drivers/acpi/dispatcher/dsutils.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: dsutils - Dispatcher utilities
   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/acdispat.h>
  48 #include <acpi/acinterp.h>
  49 #include <acpi/acnamesp.h>
  50 #include <acpi/acdebug.h>
  51
  52 #define _COMPONENT          ACPI_DISPATCHER
  53 ACPI_MODULE_NAME("dsutils")
  54
  55 /*******************************************************************************
  56  *
  57  * FUNCTION:    acpi_ds_clear_implicit_return
  58  *
  59  * PARAMETERS:  walk_state          - Current State
  60  *
  61  * RETURN:      None.
  62  *
  63  * DESCRIPTION: Clear and remove a reference on an implicit return value.  Used
  64  *              to delete "stale" return values (if enabled, the return value
  65  *              from every operator is saved at least momentarily, in case the
  66  *              parent method exits.)
  67  *
  68  ******************************************************************************/
  69 void acpi_ds_clear_implicit_return(struct acpi_walk_state *walk_state)
  70 {
  71         ACPI_FUNCTION_NAME("ds_clear_implicit_return");
  72
  73         /*
  74          * Slack must be enabled for this feature
  75          */
  76         if (!acpi_gbl_enable_interpreter_slack) {
  77                 return;
  78         }
  79
  80         if (walk_state->implicit_return_obj) {
  81                 /*
  82                  * Delete any "stale" implicit return. However, in
  83                  * complex statements, the implicit return value can be
  84                  * bubbled up several levels.
  85                  */
  86                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
  87                                   "Removing reference on stale implicit return obj %p\n",
  88                                   walk_state->implicit_return_obj));
  89
  90                 acpi_ut_remove_reference(walk_state->implicit_return_obj);
  91                 walk_state->implicit_return_obj = NULL;
  92         }
  93 }
  94
  95 #ifndef ACPI_NO_METHOD_EXECUTION
  96 /*******************************************************************************
  97  *
  98  * FUNCTION:    acpi_ds_do_implicit_return
  99  *
 100  * PARAMETERS:  return_desc         - The return value
 101  *              walk_state          - Current State
 102  *              add_reference       - True if a reference should be added to the
 103  *                                    return object
 104  *
 105  * RETURN:      TRUE if implicit return enabled, FALSE otherwise
 106  *
 107  * DESCRIPTION: Implements the optional "implicit return".  We save the result
 108  *              of every ASL operator and control method invocation in case the
 109  *              parent method exit.  Before storing a new return value, we
 110  *              delete the previous return value.
 111  *
 112  ******************************************************************************/
 113
 114 u8
 115 acpi_ds_do_implicit_return(union acpi_operand_object *return_desc,
 116                            struct acpi_walk_state *walk_state, u8 add_reference)
 117 {
 118         ACPI_FUNCTION_NAME("ds_do_implicit_return");
 119
 120         /*
 121          * Slack must be enabled for this feature, and we must
 122          * have a valid return object
 123          */
 124         if ((!acpi_gbl_enable_interpreter_slack) || (!return_desc)) {
 125                 return (FALSE);
 126         }
 127
 128         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 129                           "Result %p will be implicitly returned; Prev=%p\n",
 130                           return_desc, walk_state->implicit_return_obj));
 131
 132         /*
 133          * Delete any "stale" implicit return value first. However, in
 134          * complex statements, the implicit return value can be
 135          * bubbled up several levels, so we don't clear the value if it
 136          * is the same as the return_desc.
