drivers/acpi/acpica/psloop.c

   1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
   2 /******************************************************************************
   3  *
   4  * Module Name: psloop - Main AML parse loop
   5  *
   6  * Copyright (C) 2000 - 2018, Intel Corp.
   7  *
   8  *****************************************************************************/
   9
  10 /*
  11  * Parse the AML and build an operation tree as most interpreters, (such as
  12  * Perl) do. Parsing is done by hand rather than with a YACC generated parser
  13  * to tightly constrain stack and dynamic memory usage. Parsing is kept
  14  * flexible and the code fairly compact by parsing based on a list of AML
  15  * opcode templates in aml_op_info[].
  16  */
  17
  18 #include <acpi/acpi.h>
  19 #include "accommon.h"
  20 #include "acinterp.h"
  21 #include "acparser.h"
  22 #include "acdispat.h"
  23 #include "amlcode.h"
  24 #include "acconvert.h"
  25
  26 #define _COMPONENT          ACPI_PARSER
  27 ACPI_MODULE_NAME("psloop")
  28
  29 /* Local prototypes */
  30 static acpi_status
  31 acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
  32                       u8 * aml_op_start, union acpi_parse_object *op);
  33
  34 static void
  35 acpi_ps_link_module_code(union acpi_parse_object *parent_op,
  36                          u8 *aml_start, u32 aml_length, acpi_owner_id owner_id);
  37
  38 /*******************************************************************************
  39  *
  40  * FUNCTION:    acpi_ps_get_arguments
  41  *
  42  * PARAMETERS:  walk_state          - Current state
  43  *              aml_op_start        - Op start in AML
  44  *              op                  - Current Op
  45  *
  46  * RETURN:      Status
  47  *
  48  * DESCRIPTION: Get arguments for passed Op.
  49  *
  50  ******************************************************************************/
  51
  52 static acpi_status
  53 acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
  54                       u8 * aml_op_start, union acpi_parse_object *op)
  55 {
  56         acpi_status status = AE_OK;
  57         union acpi_parse_object *arg = NULL;
  58         const struct acpi_opcode_info *op_info;
  59
  60         ACPI_FUNCTION_TRACE_PTR(ps_get_arguments, walk_state);
  61
  62         ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
  63                           "Get arguments for opcode [%s]\n",
  64                           op->common.aml_op_name));
  65
  66         switch (op->common.aml_opcode) {
  67         case AML_BYTE_OP:       /* AML_BYTEDATA_ARG */
  68         case AML_WORD_OP:       /* AML_WORDDATA_ARG */
  69         case AML_DWORD_OP:      /* AML_DWORDATA_ARG */
  70         case AML_QWORD_OP:      /* AML_QWORDATA_ARG */
  71         case AML_STRING_OP:     /* AML_ASCIICHARLIST_ARG */
  72
  73                 /* Fill in constant or string argument directly */
  74
  75                 acpi_ps_get_next_simple_arg(&(walk_state->parser_state),
  76                                             GET_CURRENT_ARG_TYPE(walk_state->
  77                                                                  arg_types),
  78                                             op);
  79                 break;
  80
  81         case AML_INT_NAMEPATH_OP:       /* AML_NAMESTRING_ARG */
  82
  83                 status = acpi_ps_get_next_namepath(walk_state,
  84                                                    &(walk_state->parser_state),
  85                                                    op,
  86                                                    ACPI_POSSIBLE_METHOD_CALL);
  87                 if (ACPI_FAILURE(status)) {
  88                         return_ACPI_STATUS(status);
  89                 }
  90
  91                 walk_state->arg_types = 0;
  92                 break;
  93
  94         default:
  95                 /*
  96                  * Op is not a constant or string, append each argument to the Op
  97                  */
  98                 while (GET_CURRENT_ARG_TYPE(walk_state->arg_types) &&
  99                        !walk_state->arg_count) {
 100                         walk_state->aml = walk_state->parser_state.aml;
 101
 102                         switch (op->common.aml_opcode) {
 103                         case AML_METHOD_OP:
 104                         case AML_BUFFER_OP:
 105                         case AML_PACKAGE_OP:
 106                         case AML_VARIABLE_PACKAGE_OP:
 107                         case AML_WHILE_OP:
 108
 109                                 break;
 110
 111                         default:
 112
 113                                 ASL_CV_CAPTURE_COMMENTS(walk_state);
 114                                 break;
 115                         }
 116
 117                         status =
 118                             acpi_ps_get_next_arg(walk_state,
 119                                                  &(walk_state->parser_state),
 120                                                  GET_CURRENT_ARG_TYPE
 121                                                  (walk_state->arg_types), &arg);
