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         fmode_t mode = FMODE_READ;
 692
 693         if (snapshot_test)
 694                 mode |= FMODE_EXCL;
 695
 696         pm_pr_dbg("Loading hibernation image.\n");
 697
 698         lock_device_hotplug();
 699         error = create_basic_memory_bitmaps();
 700         if (error) {
 701                 swsusp_close(mode);
 702                 goto Unlock;
 703         }
 704
 705         error = swsusp_read(&flags);
 706         swsusp_close(mode);
 707         if (!error)
 708                 error = hibernation_restore(flags & SF_PLATFORM_MODE);
 709
 710         pr_err("Failed to load image, recovering.\n");
 711         swsusp_free();
 712         free_basic_memory_bitmaps();
 713  Unlock:
 714         unlock_device_hotplug();
 715
 716         return error;
 717 }
 718
 719 /**
 720  * hibernate - Carry out system hibernation, including saving the image.
 721  */
 722 int hibernate(void)
 723 {
 724         unsigned int sleep_flags;
 725         int error;
 726
 727         if (!hibernation_available()) {
 728                 pm_pr_dbg("Hibernation not available.\n");
 729                 return -EPERM;
 730         }
 731
 732         sleep_flags = lock_system_sleep();
 733         /* The snapshot device should not be opened while we're running */
 734         if (!hibernate_acquire()) {
 735                 error = -EBUSY;
 736                 goto Unlock;
 737         }
 738
 739         pr_info("hibernation entry\n");
 740         pm_prepare_console();
 741         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 742         if (error)
 743                 goto Restore;
 744
 745         ksys_sync_helper();
 746
 747         error = freeze_processes();
 748         if (error)
 749                 goto Exit;
 750
 751         /* protected by system_transition_mutex */
 752         snapshot_test = false;
 753
 754         lock_device_hotplug();
 755         /* Allocate memory management structures */
 756         error = create_basic_memory_bitmaps();
 757         if (error)
 758                 goto Thaw;
 759
 760         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 761         if (error || freezer_test_done)
 762                 goto Free_bitmaps;
 763
 764         if (in_suspend) {
 765                 unsigned int flags = 0;
 766
 767                 if (hibernation_mode == HIBERNATION_PLATFORM)
 768                         flags |= SF_PLATFORM_MODE;
 769                 if (nocompress)
 770                         flags |= SF_NOCOMPRESS_MODE;
 771                 else
 772                         flags |= SF_CRC32_MODE;
 773
 774                 pm_pr_dbg("Writing hibernation image.\n");
 775                 error = swsusp_write(flags);
 776                 swsusp_free();
 777                 if (!error) {
 778                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
 779                                 snapshot_test = true;
 780                         else
 781                                 power_down();
 782                 }
 783                 in_suspend = 0;
 784                 pm_restore_gfp_mask();
 785         } else {
 786                 pm_pr_dbg("Hibernation image restored successfully.\n");
 787         }
 788
 789  Free_bitmaps:
 790         free_basic_memory_bitmaps();
 791  Thaw:
 792         unlock_device_hotplug();
 793         if (snapshot_test) {
 794                 pm_pr_dbg("Checking hibernation image\n");
 795                 error = swsusp_check();
 796                 if (!error)
 797                         error = load_image_and_restore();
 798         }
 799         thaw_processes();
 800
 801         /* Don't bother checking whether freezer_test_done is true */
 802         freezer_test_done = false;
 803  Exit:
 804         pm_notifier_call_chain(PM_POST_HIBERNATION);
 805  Restore:
 806         pm_restore_console();
 807         hibernate_release();
 808  Unlock:
 809         unlock_system_sleep(sleep_flags);
 810         pr_info("hibernation exit\n");
 811
 812         return error;
 813 }
 814
 815 /**
 816  * hibernate_quiet_exec - Execute a function with all devices frozen.
 817  * @func: Function to execute.
 818  * @data: Data pointer to pass to @func.
 819  *
 820  * Return the @func return value or an error code if it cannot be executed.
