drivers/acpi/parser/psargs.c

   1 /******************************************************************************
   2  *
   3  * Module Name: psargs - Parse AML opcode arguments
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2006, R. Byron Moore
   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 <acpi/acparser.h>
  46 #include <acpi/amlcode.h>
  47 #include <acpi/acnamesp.h>
  48 #include <acpi/acdispat.h>
  49
  50 #define _COMPONENT          ACPI_PARSER
  51 ACPI_MODULE_NAME("psargs")
  52
  53 /* Local prototypes */
  54 static u32
  55 acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state);
  56
  57 static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
  58                                                        *parser_state);
  59
  60 /*******************************************************************************
  61  *
  62  * FUNCTION:    acpi_ps_get_next_package_length
  63  *
  64  * PARAMETERS:  parser_state        - Current parser state object
  65  *
  66  * RETURN:      Decoded package length. On completion, the AML pointer points
  67  *              past the length byte or bytes.
  68  *
  69  * DESCRIPTION: Decode and return a package length field.
  70  *              Note: Largest package length is 28 bits, from ACPI specification
  71  *
  72  ******************************************************************************/
  73
  74 static u32
  75 acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state)
  76 {
  77         u8 *aml = parser_state->aml;
  78         u32 package_length = 0;
  79         acpi_native_uint byte_count;
  80         u8 byte_zero_mask = 0x3F;       /* Default [0:5] */
  81
  82         ACPI_FUNCTION_TRACE("ps_get_next_package_length");
  83
  84         /*
  85          * Byte 0 bits [6:7] contain the number of additional bytes
  86          * used to encode the package length, either 0,1,2, or 3
  87          */
  88         byte_count = (aml[0] >> 6);
  89         parser_state->aml += (byte_count + 1);
  90
  91         /* Get bytes 3, 2, 1 as needed */
  92
  93         while (byte_count) {
  94                 /*
  95                  * Final bit positions for the package length bytes:
  96                  *      Byte3->[20:27]
  97                  *      Byte2->[12:19]
  98                  *      Byte1->[04:11]
  99                  *      Byte0->[00:03]
 100                  */
 101                 package_length |= (aml[byte_count] << ((byte_count << 3) - 4));
 102
 103                 byte_zero_mask = 0x0F;  /* Use bits [0:3] of byte 0 */
 104                 byte_count--;
 105         }
 106
 107         /* Byte 0 is a special case, either bits [0:3] or [0:5] are used */
 108
 109         package_length |= (aml[0] & byte_zero_mask);
 110         return_UINT32(package_length);
 111 }
 112
 113 /*******************************************************************************
 114  *
 115  * FUNCTION:    acpi_ps_get_next_package_end
 116  *
 117  * PARAMETERS:  parser_state        - Current parser state object
 118  *
 119  * RETURN:      Pointer to end-of-package +1
 120  *
 121  * DESCRIPTION: Get next package length and return a pointer past the end of
 122  *              the package.  Consumes the package length field
 123  *
 124  ******************************************************************************/
 125
 126 u8 *acpi_ps_get_next_package_end(struct acpi_parse_state *parser_state)
 127 {
 128         u8 *start = parser_state->aml;
 129         u32 package_length;
 130
 131         ACPI_FUNCTION_TRACE("ps_get_next_package_end");
 132
 133         /* Function below updates parser_state->Aml */
 134
 135         package_length = acpi_ps_get_next_package_length(parser_state);
 136
 137         return_PTR(start + package_length);     /* end of package */
 138 }
 139
 140 /*******************************************************************************
 141  *
 142  * FUNCTION:    acpi_ps_get_next_namestring
 143  *
 144  * PARAMETERS:  parser_state        - Current parser state object
 145  *
 146  * RETURN:      Pointer to the start of the name string (pointer points into
 147  *              the AML.
 148  *
 149  * DESCRIPTION: Get next raw namestring within the AML stream.  Handles all name
 150  *              prefix characters.  Set parser state to point past the string.
 151  *              (Name is consumed from the AML.)
