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 #ifdef CONFIG_X86
  37 #include <asm/mpspec.h>
  38 #endif
  39 #include <linux/pci.h>
  40 #include <acpi/acpi_bus.h>
  41 #include <acpi/acpi_drivers.h>
  42 #include <acpi/apei.h>
  43 #include <linux/dmi.h>
  44 #include <linux/suspend.h>
  45
  46 #include "internal.h"
  47
  48 #define _COMPONENT              ACPI_BUS_COMPONENT
  49 ACPI_MODULE_NAME("bus");
  50
  51 struct acpi_device *acpi_root;
  52 struct proc_dir_entry *acpi_root_dir;
  53 EXPORT_SYMBOL(acpi_root_dir);
  54
  55 #define STRUCT_TO_INT(s)        (*((int*)&s))
  56
  57
  58 #ifdef CONFIG_X86
  59 static int set_copy_dsdt(const struct dmi_system_id *id)
  60 {
  61         printk(KERN_NOTICE "%s detected - "
  62                 "force copy of DSDT to local memory\n", id->ident);
  63         acpi_gbl_copy_dsdt_locally = 1;
  64         return 0;
  65 }
  66
  67 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
  68         /*
  69          * Invoke DSDT corruption work-around on all Toshiba Satellite.
  70          * https://bugzilla.kernel.org/show_bug.cgi?id=14679
  71          */
  72         {
  73          .callback = set_copy_dsdt,
  74          .ident = "TOSHIBA Satellite",
  75          .matches = {
  76                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
  77                 DMI_MATCH(DMI_PRODUCT_NAME, "Satellite"),
  78                 },
  79         },
  80         {}
  81 };
  82 #else
  83 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
  84         {}
  85 };
  86 #endif
  87
  88 /* --------------------------------------------------------------------------
  89                                 Device Management
  90    -------------------------------------------------------------------------- */
  91
  92 acpi_status acpi_bus_get_status_handle(acpi_handle handle,
  93                                        unsigned long long *sta)
  94 {
  95         acpi_status status;
  96
  97         status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
  98         if (ACPI_SUCCESS(status))
  99                 return AE_OK;
 100
 101         if (status == AE_NOT_FOUND) {
 102                 *sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
 103                        ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
 104                 return AE_OK;
 105         }
 106         return status;
 107 }
 108
 109 int acpi_bus_get_status(struct acpi_device *device)
 110 {
 111         acpi_status status;
 112         unsigned long long sta;
 113
 114         status = acpi_bus_get_status_handle(device->handle, &sta);
 115         if (ACPI_FAILURE(status))
 116                 return -ENODEV;
 117
 118         STRUCT_TO_INT(device->status) = (int) sta;
 119
 120         if (device->status.functional && !device->status.present) {
 121                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
 122                        "functional but not present;\n",
 123                         device->pnp.bus_id,
 124                         (u32) STRUCT_TO_INT(device->status)));
 125         }
 126
 127         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
 128                           device->pnp.bus_id,
 129                           (u32) STRUCT_TO_INT(device->status)));
 130         return 0;
 131 }
 132 EXPORT_SYMBOL(acpi_bus_get_status);
 133
 134 void acpi_bus_private_data_handler(acpi_handle handle,
 135                                    void *context)
 136 {
 137         return;
 138 }
 139 EXPORT_SYMBOL(acpi_bus_private_data_handler);
 140
 141 int acpi_bus_get_private_data(acpi_handle handle, void **data)
 142 {
 143         acpi_status status;
 144
 145         if (!*data)
 146                 return -EINVAL;
 147
 148         status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
 149         if (ACPI_FAILURE(status) || !*data) {
 150                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
 151                                 handle));
 152                 return -ENODEV;
 153         }
 154
 155         return 0;
 156 }
 157 EXPORT_SYMBOL(acpi_bus_get_private_data);
 158
 159 void acpi_bus_no_hotplug(acpi_handle handle)
 160 {
 161         struct acpi_device *adev = NULL;
 162
 163         acpi_bus_get_device(handle, &adev);
 164         if (adev)
 165                 adev->flags.no_hotplug = true;
 166 }
 167 EXPORT_SYMBOL_GPL(acpi_bus_no_hotplug);
 168
 169 static void acpi_print_osc_error(acpi_handle handle,
 170         struct acpi_osc_context *context, char *error)
 171 {
 172         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
 173         int i;
 174
 175         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer)))
 176                 printk(KERN_DEBUG "%s\n", error);
 177         else {