 821  */
 822 int hibernate_quiet_exec(int (*func)(void *data), void *data)
 823 {
 824         unsigned int sleep_flags;
 825         int error;
 826
 827         sleep_flags = lock_system_sleep();
 828
 829         if (!hibernate_acquire()) {
 830                 error = -EBUSY;
 831                 goto unlock;
 832         }
 833
 834         pm_prepare_console();
 835
 836         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 837         if (error)
 838                 goto restore;
 839
 840         error = freeze_processes();
 841         if (error)
 842                 goto exit;
 843
 844         lock_device_hotplug();
 845
 846         pm_suspend_clear_flags();
 847
 848         error = platform_begin(true);
 849         if (error)
 850                 goto thaw;
 851
 852         error = freeze_kernel_threads();
 853         if (error)
 854                 goto thaw;
 855
 856         error = dpm_prepare(PMSG_FREEZE);
 857         if (error)
 858                 goto dpm_complete;
 859
 860         suspend_console();
 861
 862         error = dpm_suspend(PMSG_FREEZE);
 863         if (error)
 864                 goto dpm_resume;
 865
 866         error = dpm_suspend_end(PMSG_FREEZE);
 867         if (error)
 868                 goto dpm_resume;
 869
 870         error = platform_pre_snapshot(true);
 871         if (error)
 872                 goto skip;
 873
 874         error = func(data);
 875
 876 skip:
 877         platform_finish(true);
 878
 879         dpm_resume_start(PMSG_THAW);
 880
 881 dpm_resume:
 882         dpm_resume(PMSG_THAW);
 883
 884         resume_console();
 885
 886 dpm_complete:
 887         dpm_complete(PMSG_THAW);
 888
 889         thaw_kernel_threads();
 890
 891 thaw:
 892         platform_end(true);
 893
 894         unlock_device_hotplug();
 895
 896         thaw_processes();
 897
 898 exit:
 899         pm_notifier_call_chain(PM_POST_HIBERNATION);
 900
 901 restore:
 902         pm_restore_console();
 903
 904         hibernate_release();
 905
 906 unlock:
 907         unlock_system_sleep(sleep_flags);
 908
 909         return error;
 910 }
 911 EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 912
 913 /**
 914  * software_resume - Resume from a saved hibernation image.
 915  *
 916  * This routine is called as a late initcall, when all devices have been
 917  * discovered and initialized already.
 918  *
 919  * The image reading code is called to see if there is a hibernation image
 920  * available for reading.  If that is the case, devices are quiesced and the
 921  * contents of memory is restored from the saved image.
 922  *
 923  * If this is successful, control reappears in the restored target kernel in
 924  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 925  * attempts to recover gracefully and make the kernel return to the normal mode
 926  * of operation.
 927  */
 928 static int software_resume(void)
 929 {
 930         int error;
 931
 932         /*
 933          * If the user said "noresume".. bail out early.
 934          */
 935         if (noresume || !hibernation_available())
 936                 return 0;
 937
 938         /*
 939          * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 940          * is configured into the kernel. Since the regular hibernate
 941          * trigger path is via sysfs which takes a buffer mutex before
 942          * calling hibernate functions (which take system_transition_mutex)
 943          * this can cause lockdep to complain about a possible ABBA deadlock
 944          * which cannot happen since we're in the boot code here and
 945          * sysfs can't be invoked yet. Therefore, we use a subclass
 946          * here to avoid lockdep complaining.
 947          */
 948         mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
 949
 950         snapshot_test = false;
 951
 952         if (swsusp_resume_device)
 953                 goto Check_image;
 954
 955         if (!strlen(resume_file)) {
 956                 error = -ENOENT;
 957                 goto Unlock;
 958         }
 959
 960         pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 961
 962         if (resume_delay) {
 963                 pr_info("Waiting %dsec before reading resume device ...\n",
 964                         resume_delay);
 965                 ssleep(resume_delay);
 966         }
 967
 968         /* Check if the device is there */
 969         swsusp_resume_device = name_to_dev_t(resume_file);
 970         if (!swsusp_resume_device) {
 971                 /*
 972                  * Some device discovery might still be in progress; we need
 973                  * to wait for this to finish.
