drivers/acpi/dispatcher/dsmthdat.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: dsmthdat - control method arguments and local variables
   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/acdispat.h>
  47 #include <acpi/amlcode.h>
  48 #include <acpi/acnamesp.h>
  49 #include <acpi/acinterp.h>
  50
  51
  52 #define _COMPONENT          ACPI_DISPATCHER
  53          ACPI_MODULE_NAME    ("dsmthdat")
  54
  55
  56 /*******************************************************************************
  57  *
  58  * FUNCTION:    acpi_ds_method_data_init
  59  *
  60  * PARAMETERS:  walk_state          - Current walk state object
  61  *
  62  * RETURN:      Status
  63  *
  64  * DESCRIPTION: Initialize the data structures that hold the method's arguments
  65  *              and locals.  The data struct is an array of NTEs for each.
  66  *              This allows ref_of and de_ref_of to work properly for these
  67  *              special data types.
  68  *
  69  * NOTES:       walk_state fields are initialized to zero by the
  70  *              ACPI_MEM_CALLOCATE().
  71  *
  72  *              A pseudo-Namespace Node is assigned to each argument and local
  73  *              so that ref_of() can return a pointer to the Node.
  74  *
  75  ******************************************************************************/
  76
  77 void
  78 acpi_ds_method_data_init (
  79         struct acpi_walk_state          *walk_state)
  80 {
  81         u32                             i;
  82
  83
  84         ACPI_FUNCTION_TRACE ("ds_method_data_init");
  85
  86
  87         /* Init the method arguments */
  88
  89         for (i = 0; i < ACPI_METHOD_NUM_ARGS; i++) {
  90                 ACPI_MOVE_32_TO_32 (&walk_state->arguments[i].name,
  91                                    NAMEOF_ARG_NTE);
  92                 walk_state->arguments[i].name.integer |= (i << 24);
  93                 walk_state->arguments[i].descriptor   = ACPI_DESC_TYPE_NAMED;
  94                 walk_state->arguments[i].type         = ACPI_TYPE_ANY;
  95                 walk_state->arguments[i].flags        = ANOBJ_END_OF_PEER_LIST | ANOBJ_METHOD_ARG;
  96         }
  97
  98         /* Init the method locals */
  99
 100         for (i = 0; i < ACPI_METHOD_NUM_LOCALS; i++) {
 101                 ACPI_MOVE_32_TO_32 (&walk_state->local_variables[i].name,
 102                                    NAMEOF_LOCAL_NTE);
 103
 104                 walk_state->local_variables[i].name.integer |= (i << 24);
 105                 walk_state->local_variables[i].descriptor  = ACPI_DESC_TYPE_NAMED;
 106                 walk_state->local_variables[i].type        = ACPI_TYPE_ANY;
 107                 walk_state->local_variables[i].flags       = ANOBJ_END_OF_PEER_LIST | ANOBJ_METHOD_LOCAL;
 108         }
 109
 110         return_VOID;
 111 }
 112
 113
 114 /*******************************************************************************
 115  *
 116  * FUNCTION:    acpi_ds_method_data_delete_all
 117  *
 118  * PARAMETERS:  walk_state          - Current walk state object
 119  *
 120  * RETURN:      None
 121  *
 122  * DESCRIPTION: Delete method locals and arguments.  Arguments are only
 123  *              deleted if this method was called from another method.
