drivers/acpi/acpica/evgpeinit.c

   1 /******************************************************************************
   2  *
   3  * Module Name: evgpeinit - System GPE initialization and update
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2010, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include "accommon.h"
  46 #include "acevents.h"
  47 #include "acnamesp.h"
  48 #include "acinterp.h"
  49
  50 #define _COMPONENT          ACPI_EVENTS
  51 ACPI_MODULE_NAME("evgpeinit")
  52
  53 /*******************************************************************************
  54  *
  55  * FUNCTION:    acpi_ev_gpe_initialize
  56  *
  57  * PARAMETERS:  None
  58  *
  59  * RETURN:      Status
  60  *
  61  * DESCRIPTION: Initialize the GPE data structures and the FADT GPE 0/1 blocks
  62  *
  63  ******************************************************************************/
  64 acpi_status acpi_ev_gpe_initialize(void)
  65 {
  66         u32 register_count0 = 0;
  67         u32 register_count1 = 0;
  68         u32 gpe_number_max = 0;
  69         acpi_status status;
  70
  71         ACPI_FUNCTION_TRACE(ev_gpe_initialize);
  72
  73         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
  74         if (ACPI_FAILURE(status)) {
  75                 return_ACPI_STATUS(status);
  76         }
  77
  78         /*
  79          * Initialize the GPE Block(s) defined in the FADT
  80          *
  81          * Why the GPE register block lengths are divided by 2:  From the ACPI
  82          * Spec, section "General-Purpose Event Registers", we have:
  83          *
  84          * "Each register block contains two registers of equal length
  85          *  GPEx_STS and GPEx_EN (where x is 0 or 1). The length of the
  86          *  GPE0_STS and GPE0_EN registers is equal to half the GPE0_LEN
  87          *  The length of the GPE1_STS and GPE1_EN registers is equal to
  88          *  half the GPE1_LEN. If a generic register block is not supported
  89          *  then its respective block pointer and block length values in the
  90          *  FADT table contain zeros. The GPE0_LEN and GPE1_LEN do not need
  91          *  to be the same size."
  92          */
  93
  94         /*
  95          * Determine the maximum GPE number for this machine.
  96          *
  97          * Note: both GPE0 and GPE1 are optional, and either can exist without
  98          * the other.
  99          *
 100          * If EITHER the register length OR the block address are zero, then that
 101          * particular block is not supported.
 102          */
 103         if (acpi_gbl_FADT.gpe0_block_length &&
 104             acpi_gbl_FADT.xgpe0_block.address) {
 105
 106                 /* GPE block 0 exists (has both length and address > 0) */
 107
 108                 register_count0 = (u16)(acpi_gbl_FADT.gpe0_block_length / 2);
 109
 110                 gpe_number_max =
 111                     (register_count0 * ACPI_GPE_REGISTER_WIDTH) - 1;
 112
 113                 /* Install GPE Block 0 */
 114
 115                 status = acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
 116                                                   &acpi_gbl_FADT.xgpe0_block,
 117                                                   register_count0, 0,
 118                                                   acpi_gbl_FADT.sci_interrupt,
 119                                                   &acpi_gbl_gpe_fadt_blocks[0]);
 120
 121                 if (ACPI_FAILURE(status)) {
 122                         ACPI_EXCEPTION((AE_INFO, status,
 123                                         "Could not create GPE Block 0"));
 124                 }
 125         }
 126
 127         if (acpi_gbl_FADT.gpe1_block_length &&
 128             acpi_gbl_FADT.xgpe1_block.address) {
 129
 130                 /* GPE block 1 exists (has both length and address > 0) */
 131
 132                 register_count1 = (u16)(acpi_gbl_FADT.gpe1_block_length / 2);
 133
 134                 /* Check for GPE0/GPE1 overlap (if both banks exist) */
 135
 136                 if ((register_count0) &&
 137                     (gpe_number_max >= acpi_gbl_FADT.gpe1_base)) {
 138                         ACPI_ERROR((AE_INFO,
 139                                     "GPE0 block (GPE 0 to %u) overlaps the GPE1 block "
 140                                     "(GPE %u to %u) - Ignoring GPE1",
 141                                     gpe_number_max, acpi_gbl_FADT.gpe1_base,
 142                                     acpi_gbl_FADT.gpe1_base +
 143                                     ((register_count1 *
 144                                       ACPI_GPE_REGISTER_WIDTH) - 1)));
 145
 146                         /* Ignore GPE1 block by setting the register count to zero */
 147
 148                         register_count1 = 0;
 149                 } else {
 150                         /* Install GPE Block 1 */
 151
 152                         status =
 153                             acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
 154                                                      &acpi_gbl_FADT.xgpe1_block,
 155                                                      register_count1,
 156                                                      acpi_gbl_FADT.gpe1_base,
 157                                                      acpi_gbl_FADT.
