic message to print.
 252  */
 253 void swsusp_show_speed(ktime_t start, ktime_t stop,
 254                       unsigned nr_pages, char *msg)
 255 {
 256         ktime_t diff;
 257         u64 elapsed_centisecs64;
 258         unsigned int centisecs;
 259         unsigned int k;
 260         unsigned int kps;
 261
 262         diff = ktime_sub(stop, start);
 263         elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 264         centisecs = elapsed_centisecs64;
 265         if (centisecs == 0)
 266                 centisecs = 1;  /* avoid div-by-zero */
 267         k = nr_pages * (PAGE_SIZE / 1024);
 268         kps = (k * 100) / centisecs;
 269         pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 270                 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 271                 (kps % 1000) / 10);
 272 }
 273
 274 __weak int arch_resume_nosmt(void)
 275 {
 276         return 0;
 277 }
 278
 279 /**
 280  * create_image - Create a hibernation image.
 281  * @platform_mode: Whether or not to use the platform driver.
 282  *
 283  * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 284  * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 285  *
 286  * Control reappears in this routine after the subsequent restore.
 287  */
 288 static int create_image(int platform_mode)
 289 {
 290         int error;
 291
 292         error = dpm_suspend_end(PMSG_FREEZE);
 293         if (error) {
 294                 pr_err("Some devices failed to power down, aborting\n");
 295                 return error;
 296         }
 297
 298         error = platform_pre_snapshot(platform_mode);
 299         if (error || hibernation_test(TEST_PLATFORM))
 300                 goto Platform_finish;
 301
 302         error = pm_sleep_disable_secondary_cpus();
 303         if (error || hibernation_test(TEST_CPUS))
 304                 goto Enable_cpus;
 305
 306         local_irq_disable();
 307
 308         system_state = SYSTEM_SUSPEND;
 309
 310         error = syscore_suspend();
 311         if (error) {
 312                 pr_err("Some system devices failed to power down, aborting\n");
 313                 goto Enable_irqs;
 314         }
 315
 316         if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 317                 goto Power_up;
 318
 319         in_suspend = 1;
 320         save_processor_state();
 321         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 322         error = swsusp_arch_suspend();
 323         /* Restore control flow magically appears here */
 324         restore_processor_state();
 325         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 326         if (error)
 327                 pr_err("Error %d creating image\n", error);
 328
 329         if (!in_suspend) {
 330                 events_check_enabled = false;
 331                 clear_or_poison_free_pages();
 332         }
 333
 334         platform_leave(platform_mode);
 335
 336  Power_up:
 337         syscore_resume();
 338
 339  Enable_irqs:
 340         system_state = SYSTEM_RUNNING;
 341         local_irq_enable();
 342
 343  Enable_cpus:
 344         pm_sleep_enable_secondary_cpus();
 345
 346         /* Allow architectures to do nosmt-specific post-resume dances */
 347         if (!in_suspend)
 348                 error = arch_resume_nosmt();
 349
 350  Platform_finish:
 351         platform_finish(platform_mode);
 352
 353         dpm_resume_start(in_suspend ?
 354                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 355
 356         return error;
 357 }
 358
 359 /**
 360  * hibernation_snapshot - Quiesce devices and create a hibernation image.
 361  * @platform_mode: If set, use platform driver to prepare for the transition.
 362  *
 363  * This routine must be called with system_transition_mutex held.
 364  */
 365 int hibernation_snapshot(int platform_mode)
 366 {
 367         pm_message_t msg;
 368         int error;
 369
 370         pm_suspend_clear_flags();
 371         error = platform_begin(platform_mode);
 372         if (error)
 373                 goto Close;
 374
 375         /* Preallocate image memory before shutting down devices. */
 376         error = hibernate_preallocate_memory();
 377         if (error)
 378                 goto Close;
 379
 380         error = freeze_kernel_threads();
 381         if (error)
 382                 goto Cleanup;
 383
 384         if (hibernation_test(TEST_FREEZER)) {
 385
 386                 /*
 387                  * Indicate to the caller that we are returning due to a
 388                  * successful freezer test.
