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 #include <linux/export.h>
  14 #include <linux/suspend.h>
  15 #include <linux/syscalls.h>
  16 #include <linux/reboot.h>
  17 #include <linux/string.h>
  18 #include <linux/device.h>
  19 #include <linux/async.h>
  20 #include <linux/delay.h>
  21 #include <linux/fs.h>
  22 #include <linux/mount.h>
  23 #include <linux/pm.h>
  24 #include <linux/console.h>
  25 #include <linux/cpu.h>
  26 #include <linux/freezer.h>
  27 #include <linux/gfp.h>
  28 #include <linux/syscore_ops.h>
  29 #include <linux/ctype.h>
  30 #include <linux/genhd.h>
  31 #include <linux/ktime.h>
  32 #include <trace/events/power.h>
  33
  34 #include "power.h"
  35
  36
  37 static int nocompress;
  38 static int noresume;
  39 static int nohibernate;
  40 static int resume_wait;
  41 static unsigned int resume_delay;
  42 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
  43 dev_t swsusp_resume_device;
  44 sector_t swsusp_resume_block;
  45 __visible int in_suspend __nosavedata;
  46
  47 enum {
  48         HIBERNATION_INVALID,
  49         HIBERNATION_PLATFORM,
  50         HIBERNATION_SHUTDOWN,
  51         HIBERNATION_REBOOT,
  52 #ifdef CONFIG_SUSPEND
  53         HIBERNATION_SUSPEND,
  54 #endif
  55         HIBERNATION_TEST_RESUME,
  56         /* keep last */
  57         __HIBERNATION_AFTER_LAST
  58 };
  59 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  60 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  61
  62 static int hibernation_mode = HIBERNATION_SHUTDOWN;
  63
  64 bool freezer_test_done;
  65
  66 static const struct platform_hibernation_ops *hibernation_ops;
  67
  68 bool hibernation_available(void)
  69 {
  70         return (nohibernate == 0);
  71 }
  72
  73 /**
  74  * hibernation_set_ops - Set the global hibernate operations.
  75  * @ops: Hibernation operations to use in subsequent hibernation transitions.
  76  */
  77 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
  78 {
  79         if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  80             && ops->prepare && ops->finish && ops->enter && ops->pre_restore
  81             && ops->restore_cleanup && ops->leave)) {
  82                 WARN_ON(1);
  83                 return;
  84         }
  85         lock_system_sleep();
  86         hibernation_ops = ops;
  87         if (ops)
  88                 hibernation_mode = HIBERNATION_PLATFORM;
  89         else if (hibernation_mode == HIBERNATION_PLATFORM)
  90                 hibernation_mode = HIBERNATION_SHUTDOWN;
  91
  92         unlock_system_sleep();
  93 }
  94 EXPORT_SYMBOL_GPL(hibernation_set_ops);
  95
  96 static bool entering_platform_hibernation;
  97
  98 bool system_entering_hibernation(void)
  99 {
 100         return entering_platform_hibernation;
 101 }
 102 EXPORT_SYMBOL(system_entering_hibernation);
 103
 104 #ifdef CONFIG_PM_DEBUG
 105 static void hibernation_debug_sleep(void)
 106 {
 107         printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
 108         mdelay(5000);
 109 }
 110
 111 static int hibernation_test(int level)
 112 {
 113         if (pm_test_level == level) {
 114                 hibernation_debug_sleep();
 115                 return 1;
 116         }
 117         return 0;
 118 }
 119 #else /* !CONFIG_PM_DEBUG */
 120 static int hibernation_test(int level) { return 0; }
 121 #endif /* !CONFIG_PM_DEBUG */
 122
 123 /**
 124  * platform_begin - Call platform to start hibernation.
 125  * @platform_mode: Whether or not to use the platform driver.
 126  */
 127 static int platform_begin(int platform_mode)
 128 {
 129         return (platform_mode && hibernation_ops) ?
 130                 hibernation_ops->begin() : 0;
 131 }
 132
 133 /**
 134  * platform_end - Call platform to finish transition to the working state.
 135  * @platform_mode: Whether or not to use the platform driver.
 136  */
 137 static void platform_end(int platform_mode)
 138 {
 139         if (platform_mode && hibernation_ops)
 140                 hibernation_ops->end();
 141 }
 142
 143 /**
 144  * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 145  * @platform_mode: Whether or not to use the platform driver.
 146  *
 147  * Use the platform driver to prepare the system for creating a hibernate image,
 148  * if so configured, and return an error code if that fails.
 149  */
 150
 151 static int platform_pre_snapshot(int platform_mode)
 152 {
 153         return (platform_mode && hibernation_ops) ?
