drivers/acpi/acpica/evregion.c

   1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
   2 /******************************************************************************
   3  *
   4  * Module Name: evregion - Operation Region support
   5  *
   6  * Copyright (C) 2000 - 2022, Intel Corp.
   7  *
   8  *****************************************************************************/
   9
  10 #include <acpi/acpi.h>
  11 #include "accommon.h"
  12 #include "acevents.h"
  13 #include "acnamesp.h"
  14 #include "acinterp.h"
  15
  16 #define _COMPONENT          ACPI_EVENTS
  17 ACPI_MODULE_NAME("evregion")
  18
  19 extern u8 acpi_gbl_default_address_spaces[];
  20
  21 /* Local prototypes */
  22
  23 static void
  24 acpi_ev_execute_orphan_reg_method(struct acpi_namespace_node *device_node,
  25                                   acpi_adr_space_type space_id);
  26
  27 static acpi_status
  28 acpi_ev_reg_run(acpi_handle obj_handle,
  29                 u32 level, void *context, void **return_value);
  30
  31 /*******************************************************************************
  32  *
  33  * FUNCTION:    acpi_ev_initialize_op_regions
  34  *
  35  * PARAMETERS:  None
  36  *
  37  * RETURN:      Status
  38  *
  39  * DESCRIPTION: Execute _REG methods for all Operation Regions that have
  40  *              an installed default region handler.
  41  *
  42  ******************************************************************************/
  43
  44 acpi_status acpi_ev_initialize_op_regions(void)
  45 {
  46         acpi_status status;
  47         u32 i;
  48
  49         ACPI_FUNCTION_TRACE(ev_initialize_op_regions);
  50
  51         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
  52         if (ACPI_FAILURE(status)) {
  53                 return_ACPI_STATUS(status);
  54         }
  55
  56         /* Run the _REG methods for op_regions in each default address space */
  57
  58         for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++) {
  59                 /*
  60                  * Make sure the installed handler is the DEFAULT handler. If not the
  61                  * default, the _REG methods will have already been run (when the
  62                  * handler was installed)
  63                  */
  64                 if (acpi_ev_has_default_handler(acpi_gbl_root_node,
  65                                                 acpi_gbl_default_address_spaces
  66                                                 [i])) {
  67                         acpi_ev_execute_reg_methods(acpi_gbl_root_node,
  68                                                     acpi_gbl_default_address_spaces
  69                                                     [i], ACPI_REG_CONNECT);
  70                 }
  71         }
  72
  73         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
  74         return_ACPI_STATUS(status);
  75 }
  76
  77 /*******************************************************************************
  78  *
  79  * FUNCTION:    acpi_ev_address_space_dispatch
  80  *
  81  * PARAMETERS:  region_obj          - Internal region object
  82  *              field_obj           - Corresponding field. Can be NULL.
  83  *              function            - Read or Write operation
  84  *              region_offset       - Where in the region to read or write
  85  *              bit_width           - Field width in bits (8, 16, 32, or 64)
  86  *              value               - Pointer to in or out value, must be
  87  *                                    a full 64-bit integer
  88  *
  89  * RETURN:      Status
  90  *
  91  * DESCRIPTION: Dispatch an address space or operation region access to
  92  *              a previously installed handler.
  93  *
  94  * NOTE: During early initialization, we always install the default region
  95  * handlers for Memory, I/O and PCI_Config. This ensures that these operation
  96  * region address spaces are always available as per the ACPI specification.
  97  * This is especially needed in order to support the execution of
  98  * module-level AML code during loading of the ACPI tables.