 389                  */
 390                 freezer_test_done = true;
 391                 goto Thaw;
 392         }
 393
 394         error = dpm_prepare(PMSG_FREEZE);
 395         if (error) {
 396                 dpm_complete(PMSG_RECOVER);
 397                 goto Thaw;
 398         }
 399
 400         suspend_console();
 401         pm_restrict_gfp_mask();
 402
 403         error = dpm_suspend(PMSG_FREEZE);
 404
 405         if (error || hibernation_test(TEST_DEVICES))
 406                 platform_recover(platform_mode);
 407         else
 408                 error = create_image(platform_mode);
 409
 410         /*
 411          * In the case that we call create_image() above, the control
 412          * returns here (1) after the image has been created or the
 413          * image creation has failed and (2) after a successful restore.
 414          */
 415
 416         /* We may need to release the preallocated image pages here. */
 417         if (error || !in_suspend)
 418                 swsusp_free();
 419
 420         msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 421         dpm_resume(msg);
 422
 423         if (error || !in_suspend)
 424                 pm_restore_gfp_mask();
 425
 426         resume_console();
 427         dpm_complete(msg);
 428
 429  Close:
 430         platform_end(platform_mode);
 431         return error;
 432
 433  Thaw:
 434         thaw_kernel_threads();
 435  Cleanup:
 436         swsusp_free();
 437         goto Close;
 438 }
 439
 440 int __weak hibernate_resume_nonboot_cpu_disable(void)
 441 {
 442         return suspend_disable_secondary_cpus();
 443 }
 444
 445 /**
 446  * resume_target_kernel - Restore system state from a hibernation image.
 447  * @platform_mode: Whether or not to use the platform driver.
 448  *
 449  * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 450  * contents of highmem that have not been restored yet from the image and run
 451  * the low-level code that will restore the remaining contents of memory and
 452  * switch to the just restored target kernel.
 453  */
 454 static int resume_target_kernel(bool platform_mode)
 455 {
 456         int error;
 457
 458         error = dpm_suspend_end(PMSG_QUIESCE);
 459         if (error) {
 460                 pr_err("Some devices failed to power down, aborting resume\n");
 461                 return error;
 462         }
 463
 464         error = platform_pre_restore(platform_mode);
 465         if (error)
 466                 goto Cleanup;
 467
 468         cpuidle_pause();
 469
 470         error = hibernate_resume_nonboot_cpu_disable();
 471         if (error)
 472                 goto Enable_cpus;
 473
 474         local_irq_disable();
 475         system_state = SYSTEM_SUSPEND;
 476
 477         error = syscore_suspend();
 478         if (error)
 479                 goto Enable_irqs;
 480
 481         save_processor_state();
 482         error = restore_highmem();
 483         if (!error) {
 484                 error = swsusp_arch_resume();
 485                 /*
 486                  * The code below is only ever reached in case of a failure.
 487                  * Otherwise, execution continues at the place where
 488                  * swsusp_arch_suspend() was called.
 489                  */
 490                 BUG_ON(!error);
 491                 /*
 492                  * This call to restore_highmem() reverts the changes made by
 493                  * the previous one.
 494                  */
 495                 restore_highmem();
 496         }
 497         /*
 498          * The only reason why swsusp_arch_resume() can fail is memory being
 499          * very tight, so we have to free it as soon as we can to avoid
 500          * subsequent failures.
 501          */
 502         swsusp_free();
 503         restore_processor_state();
 504         touch_softlockup_watchdog();
 505
 506         syscore_resume();
 507
 508  Enable_irqs:
 509         system_state = SYSTEM_RUNNING;
 510         local_irq_enable();
 511
 512  Enable_cpus:
 513         pm_sleep_enable_secondary_cpus();
 514
 515  Cleanup:
 516         platform_restore_cleanup(platform_mode);
 517
 518         dpm_resume_start(PMSG_RECOVER);
 519
 520         return error;
 521 }
 522
 523 /**
 524  * hibernation_restore - Quiesce devices and restore from a hibernation image.
 525  * @platform_mode: If set, use platform driver to prepare for the transition.
