git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/acpica/dsopcode.c

   1 /******************************************************************************
   2  *
   3  * Module Name: dsopcode - Dispatcher Op Region support and handling of
   4  *                         "control" opcodes
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2008, Intel Corp.
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions, and the following disclaimer,
  17  *    without modification.
  18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19  *    substantially similar to the "NO WARRANTY" disclaimer below
  20  *    ("Disclaimer") and any redistribution must be conditioned upon
  21  *    including a substantially similar Disclaimer requirement for further
  22  *    binary redistribution.
  23  * 3. Neither the names of the above-listed copyright holders nor the names
  24  *    of any contributors may be used to endorse or promote products derived
  25  *    from this software without specific prior written permission.
  26  *
  27  * Alternatively, this software may be distributed under the terms of the
  28  * GNU General Public License ("GPL") version 2 as published by the Free
  29  * Software Foundation.
  30  *
  31  * NO WARRANTY
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42  * POSSIBILITY OF SUCH DAMAGES.
  43  */
  44
  45 #include <acpi/acpi.h>
  46 #include "accommon.h"
  47 #include "acparser.h"
  48 #include "amlcode.h"
  49 #include "acdispat.h"
  50 #include "acinterp.h"
  51 #include "acnamesp.h"
  52 #include "acevents.h"
  53 #include "actables.h"
  54
  55 #define _COMPONENT          ACPI_DISPATCHER
  56 ACPI_MODULE_NAME("dsopcode")
  57
  58 /* Local prototypes */
  59 static acpi_status
  60 acpi_ds_execute_arguments(struct acpi_namespace_node *node,
  61                           struct acpi_namespace_node *scope_node,
  62                           u32 aml_length, u8 * aml_start);
  63
  64 static acpi_status
  65 acpi_ds_init_buffer_field(u16 aml_opcode,
  66                           union acpi_operand_object *obj_desc,
  67                           union acpi_operand_object *buffer_desc,
  68                           union acpi_operand_object *offset_desc,
  69                           union acpi_operand_object *length_desc,
  70                           union acpi_operand_object *result_desc);
  71
  72 /*******************************************************************************
  73  *
  74  * FUNCTION:    acpi_ds_execute_arguments
  75  *
  76  * PARAMETERS:  Node                - Object NS node
  77  *              scope_node          - Parent NS node
  78  *              aml_length          - Length of executable AML
  79  *              aml_start           - Pointer to the AML
  80  *
  81  * RETURN:      Status.
  82  *
  83  * DESCRIPTION: Late (deferred) execution of region or field arguments
  84  *
  85  ******************************************************************************/
  86
  87 static acpi_status
  88 acpi_ds_execute_arguments(struct acpi_namespace_node *node,
  89                           struct acpi_namespace_node *scope_node,
  90                           u32 aml_length, u8 * aml_start)
  91 {
  92         acpi_status status;
  93         union acpi_parse_object *op;
  94         struct acpi_walk_state *walk_state;
  95
  96         ACPI_FUNCTION_TRACE(ds_execute_arguments);
  97
  98         /*
  99          * Allocate a new parser op to be the root of the parsed tree
 100          */
 101         op = acpi_ps_alloc_op(AML_INT_EVAL_SUBTREE_OP);
 102         if (!op) {
 103                 return_ACPI_STATUS(AE_NO_MEMORY);
 104         }
 105
 106         /* Save the Node for use in acpi_ps_parse_aml */
 107
 108         op->common.node = scope_node;
 109
 110         /* Create and initialize a new parser state */
 111
 112         walk_state = acpi_ds_create_walk_state(0, NULL, NULL, NULL);
 113         if (!walk_state) {
 114                 status = AE_NO_MEMORY;
 115                 goto cleanup;
 116         }
 117
 118         status = acpi_ds_init_aml_walk(walk_state, op, NULL, aml_start,
 119                                        aml_length, NULL, ACPI_IMODE_LOAD_PASS1);
 120         if (ACPI_FAILURE(status)) {
 121                 acpi_ds_delete_walk_state(walk_state);
 122                 goto cleanup;
 123         }
 124
 125         /* Mark this parse as a deferred opcode */
 126
 127         walk_state->parse_flags = ACPI_PARSE_DEFERRED_OP;
 128         walk_state->deferred_node = node;
 129
 130         /* Pass1: Parse the entire declaration */
 131
 132         status = acpi_ps_parse_aml(walk_state);
 133         if (ACPI_FAILURE(status)) {
 134                 goto cleanup;
 135         }
 136
 137         /* Get and init the Op created above */
 138
 139         op->common.node = node;
 140         acpi_ps_delete_parse_tree(op);
 141
 142         /* Evaluate the deferred arguments */
 143
 144         op = acpi_ps_alloc_op(AML_INT_EVAL_SUBTREE_OP);
 145         if (!op) {
 146                 return_ACPI_STATUS(AE_NO_MEMORY);
 147         }
 148
 149         op->common.node = scope_node;
 150
 151         /* Create and initialize a new parser state */
 152
 153         walk_state = acpi_ds_create_walk_state(0, NULL, NULL, NULL);
 154         if (!walk_state) {
 155                 status = AE_NO_MEMORY;
 156                 goto cleanup;
 157         }
 158
 159         /* Execute the opcode and arguments */
 160
 161         status = acpi_ds_init_aml_walk(walk_state, op, NULL, aml_start,
 162                                        aml_length, NULL, ACPI_IMODE_EXECUTE);
 163         if (ACPI_FAILURE(status)) {
 164                 acpi_ds_delete_walk_state(walk_state);
 165                 goto cleanup;
 166         }
 167
 168         /* Mark this execution as a deferred opcode */
 169
 170         walk_state->deferred_node = node;
 171         status = acpi_ps_parse_aml(walk_state);
 172
 173       cleanup:
 174         acpi_ps_delete_parse_tree(op);
 175         return_ACPI_STATUS(status);
 176 }
 177
 178 /*******************************************************************************
 179  *
 180  * FUNCTION:    acpi_ds_get_buffer_field_arguments
 181  *
 182  * PARAMETERS:  obj_desc        - A valid buffer_field object
 183  *
 184  * RETURN:      Status.
