kernel/power/disk.c

   1 /*
   2  * kernel/power/disk.c - 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@suse.cz>
   7  *
   8  * This file is released under the GPLv2.
   9  *
  10  */
  11
  12 #include <linux/suspend.h>
  13 #include <linux/syscalls.h>
  14 #include <linux/reboot.h>
  15 #include <linux/string.h>
  16 #include <linux/device.h>
  17 #include <linux/delay.h>
  18 #include <linux/fs.h>
  19 #include <linux/mount.h>
  20 #include <linux/pm.h>
  21 #include <linux/console.h>
  22 #include <linux/cpu.h>
  23 #include <linux/freezer.h>
  24
  25 #include "power.h"
  26
  27
  28 static int noresume = 0;
  29 char resume_file[256] = CONFIG_PM_STD_PARTITION;
  30 dev_t swsusp_resume_device;
  31 sector_t swsusp_resume_block;
  32
  33 enum {
  34         HIBERNATION_INVALID,
  35         HIBERNATION_PLATFORM,
  36         HIBERNATION_TEST,
  37         HIBERNATION_TESTPROC,
  38         HIBERNATION_SHUTDOWN,
  39         HIBERNATION_REBOOT,
  40         /* keep last */
  41         __HIBERNATION_AFTER_LAST
  42 };
  43 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  44 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  45
  46 static int hibernation_mode = HIBERNATION_SHUTDOWN;
  47
  48 static struct platform_hibernation_ops *hibernation_ops;
  49
  50 /**
  51  * hibernation_set_ops - set the global hibernate operations
  52  * @ops: the hibernation operations to use in subsequent hibernation transitions
  53  */
  54
  55 void hibernation_set_ops(struct platform_hibernation_ops *ops)
  56 {
  57         if (ops && !(ops->start && ops->pre_snapshot && ops->finish
  58             && ops->prepare && ops->enter && ops->pre_restore
  59             && ops->restore_cleanup)) {
  60                 WARN_ON(1);
  61                 return;
  62         }
  63         mutex_lock(&pm_mutex);
  64         hibernation_ops = ops;
  65         if (ops)
  66                 hibernation_mode = HIBERNATION_PLATFORM;
  67         else if (hibernation_mode == HIBERNATION_PLATFORM)
  68                 hibernation_mode = HIBERNATION_SHUTDOWN;
  69
  70         mutex_unlock(&pm_mutex);
  71 }
  72
  73 /**
  74  *      platform_start - tell the platform driver that we're starting
  75  *      hibernation
  76  */
  77
  78 static int platform_start(int platform_mode)
  79 {
  80         return (platform_mode && hibernation_ops) ?
  81                 hibernation_ops->start() : 0;
  82 }
  83
  84 /**
  85  *      platform_pre_snapshot - prepare the machine for hibernation using the
  86  *      platform driver if so configured and return an error code if it fails
  87  */
  88
  89 static int platform_pre_snapshot(int platform_mode)
  90 {
  91         return (platform_mode && hibernation_ops) ?
  92                 hibernation_ops->pre_snapshot() : 0;
  93 }
  94
  95 /**
  96  *      platform_finish - switch the machine to the normal mode of operation
  97  *      using the platform driver (must be called after platform_prepare())
  98  */
  99
 100 static void platform_finish(int platform_mode)
 101 {
 102         if (platform_mode && hibernation_ops)
 103                 hibernation_ops->finish();
 104 }
 105
 106 /**
 107  *      platform_pre_restore - prepare the platform for the restoration from a
 108  *      hibernation image.  If the restore fails after this function has been
 109  *      called, platform_restore_cleanup() must be called.
 110  */
 111
 112 static int platform_pre_restore(int platform_mode)
 113 {
 114         return (platform_mode && hibernation_ops) ?
 115                 hibernation_ops->pre_restore() : 0;
 116 }
 117
 118 /**
 119  *      platform_restore_cleanup - switch the platform to the normal mode of
 120  *      operation after a failing restore.  If platform_pre_restore() has been
 121  *      called before the failing restore, this function must be called too,
 122  *      regardless of the result of platform_pre_restore().
