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 - 2021, 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                 /*
 166                  * We must exit the interpreter because the region setup will
 167                  * potentially execute control methods (for example, the _REG method
 168                  * for this region)
 169                  */
 170                 acpi_ex_exit_interpreter();
 171
 172                 status = region_setup(region_obj, ACPI_REGION_ACTIVATE,
 173                                       context, &region_context);
 174
 175                 /* Re-enter the interpreter */
 176
 177                 acpi_ex_enter_interpreter();
 178
 179                 /* Check for failure of the Region Setup */
 180
 181                 if (ACPI_FAILURE(status)) {
 182                         ACPI_EXCEPTION((AE_INFO, status,
 183                                         "During region initialization: [%s]",
 184                                         acpi_ut_get_region_name(region_obj->
 185                                                                 region.
 186                                                                 space_id)));
 187                         return_ACPI_STATUS(status);
 188                 }
 189
 190                 /* Region initialization may have been completed by region_setup */
 191
 192                 if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
 193                         region_obj->region.flags |= AOPOBJ_SETUP_COMPLETE;
 194
 195                         /*
 196                          * Save the returned context for use in all accesses to
 197                          * the handler for this particular region
 198                          */
 199                         if (!(region_obj2->extra.region_context)) {
 200                                 region_obj2->extra.region_context =
 201                                     region_context;
 202                         }
 203                 }
 204         }
 205
 206         /* We have everything we need, we can invoke the address space handler */
 207
 208         handler = handler_desc->address_space.handler;
 209         address = (region_obj->region.address + region_offset);
 210
 211         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 212                           "Handler %p (@%p) Address %8.8X%8.8X [%s]\n",
 213                           &region_obj->region.handler->address_space, handler,
 214                           ACPI_FORMAT_UINT64(address),
 215                           acpi_ut_get_region_name(region_obj->region.
 216                                                   space_id)));
 217
 218         if (!(handler_desc->address_space.handler_flags &
 219               ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
 220                 /*
 221                  * For handlers other than the default (supplied) handlers, we must
 222                  * exit the interpreter because the handler *might* block -- we don't
 223                  * know what it will do, so we can't hold the lock on the interpreter.
 224                  */
 225                 acpi_ex_exit_interpreter();
 226         }
 227
 228         /*
 229          * Special handling for generic_serial_bus and general_purpose_io:
 230          * There are three extra parameters that must be passed to the
 231          * handler via the context:
 232          *   1) Connection buffer, a resource template from Connection() op
 233          *   2) Length of the above buffer
 234          *   3) Actual access length from the access_as() op
 235          *
 236          * Since we pass these extra parameters via the context, which is
 237          * shared between threads, we must lock the context to avoid these
 238          * parameters being changed from another thread before the handler
 239          * has completed running.
 240          *
 241          * In addition, for general_purpose_io, the Address and bit_width fields
 242          * are defined as follows:
 243          *   1) Address is the pin number index of the field (bit offset from
 244          *      the previous Connection)
 245          *   2) bit_width is the actual bit length of the field (number of pins)
 246          */
 247         if ((region_obj->region.space_id == ACPI_ADR_SPACE_GSBUS ||
 248              region_obj->region.space_id == ACPI_ADR_SPACE_GPIO) &&
 249             context && field_obj) {
 250
 251                 status =
 252                     acpi_os_acquire_mutex(context_mutex, ACPI_WAIT_FOREVER);
 253                 if (ACPI_FAILURE(status)) {
 254                         goto re_enter_interpreter;
 255                 }
 256
 257                 context_locked = TRUE;
 258
 259                 /* Get the Connection (resource_template) buffer */
 260
 261                 context->connection = field_obj->field.resource_buffer;
 262                 context->length = field_obj->field.resource_length;
 263                 context->access_length = field_obj->field.access_length;
 264
 265                 if (region_obj->region.space_id == ACPI_ADR_SPACE_GPIO) {
 266                         address = field_obj->field.pin_number_index;
 267                         bit_width = field_obj->field.bit_length;
 268                 }
 269         }
 270
 271         /* Call the handler */
 272
 273         status = handler(function, address, bit_width, value, context,
 274                          region_obj2->extra.region_context);
 275
 276         if (context_locked) {
 277                 acpi_os_release_mutex(context_mutex);
 278         }
 279
 280         if (ACPI_FAILURE(status)) {
 281                 ACPI_EXCEPTION((AE_INFO, status, "Returned by Handler for [%s]",
 282                                 acpi_ut_get_region_name(region_obj->region.
