drivers/acpi/acpica/psobject.c

   1 /******************************************************************************
   2  *
   3  * Module Name: psobject - Support for parse objects
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2017, 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
  49 #define _COMPONENT          ACPI_PARSER
  50 ACPI_MODULE_NAME("psobject")
  51
  52 /* Local prototypes */
  53 static acpi_status acpi_ps_get_aml_opcode(struct acpi_walk_state *walk_state);
  54
  55 /*******************************************************************************
  56  *
  57  * FUNCTION:    acpi_ps_get_aml_opcode
  58  *
  59  * PARAMETERS:  walk_state          - Current state
  60  *
  61  * RETURN:      Status
  62  *
  63  * DESCRIPTION: Extract the next AML opcode from the input stream.
  64  *
  65  ******************************************************************************/
  66
  67 static acpi_status acpi_ps_get_aml_opcode(struct acpi_walk_state *walk_state)
  68 {
  69         u32 aml_offset;
  70
  71         ACPI_FUNCTION_TRACE_PTR(ps_get_aml_opcode, walk_state);
  72
  73         walk_state->aml = walk_state->parser_state.aml;
  74         walk_state->opcode = acpi_ps_peek_opcode(&(walk_state->parser_state));
  75
  76         /*
  77          * First cut to determine what we have found:
  78          * 1) A valid AML opcode
  79          * 2) A name string
  80          * 3) An unknown/invalid opcode
  81          */
  82         walk_state->op_info = acpi_ps_get_opcode_info(walk_state->opcode);
  83
  84         switch (walk_state->op_info->class) {
  85         case AML_CLASS_ASCII:
  86         case AML_CLASS_PREFIX:
  87                 /*
  88                  * Starts with a valid prefix or ASCII char, this is a name
  89                  * string. Convert the bare name string to a namepath.
  90                  */
  91                 walk_state->opcode = AML_INT_NAMEPATH_OP;
  92                 walk_state->arg_types = ARGP_NAMESTRING;
  93                 break;
  94
  95         case AML_CLASS_UNKNOWN:
  96
  97                 /* The opcode is unrecognized. Complain and skip unknown opcodes */
  98
  99                 if (walk_state->pass_number == 2) {
 100                         aml_offset = (u32)ACPI_PTR_DIFF(walk_state->aml,
 101                                                         walk_state->
 102                                                         parser_state.aml_start);
 103
 104                         ACPI_ERROR((AE_INFO,
 105                                     "Unknown opcode 0x%.2X at table offset 0x%.4X, ignoring",
 106                                     walk_state->opcode,
 107                                     (u32)(aml_offset +
 108                                           sizeof(struct acpi_table_header))));
 109
 110                         ACPI_DUMP_BUFFER((walk_state->parser_state.aml - 16),
 111                                          48);
 112
 113 #ifdef ACPI_ASL_COMPILER
 114                         /*
 115                          * This is executed for the disassembler only. Output goes
 116                          * to the disassembled ASL output file.
 117                          */
 118                         acpi_os_printf
 119                             ("/*\nError: Unknown opcode 0x%.2X at table offset 0x%.4X, context:\n",
 120                              walk_state->opcode,
 121                              (u32)(aml_offset +
 122                                    sizeof(struct acpi_table_header)));
 123
 124                         /* Dump the context surrounding the invalid opcode */
 125
 126                         acpi_ut_dump_buffer(((u8 *)walk_state->parser_state.
 127                                              aml - 16), 48, DB_BYTE_DISPLAY,
 128                                             (aml_offset +
 129                                              sizeof(struct acpi_table_header) -
 130                                              16));
 131                         acpi_os_printf(" */\n");
 132 #endif
 133                 }
 134
 135                 /* Increment past one-byte or two-byte opcode */
 136
 137                 walk_state->parser_state.aml++;
 138                 if (walk_state->opcode > 0xFF) {        /* Can only happen if first byte is 0x5B */
 139                         walk_state->parser_state.aml++;
 140                 }
 141
 142                 return_ACPI_STATUS(AE_CTRL_PARSE_CONTINUE);
 143
 144         default:
 145
 146                 /* Found opcode info, this is a normal opcode */
 147
 148                 walk_state->parser_state.aml +=
 149                     acpi_ps_get_opcode_size(walk_state->opcode);
 150                 walk_state->arg_types = walk_state->op_info->parse_args;
 151                 break;
 152         }
 153
 154         return_ACPI_STATUS(AE_OK);
 155 }
 156
 157 /*******************************************************************************
 158  *
 159  * FUNCTION:    acpi_ps_build_named_op
 160  *
 161  * PARAMETERS:  walk_state          - Current state
 162  *              aml_op_start        - Begin of named Op in AML
 163  *              unnamed_op          - Early Op (not a named Op)
 164  *              op                  - Returned Op
 165  *
 166  * RETURN:      Status
 167  *
 168  * DESCRIPTION: Parse a named Op
 169  *
 170  ******************************************************************************/
 171
 172 acpi_status
 173 acpi_ps_build_named_op(struct acpi_walk_state *walk_state,
 174                        u8 *aml_op_start,
 175                        union acpi_parse_object *unnamed_op,
 176                        union acpi_parse_object **op)
 177 {
 178         acpi_status status = AE_OK;
 179         union acpi_parse_object *arg = NULL;
 180
 181         ACPI_FUNCTION_TRACE_PTR(ps_build_named_op, walk_state);
 182
 183         unnamed_op->common.value.arg = NULL;
 184         unnamed_op->common.arg_list_length = 0;
 185         unnamed_op->common.aml_opcode = walk_state->opcode;
 186
 187         /*
 188          * Get and append arguments until we find the node that contains
 189          * the name (the type ARGP_NAME).
