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 - 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
 279                 /* This name is actually a control method invocation */
 280
 281                 method_desc = acpi_ns_get_attached_object(node);
 282                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 283                                   "Control Method - %p Desc %p Path=%p\n", node,
 284                                   method_desc, path));
 285
 286                 name_op = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
 287                 if (!name_op) {
 288                         return_ACPI_STATUS(AE_NO_MEMORY);
 289                 }
 290
 291                 /* Change Arg into a METHOD CALL and attach name to it */
 292
 293                 acpi_ps_init_op(arg, AML_INT_METHODCALL_OP);
 294                 name_op->common.value.name = path;
 295
 296                 /* Point METHODCALL/NAME to the METHOD Node */
 297
 298                 name_op->common.node = node;
 299                 acpi_ps_append_arg(arg, name_op);
 300
 301                 if (!method_desc) {
 302                         ACPI_ERROR((AE_INFO,
 303                                     "Control Method %p has no attached object",
 304                                     node));
 305                         return_ACPI_STATUS(AE_AML_INTERNAL);
 306                 }
 307
 308                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 309                                   "Control Method - %p Args %X\n",
 310                                   node, method_desc->method.param_count));
 311
 312                 /* Get the number of arguments to expect */
 313
 314                 walk_state->arg_count = method_desc->method.param_count;
 315                 return_ACPI_STATUS(AE_OK);
 316         }
 317
 318         /*
 319          * Special handling if the name was not found during the lookup -
 320          * some not_found cases are allowed
 321          */
 322         if (status == AE_NOT_FOUND) {
 323
 324                 /* 1) not_found is ok during load pass 1/2 (allow forward references) */
 325
 326                 if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) !=
 327                     ACPI_PARSE_EXECUTE) {
 328                         status = AE_OK;
 329                 }
 330
 331                 /* 2) not_found during a cond_ref_of(x) is ok by definition */
 332
 333                 else if (walk_state->op->common.aml_opcode ==
 334                          AML_COND_REF_OF_OP) {
 335                         status = AE_OK;
 336                 }
 337
 338                 /*
 339                  * 3) not_found while building a Package is ok at this point, we
 340                  * may flag as an error later if slack mode is not enabled.
 341                  * (Some ASL code depends on allowing this behavior)
 342                  */
 343                 else if ((arg->common.parent) &&
 344                          ((arg->common.parent->common.aml_opcode ==
 345                            AML_PACKAGE_OP)
 346                           || (arg->common.parent->common.aml_opcode ==
 347                               AML_VAR_PACKAGE_OP))) {
 348                         status = AE_OK;
 349                 }
 350         }
 351
 352         /* Final exception check (may have been changed from code above) */
 353
 354         if (ACPI_FAILURE(status)) {
 355                 ACPI_ERROR_NAMESPACE(path, status);
 356
 357                 if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
 358                     ACPI_PARSE_EXECUTE) {
 359
 360                         /* Report a control method execution error */
 361
 362                         status = acpi_ds_method_error(status, walk_state);
 363                 }
 364         }
 365
 366         /* Save the namepath */
 367
 368         arg->common.value.name = path;
 369         return_ACPI_STATUS(status);
 370 }
 371
 372 /*******************************************************************************
 373  *
 374  * FUNCTION:    acpi_ps_get_next_simple_arg
 375  *
 376  * PARAMETERS:  parser_state        - Current parser state object
 377  *              arg_type            - The argument type (AML_*_ARG)
 378  *              Arg                 - Where the argument is returned
 379  *
 380  * RETURN:      None
 381  *
 382  * DESCRIPTION: Get the next simple argument (constant, string, or namestring)
 383  *
 384  ******************************************************************************/
 385
 386 void
 387 acpi_ps_get_next_simple_arg(struct acpi_parse_state *parser_state,
 388                             u32 arg_type, union acpi_parse_object *arg)
 389 {
 390         u32 length;
 391         u16 opcode;
 392         u8 *aml = parser_state->aml;
 393
 394         ACPI_FUNCTION_TRACE_U32(ps_get_next_simple_arg, arg_type);
 395
 396         switch (arg_type) {
 397         case ARGP_BYTEDATA:
 398
 399                 /* Get 1 byte from the AML stream */
 400
 401                 opcode = AML_BYTE_OP;
 402                 arg->common.value.integer = (acpi_integer) * aml;
 403                 length = 1;
 404                 break;
 405
 406         case ARGP_WORDDATA:
 407
 408                 /* Get 2 bytes from the AML stream */
 409
 410                 opcode = AML_WORD_OP;
 411                 ACPI_MOVE_16_TO_64(&arg->common.value.integer, aml);
 412                 length = 2;
 413                 break;