 526  *
 527  * This routine must be called with system_transition_mutex held.  If it is
 528  * successful, control reappears in the restored target kernel in
 529  * hibernation_snapshot().
 530  */
 531 int hibernation_restore(int platform_mode)
 532 {
 533         int error;
 534
 535         pm_prepare_console();
 536         suspend_console();
 537         pm_restrict_gfp_mask();
 538         error = dpm_suspend_start(PMSG_QUIESCE);
 539         if (!error) {
 540                 error = resume_target_kernel(platform_mode);
 541                 /*
 542                  * The above should either succeed and jump to the new kernel,
 543                  * or return with an error. Otherwise things are just
 544                  * undefined, so let's be paranoid.
 545                  */
 546                 BUG_ON(!error);
 547         }
 548         dpm_resume_end(PMSG_RECOVER);
 549         pm_restore_gfp_mask();
 550         resume_console();
 551         pm_restore_console();
 552         return error;
 553 }
 554
 555 /**
 556  * hibernation_platform_enter - Power off the system using the platform driver.
 557  */
 558 int hibernation_platform_enter(void)
 559 {
 560         int error;
 561
 562         if (!hibernation_ops)
 563                 return -ENOSYS;
 564
 565         /*
 566          * We have cancelled the power transition by running
 567          * hibernation_ops->finish() before saving the image, so we should let
 568          * the firmware know that we're going to enter the sleep state after all
 569          */
 570         error = hibernation_ops->begin(PMSG_HIBERNATE);
 571         if (error)
 572                 goto Close;
 573
 574         entering_platform_hibernation = true;
 575         suspend_console();
 576         error = dpm_suspend_start(PMSG_HIBERNATE);
 577         if (error) {
 578                 if (hibernation_ops->recover)
 579                         hibernation_ops->recover();
 580                 goto Resume_devices;
 581         }
 582
 583         error = dpm_suspend_end(PMSG_HIBERNATE);
 584         if (error)
 585                 goto Resume_devices;
 586
 587         error = hibernation_ops->prepare();
 588         if (error)
 589                 goto Platform_finish;
 590
 591         error = pm_sleep_disable_secondary_cpus();
 592         if (error)
 593                 goto Enable_cpus;
 594
 595         local_irq_disable();
 596         system_state = SYSTEM_SUSPEND;
 597         syscore_suspend();
 598         if (pm_wakeup_pending()) {
 599                 error = -EAGAIN;
 600                 goto Power_up;
 601         }
 602
 603         hibernation_ops->enter();
 604         /* We should never get here */
 605         while (1);
 606
 607  Power_up:
 608         syscore_resume();
 609         system_state = SYSTEM_RUNNING;
 610         local_irq_enable();
 611
 612  Enable_cpus:
 613         pm_sleep_enable_secondary_cpus();
 614
 615  Platform_finish:
 616         hibernation_ops->finish();
 617
 618         dpm_resume_start(PMSG_RESTORE);
 619
 620  Resume_devices:
 621         entering_platform_hibernation = false;
 622         dpm_resume_end(PMSG_RESTORE);
 623         resume_console();
 624
 625  Close:
 626         hibernation_ops->end();
 627
 628         return error;
 629 }
 630
 631 /**
 632  * power_down - Shut the machine down for hibernation.
 633  *
 634  * Use the platform driver, if configured, to put the system into the sleep
 635  * state corresponding to hibernation, or try to power it off or reboot,
 636  * depending on the value of hibernation_mode.
 637  */
 638 static void power_down(void)
 639 {
 640 #ifdef CONFIG_SUSPEND
 641         int error;
 642
 643         if (hibernation_mode == HIBERNATION_SUSPEND) {
 644                 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
 645                 if (error) {
 646                         hibernation_mode = hibernation_ops ?