 283                                                         space_id)));
 284
 285                 /*
 286                  * Special case for an EC timeout. These are seen so frequently
 287                  * that an additional error message is helpful
 288                  */
 289                 if ((region_obj->region.space_id == ACPI_ADR_SPACE_EC) &&
 290                     (status == AE_TIME)) {
 291                         ACPI_ERROR((AE_INFO,
 292                                     "Timeout from EC hardware or EC device driver"));
 293                 }
 294         }
 295
 296 re_enter_interpreter:
 297         if (!(handler_desc->address_space.handler_flags &
 298               ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
 299                 /*
 300                  * We just returned from a non-default handler, we must re-enter the
 301                  * interpreter
 302                  */
 303                 acpi_ex_enter_interpreter();
 304         }
 305
 306         return_ACPI_STATUS(status);
 307 }
 308
 309 /*******************************************************************************
 310  *
 311  * FUNCTION:    acpi_ev_detach_region
 312  *
 313  * PARAMETERS:  region_obj          - Region Object
 314  *              acpi_ns_is_locked   - Namespace Region Already Locked?
 315  *
 316  * RETURN:      None
 317  *
 318  * DESCRIPTION: Break the association between the handler and the region
 319  *              this is a two way association.
 320  *
 321  ******************************************************************************/
 322
 323 void
 324 acpi_ev_detach_region(union acpi_operand_object *region_obj,
 325                       u8 acpi_ns_is_locked)
 326 {
 327         union acpi_operand_object *handler_obj;
 328         union acpi_operand_object *obj_desc;
 329         union acpi_operand_object *start_desc;
 330         union acpi_operand_object **last_obj_ptr;
 331         acpi_adr_space_setup region_setup;
 332         void **region_context;
 333         union acpi_operand_object *region_obj2;
 334         acpi_status status;
 335
 336         ACPI_FUNCTION_TRACE(ev_detach_region);
 337
 338         region_obj2 = acpi_ns_get_secondary_object(region_obj);
 339         if (!region_obj2) {
 340                 return_VOID;
 341         }
 342         region_context = &region_obj2->extra.region_context;
 343
 344         /* Get the address handler from the region object */
 345
 346         handler_obj = region_obj->region.handler;
 347         if (!handler_obj) {
 348
 349                 /* This region has no handler, all done */
 350
 351                 return_VOID;
 352         }
 353
 354         /* Find this region in the handler's list */
 355
 356         obj_desc = handler_obj->address_space.region_list;
 357         start_desc = obj_desc;
 358         last_obj_ptr = &handler_obj->address_space.region_list;
 359
 360         while (obj_desc) {
 361
 362                 /* Is this the correct Region? */
 363
 364                 if (obj_desc == region_obj) {
 365                         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 366                                           "Removing Region %p from address handler %p\n",
 367                                           region_obj, handler_obj));
 368
 369                         /* This is it, remove it from the handler's list */
 370
 371                         *last_obj_ptr = obj_desc->region.next;
 372                         obj_desc->region.next = NULL;   /* Must clear field */
 373
 374                         if (acpi_ns_is_locked) {
 375                                 status =
 376                                     acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 377                                 if (ACPI_FAILURE(status)) {
 378                                         return_VOID;
 379                                 }
 380                         }
 381
 382                         /* Now stop region accesses by executing the _REG method */
 383
 384                         status =
 385                             acpi_ev_execute_reg_method(region_obj,
 386                                                        ACPI_REG_DISCONNECT);
 387                         if (ACPI_FAILURE(status)) {
 388                                 ACPI_EXCEPTION((AE_INFO, status,
 389                                                 "from region _REG, [%s]",
 390                                                 acpi_ut_get_region_name
 391                                                 (region_obj->region.space_id)));
 392                         }
 393
 394                         if (acpi_ns_is_locked) {
 395                                 status =
 396                                     acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 397                                 if (ACPI_FAILURE(status)) {
 398                                         return_VOID;
 399                                 }
 400                         }
 401
 402                         /*
 403                          * If the region has been activated, call the setup handler with
 404                          * the deactivate notification
 405                          */
 406                         if (region_obj->region.flags & AOPOBJ_SETUP_COMPLETE) {
 407                                 region_setup = handler_obj->address_space.setup;
 408                                 status =
 409                                     region_setup(region_obj,
 410                                                  ACPI_REGION_DEACTIVATE,
 411                                                  handler_obj->address_space.
