linux/drivers/acpi/acpica/dswload2.c
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   1/******************************************************************************
   2 *
   3 * Module Name: dswload2 - Dispatcher second pass namespace load callbacks
   4 *
   5 *****************************************************************************/
   6
   7/*
   8 * Copyright (C) 2000 - 2015, Intel Corp.
   9 * All rights reserved.
  10 *
  11 * Redistribution and use in source and binary forms, with or without
  12 * modification, are permitted provided that the following conditions
  13 * are met:
  14 * 1. Redistributions of source code must retain the above copyright
  15 *    notice, this list of conditions, and the following disclaimer,
  16 *    without modification.
  17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18 *    substantially similar to the "NO WARRANTY" disclaimer below
  19 *    ("Disclaimer") and any redistribution must be conditioned upon
  20 *    including a substantially similar Disclaimer requirement for further
  21 *    binary redistribution.
  22 * 3. Neither the names of the above-listed copyright holders nor the names
  23 *    of any contributors may be used to endorse or promote products derived
  24 *    from this software without specific prior written permission.
  25 *
  26 * Alternatively, this software may be distributed under the terms of the
  27 * GNU General Public License ("GPL") version 2 as published by the Free
  28 * Software Foundation.
  29 *
  30 * NO WARRANTY
  31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41 * POSSIBILITY OF SUCH DAMAGES.
  42 */
  43
  44#include <acpi/acpi.h>
  45#include "accommon.h"
  46#include "acparser.h"
  47#include "amlcode.h"
  48#include "acdispat.h"
  49#include "acinterp.h"
  50#include "acnamesp.h"
  51#include "acevents.h"
  52
  53#define _COMPONENT          ACPI_DISPATCHER
  54ACPI_MODULE_NAME("dswload2")
  55
  56/*******************************************************************************
  57 *
  58 * FUNCTION:    acpi_ds_load2_begin_op
  59 *
  60 * PARAMETERS:  walk_state      - Current state of the parse tree walk
  61 *              out_op          - Wher to return op if a new one is created
  62 *
  63 * RETURN:      Status
  64 *
  65 * DESCRIPTION: Descending callback used during the loading of ACPI tables.
  66 *
  67 ******************************************************************************/
  68acpi_status
  69acpi_ds_load2_begin_op(struct acpi_walk_state *walk_state,
  70                       union acpi_parse_object **out_op)
  71{
  72        union acpi_parse_object *op;
  73        struct acpi_namespace_node *node;
  74        acpi_status status;
  75        acpi_object_type object_type;
  76        char *buffer_ptr;
  77        u32 flags;
  78
  79        ACPI_FUNCTION_TRACE(ds_load2_begin_op);
  80
  81        op = walk_state->op;
  82        ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Op=%p State=%p\n", op,
  83                          walk_state));
  84
  85        if (op) {
  86                if ((walk_state->control_state) &&
  87                    (walk_state->control_state->common.state ==
  88                     ACPI_CONTROL_CONDITIONAL_EXECUTING)) {
  89
  90                        /* We are executing a while loop outside of a method */
  91
  92                        status = acpi_ds_exec_begin_op(walk_state, out_op);
  93                        return_ACPI_STATUS(status);
  94                }
  95
  96                /* We only care about Namespace opcodes here */
  97
  98                if ((!(walk_state->op_info->flags & AML_NSOPCODE) &&
  99                     (walk_state->opcode != AML_INT_NAMEPATH_OP)) ||
 100                    (!(walk_state->op_info->flags & AML_NAMED))) {
 101                        return_ACPI_STATUS(AE_OK);
 102                }
 103
 104                /* Get the name we are going to enter or lookup in the namespace */
 105
 106                if (walk_state->opcode == AML_INT_NAMEPATH_OP) {
 107
 108                        /* For Namepath op, get the path string */
 109
 110                        buffer_ptr = op->common.value.string;
 111                        if (!buffer_ptr) {
 112
 113                                /* No name, just exit */
 114
 115                                return_ACPI_STATUS(AE_OK);
 116                        }
 117                } else {
 118                        /* Get name from the op */
 119
 120                        buffer_ptr = ACPI_CAST_PTR(char, &op->named.name);
 121                }
 122        } else {
 123                /* Get the namestring from the raw AML */
 124
 125                buffer_ptr =
 126                    acpi_ps_get_next_namestring(&walk_state->parser_state);
 127        }
 128
 129        /* Map the opcode into an internal object type */
 130
 131        object_type = walk_state->op_info->object_type;
 132
 133        ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 134                          "State=%p Op=%p Type=%X\n", walk_state, op,
 135                          object_type));
 136
 137        switch (walk_state->opcode) {
 138        case AML_FIELD_OP:
 139        case AML_BANK_FIELD_OP:
 140        case AML_INDEX_FIELD_OP:
 141
 142                node = NULL;
 143                status = AE_OK;
 144                break;
 145
 146        case AML_INT_NAMEPATH_OP:
 147                /*
 148                 * The name_path is an object reference to an existing object.
