drivers/acpi/bus.c

   1 /*
   2  *  acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   5  *
   6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or (at
  11  *  your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful, but
  14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *  General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License along
  19  *  with this program; if not, write to the Free Software Foundation, Inc.,
  20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  21  *
  22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/ioport.h>
  28 #include <linux/kernel.h>
  29 #include <linux/list.h>
  30 #include <linux/sched.h>
  31 #include <linux/pm.h>
  32 #include <linux/device.h>
  33 #include <linux/proc_fs.h>
  34 #include <linux/acpi.h>
  35 #include <linux/slab.h>
  36 #include <linux/regulator/machine.h>
  37 #ifdef CONFIG_X86
  38 #include <asm/mpspec.h>
  39 #endif
  40 #include <linux/pci.h>
  41 #include <acpi/apei.h>
  42 #include <linux/dmi.h>
  43 #include <linux/suspend.h>
  44
  45 #include "internal.h"
  46
  47 #define _COMPONENT              ACPI_BUS_COMPONENT
  48 ACPI_MODULE_NAME("bus");
  49
  50 struct acpi_device *acpi_root;
  51 struct proc_dir_entry *acpi_root_dir;
  52 EXPORT_SYMBOL(acpi_root_dir);
  53
  54 #ifdef CONFIG_X86
  55 #ifdef CONFIG_ACPI_CUSTOM_DSDT
  56 static inline int set_copy_dsdt(const struct dmi_system_id *id)
  57 {
  58         return 0;
  59 }
  60 #else
  61 static int set_copy_dsdt(const struct dmi_system_id *id)
  62 {
  63         printk(KERN_NOTICE "%s detected - "
  64                 "force copy of DSDT to local memory\n", id->ident);
  65         acpi_gbl_copy_dsdt_locally = 1;
  66         return 0;
  67 }
  68 #endif
  69
  70 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
  71         /*
  72          * Invoke DSDT corruption work-around on all Toshiba Satellite.
  73          * https://bugzilla.kernel.org/show_bug.cgi?id=14679
  74          */
  75         {
  76          .callback = set_copy_dsdt,
  77          .ident = "TOSHIBA Satellite",
  78          .matches = {
  79                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
  80                 DMI_MATCH(DMI_PRODUCT_NAME, "Satellite"),
  81                 },
  82         },
  83         {}
  84 };
  85 #else
  86 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
  87         {}
  88 };
  89 #endif
  90
  91 /* --------------------------------------------------------------------------
  92                                 Device Management
  93    -------------------------------------------------------------------------- */
  94
  95 acpi_status acpi_bus_get_status_handle(acpi_handle handle,
  96                                        unsigned long long *sta)
  97 {
  98         acpi_status status;
  99
 100         status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
 101         if (ACPI_SUCCESS(status))
 102                 return AE_OK;
 103
 104         if (status == AE_NOT_FOUND) {
 105                 *sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
 106                        ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
 107                 return AE_OK;
 108         }
 109         return status;
 110 }
 111
 112 int acpi_bus_get_status(struct acpi_device *device)
 113 {
 114         acpi_status status;
 115         unsigned long long sta;
 116
 117         status = acpi_bus_get_status_handle(device->handle, &sta);
 118         if (ACPI_FAILURE(status))
 119                 return -ENODEV;
 120
 121         acpi_set_device_status(device, sta);
 122
 123         if (device->status.functional && !device->status.present) {
 124                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
 125                        "functional but not present;\n",
 126                         device->pnp.bus_id, (u32)sta));
 127         }
 128
 129         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
 130                           device->pnp.bus_id, (u32)sta));
 131         return 0;
 132 }
 133 EXPORT_SYMBOL(acpi_bus_get_status);
 134
 135 void acpi_bus_private_data_handler(acpi_handle handle,
 136                                    void *context)
 137 {
 138         return;
 139 }
 140 EXPORT_SYMBOL(acpi_bus_private_data_handler);
 141
 142 int acpi_bus_get_private_data(acpi_handle handle, void **data)
 143 {
 144         acpi_status status;
 145
 146         if (!*data)
 147                 return -EINVAL;
 148
 149         status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
 150         if (ACPI_FAILURE(status) || !*data) {
 151                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
 152                                 handle));
 153                 return -ENODEV;
 154         }
 155