 154                 hibernation_ops->pre_snapshot() : 0;
 155 }
 156
 157 /**
 158  * platform_leave - Call platform to prepare a transition to the working state.
 159  * @platform_mode: Whether or not to use the platform driver.
 160  *
 161  * Use the platform driver prepare to prepare the machine for switching to the
 162  * normal mode of operation.
 163  *
 164  * This routine is called on one CPU with interrupts disabled.
 165  */
 166 static void platform_leave(int platform_mode)
 167 {
 168         if (platform_mode && hibernation_ops)
 169                 hibernation_ops->leave();
 170 }
 171
 172 /**
 173  * platform_finish - Call platform to switch the system to the working state.
 174  * @platform_mode: Whether or not to use the platform driver.
 175  *
 176  * Use the platform driver to switch the machine to the normal mode of
 177  * operation.
 178  *
 179  * This routine must be called after platform_prepare().
 180  */
 181 static void platform_finish(int platform_mode)
 182 {
 183         if (platform_mode && hibernation_ops)
 184                 hibernation_ops->finish();
 185 }
 186
 187 /**
 188  * platform_pre_restore - Prepare for hibernate image restoration.
 189  * @platform_mode: Whether or not to use the platform driver.
 190  *
 191  * Use the platform driver to prepare the system for resume from a hibernation
 192  * image.
 193  *
 194  * If the restore fails after this function has been called,
 195  * platform_restore_cleanup() must be called.
 196  */
 197 static int platform_pre_restore(int platform_mode)
 198 {
 199         return (platform_mode && hibernation_ops) ?
 200                 hibernation_ops->pre_restore() : 0;
 201 }
 202
 203 /**
 204  * platform_restore_cleanup - Switch to the working state after failing restore.
 205  * @platform_mode: Whether or not to use the platform driver.
 206  *
 207  * Use the platform driver to switch the system to the normal mode of operation
 208  * after a failing restore.
 209  *
 210  * If platform_pre_restore() has been called before the failing restore, this
 211  * function must be called too, regardless of the result of
 212  * platform_pre_restore().
 213  */
 214 static void platform_restore_cleanup(int platform_mode)
 215 {
 216         if (platform_mode && hibernation_ops)
 217                 hibernation_ops->restore_cleanup();
 218 }
 219
 220 /**
 221  * platform_recover - Recover from a failure to suspend devices.
 222  * @platform_mode: Whether or not to use the platform driver.
 223  */
 224 static void platform_recover(int platform_mode)
 225 {
 226         if (platform_mode && hibernation_ops && hibernation_ops->recover)
 227                 hibernation_ops->recover();
 228 }
 229
 230 /**
 231  * swsusp_show_speed - Print time elapsed between two events during hibernation.
 232  * @start: Starting event.
 233  * @stop: Final event.
 234  * @nr_pages: Number of memory pages processed between @start and @stop.
 235  * @msg: Additional diagnostic message to print.
 236  */
 237 void swsusp_show_speed(ktime_t start, ktime_t stop,
 238                       unsigned nr_pages, char *msg)
 239 {
 240         ktime_t diff;
 241         u64 elapsed_centisecs64;
 242         unsigned int centisecs;
 243         unsigned int k;
 244         unsigned int kps;
 245
 246         diff = ktime_sub(stop, start);
 247         elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 248         centisecs = elapsed_centisecs64;
 249         if (centisecs == 0)
 250                 centisecs = 1;  /* avoid div-by-zero */
 251         k = nr_pages * (PAGE_SIZE / 1024);
 252         kps = (k * 100) / centisecs;
 253         printk(KERN_INFO "PM: %s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 254                         msg, k,
 255                         centisecs / 100, centisecs % 100,
 256                         kps / 1000, (kps % 1000) / 10);
 257 }
 258
 259 /**
 260  * create_image - Create a hibernation image.
 261  * @platform_mode: Whether or not to use the platform driver.
 262  *
 263  * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 264  * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 265  *
 266  * Control reappears in this routine after the subsequent restore.