 124  *
 125  ******************************************************************************/
 126
 127 void
 128 acpi_ds_method_data_delete_all (
 129         struct acpi_walk_state          *walk_state)
 130 {
 131         u32                             index;
 132
 133
 134         ACPI_FUNCTION_TRACE ("ds_method_data_delete_all");
 135
 136
 137         /* Detach the locals */
 138
 139         for (index = 0; index < ACPI_METHOD_NUM_LOCALS; index++) {
 140                 if (walk_state->local_variables[index].object) {
 141                         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Deleting Local%d=%p\n",
 142                                         index, walk_state->local_variables[index].object));
 143
 144                         /* Detach object (if present) and remove a reference */
 145
 146                         acpi_ns_detach_object (&walk_state->local_variables[index]);
 147                 }
 148         }
 149
 150         /* Detach the arguments */
 151
 152         for (index = 0; index < ACPI_METHOD_NUM_ARGS; index++) {
 153                 if (walk_state->arguments[index].object) {
 154                         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Deleting Arg%d=%p\n",
 155                                         index, walk_state->arguments[index].object));
 156
 157                         /* Detach object (if present) and remove a reference */
 158
 159                         acpi_ns_detach_object (&walk_state->arguments[index]);
 160                 }
 161         }
 162
 163         return_VOID;
 164 }
 165
 166
 167 /*******************************************************************************
 168  *
 169  * FUNCTION:    acpi_ds_method_data_init_args
 170  *
 171  * PARAMETERS:  *Params         - Pointer to a parameter list for the method
 172  *              max_param_count - The arg count for this method
 173  *              walk_state      - Current walk state object
 174  *
 175  * RETURN:      Status
 176  *
 177  * DESCRIPTION: Initialize arguments for a method.  The parameter list is a list
 178  *              of ACPI operand objects, either null terminated or whose length
 179  *              is defined by max_param_count.
 180  *
 181  ******************************************************************************/
 182
 183 acpi_status
 184 acpi_ds_method_data_init_args (
 185         union acpi_operand_object       **params,
 186         u32                             max_param_count,
 187         struct acpi_walk_state          *walk_state)
 188 {
 189         acpi_status                     status;
 190         u32                             index = 0;
 191
 192
 193         ACPI_FUNCTION_TRACE_PTR ("ds_method_data_init_args", params);
 194
 195
 196         if (!params) {
 197                 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "No param list passed to method\n"));
 198                 return_ACPI_STATUS (AE_OK);
 199         }
 200
 201         /* Copy passed parameters into the new method stack frame  */
 202
 203         while ((index < ACPI_METHOD_NUM_ARGS) && (index < max_param_count) && params[index]) {
 204                 /*
 205                  * A valid parameter.
 206                  * Store the argument in the method/walk descriptor.
 207                  * Do not copy the arg in order to implement call by reference
 208                  */
 209                 status = acpi_ds_method_data_set_value (AML_ARG_OP, index, params[index], walk_state);
 210                 if (ACPI_FAILURE (status)) {
 211                         return_ACPI_STATUS (status);
 212                 }
 213
 214                 index++;
 215         }
 216
 217         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "%d args passed to method\n", index));
 218         return_ACPI_STATUS (AE_OK);
 219 }
 220
 221
 222 /*******************************************************************************
 223  *
 224  * FUNCTION:    acpi_ds_method_data_get_node
 225  *
 226  * PARAMETERS:  Opcode              - Either AML_LOCAL_OP or AML_ARG_OP
 227  *              Index               - which local_var or argument whose type
 228  *                                      to get
 229  *              walk_state          - Current walk state object
 230  *
 231  * RETURN:      Get the Node associated with a local or arg.
 232  *
 233  ******************************************************************************/
 234
 235 acpi_status
 236 acpi_ds_method_data_get_node (
 237         u16                             opcode,
 238         u32                             index,
 239         struct acpi_walk_state          *walk_state,
 240         struct acpi_namespace_node      **node)
 241 {
 242         ACPI_FUNCTION_TRACE ("ds_method_data_get_node");
 243
 244
 245         /*
 246          * Method Locals and Arguments are supported
 247          */
 248         switch (opcode) {
 249         case AML_LOCAL_OP:
 250
 251                 if (index > ACPI_METHOD_MAX_LOCAL) {
 252                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Local index %d is invalid (max %d)\n",
 253                                 index, ACPI_METHOD_MAX_LOCAL));
 254                         return_ACPI_STATUS (AE_AML_INVALID_INDEX);
 255                 }
 256
 257                 /* Return a pointer to the pseudo-node */
 258
 259                 *node = &walk_state->local_variables[index];
 260                 break;
 261
 262         case AML_ARG_OP:
 263
 264                 if (index > ACPI_METHOD_MAX_ARG) {
 265                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Arg index %d is invalid (max %d)\n",
 266                                 index, ACPI_METHOD_MAX_ARG));
 267                         return_ACPI_STATUS (AE_AML_INVALID_INDEX);
 268                 }
 269
 270                 /* Return a pointer to the pseudo-node */
 271
 272                 *node = &walk_state->arguments[index];
 273                 break;
 274
 275         default:
 276                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Opcode %d is invalid\n", opcode));
 277                 return_ACPI_STATUS (AE_AML_BAD_OPCODE);
 278         }
 279
 280         return_ACPI_STATUS (AE_OK);
 281 }
 282
 283
 284 /*******************************************************************************
 285  *
 286  * FUNCTION:    acpi_ds_method_data_set_value
 287  *
 288  * PARAMETERS:  Opcode              - Either AML_LOCAL_OP or AML_ARG_OP
 289  *              Index               - which local_var or argument to get
 290  *              Object              - Object to be inserted into the stack entry
 291  *              walk_state          - Current walk state object
 292  *
 293  * RETURN:      Status
 294  *
 295  * DESCRIPTION: Insert an object onto the method stack at entry Opcode:Index.
