drivers/acpi/acpica/evregion.c

   1 /******************************************************************************
   2  *
   3  * Module Name: evregion - Operation Region support
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2013, 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("evregion")
  52
  53 extern u8 acpi_gbl_default_address_spaces[];
  54
  55 /* Local prototypes */
  56
  57 static void acpi_ev_orphan_ec_reg_method(void);
  58
  59 static acpi_status
  60 acpi_ev_reg_run(acpi_handle obj_handle,
  61                 u32 level, void *context, void **return_value);
  62
  63 /*******************************************************************************
  64  *
  65  * FUNCTION:    acpi_ev_initialize_op_regions
  66  *
  67  * PARAMETERS:  None
  68  *
  69  * RETURN:      Status
  70  *
  71  * DESCRIPTION: Execute _REG methods for all Operation Regions that have
  72  *              an installed default region handler.
  73  *
  74  ******************************************************************************/
  75
  76 acpi_status acpi_ev_initialize_op_regions(void)
  77 {
  78         acpi_status status;
  79         u32 i;
  80
  81         ACPI_FUNCTION_TRACE(ev_initialize_op_regions);
  82
  83         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
  84         if (ACPI_FAILURE(status)) {
  85                 return_ACPI_STATUS(status);
  86         }
  87
  88         /* Run the _REG methods for op_regions in each default address space */
  89
  90         for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++) {
  91                 /*
  92                  * Make sure the installed handler is the DEFAULT handler. If not the
  93                  * default, the _REG methods will have already been run (when the
  94                  * handler was installed)
  95                  */
  96                 if (acpi_ev_has_default_handler(acpi_gbl_root_node,
  97                                                 acpi_gbl_default_address_spaces
  98                                                 [i])) {
  99                         status =
 100                             acpi_ev_execute_reg_methods(acpi_gbl_root_node,
 101                                                         acpi_gbl_default_address_spaces
 102                                                         [i]);
 103                 }
 104         }
 105
 106         acpi_gbl_reg_methods_executed = TRUE;
 107
 108         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 109         return_ACPI_STATUS(status);
 110 }
 111
 112 /*******************************************************************************
 113  *
 114  * FUNCTION:    acpi_ev_address_space_dispatch
 115  *
 116  * PARAMETERS:  region_obj          - Internal region object
 117  *              field_obj           - Corresponding field. Can be NULL.
 118  *              function            - Read or Write operation
 119  *              region_offset       - Where in the region to read or write
 120  *              bit_width           - Field width in bits (8, 16, 32, or 64)
 121  *              value               - Pointer to in or out value, must be
 122  *                                    a full 64-bit integer
 123  *
 124  * RETURN:      Status
 125  *
 126  * DESCRIPTION: Dispatch an address space or operation region access to
 127  *              a previously installed handler.
 128  *
 129  ******************************************************************************/
 130
 131 acpi_status
 132 acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
 133                                union acpi_operand_object *field_obj,
 134                                u32 function,
 135                                u32 region_offset, u32 bit_width, u64 *value)
 136 {
 137         acpi_status status;
 138         acpi_adr_space_handler handler;
 139         acpi_adr_space_setup region_setup;
 140         union acpi_operand_object *handler_desc;
 141         union acpi_operand_object *region_obj2;
 142         void *region_context = NULL;
 143         struct acpi_connection_info *context;
 144
 145         ACPI_FUNCTION_TRACE(ev_address_space_dispatch);
 146
 147         region_obj2 = acpi_ns_get_secondary_object(region_obj);
 148         if (!region_obj2) {
 149                 return_ACPI_STATUS(AE_NOT_EXIST);
 150         }
 151
 152         /* Ensure that there is a handler associated with this region */
 153
 154         handler_desc = region_obj->region.handler;
 155         if (!handler_desc) {
 156                 ACPI_ERROR((AE_INFO,
 157                             "No handler for Region [%4.4s] (%p) [%s]",
 158                             acpi_ut_get_node_name(region_obj->region.node),
 159                             region_obj,
 160                             acpi_ut_get_region_name(region_obj->region.
 161                                                     space_id)));
 162
 163                 return_ACPI_STATUS(AE_NOT_EXIST);
 164         }
 165
 166         context = handler_desc->address_space.context;
 167
 168         /*
 169          * It may be the case that the region has never been initialized.