 267  */
 268 static int create_image(int platform_mode)
 269 {
 270         int error;
 271
 272         error = dpm_suspend_end(PMSG_FREEZE);
 273         if (error) {
 274                 printk(KERN_ERR "PM: Some devices failed to power down, "
 275                         "aborting hibernation\n");
 276                 return error;
 277         }
 278
 279         error = platform_pre_snapshot(platform_mode);
 280         if (error || hibernation_test(TEST_PLATFORM))
 281                 goto Platform_finish;
 282
 283         error = disable_nonboot_cpus();
 284         if (error || hibernation_test(TEST_CPUS))
 285                 goto Enable_cpus;
 286
 287         local_irq_disable();
 288
 289         system_state = SYSTEM_SUSPEND;
 290
 291         error = syscore_suspend();
 292         if (error) {
 293                 printk(KERN_ERR "PM: Some system devices failed to power down, "
 294                         "aborting hibernation\n");
 295                 goto Enable_irqs;
 296         }
 297
 298         if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 299                 goto Power_up;
 300
 301         in_suspend = 1;
 302         save_processor_state();
 303         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 304         error = swsusp_arch_suspend();
 305         /* Restore control flow magically appears here */
 306         restore_processor_state();
 307         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 308         if (error)
 309                 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
 310                         error);
 311         if (!in_suspend) {
 312                 events_check_enabled = false;
 313                 clear_free_pages();
 314         }
 315
 316         platform_leave(platform_mode);
 317
 318  Power_up:
 319         syscore_resume();
 320
 321  Enable_irqs:
 322         system_state = SYSTEM_RUNNING;
 323         local_irq_enable();
 324
 325  Enable_cpus:
 326         enable_nonboot_cpus();
 327
 328  Platform_finish:
 329         platform_finish(platform_mode);
 330
 331         dpm_resume_start(in_suspend ?
 332                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 333
 334         return error;
 335 }
 336
 337 /**
 338  * hibernation_snapshot - Quiesce devices and create a hibernation image.
 339  * @platform_mode: If set, use platform driver to prepare for the transition.
 340  *
 341  * This routine must be called with pm_mutex held.
 342  */
 343 int hibernation_snapshot(int platform_mode)
 344 {
 345         pm_message_t msg;
 346         int error;
 347
 348         pm_suspend_clear_flags();
 349         error = platform_begin(platform_mode);
 350         if (error)
 351                 goto Close;
 352
 353         /* Preallocate image memory before shutting down devices. */
 354         error = hibernate_preallocate_memory();
 355         if (error)
 356                 goto Close;
 357
 358         error = freeze_kernel_threads();
 359         if (error)
 360                 goto Cleanup;
 361
 362         if (hibernation_test(TEST_FREEZER)) {
 363
 364                 /*
 365                  * Indicate to the caller that we are returning due to a
 366                  * successful freezer test.
 367                  */
 368                 freezer_test_done = true;
 369                 goto Thaw;
 370         }
 371
 372         error = dpm_prepare(PMSG_FREEZE);
 373         if (error) {
 374                 dpm_complete(PMSG_RECOVER);
 375                 goto Thaw;
 376         }
 377
 378         suspend_console();
 379         pm_restrict_gfp_mask();
 380
 381         error = dpm_suspend(PMSG_FREEZE);
 382
 383         if (error || hibernation_test(TEST_DEVICES))
 384                 platform_recover(platform_mode);
 385         else
 386                 error = create_image(platform_mode);
 387
 388         /*
 389          * In the case that we call create_image() above, the control
 390          * returns here (1) after the image has been created or the
 391          * image creation has failed and (2) after a successful restore.
 392          */
 393
 394         /* We may need to release the preallocated image pages here. */
 395         if (error || !in_suspend)
 396                 swsusp_free();
 397
 398         msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 399         dpm_resume(msg);
 400
 401         if (error || !in_suspend)
 402                 pm_restore_gfp_mask();
 403
 404         resume_console();
 405         dpm_complete(msg);
 406
 407  Close:
 408         platform_end(platform_mode);
 409         return error;
 410
 411  Thaw:
 412         thaw_kernel_threads();
 413  Cleanup:
 414         swsusp_free();
 415         goto Close;
 416 }
 417
 418 int __weak hibernate_resume_nonboot_cpu_disable(void)
 419 {
 420         return disable_nonboot_cpus();
 421 }
 422
 423 /**
 424  * resume_target_kernel - Restore system state from a hibernation image.
 425  * @platform_mode: Whether or not to use the platform driver.
 426  *
 427  * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 428  * contents of highmem that have not been restored yet from the image and run
 429  * the low-level code that will restore the remaining contents of memory and
 430  * switch to the just restored target kernel.
 431  */
 432 static int resume_target_kernel(bool platform_mode)
 433 {
 434         int error;
 435
 436         error = dpm_suspend_end(PMSG_QUIESCE);
 437         if (error) {
 438                 printk(KERN_ERR "PM: Some devices failed to power down, "
 439                         "aborting resume\n");
 440                 return error;
 441         }
 442
 443         error = platform_pre_restore(platform_mode);
 444         if (error)
 445                 goto Cleanup;
 446
 447         error = hibernate_resume_nonboot_cpu_disable();
 448         if (error)
 449                 goto Enable_cpus;
 450
 451         local_irq_disable();
 452         system_state = SYSTEM_SUSPEND;
 453
 454         error = syscore_suspend();
 455         if (error)
 456                 goto Enable_irqs;
 457
 458         save_processor_state();
 459         error = restore_highmem();
 460         if (!error) {
 461                 error = swsusp_arch_resume();
 462                 /*
 463                  * The code below is only ever reached in case of a failure.