 647                                                 HIBERNATION_PLATFORM :
 648                                                 HIBERNATION_SHUTDOWN;
 649                 } else {
 650                         /* Restore swap signature. */
 651                         error = swsusp_unmark();
 652                         if (error)
 653                                 pr_err("Swap will be unusable! Try swapon -a.\n");
 654
 655                         return;
 656                 }
 657         }
 658 #endif
 659
 660         switch (hibernation_mode) {
 661         case HIBERNATION_REBOOT:
 662                 kernel_restart(NULL);
 663                 break;
 664         case HIBERNATION_PLATFORM:
 665                 hibernation_platform_enter();
 666                 fallthrough;
 667         case HIBERNATION_SHUTDOWN:
 668                 if (kernel_can_power_off())
 669                         kernel_power_off();
 670                 break;
 671         }
 672         kernel_halt();
 673         /*
 674          * Valid image is on the disk, if we continue we risk serious data
 675          * corruption after resume.
 676          */
 677         pr_crit("Power down manually\n");
 678         while (1)
 679                 cpu_relax();
 680 }
 681
 682 static int load_image_and_restore(void)
 683 {
 684         int error;
 685         unsigned int flags;
 686
 687         pm_pr_dbg("Loading hibernation image.\n");
 688
 689         lock_device_hotplug();
 690         error = create_basic_memory_bitmaps();
 691         if (error) {
 692                 swsusp_close(FMODE_READ | FMODE_EXCL);
 693                 goto Unlock;
 694         }
 695
 696         error = swsusp_read(&flags);
 697         swsusp_close(FMODE_READ | FMODE_EXCL);
 698         if (!error)
 699                 error = hibernation_restore(flags & SF_PLATFORM_MODE);
 700
 701         pr_err("Failed to load image, recovering.\n");
 702         swsusp_free();
 703         free_basic_memory_bitmaps();
 704  Unlock:
 705         unlock_device_hotplug();
 706
 707         return error;
 708 }
 709
 710 /**
 711  * hibernate - Carry out system hibernation, including saving the image.
 712  */
 713 int hibernate(void)
 714 {
 715         bool snapshot_test = false;
 716         int error;
 717
 718         if (!hibernation_available()) {
 719                 pm_pr_dbg("Hibernation not available.\n");
 720                 return -EPERM;
 721         }
 722
 723         lock_system_sleep();
 724         /* The snapshot device should not be opened while we're running */
 725         if (!hibernate_acquire()) {
 726                 error = -EBUSY;
 727                 goto Unlock;
 728         }
 729
 730         pr_info("hibernation entry\n");
 731         pm_prepare_console();
 732         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 733         if (error)
 734                 goto Restore;
 735
 736         ksys_sync_helper();
 737
 738         error = freeze_processes();
 739         if (error)
 740                 goto Exit;
 741
 742         lock_device_hotplug();
 743         /* Allocate memory management structures */
 744         error = create_basic_memory_bitmaps();
 745         if (error)
 746                 goto Thaw;
 747
 748         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 749         if (error || freezer_test_done)
 750                 goto Free_bitmaps;
 751
 752         if (in_suspend) {
 753                 unsigned int flags = 0;
 754
 755                 if (hibernation_mode == HIBERNATION_PLATFORM)
 756                         flags |= SF_PLATFORM_MODE;
 757                 if (nocompress)
 758                         flags |= SF_NOCOMPRESS_MODE;
 759                 else
 760                         flags |= SF_CRC32_MODE;
 761
 762                 pm_pr_dbg("Writing hibernation image.\n");
 763                 error = swsusp_write(flags);
 764                 swsusp_free();
 765                 if (!error) {
 766                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
 767                                 snapshot_test = true;
 768                         else
 769                                 power_down();
 770                 }
 771                 in_suspend = 0;
 772                 pm_restore_gfp_mask();
 773         } else {
 774                 pm_pr_dbg("Hibernation image restored successfully.\n");
 775         }
 776
 777  Free_bitmaps:
 778         free_basic_memory_bitmaps();
 779  Thaw:
 780         unlock_device_hotplug();
 781         if (snapshot_test) {
 782                 pm_pr_dbg("Checking hibernation image\n");
 783                 error = swsusp_check();
 784                 if (!error)
 785                         error = load_image_and_restore();
 786         }
 787         thaw_processes();
 788
 789         /* Don't bother checking whether freezer_test_done is true */
 790         freezer_test_done = false;
 791  Exit:
 792         pm_notifier_call_chain(PM_POST_HIBERNATION);
 793  Restore:
 794         pm_restore_console();
 795         hibernate_release();
 796  Unlock:
 797         unlock_system_sleep();
 798         pr_info("hibernation exit\n");
 799
 800         return error;
 801 }
 802
 803 /**
 804  * hibernate_quiet_exec - Execute a function with all devices frozen.
