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         error = syscore_suspend();
 290         if (error) {
 291                 printk(KERN_ERR "PM: Some system devices failed to power down, "
 292                         "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                 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
 308                         error);
 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                 printk(KERN_ERR "PM: Some devices failed to power down, "
 436                         "aborting resume\n");
 437                 return error;
 438         }
 439
 440         error = platform_pre_restore(platform_mode);
 441         if (error)
 442                 goto Cleanup;
 443
 444         error = hibernate_resume_nonboot_cpu_disable();
 445         if (error)
 446                 goto Enable_cpus;
 447
 448         local_irq_disable();
 449
 450         error = syscore_suspend();
 451         if (error)
 452                 goto Enable_irqs;
 453
 454         save_processor_state();
 455         error = restore_highmem();
 456         if (!error) {
 457                 error = swsusp_arch_resume();
 458                 /*
 459                  * The code below is only ever reached in case of a failure.
 460                  * Otherwise, execution continues at the place where
 461                  * swsusp_arch_suspend() was called.
 462                  */
 463                 BUG_ON(!error);
 464                 /*
 465                  * This call to restore_highmem() reverts the changes made by
 466                  * the previous one.
 467                  */
 468                 restore_highmem();
 469         }
 470         /*
 471          * The only reason why swsusp_arch_resume() can fail is memory being
 472          * very tight, so we have to free it as soon as we can to avoid
 473          * subsequent failures.
 474          */
 475         swsusp_free();
 476         restore_processor_state();
 477         touch_softlockup_watchdog();
 478
 479         syscore_resume();
 480
 481  Enable_irqs:
 482         local_irq_enable();
 483
 484  Enable_cpus:
 485         enable_nonboot_cpus();
 486
 487  Cleanup:
 488         platform_restore_cleanup(platform_mode);
 489
 490         dpm_resume_start(PMSG_RECOVER);
 491
 492         return error;
 493 }
 494
 495 /**
 496  * hibernation_restore - Quiesce devices and restore from a hibernation image.
 497  * @platform_mode: If set, use platform driver to prepare for the transition.
 498  *
 499  * This routine must be called with pm_mutex held.  If it is successful, control
 500  * reappears in the restored target kernel in hibernation_snapshot().
 501  */
 502 int hibernation_restore(int platform_mode)
 503 {
 504         int error;
 505
 506         pm_prepare_console();
 507         suspend_console();
 508         pm_restrict_gfp_mask();
 509         error = dpm_suspend_start(PMSG_QUIESCE);
 510         if (!error) {
 511                 error = resume_target_kernel(platform_mode);
 512                 /*
 513                  * The above should either succeed and jump to the new kernel,
 514                  * or return with an error. Otherwise things are just
 515                  * undefined, so let's be paranoid.
 516                  */
 517                 BUG_ON(!error);
 518         }
 519         dpm_resume_end(PMSG_RECOVER);
 520         pm_restore_gfp_mask();
 521         resume_console();
 522         pm_restore_console();
 523         return error;
 524 }
 525
 526 /**
 527  * hibernation_platform_enter - Power off the system using the platform driver.
 528  */
 529 int hibernation_platform_enter(void)
 530 {
 531         int error;
 532
 533         if (!hibernation_ops)
 534                 return -ENOSYS;
 535
 536         /*
 537          * We have cancelled the power transition by running
 538          * hibernation_ops->finish() before saving the image, so we should let
 539          * the firmware know that we're going to enter the sleep state after all
 540          */
 541         error = hibernation_ops->begin();
 542         if (error)
 543                 goto Close;
 544
 545         entering_platform_hibernation = true;
 546         suspend_console();
 547         error = dpm_suspend_start(PMSG_HIBERNATE);
 548         if (error) {
 549                 if (hibernation_ops->recover)
 550                         hibernation_ops->recover();
 551                 goto Resume_devices;
 552         }
 553
 554         error = dpm_suspend_end(PMSG_HIBERNATE);
 555         if (error)
 556                 goto Resume_devices;
 557
 558         error = hibernation_ops->prepare();
 559         if (error)
 560                 goto Platform_finish;
 561
 562         error = disable_nonboot_cpus();
 563         if (error)
 564                 goto Enable_cpus;
 565
 566         local_irq_disable();
 567         syscore_suspend();
 568         if (pm_wakeup_pending()) {
 569                 error = -EAGAIN;
 570                 goto Power_up;
 571         }
 572
 573         hibernation_ops->enter();
 574         /* We should never get here */
 575         while (1);
 576
 577  Power_up:
 578         syscore_resume();
 579         local_irq_enable();
 580
 581  Enable_cpus:
 582         enable_nonboot_cpus();
 583
 584  Platform_finish:
 585         hibernation_ops->finish();
 586
 587         dpm_resume_start(PMSG_RESTORE);
 588
 589  Resume_devices:
 590         entering_platform_hibernation = false;
 591         dpm_resume_end(PMSG_RESTORE);
 592         resume_console();
 593
 594  Close:
 595         hibernation_ops->end();
 596
 597         return error;
 598 }
 599
 600 /**
 601  * power_down - Shut the machine down for hibernation.