 185  *
 186  * DESCRIPTION: Get buffer_field Buffer and Index. This implements the late
 187  *              evaluation of these field attributes.
 188  *
 189  ******************************************************************************/
 190
 191 acpi_status
 192 acpi_ds_get_buffer_field_arguments(union acpi_operand_object *obj_desc)
 193 {
 194         union acpi_operand_object *extra_desc;
 195         struct acpi_namespace_node *node;
 196         acpi_status status;
 197
 198         ACPI_FUNCTION_TRACE_PTR(ds_get_buffer_field_arguments, obj_desc);
 199
 200         if (obj_desc->common.flags & AOPOBJ_DATA_VALID) {
 201                 return_ACPI_STATUS(AE_OK);
 202         }
 203
 204         /* Get the AML pointer (method object) and buffer_field node */
 205
 206         extra_desc = acpi_ns_get_secondary_object(obj_desc);
 207         node = obj_desc->buffer_field.node;
 208
 209         ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
 210                         (ACPI_TYPE_BUFFER_FIELD, node, NULL));
 211         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "[%4.4s] BufferField Arg Init\n",
 212                           acpi_ut_get_node_name(node)));
 213
 214         /* Execute the AML code for the term_arg arguments */
 215
 216         status = acpi_ds_execute_arguments(node, acpi_ns_get_parent_node(node),
 217                                            extra_desc->extra.aml_length,
 218                                            extra_desc->extra.aml_start);
 219         return_ACPI_STATUS(status);
 220 }
 221
 222 /*******************************************************************************
 223  *
 224  * FUNCTION:    acpi_ds_get_bank_field_arguments
 225  *
 226  * PARAMETERS:  obj_desc        - A valid bank_field object
 227  *
 228  * RETURN:      Status.
 229  *
 230  * DESCRIPTION: Get bank_field bank_value. This implements the late
 231  *              evaluation of these field attributes.
 232  *
 233  ******************************************************************************/
 234
 235 acpi_status
 236 acpi_ds_get_bank_field_arguments(union acpi_operand_object *obj_desc)
 237 {
 238         union acpi_operand_object *extra_desc;
 239         struct acpi_namespace_node *node;
 240         acpi_status status;
 241
 242         ACPI_FUNCTION_TRACE_PTR(ds_get_bank_field_arguments, obj_desc);
 243
 244         if (obj_desc->common.flags & AOPOBJ_DATA_VALID) {
 245                 return_ACPI_STATUS(AE_OK);
 246         }
 247
 248         /* Get the AML pointer (method object) and bank_field node */
 249
 250         extra_desc = acpi_ns_get_secondary_object(obj_desc);
 251         node = obj_desc->bank_field.node;
 252
 253         ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
 254                         (ACPI_TYPE_LOCAL_BANK_FIELD, node, NULL));
 255         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "[%4.4s] BankField Arg Init\n",
 256                           acpi_ut_get_node_name(node)));
 257
 258         /* Execute the AML code for the term_arg arguments */
 259
 260         status = acpi_ds_execute_arguments(node, acpi_ns_get_parent_node(node),
 261                                            extra_desc->extra.aml_length,
 262                                            extra_desc->extra.aml_start);
 263         return_ACPI_STATUS(status);
 264 }
 265
 266 /*******************************************************************************
 267  *
 268  * FUNCTION:    acpi_ds_get_buffer_arguments
 269  *
 270  * PARAMETERS:  obj_desc        - A valid Buffer object
 271  *
 272  * RETURN:      Status.
 273  *
 274  * DESCRIPTION: Get Buffer length and initializer byte list.  This implements
 275  *              the late evaluation of these attributes.