 464                  * Otherwise, execution continues at the place where
 465                  * swsusp_arch_suspend() was called.
 466                  */
 467                 BUG_ON(!error);
 468                 /*
 469                  * This call to restore_highmem() reverts the changes made by
 470                  * the previous one.
 471                  */
 472                 restore_highmem();
 473         }
 474         /*
 475          * The only reason why swsusp_arch_resume() can fail is memory being
 476          * very tight, so we have to free it as soon as we can to avoid
 477          * subsequent failures.
 478          */
 479         swsusp_free();
 480         restore_processor_state();
 481         touch_softlockup_watchdog();
 482
 483         syscore_resume();
 484
 485  Enable_irqs:
 486         system_state = SYSTEM_RUNNING;
 487         local_irq_enable();
 488
 489  Enable_cpus:
 490         enable_nonboot_cpus();
 491
 492  Cleanup:
 493         platform_restore_cleanup(platform_mode);
 494
 495         dpm_resume_start(PMSG_RECOVER);
 496
 497         return error;
 498 }
 499
 500 /**
 501  * hibernation_restore - Quiesce devices and restore from a hibernation image.
 502  * @platform_mode: If set, use platform driver to prepare for the transition.
 503  *
 504  * This routine must be called with pm_mutex held.  If it is successful, control
 505  * reappears in the restored target kernel in hibernation_snapshot().
 506  */
 507 int hibernation_restore(int platform_mode)
 508 {
 509         int error;
 510
 511         pm_prepare_console();
 512         suspend_console();
 513         pm_restrict_gfp_mask();
 514         error = dpm_suspend_start(PMSG_QUIESCE);
 515         if (!error) {
 516                 error = resume_target_kernel(platform_mode);
 517                 /*
 518                  * The above should either succeed and jump to the new kernel,
 519                  * or return with an error. Otherwise things are just
 520                  * undefined, so let's be paranoid.
 521                  */
 522                 BUG_ON(!error);
 523         }
 524         dpm_resume_end(PMSG_RECOVER);
 525         pm_restore_gfp_mask();
 526         resume_console();
 527         pm_restore_console();
 528         return error;
 529 }
 530
 531 /**
 532  * hibernation_platform_enter - Power off the system using the platform driver.
 533  */
 534 int hibernation_platform_enter(void)
 535 {
 536         int error;
 537
 538         if (!hibernation_ops)
 539                 return -ENOSYS;
 540
 541         /*
 542          * We have cancelled the power transition by running
 543          * hibernation_ops->finish() before saving the image, so we should let
 544          * the firmware know that we're going to enter the sleep state after all
 545          */
 546         error = hibernation_ops->begin();
 547         if (error)
 548                 goto Close;
 549
 550         entering_platform_hibernation = true;
 551         suspend_console();
 552         error = dpm_suspend_start(PMSG_HIBERNATE);
 553         if (error) {
 554                 if (hibernation_ops->recover)
 555                         hibernation_ops->recover();
 556                 goto Resume_devices;
 557         }
 558
 559         error = dpm_suspend_end(PMSG_HIBERNATE);
 560         if (error)
 561                 goto Resume_devices;
 562
 563         error = hibernation_ops->prepare();
 564         if (error)
 565                 goto Platform_finish;
 566
 567         error = disable_nonboot_cpus();
 568         if (error)
 569                 goto Enable_cpus;
 570
 571         local_irq_disable();
 572         system_state = SYSTEM_SUSPEND;
 573         syscore_suspend();
 574         if (pm_wakeup_pending()) {
 575                 error = -EAGAIN;
 576                 goto Power_up;
 577         }
 578
 579         hibernation_ops->enter();
 580         /* We should never get here */
 581         while (1);
 582
 583  Power_up:
 584         syscore_resume();
 585         system_state = SYSTEM_RUNNING;
 586         local_irq_enable();
 587
 588  Enable_cpus:
 589         enable_nonboot_cpus();
 590
 591  Platform_finish:
 592         hibernation_ops->finish();
 593
 594         dpm_resume_start(PMSG_RESTORE);
 595
 596  Resume_devices:
 597         entering_platform_hibernation = false;
 598         dpm_resume_end(PMSG_RESTORE);
 599         resume_console();
 600
 601  Close:
 602         hibernation_ops->end();
 603
 604         return error;
 605 }
 606
 607 /**
 608  * power_down - Shut the machine down for hibernation.
