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