 158                                                      sci_interrupt,
 159                                                      &acpi_gbl_gpe_fadt_blocks
 160                                                      [1]);
 161
 162                         if (ACPI_FAILURE(status)) {
 163                                 ACPI_EXCEPTION((AE_INFO, status,
 164                                                 "Could not create GPE Block 1"));
 165                         }
 166
 167                         /*
 168                          * GPE0 and GPE1 do not have to be contiguous in the GPE number
 169                          * space. However, GPE0 always starts at GPE number zero.
 170                          */
 171                         gpe_number_max = acpi_gbl_FADT.gpe1_base +
 172                             ((register_count1 * ACPI_GPE_REGISTER_WIDTH) - 1);
 173                 }
 174         }
 175
 176         /* Exit if there are no GPE registers */
 177
 178         if ((register_count0 + register_count1) == 0) {
 179
 180                 /* GPEs are not required by ACPI, this is OK */
 181
 182                 ACPI_DEBUG_PRINT((ACPI_DB_INIT,
 183                                   "There are no GPE blocks defined in the FADT\n"));
 184                 status = AE_OK;
 185                 goto cleanup;
 186         }
 187
 188         /* Check for Max GPE number out-of-range */
 189
 190         if (gpe_number_max > ACPI_GPE_MAX) {
 191                 ACPI_ERROR((AE_INFO,
 192                             "Maximum GPE number from FADT is too large: 0x%X",
 193                             gpe_number_max));
 194                 status = AE_BAD_VALUE;
 195                 goto cleanup;
 196         }
 197
 198       cleanup:
 199         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 200         return_ACPI_STATUS(AE_OK);
 201 }
 202
 203 /*******************************************************************************
 204  *
 205  * FUNCTION:    acpi_ev_update_gpes
 206  *
 207  * PARAMETERS:  table_owner_id      - ID of the newly-loaded ACPI table
 208  *
 209  * RETURN:      None
 210  *
 211  * DESCRIPTION: Check for new GPE methods (_Lxx/_Exx) made available as a
 212  *              result of a Load() or load_table() operation. If new GPE
 213  *              methods have been installed, register the new methods and
 214  *              enable and runtime GPEs that are associated with them. Also,
 215  *              run any newly loaded _PRW methods in order to discover any
 216  *              new CAN_WAKE GPEs.
 217  *
 218  ******************************************************************************/
 219
 220 void acpi_ev_update_gpes(acpi_owner_id table_owner_id)
 221 {
 222         struct acpi_gpe_xrupt_info *gpe_xrupt_info;
 223         struct acpi_gpe_block_info *gpe_block;
 224         struct acpi_gpe_walk_info walk_info;
 225         acpi_status status = AE_OK;
 226         u32 new_wake_gpe_count = 0;
 227
 228         /* We will examine only _PRW/_Lxx/_Exx methods owned by this table */
 229
 230         walk_info.owner_id = table_owner_id;
 231         walk_info.execute_by_owner_id = TRUE;
 232         walk_info.count = 0;
 233
 234         if (acpi_gbl_leave_wake_gpes_disabled) {
 235                 /*
 236                  * 1) Run any newly-loaded _PRW methods to find any GPEs that
 237                  * can now be marked as CAN_WAKE GPEs. Note: We must run the
 238                  * _PRW methods before we process the _Lxx/_Exx methods because
 239                  * we will enable all runtime GPEs associated with the new
 240                  * _Lxx/_Exx methods at the time we process those methods.