 170          * Some types of regions require special init code
 171          */
 172         if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
 173
 174                 /* This region has not been initialized yet, do it */
 175
 176                 region_setup = handler_desc->address_space.setup;
 177                 if (!region_setup) {
 178
 179                         /* No initialization routine, exit with error */
 180
 181                         ACPI_ERROR((AE_INFO,
 182                                     "No init routine for region(%p) [%s]",
 183                                     region_obj,
 184                                     acpi_ut_get_region_name(region_obj->region.
 185                                                             space_id)));
 186                         return_ACPI_STATUS(AE_NOT_EXIST);
 187                 }
 188
 189                 /*
 190                  * We must exit the interpreter because the region setup will
 191                  * potentially execute control methods (for example, the _REG method
 192                  * for this region)
 193                  */
 194                 acpi_ex_exit_interpreter();
 195
 196                 status = region_setup(region_obj, ACPI_REGION_ACTIVATE,
 197                                       context, &region_context);
 198
 199                 /* Re-enter the interpreter */
 200
 201                 acpi_ex_enter_interpreter();
 202
 203                 /* Check for failure of the Region Setup */
 204
 205                 if (ACPI_FAILURE(status)) {
 206                         ACPI_EXCEPTION((AE_INFO, status,
 207                                         "During region initialization: [%s]",
 208                                         acpi_ut_get_region_name(region_obj->
 209                                                                 region.
 210                                                                 space_id)));
 211                         return_ACPI_STATUS(status);
 212                 }
 213
 214                 /* Region initialization may have been completed by region_setup */
 215
 216                 if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
 217                         region_obj->region.flags |= AOPOBJ_SETUP_COMPLETE;
 218
 219                         if (region_obj2->extra.region_context) {
 220
 221                                 /* The handler for this region was already installed */
 222
 223                                 ACPI_FREE(region_context);
 224                         } else {
 225                                 /*
 226                                  * Save the returned context for use in all accesses to
 227                                  * this particular region
 228                                  */
 229                                 region_obj2->extra.region_context =
 230                                     region_context;
 231                         }
 232                 }
 233         }
 234
 235         /* We have everything we need, we can invoke the address space handler */
 236
 237         handler = handler_desc->address_space.handler;
 238
 239         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 240                           "Handler %p (@%p) Address %8.8X%8.8X [%s]\n",
 241                           &region_obj->region.handler->address_space, handler,
 242                           ACPI_FORMAT_NATIVE_UINT(region_obj->region.address +
 243                                                   region_offset),
 244                           acpi_ut_get_region_name(region_obj->region.
 245                                                   space_id)));
 246
 247         /*
 248          * Special handling for generic_serial_bus and general_purpose_io:
 249          * There are three extra parameters that must be passed to the
 250          * handler via the context:
 251          *   1) Connection buffer, a resource template from Connection() op.
 252          *   2) Length of the above buffer.
 253          *   3) Actual access length from the access_as() op.
 254          */
 255         if (((region_obj->region.space_id == ACPI_ADR_SPACE_GSBUS) ||
 256              (region_obj->region.space_id == ACPI_ADR_SPACE_GPIO)) &&
 257             context && field_obj) {
 258
 259                 /* Get the Connection (resource_template) buffer */
 260
 261                 context->connection = field_obj->field.resource_buffer;
 262                 context->length = field_obj->field.resource_length;
 263                 context->access_length = field_obj->field.access_length;
 264         }
 265
 266         if (!(handler_desc->address_space.handler_flags &
 267               ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
 268                 /*
 269                  * For handlers other than the default (supplied) handlers, we must
 270                  * exit the interpreter because the handler *might* block -- we don't
 271                  * know what it will do, so we can't hold the lock on the intepreter.
 272                  */
 273                 acpi_ex_exit_interpreter();
 274         }
 275
 276         /* Call the handler */
 277
 278         status = handler(function,
 279                          (region_obj->region.address + region_offset),
 280                          bit_width, value, context,
 281                          region_obj2->extra.region_context);
 282
 283         if (ACPI_FAILURE(status)) {
 284                 ACPI_EXCEPTION((AE_INFO, status, "Returned by Handler for [%s]",
 285                                 acpi_ut_get_region_name(region_obj->region.