 602  *
 603  * Use the platform driver, if configured, to put the system into the sleep
 604  * state corresponding to hibernation, or try to power it off or reboot,
 605  * depending on the value of hibernation_mode.
 606  */
 607 static void power_down(void)
 608 {
 609 #ifdef CONFIG_SUSPEND
 610         int error;
 611 #endif
 612
 613         switch (hibernation_mode) {
 614         case HIBERNATION_REBOOT:
 615                 kernel_restart(NULL);
 616                 break;
 617         case HIBERNATION_PLATFORM:
 618                 hibernation_platform_enter();
 619         case HIBERNATION_SHUTDOWN:
 620                 if (pm_power_off)
 621                         kernel_power_off();
 622                 break;
 623 #ifdef CONFIG_SUSPEND
 624         case HIBERNATION_SUSPEND:
 625                 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
 626                 if (error) {
 627                         if (hibernation_ops)
 628                                 hibernation_mode = HIBERNATION_PLATFORM;
 629                         else
 630                                 hibernation_mode = HIBERNATION_SHUTDOWN;
 631                         power_down();
 632                 }
 633                 /*
 634                  * Restore swap signature.
 635                  */
 636                 error = swsusp_unmark();
 637                 if (error)
 638                         printk(KERN_ERR "PM: Swap will be unusable! "
 639                                         "Try swapon -a.\n");
 640                 return;
 641 #endif
 642         }
 643         kernel_halt();
 644         /*
 645          * Valid image is on the disk, if we continue we risk serious data
 646          * corruption after resume.
 647          */
 648         printk(KERN_CRIT "PM: Please power down manually\n");
 649         while (1)
 650                 cpu_relax();
 651 }
 652
 653 static int load_image_and_restore(void)
 654 {
 655         int error;
 656         unsigned int flags;
 657
 658         pr_debug("PM: Loading hibernation image.\n");
 659
 660         lock_device_hotplug();
 661         error = create_basic_memory_bitmaps();
 662         if (error)
 663                 goto Unlock;
 664
 665         error = swsusp_read(&flags);
 666         swsusp_close(FMODE_READ);
 667         if (!error)
 668                 hibernation_restore(flags & SF_PLATFORM_MODE);
 669
 670         printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
 671         swsusp_free();
 672         free_basic_memory_bitmaps();
 673  Unlock:
 674         unlock_device_hotplug();
 675
 676         return error;
 677 }
 678
 679 /**
 680  * hibernate - Carry out system hibernation, including saving the image.
 681  */
 682 int hibernate(void)
 683 {
 684         int error, nr_calls = 0;
 685         bool snapshot_test = false;
 686
 687         if (!hibernation_available()) {
 688                 pr_debug("PM: Hibernation not available.\n");
 689                 return -EPERM;
 690         }
 691
 692         lock_system_sleep();
 693         /* The snapshot device should not be opened while we're running */
 694         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 695                 error = -EBUSY;
 696                 goto Unlock;
 697         }
 698
 699         pm_prepare_console();
 700         error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
 701         if (error) {
 702                 nr_calls--;
 703                 goto Exit;
 704         }
 705
 706         printk(KERN_INFO "PM: Syncing filesystems ... ");
 707         sys_sync();
 708         printk("done.\n");
 709
 710         error = freeze_processes();
 711         if (error)
 712                 goto Exit;
 713
 714         lock_device_hotplug();
 715         /* Allocate memory management structures */
 716         error = create_basic_memory_bitmaps();
 717         if (error)
 718                 goto Thaw;
 719
 720         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 721         if (error || freezer_test_done)
 722                 goto Free_bitmaps;
 723
 724         if (in_suspend) {
 725                 unsigned int flags = 0;
 726
 727                 if (hibernation_mode == HIBERNATION_PLATFORM)
 728                         flags |= SF_PLATFORM_MODE;
 729                 if (nocompress)
 730                         flags |= SF_NOCOMPRESS_MODE;
 731                 else
 732                         flags |= SF_CRC32_MODE;
 733
 734                 pr_debug("PM: writing image.\n");
 735                 error = swsusp_write(flags);
 736                 swsusp_free();
 737                 if (!error) {
 738                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
 739                                 snapshot_test = true;
 740                         else
 741                                 power_down();
 742                 }
 743                 in_suspend = 0;
 744                 pm_restore_gfp_mask();
 745         } else {
 746                 pr_debug("PM: Image restored successfully.\n");
 747         }
 748
 749  Free_bitmaps:
 750         free_basic_memory_bitmaps();
 751  Thaw:
 752         unlock_device_hotplug();
 753         if (snapshot_test) {
 754                 pr_debug("PM: Checking hibernation image\n");
 755                 error = swsusp_check();
 756                 if (!error)
 757                         error = load_image_and_restore();
 758         }
 759         thaw_processes();
 760
 761         /* Don't bother checking whether freezer_test_done is true */
 762         freezer_test_done = false;
 763  Exit:
 764         __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
 765         pm_restore_console();
 766         atomic_inc(&snapshot_device_available);
 767  Unlock:
 768         unlock_system_sleep();
 769         return error;
 770 }
 771
 772
 773 /**
 774  * software_resume - Resume from a saved hibernation image.
