git.oblomov.eu Git - linux-2.6/blob - 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
  45 #include <acpi/acpi.h>
  46 #include <acpi/acparser.h>
  47 #include <acpi/amlcode.h>
  48 #include <acpi/acdispat.h>
  49 #include <acpi/acinterp.h>
  50 #include <acpi/acnamesp.h>
  51 #include <acpi/acdebug.h>
  52
  53 #define _COMPONENT          ACPI_DISPATCHER
  54          ACPI_MODULE_NAME    ("dsutils")
  55
  56
  57 /*******************************************************************************
  58  *
  59  * FUNCTION:    acpi_ds_clear_implicit_return
  60  *
  61  * PARAMETERS:  walk_state          - Current State
  62  *
  63  * RETURN:      None.
  64  *
  65  * DESCRIPTION: Clear and remove a reference on an implicit return value.  Used
  66  *              to delete "stale" return values (if enabled, the return value
  67  *              from every operator is saved at least momentarily, in case the
  68  *              parent method exits.)
  69  *
  70  ******************************************************************************/
  71
  72 void
  73 acpi_ds_clear_implicit_return (
  74         struct acpi_walk_state          *walk_state)
  75 {
  76         ACPI_FUNCTION_NAME ("ds_clear_implicit_return");
  77
  78
  79         /*
  80          * Slack must be enabled for this feature
  81          */
  82         if (!acpi_gbl_enable_interpreter_slack) {
  83                 return;
  84         }
  85
  86         if (walk_state->implicit_return_obj) {
  87                 /*
  88                  * Delete any "stale" implicit return. However, in
  89                  * complex statements, the implicit return value can be
  90                  * bubbled up several levels.
  91                  */
  92                 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
  93                         "Removing reference on stale implicit return obj %p\n",
  94                         walk_state->implicit_return_obj));
  95
  96                 acpi_ut_remove_reference (walk_state->implicit_return_obj);
  97                 walk_state->implicit_return_obj = NULL;
  98         }
  99 }
 100
 101
 102 #ifndef ACPI_NO_METHOD_EXECUTION
 103 /*******************************************************************************
 104  *
 105  * FUNCTION:    acpi_ds_do_implicit_return
 106  *
 107  * PARAMETERS:  return_desc         - The return value
 108  *              walk_state          - Current State
 109  *              add_reference       - True if a reference should be added to the
 110  *                                    return object
 111  *
 112  * RETURN:      TRUE if implicit return enabled, FALSE otherwise
 113  *
 114  * DESCRIPTION: Implements the optional "implicit return".  We save the result
 115  *              of every ASL operator and control method invocation in case the
 116  *              parent method exit.  Before storing a new return value, we
 117  *              delete the previous return value.
 118  *
 119  ******************************************************************************/
 120
 121 u8
 122 acpi_ds_do_implicit_return (
 123         union acpi_operand_object       *return_desc,
 124         struct acpi_walk_state          *walk_state,
 125         u8                              add_reference)
 126 {
 127         ACPI_FUNCTION_NAME ("ds_do_implicit_return");
 128
 129
 130         /*
 131          * Slack must be enabled for this feature, and we must
 132          * have a valid return object
 133          */
 134         if ((!acpi_gbl_enable_interpreter_slack) ||
 135                 (!return_desc)) {
 136                 return (FALSE);
 137         }
 138
 139         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 140                         "Result %p will be implicitly returned; Prev=%p\n",
 141                         return_desc,
 142                         walk_state->implicit_return_obj));
 143
 144         /*
 145          * Delete any "stale" implicit return value first. However, in
 146          * complex statements, the implicit return value can be
 147          * bubbled up several levels, so we don't clear the value if it
 148          * is the same as the return_desc.