  99  *
 100  ******************************************************************************/
 101
 102 acpi_status
 103 acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
 104                                union acpi_operand_object *field_obj,
 105                                u32 function,
 106                                u32 region_offset, u32 bit_width, u64 *value)
 107 {
 108         acpi_status status;
 109         acpi_adr_space_handler handler;
 110         acpi_adr_space_setup region_setup;
 111         union acpi_operand_object *handler_desc;
 112         union acpi_operand_object *region_obj2;
 113         void *region_context = NULL;
 114         struct acpi_connection_info *context;
 115         acpi_mutex context_mutex;
 116         u8 context_locked;
 117         acpi_physical_address address;
 118
 119         ACPI_FUNCTION_TRACE(ev_address_space_dispatch);
 120
 121         region_obj2 = acpi_ns_get_secondary_object(region_obj);
 122         if (!region_obj2) {
 123                 return_ACPI_STATUS(AE_NOT_EXIST);
 124         }
 125
 126         /* Ensure that there is a handler associated with this region */
 127
 128         handler_desc = region_obj->region.handler;
 129         if (!handler_desc) {
 130                 ACPI_ERROR((AE_INFO,
 131                             "No handler for Region [%4.4s] (%p) [%s]",
 132                             acpi_ut_get_node_name(region_obj->region.node),
 133                             region_obj,
 134                             acpi_ut_get_region_name(region_obj->region.
 135                                                     space_id)));
 136
 137                 return_ACPI_STATUS(AE_NOT_EXIST);
 138         }
 139
 140         context = handler_desc->address_space.context;
 141         context_mutex = handler_desc->address_space.context_mutex;
 142         context_locked = FALSE;
 143
 144         /*
 145          * It may be the case that the region has never been initialized.
 146          * Some types of regions require special init code
 147          */
 148         if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
 149
 150                 /* This region has not been initialized yet, do it */
 151
 152                 region_setup = handler_desc->address_space.setup;
 153                 if (!region_setup) {
 154
 155                         /* No initialization routine, exit with error */
 156
 157                         ACPI_ERROR((AE_INFO,
 158                                     "No init routine for region(%p) [%s]",
 159                                     region_obj,
 160                                     acpi_ut_get_region_name(region_obj->region.
 161                                                             space_id)));
 162                         return_ACPI_STATUS(AE_NOT_EXIST);
 163                 }
 164
 165                 if (region_obj->region.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
 166                         struct acpi_pcc_info *ctx =
 167                             handler_desc->address_space.context;
 168
 169                         ctx->internal_buffer =
 170                             field_obj->field.internal_pcc_buffer;
 171                         ctx->length = (u16)region_obj->region.length;
 172                         ctx->subspace_id = (u8)region_obj->region.address;
 173                 }
 174
 175                 /*
 176                  * We must exit the interpreter because the region setup will
 177                  * potentially execute control methods (for example, the _REG method
 178                  * for this region)
 179                  */
 180                 acpi_ex_exit_interpreter();
 181
 182                 status = region_setup(region_obj, ACPI_REGION_ACTIVATE,
 183                                       context, &region_context);
 184
 185                 /* Re-enter the interpreter */
 186
 187                 acpi_ex_enter_interpreter();
 188
 189                 /* Check for failure of the Region Setup */
 190
 191                 if (ACPI_FAILURE(status)) {
 192                         ACPI_EXCEPTION((AE_INFO, status,
 193                                         "During region initialization: [%s]",
 194                                         acpi_ut_get_region_name(region_obj->
 195                                                                 region.
 196                                                                 space_id)));
 197                         return_ACPI_STATUS(status);
 198                 }
 199
 200                 /* Region initialization may have been completed by region_setup */
 201
 202                 if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
 203                         region_obj->region.flags |= AOPOBJ_SETUP_COMPLETE;
 204
 205                         /*
 206                          * Save the returned context for use in all accesses to
 207                          * the handler for this particular region
 208                          */
 209                         if (!(region_obj2->extra.region_context)) {
 210                                 region_obj2->extra.region_context =
 211                                     region_context;
 212                         }
 213                 }
 214         }
 215
 216         /* We have everything we need, we can invoke the address space handler */
 217
 218         handler = handler_desc->address_space.handler;
 219         address = (region_obj->region.address + region_offset);
 220
 221         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 222                           "Handler %p (@%p) Address %8.8X%8.8X [%s]\n",
 223                           &region_obj->region.handler->address_space, handler,
 224                           ACPI_FORMAT_UINT64(address),
 225                           acpi_ut_get_region_name(region_obj->region.
