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 /**
  34  *      platform_prepare - prepare the machine for hibernation using the
  35  *      platform driver if so configured and return an error code if it fails
  36  */
  37
  38 static inline int platform_prepare(void)
  39 {
  40         int error = 0;
  41
  42         switch (pm_disk_mode) {
  43         case PM_DISK_TEST:
  44         case PM_DISK_TESTPROC:
  45         case PM_DISK_SHUTDOWN:
  46         case PM_DISK_REBOOT:
  47                 break;
  48         default:
  49                 if (pm_ops && pm_ops->prepare)
  50                         error = pm_ops->prepare(PM_SUSPEND_DISK);
  51         }
  52         return error;
  53 }
  54
  55 /**
  56  *      power_down - Shut machine down for hibernate.
  57  *
  58  *      Use the platform driver, if configured so; otherwise try
  59  *      to power off or reboot.
  60  */
  61
  62 static void power_down(void)
  63 {
  64         switch (pm_disk_mode) {
  65         case PM_DISK_TEST:
  66         case PM_DISK_TESTPROC:
  67                 break;
  68         case PM_DISK_SHUTDOWN:
  69                 kernel_power_off();
  70                 break;
  71         case PM_DISK_REBOOT:
  72                 kernel_restart(NULL);
  73                 break;
  74         default:
  75                 if (pm_ops && pm_ops->enter) {
  76                         kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
  77                         pm_ops->enter(PM_SUSPEND_DISK);
  78                         break;
  79                 }
  80         }
  81         kernel_halt();
  82         /*
  83          * Valid image is on the disk, if we continue we risk serious data
  84          * corruption after resume.
  85          */
  86         printk(KERN_CRIT "Please power me down manually\n");
  87         while(1);
  88 }
  89
  90 static inline void platform_finish(void)
  91 {
  92         switch (pm_disk_mode) {
  93         case PM_DISK_TEST:
  94         case PM_DISK_TESTPROC:
  95         case PM_DISK_SHUTDOWN:
  96         case PM_DISK_REBOOT:
  97                 break;
  98         default:
  99                 if (pm_ops && pm_ops->finish)
 100                         pm_ops->finish(PM_SUSPEND_DISK);
 101         }
 102 }
 103
 104 static void unprepare_processes(void)
 105 {
 106         thaw_processes();
 107         pm_restore_console();
 108 }
 109
 110 static int prepare_processes(void)
 111 {
 112         int error = 0;
 113
 114         pm_prepare_console();
 115         if (freeze_processes()) {
 116                 error = -EBUSY;
 117                 unprepare_processes();
 118         }
 119         return error;
 120 }
 121
 122 /**
 123  *      pm_suspend_disk - The granpappy of hibernation power management.
 124  *
 125  *      If not, then call swsusp to do its thing, then figure out how
 126  *      to power down the system.
 127  */
 128
 129 int pm_suspend_disk(void)
 130 {
 131         int error;
 132
 133         error = prepare_processes();
 134         if (error)
 135                 return error;
 136
 137         if (pm_disk_mode == PM_DISK_TESTPROC) {
 138                 printk("swsusp debug: Waiting for 5 seconds.\n");
 139                 mdelay(5000);
 140                 goto Thaw;
 141         }
 142         /* Allocate memory management structures */
 143         error = create_basic_memory_bitmaps();
 144         if (error)
 145                 goto Thaw;
 146
 147         /* Free memory before shutting down devices. */
 148         error = swsusp_shrink_memory();
 149         if (error)
 150                 goto Finish;
 151
 152         error = platform_prepare();
 153         if (error)
 154                 goto Finish;
 155
 156         suspend_console();
 157         error = device_suspend(PMSG_FREEZE);
 158         if (error) {
 159                 printk(KERN_ERR "PM: Some devices failed to suspend\n");
 160                 goto Resume_devices;
 161         }
 162         error = disable_nonboot_cpus();
 163         if (error)
 164                 goto Enable_cpus;
 165
 166         if (pm_disk_mode == PM_DISK_TEST) {
 167                 printk("swsusp debug: Waiting for 5 seconds.\n");
 168                 mdelay(5000);
 169                 goto Enable_cpus;
 170         }
 171
 172         pr_debug("PM: snapshotting memory.\n");
 173         in_suspend = 1;
 174         error = swsusp_suspend();
 175         if (error)
 176                 goto Enable_cpus;
 177
 178         if (in_suspend) {
 179                 enable_nonboot_cpus();
 180                 platform_finish();
 181                 device_resume();
 182                 resume_console();
 183                 pr_debug("PM: writing image.\n");
 184                 error = swsusp_write();
 185                 if (!error)
 186                         power_down();
 187                 else {
 188                         swsusp_free();
 189                         goto Finish;
 190                 }
 191         } else {
 192                 pr_debug("PM: Image restored successfully.\n");
 193         }
 194
 195         swsusp_free();
 196  Enable_cpus:
 197         enable_nonboot_cpus();
 198  Resume_devices:
 199         platform_finish();
 200         device_resume();
 201         resume_console();
 202  Finish:
 203         free_basic_memory_bitmaps();
 204  Thaw:
 205         unprepare_processes();
 206         return error;
 207 }
 208
 209
 210 /**
 211  *      software_resume - Resume from a saved image.