 805  * @func: Function to execute.
 806  * @data: Data pointer to pass to @func.
 807  *
 808  * Return the @func return value or an error code if it cannot be executed.
 809  */
 810 int hibernate_quiet_exec(int (*func)(void *data), void *data)
 811 {
 812         int error;
 813
 814         lock_system_sleep();
 815
 816         if (!hibernate_acquire()) {
 817                 error = -EBUSY;
 818                 goto unlock;
 819         }
 820
 821         pm_prepare_console();
 822
 823         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 824         if (error)
 825                 goto restore;
 826
 827         error = freeze_processes();
 828         if (error)
 829                 goto exit;
 830
 831         lock_device_hotplug();
 832
 833         pm_suspend_clear_flags();
 834
 835         error = platform_begin(true);
 836         if (error)
 837                 goto thaw;
 838
 839         error = freeze_kernel_threads();
 840         if (error)
 841                 goto thaw;
 842
 843         error = dpm_prepare(PMSG_FREEZE);
 844         if (error)
 845                 goto dpm_complete;
 846
 847         suspend_console();
 848
 849         error = dpm_suspend(PMSG_FREEZE);
 850         if (error)
 851                 goto dpm_resume;
 852
 853         error = dpm_suspend_end(PMSG_FREEZE);
 854         if (error)
 855                 goto dpm_resume;
 856
 857         error = platform_pre_snapshot(true);
 858         if (error)
 859                 goto skip;
 860
 861         error = func(data);
 862
 863 skip:
 864         platform_finish(true);
 865
 866         dpm_resume_start(PMSG_THAW);
 867
 868 dpm_resume:
 869         dpm_resume(PMSG_THAW);
 870
 871         resume_console();
 872
 873 dpm_complete:
 874         dpm_complete(PMSG_THAW);
 875
 876         thaw_kernel_threads();
 877
 878 thaw:
 879         platform_end(true);
 880
 881         unlock_device_hotplug();
 882
 883         thaw_processes();
 884
 885 exit:
 886         pm_notifier_call_chain(PM_POST_HIBERNATION);
 887
 888 restore:
 889         pm_restore_console();
 890
 891         hibernate_release();
 892
 893 unlock:
 894         unlock_system_sleep();
 895
 896         return error;
 897 }
 898 EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 899
 900 /**
 901  * software_resume - Resume from a saved hibernation image.
 902  *
 903  * This routine is called as a late initcall, when all devices have been
 904  * discovered and initialized already.
 905  *
 906  * The image reading code is called to see if there is a hibernation image
 907  * available for reading.  If that is the case, devices are quiesced and the
 908  * contents of memory is restored from the saved image.
 909  *
 910  * If this is successful, control reappears in the restored target kernel in
 911  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 912  * attempts to recover gracefully and make the kernel return to the normal mode
 913  * of operation.
 914  */
 915 static int software_resume(void)
 916 {
 917         int error;
 918
 919         /*
 920          * If the user said "noresume".. bail out early.
 921          */
 922         if (noresume || !hibernation_available())
 923                 return 0;
 924
 925         /*
 926          * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 927          * is configured into the kernel. Since the regular hibernate
 928          * trigger path is via sysfs which takes a buffer mutex before
 929          * calling hibernate functions (which take system_transition_mutex)
 930          * this can cause lockdep to complain about a possible ABBA deadlock
 931          * which cannot happen since we're in the boot code here and
 932          * sysfs can't be invoked yet. Therefore, we use a subclass
 933          * here to avoid lockdep complaining.