 226                                                   space_id)));
 227
 228         if (!(handler_desc->address_space.handler_flags &
 229               ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
 230                 /*
 231                  * For handlers other than the default (supplied) handlers, we must
 232                  * exit the interpreter because the handler *might* block -- we don't
 233                  * know what it will do, so we can't hold the lock on the interpreter.
 234                  */
 235                 acpi_ex_exit_interpreter();
 236         }
 237
 238         /*
 239          * Special handling for generic_serial_bus and general_purpose_io:
 240          * There are three extra parameters that must be passed to the
 241          * handler via the context:
 242          *   1) Connection buffer, a resource template from Connection() op
 243          *   2) Length of the above buffer
 244          *   3) Actual access length from the access_as() op
 245          *
 246          * Since we pass these extra parameters via the context, which is
 247          * shared between threads, we must lock the context to avoid these
 248          * parameters being changed from another thread before the handler
 249          * has completed running.
 250          *
 251          * In addition, for general_purpose_io, the Address and bit_width fields
 252          * are defined as follows:
 253          *   1) Address is the pin number index of the field (bit offset from
 254          *      the previous Connection)
 255          *   2) bit_width is the actual bit length of the field (number of pins)
 256          */
 257         if ((region_obj->region.space_id == ACPI_ADR_SPACE_GSBUS ||
 258              region_obj->region.space_id == ACPI_ADR_SPACE_GPIO) &&
 259             context && field_obj) {
 260
 261                 status =
 262                     acpi_os_acquire_mutex(context_mutex, ACPI_WAIT_FOREVER);
 263                 if (ACPI_FAILURE(status)) {
 264                         goto re_enter_interpreter;
 265                 }
 266
 267                 context_locked = TRUE;
 268
 269                 /* Get the Connection (resource_template) buffer */
 270
 271                 context->connection = field_obj->field.resource_buffer;
 272                 context->length = field_obj->field.resource_length;
 273                 context->access_length = field_obj->field.access_length;
 274
 275                 if (region_obj->region.space_id == ACPI_ADR_SPACE_GPIO) {
 276                         address = field_obj->field.pin_number_index;
 277                         bit_width = field_obj->field.bit_length;
 278                 }
 279         }
 280
 281         /* Call the handler */
 282
 283         status = handler(function, address, bit_width, value, context,
 284                          region_obj2->extra.region_context);
 285
 286         if (context_locked) {
 287                 acpi_os_release_mutex(context_mutex);
 288         }
 289
 290         if (ACPI_FAILURE(status)) {
 291                 ACPI_EXCEPTION((AE_INFO, status, "Returned by Handler for [%s]",
 292                                 acpi_ut_get_region_name(region_obj->region.
 293                                                         space_id)));
 294
 295                 /*
 296                  * Special case for an EC timeout. These are seen so frequently
 297                  * that an additional error message is helpful
 298                  */
 299                 if ((region_obj->region.space_id == ACPI_ADR_SPACE_EC) &&
 300                     (status == AE_TIME)) {
 301                         ACPI_ERROR((AE_INFO,
 302                                     "Timeout from EC hardware or EC device driver"));
 303                 }
 304         }
 305
 306 re_enter_interpreter:
 307         if (!(handler_desc->address_space.handler_flags &
 308               ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
 309                 /*
 310                  * We just returned from a non-default handler, we must re-enter the
 311                  * interpreter
 312                  */
 313                 acpi_ex_enter_interpreter();
 314         }
 315
 316         return_ACPI_STATUS(status);
 317 }
 318
 319 /*******************************************************************************
 320  *
 321  * FUNCTION:    acpi_ev_detach_region
 322  *
 323  * PARAMETERS:  region_obj          - Region Object
 324  *              acpi_ns_is_locked   - Namespace Region Already Locked?