 152  *
 153  ******************************************************************************/
 154
 155 char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
 156 {
 157         u8 *start = parser_state->aml;
 158         u8 *end = parser_state->aml;
 159
 160         ACPI_FUNCTION_TRACE("ps_get_next_namestring");
 161
 162         /* Point past any namestring prefix characters (backslash or carat) */
 163
 164         while (acpi_ps_is_prefix_char(*end)) {
 165                 end++;
 166         }
 167
 168         /* Decode the path prefix character */
 169
 170         switch (*end) {
 171         case 0:
 172
 173                 /* null_name */
 174
 175                 if (end == start) {
 176                         start = NULL;
 177                 }
 178                 end++;
 179                 break;
 180
 181         case AML_DUAL_NAME_PREFIX:
 182
 183                 /* Two name segments */
 184
 185                 end += 1 + (2 * ACPI_NAME_SIZE);
 186                 break;
 187
 188         case AML_MULTI_NAME_PREFIX_OP:
 189
 190                 /* Multiple name segments, 4 chars each, count in next byte */
 191
 192                 end += 2 + (*(end + 1) * ACPI_NAME_SIZE);
 193                 break;
 194
 195         default:
 196
 197                 /* Single name segment */
 198
 199                 end += ACPI_NAME_SIZE;
 200                 break;
 201         }
 202
 203         parser_state->aml = end;
 204         return_PTR((char *)start);
 205 }
 206
 207 /*******************************************************************************
 208  *
 209  * FUNCTION:    acpi_ps_get_next_namepath
 210  *
 211  * PARAMETERS:  parser_state        - Current parser state object
 212  *              Arg                 - Where the namepath will be stored
 213  *              arg_count           - If the namepath points to a control method
 214  *                                    the method's argument is returned here.
 215  *              possible_method_call - Whether the namepath can possibly be the
 216  *                                    start of a method call
 217  *
 218  * RETURN:      Status
 219  *
 220  * DESCRIPTION: Get next name (if method call, return # of required args).
 221  *              Names are looked up in the internal namespace to determine
 222  *              if the name represents a control method.  If a method
 223  *              is found, the number of arguments to the method is returned.
 224  *              This information is critical for parsing to continue correctly.
 225  *
 226  ******************************************************************************/
 227
 228 acpi_status
 229 acpi_ps_get_next_namepath(struct acpi_walk_state *walk_state,
 230                           struct acpi_parse_state *parser_state,
 231                           union acpi_parse_object *arg, u8 possible_method_call)
 232 {
 233         char *path;
 234         union acpi_parse_object *name_op;
 235         acpi_status status;
 236         union acpi_operand_object *method_desc;
 237         struct acpi_namespace_node *node;
 238         union acpi_generic_state scope_info;
 239
 240         ACPI_FUNCTION_TRACE("ps_get_next_namepath");
 241
 242         path = acpi_ps_get_next_namestring(parser_state);
 243         acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
 244
 245         /* Null path case is allowed, just exit */
 246
 247         if (!path) {
 248                 arg->common.value.name = path;
 249                 return_ACPI_STATUS(AE_OK);
 250         }
 251
 252         /* Setup search scope info */
 253
 254         scope_info.scope.node = NULL;
 255         node = parser_state->start_node;
 256         if (node) {
 257                 scope_info.scope.node = node;
 258         }
 259
 260         /*
 261          * Lookup the name in the internal namespace. We don't want to add
 262          * anything new to the namespace here, however, so we use MODE_EXECUTE.
 263          * Allow searching of the parent tree, but don't open a new scope -
 264          * we just want to lookup the object (must be mode EXECUTE to perform
 265          * the upsearch)
 266          */
 267         status =
 268             acpi_ns_lookup(&scope_info, path, ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
 269                            ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
 270                            NULL, &node);
 271
 272         /*
 273          * If this name is a control method invocation, we must
 274          * setup the method call
 275          */
 276         if (ACPI_SUCCESS(status) &&
 277             possible_method_call && (node->type == ACPI_TYPE_METHOD)) {
 278                 /* This name is actually a control method invocation */
 279
 280                 method_desc = acpi_ns_get_attached_object(node);
 281                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 282                                   "Control Method - %p Desc %p Path=%p\n", node,
 283                                   method_desc, path));
 284
 285                 name_op = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
 286                 if (!name_op) {
 287                         return_ACPI_STATUS(AE_NO_MEMORY);
 288                 }
 289
 290                 /* Change Arg into a METHOD CALL and attach name to it */
 291
 292                 acpi_ps_init_op(arg, AML_INT_METHODCALL_OP);
 293                 name_op->common.value.name = path;
 294
 295                 /* Point METHODCALL/NAME to the METHOD Node */
 296
 297                 name_op->common.node = node;
 298                 acpi_ps_append_arg(arg, name_op);
 299
 300                 if (!method_desc) {
 301                         ACPI_ERROR((AE_INFO,
 302                                     "Control Method %p has no attached object",
 303                                     node));
 304                         return_ACPI_STATUS(AE_AML_INTERNAL);
 305                 }
 306
 307                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 308                                   "Control Method - %p Args %X\n",
 309                                   node, method_desc->method.param_count));
 310
 311                 /* Get the number of arguments to expect */
 312
 313                 walk_state->arg_count = method_desc->method.param_count;
 314                 return_ACPI_STATUS(AE_OK);
 315         }
 316
 317         /*
 318          * Special handling if the name was not found during the lookup -
 319          * some not_found cases are allowed
 320          */
 321         if (status == AE_NOT_FOUND) {
 322                 /* 1) not_found is ok during load pass 1/2 (allow forward references) */
 323
 324                 if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) !=
 325                     ACPI_PARSE_EXECUTE) {
 326                         status = AE_OK;
 327                 }
 328
 329                 /* 2) not_found during a cond_ref_of(x) is ok by definition */
 330
 331                 else if (walk_state->op->common.aml_opcode ==
 332                          AML_COND_REF_OF_OP) {
 333                         status = AE_OK;
 334                 }
 335
 336                 /*
 337                  * 3) not_found while building a Package is ok at this point, we
 338                  * may flag as an error later if slack mode is not enabled.
