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 <[email protected]>
   8  * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
   9  * Copyright (C) 2012 Bojan Smojver <[email protected]>
  10  */
  11
  12 #define pr_fmt(fmt) "PM: hibernation: " fmt
  13
  14 #include <linux/blkdev.h>
  15 #include <linux/export.h>
  16 #include <linux/suspend.h>
  17 #include <linux/reboot.h>
  18 #include <linux/string.h>
  19 #include <linux/device.h>
  20 #include <linux/async.h>
  21 #include <linux/delay.h>
  22 #include <linux/fs.h>
  23 #include <linux/mount.h>
  24 #include <linux/pm.h>
  25 #include <linux/nmi.h>
  26 #include <linux/console.h>
  27 #include <linux/cpu.h>
  28 #include <linux/freezer.h>
  29 #include <linux/gfp.h>
  30 #include <linux/syscore_ops.h>
  31 #include <linux/ctype.h>
  32 #include <linux/ktime.h>
  33 #include <linux/security.h>
  34 #include <linux/secretmem.h>
  35 #include <trace/events/power.h>
  36
  37 #include "power.h"
  38
  39
  40 static int nocompress;
  41 static int noresume;
  42 static int nohibernate;
  43 static int resume_wait;
  44 static unsigned int resume_delay;
  45 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
  46 dev_t swsusp_resume_device;
  47 sector_t swsusp_resume_block;
  48 __visible int in_suspend __nosavedata;
  49
  50 static char hibernate_compressor[CRYPTO_MAX_ALG_NAME] = CONFIG_HIBERNATION_DEF_COMP;
  51
  52 /*
  53  * Compression/decompression algorithm to be used while saving/loading
  54  * image to/from disk. This would later be used in 'kernel/power/swap.c'
  55  * to allocate comp streams.
  56  */
  57 char hib_comp_algo[CRYPTO_MAX_ALG_NAME];
  58
  59 enum {
  60         HIBERNATION_INVALID,
  61         HIBERNATION_PLATFORM,
  62         HIBERNATION_SHUTDOWN,
  63         HIBERNATION_REBOOT,
  64 #ifdef CONFIG_SUSPEND
  65         HIBERNATION_SUSPEND,
  66 #endif
  67         HIBERNATION_TEST_RESUME,
  68         /* keep last */
  69         __HIBERNATION_AFTER_LAST
  70 };
  71 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  72 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  73
  74 static int hibernation_mode = HIBERNATION_SHUTDOWN;
  75
  76 bool freezer_test_done;
  77
  78 static const struct platform_hibernation_ops *hibernation_ops;
  79
  80 static atomic_t hibernate_atomic = ATOMIC_INIT(1);
  81
  82 bool hibernate_acquire(void)
  83 {
  84         return atomic_add_unless(&hibernate_atomic, -1, 0);
  85 }
  86
  87 void hibernate_release(void)
  88 {
  89         atomic_inc(&hibernate_atomic);
  90 }
  91
  92 bool hibernation_available(void)
  93 {
  94         return nohibernate == 0 &&
  95                 !security_locked_down(LOCKDOWN_HIBERNATION) &&
  96                 !secretmem_active() && !cxl_mem_active();
  97 }
  98
  99 /**
 100  * hibernation_set_ops - Set the global hibernate operations.
 101  * @ops: Hibernation operations to use in subsequent hibernation transitions.
 102  */
 103 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
 104 {
 105         unsigned int sleep_flags;
 106
 107         if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
 108             && ops->prepare && ops->finish && ops->enter && ops->pre_restore
 109             && ops->restore_cleanup && ops->leave)) {
 110                 WARN_ON(1);
 111                 return;
 112         }
 113
 114         sleep_flags = lock_system_sleep();
 115
 116         hibernation_ops = ops;
 117         if (ops)
 118                 hibernation_mode = HIBERNATION_PLATFORM;
 119         else if (hibernation_mode == HIBERNATION_PLATFORM)
 120                 hibernation_mode = HIBERNATION_SHUTDOWN;
 121
 122         unlock_system_sleep(sleep_flags);
 123 }
 124 EXPORT_SYMBOL_GPL(hibernation_set_ops);
 125
 126 static bool entering_platform_hibernation;
 127
 128 bool system_entering_hibernation(void)
 129 {
 130         return entering_platform_hibernation;
 131 }
 132 EXPORT_SYMBOL(system_entering_hibernation);
 133
 134 #ifdef CONFIG_PM_DEBUG
 135 static void hibernation_debug_sleep(void)
 136 {
 137         pr_info("debug: Waiting for 5 seconds.\n");
 138         mdelay(5000);
 139 }
 140
 141 static int hibernation_test(int level)
 142 {
 143         if (pm_test_level == level) {
 144                 hibernation_debug_sleep();
 145                 return 1;
 146         }
 147         return 0;
 148 }
 149 #else /* !CONFIG_PM_DEBUG */
 150 static int hibernation_test(int level) { return 0; }
 151 #endif /* !CONFIG_PM_DEBUG */
 152
 153 /**
 154  * platform_begin - Call platform to start hibernation.
 155  * @platform_mode: Whether or not to use the platform driver.
 156  */
 157 static int platform_begin(int platform_mode)
 158 {
 159         return (platform_mode && hibernation_ops) ?
 160                 hibernation_ops->begin(PMSG_FREEZE) : 0;
 161 }
 162
 163 /**
 164  * platform_end - Call platform to finish transition to the working state.
 165  * @platform_mode: Whether or not to use the platform driver.
 166  */
 167 static void platform_end(int platform_mode)
 168 {
 169         if (platform_mode && hibernation_ops)
 170                 hibernation_ops->end();
 171 }
 172
 173 /**
 174  * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 175  * @platform_mode: Whether or not to use the platform driver.