 122                         if (ACPI_FAILURE(status)) {
 123                                 return_ACPI_STATUS(status);
 124                         }
 125
 126                         if (arg) {
 127                                 acpi_ps_append_arg(op, arg);
 128                         }
 129
 130                         INCREMENT_ARG_LIST(walk_state->arg_types);
 131                 }
 132
 133                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 134                                   "Final argument count: %8.8X pass %u\n",
 135                                   walk_state->arg_count,
 136                                   walk_state->pass_number));
 137
 138                 /*
 139                  * This case handles the legacy option that groups all module-level
 140                  * code blocks together and defers execution until all of the tables
 141                  * are loaded. Execute all of these blocks at this time.
 142                  * Execute any module-level code that was detected during the table
 143                  * load phase.
 144                  *
 145                  * Note: this option is deprecated and will be eliminated in the
 146                  * future. Use of this option can cause problems with AML code that
 147                  * depends upon in-order immediate execution of module-level code.
 148                  */
 149                 if (acpi_gbl_group_module_level_code &&
 150                     (walk_state->pass_number <= ACPI_IMODE_LOAD_PASS2) &&
 151                     ((walk_state->parse_flags & ACPI_PARSE_DISASSEMBLE) == 0)) {
 152                         /*
 153                          * We want to skip If/Else/While constructs during Pass1 because we
 154                          * want to actually conditionally execute the code during Pass2.
 155                          *
 156                          * Except for disassembly, where we always want to walk the
 157                          * If/Else/While packages
 158                          */
 159                         switch (op->common.aml_opcode) {
 160                         case AML_IF_OP:
 161                         case AML_ELSE_OP:
 162                         case AML_WHILE_OP:
 163                                 /*
 164                                  * Currently supported module-level opcodes are:
 165                                  * IF/ELSE/WHILE. These appear to be the most common,
 166                                  * and easiest to support since they open an AML
 167                                  * package.
 168                                  */
 169                                 if (walk_state->pass_number ==
 170                                     ACPI_IMODE_LOAD_PASS1) {
 171                                         acpi_ps_link_module_code(op->common.
 172                                                                  parent,
 173                                                                  aml_op_start,
 174                                                                  (u32)
 175                                                                  (walk_state->
 176                                                                  parser_state.
 177                                                                  pkg_end -
 178                                                                  aml_op_start),
 179                                                                  walk_state->
 180                                                                  owner_id);
 181                                 }
 182
 183                                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 184                                                   "Pass1: Skipping an If/Else/While body\n"));
 185
 186                                 /* Skip body of if/else/while in pass 1 */
 187
 188                                 walk_state->parser_state.aml =
 189                                     walk_state->parser_state.pkg_end;
 190                                 walk_state->arg_count = 0;
 191                                 break;
 192
 193                         default:
 194                                 /*
 195                                  * Check for an unsupported executable opcode at module
 196                                  * level. We must be in PASS1, the parent must be a SCOPE,
 197                                  * The opcode class must be EXECUTE, and the opcode must
 198                                  * not be an argument to another opcode.
 199                                  */
 200                                 if ((walk_state->pass_number ==
 201                                      ACPI_IMODE_LOAD_PASS1)
 202                                     && (op->common.parent->common.aml_opcode ==
 203                                         AML_SCOPE_OP)) {
 204                                         op_info =
 205                                             acpi_ps_get_opcode_info(op->common.
