kernel/drivers/acpi/acpica/evregion.c

   1 /******************************************************************************
   2  *
   3  * Module Name: evregion - Operation Region support
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2015, 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         acpi_physical_address address;
 146
 147         ACPI_FUNCTION_TRACE(ev_address_space_dispatch);
 148
 149         region_obj2 = acpi_ns_get_secondary_object(region_obj);
 150         if (!region_obj2) {
 151                 return_ACPI_STATUS(AE_NOT_EXIST);
 152         }
 153
 154         /* Ensure that there is a handler associated with this region */
 155
 156         handler_desc = region_obj->region.handler;
 157         if (!handler_desc) {
 158                 ACPI_ERROR((AE_INFO,
 159                             "No handler for Region [%4.4s] (%p) [%s]",
 160                             acpi_ut_get_node_name(region_obj->region.node),
 161                             region_obj,
 162                             acpi_ut_get_region_name(region_obj->region.
 163                                                     space_id)));
 164
 165                 return_ACPI_STATUS(AE_NOT_EXIST);
 166         }
 167
 168         context = handler_desc->address_space.context;
 169
 170         /*
 171          * It may be the case that the region has never been initialized.
 172          * Some types of regions require special init code
 173          */
 174         if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
 175
 176                 /* This region has not been initialized yet, do it */
 177
 178                 region_setup = handler_desc->address_space.setup;
 179                 if (!region_setup) {
 180
 181                         /* No initialization routine, exit with error */
 182
 183                         ACPI_ERROR((AE_INFO,
 184                                     "No init routine for region(%p) [%s]",
 185                                     region_obj,
 186                                     acpi_ut_get_region_name(region_obj->region.
 187                                                             space_id)));
 188                         return_ACPI_STATUS(AE_NOT_EXIST);
 189                 }
 190
 191                 /*
 192                  * We must exit the interpreter because the region setup will
 193                  * potentially execute control methods (for example, the _REG method
 194                  * for this region)
 195                  */
 196                 acpi_ex_exit_interpreter();
 197
 198                 status = region_setup(region_obj, ACPI_REGION_ACTIVATE,
 199                                       context, &region_context);
 200
 201                 /* Re-enter the interpreter */
 202
 203                 acpi_ex_enter_interpreter();
 204
 205                 /* Check for failure of the Region Setup */
 206
 207                 if (ACPI_FAILURE(status)) {
 208                         ACPI_EXCEPTION((AE_INFO, status,
 209                                         "During region initialization: [%s]",
 210                                         acpi_ut_get_region_name(region_obj->
 211                                                                 region.
 212                                                                 space_id)));
 213                         return_ACPI_STATUS(status);
 214                 }
 215
 216                 /* Region initialization may have been completed by region_setup */
 217
 218                 if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
 219                         region_obj->region.flags |= AOPOBJ_SETUP_COMPLETE;
 220
 221                         /*
 222                          * Save the returned context for use in all accesses to
 223                          * the handler for this particular region
 224                          */
 225                         if (!(region_obj2->extra.region_context)) {
 226                                 region_obj2->extra.region_context =
 227                                     region_context;
 228                         }
 229                 }
 230         }
 231
 232         /* We have everything we need, we can invoke the address space handler */
 233
 234         handler = handler_desc->address_space.handler;
 235         address = (region_obj->region.address + region_offset);
 236
 237         /*
 238          * Special handling for generic_serial_bus and general_purpose_io:
 239          * There are three extra parameters that must be passed to the
 240          * handler via the context:
 241          *   1) Connection buffer, a resource template from Connection() op
 242          *   2) Length of the above buffer
 243          *   3) Actual access length from the access_as() op
 244          *
 245          * In addition, for general_purpose_io, the Address and bit_width fields
 246          * are defined as follows:
 247          *   1) Address is the pin number index of the field (bit offset from
 248          *      the previous Connection)
 249          *   2) bit_width is the actual bit length of the field (number of pins)
 250          */
 251         if ((region_obj->region.space_id == ACPI_ADR_SPACE_GSBUS) &&
 252             context && field_obj) {
 253
 254                 /* Get the Connection (resource_template) buffer */
 255
 256                 context->connection = field_obj->field.resource_buffer;
 257                 context->length = field_obj->field.resource_length;
 258                 context->access_length = field_obj->field.access_length;
 259         }
 260         if ((region_obj->region.space_id == ACPI_ADR_SPACE_GPIO) &&
 261             context && field_obj) {
 262
 263                 /* Get the Connection (resource_template) buffer */
 264
 265                 context->connection = field_obj->field.resource_buffer;
 266                 context->length = field_obj->field.resource_length;
 267                 context->access_length = field_obj->field.access_length;
 268                 address = field_obj->field.pin_number_index;
 269                 bit_width = field_obj->field.bit_length;
 270         }
 271
 272         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 273                           "Handler %p (@%p) Address %8.8X%8.8X [%s]\n",
 274                           &region_obj->region.handler->address_space, handler,
 275                           ACPI_FORMAT_UINT64(address),
 276                           acpi_ut_get_region_name(region_obj->region.
