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