 123  */
 124
 125 static void platform_restore_cleanup(int platform_mode)
 126 {
 127         if (platform_mode && hibernation_ops)
 128                 hibernation_ops->restore_cleanup();
 129 }
 130
 131 /**
 132  *      hibernation_snapshot - quiesce devices and create the hibernation
 133  *      snapshot image.
 134  *      @platform_mode - if set, use the platform driver, if available, to
 135  *                       prepare the platform frimware for the power transition.
 136  *
 137  *      Must be called with pm_mutex held
 138  */
 139
 140 int hibernation_snapshot(int platform_mode)
 141 {
 142         int error;
 143
 144         /* Free memory before shutting down devices. */
 145         error = swsusp_shrink_memory();
 146         if (error)
 147                 return error;
 148
 149         error = platform_start(platform_mode);
 150         if (error)
 151                 return error;
 152
 153         suspend_console();
 154         error = device_suspend(PMSG_FREEZE);
 155         if (error)
 156                 goto Resume_console;
 157
 158         error = platform_pre_snapshot(platform_mode);
 159         if (error)
 160                 goto Resume_devices;
 161
 162         error = disable_nonboot_cpus();
 163         if (!error) {
 164                 if (hibernation_mode != HIBERNATION_TEST) {
 165                         in_suspend = 1;
 166                         error = swsusp_suspend();
 167                         /* Control returns here after successful restore */
 168                 } else {
 169                         printk("swsusp debug: Waiting for 5 seconds.\n");
 170                         mdelay(5000);
 171                 }
 172         }
 173         enable_nonboot_cpus();
 174  Resume_devices:
 175         platform_finish(platform_mode);
 176         device_resume();
 177  Resume_console:
 178         resume_console();
 179         return error;
 180 }
 181
 182 /**
 183  *      hibernation_restore - quiesce devices and restore the hibernation
 184  *      snapshot image.  If successful, control returns in hibernation_snaphot()
 185  *      @platform_mode - if set, use the platform driver, if available, to
 186  *                       prepare the platform frimware for the transition.
 187  *
 188  *      Must be called with pm_mutex held
 189  */
 190
 191 int hibernation_restore(int platform_mode)
 192 {
 193         int error;
 194
 195         pm_prepare_console();
 196         suspend_console();
 197         error = device_suspend(PMSG_PRETHAW);
 198         if (error)
 199                 goto Finish;
 200
 201         error = platform_pre_restore(platform_mode);
 202         if (!error) {
 203                 error = disable_nonboot_cpus();
 204                 if (!error)
 205                         error = swsusp_resume();
 206                 enable_nonboot_cpus();
 207         }
 208         platform_restore_cleanup(platform_mode);
 209         device_resume();
 210  Finish:
 211         resume_console();
 212         pm_restore_console();
 213         return error;
 214 }
 215
 216 /**
 217  *      hibernation_platform_enter - enter the hibernation state using the
 218  *      platform driver (if available)
 219  */
 220
 221 int hibernation_platform_enter(void)
 222 {
 223         int error;
 224
 225         if (hibernation_ops) {
 226                 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
 227                 /*
 228                  * We have cancelled the power transition by running
 229                  * hibernation_ops->finish() before saving the image, so we
 230                  * should let the firmware know that we're going to enter the
 231                  * sleep state after all
 232                  */
 233                 error = hibernation_ops->prepare();
 234                 sysdev_shutdown();
 235                 if (!error)
 236                         error = hibernation_ops->enter();
 237         } else {
 238                 error = -ENOSYS;
 239         }
 240         return error;
 241 }
 242
 243 /**
 244  *      power_down - Shut the machine down for hibernation.
 245  *
 246  *      Use the platform driver, if configured so; otherwise try
 247  *      to power off or reboot.