 276  *
 277  ******************************************************************************/
 278
 279 acpi_status acpi_ds_get_buffer_arguments(union acpi_operand_object *obj_desc)
 280 {
 281         struct acpi_namespace_node *node;
 282         acpi_status status;
 283
 284         ACPI_FUNCTION_TRACE_PTR(ds_get_buffer_arguments, obj_desc);
 285
 286         if (obj_desc->common.flags & AOPOBJ_DATA_VALID) {
 287                 return_ACPI_STATUS(AE_OK);
 288         }
 289
 290         /* Get the Buffer node */
 291
 292         node = obj_desc->buffer.node;
 293         if (!node) {
 294                 ACPI_ERROR((AE_INFO,
 295                             "No pointer back to NS node in buffer obj %p",
 296                             obj_desc));
 297                 return_ACPI_STATUS(AE_AML_INTERNAL);
 298         }
 299
 300         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Buffer Arg Init\n"));
 301
 302         /* Execute the AML code for the term_arg arguments */
 303
 304         status = acpi_ds_execute_arguments(node, node,
 305                                            obj_desc->buffer.aml_length,
 306                                            obj_desc->buffer.aml_start);
 307         return_ACPI_STATUS(status);
 308 }
 309
 310 /*******************************************************************************
 311  *
 312  * FUNCTION:    acpi_ds_get_package_arguments
 313  *
 314  * PARAMETERS:  obj_desc        - A valid Package object
 315  *
 316  * RETURN:      Status.
 317  *
 318  * DESCRIPTION: Get Package length and initializer byte list.  This implements
 319  *              the late evaluation of these attributes.
 320  *
 321  ******************************************************************************/
 322
 323 acpi_status acpi_ds_get_package_arguments(union acpi_operand_object *obj_desc)
 324 {
 325         struct acpi_namespace_node *node;
 326         acpi_status status;
 327
 328         ACPI_FUNCTION_TRACE_PTR(ds_get_package_arguments, obj_desc);
 329
 330         if (obj_desc->common.flags & AOPOBJ_DATA_VALID) {
 331                 return_ACPI_STATUS(AE_OK);
 332         }
 333
 334         /* Get the Package node */
 335
 336         node = obj_desc->package.node;
 337         if (!node) {
 338                 ACPI_ERROR((AE_INFO,
 339                             "No pointer back to NS node in package %p",
 340                             obj_desc));
 341                 return_ACPI_STATUS(AE_AML_INTERNAL);
 342         }
 343
 344         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Package Arg Init\n"));
 345
 346         /* Execute the AML code for the term_arg arguments */
 347
 348         status = acpi_ds_execute_arguments(node, node,
 349                                            obj_desc->package.aml_length,
 350                                            obj_desc->package.aml_start);
 351         return_ACPI_STATUS(status);
 352 }
 353
 354 /*****************************************************************************
 355  *
 356  * FUNCTION:    acpi_ds_get_region_arguments
 357  *
 358  * PARAMETERS:  obj_desc        - A valid region object
 359  *
 360  * RETURN:      Status.
 361  *
 362  * DESCRIPTION: Get region address and length.  This implements the late
 363  *              evaluation of these region attributes.
 364  *
 365  ****************************************************************************/
 366
 367 acpi_status acpi_ds_get_region_arguments(union acpi_operand_object *obj_desc)
 368 {
 369         struct acpi_namespace_node *node;
 370         acpi_status status;
 371         union acpi_operand_object *extra_desc;
 372
 373         ACPI_FUNCTION_TRACE_PTR(ds_get_region_arguments, obj_desc);
 374
 375         if (obj_desc->region.flags & AOPOBJ_DATA_VALID) {
 376                 return_ACPI_STATUS(AE_OK);
 377         }
 378
 379         extra_desc = acpi_ns_get_secondary_object(obj_desc);
 380         if (!extra_desc) {
 381                 return_ACPI_STATUS(AE_NOT_EXIST);
 382         }
 383
 384         /* Get the Region node */
 385
 386         node = obj_desc->region.node;
 387
 388         ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
 389                         (ACPI_TYPE_REGION, node, NULL));
 390
 391         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "[%4.4s] OpRegion Arg Init at AML %p\n",
 392                           acpi_ut_get_node_name(node),
 393                           extra_desc->extra.aml_start));
 394
 395         /* Execute the argument AML */
 396
 397         status = acpi_ds_execute_arguments(node, acpi_ns_get_parent_node(node),
 398                                            extra_desc->extra.aml_length,
 399                                            extra_desc->extra.aml_start);
 400         if (ACPI_FAILURE(status)) {
 401                 return_ACPI_STATUS(status);
 402         }
 403
 404         /* Validate the region address/length via the host OS */
 405
 406         status = acpi_os_validate_address(obj_desc->region.space_id,
 407                                           obj_desc->region.address,
 408                                           (acpi_size) obj_desc->region.length,
 409                                           acpi_ut_get_node_name(node));
 410
 411         if (ACPI_FAILURE(status)) {
 412                 /*
 413                  * Invalid address/length. We will emit an error message and mark
 414                  * the region as invalid, so that it will cause an additional error if
 415                  * it is ever used. Then return AE_OK.
