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   1 /*
   2  * sleep.c - ACPI sleep support.
   3  *
   4  * Copyright (c) 2005 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   5  * Copyright (c) 2004 David Shaohua Li <shaohua.li@intel.com>
   6  * Copyright (c) 2000-2003 Patrick Mochel
   7  * Copyright (c) 2003 Open Source Development Lab
   8  *
   9  * This file is released under the GPLv2.
  10  *
  11  */
  12
  13 #include <linux/delay.h>
  14 #include <linux/irq.h>
  15 #include <linux/dmi.h>
  16 #include <linux/device.h>
  17 #include <linux/suspend.h>
  18 #include <linux/reboot.h>
  19
  20 #include <asm/io.h>
  21
  22 #include <acpi/acpi_bus.h>
  23 #include <acpi/acpi_drivers.h>
  24
  25 #include "internal.h"
  26 #include "sleep.h"
  27
  28 u8 sleep_states[ACPI_S_STATE_COUNT];
  29
  30 static void acpi_sleep_tts_switch(u32 acpi_state)
  31 {
  32         union acpi_object in_arg = { ACPI_TYPE_INTEGER };
  33         struct acpi_object_list arg_list = { 1, &in_arg };
  34         acpi_status status = AE_OK;
  35
  36         in_arg.integer.value = acpi_state;
  37         status = acpi_evaluate_object(NULL, "\\_TTS", &arg_list, NULL);
  38         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
  39                 /*
  40                  * OS can't evaluate the _TTS object correctly. Some warning
  41                  * message will be printed. But it won't break anything.
  42                  */
  43                 printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
  44         }
  45 }
  46
  47 static int tts_notify_reboot(struct notifier_block *this,
  48                         unsigned long code, void *x)
  49 {
  50         acpi_sleep_tts_switch(ACPI_STATE_S5);
  51         return NOTIFY_DONE;
  52 }
  53
  54 static struct notifier_block tts_notifier = {
  55         .notifier_call  = tts_notify_reboot,
  56         .next           = NULL,
  57         .priority       = 0,
  58 };
  59
  60 static int acpi_sleep_prepare(u32 acpi_state)
  61 {
  62 #ifdef CONFIG_ACPI_SLEEP
  63         /* do we have a wakeup address for S2 and S3? */
  64         if (acpi_state == ACPI_STATE_S3) {
  65                 if (!acpi_wakeup_address) {
  66                         return -EFAULT;
  67                 }
  68                 acpi_set_firmware_waking_vector(
  69                                 (acpi_physical_address)acpi_wakeup_address);
  70
  71         }
  72         ACPI_FLUSH_CPU_CACHE();
  73         acpi_enable_wakeup_device_prep(acpi_state);
  74 #endif
  75         printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
  76                 acpi_state);
  77         acpi_enter_sleep_state_prep(acpi_state);
  78         return 0;
  79 }
  80
  81 #ifdef CONFIG_ACPI_SLEEP
  82 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
  83 /*
  84  * According to the ACPI specification the BIOS should make sure that ACPI is
  85  * enabled and SCI_EN bit is set on wake-up from S1 - S3 sleep states.  Still,
  86  * some BIOSes don't do that and therefore we use acpi_enable() to enable ACPI
  87  * on such systems during resume.  Unfortunately that doesn't help in
  88  * particularly pathological cases in which SCI_EN has to be set directly on
  89  * resume, although the specification states very clearly that this flag is
  90  * owned by the hardware.  The set_sci_en_on_resume variable will be set in such
  91  * cases.
  92  */
  93 static bool set_sci_en_on_resume;
  94
  95 void __init acpi_set_sci_en_on_resume(void)
  96 {
  97         set_sci_en_on_resume = true;
  98 }
  99
 100 /*
 101  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
 102  * user to request that behavior by using the 'acpi_old_suspend_ordering'
 103  * kernel command line option that causes the following variable to be set.
 104  */
 105 static bool old_suspend_ordering;
 106
 107 void __init acpi_old_suspend_ordering(void)
 108 {
 109         old_suspend_ordering = true;
 110 }
 111
 112 /**
 113  *      acpi_pm_disable_gpes - Disable the GPEs.
 114  */
 115 static int acpi_pm_disable_gpes(void)
 116 {
 117         acpi_disable_all_gpes();
 118         return 0;
 119 }
 120
 121 /**
 122  *      __acpi_pm_prepare - Prepare the platform to enter the target state.
