| 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 | enum { |
| 34 | HIBERNATION_INVALID, |
| 35 | HIBERNATION_PLATFORM, |
| 36 | HIBERNATION_TEST, |
| 37 | HIBERNATION_TESTPROC, |
| 38 | HIBERNATION_SHUTDOWN, |
| 39 | HIBERNATION_REBOOT, |
| 40 | /* keep last */ |
| 41 | __HIBERNATION_AFTER_LAST |
| 42 | }; |
| 43 | #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1) |
| 44 | #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1) |
| 45 | |
| 46 | static int hibernation_mode = HIBERNATION_SHUTDOWN; |
| 47 | |
| 48 | static struct hibernation_ops *hibernation_ops; |
| 49 | |
| 50 | /** |
| 51 | * hibernation_set_ops - set the global hibernate operations |
| 52 | * @ops: the hibernation operations to use in subsequent hibernation transitions |
| 53 | */ |
| 54 | |
| 55 | void hibernation_set_ops(struct hibernation_ops *ops) |
| 56 | { |
| 57 | if (ops && !(ops->prepare && ops->enter && ops->finish |
| 58 | && ops->pre_restore && ops->restore_cleanup)) { |
| 59 | WARN_ON(1); |
| 60 | return; |
| 61 | } |
| 62 | mutex_lock(&pm_mutex); |
| 63 | hibernation_ops = ops; |
| 64 | if (ops) |
| 65 | hibernation_mode = HIBERNATION_PLATFORM; |
| 66 | else if (hibernation_mode == HIBERNATION_PLATFORM) |
| 67 | hibernation_mode = HIBERNATION_SHUTDOWN; |
| 68 | |
| 69 | mutex_unlock(&pm_mutex); |
| 70 | } |
| 71 | |
| 72 | |
| 73 | /** |
| 74 | * platform_prepare - prepare the machine for hibernation using the |
| 75 | * platform driver if so configured and return an error code if it fails |
| 76 | */ |
| 77 | |
| 78 | static int platform_prepare(int platform_mode) |
| 79 | { |
| 80 | return (platform_mode && hibernation_ops) ? |
| 81 | hibernation_ops->prepare() : 0; |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * platform_finish - switch the machine to the normal mode of operation |
| 86 | * using the platform driver (must be called after platform_prepare()) |
| 87 | */ |
| 88 | |
| 89 | static void platform_finish(int platform_mode) |
| 90 | { |
| 91 | if (platform_mode && hibernation_ops) |
| 92 | hibernation_ops->finish(); |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * platform_pre_restore - prepare the platform for the restoration from a |
| 97 | * hibernation image. If the restore fails after this function has been |
| 98 | * called, platform_restore_cleanup() must be called. |
| 99 | */ |
| 100 | |
| 101 | static int platform_pre_restore(int platform_mode) |
| 102 | { |
| 103 | return (platform_mode && hibernation_ops) ? |
| 104 | hibernation_ops->pre_restore() : 0; |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * platform_restore_cleanup - switch the platform to the normal mode of |
| 109 | * operation after a failing restore. If platform_pre_restore() has been |
| 110 | * called before the failing restore, this function must be called too, |
| 111 | * regardless of the result of platform_pre_restore(). |
| 112 | */ |
| 113 | |
| 114 | static void platform_restore_cleanup(int platform_mode) |
| 115 | { |
| 116 | if (platform_mode && hibernation_ops) |
| 117 | hibernation_ops->restore_cleanup(); |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * hibernation_snapshot - quiesce devices and create the hibernation |
| 122 | * snapshot image. |
| 123 | * @platform_mode - if set, use the platform driver, if available, to |
| 124 | * prepare the platform frimware for the power transition. |
| 125 | * |
| 126 | * Must be called with pm_mutex held |
| 127 | */ |
| 128 | |
| 129 | int hibernation_snapshot(int platform_mode) |
| 130 | { |
| 131 | int error; |
| 132 | |
| 133 | /* Free memory before shutting down devices. */ |