 206                                                                     aml_opcode);
 207                                         if ((op_info->class ==
 208                                              AML_CLASS_EXECUTE) && (!arg)) {
 209                                                 ACPI_WARNING((AE_INFO,
 210                                                               "Unsupported module-level executable opcode "
 211                                                               "0x%.2X at table offset 0x%.4X",
 212                                                               op->common.
 213                                                               aml_opcode,
 214                                                               (u32)
 215                                                               (ACPI_PTR_DIFF
 216                                                                (aml_op_start,
 217                                                                 walk_state->
 218                                                                 parser_state.
 219                                                                 aml_start) +
 220                                                                sizeof(struct
 221                                                                       acpi_table_header))));
 222                                         }
 223                                 }
 224                                 break;
 225                         }
 226                 }
 227
 228                 /* Special processing for certain opcodes */
 229
 230                 switch (op->common.aml_opcode) {
 231                 case AML_METHOD_OP:
 232                         /*
 233                          * Skip parsing of control method because we don't have enough
 234                          * info in the first pass to parse it correctly.
 235                          *
 236                          * Save the length and address of the body
 237                          */
 238                         op->named.data = walk_state->parser_state.aml;
 239                         op->named.length = (u32)
 240                             (walk_state->parser_state.pkg_end -
 241                              walk_state->parser_state.aml);
 242
 243                         /* Skip body of method */
 244
 245                         walk_state->parser_state.aml =
 246                             walk_state->parser_state.pkg_end;
 247                         walk_state->arg_count = 0;
 248                         break;
 249
 250                 case AML_BUFFER_OP:
 251                 case AML_PACKAGE_OP:
 252                 case AML_VARIABLE_PACKAGE_OP:
 253
 254                         if ((op->common.parent) &&
 255                             (op->common.parent->common.aml_opcode ==
 256                              AML_NAME_OP)
 257                             && (walk_state->pass_number <=
 258                                 ACPI_IMODE_LOAD_PASS2)) {
 259                                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 260                                                   "Setup Package/Buffer: Pass %u, AML Ptr: %p\n",
 261                                                   walk_state->pass_number,
 262                                                   aml_op_start));
 263
 264                                 /*
 265                                  * Skip parsing of Buffers and Packages because we don't have
 266                                  * enough info in the first pass to parse them correctly.
 267                                  */
 268                                 op->named.data = aml_op_start;
 269                                 op->named.length = (u32)
 270                                     (walk_state->parser_state.pkg_end -
 271                                      aml_op_start);
 272
 273                                 /* Skip body */
 274
 275                                 walk_state->parser_state.aml =
 276                                     walk_state->parser_state.pkg_end;
 277                                 walk_state->arg_count = 0;
 278                         }
 279                         break;
 280
 281                 case AML_WHILE_OP:
 282
 283                         if (walk_state->control_state) {
 284                                 walk_state->control_state->control.package_end =
 285                                     walk_state->parser_state.pkg_end;
 286                         }
 287                         break;
 288
 289                 default:
 290
 291                         /* No action for all other opcodes */
 292
 293                         break;
 294                 }
 295
 296                 break;
 297         }
 298
 299         return_ACPI_STATUS(AE_OK);
 300 }
 301
 302 /*******************************************************************************
 303  *
 304  * FUNCTION:    acpi_ps_link_module_code
 305  *
 306  * PARAMETERS:  parent_op           - Parent parser op
 307  *              aml_start           - Pointer to the AML
 308  *              aml_length          - Length of executable AML
 309  *              owner_id            - owner_id of module level code
 310  *
 311  * RETURN:      None.
 312  *
 313  * DESCRIPTION: Wrap the module-level code with a method object and link the
 314  *              object to the global list. Note, the mutex field of the method
 315  *              object is used to link multiple module-level code objects.