 156         return 0;
 157 }
 158 EXPORT_SYMBOL(acpi_bus_get_private_data);
 159
 160 void acpi_bus_no_hotplug(acpi_handle handle)
 161 {
 162         struct acpi_device *adev = NULL;
 163
 164         acpi_bus_get_device(handle, &adev);
 165         if (adev)
 166                 adev->flags.no_hotplug = true;
 167 }
 168 EXPORT_SYMBOL_GPL(acpi_bus_no_hotplug);
 169
 170 static void acpi_print_osc_error(acpi_handle handle,
 171         struct acpi_osc_context *context, char *error)
 172 {
 173         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
 174         int i;
 175
 176         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer)))
 177                 printk(KERN_DEBUG "%s\n", error);
 178         else {
 179                 printk(KERN_DEBUG "%s:%s\n", (char *)buffer.pointer, error);
 180                 kfree(buffer.pointer);
 181         }
 182         printk(KERN_DEBUG"_OSC request data:");
 183         for (i = 0; i < context->cap.length; i += sizeof(u32))
 184                 printk("%x ", *((u32 *)(context->cap.pointer + i)));
 185         printk("\n");
 186 }
 187
 188 acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
 189 {
 190         int i;
 191         static int opc_map_to_uuid[16] = {6, 4, 2, 0, 11, 9, 16, 14, 19, 21,
 192                 24, 26, 28, 30, 32, 34};
 193
 194         if (strlen(str) != 36)
 195                 return AE_BAD_PARAMETER;
 196         for (i = 0; i < 36; i++) {
 197                 if (i == 8 || i == 13 || i == 18 || i == 23) {
 198                         if (str[i] != '-')
 199                                 return AE_BAD_PARAMETER;
 200                 } else if (!isxdigit(str[i]))
 201                         return AE_BAD_PARAMETER;
 202         }
 203         for (i = 0; i < 16; i++) {
 204                 uuid[i] = hex_to_bin(str[opc_map_to_uuid[i]]) << 4;
 205                 uuid[i] |= hex_to_bin(str[opc_map_to_uuid[i] + 1]);
 206         }
 207         return AE_OK;
 208 }
 209 EXPORT_SYMBOL_GPL(acpi_str_to_uuid);
 210
 211 acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
 212 {
 213         acpi_status status;
 214         struct acpi_object_list input;
 215         union acpi_object in_params[4];
 216         union acpi_object *out_obj;
 217         u8 uuid[16];
 218         u32 errors;
 219         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
 220
 221         if (!context)
 222                 return AE_ERROR;
 223         if (ACPI_FAILURE(acpi_str_to_uuid(context->uuid_str, uuid)))
 224                 return AE_ERROR;
 225         context->ret.length = ACPI_ALLOCATE_BUFFER;
 226         context->ret.pointer = NULL;
 227
 228         /* Setting up input parameters */
 229         input.count = 4;
 230         input.pointer = in_params;
 231         in_params[0].type               = ACPI_TYPE_BUFFER;
 232         in_params[0].buffer.length      = 16;
 233         in_params[0].buffer.pointer     = uuid;
 234         in_params[1].type               = ACPI_TYPE_INTEGER;
 235         in_params[1].integer.value      = context->rev;
 236         in_params[2].type               = ACPI_TYPE_INTEGER;
 237         in_params[2].integer.value      = context->cap.length/sizeof(u32);
 238         in_params[3].type               = ACPI_TYPE_BUFFER;
 239         in_params[3].buffer.length      = context->cap.length;
 240         in_params[3].buffer.pointer     = context->cap.pointer;
 241
 242         status = acpi_evaluate_object(handle, "_OSC", &input, &output);
 243         if (ACPI_FAILURE(status))
 244                 return status;
 245
 246         if (!output.length)
 247                 return AE_NULL_OBJECT;
 248
 249         out_obj = output.pointer;
 250         if (out_obj->type != ACPI_TYPE_BUFFER
 251                 || out_obj->buffer.length != context->cap.length) {
 252                 acpi_print_osc_error(handle, context,
 253                         "_OSC evaluation returned wrong type");
 254                 status = AE_TYPE;
 255                 goto out_kfree;
 256         }
 257         /* Need to ignore the bit0 in result code */
 258         errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
 259         if (errors) {
 260                 if (errors & OSC_REQUEST_ERROR)
 261                         acpi_print_osc_error(handle, context,
 262                                 "_OSC request failed");
 263                 if (errors & OSC_INVALID_UUID_ERROR)
 264                         acpi_print_osc_error(handle, context,
 265                                 "_OSC invalid UUID");
 266                 if (errors & OSC_INVALID_REVISION_ERROR)
 267                         acpi_print_osc_error(handle, context,
 268                                 "_OSC invalid revision");
 269                 if (errors & OSC_CAPABILITIES_MASK_ERROR) {