 412                                                  context, region_context);
 413
 414                                 /*
 415                                  * region_context should have been released by the deactivate
 416                                  * operation. We don't need access to it anymore here.
 417                                  */
 418                                 if (region_context) {
 419                                         *region_context = NULL;
 420                                 }
 421
 422                                 /* Init routine may fail, Just ignore errors */
 423
 424                                 if (ACPI_FAILURE(status)) {
 425                                         ACPI_EXCEPTION((AE_INFO, status,
 426                                                         "from region handler - deactivate, [%s]",
 427                                                         acpi_ut_get_region_name
 428                                                         (region_obj->region.
 429                                                          space_id)));
 430                                 }
 431
 432                                 region_obj->region.flags &=
 433                                     ~(AOPOBJ_SETUP_COMPLETE);
 434                         }
 435
 436                         /*
 437                          * Remove handler reference in the region
 438                          *
 439                          * NOTE: this doesn't mean that the region goes away, the region
 440                          * is just inaccessible as indicated to the _REG method
 441                          *
 442                          * If the region is on the handler's list, this must be the
 443                          * region's handler
 444                          */
 445                         region_obj->region.handler = NULL;
 446                         acpi_ut_remove_reference(handler_obj);
 447
 448                         return_VOID;
 449                 }
 450
 451                 /* Walk the linked list of handlers */
 452
 453                 last_obj_ptr = &obj_desc->region.next;
 454                 obj_desc = obj_desc->region.next;
 455
 456                 /* Prevent infinite loop if list is corrupted */
 457
 458                 if (obj_desc == start_desc) {
 459                         ACPI_ERROR((AE_INFO,
 460                                     "Circular handler list in region object %p",
 461                                     region_obj));
 462                         return_VOID;
 463                 }
 464         }
 465
 466         /* If we get here, the region was not in the handler's region list */
 467
 468         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 469                           "Cannot remove region %p from address handler %p\n",
 470                           region_obj, handler_obj));
 471
 472         return_VOID;
 473 }
 474
 475 /*******************************************************************************
 476  *
 477  * FUNCTION:    acpi_ev_attach_region
 478  *
 479  * PARAMETERS:  handler_obj         - Handler Object
 480  *              region_obj          - Region Object
 481  *              acpi_ns_is_locked   - Namespace Region Already Locked?
 482  *
 483  * RETURN:      None
 484  *
 485  * DESCRIPTION: Create the association between the handler and the region
 486  *              this is a two way association.
 487  *
 488  ******************************************************************************/
 489
 490 acpi_status
 491 acpi_ev_attach_region(union acpi_operand_object *handler_obj,
 492                       union acpi_operand_object *region_obj,
 493                       u8 acpi_ns_is_locked)
 494 {
 495
 496         ACPI_FUNCTION_TRACE(ev_attach_region);
 497
 498         /* Install the region's handler */
 499
 500         if (region_obj->region.handler) {
 501                 return_ACPI_STATUS(AE_ALREADY_EXISTS);
 502         }
 503
 504         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 505                           "Adding Region [%4.4s] %p to address handler %p [%s]\n",
 506                           acpi_ut_get_node_name(region_obj->region.node),
 507                           region_obj, handler_obj,
 508                           acpi_ut_get_region_name(region_obj->region.
