1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 2 /******************************************************************************* 3 * 4 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace 5 * 6 ******************************************************************************/ 7 8 #include <acpi/acpi.h> 9 #include "accommon.h" 10 #include "amlcode.h" 11 #include "acnamesp.h" 12 #include "acdispat.h" 13 14 #ifdef ACPI_ASL_COMPILER 15 #include "acdisasm.h" 16 #endif 17 18 #define _COMPONENT ACPI_NAMESPACE 19 ACPI_MODULE_NAME("nsaccess") 20 21 /******************************************************************************* 22 * 23 * FUNCTION: acpi_ns_root_initialize 24 * 25 * PARAMETERS: None 26 * 27 * RETURN: Status 28 * 29 * DESCRIPTION: Allocate and initialize the default root named objects 30 * 31 * MUTEX: Locks namespace for entire execution 32 * 33 ******************************************************************************/ 34 acpi_status acpi_ns_root_initialize(void) 35 { 36 acpi_status status; 37 const struct acpi_predefined_names *init_val = NULL; 38 struct acpi_namespace_node *new_node; 39 struct acpi_namespace_node *prev_node = NULL; 40 union acpi_operand_object *obj_desc; 41 acpi_string val = NULL; 42 43 ACPI_FUNCTION_TRACE(ns_root_initialize); 44 45 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE); 46 if (ACPI_FAILURE(status)) { 47 return_ACPI_STATUS(status); 48 } 49 50 /* 51 * The global root ptr is initially NULL, so a non-NULL value indicates 52 * that acpi_ns_root_initialize() has already been called; just return. 53 */ 54 if (acpi_gbl_root_node) { 55 status = AE_OK; 56 goto unlock_and_exit; 57 } 58 59 /* 60 * Tell the rest of the subsystem that the root is initialized 61 * (This is OK because the namespace is locked) 62 */ 63 acpi_gbl_root_node = &acpi_gbl_root_node_struct; 64 65 /* Enter the predefined names in the name table */ 66 67 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 68 "Entering predefined entries into namespace\n")); 69 70 /* 71 * Create the initial (default) namespace. 72 * This namespace looks like something similar to this: 73 * 74 * ACPI Namespace (from Namespace Root): 75 * 0 _GPE Scope 00203160 00 76 * 0 _PR_ Scope 002031D0 00 77 * 0 _SB_ Device 00203240 00 Notify Object: 0020ADD8 78 * 0 _SI_ Scope 002032B0 00 79 * 0 _TZ_ Device 00203320 00 80 * 0 _REV Integer 00203390 00 = 0000000000000002 81 * 0 _OS_ String 00203488 00 Len 14 "Microsoft Windows NT" 82 * 0 _GL_ Mutex 00203580 00 Object 002035F0 83 * 0 _OSI Method 00203678 00 Args 1 Len 0000 Aml 00000000 84 */ 85 for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) { 86 status = AE_OK; 87 88 /* _OSI is optional for now, will be permanent later */ 89 90 if (!strcmp(init_val->name, "_OSI") 91 && !acpi_gbl_create_osi_method) { 92 continue; 93 } 94 95 /* 96 * Create, init, and link the new predefined name 97 * Note: No need to use acpi_ns_lookup here because all the 98 * predefined names are at the root level. It is much easier to 99 * just create and link the new node(s) here. 100 */ 101 new_node = 102 ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_namespace_node)); 103 if (!new_node) { 104 status = AE_NO_MEMORY; 105 goto unlock_and_exit; 106 } 107 108 ACPI_COPY_NAMESEG(new_node->name.ascii, init_val->name); 109 new_node->descriptor_type = ACPI_DESC_TYPE_NAMED; 110 new_node->type = init_val->type; 111 112 if (!prev_node) { 113 acpi_gbl_root_node_struct.child = new_node; 114 } else { 115 prev_node->peer = new_node; 116 } 117 118 new_node->parent = &acpi_gbl_root_node_struct; 119 prev_node = new_node; 120 121 /* 122 * Name entered successfully. If entry in pre_defined_names[] specifies 123 * an initial value, create the initial value. 