 339                  * (Some ASL code depends on allowing this behavior)
 340                  */
 341                 else if ((arg->common.parent) &&
 342                          ((arg->common.parent->common.aml_opcode ==
 343                            AML_PACKAGE_OP)
 344                           || (arg->common.parent->common.aml_opcode ==
 345                               AML_VAR_PACKAGE_OP))) {
 346                         status = AE_OK;
 347                 }
 348         }
 349
 350         /* Final exception check (may have been changed from code above) */
 351
 352         if (ACPI_FAILURE(status)) {
 353                 ACPI_ERROR_NAMESPACE(path, status);
 354
 355                 if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
 356                     ACPI_PARSE_EXECUTE) {
 357                         /* Report a control method execution error */
 358
 359                         status = acpi_ds_method_error(status, walk_state);
 360                 }
 361         }
 362
 363         /* Save the namepath */
 364
 365         arg->common.value.name = path;
 366         return_ACPI_STATUS(status);
 367 }
 368
 369 /*******************************************************************************
 370  *
 371  * FUNCTION:    acpi_ps_get_next_simple_arg
 372  *
 373  * PARAMETERS:  parser_state        - Current parser state object
 374  *              arg_type            - The argument type (AML_*_ARG)
 375  *              Arg                 - Where the argument is returned
 376  *
 377  * RETURN:      None
 378  *
 379  * DESCRIPTION: Get the next simple argument (constant, string, or namestring)
 380  *
 381  ******************************************************************************/
 382
 383 void
 384 acpi_ps_get_next_simple_arg(struct acpi_parse_state *parser_state,
 385                             u32 arg_type, union acpi_parse_object *arg)
 386 {
 387         u32 length;
 388         u16 opcode;
 389         u8 *aml = parser_state->aml;
 390
 391         ACPI_FUNCTION_TRACE_U32("ps_get_next_simple_arg", arg_type);
 392
 393         switch (arg_type) {
 394         case ARGP_BYTEDATA:
 395
 396                 /* Get 1 byte from the AML stream */
 397
 398                 opcode = AML_BYTE_OP;
 399                 arg->common.value.integer = (acpi_integer) * aml;
 400                 length = 1;
 401                 break;
 402
 403         case ARGP_WORDDATA:
 404
 405                 /* Get 2 bytes from the AML stream */
 406
 407                 opcode = AML_WORD_OP;
 408                 ACPI_MOVE_16_TO_64(&arg->common.value.integer, aml);
 409                 length = 2;
 410                 break;
 411
 412         case ARGP_DWORDDATA:
 413
 414                 /* Get 4 bytes from the AML stream */
 415
 416                 opcode = AML_DWORD_OP;
 417                 ACPI_MOVE_32_TO_64(&arg->common.value.integer, aml);
 418                 length = 4;
 419                 break;
 420
 421         case ARGP_QWORDDATA:
 422
 423                 /* Get 8 bytes from the AML stream */
 424
 425                 opcode = AML_QWORD_OP;
 426                 ACPI_MOVE_64_TO_64(&arg->common.value.integer, aml);
 427                 length = 8;
 428                 break;
 429
 430         case ARGP_CHARLIST:
 431
 432                 /* Get a pointer to the string, point past the string */
 433
 434                 opcode = AML_STRING_OP;
 435                 arg->common.value.string = ACPI_CAST_PTR(char, aml);
 436
 437                 /* Find the null terminator */
 438
 439                 length = 0;
 440                 while (aml[length]) {
 441                         length++;
 442                 }
 443                 length++;
 444                 break;
 445
 446         case ARGP_NAME:
 447         case ARGP_NAMESTRING:
 448
 449                 acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
 450                 arg->common.value.name =
 451                     acpi_ps_get_next_namestring(parser_state);
 452                 return_VOID;
 453
 454         default:
 455
