kernel/power/hibernate.c

   1 /*
   2  * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
   3  *
   4  * Copyright (c) 2003 Patrick Mochel
   5  * Copyright (c) 2003 Open Source Development Lab
   6  * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
   7  * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
   8  * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
   9  *
  10  * This file is released under the GPLv2.
  11  */
  12
  13 #define pr_fmt(fmt) "PM: " fmt
  14
  15 #include <linux/export.h>
  16 #include <linux/suspend.h>
  17 #include <linux/syscalls.h>
  18 #include <linux/reboot.h>
  19 #include <linux/string.h>
  20 #include <linux/device.h>
  21 #include <linux/async.h>
  22 #include <linux/delay.h>
  23 #include <linux/fs.h>
  24 #include <linux/mount.h>
  25 #include <linux/pm.h>
  26 #include <linux/nmi.h>
  27 #include <linux/console.h>
  28 #include <linux/cpu.h>
  29 #include <linux/freezer.h>
  30 #include <linux/gfp.h>
  31 #include <linux/syscore_ops.h>
  32 #include <linux/ctype.h>
  33 #include <linux/genhd.h>
  34 #include <linux/ktime.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 enum {
  51         HIBERNATION_INVALID,
  52         HIBERNATION_PLATFORM,
  53         HIBERNATION_SHUTDOWN,
  54         HIBERNATION_REBOOT,
  55 #ifdef CONFIG_SUSPEND
  56         HIBERNATION_SUSPEND,
  57 #endif
  58         HIBERNATION_TEST_RESUME,
  59         /* keep last */
  60         __HIBERNATION_AFTER_LAST
  61 };
  62 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  63 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  64
  65 static int hibernation_mode = HIBERNATION_SHUTDOWN;
  66
  67 bool freezer_test_done;
  68
  69 static const struct platform_hibernation_ops *hibernation_ops;
  70
  71 bool hibernation_available(void)
  72 {
  73         return (nohibernate == 0);
  74 }
  75
  76 /**
  77  * hibernation_set_ops - Set the global hibernate operations.
  78  * @ops: Hibernation operations to use in subsequent hibernation transitions.
  79  */
  80 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
  81 {
  82         if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  83             && ops->prepare && ops->finish && ops->enter && ops->pre_restore
  84             && ops->restore_cleanup && ops->leave)) {
  85                 WARN_ON(1);
  86                 return;
  87         }
  88         lock_system_sleep();
  89         hibernation_ops = ops;
  90         if (ops)
  91                 hibernation_mode = HIBERNATION_PLATFORM;
  92         else if (hibernation_mode == HIBERNATION_PLATFORM)
  93                 hibernation_mode = HIBERNATION_SHUTDOWN;
  94
  95         unlock_system_sleep();
  96 }
  97 EXPORT_SYMBOL_GPL(hibernation_set_ops);
  98
  99 static bool entering_platform_hibernation;
 100
 101 bool system_entering_hibernation(void)
 102 {
 103         return entering_platform_hibernation;
 104 }
 105 EXPORT_SYMBOL(system_entering_hibernation);
 106
 107 #ifdef CONFIG_PM_DEBUG
 108 static void hibernation_debug_sleep(void)
 109 {
 110         pr_info("hibernation debug: Waiting for 5 seconds.\n");
 111         mdelay(5000);
 112 }
 113
 114 static int hibernation_test(int level)
 115 {
 116         if (pm_test_level == level) {
 117                 hibernation_debug_sleep();
 118                 return 1;
 119         }
 120         return 0;
 121 }
 122 #else /* !CONFIG_PM_DEBUG */
 123 static int hibernation_test(int level) { return 0; }
 124 #endif /* !CONFIG_PM_DEBUG */
 125
 126 /**
 127  * platform_begin - Call platform to start hibernation.
 128  * @platform_mode: Whether or not to use the platform driver.
 129  */
 130 static int platform_begin(int platform_mode)
 131 {
 132         return (platform_mode && hibernation_ops) ?
 133                 hibernation_ops->begin() : 0;
 134 }
 135
 136 /**
 137  * platform_end - Call platform to finish transition to the working state.
 138  * @platform_mode: Whether or not to use the platform driver.
 139  */
 140 static void platform_end(int platform_mode)
 141 {
 142         if (platform_mode && hibernation_ops)
 143                 hibernation_ops->end();
 144 }
 145
 146 /**
 147  * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 148  * @platform_mode: Whether or not to use the platform driver.
 149  *
 150  * Use the platform driver to prepare the system for creating a hibernate image,
 151  * if so configured, and return an error code if that fails.