 416                  */
 417                 ACPI_EXCEPTION((AE_INFO, status,
 418                                 "During address validation of OpRegion [%4.4s]",
 419                                 node->name.ascii));
 420                 obj_desc->common.flags |= AOPOBJ_INVALID;
 421                 status = AE_OK;
 422         }
 423
 424         return_ACPI_STATUS(status);
 425 }
 426
 427 /*******************************************************************************
 428  *
 429  * FUNCTION:    acpi_ds_initialize_region
 430  *
 431  * PARAMETERS:  obj_handle      - Region namespace node
 432  *
 433  * RETURN:      Status
 434  *
 435  * DESCRIPTION: Front end to ev_initialize_region
 436  *
 437  ******************************************************************************/
 438
 439 acpi_status acpi_ds_initialize_region(acpi_handle obj_handle)
 440 {
 441         union acpi_operand_object *obj_desc;
 442         acpi_status status;
 443
 444         obj_desc = acpi_ns_get_attached_object(obj_handle);
 445
 446         /* Namespace is NOT locked */
 447
 448         status = acpi_ev_initialize_region(obj_desc, FALSE);
 449         return (status);
 450 }
 451
 452 /*******************************************************************************
 453  *
 454  * FUNCTION:    acpi_ds_init_buffer_field
 455  *
 456  * PARAMETERS:  aml_opcode      - create_xxx_field
 457  *              obj_desc        - buffer_field object
 458  *              buffer_desc     - Host Buffer
 459  *              offset_desc     - Offset into buffer
 460  *              length_desc     - Length of field (CREATE_FIELD_OP only)
 461  *              result_desc     - Where to store the result
 462  *
 463  * RETURN:      Status
 464  *
 465  * DESCRIPTION: Perform actual initialization of a buffer field
 466  *
 467  ******************************************************************************/
 468
 469 static acpi_status
 470 acpi_ds_init_buffer_field(u16 aml_opcode,
 471                           union acpi_operand_object *obj_desc,
 472                           union acpi_operand_object *buffer_desc,
 473                           union acpi_operand_object *offset_desc,
 474                           union acpi_operand_object *length_desc,
 475                           union acpi_operand_object *result_desc)
 476 {
 477         u32 offset;
 478         u32 bit_offset;
 479         u32 bit_count;
 480         u8 field_flags;
 481         acpi_status status;
 482
 483         ACPI_FUNCTION_TRACE_PTR(ds_init_buffer_field, obj_desc);
 484
 485         /* Host object must be a Buffer */
 486
 487         if (ACPI_GET_OBJECT_TYPE(buffer_desc) != ACPI_TYPE_BUFFER) {
 488                 ACPI_ERROR((AE_INFO,
 489                             "Target of Create Field is not a Buffer object - %s",
 490                             acpi_ut_get_object_type_name(buffer_desc)));
 491
 492                 status = AE_AML_OPERAND_TYPE;
 493                 goto cleanup;
 494         }
 495
 496         /*
 497          * The last parameter to all of these opcodes (result_desc) started
 498          * out as a name_string, and should therefore now be a NS node
 499          * after resolution in acpi_ex_resolve_operands().
 500          */
 501         if (ACPI_GET_DESCRIPTOR_TYPE(result_desc) != ACPI_DESC_TYPE_NAMED) {
 502                 ACPI_ERROR((AE_INFO,
 503                             "(%s) destination not a NS Node [%s]",
 504                             acpi_ps_get_opcode_name(aml_opcode),
 505                             acpi_ut_get_descriptor_name(result_desc)));
 506
 507                 status = AE_AML_OPERAND_TYPE;
 508                 goto cleanup;
 509         }
 510
 511         offset = (u32) offset_desc->integer.value;
 512
 513         /*
 514          * Setup the Bit offsets and counts, according to the opcode
 515          */
 516         switch (aml_opcode) {
 517         case AML_CREATE_FIELD_OP:
 518
 519                 /* Offset is in bits, count is in bits */
 520
 521                 field_flags = AML_FIELD_ACCESS_BYTE;
 522                 bit_offset = offset;
 523                 bit_count = (u32) length_desc->integer.value;
 524
 525                 /* Must have a valid (>0) bit count */
 526
 527                 if (bit_count == 0) {
 528                         ACPI_ERROR((AE_INFO,
 529                                     "Attempt to CreateField of length zero"));
 530                         status = AE_AML_OPERAND_VALUE;
 531                         goto cleanup;
 532                 }
 533                 break;
 534
 535         case AML_CREATE_BIT_FIELD_OP:
 536
 537                 /* Offset is in bits, Field is one bit */
 538
 539                 bit_offset = offset;
 540                 bit_count = 1;
 541                 field_flags = AML_FIELD_ACCESS_BYTE;
 542                 break;
 543
 544         case AML_CREATE_BYTE_FIELD_OP:
 545
 546                 /* Offset is in bytes, field is one byte */
 547
 548                 bit_offset = 8 * offset;
 549                 bit_count = 8;
 550                 field_flags = AML_FIELD_ACCESS_BYTE;
 551                 break;
 552
 553         case AML_CREATE_WORD_FIELD_OP:
 554
 555                 /* Offset is in bytes, field is one word */
 556
 557                 bit_offset = 8 * offset;
 558                 bit_count = 16;
 559                 field_flags = AML_FIELD_ACCESS_WORD;
 560                 break;
 561
 562         case AML_CREATE_DWORD_FIELD_OP:
 563
 564                 /* Offset is in bytes, field is one dword */
 565
 566                 bit_offset = 8 * offset;
