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
 612         error = syscore_suspend();
 613         if (error)
 614                 goto Enable_irqs;
 615
 616         if (pm_wakeup_pending()) {
 617                 error = -EAGAIN;
 618                 goto Power_up;
 619         }
 620
 621         hibernation_ops->enter();
 622         /* We should never get here */
 623         while (1);
 624
 625  Power_up:
 626         syscore_resume();
 627  Enable_irqs:
 628         system_state = SYSTEM_RUNNING;
 629         local_irq_enable();
 630
 631  Enable_cpus:
 632         pm_sleep_enable_secondary_cpus();
 633
 634  Platform_finish:
 635         hibernation_ops->finish();
 636
 637         dpm_resume_start(PMSG_RESTORE);
 638
 639  Resume_devices:
 640         entering_platform_hibernation = false;
 641         dpm_resume_end(PMSG_RESTORE);
 642         resume_console();
 643
 644  Close:
 645         hibernation_ops->end();
 646
 647         return error;
 648 }
 649
 650 /**
 651  * power_down - Shut the machine down for hibernation.
 652  *
 653  * Use the platform driver, if configured, to put the system into the sleep
 654  * state corresponding to hibernation, or try to power it off or reboot,
 655  * depending on the value of hibernation_mode.
 656  */
 657 static void power_down(void)
 658 {
 659         int error;
 660
 661 #ifdef CONFIG_SUSPEND
 662         if (hibernation_mode == HIBERNATION_SUSPEND) {
 663                 error = suspend_devices_and_enter(mem_sleep_current);
 664                 if (error) {
 665                         hibernation_mode = hibernation_ops ?
 666                                                 HIBERNATION_PLATFORM :
 667                                                 HIBERNATION_SHUTDOWN;
 668                 } else {
 669                         /* Restore swap signature. */
 670                         error = swsusp_unmark();
 671                         if (error)
 672                                 pr_err("Swap will be unusable! Try swapon -a.\n");
 673
 674                         return;
 675                 }
 676         }
 677 #endif
 678
 679         switch (hibernation_mode) {
 680         case HIBERNATION_REBOOT:
 681                 kernel_restart(NULL);
 682                 break;
 683         case HIBERNATION_PLATFORM:
 684                 error = hibernation_platform_enter();
 685                 if (error == -EAGAIN || error == -EBUSY) {
 686                         swsusp_unmark();
 687                         events_check_enabled = false;
 688                         pr_info("Wakeup event detected during hibernation, rolling back.\n");
 689                         return;
 690                 }
 691                 fallthrough;
 692         case HIBERNATION_SHUTDOWN:
 693                 if (kernel_can_power_off()) {
 694                         entering_platform_hibernation = true;
 695                         kernel_power_off();
 696                         entering_platform_hibernation = false;
 697                 }
 698                 break;
 699         }
 700         kernel_halt();
 701         /*
 702          * Valid image is on the disk, if we continue we risk serious data
 703          * corruption after resume.
 704          */
 705         pr_crit("Power down manually\n");
 706         while (1)
 707                 cpu_relax();
 708 }
 709
 710 static int load_image_and_restore(void)
 711 {
 712         int error;
 713         unsigned int flags;
 714
 715         pm_pr_dbg("Loading hibernation image.\n");
 716
 717         lock_device_hotplug();
 718         error = create_basic_memory_bitmaps();
 719         if (error) {
 720                 swsusp_close();
 721                 goto Unlock;
 722         }
 723
 724         error = swsusp_read(&flags);
 725         swsusp_close();
 726         if (!error)
 727                 error = hibernation_restore(flags & SF_PLATFORM_MODE);
 728
 729         pr_err("Failed to load image, recovering.\n");
 730         swsusp_free();
 731         free_basic_memory_bitmaps();
 732  Unlock:
 733         unlock_device_hotplug();
 734
 735         return error;
 736 }
 737
 738 #define COMPRESSION_ALGO_LZO "lzo"
 739 #define COMPRESSION_ALGO_LZ4 "lz4"
 740
 741 /**
 742  * hibernate - Carry out system hibernation, including saving the image.