 176  *
 177  * Use the platform driver to prepare the system for creating a hibernate image,
 178  * if so configured, and return an error code if that fails.
 179  */
 180
 181 static int platform_pre_snapshot(int platform_mode)
 182 {
 183         return (platform_mode && hibernation_ops) ?
 184                 hibernation_ops->pre_snapshot() : 0;
 185 }
 186
 187 /**
 188  * platform_leave - Call platform to prepare a transition to the working state.
 189  * @platform_mode: Whether or not to use the platform driver.
 190  *
 191  * Use the platform driver prepare to prepare the machine for switching to the
 192  * normal mode of operation.
 193  *
 194  * This routine is called on one CPU with interrupts disabled.
 195  */
 196 static void platform_leave(int platform_mode)
 197 {
 198         if (platform_mode && hibernation_ops)
 199                 hibernation_ops->leave();
 200 }
 201
 202 /**
 203  * platform_finish - Call platform to switch the system to the working state.
 204  * @platform_mode: Whether or not to use the platform driver.
 205  *
 206  * Use the platform driver to switch the machine to the normal mode of
 207  * operation.
 208  *
 209  * This routine must be called after platform_prepare().
 210  */
 211 static void platform_finish(int platform_mode)
 212 {
 213         if (platform_mode && hibernation_ops)
 214                 hibernation_ops->finish();
 215 }
 216
 217 /**
 218  * platform_pre_restore - Prepare for hibernate image restoration.
 219  * @platform_mode: Whether or not to use the platform driver.
 220  *
 221  * Use the platform driver to prepare the system for resume from a hibernation
 222  * image.
 223  *
 224  * If the restore fails after this function has been called,
 225  * platform_restore_cleanup() must be called.
 226  */
 227 static int platform_pre_restore(int platform_mode)
 228 {
 229         return (platform_mode && hibernation_ops) ?
 230                 hibernation_ops->pre_restore() : 0;
 231 }
 232
 233 /**
 234  * platform_restore_cleanup - Switch to the working state after failing restore.
 235  * @platform_mode: Whether or not to use the platform driver.
 236  *
 237  * Use the platform driver to switch the system to the normal mode of operation
 238  * after a failing restore.
 239  *
 240  * If platform_pre_restore() has been called before the failing restore, this
 241  * function must be called too, regardless of the result of
 242  * platform_pre_restore().
 243  */
 244 static void platform_restore_cleanup(int platform_mode)
 245 {
 246         if (platform_mode && hibernation_ops)
 247                 hibernation_ops->restore_cleanup();
 248 }
 249
 250 /**
 251  * platform_recover - Recover from a failure to suspend devices.
 252  * @platform_mode: Whether or not to use the platform driver.
 253  */
 254 static void platform_recover(int platform_mode)
 255 {
 256         if (platform_mode && hibernation_ops && hibernation_ops->recover)
 257                 hibernation_ops->recover();
 258 }
 259
 260 /**
 261  * swsusp_show_speed - Print time elapsed between two events during hibernation.
 262  * @start: Starting event.
 263  * @stop: Final event.
 264  * @nr_pages: Number of memory pages processed between @start and @stop.
 265  * @msg: Additional diagnostic message to print.
 266  */
 267 void swsusp_show_speed(ktime_t start, ktime_t stop,
 268                       unsigned nr_pages, char *msg)
 269 {
 270         ktime_t diff;
 271         u64 elapsed_centisecs64;
 272         unsigned int centisecs;
 273         unsigned int k;
 274         unsigned int kps;
 275
 276         diff = ktime_sub(stop, start);
 277         elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 278         centisecs = elapsed_centisecs64;
 279         if (centisecs == 0)
 280                 centisecs = 1;  /* avoid div-by-zero */
 281         k = nr_pages * (PAGE_SIZE / 1024);
 282         kps = (k * 100) / centisecs;
 283         pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 284                 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 285                 (kps % 1000) / 10);
 286 }
 287
 288 __weak int arch_resume_nosmt(void)
 289 {
 290         return 0;
 291 }
 292
 293 /**
 294  * create_image - Create a hibernation image.
 295  * @platform_mode: Whether or not to use the platform driver.
 296  *
 297  * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 298  * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 299  *
 300  * Control reappears in this routine after the subsequent restore.
 301  */
 302 static int create_image(int platform_mode)
 303 {
 304         int error;
 305
 306         error = dpm_suspend_end(PMSG_FREEZE);
 307         if (error) {
 308                 pr_err("Some devices failed to power down, aborting\n");
 309                 return error;
 310         }
 311
 312         error = platform_pre_snapshot(platform_mode);
 313         if (error || hibernation_test(TEST_PLATFORM))
 314                 goto Platform_finish;
 315
 316         error = pm_sleep_disable_secondary_cpus();
 317         if (error || hibernation_test(TEST_CPUS))
 318                 goto Enable_cpus;
 319
 320         local_irq_disable();
 321
 322         system_state = SYSTEM_SUSPEND;
 323
 324         error = syscore_suspend();
 325         if (error) {
 326                 pr_err("Some system devices failed to power down, aborting\n");
 327                 goto Enable_irqs;
 328         }
 329
 330         if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 331                 goto Power_up;
 332
 333         in_suspend = 1;
 334         save_processor_state();
 335         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 336         error = swsusp_arch_suspend();
 337         /* Restore control flow magically appears here */
 338         restore_processor_state();
 339         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 340         if (error)
 341                 pr_err("Error %d creating image\n", error);
 342
 343         if (!in_suspend) {
 344                 events_check_enabled = false;
 345                 clear_or_poison_free_pages();
 346         }
 347
 348         platform_leave(platform_mode);
 349
 350  Power_up:
 351         syscore_resume();
 352
 353  Enable_irqs:
 354         system_state = SYSTEM_RUNNING;
 355         local_irq_enable();
 356
 357  Enable_cpus:
 358         pm_sleep_enable_secondary_cpus();
 359
 360         /* Allow architectures to do nosmt-specific post-resume dances */
 361         if (!in_suspend)
 362                 error = arch_resume_nosmt();
 363
 364  Platform_finish:
 365         platform_finish(platform_mode);
 366
 367         dpm_resume_start(in_suspend ?