 775  *
 776  * This routine is called as a late initcall, when all devices have been
 777  * discovered and initialized already.
 778  *
 779  * The image reading code is called to see if there is a hibernation image
 780  * available for reading.  If that is the case, devices are quiesced and the
 781  * contents of memory is restored from the saved image.
 782  *
 783  * If this is successful, control reappears in the restored target kernel in
 784  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 785  * attempts to recover gracefully and make the kernel return to the normal mode
 786  * of operation.
 787  */
 788 static int software_resume(void)
 789 {
 790         int error, nr_calls = 0;
 791
 792         /*
 793          * If the user said "noresume".. bail out early.
 794          */
 795         if (noresume || !hibernation_available())
 796                 return 0;
 797
 798         /*
 799          * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 800          * is configured into the kernel. Since the regular hibernate
 801          * trigger path is via sysfs which takes a buffer mutex before
 802          * calling hibernate functions (which take pm_mutex) this can
 803          * cause lockdep to complain about a possible ABBA deadlock
 804          * which cannot happen since we're in the boot code here and
 805          * sysfs can't be invoked yet. Therefore, we use a subclass
 806          * here to avoid lockdep complaining.
 807          */
 808         mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
 809
 810         if (swsusp_resume_device)
 811                 goto Check_image;
 812
 813         if (!strlen(resume_file)) {
 814                 error = -ENOENT;
 815                 goto Unlock;
 816         }
 817
 818         pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
 819
 820         if (resume_delay) {
 821                 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
 822                         resume_delay);
 823                 ssleep(resume_delay);
 824         }
 825
 826         /* Check if the device is there */
 827         swsusp_resume_device = name_to_dev_t(resume_file);
 828
 829         /*
 830          * name_to_dev_t is ineffective to verify parition if resume_file is in
 831          * integer format. (e.g. major:minor)
 832          */
 833         if (isdigit(resume_file[0]) && resume_wait) {
 834                 int partno;
 835                 while (!get_gendisk(swsusp_resume_device, &partno))
 836                         msleep(10);
 837         }
 838
 839         if (!swsusp_resume_device) {
 840                 /*
 841                  * Some device discovery might still be in progress; we need
 842                  * to wait for this to finish.
 843                  */
 844                 wait_for_device_probe();
 845
 846                 if (resume_wait) {
 847                         while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 848                                 msleep(10);
 849                         async_synchronize_full();
 850                 }
 851
 852                 swsusp_resume_device = name_to_dev_t(resume_file);
 853                 if (!swsusp_resume_device) {
 854                         error = -ENODEV;
 855                         goto Unlock;
 856                 }
 857         }
 858
 859  Check_image:
 860         pr_debug("PM: Hibernation image partition %d:%d present\n",
 861                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 862
 863         pr_debug("PM: Looking for hibernation image.\n");
 864         error = swsusp_check();
 865         if (error)
 866                 goto Unlock;
 867
 868         /* The snapshot device should not be opened while we're running */
 869         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 870                 error = -EBUSY;
 871                 swsusp_close(FMODE_READ);
 872                 goto Unlock;
 873         }
 874
 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         pr_debug("PM: 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         atomic_inc(&snapshot_device_available);
 892         /* For success case, the suspend path will release the lock */
 893  Unlock:
 894         mutex_unlock(&pm_mutex);
 895         pr_debug("PM: Hibernation image not present or could not be loaded.\n");
 896         return error;
 897  Close_Finish:
 898         swsusp_close(FMODE_READ);
 899         goto Finish;
 900 }
 901
 902 late_initcall_sync(software_resume);
 903
 904
 905 static const char * const hibernation_modes[] = {
 906         [HIBERNATION_PLATFORM]  = "platform",
 907         [HIBERNATION_SHUTDOWN]  = "shutdown",
 908         [HIBERNATION_REBOOT]    = "reboot",
 909 #ifdef CONFIG_SUSPEND
 910         [HIBERNATION_SUSPEND]   = "suspend",
 911 #endif
 912         [HIBERNATION_TEST_RESUME]       = "test_resume",
 913 };
 914
 915 /*
 916  * /sys/power/disk - Control hibernation mode.