 277                                                   space_id)));
 278
 279         if (!(handler_desc->address_space.handler_flags &
 280               ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
 281                 /*
 282                  * For handlers other than the default (supplied) handlers, we must
 283                  * exit the interpreter because the handler *might* block -- we don't
 284                  * know what it will do, so we can't hold the lock on the intepreter.
 285                  */
 286                 acpi_ex_exit_interpreter();
 287         }
 288
 289         /* Call the handler */
 290
 291         status = handler(function, address, bit_width, value, context,
 292                          region_obj2->extra.region_context);
 293
 294         if (ACPI_FAILURE(status)) {
 295                 ACPI_EXCEPTION((AE_INFO, status, "Returned by Handler for [%s]",
 296                                 acpi_ut_get_region_name(region_obj->region.
 297                                                         space_id)));
 298         }
 299
 300         if (!(handler_desc->address_space.handler_flags &
 301               ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
 302                 /*
 303                  * We just returned from a non-default handler, we must re-enter the
 304                  * interpreter
 305                  */
 306                 acpi_ex_enter_interpreter();
 307         }
 308
 309         return_ACPI_STATUS(status);
 310 }
 311
 312 /*******************************************************************************
 313  *
 314  * FUNCTION:    acpi_ev_detach_region
 315  *
 316  * PARAMETERS:  region_obj          - Region Object
 317  *              acpi_ns_is_locked   - Namespace Region Already Locked?
 318  *
 319  * RETURN:      None
 320  *
 321  * DESCRIPTION: Break the association between the handler and the region
 322  *              this is a two way association.
 323  *
 324  ******************************************************************************/
 325
 326 void
 327 acpi_ev_detach_region(union acpi_operand_object *region_obj,
 328                       u8 acpi_ns_is_locked)
 329 {
 330         union acpi_operand_object *handler_obj;
 331         union acpi_operand_object *obj_desc;
 332         union acpi_operand_object *start_desc;
 333         union acpi_operand_object **last_obj_ptr;
 334         acpi_adr_space_setup region_setup;
 335         void **region_context;
 336         union acpi_operand_object *region_obj2;
 337         acpi_status status;
 338
 339         ACPI_FUNCTION_TRACE(ev_detach_region);
 340
 341         region_obj2 = acpi_ns_get_secondary_object(region_obj);
 342         if (!region_obj2) {
 343                 return_VOID;
 344         }
 345         region_context = &region_obj2->extra.region_context;
 346
 347         /* Get the address handler from the region object */
 348
 349         handler_obj = region_obj->region.handler;
 350         if (!handler_obj) {
 351
 352                 /* This region has no handler, all done */
 353
 354                 return_VOID;
 355         }
 356
 357         /* Find this region in the handler's list */
 358
 359         obj_desc = handler_obj->address_space.region_list;
 360         start_desc = obj_desc;
 361         last_obj_ptr = &handler_obj->address_space.region_list;
 362
 363         while (obj_desc) {
 364
 365                 /* Is this the correct Region? */
 366
 367                 if (obj_desc == region_obj) {
 368                         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 369                                           "Removing Region %p from address handler %p\n",
 370                                           region_obj, handler_obj));
 371
 372                         /* This is it, remove it from the handler's list */
 373
 374                         *last_obj_ptr = obj_desc->region.next;
 375                         obj_desc->region.next = NULL;   /* Must clear field */
 376
 377                         if (acpi_ns_is_locked) {
 378                                 status =
 379                                     acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 380                                 if (ACPI_FAILURE(status)) {
 381                                         return_VOID;
 382                                 }
 383                         }
 384
 385                         /* Now stop region accesses by executing the _REG method */
 386
 387                         status =
 388                             acpi_ev_execute_reg_method(region_obj,
 389                                                        ACPI_REG_DISCONNECT);
 390                         if (ACPI_FAILURE(status)) {
 391                                 ACPI_EXCEPTION((AE_INFO, status,
 392                                                 "from region _REG, [%s]",
 393                                                 acpi_ut_get_region_name
 394                                                 (region_obj->region.space_id)));
 395                         }
 396
 397                         if (acpi_ns_is_locked) {
 398                                 status =
 399                                     acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 400                                 if (ACPI_FAILURE(status)) {
 401                                         return_VOID;
 402                                 }
 403                         }
 404
 405                         /*
 406                          * If the region has been activated, call the setup handler with
 407                          * the deactivate notification
 408                          */
 409                         if (region_obj->region.flags & AOPOBJ_SETUP_COMPLETE) {
 410                                 region_setup = handler_obj->address_space.setup;
 411                                 status =
 412                                     region_setup(region_obj,
 413                                                  ACPI_REGION_DEACTIVATE,
 414                                                  handler_obj->address_space.