 743  */
 744 int hibernate(void)
 745 {
 746         bool snapshot_test = false;
 747         unsigned int sleep_flags;
 748         int error;
 749
 750         if (!hibernation_available()) {
 751                 pm_pr_dbg("Hibernation not available.\n");
 752                 return -EPERM;
 753         }
 754
 755         /*
 756          * Query for the compression algorithm support if compression is enabled.
 757          */
 758         if (!nocompress) {
 759                 strscpy(hib_comp_algo, hibernate_compressor, sizeof(hib_comp_algo));
 760                 if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
 761                         pr_err("%s compression is not available\n", hib_comp_algo);
 762                         return -EOPNOTSUPP;
 763                 }
 764         }
 765
 766         sleep_flags = lock_system_sleep();
 767         /* The snapshot device should not be opened while we're running */
 768         if (!hibernate_acquire()) {
 769                 error = -EBUSY;
 770                 goto Unlock;
 771         }
 772
 773         pr_info("hibernation entry\n");
 774         pm_prepare_console();
 775         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 776         if (error)
 777                 goto Restore;
 778
 779         ksys_sync_helper();
 780
 781         error = freeze_processes();
 782         if (error)
 783                 goto Exit;
 784
 785         lock_device_hotplug();
 786         /* Allocate memory management structures */
 787         error = create_basic_memory_bitmaps();
 788         if (error)
 789                 goto Thaw;
 790
 791         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 792         if (error || freezer_test_done)
 793                 goto Free_bitmaps;
 794
 795         if (in_suspend) {
 796                 unsigned int flags = 0;
 797
 798                 if (hibernation_mode == HIBERNATION_PLATFORM)
 799                         flags |= SF_PLATFORM_MODE;
 800                 if (nocompress) {
 801                         flags |= SF_NOCOMPRESS_MODE;
 802                 } else {
 803                         flags |= SF_CRC32_MODE;
 804
 805                         /*
 806                          * By default, LZO compression is enabled. Use SF_COMPRESSION_ALG_LZ4
 807                          * to override this behaviour and use LZ4.
 808                          *
 809                          * Refer kernel/power/power.h for more details
 810                          */
 811
 812                         if (!strcmp(hib_comp_algo, COMPRESSION_ALGO_LZ4))
 813                                 flags |= SF_COMPRESSION_ALG_LZ4;
 814                         else
 815                                 flags |= SF_COMPRESSION_ALG_LZO;
 816                 }
 817
 818                 pm_pr_dbg("Writing hibernation image.\n");
 819                 error = swsusp_write(flags);
 820                 swsusp_free();
 821                 if (!error) {
 822                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
 823                                 snapshot_test = true;
 824                         else
 825                                 power_down();
 826                 }
 827                 in_suspend = 0;
 828                 pm_restore_gfp_mask();
 829         } else {
 830                 pm_pr_dbg("Hibernation image restored successfully.\n");
 831         }
 832
 833  Free_bitmaps:
 834         free_basic_memory_bitmaps();
 835  Thaw:
 836         unlock_device_hotplug();
 837         if (snapshot_test) {
 838                 pm_pr_dbg("Checking hibernation image\n");
 839                 error = swsusp_check(false);
 840                 if (!error)
 841                         error = load_image_and_restore();
 842         }
 843         thaw_processes();
 844
 845         /* Don't bother checking whether freezer_test_done is true */
 846         freezer_test_done = false;
 847  Exit:
 848         pm_notifier_call_chain(PM_POST_HIBERNATION);
 849  Restore:
 850         pm_restore_console();
 851         hibernate_release();
 852  Unlock:
 853         unlock_system_sleep(sleep_flags);
 854         pr_info("hibernation exit\n");
 855
 856         return error;
 857 }
 858
 859 /**
 860  * hibernate_quiet_exec - Execute a function with all devices frozen.