 974                  */
 975                 wait_for_device_probe();
 976
 977                 if (resume_wait) {
 978                         while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 979                                 msleep(10);
 980                         async_synchronize_full();
 981                 }
 982
 983                 swsusp_resume_device = name_to_dev_t(resume_file);
 984                 if (!swsusp_resume_device) {
 985                         error = -ENODEV;
 986                         goto Unlock;
 987                 }
 988         }
 989
 990  Check_image:
 991         pm_pr_dbg("Hibernation image partition %d:%d present\n",
 992                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 993
 994         pm_pr_dbg("Looking for hibernation image.\n");
 995         error = swsusp_check();
 996         if (error)
 997                 goto Unlock;
 998
 999         /* The snapshot device should not be opened while we're running */
1000         if (!hibernate_acquire()) {
1001                 error = -EBUSY;
1002                 swsusp_close(FMODE_READ | FMODE_EXCL);
1003                 goto Unlock;
1004         }
1005
1006         pr_info("resume from hibernation\n");
1007         pm_prepare_console();
1008         error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
1009         if (error)
1010                 goto Restore;
1011
1012         pm_pr_dbg("Preparing processes for hibernation restore.\n");
1013         error = freeze_processes();
1014         if (error)
1015                 goto Close_Finish;
1016
1017         error = freeze_kernel_threads();
1018         if (error) {
1019                 thaw_processes();
1020                 goto Close_Finish;
1021         }
1022
1023         error = load_image_and_restore();
1024         thaw_processes();
1025  Finish:
1026         pm_notifier_call_chain(PM_POST_RESTORE);
1027  Restore:
1028         pm_restore_console();
1029         pr_info("resume failed (%d)\n", error);
1030         hibernate_release();
1031         /* For success case, the suspend path will release the lock */
1032  Unlock:
1033         mutex_unlock(&system_transition_mutex);
1034         pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1035         return error;
1036  Close_Finish:
1037         swsusp_close(FMODE_READ | FMODE_EXCL);
1038         goto Finish;
1039 }
1040
1041 late_initcall_sync(software_resume);
1042
1043
1044 static const char * const hibernation_modes[] = {
1045         [HIBERNATION_PLATFORM]  = "platform",
1046         [HIBERNATION_SHUTDOWN]  = "shutdown",
1047         [HIBERNATION_REBOOT]    = "reboot",
1048 #ifdef CONFIG_SUSPEND
1049         [HIBERNATION_SUSPEND]   = "suspend",
1050 #endif
1051         [HIBERNATION_TEST_RESUME]       = "test_resume",
1052 };
1053
1054 /*
1055  * /sys/power/disk - Control hibernation mode.
1056  *
1057  * Hibernation can be handled in several ways.  There are a few different ways
1058  * to put the system into the sleep state: using the platform driver (e.g. ACPI
1059  * or other hibernation_ops), powering it off or rebooting it (for testing
1060  * mostly).
1061  *
1062  * The sysfs file /sys/power/disk provides an interface for selecting the
1063  * hibernation mode to use.  Reading from this file causes the available modes
1064  * to be printed.  There are 3 modes that can be supported:
1065  *
1066  *      'platform'
1067  *      'shutdown'
1068  *      'reboot'
1069  *
1070  * If a platform hibernation driver is in use, 'platform' will be supported
1071  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1072  * The selected option (i.e. the one corresponding to the current value of
1073  * hibernation_mode) is enclosed by a square bracket.
1074  *
1075  * To select a given hibernation mode it is necessary to write the mode's
1076  * string representation (as returned by reading from /sys/power/disk) back
1077  * into /sys/power/disk.