 415                                                  context, region_context);
 416
 417                                 /*
 418                                  * region_context should have been released by the deactivate
 419                                  * operation. We don't need access to it anymore here.
 420                                  */
 421                                 if (region_context) {
 422                                         *region_context = NULL;
 423                                 }
 424
 425                                 /* Init routine may fail, Just ignore errors */
 426
 427                                 if (ACPI_FAILURE(status)) {
 428                                         ACPI_EXCEPTION((AE_INFO, status,
 429                                                         "from region handler - deactivate, [%s]",
 430                                                         acpi_ut_get_region_name
 431                                                         (region_obj->region.
 432                                                          space_id)));
 433                                 }
 434
 435                                 region_obj->region.flags &=
 436                                     ~(AOPOBJ_SETUP_COMPLETE);
 437                         }
 438
 439                         /*
 440                          * Remove handler reference in the region
 441                          *
 442                          * NOTE: this doesn't mean that the region goes away, the region
 443                          * is just inaccessible as indicated to the _REG method
 444                          *
 445                          * If the region is on the handler's list, this must be the
 446                          * region's handler
 447                          */
 448                         region_obj->region.handler = NULL;
 449                         acpi_ut_remove_reference(handler_obj);
 450
 451                         return_VOID;
 452                 }
 453
 454                 /* Walk the linked list of handlers */
 455
 456                 last_obj_ptr = &obj_desc->region.next;
 457                 obj_desc = obj_desc->region.next;
 458
 459                 /* Prevent infinite loop if list is corrupted */
 460
 461                 if (obj_desc == start_desc) {
 462                         ACPI_ERROR((AE_INFO,
 463                                     "Circular handler list in region object %p",
 464                                     region_obj));
 465                         return_VOID;
 466                 }
 467         }
 468
 469         /* If we get here, the region was not in the handler's region list */
 470
 471         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 472                           "Cannot remove region %p from address handler %p\n",
 473                           region_obj, handler_obj));
 474
 475         return_VOID;
 476 }
 477
 478 /*******************************************************************************
 479  *
 480  * FUNCTION:    acpi_ev_attach_region
 481  *
 482  * PARAMETERS:  handler_obj         - Handler Object
 483  *              region_obj          - Region Object
 484  *              acpi_ns_is_locked   - Namespace Region Already Locked?
 485  *
 486  * RETURN:      None
 487  *
 488  * DESCRIPTION: Create the association between the handler and the region
 489  *              this is a two way association.
 490  *
 491  ******************************************************************************/
 492
 493 acpi_status
 494 acpi_ev_attach_region(union acpi_operand_object *handler_obj,
 495                       union acpi_operand_object *region_obj,
 496                       u8 acpi_ns_is_locked)
 497 {
 498
 499         ACPI_FUNCTION_TRACE(ev_attach_region);
 500
 501         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 502                           "Adding Region [%4.4s] %p to address handler %p [%s]\n",
 503                           acpi_ut_get_node_name(region_obj->region.node),
 504                           region_obj, handler_obj,
 505                           acpi_ut_get_region_name(region_obj->region.
