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 bool snapshot_test;
  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() && !cxl_mem_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         unsigned int sleep_flags;
  97
  98         if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  99             && ops->prepare && ops->finish && ops->enter && ops->pre_restore
 100             && ops->restore_cleanup && ops->leave)) {
 101                 WARN_ON(1);
 102                 return;
 103         }
 104
 105         sleep_flags = lock_system_sleep();
 106
 107         hibernation_ops = ops;
 108         if (ops)
 109                 hibernation_mode = HIBERNATION_PLATFORM;
 110         else if (hibernation_mode == HIBERNATION_PLATFORM)
 111                 hibernation_mode = HIBERNATION_SHUTDOWN;
 112
 113         unlock_system_sleep(sleep_flags);
 114 }
 115 EXPORT_SYMBOL_GPL(hibernation_set_ops);
 116
 117 static bool entering_platform_hibernation;
 118
 119 bool system_entering_hibernation(void)
 120 {
 121         return entering_platform_hibernation;
 122 }
 123 EXPORT_SYMBOL(system_entering_hibernation);
 124
 125 #ifdef CONFIG_PM_DEBUG
 126 static void hibernation_debug_sleep(void)
 127 {
 128         pr_info("debug: Waiting for 5 seconds.\n");
 129         mdelay(5000);
 130 }
 131
 132 static int hibernation_test(int level)
 133 {
 134         if (pm_test_level == level) {
 135                 hibernation_debug_sleep();
 136                 return 1;
 137         }
 138         return 0;
 139 }
 140 #else /* !CONFIG_PM_DEBUG */
 141 static int hibernation_test(int level) { return 0; }
 142 #endif /* !CONFIG_PM_DEBUG */
 143
 144 /**
 145  * platform_begin - Call platform to start hibernation.
 146  * @platform_mode: Whether or not to use the platform driver.
 147  */
 148 static int platform_begin(int platform_mode)
 149 {
 150         return (platform_mode && hibernation_ops) ?
 151                 hibernation_ops->begin(PMSG_FREEZE) : 0;
 152 }
 153
 154 /**
 155  * platform_end - Call platform to finish transition to the working state.
 156  * @platform_mode: Whether or not to use the platform driver.
 157  */
 158 static void platform_end(int platform_mode)
 159 {
 160         if (platform_mode && hibernation_ops)
 161                 hibernation_ops->end();
 162 }
 163
 164 /**
 165  * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 166  * @platform_mode: Whether or not to use the platform driver.
 167  *
 168  * Use the platform driver to prepare the system for creating a hibernate image,
 169  * if so configured, and return an error code if that fails.
 170  */
 171
 172 static int platform_pre_snapshot(int platform_mode)
 173 {
 174         return (platform_mode && hibernation_ops) ?
 175                 hibernation_ops->pre_snapshot() : 0;
 176 }
 177
 178 /**
 179  * platform_leave - Call platform to prepare a transition to the working state.
 180  * @platform_mode: Whether or not to use the platform driver.
 181  *
 182  * Use the platform driver prepare to prepare the machine for switching to the
 183  * normal mode of operation.
 184  *
 185  * This routine is called on one CPU with interrupts disabled.
 186  */
 187 static void platform_leave(int platform_mode)
 188 {
 189         if (platform_mode && hibernation_ops)
 190                 hibernation_ops->leave();
 191 }
 192
 193 /**
 194  * platform_finish - Call platform to switch the system to the working state.
 195  * @platform_mode: Whether or not to use the platform driver.
 196  *
 197  * Use the platform driver to switch the machine to the normal mode of
 198  * operation.
 199  *
 200  * This routine must be called after platform_prepare().
 201  */
 202 static void platform_finish(int platform_mode)
 203 {
 204         if (platform_mode && hibernation_ops)
 205                 hibernation_ops->finish();
 206 }
 207
 208 /**
 209  * platform_pre_restore - Prepare for hibernate image restoration.
 210  * @platform_mode: Whether or not to use the platform driver.
 211  *
 212  * Use the platform driver to prepare the system for resume from a hibernation
 213  * image.
 214  *
 215  * If the restore fails after this function has been called,
 216  * platform_restore_cleanup() must be called.
 217  */
 218 static int platform_pre_restore(int platform_mode)
 219 {
 220         return (platform_mode && hibernation_ops) ?
 221                 hibernation_ops->pre_restore() : 0;
 222 }
 223
 224 /**
 225  * platform_restore_cleanup - Switch to the working state after failing restore.
 226  * @platform_mode: Whether or not to use the platform driver.
 227  *
 228  * Use the platform driver to switch the system to the normal mode of operation
 229  * after a failing restore.
 230  *
 231  * If platform_pre_restore() has been called before the failing restore, this
 232  * function must be called too, regardless of the result of
 233  * platform_pre_restore().
