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         /* Free memory before shutting down devices. */
 143         error = swsusp_shrink_memory();
 144         if (error)
 145                 goto Thaw;
 146
 147         error = platform_prepare();
 148         if (error)
 149                 goto Thaw;
 150
 151         suspend_console();
 152         error = device_suspend(PMSG_FREEZE);
 153         if (error) {
 154                 printk(KERN_ERR "PM: Some devices failed to suspend\n");
 155                 goto Resume_devices;
 156         }
 157         error = disable_nonboot_cpus();
 158         if (error)
 159                 goto Enable_cpus;
 160
 161         if (pm_disk_mode == PM_DISK_TEST) {
 162                 printk("swsusp debug: Waiting for 5 seconds.\n");
 163                 mdelay(5000);
 164                 goto Enable_cpus;
 165         }
 166
 167         pr_debug("PM: snapshotting memory.\n");
 168         in_suspend = 1;
 169         error = swsusp_suspend();
 170         if (error)
 171                 goto Enable_cpus;
 172
 173         if (in_suspend) {
 174                 enable_nonboot_cpus();
 175                 platform_finish();
 176                 device_resume();
 177                 resume_console();
 178                 pr_debug("PM: writing image.\n");
 179                 error = swsusp_write();
 180                 if (!error)
 181                         power_down();
 182                 else {
 183                         swsusp_free();
 184                         goto Thaw;
 185                 }
 186         } else {
 187                 pr_debug("PM: Image restored successfully.\n");
 188         }
 189
 190         swsusp_free();
 191  Enable_cpus:
 192         enable_nonboot_cpus();
 193  Resume_devices:
 194         platform_finish();
 195         device_resume();
 196         resume_console();
 197  Thaw:
 198         unprepare_processes();
 199         return error;
 200 }
 201
 202
 203 /**
 204  *      software_resume - Resume from a saved image.
 205  *
 206  *      Called as a late_initcall (so all devices are discovered and
 207  *      initialized), we call swsusp to see if we have a saved image or not.
 208  *      If so, we quiesce devices, the restore the saved image. We will
 209  *      return above (in pm_suspend_disk() ) if everything goes well.
 210  *      Otherwise, we fail gracefully and return to the normally
 211  *      scheduled program.
 212  *
 213  */
 214
 215 static int software_resume(void)
 216 {
 217         int error;
 218
 219         mutex_lock(&pm_mutex);
 220         if (!swsusp_resume_device) {
 221                 if (!strlen(resume_file)) {
 222                         mutex_unlock(&pm_mutex);
 223                         return -ENOENT;
 224                 }
 225                 swsusp_resume_device = name_to_dev_t(resume_file);
 226                 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
 227         } else {
 228                 pr_debug("swsusp: Resume From Partition %d:%d\n",
 229                          MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 230         }
 231
 232         if (noresume) {
 233                 /**
 234                  * FIXME: If noresume is specified, we need to find the partition
 235                  * and reset it back to normal swap space.
 236                  */
 237                 mutex_unlock(&pm_mutex);
 238                 return 0;
 239         }
 240
 241         pr_debug("PM: Checking swsusp image.\n");
 242
 243         error = swsusp_check();
 244         if (error)
 245                 goto Done;
 246
 247         pr_debug("PM: Preparing processes for restore.\n");
 248
 249         error = prepare_processes();
 250         if (error) {
 251                 swsusp_close();
 252                 goto Done;
 253         }
 254
 255         pr_debug("PM: Reading swsusp image.\n");
 256
 257         error = swsusp_read();
 258         if (error) {
 259                 swsusp_free();
 260                 goto Thaw;
 261         }
 262
 263         pr_debug("PM: Preparing devices for restore.\n");
 264
 265         suspend_console();
 266         error = device_suspend(PMSG_PRETHAW);
 267         if (error)
 268                 goto Free;
 269
 270         error = disable_nonboot_cpus();
 271         if (!error)
 272                 swsusp_resume();
 273
 274         enable_nonboot_cpus();
 275  Free:
 276         swsusp_free();
 277         device_resume();
 278         resume_console();
 279  Thaw:
 280         printk(KERN_ERR "PM: Restore failed, recovering.\n");
 281         unprepare_processes();
 282  Done:
 283         /* For success case, the suspend path will release the lock */
 284         mutex_unlock(&pm_mutex);
 285         pr_debug("PM: Resume from disk failed.\n");
 286         return 0;
 287 }
 288
 289 late_initcall(software_resume);
 290
 291
 292 static const char * const pm_disk_modes[] = {
 293         [PM_DISK_PLATFORM]      = "platform",
 294         [PM_DISK_SHUTDOWN]      = "shutdown",
 295         [PM_DISK_REBOOT]        = "reboot",
 296         [PM_DISK_TEST]          = "test",
 297         [PM_DISK_TESTPROC]      = "testproc",
 298 };
 299
 300 /**
 301  *      disk - Control suspend-to-disk mode
 302  *
 303  *      Suspend-to-disk can be handled in several ways. We have a few options
 304  *      for putting the system to sleep - using the platform driver (e.g. ACPI
 305  *      or other pm_ops), powering off the system or rebooting the system
 306  *      (for testing) as well as the two test modes.
