git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/parser/psargs.c

   1 /******************************************************************************
   2  *
   3  * Module Name: psargs - Parse AML opcode arguments
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2005, 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
  45 #include <acpi/acpi.h>
  46 #include <acpi/acparser.h>
  47 #include <acpi/amlcode.h>
  48 #include <acpi/acnamesp.h>
  49
  50 #define _COMPONENT          ACPI_PARSER
  51          ACPI_MODULE_NAME    ("psargs")
  52
  53 /* Local prototypes */
  54
  55 static u32
  56 acpi_ps_get_next_package_length (
  57         struct acpi_parse_state         *parser_state);
  58
  59 static union acpi_parse_object *
  60 acpi_ps_get_next_field (
  61         struct acpi_parse_state         *parser_state);
  62
  63
  64 /*******************************************************************************
  65  *
  66  * FUNCTION:    acpi_ps_get_next_package_length
  67  *
  68  * PARAMETERS:  parser_state        - Current parser state object
  69  *
  70  * RETURN:      Decoded package length.  On completion, the AML pointer points
  71  *              past the length byte or bytes.
  72  *
  73  * DESCRIPTION: Decode and return a package length field
  74  *
  75  ******************************************************************************/
  76
  77 static u32
  78 acpi_ps_get_next_package_length (
  79         struct acpi_parse_state         *parser_state)
  80 {
  81         u32                             encoded_length;
  82         u32                             length = 0;
  83
  84
  85         ACPI_FUNCTION_TRACE ("ps_get_next_package_length");
  86
  87
  88         encoded_length = (u32) ACPI_GET8 (parser_state->aml);
  89         parser_state->aml++;
  90
  91         switch (encoded_length >> 6) /* bits 6-7 contain encoding scheme */ {
  92         case 0: /* 1-byte encoding (bits 0-5) */
  93
  94                 length = (encoded_length & 0x3F);
  95                 break;
  96
  97
  98         case 1: /* 2-byte encoding (next byte + bits 0-3) */
  99
 100                 length = ((ACPI_GET8 (parser_state->aml) << 04) |
 101                                  (encoded_length & 0x0F));
 102                 parser_state->aml++;
 103                 break;
 104
 105
 106         case 2: /* 3-byte encoding (next 2 bytes + bits 0-3) */
 107
 108                 length = ((ACPI_GET8 (parser_state->aml + 1) << 12) |
 109                                   (ACPI_GET8 (parser_state->aml)    << 04) |
 110                                   (encoded_length & 0x0F));
 111                 parser_state->aml += 2;
 112                 break;
 113
 114
 115         case 3: /* 4-byte encoding (next 3 bytes + bits 0-3) */
 116
 117                 length = ((ACPI_GET8 (parser_state->aml + 2) << 20) |
 118                                   (ACPI_GET8 (parser_state->aml + 1) << 12) |
 119                                   (ACPI_GET8 (parser_state->aml)    << 04) |
 120                                   (encoded_length & 0x0F));
 121                 parser_state->aml += 3;
 122                 break;
 123
 124         default:
 125
 126                 /* Can't get here, only 2 bits / 4 cases */
 127                 break;
 128         }
 129
 130         return_VALUE (length);
 131 }
 132
 133
 134 /*******************************************************************************
 135  *
 136  * FUNCTION:    acpi_ps_get_next_package_end
 137  *
 138  * PARAMETERS:  parser_state        - Current parser state object
 139  *
 140  * RETURN:      Pointer to end-of-package +1
 141  *
 142  * DESCRIPTION: Get next package length and return a pointer past the end of
 143  *              the package.  Consumes the package length field
 144  *
 145  ******************************************************************************/
 146
 147 u8 *
 148 acpi_ps_get_next_package_end (
 149         struct acpi_parse_state         *parser_state)
 150 {
 151         u8                              *start = parser_state->aml;
 152         acpi_native_uint                length;
 153
 154
 155         ACPI_FUNCTION_TRACE ("ps_get_next_package_end");
 156
 157
 158         /* Function below changes parser_state->Aml */
 159
 160         length = (acpi_native_uint) acpi_ps_get_next_package_length (parser_state);
 161
 162         return_PTR (start + length); /* end of package */
 163 }
 164
 165
 166 /*******************************************************************************
 167  *
 168  * FUNCTION:    acpi_ps_get_next_namestring
 169  *
 170  * PARAMETERS:  parser_state        - Current parser state object
 171  *
 172  * RETURN:      Pointer to the start of the name string (pointer points into
 173  *              the AML.
