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         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 304         if (error)
 305                 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
 306                         error);
 307         /* Restore control flow magically appears here */
 308         restore_processor_state();
 309         if (!in_suspend)
 310                 events_check_enabled = false;
 311
 312         platform_leave(platform_mode);
 313
 314  Power_up:
 315         syscore_resume();
 316
 317  Enable_irqs:
 318         local_irq_enable();
 319
 320  Enable_cpus:
 321         enable_nonboot_cpus();
 322
 323  Platform_finish:
 324         platform_finish(platform_mode);
 325
 326         dpm_resume_start(in_suspend ?
 327                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 328
 329         return error;
 330 }
 331
 332 /**
 333  * hibernation_snapshot - Quiesce devices and create a hibernation image.
 334  * @platform_mode: If set, use platform driver to prepare for the transition.
 335  *
 336  * This routine must be called with pm_mutex held.
 337  */
 338 int hibernation_snapshot(int platform_mode)
 339 {
 340         pm_message_t msg;
 341         int error;
 342
 343         pm_suspend_clear_flags();
 344         error = platform_begin(platform_mode);
 345         if (error)
 346                 goto Close;
 347
 348         /* Preallocate image memory before shutting down devices. */
 349         error = hibernate_preallocate_memory();
 350         if (error)
 351                 goto Close;
 352
 353         error = freeze_kernel_threads();
 354         if (error)
 355                 goto Cleanup;
 356
 357         if (hibernation_test(TEST_FREEZER)) {
 358
 359                 /*
 360                  * Indicate to the caller that we are returning due to a
 361                  * successful freezer test.
 362                  */
 363                 freezer_test_done = true;
 364                 goto Thaw;
 365         }
 366
 367         error = dpm_prepare(PMSG_FREEZE);
 368         if (error) {
 369                 dpm_complete(PMSG_RECOVER);
 370                 goto Thaw;
 371         }
 372
 373         suspend_console();
 374         pm_restrict_gfp_mask();
 375
 376         error = dpm_suspend(PMSG_FREEZE);
 377
 378         if (error || hibernation_test(TEST_DEVICES))
 379                 platform_recover(platform_mode);
 380         else
 381                 error = create_image(platform_mode);
 382
 383         /*
 384          * In the case that we call create_image() above, the control
 385          * returns here (1) after the image has been created or the
 386          * image creation has failed and (2) after a successful restore.
 387          */
 388
 389         /* We may need to release the preallocated image pages here. */
 390         if (error || !in_suspend)
 391                 swsusp_free();
 392
 393         msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 394         dpm_resume(msg);
 395
 396         if (error || !in_suspend)
 397                 pm_restore_gfp_mask();
 398
 399         resume_console();
 400         dpm_complete(msg);
 401
 402  Close:
 403         platform_end(platform_mode);
 404         return error;
 405
 406  Thaw:
 407         thaw_kernel_threads();
 408  Cleanup:
 409         swsusp_free();
 410         goto Close;
 411 }
 412
 413 int __weak hibernate_resume_nonboot_cpu_disable(void)
 414 {
 415         return disable_nonboot_cpus();
 416 }
 417
 418 /**
 419  * resume_target_kernel - Restore system state from a hibernation image.
 420  * @platform_mode: Whether or not to use the platform driver.
 421  *
 422  * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 423  * contents of highmem that have not been restored yet from the image and run
 424  * the low-level code that will restore the remaining contents of memory and
 425  * switch to the just restored target kernel.
 426  */
 427 static int resume_target_kernel(bool platform_mode)
 428 {
 429         int error;
 430
 431         error = dpm_suspend_end(PMSG_QUIESCE);
 432         if (error) {
 433                 printk(KERN_ERR "PM: Some devices failed to power down, "
 434                         "aborting resume\n");
 435                 return error;
 436         }
 437
 438         error = platform_pre_restore(platform_mode);
 439         if (error)
 440                 goto Cleanup;
 441
 442         error = hibernate_resume_nonboot_cpu_disable();
 443         if (error)
 444                 goto Enable_cpus;
 445
 446         local_irq_disable();
 447
 448         error = syscore_suspend();
 449         if (error)
 450                 goto Enable_irqs;
 451
 452         save_processor_state();
 453         error = restore_highmem();
 454         if (!error) {
 455                 error = swsusp_arch_resume();
 456                 /*
 457                  * The code below is only ever reached in case of a failure.