124 */ 125 if (init_val->val) { 126 status = acpi_os_predefined_override(init_val, &val); 127 if (ACPI_FAILURE(status)) { 128 ACPI_ERROR((AE_INFO, 129 "Could not override predefined %s", 130 init_val->name)); 131 } 132 133 if (!val) { 134 val = init_val->val; 135 } 136 137 /* 138 * Entry requests an initial value, allocate a 139 * descriptor for it. 140 */ 141 obj_desc = 142 acpi_ut_create_internal_object(init_val->type); 143 if (!obj_desc) { 144 status = AE_NO_MEMORY; 145 goto unlock_and_exit; 146 } 147 148 /* 149 * Convert value string from table entry to 150 * internal representation. Only types actually 151 * used for initial values are implemented here. 152 */ 153 switch (init_val->type) { 154 case ACPI_TYPE_METHOD: 155 156 obj_desc->method.param_count = 157 (u8) ACPI_TO_INTEGER(val); 158 obj_desc->common.flags |= AOPOBJ_DATA_VALID; 159 160 #if defined (ACPI_ASL_COMPILER) 161 162 /* Save the parameter count for the iASL compiler */ 163 164 new_node->value = obj_desc->method.param_count; 165 #else 166 /* Mark this as a very SPECIAL method (_OSI) */ 167 168 obj_desc->method.info_flags = 169 ACPI_METHOD_INTERNAL_ONLY; 170 obj_desc->method.dispatch.implementation = 171 acpi_ut_osi_implementation; 172 #endif 173 break; 174 175 case ACPI_TYPE_INTEGER: 176 177 obj_desc->integer.value = ACPI_TO_INTEGER(val); 178 break; 179 180 case ACPI_TYPE_STRING: 181 182 /* Build an object around the static string */ 183 184 obj_desc->string.length = (u32)strlen(val); 185 obj_desc->string.pointer = val; 186 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER; 187 break; 188 189 case ACPI_TYPE_MUTEX: 190 191 obj_desc->mutex.node = new_node; 192 obj_desc->mutex.sync_level = 193 (u8) (ACPI_TO_INTEGER(val) - 1); 194 195 /* Create a mutex */ 196 197 status = 198 acpi_os_create_mutex(&obj_desc->mutex. 199 os_mutex); 200 if (ACPI_FAILURE(status)) { 201 acpi_ut_remove_reference(obj_desc); 202 goto unlock_and_exit; 203 } 204 205 /* Special case for ACPI Global Lock */ 206 207 if (strcmp(init_val->name, "_GL_") == 0) { 208 acpi_gbl_global_lock_mutex = obj_desc; 209 210 /* Create additional counting semaphore for global lock */ 211 212 status = 213 acpi_os_create_semaphore(1, 0, 214 &acpi_gbl_global_lock_semaphore); 215 if (ACPI_FAILURE(status)) { 216 acpi_ut_remove_reference 217 (obj_desc); 218 goto unlock_and_exit; 219 } 220 } 221 break; 222 223 default: 224 225 ACPI_ERROR((AE_INFO, 226 "Unsupported initial type value 0x%X", 227 init_val->type)); 228 acpi_ut_remove_reference(obj_desc); 229 obj_desc = NULL; 230 continue; 231 } 232 233 /* Store pointer to value descriptor in the Node */ 234 235 status = acpi_ns_attach_object(new_node, obj_desc, 236 obj_desc->common.type); 237 238 /* Remove local reference to the object */ 239 240 acpi_ut_remove_reference(obj_desc); 241 } 242 } 243 244 unlock_and_exit: 245 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE); 246 247 /* Save a handle to "_GPE", it is always present */ 248 249 if (ACPI_SUCCESS(status)) { 250 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH, 251 &acpi_gbl_fadt_gpe_device); 252 } 253 254 return_ACPI_STATUS(status); 255 } 256 257 /******************************************************************************* 258 * 259 * FUNCTION: acpi_ns_lookup 260 * 261 * PARAMETERS: scope_info - Current scope info block 262 * pathname - Search pathname, in internal format 263 * (as represented in the AML stream) 264 * type - Type associated with name 265 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found 266 * flags - Flags describing the search restrictions 267 * walk_state - Current state of the walk 268 * return_node - Where the Node is placed (if found 269 * or created successfully) 270 * 271 * RETURN: Status 272 * 273 * DESCRIPTION: Find or enter the passed name in the name space. 