 286                                                         space_id)));
 287         }
 288
 289         if (!(handler_desc->address_space.handler_flags &
 290               ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
 291                 /*
 292                  * We just returned from a non-default handler, we must re-enter the
 293                  * interpreter
 294                  */
 295                 acpi_ex_enter_interpreter();
 296         }
 297
 298         return_ACPI_STATUS(status);
 299 }
 300
 301 /*******************************************************************************
 302  *
 303  * FUNCTION:    acpi_ev_detach_region
 304  *
 305  * PARAMETERS:  region_obj          - Region Object
 306  *              acpi_ns_is_locked   - Namespace Region Already Locked?
 307  *
 308  * RETURN:      None
 309  *
 310  * DESCRIPTION: Break the association between the handler and the region
 311  *              this is a two way association.
 312  *
 313  ******************************************************************************/
 314
 315 void
 316 acpi_ev_detach_region(union acpi_operand_object *region_obj,
 317                       u8 acpi_ns_is_locked)
 318 {
 319         union acpi_operand_object *handler_obj;
 320         union acpi_operand_object *obj_desc;
 321         union acpi_operand_object **last_obj_ptr;
 322         acpi_adr_space_setup region_setup;
 323         void **region_context;
 324         union acpi_operand_object *region_obj2;
 325         acpi_status status;
 326
 327         ACPI_FUNCTION_TRACE(ev_detach_region);
 328
 329         region_obj2 = acpi_ns_get_secondary_object(region_obj);
 330         if (!region_obj2) {
 331                 return_VOID;
 332         }
 333         region_context = &region_obj2->extra.region_context;
 334
 335         /* Get the address handler from the region object */
 336
 337         handler_obj = region_obj->region.handler;
 338         if (!handler_obj) {
 339
 340                 /* This region has no handler, all done */
 341
 342                 return_VOID;
 343         }
 344
 345         /* Find this region in the handler's list */
 346
 347         obj_desc = handler_obj->address_space.region_list;
 348         last_obj_ptr = &handler_obj->address_space.region_list;
 349
 350         while (obj_desc) {
 351
 352                 /* Is this the correct Region? */
 353
 354                 if (obj_desc == region_obj) {
 355                         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 356                                           "Removing Region %p from address handler %p\n",
 357                                           region_obj, handler_obj));
 358
 359                         /* This is it, remove it from the handler's list */
 360
 361                         *last_obj_ptr = obj_desc->region.next;
 362                         obj_desc->region.next = NULL;   /* Must clear field */
 363
 364                         if (acpi_ns_is_locked) {
 365                                 status =
 366                                     acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 367                                 if (ACPI_FAILURE(status)) {
 368                                         return_VOID;
 369                                 }
 370                         }
 371
 372                         /* Now stop region accesses by executing the _REG method */
 373
 374                         status =
 375                             acpi_ev_execute_reg_method(region_obj,
 376                                                        ACPI_REG_DISCONNECT);
 377                         if (ACPI_FAILURE(status)) {
 378                                 ACPI_EXCEPTION((AE_INFO, status,
 379                                                 "from region _REG, [%s]",
 380                                                 acpi_ut_get_region_name
 381                                                 (region_obj->region.space_id)));
 382                         }
 383
 384                         if (acpi_ns_is_locked) {
 385                                 status =
 386                                     acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 387                                 if (ACPI_FAILURE(status)) {
 388                                         return_VOID;
 389                                 }
 390                         }
 391
 392                         /*
 393                          * If the region has been activated, call the setup handler with
 394                          * the deactivate notification
 395                          */
 396                         if (region_obj->region.flags & AOPOBJ_SETUP_COMPLETE) {
 397                                 region_setup = handler_obj->address_space.setup;
 398                                 status =
 399                                     region_setup(region_obj,
 400                                                  ACPI_REGION_DEACTIVATE,
 401                                                  handler_obj->address_space.
 402                                                  context, region_context);
 403
 404                                 /* Init routine may fail, Just ignore errors */
 405
 406                                 if (ACPI_FAILURE(status)) {
 407                                         ACPI_EXCEPTION((AE_INFO, status,
 408                                                         "from region handler - deactivate, [%s]",
 409                                                         acpi_ut_get_region_name
 410                                                         (region_obj->region.