 149                 * Don't enter the name into the namespace, but look it up
 150                 * for use later.
 151                 */
 152                status =
 153                    acpi_ns_lookup(walk_state->scope_info, buffer_ptr,
 154                                   object_type, ACPI_IMODE_EXECUTE,
 155                                   ACPI_NS_SEARCH_PARENT, walk_state, &(node));
 156                break;
 157
 158        case AML_SCOPE_OP:
 159
 160                /* Special case for Scope(\) -> refers to the Root node */
 161
 162                if (op && (op->named.node == acpi_gbl_root_node)) {
 163                        node = op->named.node;
 164
 165                        status =
 166                            acpi_ds_scope_stack_push(node, object_type,
 167                                                     walk_state);
 168                        if (ACPI_FAILURE(status)) {
 169                                return_ACPI_STATUS(status);
 170                        }
 171                } else {
 172                        /*
 173                         * The Path is an object reference to an existing object.
 174                         * Don't enter the name into the namespace, but look it up
 175                         * for use later.
 176                         */
 177                        status =
 178                            acpi_ns_lookup(walk_state->scope_info, buffer_ptr,
 179                                           object_type, ACPI_IMODE_EXECUTE,
 180                                           ACPI_NS_SEARCH_PARENT, walk_state,
 181                                           &(node));
 182                        if (ACPI_FAILURE(status)) {
 183#ifdef ACPI_ASL_COMPILER
 184                                if (status == AE_NOT_FOUND) {
 185                                        status = AE_OK;
 186                                } else {
 187                                        ACPI_ERROR_NAMESPACE(buffer_ptr,
 188                                                             status);
 189                                }
 190#else
 191                                ACPI_ERROR_NAMESPACE(buffer_ptr, status);
 192#endif
 193                                return_ACPI_STATUS(status);
 194                        }
 195                }
 196
 197                /*
 198                 * We must check to make sure that the target is
 199                 * one of the opcodes that actually opens a scope
 200                 */
 201                switch (node->type) {
 202                case ACPI_TYPE_ANY:
 203                case ACPI_TYPE_LOCAL_SCOPE:     /* Scope */
 204                case ACPI_TYPE_DEVICE:
 205                case ACPI_TYPE_POWER:
 206                case ACPI_TYPE_PROCESSOR:
 207                case ACPI_TYPE_THERMAL:
 208
 209                        /* These are acceptable types */
 210                        break;
 211
 212                case ACPI_TYPE_INTEGER:
 213                case ACPI_TYPE_STRING:
 214                case ACPI_TYPE_BUFFER:
 215
 216                        /*
 217                         * These types we will allow, but we will change the type.
 218                         * This enables some existing code of the form:
 219                         *
 220                         *  Name (DEB, 0)
 221                         *  Scope (DEB) { ... }
 222                         */
 223                        ACPI_WARNING((AE_INFO,
 224                                      "Type override - [%4.4s] had invalid type (%s) "
 225                                      "for Scope operator, changed to type ANY",
 226                                      acpi_ut_get_node_name(node),
 227                                      acpi_ut_get_type_name(node->type)));
 228
 229                        node->type = ACPI_TYPE_ANY;
 230                        walk_state->scope_info->common.value = ACPI_TYPE_ANY;
 231                        break;
 232
 233                case ACPI_TYPE_METHOD:
 234
 235                        /*
 236                         * Allow scope change to root during execution of module-level
 237                         * code. Root is typed METHOD during this time.