 456                 ACPI_ERROR((AE_INFO, "Invalid arg_type %X", arg_type));
 457                 return_VOID;
 458         }
 459
 460         acpi_ps_init_op(arg, opcode);
 461         parser_state->aml += length;
 462         return_VOID;
 463 }
 464
 465 /*******************************************************************************
 466  *
 467  * FUNCTION:    acpi_ps_get_next_field
 468  *
 469  * PARAMETERS:  parser_state        - Current parser state object
 470  *
 471  * RETURN:      A newly allocated FIELD op
 472  *
 473  * DESCRIPTION: Get next field (named_field, reserved_field, or access_field)
 474  *
 475  ******************************************************************************/
 476
 477 static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
 478                                                        *parser_state)
 479 {
 480         u32 aml_offset = (u32)
 481             ACPI_PTR_DIFF(parser_state->aml,
 482                           parser_state->aml_start);
 483         union acpi_parse_object *field;
 484         u16 opcode;
 485         u32 name;
 486
 487         ACPI_FUNCTION_TRACE("ps_get_next_field");
 488
 489         /* Determine field type */
 490
 491         switch (ACPI_GET8(parser_state->aml)) {
 492         default:
 493
 494                 opcode = AML_INT_NAMEDFIELD_OP;
 495                 break;
 496
 497         case 0x00:
 498
 499                 opcode = AML_INT_RESERVEDFIELD_OP;
 500                 parser_state->aml++;
 501                 break;
 502
 503         case 0x01:
 504
 505                 opcode = AML_INT_ACCESSFIELD_OP;
 506                 parser_state->aml++;
 507                 break;
 508         }
 509
 510         /* Allocate a new field op */
 511
 512         field = acpi_ps_alloc_op(opcode);
 513         if (!field) {
 514                 return_PTR(NULL);
 515         }
 516
 517         field->common.aml_offset = aml_offset;
 518
 519         /* Decode the field type */
 520
 521         switch (opcode) {
 522         case AML_INT_NAMEDFIELD_OP:
 523
 524                 /* Get the 4-character name */
 525
 526                 ACPI_MOVE_32_TO_32(&name, parser_state->aml);
 527                 acpi_ps_set_name(field, name);
 528                 parser_state->aml += ACPI_NAME_SIZE;
 529
 530                 /* Get the length which is encoded as a package length */
 531
 532                 field->common.value.size =
 533                     acpi_ps_get_next_package_length(parser_state);
 534                 break;
 535
 536         case AML_INT_RESERVEDFIELD_OP:
 537
 538                 /* Get the length which is encoded as a package length */
 539
 540                 field->common.value.size =
 541                     acpi_ps_get_next_package_length(parser_state);
 542                 break;
 543
 544         case AML_INT_ACCESSFIELD_OP:
 545
 546                 /*
 547                  * Get access_type and access_attrib and merge into the field Op
 548                  * access_type is first operand, access_attribute is second
 549                  */
 550                 field->common.value.integer =
 551                     (((u32) ACPI_GET8(parser_state->aml) << 8));
 552                 parser_state->aml++;
 553                 field->common.value.integer |= ACPI_GET8(parser_state->aml);
 554                 parser_state->aml++;
 555                 break;
 556
 557         default:
 558
 559                 /* Opcode was set in previous switch */
 560                 break;
 561         }
 562
 563         return_PTR(field);
 564 }
 565
 566 /*******************************************************************************
 567  *
 568  * FUNCTION:    acpi_ps_get_next_arg
 569  *
 570  * PARAMETERS:  walk_state          - Current state
 571  *              parser_state        - Current parser state object
 572  *              arg_type            - The argument type (AML_*_ARG)
 573  *              return_arg          - Where the next arg is returned
 574  *
 575  * RETURN:      Status, and an op object containing the next argument.