 458                  * Otherwise, execution continues at the place where
 459                  * swsusp_arch_suspend() was called.
 460                  */
 461                 BUG_ON(!error);
 462                 /*
 463                  * This call to restore_highmem() reverts the changes made by
 464                  * the previous one.
 465                  */
 466                 restore_highmem();
 467         }
 468         /*
 469          * The only reason why swsusp_arch_resume() can fail is memory being
 470          * very tight, so we have to free it as soon as we can to avoid
 471          * subsequent failures.
 472          */
 473         swsusp_free();
 474         restore_processor_state();
 475         touch_softlockup_watchdog();
 476
 477         syscore_resume();
 478
 479  Enable_irqs:
 480         local_irq_enable();
 481
 482  Enable_cpus:
 483         enable_nonboot_cpus();
 484
 485  Cleanup:
 486         platform_restore_cleanup(platform_mode);
 487
 488         dpm_resume_start(PMSG_RECOVER);
 489
 490         return error;
 491 }
 492
 493 /**
 494  * hibernation_restore - Quiesce devices and restore from a hibernation image.
 495  * @platform_mode: If set, use platform driver to prepare for the transition.
 496  *
 497  * This routine must be called with pm_mutex held.  If it is successful, control
 498  * reappears in the restored target kernel in hibernation_snapshot().
 499  */
 500 int hibernation_restore(int platform_mode)
 501 {
 502         int error;
 503
 504         pm_prepare_console();
 505         suspend_console();
 506         pm_restrict_gfp_mask();
 507         error = dpm_suspend_start(PMSG_QUIESCE);
 508         if (!error) {
 509                 error = resume_target_kernel(platform_mode);
 510                 /*
 511                  * The above should either succeed and jump to the new kernel,
 512                  * or return with an error. Otherwise things are just
 513                  * undefined, so let's be paranoid.
 514                  */
 515                 BUG_ON(!error);
 516         }
 517         dpm_resume_end(PMSG_RECOVER);
 518         pm_restore_gfp_mask();
 519         resume_console();
 520         pm_restore_console();
 521         return error;
 522 }
 523
 524 /**
 525  * hibernation_platform_enter - Power off the system using the platform driver.
 526  */
 527 int hibernation_platform_enter(void)
 528 {
 529         int error;
 530
 531         if (!hibernation_ops)
 532                 return -ENOSYS;
 533
 534         /*
 535          * We have cancelled the power transition by running
 536          * hibernation_ops->finish() before saving the image, so we should let
 537          * the firmware know that we're going to enter the sleep state after all
 538          */
 539         error = hibernation_ops->begin();
 540         if (error)
 541                 goto Close;
 542
 543         entering_platform_hibernation = true;
 544         suspend_console();
 545         error = dpm_suspend_start(PMSG_HIBERNATE);
 546         if (error) {
 547                 if (hibernation_ops->recover)
 548                         hibernation_ops->recover();
 549                 goto Resume_devices;
 550         }
 551
 552         error = dpm_suspend_end(PMSG_HIBERNATE);
 553         if (error)
 554                 goto Resume_devices;
 555
 556         error = hibernation_ops->prepare();
 557         if (error)
 558                 goto Platform_finish;
 559
 560         error = disable_nonboot_cpus();
 561         if (error)
 562                 goto Enable_cpus;
 563
 564         local_irq_disable();
 565         syscore_suspend();
 566         if (pm_wakeup_pending()) {
 567                 error = -EAGAIN;
 568                 goto Power_up;
 569         }
 570
 571         hibernation_ops->enter();
 572         /* We should never get here */
 573         while (1);
 574
 575  Power_up:
 576         syscore_resume();
 577         local_irq_enable();
 578
 579  Enable_cpus:
 580         enable_nonboot_cpus();
 581
 582  Platform_finish:
 583         hibernation_ops->finish();
 584
 585         dpm_resume_start(PMSG_RESTORE);
 586
 587  Resume_devices:
 588         entering_platform_hibernation = false;
 589         dpm_resume_end(PMSG_RESTORE);
 590         resume_console();
 591
 592  Close:
 593         hibernation_ops->end();
 594
 595         return error;
 596 }
 597
 598 /**
 599  * power_down - Shut the machine down for hibernation.