 861  * @func: Function to execute.
 862  * @data: Data pointer to pass to @func.
 863  *
 864  * Return the @func return value or an error code if it cannot be executed.
 865  */
 866 int hibernate_quiet_exec(int (*func)(void *data), void *data)
 867 {
 868         unsigned int sleep_flags;
 869         int error;
 870
 871         sleep_flags = lock_system_sleep();
 872
 873         if (!hibernate_acquire()) {
 874                 error = -EBUSY;
 875                 goto unlock;
 876         }
 877
 878         pm_prepare_console();
 879
 880         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 881         if (error)
 882                 goto restore;
 883
 884         error = freeze_processes();
 885         if (error)
 886                 goto exit;
 887
 888         lock_device_hotplug();
 889
 890         pm_suspend_clear_flags();
 891
 892         error = platform_begin(true);
 893         if (error)
 894                 goto thaw;
 895
 896         error = freeze_kernel_threads();
 897         if (error)
 898                 goto thaw;
 899
 900         error = dpm_prepare(PMSG_FREEZE);
 901         if (error)
 902                 goto dpm_complete;
 903
 904         suspend_console();
 905
 906         error = dpm_suspend(PMSG_FREEZE);
 907         if (error)
 908                 goto dpm_resume;
 909
 910         error = dpm_suspend_end(PMSG_FREEZE);
 911         if (error)
 912                 goto dpm_resume;
 913
 914         error = platform_pre_snapshot(true);
 915         if (error)
 916                 goto skip;
 917
 918         error = func(data);
 919
 920 skip:
 921         platform_finish(true);
 922
 923         dpm_resume_start(PMSG_THAW);
 924
 925 dpm_resume:
 926         dpm_resume(PMSG_THAW);
 927
 928         resume_console();
 929
 930 dpm_complete:
 931         dpm_complete(PMSG_THAW);
 932
 933         thaw_kernel_threads();
 934
 935 thaw:
 936         platform_end(true);
 937
 938         unlock_device_hotplug();
 939
 940         thaw_processes();
 941
 942 exit:
 943         pm_notifier_call_chain(PM_POST_HIBERNATION);
 944
 945 restore:
 946         pm_restore_console();
 947
 948         hibernate_release();
 949
 950 unlock:
 951         unlock_system_sleep(sleep_flags);
 952
 953         return error;
 954 }
 955 EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 956
 957 static int __init find_resume_device(void)
 958 {
 959         if (!strlen(resume_file))
 960                 return -ENOENT;
 961
 962         pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 963
 964         if (resume_delay) {
 965                 pr_info("Waiting %dsec before reading resume device ...\n",
 966                         resume_delay);
 967                 ssleep(resume_delay);
 968         }
 969
 970         /* Check if the device is there */
 971         if (!early_lookup_bdev(resume_file, &swsusp_resume_device))
 972                 return 0;
 973
 974         /*
 975          * Some device discovery might still be in progress; we need to wait for
 976          * this to finish.
 977          */
 978         wait_for_device_probe();
 979         if (resume_wait) {
 980                 while (early_lookup_bdev(resume_file, &swsusp_resume_device))
 981                         msleep(10);
 982                 async_synchronize_full();
 983         }
 984
 985         return early_lookup_bdev(resume_file, &swsusp_resume_device);
 986 }
 987
 988 static int software_resume(void)
 989 {
 990         int error;
 991
 992         pm_pr_dbg("Hibernation image partition %d:%d present\n",
 993                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 994
 995         pm_pr_dbg("Looking for hibernation image.\n");
 996
 997         mutex_lock(&system_transition_mutex);
 998         error = swsusp_check(true);
 999         if (error)
1000                 goto Unlock;
1001
1002         /*
1003          * Check if the hibernation image is compressed. If so, query for
1004          * the algorithm support.