 152  */
 153
 154 static int platform_pre_snapshot(int platform_mode)
 155 {
 156         return (platform_mode && hibernation_ops) ?
 157                 hibernation_ops->pre_snapshot() : 0;
 158 }
 159
 160 /**
 161  * platform_leave - Call platform to prepare a transition to the working state.
 162  * @platform_mode: Whether or not to use the platform driver.
 163  *
 164  * Use the platform driver prepare to prepare the machine for switching to the
 165  * normal mode of operation.
 166  *
 167  * This routine is called on one CPU with interrupts disabled.
 168  */
 169 static void platform_leave(int platform_mode)
 170 {
 171         if (platform_mode && hibernation_ops)
 172                 hibernation_ops->leave();
 173 }
 174
 175 /**
 176  * platform_finish - Call platform to switch the system to the working state.
 177  * @platform_mode: Whether or not to use the platform driver.
 178  *
 179  * Use the platform driver to switch the machine to the normal mode of
 180  * operation.
 181  *
 182  * This routine must be called after platform_prepare().
 183  */
 184 static void platform_finish(int platform_mode)
 185 {
 186         if (platform_mode && hibernation_ops)
 187                 hibernation_ops->finish();
 188 }
 189
 190 /**
 191  * platform_pre_restore - Prepare for hibernate image restoration.
 192  * @platform_mode: Whether or not to use the platform driver.
 193  *
 194  * Use the platform driver to prepare the system for resume from a hibernation
 195  * image.
 196  *
 197  * If the restore fails after this function has been called,
 198  * platform_restore_cleanup() must be called.
 199  */
 200 static int platform_pre_restore(int platform_mode)
 201 {
 202         return (platform_mode && hibernation_ops) ?
 203                 hibernation_ops->pre_restore() : 0;
 204 }
 205
 206 /**
 207  * platform_restore_cleanup - Switch to the working state after failing restore.
 208  * @platform_mode: Whether or not to use the platform driver.
 209  *
 210  * Use the platform driver to switch the system to the normal mode of operation
 211  * after a failing restore.
 212  *
 213  * If platform_pre_restore() has been called before the failing restore, this
 214  * function must be called too, regardless of the result of
 215  * platform_pre_restore().
 216  */
 217 static void platform_restore_cleanup(int platform_mode)
 218 {
 219         if (platform_mode && hibernation_ops)
 220                 hibernation_ops->restore_cleanup();
 221 }
 222
 223 /**
 224  * platform_recover - Recover from a failure to suspend devices.
 225  * @platform_mode: Whether or not to use the platform driver.
 226  */
 227 static void platform_recover(int platform_mode)
 228 {
 229         if (platform_mode && hibernation_ops && hibernation_ops->recover)
 230                 hibernation_ops->recover();
 231 }
 232
 233 /**
 234  * swsusp_show_speed - Print time elapsed between two events during hibernation.
 235  * @start: Starting event.
 236  * @stop: Final event.
 237  * @nr_pages: Number of memory pages processed between @start and @stop.
 238  * @msg: Additional diagnostic message to print.
 239  */
 240 void swsusp_show_speed(ktime_t start, ktime_t stop,
 241                       unsigned nr_pages, char *msg)
 242 {
 243         ktime_t diff;
 244         u64 elapsed_centisecs64;
 245         unsigned int centisecs;
 246         unsigned int k;
 247         unsigned int kps;
 248
 249         diff = ktime_sub(stop, start);
 250         elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 251         centisecs = elapsed_centisecs64;
 252         if (centisecs == 0)
 253                 centisecs = 1;  /* avoid div-by-zero */
 254         k = nr_pages * (PAGE_SIZE / 1024);
 255         kps = (k * 100) / centisecs;
 256         pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 257                 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 258                 (kps % 1000) / 10);
 259 }
 260
 261 /**
 262  * create_image - Create a hibernation image.
 263  * @platform_mode: Whether or not to use the platform driver.
 264  *
 265  * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 266  * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 267  *
 268  * Control reappears in this routine after the subsequent restore.