 178                 printk(KERN_DEBUG "%s:%s\n", (char *)buffer.pointer, error);
 179                 kfree(buffer.pointer);
 180         }
 181         printk(KERN_DEBUG"_OSC request data:");
 182         for (i = 0; i < context->cap.length; i += sizeof(u32))
 183                 printk("%x ", *((u32 *)(context->cap.pointer + i)));
 184         printk("\n");
 185 }
 186
 187 acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
 188 {
 189         int i;
 190         static int opc_map_to_uuid[16] = {6, 4, 2, 0, 11, 9, 16, 14, 19, 21,
 191                 24, 26, 28, 30, 32, 34};
 192
 193         if (strlen(str) != 36)
 194                 return AE_BAD_PARAMETER;
 195         for (i = 0; i < 36; i++) {
 196                 if (i == 8 || i == 13 || i == 18 || i == 23) {
 197                         if (str[i] != '-')
 198                                 return AE_BAD_PARAMETER;
 199                 } else if (!isxdigit(str[i]))
 200                         return AE_BAD_PARAMETER;
 201         }
 202         for (i = 0; i < 16; i++) {
 203                 uuid[i] = hex_to_bin(str[opc_map_to_uuid[i]]) << 4;
 204                 uuid[i] |= hex_to_bin(str[opc_map_to_uuid[i] + 1]);
 205         }
 206         return AE_OK;
 207 }
 208 EXPORT_SYMBOL_GPL(acpi_str_to_uuid);
 209
 210 acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
 211 {
 212         acpi_status status;
 213         struct acpi_object_list input;
 214         union acpi_object in_params[4];
 215         union acpi_object *out_obj;
 216         u8 uuid[16];
 217         u32 errors;
 218         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
 219
 220         if (!context)
 221                 return AE_ERROR;
 222         if (ACPI_FAILURE(acpi_str_to_uuid(context->uuid_str, uuid)))
 223                 return AE_ERROR;
 224         context->ret.length = ACPI_ALLOCATE_BUFFER;
 225         context->ret.pointer = NULL;
 226
 227         /* Setting up input parameters */
 228         input.count = 4;
 229         input.pointer = in_params;
 230         in_params[0].type               = ACPI_TYPE_BUFFER;
 231         in_params[0].buffer.length      = 16;
 232         in_params[0].buffer.pointer     = uuid;
 233         in_params[1].type               = ACPI_TYPE_INTEGER;
 234         in_params[1].integer.value      = context->rev;
 235         in_params[2].type               = ACPI_TYPE_INTEGER;
 236         in_params[2].integer.value      = context->cap.length/sizeof(u32);
 237         in_params[3].type               = ACPI_TYPE_BUFFER;
 238         in_params[3].buffer.length      = context->cap.length;
 239         in_params[3].buffer.pointer     = context->cap.pointer;
 240
 241         status = acpi_evaluate_object(handle, "_OSC", &input, &output);
 242         if (ACPI_FAILURE(status))
 243                 return status;
 244
 245         if (!output.length)
 246                 return AE_NULL_OBJECT;
 247
 248         out_obj = output.pointer;
 249         if (out_obj->type != ACPI_TYPE_BUFFER
 250                 || out_obj->buffer.length != context->cap.length) {
 251                 acpi_print_osc_error(handle, context,
 252                         "_OSC evaluation returned wrong type");
 253                 status = AE_TYPE;
 254                 goto out_kfree;
 255         }
 256         /* Need to ignore the bit0 in result code */
 257         errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
 258         if (errors) {
 259                 if (errors & OSC_REQUEST_ERROR)
 260                         acpi_print_osc_error(handle, context,
 261                                 "_OSC request failed");
 262                 if (errors & OSC_INVALID_UUID_ERROR)
 263                         acpi_print_osc_error(handle, context,
 264                                 "_OSC invalid UUID");
 265                 if (errors & OSC_INVALID_REVISION_ERROR)
 266                         acpi_print_osc_error(handle, context,
 267                                 "_OSC invalid revision");
 268                 if (errors & OSC_CAPABILITIES_MASK_ERROR) {
 269                         if (((u32 *)context->cap.pointer)[OSC_QUERY_DWORD]
 270                             & OSC_QUERY_ENABLE)
 271                                 goto out_success;
 272                         status = AE_SUPPORT;
 273                         goto out_kfree;
 274                 }
 275                 status = AE_ERROR;
 276                 goto out_kfree;
 277         }
 278 out_success:
 279         context->ret.length = out_obj->buffer.length;
 280         context->ret.pointer = kmemdup(out_obj->buffer.pointer,
 281                                        context->ret.length, GFP_KERNEL);
 282         if (!context->ret.pointer) {
 283                 status =  AE_NO_MEMORY;
 284                 goto out_kfree;
 285         }
