drivers/acpi/sleep.c

   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 #include <linux/acpi.h>
  20
  21 #include <asm/io.h>
  22
  23 #include <acpi/acpi_bus.h>
  24 #include <acpi/acpi_drivers.h>
  25
  26 #include "internal.h"
  27 #include "sleep.h"
  28
  29 static u8 sleep_states[ACPI_S_STATE_COUNT];
  30
  31 static void acpi_sleep_tts_switch(u32 acpi_state)
  32 {
  33         union acpi_object in_arg = { ACPI_TYPE_INTEGER };
  34         struct acpi_object_list arg_list = { 1, &in_arg };
  35         acpi_status status = AE_OK;
  36
  37         in_arg.integer.value = acpi_state;
  38         status = acpi_evaluate_object(NULL, "\\_TTS", &arg_list, NULL);
  39         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
  40                 /*
  41                  * OS can't evaluate the _TTS object correctly. Some warning
  42                  * message will be printed. But it won't break anything.
  43                  */
  44                 printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
  45         }
  46 }
  47
  48 static int tts_notify_reboot(struct notifier_block *this,
  49                         unsigned long code, void *x)
  50 {
  51         acpi_sleep_tts_switch(ACPI_STATE_S5);
  52         return NOTIFY_DONE;
  53 }
  54
  55 static struct notifier_block tts_notifier = {
  56         .notifier_call  = tts_notify_reboot,
  57         .next           = NULL,
  58         .priority       = 0,
  59 };
  60
  61 static int acpi_sleep_prepare(u32 acpi_state)
  62 {
  63 #ifdef CONFIG_ACPI_SLEEP
  64         /* do we have a wakeup address for S2 and S3? */
  65         if (acpi_state == ACPI_STATE_S3) {
  66                 if (!acpi_wakeup_address) {
  67                         return -EFAULT;
  68                 }
  69                 acpi_set_firmware_waking_vector(
  70                                 (acpi_physical_address)acpi_wakeup_address);
  71
  72         }
  73         ACPI_FLUSH_CPU_CACHE();
  74 #endif
  75         printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
  76                 acpi_state);
  77         acpi_enable_wakeup_devices(acpi_state);
  78         acpi_enter_sleep_state_prep(acpi_state);
  79         return 0;
  80 }
  81
  82 #ifdef CONFIG_ACPI_SLEEP
  83 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
  84
  85 /*
  86  * The ACPI specification wants us to save NVS memory regions during hibernation
  87  * and to restore them during the subsequent resume.  Windows does that also for
  88  * suspend to RAM.  However, it is known that this mechanism does not work on
  89  * all machines, so we allow the user to disable it with the help of the
  90  * 'acpi_sleep=nonvs' kernel command line option.
  91  */
  92 static bool nvs_nosave;
  93
  94 void __init acpi_nvs_nosave(void)
  95 {
  96         nvs_nosave = true;
  97 }
  98
  99 /*
 100  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
 101  * user to request that behavior by using the 'acpi_old_suspend_ordering'
 102  * kernel command line option that causes the following variable to be set.
 103  */
 104 static bool old_suspend_ordering;
 105
 106 void __init acpi_old_suspend_ordering(void)
 107 {
 108         old_suspend_ordering = true;
 109 }
 110
 111 /**
 112  * acpi_pm_freeze - Disable the GPEs and suspend EC transactions.
 113  */
 114 static int acpi_pm_freeze(void)
 115 {
 116         acpi_disable_all_gpes();
 117         acpi_os_wait_events_complete(NULL);
 118         acpi_ec_block_transactions();
 119         return 0;
 120 }
 121
 122 /**
 123  * acpi_pre_suspend - Enable wakeup devices, "freeze" EC and save NVS.
 124  */
 125 static int acpi_pm_pre_suspend(void)
 126 {
 127         acpi_pm_freeze();
 128         return suspend_nvs_save();
 129 }
 130
 131 /**
 132  *      __acpi_pm_prepare - Prepare the platform to enter the target state.
 133  *
 134  *      If necessary, set the firmware waking vector and do arch-specific
 135  *      nastiness to get the wakeup code to the waking vector.