 123  *
 124  *      If necessary, set the firmware waking vector and do arch-specific
 125  *      nastiness to get the wakeup code to the waking vector.
 126  */
 127 static int __acpi_pm_prepare(void)
 128 {
 129         int error = acpi_sleep_prepare(acpi_target_sleep_state);
 130
 131         if (error)
 132                 acpi_target_sleep_state = ACPI_STATE_S0;
 133         return error;
 134 }
 135
 136 /**
 137  *      acpi_pm_prepare - Prepare the platform to enter the target sleep
 138  *              state and disable the GPEs.
 139  */
 140 static int acpi_pm_prepare(void)
 141 {
 142         int error = __acpi_pm_prepare();
 143
 144         if (!error)
 145                 acpi_disable_all_gpes();
 146         return error;
 147 }
 148
 149 /**
 150  *      acpi_pm_finish - Instruct the platform to leave a sleep state.
 151  *
 152  *      This is called after we wake back up (or if entering the sleep state
 153  *      failed).
 154  */
 155 static void acpi_pm_finish(void)
 156 {
 157         u32 acpi_state = acpi_target_sleep_state;
 158
 159         if (acpi_state == ACPI_STATE_S0)
 160                 return;
 161
 162         printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
 163                 acpi_state);
 164         acpi_disable_wakeup_device(acpi_state);
 165         acpi_leave_sleep_state(acpi_state);
 166
 167         /* reset firmware waking vector */
 168         acpi_set_firmware_waking_vector((acpi_physical_address) 0);
 169
 170         acpi_target_sleep_state = ACPI_STATE_S0;
 171 }
 172
 173 /**
 174  *      acpi_pm_end - Finish up suspend sequence.
 175  */
 176 static void acpi_pm_end(void)
 177 {
 178         /*
 179          * This is necessary in case acpi_pm_finish() is not called during a
 180          * failing transition to a sleep state.
 181          */
 182         acpi_target_sleep_state = ACPI_STATE_S0;
 183         acpi_sleep_tts_switch(acpi_target_sleep_state);
 184 }
 185 #else /* !CONFIG_ACPI_SLEEP */
 186 #define acpi_target_sleep_state ACPI_STATE_S0
 187 #endif /* CONFIG_ACPI_SLEEP */
 188
 189 #ifdef CONFIG_SUSPEND
 190 extern void do_suspend_lowlevel(void);
 191
 192 static u32 acpi_suspend_states[] = {
 193         [PM_SUSPEND_ON] = ACPI_STATE_S0,
 194         [PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
 195         [PM_SUSPEND_MEM] = ACPI_STATE_S3,
 196         [PM_SUSPEND_MAX] = ACPI_STATE_S5
 197 };
 198
 199 /**
 200  *      acpi_suspend_begin - Set the target system sleep state to the state
 201  *              associated with given @pm_state, if supported.
 202  */
 203 static int acpi_suspend_begin(suspend_state_t pm_state)
 204 {
 205         u32 acpi_state = acpi_suspend_states[pm_state];
 206         int error = 0;
 207
 208         if (sleep_states[acpi_state]) {
 209                 acpi_target_sleep_state = acpi_state;
 210                 acpi_sleep_tts_switch(acpi_target_sleep_state);
 211         } else {
 212                 printk(KERN_ERR "ACPI does not support this state: %d\n",
 213                         pm_state);
 214                 error = -ENOSYS;
 215         }
 216         return error;
 217 }
 218
 219 /**
 220  *      acpi_suspend_enter - Actually enter a sleep state.
 221  *      @pm_state: ignored
 222  *
 223  *      Flush caches and go to sleep. For STR we have to call arch-specific
 224  *      assembly, which in turn call acpi_enter_sleep_state().
 225  *      It's unfortunate, but it works. Please fix if you're feeling frisky.