 190          */
 191         while (GET_CURRENT_ARG_TYPE(walk_state->arg_types) &&
 192                (GET_CURRENT_ARG_TYPE(walk_state->arg_types) != ARGP_NAME)) {
 193                 status =
 194                     acpi_ps_get_next_arg(walk_state,
 195                                          &(walk_state->parser_state),
 196                                          GET_CURRENT_ARG_TYPE(walk_state->
 197                                                               arg_types), &arg);
 198                 if (ACPI_FAILURE(status)) {
 199                         return_ACPI_STATUS(status);
 200                 }
 201
 202                 acpi_ps_append_arg(unnamed_op, arg);
 203                 INCREMENT_ARG_LIST(walk_state->arg_types);
 204         }
 205
 206         /*
 207          * Make sure that we found a NAME and didn't run out of arguments
 208          */
 209         if (!GET_CURRENT_ARG_TYPE(walk_state->arg_types)) {
 210                 return_ACPI_STATUS(AE_AML_NO_OPERAND);
 211         }
 212
 213         /* We know that this arg is a name, move to next arg */
 214
 215         INCREMENT_ARG_LIST(walk_state->arg_types);
 216
 217         /*
 218          * Find the object. This will either insert the object into
 219          * the namespace or simply look it up
 220          */
 221         walk_state->op = NULL;
 222
 223         status = walk_state->descending_callback(walk_state, op);
 224         if (ACPI_FAILURE(status)) {
 225                 if (status != AE_CTRL_TERMINATE) {
 226                         ACPI_EXCEPTION((AE_INFO, status,
 227                                         "During name lookup/catalog"));
 228                 }
 229                 return_ACPI_STATUS(status);
 230         }
 231
 232         if (!*op) {
 233                 return_ACPI_STATUS(AE_CTRL_PARSE_CONTINUE);
 234         }
 235
 236         status = acpi_ps_next_parse_state(walk_state, *op, status);
 237         if (ACPI_FAILURE(status)) {
 238                 if (status == AE_CTRL_PENDING) {
 239                         status = AE_CTRL_PARSE_PENDING;
 240                 }
 241                 return_ACPI_STATUS(status);
 242         }
 243
 244         acpi_ps_append_arg(*op, unnamed_op->common.value.arg);
 245
 246         if ((*op)->common.aml_opcode == AML_REGION_OP ||
 247             (*op)->common.aml_opcode == AML_DATA_REGION_OP) {
 248                 /*
 249                  * Defer final parsing of an operation_region body, because we don't
 250                  * have enough info in the first pass to parse it correctly (i.e.,
 251                  * there may be method calls within the term_arg elements of the body.)
 252                  *
 253                  * However, we must continue parsing because the opregion is not a
 254                  * standalone package -- we don't know where the end is at this point.