 149          */
 150         if (walk_state->implicit_return_obj) {
 151                 if (walk_state->implicit_return_obj == return_desc) {
 152                         return (TRUE);
 153                 }
 154                 acpi_ds_clear_implicit_return (walk_state);
 155         }
 156
 157         /* Save the implicit return value, add a reference if requested */
 158
 159         walk_state->implicit_return_obj = return_desc;
 160         if (add_reference) {
 161                 acpi_ut_add_reference (return_desc);
 162         }
 163
 164         return (TRUE);
 165 }
 166
 167
 168 /*******************************************************************************
 169  *
 170  * FUNCTION:    acpi_ds_is_result_used
 171  *
 172  * PARAMETERS:  Op                  - Current Op
 173  *              walk_state          - Current State
 174  *
 175  * RETURN:      TRUE if result is used, FALSE otherwise
 176  *
 177  * DESCRIPTION: Check if a result object will be used by the parent
 178  *
 179  ******************************************************************************/
 180
 181 u8
 182 acpi_ds_is_result_used (
 183         union acpi_parse_object         *op,
 184         struct acpi_walk_state          *walk_state)
 185 {
 186         const struct acpi_opcode_info   *parent_info;
 187
 188         ACPI_FUNCTION_TRACE_PTR ("ds_is_result_used", op);
 189
 190
 191         /* Must have both an Op and a Result Object */
 192
 193         if (!op) {
 194                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Null Op\n"));
 195                 return_VALUE (TRUE);
 196         }
 197
 198         /*
 199          * We know that this operator is not a
 200          * Return() operator (would not come here.) The following code is the
 201          * optional support for a so-called "implicit return". Some AML code
 202          * assumes that the last value of the method is "implicitly" returned
 203          * to the caller. Just save the last result as the return value.
 204          * NOTE: this is optional because the ASL language does not actually
 205          * support this behavior.
 206          */
 207         (void) acpi_ds_do_implicit_return (walk_state->result_obj, walk_state, TRUE);
 208
 209         /*
 210          * Now determine if the parent will use the result
 211          *
 212          * If there is no parent, or the parent is a scope_op, we are executing
 213          * at the method level. An executing method typically has no parent,
 214          * since each method is parsed separately.  A method invoked externally
 215          * via execute_control_method has a scope_op as the parent.
 216          */
 217         if ((!op->common.parent) ||
 218                 (op->common.parent->common.aml_opcode == AML_SCOPE_OP)) {
 219                 /* No parent, the return value cannot possibly be used */
 220
 221                 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 222                         "At Method level, result of [%s] not used\n",
 223                         acpi_ps_get_opcode_name (op->common.aml_opcode)));
 224                 return_VALUE (FALSE);
 225         }
 226
 227         /* Get info on the parent. The root_op is AML_SCOPE */
 228
 229         parent_info = acpi_ps_get_opcode_info (op->common.parent->common.aml_opcode);
 230         if (parent_info->class == AML_CLASS_UNKNOWN) {
 231                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
 232                         "Unknown parent opcode. Op=%p\n", op));
 233                 return_VALUE (FALSE);
 234         }
 235
 236         /*
 237          * Decide what to do with the result based on the parent.  If
 238          * the parent opcode will not use the result, delete the object.
 239          * Otherwise leave it as is, it will be deleted when it is used
 240          * as an operand later.
 241          */
 242         switch (parent_info->class) {
 243         case AML_CLASS_CONTROL:
 244
 245                 switch (op->common.parent->common.aml_opcode) {
 246                 case AML_RETURN_OP:
 247
 248                         /* Never delete the return value associated with a return opcode */
 249
 250                         goto result_used;
 251
 252                 case AML_IF_OP:
 253                 case AML_WHILE_OP:
 254
 255                         /*
 256                          * If we are executing the predicate AND this is the predicate op,
 257                          * we will use the return value
 258                          */
 259                         if ((walk_state->control_state->common.state == ACPI_CONTROL_PREDICATE_EXECUTING) &&
 260                                 (walk_state->control_state->control.predicate_op == op)) {
 261                                 goto result_used;
 262                         }
 263                         break;
 264
 265                 default:
 266                         /* Ignore other control opcodes */
 267                         break;
 268                 }
 269
 270                 /* The general control opcode returns no result */
 271
 272                 goto result_not_used;
 273
 274
 275         case AML_CLASS_CREATE:
 276
 277                 /*
 278                  * These opcodes allow term_arg(s) as operands and therefore
 279                  * the operands can be method calls.  The result is used.
