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