 609  *
 610  * Use the platform driver, if configured, to put the system into the sleep
 611  * state corresponding to hibernation, or try to power it off or reboot,
 612  * depending on the value of hibernation_mode.
 613  */
 614 static void power_down(void)
 615 {
 616 #ifdef CONFIG_SUSPEND
 617         int error;
 618 #endif
 619
 620         switch (hibernation_mode) {
 621         case HIBERNATION_REBOOT:
 622                 kernel_restart(NULL);
 623                 break;
 624         case HIBERNATION_PLATFORM:
 625                 hibernation_platform_enter();
 626         case HIBERNATION_SHUTDOWN:
 627                 if (pm_power_off)
 628                         kernel_power_off();
 629                 break;
 630 #ifdef CONFIG_SUSPEND
 631         case HIBERNATION_SUSPEND:
 632                 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
 633                 if (error) {
 634                         if (hibernation_ops)
 635                                 hibernation_mode = HIBERNATION_PLATFORM;
 636                         else
 637                                 hibernation_mode = HIBERNATION_SHUTDOWN;
 638                         power_down();
 639                 }
 640                 /*
 641                  * Restore swap signature.
 642                  */
 643                 error = swsusp_unmark();
 644                 if (error)
 645                         printk(KERN_ERR "PM: Swap will be unusable! "
 646                                         "Try swapon -a.\n");
 647                 return;
 648 #endif
 649         }
 650         kernel_halt();
 651         /*
 652          * Valid image is on the disk, if we continue we risk serious data
 653          * corruption after resume.
 654          */
 655         printk(KERN_CRIT "PM: Please power down manually\n");
 656         while (1)
 657                 cpu_relax();
 658 }
 659
 660 static int load_image_and_restore(void)
 661 {
 662         int error;
 663         unsigned int flags;
 664
 665         pr_debug("PM: Loading hibernation image.\n");
 666
 667         lock_device_hotplug();
 668         error = create_basic_memory_bitmaps();
 669         if (error)
 670                 goto Unlock;
 671
 672         error = swsusp_read(&flags);
 673         swsusp_close(FMODE_READ);
 674         if (!error)
 675                 hibernation_restore(flags & SF_PLATFORM_MODE);
 676
 677         printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
 678         swsusp_free();
 679         free_basic_memory_bitmaps();
 680  Unlock:
 681         unlock_device_hotplug();
 682
 683         return error;
 684 }
 685
 686 #ifndef CONFIG_SUSPEND
 687 bool pm_in_action;
 688 #endif
 689
 690 /**
 691  * hibernate - Carry out system hibernation, including saving the image.
 692  */
 693 int hibernate(void)
 694 {
 695         int error, nr_calls = 0;
 696         bool snapshot_test = false;
 697
 698         if (!hibernation_available()) {
 699                 pr_debug("PM: Hibernation not available.\n");
 700                 return -EPERM;
 701         }
 702
 703         pm_in_action = true;
 704
 705         lock_system_sleep();
 706         /* The snapshot device should not be opened while we're running */
 707         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 708                 error = -EBUSY;
 709                 goto Unlock;
 710         }
 711
 712         pm_prepare_console();
 713         error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
 714         if (error) {
 715                 nr_calls--;
 716                 goto Exit;
 717         }
 718
 719         printk(KERN_INFO "PM: Syncing filesystems ... ");
 720         sys_sync();
 721         printk("done.\n");
 722
 723         error = freeze_processes();
 724         if (error)
 725                 goto Exit;
 726
 727         lock_device_hotplug();
 728         /* Allocate memory management structures */
 729         error = create_basic_memory_bitmaps();
 730         if (error)
 731                 goto Thaw;
 732
 733         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 734         if (error || freezer_test_done)
 735                 goto Free_bitmaps;
 736
 737         if (in_suspend) {
 738                 unsigned int flags = 0;
 739
 740                 if (hibernation_mode == HIBERNATION_PLATFORM)
 741                         flags |= SF_PLATFORM_MODE;
 742                 if (nocompress)
 743                         flags |= SF_NOCOMPRESS_MODE;
 744                 else
 745                         flags |= SF_CRC32_MODE;
 746
 747                 pr_debug("PM: writing image.\n");
 748                 error = swsusp_write(flags);
 749                 swsusp_free();
 750                 if (!error) {
 751                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
 752                                 snapshot_test = true;
 753                         else
 754                                 power_down();
 755                 }
 756                 in_suspend = 0;
 757                 pm_restore_gfp_mask();
 758         } else {
 759                 pr_debug("PM: Image restored successfully.\n");
 760         }
 761
 762  Free_bitmaps:
 763         free_basic_memory_bitmaps();
 764  Thaw:
 765         unlock_device_hotplug();
 766         if (snapshot_test) {
 767                 pr_debug("PM: Checking hibernation image\n");
 768                 error = swsusp_check();
 769                 if (!error)
 770                         error = load_image_and_restore();
 771         }
 772         thaw_processes();
 773
 774         /* Don't bother checking whether freezer_test_done is true */
 775         freezer_test_done = false;
 776  Exit:
 777         __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
 778         pm_restore_console();
 779         atomic_inc(&snapshot_device_available);
 780  Unlock:
 781         unlock_system_sleep();
 782         pm_in_action = false;
 783         return error;
 784 }
 785
 786
 787 /**
 788  * software_resume - Resume from a saved hibernation image.