 280                  */
 281                 goto result_used;
 282
 283
 284         case AML_CLASS_NAMED_OBJECT:
 285
 286                 if ((op->common.parent->common.aml_opcode == AML_REGION_OP)      ||
 287                         (op->common.parent->common.aml_opcode == AML_DATA_REGION_OP) ||
 288                         (op->common.parent->common.aml_opcode == AML_PACKAGE_OP)     ||
 289                         (op->common.parent->common.aml_opcode == AML_VAR_PACKAGE_OP) ||
 290                         (op->common.parent->common.aml_opcode == AML_BUFFER_OP)      ||
 291                         (op->common.parent->common.aml_opcode == AML_INT_EVAL_SUBTREE_OP)) {
 292                         /*
 293                          * These opcodes allow term_arg(s) as operands and therefore
 294                          * the operands can be method calls.  The result is used.
 295                          */
 296                         goto result_used;
 297                 }
 298
 299                 goto result_not_used;
 300
 301
 302         default:
 303
 304                 /*
 305                  * In all other cases. the parent will actually use the return
 306                  * object, so keep it.
 307                  */
 308                 goto result_used;
 309         }
 310
 311
 312 result_used:
 313         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 314                 "Result of [%s] used by Parent [%s] Op=%p\n",
 315                 acpi_ps_get_opcode_name (op->common.aml_opcode),
 316                 acpi_ps_get_opcode_name (op->common.parent->common.aml_opcode), op));
 317
 318         return_VALUE (TRUE);
 319
 320
 321 result_not_used:
 322         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 323                 "Result of [%s] not used by Parent [%s] Op=%p\n",
 324                 acpi_ps_get_opcode_name (op->common.aml_opcode),
 325                 acpi_ps_get_opcode_name (op->common.parent->common.aml_opcode), op));
 326
 327         return_VALUE (FALSE);
 328 }
 329
 330
 331 /*******************************************************************************
 332  *
 333  * FUNCTION:    acpi_ds_delete_result_if_not_used
 334  *
 335  * PARAMETERS:  Op              - Current parse Op
 336  *              result_obj      - Result of the operation
 337  *              walk_state      - Current state
 338  *
 339  * RETURN:      Status
 340  *
 341  * DESCRIPTION: Used after interpretation of an opcode.  If there is an internal
 342  *              result descriptor, check if the parent opcode will actually use
 343  *              this result.  If not, delete the result now so that it will
 344  *              not become orphaned.
 345  *
 346  ******************************************************************************/
 347
 348 void
 349 acpi_ds_delete_result_if_not_used (
 350         union acpi_parse_object         *op,
 351         union acpi_operand_object       *result_obj,
 352         struct acpi_walk_state          *walk_state)
 353 {
 354         union acpi_operand_object       *obj_desc;
 355         acpi_status                     status;
 356
 357
 358         ACPI_FUNCTION_TRACE_PTR ("ds_delete_result_if_not_used", result_obj);
 359
 360
 361         if (!op) {
 362                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Null Op\n"));
 363                 return_VOID;
 364         }
 365
 366         if (!result_obj) {
 367                 return_VOID;
 368         }
 369
 370         if (!acpi_ds_is_result_used (op, walk_state)) {
 371                 /* Must pop the result stack (obj_desc should be equal to result_obj) */
 372
 373                 status = acpi_ds_result_pop (&obj_desc, walk_state);
 374                 if (ACPI_SUCCESS (status)) {
 375                         acpi_ut_remove_reference (result_obj);
 376                 }
 377         }
 378
 379         return_VOID;
 380 }
 381
 382
 383 /*******************************************************************************
 384  *
 385  * FUNCTION:    acpi_ds_resolve_operands
 386  *
 387  * PARAMETERS:  walk_state          - Current walk state with operands on stack
 388  *
 389  * RETURN:      Status
 390  *
 391  * DESCRIPTION: Resolve all operands to their values.  Used to prepare
 392  *              arguments to a control method invocation (a call from one
 393  *              method to another.)
 394  *
 395  ******************************************************************************/
 396
 397 acpi_status
 398 acpi_ds_resolve_operands (
 399         struct acpi_walk_state          *walk_state)
 400 {
 401         u32                             i;
 402         acpi_status                     status = AE_OK;
 403
 404
 405         ACPI_FUNCTION_TRACE_PTR ("ds_resolve_operands", walk_state);
 406
 407
 408         /*
 409          * Attempt to resolve each of the valid operands
 410          * Method arguments are passed by reference, not by value.  This means
 411          * that the actual objects are passed, not copies of the objects.