 316  *
 317  * NOTE: In this legacy option, each block of detected executable AML
 318  * code that is outside of any control method is wrapped with a temporary
 319  * control method object and placed on a global list below.
 320  *
 321  * This function executes the module-level code for all tables only after
 322  * all of the tables have been loaded. It is a legacy option and is
 323  * not compatible with other ACPI implementations. See acpi_ns_load_table.
 324  *
 325  * This function will be removed when the legacy option is removed.
 326  *
 327  ******************************************************************************/
 328
 329 static void
 330 acpi_ps_link_module_code(union acpi_parse_object *parent_op,
 331                          u8 *aml_start, u32 aml_length, acpi_owner_id owner_id)
 332 {
 333         union acpi_operand_object *prev;
 334         union acpi_operand_object *next;
 335         union acpi_operand_object *method_obj;
 336         struct acpi_namespace_node *parent_node;
 337
 338         ACPI_FUNCTION_TRACE(ps_link_module_code);
 339
 340         /* Get the tail of the list */
 341
 342         prev = next = acpi_gbl_module_code_list;
 343         while (next) {
 344                 prev = next;
 345                 next = next->method.mutex;
 346         }
 347
 348         /*
 349          * Insert the module level code into the list. Merge it if it is
 350          * adjacent to the previous element.
 351          */
 352         if (!prev ||
 353             ((prev->method.aml_start + prev->method.aml_length) != aml_start)) {
 354
 355                 /* Create, initialize, and link a new temporary method object */
 356
 357                 method_obj = acpi_ut_create_internal_object(ACPI_TYPE_METHOD);
 358                 if (!method_obj) {
 359                         return_VOID;
 360                 }
 361
 362                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 363                                   "Create/Link new code block: %p\n",
 364                                   method_obj));
 365
 366                 if (parent_op->common.node) {
 367                         parent_node = parent_op->common.node;
 368                 } else {
 369                         parent_node = acpi_gbl_root_node;
 370                 }
 371
 372                 method_obj->method.aml_start = aml_start;
 373                 method_obj->method.aml_length = aml_length;
 374                 method_obj->method.owner_id = owner_id;
 375                 method_obj->method.info_flags |= ACPI_METHOD_MODULE_LEVEL;
 376
 377                 /*
 378                  * Save the parent node in next_object. This is cheating, but we
 379                  * don't want to expand the method object.
 380                  */
 381                 method_obj->method.next_object =
 382                     ACPI_CAST_PTR(union acpi_operand_object, parent_node);
 383
 384                 if (!prev) {
 385                         acpi_gbl_module_code_list = method_obj;
 386                 } else {
 387                         prev->method.mutex = method_obj;
 388                 }
 389         } else {
 390                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 391                                   "Appending to existing code block: %p\n",
 392                                   prev));
 393
 394                 prev->method.aml_length += aml_length;
 395         }
 396
 397         return_VOID;
 398 }
 399
 400 /*******************************************************************************
 401  *
 402  * FUNCTION:    acpi_ps_parse_loop
 403  *
 404  * PARAMETERS:  walk_state          - Current state
 405  *
 406  * RETURN:      Status
 407  *
 408  * DESCRIPTION: Parse AML (pointed to by the current parser state) and return
 409  *              a tree of ops.
 410  *
 411  ******************************************************************************/
 412
 413 acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
 414 {
 415         acpi_status status = AE_OK;
 416         union acpi_parse_object *op = NULL;     /* current op */
 417         struct acpi_parse_state *parser_state;
 418         u8 *aml_op_start = NULL;
 419
 420         ACPI_FUNCTION_TRACE_PTR(ps_parse_loop, walk_state);
 421
 422         if (walk_state->descending_callback == NULL) {
 423                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 424         }
 425
 426         parser_state = &walk_state->parser_state;
 427         walk_state->arg_types = 0;
 428
 429 #if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))
 430
 431         if (walk_state->walk_type & ACPI_WALK_METHOD_RESTART) {
 432
 433                 /* We are restarting a preempted control method */
 434
 435                 if (acpi_ps_has_completed_scope(parser_state)) {
 436                         /*
 437                          * We must check if a predicate to an IF or WHILE statement
 438                          * was just completed
 439                          */
 440                         if ((parser_state->scope->parse_scope.op) &&
 441                             ((parser_state->scope->parse_scope.op->common.