 269  */
 270 static int create_image(int platform_mode)
 271 {
 272         int error;
 273
 274         error = dpm_suspend_end(PMSG_FREEZE);
 275         if (error) {
 276                 pr_err("Some devices failed to power down, aborting hibernation\n");
 277                 return error;
 278         }
 279
 280         error = platform_pre_snapshot(platform_mode);
 281         if (error || hibernation_test(TEST_PLATFORM))
 282                 goto Platform_finish;
 283
 284         error = disable_nonboot_cpus();
 285         if (error || hibernation_test(TEST_CPUS))
 286                 goto Enable_cpus;
 287
 288         local_irq_disable();
 289
 290         error = syscore_suspend();
 291         if (error) {
 292                 pr_err("Some system devices failed to power down, aborting hibernation\n");
 293                 goto Enable_irqs;
 294         }
 295
 296         if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 297                 goto Power_up;
 298
 299         in_suspend = 1;
 300         save_processor_state();
 301         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 302         error = swsusp_arch_suspend();
 303         /* Restore control flow magically appears here */
 304         restore_processor_state();
 305         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 306         if (error)
 307                 pr_err("Error %d creating hibernation image\n", error);
 308
 309         if (!in_suspend) {
 310                 events_check_enabled = false;
 311                 clear_free_pages();
 312         }
 313
 314         platform_leave(platform_mode);
 315
 316  Power_up:
 317         syscore_resume();
 318
 319  Enable_irqs:
 320         local_irq_enable();
 321
 322  Enable_cpus:
 323         enable_nonboot_cpus();
 324
 325  Platform_finish:
 326         platform_finish(platform_mode);
 327
 328         dpm_resume_start(in_suspend ?
 329                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 330
 331         return error;
 332 }
 333
 334 /**
 335  * hibernation_snapshot - Quiesce devices and create a hibernation image.
 336  * @platform_mode: If set, use platform driver to prepare for the transition.
 337  *
 338  * This routine must be called with pm_mutex held.
 339  */
 340 int hibernation_snapshot(int platform_mode)
 341 {
 342         pm_message_t msg;
 343         int error;
 344
 345         pm_suspend_clear_flags();
 346         error = platform_begin(platform_mode);
 347         if (error)
 348                 goto Close;
 349
 350         /* Preallocate image memory before shutting down devices. */
 351         error = hibernate_preallocate_memory();
 352         if (error)
 353                 goto Close;
 354
 355         error = freeze_kernel_threads();
 356         if (error)
 357                 goto Cleanup;
 358
 359         if (hibernation_test(TEST_FREEZER)) {
 360
 361                 /*
 362                  * Indicate to the caller that we are returning due to a
 363                  * successful freezer test.
 364                  */
 365                 freezer_test_done = true;
 366                 goto Thaw;
 367         }
 368
 369         error = dpm_prepare(PMSG_FREEZE);
 370         if (error) {
 371                 dpm_complete(PMSG_RECOVER);
 372                 goto Thaw;
 373         }
 374
 375         suspend_console();
 376         pm_restrict_gfp_mask();
 377
 378         error = dpm_suspend(PMSG_FREEZE);
 379
 380         if (error || hibernation_test(TEST_DEVICES))
 381                 platform_recover(platform_mode);
 382         else
 383                 error = create_image(platform_mode);
 384
 385         /*
 386          * In the case that we call create_image() above, the control
 387          * returns here (1) after the image has been created or the
 388          * image creation has failed and (2) after a successful restore.
 389          */
 390
 391         /* We may need to release the preallocated image pages here. */
 392         if (error || !in_suspend)
 393                 swsusp_free();
 394
 395         msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 396         dpm_resume(msg);
 397
 398         if (error || !in_suspend)
 399                 pm_restore_gfp_mask();
 400
 401         resume_console();
 402         dpm_complete(msg);
 403
 404  Close:
 405         platform_end(platform_mode);
 406         return error;
 407
 408  Thaw:
 409         thaw_kernel_threads();
 410  Cleanup:
 411         swsusp_free();
 412         goto Close;
 413 }
 414
 415 int __weak hibernate_resume_nonboot_cpu_disable(void)
 416 {
 417         return disable_nonboot_cpus();
 418 }
 419
 420 /**
 421  * resume_target_kernel - Restore system state from a hibernation image.
 422  * @platform_mode: Whether or not to use the platform driver.
 423  *
 424  * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 425  * contents of highmem that have not been restored yet from the image and run
 426  * the low-level code that will restore the remaining contents of memory and
 427  * switch to the just restored target kernel.
 428  */
 429 static int resume_target_kernel(bool platform_mode)
 430 {
 431         int error;
 432
 433         error = dpm_suspend_end(PMSG_QUIESCE);
 434         if (error) {
 435                 pr_err("Some devices failed to power down, aborting resume\n");
 436                 return error;
 437         }
 438
 439         error = platform_pre_restore(platform_mode);
 440         if (error)
 441                 goto Cleanup;
 442
 443         error = hibernate_resume_nonboot_cpu_disable();
 444         if (error)
 445                 goto Enable_cpus;
 446
 447         local_irq_disable();
 448
 449         error = syscore_suspend();
 450         if (error)
 451                 goto Enable_irqs;
 452
 453         save_processor_state();
 454         error = restore_highmem();
 455         if (!error) {
 456                 error = swsusp_arch_resume();
 457                 /*
 458                  * The code below is only ever reached in case of a failure.