 296  *              Note: There is no "implicit conversion" for locals.
 297  *
 298  ******************************************************************************/
 299
 300 acpi_status
 301 acpi_ds_method_data_set_value (
 302         u16                             opcode,
 303         u32                             index,
 304         union acpi_operand_object       *object,
 305         struct acpi_walk_state          *walk_state)
 306 {
 307         acpi_status                     status;
 308         struct acpi_namespace_node      *node;
 309
 310
 311         ACPI_FUNCTION_TRACE ("ds_method_data_set_value");
 312
 313
 314         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
 315                 "new_obj %p Opcode %X, Refs=%d [%s]\n", object,
 316                 opcode, object->common.reference_count,
 317                 acpi_ut_get_type_name (object->common.type)));
 318
 319         /* Get the namespace node for the arg/local */
 320
 321         status = acpi_ds_method_data_get_node (opcode, index, walk_state, &node);
 322         if (ACPI_FAILURE (status)) {
 323                 return_ACPI_STATUS (status);
 324         }
 325
 326         /*
 327          * Increment ref count so object can't be deleted while installed.
 328          * NOTE: We do not copy the object in order to preserve the call by
 329          * reference semantics of ACPI Control Method invocation.
 330          * (See ACPI specification 2.0_c)
 331          */
 332         acpi_ut_add_reference (object);
 333
 334         /* Install the object */
 335
 336         node->object = object;
 337         return_ACPI_STATUS (status);
 338 }
 339
 340
 341 /*******************************************************************************
 342  *
 343  * FUNCTION:    acpi_ds_method_data_get_type
 344  *
 345  * PARAMETERS:  Opcode              - Either AML_LOCAL_OP or AML_ARG_OP
 346  *              Index               - which local_var or argument whose type
 347  *                                      to get
 348  *              walk_state          - Current walk state object
 349  *
 350  * RETURN:      Data type of current value of the selected Arg or Local
 351  *
 352  ******************************************************************************/
 353 #ifdef ACPI_FUTURE_USAGE
 354 acpi_object_type
 355 acpi_ds_method_data_get_type (
 356         u16                             opcode,
 357         u32                             index,
 358         struct acpi_walk_state          *walk_state)
 359 {
 360         acpi_status                     status;
 361         struct acpi_namespace_node      *node;
 362         union acpi_operand_object       *object;
 363
 364
 365         ACPI_FUNCTION_TRACE ("ds_method_data_get_type");
 366
 367
 368         /* Get the namespace node for the arg/local */
 369
 370         status = acpi_ds_method_data_get_node (opcode, index, walk_state, &node);
 371         if (ACPI_FAILURE (status)) {
 372                 return_VALUE ((ACPI_TYPE_NOT_FOUND));
 373         }
 374
 375         /* Get the object */
 376
 377         object = acpi_ns_get_attached_object (node);
 378         if (!object) {
 379                 /* Uninitialized local/arg, return TYPE_ANY */
 380
 381                 return_VALUE (ACPI_TYPE_ANY);
 382         }
 383
 384         /* Get the object type */
 385
 386         return_VALUE (ACPI_GET_OBJECT_TYPE (object));
 387 }
 388 #endif  /*  ACPI_FUTURE_USAGE  */
 389
 390
 391 /*******************************************************************************
 392  *
 393  * FUNCTION:    acpi_ds_method_data_get_value
 394  *
 395  * PARAMETERS:  Opcode              - Either AML_LOCAL_OP or AML_ARG_OP
 396  *              Index               - which local_var or argument to get
 397  *              walk_state          - Current walk state object
 398  *              *dest_desc          - Ptr to Descriptor into which selected Arg
 399  *                                    or Local value should be copied
 400  *
 401  * RETURN:      Status
 402  *
 403  * DESCRIPTION: Retrieve value of selected Arg or Local from the method frame
 404  *              at the current top of the method stack.