 248  */
 249
 250 static void power_down(void)
 251 {
 252         switch (hibernation_mode) {
 253         case HIBERNATION_TEST:
 254         case HIBERNATION_TESTPROC:
 255                 break;
 256         case HIBERNATION_SHUTDOWN:
 257                 kernel_power_off();
 258                 break;
 259         case HIBERNATION_REBOOT:
 260                 kernel_restart(NULL);
 261                 break;
 262         case HIBERNATION_PLATFORM:
 263                 hibernation_platform_enter();
 264         }
 265         kernel_halt();
 266         /*
 267          * Valid image is on the disk, if we continue we risk serious data
 268          * corruption after resume.
 269          */
 270         printk(KERN_CRIT "Please power me down manually\n");
 271         while(1);
 272 }
 273
 274 static void unprepare_processes(void)
 275 {
 276         thaw_processes();
 277         pm_restore_console();
 278 }
 279
 280 static int prepare_processes(void)
 281 {
 282         int error = 0;
 283
 284         pm_prepare_console();
 285         if (freeze_processes()) {
 286                 error = -EBUSY;
 287                 unprepare_processes();
 288         }
 289         return error;
 290 }
 291
 292 /**
 293  *      hibernate - The granpappy of the built-in hibernation management
 294  */
 295
 296 int hibernate(void)
 297 {
 298         int error;
 299
 300         mutex_lock(&pm_mutex);
 301         /* The snapshot device should not be opened while we're running */
 302         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 303                 error = -EBUSY;
 304                 goto Unlock;
 305         }
 306
 307         error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
 308         if (error)
 309                 goto Exit;
 310
 311         /* Allocate memory management structures */
 312         error = create_basic_memory_bitmaps();
 313         if (error)
 314                 goto Exit;
 315
 316         printk("Syncing filesystems ... ");
 317         sys_sync();
 318         printk("done.\n");
 319
 320         error = prepare_processes();
 321         if (error)
 322                 goto Finish;
 323
 324         if (hibernation_mode == HIBERNATION_TESTPROC) {
 325                 printk("swsusp debug: Waiting for 5 seconds.\n");
 326                 mdelay(5000);
 327                 goto Thaw;
 328         }
 329         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 330         if (in_suspend && !error) {
 331                 unsigned int flags = 0;
 332
 333                 if (hibernation_mode == HIBERNATION_PLATFORM)
 334                         flags |= SF_PLATFORM_MODE;
 335                 pr_debug("PM: writing image.\n");
 336                 error = swsusp_write(flags);
 337                 swsusp_free();
 338                 if (!error)
 339                         power_down();
 340         } else {
 341                 pr_debug("PM: Image restored successfully.\n");
 342                 swsusp_free();
 343         }
 344  Thaw:
 345         unprepare_processes();
 346  Finish:
 347         free_basic_memory_bitmaps();
 348  Exit:
 349         pm_notifier_call_chain(PM_POST_HIBERNATION);
 350         atomic_inc(&snapshot_device_available);
 351  Unlock:
 352         mutex_unlock(&pm_mutex);
 353         return error;
 354 }
 355
 356
 357 /**
 358  *      software_resume - Resume from a saved image.
 359  *
 360  *      Called as a late_initcall (so all devices are discovered and
 361  *      initialized), we call swsusp to see if we have a saved image or not.
 362  *      If so, we quiesce devices, the restore the saved image. We will
 363  *      return above (in hibernate() ) if everything goes well.
 364  *      Otherwise, we fail gracefully and return to the normally
 365  *      scheduled program.
 366  *
 367  */
 368
 369 static int software_resume(void)
 370 {
 371         int error;
 372         unsigned int flags;
 373
 374         mutex_lock(&pm_mutex);
 375         if (!swsusp_resume_device) {
 376                 if (!strlen(resume_file)) {
 377                         mutex_unlock(&pm_mutex);
 378                         return -ENOENT;
 379                 }
 380                 swsusp_resume_device = name_to_dev_t(resume_file);
 381                 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
 382         } else {
 383                 pr_debug("swsusp: Resume From Partition %d:%d\n",
 384                          MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 385         }
 386
 387         if (noresume) {
 388                 /**
 389                  * FIXME: If noresume is specified, we need to find the partition
 390                  * and reset it back to normal swap space.