 325  *
 326  * RETURN:      None
 327  *
 328  * DESCRIPTION: Break the association between the handler and the region
 329  *              this is a two way association.
 330  *
 331  ******************************************************************************/
 332
 333 void
 334 acpi_ev_detach_region(union acpi_operand_object *region_obj,
 335                       u8 acpi_ns_is_locked)
 336 {
 337         union acpi_operand_object *handler_obj;
 338         union acpi_operand_object *obj_desc;
 339         union acpi_operand_object *start_desc;
 340         union acpi_operand_object **last_obj_ptr;
 341         acpi_adr_space_setup region_setup;
 342         void **region_context;
 343         union acpi_operand_object *region_obj2;
 344         acpi_status status;
 345
 346         ACPI_FUNCTION_TRACE(ev_detach_region);
 347
 348         region_obj2 = acpi_ns_get_secondary_object(region_obj);
 349         if (!region_obj2) {
 350                 return_VOID;
 351         }
 352         region_context = &region_obj2->extra.region_context;
 353
 354         /* Get the address handler from the region object */
 355
 356         handler_obj = region_obj->region.handler;
 357         if (!handler_obj) {
 358
 359                 /* This region has no handler, all done */
 360
 361                 return_VOID;
 362         }
 363
 364         /* Find this region in the handler's list */
 365
 366         obj_desc = handler_obj->address_space.region_list;
 367         start_desc = obj_desc;
 368         last_obj_ptr = &handler_obj->address_space.region_list;
 369
 370         while (obj_desc) {
 371
 372                 /* Is this the correct Region? */
 373
 374                 if (obj_desc == region_obj) {
 375                         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 376                                           "Removing Region %p from address handler %p\n",
 377                                           region_obj, handler_obj));
 378
 379                         /* This is it, remove it from the handler's list */
 380
 381                         *last_obj_ptr = obj_desc->region.next;
 382                         obj_desc->region.next = NULL;   /* Must clear field */
 383
 384                         if (acpi_ns_is_locked) {
 385                                 status =
 386                                     acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 387                                 if (ACPI_FAILURE(status)) {
 388                                         return_VOID;
 389                                 }
 390                         }
 391
 392                         /* Now stop region accesses by executing the _REG method */
 393
 394                         status =
 395                             acpi_ev_execute_reg_method(region_obj,
 396                                                        ACPI_REG_DISCONNECT);
 397                         if (ACPI_FAILURE(status)) {
 398                                 ACPI_EXCEPTION((AE_INFO, status,
 399                                                 "from region _REG, [%s]",
 400                                                 acpi_ut_get_region_name
 401                                                 (region_obj->region.space_id)));
 402                         }
 403
 404                         if (acpi_ns_is_locked) {
 405                                 status =
 406                                     acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 407                                 if (ACPI_FAILURE(status)) {
 408                                         return_VOID;
 409                                 }
 410                         }
 411
 412                         /*
 413                          * If the region has been activated, call the setup handler with
 414                          * the deactivate notification
 415                          */
 416                         if (region_obj->region.flags & AOPOBJ_SETUP_COMPLETE) {
 417                                 region_setup = handler_obj->address_space.setup;
 418                                 status =
 419                                     region_setup(region_obj,
 420                                                  ACPI_REGION_DEACTIVATE,
 421                                                  handler_obj->address_space.
 422                                                  context, region_context);
 423
 424                                 /*
 425                                  * region_context should have been released by the deactivate
 426                                  * operation. We don't need access to it anymore here.
 427                                  */
 428                                 if (region_context) {
 429                                         *region_context = NULL;
 430                                 }
 431
 432                                 /* Init routine may fail, Just ignore errors */
 433
 434                                 if (ACPI_FAILURE(status)) {
 435                                         ACPI_EXCEPTION((AE_INFO, status,
 436                                                         "from region handler - deactivate, [%s]",
 437                                                         acpi_ut_get_region_name
 438                                                         (region_obj->region.
