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