 600  *
 601  * Use the platform driver, if configured, to put the system into the sleep
 602  * state corresponding to hibernation, or try to power it off or reboot,
 603  * depending on the value of hibernation_mode.
 604  */
 605 static void power_down(void)
 606 {
 607 #ifdef CONFIG_SUSPEND
 608         int error;
 609 #endif
 610
 611         switch (hibernation_mode) {
 612         case HIBERNATION_REBOOT:
 613                 kernel_restart(NULL);
 614                 break;
 615         case HIBERNATION_PLATFORM:
 616                 hibernation_platform_enter();
 617         case HIBERNATION_SHUTDOWN:
 618                 if (pm_power_off)
 619                         kernel_power_off();
 620                 break;
 621 #ifdef CONFIG_SUSPEND
 622         case HIBERNATION_SUSPEND:
 623                 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
 624                 if (error) {
 625                         if (hibernation_ops)
 626                                 hibernation_mode = HIBERNATION_PLATFORM;
 627                         else
 628                                 hibernation_mode = HIBERNATION_SHUTDOWN;
 629                         power_down();
 630                 }
 631                 /*
 632                  * Restore swap signature.
 633                  */
 634                 error = swsusp_unmark();
 635                 if (error)
 636                         printk(KERN_ERR "PM: Swap will be unusable! "
 637                                         "Try swapon -a.\n");
 638                 return;
 639 #endif
 640         }
 641         kernel_halt();
 642         /*
 643          * Valid image is on the disk, if we continue we risk serious data
 644          * corruption after resume.
 645          */
 646         printk(KERN_CRIT "PM: Please power down manually\n");
 647         while (1)
 648                 cpu_relax();
 649 }
 650
 651 static int load_image_and_restore(void)
 652 {
 653         int error;
 654         unsigned int flags;
 655
 656         pr_debug("PM: Loading hibernation image.\n");
 657
 658         lock_device_hotplug();
 659         error = create_basic_memory_bitmaps();
 660         if (error)
 661                 goto Unlock;
 662
 663         error = swsusp_read(&flags);
 664         swsusp_close(FMODE_READ);
 665         if (!error)
 666                 hibernation_restore(flags & SF_PLATFORM_MODE);
 667
 668         printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
 669         swsusp_free();
 670         free_basic_memory_bitmaps();
 671  Unlock:
 672         unlock_device_hotplug();
 673
 674         return error;
 675 }
 676
 677 /**
 678  * hibernate - Carry out system hibernation, including saving the image.
 679  */
 680 int hibernate(void)
 681 {
 682         int error, nr_calls = 0;
 683         bool snapshot_test = false;
 684
 685         if (!hibernation_available()) {
 686                 pr_debug("PM: Hibernation not available.\n");
 687                 return -EPERM;
 688         }
 689
 690         lock_system_sleep();
 691         /* The snapshot device should not be opened while we're running */
 692         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 693                 error = -EBUSY;
 694                 goto Unlock;
 695         }
 696
 697         pm_prepare_console();
 698         error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
 699         if (error) {
 700                 nr_calls--;
 701                 goto Exit;
 702         }
 703
 704         printk(KERN_INFO "PM: Syncing filesystems ... ");
 705         sys_sync();
 706         printk("done.\n");
 707
 708         error = freeze_processes();
 709         if (error)
 710                 goto Exit;
 711
 712         lock_device_hotplug();
 713         /* Allocate memory management structures */
 714         error = create_basic_memory_bitmaps();
 715         if (error)
 716                 goto Thaw;
 717
 718         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 719         if (error || freezer_test_done)
 720                 goto Free_bitmaps;
 721
 722         if (in_suspend) {
 723                 unsigned int flags = 0;
 724
 725                 if (hibernation_mode == HIBERNATION_PLATFORM)
 726                         flags |= SF_PLATFORM_MODE;
 727                 if (nocompress)
 728                         flags |= SF_NOCOMPRESS_MODE;
 729                 else
 730                         flags |= SF_CRC32_MODE;
 731
 732                 pr_debug("PM: writing image.\n");
 733                 error = swsusp_write(flags);
 734                 swsusp_free();
 735                 if (!error) {
 736                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
 737                                 snapshot_test = true;
 738                         else
 739                                 power_down();
 740                 }
 741                 in_suspend = 0;
 742                 pm_restore_gfp_mask();
 743         } else {
 744                 pr_debug("PM: Image restored successfully.\n");
 745         }
 746
 747  Free_bitmaps:
 748         free_basic_memory_bitmaps();
 749  Thaw:
 750         unlock_device_hotplug();
 751         if (snapshot_test) {
 752                 pr_debug("PM: Checking hibernation image\n");
 753                 error = swsusp_check();
 754                 if (!error)
 755                         error = load_image_and_restore();
 756         }
 757         thaw_processes();
 758
 759         /* Don't bother checking whether freezer_test_done is true */
 760         freezer_test_done = false;
 761  Exit:
 762         __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
 763         pm_restore_console();
 764         atomic_inc(&snapshot_device_available);
 765  Unlock:
 766         unlock_system_sleep();
 767         return error;
 768 }
 769
 770
 771 /**
 772  * software_resume - Resume from a saved hibernation image.