 234  */
 235 static void platform_restore_cleanup(int platform_mode)
 236 {
 237         if (platform_mode && hibernation_ops)
 238                 hibernation_ops->restore_cleanup();
 239 }
 240
 241 /**
 242  * platform_recover - Recover from a failure to suspend devices.
 243  * @platform_mode: Whether or not to use the platform driver.
 244  */
 245 static void platform_recover(int platform_mode)
 246 {
 247         if (platform_mode && hibernation_ops && hibernation_ops->recover)
 248                 hibernation_ops->recover();
 249 }
 250
 251 /**
 252  * swsusp_show_speed - Print time elapsed between two events during hibernation.
 253  * @start: Starting event.
 254  * @stop: Final event.
 255  * @nr_pages: Number of memory pages processed between @start and @stop.
 256  * @msg: Additional diagnostic message to print.
 257  */
 258 void swsusp_show_speed(ktime_t start, ktime_t stop,
 259                       unsigned nr_pages, char *msg)
 260 {
 261         ktime_t diff;
 262         u64 elapsed_centisecs64;
 263         unsigned int centisecs;
 264         unsigned int k;
 265         unsigned int kps;
 266
 267         diff = ktime_sub(stop, start);
 268         elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 269         centisecs = elapsed_centisecs64;
 270         if (centisecs == 0)
 271                 centisecs = 1;  /* avoid div-by-zero */
 272         k = nr_pages * (PAGE_SIZE / 1024);
 273         kps = (k * 100) / centisecs;
 274         pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 275                 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 276                 (kps % 1000) / 10);
 277 }
 278
 279 __weak int arch_resume_nosmt(void)
 280 {
 281         return 0;
 282 }
 283
 284 /**
 285  * create_image - Create a hibernation image.
 286  * @platform_mode: Whether or not to use the platform driver.
 287  *
 288  * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 289  * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 290  *
 291  * Control reappears in this routine after the subsequent restore.
 292  */
 293 static int create_image(int platform_mode)
 294 {
 295         int error;
 296
 297         error = dpm_suspend_end(PMSG_FREEZE);
 298         if (error) {
 299                 pr_err("Some devices failed to power down, aborting\n");
 300                 return error;
 301         }
 302
 303         error = platform_pre_snapshot(platform_mode);
 304         if (error || hibernation_test(TEST_PLATFORM))
 305                 goto Platform_finish;
 306
 307         error = pm_sleep_disable_secondary_cpus();
 308         if (error || hibernation_test(TEST_CPUS))
 309                 goto Enable_cpus;
 310
 311         local_irq_disable();
 312
 313         system_state = SYSTEM_SUSPEND;
 314
 315         error = syscore_suspend();
 316         if (error) {
 317                 pr_err("Some system devices failed to power down, aborting\n");
 318                 goto Enable_irqs;
 319         }
 320
 321         if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 322                 goto Power_up;
 323
 324         in_suspend = 1;
 325         save_processor_state();
 326         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 327         error = swsusp_arch_suspend();
 328         /* Restore control flow magically appears here */
 329         restore_processor_state();
 330         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 331         if (error)
 332                 pr_err("Error %d creating image\n", error);
 333
 334         if (!in_suspend) {
 335                 events_check_enabled = false;
 336                 clear_or_poison_free_pages();
 337         }
 338
 339         platform_leave(platform_mode);
 340
 341  Power_up:
 342         syscore_resume();
 343
 344  Enable_irqs:
 345         system_state = SYSTEM_RUNNING;
 346         local_irq_enable();
 347
 348  Enable_cpus:
 349         pm_sleep_enable_secondary_cpus();
 350
 351         /* Allow architectures to do nosmt-specific post-resume dances */
 352         if (!in_suspend)
 353                 error = arch_resume_nosmt();
 354
 355  Platform_finish:
 356         platform_finish(platform_mode);
 357
 358         dpm_resume_start(in_suspend ?
 359                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 360
 361         return error;
 362 }
 363
 364 /**
 365  * hibernation_snapshot - Quiesce devices and create a hibernation image.
 366  * @platform_mode: If set, use platform driver to prepare for the transition.
 367  *
 368  * This routine must be called with system_transition_mutex held.
 369  */
 370 int hibernation_snapshot(int platform_mode)
 371 {
 372         pm_message_t msg;
 373         int error;
 374
 375         pm_suspend_clear_flags();
 376         error = platform_begin(platform_mode);
 377         if (error)
 378                 goto Close;
 379
 380         /* Preallocate image memory before shutting down devices. */
 381         error = hibernate_preallocate_memory();
 382         if (error)
 383                 goto Close;
 384
 385         error = freeze_kernel_threads();
 386         if (error)
 387                 goto Cleanup;
 388
 389         if (hibernation_test(TEST_FREEZER)) {
 390
 391                 /*
 392                  * Indicate to the caller that we are returning due to a
 393                  * successful freezer test.