 412          */
 413         for (i = 0; i < walk_state->num_operands; i++) {
 414                 status = acpi_ex_resolve_to_value (&walk_state->operands[i], walk_state);
 415                 if (ACPI_FAILURE (status)) {
 416                         break;
 417                 }
 418         }
 419
 420         return_ACPI_STATUS (status);
 421 }
 422
 423
 424 /*******************************************************************************
 425  *
 426  * FUNCTION:    acpi_ds_clear_operands
 427  *
 428  * PARAMETERS:  walk_state          - Current walk state with operands on stack
 429  *
 430  * RETURN:      None
 431  *
 432  * DESCRIPTION: Clear all operands on the current walk state operand stack.
 433  *
 434  ******************************************************************************/
 435
 436 void
 437 acpi_ds_clear_operands (
 438         struct acpi_walk_state          *walk_state)
 439 {
 440         u32                             i;
 441
 442
 443         ACPI_FUNCTION_TRACE_PTR ("ds_clear_operands", walk_state);
 444
 445
 446         /* Remove a reference on each operand on the stack */
 447
 448         for (i = 0; i < walk_state->num_operands; i++) {
 449                 /*
 450                  * Remove a reference to all operands, including both
 451                  * "Arguments" and "Targets".
 452                  */
 453                 acpi_ut_remove_reference (walk_state->operands[i]);
 454                 walk_state->operands[i] = NULL;
 455         }
 456
 457         walk_state->num_operands = 0;
 458         return_VOID;
 459 }
 460 #endif
 461
 462
 463 /*******************************************************************************
 464  *
 465  * FUNCTION:    acpi_ds_create_operand
 466  *
 467  * PARAMETERS:  walk_state      - Current walk state
 468  *              Arg             - Parse object for the argument
 469  *              arg_index       - Which argument (zero based)
 470  *
 471  * RETURN:      Status
 472  *
 473  * DESCRIPTION: Translate a parse tree object that is an argument to an AML
 474  *              opcode to the equivalent interpreter object.  This may include
 475  *              looking up a name or entering a new name into the internal
 476  *              namespace.
 477  *
 478  ******************************************************************************/
 479
 480 acpi_status
 481 acpi_ds_create_operand (
 482         struct acpi_walk_state          *walk_state,
 483         union acpi_parse_object         *arg,
 484         u32                             arg_index)
 485 {
 486         acpi_status                     status = AE_OK;
 487         char                            *name_string;
 488         u32                             name_length;
 489         union acpi_operand_object       *obj_desc;
 490         union acpi_parse_object         *parent_op;
 491         u16                             opcode;
 492         acpi_interpreter_mode           interpreter_mode;
 493         const struct acpi_opcode_info   *op_info;
 494
 495
 496         ACPI_FUNCTION_TRACE_PTR ("ds_create_operand", arg);
 497
 498
 499         /* A valid name must be looked up in the namespace */
 500
 501         if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
 502                 (arg->common.value.string)) {
 503                 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n", arg));
 504
 505                 /* Get the entire name string from the AML stream */
 506
 507                 status = acpi_ex_get_name_string (ACPI_TYPE_ANY, arg->common.value.buffer,
 508                                   &name_string, &name_length);
 509
 510                 if (ACPI_FAILURE (status)) {
 511                         return_ACPI_STATUS (status);
 512                 }
 513
 514                 /* All prefixes have been handled, and the name is in name_string */
 515
 516                 /*
 517                  * Special handling for buffer_field declarations. This is a deferred
 518                  * opcode that unfortunately defines the field name as the last
 519                  * parameter instead of the first.  We get here when we are performing
 520                  * the deferred execution, so the actual name of the field is already
 521                  * in the namespace.  We don't want to attempt to look it up again
 522                  * because we may be executing in a different scope than where the
 523                  * actual opcode exists.