 567                 bit_count = 32;
 568                 field_flags = AML_FIELD_ACCESS_DWORD;
 569                 break;
 570
 571         case AML_CREATE_QWORD_FIELD_OP:
 572
 573                 /* Offset is in bytes, field is one qword */
 574
 575                 bit_offset = 8 * offset;
 576                 bit_count = 64;
 577                 field_flags = AML_FIELD_ACCESS_QWORD;
 578                 break;
 579
 580         default:
 581
 582                 ACPI_ERROR((AE_INFO,
 583                             "Unknown field creation opcode %02x", aml_opcode));
 584                 status = AE_AML_BAD_OPCODE;
 585                 goto cleanup;
 586         }
 587
 588         /* Entire field must fit within the current length of the buffer */
 589
 590         if ((bit_offset + bit_count) > (8 * (u32) buffer_desc->buffer.length)) {
 591                 ACPI_ERROR((AE_INFO,
 592                             "Field [%4.4s] at %d exceeds Buffer [%4.4s] size %d (bits)",
 593                             acpi_ut_get_node_name(result_desc),
 594                             bit_offset + bit_count,
 595                             acpi_ut_get_node_name(buffer_desc->buffer.node),
 596                             8 * (u32) buffer_desc->buffer.length));
 597                 status = AE_AML_BUFFER_LIMIT;
 598                 goto cleanup;
 599         }
 600
 601         /*
 602          * Initialize areas of the field object that are common to all fields
 603          * For field_flags, use LOCK_RULE = 0 (NO_LOCK),
 604          * UPDATE_RULE = 0 (UPDATE_PRESERVE)
 605          */
 606         status = acpi_ex_prep_common_field_object(obj_desc, field_flags, 0,
 607                                                   bit_offset, bit_count);
 608         if (ACPI_FAILURE(status)) {
 609                 goto cleanup;
 610         }
 611
 612         obj_desc->buffer_field.buffer_obj = buffer_desc;
 613
 614         /* Reference count for buffer_desc inherits obj_desc count */
 615
 616         buffer_desc->common.reference_count = (u16)
 617             (buffer_desc->common.reference_count +
 618              obj_desc->common.reference_count);
 619
 620       cleanup:
 621
 622         /* Always delete the operands */
 623
 624         acpi_ut_remove_reference(offset_desc);
 625         acpi_ut_remove_reference(buffer_desc);
 626
 627         if (aml_opcode == AML_CREATE_FIELD_OP) {
 628                 acpi_ut_remove_reference(length_desc);
 629         }
 630
 631         /* On failure, delete the result descriptor */
 632
 633         if (ACPI_FAILURE(status)) {
 634                 acpi_ut_remove_reference(result_desc);  /* Result descriptor */
 635         } else {
 636                 /* Now the address and length are valid for this buffer_field */
 637
 638                 obj_desc->buffer_field.flags |= AOPOBJ_DATA_VALID;
 639         }
 640
 641         return_ACPI_STATUS(status);
 642 }
 643
 644 /*******************************************************************************
 645  *
 646  * FUNCTION:    acpi_ds_eval_buffer_field_operands
 647  *
 648  * PARAMETERS:  walk_state      - Current walk
 649  *              Op              - A valid buffer_field Op object
 650  *
 651  * RETURN:      Status
 652  *
 653  * DESCRIPTION: Get buffer_field Buffer and Index
 654  *              Called from acpi_ds_exec_end_op during buffer_field parse tree walk
 655  *
 656  ******************************************************************************/
 657
 658 acpi_status
 659 acpi_ds_eval_buffer_field_operands(struct acpi_walk_state *walk_state,
 660                                    union acpi_parse_object *op)
 661 {
 662         acpi_status status;
 663         union acpi_operand_object *obj_desc;
 664         struct acpi_namespace_node *node;
 665         union acpi_parse_object *next_op;
 666
 667         ACPI_FUNCTION_TRACE_PTR(ds_eval_buffer_field_operands, op);
 668
 669         /*
 670          * This is where we evaluate the address and length fields of the
 671          * create_xxx_field declaration
 672          */
 673         node = op->common.node;
 674
 675         /* next_op points to the op that holds the Buffer */
 676
 677         next_op = op->common.value.arg;
 678
 679         /* Evaluate/create the address and length operands */
 680
 681         status = acpi_ds_create_operands(walk_state, next_op);
 682         if (ACPI_FAILURE(status)) {
 683                 return_ACPI_STATUS(status);
 684         }
 685
 686         obj_desc = acpi_ns_get_attached_object(node);
 687         if (!obj_desc) {
 688                 return_ACPI_STATUS(AE_NOT_EXIST);
 689         }
 690
 691         /* Resolve the operands */
 692
 693         status = acpi_ex_resolve_operands(op->common.aml_opcode,
 694                                           ACPI_WALK_OPERANDS, walk_state);
 695         if (ACPI_FAILURE(status)) {
 696                 ACPI_ERROR((AE_INFO, "(%s) bad operand(s) (%X)",
 697                             acpi_ps_get_opcode_name(op->common.aml_opcode),
 698                             status));
 699
 700                 return_ACPI_STATUS(status);
 701         }
 702
 703         /* Initialize the Buffer Field */
 704
 705         if (op->common.aml_opcode == AML_CREATE_FIELD_OP) {
 706
 707                 /* NOTE: Slightly different operands for this opcode */
 708
 709                 status =
 710                     acpi_ds_init_buffer_field(op->common.aml_opcode, obj_desc,
 711                                               walk_state->operands[0],
 712                                               walk_state->operands[1],