 226  */
 227 static int acpi_suspend_enter(suspend_state_t pm_state)
 228 {
 229         acpi_status status = AE_OK;
 230         unsigned long flags = 0;
 231         u32 acpi_state = acpi_target_sleep_state;
 232
 233         ACPI_FLUSH_CPU_CACHE();
 234
 235         /* Do arch specific saving of state. */
 236         if (acpi_state == ACPI_STATE_S3) {
 237                 int error = acpi_save_state_mem();
 238
 239                 if (error)
 240                         return error;
 241         }
 242
 243         local_irq_save(flags);
 244         acpi_enable_wakeup_device(acpi_state);
 245         switch (acpi_state) {
 246         case ACPI_STATE_S1:
 247                 barrier();
 248                 status = acpi_enter_sleep_state(acpi_state);
 249                 break;
 250
 251         case ACPI_STATE_S3:
 252                 do_suspend_lowlevel();
 253                 break;
 254         }
 255
 256         /* If ACPI is not enabled by the BIOS, we need to enable it here. */
 257         if (set_sci_en_on_resume)
 258                 acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);
 259         else
 260                 acpi_enable();
 261
 262         /* Reprogram control registers and execute _BFS */
 263         acpi_leave_sleep_state_prep(acpi_state);
 264
 265         /* ACPI 3.0 specs (P62) says that it's the responsibility
 266          * of the OSPM to clear the status bit [ implying that the
 267          * POWER_BUTTON event should not reach userspace ]
 268          */
 269         if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
 270                 acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
 271
 272         /*
 273          * Disable and clear GPE status before interrupt is enabled. Some GPEs
 274          * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
 275          * acpi_leave_sleep_state will reenable specific GPEs later
 276          */
 277         acpi_disable_all_gpes();
 278
 279         local_irq_restore(flags);
 280         printk(KERN_DEBUG "Back to C!\n");
 281
 282         /* restore processor state */
 283         if (acpi_state == ACPI_STATE_S3)
 284                 acpi_restore_state_mem();
 285
 286         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
 287 }
 288
 289 static int acpi_suspend_state_valid(suspend_state_t pm_state)
 290 {
 291         u32 acpi_state;
 292
 293         switch (pm_state) {
 294         case PM_SUSPEND_ON:
 295         case PM_SUSPEND_STANDBY:
 296         case PM_SUSPEND_MEM:
 297                 acpi_state = acpi_suspend_states[pm_state];
 298
 299                 return sleep_states[acpi_state];
 300         default:
 301                 return 0;
 302         }
 303 }
 304
 305 static struct platform_suspend_ops acpi_suspend_ops = {
 306         .valid = acpi_suspend_state_valid,
 307         .begin = acpi_suspend_begin,
 308         .prepare_late = acpi_pm_prepare,
 309         .enter = acpi_suspend_enter,
 310         .wake = acpi_pm_finish,
 311         .end = acpi_pm_end,
 312 };
 313
 314 /**
 315  *      acpi_suspend_begin_old - Set the target system sleep state to the
 316  *              state associated with given @pm_state, if supported, and
 317  *              execute the _PTS control method.  This function is used if the
 318  *              pre-ACPI 2.0 suspend ordering has been requested.
 319  */
 320 static int acpi_suspend_begin_old(suspend_state_t pm_state)
 321 {
 322         int error = acpi_suspend_begin(pm_state);
 323
 324         if (!error)
 325                 error = __acpi_pm_prepare();
 326         return error;
 327 }
 328
 329 /*
 330  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
 331  * been requested.
 332  */
 333 static struct platform_suspend_ops acpi_suspend_ops_old = {
 334         .valid = acpi_suspend_state_valid,
 335         .begin = acpi_suspend_begin_old,
 336         .prepare_late = acpi_pm_disable_gpes,
 337         .enter = acpi_suspend_enter,
 338         .wake = acpi_pm_finish,
 339         .end = acpi_pm_end,
 340         .recover = acpi_pm_finish,
 341 };
 342
 343 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
 344 {
 345         old_suspend_ordering = true;
 346         return 0;
 347 }
 348
 349 static int __init init_set_sci_en_on_resume(const struct dmi_system_id *d)
 350 {
 351         set_sci_en_on_resume = true;
 352         return 0;
 353 }
 354
 355 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
 356         {
 357         .callback = init_old_suspend_ordering,
 358         .ident = "Abit KN9 (nForce4 variant)",
 359         .matches = {
 360                 DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
 361                 DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
 362                 },
 363         },
 364         {
 365         .callback = init_old_suspend_ordering,
 366         .ident = "HP xw4600 Workstation",
 367         .matches = {
 368                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 369                 DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
 370                 },
 371         },
 372         {
 373         .callback = init_set_sci_en_on_resume,
 374         .ident = "Apple MacBook 1,1",
 375         .matches = {
 376                 DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
 377                 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook1,1"),
 378                 },
 379         },
 380         {
 381         .callback = init_set_sci_en_on_resume,
 382         .ident = "Apple MacMini 1,1",
 383         .matches = {
 384                 DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