 509                                                   space_id)));
 510
 511         /* Link this region to the front of the handler's list */
 512
 513         region_obj->region.next = handler_obj->address_space.region_list;
 514         handler_obj->address_space.region_list = region_obj;
 515         region_obj->region.handler = handler_obj;
 516         acpi_ut_add_reference(handler_obj);
 517
 518         return_ACPI_STATUS(AE_OK);
 519 }
 520
 521 /*******************************************************************************
 522  *
 523  * FUNCTION:    acpi_ev_execute_reg_method
 524  *
 525  * PARAMETERS:  region_obj          - Region object
 526  *              function            - Passed to _REG: On (1) or Off (0)
 527  *
 528  * RETURN:      Status
 529  *
 530  * DESCRIPTION: Execute _REG method for a region
 531  *
 532  ******************************************************************************/
 533
 534 acpi_status
 535 acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
 536 {
 537         struct acpi_evaluate_info *info;
 538         union acpi_operand_object *args[3];
 539         union acpi_operand_object *region_obj2;
 540         const acpi_name *reg_name_ptr =
 541             ACPI_CAST_PTR(acpi_name, METHOD_NAME__REG);
 542         struct acpi_namespace_node *method_node;
 543         struct acpi_namespace_node *node;
 544         acpi_status status;
 545
 546         ACPI_FUNCTION_TRACE(ev_execute_reg_method);
 547
 548         if (!acpi_gbl_namespace_initialized ||
 549             region_obj->region.handler == NULL) {
 550                 return_ACPI_STATUS(AE_OK);
 551         }
 552
 553         region_obj2 = acpi_ns_get_secondary_object(region_obj);
 554         if (!region_obj2) {
 555                 return_ACPI_STATUS(AE_NOT_EXIST);
 556         }
 557
 558         /*
 559          * Find any "_REG" method associated with this region definition.
 560          * The method should always be updated as this function may be
 561          * invoked after a namespace change.
 562          */
 563         node = region_obj->region.node->parent;
 564         status =
 565             acpi_ns_search_one_scope(*reg_name_ptr, node, ACPI_TYPE_METHOD,
 566                                      &method_node);
 567         if (ACPI_SUCCESS(status)) {
 568                 /*
 569                  * The _REG method is optional and there can be only one per
 570                  * region definition. This will be executed when the handler is
 571                  * attached or removed.
 572                  */
 573                 region_obj2->extra.method_REG = method_node;
 574         }
 575         if (region_obj2->extra.method_REG == NULL) {
 576                 return_ACPI_STATUS(AE_OK);
 577         }
 578
 579         /* _REG(DISCONNECT) should be paired with _REG(CONNECT) */
 580
 581         if ((function == ACPI_REG_CONNECT &&
 582              region_obj->common.flags & AOPOBJ_REG_CONNECTED) ||
 583             (function == ACPI_REG_DISCONNECT &&
 584              !(region_obj->common.flags & AOPOBJ_REG_CONNECTED))) {
 585                 return_ACPI_STATUS(AE_OK);
 586         }
 587
 588         /* Allocate and initialize the evaluation information block */
 589
 590         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 591         if (!info) {
 592                 return_ACPI_STATUS(AE_NO_MEMORY);
 593         }
 594
 595         info->prefix_node = region_obj2->extra.method_REG;
 596         info->relative_pathname = NULL;
 597         info->parameters = args;
 598         info->flags = ACPI_IGNORE_RETURN_VALUE;
 599
 600         /*
 601          * The _REG method has two arguments:
 602          *
 603          * arg0 - Integer:
 604          *  Operation region space ID Same value as region_obj->Region.space_id
 605          *
 606          * arg1 - Integer:
 607          *  connection status 1 for connecting the handler, 0 for disconnecting
 608          *  the handler (Passed as a parameter)
 609          */
 610         args[0] =
 611             acpi_ut_create_integer_object((u64)region_obj->region.space_id);
 612         if (!args[0]) {
 613                 status = AE_NO_MEMORY;
 614                 goto cleanup1;
 615         }
 616
 617         args[1] = acpi_ut_create_integer_object((u64)function);
 618         if (!args[1]) {
 619                 status = AE_NO_MEMORY;
 620                 goto cleanup2;
 621         }
 622
 623         args[2] = NULL;         /* Terminate list */
 624
 625         /* Execute the method, no return value */
 626
 627         ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
 628                         (ACPI_TYPE_METHOD, info->prefix_node, NULL));
 629
 630         status = acpi_ns_evaluate(info);
 631         acpi_ut_remove_reference(args[1]);
 632
 633         if (ACPI_FAILURE(status)) {
 634                 goto cleanup2;
 635         }
 636
 637         if (function == ACPI_REG_CONNECT) {
 638                 region_obj->common.flags |= AOPOBJ_REG_CONNECTED;
 639         } else {
 640                 region_obj->common.flags &= ~AOPOBJ_REG_CONNECTED;
 641         }
 642
 643 cleanup2:
 644         acpi_ut_remove_reference(args[0]);
 645
 646 cleanup1:
 647         ACPI_FREE(info);
 648         return_ACPI_STATUS(status);
 649 }
 650
 651 /*******************************************************************************
 652  *
 653  * FUNCTION:    acpi_ev_execute_reg_methods
 654  *
 655  * PARAMETERS:  node            - Namespace node for the device
 656  *              space_id        - The address space ID
 657  *              function        - Passed to _REG: On (1) or Off (0)
 658  *
 659  * RETURN:      None
 660  *
 661  * DESCRIPTION: Run all _REG methods for the input Space ID;
 662  *              Note: assumes namespace is locked, or system init time.