 411                                                          space_id)));
 412                                 }
 413
 414                                 region_obj->region.flags &=
 415                                     ~(AOPOBJ_SETUP_COMPLETE);
 416                         }
 417
 418                         /*
 419                          * Remove handler reference in the region
 420                          *
 421                          * NOTE: this doesn't mean that the region goes away, the region
 422                          * is just inaccessible as indicated to the _REG method
 423                          *
 424                          * If the region is on the handler's list, this must be the
 425                          * region's handler
 426                          */
 427                         region_obj->region.handler = NULL;
 428                         acpi_ut_remove_reference(handler_obj);
 429
 430                         return_VOID;
 431                 }
 432
 433                 /* Walk the linked list of handlers */
 434
 435                 last_obj_ptr = &obj_desc->region.next;
 436                 obj_desc = obj_desc->region.next;
 437         }
 438
 439         /* If we get here, the region was not in the handler's region list */
 440
 441         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 442                           "Cannot remove region %p from address handler %p\n",
 443                           region_obj, handler_obj));
 444
 445         return_VOID;
 446 }
 447
 448 /*******************************************************************************
 449  *
 450  * FUNCTION:    acpi_ev_attach_region
 451  *
 452  * PARAMETERS:  handler_obj         - Handler Object
 453  *              region_obj          - Region Object
 454  *              acpi_ns_is_locked   - Namespace Region Already Locked?
 455  *
 456  * RETURN:      None
 457  *
 458  * DESCRIPTION: Create the association between the handler and the region
 459  *              this is a two way association.
 460  *
 461  ******************************************************************************/
 462
 463 acpi_status
 464 acpi_ev_attach_region(union acpi_operand_object *handler_obj,
 465                       union acpi_operand_object *region_obj,
 466                       u8 acpi_ns_is_locked)
 467 {
 468
 469         ACPI_FUNCTION_TRACE(ev_attach_region);
 470
 471         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 472                           "Adding Region [%4.4s] %p to address handler %p [%s]\n",
 473                           acpi_ut_get_node_name(region_obj->region.node),
 474                           region_obj, handler_obj,
 475                           acpi_ut_get_region_name(region_obj->region.
 476                                                   space_id)));
 477
 478         /* Link this region to the front of the handler's list */
 479
 480         region_obj->region.next = handler_obj->address_space.region_list;
 481         handler_obj->address_space.region_list = region_obj;
 482
 483         /* Install the region's handler */
 484
 485         if (region_obj->region.handler) {
 486                 return_ACPI_STATUS(AE_ALREADY_EXISTS);
 487         }
 488
 489         region_obj->region.handler = handler_obj;
 490         acpi_ut_add_reference(handler_obj);
 491
 492         return_ACPI_STATUS(AE_OK);
 493 }
 494
 495 /*******************************************************************************
 496  *
 497  * FUNCTION:    acpi_ev_execute_reg_method
 498  *
 499  * PARAMETERS:  region_obj          - Region object
 500  *              function            - Passed to _REG: On (1) or Off (0)
 501  *
 502  * RETURN:      Status
 503  *
 504  * DESCRIPTION: Execute _REG method for a region
 505  *
 506  ******************************************************************************/
 507
 508 acpi_status
 509 acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
 510 {
 511         struct acpi_evaluate_info *info;
 512         union acpi_operand_object *args[3];
 513         union acpi_operand_object *region_obj2;
 514         acpi_status status;
 515
 516         ACPI_FUNCTION_TRACE(ev_execute_reg_method);
 517
 518         region_obj2 = acpi_ns_get_secondary_object(region_obj);
 519         if (!region_obj2) {
 520                 return_ACPI_STATUS(AE_NOT_EXIST);
 521         }
 522
 523         if (region_obj2->extra.method_REG == NULL) {
 524                 return_ACPI_STATUS(AE_OK);
 525         }
 526
 527         /* Allocate and initialize the evaluation information block */
 528
 529         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 530         if (!info) {
 531                 return_ACPI_STATUS(AE_NO_MEMORY);
 532         }
 533
 534         info->prefix_node = region_obj2->extra.method_REG;
 535         info->pathname = NULL;
 536         info->parameters = args;
 537         info->flags = ACPI_IGNORE_RETURN_VALUE;
 538
 539         /*
 540          * The _REG method has two arguments:
 541          *
 542          * arg0 - Integer:
 543          *  Operation region space ID Same value as region_obj->Region.space_id
 544          *
 545          * arg1 - Integer:
 546          *  connection status 1 for connecting the handler, 0 for disconnecting
 547          *  the handler (Passed as a parameter)