 174  *
 175  * DESCRIPTION: Get next raw namestring within the AML stream.  Handles all name
 176  *              prefix characters.  Set parser state to point past the string.
 177  *              (Name is consumed from the AML.)
 178  *
 179  ******************************************************************************/
 180
 181 char *
 182 acpi_ps_get_next_namestring (
 183         struct acpi_parse_state         *parser_state)
 184 {
 185         u8                              *start = parser_state->aml;
 186         u8                              *end = parser_state->aml;
 187
 188
 189         ACPI_FUNCTION_TRACE ("ps_get_next_namestring");
 190
 191
 192         /* Handle multiple prefix characters */
 193
 194         while (acpi_ps_is_prefix_char (ACPI_GET8 (end))) {
 195                 /* Include prefix '\\' or '^' */
 196
 197                 end++;
 198         }
 199
 200         /* Decode the path */
 201
 202         switch (ACPI_GET8 (end)) {
 203         case 0:
 204
 205                 /* null_name */
 206
 207                 if (end == start) {
 208                         start = NULL;
 209                 }
 210                 end++;
 211                 break;
 212
 213         case AML_DUAL_NAME_PREFIX:
 214
 215                 /* Two name segments */
 216
 217                 end += 1 + (2 * ACPI_NAME_SIZE);
 218                 break;
 219
 220         case AML_MULTI_NAME_PREFIX_OP:
 221
 222                 /* Multiple name segments, 4 chars each */
 223
 224                 end += 2 + ((acpi_size) ACPI_GET8 (end + 1) * ACPI_NAME_SIZE);
 225                 break;
 226
 227         default:
 228
 229                 /* Single name segment */
 230
 231                 end += ACPI_NAME_SIZE;
 232                 break;
 233         }
 234
 235         parser_state->aml = (u8*) end;
 236         return_PTR ((char *) start);
 237 }
 238
 239
 240 /*******************************************************************************
 241  *
 242  * FUNCTION:    acpi_ps_get_next_namepath
 243  *
 244  * PARAMETERS:  parser_state        - Current parser state object
 245  *              Arg                 - Where the namepath will be stored
 246  *              arg_count           - If the namepath points to a control method
 247  *                                    the method's argument is returned here.
 248  *              method_call         - Whether the namepath can possibly be the
 249  *                                    start of a method call
 250  *
 251  * RETURN:      Status
 252  *
 253  * DESCRIPTION: Get next name (if method call, return # of required args).
 254  *              Names are looked up in the internal namespace to determine
 255  *              if the name represents a control method.  If a method
 256  *              is found, the number of arguments to the method is returned.
 257  *              This information is critical for parsing to continue correctly.