1005          */
1006         if (!(swsusp_header_flags & SF_NOCOMPRESS_MODE)) {
1007                 if (swsusp_header_flags & SF_COMPRESSION_ALG_LZ4)
1008                         strscpy(hib_comp_algo, COMPRESSION_ALGO_LZ4, sizeof(hib_comp_algo));
1009                 else
1010                         strscpy(hib_comp_algo, COMPRESSION_ALGO_LZO, sizeof(hib_comp_algo));
1011                 if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
1012                         pr_err("%s compression is not available\n", hib_comp_algo);
1013                         error = -EOPNOTSUPP;
1014                         goto Unlock;
1015                 }
1016         }
1017
1018         /* The snapshot device should not be opened while we're running */
1019         if (!hibernate_acquire()) {
1020                 error = -EBUSY;
1021                 swsusp_close();
1022                 goto Unlock;
1023         }
1024
1025         pr_info("resume from hibernation\n");
1026         pm_prepare_console();
1027         error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
1028         if (error)
1029                 goto Restore;
1030
1031         pm_pr_dbg("Preparing processes for hibernation restore.\n");
1032         error = freeze_processes();
1033         if (error)
1034                 goto Close_Finish;
1035
1036         error = freeze_kernel_threads();
1037         if (error) {
1038                 thaw_processes();
1039                 goto Close_Finish;
1040         }
1041
1042         error = load_image_and_restore();
1043         thaw_processes();
1044  Finish:
1045         pm_notifier_call_chain(PM_POST_RESTORE);
1046  Restore:
1047         pm_restore_console();
1048         pr_info("resume failed (%d)\n", error);
1049         hibernate_release();
1050         /* For success case, the suspend path will release the lock */
1051  Unlock:
1052         mutex_unlock(&system_transition_mutex);
1053         pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1054         return error;
1055  Close_Finish:
1056         swsusp_close();
1057         goto Finish;
1058 }
1059
1060 /**
1061  * software_resume_initcall - Resume from a saved hibernation image.
1062  *
1063  * This routine is called as a late initcall, when all devices have been
1064  * discovered and initialized already.
1065  *
1066  * The image reading code is called to see if there is a hibernation image
1067  * available for reading.  If that is the case, devices are quiesced and the
1068  * contents of memory is restored from the saved image.
1069  *
1070  * If this is successful, control reappears in the restored target kernel in
1071  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
1072  * attempts to recover gracefully and make the kernel return to the normal mode
1073  * of operation.
1074  */
1075 static int __init software_resume_initcall(void)
1076 {
1077         /*
1078          * If the user said "noresume".. bail out early.
1079          */
1080         if (noresume || !hibernation_available())
1081                 return 0;
1082
1083         if (!swsusp_resume_device) {
1084                 int error = find_resume_device();
1085
1086                 if (error)
1087                         return error;
1088         }
1089
1090         return software_resume();
1091 }
1092 late_initcall_sync(software_resume_initcall);
1093
1094
1095 static const char * const hibernation_modes[] = {
1096         [HIBERNATION_PLATFORM]  = "platform",
1097         [HIBERNATION_SHUTDOWN]  = "shutdown",
1098         [HIBERNATION_REBOOT]    = "reboot",
1099 #ifdef CONFIG_SUSPEND
1100         [HIBERNATION_SUSPEND]   = "suspend",
1101 #endif
1102         [HIBERNATION_TEST_RESUME]       = "test_resume",
1103 };
1104
1105 /*
1106  * /sys/power/disk - Control hibernation mode.
1107  *
1108  * Hibernation can be handled in several ways.  There are a few different ways
1109  * to put the system into the sleep state: using the platform driver (e.g. ACPI
1110  * or other hibernation_ops), powering it off or rebooting it (for testing
1111  * mostly).