 286         status =  AE_OK;
 287
 288 out_kfree:
 289         kfree(output.pointer);
 290         if (status != AE_OK)
 291                 context->ret.pointer = NULL;
 292         return status;
 293 }
 294 EXPORT_SYMBOL(acpi_run_osc);
 295
 296 bool osc_sb_apei_support_acked;
 297 static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
 298 static void acpi_bus_osc_support(void)
 299 {
 300         u32 capbuf[2];
 301         struct acpi_osc_context context = {
 302                 .uuid_str = sb_uuid_str,
 303                 .rev = 1,
 304                 .cap.length = 8,
 305                 .cap.pointer = capbuf,
 306         };
 307         acpi_handle handle;
 308
 309         capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
 310         capbuf[OSC_SUPPORT_DWORD] = OSC_SB_PR3_SUPPORT; /* _PR3 is in use */
 311 #if defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR) ||\
 312                         defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR_MODULE)
 313         capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PAD_SUPPORT;
 314 #endif
 315
 316 #if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
 317         capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PPC_OST_SUPPORT;
 318 #endif
 319
 320 #ifdef ACPI_HOTPLUG_OST
 321         capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT;
 322 #endif
 323
 324         if (!ghes_disable)
 325                 capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT;
 326         if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
 327                 return;
 328         if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) {
 329                 u32 *capbuf_ret = context.ret.pointer;
 330                 if (context.ret.length > OSC_SUPPORT_DWORD)
 331                         osc_sb_apei_support_acked =
 332                                 capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
 333                 kfree(context.ret.pointer);
 334         }
 335         /* do we need to check other returned cap? Sounds no */
 336 }
 337
 338 /* --------------------------------------------------------------------------
 339                              Notification Handling
 340    -------------------------------------------------------------------------- */
 341
 342 static void acpi_bus_check_device(acpi_handle handle)
 343 {
 344         struct acpi_device *device;
 345         acpi_status status;
 346         struct acpi_device_status old_status;
 347
 348         if (acpi_bus_get_device(handle, &device))
 349                 return;
 350         if (!device)
 351                 return;
 352
 353         old_status = device->status;
 354
 355         /*
 356          * Make sure this device's parent is present before we go about
 357          * messing with the device.
 358          */
 359         if (device->parent && !device->parent->status.present) {
 360                 device->status = device->parent->status;
 361                 return;
 362         }
 363
 364         status = acpi_bus_get_status(device);
 365         if (ACPI_FAILURE(status))
 366                 return;
 367
 368         if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
 369                 return;
 370
 371         /*
 372          * Device Insertion/Removal
 373          */
 374         if ((device->status.present) && !(old_status.present)) {
 375                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
 376                 /* TBD: Handle device insertion */
 377         } else if (!(device->status.present) && (old_status.present)) {
 378                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
 379                 /* TBD: Handle device removal */
 380         }
 381 }
 382
 383 static void acpi_bus_check_scope(acpi_handle handle)
 384 {
 385         /* Status Change? */
 386         acpi_bus_check_device(handle);
 387
 388         /*
 389          * TBD: Enumerate child devices within this device's scope and
 390          *       run acpi_bus_check_device()'s on them.
 391          */
 392 }
 393
 394 /**
 395  * acpi_bus_notify
 396  * ---------------
 397  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
 398  */
 399 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
 400 {
 401         struct acpi_device *device = NULL;
 402         struct acpi_driver *driver;
 403
 404         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Notification %#02x to handle %p\n",
 405                           type, handle));
 406
 407         switch (type) {
 408
 409         case ACPI_NOTIFY_BUS_CHECK:
 410                 acpi_bus_check_scope(handle);
 411                 /*
 412                  * TBD: We'll need to outsource certain events to non-ACPI
 413                  *      drivers via the device manager (device.c).