274 * Log an error if name not found in Exec mode. 275 * 276 * MUTEX: Assumes namespace is locked. 277 * 278 ******************************************************************************/ 279 280 acpi_status 281 acpi_ns_lookup(union acpi_generic_state *scope_info, 282 char *pathname, 283 acpi_object_type type, 284 acpi_interpreter_mode interpreter_mode, 285 u32 flags, 286 struct acpi_walk_state *walk_state, 287 struct acpi_namespace_node **return_node) 288 { 289 acpi_status status; 290 char *path = pathname; 291 char *external_path; 292 struct acpi_namespace_node *prefix_node; 293 struct acpi_namespace_node *current_node = NULL; 294 struct acpi_namespace_node *this_node = NULL; 295 u32 num_segments; 296 u32 num_carats; 297 acpi_name simple_name; 298 acpi_object_type type_to_check_for; 299 acpi_object_type this_search_type; 300 u32 search_parent_flag = ACPI_NS_SEARCH_PARENT; 301 u32 local_flags; 302 acpi_interpreter_mode local_interpreter_mode; 303 304 ACPI_FUNCTION_TRACE(ns_lookup); 305 306 if (!return_node) { 307 return_ACPI_STATUS(AE_BAD_PARAMETER); 308 } 309 310 local_flags = flags & 311 ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_OVERRIDE_IF_FOUND | 312 ACPI_NS_SEARCH_PARENT); 313 *return_node = ACPI_ENTRY_NOT_FOUND; 314 acpi_gbl_ns_lookup_count++; 315 316 if (!acpi_gbl_root_node) { 317 return_ACPI_STATUS(AE_NO_NAMESPACE); 318 } 319 320 /* Get the prefix scope. A null scope means use the root scope */ 321 322 if ((!scope_info) || (!scope_info->scope.node)) { 323 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 324 "Null scope prefix, using root node (%p)\n", 325 acpi_gbl_root_node)); 326 327 prefix_node = acpi_gbl_root_node; 328 } else { 329 prefix_node = scope_info->scope.node; 330 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) != 331 ACPI_DESC_TYPE_NAMED) { 332 ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]", 333 prefix_node, 334 acpi_ut_get_descriptor_name(prefix_node))); 335 return_ACPI_STATUS(AE_AML_INTERNAL); 336 } 337 338 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) { 339 /* 340 * This node might not be a actual "scope" node (such as a 341 * Device/Method, etc.) It could be a Package or other object 342 * node. Backup up the tree to find the containing scope node. 343 */ 344 while (!acpi_ns_opens_scope(prefix_node->type) && 345 prefix_node->type != ACPI_TYPE_ANY) { 346 prefix_node = prefix_node->parent; 347 } 348 } 349 } 350 351 /* Save type. TBD: may be no longer necessary */ 352 353 type_to_check_for = type; 354 355 /* 356 * Begin examination of the actual pathname 357 */ 358 if (!pathname) { 359 360 /* A Null name_path is allowed and refers to the root */ 361 362 num_segments = 0; 363 this_node = acpi_gbl_root_node; 364 path = ""; 365 366 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 367 "Null Pathname (Zero segments), Flags=%X\n", 368 flags)); 369 } else { 370 /* 371 * Name pointer is valid (and must be in internal name format) 372 * 373 * Check for scope prefixes: 374 * 375 * As represented in the AML stream, a namepath consists of an 376 * optional scope prefix followed by a name segment part. 377 * 378 * If present, the scope prefix is either a Root Prefix (in 379 * which case the name is fully qualified), or one or more 380 * Parent Prefixes (in which case the name's scope is relative 381 * to the current scope). 