 137          */
 138         if (walk_state->implicit_return_obj) {
 139                 if (walk_state->implicit_return_obj == return_desc) {
 140                         return (TRUE);
 141                 }
 142                 acpi_ds_clear_implicit_return(walk_state);
 143         }
 144
 145         /* Save the implicit return value, add a reference if requested */
 146
 147         walk_state->implicit_return_obj = return_desc;
 148         if (add_reference) {
 149                 acpi_ut_add_reference(return_desc);
 150         }
 151
 152         return (TRUE);
 153 }
 154
 155 /*******************************************************************************
 156  *
 157  * FUNCTION:    acpi_ds_is_result_used
 158  *
 159  * PARAMETERS:  Op                  - Current Op
 160  *              walk_state          - Current State
 161  *
 162  * RETURN:      TRUE if result is used, FALSE otherwise
 163  *
 164  * DESCRIPTION: Check if a result object will be used by the parent
 165  *
 166  ******************************************************************************/
 167
 168 u8
 169 acpi_ds_is_result_used(union acpi_parse_object * op,
 170                        struct acpi_walk_state * walk_state)
 171 {
 172         const struct acpi_opcode_info *parent_info;
 173
 174         ACPI_FUNCTION_TRACE_PTR("ds_is_result_used", op);
 175
 176         /* Must have both an Op and a Result Object */
 177
 178         if (!op) {
 179                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Null Op\n"));
 180                 return_VALUE(TRUE);
 181         }
 182
 183         /*
 184          * We know that this operator is not a
 185          * Return() operator (would not come here.) The following code is the
 186          * optional support for a so-called "implicit return". Some AML code
 187          * assumes that the last value of the method is "implicitly" returned
 188          * to the caller. Just save the last result as the return value.
 189          * NOTE: this is optional because the ASL language does not actually
 190          * support this behavior.
 191          */
 192         (void)acpi_ds_do_implicit_return(walk_state->result_obj, walk_state,
 193                                          TRUE);
 194
 195         /*
 196          * Now determine if the parent will use the result
 197          *
 198          * If there is no parent, or the parent is a scope_op, we are executing
 199          * at the method level. An executing method typically has no parent,
 200          * since each method is parsed separately.  A method invoked externally
 201          * via execute_control_method has a scope_op as the parent.
 202          */
 203         if ((!op->common.parent) ||
 204             (op->common.parent->common.aml_opcode == AML_SCOPE_OP)) {
 205                 /* No parent, the return value cannot possibly be used */
 206
 207                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 208                                   "At Method level, result of [%s] not used\n",
 209                                   acpi_ps_get_opcode_name(op->common.
 210                                                           aml_opcode)));
 211                 return_VALUE(FALSE);
 212         }
 213
 214         /* Get info on the parent. The root_op is AML_SCOPE */
 215
 216         parent_info =
 217             acpi_ps_get_opcode_info(op->common.parent->common.aml_opcode);
 218         if (parent_info->class == AML_CLASS_UNKNOWN) {
 219                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 220                                   "Unknown parent opcode. Op=%p\n", op));
 221                 return_VALUE(FALSE);
 222         }
 223
 224         /*
 225          * Decide what to do with the result based on the parent.  If
 226          * the parent opcode will not use the result, delete the object.
 227          * Otherwise leave it as is, it will be deleted when it is used
 228          * as an operand later.
 229          */
 230         switch (parent_info->class) {
 231         case AML_CLASS_CONTROL:
 232
 233                 switch (op->common.parent->common.aml_opcode) {
 234                 case AML_RETURN_OP:
 235
 236                         /* Never delete the return value associated with a return opcode */
 237
 238                         goto result_used;
 239
 240                 case AML_IF_OP:
 241                 case AML_WHILE_OP:
 242
 243                         /*
 244                          * If we are executing the predicate AND this is the predicate op,
 245                          * we will use the return value
 246                          */
 247                         if ((walk_state->control_state->common.state ==
 248                              ACPI_CONTROL_PREDICATE_EXECUTING)
 249                             && (walk_state->control_state->control.
 250                                 predicate_op == op)) {
 251                                 goto result_used;
 252                         }
 253                         break;
 254
 255                 default:
 256                         /* Ignore other control opcodes */
 257                         break;
 258                 }
 259
 260                 /* The general control opcode returns no result */
 261
 262                 goto result_not_used;
 263
 264         case AML_CLASS_CREATE:
 265
 266                 /*
 267                  * These opcodes allow term_arg(s) as operands and therefore
 268                  * the operands can be method calls.  The result is used.