 405  *              Used only in acpi_ex_resolve_to_value().
 406  *
 407  ******************************************************************************/
 408
 409 acpi_status
 410 acpi_ds_method_data_get_value (
 411         u16                             opcode,
 412         u32                             index,
 413         struct acpi_walk_state          *walk_state,
 414         union acpi_operand_object       **dest_desc)
 415 {
 416         acpi_status                     status;
 417         struct acpi_namespace_node      *node;
 418         union acpi_operand_object       *object;
 419
 420
 421         ACPI_FUNCTION_TRACE ("ds_method_data_get_value");
 422
 423
 424         /* Validate the object descriptor */
 425
 426         if (!dest_desc) {
 427                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Null object descriptor pointer\n"));
 428                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 429         }
 430
 431         /* Get the namespace node for the arg/local */
 432
 433         status = acpi_ds_method_data_get_node (opcode, index, walk_state, &node);
 434         if (ACPI_FAILURE (status)) {
 435                 return_ACPI_STATUS (status);
 436         }
 437
 438         /* Get the object from the node */
 439
 440         object = node->object;
 441
 442         /* Examine the returned object, it must be valid. */
 443
 444         if (!object) {
 445                 /*
 446                  * Index points to uninitialized object.
 447                  * This means that either 1) The expected argument was
 448                  * not passed to the method, or 2) A local variable
 449                  * was referenced by the method (via the ASL)
 450                  * before it was initialized.  Either case is an error.
 451                  */
 452
 453                 /* If slack enabled, init the local_x/arg_x to an Integer of value zero */
 454
 455                 if (acpi_gbl_enable_interpreter_slack) {
 456                         object = acpi_ut_create_internal_object (ACPI_TYPE_INTEGER);
 457                         if (!object) {
 458                                 return_ACPI_STATUS (AE_NO_MEMORY);
 459                         }
 460
 461                         object->integer.value = 0;
 462                         node->object = object;
 463                 }
 464
 465                 /* Otherwise, return the error */
 466
 467                 else switch (opcode) {
 468                 case AML_ARG_OP:
 469
 470                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Uninitialized Arg[%d] at node %p\n",
 471                                 index, node));
 472
 473                         return_ACPI_STATUS (AE_AML_UNINITIALIZED_ARG);
 474
 475                 case AML_LOCAL_OP:
 476
 477                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Uninitialized Local[%d] at node %p\n",
 478                                 index, node));
 479
 480                         return_ACPI_STATUS (AE_AML_UNINITIALIZED_LOCAL);
 481
 482                 default:
 483                         ACPI_REPORT_ERROR (("Not Arg/Local opcode: %X\n", opcode));
 484                         return_ACPI_STATUS (AE_AML_INTERNAL);
 485                 }
 486         }
 487
 488         /*
 489          * The Index points to an initialized and valid object.