382 */ 383 if (*path == (u8) AML_ROOT_PREFIX) { 384 385 /* Pathname is fully qualified, start from the root */ 386 387 this_node = acpi_gbl_root_node; 388 search_parent_flag = ACPI_NS_NO_UPSEARCH; 389 390 /* Point to name segment part */ 391 392 path++; 393 394 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 395 "Path is absolute from root [%p]\n", 396 this_node)); 397 } else { 398 /* Pathname is relative to current scope, start there */ 399 400 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 401 "Searching relative to prefix scope [%4.4s] (%p)\n", 402 acpi_ut_get_node_name(prefix_node), 403 prefix_node)); 404 405 /* 406 * Handle multiple Parent Prefixes (carat) by just getting 407 * the parent node for each prefix instance. 408 */ 409 this_node = prefix_node; 410 num_carats = 0; 411 while (*path == (u8) AML_PARENT_PREFIX) { 412 413 /* Name is fully qualified, no search rules apply */ 414 415 search_parent_flag = ACPI_NS_NO_UPSEARCH; 416 417 /* 418 * Point past this prefix to the name segment 419 * part or the next Parent Prefix 420 */ 421 path++; 422 423 /* Backup to the parent node */ 424 425 num_carats++; 426 this_node = this_node->parent; 427 if (!this_node) { 428 /* 429 * Current scope has no parent scope. Externalize 430 * the internal path for error message. 431 */ 432 status = 433 acpi_ns_externalize_name 434 (ACPI_UINT32_MAX, pathname, NULL, 435 &external_path); 436 if (ACPI_SUCCESS(status)) { 437 ACPI_ERROR((AE_INFO, 438 "%s: Path has too many parent prefixes (^)", 439 external_path)); 440 441 ACPI_FREE(external_path); 442 } 443 444 return_ACPI_STATUS(AE_NOT_FOUND); 445 } 446 } 447 448 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) { 449 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 450 "Search scope is [%4.4s], path has %u carat(s)\n", 451 acpi_ut_get_node_name 452 (this_node), num_carats)); 453 } 454 } 455 456 /* 457 * Determine the number of ACPI name segments in this pathname. 458 * 459 * The segment part consists of either: 460 * - A Null name segment (0) 461 * - A dual_name_prefix followed by two 4-byte name segments 462 * - A multi_name_prefix followed by a byte indicating the 463 * number of segments and the segments themselves. 464 * - A single 4-byte name segment 465 * 466 * Examine the name prefix opcode, if any, to determine the number of 467 * segments. 468 */ 469 switch (*path) { 470 case 0: 471 /* 472 * Null name after a root or parent prefixes. We already 473 * have the correct target node and there are no name segments. 474 */ 475 num_segments = 0; 476 type = this_node->type; 477 478 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 479 "Prefix-only Pathname (Zero name segments), Flags=%X\n", 480 flags)); 481 break; 482 483 case AML_DUAL_NAME_PREFIX: 484 485 /* More than one name_seg, search rules do not apply */ 486 487 search_parent_flag = ACPI_NS_NO_UPSEARCH; 488 489 /* Two segments, point to first name segment */ 490 491 num_segments = 2; 492 path++; 493 494 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 495 "Dual Pathname (2 segments, Flags=%X)\n", 496 flags)); 497 break; 498 499 case AML_MULTI_NAME_PREFIX: 500 501 /* More than one name_seg, search rules do not apply */ 502 503 search_parent_flag = ACPI_NS_NO_UPSEARCH; 504 