 241                  *
 242                  * Unlock interpreter so that we can run the _PRW methods.
 243                  */
 244                 walk_info.gpe_block = NULL;
 245                 walk_info.gpe_device = NULL;
 246
 247                 acpi_ex_exit_interpreter();
 248
 249                 status =
 250                     acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 251                                            ACPI_UINT32_MAX,
 252                                            ACPI_NS_WALK_NO_UNLOCK,
 253                                            acpi_ev_match_prw_and_gpe, NULL,
 254                                            &walk_info, NULL);
 255                 if (ACPI_FAILURE(status)) {
 256                         ACPI_EXCEPTION((AE_INFO, status,
 257                                         "While executing _PRW methods"));
 258                 }
 259
 260                 acpi_ex_enter_interpreter();
 261                 new_wake_gpe_count = walk_info.count;
 262         }
 263
 264         /*
 265          * 2) Find any _Lxx/_Exx GPE methods that have just been loaded.
 266          *
 267          * Any GPEs that correspond to new _Lxx/_Exx methods and are not
 268          * marked as CAN_WAKE are immediately enabled.
 269          *
 270          * Examine the namespace underneath each gpe_device within the
 271          * gpe_block lists.
 272          */
 273         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 274         if (ACPI_FAILURE(status)) {
 275                 return;
 276         }
 277
 278         walk_info.count = 0;
 279         walk_info.enable_this_gpe = TRUE;
 280
 281         /* Walk the interrupt level descriptor list */
 282
 283         gpe_xrupt_info = acpi_gbl_gpe_xrupt_list_head;
 284         while (gpe_xrupt_info) {
 285
 286                 /* Walk all Gpe Blocks attached to this interrupt level */
 287
 288                 gpe_block = gpe_xrupt_info->gpe_block_list_head;
 289                 while (gpe_block) {
 290                         walk_info.gpe_block = gpe_block;
 291                         walk_info.gpe_device = gpe_block->node;
 292
 293                         status = acpi_ns_walk_namespace(ACPI_TYPE_METHOD,
 294                                                         walk_info.gpe_device,
 295                                                         ACPI_UINT32_MAX,
 296                                                         ACPI_NS_WALK_NO_UNLOCK,
 297                                                         acpi_ev_match_gpe_method,
 298                                                         NULL, &walk_info, NULL);
 299                         if (ACPI_FAILURE(status)) {
 300                                 ACPI_EXCEPTION((AE_INFO, status,
 301                                                 "While decoding _Lxx/_Exx methods"));
 302                         }
 303
 304                         gpe_block = gpe_block->next;
 305                 }
 306
 307                 gpe_xrupt_info = gpe_xrupt_info->next;
 308         }
 309
 310         if (walk_info.count || new_wake_gpe_count) {
 311                 ACPI_INFO((AE_INFO,
 312                            "Enabled %u new runtime GPEs, added %u new wakeup GPEs",
 313                            walk_info.count, new_wake_gpe_count));
 314         }
 315
 316         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 317         return;
 318 }
 319
 320 /*******************************************************************************
 321  *
 322  * FUNCTION:    acpi_ev_match_gpe_method
 323  *
 324  * PARAMETERS:  Callback from walk_namespace
 325  *
 326  * RETURN:      Status
 327  *
 328  * DESCRIPTION: Called from acpi_walk_namespace. Expects each object to be a
 329  *              control method under the _GPE portion of the namespace.
 330  *              Extract the name and GPE type from the object, saving this
 331  *              information for quick lookup during GPE dispatch. Allows a
 332  *              per-owner_id evaluation if execute_by_owner_id is TRUE in the
 333  *              walk_info parameter block.
 334  *
 335  *              The name of each GPE control method is of the form:
 336  *              "_Lxx" or "_Exx", where:
 337  *                  L      - means that the GPE is level triggered
 338  *                  E      - means that the GPE is edge triggered
 339  *                  xx     - is the GPE number [in HEX]
 340  *
 341  * If walk_info->execute_by_owner_id is TRUE, we only execute examine GPE methods
 342  *    with that owner.