 439                                                          space_id)));
 440                                 }
 441
 442                                 region_obj->region.flags &=
 443                                     ~(AOPOBJ_SETUP_COMPLETE);
 444                         }
 445
 446                         /*
 447                          * Remove handler reference in the region
 448                          *
 449                          * NOTE: this doesn't mean that the region goes away, the region
 450                          * is just inaccessible as indicated to the _REG method
 451                          *
 452                          * If the region is on the handler's list, this must be the
 453                          * region's handler
 454                          */
 455                         region_obj->region.handler = NULL;
 456                         acpi_ut_remove_reference(handler_obj);
 457
 458                         return_VOID;
 459                 }
 460
 461                 /* Walk the linked list of handlers */
 462
 463                 last_obj_ptr = &obj_desc->region.next;
 464                 obj_desc = obj_desc->region.next;
 465
 466                 /* Prevent infinite loop if list is corrupted */
 467
 468                 if (obj_desc == start_desc) {
 469                         ACPI_ERROR((AE_INFO,
 470                                     "Circular handler list in region object %p",
 471                                     region_obj));
 472                         return_VOID;
 473                 }
 474         }
 475
 476         /* If we get here, the region was not in the handler's region list */
 477
 478         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 479                           "Cannot remove region %p from address handler %p\n",
 480                           region_obj, handler_obj));
 481
 482         return_VOID;
 483 }
 484
 485 /*******************************************************************************
 486  *
 487  * FUNCTION:    acpi_ev_attach_region
 488  *
 489  * PARAMETERS:  handler_obj         - Handler Object
 490  *              region_obj          - Region Object
 491  *              acpi_ns_is_locked   - Namespace Region Already Locked?
 492  *
 493  * RETURN:      None
 494  *
 495  * DESCRIPTION: Create the association between the handler and the region
 496  *              this is a two way association.
 497  *
 498  ******************************************************************************/
 499
 500 acpi_status
 501 acpi_ev_attach_region(union acpi_operand_object *handler_obj,
 502                       union acpi_operand_object *region_obj,
 503                       u8 acpi_ns_is_locked)
 504 {
 505
 506         ACPI_FUNCTION_TRACE(ev_attach_region);
 507
 508         /* Install the region's handler */
 509
 510         if (region_obj->region.handler) {
 511                 return_ACPI_STATUS(AE_ALREADY_EXISTS);
 512         }
 513
 514         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 515                           "Adding Region [%4.4s] %p to address handler %p [%s]\n",
 516                           acpi_ut_get_node_name(region_obj->region.node),
 517                           region_obj, handler_obj,
 518                           acpi_ut_get_region_name(region_obj->region.
 519                                                   space_id)));
 520
 521         /* Link this region to the front of the handler's list */
 522
 523         region_obj->region.next = handler_obj->address_space.region_list;
 524         handler_obj->address_space.region_list = region_obj;
 525         region_obj->region.handler = handler_obj;
 526         acpi_ut_add_reference(handler_obj);
 527
 528         return_ACPI_STATUS(AE_OK);
 529 }
 530
 531 /*******************************************************************************
 532  *
 533  * FUNCTION:    acpi_ev_execute_reg_method
 534  *
 535  * PARAMETERS:  region_obj          - Region object
 536  *              function            - Passed to _REG: On (1) or Off (0)
 537  *
 538  * RETURN:      Status
 539  *
 540  * DESCRIPTION: Execute _REG method for a region
 541  *
 542  ******************************************************************************/
 543
 544 acpi_status
 545 acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
 546 {
 547         struct acpi_evaluate_info *info;
 548         union acpi_operand_object *args[3];
 549         union acpi_operand_object *region_obj2;
 550         const acpi_name *reg_name_ptr =
 551             ACPI_CAST_PTR(acpi_name, METHOD_NAME__REG);
 552         struct acpi_namespace_node *method_node;
 553         struct acpi_namespace_node *node;
 554         acpi_status status;
 555
 556         ACPI_FUNCTION_TRACE(ev_execute_reg_method);
 557
 558         if (!acpi_gbl_namespace_initialized ||
 559             region_obj->region.handler == NULL) {
 560                 return_ACPI_STATUS(AE_OK);
 561         }
 562
 563         region_obj2 = acpi_ns_get_secondary_object(region_obj);
 564         if (!region_obj2) {
 565                 return_ACPI_STATUS(AE_NOT_EXIST);
 566         }
 567
 568         /*
 569          * Find any "_REG" method associated with this region definition.
