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