 343  * If walk_info->enable_this_gpe is TRUE, the GPE that is referred to by a GPE
 344  *    method is immediately enabled (Used for Load/load_table operators)
 345  *
 346  ******************************************************************************/
 347
 348 acpi_status
 349 acpi_ev_match_gpe_method(acpi_handle obj_handle,
 350                          u32 level, void *context, void **return_value)
 351 {
 352         struct acpi_namespace_node *method_node =
 353             ACPI_CAST_PTR(struct acpi_namespace_node, obj_handle);
 354         struct acpi_gpe_walk_info *walk_info =
 355             ACPI_CAST_PTR(struct acpi_gpe_walk_info, context);
 356         struct acpi_gpe_event_info *gpe_event_info;
 357         struct acpi_namespace_node *gpe_device;
 358         acpi_status status;
 359         u32 gpe_number;
 360         char name[ACPI_NAME_SIZE + 1];
 361         u8 type;
 362
 363         ACPI_FUNCTION_TRACE(ev_match_gpe_method);
 364
 365         /* Check if requested owner_id matches this owner_id */
 366
 367         if ((walk_info->execute_by_owner_id) &&
 368             (method_node->owner_id != walk_info->owner_id)) {
 369                 return_ACPI_STATUS(AE_OK);
 370         }
 371
 372         /*
 373          * Match and decode the _Lxx and _Exx GPE method names
 374          *
 375          * 1) Extract the method name and null terminate it
 376          */
 377         ACPI_MOVE_32_TO_32(name, &method_node->name.integer);
 378         name[ACPI_NAME_SIZE] = 0;
 379
 380         /* 2) Name must begin with an underscore */
 381
 382         if (name[0] != '_') {
 383                 return_ACPI_STATUS(AE_OK);      /* Ignore this method */
 384         }
 385
 386         /*
 387          * 3) Edge/Level determination is based on the 2nd character
 388          *    of the method name
 389          *
 390          * NOTE: Default GPE type is RUNTIME only. Later, if a _PRW object is
 391          * found that points to this GPE, the ACPI_GPE_CAN_WAKE flag is set.
 392          */
 393         switch (name[1]) {
 394         case 'L':
 395                 type = ACPI_GPE_LEVEL_TRIGGERED;
 396                 break;
 397
 398         case 'E':
 399                 type = ACPI_GPE_EDGE_TRIGGERED;
 400                 break;
 401
 402         default:
 403                 /* Unknown method type, just ignore it */
 404
 405                 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
 406                                   "Ignoring unknown GPE method type: %s "
 407                                   "(name not of form _Lxx or _Exx)", name));
 408                 return_ACPI_STATUS(AE_OK);
 409         }
 410
 411         /* 4) The last two characters of the name are the hex GPE Number */
 412
 413         gpe_number = ACPI_STRTOUL(&name[2], NULL, 16);
 414         if (gpe_number == ACPI_UINT32_MAX) {
 415
 416                 /* Conversion failed; invalid method, just ignore it */
 417
 418                 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
 419                                   "Could not extract GPE number from name: %s "
 420                                   "(name is not of form _Lxx or _Exx)", name));
 421                 return_ACPI_STATUS(AE_OK);
 422         }
 423
 424         /* Ensure that we have a valid GPE number for this GPE block */
 425
 426         gpe_event_info =
 427             acpi_ev_low_get_gpe_info(gpe_number, walk_info->gpe_block);
 428         if (!gpe_event_info) {
 429                 /*
 430                  * This gpe_number is not valid for this GPE block, just ignore it.
 431                  * However, it may be valid for a different GPE block, since GPE0
 432                  * and GPE1 methods both appear under \_GPE.