 773  *
 774  * This routine is called as a late initcall, when all devices have been
 775  * discovered and initialized already.
 776  *
 777  * The image reading code is called to see if there is a hibernation image
 778  * available for reading.  If that is the case, devices are quiesced and the
 779  * contents of memory is restored from the saved image.
 780  *
 781  * If this is successful, control reappears in the restored target kernel in
 782  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 783  * attempts to recover gracefully and make the kernel return to the normal mode
 784  * of operation.
 785  */
 786 static int software_resume(void)
 787 {
 788         int error, nr_calls = 0;
 789
 790         /*
 791          * If the user said "noresume".. bail out early.
 792          */
 793         if (noresume || !hibernation_available())
 794                 return 0;
 795
 796         /*
 797          * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 798          * is configured into the kernel. Since the regular hibernate
 799          * trigger path is via sysfs which takes a buffer mutex before
 800          * calling hibernate functions (which take pm_mutex) this can
 801          * cause lockdep to complain about a possible ABBA deadlock
 802          * which cannot happen since we're in the boot code here and
 803          * sysfs can't be invoked yet. Therefore, we use a subclass
 804          * here to avoid lockdep complaining.
 805          */
 806         mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
 807
 808         if (swsusp_resume_device)
 809                 goto Check_image;
 810
 811         if (!strlen(resume_file)) {
 812                 error = -ENOENT;
 813                 goto Unlock;
 814         }
 815
 816         pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
 817
 818         if (resume_delay) {
 819                 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
 820                         resume_delay);
 821                 ssleep(resume_delay);
 822         }
 823
 824         /* Check if the device is there */
 825         swsusp_resume_device = name_to_dev_t(resume_file);
 826
 827         /*
 828          * name_to_dev_t is ineffective to verify parition if resume_file is in
 829          * integer format. (e.g. major:minor)
 830          */
 831         if (isdigit(resume_file[0]) && resume_wait) {
 832                 int partno;
 833                 while (!get_gendisk(swsusp_resume_device, &partno))
 834                         msleep(10);
 835         }
 836
 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);
 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         error = load_image_and_restore();
 885         thaw_processes();
 886  Finish:
 887         __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
 888         pm_restore_console();
 889         atomic_inc(&snapshot_device_available);
 890         /* For success case, the suspend path will release the lock */
 891  Unlock:
 892         mutex_unlock(&pm_mutex);
 893         pr_debug("PM: Hibernation image not present or could not be loaded.\n");
 894         return error;
 895  Close_Finish:
 896         swsusp_close(FMODE_READ);
 897         goto Finish;
 898 }
 899
 900 late_initcall_sync(software_resume);
 901
 902
 903 static const char * const hibernation_modes[] = {
 904         [HIBERNATION_PLATFORM]  = "platform",
 905         [HIBERNATION_SHUTDOWN]  = "shutdown",
 906         [HIBERNATION_REBOOT]    = "reboot",
 907 #ifdef CONFIG_SUSPEND
 908         [HIBERNATION_SUSPEND]   = "suspend",
 909 #endif
 910         [HIBERNATION_TEST_RESUME]       = "test_resume",
 911 };
 912
 913 /*
 914  * /sys/power/disk - Control hibernation mode.