 136  */
 137 static int __acpi_pm_prepare(void)
 138 {
 139         int error = acpi_sleep_prepare(acpi_target_sleep_state);
 140         if (error)
 141                 acpi_target_sleep_state = ACPI_STATE_S0;
 142
 143         return error;
 144 }
 145
 146 /**
 147  *      acpi_pm_prepare - Prepare the platform to enter the target sleep
 148  *              state and disable the GPEs.
 149  */
 150 static int acpi_pm_prepare(void)
 151 {
 152         int error = __acpi_pm_prepare();
 153         if (!error)
 154                 error = acpi_pm_pre_suspend();
 155
 156         return error;
 157 }
 158
 159 /**
 160  *      acpi_pm_finish - Instruct the platform to leave a sleep state.
 161  *
 162  *      This is called after we wake back up (or if entering the sleep state
 163  *      failed).
 164  */
 165 static void acpi_pm_finish(void)
 166 {
 167         u32 acpi_state = acpi_target_sleep_state;
 168
 169         acpi_ec_unblock_transactions();
 170         suspend_nvs_free();
 171
 172         if (acpi_state == ACPI_STATE_S0)
 173                 return;
 174
 175         printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
 176                 acpi_state);
 177         acpi_disable_wakeup_devices(acpi_state);
 178         acpi_leave_sleep_state(acpi_state);
 179
 180         /* reset firmware waking vector */
 181         acpi_set_firmware_waking_vector((acpi_physical_address) 0);
 182
 183         acpi_target_sleep_state = ACPI_STATE_S0;
 184 }
 185
 186 /**
 187  *      acpi_pm_end - Finish up suspend sequence.
 188  */
 189 static void acpi_pm_end(void)
 190 {
 191         /*
 192          * This is necessary in case acpi_pm_finish() is not called during a
 193          * failing transition to a sleep state.
 194          */
 195         acpi_target_sleep_state = ACPI_STATE_S0;
 196         acpi_sleep_tts_switch(acpi_target_sleep_state);
 197 }
 198 #else /* !CONFIG_ACPI_SLEEP */
 199 #define acpi_target_sleep_state ACPI_STATE_S0
 200 #endif /* CONFIG_ACPI_SLEEP */
 201
 202 #ifdef CONFIG_SUSPEND
 203 static u32 acpi_suspend_states[] = {
 204         [PM_SUSPEND_ON] = ACPI_STATE_S0,
 205         [PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
 206         [PM_SUSPEND_MEM] = ACPI_STATE_S3,
 207         [PM_SUSPEND_MAX] = ACPI_STATE_S5
 208 };
 209
 210 /**
 211  *      acpi_suspend_begin - Set the target system sleep state to the state
 212  *              associated with given @pm_state, if supported.
 213  */
 214 static int acpi_suspend_begin(suspend_state_t pm_state)
 215 {
 216         u32 acpi_state = acpi_suspend_states[pm_state];
 217         int error = 0;
 218
 219         error = nvs_nosave ? 0 : suspend_nvs_alloc();
 220         if (error)
 221                 return error;
 222
 223         if (sleep_states[acpi_state]) {
 224                 acpi_target_sleep_state = acpi_state;
 225                 acpi_sleep_tts_switch(acpi_target_sleep_state);
 226         } else {
 227                 printk(KERN_ERR "ACPI does not support this state: %d\n",
 228                         pm_state);
 229                 error = -ENOSYS;
 230         }
 231         return error;
 232 }
 233
 234 /**
 235  *      acpi_suspend_enter - Actually enter a sleep state.
 236  *      @pm_state: ignored
 237  *
 238  *      Flush caches and go to sleep. For STR we have to call arch-specific
 239  *      assembly, which in turn call acpi_enter_sleep_state().
 240  *      It's unfortunate, but it works. Please fix if you're feeling frisky.