 391                  */
 392                 mutex_unlock(&pm_mutex);
 393                 return 0;
 394         }
 395
 396         pr_debug("PM: Checking swsusp image.\n");
 397         error = swsusp_check();
 398         if (error)
 399                 goto Unlock;
 400
 401         /* The snapshot device should not be opened while we're running */
 402         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 403                 error = -EBUSY;
 404                 goto Unlock;
 405         }
 406
 407         error = create_basic_memory_bitmaps();
 408         if (error)
 409                 goto Finish;
 410
 411         pr_debug("PM: Preparing processes for restore.\n");
 412         error = prepare_processes();
 413         if (error) {
 414                 swsusp_close();
 415                 goto Done;
 416         }
 417
 418         pr_debug("PM: Reading swsusp image.\n");
 419
 420         error = swsusp_read(&flags);
 421         if (!error)
 422                 hibernation_restore(flags & SF_PLATFORM_MODE);
 423
 424         printk(KERN_ERR "PM: Restore failed, recovering.\n");
 425         swsusp_free();
 426         unprepare_processes();
 427  Done:
 428         free_basic_memory_bitmaps();
 429  Finish:
 430         atomic_inc(&snapshot_device_available);
 431         /* For success case, the suspend path will release the lock */
 432  Unlock:
 433         mutex_unlock(&pm_mutex);
 434         pr_debug("PM: Resume from disk failed.\n");
 435         return error;
 436 }
 437
 438 late_initcall(software_resume);
 439
 440
 441 static const char * const hibernation_modes[] = {
 442         [HIBERNATION_PLATFORM]  = "platform",
 443         [HIBERNATION_SHUTDOWN]  = "shutdown",
 444         [HIBERNATION_REBOOT]    = "reboot",
 445         [HIBERNATION_TEST]      = "test",
 446         [HIBERNATION_TESTPROC]  = "testproc",
 447 };
 448
 449 /**
 450  *      disk - Control hibernation mode
 451  *
 452  *      Suspend-to-disk can be handled in several ways. We have a few options
 453  *      for putting the system to sleep - using the platform driver (e.g. ACPI
 454  *      or other hibernation_ops), powering off the system or rebooting the
 455  *      system (for testing) as well as the two test modes.
 456  *
 457  *      The system can support 'platform', and that is known a priori (and
 458  *      encoded by the presence of hibernation_ops). However, the user may
 459  *      choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
 460  *      test modes, 'test' or 'testproc'.
 461  *
 462  *      show() will display what the mode is currently set to.
 463  *      store() will accept one of
 464  *
 465  *      'platform'
 466  *      'shutdown'
 467  *      'reboot'
 468  *      'test'
 469  *      'testproc'
 470  *
 471  *      It will only change to 'platform' if the system
 472  *      supports it (as determined by having hibernation_ops).