 255                  *
 256                  * (Length is unknown until parse of the body complete)
 257                  */
 258                 (*op)->named.data = aml_op_start;
 259                 (*op)->named.length = 0;
 260         }
 261
 262         return_ACPI_STATUS(AE_OK);
 263 }
 264
 265 /*******************************************************************************
 266  *
 267  * FUNCTION:    acpi_ps_create_op
 268  *
 269  * PARAMETERS:  walk_state          - Current state
 270  *              aml_op_start        - Op start in AML
 271  *              new_op              - Returned Op
 272  *
 273  * RETURN:      Status
 274  *
 275  * DESCRIPTION: Get Op from AML
 276  *
 277  ******************************************************************************/
 278
 279 acpi_status
 280 acpi_ps_create_op(struct acpi_walk_state *walk_state,
 281                   u8 *aml_op_start, union acpi_parse_object **new_op)
 282 {
 283         acpi_status status = AE_OK;
 284         union acpi_parse_object *op;
 285         union acpi_parse_object *named_op = NULL;
 286         union acpi_parse_object *parent_scope;
 287         u8 argument_count;
 288         const struct acpi_opcode_info *op_info;
 289
 290         ACPI_FUNCTION_TRACE_PTR(ps_create_op, walk_state);
 291
 292         status = acpi_ps_get_aml_opcode(walk_state);
 293         if (status == AE_CTRL_PARSE_CONTINUE) {
 294                 return_ACPI_STATUS(AE_CTRL_PARSE_CONTINUE);
 295         }
 296
 297         /* Create Op structure and append to parent's argument list */
 298
 299         walk_state->op_info = acpi_ps_get_opcode_info(walk_state->opcode);
 300         op = acpi_ps_alloc_op(walk_state->opcode, aml_op_start);
 301         if (!op) {
 302                 return_ACPI_STATUS(AE_NO_MEMORY);
 303         }
 304
 305         if (walk_state->op_info->flags & AML_NAMED) {
 306                 status =
 307                     acpi_ps_build_named_op(walk_state, aml_op_start, op,
 308                                            &named_op);
 309                 acpi_ps_free_op(op);
 310                 if (ACPI_FAILURE(status)) {
 311                         return_ACPI_STATUS(status);
 312                 }
 313
 314                 *new_op = named_op;
 315                 return_ACPI_STATUS(AE_OK);
 316         }
 317
 318         /* Not a named opcode, just allocate Op and append to parent */
 319
 320         if (walk_state->op_info->flags & AML_CREATE) {
 321                 /*
 322                  * Backup to beginning of create_XXXfield declaration
 323                  * body_length is unknown until we parse the body
 324                  */
 325                 op->named.data = aml_op_start;
 326                 op->named.length = 0;
 327         }
 328
 329         if (walk_state->opcode == AML_BANK_FIELD_OP) {
 330                 /*
 331                  * Backup to beginning of bank_field declaration
 332                  * body_length is unknown until we parse the body
 333                  */
 334                 op->named.data = aml_op_start;
 335                 op->named.length = 0;
 336         }
 337
 338         parent_scope = acpi_ps_get_parent_scope(&(walk_state->parser_state));
 339         acpi_ps_append_arg(parent_scope, op);
 340
 341         if (parent_scope) {
 342                 op_info =
 343                     acpi_ps_get_opcode_info(parent_scope->common.aml_opcode);
 344                 if (op_info->flags & AML_HAS_TARGET) {
 345                         argument_count =
 346                             acpi_ps_get_argument_count(op_info->type);
 347                         if (parent_scope->common.arg_list_length >
 348                             argument_count) {
 349                                 op->common.flags |= ACPI_PARSEOP_TARGET;
 350                         }
 351                 }
 352
 353                 /*
 354                  * Special case for both Increment() and Decrement(), where
 355                  * the lone argument is both a source and a target.
 356                  */
 357                 else if ((parent_scope->common.aml_opcode == AML_INCREMENT_OP)
 358                          || (parent_scope->common.aml_opcode ==
 359                              AML_DECREMENT_OP)) {
 360                         op->common.flags |= ACPI_PARSEOP_TARGET;
 361                 }
 362         }
 363
 364         if (walk_state->descending_callback != NULL) {
 365                 /*
 366                  * Find the object. This will either insert the object into
 367                  * the namespace or simply look it up
 368                  */
 369                 walk_state->op = *new_op = op;
 370
 371                 status = walk_state->descending_callback(walk_state, &op);
 372                 status = acpi_ps_next_parse_state(walk_state, op, status);
 373                 if (status == AE_CTRL_PENDING) {
 374                         status = AE_CTRL_PARSE_PENDING;
 375                 }
 376         }
 377
 378         return_ACPI_STATUS(status);
 379 }
 380
 381 /*******************************************************************************
 382  *
 383  * FUNCTION:    acpi_ps_complete_op
 384  *
 385  * PARAMETERS:  walk_state          - Current state
 386  *              op                  - Returned Op
 387  *              status              - Parse status before complete Op
 388  *
 389  * RETURN:      Status
 390  *
 391  * DESCRIPTION: Complete Op
 392  *
 393  ******************************************************************************/
 394
 395 acpi_status
 396 acpi_ps_complete_op(struct acpi_walk_state *walk_state,
 397                     union acpi_parse_object **op, acpi_status status)
 398 {
 399         acpi_status status2;
 400
 401         ACPI_FUNCTION_TRACE_PTR(ps_complete_op, walk_state);
 402
 403         /*
 404          * Finished one argument of the containing scope
 405          */
 406         walk_state->parser_state.scope->parse_scope.arg_count--;
 407
 408         /* Close this Op (will result in parse subtree deletion) */
 409
 410         status2 = acpi_ps_complete_this_op(walk_state, *op);
 411         if (ACPI_FAILURE(status2)) {