 459                  * Otherwise, execution continues at the place where
 460                  * swsusp_arch_suspend() was called.
 461                  */
 462                 BUG_ON(!error);
 463                 /*
 464                  * This call to restore_highmem() reverts the changes made by
 465                  * the previous one.
 466                  */
 467                 restore_highmem();
 468         }
 469         /*
 470          * The only reason why swsusp_arch_resume() can fail is memory being
 471          * very tight, so we have to free it as soon as we can to avoid
 472          * subsequent failures.
 473          */
 474         swsusp_free();
 475         restore_processor_state();
 476         touch_softlockup_watchdog();
 477
 478         syscore_resume();
 479
 480  Enable_irqs:
 481         local_irq_enable();
 482
 483  Enable_cpus:
 484         enable_nonboot_cpus();
 485
 486  Cleanup:
 487         platform_restore_cleanup(platform_mode);
 488
 489         dpm_resume_start(PMSG_RECOVER);
 490
 491         return error;
 492 }
 493
 494 /**
 495  * hibernation_restore - Quiesce devices and restore from a hibernation image.
 496  * @platform_mode: If set, use platform driver to prepare for the transition.
 497  *
 498  * This routine must be called with pm_mutex held.  If it is successful, control
 499  * reappears in the restored target kernel in hibernation_snapshot().
 500  */
 501 int hibernation_restore(int platform_mode)
 502 {
 503         int error;
 504
 505         pm_prepare_console();
 506         suspend_console();
 507         pm_restrict_gfp_mask();
 508         error = dpm_suspend_start(PMSG_QUIESCE);
 509         if (!error) {
 510                 error = resume_target_kernel(platform_mode);
 511                 /*
 512                  * The above should either succeed and jump to the new kernel,
 513                  * or return with an error. Otherwise things are just
 514                  * undefined, so let's be paranoid.
 515                  */
 516                 BUG_ON(!error);
 517         }
 518         dpm_resume_end(PMSG_RECOVER);
 519         pm_restore_gfp_mask();
 520         resume_console();
 521         pm_restore_console();
 522         return error;
 523 }
 524
 525 /**
 526  * hibernation_platform_enter - Power off the system using the platform driver.
 527  */
 528 int hibernation_platform_enter(void)
 529 {
 530         int error;
 531
 532         if (!hibernation_ops)
 533                 return -ENOSYS;
 534
 535         /*
 536          * We have cancelled the power transition by running
 537          * hibernation_ops->finish() before saving the image, so we should let
 538          * the firmware know that we're going to enter the sleep state after all
 539          */
 540         error = hibernation_ops->begin();
 541         if (error)
 542                 goto Close;
 543
 544         entering_platform_hibernation = true;
 545         suspend_console();
 546         error = dpm_suspend_start(PMSG_HIBERNATE);
 547         if (error) {
 548                 if (hibernation_ops->recover)
 549                         hibernation_ops->recover();
 550                 goto Resume_devices;
 551         }
 552
 553         error = dpm_suspend_end(PMSG_HIBERNATE);
 554         if (error)
 555                 goto Resume_devices;
 556
 557         error = hibernation_ops->prepare();
 558         if (error)
 559                 goto Platform_finish;
 560
 561         error = disable_nonboot_cpus();
 562         if (error)
 563                 goto Enable_cpus;
 564
 565         local_irq_disable();
 566         syscore_suspend();
 567         if (pm_wakeup_pending()) {
 568                 error = -EAGAIN;
 569                 goto Power_up;
 570         }
 571
 572         hibernation_ops->enter();
 573         /* We should never get here */
 574         while (1);
 575
 576  Power_up:
 577         syscore_resume();
 578         local_irq_enable();
 579
 580  Enable_cpus:
 581         enable_nonboot_cpus();
 582
 583  Platform_finish:
 584         hibernation_ops->finish();
 585
 586         dpm_resume_start(PMSG_RESTORE);
 587
 588  Resume_devices:
 589         entering_platform_hibernation = false;
 590         dpm_resume_end(PMSG_RESTORE);
 591         resume_console();
 592
 593  Close:
 594         hibernation_ops->end();
 595
 596         return error;
 597 }
 598
 599 /**
 600  * power_down - Shut the machine down for hibernation.
 601  *
 602  * Use the platform driver, if configured, to put the system into the sleep
 603  * state corresponding to hibernation, or try to power it off or reboot,
 604  * depending on the value of hibernation_mode.