 917  *
 918  * Hibernation can be handled in several ways.  There are a few different ways
 919  * to put the system into the sleep state: using the platform driver (e.g. ACPI
 920  * or other hibernation_ops), powering it off or rebooting it (for testing
 921  * mostly).
 922  *
 923  * The sysfs file /sys/power/disk provides an interface for selecting the
 924  * hibernation mode to use.  Reading from this file causes the available modes
 925  * to be printed.  There are 3 modes that can be supported:
 926  *
 927  *      'platform'
 928  *      'shutdown'
 929  *      'reboot'
 930  *
 931  * If a platform hibernation driver is in use, 'platform' will be supported
 932  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
 933  * The selected option (i.e. the one corresponding to the current value of
 934  * hibernation_mode) is enclosed by a square bracket.
 935  *
 936  * To select a given hibernation mode it is necessary to write the mode's
 937  * string representation (as returned by reading from /sys/power/disk) back
 938  * into /sys/power/disk.
 939  */
 940
 941 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 942                          char *buf)
 943 {
 944         int i;
 945         char *start = buf;
 946
 947         if (!hibernation_available())
 948                 return sprintf(buf, "[disabled]\n");
 949
 950         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 951                 if (!hibernation_modes[i])
 952                         continue;
 953                 switch (i) {
 954                 case HIBERNATION_SHUTDOWN:
 955                 case HIBERNATION_REBOOT:
 956 #ifdef CONFIG_SUSPEND
 957                 case HIBERNATION_SUSPEND:
 958 #endif
 959                 case HIBERNATION_TEST_RESUME:
 960                         break;
 961                 case HIBERNATION_PLATFORM:
 962                         if (hibernation_ops)
 963                                 break;
 964                         /* not a valid mode, continue with loop */
 965                         continue;
 966                 }
 967                 if (i == hibernation_mode)
 968                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
 969                 else
 970                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
 971         }
 972         buf += sprintf(buf, "\n");
 973         return buf-start;
 974 }
 975
 976 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 977                           const char *buf, size_t n)
 978 {
 979         int error = 0;
 980         int i;
 981         int len;
 982         char *p;
 983         int mode = HIBERNATION_INVALID;
 984
 985         if (!hibernation_available())
 986                 return -EPERM;
 987
 988         p = memchr(buf, '\n', n);
 989         len = p ? p - buf : n;
 990
 991         lock_system_sleep();
 992         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 993                 if (len == strlen(hibernation_modes[i])
 994                     && !strncmp(buf, hibernation_modes[i], len)) {
 995                         mode = i;
 996                         break;
 997                 }
 998         }
 999         if (mode != HIBERNATION_INVALID) {
1000                 switch (mode) {
1001                 case HIBERNATION_SHUTDOWN:
1002                 case HIBERNATION_REBOOT:
1003 #ifdef CONFIG_SUSPEND
1004                 case HIBERNATION_SUSPEND:
1005 #endif
1006                 case HIBERNATION_TEST_RESUME:
1007                         hibernation_mode = mode;
1008                         break;
1009                 case HIBERNATION_PLATFORM:
1010                         if (hibernation_ops)
1011                                 hibernation_mode = mode;
1012                         else
1013                                 error = -EINVAL;
1014                 }
1015         } else
1016                 error = -EINVAL;
1017
1018         if (!error)
1019                 pr_debug("PM: Hibernation mode set to '%s'\n",
1020                          hibernation_modes[mode]);
1021         unlock_system_sleep();
1022         return error ? error : n;
1023 }
1024
1025 power_attr(disk);
1026
1027 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1028                            char *buf)
1029 {
1030         return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
1031                        MINOR(swsusp_resume_device));
1032 }
1033
1034 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1035                             const char *buf, size_t n)