 412                 return_ACPI_STATUS(status2);
 413         }
 414
 415         *op = NULL;
 416
 417         switch (status) {
 418         case AE_OK:
 419
 420                 break;
 421
 422         case AE_CTRL_TRANSFER:
 423
 424                 /* We are about to transfer to a called method */
 425
 426                 walk_state->prev_op = NULL;
 427                 walk_state->prev_arg_types = walk_state->arg_types;
 428                 return_ACPI_STATUS(status);
 429
 430         case AE_CTRL_END:
 431
 432                 acpi_ps_pop_scope(&(walk_state->parser_state), op,
 433                                   &walk_state->arg_types,
 434                                   &walk_state->arg_count);
 435
 436                 if (*op) {
 437                         walk_state->op = *op;
 438                         walk_state->op_info =
 439                             acpi_ps_get_opcode_info((*op)->common.aml_opcode);
 440                         walk_state->opcode = (*op)->common.aml_opcode;
 441
 442                         status = walk_state->ascending_callback(walk_state);
 443                         status =
 444                             acpi_ps_next_parse_state(walk_state, *op, status);
 445
 446                         status2 = acpi_ps_complete_this_op(walk_state, *op);
 447                         if (ACPI_FAILURE(status2)) {
 448                                 return_ACPI_STATUS(status2);
 449                         }
 450                 }
 451
 452                 status = AE_OK;
 453                 break;
 454
 455         case AE_CTRL_BREAK:
 456         case AE_CTRL_CONTINUE:
 457
 458                 /* Pop off scopes until we find the While */
 459
 460                 while (!(*op) || ((*op)->common.aml_opcode != AML_WHILE_OP)) {
 461                         acpi_ps_pop_scope(&(walk_state->parser_state), op,
 462                                           &walk_state->arg_types,
 463                                           &walk_state->arg_count);
 464                 }
 465
 466                 /* Close this iteration of the While loop */
 467
 468                 walk_state->op = *op;
 469                 walk_state->op_info =
 470                     acpi_ps_get_opcode_info((*op)->common.aml_opcode);
 471                 walk_state->opcode = (*op)->common.aml_opcode;
 472
 473                 status = walk_state->ascending_callback(walk_state);
 474                 status = acpi_ps_next_parse_state(walk_state, *op, status);
 475
 476                 status2 = acpi_ps_complete_this_op(walk_state, *op);
 477                 if (ACPI_FAILURE(status2)) {
 478                         return_ACPI_STATUS(status2);
 479                 }
 480
 481                 status = AE_OK;
 482                 break;
 483
 484         case AE_CTRL_TERMINATE:
 485
 486                 /* Clean up */
 487                 do {
 488                         if (*op) {
 489                                 status2 =
 490                                     acpi_ps_complete_this_op(walk_state, *op);
 491                                 if (ACPI_FAILURE(status2)) {
 492                                         return_ACPI_STATUS(status2);
 493                                 }
 494
 495                                 acpi_ut_delete_generic_state
 496                                     (acpi_ut_pop_generic_state
 497                                      (&walk_state->control_state));
 498                         }
 499
 500                         acpi_ps_pop_scope(&(walk_state->parser_state), op,
 501                                           &walk_state->arg_types,
 502                                           &walk_state->arg_count);
 503
 504                 } while (*op);
 505
 506                 return_ACPI_STATUS(AE_OK);
 507
 508         default:                /* All other non-AE_OK status */
 509
 510                 do {
 511                         if (*op) {
 512                                 status2 =
 513                                     acpi_ps_complete_this_op(walk_state, *op);
 514                                 if (ACPI_FAILURE(status2)) {
 515                                         return_ACPI_STATUS(status2);
 516                                 }
 517                         }
 518
 519                         acpi_ps_pop_scope(&(walk_state->parser_state), op,
 520                                           &walk_state->arg_types,
 521                                           &walk_state->arg_count);
 522
 523                 } while (*op);
 524
 525 #if 0
 526                 /*
 527                  * TBD: Cleanup parse ops on error
 528                  */
 529                 if (*op == NULL) {
 530                         acpi_ps_pop_scope(parser_state, op,
 531                                           &walk_state->arg_types,
 532                                           &walk_state->arg_count);
 533                 }
 534 #endif
 535                 walk_state->prev_op = NULL;
 536                 walk_state->prev_arg_types = walk_state->arg_types;
 537                 return_ACPI_STATUS(status);
 538         }
 539
 540         /* This scope complete? */
 541
 542         if (acpi_ps_has_completed_scope(&(walk_state->parser_state))) {
 543                 acpi_ps_pop_scope(&(walk_state->parser_state), op,
 544                                   &walk_state->arg_types,
 545                                   &walk_state->arg_count);
 546                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "Popped scope, Op=%p\n", *op));
 547         } else {
 548                 *op = NULL;
 549         }
 550
 551         return_ACPI_STATUS(AE_OK);
 552 }
 553
 554 /*******************************************************************************
 555  *
 556  * FUNCTION:    acpi_ps_complete_final_op
 557  *
 558  * PARAMETERS:  walk_state          - Current state
 559  *              op                  - Current Op
 560  *              status              - Current parse status before complete last
 561  *                                    Op
 562  *
 563  * RETURN:      Status
 564  *
 565  * DESCRIPTION: Complete last Op.