 241  */
 242 static int acpi_suspend_enter(suspend_state_t pm_state)
 243 {
 244         acpi_status status = AE_OK;
 245         u32 acpi_state = acpi_target_sleep_state;
 246         int error;
 247
 248         ACPI_FLUSH_CPU_CACHE();
 249
 250         switch (acpi_state) {
 251         case ACPI_STATE_S1:
 252                 barrier();
 253                 status = acpi_enter_sleep_state(acpi_state);
 254                 break;
 255
 256         case ACPI_STATE_S3:
 257                 error = acpi_suspend_lowlevel();
 258                 if (error)
 259                         return error;
 260                 pr_info(PREFIX "Low-level resume complete\n");
 261                 break;
 262         }
 263
 264         /* This violates the spec but is required for bug compatibility. */
 265         acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);
 266
 267         /* Reprogram control registers and execute _BFS */
 268         acpi_leave_sleep_state_prep(acpi_state);
 269
 270         /* ACPI 3.0 specs (P62) says that it's the responsibility
 271          * of the OSPM to clear the status bit [ implying that the
 272          * POWER_BUTTON event should not reach userspace ]
 273          */
 274         if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
 275                 acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
 276
 277         /*
 278          * Disable and clear GPE status before interrupt is enabled. Some GPEs
 279          * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
 280          * acpi_leave_sleep_state will reenable specific GPEs later
 281          */
 282         acpi_disable_all_gpes();
 283         /* Allow EC transactions to happen. */
 284         acpi_ec_unblock_transactions_early();
 285
 286         suspend_nvs_restore();
 287
 288         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
 289 }
 290
 291 static int acpi_suspend_state_valid(suspend_state_t pm_state)
 292 {
 293         u32 acpi_state;
 294
 295         switch (pm_state) {
 296         case PM_SUSPEND_ON:
 297         case PM_SUSPEND_STANDBY:
 298         case PM_SUSPEND_MEM:
 299                 acpi_state = acpi_suspend_states[pm_state];
 300
 301                 return sleep_states[acpi_state];
 302         default:
 303                 return 0;
 304         }
 305 }
 306
 307 static const struct platform_suspend_ops acpi_suspend_ops = {
 308         .valid = acpi_suspend_state_valid,
 309         .begin = acpi_suspend_begin,
 310         .prepare_late = acpi_pm_prepare,
 311         .enter = acpi_suspend_enter,
 312         .wake = acpi_pm_finish,
 313         .end = acpi_pm_end,
 314 };
 315
 316 /**
 317  *      acpi_suspend_begin_old - Set the target system sleep state to the
 318  *              state associated with given @pm_state, if supported, and
 319  *              execute the _PTS control method.  This function is used if the
 320  *              pre-ACPI 2.0 suspend ordering has been requested.
 321  */
 322 static int acpi_suspend_begin_old(suspend_state_t pm_state)
 323 {
 324         int error = acpi_suspend_begin(pm_state);
 325         if (!error)
 326                 error = __acpi_pm_prepare();
 327
 328         return error;
 329 }
 330
 331 /*
 332  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
 333  * been requested.