 442                               aml_opcode == AML_IF_OP)
 443                              || (parser_state->scope->parse_scope.op->common.
 444                                  aml_opcode == AML_WHILE_OP))
 445                             && (walk_state->control_state)
 446                             && (walk_state->control_state->common.state ==
 447                                 ACPI_CONTROL_PREDICATE_EXECUTING)) {
 448                                 /*
 449                                  * A predicate was just completed, get the value of the
 450                                  * predicate and branch based on that value
 451                                  */
 452                                 walk_state->op = NULL;
 453                                 status =
 454                                     acpi_ds_get_predicate_value(walk_state,
 455                                                                 ACPI_TO_POINTER
 456                                                                 (TRUE));
 457                                 if (ACPI_FAILURE(status)
 458                                     && ((status & AE_CODE_MASK) !=
 459                                         AE_CODE_CONTROL)) {
 460                                         if (status == AE_AML_NO_RETURN_VALUE) {
 461                                                 ACPI_EXCEPTION((AE_INFO, status,
 462                                                                 "Invoked method did not return a value"));
 463                                         }
 464
 465                                         ACPI_EXCEPTION((AE_INFO, status,
 466                                                         "GetPredicate Failed"));
 467                                         return_ACPI_STATUS(status);
 468                                 }
 469
 470                                 status =
 471                                     acpi_ps_next_parse_state(walk_state, op,
 472                                                              status);
 473                         }
 474
 475                         acpi_ps_pop_scope(parser_state, &op,
 476                                           &walk_state->arg_types,
 477                                           &walk_state->arg_count);
 478                         ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 479                                           "Popped scope, Op=%p\n", op));
 480                 } else if (walk_state->prev_op) {
 481
 482                         /* We were in the middle of an op */
 483
 484                         op = walk_state->prev_op;
 485                         walk_state->arg_types = walk_state->prev_arg_types;
 486                 }
 487         }
 488 #endif
 489
 490         /* Iterative parsing loop, while there is more AML to process: */
 491
 492         while ((parser_state->aml < parser_state->aml_end) || (op)) {
 493                 ASL_CV_CAPTURE_COMMENTS(walk_state);
 494
 495                 aml_op_start = parser_state->aml;
 496                 if (!op) {
 497                         status =
 498                             acpi_ps_create_op(walk_state, aml_op_start, &op);
 499                         if (ACPI_FAILURE(status)) {
 500                                 /*
 501                                  * ACPI_PARSE_MODULE_LEVEL means that we are loading a table by
 502                                  * executing it as a control method. However, if we encounter
 503                                  * an error while loading the table, we need to keep trying to
 504                                  * load the table rather than aborting the table load. Set the
 505                                  * status to AE_OK to proceed with the table load.
 506                                  */
 507                                 if ((walk_state->
 508                                      parse_flags & ACPI_PARSE_MODULE_LEVEL)
 509                                     && status == AE_ALREADY_EXISTS) {
 510                                         status = AE_OK;
 511                                 }
 512                                 if (status == AE_CTRL_PARSE_CONTINUE) {
 513                                         continue;
 514                                 }
 515
 516                                 if (status == AE_CTRL_PARSE_PENDING) {
 517                                         status = AE_OK;
 518                                 }
 519
 520                                 if (status == AE_CTRL_TERMINATE) {
 521                                         return_ACPI_STATUS(status);
 522                                 }
 523
 524                                 status =
 525                                     acpi_ps_complete_op(walk_state, &op,
 526                                                         status);
 527                                 if (ACPI_FAILURE(status)) {
 528                                         return_ACPI_STATUS(status);
 529                                 }
 530                                 if (walk_state->opcode == AML_SCOPE_OP) {
 531                                         /*
 532                                          * If the scope op fails to parse, skip the body of the
 533                                          * scope op because the parse failure indicates that the
 534                                          * device may not exist.
