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