 566  *
 567  ******************************************************************************/
 568
 569 acpi_status
 570 acpi_ps_complete_final_op(struct acpi_walk_state *walk_state,
 571                           union acpi_parse_object *op, acpi_status status)
 572 {
 573         acpi_status status2;
 574
 575         ACPI_FUNCTION_TRACE_PTR(ps_complete_final_op, walk_state);
 576
 577         /*
 578          * Complete the last Op (if not completed), and clear the scope stack.
 579          * It is easily possible to end an AML "package" with an unbounded number
 580          * of open scopes (such as when several ASL blocks are closed with
 581          * sequential closing braces). We want to terminate each one cleanly.
 582          */
 583         ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "AML package complete at Op %p\n",
 584                           op));
 585         do {
 586                 if (op) {
 587                         if (walk_state->ascending_callback != NULL) {
 588                                 walk_state->op = op;
 589                                 walk_state->op_info =
 590                                     acpi_ps_get_opcode_info(op->common.
 591                                                             aml_opcode);
 592                                 walk_state->opcode = op->common.aml_opcode;
 593
 594                                 status =
 595                                     walk_state->ascending_callback(walk_state);
 596                                 status =
 597                                     acpi_ps_next_parse_state(walk_state, op,
 598                                                              status);
 599                                 if (status == AE_CTRL_PENDING) {
 600                                         status =
 601                                             acpi_ps_complete_op(walk_state, &op,
 602                                                                 AE_OK);
 603                                         if (ACPI_FAILURE(status)) {
 604                                                 return_ACPI_STATUS(status);
 605                                         }
 606                                 }
 607
 608                                 if (status == AE_CTRL_TERMINATE) {
 609                                         status = AE_OK;
 610
 611                                         /* Clean up */
 612                                         do {
 613                                                 if (op) {
 614                                                         status2 =
 615                                                             acpi_ps_complete_this_op
 616                                                             (walk_state, op);
 617                                                         if (ACPI_FAILURE
 618                                                             (status2)) {
 619                                                                 return_ACPI_STATUS
 620                                                                     (status2);
 621                                                         }
 622                                                 }
 623
 624                                                 acpi_ps_pop_scope(&
 625                                                                   (walk_state->
 626                                                                    parser_state),
 627                                                                   &op,
 628                                                                   &walk_state->
 629                                                                   arg_types,
 630                                                                   &walk_state->
 631                                                                   arg_count);
 632
 633                                         } while (op);
 634
 635                                         return_ACPI_STATUS(status);
 636                                 }
 637
 638                                 else if (ACPI_FAILURE(status)) {
 639
 640                                         /* First error is most important */
 641
 642                                         (void)
 643                                             acpi_ps_complete_this_op(walk_state,
 644                                                                      op);
 645                                         return_ACPI_STATUS(status);
 646                                 }
 647                         }
 648
 649                         status2 = acpi_ps_complete_this_op(walk_state, op);
 650                         if (ACPI_FAILURE(status2)) {
 651                                 return_ACPI_STATUS(status2);
 652                         }
 653                 }
 654
 655                 acpi_ps_pop_scope(&(walk_state->parser_state), &op,
 656                                   &walk_state->arg_types,
 657                                   &walk_state->arg_count);
 658
 659         } while (op);
 660
 661         return_ACPI_STATUS(status);
 662 }