| 134 | error = swsusp_shrink_memory(); |
| 135 | if (error) |
| 136 | return error; |
| 137 | |
| 138 | suspend_console(); |
| 139 | error = device_suspend(PMSG_FREEZE); |
| 140 | if (error) |
| 141 | goto Resume_console; |
| 142 | |
| 143 | error = platform_prepare(platform_mode); |
| 144 | if (error) |
| 145 | goto Resume_devices; |
| 146 | |
| 147 | error = disable_nonboot_cpus(); |
| 148 | if (!error) { |
| 149 | if (hibernation_mode != HIBERNATION_TEST) { |
| 150 | in_suspend = 1; |
| 151 | error = swsusp_suspend(); |
| 152 | /* Control returns here after successful restore */ |
| 153 | } else { |
| 154 | printk("swsusp debug: Waiting for 5 seconds.\n"); |
| 155 | mdelay(5000); |
| 156 | } |
| 157 | } |
| 158 | enable_nonboot_cpus(); |
| 159 | Resume_devices: |
| 160 | platform_finish(platform_mode); |
| 161 | device_resume(); |
| 162 | Resume_console: |
| 163 | resume_console(); |
| 164 | return error; |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * hibernation_restore - quiesce devices and restore the hibernation |
| 169 | * snapshot image. If successful, control returns in hibernation_snaphot() |
| 170 | * @platform_mode - if set, use the platform driver, if available, to |
| 171 | * prepare the platform frimware for the transition. |
| 172 | * |
| 173 | * Must be called with pm_mutex held |
| 174 | */ |
| 175 | |
| 176 | int hibernation_restore(int platform_mode) |
| 177 | { |
| 178 | int error; |
| 179 | |
| 180 | pm_prepare_console(); |
| 181 | suspend_console(); |
| 182 | error = device_suspend(PMSG_PRETHAW); |
| 183 | if (error) |
| 184 | goto Finish; |
| 185 | |
| 186 | error = platform_pre_restore(platform_mode); |
| 187 | if (!error) { |
| 188 | error = disable_nonboot_cpus(); |
| 189 | if (!error) |
| 190 | error = swsusp_resume(); |
| 191 | enable_nonboot_cpus(); |
| 192 | } |
| 193 | platform_restore_cleanup(platform_mode); |
| 194 | device_resume(); |
| 195 | Finish: |
| 196 | resume_console(); |
| 197 | pm_restore_console(); |
| 198 | return error; |
| 199 | } |
| 200 | |
| 201 | /** |
| 202 | * hibernation_platform_enter - enter the hibernation state using the |
| 203 | * platform driver (if available) |
| 204 | */ |
| 205 | |
| 206 | int hibernation_platform_enter(void) |
| 207 | { |
| 208 | if (hibernation_ops) { |
| 209 | kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK); |
| 210 | return hibernation_ops->enter(); |
| 211 | } else { |
| 212 | return -ENOSYS; |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * power_down - Shut the machine down for hibernation. |
| 218 | * |
| 219 | * Use the platform driver, if configured so; otherwise try |
| 220 | * to power off or reboot. |
| 221 | */ |
| 222 | |
| 223 | static void power_down(void) |
| 224 | { |
| 225 | switch (hibernation_mode) { |
| 226 | case HIBERNATION_TEST: |
| 227 | case HIBERNATION_TESTPROC: |
| 228 | break; |
| 229 | case HIBERNATION_SHUTDOWN: |
| 230 | kernel_power_off(); |
| 231 | break; |
| 232 | case HIBERNATION_REBOOT: |
| 233 | kernel_restart(NULL); |
| 234 | break; |
| 235 | case HIBERNATION_PLATFORM: |
| 236 | hibernation_platform_enter(); |
| 237 | } |
| 238 | kernel_halt(); |
| 239 | /* |
| 240 | * Valid image is on the disk, if we continue we risk serious data |
| 241 | * corruption after resume. |
| 242 | */ |
| 243 | printk(KERN_CRIT "Please power me down manually\n"); |
| 244 | while(1); |
| 245 | } |
| 246 | |
| 247 | static void unprepare_processes(void) |
| 248 | { |
| 249 | thaw_processes(); |
| 250 | pm_restore_console(); |
| 251 | } |
| 252 | |
| 253 | static int prepare_processes(void) |
| 254 | { |
| 255 | int error = 0; |