 258  *
 259  ******************************************************************************/
 260
 261 acpi_status
 262 acpi_ps_get_next_namepath (
 263         struct acpi_walk_state          *walk_state,
 264         struct acpi_parse_state         *parser_state,
 265         union acpi_parse_object         *arg,
 266         u8                              method_call)
 267 {
 268         char                            *path;
 269         union acpi_parse_object         *name_op;
 270         acpi_status                     status = AE_OK;
 271         union acpi_operand_object       *method_desc;
 272         struct acpi_namespace_node      *node;
 273         union acpi_generic_state        scope_info;
 274
 275
 276         ACPI_FUNCTION_TRACE ("ps_get_next_namepath");
 277
 278
 279         path = acpi_ps_get_next_namestring (parser_state);
 280
 281         /* Null path case is allowed */
 282
 283         if (path) {
 284                 /*
 285                  * Lookup the name in the internal namespace
 286                  */
 287                 scope_info.scope.node = NULL;
 288                 node = parser_state->start_node;
 289                 if (node) {
 290                         scope_info.scope.node = node;
 291                 }
 292
 293                 /*
 294                  * Lookup object.  We don't want to add anything new to the namespace
 295                  * here, however.  So we use MODE_EXECUTE.  Allow searching of the
 296                  * parent tree, but don't open a new scope -- we just want to lookup the
 297                  * object  (MUST BE mode EXECUTE to perform upsearch)
 298                  */
 299                 status = acpi_ns_lookup (&scope_info, path, ACPI_TYPE_ANY,
 300                                  ACPI_IMODE_EXECUTE,
 301                                  ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
 302                                  NULL, &node);
 303                 if (ACPI_SUCCESS (status) && method_call) {
 304                         if (node->type == ACPI_TYPE_METHOD) {
 305                                 /* This name is actually a control method invocation */
 306
 307                                 method_desc = acpi_ns_get_attached_object (node);
 308                                 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
 309                                         "Control Method - %p Desc %p Path=%p\n",
 310                                         node, method_desc, path));
 311
 312                                 name_op = acpi_ps_alloc_op (AML_INT_NAMEPATH_OP);
 313                                 if (!name_op) {
 314                                         return_ACPI_STATUS (AE_NO_MEMORY);
 315                                 }
 316
 317                                 /* Change arg into a METHOD CALL and attach name to it */
 318
 319                                 acpi_ps_init_op (arg, AML_INT_METHODCALL_OP);
 320                                 name_op->common.value.name = path;
 321
 322                                 /* Point METHODCALL/NAME to the METHOD Node */
 323
 324                                 name_op->common.node = node;
 325                                 acpi_ps_append_arg (arg, name_op);
 326
 327                                 if (!method_desc) {
 328                                         ACPI_REPORT_ERROR ((
 329                                                 "ps_get_next_namepath: Control Method %p has no attached object\n",
 330                                                 node));
 331                                         return_ACPI_STATUS (AE_AML_INTERNAL);
 332                                 }
 333
 334                                 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
 335                                         "Control Method - %p Args %X\n",
 336                                         node, method_desc->method.param_count));
 337
 338                                 /* Get the number of arguments to expect */
 339
 340                                 walk_state->arg_count = method_desc->method.param_count;
 341                                 return_ACPI_STATUS (AE_OK);
 342                         }
 343
 344                         /*
 345                          * Else this is normal named object reference.
 346                          * Just init the NAMEPATH object with the pathname.
 347                          * (See code below)
 348                          */
 349                 }
 350
 351                 if (ACPI_FAILURE (status)) {
 352                         /*
 353                          * 1) Any error other than NOT_FOUND is always severe
 354                          * 2) NOT_FOUND is only important if we are executing a method.
 355                          * 3) If executing a cond_ref_of opcode, NOT_FOUND is ok.
 356                          */
 357                         if ((((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) == ACPI_PARSE_EXECUTE) &&
 358                                 (status == AE_NOT_FOUND)                                                &&
 359                                 (walk_state->op->common.aml_opcode != AML_COND_REF_OF_OP)) ||
 360
 361                                 (status != AE_NOT_FOUND)) {
 362                                 ACPI_REPORT_NSERROR (path, status);
 363
 364                                 acpi_os_printf ("search_node %p start_node %p return_node %p\n",
 365                                         scope_info.scope.node, parser_state->start_node, node);
 366
 367
 368                         }
 369                         else {
 370                                 /*
 371                                  * We got a NOT_FOUND during table load or we encountered
 372                                  * a cond_ref_of(x) where the target does not exist.
 373                                  * Either case is ok
 374                                  */
 375                                 status = AE_OK;
 376                         }
 377                 }
 378         }
 379
 380         /*
 381          * Regardless of success/failure above,
 382          * Just initialize the Op with the pathname.