 934          */
 935         mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
 936
 937         if (swsusp_resume_device)
 938                 goto Check_image;
 939
 940         if (!strlen(resume_file)) {
 941                 error = -ENOENT;
 942                 goto Unlock;
 943         }
 944
 945         pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 946
 947         if (resume_delay) {
 948                 pr_info("Waiting %dsec before reading resume device ...\n",
 949                         resume_delay);
 950                 ssleep(resume_delay);
 951         }
 952
 953         /* Check if the device is there */
 954         swsusp_resume_device = name_to_dev_t(resume_file);
 955         if (!swsusp_resume_device) {
 956                 /*
 957                  * Some device discovery might still be in progress; we need
 958                  * to wait for this to finish.
 959                  */
 960                 wait_for_device_probe();
 961
 962                 if (resume_wait) {
 963                         while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 964                                 msleep(10);
 965                         async_synchronize_full();
 966                 }
 967
 968                 swsusp_resume_device = name_to_dev_t(resume_file);
 969                 if (!swsusp_resume_device) {
 970                         error = -ENODEV;
 971                         goto Unlock;
 972                 }
 973         }
 974
 975  Check_image:
 976         pm_pr_dbg("Hibernation image partition %d:%d present\n",
 977                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 978
 979         pm_pr_dbg("Looking for hibernation image.\n");
 980         error = swsusp_check();
 981         if (error)
 982                 goto Unlock;
 983
 984         /* The snapshot device should not be opened while we're running */
 985         if (!hibernate_acquire()) {
 986                 error = -EBUSY;
 987                 swsusp_close(FMODE_READ | FMODE_EXCL);
 988                 goto Unlock;
 989         }
 990
 991         pr_info("resume from hibernation\n");
 992         pm_prepare_console();
 993         error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
 994         if (error)
 995                 goto Restore;
 996
 997         pm_pr_dbg("Preparing processes for hibernation restore.\n");
 998         error = freeze_processes();
 999         if (error)
1000                 goto Close_Finish;
1001
1002         error = freeze_kernel_threads();
1003         if (error) {
1004                 thaw_processes();
1005                 goto Close_Finish;
1006         }
1007
1008         error = load_image_and_restore();
1009         thaw_processes();
1010  Finish:
1011         pm_notifier_call_chain(PM_POST_RESTORE);
1012  Restore:
1013         pm_restore_console();
1014         pr_info("resume failed (%d)\n", error);
1015         hibernate_release();
1016         /* For success case, the suspend path will release the lock */
1017  Unlock:
1018         mutex_unlock(&system_transition_mutex);
1019         pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1020         return error;
1021  Close_Finish:
1022         swsusp_close(FMODE_READ | FMODE_EXCL);
1023         goto Finish;
1024 }
1025
1026 late_initcall_sync(software_resume);
1027
1028
1029 static const char * const hibernation_modes[] = {
1030         [HIBERNATION_PLATFORM]  = "platform",
1031         [HIBERNATION_SHUTDOWN]  = "shutdown",
1032         [HIBERNATION_REBOOT]    = "reboot",
1033 #ifdef CONFIG_SUSPEND
1034         [HIBERNATION_SUSPEND]   = "suspend",
1035 #endif
1036         [HIBERNATION_TEST_RESUME]       = "test_resume",
1037 };
1038
1039 /*
1040  * /sys/power/disk - Control hibernation mode.
1041  *
1042  * Hibernation can be handled in several ways.  There are a few different ways
1043  * to put the system into the sleep state: using the platform driver (e.g. ACPI
1044  * or other hibernation_ops), powering it off or rebooting it (for testing
1045  * mostly).
1046  *
1047  * The sysfs file /sys/power/disk provides an interface for selecting the
1048  * hibernation mode to use.  Reading from this file causes the available modes
1049  * to be printed.  There are 3 modes that can be supported:
1050  *
1051  *      'platform'
1052  *      'shutdown'
1053  *      'reboot'
1054  *
1055  * If a platform hibernation driver is in use, 'platform' will be supported
1056  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1057  * The selected option (i.e. the one corresponding to the current value of
1058  * hibernation_mode) is enclosed by a square bracket.
