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
  24 #include "power.h"
  25
  26
  27 static int noresume = 0;
  28 char resume_file[256] = CONFIG_PM_STD_PARTITION;
  29 dev_t swsusp_resume_device;
  30 sector_t swsusp_resume_block;
  31
  32 /**
  33  *      platform_prepare - prepare the machine for hibernation using the
  34  *      platform driver if so configured and return an error code if it fails
  35  */
  36
  37 static inline int platform_prepare(void)
  38 {
  39         int error = 0;
  40
  41         if (pm_disk_mode == PM_DISK_PLATFORM) {
  42                 if (pm_ops && pm_ops->prepare)
  43                         error = pm_ops->prepare(PM_SUSPEND_DISK);
  44         }
  45         return error;
  46 }
  47
  48 /**
  49  *      power_down - Shut machine down for hibernate.
  50  *      @mode:          Suspend-to-disk mode
  51  *
  52  *      Use the platform driver, if configured so, and return gracefully if it
  53  *      fails.
  54  *      Otherwise, try to power off and reboot. If they fail, halt the machine,
  55  *      there ain't no turning back.
  56  */
  57
  58 static void power_down(suspend_disk_method_t mode)
  59 {
  60         int error = 0;
  61
  62         switch(mode) {
  63         case PM_DISK_PLATFORM:
  64                 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
  65                 error = pm_ops->enter(PM_SUSPEND_DISK);
  66                 break;
  67         case PM_DISK_SHUTDOWN:
  68                 kernel_power_off();
  69                 break;
  70         case PM_DISK_REBOOT:
  71                 kernel_restart(NULL);
  72                 break;
  73         }
  74         kernel_halt();
  75         /* Valid image is on the disk, if we continue we risk serious data corruption
  76            after resume. */
  77         printk(KERN_CRIT "Please power me down manually\n");
  78         while(1);
  79 }
  80
  81 static inline void platform_finish(void)
  82 {
  83         if (pm_disk_mode == PM_DISK_PLATFORM) {
  84                 if (pm_ops && pm_ops->finish)
  85                         pm_ops->finish(PM_SUSPEND_DISK);
  86         }
  87 }
  88
  89 static int prepare_processes(void)
  90 {
  91         int error = 0;
  92
  93         pm_prepare_console();
  94
  95         error = disable_nonboot_cpus();
  96         if (error)
  97                 goto enable_cpus;
  98
  99         if (freeze_processes()) {
 100                 error = -EBUSY;
 101                 goto thaw;
 102         }
 103
 104         if (pm_disk_mode == PM_DISK_TESTPROC) {
 105                 printk("swsusp debug: Waiting for 5 seconds.\n");
 106                 mdelay(5000);
 107                 goto thaw;
 108         }
 109
 110         error = platform_prepare();
 111         if (error)
 112                 goto thaw;
 113
 114         /* Free memory before shutting down devices. */
 115         if (!(error = swsusp_shrink_memory()))
 116                 return 0;
 117
 118         platform_finish();
 119 thaw:
 120         thaw_processes();
 121 enable_cpus:
 122         enable_nonboot_cpus();
 123         pm_restore_console();
 124         return error;
 125 }
 126
 127 static void unprepare_processes(void)
 128 {
 129         platform_finish();
 130         thaw_processes();
 131         enable_nonboot_cpus();
 132         pm_restore_console();
 133 }
 134
 135 /**
 136  *      pm_suspend_disk - The granpappy of hibernation power management.
 137  *
 138  *      If we're going through the firmware, then get it over with quickly.
 139  *
 140  *      If not, then call swsusp to do its thing, then figure out how
 141  *      to power down the system.
 142  */
 143
 144 int pm_suspend_disk(void)
 145 {
 146         int error;
 147
 148         error = prepare_processes();
 149         if (error)
 150                 return error;
 151
 152         if (pm_disk_mode == PM_DISK_TESTPROC)
 153                 goto Thaw;
 154
 155         suspend_console();
 156         error = device_suspend(PMSG_FREEZE);
 157         if (error) {
 158                 resume_console();
 159                 printk("Some devices failed to suspend\n");
 160                 goto Thaw;
 161         }
 162
 163         if (pm_disk_mode == PM_DISK_TEST) {
 164                 printk("swsusp debug: Waiting for 5 seconds.\n");
 165                 mdelay(5000);
 166                 goto Done;
 167         }
 168
 169         pr_debug("PM: snapshotting memory.\n");
 170         in_suspend = 1;
 171         if ((error = swsusp_suspend()))
 172                 goto Done;
 173
 174         if (in_suspend) {
 175                 device_resume();
 176                 resume_console();
 177                 pr_debug("PM: writing image.\n");
 178                 error = swsusp_write();
 179                 if (!error)
 180                         power_down(pm_disk_mode);
 181                 else {
 182                         swsusp_free();
 183                         goto Thaw;
 184                 }
 185         } else {
 186                 pr_debug("PM: Image restored successfully.\n");
 187         }
 188
 189         swsusp_free();
 190  Done:
 191         device_resume();
 192         resume_console();
 193  Thaw:
 194         unprepare_processes();
 195         return error;
 196 }
 197
 198
 199 /**
 200  *      software_resume - Resume from a saved image.