 414                  */
 415                 break;
 416
 417         case ACPI_NOTIFY_DEVICE_CHECK:
 418                 acpi_bus_check_device(handle);
 419                 /*
 420                  * TBD: We'll need to outsource certain events to non-ACPI
 421                  *      drivers via the device manager (device.c).
 422                  */
 423                 break;
 424
 425         case ACPI_NOTIFY_DEVICE_WAKE:
 426                 /* TBD */
 427                 break;
 428
 429         case ACPI_NOTIFY_EJECT_REQUEST:
 430                 /* TBD */
 431                 break;
 432
 433         case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
 434                 /* TBD: Exactly what does 'light' mean? */
 435                 break;
 436
 437         case ACPI_NOTIFY_FREQUENCY_MISMATCH:
 438                 /* TBD */
 439                 break;
 440
 441         case ACPI_NOTIFY_BUS_MODE_MISMATCH:
 442                 /* TBD */
 443                 break;
 444
 445         case ACPI_NOTIFY_POWER_FAULT:
 446                 /* TBD */
 447                 break;
 448
 449         default:
 450                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 451                                   "Received unknown/unsupported notification [%08x]\n",
 452                                   type));
 453                 break;
 454         }
 455
 456         acpi_bus_get_device(handle, &device);
 457         if (device) {
 458                 driver = device->driver;
 459                 if (driver && driver->ops.notify &&
 460                     (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
 461                         driver->ops.notify(device, type);
 462         }
 463 }
 464
 465 /* --------------------------------------------------------------------------
 466                              Initialization/Cleanup
 467    -------------------------------------------------------------------------- */
 468
 469 static int __init acpi_bus_init_irq(void)
 470 {
 471         acpi_status status;
 472         char *message = NULL;
 473
 474
 475         /*
 476          * Let the system know what interrupt model we are using by
 477          * evaluating the \_PIC object, if exists.
 478          */
 479
 480         switch (acpi_irq_model) {
 481         case ACPI_IRQ_MODEL_PIC:
 482                 message = "PIC";
 483                 break;
 484         case ACPI_IRQ_MODEL_IOAPIC:
 485                 message = "IOAPIC";
 486                 break;
 487         case ACPI_IRQ_MODEL_IOSAPIC:
 488                 message = "IOSAPIC";
 489                 break;
 490         case ACPI_IRQ_MODEL_PLATFORM:
 491                 message = "platform specific model";
 492                 break;
 493         default:
 494                 printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
 495                 return -ENODEV;
 496         }
 497
 498         printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
 499
 500         status = acpi_execute_simple_method(NULL, "\\_PIC", acpi_irq_model);
 501         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 502                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
 503                 return -ENODEV;
 504         }
 505
 506         return 0;
 507 }
 508
 509 u8 acpi_gbl_permanent_mmap;
 510
 511
 512 void __init acpi_early_init(void)
 513 {
 514         acpi_status status;
 515
 516         if (acpi_disabled)
 517                 return;
 518
 519         printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
 520
 521         /* enable workarounds, unless strict ACPI spec. compliance */
 522         if (!acpi_strict)
 523                 acpi_gbl_enable_interpreter_slack = TRUE;
 524
 525         acpi_gbl_permanent_mmap = 1;
 526
 527         /*
 528          * If the machine falls into the DMI check table,
 529          * DSDT will be copied to memory
 530          */
 531         dmi_check_system(dsdt_dmi_table);
 532
 533         status = acpi_reallocate_root_table();
 534         if (ACPI_FAILURE(status)) {
 535                 printk(KERN_ERR PREFIX
 536                        "Unable to reallocate ACPI tables\n");
 537                 goto error0;
 538         }
 539
 540         status = acpi_initialize_subsystem();
 541         if (ACPI_FAILURE(status)) {
 542                 printk(KERN_ERR PREFIX
 543                        "Unable to initialize the ACPI Interpreter\n");
 544                 goto error0;
 545         }
 546
 547         status = acpi_load_tables();
 548         if (ACPI_FAILURE(status)) {
 549                 printk(KERN_ERR PREFIX
 550                        "Unable to load the System Description Tables\n");
 551                 goto error0;
 552         }
 553
 554 #ifdef CONFIG_X86
 555         if (!acpi_ioapic) {
 556                 /* compatible (0) means level (3) */
 557                 if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
 558                         acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
 559                         acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
 560                 }
 561                 /* Set PIC-mode SCI trigger type */
 562                 acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
 563                                          (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
 564         } else {
 565                 /*
 566                  * now that acpi_gbl_FADT is initialized,
 567                  * update it with result from INT_SRC_OVR parsing
 568                  */
 569                 acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
 570         }
 571 #endif
 572
 573         status = acpi_enable_subsystem(~ACPI_NO_ACPI_ENABLE);
 574         if (ACPI_FAILURE(status)) {
 575                 printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
 576                 goto error0;
 577         }
 578
 579         return;
 580
 581       error0:
 582         disable_acpi();
 583         return;
 584 }
 585
 586 static int __init acpi_bus_init(void)
 587 {
 588         int result;
 589         acpi_status status;
 590
 591         acpi_os_initialize1();
 592
 593         status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);
 594         if (ACPI_FAILURE(status)) {
 595                 printk(KERN_ERR PREFIX
 596                        "Unable to start the ACPI Interpreter\n");
 597                 goto error1;
 598         }
 599
 600         /*
 601          * ACPI 2.0 requires the EC driver to be loaded and work before
 602          * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
 603          * is called).