 506                                                   space_id)));
 507
 508         /* Link this region to the front of the handler's list */
 509
 510         region_obj->region.next = handler_obj->address_space.region_list;
 511         handler_obj->address_space.region_list = region_obj;
 512
 513         /* Install the region's handler */
 514
 515         if (region_obj->region.handler) {
 516                 return_ACPI_STATUS(AE_ALREADY_EXISTS);
 517         }
 518
 519         region_obj->region.handler = handler_obj;
 520         acpi_ut_add_reference(handler_obj);
 521
 522         return_ACPI_STATUS(AE_OK);
 523 }
 524
 525 /*******************************************************************************
 526  *
 527  * FUNCTION:    acpi_ev_execute_reg_method
 528  *
 529  * PARAMETERS:  region_obj          - Region object
 530  *              function            - Passed to _REG: On (1) or Off (0)
 531  *
 532  * RETURN:      Status
 533  *
 534  * DESCRIPTION: Execute _REG method for a region
 535  *
 536  ******************************************************************************/
 537
 538 acpi_status
 539 acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
 540 {
 541         struct acpi_evaluate_info *info;
 542         union acpi_operand_object *args[3];
 543         union acpi_operand_object *region_obj2;
 544         acpi_status status;
 545
 546         ACPI_FUNCTION_TRACE(ev_execute_reg_method);
 547
 548         region_obj2 = acpi_ns_get_secondary_object(region_obj);
 549         if (!region_obj2) {
 550                 return_ACPI_STATUS(AE_NOT_EXIST);
 551         }
 552
 553         if (region_obj2->extra.method_REG == NULL) {
 554                 return_ACPI_STATUS(AE_OK);
 555         }
 556
 557         /* Allocate and initialize the evaluation information block */
 558
 559         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 560         if (!info) {
 561                 return_ACPI_STATUS(AE_NO_MEMORY);
 562         }
 563
 564         info->prefix_node = region_obj2->extra.method_REG;
 565         info->relative_pathname = NULL;
 566         info->parameters = args;
 567         info->flags = ACPI_IGNORE_RETURN_VALUE;
 568
 569         /*
 570          * The _REG method has two arguments:
 571          *
 572          * arg0 - Integer:
 573          *  Operation region space ID Same value as region_obj->Region.space_id
 574          *
 575          * arg1 - Integer:
 576          *  connection status 1 for connecting the handler, 0 for disconnecting
 577          *  the handler (Passed as a parameter)
 578          */
 579         args[0] =
 580             acpi_ut_create_integer_object((u64)region_obj->region.space_id);
 581         if (!args[0]) {
 582                 status = AE_NO_MEMORY;
 583                 goto cleanup1;
 584         }
 585
 586         args[1] = acpi_ut_create_integer_object((u64)function);
 587         if (!args[1]) {
 588                 status = AE_NO_MEMORY;
 589                 goto cleanup2;
 590         }
 591
 592         args[2] = NULL;         /* Terminate list */
 593
 594         /* Execute the method, no return value */
 595
 596         ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
 597                         (ACPI_TYPE_METHOD, info->prefix_node, NULL));
 598
 599         status = acpi_ns_evaluate(info);
 600         acpi_ut_remove_reference(args[1]);
 601
 602 cleanup2:
 603         acpi_ut_remove_reference(args[0]);
 604
 605 cleanup1:
 606         ACPI_FREE(info);
 607         return_ACPI_STATUS(status);
 608 }
 609
 610 /*******************************************************************************
 611  *
 612  * FUNCTION:    acpi_ev_execute_reg_methods
 613  *
 614  * PARAMETERS:  node            - Namespace node for the device
 615  *              space_id        - The address space ID
 616  *
 617  * RETURN:      Status
 618  *
 619  * DESCRIPTION: Run all _REG methods for the input Space ID;
 620  *              Note: assumes namespace is locked, or system init time.
 621  *
 622  ******************************************************************************/
 623
 624 acpi_status
 625 acpi_ev_execute_reg_methods(struct acpi_namespace_node *node,
 626                             acpi_adr_space_type space_id)
 627 {
 628         acpi_status status;
 629
 630         ACPI_FUNCTION_TRACE(ev_execute_reg_methods);
 631
 632         /*
 633          * Run all _REG methods for all Operation Regions for this space ID. This
 634          * is a separate walk in order to handle any interdependencies between
 635          * regions and _REG methods. (i.e. handlers must be installed for all
 636          * regions of this Space ID before we can run any _REG methods)
 637          */
 638         status = acpi_ns_walk_namespace(ACPI_TYPE_ANY, node, ACPI_UINT32_MAX,
 639                                         ACPI_NS_WALK_UNLOCK, acpi_ev_reg_run,
 640                                         NULL, &space_id, NULL);
 641
 642         /* Special case for EC: handle "orphan" _REG methods with no region */
 643
 644         if (space_id == ACPI_ADR_SPACE_EC) {
 645                 acpi_ev_orphan_ec_reg_method(node);
 646         }
 647
 648         return_ACPI_STATUS(status);
 649 }
 650
 651 /*******************************************************************************
 652  *
 653  * FUNCTION:    acpi_ev_reg_run
 654  *
 655  * PARAMETERS:  walk_namespace callback
 656  *
