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