 604          *
 605          * This is accomplished by looking for the ECDT table, and getting
 606          * the EC parameters out of that.
 607          */
 608         status = acpi_ec_ecdt_probe();
 609         /* Ignore result. Not having an ECDT is not fatal. */
 610
 611         status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
 612         if (ACPI_FAILURE(status)) {
 613                 printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
 614                 goto error1;
 615         }
 616
 617         /*
 618          * _OSC method may exist in module level code,
 619          * so it must be run after ACPI_FULL_INITIALIZATION
 620          */
 621         acpi_bus_osc_support();
 622
 623         /*
 624          * _PDC control method may load dynamic SSDT tables,
 625          * and we need to install the table handler before that.
 626          */
 627         acpi_sysfs_init();
 628
 629         acpi_early_processor_set_pdc();
 630
 631         /*
 632          * Maybe EC region is required at bus_scan/acpi_get_devices. So it
 633          * is necessary to enable it as early as possible.
 634          */
 635         acpi_boot_ec_enable();
 636
 637         printk(KERN_INFO PREFIX "Interpreter enabled\n");
 638
 639         /* Initialize sleep structures */
 640         acpi_sleep_init();
 641
 642         /*
 643          * Get the system interrupt model and evaluate \_PIC.
 644          */
 645         result = acpi_bus_init_irq();
 646         if (result)
 647                 goto error1;
 648
 649         /*
 650          * Register the for all standard device notifications.
 651          */
 652         status =
 653             acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
 654                                         &acpi_bus_notify, NULL);
 655         if (ACPI_FAILURE(status)) {
 656                 printk(KERN_ERR PREFIX
 657                        "Unable to register for device notifications\n");
 658                 goto error1;
 659         }
 660
 661         /*
 662          * Create the top ACPI proc directory
 663          */
 664         acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
 665
 666         return 0;
 667
 668         /* Mimic structured exception handling */
 669       error1:
 670         acpi_terminate();
 671         return -ENODEV;
 672 }
 673
 674 struct kobject *acpi_kobj;
 675 EXPORT_SYMBOL_GPL(acpi_kobj);
 676
 677 static int __init acpi_init(void)
 678 {
 679         int result;
 680
 681         if (acpi_disabled) {
 682                 printk(KERN_INFO PREFIX "Interpreter disabled.\n");
 683                 return -ENODEV;
 684         }
 685
 686         acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
 687         if (!acpi_kobj) {
 688                 printk(KERN_WARNING "%s: kset create error\n", __func__);
 689                 acpi_kobj = NULL;
 690         }
 691
 692         init_acpi_device_notify();
 693         result = acpi_bus_init();
 694         if (result) {
 695                 disable_acpi();
 696                 return result;
 697         }
 698
 699         pci_mmcfg_late_init();
 700         acpi_scan_init();
 701         acpi_ec_init();
 702         acpi_debugfs_init();
 703         acpi_sleep_proc_init();
 704         acpi_wakeup_device_init();
 705         return 0;
 706 }
 707
 708 subsys_initcall(acpi_init);