 548          */
 549         args[0] =
 550             acpi_ut_create_integer_object((u64)region_obj->region.space_id);
 551         if (!args[0]) {
 552                 status = AE_NO_MEMORY;
 553                 goto cleanup1;
 554         }
 555
 556         args[1] = acpi_ut_create_integer_object((u64)function);
 557         if (!args[1]) {
 558                 status = AE_NO_MEMORY;
 559                 goto cleanup2;
 560         }
 561
 562         args[2] = NULL;         /* Terminate list */
 563
 564         /* Execute the method, no return value */
 565
 566         ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
 567                         (ACPI_TYPE_METHOD, info->prefix_node, NULL));
 568
 569         status = acpi_ns_evaluate(info);
 570         acpi_ut_remove_reference(args[1]);
 571
 572       cleanup2:
 573         acpi_ut_remove_reference(args[0]);
 574
 575       cleanup1:
 576         ACPI_FREE(info);
 577         return_ACPI_STATUS(status);
 578 }
 579
 580 /*******************************************************************************
 581  *
 582  * FUNCTION:    acpi_ev_execute_reg_methods
 583  *
 584  * PARAMETERS:  node            - Namespace node for the device
 585  *              space_id        - The address space ID
 586  *
 587  * RETURN:      Status
 588  *
 589  * DESCRIPTION: Run all _REG methods for the input Space ID;
 590  *              Note: assumes namespace is locked, or system init time.
 591  *
 592  ******************************************************************************/
 593
 594 acpi_status
 595 acpi_ev_execute_reg_methods(struct acpi_namespace_node *node,
 596                             acpi_adr_space_type space_id)
 597 {
 598         acpi_status status;
 599
 600         ACPI_FUNCTION_TRACE(ev_execute_reg_methods);
 601
 602         /*
 603          * Run all _REG methods for all Operation Regions for this space ID. This
 604          * is a separate walk in order to handle any interdependencies between
 605          * regions and _REG methods. (i.e. handlers must be installed for all
 606          * regions of this Space ID before we can run any _REG methods)
 607          */
 608         status = acpi_ns_walk_namespace(ACPI_TYPE_ANY, node, ACPI_UINT32_MAX,
 609                                         ACPI_NS_WALK_UNLOCK, acpi_ev_reg_run,
 610                                         NULL, &space_id, NULL);
 611
 612         /* Special case for EC: handle "orphan" _REG methods with no region */
 613
 614         if (space_id == ACPI_ADR_SPACE_EC) {
 615                 acpi_ev_orphan_ec_reg_method();
 616         }
 617
 618         return_ACPI_STATUS(status);
 619 }
 620
 621 /*******************************************************************************
 622  *
 623  * FUNCTION:    acpi_ev_reg_run
 624  *
 625  * PARAMETERS:  walk_namespace callback
 626  *
 627  * DESCRIPTION: Run _REG method for region objects of the requested spaceID
 628  *
 629  ******************************************************************************/
 630
 631 static acpi_status
 632 acpi_ev_reg_run(acpi_handle obj_handle,
 633                 u32 level, void *context, void **return_value)
 634 {
 635         union acpi_operand_object *obj_desc;
 636         struct acpi_namespace_node *node;
 637         acpi_adr_space_type space_id;
 638         acpi_status status;
 639
 640         space_id = *ACPI_CAST_PTR(acpi_adr_space_type, context);
 641
 642         /* Convert and validate the device handle */
 643
 644         node = acpi_ns_validate_handle(obj_handle);
 645         if (!node) {
 646                 return (AE_BAD_PARAMETER);
 647         }
 648
 649         /*
 650          * We only care about regions.and objects that are allowed to have address
 651          * space handlers
 652          */
 653         if ((node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
 654                 return (AE_OK);
 655         }
 656
 657         /* Check for an existing internal object */
 658
 659         obj_desc = acpi_ns_get_attached_object(node);
 660         if (!obj_desc) {
 661
 662                 /* No object, just exit */
 663
 664                 return (AE_OK);
 665         }
 666
 667         /* Object is a Region */
 668
 669         if (obj_desc->region.space_id != space_id) {
 670
 671                 /* This region is for a different address space, just ignore it */
 672
 673                 return (AE_OK);
 674         }
 675
 676         status = acpi_ev_execute_reg_method(obj_desc, ACPI_REG_CONNECT);
 677         return (status);
 678 }
 679
 680 /*******************************************************************************
 681  *
 682  * FUNCTION:    acpi_ev_orphan_ec_reg_method
 683  *
 684  * PARAMETERS:  None
 685  *
 686  * RETURN:      None
 687  *
 688  * DESCRIPTION: Execute an "orphan" _REG method that appears under the EC
 689  *              device. This is a _REG method that has no corresponding region
 690  *              within the EC device scope. The orphan _REG method appears to
 691  *              have been enabled by the description of the ECDT in the ACPI
 692  *              specification: "The availability of the region space can be
 693  *              detected by providing a _REG method object underneath the
 694  *              Embedded Controller device."