 368                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 369
 370         return error;
 371 }
 372
 373 /**
 374  * hibernation_snapshot - Quiesce devices and create a hibernation image.
 375  * @platform_mode: If set, use platform driver to prepare for the transition.
 376  *
 377  * This routine must be called with system_transition_mutex held.
 378  */
 379 int hibernation_snapshot(int platform_mode)
 380 {
 381         pm_message_t msg;
 382         int error;
 383
 384         pm_suspend_clear_flags();
 385         error = platform_begin(platform_mode);
 386         if (error)
 387                 goto Close;
 388
 389         /* Preallocate image memory before shutting down devices. */
 390         error = hibernate_preallocate_memory();
 391         if (error)
 392                 goto Close;
 393
 394         error = freeze_kernel_threads();
 395         if (error)
 396                 goto Cleanup;
 397
 398         if (hibernation_test(TEST_FREEZER)) {
 399
 400                 /*
 401                  * Indicate to the caller that we are returning due to a
 402                  * successful freezer test.
 403                  */
 404                 freezer_test_done = true;
 405                 goto Thaw;
 406         }
 407
 408         error = dpm_prepare(PMSG_FREEZE);
 409         if (error) {
 410                 dpm_complete(PMSG_RECOVER);
 411                 goto Thaw;
 412         }
 413
 414         suspend_console();
 415         pm_restrict_gfp_mask();
 416
 417         error = dpm_suspend(PMSG_FREEZE);
 418
 419         if (error || hibernation_test(TEST_DEVICES))
 420                 platform_recover(platform_mode);
 421         else
 422                 error = create_image(platform_mode);
 423
 424         /*
 425          * In the case that we call create_image() above, the control
 426          * returns here (1) after the image has been created or the
 427          * image creation has failed and (2) after a successful restore.
 428          */
 429
 430         /* We may need to release the preallocated image pages here. */
 431         if (error || !in_suspend)
 432                 swsusp_free();
 433
 434         msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 435         dpm_resume(msg);
 436
 437         if (error || !in_suspend)
 438                 pm_restore_gfp_mask();
 439
 440         resume_console();
 441         dpm_complete(msg);
 442
 443  Close:
 444         platform_end(platform_mode);
 445         return error;
 446
 447  Thaw:
 448         thaw_kernel_threads();
 449  Cleanup:
 450         swsusp_free();
 451         goto Close;
 452 }
 453
 454 int __weak hibernate_resume_nonboot_cpu_disable(void)
 455 {
 456         return suspend_disable_secondary_cpus();
 457 }
 458
 459 /**
 460  * resume_target_kernel - Restore system state from a hibernation image.
 461  * @platform_mode: Whether or not to use the platform driver.
 462  *
 463  * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 464  * contents of highmem that have not been restored yet from the image and run
 465  * the low-level code that will restore the remaining contents of memory and
 466  * switch to the just restored target kernel.
 467  */
 468 static int resume_target_kernel(bool platform_mode)
 469 {
 470         int error;
 471
 472         error = dpm_suspend_end(PMSG_QUIESCE);
 473         if (error) {
 474                 pr_err("Some devices failed to power down, aborting resume\n");
 475                 return error;
 476         }
 477
 478         error = platform_pre_restore(platform_mode);
 479         if (error)
 480                 goto Cleanup;
 481
 482         cpuidle_pause();
 483
 484         error = hibernate_resume_nonboot_cpu_disable();
 485         if (error)
 486                 goto Enable_cpus;
 487
 488         local_irq_disable();
 489         system_state = SYSTEM_SUSPEND;
 490
 491         error = syscore_suspend();
 492         if (error)
 493                 goto Enable_irqs;
 494
 495         save_processor_state();
 496         error = restore_highmem();
 497         if (!error) {
 498                 error = swsusp_arch_resume();
 499                 /*
 500                  * The code below is only ever reached in case of a failure.
 501                  * Otherwise, execution continues at the place where
 502                  * swsusp_arch_suspend() was called.
 503                  */
 504                 BUG_ON(!error);
 505                 /*
 506                  * This call to restore_highmem() reverts the changes made by
 507                  * the previous one.
 508                  */
 509                 restore_highmem();
 510         }
 511         /*
 512          * The only reason why swsusp_arch_resume() can fail is memory being
 513          * very tight, so we have to free it as soon as we can to avoid
 514          * subsequent failures.
 515          */
 516         swsusp_free();
 517         restore_processor_state();
 518         touch_softlockup_watchdog();
 519
 520         syscore_resume();
 521
 522  Enable_irqs:
 523         system_state = SYSTEM_RUNNING;
 524         local_irq_enable();
 525
 526  Enable_cpus:
 527         pm_sleep_enable_secondary_cpus();
 528
 529  Cleanup:
 530         platform_restore_cleanup(platform_mode);
 531
 532         dpm_resume_start(PMSG_RECOVER);
 533
 534         return error;
 535 }
 536
 537 /**
 538  * hibernation_restore - Quiesce devices and restore from a hibernation image.
 539  * @platform_mode: If set, use platform driver to prepare for the transition.
 540  *
 541  * This routine must be called with system_transition_mutex held.  If it is
 542  * successful, control reappears in the restored target kernel in
 543  * hibernation_snapshot().