 605  */
 606 static void power_down(void)
 607 {
 608 #ifdef CONFIG_SUSPEND
 609         int error;
 610
 611         if (hibernation_mode == HIBERNATION_SUSPEND) {
 612                 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
 613                 if (error) {
 614                         hibernation_mode = hibernation_ops ?
 615                                                 HIBERNATION_PLATFORM :
 616                                                 HIBERNATION_SHUTDOWN;
 617                 } else {
 618                         /* Restore swap signature. */
 619                         error = swsusp_unmark();
 620                         if (error)
 621                                 pr_err("Swap will be unusable! Try swapon -a.\n");
 622
 623                         return;
 624                 }
 625         }
 626 #endif
 627
 628         switch (hibernation_mode) {
 629         case HIBERNATION_REBOOT:
 630                 kernel_restart(NULL);
 631                 break;
 632         case HIBERNATION_PLATFORM:
 633                 hibernation_platform_enter();
 634         case HIBERNATION_SHUTDOWN:
 635                 if (pm_power_off)
 636                         kernel_power_off();
 637                 break;
 638         }
 639         kernel_halt();
 640         /*
 641          * Valid image is on the disk, if we continue we risk serious data
 642          * corruption after resume.
 643          */
 644         pr_crit("Power down manually\n");
 645         while (1)
 646                 cpu_relax();
 647 }
 648
 649 static int load_image_and_restore(void)
 650 {
 651         int error;
 652         unsigned int flags;
 653
 654         pm_pr_dbg("Loading hibernation image.\n");
 655
 656         lock_device_hotplug();
 657         error = create_basic_memory_bitmaps();
 658         if (error)
 659                 goto Unlock;
 660
 661         error = swsusp_read(&flags);
 662         swsusp_close(FMODE_READ);
 663         if (!error)
 664                 hibernation_restore(flags & SF_PLATFORM_MODE);
 665
 666         pr_err("Failed to load hibernation image, recovering.\n");
 667         swsusp_free();
 668         free_basic_memory_bitmaps();
 669  Unlock:
 670         unlock_device_hotplug();
 671
 672         return error;
 673 }
 674
 675 /**
 676  * hibernate - Carry out system hibernation, including saving the image.
 677  */
 678 int hibernate(void)
 679 {
 680         int error, nr_calls = 0;
 681         bool snapshot_test = false;
 682
 683         if (!hibernation_available()) {
 684                 pm_pr_dbg("Hibernation not available.\n");
 685                 return -EPERM;
 686         }
 687
 688         lock_system_sleep();
 689         /* The snapshot device should not be opened while we're running */
 690         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 691                 error = -EBUSY;
 692                 goto Unlock;
 693         }
 694
 695         pr_info("hibernation entry\n");
 696         pm_prepare_console();
 697         error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
 698         if (error) {
 699                 nr_calls--;
 700                 goto Exit;
 701         }
 702
 703         pr_info("Syncing filesystems ... \n");
 704         ksys_sync();
 705         pr_info("done.\n");
 706
 707         error = freeze_processes();
 708         if (error)
 709                 goto Exit;
 710
 711         lock_device_hotplug();
 712         /* Allocate memory management structures */
 713         error = create_basic_memory_bitmaps();
 714         if (error)
 715                 goto Thaw;
 716
 717         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 718         if (error || freezer_test_done)
 719                 goto Free_bitmaps;
 720
 721         if (in_suspend) {
 722                 unsigned int flags = 0;
 723
 724                 if (hibernation_mode == HIBERNATION_PLATFORM)
 725                         flags |= SF_PLATFORM_MODE;
 726                 if (nocompress)
 727                         flags |= SF_NOCOMPRESS_MODE;
 728                 else
 729                         flags |= SF_CRC32_MODE;
 730
 731                 pm_pr_dbg("Writing image.\n");
 732                 error = swsusp_write(flags);
 733                 swsusp_free();
 734                 if (!error) {
 735                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
 736                                 snapshot_test = true;
 737                         else
 738                                 power_down();
 739                 }
 740                 in_suspend = 0;
 741                 pm_restore_gfp_mask();
 742         } else {
 743                 pm_pr_dbg("Image restored successfully.\n");
 744         }
 745
 746  Free_bitmaps:
 747         free_basic_memory_bitmaps();
 748  Thaw:
 749         unlock_device_hotplug();
 750         if (snapshot_test) {
 751                 pm_pr_dbg("Checking hibernation image\n");
 752                 error = swsusp_check();
 753                 if (!error)
 754                         error = load_image_and_restore();
 755         }
 756         thaw_processes();
 757
 758         /* Don't bother checking whether freezer_test_done is true */
 759         freezer_test_done = false;
 760  Exit:
 761         __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
 762         pm_restore_console();
 763         atomic_inc(&snapshot_device_available);
 764  Unlock:
 765         unlock_system_sleep();
 766         pr_info("hibernation exit\n");
 767
 768         return error;
 769 }
 770
 771
 772 /**
 773  * software_resume - Resume from a saved hibernation image.