 385                 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini1,1"),
 386                 },
 387         },
 388         {
 389         .callback = init_old_suspend_ordering,
 390         .ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
 391         .matches = {
 392                 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTek Computer INC."),
 393                 DMI_MATCH(DMI_BOARD_NAME, "M2N8L"),
 394                 },
 395         },
 396         {
 397         .callback = init_set_sci_en_on_resume,
 398         .ident = "Toshiba Satellite L300",
 399         .matches = {
 400                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 401                 DMI_MATCH(DMI_PRODUCT_NAME, "Satellite L300"),
 402                 },
 403         },
 404         {
 405         .callback = init_set_sci_en_on_resume,
 406         .ident = "Hewlett-Packard HP G7000 Notebook PC",
 407         .matches = {
 408                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 409                 DMI_MATCH(DMI_PRODUCT_NAME, "HP G7000 Notebook PC"),
 410                 },
 411         },
 412         {
 413         .callback = init_set_sci_en_on_resume,
 414         .ident = "Hewlett-Packard HP Pavilion dv3 Notebook PC",
 415         .matches = {
 416                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 417                 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv3 Notebook PC"),
 418                 },
 419         },
 420         {
 421         .callback = init_set_sci_en_on_resume,
 422         .ident = "Hewlett-Packard Pavilion dv4",
 423         .matches = {
 424                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 425                 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv4"),
 426                 },
 427         },
 428         {
 429         .callback = init_set_sci_en_on_resume,
 430         .ident = "Hewlett-Packard Pavilion dv7",
 431         .matches = {
 432                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 433                 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv7"),
 434                 },
 435         },
 436         {
 437         .callback = init_set_sci_en_on_resume,
 438         .ident = "Hewlett-Packard Compaq Presario C700 Notebook PC",
 439         .matches = {
 440                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 441                 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq Presario C700 Notebook PC"),
 442                 },
 443         },
 444         {
 445         .callback = init_set_sci_en_on_resume,
 446         .ident = "Hewlett-Packard Compaq Presario CQ40 Notebook PC",
 447         .matches = {
 448                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 449                 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq Presario CQ40 Notebook PC"),
 450                 },
 451         },
 452         {
 453         .callback = init_old_suspend_ordering,
 454         .ident = "Panasonic CF51-2L",
 455         .matches = {
 456                 DMI_MATCH(DMI_BOARD_VENDOR,
 457                                 "Matsushita Electric Industrial Co.,Ltd."),
 458                 DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
 459                 },
 460         },
 461         {},
 462 };
 463 #endif /* CONFIG_SUSPEND */
 464
 465 #ifdef CONFIG_HIBERNATION
 466 /*
 467  * The ACPI specification wants us to save NVS memory regions during hibernation
 468  * and to restore them during the subsequent resume.  However, it is not certain
 469  * if this mechanism is going to work on all machines, so we allow the user to
 470  * disable this mechanism using the 'acpi_sleep=s4_nonvs' kernel command line
 471  * option.
 472  */
 473 static bool s4_no_nvs;
 474
 475 void __init acpi_s4_no_nvs(void)
 476 {
 477         s4_no_nvs = true;
 478 }
 479
 480 static unsigned long s4_hardware_signature;
 481 static struct acpi_table_facs *facs;
 482 static bool nosigcheck;
 483
 484 void __init acpi_no_s4_hw_signature(void)
 485 {
 486         nosigcheck = true;
 487 }
 488
 489 static int acpi_hibernation_begin(void)
 490 {
 491         int error;
 492
 493         error = s4_no_nvs ? 0 : hibernate_nvs_alloc();
 494         if (!error) {
 495                 acpi_target_sleep_state = ACPI_STATE_S4;
 496                 acpi_sleep_tts_switch(acpi_target_sleep_state);
 497         }
 498
 499         return error;
 500 }
 501
 502 static int acpi_hibernation_pre_snapshot(void)
 503 {
 504         int error = acpi_pm_prepare();
 505
 506         if (!error)
 507                 hibernate_nvs_save();
 508
 509         return error;
 510 }
 511
 512 static int acpi_hibernation_enter(void)
 513 {
 514         acpi_status status = AE_OK;
 515         unsigned long flags = 0;
 516
 517         ACPI_FLUSH_CPU_CACHE();
 518
 519         local_irq_save(flags);
 520         acpi_enable_wakeup_device(ACPI_STATE_S4);
 521         /* This shouldn't return.  If it returns, we have a problem */
 522         status = acpi_enter_sleep_state(ACPI_STATE_S4);
 523         /* Reprogram control registers and execute _BFS */
 524         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
 525         local_irq_restore(flags);
 526
 527         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
 528 }
 529
 530 static void acpi_hibernation_finish(void)
 531 {
 532         hibernate_nvs_free();
 533         acpi_pm_finish();
 534 }
 535
 536 static void acpi_hibernation_leave(void)
 537 {
 538         /*
 539          * If ACPI is not enabled by the BIOS and the boot kernel, we need to
 540          * enable it here.