 657  * DESCRIPTION: Run _REG method for region objects of the requested spaceID
 658  *
 659  ******************************************************************************/
 660
 661 static acpi_status
 662 acpi_ev_reg_run(acpi_handle obj_handle,
 663                 u32 level, void *context, void **return_value)
 664 {
 665         union acpi_operand_object *obj_desc;
 666         struct acpi_namespace_node *node;
 667         acpi_adr_space_type space_id;
 668         acpi_status status;
 669
 670         space_id = *ACPI_CAST_PTR(acpi_adr_space_type, context);
 671
 672         /* Convert and validate the device handle */
 673
 674         node = acpi_ns_validate_handle(obj_handle);
 675         if (!node) {
 676                 return (AE_BAD_PARAMETER);
 677         }
 678
 679         /*
 680          * We only care about regions.and objects that are allowed to have address
 681          * space handlers
 682          */
 683         if ((node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
 684                 return (AE_OK);
 685         }
 686
 687         /* Check for an existing internal object */
 688
 689         obj_desc = acpi_ns_get_attached_object(node);
 690         if (!obj_desc) {
 691
 692                 /* No object, just exit */
 693
 694                 return (AE_OK);
 695         }
 696
 697         /* Object is a Region */
 698
 699         if (obj_desc->region.space_id != space_id) {
 700
 701                 /* This region is for a different address space, just ignore it */
 702
 703                 return (AE_OK);
 704         }
 705
 706         status = acpi_ev_execute_reg_method(obj_desc, ACPI_REG_CONNECT);
 707         return (status);
 708 }
 709
 710 /*******************************************************************************
 711  *
 712  * FUNCTION:    acpi_ev_orphan_ec_reg_method
 713  *
 714  * PARAMETERS:  ec_device_node      - Namespace node for an EC device
 715  *
 716  * RETURN:      None
 717  *
 718  * DESCRIPTION: Execute an "orphan" _REG method that appears under the EC
 719  *              device. This is a _REG method that has no corresponding region
 720  *              within the EC device scope. The orphan _REG method appears to
 721  *              have been enabled by the description of the ECDT in the ACPI
 722  *              specification: "The availability of the region space can be
 723  *              detected by providing a _REG method object underneath the
 724  *              Embedded Controller device."
 725  *
 726  *              To quickly access the EC device, we use the ec_device_node used
 727  *              during EC handler installation. Otherwise, we would need to
 728  *              perform a time consuming namespace walk, executing _HID
 729  *              methods to find the EC device.
 730  *
 731  *  MUTEX:      Assumes the namespace is locked
 732  *
 733  ******************************************************************************/
 734
 735 static void
 736 acpi_ev_orphan_ec_reg_method(struct acpi_namespace_node *ec_device_node)
 737 {
 738         acpi_handle reg_method;
 739         struct acpi_namespace_node *next_node;
 740         acpi_status status;
 741         struct acpi_object_list args;
 742         union acpi_object objects[2];
 743
 744         ACPI_FUNCTION_TRACE(ev_orphan_ec_reg_method);
 745
 746         if (!ec_device_node) {
 747                 return_VOID;
 748         }
 749
 750         /* Namespace is currently locked, must release */
 751
 752         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 753
 754         /* Get a handle to a _REG method immediately under the EC device */
 755
 756         status = acpi_get_handle(ec_device_node, METHOD_NAME__REG, &reg_method);
 757         if (ACPI_FAILURE(status)) {
 758                 goto exit;      /* There is no _REG method present */
 759         }
 760
 761         /*
 762          * Execute the _REG method only if there is no Operation Region in
 763          * this scope with the Embedded Controller space ID. Otherwise, it
 764          * will already have been executed. Note, this allows for Regions
 765          * with other space IDs to be present; but the code below will then
 766          * execute the _REG method with the embedded_control space_ID argument.
 767          */
 768         next_node = acpi_ns_get_next_node(ec_device_node, NULL);
 769         while (next_node) {
 770                 if ((next_node->type == ACPI_TYPE_REGION) &&
 771                     (next_node->object) &&
 772                     (next_node->object->region.space_id == ACPI_ADR_SPACE_EC)) {
 773                         goto exit;      /* Do not execute the _REG */
 774                 }
 775
 776                 next_node = acpi_ns_get_next_node(ec_device_node, next_node);
 777         }
 778
 779         /* Evaluate the _REG(embedded_control,Connect) method */
 780
 781         args.count = 2;
 782         args.pointer = objects;
 783         objects[0].type = ACPI_TYPE_INTEGER;
 784         objects[0].integer.value = ACPI_ADR_SPACE_EC;
 785         objects[1].type = ACPI_TYPE_INTEGER;
 786         objects[1].integer.value = ACPI_REG_CONNECT;
 787
 788         status = acpi_evaluate_object(reg_method, NULL, &args, NULL);
 789
 790 exit:
 791         /* We ignore all errors from above, don't care */
 792
 793         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 794         return_VOID;
 795 }