 212  *
 213  *      Called as a late_initcall (so all devices are discovered and
 214  *      initialized), we call swsusp to see if we have a saved image or not.
 215  *      If so, we quiesce devices, the restore the saved image. We will
 216  *      return above (in pm_suspend_disk() ) if everything goes well.
 217  *      Otherwise, we fail gracefully and return to the normally
 218  *      scheduled program.
 219  *
 220  */
 221
 222 static int software_resume(void)
 223 {
 224         int error;
 225
 226         mutex_lock(&pm_mutex);
 227         if (!swsusp_resume_device) {
 228                 if (!strlen(resume_file)) {
 229                         mutex_unlock(&pm_mutex);
 230                         return -ENOENT;
 231                 }
 232                 swsusp_resume_device = name_to_dev_t(resume_file);
 233                 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
 234         } else {
 235                 pr_debug("swsusp: Resume From Partition %d:%d\n",
 236                          MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 237         }
 238
 239         if (noresume) {
 240                 /**
 241                  * FIXME: If noresume is specified, we need to find the partition
 242                  * and reset it back to normal swap space.
 243                  */
 244                 mutex_unlock(&pm_mutex);
 245                 return 0;
 246         }
 247
 248         pr_debug("PM: Checking swsusp image.\n");
 249         error = swsusp_check();
 250         if (error)
 251                 goto Unlock;
 252
 253         error = create_basic_memory_bitmaps();
 254         if (error)
 255                 goto Unlock;
 256
 257         pr_debug("PM: Preparing processes for restore.\n");
 258         error = prepare_processes();
 259         if (error) {
 260                 swsusp_close();
 261                 goto Done;
 262         }
 263
 264         pr_debug("PM: Reading swsusp image.\n");
 265
 266         error = swsusp_read();
 267         if (error) {
 268                 swsusp_free();
 269                 goto Thaw;
 270         }
 271
 272         pr_debug("PM: Preparing devices for restore.\n");
 273
 274         suspend_console();
 275         error = device_suspend(PMSG_PRETHAW);
 276         if (error)
 277                 goto Free;
 278
 279         error = disable_nonboot_cpus();
 280         if (!error)
 281                 swsusp_resume();
 282
 283         enable_nonboot_cpus();
 284  Free:
 285         swsusp_free();
 286         device_resume();
 287         resume_console();
 288  Thaw:
 289         printk(KERN_ERR "PM: Restore failed, recovering.\n");
 290         unprepare_processes();
 291  Done:
 292         free_basic_memory_bitmaps();
 293         /* For success case, the suspend path will release the lock */
 294  Unlock:
 295         mutex_unlock(&pm_mutex);
 296         pr_debug("PM: Resume from disk failed.\n");
 297         return 0;
 298 }
 299
 300 late_initcall(software_resume);
 301
 302
 303 static const char * const pm_disk_modes[] = {
 304         [PM_DISK_PLATFORM]      = "platform",
 305         [PM_DISK_SHUTDOWN]      = "shutdown",
 306         [PM_DISK_REBOOT]        = "reboot",
 307         [PM_DISK_TEST]          = "test",
 308         [PM_DISK_TESTPROC]      = "testproc",
 309 };
 310
 311 /**
 312  *      disk - Control suspend-to-disk mode
 313  *
 314  *      Suspend-to-disk can be handled in several ways. We have a few options
 315  *      for putting the system to sleep - using the platform driver (e.g. ACPI
 316  *      or other pm_ops), powering off the system or rebooting the system
 317  *      (for testing) as well as the two test modes.
 318  *
 319  *      The system can support 'platform', and that is known a priori (and
 320  *      encoded in pm_ops). However, the user may choose 'shutdown' or 'reboot'
 321  *      as alternatives, as well as the test modes 'test' and 'testproc'.
 322  *
 323  *      show() will display what the mode is currently set to.