 789  *
 790  * This routine is called as a late initcall, when all devices have been
 791  * discovered and initialized already.
 792  *
 793  * The image reading code is called to see if there is a hibernation image
 794  * available for reading.  If that is the case, devices are quiesced and the
 795  * contents of memory is restored from the saved image.
 796  *
 797  * If this is successful, control reappears in the restored target kernel in
 798  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 799  * attempts to recover gracefully and make the kernel return to the normal mode
 800  * of operation.
 801  */
 802 static int software_resume(void)
 803 {
 804         int error, nr_calls = 0;
 805
 806         /*
 807          * If the user said "noresume".. bail out early.
 808          */
 809         if (noresume || !hibernation_available())
 810                 return 0;
 811
 812         /*
 813          * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 814          * is configured into the kernel. Since the regular hibernate
 815          * trigger path is via sysfs which takes a buffer mutex before
 816          * calling hibernate functions (which take pm_mutex) this can
 817          * cause lockdep to complain about a possible ABBA deadlock
 818          * which cannot happen since we're in the boot code here and
 819          * sysfs can't be invoked yet. Therefore, we use a subclass
 820          * here to avoid lockdep complaining.
 821          */
 822         mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
 823
 824         if (swsusp_resume_device)
 825                 goto Check_image;
 826
 827         if (!strlen(resume_file)) {
 828                 error = -ENOENT;
 829                 goto Unlock;
 830         }
 831
 832         pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
 833
 834         if (resume_delay) {
 835                 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
 836                         resume_delay);
 837                 ssleep(resume_delay);
 838         }
 839
 840         /* Check if the device is there */
 841         swsusp_resume_device = name_to_dev_t(resume_file);
 842
 843         /*
 844          * name_to_dev_t is ineffective to verify parition if resume_file is in
 845          * integer format. (e.g. major:minor)
 846          */
 847         if (isdigit(resume_file[0]) && resume_wait) {
 848                 int partno;
 849                 while (!get_gendisk(swsusp_resume_device, &partno))
 850                         msleep(10);
 851         }
 852
 853         if (!swsusp_resume_device) {
 854                 /*
 855                  * Some device discovery might still be in progress; we need
 856                  * to wait for this to finish.
 857                  */
 858                 wait_for_device_probe();
 859
 860                 if (resume_wait) {
 861                         while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 862                                 msleep(10);
 863                         async_synchronize_full();
 864                 }
 865
 866                 swsusp_resume_device = name_to_dev_t(resume_file);
 867                 if (!swsusp_resume_device) {
 868                         error = -ENODEV;
 869                         goto Unlock;
 870                 }
 871         }
 872
 873  Check_image:
 874         pr_debug("PM: Hibernation image partition %d:%d present\n",
 875                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 876
 877         pr_debug("PM: Looking for hibernation image.\n");
 878         error = swsusp_check();
 879         if (error)
 880                 goto Unlock;
 881
 882         /* The snapshot device should not be opened while we're running */
 883         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 884                 error = -EBUSY;
 885                 swsusp_close(FMODE_READ);
 886                 goto Unlock;
 887         }
 888
 889         pm_prepare_console();
 890         error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
 891         if (error) {
 892                 nr_calls--;
 893                 goto Close_Finish;
 894         }
 895
 896         pr_debug("PM: Preparing processes for restore.\n");
 897         error = freeze_processes();
 898         if (error)
 899                 goto Close_Finish;
 900         error = load_image_and_restore();
 901         thaw_processes();
 902  Finish:
 903         __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
 904         pm_restore_console();
 905         atomic_inc(&snapshot_device_available);
 906         /* For success case, the suspend path will release the lock */
 907  Unlock:
 908         mutex_unlock(&pm_mutex);
 909         pr_debug("PM: Hibernation image not present or could not be loaded.\n");
 910         return error;
 911  Close_Finish:
 912         swsusp_close(FMODE_READ);
 913         goto Finish;
 914 }
 915
 916 late_initcall_sync(software_resume);
 917
 918
 919 static const char * const hibernation_modes[] = {
 920         [HIBERNATION_PLATFORM]  = "platform",
 921         [HIBERNATION_SHUTDOWN]  = "shutdown",
 922         [HIBERNATION_REBOOT]    = "reboot",
 923 #ifdef CONFIG_SUSPEND
 924         [HIBERNATION_SUSPEND]   = "suspend",
 925 #endif
 926         [HIBERNATION_TEST_RESUME]       = "test_resume",
 927 };
 928
 929 /*
 930  * /sys/power/disk - Control hibernation mode.