1078  */
1079
1080 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1081                          char *buf)
1082 {
1083         int i;
1084         char *start = buf;
1085
1086         if (!hibernation_available())
1087                 return sprintf(buf, "[disabled]\n");
1088
1089         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1090                 if (!hibernation_modes[i])
1091                         continue;
1092                 switch (i) {
1093                 case HIBERNATION_SHUTDOWN:
1094                 case HIBERNATION_REBOOT:
1095 #ifdef CONFIG_SUSPEND
1096                 case HIBERNATION_SUSPEND:
1097 #endif
1098                 case HIBERNATION_TEST_RESUME:
1099                         break;
1100                 case HIBERNATION_PLATFORM:
1101                         if (hibernation_ops)
1102                                 break;
1103                         /* not a valid mode, continue with loop */
1104                         continue;
1105                 }
1106                 if (i == hibernation_mode)
1107                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1108                 else
1109                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
1110         }
1111         buf += sprintf(buf, "\n");
1112         return buf-start;
1113 }
1114
1115 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1116                           const char *buf, size_t n)
1117 {
1118         int mode = HIBERNATION_INVALID;
1119         unsigned int sleep_flags;
1120         int error = 0;
1121         int len;
1122         char *p;
1123         int i;
1124
1125         if (!hibernation_available())
1126                 return -EPERM;
1127
1128         p = memchr(buf, '\n', n);
1129         len = p ? p - buf : n;
1130
1131         sleep_flags = lock_system_sleep();
1132         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1133                 if (len == strlen(hibernation_modes[i])
1134                     && !strncmp(buf, hibernation_modes[i], len)) {
1135                         mode = i;
1136                         break;
1137                 }
1138         }
1139         if (mode != HIBERNATION_INVALID) {
1140                 switch (mode) {
1141                 case HIBERNATION_SHUTDOWN:
1142                 case HIBERNATION_REBOOT:
1143 #ifdef CONFIG_SUSPEND
1144                 case HIBERNATION_SUSPEND:
1145 #endif
1146                 case HIBERNATION_TEST_RESUME:
1147                         hibernation_mode = mode;
1148                         break;
1149                 case HIBERNATION_PLATFORM:
1150                         if (hibernation_ops)
1151                                 hibernation_mode = mode;
1152                         else
1153                                 error = -EINVAL;
1154                 }
1155         } else
1156                 error = -EINVAL;
1157
1158         if (!error)
1159                 pm_pr_dbg("Hibernation mode set to '%s'\n",
1160                                hibernation_modes[mode]);
1161         unlock_system_sleep(sleep_flags);
1162         return error ? error : n;
1163 }
1164
1165 power_attr(disk);
1166
1167 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1168                            char *buf)
1169 {
1170         return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1171                        MINOR(swsusp_resume_device));
1172 }
1173
1174 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1175                             const char *buf, size_t n)
1176 {
1177         unsigned int sleep_flags;
1178         int len = n;
1179         char *name;
1180         dev_t res;
1181
1182         if (len && buf[len-1] == '\n')
1183                 len--;
1184         name = kstrndup(buf, len, GFP_KERNEL);
1185         if (!name)
1186                 return -ENOMEM;
1187
1188         res = name_to_dev_t(name);
1189         kfree(name);
1190         if (!res)
1191                 return -EINVAL;
1192
1193         sleep_flags = lock_system_sleep();
1194         swsusp_resume_device = res;
1195         unlock_system_sleep(sleep_flags);
1196
1197         pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1198                   swsusp_resume_device);
1199         noresume = 0;
1200         software_resume();
1201         return n;
1202 }
1203
1204 power_attr(resume);
1205
1206 static ssize_t resume_offset_show(struct kobject *kobj,