 541          */
 542         acpi_enable();
 543         /* Reprogram control registers and execute _BFS */
 544         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
 545         /* Check the hardware signature */
 546         if (facs && s4_hardware_signature != facs->hardware_signature) {
 547                 printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
 548                         "cannot resume!\n");
 549                 panic("ACPI S4 hardware signature mismatch");
 550         }
 551         /* Restore the NVS memory area */
 552         hibernate_nvs_restore();
 553 }
 554
 555 static void acpi_pm_enable_gpes(void)
 556 {
 557         acpi_enable_all_runtime_gpes();
 558 }
 559
 560 static struct platform_hibernation_ops acpi_hibernation_ops = {
 561         .begin = acpi_hibernation_begin,
 562         .end = acpi_pm_end,
 563         .pre_snapshot = acpi_hibernation_pre_snapshot,
 564         .finish = acpi_hibernation_finish,
 565         .prepare = acpi_pm_prepare,
 566         .enter = acpi_hibernation_enter,
 567         .leave = acpi_hibernation_leave,
 568         .pre_restore = acpi_pm_disable_gpes,
 569         .restore_cleanup = acpi_pm_enable_gpes,
 570 };
 571
 572 /**
 573  *      acpi_hibernation_begin_old - Set the target system sleep state to
 574  *              ACPI_STATE_S4 and execute the _PTS control method.  This
 575  *              function is used if the pre-ACPI 2.0 suspend ordering has been
 576  *              requested.
 577  */
 578 static int acpi_hibernation_begin_old(void)
 579 {
 580         int error;
 581         /*
 582          * The _TTS object should always be evaluated before the _PTS object.
 583          * When the old_suspended_ordering is true, the _PTS object is
 584          * evaluated in the acpi_sleep_prepare.
 585          */
 586         acpi_sleep_tts_switch(ACPI_STATE_S4);
 587
 588         error = acpi_sleep_prepare(ACPI_STATE_S4);
 589
 590         if (!error) {
 591                 if (!s4_no_nvs)
 592                         error = hibernate_nvs_alloc();
 593                 if (!error)
 594                         acpi_target_sleep_state = ACPI_STATE_S4;
 595         }
 596         return error;
 597 }
 598
 599 static int acpi_hibernation_pre_snapshot_old(void)
 600 {
 601         int error = acpi_pm_disable_gpes();
 602
 603         if (!error)
 604                 hibernate_nvs_save();
 605
 606         return error;
 607 }
 608
 609 /*
 610  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
 611  * been requested.