1112  *
1113  * The sysfs file /sys/power/disk provides an interface for selecting the
1114  * hibernation mode to use.  Reading from this file causes the available modes
1115  * to be printed.  There are 3 modes that can be supported:
1116  *
1117  *      'platform'
1118  *      'shutdown'
1119  *      'reboot'
1120  *
1121  * If a platform hibernation driver is in use, 'platform' will be supported
1122  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1123  * The selected option (i.e. the one corresponding to the current value of
1124  * hibernation_mode) is enclosed by a square bracket.
1125  *
1126  * To select a given hibernation mode it is necessary to write the mode's
1127  * string representation (as returned by reading from /sys/power/disk) back
1128  * into /sys/power/disk.
1129  */
1130
1131 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1132                          char *buf)
1133 {
1134         ssize_t count = 0;
1135         int i;
1136
1137         if (!hibernation_available())
1138                 return sysfs_emit(buf, "[disabled]\n");
1139
1140         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1141                 if (!hibernation_modes[i])
1142                         continue;
1143                 switch (i) {
1144                 case HIBERNATION_SHUTDOWN:
1145                 case HIBERNATION_REBOOT:
1146 #ifdef CONFIG_SUSPEND
1147                 case HIBERNATION_SUSPEND:
1148 #endif
1149                 case HIBERNATION_TEST_RESUME:
1150                         break;
1151                 case HIBERNATION_PLATFORM:
1152                         if (hibernation_ops)
1153                                 break;
1154                         /* not a valid mode, continue with loop */
1155                         continue;
1156                 }
1157                 if (i == hibernation_mode)
1158                         count += sysfs_emit_at(buf, count, "[%s] ", hibernation_modes[i]);
1159                 else
1160                         count += sysfs_emit_at(buf, count, "%s ", hibernation_modes[i]);
1161         }
1162
1163         /* Convert the last space to a newline if needed. */
1164         if (count > 0)
1165                 buf[count - 1] = '\n';
1166
1167         return count;
1168 }
1169
1170 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1171                           const char *buf, size_t n)
1172 {
1173         int mode = HIBERNATION_INVALID;
1174         unsigned int sleep_flags;
1175         int error = 0;
1176         int len;
1177         char *p;
1178         int i;
1179
1180         if (!hibernation_available())
1181                 return -EPERM;
1182
1183         p = memchr(buf, '\n', n);
1184         len = p ? p - buf : n;
1185
1186         sleep_flags = lock_system_sleep();
1187         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1188                 if (len == strlen(hibernation_modes[i])
1189                     && !strncmp(buf, hibernation_modes[i], len)) {
1190                         mode = i;
1191                         break;
1192                 }
1193         }
1194         if (mode != HIBERNATION_INVALID) {
1195                 switch (mode) {
1196                 case HIBERNATION_SHUTDOWN:
1197                 case HIBERNATION_REBOOT:
1198 #ifdef CONFIG_SUSPEND
1199                 case HIBERNATION_SUSPEND:
1200 #endif
1201                 case HIBERNATION_TEST_RESUME:
1202                         hibernation_mode = mode;
1203                         break;
1204                 case HIBERNATION_PLATFORM:
1205                         if (hibernation_ops)
1206                                 hibernation_mode = mode;
1207                         else
1208                                 error = -EINVAL;
1209                 }
1210         } else
1211                 error = -EINVAL;
1212
1213         if (!error)
1214                 pm_pr_dbg("Hibernation mode set to '%s'\n",
1215                                hibernation_modes[mode]);
1216         unlock_system_sleep(sleep_flags);
1217         return error ? error : n;
1218 }
1219
1220 power_attr(disk);
1221
1222 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1223                            char *buf)