 433                  */
 434                 return_ACPI_STATUS(AE_OK);
 435         }
 436
 437         if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
 438             ACPI_GPE_DISPATCH_HANDLER) {
 439
 440                 /* If there is already a handler, ignore this GPE method */
 441
 442                 return_ACPI_STATUS(AE_OK);
 443         }
 444
 445         if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
 446             ACPI_GPE_DISPATCH_METHOD) {
 447                 /*
 448                  * If there is already a method, ignore this method. But check
 449                  * for a type mismatch (if both the _Lxx AND _Exx exist)
 450                  */
 451                 if (type != (gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK)) {
 452                         ACPI_ERROR((AE_INFO,
 453                                     "For GPE 0x%.2X, found both _L%2.2X and _E%2.2X methods",
 454                                     gpe_number, gpe_number, gpe_number));
 455                 }
 456                 return_ACPI_STATUS(AE_OK);
 457         }
 458
 459         /*
 460          * Add the GPE information from above to the gpe_event_info block for
 461          * use during dispatch of this GPE.
 462          */
 463         gpe_event_info->flags |= (u8)(type | ACPI_GPE_DISPATCH_METHOD);
 464         gpe_event_info->dispatch.method_node = method_node;
 465
 466         /*
 467          * Enable this GPE if requested. This only happens when during the
 468          * execution of a Load or load_table operator. We have found a new
 469          * GPE method and want to immediately enable the GPE if it is a
 470          * runtime GPE.
 471          */
 472         if (walk_info->enable_this_gpe) {
 473
 474                 /* Ignore GPEs that can wake the system */
 475
 476                 if (!(gpe_event_info->flags & ACPI_GPE_CAN_WAKE) ||
 477                     !acpi_gbl_leave_wake_gpes_disabled) {
 478                         walk_info->count++;
 479                         gpe_device = walk_info->gpe_device;
 480
 481                         if (gpe_device == acpi_gbl_fadt_gpe_device) {
 482                                 gpe_device = NULL;
 483                         }
 484
 485                         status = acpi_enable_gpe(gpe_device, gpe_number);
 486                         if (ACPI_FAILURE(status)) {
 487                                 ACPI_EXCEPTION((AE_INFO, status,
 488                                                 "Could not enable GPE 0x%02X",
 489                                                 gpe_number));
 490                         }
 491                 }
 492         }
 493
 494         ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
 495                           "Registered GPE method %s as GPE number 0x%.2X\n",
 496                           name, gpe_number));
 497         return_ACPI_STATUS(AE_OK);
 498 }
 499
 500 /*******************************************************************************
 501  *
 502  * FUNCTION:    acpi_ev_match_prw_and_gpe
 503  *
 504  * PARAMETERS:  Callback from walk_namespace
 505  *
 506  * RETURN:      Status. NOTE: We ignore errors so that the _PRW walk is
 507  *              not aborted on a single _PRW failure.
 508  *
 509  * DESCRIPTION: Called from acpi_walk_namespace. Expects each object to be a
 510  *              Device. Run the _PRW method. If present, extract the GPE
 511  *              number and mark the GPE as a CAN_WAKE GPE. Allows a
 512  *              per-owner_id execution if execute_by_owner_id is TRUE in the
 513  *              walk_info parameter block.
 514  *
 515  * If walk_info->execute_by_owner_id is TRUE, we only execute _PRWs with that
 516  *    owner.
 517  * If walk_info->gpe_device is NULL, we execute every _PRW found. Otherwise,
 518  *    we only execute _PRWs that refer to the input gpe_device.