 270                         if (((u32 *)context->cap.pointer)[OSC_QUERY_DWORD]
 271                             & OSC_QUERY_ENABLE)
 272                                 goto out_success;
 273                         status = AE_SUPPORT;
 274                         goto out_kfree;
 275                 }
 276                 status = AE_ERROR;
 277                 goto out_kfree;
 278         }
 279 out_success:
 280         context->ret.length = out_obj->buffer.length;
 281         context->ret.pointer = kmemdup(out_obj->buffer.pointer,
 282                                        context->ret.length, GFP_KERNEL);
 283         if (!context->ret.pointer) {
 284                 status =  AE_NO_MEMORY;
 285                 goto out_kfree;
 286         }
 287         status =  AE_OK;
 288
 289 out_kfree:
 290         kfree(output.pointer);
 291         if (status != AE_OK)
 292                 context->ret.pointer = NULL;
 293         return status;
 294 }
 295 EXPORT_SYMBOL(acpi_run_osc);
 296
 297 bool osc_sb_apei_support_acked;
 298 static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
 299 static void acpi_bus_osc_support(void)
 300 {
 301         u32 capbuf[2];
 302         struct acpi_osc_context context = {
 303                 .uuid_str = sb_uuid_str,
 304                 .rev = 1,
 305                 .cap.length = 8,
 306                 .cap.pointer = capbuf,
 307         };
 308         acpi_handle handle;
 309
 310         capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
 311         capbuf[OSC_SUPPORT_DWORD] = OSC_SB_PR3_SUPPORT; /* _PR3 is in use */
 312 #if defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR) ||\
 313                         defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR_MODULE)
 314         capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PAD_SUPPORT;
 315 #endif
 316
 317 #if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
 318         capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PPC_OST_SUPPORT;
 319 #endif
 320
 321 #ifdef ACPI_HOTPLUG_OST
 322         capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT;
 323 #endif
 324
 325         if (!ghes_disable)
 326                 capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT;
 327         if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
 328                 return;
 329         if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) {
 330                 u32 *capbuf_ret = context.ret.pointer;
 331                 if (context.ret.length > OSC_SUPPORT_DWORD)
 332                         osc_sb_apei_support_acked =
 333                                 capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
 334                 kfree(context.ret.pointer);
 335         }
 336         /* do we need to check other returned cap? Sounds no */
 337 }
 338
 339 /* --------------------------------------------------------------------------
 340                              Notification Handling
 341    -------------------------------------------------------------------------- */
 342
 343 /**
 344  * acpi_bus_notify
 345  * ---------------
 346  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
 347  */
 348 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
 349 {
 350         struct acpi_device *device = NULL;
 351         struct acpi_driver *driver;
 352
 353         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Notification %#02x to handle %p\n",
 354                           type, handle));
 355
 356         switch (type) {
 357
 358         case ACPI_NOTIFY_BUS_CHECK:
 359                 /* TBD */
 360                 break;
 361
 362         case ACPI_NOTIFY_DEVICE_CHECK:
 363                 /* TBD */
 364                 break;
 365
 366         case ACPI_NOTIFY_DEVICE_WAKE:
 367                 /* TBD */
 368                 break;
 369
 370         case ACPI_NOTIFY_EJECT_REQUEST:
 371                 /* TBD */
 372                 break;
 373
 374         case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
 375                 /* TBD: Exactly what does 'light' mean? */
 376                 break;
 377
 378         case ACPI_NOTIFY_FREQUENCY_MISMATCH:
 379                 /* TBD */
 380                 break;
 381
 382         case ACPI_NOTIFY_BUS_MODE_MISMATCH:
 383                 /* TBD */
 384                 break;
 385
 386         case ACPI_NOTIFY_POWER_FAULT:
 387                 /* TBD */
 388                 break;
 389
 390         default:
 391                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 392                                   "Received unknown/unsupported notification [%08x]\n",
 393                                   type));
 394                 break;
 395         }
 396