1059  *
1060  * To select a given hibernation mode it is necessary to write the mode's
1061  * string representation (as returned by reading from /sys/power/disk) back
1062  * into /sys/power/disk.
1063  */
1064
1065 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1066                          char *buf)
1067 {
1068         int i;
1069         char *start = buf;
1070
1071         if (!hibernation_available())
1072                 return sprintf(buf, "[disabled]\n");
1073
1074         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1075                 if (!hibernation_modes[i])
1076                         continue;
1077                 switch (i) {
1078                 case HIBERNATION_SHUTDOWN:
1079                 case HIBERNATION_REBOOT:
1080 #ifdef CONFIG_SUSPEND
1081                 case HIBERNATION_SUSPEND:
1082 #endif
1083                 case HIBERNATION_TEST_RESUME:
1084                         break;
1085                 case HIBERNATION_PLATFORM:
1086                         if (hibernation_ops)
1087                                 break;
1088                         /* not a valid mode, continue with loop */
1089                         continue;
1090                 }
1091                 if (i == hibernation_mode)
1092                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1093                 else
1094                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
1095         }
1096         buf += sprintf(buf, "\n");
1097         return buf-start;
1098 }
1099
1100 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1101                           const char *buf, size_t n)
1102 {
1103         int error = 0;
1104         int i;
1105         int len;
1106         char *p;
1107         int mode = HIBERNATION_INVALID;
1108
1109         if (!hibernation_available())
1110                 return -EPERM;
1111
1112         p = memchr(buf, '\n', n);
1113         len = p ? p - buf : n;
1114
1115         lock_system_sleep();
1116         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1117                 if (len == strlen(hibernation_modes[i])
1118                     && !strncmp(buf, hibernation_modes[i], len)) {
1119                         mode = i;
1120                         break;
1121                 }
1122         }
1123         if (mode != HIBERNATION_INVALID) {
1124                 switch (mode) {
1125                 case HIBERNATION_SHUTDOWN:
1126                 case HIBERNATION_REBOOT:
1127 #ifdef CONFIG_SUSPEND
1128                 case HIBERNATION_SUSPEND:
1129 #endif
1130                 case HIBERNATION_TEST_RESUME:
1131                         hibernation_mode = mode;
1132                         break;
1133                 case HIBERNATION_PLATFORM:
1134                         if (hibernation_ops)
1135                                 hibernation_mode = mode;
1136                         else
1137                                 error = -EINVAL;
1138                 }
1139         } else
1140                 error = -EINVAL;
1141
1142         if (!error)
1143                 pm_pr_dbg("Hibernation mode set to '%s'\n",
1144                                hibernation_modes[mode]);
1145         unlock_system_sleep();
1146         return error ? error : n;
1147 }
1148
1149 power_attr(disk);
1150
1151 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1152                            char *buf)
1153 {
1154         return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1155                        MINOR(swsusp_resume_device));
1156 }
1157
1158 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1159                             const char *buf, size_t n)
1160 {
1161         dev_t res;
1162         int len = n;
1163         char *name;
1164
1165         if (len && buf[len-1] == '\n')
1166                 len--;
1167         name = kstrndup(buf, len, GFP_KERNEL);
1168         if (!name)
1169                 return -ENOMEM;
1170
1171         res = name_to_dev_t(name);
1172         kfree(name);
1173         if (!res)
1174                 return -EINVAL;
1175
1176         lock_system_sleep();
1177         swsusp_resume_device = res;
1178         unlock_system_sleep();
1179         pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1180                   swsusp_resume_device);
1181         noresume = 0;
1182         software_resume();
1183         return n;
1184 }
1185
1186 power_attr(resume);
1187
1188 static ssize_t resume_offset_show(struct kobject *kobj,