 695  *
 696  *              To quickly access the EC device, we use the EC_ID that appears
 697  *              within the ECDT. Otherwise, we would need to perform a time-
 698  *              consuming namespace walk, executing _HID methods to find the
 699  *              EC device.
 700  *
 701  ******************************************************************************/
 702
 703 static void acpi_ev_orphan_ec_reg_method(void)
 704 {
 705         struct acpi_table_ecdt *table;
 706         acpi_status status;
 707         struct acpi_object_list args;
 708         union acpi_object objects[2];
 709         struct acpi_namespace_node *ec_device_node;
 710         struct acpi_namespace_node *reg_method;
 711         struct acpi_namespace_node *next_node;
 712
 713         ACPI_FUNCTION_TRACE(ev_orphan_ec_reg_method);
 714
 715         /* Get the ECDT (if present in system) */
 716
 717         status = acpi_get_table(ACPI_SIG_ECDT, 0,
 718                                 ACPI_CAST_INDIRECT_PTR(struct acpi_table_header,
 719                                                        &table));
 720         if (ACPI_FAILURE(status)) {
 721                 return_VOID;
 722         }
 723
 724         /* We need a valid EC_ID string */
 725
 726         if (!(*table->id)) {
 727                 return_VOID;
 728         }
 729
 730         /* Namespace is currently locked, must release */
 731
 732         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 733
 734         /* Get a handle to the EC device referenced in the ECDT */
 735
 736         status = acpi_get_handle(NULL,
 737                                  ACPI_CAST_PTR(char, table->id),
 738                                  ACPI_CAST_PTR(acpi_handle, &ec_device_node));
 739         if (ACPI_FAILURE(status)) {
 740                 goto exit;
 741         }
 742
 743         /* Get a handle to a _REG method immediately under the EC device */
 744
 745         status = acpi_get_handle(ec_device_node,
 746                                  METHOD_NAME__REG, ACPI_CAST_PTR(acpi_handle,
 747                                                                  &reg_method));
 748         if (ACPI_FAILURE(status)) {
 749                 goto exit;
 750         }
 751
 752         /*
 753          * Execute the _REG method only if there is no Operation Region in
 754          * this scope with the Embedded Controller space ID. Otherwise, it
 755          * will already have been executed. Note, this allows for Regions
 756          * with other space IDs to be present; but the code below will then
 757          * execute the _REG method with the EC space ID argument.
 758          */
 759         next_node = acpi_ns_get_next_node(ec_device_node, NULL);
 760         while (next_node) {
 761                 if ((next_node->type == ACPI_TYPE_REGION) &&
 762                     (next_node->object) &&
 763                     (next_node->object->region.space_id == ACPI_ADR_SPACE_EC)) {
 764                         goto exit;      /* Do not execute _REG */
 765                 }
 766                 next_node = acpi_ns_get_next_node(ec_device_node, next_node);
 767         }
 768
 769         /* Evaluate the _REG(EC,Connect) method */
 770
 771         args.count = 2;
 772         args.pointer = objects;
 773         objects[0].type = ACPI_TYPE_INTEGER;
 774         objects[0].integer.value = ACPI_ADR_SPACE_EC;
 775         objects[1].type = ACPI_TYPE_INTEGER;
 776         objects[1].integer.value = ACPI_REG_CONNECT;
 777
 778         status = acpi_evaluate_object(reg_method, NULL, &args, NULL);
 779
 780       exit:
 781         /* We ignore all errors from above, don't care */
 782
 783         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 784         return_VOID;
 785 }