 334  */
 335 static const struct platform_suspend_ops acpi_suspend_ops_old = {
 336         .valid = acpi_suspend_state_valid,
 337         .begin = acpi_suspend_begin_old,
 338         .prepare_late = acpi_pm_pre_suspend,
 339         .enter = acpi_suspend_enter,
 340         .wake = acpi_pm_finish,
 341         .end = acpi_pm_end,
 342         .recover = acpi_pm_finish,
 343 };
 344
 345 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
 346 {
 347         old_suspend_ordering = true;
 348         return 0;
 349 }
 350
 351 static int __init init_nvs_nosave(const struct dmi_system_id *d)
 352 {
 353         acpi_nvs_nosave();
 354         return 0;
 355 }
 356
 357 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
 358         {
 359         .callback = init_old_suspend_ordering,
 360         .ident = "Abit KN9 (nForce4 variant)",
 361         .matches = {
 362                 DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
 363                 DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
 364                 },
 365         },
 366         {
 367         .callback = init_old_suspend_ordering,
 368         .ident = "HP xw4600 Workstation",
 369         .matches = {
 370                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 371                 DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
 372                 },
 373         },
 374         {
 375         .callback = init_old_suspend_ordering,
 376         .ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
 377         .matches = {
 378                 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTek Computer INC."),
 379                 DMI_MATCH(DMI_BOARD_NAME, "M2N8L"),
 380                 },
 381         },
 382         {
 383         .callback = init_old_suspend_ordering,
 384         .ident = "Panasonic CF51-2L",
 385         .matches = {
 386                 DMI_MATCH(DMI_BOARD_VENDOR,
 387                                 "Matsushita Electric Industrial Co.,Ltd."),
 388                 DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
 389                 },
 390         },
 391         {
 392         .callback = init_nvs_nosave,
 393         .ident = "Sony Vaio VGN-SR11M",
 394         .matches = {
 395                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 396                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR11M"),
 397                 },
 398         },
 399         {
 400         .callback = init_nvs_nosave,
 401         .ident = "Everex StepNote Series",
 402         .matches = {
 403                 DMI_MATCH(DMI_SYS_VENDOR, "Everex Systems, Inc."),
 404                 DMI_MATCH(DMI_PRODUCT_NAME, "Everex StepNote Series"),
 405                 },
 406         },
 407         {
 408         .callback = init_nvs_nosave,
 409         .ident = "Sony Vaio VPCEB1Z1E",
 410         .matches = {
 411                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 412                 DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB1Z1E"),
 413                 },
 414         },
 415         {
 416         .callback = init_nvs_nosave,
 417         .ident = "Sony Vaio VGN-NW130D",
 418         .matches = {
 419                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 420                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-NW130D"),
 421                 },
 422         },
 423         {
 424         .callback = init_nvs_nosave,
 425         .ident = "Sony Vaio VPCCW29FX",
 426         .matches = {
 427                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 428                 DMI_MATCH(DMI_PRODUCT_NAME, "VPCCW29FX"),
 429                 },
 430         },
 431         {
 432         .callback = init_nvs_nosave,
 433         .ident = "Averatec AV1020-ED2",
 434         .matches = {
 435                 DMI_MATCH(DMI_SYS_VENDOR, "AVERATEC"),
 436                 DMI_MATCH(DMI_PRODUCT_NAME, "1000 Series"),
 437                 },
 438         },
 439         {
 440         .callback = init_nvs_nosave,
 441         .ident = "Asus K54C",
 442         .matches = {
 443                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 444                 DMI_MATCH(DMI_PRODUCT_NAME, "K54C"),
 445                 },
 446         },
 447         {
 448         .callback = init_nvs_nosave,
 449         .ident = "Asus K54HR",
 450         .matches = {
 451                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 452                 DMI_MATCH(DMI_PRODUCT_NAME, "K54HR"),
 453                 },
 454         },
 455         {},
 456 };
 457 #endif /* CONFIG_SUSPEND */
 458
 459 #ifdef CONFIG_HIBERNATION
 460 static unsigned long s4_hardware_signature;
 461 static struct acpi_table_facs *facs;
 462 static bool nosigcheck;
 463
 464 void __init acpi_no_s4_hw_signature(void)
 465 {
 466         nosigcheck = true;
 467 }
 468
 469 static int acpi_hibernation_begin(void)
 470 {
 471         int error;
 472
 473         error = nvs_nosave ? 0 : suspend_nvs_alloc();
 474         if (!error) {
 475                 acpi_target_sleep_state = ACPI_STATE_S4;
 476                 acpi_sleep_tts_switch(acpi_target_sleep_state);
 477         }
 478
 479         return error;
 480 }
 481
 482 static int acpi_hibernation_enter(void)
 483 {
 484         acpi_status status = AE_OK;
 485
 486         ACPI_FLUSH_CPU_CACHE();
 487
 488         /* This shouldn't return.  If it returns, we have a problem */
 489         status = acpi_enter_sleep_state(ACPI_STATE_S4);
 490         /* Reprogram control registers and execute _BFS */
 491         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
 492
 493         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
 494 }
 495
 496 static void acpi_hibernation_leave(void)
 497 {
 498         /*
 499          * If ACPI is not enabled by the BIOS and the boot kernel, we need to
 500          * enable it here.