 570          * The method should always be updated as this function may be
 571          * invoked after a namespace change.
 572          */
 573         node = region_obj->region.node->parent;
 574         status =
 575             acpi_ns_search_one_scope(*reg_name_ptr, node, ACPI_TYPE_METHOD,
 576                                      &method_node);
 577         if (ACPI_SUCCESS(status)) {
 578                 /*
 579                  * The _REG method is optional and there can be only one per
 580                  * region definition. This will be executed when the handler is
 581                  * attached or removed.
 582                  */
 583                 region_obj2->extra.method_REG = method_node;
 584         }
 585         if (region_obj2->extra.method_REG == NULL) {
 586                 return_ACPI_STATUS(AE_OK);
 587         }
 588
 589         /* _REG(DISCONNECT) should be paired with _REG(CONNECT) */
 590
 591         if ((function == ACPI_REG_CONNECT &&
 592              region_obj->common.flags & AOPOBJ_REG_CONNECTED) ||
 593             (function == ACPI_REG_DISCONNECT &&
 594              !(region_obj->common.flags & AOPOBJ_REG_CONNECTED))) {
 595                 return_ACPI_STATUS(AE_OK);
 596         }
 597
 598         /* Allocate and initialize the evaluation information block */
 599
 600         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 601         if (!info) {
 602                 return_ACPI_STATUS(AE_NO_MEMORY);
 603         }
 604
 605         info->prefix_node = region_obj2->extra.method_REG;
 606         info->relative_pathname = NULL;
 607         info->parameters = args;
 608         info->flags = ACPI_IGNORE_RETURN_VALUE;
 609
 610         /*
 611          * The _REG method has two arguments:
 612          *
 613          * arg0 - Integer:
 614          *  Operation region space ID Same value as region_obj->Region.space_id
 615          *
 616          * arg1 - Integer:
 617          *  connection status 1 for connecting the handler, 0 for disconnecting
 618          *  the handler (Passed as a parameter)
 619          */
 620         args[0] =
 621             acpi_ut_create_integer_object((u64)region_obj->region.space_id);
 622         if (!args[0]) {
 623                 status = AE_NO_MEMORY;
 624                 goto cleanup1;
 625         }
 626
 627         args[1] = acpi_ut_create_integer_object((u64)function);
 628         if (!args[1]) {
 629                 status = AE_NO_MEMORY;
 630                 goto cleanup2;
 631         }
 632
 633         args[2] = NULL;         /* Terminate list */
 634
 635         /* Execute the method, no return value */
 636
 637         ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
 638                         (ACPI_TYPE_METHOD, info->prefix_node, NULL));
 639
 640         status = acpi_ns_evaluate(info);
 641         acpi_ut_remove_reference(args[1]);
 642
 643         if (ACPI_FAILURE(status)) {
 644                 goto cleanup2;
 645         }
 646
 647         if (function == ACPI_REG_CONNECT) {
 648                 region_obj->common.flags |= AOPOBJ_REG_CONNECTED;
 649         } else {
 650                 region_obj->common.flags &= ~AOPOBJ_REG_CONNECTED;
 651         }
 652
 653 cleanup2:
 654         acpi_ut_remove_reference(args[0]);
 655
 656 cleanup1:
 657         ACPI_FREE(info);
 658         return_ACPI_STATUS(status);
 659 }
 660
 661 /*******************************************************************************
 662  *
 663  * FUNCTION:    acpi_ev_execute_reg_methods
 664  *
 665  * PARAMETERS:  node            - Namespace node for the device
 666  *              space_id        - The address space ID
 667  *              function        - Passed to _REG: On (1) or Off (0)
 668  *
 669  * RETURN:      None
 670  *
 671  * DESCRIPTION: Run all _REG methods for the input Space ID;
 672  *              Note: assumes namespace is locked, or system init time.