1036 {
1037         dev_t res;
1038         int len = n;
1039         char *name;
1040
1041         if (len && buf[len-1] == '\n')
1042                 len--;
1043         name = kstrndup(buf, len, GFP_KERNEL);
1044         if (!name)
1045                 return -ENOMEM;
1046
1047         res = name_to_dev_t(name);
1048         kfree(name);
1049         if (!res)
1050                 return -EINVAL;
1051
1052         lock_system_sleep();
1053         swsusp_resume_device = res;
1054         unlock_system_sleep();
1055         printk(KERN_INFO "PM: Starting manual resume from disk\n");
1056         noresume = 0;
1057         software_resume();
1058         return n;
1059 }
1060
1061 power_attr(resume);
1062
1063 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1064                                char *buf)
1065 {
1066         return sprintf(buf, "%lu\n", image_size);
1067 }
1068
1069 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1070                                 const char *buf, size_t n)
1071 {
1072         unsigned long size;
1073
1074         if (sscanf(buf, "%lu", &size) == 1) {
1075                 image_size = size;
1076                 return n;
1077         }
1078
1079         return -EINVAL;
1080 }
1081
1082 power_attr(image_size);
1083
1084 static ssize_t reserved_size_show(struct kobject *kobj,
1085                                   struct kobj_attribute *attr, char *buf)
1086 {
1087         return sprintf(buf, "%lu\n", reserved_size);
1088 }
1089
1090 static ssize_t reserved_size_store(struct kobject *kobj,
1091                                    struct kobj_attribute *attr,
1092                                    const char *buf, size_t n)
1093 {
1094         unsigned long size;
1095
1096         if (sscanf(buf, "%lu", &size) == 1) {
1097                 reserved_size = size;
1098                 return n;
1099         }
1100
1101         return -EINVAL;
1102 }
1103
1104 power_attr(reserved_size);
1105
1106 static struct attribute * g[] = {
1107         &disk_attr.attr,
1108         &resume_attr.attr,
1109         &image_size_attr.attr,
1110         &reserved_size_attr.attr,
1111         NULL,
1112 };
1113
1114
1115 static struct attribute_group attr_group = {
1116         .attrs = g,
1117 };
1118
1119
1120 static int __init pm_disk_init(void)
1121 {
1122         return sysfs_create_group(power_kobj, &attr_group);
1123 }
1124
1125 core_initcall(pm_disk_init);
1126
1127
1128 static int __init resume_setup(char *str)
1129 {
1130         if (noresume)
1131                 return 1;
1132
1133         strncpy( resume_file, str, 255 );
1134         return 1;
1135 }
1136
1137 static int __init resume_offset_setup(char *str)
1138 {
1139         unsigned long long offset;
1140
1141         if (noresume)
1142                 return 1;
1143
1144         if (sscanf(str, "%llu", &offset) == 1)
1145                 swsusp_resume_block = offset;
1146
1147         return 1;
1148 }
1149
1150 static int __init hibernate_setup(char *str)
1151 {
1152         if (!strncmp(str, "noresume", 8)) {
1153                 noresume = 1;
1154         } else if (!strncmp(str, "nocompress", 10)) {
1155                 nocompress = 1;
1156         } else if (!strncmp(str, "no", 2)) {
1157                 noresume = 1;
1158                 nohibernate = 1;
1159         } else if (IS_ENABLED(CONFIG_DEBUG_RODATA)
1160                    && !strncmp(str, "protect_image", 13)) {
1161                 enable_restore_image_protection();
1162         }
1163         return 1;
1164 }
1165
1166 static int __init noresume_setup(char *str)
1167 {
1168         noresume = 1;
1169         return 1;
1170 }
1171
1172 static int __init resumewait_setup(char *str)
1173 {
1174         resume_wait = 1;
1175         return 1;
1176 }
1177
1178 static int __init resumedelay_setup(char *str)
1179 {
1180         int rc = kstrtouint(str, 0, &resume_delay);
1181
1182         if (rc)
1183                 return rc;
1184         return 1;
1185 }
1186
1187 static int __init nohibernate_setup(char *str)
1188 {
1189         noresume = 1;
1190         nohibernate = 1;
1191         return 1;
1192 }
1193
1194 __setup("noresume", noresume_setup);
1195 __setup("resume_offset=", resume_offset_setup);
1196 __setup("resume=", resume_setup);
1197 __setup("hibernate=", hibernate_setup);
1198 __setup("resumewait", resumewait_setup);
1199 __setup("resumedelay=", resumedelay_setup);
1200 __setup("nohibernate", nohibernate_setup);