 524                  */
 525                 if ((walk_state->deferred_node) &&
 526                         (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD) &&
 527                         (arg_index != 0)) {
 528                         obj_desc = ACPI_CAST_PTR (
 529                                          union acpi_operand_object, walk_state->deferred_node);
 530                         status = AE_OK;
 531                 }
 532                 else    /* All other opcodes */ {
 533                         /*
 534                          * Differentiate between a namespace "create" operation
 535                          * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
 536                          * IMODE_EXECUTE) in order to support the creation of
 537                          * namespace objects during the execution of control methods.
 538                          */
 539                         parent_op = arg->common.parent;
 540                         op_info = acpi_ps_get_opcode_info (parent_op->common.aml_opcode);
 541                         if ((op_info->flags & AML_NSNODE) &&
 542                                 (parent_op->common.aml_opcode != AML_INT_METHODCALL_OP) &&
 543                                 (parent_op->common.aml_opcode != AML_REGION_OP) &&
 544                                 (parent_op->common.aml_opcode != AML_INT_NAMEPATH_OP)) {
 545                                 /* Enter name into namespace if not found */
 546
 547                                 interpreter_mode = ACPI_IMODE_LOAD_PASS2;
 548                         }
 549                         else {
 550                                 /* Return a failure if name not found */
 551
 552                                 interpreter_mode = ACPI_IMODE_EXECUTE;
 553                         }
 554
 555                         status = acpi_ns_lookup (walk_state->scope_info, name_string,
 556                                          ACPI_TYPE_ANY, interpreter_mode,
 557                                          ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
 558                                          walk_state,
 559                                          ACPI_CAST_INDIRECT_PTR (struct acpi_namespace_node, &obj_desc));
 560                         /*
 561                          * The only case where we pass through (ignore) a NOT_FOUND
 562                          * error is for the cond_ref_of opcode.
 563                          */
 564                         if (status == AE_NOT_FOUND) {
 565                                 if (parent_op->common.aml_opcode == AML_COND_REF_OF_OP) {
 566                                         /*
 567                                          * For the Conditional Reference op, it's OK if
 568                                          * the name is not found;  We just need a way to
 569                                          * indicate this to the interpreter, set the
 570                                          * object to the root
 571                                          */
 572                                         obj_desc = ACPI_CAST_PTR (
 573                                                          union acpi_operand_object, acpi_gbl_root_node);
 574                                         status = AE_OK;
 575                                 }
 576                                 else {
 577                                         /*
 578                                          * We just plain didn't find it -- which is a
 579                                          * very serious error at this point
 580                                          */
 581                                         status = AE_AML_NAME_NOT_FOUND;
 582                                 }
 583                         }
 584
 585                         if (ACPI_FAILURE (status)) {
 586                                 ACPI_REPORT_NSERROR (name_string, status);
 587                         }
 588                 }
 589
 590                 /* Free the namestring created above */
 591
 592                 ACPI_MEM_FREE (name_string);
 593
 594                 /* Check status from the lookup */
 595
 596                 if (ACPI_FAILURE (status)) {
 597                         return_ACPI_STATUS (status);
 598                 }
 599
 600                 /* Put the resulting object onto the current object stack */
 601
 602                 status = acpi_ds_obj_stack_push (obj_desc, walk_state);
 603                 if (ACPI_FAILURE (status)) {
 604                         return_ACPI_STATUS (status);
 605                 }
 606                 ACPI_DEBUGGER_EXEC (acpi_db_display_argument_object (obj_desc, walk_state));
 607         }
 608         else {
 609                 /* Check for null name case */
 610
 611                 if (arg->common.aml_opcode == AML_INT_NAMEPATH_OP) {
 612                         /*
 613                          * If the name is null, this means that this is an
 614                          * optional result parameter that was not specified
 615                          * in the original ASL.  Create a Zero Constant for a
 616                          * placeholder.  (Store to a constant is a Noop.)
