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