 774  *
 775  * This routine is called as a late initcall, when all devices have been
 776  * discovered and initialized already.
 777  *
 778  * The image reading code is called to see if there is a hibernation image
 779  * available for reading.  If that is the case, devices are quiesced and the
 780  * contents of memory is restored from the saved image.
 781  *
 782  * If this is successful, control reappears in the restored target kernel in
 783  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 784  * attempts to recover gracefully and make the kernel return to the normal mode
 785  * of operation.
 786  */
 787 static int software_resume(void)
 788 {
 789         int error, nr_calls = 0;
 790
 791         /*
 792          * If the user said "noresume".. bail out early.
 793          */
 794         if (noresume || !hibernation_available())
 795                 return 0;
 796
 797         /*
 798          * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 799          * is configured into the kernel. Since the regular hibernate
 800          * trigger path is via sysfs which takes a buffer mutex before
 801          * calling hibernate functions (which take pm_mutex) this can
 802          * cause lockdep to complain about a possible ABBA deadlock
 803          * which cannot happen since we're in the boot code here and
 804          * sysfs can't be invoked yet. Therefore, we use a subclass
 805          * here to avoid lockdep complaining.
 806          */
 807         mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
 808
 809         if (swsusp_resume_device)
 810                 goto Check_image;
 811
 812         if (!strlen(resume_file)) {
 813                 error = -ENOENT;
 814                 goto Unlock;
 815         }
 816
 817         pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 818
 819         if (resume_delay) {
 820                 pr_info("Waiting %dsec before reading resume device ...\n",
 821                         resume_delay);
 822                 ssleep(resume_delay);
 823         }
 824
 825         /* Check if the device is there */
 826         swsusp_resume_device = name_to_dev_t(resume_file);
 827
 828         /*
 829          * name_to_dev_t is ineffective to verify parition if resume_file is in
 830          * integer format. (e.g. major:minor)
 831          */
 832         if (isdigit(resume_file[0]) && resume_wait) {
 833                 int partno;
 834                 while (!get_gendisk(swsusp_resume_device, &partno))
 835                         msleep(10);
 836         }
 837
 838         if (!swsusp_resume_device) {
 839                 /*
 840                  * Some device discovery might still be in progress; we need
 841                  * to wait for this to finish.
 842                  */
 843                 wait_for_device_probe();
 844
 845                 if (resume_wait) {
 846                         while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 847                                 msleep(10);
 848                         async_synchronize_full();
 849                 }
 850
 851                 swsusp_resume_device = name_to_dev_t(resume_file);
 852                 if (!swsusp_resume_device) {
 853                         error = -ENODEV;
 854                         goto Unlock;
 855                 }
 856         }
 857
 858  Check_image:
 859         pm_pr_dbg("Hibernation image partition %d:%d present\n",
 860                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 861
 862         pm_pr_dbg("Looking for hibernation image.\n");
 863         error = swsusp_check();
 864         if (error)
 865                 goto Unlock;
 866
 867         /* The snapshot device should not be opened while we're running */
 868         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 869                 error = -EBUSY;
 870                 swsusp_close(FMODE_READ);
 871                 goto Unlock;
 872         }
 873
 874         pr_info("resume from hibernation\n");
 875         pm_prepare_console();
 876         error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
 877         if (error) {
 878                 nr_calls--;
 879                 goto Close_Finish;
 880         }
 881
 882         pm_pr_dbg("Preparing processes for restore.\n");
 883         error = freeze_processes();
 884         if (error)
 885                 goto Close_Finish;
 886         error = load_image_and_restore();
 887         thaw_processes();
 888  Finish:
 889         __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
 890         pm_restore_console();
 891         pr_info("resume from hibernation failed (%d)\n", error);
 892         atomic_inc(&snapshot_device_available);
 893         /* For success case, the suspend path will release the lock */
 894  Unlock:
 895         mutex_unlock(&pm_mutex);
 896         pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
 897         return error;
 898  Close_Finish:
 899         swsusp_close(FMODE_READ);
 900         goto Finish;
 901 }
 902
 903 late_initcall_sync(software_resume);
 904
 905
 906 static const char * const hibernation_modes[] = {
 907         [HIBERNATION_PLATFORM]  = "platform",
 908         [HIBERNATION_SHUTDOWN]  = "shutdown",
 909         [HIBERNATION_REBOOT]    = "reboot",
 910 #ifdef CONFIG_SUSPEND
 911         [HIBERNATION_SUSPEND]   = "suspend",
 912 #endif
 913         [HIBERNATION_TEST_RESUME]       = "test_resume",
 914 };
 915
 916 /*
 917  * /sys/power/disk - Control hibernation mode.