 201  *
 202  *      Called as a late_initcall (so all devices are discovered and
 203  *      initialized), we call swsusp to see if we have a saved image or not.
 204  *      If so, we quiesce devices, the restore the saved image. We will
 205  *      return above (in pm_suspend_disk() ) if everything goes well.
 206  *      Otherwise, we fail gracefully and return to the normally
 207  *      scheduled program.
 208  *
 209  */
 210
 211 static int software_resume(void)
 212 {
 213         int error;
 214
 215         down(&pm_sem);
 216         if (!swsusp_resume_device) {
 217                 if (!strlen(resume_file)) {
 218                         up(&pm_sem);
 219                         return -ENOENT;
 220                 }
 221                 swsusp_resume_device = name_to_dev_t(resume_file);
 222                 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
 223         } else {
 224                 pr_debug("swsusp: Resume From Partition %d:%d\n",
 225                          MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 226         }
 227
 228         if (noresume) {
 229                 /**
 230                  * FIXME: If noresume is specified, we need to find the partition
 231                  * and reset it back to normal swap space.
 232                  */
 233                 up(&pm_sem);
 234                 return 0;
 235         }
 236
 237         pr_debug("PM: Checking swsusp image.\n");
 238
 239         if ((error = swsusp_check()))
 240                 goto Done;
 241
 242         pr_debug("PM: Preparing processes for restore.\n");
 243
 244         if ((error = prepare_processes())) {
 245                 swsusp_close();
 246                 goto Done;
 247         }
 248
 249         pr_debug("PM: Reading swsusp image.\n");
 250
 251         if ((error = swsusp_read())) {
 252                 swsusp_free();
 253                 goto Thaw;
 254         }
 255
 256         pr_debug("PM: Preparing devices for restore.\n");
 257
 258         suspend_console();
 259         if ((error = device_suspend(PMSG_PRETHAW))) {
 260                 resume_console();
 261                 printk("Some devices failed to suspend\n");
 262                 swsusp_free();
 263                 goto Thaw;
 264         }
 265
 266         mb();
 267
 268         pr_debug("PM: Restoring saved image.\n");
 269         swsusp_resume();
 270         pr_debug("PM: Restore failed, recovering.n");
 271         device_resume();
 272         resume_console();
 273  Thaw:
 274         unprepare_processes();
 275  Done:
 276         /* For success case, the suspend path will release the lock */
 277         up(&pm_sem);
 278         pr_debug("PM: Resume from disk failed.\n");
 279         return 0;
 280 }
 281
 282 late_initcall(software_resume);
 283
 284
 285 static const char * const pm_disk_modes[] = {
 286         [PM_DISK_FIRMWARE]      = "firmware",
 287         [PM_DISK_PLATFORM]      = "platform",
 288         [PM_DISK_SHUTDOWN]      = "shutdown",
 289         [PM_DISK_REBOOT]        = "reboot",
 290         [PM_DISK_TEST]          = "test",
 291         [PM_DISK_TESTPROC]      = "testproc",
 292 };
 293
 294 /**
 295  *      disk - Control suspend-to-disk mode
 296  *
 297  *      Suspend-to-disk can be handled in several ways. The greatest
 298  *      distinction is who writes memory to disk - the firmware or the OS.
 299  *      If the firmware does it, we assume that it also handles suspending
 300  *      the system.
 301  *      If the OS does it, then we have three options for putting the system
 302  *      to sleep - using the platform driver (e.g. ACPI or other PM registers),
 303  *      powering off the system or rebooting the system (for testing).
 304  *
 305  *      The system will support either 'firmware' or 'platform', and that is
 306  *      known a priori (and encoded in pm_ops). But, the user may choose
 307  *      'shutdown' or 'reboot' as alternatives.