 544  */
 545 int hibernation_restore(int platform_mode)
 546 {
 547         int error;
 548
 549         pm_prepare_console();
 550         suspend_console();
 551         pm_restrict_gfp_mask();
 552         error = dpm_suspend_start(PMSG_QUIESCE);
 553         if (!error) {
 554                 error = resume_target_kernel(platform_mode);
 555                 /*
 556                  * The above should either succeed and jump to the new kernel,
 557                  * or return with an error. Otherwise things are just
 558                  * undefined, so let's be paranoid.
 559                  */
 560                 BUG_ON(!error);
 561         }
 562         dpm_resume_end(PMSG_RECOVER);
 563         pm_restore_gfp_mask();
 564         resume_console();
 565         pm_restore_console();
 566         return error;
 567 }
 568
 569 /**
 570  * hibernation_platform_enter - Power off the system using the platform driver.
 571  */
 572 int hibernation_platform_enter(void)
 573 {
 574         int error;
 575
 576         if (!hibernation_ops)
 577                 return -ENOSYS;
 578
 579         /*
 580          * We have cancelled the power transition by running
 581          * hibernation_ops->finish() before saving the image, so we should let
 582          * the firmware know that we're going to enter the sleep state after all
 583          */
 584         error = hibernation_ops->begin(PMSG_HIBERNATE);
 585         if (error)
 586                 goto Close;
 587
 588         entering_platform_hibernation = true;
 589         suspend_console();
 590         error = dpm_suspend_start(PMSG_HIBERNATE);
 591         if (error) {
 592                 if (hibernation_ops->recover)
 593                         hibernation_ops->recover();
 594                 goto Resume_devices;
 595         }
 596
 597         error = dpm_suspend_end(PMSG_HIBERNATE);
 598         if (error)
 599                 goto Resume_devices;
 600
 601         error = hibernation_ops->prepare();
 602         if (error)
 603                 goto Platform_finish;
 604
 605         error = pm_sleep_disable_secondary_cpus();
 606         if (error)
 607                 goto Enable_cpus;
 608
 609         local_irq_disable();
 610         system_state = SYSTEM_SUSPEND;
 611         syscore_suspend();
 612         if (pm_wakeup_pending()) {
 613                 error = -EAGAIN;
 614                 goto Power_up;
 615         }
 616
 617         hibernation_ops->enter();
 618         /* We should never get here */
 619         while (1);
 620
 621  Power_up:
 622         syscore_resume();
 623         system_state = SYSTEM_RUNNING;
 624         local_irq_enable();
 625
 626  Enable_cpus:
 627         pm_sleep_enable_secondary_cpus();
 628
 629  Platform_finish:
 630         hibernation_ops->finish();
 631
 632         dpm_resume_start(PMSG_RESTORE);
 633
 634  Resume_devices:
 635         entering_platform_hibernation = false;
 636         dpm_resume_end(PMSG_RESTORE);
 637         resume_console();
 638
 639  Close:
 640         hibernation_ops->end();
 641
 642         return error;
 643 }
 644
 645 /**
 646  * power_down - Shut the machine down for hibernation.
 647  *
 648  * Use the platform driver, if configured, to put the system into the sleep
 649  * state corresponding to hibernation, or try to power it off or reboot,
 650  * depending on the value of hibernation_mode.
 651  */
 652 static void power_down(void)
 653 {
 654         int error;
 655
 656 #ifdef CONFIG_SUSPEND
 657         if (hibernation_mode == HIBERNATION_SUSPEND) {
 658                 error = suspend_devices_and_enter(mem_sleep_current);
 659                 if (error) {
 660                         hibernation_mode = hibernation_ops ?
 661                                                 HIBERNATION_PLATFORM :
 662                                                 HIBERNATION_SHUTDOWN;
 663                 } else {
 664                         /* Restore swap signature. */
 665                         error = swsusp_unmark();
 666                         if (error)
 667                                 pr_err("Swap will be unusable! Try swapon -a.\n");
 668
 669                         return;
 670                 }
 671         }
 672 #endif
 673
 674         switch (hibernation_mode) {
 675         case HIBERNATION_REBOOT:
 676                 kernel_restart(NULL);
 677                 break;
 678         case HIBERNATION_PLATFORM:
 679                 error = hibernation_platform_enter();
 680                 if (error == -EAGAIN || error == -EBUSY) {
 681                         swsusp_unmark();
 682                         events_check_enabled = false;
 683                         pr_info("Wakeup event detected during hibernation, rolling back.\n");
 684                         return;
 685                 }
 686                 fallthrough;
 687         case HIBERNATION_SHUTDOWN:
 688                 if (kernel_can_power_off()) {
 689                         entering_platform_hibernation = true;
 690                         kernel_power_off();
 691                         entering_platform_hibernation = false;
 692                 }
 693                 break;
 694         }
 695         kernel_halt();
 696         /*
 697          * Valid image is on the disk, if we continue we risk serious data
 698          * corruption after resume.
 699          */
 700         pr_crit("Power down manually\n");
 701         while (1)
 702                 cpu_relax();
 703 }
 704
 705 static int load_image_and_restore(void)
 706 {
 707         int error;
 708         unsigned int flags;
 709
 710         pm_pr_dbg("Loading hibernation image.\n");
 711
 712         lock_device_hotplug();
 713         error = create_basic_memory_bitmaps();
 714         if (error) {
 715                 swsusp_close();
 716                 goto Unlock;
 717         }
 718
 719         error = swsusp_read(&flags);
 720         swsusp_close();
 721         if (!error)
 722                 error = hibernation_restore(flags & SF_PLATFORM_MODE);
 723
 724         pr_err("Failed to load image, recovering.\n");
 725         swsusp_free();
 726         free_basic_memory_bitmaps();
 727  Unlock:
 728         unlock_device_hotplug();
 729
 730         return error;
 731 }
 732
 733 #define COMPRESSION_ALGO_LZO "lzo"
 734 #define COMPRESSION_ALGO_LZ4 "lz4"
 735
 736 /**
 737  * hibernate - Carry out system hibernation, including saving the image.