 663  *
 664  ******************************************************************************/
 665
 666 void
 667 acpi_ev_execute_reg_methods(struct acpi_namespace_node *node,
 668                             acpi_adr_space_type space_id, u32 function)
 669 {
 670         struct acpi_reg_walk_info info;
 671
 672         ACPI_FUNCTION_TRACE(ev_execute_reg_methods);
 673
 674         /*
 675          * These address spaces do not need a call to _REG, since the ACPI
 676          * specification defines them as: "must always be accessible". Since
 677          * they never change state (never become unavailable), no need to ever
 678          * call _REG on them. Also, a data_table is not a "real" address space,
 679          * so do not call _REG. September 2018.
 680          */
 681         if ((space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) ||
 682             (space_id == ACPI_ADR_SPACE_SYSTEM_IO) ||
 683             (space_id == ACPI_ADR_SPACE_DATA_TABLE)) {
 684                 return_VOID;
 685         }
 686
 687         info.space_id = space_id;
 688         info.function = function;
 689         info.reg_run_count = 0;
 690
 691         ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES,
 692                               "    Running _REG methods for SpaceId %s\n",
 693                               acpi_ut_get_region_name(info.space_id)));
 694
 695         /*
 696          * Run all _REG methods for all Operation Regions for this space ID. This
 697          * is a separate walk in order to handle any interdependencies between
 698          * regions and _REG methods. (i.e. handlers must be installed for all
 699          * regions of this Space ID before we can run any _REG methods)
 700          */
 701         (void)acpi_ns_walk_namespace(ACPI_TYPE_ANY, node, ACPI_UINT32_MAX,
 702                                      ACPI_NS_WALK_UNLOCK, acpi_ev_reg_run, NULL,
 703                                      &info, NULL);
 704
 705         /*
 706          * Special case for EC and GPIO: handle "orphan" _REG methods with
 707          * no region.
 708          */
 709         if (space_id == ACPI_ADR_SPACE_EC || space_id == ACPI_ADR_SPACE_GPIO) {
 710                 acpi_ev_execute_orphan_reg_method(node, space_id);
 711         }
 712
 713         ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES,
 714                               "    Executed %u _REG methods for SpaceId %s\n",
 715                               info.reg_run_count,
 716                               acpi_ut_get_region_name(info.space_id)));
 717
 718         return_VOID;
 719 }
 720
 721 /*******************************************************************************
 722  *
 723  * FUNCTION:    acpi_ev_reg_run
 724  *
 725  * PARAMETERS:  walk_namespace callback
 726  *
 727  * DESCRIPTION: Run _REG method for region objects of the requested spaceID
 728  *
 729  ******************************************************************************/
 730
 731 static acpi_status
 732 acpi_ev_reg_run(acpi_handle obj_handle,
 733                 u32 level, void *context, void **return_value)
 734 {
 735         union acpi_operand_object *obj_desc;
 736         struct acpi_namespace_node *node;
 737         acpi_status status;
 738         struct acpi_reg_walk_info *info;
 739
 740         info = ACPI_CAST_PTR(struct acpi_reg_walk_info, context);
 741
 742         /* Convert and validate the device handle */
 743
 744         node = acpi_ns_validate_handle(obj_handle);
 745         if (!node) {
 746                 return (AE_BAD_PARAMETER);
 747         }
 748
 749         /*
 750          * We only care about regions and objects that are allowed to have
 751          * address space handlers
 752          */
 753         if ((node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
 754                 return (AE_OK);
 755         }
 756
 757         /* Check for an existing internal object */
 758
 759         obj_desc = acpi_ns_get_attached_object(node);
 760         if (!obj_desc) {
 761
 762                 /* No object, just exit */