 238                         */
 239                        if ((node == acpi_gbl_root_node) &&
 240                            (walk_state->
 241                             parse_flags & ACPI_PARSE_MODULE_LEVEL)) {
 242                                break;
 243                        }
 244
 245                        /*lint -fallthrough */
 246
 247                default:
 248
 249                        /* All other types are an error */
 250
 251                        ACPI_ERROR((AE_INFO,
 252                                    "Invalid type (%s) for target of "
 253                                    "Scope operator [%4.4s] (Cannot override)",
 254                                    acpi_ut_get_type_name(node->type),
 255                                    acpi_ut_get_node_name(node)));
 256
 257                        return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 258                }
 259                break;
 260
 261        default:
 262
 263                /* All other opcodes */
 264
 265                if (op && op->common.node) {
 266
 267                        /* This op/node was previously entered into the namespace */
 268
 269                        node = op->common.node;
 270
 271                        if (acpi_ns_opens_scope(object_type)) {
 272                                status =
 273                                    acpi_ds_scope_stack_push(node, object_type,
 274                                                             walk_state);
 275                                if (ACPI_FAILURE(status)) {
 276                                        return_ACPI_STATUS(status);
 277                                }
 278                        }
 279
 280                        return_ACPI_STATUS(AE_OK);
 281                }
 282
 283                /*
 284                 * Enter the named type into the internal namespace. We enter the name
 285                 * as we go downward in the parse tree. Any necessary subobjects that
 286                 * involve arguments to the opcode must be created as we go back up the
 287                 * parse tree later.
 288                 *
 289                 * Note: Name may already exist if we are executing a deferred opcode.
 290                 */
 291                if (walk_state->deferred_node) {
 292
 293                        /* This name is already in the namespace, get the node */
 294
 295                        node = walk_state->deferred_node;
 296                        status = AE_OK;
 297                        break;
 298                }
 299
 300                flags = ACPI_NS_NO_UPSEARCH;
 301                if (walk_state->pass_number == ACPI_IMODE_EXECUTE) {
 302
 303                        /* Execution mode, node cannot already exist, node is temporary */
 304
 305                        flags |= ACPI_NS_ERROR_IF_FOUND;
 306
 307                        if (!
 308                            (walk_state->
 309                             parse_flags & ACPI_PARSE_MODULE_LEVEL)) {
 310                                flags |= ACPI_NS_TEMPORARY;
 311                        }
 312                }
 313
 314                /* Add new entry or lookup existing entry */
 315
 316                status =
 317                    acpi_ns_lookup(walk_state->scope_info, buffer_ptr,
 318                                   object_type, ACPI_IMODE_LOAD_PASS2, flags,
 319                                   walk_state, &node);
 320
 321                if (ACPI_SUCCESS(status) && (flags & ACPI_NS_TEMPORARY)) {
 322                        ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 323                                          "***New Node [%4.4s] %p is temporary\n",
 324                                          acpi_ut_get_node_name(node), node));
 325                }
 326                break;
 327        }
 328
 329        if (ACPI_FAILURE(status)) {
 330                ACPI_ERROR_NAMESPACE(buffer_ptr, status);
 331                return_ACPI_STATUS(status);
 332        }
 333
 334        if (!op) {
 335
 336                /* Create a new op */
 337
 338                op = acpi_ps_alloc_op(walk_state->opcode);
 339                if (!op) {
 340                        return_ACPI_STATUS(AE_NO_MEMORY);
 341                }
 342
 343                /* Initialize the new op */
 344
 345                if (node) {
 346                        op->named.name = node->name.integer;
 347                }
 348                *out_op = op;
 349        }
 350
 351        /*
 352         * Put the Node in the "op" object that the parser uses, so we
 353         * can get it again quickly when this scope is closed
 354         */
 355        op->common.node = node;
 356        return_ACPI_STATUS(status);
 357}
 358
 359/*******************************************************************************
 360 *
 361 * FUNCTION:    acpi_ds_load2_end_op
 362 *
 363 * PARAMETERS:  walk_state      - Current state of the parse tree walk
 364 *
 365 * RETURN:      Status
 366 *
 367 * DESCRIPTION: Ascending callback used during the loading of the namespace,
 368 *              both control methods and everything else.