 673  *
 674  ******************************************************************************/
 675
 676 void
 677 acpi_ev_execute_reg_methods(struct acpi_namespace_node *node,
 678                             acpi_adr_space_type space_id, u32 function)
 679 {
 680         struct acpi_reg_walk_info info;
 681
 682         ACPI_FUNCTION_TRACE(ev_execute_reg_methods);
 683
 684         /*
 685          * These address spaces do not need a call to _REG, since the ACPI
 686          * specification defines them as: "must always be accessible". Since
 687          * they never change state (never become unavailable), no need to ever
 688          * call _REG on them. Also, a data_table is not a "real" address space,
 689          * so do not call _REG. September 2018.
 690          */
 691         if ((space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) ||
 692             (space_id == ACPI_ADR_SPACE_SYSTEM_IO) ||
 693             (space_id == ACPI_ADR_SPACE_DATA_TABLE)) {
 694                 return_VOID;
 695         }
 696
 697         info.space_id = space_id;
 698         info.function = function;
 699         info.reg_run_count = 0;
 700
 701         ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES,
 702                               "    Running _REG methods for SpaceId %s\n",
 703                               acpi_ut_get_region_name(info.space_id)));
 704
 705         /*
 706          * Run all _REG methods for all Operation Regions for this space ID. This
 707          * is a separate walk in order to handle any interdependencies between
 708          * regions and _REG methods. (i.e. handlers must be installed for all
 709          * regions of this Space ID before we can run any _REG methods)
 710          */
 711         (void)acpi_ns_walk_namespace(ACPI_TYPE_ANY, node, ACPI_UINT32_MAX,
 712                                      ACPI_NS_WALK_UNLOCK, acpi_ev_reg_run, NULL,
 713                                      &info, NULL);
 714
 715         /*
 716          * Special case for EC and GPIO: handle "orphan" _REG methods with
 717          * no region.
 718          */
 719         if (space_id == ACPI_ADR_SPACE_EC || space_id == ACPI_ADR_SPACE_GPIO) {
 720                 acpi_ev_execute_orphan_reg_method(node, space_id);
 721         }
 722
 723         ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES,
 724                               "    Executed %u _REG methods for SpaceId %s\n",
 725                               info.reg_run_count,
 726                               acpi_ut_get_region_name(info.space_id)));
 727
 728         return_VOID;
 729 }
 730
 731 /*******************************************************************************
 732  *
 733  * FUNCTION:    acpi_ev_reg_run
 734  *
 735  * PARAMETERS:  walk_namespace callback
 736  *
 737  * DESCRIPTION: Run _REG method for region objects of the requested spaceID
 738  *
 739  ******************************************************************************/
 740
 741 static acpi_status
 742 acpi_ev_reg_run(acpi_handle obj_handle,
 743                 u32 level, void *context, void **return_value)
 744 {
 745         union acpi_operand_object *obj_desc;
 746         struct acpi_namespace_node *node;
 747         acpi_status status;
 748         struct acpi_reg_walk_info *info;
 749
 750         info = ACPI_CAST_PTR(struct acpi_reg_walk_info, context);
 751
 752         /* Convert and validate the device handle */
 753
 754         node = acpi_ns_validate_handle(obj_handle);
 755         if (!node) {
 756                 return (AE_BAD_PARAMETER);
 757         }
 758
 759         /*
 760          * We only care about regions and objects that are allowed to have
 761          * address space handlers
 762          */
 763         if ((node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
 764                 return (AE_OK);
 765         }
 766
 767         /* Check for an existing internal object */
 768
 769         obj_desc = acpi_ns_get_attached_object(node);
 770         if (!obj_desc) {
 771
 772                 /* No object, just exit */