 473  */
 474
 475 static ssize_t disk_show(struct kset *kset, char *buf)
 476 {
 477         int i;
 478         char *start = buf;
 479
 480         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 481                 if (!hibernation_modes[i])
 482                         continue;
 483                 switch (i) {
 484                 case HIBERNATION_SHUTDOWN:
 485                 case HIBERNATION_REBOOT:
 486                 case HIBERNATION_TEST:
 487                 case HIBERNATION_TESTPROC:
 488                         break;
 489                 case HIBERNATION_PLATFORM:
 490                         if (hibernation_ops)
 491                                 break;
 492                         /* not a valid mode, continue with loop */
 493                         continue;
 494                 }
 495                 if (i == hibernation_mode)
 496                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
 497                 else
 498                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
 499         }
 500         buf += sprintf(buf, "\n");
 501         return buf-start;
 502 }
 503
 504
 505 static ssize_t disk_store(struct kset *kset, const char *buf, size_t n)
 506 {
 507         int error = 0;
 508         int i;
 509         int len;
 510         char *p;
 511         int mode = HIBERNATION_INVALID;
 512
 513         p = memchr(buf, '\n', n);
 514         len = p ? p - buf : n;
 515
 516         mutex_lock(&pm_mutex);
 517         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 518                 if (len == strlen(hibernation_modes[i])
 519                     && !strncmp(buf, hibernation_modes[i], len)) {
 520                         mode = i;
 521                         break;
 522                 }
 523         }
 524         if (mode != HIBERNATION_INVALID) {
 525                 switch (mode) {
 526                 case HIBERNATION_SHUTDOWN:
 527                 case HIBERNATION_REBOOT:
 528                 case HIBERNATION_TEST:
 529                 case HIBERNATION_TESTPROC:
 530                         hibernation_mode = mode;
 531                         break;
 532                 case HIBERNATION_PLATFORM:
 533                         if (hibernation_ops)
 534                                 hibernation_mode = mode;
 535                         else
 536                                 error = -EINVAL;
 537                 }
 538         } else
 539                 error = -EINVAL;
 540
 541         if (!error)
 542                 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
 543                          hibernation_modes[mode]);
 544         mutex_unlock(&pm_mutex);
 545         return error ? error : n;
 546 }
 547
 548 power_attr(disk);
 549
 550 static ssize_t resume_show(struct kset *kset, char *buf)
 551 {
 552         return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
 553                        MINOR(swsusp_resume_device));
 554 }
 555
 556 static ssize_t resume_store(struct kset *kset, const char *buf, size_t n)
 557 {
 558         unsigned int maj, min;
 559         dev_t res;
 560         int ret = -EINVAL;
 561
 562         if (sscanf(buf, "%u:%u", &maj, &min) != 2)
 563                 goto out;
 564
 565         res = MKDEV(maj,min);
 566         if (maj != MAJOR(res) || min != MINOR(res))
 567                 goto out;
 568
 569         mutex_lock(&pm_mutex);
 570         swsusp_resume_device = res;
 571         mutex_unlock(&pm_mutex);
 572         printk("Attempting manual resume\n");
 573         noresume = 0;
 574         software_resume();
 575         ret = n;
 576  out:
 577         return ret;
 578 }
 579
 580 power_attr(resume);
 581
 582 static ssize_t image_size_show(struct kset *kset, char *buf)
 583 {
 584         return sprintf(buf, "%lu\n", image_size);
 585 }
 586
 587 static ssize_t image_size_store(struct kset *kset, const char *buf, size_t n)
 588 {
 589         unsigned long size;
 590
 591         if (sscanf(buf, "%lu", &size) == 1) {
 592                 image_size = size;
 593                 return n;
 594         }
 595
 596         return -EINVAL;
 597 }
 598
 599 power_attr(image_size);
 600
 601 static struct attribute * g[] = {
 602         &disk_attr.attr,
 603         &resume_attr.attr,
 604         &image_size_attr.attr,
 605         NULL,
 606 };
 607
 608
 609 static struct attribute_group attr_group = {
 610         .attrs = g,
 611 };
 612
 613
 614 static int __init pm_disk_init(void)
 615 {
 616         return sysfs_create_group(&power_subsys.kobj, &attr_group);
 617 }
 618
 619 core_initcall(pm_disk_init);
 620
 621
 622 static int __init resume_setup(char *str)
 623 {
 624         if (noresume)
 625                 return 1;
 626
 627         strncpy( resume_file, str, 255 );
 628         return 1;
 629 }
 630
 631 static int __init resume_offset_setup(char *str)
 632 {
 633         unsigned long long offset;
 634
 635         if (noresume)
 636                 return 1;
 637
 638         if (sscanf(str, "%llu", &offset) == 1)
 639                 swsusp_resume_block = offset;
 640
 641         return 1;
 642 }
 643
 644 static int __init noresume_setup(char *str)
 645 {
 646         noresume = 1;
 647         return 1;
 648 }
 649
 650 __setup("noresume", noresume_setup);
 651 __setup("resume_offset=", resume_offset_setup);
 652 __setup("resume=", resume_setup);