 369 *
 370 ******************************************************************************/
 371
 372acpi_status acpi_ds_load2_end_op(struct acpi_walk_state *walk_state)
 373{
 374        union acpi_parse_object *op;
 375        acpi_status status = AE_OK;
 376        acpi_object_type object_type;
 377        struct acpi_namespace_node *node;
 378        union acpi_parse_object *arg;
 379        struct acpi_namespace_node *new_node;
 380#ifndef ACPI_NO_METHOD_EXECUTION
 381        u32 i;
 382        u8 region_space;
 383#endif
 384
 385        ACPI_FUNCTION_TRACE(ds_load2_end_op);
 386
 387        op = walk_state->op;
 388        ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Opcode [%s] Op %p State %p\n",
 389                          walk_state->op_info->name, op, walk_state));
 390
 391        /* Check if opcode had an associated namespace object */
 392
 393        if (!(walk_state->op_info->flags & AML_NSOBJECT)) {
 394                return_ACPI_STATUS(AE_OK);
 395        }
 396
 397        if (op->common.aml_opcode == AML_SCOPE_OP) {
 398                ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 399                                  "Ending scope Op=%p State=%p\n", op,
 400                                  walk_state));
 401        }
 402
 403        object_type = walk_state->op_info->object_type;
 404
 405        /*
 406         * Get the Node/name from the earlier lookup
 407         * (It was saved in the *op structure)
 408         */
 409        node = op->common.node;
 410
 411        /*
 412         * Put the Node on the object stack (Contains the ACPI Name of
 413         * this object)
 414         */
 415        walk_state->operands[0] = (void *)node;
 416        walk_state->num_operands = 1;
 417
 418        /* Pop the scope stack */
 419
 420        if (acpi_ns_opens_scope(object_type) &&
 421            (op->common.aml_opcode != AML_INT_METHODCALL_OP)) {
 422                ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 423                                  "(%s) Popping scope for Op %p\n",
 424                                  acpi_ut_get_type_name(object_type), op));
 425
 426                status = acpi_ds_scope_stack_pop(walk_state);
 427                if (ACPI_FAILURE(status)) {
 428                        goto cleanup;
 429                }
 430        }
 431
 432        /*
 433         * Named operations are as follows:
 434         *
 435         * AML_ALIAS
 436         * AML_BANKFIELD
 437         * AML_CREATEBITFIELD
 438         * AML_CREATEBYTEFIELD
 439         * AML_CREATEDWORDFIELD
 440         * AML_CREATEFIELD
 441         * AML_CREATEQWORDFIELD
 442         * AML_CREATEWORDFIELD
 443         * AML_DATA_REGION
 444         * AML_DEVICE
 445         * AML_EVENT
 446         * AML_FIELD
 447         * AML_INDEXFIELD
 448         * AML_METHOD
 449         * AML_METHODCALL
 450         * AML_MUTEX
 451         * AML_NAME
 452         * AML_NAMEDFIELD
 453         * AML_OPREGION
 454         * AML_POWERRES
 455         * AML_PROCESSOR
 456         * AML_SCOPE
 457         * AML_THERMALZONE
 458         */
 459
 460        ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 461                          "Create-Load [%s] State=%p Op=%p NamedObj=%p\n",
 462                          acpi_ps_get_opcode_name(op->common.aml_opcode),
 463                          walk_state, op, node));
 464
 465        /* Decode the opcode */
 466
 467        arg = op->common.value.arg;
 468
 469        switch (walk_state->op_info->type) {
 470#ifndef ACPI_NO_METHOD_EXECUTION
 471
 472        case AML_TYPE_CREATE_FIELD:
 473                /*
 474                 * Create the field object, but the field buffer and index must
 475                 * be evaluated later during the execution phase
 476                 */
 477                status = acpi_ds_create_buffer_field(op, walk_state);
 478                break;
 479
 480        case AML_TYPE_NAMED_FIELD:
 481                /*
 482                 * If we are executing a method, initialize the field
 483                 */
 484                if (walk_state->method_node) {
 485                        status = acpi_ds_init_field_objects(op, walk_state);
 486                }
 487
 488                switch (op->common.aml_opcode) {
 489                case AML_INDEX_FIELD_OP:
 490
 491                        status =
 492                            acpi_ds_create_index_field(op,
 493                                                       (acpi_handle) arg->
 494                                                       common.node, walk_state);
 495                        break;
 496
 497                case AML_BANK_FIELD_OP:
 498
 499                        status =
 500                            acpi_ds_create_bank_field(op, arg->common.node,
 501                                                      walk_state);
 502                        break;
 503
 504                case AML_FIELD_OP:
 505
 506                        status =