 324  *      store() will accept one of
 325  *
 326  *      'platform'
 327  *      'shutdown'
 328  *      'reboot'
 329  *      'test'
 330  *      'testproc'
 331  *
 332  *      It will only change to 'platform' if the system
 333  *      supports it (as determined from pm_ops->pm_disk_mode).
 334  */
 335
 336 static ssize_t disk_show(struct kset *kset, char *buf)
 337 {
 338         return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
 339 }
 340
 341
 342 static ssize_t disk_store(struct kset *kset, const char *buf, size_t n)
 343 {
 344         int error = 0;
 345         int i;
 346         int len;
 347         char *p;
 348         suspend_disk_method_t mode = 0;
 349
 350         p = memchr(buf, '\n', n);
 351         len = p ? p - buf : n;
 352
 353         mutex_lock(&pm_mutex);
 354         for (i = PM_DISK_PLATFORM; i < PM_DISK_MAX; i++) {
 355                 if (!strncmp(buf, pm_disk_modes[i], len)) {
 356                         mode = i;
 357                         break;
 358                 }
 359         }
 360         if (mode) {
 361                 switch (mode) {
 362                 case PM_DISK_SHUTDOWN:
 363                 case PM_DISK_REBOOT:
 364                 case PM_DISK_TEST:
 365                 case PM_DISK_TESTPROC:
 366                         pm_disk_mode = mode;
 367                         break;
 368                 default:
 369                         if (pm_ops && pm_ops->enter &&
 370                             (mode == pm_ops->pm_disk_mode))
 371                                 pm_disk_mode = mode;
 372                         else
 373                                 error = -EINVAL;
 374                 }
 375         } else {
 376                 error = -EINVAL;
 377         }
 378
 379         pr_debug("PM: suspend-to-disk mode set to '%s'\n",
 380                  pm_disk_modes[mode]);
 381         mutex_unlock(&pm_mutex);
 382         return error ? error : n;
 383 }
 384
 385 power_attr(disk);
 386
 387 static ssize_t resume_show(struct kset *kset, char *buf)
 388 {
 389         return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
 390                        MINOR(swsusp_resume_device));
 391 }
 392
 393 static ssize_t resume_store(struct kset *kset, const char *buf, size_t n)
 394 {
 395         unsigned int maj, min;
 396         dev_t res;
 397         int ret = -EINVAL;
 398
 399         if (sscanf(buf, "%u:%u", &maj, &min) != 2)
 400                 goto out;
 401
 402         res = MKDEV(maj,min);
 403         if (maj != MAJOR(res) || min != MINOR(res))
 404                 goto out;
 405
 406         mutex_lock(&pm_mutex);
 407         swsusp_resume_device = res;
 408         mutex_unlock(&pm_mutex);
 409         printk("Attempting manual resume\n");
 410         noresume = 0;
 411         software_resume();
 412         ret = n;
 413  out:
 414         return ret;
 415 }
 416
 417 power_attr(resume);
 418
 419 static ssize_t image_size_show(struct kset *kset, char *buf)
 420 {
 421         return sprintf(buf, "%lu\n", image_size);
 422 }
 423
 424 static ssize_t image_size_store(struct kset *kset, const char *buf, size_t n)
 425 {
 426         unsigned long size;
 427
 428         if (sscanf(buf, "%lu", &size) == 1) {
 429                 image_size = size;
 430                 return n;
 431         }
 432
 433         return -EINVAL;
 434 }
 435
 436 power_attr(image_size);
 437
 438 static struct attribute * g[] = {
 439         &disk_attr.attr,
 440         &resume_attr.attr,
 441         &image_size_attr.attr,
 442         NULL,
 443 };
 444
 445
 446 static struct attribute_group attr_group = {
 447         .attrs = g,
 448 };
 449
 450
 451 static int __init pm_disk_init(void)
 452 {
 453         return sysfs_create_group(&power_subsys.kobj, &attr_group);
 454 }
 455
 456 core_initcall(pm_disk_init);
 457
 458
 459 static int __init resume_setup(char *str)
 460 {
 461         if (noresume)
 462                 return 1;
 463
 464         strncpy( resume_file, str, 255 );
 465         return 1;
 466 }
 467
 468 static int __init resume_offset_setup(char *str)
 469 {
 470         unsigned long long offset;
 471
 472         if (noresume)
 473                 return 1;
 474
 475         if (sscanf(str, "%llu", &offset) == 1)
 476                 swsusp_resume_block = offset;
 477
 478         return 1;
 479 }
 480
 481 static int __init noresume_setup(char *str)
 482 {
 483         noresume = 1;
 484         return 1;
 485 }
 486
 487 __setup("noresume", noresume_setup);
 488 __setup("resume_offset=", resume_offset_setup);
 489 __setup("resume=", resume_setup);