 490          * Return an additional reference to the object
 491          */
 492         *dest_desc = object;
 493         acpi_ut_add_reference (object);
 494
 495         return_ACPI_STATUS (AE_OK);
 496 }
 497
 498
 499 /*******************************************************************************
 500  *
 501  * FUNCTION:    acpi_ds_method_data_delete_value
 502  *
 503  * PARAMETERS:  Opcode              - Either AML_LOCAL_OP or AML_ARG_OP
 504  *              Index               - which local_var or argument to delete
 505  *              walk_state          - Current walk state object
 506  *
 507  * RETURN:      None
 508  *
 509  * DESCRIPTION: Delete the entry at Opcode:Index on the method stack.  Inserts
 510  *              a null into the stack slot after the object is deleted.
 511  *
 512  ******************************************************************************/
 513
 514 void
 515 acpi_ds_method_data_delete_value (
 516         u16                             opcode,
 517         u32                             index,
 518         struct acpi_walk_state          *walk_state)
 519 {
 520         acpi_status                     status;
 521         struct acpi_namespace_node      *node;
 522         union acpi_operand_object       *object;
 523
 524
 525         ACPI_FUNCTION_TRACE ("ds_method_data_delete_value");
 526
 527
 528         /* Get the namespace node for the arg/local */
 529
 530         status = acpi_ds_method_data_get_node (opcode, index, walk_state, &node);
 531         if (ACPI_FAILURE (status)) {
 532                 return_VOID;
 533         }
 534
 535         /* Get the associated object */
 536
 537         object = acpi_ns_get_attached_object (node);
 538
 539         /*
 540          * Undefine the Arg or Local by setting its descriptor
 541          * pointer to NULL. Locals/Args can contain both
 542          * ACPI_OPERAND_OBJECTS and ACPI_NAMESPACE_NODEs
 543          */
 544         node->object = NULL;
 545
 546         if ((object) &&
 547                 (ACPI_GET_DESCRIPTOR_TYPE (object) == ACPI_DESC_TYPE_OPERAND)) {
 548                 /*
 549                  * There is a valid object.
 550                  * Decrement the reference count by one to balance the
 551                  * increment when the object was stored.
 552                  */
 553                 acpi_ut_remove_reference (object);
 554         }
 555
 556         return_VOID;
 557 }
 558
 559
 560 /*******************************************************************************
 561  *
 562  * FUNCTION:    acpi_ds_store_object_to_local
 563  *
 564  * PARAMETERS:  Opcode              - Either AML_LOCAL_OP or AML_ARG_OP
 565  *              Index               - which local_var or argument to set
 566  *              obj_desc            - Value to be stored
 567  *              walk_state          - Current walk state
 568  *
 569  * RETURN:      Status
 570  *
 571  * DESCRIPTION: Store a value in an Arg or Local.  The obj_desc is installed
 572  *              as the new value for the Arg or Local and the reference count
 573  *              for obj_desc is incremented.
 574  *
 575  ******************************************************************************/
 576
 577 acpi_status
 578 acpi_ds_store_object_to_local (
 579         u16                             opcode,
 580         u32                             index,
 581         union acpi_operand_object       *obj_desc,
 582         struct acpi_walk_state          *walk_state)
 583 {
 584         acpi_status                     status;
 585         struct acpi_namespace_node      *node;
 586         union acpi_operand_object       *current_obj_desc;
 587         union acpi_operand_object       *new_obj_desc;
 588
 589
 590         ACPI_FUNCTION_TRACE ("ds_store_object_to_local");
 591         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Opcode=%X Index=%d Obj=%p\n",
 592                 opcode, index, obj_desc));
 593
 594         /* Parameter validation */
 595
 596         if (!obj_desc) {
 597                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 598         }
 599
 600         /* Get the namespace node for the arg/local */
 601
 602         status = acpi_ds_method_data_get_node (opcode, index, walk_state, &node);
 603         if (ACPI_FAILURE (status)) {
 604                 return_ACPI_STATUS (status);
 605         }
 606
 607         current_obj_desc = acpi_ns_get_attached_object (node);
 608         if (current_obj_desc == obj_desc) {
 609                 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Obj=%p already installed!\n",
 610                         obj_desc));
 611                 return_ACPI_STATUS (status);
 612         }
 613
 614         /*
 615          * If the reference count on the object is more than one, we must
 616          * take a copy of the object before we store.  A reference count
 617          * of exactly 1 means that the object was just created during the
 618          * evaluation of an expression, and we can safely use it since it
 619          * is not used anywhere else.