 501          */
 502         acpi_enable();
 503         /* Reprogram control registers and execute _BFS */
 504         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
 505         /* Check the hardware signature */
 506         if (facs && s4_hardware_signature != facs->hardware_signature) {
 507                 printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
 508                         "cannot resume!\n");
 509                 panic("ACPI S4 hardware signature mismatch");
 510         }
 511         /* Restore the NVS memory area */
 512         suspend_nvs_restore();
 513         /* Allow EC transactions to happen. */
 514         acpi_ec_unblock_transactions_early();
 515 }
 516
 517 static void acpi_pm_thaw(void)
 518 {
 519         acpi_ec_unblock_transactions();
 520         acpi_enable_all_runtime_gpes();
 521 }
 522
 523 static const struct platform_hibernation_ops acpi_hibernation_ops = {
 524         .begin = acpi_hibernation_begin,
 525         .end = acpi_pm_end,
 526         .pre_snapshot = acpi_pm_prepare,
 527         .finish = acpi_pm_finish,
 528         .prepare = acpi_pm_prepare,
 529         .enter = acpi_hibernation_enter,
 530         .leave = acpi_hibernation_leave,
 531         .pre_restore = acpi_pm_freeze,
 532         .restore_cleanup = acpi_pm_thaw,
 533 };
 534
 535 /**
 536  *      acpi_hibernation_begin_old - Set the target system sleep state to
 537  *              ACPI_STATE_S4 and execute the _PTS control method.  This
 538  *              function is used if the pre-ACPI 2.0 suspend ordering has been
 539  *              requested.
 540  */
 541 static int acpi_hibernation_begin_old(void)
 542 {
 543         int error;
 544         /*
 545          * The _TTS object should always be evaluated before the _PTS object.
 546          * When the old_suspended_ordering is true, the _PTS object is
 547          * evaluated in the acpi_sleep_prepare.
 548          */
 549         acpi_sleep_tts_switch(ACPI_STATE_S4);
 550
 551         error = acpi_sleep_prepare(ACPI_STATE_S4);
 552
 553         if (!error) {
 554                 if (!nvs_nosave)
 555                         error = suspend_nvs_alloc();
 556                 if (!error)
 557                         acpi_target_sleep_state = ACPI_STATE_S4;
 558         }
 559         return error;
 560 }
 561
 562 /*
 563  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
 564  * been requested.
 565  */
 566 static const struct platform_hibernation_ops acpi_hibernation_ops_old = {
 567         .begin = acpi_hibernation_begin_old,
 568         .end = acpi_pm_end,
 569         .pre_snapshot = acpi_pm_pre_suspend,
 570         .prepare = acpi_pm_freeze,
 571         .finish = acpi_pm_finish,
 572         .enter = acpi_hibernation_enter,
 573         .leave = acpi_hibernation_leave,
 574         .pre_restore = acpi_pm_freeze,
 575         .restore_cleanup = acpi_pm_thaw,
 576         .recover = acpi_pm_finish,
 577 };
 578 #endif /* CONFIG_HIBERNATION */
 579
 580 int acpi_suspend(u32 acpi_state)
 581 {
 582         suspend_state_t states[] = {
 583                 [1] = PM_SUSPEND_STANDBY,
 584                 [3] = PM_SUSPEND_MEM,
 585                 [5] = PM_SUSPEND_MAX
 586         };
 587
 588         if (acpi_state < 6 && states[acpi_state])
 589                 return pm_suspend(states[acpi_state]);
 590         if (acpi_state == 4)
 591                 return hibernate();
 592         return -EINVAL;
 593 }
 594
 595 #ifdef CONFIG_PM
 596 /**
 597  *      acpi_pm_device_sleep_state - return preferred power state of ACPI device
 598  *              in the system sleep state given by %acpi_target_sleep_state
 599  *      @dev: device to examine; its driver model wakeup flags control
 600  *              whether it should be able to wake up the system
 601  *      @d_min_p: used to store the upper limit of allowed states range
 602  *      Return value: preferred power state of the device on success, -ENODEV on
 603  *              failure (ie. if there's no 'struct acpi_device' for @dev)
 604  *
 605  *      Find the lowest power (highest number) ACPI device power state that
 606  *      device @dev can be in while the system is in the sleep state represented
 607  *      by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
 608  *      able to wake up the system from this sleep state.  If @d_min_p is set,
 609  *      the highest power (lowest number) device power state of @dev allowed
 610  *      in this system sleep state is stored at the location pointed to by it.