 414
 415         case ARGP_DWORDDATA:
 416
 417                 /* Get 4 bytes from the AML stream */
 418
 419                 opcode = AML_DWORD_OP;
 420                 ACPI_MOVE_32_TO_64(&arg->common.value.integer, aml);
 421                 length = 4;
 422                 break;
 423
 424         case ARGP_QWORDDATA:
 425
 426                 /* Get 8 bytes from the AML stream */
 427
 428                 opcode = AML_QWORD_OP;
 429                 ACPI_MOVE_64_TO_64(&arg->common.value.integer, aml);
 430                 length = 8;
 431                 break;
 432
 433         case ARGP_CHARLIST:
 434
 435                 /* Get a pointer to the string, point past the string */
 436
 437                 opcode = AML_STRING_OP;
 438                 arg->common.value.string = ACPI_CAST_PTR(char, aml);
 439
 440                 /* Find the null terminator */
 441
 442                 length = 0;
 443                 while (aml[length]) {
 444                         length++;
 445                 }
 446                 length++;
 447                 break;
 448
 449         case ARGP_NAME:
 450         case ARGP_NAMESTRING:
 451
 452                 acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
 453                 arg->common.value.name =
 454                     acpi_ps_get_next_namestring(parser_state);
 455                 return_VOID;
 456
 457         default:
 458
 459                 ACPI_ERROR((AE_INFO, "Invalid ArgType %X", arg_type));
 460                 return_VOID;
 461         }
 462
 463         acpi_ps_init_op(arg, opcode);
 464         parser_state->aml += length;
 465         return_VOID;
 466 }
 467
 468 /*******************************************************************************
 469  *
 470  * FUNCTION:    acpi_ps_get_next_field
 471  *
 472  * PARAMETERS:  parser_state        - Current parser state object
 473  *
 474  * RETURN:      A newly allocated FIELD op
 475  *
 476  * DESCRIPTION: Get next field (named_field, reserved_field, or access_field)
 477  *
 478  ******************************************************************************/
 479
 480 static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
 481                                                        *parser_state)
 482 {
 483         u32 aml_offset = (u32)
 484             ACPI_PTR_DIFF(parser_state->aml,
 485                           parser_state->aml_start);
 486         union acpi_parse_object *field;
 487         u16 opcode;
 488         u32 name;
 489
 490         ACPI_FUNCTION_TRACE(ps_get_next_field);
 491
 492         /* Determine field type */
 493
 494         switch (ACPI_GET8(parser_state->aml)) {
 495         default:
 496
 497                 opcode = AML_INT_NAMEDFIELD_OP;
 498                 break;
 499
 500         case 0x00:
 501
 502                 opcode = AML_INT_RESERVEDFIELD_OP;
 503                 parser_state->aml++;
 504                 break;
 505
 506         case 0x01:
 507
 508                 opcode = AML_INT_ACCESSFIELD_OP;
 509                 parser_state->aml++;
 510                 break;
 511         }
 512
 513         /* Allocate a new field op */
 514
 515         field = acpi_ps_alloc_op(opcode);
 516         if (!field) {
 517                 return_PTR(NULL);
 518         }
 519
 520         field->common.aml_offset = aml_offset;
 521
 522         /* Decode the field type */
 523
 524         switch (opcode) {
 525         case AML_INT_NAMEDFIELD_OP:
 526
 527                 /* Get the 4-character name */
 528
 529                 ACPI_MOVE_32_TO_32(&name, parser_state->aml);
 530                 acpi_ps_set_name(field, name);
 531                 parser_state->aml += ACPI_NAME_SIZE;
 532
 533                 /* Get the length which is encoded as a package length */
 534
 535                 field->common.value.size =
 536                     acpi_ps_get_next_package_length(parser_state);
 537                 break;
 538
 539         case AML_INT_RESERVEDFIELD_OP:
 540
 541                 /* Get the length which is encoded as a package length */
 542
 543                 field->common.value.size =
 544                     acpi_ps_get_next_package_length(parser_state);
 545                 break;
 546
 547         case AML_INT_ACCESSFIELD_OP:
 548
 549                 /*
 550                  * Get access_type and access_attrib and merge into the field Op
 551                  * access_type is first operand, access_attribute is second
 552                  */
 553                 field->common.value.integer =
 554                     (((u32) ACPI_GET8(parser_state->aml) << 8));
 555                 parser_state->aml++;
 556                 field->common.value.integer |= ACPI_GET8(parser_state->aml);
 557                 parser_state->aml++;
 558                 break;
 559
 560         default:
 561
 562                 /* Opcode was set in previous switch */
 563                 break;
 564         }
 565
 566         return_PTR(field);
 567 }
 568
 569 /*******************************************************************************
 570  *
 571  * FUNCTION:    acpi_ps_get_next_arg
 572  *
 573  * PARAMETERS:  walk_state          - Current state
 574  *              parser_state        - Current parser state object
 575  *              arg_type            - The argument type (AML_*_ARG)
 576  *              return_arg          - Where the next arg is returned
 577  *
 578  * RETURN:      Status, and an op object containing the next argument.