 394                  */
 395                 freezer_test_done = true;
 396                 goto Thaw;
 397         }
 398
 399         error = dpm_prepare(PMSG_FREEZE);
 400         if (error) {
 401                 dpm_complete(PMSG_RECOVER);
 402                 goto Thaw;
 403         }
 404
 405         suspend_console();
 406         pm_restrict_gfp_mask();
 407
 408         error = dpm_suspend(PMSG_FREEZE);
 409
 410         if (error || hibernation_test(TEST_DEVICES))
 411                 platform_recover(platform_mode);
 412         else
 413                 error = create_image(platform_mode);
 414
 415         /*
 416          * In the case that we call create_image() above, the control
 417          * returns here (1) after the image has been created or the
 418          * image creation has failed and (2) after a successful restore.
 419          */
 420
 421         /* We may need to release the preallocated image pages here. */
 422         if (error || !in_suspend)
 423                 swsusp_free();
 424
 425         msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 426         dpm_resume(msg);
 427
 428         if (error || !in_suspend)
 429                 pm_restore_gfp_mask();
 430
 431         resume_console();
 432         dpm_complete(msg);
 433
 434  Close:
 435         platform_end(platform_mode);
 436         return error;
 437
 438  Thaw:
 439         thaw_kernel_threads();
 440  Cleanup:
 441         swsusp_free();
 442         goto Close;
 443 }
 444
 445 int __weak hibernate_resume_nonboot_cpu_disable(void)
 446 {
 447         return suspend_disable_secondary_cpus();
 448 }
 449
 450 /**
 451  * resume_target_kernel - Restore system state from a hibernation image.
 452  * @platform_mode: Whether or not to use the platform driver.
 453  *
 454  * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 455  * contents of highmem that have not been restored yet from the image and run
 456  * the low-level code that will restore the remaining contents of memory and
 457  * switch to the just restored target kernel.
 458  */
 459 static int resume_target_kernel(bool platform_mode)
 460 {
 461         int error;
 462
 463         error = dpm_suspend_end(PMSG_QUIESCE);
 464         if (error) {
 465                 pr_err("Some devices failed to power down, aborting resume\n");
 466                 return error;
 467         }
 468
 469         error = platform_pre_restore(platform_mode);
 470         if (error)
 471                 goto Cleanup;
 472
 473         cpuidle_pause();
 474
 475         error = hibernate_resume_nonboot_cpu_disable();
 476         if (error)
 477                 goto Enable_cpus;
 478
 479         local_irq_disable();
 480         system_state = SYSTEM_SUSPEND;
 481
 482         error = syscore_suspend();
 483         if (error)
 484                 goto Enable_irqs;
 485
 486         save_processor_state();
 487         error = restore_highmem();
 488         if (!error) {
 489                 error = swsusp_arch_resume();
 490                 /*
 491                  * The code below is only ever reached in case of a failure.
 492                  * Otherwise, execution continues at the place where
 493                  * swsusp_arch_suspend() was called.
 494                  */
 495                 BUG_ON(!error);
 496                 /*
 497                  * This call to restore_highmem() reverts the changes made by
 498                  * the previous one.
 499                  */
 500                 restore_highmem();
 501         }
 502         /*
 503          * The only reason why swsusp_arch_resume() can fail is memory being
 504          * very tight, so we have to free it as soon as we can to avoid
 505          * subsequent failures.
 506          */
 507         swsusp_free();
 508         restore_processor_state();
 509         touch_softlockup_watchdog();
 510
 511         syscore_resume();
 512
 513  Enable_irqs:
 514         system_state = SYSTEM_RUNNING;
 515         local_irq_enable();
 516
 517  Enable_cpus:
 518         pm_sleep_enable_secondary_cpus();
 519
 520  Cleanup:
 521         platform_restore_cleanup(platform_mode);
 522
 523         dpm_resume_start(PMSG_RECOVER);
 524
 525         return error;
 526 }
 527
 528 /**
 529  * hibernation_restore - Quiesce devices and restore from a hibernation image.
 530  * @platform_mode: If set, use platform driver to prepare for the transition.
 531  *
 532  * This routine must be called with system_transition_mutex held.  If it is
 533  * successful, control reappears in the restored target kernel in
 534  * hibernation_snapshot().
 535  */
 536 int hibernation_restore(int platform_mode)
 537 {
 538         int error;
 539
 540         pm_prepare_console();
 541         suspend_console();
 542         pm_restrict_gfp_mask();
 543         error = dpm_suspend_start(PMSG_QUIESCE);
 544         if (!error) {
 545                 error = resume_target_kernel(platform_mode);
 546                 /*
 547                  * The above should either succeed and jump to the new kernel,
 548                  * or return with an error. Otherwise things are just
 549                  * undefined, so let's be paranoid.