1224 {
1225         return sysfs_emit(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1226                           MINOR(swsusp_resume_device));
1227 }
1228
1229 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1230                             const char *buf, size_t n)
1231 {
1232         unsigned int sleep_flags;
1233         int len = n;
1234         char *name;
1235         dev_t dev;
1236         int error;
1237
1238         if (!hibernation_available())
1239                 return n;
1240
1241         if (len && buf[len-1] == '\n')
1242                 len--;
1243         name = kstrndup(buf, len, GFP_KERNEL);
1244         if (!name)
1245                 return -ENOMEM;
1246
1247         error = lookup_bdev(name, &dev);
1248         if (error) {
1249                 unsigned maj, min, offset;
1250                 char *p, dummy;
1251
1252                 error = 0;
1253                 if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
1254                     sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
1255                                 &dummy) == 3) {
1256                         dev = MKDEV(maj, min);
1257                         if (maj != MAJOR(dev) || min != MINOR(dev))
1258                                 error = -EINVAL;
1259                 } else {
1260                         dev = new_decode_dev(simple_strtoul(name, &p, 16));
1261                         if (*p)
1262                                 error = -EINVAL;
1263                 }
1264         }
1265         kfree(name);
1266         if (error)
1267                 return error;
1268
1269         sleep_flags = lock_system_sleep();
1270         swsusp_resume_device = dev;
1271         unlock_system_sleep(sleep_flags);
1272
1273         pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1274                   swsusp_resume_device);
1275         noresume = 0;
1276         software_resume();
1277         return n;
1278 }
1279
1280 power_attr(resume);
1281
1282 static ssize_t resume_offset_show(struct kobject *kobj,
1283                                   struct kobj_attribute *attr, char *buf)
1284 {
1285         return sysfs_emit(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1286 }
1287
1288 static ssize_t resume_offset_store(struct kobject *kobj,
1289                                    struct kobj_attribute *attr, const char *buf,
1290                                    size_t n)
1291 {
1292         unsigned long long offset;
1293         int rc;
1294
1295         rc = kstrtoull(buf, 0, &offset);
1296         if (rc)
1297                 return rc;
1298         swsusp_resume_block = offset;
1299
1300         return n;
1301 }
1302
1303 power_attr(resume_offset);
1304
1305 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1306                                char *buf)
1307 {
1308         return sysfs_emit(buf, "%lu\n", image_size);
1309 }
1310
1311 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1312                                 const char *buf, size_t n)
1313 {
1314         unsigned long size;
1315
1316         if (sscanf(buf, "%lu", &size) == 1) {
1317                 image_size = size;
1318                 return n;
1319         }
1320
1321         return -EINVAL;
1322 }
1323
1324 power_attr(image_size);
1325
1326 static ssize_t reserved_size_show(struct kobject *kobj,
1327                                   struct kobj_attribute *attr, char *buf)
1328 {
1329         return sysfs_emit(buf, "%lu\n", reserved_size);
1330 }
1331
1332 static ssize_t reserved_size_store(struct kobject *kobj,
1333                                    struct kobj_attribute *attr,
1334                                    const char *buf, size_t n)
1335 {
1336         unsigned long size;
1337
1338         if (sscanf(buf, "%lu", &size) == 1) {
1339                 reserved_size = size;
1340                 return n;
1341         }
1342
1343         return -EINVAL;
1344 }
1345
1346 power_attr(reserved_size);
1347
1348 static struct attribute *g[] = {
1349         &disk_attr.attr,
1350         &resume_offset_attr.attr,
1351         &resume_attr.attr,
1352         &image_size_attr.attr,