 612  */
 613 static struct platform_hibernation_ops acpi_hibernation_ops_old = {
 614         .begin = acpi_hibernation_begin_old,
 615         .end = acpi_pm_end,
 616         .pre_snapshot = acpi_hibernation_pre_snapshot_old,
 617         .finish = acpi_hibernation_finish,
 618         .prepare = acpi_pm_disable_gpes,
 619         .enter = acpi_hibernation_enter,
 620         .leave = acpi_hibernation_leave,
 621         .pre_restore = acpi_pm_disable_gpes,
 622         .restore_cleanup = acpi_pm_enable_gpes,
 623         .recover = acpi_pm_finish,
 624 };
 625 #endif /* CONFIG_HIBERNATION */
 626
 627 int acpi_suspend(u32 acpi_state)
 628 {
 629         suspend_state_t states[] = {
 630                 [1] = PM_SUSPEND_STANDBY,
 631                 [3] = PM_SUSPEND_MEM,
 632                 [5] = PM_SUSPEND_MAX
 633         };
 634
 635         if (acpi_state < 6 && states[acpi_state])
 636                 return pm_suspend(states[acpi_state]);
 637         if (acpi_state == 4)
 638                 return hibernate();
 639         return -EINVAL;
 640 }
 641
 642 #ifdef CONFIG_PM_SLEEP
 643 /**
 644  *      acpi_pm_device_sleep_state - return preferred power state of ACPI device
 645  *              in the system sleep state given by %acpi_target_sleep_state
 646  *      @dev: device to examine; its driver model wakeup flags control
 647  *              whether it should be able to wake up the system
 648  *      @d_min_p: used to store the upper limit of allowed states range
 649  *      Return value: preferred power state of the device on success, -ENODEV on
 650  *              failure (ie. if there's no 'struct acpi_device' for @dev)
 651  *
 652  *      Find the lowest power (highest number) ACPI device power state that
 653  *      device @dev can be in while the system is in the sleep state represented
 654  *      by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
 655  *      able to wake up the system from this sleep state.  If @d_min_p is set,
 656  *      the highest power (lowest number) device power state of @dev allowed
 657  *      in this system sleep state is stored at the location pointed to by it.
 658  *
 659  *      The caller must ensure that @dev is valid before using this function.
 660  *      The caller is also responsible for figuring out if the device is
 661  *      supposed to be able to wake up the system and passing this information
 662  *      via @wake.
 663  */
 664
 665 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
 666 {
 667         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 668         struct acpi_device *adev;
 669         char acpi_method[] = "_SxD";
 670         unsigned long long d_min, d_max;
 671
 672         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
 673                 printk(KERN_DEBUG "ACPI handle has no context!\n");
 674                 return -ENODEV;
 675         }
 676
 677         acpi_method[2] = '0' + acpi_target_sleep_state;
 678         /*
 679          * If the sleep state is S0, we will return D3, but if the device has
 680          * _S0W, we will use the value from _S0W
 681          */
 682         d_min = ACPI_STATE_D0;
 683         d_max = ACPI_STATE_D3;
 684
 685         /*
 686          * If present, _SxD methods return the minimum D-state (highest power
 687          * state) we can use for the corresponding S-states.  Otherwise, the
 688          * minimum D-state is D0 (ACPI 3.x).
 689          *
 690          * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
 691          * provided -- that's our fault recovery, we ignore retval.
 692          */
 693         if (acpi_target_sleep_state > ACPI_STATE_S0)
 694                 acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
 695
 696         /*
 697          * If _PRW says we can wake up the system from the target sleep state,
 698          * the D-state returned by _SxD is sufficient for that (we assume a
 699          * wakeup-aware driver if wake is set).  Still, if _SxW exists
 700          * (ACPI 3.x), it should return the maximum (lowest power) D-state that
 701          * can wake the system.  _S0W may be valid, too.
 702          */
 703         if (acpi_target_sleep_state == ACPI_STATE_S0 ||
 704             (device_may_wakeup(dev) && adev->wakeup.state.enabled &&
 705              adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
 706                 acpi_status status;
 707
 708                 acpi_method[3] = 'W';
 709                 status = acpi_evaluate_integer(handle, acpi_method, NULL,
 710                                                 &d_max);
 711                 if (ACPI_FAILURE(status)) {
 712                         d_max = d_min;
 713                 } else if (d_max < d_min) {
 714                         /* Warn the user of the broken DSDT */
 715                         printk(KERN_WARNING "ACPI: Wrong value from %s\n",
 716                                 acpi_method);
 717                         /* Sanitize it */
 718                         d_min = d_max;
 719                 }
 720         }
 721
 722         if (d_min_p)
 723                 *d_min_p = d_min;
 724         return d_max;
 725 }
 726
 727 /**
 728  *      acpi_pm_device_sleep_wake - enable or disable the system wake-up
 729  *                                  capability of given device
 730  *      @dev: device to handle
 731  *      @enable: 'true' - enable, 'false' - disable the wake-up capability
 732  */
 733 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
 734 {
 735         acpi_handle handle;
 736         struct acpi_device *adev;
 737         int error;
 738
 739         if (!device_can_wakeup(dev))
 740                 return -EINVAL;
 741
 742         handle = DEVICE_ACPI_HANDLE(dev);
 743         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
 744                 dev_dbg(dev, "ACPI handle has no context in %s!\n", __func__);
 745                 return -ENODEV;
 746         }
 747
 748         error = enable ?