 738  */
 739 int hibernate(void)
 740 {
 741         bool snapshot_test = false;
 742         unsigned int sleep_flags;
 743         int error;
 744
 745         if (!hibernation_available()) {
 746                 pm_pr_dbg("Hibernation not available.\n");
 747                 return -EPERM;
 748         }
 749
 750         /*
 751          * Query for the compression algorithm support if compression is enabled.
 752          */
 753         if (!nocompress) {
 754                 strscpy(hib_comp_algo, hibernate_compressor, sizeof(hib_comp_algo));
 755                 if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
 756                         pr_err("%s compression is not available\n", hib_comp_algo);
 757                         return -EOPNOTSUPP;
 758                 }
 759         }
 760
 761         sleep_flags = lock_system_sleep();
 762         /* The snapshot device should not be opened while we're running */
 763         if (!hibernate_acquire()) {
 764                 error = -EBUSY;
 765                 goto Unlock;
 766         }
 767
 768         pr_info("hibernation entry\n");
 769         pm_prepare_console();
 770         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 771         if (error)
 772                 goto Restore;
 773
 774         ksys_sync_helper();
 775
 776         error = freeze_processes();
 777         if (error)
 778                 goto Exit;
 779
 780         lock_device_hotplug();
 781         /* Allocate memory management structures */
 782         error = create_basic_memory_bitmaps();
 783         if (error)
 784                 goto Thaw;
 785
 786         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 787         if (error || freezer_test_done)
 788                 goto Free_bitmaps;
 789
 790         if (in_suspend) {
 791                 unsigned int flags = 0;
 792
 793                 if (hibernation_mode == HIBERNATION_PLATFORM)
 794                         flags |= SF_PLATFORM_MODE;
 795                 if (nocompress) {
 796                         flags |= SF_NOCOMPRESS_MODE;
 797                 } else {
 798                         flags |= SF_CRC32_MODE;
 799
 800                         /*
 801                          * By default, LZO compression is enabled. Use SF_COMPRESSION_ALG_LZ4
 802                          * to override this behaviour and use LZ4.
 803                          *
 804                          * Refer kernel/power/power.h for more details
 805                          */
 806
 807                         if (!strcmp(hib_comp_algo, COMPRESSION_ALGO_LZ4))
 808                                 flags |= SF_COMPRESSION_ALG_LZ4;
 809                         else
 810                                 flags |= SF_COMPRESSION_ALG_LZO;
 811                 }
 812
 813                 pm_pr_dbg("Writing hibernation image.\n");
 814                 error = swsusp_write(flags);
 815                 swsusp_free();
 816                 if (!error) {
 817                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
 818                                 snapshot_test = true;
 819                         else
 820                                 power_down();
 821                 }
 822                 in_suspend = 0;
 823                 pm_restore_gfp_mask();
 824         } else {
 825                 pm_pr_dbg("Hibernation image restored successfully.\n");
 826         }
 827
 828  Free_bitmaps:
 829         free_basic_memory_bitmaps();
 830  Thaw:
 831         unlock_device_hotplug();
 832         if (snapshot_test) {
 833                 pm_pr_dbg("Checking hibernation image\n");
 834                 error = swsusp_check(false);
 835                 if (!error)
 836                         error = load_image_and_restore();
 837         }
 838         thaw_processes();
 839
 840         /* Don't bother checking whether freezer_test_done is true */
 841         freezer_test_done = false;
 842  Exit:
 843         pm_notifier_call_chain(PM_POST_HIBERNATION);
 844  Restore:
 845         pm_restore_console();
 846         hibernate_release();
 847  Unlock:
 848         unlock_system_sleep(sleep_flags);
 849         pr_info("hibernation exit\n");
 850
 851         return error;
 852 }
 853
 854 /**
 855  * hibernate_quiet_exec - Execute a function with all devices frozen.
 856  * @func: Function to execute.
 857  * @data: Data pointer to pass to @func.
 858  *
 859  * Return the @func return value or an error code if it cannot be executed.
 860  */
 861 int hibernate_quiet_exec(int (*func)(void *data), void *data)
 862 {
 863         unsigned int sleep_flags;
 864         int error;
 865
 866         sleep_flags = lock_system_sleep();
 867
 868         if (!hibernate_acquire()) {
 869                 error = -EBUSY;
 870                 goto unlock;
 871         }
 872
 873         pm_prepare_console();
 874
 875         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 876         if (error)
 877                 goto restore;
 878
 879         error = freeze_processes();
 880         if (error)
 881                 goto exit;
 882
 883         lock_device_hotplug();
 884
 885         pm_suspend_clear_flags();
 886
 887         error = platform_begin(true);
 888         if (error)
 889                 goto thaw;
 890
 891         error = freeze_kernel_threads();
 892         if (error)
 893                 goto thaw;
 894
 895         error = dpm_prepare(PMSG_FREEZE);
 896         if (error)
 897                 goto dpm_complete;
 898
 899         suspend_console();
 900
 901         error = dpm_suspend(PMSG_FREEZE);
 902         if (error)
 903                 goto dpm_resume;
 904
 905         error = dpm_suspend_end(PMSG_FREEZE);
 906         if (error)
 907                 goto dpm_resume;
 908
 909         error = platform_pre_snapshot(true);
 910         if (error)
 911                 goto skip;
 912
 913         error = func(data);
 914
 915 skip:
 916         platform_finish(true);
 917
 918         dpm_resume_start(PMSG_THAW);
 919
 920 dpm_resume:
 921         dpm_resume(PMSG_THAW);
 922
 923         resume_console();
 924
 925 dpm_complete:
 926         dpm_complete(PMSG_THAW);
 927
 928         thaw_kernel_threads();
 929
 930 thaw:
 931         platform_end(true);
 932
 933         unlock_device_hotplug();
 934
 935         thaw_processes();
 936
 937 exit:
 938         pm_notifier_call_chain(PM_POST_HIBERNATION);
 939
 940 restore:
 941         pm_restore_console();
 942
 943         hibernate_release();
 944
 945 unlock:
 946         unlock_system_sleep(sleep_flags);
 947
 948         return error;
 949 }
 950 EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 951
 952 static int __init find_resume_device(void)
 953 {
 954         if (!strlen(resume_file))
 955                 return -ENOENT;
 956
 957         pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 958
 959         if (resume_delay) {
 960                 pr_info("Waiting %dsec before reading resume device ...\n",
 961                         resume_delay);
 962                 ssleep(resume_delay);
 963         }
 964
 965         /* Check if the device is there */
 966         if (!early_lookup_bdev(resume_file, &swsusp_resume_device))
 967                 return 0;
 968
 969         /*
 970          * Some device discovery might still be in progress; we need to wait for
 971          * this to finish.