1353         &reserved_size_attr.attr,
1354         NULL,
1355 };
1356
1357
1358 static const struct attribute_group attr_group = {
1359         .attrs = g,
1360 };
1361
1362
1363 static int __init pm_disk_init(void)
1364 {
1365         return sysfs_create_group(power_kobj, &attr_group);
1366 }
1367
1368 core_initcall(pm_disk_init);
1369
1370
1371 static int __init resume_setup(char *str)
1372 {
1373         if (noresume)
1374                 return 1;
1375
1376         strscpy(resume_file, str);
1377         return 1;
1378 }
1379
1380 static int __init resume_offset_setup(char *str)
1381 {
1382         unsigned long long offset;
1383
1384         if (noresume)
1385                 return 1;
1386
1387         if (sscanf(str, "%llu", &offset) == 1)
1388                 swsusp_resume_block = offset;
1389
1390         return 1;
1391 }
1392
1393 static int __init hibernate_setup(char *str)
1394 {
1395         if (!strncmp(str, "noresume", 8)) {
1396                 noresume = 1;
1397         } else if (!strncmp(str, "nocompress", 10)) {
1398                 nocompress = 1;
1399         } else if (!strncmp(str, "no", 2)) {
1400                 noresume = 1;
1401                 nohibernate = 1;
1402         } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1403                    && !strncmp(str, "protect_image", 13)) {
1404                 enable_restore_image_protection();
1405         }
1406         return 1;
1407 }
1408
1409 static int __init noresume_setup(char *str)
1410 {
1411         noresume = 1;
1412         return 1;
1413 }
1414
1415 static int __init resumewait_setup(char *str)
1416 {
1417         resume_wait = 1;
1418         return 1;
1419 }
1420
1421 static int __init resumedelay_setup(char *str)
1422 {
1423         int rc = kstrtouint(str, 0, &resume_delay);
1424
1425         if (rc)
1426                 pr_warn("resumedelay: bad option string '%s'\n", str);
1427         return 1;
1428 }
1429
1430 static int __init nohibernate_setup(char *str)
1431 {
1432         noresume = 1;
1433         nohibernate = 1;
1434         return 1;
1435 }
1436
1437 static const char * const comp_alg_enabled[] = {
1438 #if IS_ENABLED(CONFIG_CRYPTO_LZO)
1439         COMPRESSION_ALGO_LZO,
1440 #endif
1441 #if IS_ENABLED(CONFIG_CRYPTO_LZ4)
1442         COMPRESSION_ALGO_LZ4,
1443 #endif
1444 };
1445
1446 static int hibernate_compressor_param_set(const char *compressor,
1447                 const struct kernel_param *kp)
1448 {
1449         unsigned int sleep_flags;
1450         int index, ret;
1451
1452         sleep_flags = lock_system_sleep();
1453
1454         index = sysfs_match_string(comp_alg_enabled, compressor);
1455         if (index >= 0) {
1456                 ret = param_set_copystring(comp_alg_enabled[index], kp);
1457                 if (!ret)
1458                         strscpy(hib_comp_algo, comp_alg_enabled[index],
1459                                 sizeof(hib_comp_algo));
1460         } else {
1461                 ret = index;
1462         }
1463
1464         unlock_system_sleep(sleep_flags);
1465
1466         if (ret)
1467                 pr_debug("Cannot set specified compressor %s\n",
1468                          compressor);
1469
1470         return ret;
1471 }
1472
1473 static const struct kernel_param_ops hibernate_compressor_param_ops = {
1474         .set    = hibernate_compressor_param_set,
1475         .get    = param_get_string,
1476 };
1477
1478 static struct kparam_string hibernate_compressor_param_string = {
1479         .maxlen = sizeof(hibernate_compressor),
1480         .string = hibernate_compressor,
1481 };
1482
1483 module_param_cb(compressor, &hibernate_compressor_param_ops,
1484                 &hibernate_compressor_param_string, 0644);
1485 MODULE_PARM_DESC(compressor,
1486                  "Compression algorithm to be used with hibernation");
1487
1488 __setup("noresume", noresume_setup);
1489 __setup("resume_offset=", resume_offset_setup);
1490 __setup("resume=", resume_setup);
1491 __setup("hibernate=", hibernate_setup);
1492 __setup("resumewait", resumewait_setup);
1493 __setup("resumedelay=", resumedelay_setup);
1494 __setup("nohibernate", nohibernate_setup);