 763
 764                 return (AE_OK);
 765         }
 766
 767         /* Object is a Region */
 768
 769         if (obj_desc->region.space_id != info->space_id) {
 770
 771                 /* This region is for a different address space, just ignore it */
 772
 773                 return (AE_OK);
 774         }
 775
 776         info->reg_run_count++;
 777         status = acpi_ev_execute_reg_method(obj_desc, info->function);
 778         return (status);
 779 }
 780
 781 /*******************************************************************************
 782  *
 783  * FUNCTION:    acpi_ev_execute_orphan_reg_method
 784  *
 785  * PARAMETERS:  device_node         - Namespace node for an ACPI device
 786  *              space_id            - The address space ID
 787  *
 788  * RETURN:      None
 789  *
 790  * DESCRIPTION: Execute an "orphan" _REG method that appears under an ACPI
 791  *              device. This is a _REG method that has no corresponding region
 792  *              within the device's scope. ACPI tables depending on these
 793  *              "orphan" _REG methods have been seen for both EC and GPIO
 794  *              Operation Regions. Presumably the Windows ACPI implementation
 795  *              always calls the _REG method independent of the presence of
 796  *              an actual Operation Region with the correct address space ID.
 797  *
 798  *  MUTEX:      Assumes the namespace is locked
 799  *
 800  ******************************************************************************/
 801
 802 static void
 803 acpi_ev_execute_orphan_reg_method(struct acpi_namespace_node *device_node,
 804                                   acpi_adr_space_type space_id)
 805 {
 806         acpi_handle reg_method;
 807         struct acpi_namespace_node *next_node;
 808         acpi_status status;
 809         struct acpi_object_list args;
 810         union acpi_object objects[2];
 811
 812         ACPI_FUNCTION_TRACE(ev_execute_orphan_reg_method);
 813
 814         if (!device_node) {
 815                 return_VOID;
 816         }
 817
 818         /* Namespace is currently locked, must release */
 819
 820         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 821
 822         /* Get a handle to a _REG method immediately under the EC device */
 823
 824         status = acpi_get_handle(device_node, METHOD_NAME__REG, &reg_method);
 825         if (ACPI_FAILURE(status)) {
 826                 goto exit;      /* There is no _REG method present */
 827         }
 828
 829         /*
 830          * Execute the _REG method only if there is no Operation Region in
 831          * this scope with the Embedded Controller space ID. Otherwise, it
 832          * will already have been executed. Note, this allows for Regions
 833          * with other space IDs to be present; but the code below will then
 834          * execute the _REG method with the embedded_control space_ID argument.
 835          */
 836         next_node = acpi_ns_get_next_node(device_node, NULL);
 837         while (next_node) {
 838                 if ((next_node->type == ACPI_TYPE_REGION) &&
 839                     (next_node->object) &&
 840                     (next_node->object->region.space_id == space_id)) {
 841                         goto exit;      /* Do not execute the _REG */
 842                 }
 843
 844                 next_node = acpi_ns_get_next_node(device_node, next_node);
 845         }
 846
 847         /* Evaluate the _REG(space_id,Connect) method */
 848
 849         args.count = 2;
 850         args.pointer = objects;
 851         objects[0].type = ACPI_TYPE_INTEGER;
 852         objects[0].integer.value = space_id;
 853         objects[1].type = ACPI_TYPE_INTEGER;
 854         objects[1].integer.value = ACPI_REG_CONNECT;
 855
 856         (void)acpi_evaluate_object(reg_method, NULL, &args, NULL);
 857
 858 exit:
 859         /* We ignore all errors from above, don't care */
 860
 861         (void)acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 862         return_VOID;
 863 }