| 256 | |
| 257 | pm_prepare_console(); |
| 258 | if (freeze_processes()) { |
| 259 | error = -EBUSY; |
| 260 | unprepare_processes(); |
| 261 | } |
| 262 | return error; |
| 263 | } |
| 264 | |
| 265 | /** |
| 266 | * hibernate - The granpappy of the built-in hibernation management |
| 267 | */ |
| 268 | |
| 269 | int hibernate(void) |
| 270 | { |
| 271 | int error; |
| 272 | |
| 273 | /* The snapshot device should not be opened while we're running */ |
| 274 | if (!atomic_add_unless(&snapshot_device_available, -1, 0)) |
| 275 | return -EBUSY; |
| 276 | |
| 277 | /* Allocate memory management structures */ |
| 278 | error = create_basic_memory_bitmaps(); |
| 279 | if (error) |
| 280 | goto Exit; |
| 281 | |
| 282 | error = prepare_processes(); |
| 283 | if (error) |
| 284 | goto Finish; |
| 285 | |
| 286 | mutex_lock(&pm_mutex); |
| 287 | if (hibernation_mode == HIBERNATION_TESTPROC) { |
| 288 | printk("swsusp debug: Waiting for 5 seconds.\n"); |
| 289 | mdelay(5000); |
| 290 | goto Thaw; |
| 291 | } |
| 292 | error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM); |
| 293 | if (in_suspend && !error) { |
| 294 | unsigned int flags = 0; |
| 295 | |
| 296 | if (hibernation_mode == HIBERNATION_PLATFORM) |
| 297 | flags |= SF_PLATFORM_MODE; |
| 298 | pr_debug("PM: writing image.\n"); |
| 299 | error = swsusp_write(flags); |
| 300 | swsusp_free(); |
| 301 | if (!error) |
| 302 | power_down(); |
| 303 | } else { |
| 304 | pr_debug("PM: Image restored successfully.\n"); |
| 305 | swsusp_free(); |
| 306 | } |
| 307 | Thaw: |
| 308 | mutex_unlock(&pm_mutex); |
| 309 | unprepare_processes(); |
| 310 | Finish: |
| 311 | free_basic_memory_bitmaps(); |
| 312 | Exit: |
| 313 | atomic_inc(&snapshot_device_available); |
| 314 | return error; |
| 315 | } |
| 316 | |
| 317 | |
| 318 | /** |
| 319 | * software_resume - Resume from a saved image. |
| 320 | * |
| 321 | * Called as a late_initcall (so all devices are discovered and |
| 322 | * initialized), we call swsusp to see if we have a saved image or not. |
| 323 | * If so, we quiesce devices, the restore the saved image. We will |
| 324 | * return above (in hibernate() ) if everything goes well. |
| 325 | * Otherwise, we fail gracefully and return to the normally |
| 326 | * scheduled program. |
| 327 | * |
| 328 | */ |
| 329 | |
| 330 | static int software_resume(void) |
| 331 | { |
| 332 | int error; |
| 333 | unsigned int flags; |
| 334 | |
| 335 | mutex_lock(&pm_mutex); |
| 336 | if (!swsusp_resume_device) { |
| 337 | if (!strlen(resume_file)) { |
| 338 | mutex_unlock(&pm_mutex); |
| 339 | return -ENOENT; |
| 340 | } |
| 341 | swsusp_resume_device = name_to_dev_t(resume_file); |
| 342 | pr_debug("swsusp: Resume From Partition %s\n", resume_file); |
| 343 | } else { |
| 344 | pr_debug("swsusp: Resume From Partition %d:%d\n", |
| 345 | MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); |
| 346 | } |
| 347 | |
| 348 | if (noresume) { |
| 349 | /** |
| 350 | * FIXME: If noresume is specified, we need to find the partition |
| 351 | * and reset it back to normal swap space. |
| 352 | */ |
| 353 | mutex_unlock(&pm_mutex); |
| 354 | return 0; |
| 355 | } |
| 356 | |
| 357 | pr_debug("PM: Checking swsusp image.\n"); |
| 358 | error = swsusp_check(); |
| 359 | if (error) |
| 360 | goto Unlock; |
| 361 | |
| 362 | /* The snapshot device should not be opened while we're running */ |
| 363 | if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { |
| 364 | error = -EBUSY; |
| 365 | goto Unlock; |
| 366 | } |
| 367 | |
| 368 | error = create_basic_memory_bitmaps(); |
| 369 | if (error) |
| 370 | goto Finish; |