 519  *
 520  ******************************************************************************/
 521
 522 acpi_status
 523 acpi_ev_match_prw_and_gpe(acpi_handle obj_handle,
 524                           u32 level, void *context, void **return_value)
 525 {
 526         struct acpi_gpe_walk_info *walk_info =
 527             ACPI_CAST_PTR(struct acpi_gpe_walk_info, context);
 528         struct acpi_namespace_node *gpe_device;
 529         struct acpi_gpe_block_info *gpe_block;
 530         struct acpi_namespace_node *target_gpe_device;
 531         struct acpi_namespace_node *prw_node;
 532         struct acpi_gpe_event_info *gpe_event_info;
 533         union acpi_operand_object *pkg_desc;
 534         union acpi_operand_object *obj_desc;
 535         u32 gpe_number;
 536         acpi_status status;
 537
 538         ACPI_FUNCTION_TRACE(ev_match_prw_and_gpe);
 539
 540         /* Check for a _PRW method under this device */
 541
 542         status = acpi_ns_get_node(obj_handle, METHOD_NAME__PRW,
 543                                   ACPI_NS_NO_UPSEARCH, &prw_node);
 544         if (ACPI_FAILURE(status)) {
 545                 return_ACPI_STATUS(AE_OK);
 546         }
 547
 548         /* Check if requested owner_id matches this owner_id */
 549
 550         if ((walk_info->execute_by_owner_id) &&
 551             (prw_node->owner_id != walk_info->owner_id)) {
 552                 return_ACPI_STATUS(AE_OK);
 553         }
 554
 555         /* Execute the _PRW */
 556
 557         status = acpi_ut_evaluate_object(prw_node, NULL,
 558                                          ACPI_BTYPE_PACKAGE, &pkg_desc);
 559         if (ACPI_FAILURE(status)) {
 560                 return_ACPI_STATUS(AE_OK);
 561         }
 562
 563         /* The returned _PRW package must have at least two elements */
 564
 565         if (pkg_desc->package.count < 2) {
 566                 goto cleanup;
 567         }
 568
 569         /* Extract pointers from the input context */
 570
 571         gpe_device = walk_info->gpe_device;
 572         gpe_block = walk_info->gpe_block;
 573
 574         /*
 575          * The _PRW object must return a package, we are only interested
 576          * in the first element
 577          */
 578         obj_desc = pkg_desc->package.elements[0];
 579
 580         if (obj_desc->common.type == ACPI_TYPE_INTEGER) {
 581
 582                 /* Use FADT-defined GPE device (from definition of _PRW) */
 583
 584                 target_gpe_device = NULL;
 585                 if (gpe_device) {
 586                         target_gpe_device = acpi_gbl_fadt_gpe_device;
 587                 }
 588
 589                 /* Integer is the GPE number in the FADT described GPE blocks */
 590
 591                 gpe_number = (u32)obj_desc->integer.value;
 592         } else if (obj_desc->common.type == ACPI_TYPE_PACKAGE) {
 593
 594                 /* Package contains a GPE reference and GPE number within a GPE block */
 595
 596                 if ((obj_desc->package.count < 2) ||
 597                     ((obj_desc->package.elements[0])->common.type !=
 598                      ACPI_TYPE_LOCAL_REFERENCE) ||
 599                     ((obj_desc->package.elements[1])->common.type !=
 600                      ACPI_TYPE_INTEGER)) {
 601                         goto cleanup;
 602                 }
 603
 604                 /* Get GPE block reference and decode */
 605
 606                 target_gpe_device =
 607                     obj_desc->package.elements[0]->reference.node;
 608                 gpe_number = (u32)obj_desc->package.elements[1]->integer.value;
 609         } else {
 610                 /* Unknown type, just ignore it */
 611
 612                 goto cleanup;
 613         }
 614
 615         /* Get the gpe_event_info for this GPE */
 616
 617         if (gpe_device) {
 618                 /*
 619                  * Is this GPE within this block?
 620                  *
 621                  * TRUE if and only if these conditions are true:
 622                  *     1) The GPE devices match.
 623                  *     2) The GPE index(number) is within the range of the Gpe Block
 624                  *          associated with the GPE device.
 625                  */
 626                 if (gpe_device != target_gpe_device) {
 627                         goto cleanup;
 628                 }
 629
 630                 gpe_event_info =
 631                     acpi_ev_low_get_gpe_info(gpe_number, gpe_block);
 632         } else {
 633                 /* gpe_device is NULL, just match the target_device and gpe_number */
 634
 635                 gpe_event_info =
 636                     acpi_ev_get_gpe_event_info(target_gpe_device, gpe_number);
 637         }
 638
 639         if (gpe_event_info) {
 640                 if (!(gpe_event_info->flags & ACPI_GPE_CAN_WAKE)) {
 641
 642                         /* This GPE can wake the system */
 643
 644                         gpe_event_info->flags |= ACPI_GPE_CAN_WAKE;
 645                         walk_info->count++;
 646                 }
 647         }
 648
 649       cleanup:
 650         acpi_ut_remove_reference(pkg_desc);
 651         return_ACPI_STATUS(AE_OK);
 652 }