 397         acpi_bus_get_device(handle, &device);
 398         if (device) {
 399                 driver = device->driver;
 400                 if (driver && driver->ops.notify &&
 401                     (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
 402                         driver->ops.notify(device, type);
 403         }
 404 }
 405
 406 /* --------------------------------------------------------------------------
 407                              Initialization/Cleanup
 408    -------------------------------------------------------------------------- */
 409
 410 static int __init acpi_bus_init_irq(void)
 411 {
 412         acpi_status status;
 413         char *message = NULL;
 414
 415
 416         /*
 417          * Let the system know what interrupt model we are using by
 418          * evaluating the \_PIC object, if exists.
 419          */
 420
 421         switch (acpi_irq_model) {
 422         case ACPI_IRQ_MODEL_PIC:
 423                 message = "PIC";
 424                 break;
 425         case ACPI_IRQ_MODEL_IOAPIC:
 426                 message = "IOAPIC";
 427                 break;
 428         case ACPI_IRQ_MODEL_IOSAPIC:
 429                 message = "IOSAPIC";
 430                 break;
 431         case ACPI_IRQ_MODEL_PLATFORM:
 432                 message = "platform specific model";
 433                 break;
 434         default:
 435                 printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
 436                 return -ENODEV;
 437         }
 438
 439         printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
 440
 441         status = acpi_execute_simple_method(NULL, "\\_PIC", acpi_irq_model);
 442         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 443                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
 444                 return -ENODEV;
 445         }
 446
 447         return 0;
 448 }
 449
 450 u8 acpi_gbl_permanent_mmap;
 451
 452
 453 void __init acpi_early_init(void)
 454 {
 455         acpi_status status;
 456
 457         if (acpi_disabled)
 458                 return;
 459
 460         printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
 461
 462         /* enable workarounds, unless strict ACPI spec. compliance */
 463         if (!acpi_strict)
 464                 acpi_gbl_enable_interpreter_slack = TRUE;
 465
 466         acpi_gbl_permanent_mmap = 1;
 467
 468         /*
 469          * If the machine falls into the DMI check table,
 470          * DSDT will be copied to memory
 471          */
 472         dmi_check_system(dsdt_dmi_table);
 473
 474         status = acpi_reallocate_root_table();
 475         if (ACPI_FAILURE(status)) {
 476                 printk(KERN_ERR PREFIX
 477                        "Unable to reallocate ACPI tables\n");
 478                 goto error0;
 479         }
 480
 481         status = acpi_initialize_subsystem();
 482         if (ACPI_FAILURE(status)) {
 483                 printk(KERN_ERR PREFIX
 484                        "Unable to initialize the ACPI Interpreter\n");
 485                 goto error0;
 486         }
 487
 488         status = acpi_load_tables();
 489         if (ACPI_FAILURE(status)) {
 490                 printk(KERN_ERR PREFIX
 491                        "Unable to load the System Description Tables\n");
 492                 goto error0;
 493         }
 494
 495 #ifdef CONFIG_X86
 496         if (!acpi_ioapic) {
 497                 /* compatible (0) means level (3) */
 498                 if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
 499                         acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
 500                         acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
 501                 }
 502                 /* Set PIC-mode SCI trigger type */
 503                 acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
 504                                          (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
 505         } else {
 506                 /*
 507                  * now that acpi_gbl_FADT is initialized,
 508                  * update it with result from INT_SRC_OVR parsing
 509                  */
 510                 acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
 511         }
 512 #endif
 513
 514         status = acpi_enable_subsystem(~ACPI_NO_ACPI_ENABLE);
 515         if (ACPI_FAILURE(status)) {
 516                 printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
 517                 goto error0;
 518         }
 519
 520         /*
 521          * If the system is using ACPI then we can be reasonably
 522          * confident that any regulators are managed by the firmware
 523          * so tell the regulator core it has everything it needs to
 524          * know.