 550                  */
 551                 BUG_ON(!error);
 552         }
 553         dpm_resume_end(PMSG_RECOVER);
 554         pm_restore_gfp_mask();
 555         resume_console();
 556         pm_restore_console();
 557         return error;
 558 }
 559
 560 /**
 561  * hibernation_platform_enter - Power off the system using the platform driver.
 562  */
 563 int hibernation_platform_enter(void)
 564 {
 565         int error;
 566
 567         if (!hibernation_ops)
 568                 return -ENOSYS;
 569
 570         /*
 571          * We have cancelled the power transition by running
 572          * hibernation_ops->finish() before saving the image, so we should let
 573          * the firmware know that we're going to enter the sleep state after all
 574          */
 575         error = hibernation_ops->begin(PMSG_HIBERNATE);
 576         if (error)
 577                 goto Close;
 578
 579         entering_platform_hibernation = true;
 580         suspend_console();
 581         error = dpm_suspend_start(PMSG_HIBERNATE);
 582         if (error) {
 583                 if (hibernation_ops->recover)
 584                         hibernation_ops->recover();
 585                 goto Resume_devices;
 586         }
 587
 588         error = dpm_suspend_end(PMSG_HIBERNATE);
 589         if (error)
 590                 goto Resume_devices;
 591
 592         error = hibernation_ops->prepare();
 593         if (error)
 594                 goto Platform_finish;
 595
 596         error = pm_sleep_disable_secondary_cpus();
 597         if (error)
 598                 goto Enable_cpus;
 599
 600         local_irq_disable();
 601         system_state = SYSTEM_SUSPEND;
 602         syscore_suspend();
 603         if (pm_wakeup_pending()) {
 604                 error = -EAGAIN;
 605                 goto Power_up;
 606         }
 607
 608         hibernation_ops->enter();
 609         /* We should never get here */
 610         while (1);
 611
 612  Power_up:
 613         syscore_resume();
 614         system_state = SYSTEM_RUNNING;
 615         local_irq_enable();
 616
 617  Enable_cpus:
 618         pm_sleep_enable_secondary_cpus();
 619
 620  Platform_finish:
 621         hibernation_ops->finish();
 622
 623         dpm_resume_start(PMSG_RESTORE);
 624
 625  Resume_devices:
 626         entering_platform_hibernation = false;
 627         dpm_resume_end(PMSG_RESTORE);
 628         resume_console();
 629
 630  Close:
 631         hibernation_ops->end();
 632
 633         return error;
 634 }
 635
 636 /**
 637  * power_down - Shut the machine down for hibernation.
 638  *
 639  * Use the platform driver, if configured, to put the system into the sleep
 640  * state corresponding to hibernation, or try to power it off or reboot,
 641  * depending on the value of hibernation_mode.
 642  */
 643 static void power_down(void)
 644 {
 645 #ifdef CONFIG_SUSPEND
 646         int error;
 647
 648         if (hibernation_mode == HIBERNATION_SUSPEND) {
 649                 error = suspend_devices_and_enter(mem_sleep_current);
 650                 if (error) {
 651                         hibernation_mode = hibernation_ops ?
 652                                                 HIBERNATION_PLATFORM :
 653                                                 HIBERNATION_SHUTDOWN;
 654                 } else {
 655                         /* Restore swap signature. */
 656                         error = swsusp_unmark();
 657                         if (error)
 658                                 pr_err("Swap will be unusable! Try swapon -a.\n");
 659
 660                         return;
 661                 }
 662         }
 663 #endif
 664
 665         switch (hibernation_mode) {
 666         case HIBERNATION_REBOOT:
 667                 kernel_restart(NULL);
 668                 break;
 669         case HIBERNATION_PLATFORM:
 670                 hibernation_platform_enter();
 671                 fallthrough;
 672         case HIBERNATION_SHUTDOWN:
 673                 if (kernel_can_power_off())
 674                         kernel_power_off();
 675                 break;
 676         }
 677         kernel_halt();
 678         /*
 679          * Valid image is on the disk, if we continue we risk serious data
 680          * corruption after resume.
 681          */
 682         pr_crit("Power down manually\n");
 683         while (1)
 684                 cpu_relax();
 685 }
 686
 687 static int load_image_and_restore(void)
 688 {
 689         int error;
 690         unsigned int flags;
 691
 692         pm_pr_dbg("Loading hibernation image.\n");
 693
 694         lock_device_hotplug();
 695         error = create_basic_memory_bitmaps();
 696         if (error) {
 697                 swsusp_close(FMODE_READ | FMODE_EXCL);
 698                 goto Unlock;
 699         }
 700
 701         error = swsusp_read(&flags);
 702         swsusp_close(FMODE_READ | FMODE_EXCL);
 703         if (!error)
 704                 error = hibernation_restore(flags & SF_PLATFORM_MODE);
 705
 706         pr_err("Failed to load image, recovering.\n");
 707         swsusp_free();
 708         free_basic_memory_bitmaps();
 709  Unlock:
 710         unlock_device_hotplug();
 711
 712         return error;
 713 }
 714
 715 /**
 716  * hibernate - Carry out system hibernation, including saving the image.