 972          */
 973         wait_for_device_probe();
 974         if (resume_wait) {
 975                 while (early_lookup_bdev(resume_file, &swsusp_resume_device))
 976                         msleep(10);
 977                 async_synchronize_full();
 978         }
 979
 980         return early_lookup_bdev(resume_file, &swsusp_resume_device);
 981 }
 982
 983 static int software_resume(void)
 984 {
 985         int error;
 986
 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
 992         mutex_lock(&system_transition_mutex);
 993         error = swsusp_check(true);
 994         if (error)
 995                 goto Unlock;
 996
 997         /*
 998          * Check if the hibernation image is compressed. If so, query for
 999          * the algorithm support.
1000          */
1001         if (!(swsusp_header_flags & SF_NOCOMPRESS_MODE)) {
1002                 if (swsusp_header_flags & SF_COMPRESSION_ALG_LZ4)
1003                         strscpy(hib_comp_algo, COMPRESSION_ALGO_LZ4, sizeof(hib_comp_algo));
1004                 else
1005                         strscpy(hib_comp_algo, COMPRESSION_ALGO_LZO, sizeof(hib_comp_algo));
1006                 if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
1007                         pr_err("%s compression is not available\n", hib_comp_algo);
1008                         error = -EOPNOTSUPP;
1009                         goto Unlock;
1010                 }
1011         }
1012
1013         /* The snapshot device should not be opened while we're running */
1014         if (!hibernate_acquire()) {
1015                 error = -EBUSY;
1016                 swsusp_close();
1017                 goto Unlock;
1018         }
1019
1020         pr_info("resume from hibernation\n");
1021         pm_prepare_console();
1022         error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
1023         if (error)
1024                 goto Restore;
1025
1026         pm_pr_dbg("Preparing processes for hibernation restore.\n");
1027         error = freeze_processes();
1028         if (error)
1029                 goto Close_Finish;
1030
1031         error = freeze_kernel_threads();
1032         if (error) {
1033                 thaw_processes();
1034                 goto Close_Finish;
1035         }
1036
1037         error = load_image_and_restore();
1038         thaw_processes();
1039  Finish:
1040         pm_notifier_call_chain(PM_POST_RESTORE);
1041  Restore:
1042         pm_restore_console();
1043         pr_info("resume failed (%d)\n", error);
1044         hibernate_release();
1045         /* For success case, the suspend path will release the lock */
1046  Unlock:
1047         mutex_unlock(&system_transition_mutex);
1048         pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1049         return error;
1050  Close_Finish:
1051         swsusp_close();
1052         goto Finish;
1053 }
1054
1055 /**
1056  * software_resume_initcall - Resume from a saved hibernation image.
1057  *
1058  * This routine is called as a late initcall, when all devices have been
1059  * discovered and initialized already.
1060  *
1061  * The image reading code is called to see if there is a hibernation image
1062  * available for reading.  If that is the case, devices are quiesced and the
1063  * contents of memory is restored from the saved image.
1064  *
1065  * If this is successful, control reappears in the restored target kernel in
1066  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
1067  * attempts to recover gracefully and make the kernel return to the normal mode
1068  * of operation.
1069  */
1070 static int __init software_resume_initcall(void)
1071 {
1072         /*
1073          * If the user said "noresume".. bail out early.
1074          */
1075         if (noresume || !hibernation_available())
1076                 return 0;
1077
1078         if (!swsusp_resume_device) {
1079                 int error = find_resume_device();
1080
1081                 if (error)
1082                         return error;
1083         }
1084
1085         return software_resume();
1086 }
1087 late_initcall_sync(software_resume_initcall);
1088
1089
1090 static const char * const hibernation_modes[] = {
1091         [HIBERNATION_PLATFORM]  = "platform",
1092         [HIBERNATION_SHUTDOWN]  = "shutdown",
1093         [HIBERNATION_REBOOT]    = "reboot",
1094 #ifdef CONFIG_SUSPEND
1095         [HIBERNATION_SUSPEND]   = "suspend",
1096 #endif
1097         [HIBERNATION_TEST_RESUME]       = "test_resume",
1098 };
1099
1100 /*
1101  * /sys/power/disk - Control hibernation mode.
1102  *
1103  * Hibernation can be handled in several ways.  There are a few different ways
1104  * to put the system into the sleep state: using the platform driver (e.g. ACPI
1105  * or other hibernation_ops), powering it off or rebooting it (for testing
1106  * mostly).