 915  *
 916  * Hibernation can be handled in several ways.  There are a few different ways
 917  * to put the system into the sleep state: using the platform driver (e.g. ACPI
 918  * or other hibernation_ops), powering it off or rebooting it (for testing
 919  * mostly).
 920  *
 921  * The sysfs file /sys/power/disk provides an interface for selecting the
 922  * hibernation mode to use.  Reading from this file causes the available modes
 923  * to be printed.  There are 3 modes that can be supported:
 924  *
 925  *      'platform'
 926  *      'shutdown'
 927  *      'reboot'
 928  *
 929  * If a platform hibernation driver is in use, 'platform' will be supported
 930  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
 931  * The selected option (i.e. the one corresponding to the current value of
 932  * hibernation_mode) is enclosed by a square bracket.
 933  *
 934  * To select a given hibernation mode it is necessary to write the mode's
 935  * string representation (as returned by reading from /sys/power/disk) back
 936  * into /sys/power/disk.
 937  */
 938
 939 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 940                          char *buf)
 941 {
 942         int i;
 943         char *start = buf;
 944
 945         if (!hibernation_available())
 946                 return sprintf(buf, "[disabled]\n");
 947
 948         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 949                 if (!hibernation_modes[i])
 950                         continue;
 951                 switch (i) {
 952                 case HIBERNATION_SHUTDOWN:
 953                 case HIBERNATION_REBOOT:
 954 #ifdef CONFIG_SUSPEND
 955                 case HIBERNATION_SUSPEND:
 956 #endif
 957                 case HIBERNATION_TEST_RESUME:
 958                         break;
 959                 case HIBERNATION_PLATFORM:
 960                         if (hibernation_ops)
 961                                 break;
 962                         /* not a valid mode, continue with loop */
 963                         continue;
 964                 }
 965                 if (i == hibernation_mode)
 966                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
 967                 else
 968                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
 969         }
 970         buf += sprintf(buf, "\n");
 971         return buf-start;
 972 }
 973
 974 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 975                           const char *buf, size_t n)
 976 {
 977         int error = 0;
 978         int i;
 979         int len;
 980         char *p;
 981         int mode = HIBERNATION_INVALID;
 982
 983         if (!hibernation_available())
 984                 return -EPERM;
 985
 986         p = memchr(buf, '\n', n);
 987         len = p ? p - buf : n;
 988
 989         lock_system_sleep();
 990         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 991                 if (len == strlen(hibernation_modes[i])
 992                     && !strncmp(buf, hibernation_modes[i], len)) {
 993                         mode = i;
 994                         break;
 995                 }
 996         }
 997         if (mode != HIBERNATION_INVALID) {
 998                 switch (mode) {
 999                 case HIBERNATION_SHUTDOWN:
1000                 case HIBERNATION_REBOOT:
1001 #ifdef CONFIG_SUSPEND
1002                 case HIBERNATION_SUSPEND:
1003 #endif
1004                 case HIBERNATION_TEST_RESUME:
1005                         hibernation_mode = mode;
1006                         break;
1007                 case HIBERNATION_PLATFORM:
1008                         if (hibernation_ops)
1009                                 hibernation_mode = mode;
1010                         else
1011                                 error = -EINVAL;
1012                 }
1013         } else
1014                 error = -EINVAL;
1015
1016         if (!error)
1017                 pr_debug("PM: Hibernation mode set to '%s'\n",
1018                          hibernation_modes[mode]);
1019         unlock_system_sleep();
1020         return error ? error : n;
1021 }
1022
1023 power_attr(disk);
1024
1025 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1026                            char *buf)
1027 {
1028         return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
1029                        MINOR(swsusp_resume_device));
1030 }
1031
1032 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1033                             const char *buf, size_t n)
1034 {
1035         dev_t res;
1036         int len = n;
1037         char *name;
1038
1039         if (len && buf[len-1] == '\n')