 713                                               walk_state->operands[2],
 714                                               walk_state->operands[3]);
 715         } else {
 716                 /* All other, create_xxx_field opcodes */
 717
 718                 status =
 719                     acpi_ds_init_buffer_field(op->common.aml_opcode, obj_desc,
 720                                               walk_state->operands[0],
 721                                               walk_state->operands[1], NULL,
 722                                               walk_state->operands[2]);
 723         }
 724
 725         return_ACPI_STATUS(status);
 726 }
 727
 728 /*******************************************************************************
 729  *
 730  * FUNCTION:    acpi_ds_eval_region_operands
 731  *
 732  * PARAMETERS:  walk_state      - Current walk
 733  *              Op              - A valid region Op object
 734  *
 735  * RETURN:      Status
 736  *
 737  * DESCRIPTION: Get region address and length
 738  *              Called from acpi_ds_exec_end_op during op_region parse tree walk
 739  *
 740  ******************************************************************************/
 741
 742 acpi_status
 743 acpi_ds_eval_region_operands(struct acpi_walk_state *walk_state,
 744                              union acpi_parse_object *op)
 745 {
 746         acpi_status status;
 747         union acpi_operand_object *obj_desc;
 748         union acpi_operand_object *operand_desc;
 749         struct acpi_namespace_node *node;
 750         union acpi_parse_object *next_op;
 751
 752         ACPI_FUNCTION_TRACE_PTR(ds_eval_region_operands, op);
 753
 754         /*
 755          * This is where we evaluate the address and length fields of the
 756          * op_region declaration
 757          */
 758         node = op->common.node;
 759
 760         /* next_op points to the op that holds the space_iD */
 761
 762         next_op = op->common.value.arg;
 763
 764         /* next_op points to address op */
 765
 766         next_op = next_op->common.next;
 767
 768         /* Evaluate/create the address and length operands */
 769
 770         status = acpi_ds_create_operands(walk_state, next_op);
 771         if (ACPI_FAILURE(status)) {
 772                 return_ACPI_STATUS(status);
 773         }
 774
 775         /* Resolve the length and address operands to numbers */
 776
 777         status = acpi_ex_resolve_operands(op->common.aml_opcode,
 778                                           ACPI_WALK_OPERANDS, walk_state);
 779         if (ACPI_FAILURE(status)) {
 780                 return_ACPI_STATUS(status);
 781         }
 782
 783         obj_desc = acpi_ns_get_attached_object(node);
 784         if (!obj_desc) {
 785                 return_ACPI_STATUS(AE_NOT_EXIST);
 786         }
 787
 788         /*
 789          * Get the length operand and save it
 790          * (at Top of stack)
 791          */
 792         operand_desc = walk_state->operands[walk_state->num_operands - 1];
 793
 794         obj_desc->region.length = (u32) operand_desc->integer.value;
 795         acpi_ut_remove_reference(operand_desc);
 796
 797         /*
 798          * Get the address and save it
 799          * (at top of stack - 1)
 800          */
 801         operand_desc = walk_state->operands[walk_state->num_operands - 2];
 802
 803         obj_desc->region.address = (acpi_physical_address)
 804             operand_desc->integer.value;
 805         acpi_ut_remove_reference(operand_desc);
 806
 807         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "RgnObj %p Addr %8.8X%8.8X Len %X\n",
 808                           obj_desc,
 809                           ACPI_FORMAT_NATIVE_UINT(obj_desc->region.address),
 810                           obj_desc->region.length));
 811
 812         /* Now the address and length are valid for this opregion */
 813
 814         obj_desc->region.flags |= AOPOBJ_DATA_VALID;
 815
 816         return_ACPI_STATUS(status);
 817 }
 818
 819 /*******************************************************************************
 820  *
 821  * FUNCTION:    acpi_ds_eval_table_region_operands
 822  *
 823  * PARAMETERS:  walk_state      - Current walk
 824  *              Op              - A valid region Op object
 825  *
 826  * RETURN:      Status
 827  *
 828  * DESCRIPTION: Get region address and length
 829  *              Called from acpi_ds_exec_end_op during data_table_region parse tree walk
 830  *
 831  ******************************************************************************/
 832
 833 acpi_status
 834 acpi_ds_eval_table_region_operands(struct acpi_walk_state *walk_state,
 835                                    union acpi_parse_object *op)
 836 {
 837         acpi_status status;
 838         union acpi_operand_object *obj_desc;
 839         union acpi_operand_object **operand;
 840         struct acpi_namespace_node *node;
 841         union acpi_parse_object *next_op;
 842         u32 table_index;
 843         struct acpi_table_header *table;
 844
 845         ACPI_FUNCTION_TRACE_PTR(ds_eval_table_region_operands, op);
 846
 847         /*
 848          * This is where we evaluate the signature_string and oem_iDString
 849          * and oem_table_iDString of the data_table_region declaration
 850          */
 851         node = op->common.node;
 852
 853         /* next_op points to signature_string op */
 854
 855         next_op = op->common.value.arg;
 856
 857         /*
 858          * Evaluate/create the signature_string and oem_iDString
 859          * and oem_table_iDString operands