 507                            acpi_ds_create_field(op, arg->common.node,
 508                                                 walk_state);
 509                        break;
 510
 511                default:
 512
 513                        /* All NAMED_FIELD opcodes must be handled above */
 514                        break;
 515                }
 516                break;
 517
 518        case AML_TYPE_NAMED_SIMPLE:
 519
 520                status = acpi_ds_create_operands(walk_state, arg);
 521                if (ACPI_FAILURE(status)) {
 522                        goto cleanup;
 523                }
 524
 525                switch (op->common.aml_opcode) {
 526                case AML_PROCESSOR_OP:
 527
 528                        status = acpi_ex_create_processor(walk_state);
 529                        break;
 530
 531                case AML_POWER_RES_OP:
 532
 533                        status = acpi_ex_create_power_resource(walk_state);
 534                        break;
 535
 536                case AML_MUTEX_OP:
 537
 538                        status = acpi_ex_create_mutex(walk_state);
 539                        break;
 540
 541                case AML_EVENT_OP:
 542
 543                        status = acpi_ex_create_event(walk_state);
 544                        break;
 545
 546                case AML_ALIAS_OP:
 547
 548                        status = acpi_ex_create_alias(walk_state);
 549                        break;
 550
 551                default:
 552
 553                        /* Unknown opcode */
 554
 555                        status = AE_OK;
 556                        goto cleanup;
 557                }
 558
 559                /* Delete operands */
 560
 561                for (i = 1; i < walk_state->num_operands; i++) {
 562                        acpi_ut_remove_reference(walk_state->operands[i]);
 563                        walk_state->operands[i] = NULL;
 564                }
 565
 566                break;
 567#endif                          /* ACPI_NO_METHOD_EXECUTION */
 568
 569        case AML_TYPE_NAMED_COMPLEX:
 570
 571                switch (op->common.aml_opcode) {
 572#ifndef ACPI_NO_METHOD_EXECUTION
 573                case AML_REGION_OP:
 574                case AML_DATA_REGION_OP:
 575
 576                        if (op->common.aml_opcode == AML_REGION_OP) {
 577                                region_space = (acpi_adr_space_type)
 578                                    ((op->common.value.arg)->common.value.
 579                                     integer);
 580                        } else {
 581                                region_space = ACPI_ADR_SPACE_DATA_TABLE;
 582                        }
 583
 584                        /*
 585                         * The op_region is not fully parsed at this time. The only valid
 586                         * argument is the space_id. (We must save the address of the
 587                         * AML of the address and length operands)
 588                         *
 589                         * If we have a valid region, initialize it. The namespace is
 590                         * unlocked at this point.
 591                         *
 592                         * Need to unlock interpreter if it is locked (if we are running
 593                         * a control method), in order to allow _REG methods to be run
 594                         * during acpi_ev_initialize_region.
 595                         */
 596                        if (walk_state->method_node) {
 597                                /*
 598                                 * Executing a method: initialize the region and unlock
 599                                 * the interpreter
 600                                 */
 601                                status =
 602                                    acpi_ex_create_region(op->named.data,
 603                                                          op->named.length,
 604                                                          region_space,
 605                                                          walk_state);
 606                                if (ACPI_FAILURE(status)) {
 607                                        return_ACPI_STATUS(status);
 608                                }
 609
 610                                acpi_ex_exit_interpreter();
 611                        }
 612
 613                        status =
 614                            acpi_ev_initialize_region
 615                            (acpi_ns_get_attached_object(node), FALSE);
 616                        if (walk_state->method_node) {
 617                                acpi_ex_enter_interpreter();
 618                        }
 619
 620                        if (ACPI_FAILURE(status)) {
 621                                /*
 622                                 *  If AE_NOT_EXIST is returned, it is not fatal
 623                                 *  because many regions get created before a handler
 624                                 *  is installed for said region.