505 /* Extract segment count, point to first name segment */ 506 507 path++; 508 num_segments = (u32) (u8) * path; 509 path++; 510 511 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 512 "Multi Pathname (%u Segments, Flags=%X)\n", 513 num_segments, flags)); 514 break; 515 516 default: 517 /* 518 * Not a Null name, no Dual or Multi prefix, hence there is 519 * only one name segment and Pathname is already pointing to it. 520 */ 521 num_segments = 1; 522 523 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 524 "Simple Pathname (1 segment, Flags=%X)\n", 525 flags)); 526 break; 527 } 528 529 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path)); 530 } 531 532 /* 533 * Search namespace for each segment of the name. Loop through and 534 * verify (or add to the namespace) each name segment. 535 * 536 * The object type is significant only at the last name 537 * segment. (We don't care about the types along the path, only 538 * the type of the final target object.) 539 */ 540 this_search_type = ACPI_TYPE_ANY; 541 current_node = this_node; 542 543 while (num_segments && current_node) { 544 num_segments--; 545 if (!num_segments) { 546 547 /* This is the last segment, enable typechecking */ 548 549 this_search_type = type; 550 551 /* 552 * Only allow automatic parent search (search rules) if the caller 553 * requested it AND we have a single, non-fully-qualified name_seg 554 */ 555 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) && 556 (flags & ACPI_NS_SEARCH_PARENT)) { 557 local_flags |= ACPI_NS_SEARCH_PARENT; 558 } 559 560 /* Set error flag according to caller */ 561 562 if (flags & ACPI_NS_ERROR_IF_FOUND) { 563 local_flags |= ACPI_NS_ERROR_IF_FOUND; 564 } 565 566 /* Set override flag according to caller */ 567 568 if (flags & ACPI_NS_OVERRIDE_IF_FOUND) { 569 local_flags |= ACPI_NS_OVERRIDE_IF_FOUND; 570 } 571 } 572 573 /* Handle opcodes that create a new name_seg via a full name_path */ 574 575 local_interpreter_mode = interpreter_mode; 576 if ((flags & ACPI_NS_PREFIX_MUST_EXIST) && (num_segments > 0)) { 577 578 /* Every element of the path must exist (except for the final name_seg) */ 579 580 local_interpreter_mode = ACPI_IMODE_EXECUTE; 581 } 582 583 /* Extract one ACPI name from the front of the pathname */ 584 585 ACPI_MOVE_32_TO_32(&simple_name, path); 586 587 /* Try to find the single (4 character) ACPI name */ 588 589 status = 590 acpi_ns_search_and_enter(simple_name, walk_state, 591 current_node, 592 local_interpreter_mode, 593 this_search_type, local_flags, 594 &this_node); 595 if (ACPI_FAILURE(status)) { 596 if (status == AE_NOT_FOUND) { 597 #if !defined ACPI_ASL_COMPILER /* Note: iASL reports this error by itself, not needed here */ 598 if (flags & ACPI_NS_PREFIX_MUST_EXIST) { 599 acpi_os_printf(ACPI_MSG_BIOS_ERROR 600 "Object does not exist: %4.4s\n", 601 &simple_name); 602 } 603 #endif 604 /* Name not found in ACPI namespace */ 605 606 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 607 "Name [%4.4s] not found in scope [%4.4s] %p\n", 608 (char *)&simple_name, 609 (char *)¤t_node->name, 610 current_node)); 611 } 612 #ifdef ACPI_EXEC_APP 613 if ((status == AE_ALREADY_EXISTS) && 614 (this_node->flags & ANOBJ_NODE_EARLY_INIT)) { 615 this_node->flags &= ~ANOBJ_NODE_EARLY_INIT; 616 status = AE_OK; 617 } 618 #endif 619 620 #ifdef ACPI_ASL_COMPILER 621 /* 622 * If this ACPI name already exists within the namespace as an 623 * external declaration, then mark the external as a conflicting 624 * declaration and proceed to process the current node as if it did 625 * not exist in the namespace. If this node is not processed as 626 * normal, then it could cause improper namespace resolution 627 * by failing to open a new scope. 