 931  *
 932  * Hibernation can be handled in several ways.  There are a few different ways
 933  * to put the system into the sleep state: using the platform driver (e.g. ACPI
 934  * or other hibernation_ops), powering it off or rebooting it (for testing
 935  * mostly).
 936  *
 937  * The sysfs file /sys/power/disk provides an interface for selecting the
 938  * hibernation mode to use.  Reading from this file causes the available modes
 939  * to be printed.  There are 3 modes that can be supported:
 940  *
 941  *      'platform'
 942  *      'shutdown'
 943  *      'reboot'
 944  *
 945  * If a platform hibernation driver is in use, 'platform' will be supported
 946  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
 947  * The selected option (i.e. the one corresponding to the current value of
 948  * hibernation_mode) is enclosed by a square bracket.
 949  *
 950  * To select a given hibernation mode it is necessary to write the mode's
 951  * string representation (as returned by reading from /sys/power/disk) back
 952  * into /sys/power/disk.
 953  */
 954
 955 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 956                          char *buf)
 957 {
 958         int i;
 959         char *start = buf;
 960
 961         if (!hibernation_available())
 962                 return sprintf(buf, "[disabled]\n");
 963
 964         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 965                 if (!hibernation_modes[i])
 966                         continue;
 967                 switch (i) {
 968                 case HIBERNATION_SHUTDOWN:
 969                 case HIBERNATION_REBOOT:
 970 #ifdef CONFIG_SUSPEND
 971                 case HIBERNATION_SUSPEND:
 972 #endif
 973                 case HIBERNATION_TEST_RESUME:
 974                         break;
 975                 case HIBERNATION_PLATFORM:
 976                         if (hibernation_ops)
 977                                 break;
 978                         /* not a valid mode, continue with loop */
 979                         continue;
 980                 }
 981                 if (i == hibernation_mode)
 982                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
 983                 else
 984                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
 985         }
 986         buf += sprintf(buf, "\n");
 987         return buf-start;
 988 }
 989
 990 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 991                           const char *buf, size_t n)
 992 {
 993         int error = 0;
 994         int i;
 995         int len;
 996         char *p;
 997         int mode = HIBERNATION_INVALID;
 998
 999         if (!hibernation_available())
1000                 return -EPERM;
1001
1002         p = memchr(buf, '\n', n);
1003         len = p ? p - buf : n;
1004
1005         lock_system_sleep();
1006         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1007                 if (len == strlen(hibernation_modes[i])
1008                     && !strncmp(buf, hibernation_modes[i], len)) {
1009                         mode = i;
1010                         break;
1011                 }
1012         }
1013         if (mode != HIBERNATION_INVALID) {
1014                 switch (mode) {
1015                 case HIBERNATION_SHUTDOWN:
1016                 case HIBERNATION_REBOOT:
1017 #ifdef CONFIG_SUSPEND
1018                 case HIBERNATION_SUSPEND:
1019 #endif
1020                 case HIBERNATION_TEST_RESUME:
1021                         hibernation_mode = mode;
1022                         break;
1023                 case HIBERNATION_PLATFORM:
1024                         if (hibernation_ops)
1025                                 hibernation_mode = mode;
1026                         else
1027                                 error = -EINVAL;
1028                 }
1029         } else
1030                 error = -EINVAL;
1031
1032         if (!error)
1033                 pr_debug("PM: Hibernation mode set to '%s'\n",
1034                          hibernation_modes[mode]);
1035         unlock_system_sleep();
1036         return error ? error : n;
1037 }
1038
1039 power_attr(disk);
1040
1041 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1042                            char *buf)
1043 {
1044         return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
1045                        MINOR(swsusp_resume_device));
1046 }
1047
1048 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1049                             const char *buf, size_t n)