 269                  */
 270                 goto result_used;
 271
 272         case AML_CLASS_NAMED_OBJECT:
 273
 274                 if ((op->common.parent->common.aml_opcode == AML_REGION_OP) ||
 275                     (op->common.parent->common.aml_opcode == AML_DATA_REGION_OP)
 276                     || (op->common.parent->common.aml_opcode == AML_PACKAGE_OP)
 277                     || (op->common.parent->common.aml_opcode ==
 278                         AML_VAR_PACKAGE_OP)
 279                     || (op->common.parent->common.aml_opcode == AML_BUFFER_OP)
 280                     || (op->common.parent->common.aml_opcode ==
 281                         AML_INT_EVAL_SUBTREE_OP)) {
 282                         /*
 283                          * These opcodes allow term_arg(s) as operands and therefore
 284                          * the operands can be method calls.  The result is used.
 285                          */
 286                         goto result_used;
 287                 }
 288
 289                 goto result_not_used;
 290
 291         default:
 292
 293                 /*
 294                  * In all other cases. the parent will actually use the return
 295                  * object, so keep it.
 296                  */
 297                 goto result_used;
 298         }
 299
 300       result_used:
 301         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 302                           "Result of [%s] used by Parent [%s] Op=%p\n",
 303                           acpi_ps_get_opcode_name(op->common.aml_opcode),
 304                           acpi_ps_get_opcode_name(op->common.parent->common.
 305                                                   aml_opcode), op));
 306
 307         return_VALUE(TRUE);
 308
 309       result_not_used:
 310         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 311                           "Result of [%s] not used by Parent [%s] Op=%p\n",
 312                           acpi_ps_get_opcode_name(op->common.aml_opcode),
 313                           acpi_ps_get_opcode_name(op->common.parent->common.
 314                                                   aml_opcode), op));
 315
 316         return_VALUE(FALSE);
 317 }
 318
 319 /*******************************************************************************
 320  *
 321  * FUNCTION:    acpi_ds_delete_result_if_not_used
 322  *
 323  * PARAMETERS:  Op              - Current parse Op
 324  *              result_obj      - Result of the operation
 325  *              walk_state      - Current state
 326  *
 327  * RETURN:      Status
 328  *
 329  * DESCRIPTION: Used after interpretation of an opcode.  If there is an internal
 330  *              result descriptor, check if the parent opcode will actually use
 331  *              this result.  If not, delete the result now so that it will
 332  *              not become orphaned.
 333  *
 334  ******************************************************************************/
 335
 336 void
 337 acpi_ds_delete_result_if_not_used(union acpi_parse_object *op,
 338                                   union acpi_operand_object *result_obj,
 339                                   struct acpi_walk_state *walk_state)
 340 {
 341         union acpi_operand_object *obj_desc;
 342         acpi_status status;
 343
 344         ACPI_FUNCTION_TRACE_PTR("ds_delete_result_if_not_used", result_obj);
 345
 346         if (!op) {
 347                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Null Op\n"));
 348                 return_VOID;
 349         }
 350
 351         if (!result_obj) {
 352                 return_VOID;
 353         }
 354
 355         if (!acpi_ds_is_result_used(op, walk_state)) {
 356                 /* Must pop the result stack (obj_desc should be equal to result_obj) */
 357
 358                 status = acpi_ds_result_pop(&obj_desc, walk_state);
 359                 if (ACPI_SUCCESS(status)) {
 360                         acpi_ut_remove_reference(result_obj);
 361                 }
 362         }
 363
 364         return_VOID;
 365 }
 366
 367 /*******************************************************************************
 368  *
 369  * FUNCTION:    acpi_ds_resolve_operands
 370  *
 371  * PARAMETERS:  walk_state          - Current walk state with operands on stack
 372  *
 373  * RETURN:      Status
 374  *
 375  * DESCRIPTION: Resolve all operands to their values.  Used to prepare
 376  *              arguments to a control method invocation (a call from one
 377  *              method to another.)
 378  *
 379  ******************************************************************************/
 380
 381 acpi_status acpi_ds_resolve_operands(struct acpi_walk_state *walk_state)
 382 {
 383         u32 i;
 384         acpi_status status = AE_OK;
 385
 386         ACPI_FUNCTION_TRACE_PTR("ds_resolve_operands", walk_state);
 387
 388         /*
 389          * Attempt to resolve each of the valid operands
 390          * Method arguments are passed by reference, not by value.  This means
 391          * that the actual objects are passed, not copies of the objects.