 625                                 */
 626                                if (AE_NOT_EXIST == status) {
 627                                        status = AE_OK;
 628                                }
 629                        }
 630                        break;
 631
 632                case AML_NAME_OP:
 633
 634                        status = acpi_ds_create_node(walk_state, node, op);
 635                        break;
 636
 637                case AML_METHOD_OP:
 638                        /*
 639                         * method_op pkg_length name_string method_flags term_list
 640                         *
 641                         * Note: We must create the method node/object pair as soon as we
 642                         * see the method declaration. This allows later pass1 parsing
 643                         * of invocations of the method (need to know the number of
 644                         * arguments.)
 645                         */
 646                        ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 647                                          "LOADING-Method: State=%p Op=%p NamedObj=%p\n",
 648                                          walk_state, op, op->named.node));
 649
 650                        if (!acpi_ns_get_attached_object(op->named.node)) {
 651                                walk_state->operands[0] =
 652                                    ACPI_CAST_PTR(void, op->named.node);
 653                                walk_state->num_operands = 1;
 654
 655                                status =
 656                                    acpi_ds_create_operands(walk_state,
 657                                                            op->common.value.
 658                                                            arg);
 659                                if (ACPI_SUCCESS(status)) {
 660                                        status =
 661                                            acpi_ex_create_method(op->named.
 662                                                                  data,
 663                                                                  op->named.
 664                                                                  length,
 665                                                                  walk_state);
 666                                }
 667                                walk_state->operands[0] = NULL;
 668                                walk_state->num_operands = 0;
 669
 670                                if (ACPI_FAILURE(status)) {
 671                                        return_ACPI_STATUS(status);
 672                                }
 673                        }
 674                        break;
 675
 676#endif                          /* ACPI_NO_METHOD_EXECUTION */
 677
 678                default:
 679
 680                        /* All NAMED_COMPLEX opcodes must be handled above */
 681                        break;
 682                }
 683                break;
 684
 685        case AML_CLASS_INTERNAL:
 686
 687                /* case AML_INT_NAMEPATH_OP: */
 688                break;
 689
 690        case AML_CLASS_METHOD_CALL:
 691
 692                ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 693                                  "RESOLVING-MethodCall: State=%p Op=%p NamedObj=%p\n",
 694                                  walk_state, op, node));
 695
 696                /*
 697                 * Lookup the method name and save the Node
 698                 */
 699                status =
 700                    acpi_ns_lookup(walk_state->scope_info,
 701                                   arg->common.value.string, ACPI_TYPE_ANY,
 702                                   ACPI_IMODE_LOAD_PASS2,
 703                                   ACPI_NS_SEARCH_PARENT |
 704                                   ACPI_NS_DONT_OPEN_SCOPE, walk_state,
 705                                   &(new_node));
 706                if (ACPI_SUCCESS(status)) {
 707                        /*
 708                         * Make sure that what we found is indeed a method
 709                         * We didn't search for a method on purpose, to see if the name
 710                         * would resolve
 711                         */
 712                        if (new_node->type != ACPI_TYPE_METHOD) {
 713                                status = AE_AML_OPERAND_TYPE;
 714                        }
 715
 716                        /* We could put the returned object (Node) on the object stack for
 717                         * later, but for now, we will put it in the "op" object that the
 718                         * parser uses, so we can get it again at the end of this scope
 719                         */
 720                        op->common.node = new_node;
 721                } else {
 722                        ACPI_ERROR_NAMESPACE(arg->common.value.string, status);
 723                }
 724                break;
 725
 726        default:
 727
 728                break;
 729        }
 730
 731cleanup:
 732
 733        /* Remove the Node pushed at the very beginning */
 734
 735        walk_state->operands[0] = NULL;
 736        walk_state->num_operands = 0;
 737        return_ACPI_STATUS(status);
 738}
 739