 307  *
 308  *      The system can support 'platform', and that is known a priori (and
 309  *      encoded in pm_ops). However, the user may choose 'shutdown' or 'reboot'
 310  *      as alternatives, as well as the test modes 'test' and 'testproc'.
 311  *
 312  *      show() will display what the mode is currently set to.
 313  *      store() will accept one of
 314  *
 315  *      'platform'
 316  *      'shutdown'
 317  *      'reboot'
 318  *      'test'
 319  *      'testproc'
 320  *
 321  *      It will only change to 'platform' if the system
 322  *      supports it (as determined from pm_ops->pm_disk_mode).
 323  */
 324
 325 static ssize_t disk_show(struct kset *kset, char *buf)
 326 {
 327         return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
 328 }
 329
 330
 331 static ssize_t disk_store(struct kset *kset, const char *buf, size_t n)
 332 {
 333         int error = 0;
 334         int i;
 335         int len;
 336         char *p;
 337         suspend_disk_method_t mode = 0;
 338
 339         p = memchr(buf, '\n', n);
 340         len = p ? p - buf : n;
 341
 342         mutex_lock(&pm_mutex);
 343         for (i = PM_DISK_PLATFORM; i < PM_DISK_MAX; i++) {
 344                 if (!strncmp(buf, pm_disk_modes[i], len)) {
 345                         mode = i;
 346                         break;
 347                 }
 348         }
 349         if (mode) {
 350                 switch (mode) {
 351                 case PM_DISK_SHUTDOWN:
 352                 case PM_DISK_REBOOT:
 353                 case PM_DISK_TEST:
 354                 case PM_DISK_TESTPROC:
 355                         pm_disk_mode = mode;
 356                         break;
 357                 default:
 358                         if (pm_ops && pm_ops->enter &&
 359                             (mode == pm_ops->pm_disk_mode))
 360                                 pm_disk_mode = mode;
 361                         else
 362                                 error = -EINVAL;
 363                 }
 364         } else {
 365                 error = -EINVAL;
 366         }
 367
 368         pr_debug("PM: suspend-to-disk mode set to '%s'\n",
 369                  pm_disk_modes[mode]);
 370         mutex_unlock(&pm_mutex);
 371         return error ? error : n;
 372 }
 373
 374 power_attr(disk);
 375
 376 static ssize_t resume_show(struct kset *kset, char *buf)
 377 {
 378         return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
 379                        MINOR(swsusp_resume_device));
 380 }
 381
 382 static ssize_t resume_store(struct kset *kset, const char *buf, size_t n)
 383 {
 384         unsigned int maj, min;
 385         dev_t res;
 386         int ret = -EINVAL;
 387
 388         if (sscanf(buf, "%u:%u", &maj, &min) != 2)
 389                 goto out;
 390
 391         res = MKDEV(maj,min);
 392         if (maj != MAJOR(res) || min != MINOR(res))
 393                 goto out;
 394
 395         mutex_lock(&pm_mutex);
 396         swsusp_resume_device = res;
 397         mutex_unlock(&pm_mutex);
 398         printk("Attempting manual resume\n");
 399         noresume = 0;
 400         software_resume();
 401         ret = n;
 402  out:
 403         return ret;
 404 }
 405
 406 power_attr(resume);
 407
 408 static ssize_t image_size_show(struct kset *kset, char *buf)
 409 {
 410         return sprintf(buf, "%lu\n", image_size);
 411 }
 412
 413 static ssize_t image_size_store(struct kset *kset, const char *buf, size_t n)
 414 {
 415         unsigned long size;
 416
 417         if (sscanf(buf, "%lu", &size) == 1) {
 418                 image_size = size;
 419                 return n;
 420         }
 421
 422         return -EINVAL;
 423 }
 424
 425 power_attr(image_size);
 426
 427 static struct attribute * g[] = {
 428         &disk_attr.attr,
 429         &resume_attr.attr,
 430         &image_size_attr.attr,
 431         NULL,
 432 };
 433
 434
 435 static struct attribute_group attr_group = {
 436         .attrs = g,
 437 };
 438
 439
 440 static int __init pm_disk_init(void)
 441 {
 442         return sysfs_create_group(&power_subsys.kobj, &attr_group);
 443 }
 444
 445 core_initcall(pm_disk_init);
 446
 447
 448 static int __init resume_setup(char *str)
 449 {
 450         if (noresume)
 451                 return 1;
 452
 453         strncpy( resume_file, str, 255 );
 454         return 1;
 455 }
 456
 457 static int __init resume_offset_setup(char *str)
 458 {
 459         unsigned long long offset;
 460
 461         if (noresume)
 462                 return 1;
 463
 464         if (sscanf(str, "%llu", &offset) == 1)
 465                 swsusp_resume_block = offset;
 466
 467         return 1;
 468 }
 469
 470 static int __init noresume_setup(char *str)
 471 {
 472         noresume = 1;
 473         return 1;
 474 }
 475
 476 __setup("noresume", noresume_setup);
 477 __setup("resume_offset=", resume_offset_setup);
 478 __setup("resume=", resume_setup);