1107  *
1108  * The sysfs file /sys/power/disk provides an interface for selecting the
1109  * hibernation mode to use.  Reading from this file causes the available modes
1110  * to be printed.  There are 3 modes that can be supported:
1111  *
1112  *      'platform'
1113  *      'shutdown'
1114  *      'reboot'
1115  *
1116  * If a platform hibernation driver is in use, 'platform' will be supported
1117  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1118  * The selected option (i.e. the one corresponding to the current value of
1119  * hibernation_mode) is enclosed by a square bracket.
1120  *
1121  * To select a given hibernation mode it is necessary to write the mode's
1122  * string representation (as returned by reading from /sys/power/disk) back
1123  * into /sys/power/disk.
1124  */
1125
1126 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1127                          char *buf)
1128 {
1129         ssize_t count = 0;
1130         int i;
1131
1132         if (!hibernation_available())
1133                 return sysfs_emit(buf, "[disabled]\n");
1134
1135         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1136                 if (!hibernation_modes[i])
1137                         continue;
1138                 switch (i) {
1139                 case HIBERNATION_SHUTDOWN:
1140                 case HIBERNATION_REBOOT:
1141 #ifdef CONFIG_SUSPEND
1142                 case HIBERNATION_SUSPEND:
1143 #endif
1144                 case HIBERNATION_TEST_RESUME:
1145                         break;
1146                 case HIBERNATION_PLATFORM:
1147                         if (hibernation_ops)
1148                                 break;
1149                         /* not a valid mode, continue with loop */
1150                         continue;
1151                 }
1152                 if (i == hibernation_mode)
1153                         count += sysfs_emit_at(buf, count, "[%s] ", hibernation_modes[i]);
1154                 else
1155                         count += sysfs_emit_at(buf, count, "%s ", hibernation_modes[i]);
1156         }
1157
1158         /* Convert the last space to a newline if needed. */
1159         if (count > 0)
1160                 buf[count - 1] = '\n';
1161
1162         return count;
1163 }
1164
1165 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1166                           const char *buf, size_t n)
1167 {
1168         int mode = HIBERNATION_INVALID;
1169         unsigned int sleep_flags;
1170         int error = 0;
1171         int len;
1172         char *p;
1173         int i;
1174
1175         if (!hibernation_available())
1176                 return -EPERM;
1177
1178         p = memchr(buf, '\n', n);
1179         len = p ? p - buf : n;
1180
1181         sleep_flags = lock_system_sleep();
1182         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1183                 if (len == strlen(hibernation_modes[i])
1184                     && !strncmp(buf, hibernation_modes[i], len)) {
1185                         mode = i;
1186                         break;
1187                 }
1188         }
1189         if (mode != HIBERNATION_INVALID) {
1190                 switch (mode) {
1191                 case HIBERNATION_SHUTDOWN:
1192                 case HIBERNATION_REBOOT:
1193 #ifdef CONFIG_SUSPEND
1194                 case HIBERNATION_SUSPEND:
1195 #endif
1196                 case HIBERNATION_TEST_RESUME:
1197                         hibernation_mode = mode;
1198                         break;
1199                 case HIBERNATION_PLATFORM:
1200                         if (hibernation_ops)
1201                                 hibernation_mode = mode;
1202                         else
1203                                 error = -EINVAL;
1204                 }
1205         } else
1206                 error = -EINVAL;
1207
1208         if (!error)
1209                 pm_pr_dbg("Hibernation mode set to '%s'\n",
1210                                hibernation_modes[mode]);
1211         unlock_system_sleep(sleep_flags);
1212         return error ? error : n;
1213 }
1214
1215 power_attr(disk);
1216
1217 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1218                            char *buf)
1219 {
1220         return sysfs_emit(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1221                           MINOR(swsusp_resume_device));
1222 }
1223
1224 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1225                             const char *buf, size_t n)
1226 {
1227         unsigned int sleep_flags;
1228         int len = n;
1229         char *name;
1230         dev_t dev;
1231         int error;
1232
1233         if (!hibernation_available())
1234                 return n;
1235
1236         if (len && buf[len-1] == '\n')
1237                 len--;
1238         name = kstrndup(buf, len, GFP_KERNEL);
1239         if (!name)
1240                 return -ENOMEM;
1241
1242         error = lookup_bdev(name, &dev);
1243         if (error) {
1244                 unsigned maj, min, offset;
1245                 char *p, dummy;
1246
1247                 error = 0;
1248                 if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
1249                     sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
1250                                 &dummy) == 3) {
1251                         dev = MKDEV(maj, min);
1252                         if (maj != MAJOR(dev) || min != MINOR(dev))
1253                                 error = -EINVAL;
1254                 } else {
1255                         dev = new_decode_dev(simple_strtoul(name, &p, 16));
1256                         if (*p)
1257                                 error = -EINVAL;
1258                 }
1259         }
1260         kfree(name);
1261         if (error)
1262                 return error;
1263
1264         sleep_flags = lock_system_sleep();
1265         swsusp_resume_device = dev;
1266         unlock_system_sleep(sleep_flags);
1267
1268         pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1269                   swsusp_resume_device);
1270         noresume = 0;
1271         software_resume();
1272         return n;
1273 }
1274
1275 power_attr(resume);
1276
1277 static ssize_t resume_offset_show(struct kobject *kobj,