1040                 len--;
1041         name = kstrndup(buf, len, GFP_KERNEL);
1042         if (!name)
1043                 return -ENOMEM;
1044
1045         res = name_to_dev_t(name);
1046         kfree(name);
1047         if (!res)
1048                 return -EINVAL;
1049
1050         lock_system_sleep();
1051         swsusp_resume_device = res;
1052         unlock_system_sleep();
1053         printk(KERN_INFO "PM: Starting manual resume from disk\n");
1054         noresume = 0;
1055         software_resume();
1056         return n;
1057 }
1058
1059 power_attr(resume);
1060
1061 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1062                                char *buf)
1063 {
1064         return sprintf(buf, "%lu\n", image_size);
1065 }
1066
1067 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1068                                 const char *buf, size_t n)
1069 {
1070         unsigned long size;
1071
1072         if (sscanf(buf, "%lu", &size) == 1) {
1073                 image_size = size;
1074                 return n;
1075         }
1076
1077         return -EINVAL;
1078 }
1079
1080 power_attr(image_size);
1081
1082 static ssize_t reserved_size_show(struct kobject *kobj,
1083                                   struct kobj_attribute *attr, char *buf)
1084 {
1085         return sprintf(buf, "%lu\n", reserved_size);
1086 }
1087
1088 static ssize_t reserved_size_store(struct kobject *kobj,
1089                                    struct kobj_attribute *attr,
1090                                    const char *buf, size_t n)
1091 {
1092         unsigned long size;
1093
1094         if (sscanf(buf, "%lu", &size) == 1) {
1095                 reserved_size = size;
1096                 return n;
1097         }
1098
1099         return -EINVAL;
1100 }
1101
1102 power_attr(reserved_size);
1103
1104 static struct attribute * g[] = {
1105         &disk_attr.attr,
1106         &resume_attr.attr,
1107         &image_size_attr.attr,
1108         &reserved_size_attr.attr,
1109         NULL,
1110 };
1111
1112
1113 static struct attribute_group attr_group = {
1114         .attrs = g,
1115 };
1116
1117
1118 static int __init pm_disk_init(void)
1119 {
1120         return sysfs_create_group(power_kobj, &attr_group);
1121 }
1122
1123 core_initcall(pm_disk_init);
1124
1125
1126 static int __init resume_setup(char *str)
1127 {
1128         if (noresume)
1129                 return 1;
1130
1131         strncpy( resume_file, str, 255 );
1132         return 1;
1133 }
1134
1135 static int __init resume_offset_setup(char *str)
1136 {
1137         unsigned long long offset;
1138
1139         if (noresume)
1140                 return 1;
1141
1142         if (sscanf(str, "%llu", &offset) == 1)
1143                 swsusp_resume_block = offset;
1144
1145         return 1;
1146 }
1147
1148 static int __init hibernate_setup(char *str)
1149 {
1150         if (!strncmp(str, "noresume", 8)) {
1151                 noresume = 1;
1152         } else if (!strncmp(str, "nocompress", 10)) {
1153                 nocompress = 1;
1154         } else if (!strncmp(str, "no", 2)) {
1155                 noresume = 1;
1156                 nohibernate = 1;
1157         } else if (IS_ENABLED(CONFIG_DEBUG_RODATA)
1158                    && !strncmp(str, "protect_image", 13)) {
1159                 enable_restore_image_protection();
1160         }
1161         return 1;
1162 }
1163
1164 static int __init noresume_setup(char *str)
1165 {
1166         noresume = 1;
1167         return 1;
1168 }
1169
1170 static int __init resumewait_setup(char *str)
1171 {
1172         resume_wait = 1;
1173         return 1;
1174 }
1175
1176 static int __init resumedelay_setup(char *str)
1177 {
1178         int rc = kstrtouint(str, 0, &resume_delay);
1179
1180         if (rc)
1181                 return rc;
1182         return 1;
1183 }
1184
1185 static int __init nohibernate_setup(char *str)
1186 {
1187         noresume = 1;
1188         nohibernate = 1;
1189         return 1;
1190 }
1191
1192 static int __init page_poison_nohibernate_setup(char *str)
1193 {
1194 #ifdef CONFIG_PAGE_POISONING_ZERO
1195         /*
1196          * The zeroing option for page poison skips the checks on alloc.
1197          * since hibernation doesn't save free pages there's no way to
1198          * guarantee the pages will still be zeroed.
1199          */
1200         if (!strcmp(str, "on")) {
1201                 pr_info("Disabling hibernation due to page poisoning\n");
1202                 return nohibernate_setup(str);
1203         }
1204 #endif
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);
1215 __setup("page_poison=", page_poison_nohibernate_setup);