 576  *
 577  * DESCRIPTION: Get next argument (including complex list arguments that require
 578  *              pushing the parser stack)
 579  *
 580  ******************************************************************************/
 581
 582 acpi_status
 583 acpi_ps_get_next_arg(struct acpi_walk_state *walk_state,
 584                      struct acpi_parse_state *parser_state,
 585                      u32 arg_type, union acpi_parse_object **return_arg)
 586 {
 587         union acpi_parse_object *arg = NULL;
 588         union acpi_parse_object *prev = NULL;
 589         union acpi_parse_object *field;
 590         u32 subop;
 591         acpi_status status = AE_OK;
 592
 593         ACPI_FUNCTION_TRACE_PTR("ps_get_next_arg", parser_state);
 594
 595         switch (arg_type) {
 596         case ARGP_BYTEDATA:
 597         case ARGP_WORDDATA:
 598         case ARGP_DWORDDATA:
 599         case ARGP_CHARLIST:
 600         case ARGP_NAME:
 601         case ARGP_NAMESTRING:
 602
 603                 /* Constants, strings, and namestrings are all the same size */
 604
 605                 arg = acpi_ps_alloc_op(AML_BYTE_OP);
 606                 if (!arg) {
 607                         return_ACPI_STATUS(AE_NO_MEMORY);
 608                 }
 609                 acpi_ps_get_next_simple_arg(parser_state, arg_type, arg);
 610                 break;
 611
 612         case ARGP_PKGLENGTH:
 613
 614                 /* Package length, nothing returned */
 615
 616                 parser_state->pkg_end =
 617                     acpi_ps_get_next_package_end(parser_state);
 618                 break;
 619
 620         case ARGP_FIELDLIST:
 621
 622                 if (parser_state->aml < parser_state->pkg_end) {
 623                         /* Non-empty list */
 624
 625                         while (parser_state->aml < parser_state->pkg_end) {
 626                                 field = acpi_ps_get_next_field(parser_state);
 627                                 if (!field) {
 628                                         return_ACPI_STATUS(AE_NO_MEMORY);
 629                                 }
 630
 631                                 if (prev) {
 632                                         prev->common.next = field;
 633                                 } else {
 634                                         arg = field;
 635                                 }
 636                                 prev = field;
 637                         }
 638
 639                         /* Skip to End of byte data */
 640
 641                         parser_state->aml = parser_state->pkg_end;
 642                 }
 643                 break;
 644
 645         case ARGP_BYTELIST:
 646
 647                 if (parser_state->aml < parser_state->pkg_end) {
 648                         /* Non-empty list */
 649
 650                         arg = acpi_ps_alloc_op(AML_INT_BYTELIST_OP);
 651                         if (!arg) {
 652                                 return_ACPI_STATUS(AE_NO_MEMORY);
 653                         }
 654
 655                         /* Fill in bytelist data */
 656
 657                         arg->common.value.size = (u32)
 658                             ACPI_PTR_DIFF(parser_state->pkg_end,
 659                                           parser_state->aml);
 660                         arg->named.data = parser_state->aml;
 661
 662                         /* Skip to End of byte data */
 663
 664                         parser_state->aml = parser_state->pkg_end;
 665                 }
 666                 break;
 667
 668         case ARGP_TARGET:
 669         case ARGP_SUPERNAME:
 670         case ARGP_SIMPLENAME:
 671
 672                 subop = acpi_ps_peek_opcode(parser_state);
 673                 if (subop == 0 ||
 674                     acpi_ps_is_leading_char(subop) ||
 675                     acpi_ps_is_prefix_char(subop)) {
 676                         /* null_name or name_string */
 677
 678                         arg = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
 679                         if (!arg) {
 680                                 return_ACPI_STATUS(AE_NO_MEMORY);
 681                         }
 682
 683                         status =
 684                             acpi_ps_get_next_namepath(walk_state, parser_state,
 685                                                       arg, 0);
 686                 } else {
 687                         /* Single complex argument, nothing returned */
 688
 689                         walk_state->arg_count = 1;
 690                 }
 691                 break;
 692
 693         case ARGP_DATAOBJ:
 694         case ARGP_TERMARG:
 695
 696                 /* Single complex argument, nothing returned */
 697
 698                 walk_state->arg_count = 1;
 699                 break;
 700
 701         case ARGP_DATAOBJLIST:
 702         case ARGP_TERMLIST:
 703         case ARGP_OBJLIST:
 704
 705                 if (parser_state->aml < parser_state->pkg_end) {
 706                         /* Non-empty list of variable arguments, nothing returned */
 707
 708                         walk_state->arg_count = ACPI_VAR_ARGS;
 709                 }
 710                 break;
 711
 712         default:
 713
 714                 ACPI_ERROR((AE_INFO, "Invalid arg_type: %X", arg_type));
 715                 status = AE_AML_OPERAND_TYPE;
 716                 break;
 717         }
 718
 719         *return_arg = arg;
 720         return_ACPI_STATUS(status);
 721 }