 383          */
 384         acpi_ps_init_op (arg, AML_INT_NAMEPATH_OP);
 385         arg->common.value.name = path;
 386
 387         return_ACPI_STATUS (status);
 388 }
 389
 390
 391 /*******************************************************************************
 392  *
 393  * FUNCTION:    acpi_ps_get_next_simple_arg
 394  *
 395  * PARAMETERS:  parser_state        - Current parser state object
 396  *              arg_type            - The argument type (AML_*_ARG)
 397  *              Arg                 - Where the argument is returned
 398  *
 399  * RETURN:      None
 400  *
 401  * DESCRIPTION: Get the next simple argument (constant, string, or namestring)
 402  *
 403  ******************************************************************************/
 404
 405 void
 406 acpi_ps_get_next_simple_arg (
 407         struct acpi_parse_state         *parser_state,
 408         u32                             arg_type,
 409         union acpi_parse_object         *arg)
 410 {
 411
 412         ACPI_FUNCTION_TRACE_U32 ("ps_get_next_simple_arg", arg_type);
 413
 414
 415         switch (arg_type) {
 416         case ARGP_BYTEDATA:
 417
 418                 acpi_ps_init_op (arg, AML_BYTE_OP);
 419                 arg->common.value.integer = (u32) ACPI_GET8 (parser_state->aml);
 420                 parser_state->aml++;
 421                 break;
 422
 423
 424         case ARGP_WORDDATA:
 425
 426                 acpi_ps_init_op (arg, AML_WORD_OP);
 427
 428                 /* Get 2 bytes from the AML stream */
 429
 430                 ACPI_MOVE_16_TO_32 (&arg->common.value.integer, parser_state->aml);
 431                 parser_state->aml += 2;
 432                 break;
 433
 434
 435         case ARGP_DWORDDATA:
 436
 437                 acpi_ps_init_op (arg, AML_DWORD_OP);
 438
 439                 /* Get 4 bytes from the AML stream */
 440
 441                 ACPI_MOVE_32_TO_32 (&arg->common.value.integer, parser_state->aml);
 442                 parser_state->aml += 4;
 443                 break;
 444
 445
 446         case ARGP_QWORDDATA:
 447
 448                 acpi_ps_init_op (arg, AML_QWORD_OP);
 449
 450                 /* Get 8 bytes from the AML stream */
 451
 452                 ACPI_MOVE_64_TO_64 (&arg->common.value.integer, parser_state->aml);
 453                 parser_state->aml += 8;
 454                 break;
 455
 456
 457         case ARGP_CHARLIST:
 458
 459                 acpi_ps_init_op (arg, AML_STRING_OP);
 460                 arg->common.value.string = (char *) parser_state->aml;
 461
 462                 while (ACPI_GET8 (parser_state->aml) != '\0') {
 463                         parser_state->aml++;
 464                 }
 465                 parser_state->aml++;
 466                 break;
 467
 468
 469         case ARGP_NAME:
 470         case ARGP_NAMESTRING:
 471
 472                 acpi_ps_init_op (arg, AML_INT_NAMEPATH_OP);
 473                 arg->common.value.name = acpi_ps_get_next_namestring (parser_state);
 474                 break;
 475
 476
 477         default:
 478
 479                 ACPI_REPORT_ERROR (("Invalid arg_type %X\n", arg_type));
 480                 break;
 481         }
 482
 483         return_VOID;
 484 }
 485
 486
 487 /*******************************************************************************
 488  *
 489  * FUNCTION:    acpi_ps_get_next_field
 490  *
 491  * PARAMETERS:  parser_state        - Current parser state object
 492  *
 493  * RETURN:      A newly allocated FIELD op
 494  *
 495  * DESCRIPTION: Get next field (named_field, reserved_field, or access_field)
