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