 535                                          */
 536                                         walk_state->parser_state.aml =
 537                                             walk_state->aml + 1;
 538                                         walk_state->parser_state.aml =
 539                                             acpi_ps_get_next_package_end
 540                                             (&walk_state->parser_state);
 541                                         walk_state->aml =
 542                                             walk_state->parser_state.aml;
 543                                         ACPI_ERROR((AE_INFO,
 544                                                     "Skipping Scope block"));
 545                                 }
 546
 547                                 continue;
 548                         }
 549
 550                         acpi_ex_start_trace_opcode(op, walk_state);
 551                 }
 552
 553                 /*
 554                  * Start arg_count at zero because we don't know if there are
 555                  * any args yet
 556                  */
 557                 walk_state->arg_count = 0;
 558
 559                 switch (op->common.aml_opcode) {
 560                 case AML_BYTE_OP:
 561                 case AML_WORD_OP:
 562                 case AML_DWORD_OP:
 563                 case AML_QWORD_OP:
 564
 565                         break;
 566
 567                 default:
 568
 569                         ASL_CV_CAPTURE_COMMENTS(walk_state);
 570                         break;
 571                 }
 572
 573                 /* Are there any arguments that must be processed? */
 574
 575                 if (walk_state->arg_types) {
 576
 577                         /* Get arguments */
 578
 579                         status =
 580                             acpi_ps_get_arguments(walk_state, aml_op_start, op);
 581                         if (ACPI_FAILURE(status)) {
 582                                 status =
 583                                     acpi_ps_complete_op(walk_state, &op,
 584                                                         status);
 585                                 if (ACPI_FAILURE(status)) {
 586                                         return_ACPI_STATUS(status);
 587                                 }
 588                                 if ((walk_state->control_state) &&
 589                                     ((walk_state->control_state->control.
 590                                       opcode == AML_IF_OP)
 591                                      || (walk_state->control_state->control.
 592                                          opcode == AML_WHILE_OP))) {
 593                                         /*
 594                                          * If the if/while op fails to parse, we will skip parsing
 595                                          * the body of the op.
 596                                          */
 597                                         parser_state->aml =
 598                                             walk_state->control_state->control.
 599                                             aml_predicate_start + 1;
 600                                         parser_state->aml =
 601                                             acpi_ps_get_next_package_end
 602                                             (parser_state);
 603                                         walk_state->aml = parser_state->aml;
 604
 605                                         ACPI_ERROR((AE_INFO,
 606                                                     "Skipping While/If block"));
 607                                         if (*walk_state->aml == AML_ELSE_OP) {
 608                                                 ACPI_ERROR((AE_INFO,
 609                                                             "Skipping Else block"));
 610                                                 walk_state->parser_state.aml =
 611                                                     walk_state->aml + 1;
 612                                                 walk_state->parser_state.aml =
 613                                                     acpi_ps_get_next_package_end
 614                                                     (parser_state);
 615                                                 walk_state->aml =
 616                                                     parser_state->aml;
 617                                         }
 618                                         ACPI_FREE(acpi_ut_pop_generic_state
 619                                                   (&walk_state->control_state));
 620                                 }
 621                                 op = NULL;
 622                                 continue;
 623                         }
 624                 }
 625
 626                 /* Check for arguments that need to be processed */
 627
 628                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 629                                   "Parseloop: argument count: %8.8X\n",
 630                                   walk_state->arg_count));
 631
 632                 if (walk_state->arg_count) {
 633                         /*
 634                          * There are arguments (complex ones), push Op and
 635                          * prepare for argument
 636                          */
 637                         status = acpi_ps_push_scope(parser_state, op,
 638                                                     walk_state->arg_types,
 639                                                     walk_state->arg_count);
 640                         if (ACPI_FAILURE(status)) {
 641                                 status =
 642                                     acpi_ps_complete_op(walk_state, &op,
 643                                                         status);
 644                                 if (ACPI_FAILURE(status)) {
 645                                         return_ACPI_STATUS(status);
 646                                 }
 647
 648                                 continue;
 649                         }
 650
 651                         op = NULL;
 652                         continue;
 653                 }
 654
 655                 /*
 656                  * All arguments have been processed -- Op is complete,
 657                  * prepare for next
 658                  */
 659                 walk_state->op_info =
 660                     acpi_ps_get_opcode_info(op->common.aml_opcode);
 661                 if (walk_state->op_info->flags & AML_NAMED) {
 662                         if (op->common.aml_opcode == AML_REGION_OP ||
 663                             op->common.aml_opcode == AML_DATA_REGION_OP) {
 664                                 /*
 665                                  * Skip parsing of control method or opregion body,
 666                                  * because we don't have enough info in the first pass
 667                                  * to parse them correctly.