1189                                   struct kobj_attribute *attr, char *buf)
1190 {
1191         return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1192 }
1193
1194 static ssize_t resume_offset_store(struct kobject *kobj,
1195                                    struct kobj_attribute *attr, const char *buf,
1196                                    size_t n)
1197 {
1198         unsigned long long offset;
1199         int rc;
1200
1201         rc = kstrtoull(buf, 0, &offset);
1202         if (rc)
1203                 return rc;
1204         swsusp_resume_block = offset;
1205
1206         return n;
1207 }
1208
1209 power_attr(resume_offset);
1210
1211 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1212                                char *buf)
1213 {
1214         return sprintf(buf, "%lu\n", image_size);
1215 }
1216
1217 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1218                                 const char *buf, size_t n)
1219 {
1220         unsigned long size;
1221
1222         if (sscanf(buf, "%lu", &size) == 1) {
1223                 image_size = size;
1224                 return n;
1225         }
1226
1227         return -EINVAL;
1228 }
1229
1230 power_attr(image_size);
1231
1232 static ssize_t reserved_size_show(struct kobject *kobj,
1233                                   struct kobj_attribute *attr, char *buf)
1234 {
1235         return sprintf(buf, "%lu\n", reserved_size);
1236 }
1237
1238 static ssize_t reserved_size_store(struct kobject *kobj,
1239                                    struct kobj_attribute *attr,
1240                                    const char *buf, size_t n)
1241 {
1242         unsigned long size;
1243
1244         if (sscanf(buf, "%lu", &size) == 1) {
1245                 reserved_size = size;
1246                 return n;
1247         }
1248
1249         return -EINVAL;
1250 }
1251
1252 power_attr(reserved_size);
1253
1254 static struct attribute *g[] = {
1255         &disk_attr.attr,
1256         &resume_offset_attr.attr,
1257         &resume_attr.attr,
1258         &image_size_attr.attr,
1259         &reserved_size_attr.attr,
1260         NULL,
1261 };
1262
1263
1264 static const struct attribute_group attr_group = {
1265         .attrs = g,
1266 };
1267
1268
1269 static int __init pm_disk_init(void)
1270 {
1271         return sysfs_create_group(power_kobj, &attr_group);
1272 }
1273
1274 core_initcall(pm_disk_init);
1275
1276
1277 static int __init resume_setup(char *str)
1278 {
1279         if (noresume)
1280                 return 1;
1281
1282         strncpy(resume_file, str, 255);
1283         return 1;
1284 }
1285
1286 static int __init resume_offset_setup(char *str)
1287 {
1288         unsigned long long offset;
1289
1290         if (noresume)
1291                 return 1;
1292
1293         if (sscanf(str, "%llu", &offset) == 1)
1294                 swsusp_resume_block = offset;
1295
1296         return 1;
1297 }
1298
1299 static int __init hibernate_setup(char *str)
1300 {
1301         if (!strncmp(str, "noresume", 8)) {
1302                 noresume = 1;
1303         } else if (!strncmp(str, "nocompress", 10)) {
1304                 nocompress = 1;
1305         } else if (!strncmp(str, "no", 2)) {
1306                 noresume = 1;
1307                 nohibernate = 1;
1308         } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1309                    && !strncmp(str, "protect_image", 13)) {
1310                 enable_restore_image_protection();
1311         }
1312         return 1;
1313 }
1314
1315 static int __init noresume_setup(char *str)
1316 {
1317         noresume = 1;
1318         return 1;
1319 }
1320
1321 static int __init resumewait_setup(char *str)
1322 {
1323         resume_wait = 1;
1324         return 1;
1325 }
1326
1327 static int __init resumedelay_setup(char *str)
1328 {
1329         int rc = kstrtouint(str, 0, &resume_delay);
1330
1331         if (rc)
1332                 pr_warn("resumedelay: bad option string '%s'\n", str);
1333         return 1;
1334 }
1335
1336 static int __init nohibernate_setup(char *str)
1337 {
1338         noresume = 1;
1339         nohibernate = 1;
1340         return 1;
1341 }
1342
1343 __setup("noresume", noresume_setup);
1344 __setup("resume_offset=", resume_offset_setup);
1345 __setup("resume=", resume_setup);
1346 __setup("hibernate=", hibernate_setup);
1347 __setup("resumewait", resumewait_setup);
1348 __setup("resumedelay=", resumedelay_setup);
1349 __setup("nohibernate", nohibernate_setup);