 611  *
 612  *      The caller must ensure that @dev is valid before using this function.
 613  *      The caller is also responsible for figuring out if the device is
 614  *      supposed to be able to wake up the system and passing this information
 615  *      via @wake.
 616  */
 617
 618 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
 619 {
 620         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 621         struct acpi_device *adev;
 622         char acpi_method[] = "_SxD";
 623         unsigned long long d_min, d_max;
 624
 625         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
 626                 printk(KERN_DEBUG "ACPI handle has no context!\n");
 627                 return -ENODEV;
 628         }
 629
 630         acpi_method[2] = '0' + acpi_target_sleep_state;
 631         /*
 632          * If the sleep state is S0, we will return D3, but if the device has
 633          * _S0W, we will use the value from _S0W
 634          */
 635         d_min = ACPI_STATE_D0;
 636         d_max = ACPI_STATE_D3;
 637
 638         /*
 639          * If present, _SxD methods return the minimum D-state (highest power
 640          * state) we can use for the corresponding S-states.  Otherwise, the
 641          * minimum D-state is D0 (ACPI 3.x).
 642          *
 643          * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
 644          * provided -- that's our fault recovery, we ignore retval.
 645          */
 646         if (acpi_target_sleep_state > ACPI_STATE_S0)
 647                 acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
 648
 649         /*
 650          * If _PRW says we can wake up the system from the target sleep state,
 651          * the D-state returned by _SxD is sufficient for that (we assume a
 652          * wakeup-aware driver if wake is set).  Still, if _SxW exists
 653          * (ACPI 3.x), it should return the maximum (lowest power) D-state that
 654          * can wake the system.  _S0W may be valid, too.
 655          */
 656         if (acpi_target_sleep_state == ACPI_STATE_S0 ||
 657             (device_may_wakeup(dev) &&
 658              adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
 659                 acpi_status status;
 660
 661                 acpi_method[3] = 'W';
 662                 status = acpi_evaluate_integer(handle, acpi_method, NULL,
 663                                                 &d_max);
 664                 if (ACPI_FAILURE(status)) {
 665                         if (acpi_target_sleep_state != ACPI_STATE_S0 ||
 666                             status != AE_NOT_FOUND)
 667                                 d_max = d_min;
 668                 } else if (d_max < d_min) {
 669                         /* Warn the user of the broken DSDT */
 670                         printk(KERN_WARNING "ACPI: Wrong value from %s\n",
 671                                 acpi_method);
 672                         /* Sanitize it */
 673                         d_min = d_max;
 674                 }
 675         }
 676
 677         if (d_min_p)
 678                 *d_min_p = d_min;
 679         return d_max;
 680 }
 681 #endif /* CONFIG_PM */
 682
 683 #ifdef CONFIG_PM_SLEEP
 684 /**
 685  *      acpi_pm_device_sleep_wake - enable or disable the system wake-up
 686  *                                  capability of given device
 687  *      @dev: device to handle
 688  *      @enable: 'true' - enable, 'false' - disable the wake-up capability
 689  */
 690 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
 691 {
 692         acpi_handle handle;
 693         struct acpi_device *adev;
 694         int error;
 695
 696         if (!device_can_wakeup(dev))
 697                 return -EINVAL;
 698
 699         handle = DEVICE_ACPI_HANDLE(dev);
 700         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
 701                 dev_dbg(dev, "ACPI handle has no context in %s!\n", __func__);
 702                 return -ENODEV;
 703         }
 704
 705         error = enable ?