 525          */
 526         regulator_has_full_constraints();
 527
 528         return;
 529
 530       error0:
 531         disable_acpi();
 532         return;
 533 }
 534
 535 static int __init acpi_bus_init(void)
 536 {
 537         int result;
 538         acpi_status status;
 539
 540         acpi_os_initialize1();
 541
 542         status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);
 543         if (ACPI_FAILURE(status)) {
 544                 printk(KERN_ERR PREFIX
 545                        "Unable to start the ACPI Interpreter\n");
 546                 goto error1;
 547         }
 548
 549         /*
 550          * ACPI 2.0 requires the EC driver to be loaded and work before
 551          * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
 552          * is called).
 553          *
 554          * This is accomplished by looking for the ECDT table, and getting
 555          * the EC parameters out of that.
 556          */
 557         status = acpi_ec_ecdt_probe();
 558         /* Ignore result. Not having an ECDT is not fatal. */
 559
 560         status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
 561         if (ACPI_FAILURE(status)) {
 562                 printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
 563                 goto error1;
 564         }
 565
 566         /*
 567          * _OSC method may exist in module level code,
 568          * so it must be run after ACPI_FULL_INITIALIZATION
 569          */
 570         acpi_bus_osc_support();
 571
 572         /*
 573          * _PDC control method may load dynamic SSDT tables,
 574          * and we need to install the table handler before that.
 575          */
 576         acpi_sysfs_init();
 577
 578         acpi_early_processor_set_pdc();
 579
 580         /*
 581          * Maybe EC region is required at bus_scan/acpi_get_devices. So it
 582          * is necessary to enable it as early as possible.
 583          */
 584         acpi_boot_ec_enable();
 585
 586         printk(KERN_INFO PREFIX "Interpreter enabled\n");
 587
 588         /* Initialize sleep structures */
 589         acpi_sleep_init();
 590
 591         /*
 592          * Get the system interrupt model and evaluate \_PIC.
 593          */
 594         result = acpi_bus_init_irq();
 595         if (result)
 596                 goto error1;
 597
 598         /*
 599          * Register the for all standard device notifications.
 600          */
 601         status =
 602             acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
 603                                         &acpi_bus_notify, NULL);
 604         if (ACPI_FAILURE(status)) {
 605                 printk(KERN_ERR PREFIX
 606                        "Unable to register for device notifications\n");
 607                 goto error1;
 608         }
 609
 610         /*
 611          * Create the top ACPI proc directory
 612          */
 613         acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
 614
 615         return 0;
 616
 617         /* Mimic structured exception handling */
 618       error1:
 619         acpi_terminate();
 620         return -ENODEV;
 621 }
 622
 623 struct kobject *acpi_kobj;
 624 EXPORT_SYMBOL_GPL(acpi_kobj);
 625
 626 static int __init acpi_init(void)
 627 {
 628         int result;
 629
 630         if (acpi_disabled) {
 631                 printk(KERN_INFO PREFIX "Interpreter disabled.\n");
 632                 return -ENODEV;
 633         }
 634
 635         acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
 636         if (!acpi_kobj) {
 637                 printk(KERN_WARNING "%s: kset create error\n", __func__);
 638                 acpi_kobj = NULL;
 639         }
 640
 641         init_acpi_device_notify();
 642         result = acpi_bus_init();
 643         if (result) {
 644                 disable_acpi();
 645                 return result;
 646         }
 647
 648         pci_mmcfg_late_init();
 649         acpi_scan_init();
 650         acpi_ec_init();
 651         acpi_debugfs_init();
 652         acpi_sleep_proc_init();
 653         acpi_wakeup_device_init();
 654         return 0;
 655 }
 656
 657 subsys_initcall(acpi_init);