 496  *
 497  ******************************************************************************/
 498
 499 static union acpi_parse_object *
 500 acpi_ps_get_next_field (
 501         struct acpi_parse_state         *parser_state)
 502 {
 503         u32                             aml_offset = (u32)
 504                           ACPI_PTR_DIFF (parser_state->aml,
 505                                            parser_state->aml_start);
 506         union acpi_parse_object         *field;
 507         u16                             opcode;
 508         u32                             name;
 509
 510
 511         ACPI_FUNCTION_TRACE ("ps_get_next_field");
 512
 513
 514         /* Determine field type */
 515
 516         switch (ACPI_GET8 (parser_state->aml)) {
 517         default:
 518
 519                 opcode = AML_INT_NAMEDFIELD_OP;
 520                 break;
 521
 522         case 0x00:
 523
 524                 opcode = AML_INT_RESERVEDFIELD_OP;
 525                 parser_state->aml++;
 526                 break;
 527
 528         case 0x01:
 529
 530                 opcode = AML_INT_ACCESSFIELD_OP;
 531                 parser_state->aml++;
 532                 break;
 533         }
 534
 535         /* Allocate a new field op */
 536
 537         field = acpi_ps_alloc_op (opcode);
 538         if (!field) {
 539                 return_PTR (NULL);
 540         }
 541
 542         field->common.aml_offset = aml_offset;
 543
 544         /* Decode the field type */
 545
 546         switch (opcode) {
 547         case AML_INT_NAMEDFIELD_OP:
 548
 549                 /* Get the 4-character name */
 550
 551                 ACPI_MOVE_32_TO_32 (&name, parser_state->aml);
 552                 acpi_ps_set_name (field, name);
 553                 parser_state->aml += ACPI_NAME_SIZE;
 554
 555                 /* Get the length which is encoded as a package length */
 556
 557                 field->common.value.size = acpi_ps_get_next_package_length (parser_state);
 558                 break;
 559
 560
 561         case AML_INT_RESERVEDFIELD_OP:
 562
 563                 /* Get the length which is encoded as a package length */
 564
 565                 field->common.value.size = acpi_ps_get_next_package_length (parser_state);
 566                 break;
 567
 568
 569         case AML_INT_ACCESSFIELD_OP:
 570
 571                 /*
 572                  * Get access_type and access_attrib and merge into the field Op
 573                  * access_type is first operand, access_attribute is second
 574                  */
 575                 field->common.value.integer = (ACPI_GET8 (parser_state->aml) << 8);
 576                 parser_state->aml++;
 577                 field->common.value.integer |= ACPI_GET8 (parser_state->aml);
 578                 parser_state->aml++;
 579                 break;
 580
 581         default:
 582
 583                 /* Opcode was set in previous switch */
 584                 break;
 585         }
 586
 587         return_PTR (field);
 588 }
 589
 590
 591 /*******************************************************************************
 592  *
 593  * FUNCTION:    acpi_ps_get_next_arg
 594  *
 595  * PARAMETERS:  walk_state          - Current state
 596  *              parser_state        - Current parser state object
 597  *              arg_type            - The argument type (AML_*_ARG)
 598  *              return_arg          - Where the next arg is returned
 599  *
 600  * RETURN:      Status, and an op object containing the next argument.