 918  *
 919  * Hibernation can be handled in several ways.  There are a few different ways
 920  * to put the system into the sleep state: using the platform driver (e.g. ACPI
 921  * or other hibernation_ops), powering it off or rebooting it (for testing
 922  * mostly).
 923  *
 924  * The sysfs file /sys/power/disk provides an interface for selecting the
 925  * hibernation mode to use.  Reading from this file causes the available modes
 926  * to be printed.  There are 3 modes that can be supported:
 927  *
 928  *      'platform'
 929  *      'shutdown'
 930  *      'reboot'
 931  *
 932  * If a platform hibernation driver is in use, 'platform' will be supported
 933  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
 934  * The selected option (i.e. the one corresponding to the current value of
 935  * hibernation_mode) is enclosed by a square bracket.
 936  *
 937  * To select a given hibernation mode it is necessary to write the mode's
 938  * string representation (as returned by reading from /sys/power/disk) back
 939  * into /sys/power/disk.
 940  */
 941
 942 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 943                          char *buf)
 944 {
 945         int i;
 946         char *start = buf;
 947
 948         if (!hibernation_available())
 949                 return sprintf(buf, "[disabled]\n");
 950
 951         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 952                 if (!hibernation_modes[i])
 953                         continue;
 954                 switch (i) {
 955                 case HIBERNATION_SHUTDOWN:
 956                 case HIBERNATION_REBOOT:
 957 #ifdef CONFIG_SUSPEND
 958                 case HIBERNATION_SUSPEND:
 959 #endif
 960                 case HIBERNATION_TEST_RESUME:
 961                         break;
 962                 case HIBERNATION_PLATFORM:
 963                         if (hibernation_ops)
 964                                 break;
 965                         /* not a valid mode, continue with loop */
 966                         continue;
 967                 }
 968                 if (i == hibernation_mode)
 969                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
 970                 else
 971                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
 972         }
 973         buf += sprintf(buf, "\n");
 974         return buf-start;
 975 }
 976
 977 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 978                           const char *buf, size_t n)
 979 {
 980         int error = 0;
 981         int i;
 982         int len;
 983         char *p;
 984         int mode = HIBERNATION_INVALID;
 985
 986         if (!hibernation_available())
 987                 return -EPERM;
 988
 989         p = memchr(buf, '\n', n);
 990         len = p ? p - buf : n;
 991
 992         lock_system_sleep();
 993         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 994                 if (len == strlen(hibernation_modes[i])
 995                     && !strncmp(buf, hibernation_modes[i], len)) {
 996                         mode = i;
 997                         break;
 998                 }
 999         }
1000         if (mode != HIBERNATION_INVALID) {
1001                 switch (mode) {
1002                 case HIBERNATION_SHUTDOWN:
1003                 case HIBERNATION_REBOOT:
1004 #ifdef CONFIG_SUSPEND
1005                 case HIBERNATION_SUSPEND:
1006 #endif
1007                 case HIBERNATION_TEST_RESUME:
1008                         hibernation_mode = mode;
1009                         break;
1010                 case HIBERNATION_PLATFORM:
1011                         if (hibernation_ops)
1012                                 hibernation_mode = mode;
1013                         else
1014                                 error = -EINVAL;
1015                 }
1016         } else
1017                 error = -EINVAL;
1018
1019         if (!error)
1020                 pm_pr_dbg("Hibernation mode set to '%s'\n",
1021                                hibernation_modes[mode]);
1022         unlock_system_sleep();
1023         return error ? error : n;
1024 }
1025
1026 power_attr(disk);
1027
1028 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1029                            char *buf)
1030 {
1031         return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
1032                        MINOR(swsusp_resume_device));
1033 }
1034
1035 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1036                             const char *buf, size_t n)
1037 {
1038         dev_t res;
1039         int len = n;
1040         char *name;
1041
1042         if (len && buf[len-1] == '\n')
1043                 len--;
1044         name = kstrndup(buf, len, GFP_KERNEL);
1045         if (!name)
1046                 return -ENOMEM;
1047
1048         res = name_to_dev_t(name);
1049         kfree(name);