 717  */
 718 int hibernate(void)
 719 {
 720         unsigned int sleep_flags;
 721         int error;
 722
 723         if (!hibernation_available()) {
 724                 pm_pr_dbg("Hibernation not available.\n");
 725                 return -EPERM;
 726         }
 727
 728         sleep_flags = lock_system_sleep();
 729         /* The snapshot device should not be opened while we're running */
 730         if (!hibernate_acquire()) {
 731                 error = -EBUSY;
 732                 goto Unlock;
 733         }
 734
 735         pr_info("hibernation entry\n");
 736         pm_prepare_console();
 737         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 738         if (error)
 739                 goto Restore;
 740
 741         ksys_sync_helper();
 742
 743         error = freeze_processes();
 744         if (error)
 745                 goto Exit;
 746
 747         /* protected by system_transition_mutex */
 748         snapshot_test = false;
 749
 750         lock_device_hotplug();
 751         /* Allocate memory management structures */
 752         error = create_basic_memory_bitmaps();
 753         if (error)
 754                 goto Thaw;
 755
 756         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 757         if (error || freezer_test_done)
 758                 goto Free_bitmaps;
 759
 760         if (in_suspend) {
 761                 unsigned int flags = 0;
 762
 763                 if (hibernation_mode == HIBERNATION_PLATFORM)
 764                         flags |= SF_PLATFORM_MODE;
 765                 if (nocompress)
 766                         flags |= SF_NOCOMPRESS_MODE;
 767                 else
 768                         flags |= SF_CRC32_MODE;
 769
 770                 pm_pr_dbg("Writing hibernation image.\n");
 771                 error = swsusp_write(flags);
 772                 swsusp_free();
 773                 if (!error) {
 774                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
 775                                 snapshot_test = true;
 776                         else
 777                                 power_down();
 778                 }
 779                 in_suspend = 0;
 780                 pm_restore_gfp_mask();
 781         } else {
 782                 pm_pr_dbg("Hibernation image restored successfully.\n");
 783         }
 784
 785  Free_bitmaps:
 786         free_basic_memory_bitmaps();
 787  Thaw:
 788         unlock_device_hotplug();
 789         if (snapshot_test) {
 790                 pm_pr_dbg("Checking hibernation image\n");
 791                 error = swsusp_check();
 792                 if (!error)
 793                         error = load_image_and_restore();
 794         }
 795         thaw_processes();
 796
 797         /* Don't bother checking whether freezer_test_done is true */
 798         freezer_test_done = false;
 799  Exit:
 800         pm_notifier_call_chain(PM_POST_HIBERNATION);
 801  Restore:
 802         pm_restore_console();
 803         hibernate_release();
 804  Unlock:
 805         unlock_system_sleep(sleep_flags);
 806         pr_info("hibernation exit\n");
 807
 808         return error;
 809 }
 810
 811 /**
 812  * hibernate_quiet_exec - Execute a function with all devices frozen.
 813  * @func: Function to execute.
 814  * @data: Data pointer to pass to @func.
 815  *
 816  * Return the @func return value or an error code if it cannot be executed.
 817  */
 818 int hibernate_quiet_exec(int (*func)(void *data), void *data)
 819 {
 820         unsigned int sleep_flags;
 821         int error;
 822
 823         sleep_flags = lock_system_sleep();
 824
 825         if (!hibernate_acquire()) {
 826                 error = -EBUSY;
 827                 goto unlock;
 828         }
 829
 830         pm_prepare_console();
 831
 832         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 833         if (error)
 834                 goto restore;
 835
 836         error = freeze_processes();
 837         if (error)
 838                 goto exit;
 839
 840         lock_device_hotplug();
 841
 842         pm_suspend_clear_flags();
 843
 844         error = platform_begin(true);
 845         if (error)
 846                 goto thaw;
 847
 848         error = freeze_kernel_threads();
 849         if (error)
 850                 goto thaw;
 851
 852         error = dpm_prepare(PMSG_FREEZE);
 853         if (error)
 854                 goto dpm_complete;
 855
 856         suspend_console();
 857
 858         error = dpm_suspend(PMSG_FREEZE);
 859         if (error)
 860                 goto dpm_resume;
 861
 862         error = dpm_suspend_end(PMSG_FREEZE);
 863         if (error)
 864                 goto dpm_resume;
 865
 866         error = platform_pre_snapshot(true);
 867         if (error)
 868                 goto skip;
 869
 870         error = func(data);
 871
 872 skip:
 873         platform_finish(true);
 874
 875         dpm_resume_start(PMSG_THAW);
 876
 877 dpm_resume:
 878         dpm_resume(PMSG_THAW);
 879
 880         resume_console();
 881
 882 dpm_complete:
 883         dpm_complete(PMSG_THAW);
 884
 885         thaw_kernel_threads();
 886
 887 thaw:
 888         platform_end(true);
 889
 890         unlock_device_hotplug();
 891
 892         thaw_processes();
 893
 894 exit:
 895         pm_notifier_call_chain(PM_POST_HIBERNATION);
 896
 897 restore:
 898         pm_restore_console();
 899
 900         hibernate_release();
 901
 902 unlock:
 903         unlock_system_sleep(sleep_flags);
 904
 905         return error;
 906 }
 907 EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 908
 909 /**
 910  * software_resume - Resume from a saved hibernation image.