 392          */
 393         for (i = 0; i < walk_state->num_operands; i++) {
 394                 status =
 395                     acpi_ex_resolve_to_value(&walk_state->operands[i],
 396                                              walk_state);
 397                 if (ACPI_FAILURE(status)) {
 398                         break;
 399                 }
 400         }
 401
 402         return_ACPI_STATUS(status);
 403 }
 404
 405 /*******************************************************************************
 406  *
 407  * FUNCTION:    acpi_ds_clear_operands
 408  *
 409  * PARAMETERS:  walk_state          - Current walk state with operands on stack
 410  *
 411  * RETURN:      None
 412  *
 413  * DESCRIPTION: Clear all operands on the current walk state operand stack.
 414  *
 415  ******************************************************************************/
 416
 417 void acpi_ds_clear_operands(struct acpi_walk_state *walk_state)
 418 {
 419         u32 i;
 420
 421         ACPI_FUNCTION_TRACE_PTR("ds_clear_operands", walk_state);
 422
 423         /* Remove a reference on each operand on the stack */
 424
 425         for (i = 0; i < walk_state->num_operands; i++) {
 426                 /*
 427                  * Remove a reference to all operands, including both
 428                  * "Arguments" and "Targets".
 429                  */
 430                 acpi_ut_remove_reference(walk_state->operands[i]);
 431                 walk_state->operands[i] = NULL;
 432         }
 433
 434         walk_state->num_operands = 0;
 435         return_VOID;
 436 }
 437 #endif
 438
 439 /*******************************************************************************
 440  *
 441  * FUNCTION:    acpi_ds_create_operand
 442  *
 443  * PARAMETERS:  walk_state      - Current walk state
 444  *              Arg             - Parse object for the argument
 445  *              arg_index       - Which argument (zero based)
 446  *
 447  * RETURN:      Status
 448  *
 449  * DESCRIPTION: Translate a parse tree object that is an argument to an AML
 450  *              opcode to the equivalent interpreter object.  This may include
 451  *              looking up a name or entering a new name into the internal
 452  *              namespace.
 453  *
 454  ******************************************************************************/
 455
 456 acpi_status
 457 acpi_ds_create_operand(struct acpi_walk_state *walk_state,
 458                        union acpi_parse_object *arg, u32 arg_index)
 459 {
 460         acpi_status status = AE_OK;
 461         char *name_string;
 462         u32 name_length;
 463         union acpi_operand_object *obj_desc;
 464         union acpi_parse_object *parent_op;
 465         u16 opcode;
 466         acpi_interpreter_mode interpreter_mode;
 467         const struct acpi_opcode_info *op_info;
 468
 469         ACPI_FUNCTION_TRACE_PTR("ds_create_operand", arg);
 470
 471         /* A valid name must be looked up in the namespace */
 472
 473         if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
 474             (arg->common.value.string)) {
 475                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n",
 476                                   arg));
 477
 478                 /* Get the entire name string from the AML stream */
 479
 480                 status =
 481                     acpi_ex_get_name_string(ACPI_TYPE_ANY,
 482                                             arg->common.value.buffer,
 483                                             &name_string, &name_length);
 484
 485                 if (ACPI_FAILURE(status)) {
 486                         return_ACPI_STATUS(status);
 487                 }
 488
 489                 /* All prefixes have been handled, and the name is in name_string */
 490
 491                 /*
 492                  * Special handling for buffer_field declarations. This is a deferred
 493                  * opcode that unfortunately defines the field name as the last
 494                  * parameter instead of the first.  We get here when we are performing
 495                  * the deferred execution, so the actual name of the field is already
 496                  * in the namespace.  We don't want to attempt to look it up again
 497                  * because we may be executing in a different scope than where the
 498                  * actual opcode exists.
 499                  */
 500                 if ((walk_state->deferred_node) &&
 501                     (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD)
 502                     && (arg_index != 0)) {
 503                         obj_desc =
 504                             ACPI_CAST_PTR(union acpi_operand_object,
 505                                           walk_state->deferred_node);
 506                         status = AE_OK;
 507                 } else {        /* All other opcodes */
 508
 509                         /*
 510                          * Differentiate between a namespace "create" operation
 511                          * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
 512                          * IMODE_EXECUTE) in order to support the creation of
 513                          * namespace objects during the execution of control methods.