 579  *
 580  * DESCRIPTION: Get next argument (including complex list arguments that require
 581  *              pushing the parser stack)
 582  *
 583  ******************************************************************************/
 584
 585 acpi_status
 586 acpi_ps_get_next_arg(struct acpi_walk_state *walk_state,
 587                      struct acpi_parse_state *parser_state,
 588                      u32 arg_type, union acpi_parse_object **return_arg)
 589 {
 590         union acpi_parse_object *arg = NULL;
 591         union acpi_parse_object *prev = NULL;
 592         union acpi_parse_object *field;
 593         u32 subop;
 594         acpi_status status = AE_OK;
 595
 596         ACPI_FUNCTION_TRACE_PTR(ps_get_next_arg, parser_state);
 597
 598         switch (arg_type) {
 599         case ARGP_BYTEDATA:
 600         case ARGP_WORDDATA:
 601         case ARGP_DWORDDATA:
 602         case ARGP_CHARLIST:
 603         case ARGP_NAME:
 604         case ARGP_NAMESTRING:
 605
 606                 /* Constants, strings, and namestrings are all the same size */
 607
 608                 arg = acpi_ps_alloc_op(AML_BYTE_OP);
 609                 if (!arg) {
 610                         return_ACPI_STATUS(AE_NO_MEMORY);
 611                 }
 612                 acpi_ps_get_next_simple_arg(parser_state, arg_type, arg);
 613                 break;
 614
 615         case ARGP_PKGLENGTH:
 616
 617                 /* Package length, nothing returned */
 618
 619                 parser_state->pkg_end =
 620                     acpi_ps_get_next_package_end(parser_state);
 621                 break;
 622
 623         case ARGP_FIELDLIST:
 624
 625                 if (parser_state->aml < parser_state->pkg_end) {
 626
 627                         /* Non-empty list */
 628
 629                         while (parser_state->aml < parser_state->pkg_end) {
 630                                 field = acpi_ps_get_next_field(parser_state);
 631                                 if (!field) {
 632                                         return_ACPI_STATUS(AE_NO_MEMORY);
 633                                 }
 634
 635                                 if (prev) {
 636                                         prev->common.next = field;
 637                                 } else {
 638                                         arg = field;
 639                                 }
 640                                 prev = field;
 641                         }
 642
 643                         /* Skip to End of byte data */
 644
 645                         parser_state->aml = parser_state->pkg_end;
 646                 }
 647                 break;
 648
 649         case ARGP_BYTELIST:
 650
 651                 if (parser_state->aml < parser_state->pkg_end) {
 652
 653                         /* Non-empty list */
 654
 655                         arg = acpi_ps_alloc_op(AML_INT_BYTELIST_OP);
 656                         if (!arg) {
 657                                 return_ACPI_STATUS(AE_NO_MEMORY);
 658                         }
 659
 660                         /* Fill in bytelist data */
 661
 662                         arg->common.value.size = (u32)
 663                             ACPI_PTR_DIFF(parser_state->pkg_end,
 664                                           parser_state->aml);
 665                         arg->named.data = parser_state->aml;
 666
 667                         /* Skip to End of byte data */
 668
 669                         parser_state->aml = parser_state->pkg_end;
 670                 }
 671                 break;
 672
 673         case ARGP_TARGET:
 674         case ARGP_SUPERNAME:
 675         case ARGP_SIMPLENAME:
 676
 677                 subop = acpi_ps_peek_opcode(parser_state);
 678                 if (subop == 0 ||
 679                     acpi_ps_is_leading_char(subop) ||
 680                     acpi_ps_is_prefix_char(subop)) {
 681
 682                         /* null_name or name_string */
 683
 684                         arg = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
 685                         if (!arg) {
 686                                 return_ACPI_STATUS(AE_NO_MEMORY);
 687                         }
 688
 689                         status =
 690                             acpi_ps_get_next_namepath(walk_state, parser_state,
 691                                                       arg, 0);
 692                 } else {
 693                         /* Single complex argument, nothing returned */
 694
 695                         walk_state->arg_count = 1;
 696                 }
 697                 break;
 698
 699         case ARGP_DATAOBJ:
 700         case ARGP_TERMARG:
 701
 702                 /* Single complex argument, nothing returned */
 703
 704                 walk_state->arg_count = 1;
 705                 break;
 706
 707         case ARGP_DATAOBJLIST:
 708         case ARGP_TERMLIST:
 709         case ARGP_OBJLIST:
 710
 711                 if (parser_state->aml < parser_state->pkg_end) {
 712
 713                         /* Non-empty list of variable arguments, nothing returned */
 714
 715                         walk_state->arg_count = ACPI_VAR_ARGS;
 716                 }
 717                 break;
 718
 719         default:
 720
 721                 ACPI_ERROR((AE_INFO, "Invalid ArgType: %X", arg_type));
 722                 status = AE_AML_OPERAND_TYPE;
 723                 break;
 724         }
 725
 726         *return_arg = arg;
 727         return_ACPI_STATUS(status);
 728 }