628 */ 629 if (acpi_gbl_disasm_flag && 630 (status == AE_ALREADY_EXISTS) && 631 ((this_node->flags & ANOBJ_IS_EXTERNAL) || 632 (walk_state 633 && walk_state->opcode == AML_EXTERNAL_OP))) { 634 this_node->flags &= ~ANOBJ_IS_EXTERNAL; 635 this_node->type = (u8)this_search_type; 636 if (walk_state->opcode != AML_EXTERNAL_OP) { 637 acpi_dm_mark_external_conflict 638 (this_node); 639 } 640 break; 641 } 642 #endif 643 644 *return_node = this_node; 645 return_ACPI_STATUS(status); 646 } 647 648 /* More segments to follow? */ 649 650 if (num_segments > 0) { 651 /* 652 * If we have an alias to an object that opens a scope (such as a 653 * device or processor), we need to dereference the alias here so 654 * that we can access any children of the original node (via the 655 * remaining segments). 656 */ 657 if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) { 658 if (!this_node->object) { 659 return_ACPI_STATUS(AE_NOT_EXIST); 660 } 661 662 if (acpi_ns_opens_scope 663 (((struct acpi_namespace_node *) 664 this_node->object)->type)) { 665 this_node = 666 (struct acpi_namespace_node *) 667 this_node->object; 668 } 669 } 670 } 671 672 /* Special handling for the last segment (num_segments == 0) */ 673 674 else { 675 /* 676 * Sanity typecheck of the target object: 677 * 678 * If 1) This is the last segment (num_segments == 0) 679 * 2) And we are looking for a specific type 680 * (Not checking for TYPE_ANY) 681 * 3) Which is not an alias 682 * 4) Which is not a local type (TYPE_SCOPE) 683 * 5) And the type of target object is known (not TYPE_ANY) 684 * 6) And target object does not match what we are looking for 685 * 686 * Then we have a type mismatch. Just warn and ignore it. 687 */ 688 if ((type_to_check_for != ACPI_TYPE_ANY) && 689 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) && 690 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS) 691 && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE) 692 && (this_node->type != ACPI_TYPE_ANY) 693 && (this_node->type != type_to_check_for)) { 694 695 /* Complain about a type mismatch */ 696 697 ACPI_WARNING((AE_INFO, 698 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)", 699 ACPI_CAST_PTR(char, &simple_name), 700 acpi_ut_get_type_name(this_node-> 701 type), 702 acpi_ut_get_type_name 703 (type_to_check_for))); 704 } 705 706 /* 707 * If this is the last name segment and we are not looking for a 708 * specific type, but the type of found object is known, use that 709 * type to (later) see if it opens a scope. 710 */ 711 if (type == ACPI_TYPE_ANY) { 712 type = this_node->type; 713 } 714 } 715 716 /* Point to next name segment and make this node current */ 717 718 path += ACPI_NAMESEG_SIZE; 719 current_node = this_node; 720 } 721 722 /* Always check if we need to open a new scope */ 723 724 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) { 725 /* 726 * If entry is a type which opens a scope, push the new scope on the 727 * scope stack. 728 */ 729 if (acpi_ns_opens_scope(type)) { 730 status = 731 acpi_ds_scope_stack_push(this_node, type, 732 walk_state); 733 if (ACPI_FAILURE(status)) { 734 return_ACPI_STATUS(status); 735 } 736 } 737 } 738 #ifdef ACPI_EXEC_APP 739 if (flags & ACPI_NS_EARLY_INIT) { 740 this_node->flags |= ANOBJ_NODE_EARLY_INIT; 741 } 742 #endif 743 744 *return_node = this_node; 745 return_ACPI_STATUS(AE_OK); 746 } 747