1050         if (!res)
1051                 return -EINVAL;
1052
1053         lock_system_sleep();
1054         swsusp_resume_device = res;
1055         unlock_system_sleep();
1056         pm_pr_dbg("Configured resume from disk to %u\n", swsusp_resume_device);
1057         noresume = 0;
1058         software_resume();
1059         return n;
1060 }
1061
1062 power_attr(resume);
1063
1064 static ssize_t resume_offset_show(struct kobject *kobj,
1065                                   struct kobj_attribute *attr, char *buf)
1066 {
1067         return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1068 }
1069
1070 static ssize_t resume_offset_store(struct kobject *kobj,
1071                                    struct kobj_attribute *attr, const char *buf,
1072                                    size_t n)
1073 {
1074         unsigned long long offset;
1075         int rc;
1076
1077         rc = kstrtoull(buf, 0, &offset);
1078         if (rc)
1079                 return rc;
1080         swsusp_resume_block = offset;
1081
1082         return n;
1083 }
1084
1085 power_attr(resume_offset);
1086
1087 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1088                                char *buf)
1089 {
1090         return sprintf(buf, "%lu\n", image_size);
1091 }
1092
1093 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1094                                 const char *buf, size_t n)
1095 {
1096         unsigned long size;
1097
1098         if (sscanf(buf, "%lu", &size) == 1) {
1099                 image_size = size;
1100                 return n;
1101         }
1102
1103         return -EINVAL;
1104 }
1105
1106 power_attr(image_size);
1107
1108 static ssize_t reserved_size_show(struct kobject *kobj,
1109                                   struct kobj_attribute *attr, char *buf)
1110 {
1111         return sprintf(buf, "%lu\n", reserved_size);
1112 }
1113
1114 static ssize_t reserved_size_store(struct kobject *kobj,
1115                                    struct kobj_attribute *attr,
1116                                    const char *buf, size_t n)
1117 {
1118         unsigned long size;
1119
1120         if (sscanf(buf, "%lu", &size) == 1) {
1121                 reserved_size = size;
1122                 return n;
1123         }
1124
1125         return -EINVAL;
1126 }
1127
1128 power_attr(reserved_size);
1129
1130 static struct attribute * g[] = {
1131         &disk_attr.attr,
1132         &resume_offset_attr.attr,
1133         &resume_attr.attr,
1134         &image_size_attr.attr,
1135         &reserved_size_attr.attr,
1136         NULL,
1137 };
1138
1139
1140 static const struct attribute_group attr_group = {
1141         .attrs = g,
1142 };
1143
1144
1145 static int __init pm_disk_init(void)
1146 {
1147         return sysfs_create_group(power_kobj, &attr_group);
1148 }
1149
1150 core_initcall(pm_disk_init);
1151
1152
1153 static int __init resume_setup(char *str)
1154 {
1155         if (noresume)
1156                 return 1;
1157
1158         strncpy( resume_file, str, 255 );
1159         return 1;
1160 }
1161
1162 static int __init resume_offset_setup(char *str)
1163 {
1164         unsigned long long offset;
1165
1166         if (noresume)
1167                 return 1;
1168
1169         if (sscanf(str, "%llu", &offset) == 1)
1170                 swsusp_resume_block = offset;
1171
1172         return 1;
1173 }
1174
1175 static int __init hibernate_setup(char *str)
1176 {
1177         if (!strncmp(str, "noresume", 8)) {
1178                 noresume = 1;
1179         } else if (!strncmp(str, "nocompress", 10)) {
1180                 nocompress = 1;
1181         } else if (!strncmp(str, "no", 2)) {
1182                 noresume = 1;
1183                 nohibernate = 1;
1184         } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1185                    && !strncmp(str, "protect_image", 13)) {
1186                 enable_restore_image_protection();
1187         }
1188         return 1;
1189 }
1190
1191 static int __init noresume_setup(char *str)
1192 {
1193         noresume = 1;
1194         return 1;
1195 }
1196
1197 static int __init resumewait_setup(char *str)
1198 {
1199         resume_wait = 1;
1200         return 1;
1201 }
1202
1203 static int __init resumedelay_setup(char *str)
1204 {
1205         int rc = kstrtouint(str, 0, &resume_delay);
1206
1207         if (rc)
1208                 return rc;
1209         return 1;
1210 }
1211
1212 static int __init nohibernate_setup(char *str)
1213 {
1214         noresume = 1;
1215         nohibernate = 1;
1216         return 1;
1217 }
1218
1219 __setup("noresume", noresume_setup);
1220 __setup("resume_offset=", resume_offset_setup);
1221 __setup("resume=", resume_setup);
1222 __setup("hibernate=", hibernate_setup);
1223 __setup("resumewait", resumewait_setup);
1224 __setup("resumedelay=", resumedelay_setup);
1225 __setup("nohibernate", nohibernate_setup);