1207                                   struct kobj_attribute *attr, char *buf)
1208 {
1209         return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1210 }
1211
1212 static ssize_t resume_offset_store(struct kobject *kobj,
1213                                    struct kobj_attribute *attr, const char *buf,
1214                                    size_t n)
1215 {
1216         unsigned long long offset;
1217         int rc;
1218
1219         rc = kstrtoull(buf, 0, &offset);
1220         if (rc)
1221                 return rc;
1222         swsusp_resume_block = offset;
1223
1224         return n;
1225 }
1226
1227 power_attr(resume_offset);
1228
1229 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1230                                char *buf)
1231 {
1232         return sprintf(buf, "%lu\n", image_size);
1233 }
1234
1235 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1236                                 const char *buf, size_t n)
1237 {
1238         unsigned long size;
1239
1240         if (sscanf(buf, "%lu", &size) == 1) {
1241                 image_size = size;
1242                 return n;
1243         }
1244
1245         return -EINVAL;
1246 }
1247
1248 power_attr(image_size);
1249
1250 static ssize_t reserved_size_show(struct kobject *kobj,
1251                                   struct kobj_attribute *attr, char *buf)
1252 {
1253         return sprintf(buf, "%lu\n", reserved_size);
1254 }
1255
1256 static ssize_t reserved_size_store(struct kobject *kobj,
1257                                    struct kobj_attribute *attr,
1258                                    const char *buf, size_t n)
1259 {
1260         unsigned long size;
1261
1262         if (sscanf(buf, "%lu", &size) == 1) {
1263                 reserved_size = size;
1264                 return n;
1265         }
1266
1267         return -EINVAL;
1268 }
1269
1270 power_attr(reserved_size);
1271
1272 static struct attribute *g[] = {
1273         &disk_attr.attr,
1274         &resume_offset_attr.attr,
1275         &resume_attr.attr,
1276         &image_size_attr.attr,
1277         &reserved_size_attr.attr,
1278         NULL,
1279 };
1280
1281
1282 static const struct attribute_group attr_group = {
1283         .attrs = g,
1284 };
1285
1286
1287 static int __init pm_disk_init(void)
1288 {
1289         return sysfs_create_group(power_kobj, &attr_group);
1290 }
1291
1292 core_initcall(pm_disk_init);
1293
1294
1295 static int __init resume_setup(char *str)
1296 {
1297         if (noresume)
1298                 return 1;
1299
1300         strncpy(resume_file, str, 255);
1301         return 1;
1302 }
1303
1304 static int __init resume_offset_setup(char *str)
1305 {
1306         unsigned long long offset;
1307
1308         if (noresume)
1309                 return 1;
1310
1311         if (sscanf(str, "%llu", &offset) == 1)
1312                 swsusp_resume_block = offset;
1313
1314         return 1;
1315 }
1316
1317 static int __init hibernate_setup(char *str)
1318 {
1319         if (!strncmp(str, "noresume", 8)) {
1320                 noresume = 1;
1321         } else if (!strncmp(str, "nocompress", 10)) {
1322                 nocompress = 1;
1323         } else if (!strncmp(str, "no", 2)) {
1324                 noresume = 1;
1325                 nohibernate = 1;
1326         } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1327                    && !strncmp(str, "protect_image", 13)) {
1328                 enable_restore_image_protection();
1329         }
1330         return 1;
1331 }
1332
1333 static int __init noresume_setup(char *str)
1334 {
1335         noresume = 1;
1336         return 1;
1337 }
1338
1339 static int __init resumewait_setup(char *str)
1340 {
1341         resume_wait = 1;
1342         return 1;
1343 }
1344
1345 static int __init resumedelay_setup(char *str)
1346 {
1347         int rc = kstrtouint(str, 0, &resume_delay);
1348
1349         if (rc)
1350                 pr_warn("resumedelay: bad option string '%s'\n", str);
1351         return 1;
1352 }
1353
1354 static int __init nohibernate_setup(char *str)
1355 {
1356         noresume = 1;
1357         nohibernate = 1;
1358         return 1;
1359 }
1360
1361 __setup("noresume", noresume_setup);
1362 __setup("resume_offset=", resume_offset_setup);
1363 __setup("resume=", resume_setup);
1364 __setup("hibernate=", hibernate_setup);
1365 __setup("resumewait", resumewait_setup);
1366 __setup("resumedelay=", resumedelay_setup);
1367 __setup("nohibernate", nohibernate_setup);