 773
 774                 return (AE_OK);
 775         }
 776
 777         /* Object is a Region */
 778
 779         if (obj_desc->region.space_id != info->space_id) {
 780
 781                 /* This region is for a different address space, just ignore it */
 782
 783                 return (AE_OK);
 784         }
 785
 786         info->reg_run_count++;
 787         status = acpi_ev_execute_reg_method(obj_desc, info->function);
 788         return (status);
 789 }
 790
 791 /*******************************************************************************
 792  *
 793  * FUNCTION:    acpi_ev_execute_orphan_reg_method
 794  *
 795  * PARAMETERS:  device_node         - Namespace node for an ACPI device
 796  *              space_id            - The address space ID
 797  *
 798  * RETURN:      None
 799  *
 800  * DESCRIPTION: Execute an "orphan" _REG method that appears under an ACPI
 801  *              device. This is a _REG method that has no corresponding region
 802  *              within the device's scope. ACPI tables depending on these
 803  *              "orphan" _REG methods have been seen for both EC and GPIO
 804  *              Operation Regions. Presumably the Windows ACPI implementation
 805  *              always calls the _REG method independent of the presence of
 806  *              an actual Operation Region with the correct address space ID.
 807  *
 808  *  MUTEX:      Assumes the namespace is locked
 809  *
 810  ******************************************************************************/
 811
 812 static void
 813 acpi_ev_execute_orphan_reg_method(struct acpi_namespace_node *device_node,
 814                                   acpi_adr_space_type space_id)
 815 {
 816         acpi_handle reg_method;
 817         struct acpi_namespace_node *next_node;
 818         acpi_status status;
 819         struct acpi_object_list args;
 820         union acpi_object objects[2];
 821
 822         ACPI_FUNCTION_TRACE(ev_execute_orphan_reg_method);
 823
 824         if (!device_node) {
 825                 return_VOID;
 826         }
 827
 828         /* Namespace is currently locked, must release */
 829
 830         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 831
 832         /* Get a handle to a _REG method immediately under the EC device */
 833
 834         status = acpi_get_handle(device_node, METHOD_NAME__REG, &reg_method);
 835         if (ACPI_FAILURE(status)) {
 836                 goto exit;      /* There is no _REG method present */
 837         }
 838
 839         /*
 840          * Execute the _REG method only if there is no Operation Region in
 841          * this scope with the Embedded Controller space ID. Otherwise, it
 842          * will already have been executed. Note, this allows for Regions
 843          * with other space IDs to be present; but the code below will then
 844          * execute the _REG method with the embedded_control space_ID argument.
 845          */
 846         next_node = acpi_ns_get_next_node(device_node, NULL);
 847         while (next_node) {
 848                 if ((next_node->type == ACPI_TYPE_REGION) &&
 849                     (next_node->object) &&
 850                     (next_node->object->region.space_id == space_id)) {
 851                         goto exit;      /* Do not execute the _REG */
 852                 }
 853
 854                 next_node = acpi_ns_get_next_node(device_node, next_node);
 855         }
 856
 857         /* Evaluate the _REG(space_id,Connect) method */
 858
 859         args.count = 2;
 860         args.pointer = objects;
 861         objects[0].type = ACPI_TYPE_INTEGER;
 862         objects[0].integer.value = space_id;
 863         objects[1].type = ACPI_TYPE_INTEGER;
 864         objects[1].integer.value = ACPI_REG_CONNECT;
 865
 866         (void)acpi_evaluate_object(reg_method, NULL, &args, NULL);
 867
 868 exit:
 869         /* We ignore all errors from above, don't care */
 870
 871         (void)acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 872         return_VOID;
 873 }