| 371 | |
| 372 | pr_debug("PM: Preparing processes for restore.\n"); |
| 373 | error = prepare_processes(); |
| 374 | if (error) { |
| 375 | swsusp_close(); |
| 376 | goto Done; |
| 377 | } |
| 378 | |
| 379 | pr_debug("PM: Reading swsusp image.\n"); |
| 380 | |
| 381 | error = swsusp_read(&flags); |
| 382 | if (!error) |
| 383 | hibernation_restore(flags & SF_PLATFORM_MODE); |
| 384 | |
| 385 | printk(KERN_ERR "PM: Restore failed, recovering.\n"); |
| 386 | swsusp_free(); |
| 387 | unprepare_processes(); |
| 388 | Done: |
| 389 | free_basic_memory_bitmaps(); |
| 390 | Finish: |
| 391 | atomic_inc(&snapshot_device_available); |
| 392 | /* For success case, the suspend path will release the lock */ |
| 393 | Unlock: |
| 394 | mutex_unlock(&pm_mutex); |
| 395 | pr_debug("PM: Resume from disk failed.\n"); |
| 396 | return error; |
| 397 | } |
| 398 | |
| 399 | late_initcall(software_resume); |
| 400 | |
| 401 | |
| 402 | static const char * const hibernation_modes[] = { |
| 403 | [HIBERNATION_PLATFORM] = "platform", |
| 404 | [HIBERNATION_SHUTDOWN] = "shutdown", |
| 405 | [HIBERNATION_REBOOT] = "reboot", |
| 406 | [HIBERNATION_TEST] = "test", |
| 407 | [HIBERNATION_TESTPROC] = "testproc", |
| 408 | }; |
| 409 | |
| 410 | /** |
| 411 | * disk - Control hibernation mode |
| 412 | * |
| 413 | * Suspend-to-disk can be handled in several ways. We have a few options |
| 414 | * for putting the system to sleep - using the platform driver (e.g. ACPI |
| 415 | * or other hibernation_ops), powering off the system or rebooting the |
| 416 | * system (for testing) as well as the two test modes. |
| 417 | * |
| 418 | * The system can support 'platform', and that is known a priori (and |
| 419 | * encoded by the presence of hibernation_ops). However, the user may |
| 420 | * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the |
| 421 | * test modes, 'test' or 'testproc'. |
| 422 | * |
| 423 | * show() will display what the mode is currently set to. |
| 424 | * store() will accept one of |
| 425 | * |
| 426 | * 'platform' |
| 427 | * 'shutdown' |
| 428 | * 'reboot' |
| 429 | * 'test' |
| 430 | * 'testproc' |
| 431 | * |
| 432 | * It will only change to 'platform' if the system |
| 433 | * supports it (as determined by having hibernation_ops). |
| 434 | */ |
| 435 | |
| 436 | static ssize_t disk_show(struct kset *kset, char *buf) |
| 437 | { |
| 438 | int i; |
| 439 | char *start = buf; |
| 440 | |
| 441 | for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) { |
| 442 | if (!hibernation_modes[i]) |
| 443 | continue; |
| 444 | switch (i) { |
| 445 | case HIBERNATION_SHUTDOWN: |
| 446 | case HIBERNATION_REBOOT: |
| 447 | case HIBERNATION_TEST: |
| 448 | case HIBERNATION_TESTPROC: |
| 449 | break; |
| 450 | case HIBERNATION_PLATFORM: |
| 451 | if (hibernation_ops) |
| 452 | break; |
| 453 | /* not a valid mode, continue with loop */ |
| 454 | continue; |
| 455 | } |
| 456 | if (i == hibernation_mode) |
| 457 | buf += sprintf(buf, "[%s] ", hibernation_modes[i]); |
| 458 | else |
| 459 | buf += sprintf(buf, "%s ", hibernation_modes[i]); |
| 460 | } |
| 461 | buf += sprintf(buf, "\n"); |
| 462 | return buf-start; |
| 463 | } |
| 464 | |
| 465 | |
| 466 | static ssize_t disk_store(struct kset *kset, const char *buf, size_t n) |
| 467 | { |
| 468 | int error = 0; |
| 469 | int i; |
| 470 | int len; |
| 471 | char *p; |
| 472 | int mode = HIBERNATION_INVALID; |
| 473 | |
| 474 | p = memchr(buf, '\n', n); |
| 475 | len = p ? p - buf : n; |
| 476 | |
| 477 | mutex_lock(&pm_mutex); |
| 478 | for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) { |