 514                          */
 515                         parent_op = arg->common.parent;
 516                         op_info =
 517                             acpi_ps_get_opcode_info(parent_op->common.
 518                                                     aml_opcode);
 519                         if ((op_info->flags & AML_NSNODE)
 520                             && (parent_op->common.aml_opcode !=
 521                                 AML_INT_METHODCALL_OP)
 522                             && (parent_op->common.aml_opcode != AML_REGION_OP)
 523                             && (parent_op->common.aml_opcode !=
 524                                 AML_INT_NAMEPATH_OP)) {
 525                                 /* Enter name into namespace if not found */
 526
 527                                 interpreter_mode = ACPI_IMODE_LOAD_PASS2;
 528                         } else {
 529                                 /* Return a failure if name not found */
 530
 531                                 interpreter_mode = ACPI_IMODE_EXECUTE;
 532                         }
 533
 534                         status =
 535                             acpi_ns_lookup(walk_state->scope_info, name_string,
 536                                            ACPI_TYPE_ANY, interpreter_mode,
 537                                            ACPI_NS_SEARCH_PARENT |
 538                                            ACPI_NS_DONT_OPEN_SCOPE, walk_state,
 539                                            ACPI_CAST_INDIRECT_PTR(struct
 540                                                                   acpi_namespace_node,
 541                                                                   &obj_desc));
 542                         /*
 543                          * The only case where we pass through (ignore) a NOT_FOUND
 544                          * error is for the cond_ref_of opcode.
 545                          */
 546                         if (status == AE_NOT_FOUND) {
 547                                 if (parent_op->common.aml_opcode ==
 548                                     AML_COND_REF_OF_OP) {
 549                                         /*
 550                                          * For the Conditional Reference op, it's OK if
 551                                          * the name is not found;  We just need a way to
 552                                          * indicate this to the interpreter, set the
 553                                          * object to the root
 554                                          */
 555                                         obj_desc =
 556                                             ACPI_CAST_PTR(union
 557                                                           acpi_operand_object,
 558                                                           acpi_gbl_root_node);
 559                                         status = AE_OK;
 560                                 } else {
 561                                         /*
 562                                          * We just plain didn't find it -- which is a
 563                                          * very serious error at this point
 564                                          */
 565                                         status = AE_AML_NAME_NOT_FOUND;
 566                                 }
 567                         }
 568
 569                         if (ACPI_FAILURE(status)) {
 570                                 ACPI_REPORT_NSERROR(name_string, status);
 571                         }
 572                 }
 573
 574                 /* Free the namestring created above */
 575
 576                 ACPI_MEM_FREE(name_string);
 577
 578                 /* Check status from the lookup */
 579
 580                 if (ACPI_FAILURE(status)) {
 581                         return_ACPI_STATUS(status);
 582                 }
 583
 584                 /* Put the resulting object onto the current object stack */
 585
 586                 status = acpi_ds_obj_stack_push(obj_desc, walk_state);
 587                 if (ACPI_FAILURE(status)) {
 588                         return_ACPI_STATUS(status);
 589                 }
 590                 ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object
 591                                    (obj_desc, walk_state));
 592         } else {
 593                 /* Check for null name case */
 594
 595                 if (arg->common.aml_opcode == AML_INT_NAMEPATH_OP) {
 596                         /*
 597                          * If the name is null, this means that this is an
 598                          * optional result parameter that was not specified
 599                          * in the original ASL.  Create a Zero Constant for a
 600                          * placeholder.  (Store to a constant is a Noop.)