 860          */
 861         status = acpi_ds_create_operands(walk_state, next_op);
 862         if (ACPI_FAILURE(status)) {
 863                 return_ACPI_STATUS(status);
 864         }
 865
 866         /*
 867          * Resolve the signature_string and oem_iDString
 868          * and oem_table_iDString operands
 869          */
 870         status = acpi_ex_resolve_operands(op->common.aml_opcode,
 871                                           ACPI_WALK_OPERANDS, walk_state);
 872         if (ACPI_FAILURE(status)) {
 873                 return_ACPI_STATUS(status);
 874         }
 875
 876         operand = &walk_state->operands[0];
 877
 878         /* Find the ACPI table */
 879
 880         status = acpi_tb_find_table(operand[0]->string.pointer,
 881                                     operand[1]->string.pointer,
 882                                     operand[2]->string.pointer, &table_index);
 883         if (ACPI_FAILURE(status)) {
 884                 return_ACPI_STATUS(status);
 885         }
 886
 887         acpi_ut_remove_reference(operand[0]);
 888         acpi_ut_remove_reference(operand[1]);
 889         acpi_ut_remove_reference(operand[2]);
 890
 891         status = acpi_get_table_by_index(table_index, &table);
 892         if (ACPI_FAILURE(status)) {
 893                 return_ACPI_STATUS(status);
 894         }
 895
 896         obj_desc = acpi_ns_get_attached_object(node);
 897         if (!obj_desc) {
 898                 return_ACPI_STATUS(AE_NOT_EXIST);
 899         }
 900
 901         obj_desc->region.address =
 902             (acpi_physical_address) ACPI_TO_INTEGER(table);
 903         obj_desc->region.length = table->length;
 904
 905         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "RgnObj %p Addr %8.8X%8.8X Len %X\n",
 906                           obj_desc,
 907                           ACPI_FORMAT_NATIVE_UINT(obj_desc->region.address),
 908                           obj_desc->region.length));
 909
 910         /* Now the address and length are valid for this opregion */
 911
 912         obj_desc->region.flags |= AOPOBJ_DATA_VALID;
 913
 914         return_ACPI_STATUS(status);
 915 }
 916
 917 /*******************************************************************************
 918  *
 919  * FUNCTION:    acpi_ds_eval_data_object_operands
 920  *
 921  * PARAMETERS:  walk_state      - Current walk
 922  *              Op              - A valid data_object Op object
 923  *              obj_desc        - data_object
 924  *
 925  * RETURN:      Status
 926  *
 927  * DESCRIPTION: Get the operands and complete the following data object types:
 928  *              Buffer, Package.
 929  *
 930  ******************************************************************************/
 931
 932 acpi_status
 933 acpi_ds_eval_data_object_operands(struct acpi_walk_state *walk_state,
 934                                   union acpi_parse_object *op,
 935                                   union acpi_operand_object *obj_desc)
 936 {
 937         acpi_status status;
 938         union acpi_operand_object *arg_desc;
 939         u32 length;
 940
 941         ACPI_FUNCTION_TRACE(ds_eval_data_object_operands);
 942
 943         /* The first operand (for all of these data objects) is the length */
 944
 945         /*
 946          * Set proper index into operand stack for acpi_ds_obj_stack_push
 947          * invoked inside acpi_ds_create_operand.
 948          */
 949         walk_state->operand_index = walk_state->num_operands;
 950
 951         status = acpi_ds_create_operand(walk_state, op->common.value.arg, 1);
 952         if (ACPI_FAILURE(status)) {
 953                 return_ACPI_STATUS(status);
 954         }
 955
 956         status = acpi_ex_resolve_operands(walk_state->opcode,
 957                                           &(walk_state->
 958                                             operands[walk_state->num_operands -
 959                                                      1]), walk_state);
 960         if (ACPI_FAILURE(status)) {
 961                 return_ACPI_STATUS(status);
 962         }
 963
 964         /* Extract length operand */
 965
 966         arg_desc = walk_state->operands[walk_state->num_operands - 1];
 967         length = (u32) arg_desc->integer.value;
 968
 969         /* Cleanup for length operand */
 970
 971         status = acpi_ds_obj_stack_pop(1, walk_state);
 972         if (ACPI_FAILURE(status)) {
 973                 return_ACPI_STATUS(status);
 974         }
 975
 976         acpi_ut_remove_reference(arg_desc);
 977
 978         /*
 979          * Create the actual data object
 980          */
 981         switch (op->common.aml_opcode) {
 982         case AML_BUFFER_OP:
 983
 984                 status =
 985                     acpi_ds_build_internal_buffer_obj(walk_state, op, length,
 986                                                       &obj_desc);
 987                 break;
 988
 989         case AML_PACKAGE_OP:
 990         case AML_VAR_PACKAGE_OP:
 991
 992                 status =
 993                     acpi_ds_build_internal_package_obj(walk_state, op, length,
 994                                                        &obj_desc);
 995                 break;
 996
 997         default:
 998                 return_ACPI_STATUS(AE_AML_BAD_OPCODE);
 999         }
1000
1001         if (ACPI_SUCCESS(status)) {
1002                 /*
1003                  * Return the object in the walk_state, unless the parent is a package -
1004                  * in this case, the return object will be stored in the parse tree
1005                  * for the package.