 911  *
 912  * This routine is called as a late initcall, when all devices have been
 913  * discovered and initialized already.
 914  *
 915  * The image reading code is called to see if there is a hibernation image
 916  * available for reading.  If that is the case, devices are quiesced and the
 917  * contents of memory is restored from the saved image.
 918  *
 919  * If this is successful, control reappears in the restored target kernel in
 920  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 921  * attempts to recover gracefully and make the kernel return to the normal mode
 922  * of operation.
 923  */
 924 static int software_resume(void)
 925 {
 926         int error;
 927
 928         /*
 929          * If the user said "noresume".. bail out early.
 930          */
 931         if (noresume || !hibernation_available())
 932                 return 0;
 933
 934         /*
 935          * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 936          * is configured into the kernel. Since the regular hibernate
 937          * trigger path is via sysfs which takes a buffer mutex before
 938          * calling hibernate functions (which take system_transition_mutex)
 939          * this can cause lockdep to complain about a possible ABBA deadlock
 940          * which cannot happen since we're in the boot code here and
 941          * sysfs can't be invoked yet. Therefore, we use a subclass
 942          * here to avoid lockdep complaining.
 943          */
 944         mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
 945
 946         snapshot_test = false;
 947
 948         if (swsusp_resume_device)
 949                 goto Check_image;
 950
 951         if (!strlen(resume_file)) {
 952                 error = -ENOENT;
 953                 goto Unlock;
 954         }
 955
 956         pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 957
 958         if (resume_delay) {
 959                 pr_info("Waiting %dsec before reading resume device ...\n",
 960                         resume_delay);
 961                 ssleep(resume_delay);
 962         }
 963
 964         /* Check if the device is there */
 965         swsusp_resume_device = name_to_dev_t(resume_file);
 966         if (!swsusp_resume_device) {
 967                 /*
 968                  * Some device discovery might still be in progress; we need
 969                  * to wait for this to finish.
 970                  */
 971                 wait_for_device_probe();
 972
 973                 if (resume_wait) {
 974                         while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 975                                 msleep(10);
 976                         async_synchronize_full();
 977                 }
 978
 979                 swsusp_resume_device = name_to_dev_t(resume_file);
 980                 if (!swsusp_resume_device) {
 981                         error = -ENODEV;
 982                         goto Unlock;
 983                 }
 984         }
 985
 986  Check_image:
 987         pm_pr_dbg("Hibernation image partition %d:%d present\n",
 988                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 989
 990         pm_pr_dbg("Looking for hibernation image.\n");
 991         error = swsusp_check();
 992         if (error)
 993                 goto Unlock;
 994
 995         /* The snapshot device should not be opened while we're running */
 996         if (!hibernate_acquire()) {
 997                 error = -EBUSY;
 998                 swsusp_close(FMODE_READ | FMODE_EXCL);
 999                 goto Unlock;
1000         }
1001
1002         pr_info("resume from hibernation\n");
1003         pm_prepare_console();
1004         error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
1005         if (error)
1006                 goto Restore;
1007
1008         pm_pr_dbg("Preparing processes for hibernation restore.\n");
1009         error = freeze_processes();
1010         if (error)
1011                 goto Close_Finish;
1012
1013         error = freeze_kernel_threads();
1014         if (error) {
1015                 thaw_processes();
1016                 goto Close_Finish;
1017         }
1018
1019         error = load_image_and_restore();
1020         thaw_processes();
1021  Finish:
1022         pm_notifier_call_chain(PM_POST_RESTORE);
1023  Restore:
1024         pm_restore_console();
1025         pr_info("resume failed (%d)\n", error);
1026         hibernate_release();
1027         /* For success case, the suspend path will release the lock */
1028  Unlock:
1029         mutex_unlock(&system_transition_mutex);
1030         pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1031         return error;
1032  Close_Finish:
1033         swsusp_close(FMODE_READ | FMODE_EXCL);
1034         goto Finish;
1035 }
1036
1037 late_initcall_sync(software_resume);
1038
1039
1040 static const char * const hibernation_modes[] = {
1041         [HIBERNATION_PLATFORM]  = "platform",
1042         [HIBERNATION_SHUTDOWN]  = "shutdown",
1043         [HIBERNATION_REBOOT]    = "reboot",
1044 #ifdef CONFIG_SUSPEND
1045         [HIBERNATION_SUSPEND]   = "suspend",
1046 #endif
1047         [HIBERNATION_TEST_RESUME]       = "test_resume",
1048 };
1049
1050 /*
1051  * /sys/power/disk - Control hibernation mode.