 668                                  *
 669                                  * Completed parsing an op_region declaration, we now
 670                                  * know the length.
 671                                  */
 672                                 op->named.length =
 673                                     (u32) (parser_state->aml - op->named.data);
 674                         }
 675                 }
 676
 677                 if (walk_state->op_info->flags & AML_CREATE) {
 678                         /*
 679                          * Backup to beginning of create_XXXfield declaration (1 for
 680                          * Opcode)
 681                          *
 682                          * body_length is unknown until we parse the body
 683                          */
 684                         op->named.length =
 685                             (u32) (parser_state->aml - op->named.data);
 686                 }
 687
 688                 if (op->common.aml_opcode == AML_BANK_FIELD_OP) {
 689                         /*
 690                          * Backup to beginning of bank_field declaration
 691                          *
 692                          * body_length is unknown until we parse the body
 693                          */
 694                         op->named.length =
 695                             (u32) (parser_state->aml - op->named.data);
 696                 }
 697
 698                 /* This op complete, notify the dispatcher */
 699
 700                 if (walk_state->ascending_callback != NULL) {
 701                         walk_state->op = op;
 702                         walk_state->opcode = op->common.aml_opcode;
 703
 704                         status = walk_state->ascending_callback(walk_state);
 705                         status =
 706                             acpi_ps_next_parse_state(walk_state, op, status);
 707                         if (status == AE_CTRL_PENDING) {
 708                                 status = AE_OK;
 709                         } else
 710                             if ((walk_state->
 711                                  parse_flags & ACPI_PARSE_MODULE_LEVEL)
 712                                 && status != AE_CTRL_TRANSFER
 713                                 && ACPI_FAILURE(status)) {
 714                                 /*
 715                                  * ACPI_PARSE_MODULE_LEVEL flag means that we are currently
 716                                  * loading a table by executing it as a control method.
 717                                  * However, if we encounter an error while loading the table,
 718                                  * we need to keep trying to load the table rather than
 719                                  * aborting the table load (setting the status to AE_OK
 720                                  * continues the table load). If we get a failure at this
 721                                  * point, it means that the dispatcher got an error while
 722                                  * processing Op (most likely an AML operand error) or a
 723                                  * control method was called from module level and the
 724                                  * dispatcher returned AE_CTRL_TRANSFER. In the latter case,
 725                                  * leave the status alone, there's nothing wrong with it.
 726                                  */
 727                                 status = AE_OK;
 728                         }
 729                 }
 730
 731                 status = acpi_ps_complete_op(walk_state, &op, status);
 732                 if (ACPI_FAILURE(status)) {
 733                         return_ACPI_STATUS(status);
 734                 }
 735
 736         }                       /* while parser_state->Aml */
 737
 738         status = acpi_ps_complete_final_op(walk_state, op, status);
 739         return_ACPI_STATUS(status);
 740 }