 308  *
 309  *      show() will display what the mode is currently set to.
 310  *      store() will accept one of
 311  *
 312  *      'firmware'
 313  *      'platform'
 314  *      'shutdown'
 315  *      'reboot'
 316  *
 317  *      It will only change to 'firmware' or 'platform' if the system
 318  *      supports it (as determined from pm_ops->pm_disk_mode).
 319  */
 320
 321 static ssize_t disk_show(struct subsystem * subsys, char * buf)
 322 {
 323         return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
 324 }
 325
 326
 327 static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
 328 {
 329         int error = 0;
 330         int i;
 331         int len;
 332         char *p;
 333         suspend_disk_method_t mode = 0;
 334
 335         p = memchr(buf, '\n', n);
 336         len = p ? p - buf : n;
 337
 338         down(&pm_sem);
 339         for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
 340                 if (!strncmp(buf, pm_disk_modes[i], len)) {
 341                         mode = i;
 342                         break;
 343                 }
 344         }
 345         if (mode) {
 346                 if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT ||
 347                      mode == PM_DISK_TEST || mode == PM_DISK_TESTPROC) {
 348                         pm_disk_mode = mode;
 349                 } else {
 350                         if (pm_ops && pm_ops->enter &&
 351                             (mode == pm_ops->pm_disk_mode))
 352                                 pm_disk_mode = mode;
 353                         else
 354                                 error = -EINVAL;
 355                 }
 356         } else {
 357                 error = -EINVAL;
 358         }
 359
 360         pr_debug("PM: suspend-to-disk mode set to '%s'\n",
 361                  pm_disk_modes[mode]);
 362         up(&pm_sem);
 363         return error ? error : n;
 364 }
 365
 366 power_attr(disk);
 367
 368 static ssize_t resume_show(struct subsystem * subsys, char *buf)
 369 {
 370         return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
 371                        MINOR(swsusp_resume_device));
 372 }
 373
 374 static ssize_t resume_store(struct subsystem *subsys, const char *buf, size_t n)
 375 {
 376         unsigned int maj, min;
 377         dev_t res;
 378         int ret = -EINVAL;
 379
 380         if (sscanf(buf, "%u:%u", &maj, &min) != 2)
 381                 goto out;
 382
 383         res = MKDEV(maj,min);
 384         if (maj != MAJOR(res) || min != MINOR(res))
 385                 goto out;
 386
 387         down(&pm_sem);
 388         swsusp_resume_device = res;
 389         up(&pm_sem);
 390         printk("Attempting manual resume\n");
 391         noresume = 0;
 392         software_resume();
 393         ret = n;
 394 out:
 395         return ret;
 396 }
 397
 398 power_attr(resume);
 399
 400 static ssize_t image_size_show(struct subsystem * subsys, char *buf)
 401 {
 402         return sprintf(buf, "%lu\n", image_size);
 403 }
 404
 405 static ssize_t image_size_store(struct subsystem * subsys, const char * buf, size_t n)
 406 {
 407         unsigned long size;
 408
 409         if (sscanf(buf, "%lu", &size) == 1) {
 410                 image_size = size;
 411                 return n;
 412         }
 413
 414         return -EINVAL;
 415 }
 416
 417 power_attr(image_size);
 418
 419 static struct attribute * g[] = {
 420         &disk_attr.attr,
 421         &resume_attr.attr,
 422         &image_size_attr.attr,
 423         NULL,
 424 };
 425
 426
 427 static struct attribute_group attr_group = {
 428         .attrs = g,
 429 };
 430
 431
 432 static int __init pm_disk_init(void)
 433 {
 434         return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
 435 }
 436
 437 core_initcall(pm_disk_init);
 438
 439
 440 static int __init resume_setup(char *str)
 441 {
 442         if (noresume)
 443                 return 1;
 444
 445         strncpy( resume_file, str, 255 );
 446         return 1;
 447 }
 448
 449 static int __init resume_offset_setup(char *str)
 450 {
 451         unsigned long long offset;
 452
 453         if (noresume)
 454                 return 1;
 455
 456         if (sscanf(str, "%llu", &offset) == 1)
 457                 swsusp_resume_block = offset;
 458
 459         return 1;
 460 }
 461
 462 static int __init noresume_setup(char *str)
 463 {
 464         noresume = 1;
 465         return 1;
 466 }
 467
 468 __setup("noresume", noresume_setup);
 469 __setup("resume_offset=", resume_offset_setup);
 470 __setup("resume=", resume_setup);