1278                                   struct kobj_attribute *attr, char *buf)
1279 {
1280         return sysfs_emit(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1281 }
1282
1283 static ssize_t resume_offset_store(struct kobject *kobj,
1284                                    struct kobj_attribute *attr, const char *buf,
1285                                    size_t n)
1286 {
1287         unsigned long long offset;
1288         int rc;
1289
1290         rc = kstrtoull(buf, 0, &offset);
1291         if (rc)
1292                 return rc;
1293         swsusp_resume_block = offset;
1294
1295         return n;
1296 }
1297
1298 power_attr(resume_offset);
1299
1300 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1301                                char *buf)
1302 {
1303         return sysfs_emit(buf, "%lu\n", image_size);
1304 }
1305
1306 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1307                                 const char *buf, size_t n)
1308 {
1309         unsigned long size;
1310
1311         if (sscanf(buf, "%lu", &size) == 1) {
1312                 image_size = size;
1313                 return n;
1314         }
1315
1316         return -EINVAL;
1317 }
1318
1319 power_attr(image_size);
1320
1321 static ssize_t reserved_size_show(struct kobject *kobj,
1322                                   struct kobj_attribute *attr, char *buf)
1323 {
1324         return sysfs_emit(buf, "%lu\n", reserved_size);
1325 }
1326
1327 static ssize_t reserved_size_store(struct kobject *kobj,
1328                                    struct kobj_attribute *attr,
1329                                    const char *buf, size_t n)
1330 {
1331         unsigned long size;
1332
1333         if (sscanf(buf, "%lu", &size) == 1) {
1334                 reserved_size = size;
1335                 return n;
1336         }
1337
1338         return -EINVAL;
1339 }
1340
1341 power_attr(reserved_size);
1342
1343 static struct attribute *g[] = {
1344         &disk_attr.attr,
1345         &resume_offset_attr.attr,
1346         &resume_attr.attr,
1347         &image_size_attr.attr,
1348         &reserved_size_attr.attr,
1349         NULL,
1350 };
1351
1352
1353 static const struct attribute_group attr_group = {
1354         .attrs = g,
1355 };
1356
1357
1358 static int __init pm_disk_init(void)
1359 {
1360         return sysfs_create_group(power_kobj, &attr_group);
1361 }
1362
1363 core_initcall(pm_disk_init);
1364
1365
1366 static int __init resume_setup(char *str)
1367 {
1368         if (noresume)
1369                 return 1;
1370
1371         strscpy(resume_file, str);
1372         return 1;
1373 }
1374
1375 static int __init resume_offset_setup(char *str)
1376 {
1377         unsigned long long offset;
1378
1379         if (noresume)
1380                 return 1;
1381
1382         if (sscanf(str, "%llu", &offset) == 1)
1383                 swsusp_resume_block = offset;
1384
1385         return 1;
1386 }
1387
1388 static int __init hibernate_setup(char *str)
1389 {
1390         if (!strncmp(str, "noresume", 8)) {
1391                 noresume = 1;
1392         } else if (!strncmp(str, "nocompress", 10)) {
1393                 nocompress = 1;
1394         } else if (!strncmp(str, "no", 2)) {
1395                 noresume = 1;
1396                 nohibernate = 1;
1397         } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1398                    && !strncmp(str, "protect_image", 13)) {
1399                 enable_restore_image_protection();
1400         }
1401         return 1;
1402 }
1403
1404 static int __init noresume_setup(char *str)
1405 {
1406         noresume = 1;
1407         return 1;
1408 }
1409
1410 static int __init resumewait_setup(char *str)
1411 {
1412         resume_wait = 1;
1413         return 1;
1414 }
1415
1416 static int __init resumedelay_setup(char *str)
1417 {
1418         int rc = kstrtouint(str, 0, &resume_delay);
1419
1420         if (rc)
1421                 pr_warn("resumedelay: bad option string '%s'\n", str);
1422         return 1;
1423 }
1424
1425 static int __init nohibernate_setup(char *str)
1426 {
1427         noresume = 1;
1428         nohibernate = 1;
1429         return 1;
1430 }
1431
1432 static const char * const comp_alg_enabled[] = {
1433 #if IS_ENABLED(CONFIG_CRYPTO_LZO)
1434         COMPRESSION_ALGO_LZO,
1435 #endif
1436 #if IS_ENABLED(CONFIG_CRYPTO_LZ4)
1437         COMPRESSION_ALGO_LZ4,
1438 #endif
1439 };
1440
1441 static int hibernate_compressor_param_set(const char *compressor,
1442                 const struct kernel_param *kp)
1443 {
1444         unsigned int sleep_flags;
1445         int index, ret;
1446
1447         sleep_flags = lock_system_sleep();
1448
1449         index = sysfs_match_string(comp_alg_enabled, compressor);
1450         if (index >= 0) {
1451                 ret = param_set_copystring(comp_alg_enabled[index], kp);
1452                 if (!ret)
1453                         strscpy(hib_comp_algo, comp_alg_enabled[index],
1454                                 sizeof(hib_comp_algo));
1455         } else {
1456                 ret = index;
1457         }
1458
1459         unlock_system_sleep(sleep_flags);
1460
1461         if (ret)
1462                 pr_debug("Cannot set specified compressor %s\n",
1463                          compressor);
1464
1465         return ret;
1466 }
1467
1468 static const struct kernel_param_ops hibernate_compressor_param_ops = {
1469         .set    = hibernate_compressor_param_set,
1470         .get    = param_get_string,
1471 };
1472
1473 static struct kparam_string hibernate_compressor_param_string = {
1474         .maxlen = sizeof(hibernate_compressor),
1475         .string = hibernate_compressor,
1476 };
1477
1478 module_param_cb(compressor, &hibernate_compressor_param_ops,
1479                 &hibernate_compressor_param_string, 0644);
1480 MODULE_PARM_DESC(compressor,
1481                  "Compression algorithm to be used with hibernation");
1482
1483 __setup("noresume", noresume_setup);
1484 __setup("resume_offset=", resume_offset_setup);
1485 __setup("resume=", resume_setup);
1486 __setup("hibernate=", hibernate_setup);
1487 __setup("resumewait", resumewait_setup);
1488 __setup("resumedelay=", resumedelay_setup);
1489 __setup("nohibernate", nohibernate_setup);