 617                          */
 618                         opcode = AML_ZERO_OP;       /* Has no arguments! */
 619
 620                         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 621                                 "Null namepath: Arg=%p\n", arg));
 622                 }
 623                 else {
 624                         opcode = arg->common.aml_opcode;
 625                 }
 626
 627                 /* Get the object type of the argument */
 628
 629                 op_info = acpi_ps_get_opcode_info (opcode);
 630                 if (op_info->object_type == ACPI_TYPE_INVALID) {
 631                         return_ACPI_STATUS (AE_NOT_IMPLEMENTED);
 632                 }
 633
 634                 if (op_info->flags & AML_HAS_RETVAL) {
 635                         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 636                                 "Argument previously created, already stacked \n"));
 637
 638                         ACPI_DEBUGGER_EXEC (acpi_db_display_argument_object (
 639                                 walk_state->operands [walk_state->num_operands - 1], walk_state));
 640
 641                         /*
 642                          * Use value that was already previously returned
 643                          * by the evaluation of this argument
 644                          */
 645                         status = acpi_ds_result_pop_from_bottom (&obj_desc, walk_state);
 646                         if (ACPI_FAILURE (status)) {
 647                                 /*
 648                                  * Only error is underflow, and this indicates
 649                                  * a missing or null operand!
 650                                  */
 651                                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
 652                                         "Missing or null operand, %s\n",
 653                                         acpi_format_exception (status)));
 654                                 return_ACPI_STATUS (status);
 655                         }
 656                 }
 657                 else {
 658                         /* Create an ACPI_INTERNAL_OBJECT for the argument */
 659
 660                         obj_desc = acpi_ut_create_internal_object (op_info->object_type);
 661                         if (!obj_desc) {
 662                                 return_ACPI_STATUS (AE_NO_MEMORY);
 663                         }
 664
 665                         /* Initialize the new object */
 666
 667                         status = acpi_ds_init_object_from_op (
 668                                          walk_state, arg, opcode, &obj_desc);
 669                         if (ACPI_FAILURE (status)) {
 670                                 acpi_ut_delete_object_desc (obj_desc);
 671                                 return_ACPI_STATUS (status);
 672                         }
 673                 }
 674
 675                 /* Put the operand object on the object stack */
 676
 677                 status = acpi_ds_obj_stack_push (obj_desc, walk_state);
 678                 if (ACPI_FAILURE (status)) {
 679                         return_ACPI_STATUS (status);
 680                 }
 681
 682                 ACPI_DEBUGGER_EXEC (acpi_db_display_argument_object (obj_desc, walk_state));
 683         }
 684
 685         return_ACPI_STATUS (AE_OK);
 686 }
 687
 688
 689 /*******************************************************************************
 690  *
 691  * FUNCTION:    acpi_ds_create_operands
 692  *
 693  * PARAMETERS:  walk_state          - Current state
 694  *              first_arg           - First argument of a parser argument tree
 695  *
 696  * RETURN:      Status
 697  *
 698  * DESCRIPTION: Convert an operator's arguments from a parse tree format to
 699  *              namespace objects and place those argument object on the object
 700  *              stack in preparation for evaluation by the interpreter.
 701  *
 702  ******************************************************************************/
 703
 704 acpi_status
 705 acpi_ds_create_operands (
 706         struct acpi_walk_state          *walk_state,
 707         union acpi_parse_object         *first_arg)
 708 {
 709         acpi_status                     status = AE_OK;
 710         union acpi_parse_object         *arg;
 711         u32                             arg_count = 0;
 712
 713
 714         ACPI_FUNCTION_TRACE_PTR ("ds_create_operands", first_arg);
 715
 716
 717         /* For all arguments in the list... */
 718
 719         arg = first_arg;
 720         while (arg) {
 721                 status = acpi_ds_create_operand (walk_state, arg, arg_count);
 722                 if (ACPI_FAILURE (status)) {
 723                         goto cleanup;
 724                 }
 725
 726                 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Arg #%d (%p) done, Arg1=%p\n",
 727                         arg_count, arg, first_arg));
 728
 729                 /* Move on to next argument, if any */
 730
 731                 arg = arg->common.next;
 732                 arg_count++;
 733         }
 734
 735         return_ACPI_STATUS (status);
 736
 737
 738 cleanup:
 739         /*
 740          * We must undo everything done above; meaning that we must
 741          * pop everything off of the operand stack and delete those
 742          * objects
 743          */
 744         (void) acpi_ds_obj_stack_pop_and_delete (arg_count, walk_state);
 745
 746         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "While creating Arg %d - %s\n",
 747                 (arg_count + 1), acpi_format_exception (status)));
 748         return_ACPI_STATUS (status);
 749 }
 750
 751