 601                          */
 602                         opcode = AML_ZERO_OP;   /* Has no arguments! */
 603
 604                         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 605                                           "Null namepath: Arg=%p\n", arg));
 606                 } else {
 607                         opcode = arg->common.aml_opcode;
 608                 }
 609
 610                 /* Get the object type of the argument */
 611
 612                 op_info = acpi_ps_get_opcode_info(opcode);
 613                 if (op_info->object_type == ACPI_TYPE_INVALID) {
 614                         return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
 615                 }
 616
 617                 if (op_info->flags & AML_HAS_RETVAL) {
 618                         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 619                                           "Argument previously created, already stacked \n"));
 620
 621                         ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object
 622                                            (walk_state->
 623                                             operands[walk_state->num_operands -
 624                                                      1], walk_state));
 625
 626                         /*
 627                          * Use value that was already previously returned
 628                          * by the evaluation of this argument
 629                          */
 630                         status =
 631                             acpi_ds_result_pop_from_bottom(&obj_desc,
 632                                                            walk_state);
 633                         if (ACPI_FAILURE(status)) {
 634                                 /*
 635                                  * Only error is underflow, and this indicates
 636                                  * a missing or null operand!
 637                                  */
 638                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 639                                                   "Missing or null operand, %s\n",
 640                                                   acpi_format_exception
 641                                                   (status)));
 642                                 return_ACPI_STATUS(status);
 643                         }
 644                 } else {
 645                         /* Create an ACPI_INTERNAL_OBJECT for the argument */
 646
 647                         obj_desc =
 648                             acpi_ut_create_internal_object(op_info->
 649                                                            object_type);
 650                         if (!obj_desc) {
 651                                 return_ACPI_STATUS(AE_NO_MEMORY);
 652                         }
 653
 654                         /* Initialize the new object */
 655
 656                         status =
 657                             acpi_ds_init_object_from_op(walk_state, arg, opcode,
 658                                                         &obj_desc);
 659                         if (ACPI_FAILURE(status)) {
 660                                 acpi_ut_delete_object_desc(obj_desc);
 661                                 return_ACPI_STATUS(status);
 662                         }
 663                 }
 664
 665                 /* Put the operand object on the object stack */
 666
 667                 status = acpi_ds_obj_stack_push(obj_desc, walk_state);
 668                 if (ACPI_FAILURE(status)) {
 669                         return_ACPI_STATUS(status);
 670                 }
 671
 672                 ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object
 673                                    (obj_desc, walk_state));
 674         }
 675
 676         return_ACPI_STATUS(AE_OK);
 677 }
 678
 679 /*******************************************************************************
 680  *
 681  * FUNCTION:    acpi_ds_create_operands
 682  *
 683  * PARAMETERS:  walk_state          - Current state
 684  *              first_arg           - First argument of a parser argument tree
 685  *
 686  * RETURN:      Status
 687  *
 688  * DESCRIPTION: Convert an operator's arguments from a parse tree format to
 689  *              namespace objects and place those argument object on the object
 690  *              stack in preparation for evaluation by the interpreter.
 691  *
 692  ******************************************************************************/
 693
 694 acpi_status
 695 acpi_ds_create_operands(struct acpi_walk_state *walk_state,
 696                         union acpi_parse_object *first_arg)
 697 {
 698         acpi_status status = AE_OK;
 699         union acpi_parse_object *arg;
 700         u32 arg_count = 0;
 701
 702         ACPI_FUNCTION_TRACE_PTR("ds_create_operands", first_arg);
 703
 704         /* For all arguments in the list... */
 705
 706         arg = first_arg;
 707         while (arg) {
 708                 status = acpi_ds_create_operand(walk_state, arg, arg_count);
 709                 if (ACPI_FAILURE(status)) {
 710                         goto cleanup;
 711                 }
 712
 713                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 714                                   "Arg #%d (%p) done, Arg1=%p\n", arg_count,
 715                                   arg, first_arg));
 716
 717                 /* Move on to next argument, if any */
 718
 719                 arg = arg->common.next;
 720                 arg_count++;
 721         }
 722
 723         return_ACPI_STATUS(status);
 724
 725       cleanup:
 726         /*
 727          * We must undo everything done above; meaning that we must
 728          * pop everything off of the operand stack and delete those
 729          * objects
 730          */
 731         (void)acpi_ds_obj_stack_pop_and_delete(arg_count, walk_state);
 732
 733         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "While creating Arg %d - %s\n",
 734                           (arg_count + 1), acpi_format_exception(status)));
 735         return_ACPI_STATUS(status);
 736 }