 601  *
 602  * DESCRIPTION: Get next argument (including complex list arguments that require
 603  *              pushing the parser stack)
 604  *
 605  ******************************************************************************/
 606
 607 acpi_status
 608 acpi_ps_get_next_arg (
 609         struct acpi_walk_state          *walk_state,
 610         struct acpi_parse_state         *parser_state,
 611         u32                             arg_type,
 612         union acpi_parse_object         **return_arg)
 613 {
 614         union acpi_parse_object         *arg = NULL;
 615         union acpi_parse_object         *prev = NULL;
 616         union acpi_parse_object         *field;
 617         u32                             subop;
 618         acpi_status                     status = AE_OK;
 619
 620
 621         ACPI_FUNCTION_TRACE_PTR ("ps_get_next_arg", parser_state);
 622
 623
 624         switch (arg_type) {
 625         case ARGP_BYTEDATA:
 626         case ARGP_WORDDATA:
 627         case ARGP_DWORDDATA:
 628         case ARGP_CHARLIST:
 629         case ARGP_NAME:
 630         case ARGP_NAMESTRING:
 631
 632                 /* Constants, strings, and namestrings are all the same size */
 633
 634                 arg = acpi_ps_alloc_op (AML_BYTE_OP);
 635                 if (!arg) {
 636                         return_ACPI_STATUS (AE_NO_MEMORY);
 637                 }
 638                 acpi_ps_get_next_simple_arg (parser_state, arg_type, arg);
 639                 break;
 640
 641
 642         case ARGP_PKGLENGTH:
 643
 644                 /* Package length, nothing returned */
 645
 646                 parser_state->pkg_end = acpi_ps_get_next_package_end (parser_state);
 647                 break;
 648
 649
 650         case ARGP_FIELDLIST:
 651
 652                 if (parser_state->aml < parser_state->pkg_end) {
 653                         /* Non-empty list */
 654
 655                         while (parser_state->aml < parser_state->pkg_end) {
 656                                 field = acpi_ps_get_next_field (parser_state);
 657                                 if (!field) {
 658                                         return_ACPI_STATUS (AE_NO_MEMORY);
 659                                 }
 660
 661                                 if (prev) {
 662                                         prev->common.next = field;
 663                                 }
 664                                 else {
 665                                         arg = field;
 666                                 }
 667                                 prev = field;
 668                         }
 669
 670                         /* Skip to End of byte data */
 671
 672                         parser_state->aml = parser_state->pkg_end;
 673                 }
 674                 break;
 675
 676
 677         case ARGP_BYTELIST:
 678
 679                 if (parser_state->aml < parser_state->pkg_end) {
 680                         /* Non-empty list */
 681
 682                         arg = acpi_ps_alloc_op (AML_INT_BYTELIST_OP);
 683                         if (!arg) {
 684                                 return_ACPI_STATUS (AE_NO_MEMORY);
 685                         }
 686
 687                         /* Fill in bytelist data */
 688
 689                         arg->common.value.size = (u32)
 690                                 ACPI_PTR_DIFF (parser_state->pkg_end, parser_state->aml);
 691                         arg->named.data = parser_state->aml;
 692
 693                         /* Skip to End of byte data */
 694
 695                         parser_state->aml = parser_state->pkg_end;
 696                 }
 697                 break;
 698
 699
 700         case ARGP_TARGET:
 701         case ARGP_SUPERNAME:
 702         case ARGP_SIMPLENAME:
 703
 704                 subop = acpi_ps_peek_opcode (parser_state);
 705                 if (subop == 0                  ||
 706                         acpi_ps_is_leading_char (subop) ||
 707                         acpi_ps_is_prefix_char (subop)) {
 708                         /* null_name or name_string */
 709
 710                         arg = acpi_ps_alloc_op (AML_INT_NAMEPATH_OP);
 711                         if (!arg) {
 712                                 return_ACPI_STATUS (AE_NO_MEMORY);
 713                         }
 714
 715                         status = acpi_ps_get_next_namepath (walk_state, parser_state, arg, 0);
 716                 }
 717                 else {
 718                         /* Single complex argument, nothing returned */
 719
 720                         walk_state->arg_count = 1;
 721                 }
 722                 break;
 723
 724
 725         case ARGP_DATAOBJ:
 726         case ARGP_TERMARG:
 727
 728                 /* Single complex argument, nothing returned */
 729
 730                 walk_state->arg_count = 1;
 731                 break;
 732
 733
 734         case ARGP_DATAOBJLIST:
 735         case ARGP_TERMLIST:
 736         case ARGP_OBJLIST:
 737
 738                 if (parser_state->aml < parser_state->pkg_end) {
 739                         /* Non-empty list of variable arguments, nothing returned */
 740
 741                         walk_state->arg_count = ACPI_VAR_ARGS;
 742                 }
 743                 break;
 744
 745
 746         default:
 747
 748                 ACPI_REPORT_ERROR (("Invalid arg_type: %X\n", arg_type));
 749                 status = AE_AML_OPERAND_TYPE;
 750                 break;
 751         }
 752
 753         *return_arg = arg;
 754         return_ACPI_STATUS (status);
 755 }