1050 {
1051         dev_t res;
1052         int len = n;
1053         char *name;
1054
1055         if (len && buf[len-1] == '\n')
1056                 len--;
1057         name = kstrndup(buf, len, GFP_KERNEL);
1058         if (!name)
1059                 return -ENOMEM;
1060
1061         res = name_to_dev_t(name);
1062         kfree(name);
1063         if (!res)
1064                 return -EINVAL;
1065
1066         lock_system_sleep();
1067         swsusp_resume_device = res;
1068         unlock_system_sleep();
1069         printk(KERN_INFO "PM: Starting manual resume from disk\n");
1070         noresume = 0;
1071         software_resume();
1072         return n;
1073 }
1074
1075 power_attr(resume);
1076
1077 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1078                                char *buf)
1079 {
1080         return sprintf(buf, "%lu\n", image_size);
1081 }
1082
1083 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1084                                 const char *buf, size_t n)
1085 {
1086         unsigned long size;
1087
1088         if (sscanf(buf, "%lu", &size) == 1) {
1089                 image_size = size;
1090                 return n;
1091         }
1092
1093         return -EINVAL;
1094 }
1095
1096 power_attr(image_size);
1097
1098 static ssize_t reserved_size_show(struct kobject *kobj,
1099                                   struct kobj_attribute *attr, char *buf)
1100 {
1101         return sprintf(buf, "%lu\n", reserved_size);
1102 }
1103
1104 static ssize_t reserved_size_store(struct kobject *kobj,
1105                                    struct kobj_attribute *attr,
1106                                    const char *buf, size_t n)
1107 {
1108         unsigned long size;
1109
1110         if (sscanf(buf, "%lu", &size) == 1) {
1111                 reserved_size = size;
1112                 return n;
1113         }
1114
1115         return -EINVAL;
1116 }
1117
1118 power_attr(reserved_size);
1119
1120 static struct attribute * g[] = {
1121         &disk_attr.attr,
1122         &resume_attr.attr,
1123         &image_size_attr.attr,
1124         &reserved_size_attr.attr,
1125         NULL,
1126 };
1127
1128
1129 static struct attribute_group attr_group = {
1130         .attrs = g,
1131 };
1132
1133
1134 static int __init pm_disk_init(void)
1135 {
1136         return sysfs_create_group(power_kobj, &attr_group);
1137 }
1138
1139 core_initcall(pm_disk_init);
1140
1141
1142 static int __init resume_setup(char *str)
1143 {
1144         if (noresume)
1145                 return 1;
1146
1147         strncpy( resume_file, str, 255 );
1148         return 1;
1149 }
1150
1151 static int __init resume_offset_setup(char *str)
1152 {
1153         unsigned long long offset;
1154
1155         if (noresume)
1156                 return 1;
1157
1158         if (sscanf(str, "%llu", &offset) == 1)
1159                 swsusp_resume_block = offset;
1160
1161         return 1;
1162 }
1163
1164 static int __init hibernate_setup(char *str)
1165 {
1166         if (!strncmp(str, "noresume", 8)) {
1167                 noresume = 1;
1168         } else if (!strncmp(str, "nocompress", 10)) {
1169                 nocompress = 1;
1170         } else if (!strncmp(str, "no", 2)) {
1171                 noresume = 1;
1172                 nohibernate = 1;
1173         } else if (IS_ENABLED(CONFIG_DEBUG_RODATA)
1174                    && !strncmp(str, "protect_image", 13)) {
1175                 enable_restore_image_protection();
1176         }
1177         return 1;
1178 }
1179
1180 static int __init noresume_setup(char *str)
1181 {
1182         noresume = 1;
1183         return 1;
1184 }
1185
1186 static int __init resumewait_setup(char *str)
1187 {
1188         resume_wait = 1;
1189         return 1;
1190 }
1191
1192 static int __init resumedelay_setup(char *str)
1193 {
1194         int rc = kstrtouint(str, 0, &resume_delay);
1195
1196         if (rc)
1197                 return rc;
1198         return 1;
1199 }
1200
1201 static int __init nohibernate_setup(char *str)
1202 {
1203         noresume = 1;
1204         nohibernate = 1;
1205         return 1;
1206 }
1207
1208 __setup("noresume", noresume_setup);
1209 __setup("resume_offset=", resume_offset_setup);
1210 __setup("resume=", resume_setup);
1211 __setup("hibernate=", hibernate_setup);
1212 __setup("resumewait", resumewait_setup);
1213 __setup("resumedelay=", resumedelay_setup);
1214 __setup("nohibernate", nohibernate_setup);