1052  *
1053  * Hibernation can be handled in several ways.  There are a few different ways
1054  * to put the system into the sleep state: using the platform driver (e.g. ACPI
1055  * or other hibernation_ops), powering it off or rebooting it (for testing
1056  * mostly).
1057  *
1058  * The sysfs file /sys/power/disk provides an interface for selecting the
1059  * hibernation mode to use.  Reading from this file causes the available modes
1060  * to be printed.  There are 3 modes that can be supported:
1061  *
1062  *      'platform'
1063  *      'shutdown'
1064  *      'reboot'
1065  *
1066  * If a platform hibernation driver is in use, 'platform' will be supported
1067  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1068  * The selected option (i.e. the one corresponding to the current value of
1069  * hibernation_mode) is enclosed by a square bracket.
1070  *
1071  * To select a given hibernation mode it is necessary to write the mode's
1072  * string representation (as returned by reading from /sys/power/disk) back
1073  * into /sys/power/disk.
1074  */
1075
1076 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1077                          char *buf)
1078 {
1079         int i;
1080         char *start = buf;
1081
1082         if (!hibernation_available())
1083                 return sprintf(buf, "[disabled]\n");
1084
1085         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1086                 if (!hibernation_modes[i])
1087                         continue;
1088                 switch (i) {
1089                 case HIBERNATION_SHUTDOWN:
1090                 case HIBERNATION_REBOOT:
1091 #ifdef CONFIG_SUSPEND
1092                 case HIBERNATION_SUSPEND:
1093 #endif
1094                 case HIBERNATION_TEST_RESUME:
1095                         break;
1096                 case HIBERNATION_PLATFORM:
1097                         if (hibernation_ops)
1098                                 break;
1099                         /* not a valid mode, continue with loop */
1100                         continue;
1101                 }
1102                 if (i == hibernation_mode)
1103                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1104                 else
1105                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
1106         }
1107         buf += sprintf(buf, "\n");
1108         return buf-start;
1109 }
1110
1111 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1112                           const char *buf, size_t n)
1113 {
1114         int mode = HIBERNATION_INVALID;
1115         unsigned int sleep_flags;
1116         int error = 0;
1117         int len;
1118         char *p;
1119         int i;
1120
1121         if (!hibernation_available())
1122                 return -EPERM;
1123
1124         p = memchr(buf, '\n', n);
1125         len = p ? p - buf : n;
1126
1127         sleep_flags = lock_system_sleep();
1128         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1129                 if (len == strlen(hibernation_modes[i])
1130                     && !strncmp(buf, hibernation_modes[i], len)) {
1131                         mode = i;
1132                         break;
1133                 }
1134         }
1135         if (mode != HIBERNATION_INVALID) {
1136                 switch (mode) {
1137                 case HIBERNATION_SHUTDOWN:
1138                 case HIBERNATION_REBOOT:
1139 #ifdef CONFIG_SUSPEND
1140                 case HIBERNATION_SUSPEND:
1141 #endif
1142                 case HIBERNATION_TEST_RESUME:
1143                         hibernation_mode = mode;
1144                         break;
1145                 case HIBERNATION_PLATFORM:
1146                         if (hibernation_ops)
1147                                 hibernation_mode = mode;
1148                         else
1149                                 error = -EINVAL;
1150                 }
1151         } else
1152                 error = -EINVAL;
1153
1154         if (!error)
1155                 pm_pr_dbg("Hibernation mode set to '%s'\n",
1156                                hibernation_modes[mode]);
1157         unlock_system_sleep(sleep_flags);
1158         return error ? error : n;
1159 }
1160
1161 power_attr(disk);
1162
1163 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1164                            char *buf)
1165 {
1166         return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1167                        MINOR(swsusp_resume_device));
1168 }
1169
1170 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1171                             const char *buf, size_t n)
1172 {
1173         unsigned int sleep_flags;
1174         int len = n;
1175         char *name;
1176         dev_t res;
1177
1178         if (len && buf[len-1] == '\n')
1179                 len--;
1180         name = kstrndup(buf, len, GFP_KERNEL);
1181         if (!name)
1182                 return -ENOMEM;
1183
1184         res = name_to_dev_t(name);
1185         kfree(name);