| 479 | if (len == strlen(hibernation_modes[i]) |
| 480 | && !strncmp(buf, hibernation_modes[i], len)) { |
| 481 | mode = i; |
| 482 | break; |
| 483 | } |
| 484 | } |
| 485 | if (mode != HIBERNATION_INVALID) { |
| 486 | switch (mode) { |
| 487 | case HIBERNATION_SHUTDOWN: |
| 488 | case HIBERNATION_REBOOT: |
| 489 | case HIBERNATION_TEST: |
| 490 | case HIBERNATION_TESTPROC: |
| 491 | hibernation_mode = mode; |
| 492 | break; |
| 493 | case HIBERNATION_PLATFORM: |
| 494 | if (hibernation_ops) |
| 495 | hibernation_mode = mode; |
| 496 | else |
| 497 | error = -EINVAL; |
| 498 | } |
| 499 | } else |
| 500 | error = -EINVAL; |
| 501 | |
| 502 | if (!error) |
| 503 | pr_debug("PM: suspend-to-disk mode set to '%s'\n", |
| 504 | hibernation_modes[mode]); |
| 505 | mutex_unlock(&pm_mutex); |
| 506 | return error ? error : n; |
| 507 | } |
| 508 | |
| 509 | power_attr(disk); |
| 510 | |
| 511 | static ssize_t resume_show(struct kset *kset, char *buf) |
| 512 | { |
| 513 | return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device), |
| 514 | MINOR(swsusp_resume_device)); |
| 515 | } |
| 516 | |
| 517 | static ssize_t resume_store(struct kset *kset, const char *buf, size_t n) |
| 518 | { |
| 519 | unsigned int maj, min; |
| 520 | dev_t res; |
| 521 | int ret = -EINVAL; |
| 522 | |
| 523 | if (sscanf(buf, "%u:%u", &maj, &min) != 2) |
| 524 | goto out; |
| 525 | |
| 526 | res = MKDEV(maj,min); |
| 527 | if (maj != MAJOR(res) || min != MINOR(res)) |
| 528 | goto out; |
| 529 | |
| 530 | mutex_lock(&pm_mutex); |
| 531 | swsusp_resume_device = res; |
| 532 | mutex_unlock(&pm_mutex); |
| 533 | printk("Attempting manual resume\n"); |
| 534 | noresume = 0; |
| 535 | software_resume(); |
| 536 | ret = n; |
| 537 | out: |
| 538 | return ret; |
| 539 | } |
| 540 | |
| 541 | power_attr(resume); |
| 542 | |
| 543 | static ssize_t image_size_show(struct kset *kset, char *buf) |
| 544 | { |
| 545 | return sprintf(buf, "%lu\n", image_size); |
| 546 | } |
| 547 | |
| 548 | static ssize_t image_size_store(struct kset *kset, const char *buf, size_t n) |
| 549 | { |
| 550 | unsigned long size; |
| 551 | |
| 552 | if (sscanf(buf, "%lu", &size) == 1) { |
| 553 | image_size = size; |
| 554 | return n; |
| 555 | } |
| 556 | |
| 557 | return -EINVAL; |
| 558 | } |
| 559 | |
| 560 | power_attr(image_size); |
| 561 | |
| 562 | static struct attribute * g[] = { |
| 563 | &disk_attr.attr, |
| 564 | &resume_attr.attr, |
| 565 | &image_size_attr.attr, |
| 566 | NULL, |
| 567 | }; |
| 568 | |
| 569 | |
| 570 | static struct attribute_group attr_group = { |
| 571 | .attrs = g, |
| 572 | }; |
| 573 | |
| 574 | |
| 575 | static int __init pm_disk_init(void) |
| 576 | { |
| 577 | return sysfs_create_group(&power_subsys.kobj, &attr_group); |
| 578 | } |
| 579 | |
| 580 | core_initcall(pm_disk_init); |
| 581 | |
| 582 | |
| 583 | static int __init resume_setup(char *str) |
| 584 | { |
| 585 | if (noresume) |
| 586 | return 1; |
| 587 | |
| 588 | strncpy( resume_file, str, 255 ); |
| 589 | return 1; |
| 590 | } |
| 591 | |
| 592 | static int __init resume_offset_setup(char *str) |
| 593 | { |
| 594 | unsigned long long offset; |
| 595 | |
| 596 | if (noresume) |
| 597 | return 1; |
| 598 | |
| 599 | if (sscanf(str, "%llu", &offset) == 1) |
| 600 | swsusp_resume_block = offset; |
| 601 | |
| 602 | return 1; |
| 603 | } |
| 604 | |
| 605 | static int __init noresume_setup(char *str) |
| 606 | { |
| 607 | noresume = 1; |
| 608 | return 1; |
| 609 | } |
| 610 | |
| 611 | __setup("noresume", noresume_setup); |
| 612 | __setup("resume_offset=", resume_offset_setup); |
| 613 | __setup("resume=", resume_setup); |