 620          */
 621         new_obj_desc = obj_desc;
 622         if (obj_desc->common.reference_count > 1) {
 623                 status = acpi_ut_copy_iobject_to_iobject (obj_desc, &new_obj_desc, walk_state);
 624                 if (ACPI_FAILURE (status)) {
 625                         return_ACPI_STATUS (status);
 626                 }
 627         }
 628
 629         /*
 630          * If there is an object already in this slot, we either
 631          * have to delete it, or if this is an argument and there
 632          * is an object reference stored there, we have to do
 633          * an indirect store!
 634          */
 635         if (current_obj_desc) {
 636                 /*
 637                  * Check for an indirect store if an argument
 638                  * contains an object reference (stored as an Node).
 639                  * We don't allow this automatic dereferencing for
 640                  * locals, since a store to a local should overwrite
 641                  * anything there, including an object reference.
 642                  *
 643                  * If both Arg0 and Local0 contain ref_of (Local4):
 644                  *
 645                  * Store (1, Arg0)             - Causes indirect store to local4
 646                  * Store (1, Local0)           - Stores 1 in local0, overwriting
 647                  *                                  the reference to local4
 648                  * Store (1, de_refof (Local0)) - Causes indirect store to local4
 649                  *
 650                  * Weird, but true.
 651                  */
 652                 if (opcode == AML_ARG_OP) {
 653                         /*
 654                          * Make sure that the object is the correct type.  This may be overkill, but
 655                          * it is here because references were NS nodes in the past.  Now they are
 656                          * operand objects of type Reference.
 657                          */
 658                         if (ACPI_GET_DESCRIPTOR_TYPE (current_obj_desc) != ACPI_DESC_TYPE_OPERAND) {
 659                                 ACPI_REPORT_ERROR (("Invalid descriptor type while storing to method arg: [%s]\n",
 660                                                 acpi_ut_get_descriptor_name (current_obj_desc)));
 661                                 return_ACPI_STATUS (AE_AML_INTERNAL);
 662                         }
 663
 664                         /*
 665                          * If we have a valid reference object that came from ref_of(), do the
 666                          * indirect store
 667                          */
 668                         if ((current_obj_desc->common.type == ACPI_TYPE_LOCAL_REFERENCE) &&
 669                                 (current_obj_desc->reference.opcode == AML_REF_OF_OP)) {
 670                                 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
 671                                                 "Arg (%p) is an obj_ref(Node), storing in node %p\n",
 672                                                 new_obj_desc, current_obj_desc));
 673
 674                                 /*
 675                                  * Store this object to the Node (perform the indirect store)
 676                                  * NOTE: No implicit conversion is performed, as per the ACPI
 677                                  * specification rules on storing to Locals/Args.
 678                                  */
 679                                 status = acpi_ex_store_object_to_node (new_obj_desc,
 680                                                  current_obj_desc->reference.object, walk_state,
 681                                                  ACPI_NO_IMPLICIT_CONVERSION);
 682
 683                                 /* Remove local reference if we copied the object above */
 684
 685                                 if (new_obj_desc != obj_desc) {
 686                                         acpi_ut_remove_reference (new_obj_desc);
 687                                 }
 688                                 return_ACPI_STATUS (status);
 689                         }
 690                 }
 691
 692                 /*
 693                  * Delete the existing object
 694                  * before storing the new one
 695                  */
 696                 acpi_ds_method_data_delete_value (opcode, index, walk_state);
 697         }
 698
 699         /*
 700          * Install the Obj descriptor (*new_obj_desc) into
 701          * the descriptor for the Arg or Local.
 702          * (increments the object reference count by one)
 703          */
 704         status = acpi_ds_method_data_set_value (opcode, index, new_obj_desc, walk_state);
 705
 706         /* Remove local reference if we copied the object above */
 707
 708         if (new_obj_desc != obj_desc) {
 709                 acpi_ut_remove_reference (new_obj_desc);
 710         }
 711
 712         return_ACPI_STATUS (status);
 713 }
 714
 715