1186         if (!res)
1187                 return -EINVAL;
1188
1189         sleep_flags = lock_system_sleep();
1190         swsusp_resume_device = res;
1191         unlock_system_sleep(sleep_flags);
1192
1193         pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1194                   swsusp_resume_device);
1195         noresume = 0;
1196         software_resume();
1197         return n;
1198 }
1199
1200 power_attr(resume);
1201
1202 static ssize_t resume_offset_show(struct kobject *kobj,
1203                                   struct kobj_attribute *attr, char *buf)
1204 {
1205         return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1206 }
1207
1208 static ssize_t resume_offset_store(struct kobject *kobj,
1209                                    struct kobj_attribute *attr, const char *buf,
1210                                    size_t n)
1211 {
1212         unsigned long long offset;
1213         int rc;
1214
1215         rc = kstrtoull(buf, 0, &offset);
1216         if (rc)
1217                 return rc;
1218         swsusp_resume_block = offset;
1219
1220         return n;
1221 }
1222
1223 power_attr(resume_offset);
1224
1225 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1226                                char *buf)
1227 {
1228         return sprintf(buf, "%lu\n", image_size);
1229 }
1230
1231 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1232                                 const char *buf, size_t n)
1233 {
1234         unsigned long size;
1235
1236         if (sscanf(buf, "%lu", &size) == 1) {
1237                 image_size = size;
1238                 return n;
1239         }
1240
1241         return -EINVAL;
1242 }
1243
1244 power_attr(image_size);
1245
1246 static ssize_t reserved_size_show(struct kobject *kobj,
1247                                   struct kobj_attribute *attr, char *buf)
1248 {
1249         return sprintf(buf, "%lu\n", reserved_size);
1250 }
1251
1252 static ssize_t reserved_size_store(struct kobject *kobj,
1253                                    struct kobj_attribute *attr,
1254                                    const char *buf, size_t n)
1255 {
1256         unsigned long size;
1257
1258         if (sscanf(buf, "%lu", &size) == 1) {
1259                 reserved_size = size;
1260                 return n;
1261         }
1262
1263         return -EINVAL;
1264 }
1265
1266 power_attr(reserved_size);
1267
1268 static struct attribute *g[] = {
1269         &disk_attr.attr,
1270         &resume_offset_attr.attr,
1271         &resume_attr.attr,
1272         &image_size_attr.attr,
1273         &reserved_size_attr.attr,
1274         NULL,
1275 };
1276
1277
1278 static const struct attribute_group attr_group = {
1279         .attrs = g,
1280 };
1281
1282
1283 static int __init pm_disk_init(void)
1284 {
1285         return sysfs_create_group(power_kobj, &attr_group);
1286 }
1287
1288 core_initcall(pm_disk_init);
1289
1290
1291 static int __init resume_setup(char *str)
1292 {
1293         if (noresume)
1294                 return 1;
1295
1296         strncpy(resume_file, str, 255);
1297         return 1;
1298 }
1299
1300 static int __init resume_offset_setup(char *str)
1301 {
1302         unsigned long long offset;
1303
1304         if (noresume)
1305                 return 1;
1306
1307         if (sscanf(str, "%llu", &offset) == 1)
1308                 swsusp_resume_block = offset;
1309
1310         return 1;
1311 }
1312
1313 static int __init hibernate_setup(char *str)
1314 {
1315         if (!strncmp(str, "noresume", 8)) {
1316                 noresume = 1;
1317         } else if (!strncmp(str, "nocompress", 10)) {
1318                 nocompress = 1;
1319         } else if (!strncmp(str, "no", 2)) {
1320                 noresume = 1;
1321                 nohibernate = 1;
1322         } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1323                    && !strncmp(str, "protect_image", 13)) {
1324                 enable_restore_image_protection();
1325         }
1326         return 1;
1327 }
1328
1329 static int __init noresume_setup(char *str)
1330 {
1331         noresume = 1;
1332         return 1;
1333 }
1334
1335 static int __init resumewait_setup(char *str)
1336 {
1337         resume_wait = 1;
1338         return 1;
1339 }
1340
1341 static int __init resumedelay_setup(char *str)
1342 {
1343         int rc = kstrtouint(str, 0, &resume_delay);
1344
1345         if (rc)
1346                 pr_warn("resumedelay: bad option string '%s'\n", str);
1347         return 1;
1348 }
1349
1350 static int __init nohibernate_setup(char *str)
1351 {
1352         noresume = 1;
1353         nohibernate = 1;
1354         return 1;
1355 }
1356
1357 __setup("noresume", noresume_setup);
1358 __setup("resume_offset=", resume_offset_setup);
1359 __setup("resume=", resume_setup);
1360 __setup("hibernate=", hibernate_setup);
1361 __setup("resumewait", resumewait_setup);
1362 __setup("resumedelay=", resumedelay_setup);
1363 __setup("nohibernate", nohibernate_setup);