 706                 acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
 707                 acpi_disable_wakeup_device_power(adev);
 708         if (!error)
 709                 dev_info(dev, "wake-up capability %s by ACPI\n",
 710                                 enable ? "enabled" : "disabled");
 711
 712         return error;
 713 }
 714 #endif  /* CONFIG_PM_SLEEP */
 715
 716 static void acpi_power_off_prepare(void)
 717 {
 718         /* Prepare to power off the system */
 719         acpi_sleep_prepare(ACPI_STATE_S5);
 720         acpi_disable_all_gpes();
 721 }
 722
 723 static void acpi_power_off(void)
 724 {
 725         /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
 726         printk(KERN_DEBUG "%s called\n", __func__);
 727         local_irq_disable();
 728         acpi_enter_sleep_state(ACPI_STATE_S5);
 729 }
 730
 731 /*
 732  * ACPI 2.0 created the optional _GTS and _BFS,
 733  * but industry adoption has been neither rapid nor broad.
 734  *
 735  * Linux gets into trouble when it executes poorly validated
 736  * paths through the BIOS, so disable _GTS and _BFS by default,
 737  * but do speak up and offer the option to enable them.
 738  */
 739 static void __init acpi_gts_bfs_check(void)
 740 {
 741         acpi_handle dummy;
 742
 743         if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__GTS, &dummy)))
 744         {
 745                 printk(KERN_NOTICE PREFIX "BIOS offers _GTS\n");
 746                 printk(KERN_NOTICE PREFIX "If \"acpi.gts=1\" improves suspend, "
 747                         "please notify linux-acpi@vger.kernel.org\n");
 748         }
 749         if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__BFS, &dummy)))
 750         {
 751                 printk(KERN_NOTICE PREFIX "BIOS offers _BFS\n");
 752                 printk(KERN_NOTICE PREFIX "If \"acpi.bfs=1\" improves resume, "
 753                         "please notify linux-acpi@vger.kernel.org\n");
 754         }
 755 }
 756
 757 int __init acpi_sleep_init(void)
 758 {
 759         acpi_status status;
 760         u8 type_a, type_b;
 761 #ifdef CONFIG_SUSPEND
 762         int i = 0;
 763
 764         dmi_check_system(acpisleep_dmi_table);
 765 #endif
 766
 767         if (acpi_disabled)
 768                 return 0;
 769
 770         sleep_states[ACPI_STATE_S0] = 1;
 771         printk(KERN_INFO PREFIX "(supports S0");
 772
 773 #ifdef CONFIG_SUSPEND
 774         for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
 775                 status = acpi_get_sleep_type_data(i, &type_a, &type_b);
 776                 if (ACPI_SUCCESS(status)) {
 777                         sleep_states[i] = 1;
 778                         printk(" S%d", i);
 779                 }
 780         }
 781
 782         suspend_set_ops(old_suspend_ordering ?
 783                 &acpi_suspend_ops_old : &acpi_suspend_ops);
 784 #endif
 785
 786 #ifdef CONFIG_HIBERNATION
 787         status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
 788         if (ACPI_SUCCESS(status)) {
 789                 hibernation_set_ops(old_suspend_ordering ?
 790                         &acpi_hibernation_ops_old : &acpi_hibernation_ops);
 791                 sleep_states[ACPI_STATE_S4] = 1;
 792                 printk(" S4");
 793                 if (!nosigcheck) {
 794                         acpi_get_table(ACPI_SIG_FACS, 1,
 795                                 (struct acpi_table_header **)&facs);
 796                         if (facs)
 797                                 s4_hardware_signature =
 798                                         facs->hardware_signature;
 799                 }
 800         }
 801 #endif
 802         status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
 803         if (ACPI_SUCCESS(status)) {
 804                 sleep_states[ACPI_STATE_S5] = 1;
 805                 printk(" S5");
 806                 pm_power_off_prepare = acpi_power_off_prepare;
 807                 pm_power_off = acpi_power_off;
 808         }
 809         printk(")\n");
 810         /*
 811          * Register the tts_notifier to reboot notifier list so that the _TTS
 812          * object can also be evaluated when the system enters S5.
 813          */
 814         register_reboot_notifier(&tts_notifier);
 815         acpi_gts_bfs_check();
 816         return 0;
 817 }