 749                 acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
 750                 acpi_disable_wakeup_device_power(adev);
 751         if (!error)
 752                 dev_info(dev, "wake-up capability %s by ACPI\n",
 753                                 enable ? "enabled" : "disabled");
 754
 755         return error;
 756 }
 757 #endif
 758
 759 static void acpi_power_off_prepare(void)
 760 {
 761         /* Prepare to power off the system */
 762         acpi_sleep_prepare(ACPI_STATE_S5);
 763         acpi_disable_all_gpes();
 764 }
 765
 766 static void acpi_power_off(void)
 767 {
 768         /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
 769         printk(KERN_DEBUG "%s called\n", __func__);
 770         local_irq_disable();
 771         acpi_enable_wakeup_device(ACPI_STATE_S5);
 772         acpi_enter_sleep_state(ACPI_STATE_S5);
 773 }
 774
 775 /*
 776  * ACPI 2.0 created the optional _GTS and _BFS,
 777  * but industry adoption has been neither rapid nor broad.
 778  *
 779  * Linux gets into trouble when it executes poorly validated
 780  * paths through the BIOS, so disable _GTS and _BFS by default,
 781  * but do speak up and offer the option to enable them.
 782  */
 783 void __init acpi_gts_bfs_check(void)
 784 {
 785         acpi_handle dummy;
 786
 787         if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__GTS, &dummy)))
 788         {
 789                 printk(KERN_NOTICE PREFIX "BIOS offers _GTS\n");
 790                 printk(KERN_NOTICE PREFIX "If \"acpi.gts=1\" improves suspend, "
 791                         "please notify linux-acpi@vger.kernel.org\n");
 792         }
 793         if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__BFS, &dummy)))
 794         {
 795                 printk(KERN_NOTICE PREFIX "BIOS offers _BFS\n");
 796                 printk(KERN_NOTICE PREFIX "If \"acpi.bfs=1\" improves resume, "
 797                         "please notify linux-acpi@vger.kernel.org\n");
 798         }
 799 }
 800
 801 int __init acpi_sleep_init(void)
 802 {
 803         acpi_status status;
 804         u8 type_a, type_b;
 805 #ifdef CONFIG_SUSPEND
 806         int i = 0;
 807
 808         dmi_check_system(acpisleep_dmi_table);
 809 #endif
 810
 811         if (acpi_disabled)
 812                 return 0;
 813
 814         sleep_states[ACPI_STATE_S0] = 1;
 815         printk(KERN_INFO PREFIX "(supports S0");
 816
 817 #ifdef CONFIG_SUSPEND
 818         for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
 819                 status = acpi_get_sleep_type_data(i, &type_a, &type_b);
 820                 if (ACPI_SUCCESS(status)) {
 821                         sleep_states[i] = 1;
 822                         printk(" S%d", i);
 823                 }
 824         }
 825
 826         suspend_set_ops(old_suspend_ordering ?
 827                 &acpi_suspend_ops_old : &acpi_suspend_ops);
 828 #endif
 829
 830 #ifdef CONFIG_HIBERNATION
 831         status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
 832         if (ACPI_SUCCESS(status)) {
 833                 hibernation_set_ops(old_suspend_ordering ?
 834                         &acpi_hibernation_ops_old : &acpi_hibernation_ops);
 835                 sleep_states[ACPI_STATE_S4] = 1;
 836                 printk(" S4");
 837                 if (!nosigcheck) {
 838                         acpi_get_table(ACPI_SIG_FACS, 1,
 839                                 (struct acpi_table_header **)&facs);
 840                         if (facs)
 841                                 s4_hardware_signature =
 842                                         facs->hardware_signature;
 843                 }
 844         }
 845 #endif
 846         status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
 847         if (ACPI_SUCCESS(status)) {
 848                 sleep_states[ACPI_STATE_S5] = 1;
 849                 printk(" S5");
 850                 pm_power_off_prepare = acpi_power_off_prepare;
 851                 pm_power_off = acpi_power_off;
 852         }
 853         printk(")\n");
 854         /*
 855          * Register the tts_notifier to reboot notifier list so that the _TTS
 856          * object can also be evaluated when the system enters S5.
 857          */
 858         register_reboot_notifier(&tts_notifier);
 859         acpi_gts_bfs_check();
 860         return 0;
 861 }