1006                  */
1007                 if ((!op->common.parent) ||
1008                     ((op->common.parent->common.aml_opcode != AML_PACKAGE_OP) &&
1009                      (op->common.parent->common.aml_opcode !=
1010                       AML_VAR_PACKAGE_OP)
1011                      && (op->common.parent->common.aml_opcode != AML_NAME_OP))) {
1012                         walk_state->result_obj = obj_desc;
1013                 }
1014         }
1015
1016         return_ACPI_STATUS(status);
1017 }
1018
1019 /*******************************************************************************
1020  *
1021  * FUNCTION:    acpi_ds_eval_bank_field_operands
1022  *
1023  * PARAMETERS:  walk_state      - Current walk
1024  *              Op              - A valid bank_field Op object
1025  *
1026  * RETURN:      Status
1027  *
1028  * DESCRIPTION: Get bank_field bank_value
1029  *              Called from acpi_ds_exec_end_op during bank_field parse tree walk
1030  *
1031  ******************************************************************************/
1032
1033 acpi_status
1034 acpi_ds_eval_bank_field_operands(struct acpi_walk_state *walk_state,
1035                                  union acpi_parse_object *op)
1036 {
1037         acpi_status status;
1038         union acpi_operand_object *obj_desc;
1039         union acpi_operand_object *operand_desc;
1040         struct acpi_namespace_node *node;
1041         union acpi_parse_object *next_op;
1042         union acpi_parse_object *arg;
1043
1044         ACPI_FUNCTION_TRACE_PTR(ds_eval_bank_field_operands, op);
1045
1046         /*
1047          * This is where we evaluate the bank_value field of the
1048          * bank_field declaration
1049          */
1050
1051         /* next_op points to the op that holds the Region */
1052
1053         next_op = op->common.value.arg;
1054
1055         /* next_op points to the op that holds the Bank Register */
1056
1057         next_op = next_op->common.next;
1058
1059         /* next_op points to the op that holds the Bank Value */
1060
1061         next_op = next_op->common.next;
1062
1063         /*
1064          * Set proper index into operand stack for acpi_ds_obj_stack_push
1065          * invoked inside acpi_ds_create_operand.
1066          *
1067          * We use walk_state->Operands[0] to store the evaluated bank_value
1068          */
1069         walk_state->operand_index = 0;
1070
1071         status = acpi_ds_create_operand(walk_state, next_op, 0);
1072         if (ACPI_FAILURE(status)) {
1073                 return_ACPI_STATUS(status);
1074         }
1075
1076         status = acpi_ex_resolve_to_value(&walk_state->operands[0], walk_state);
1077         if (ACPI_FAILURE(status)) {
1078                 return_ACPI_STATUS(status);
1079         }
1080
1081         ACPI_DUMP_OPERANDS(ACPI_WALK_OPERANDS,
1082                            acpi_ps_get_opcode_name(op->common.aml_opcode), 1);
1083         /*
1084          * Get the bank_value operand and save it
1085          * (at Top of stack)
1086          */
1087         operand_desc = walk_state->operands[0];
1088
1089         /* Arg points to the start Bank Field */
1090
1091         arg = acpi_ps_get_arg(op, 4);
1092         while (arg) {
1093
1094                 /* Ignore OFFSET and ACCESSAS terms here */
1095
1096                 if (arg->common.aml_opcode == AML_INT_NAMEDFIELD_OP) {
1097                         node = arg->common.node;
1098
1099                         obj_desc = acpi_ns_get_attached_object(node);
1100                         if (!obj_desc) {
1101                                 return_ACPI_STATUS(AE_NOT_EXIST);
1102                         }
1103
1104                         obj_desc->bank_field.value =
1105                             (u32) operand_desc->integer.value;
1106                 }
1107
1108                 /* Move to next field in the list */
1109
1110                 arg = arg->common.next;
1111         }
1112
1113         acpi_ut_remove_reference(operand_desc);
1114         return_ACPI_STATUS(status);
1115 }
1116
1117 /*******************************************************************************
1118  *
1119  * FUNCTION:    acpi_ds_exec_begin_control_op
1120  *
1121  * PARAMETERS:  walk_list       - The list that owns the walk stack
1122  *              Op              - The control Op
1123  *
1124  * RETURN:      Status
1125  *
1126  * DESCRIPTION: Handles all control ops encountered during control method
1127  *              execution.
1128  *
1129  ******************************************************************************/
1130
1131 acpi_status
1132 acpi_ds_exec_begin_control_op(struct acpi_walk_state *walk_state,
1133                               union acpi_parse_object *op)
1134 {
1135         acpi_status status = AE_OK;
1136         union acpi_generic_state *control_state;
1137
1138         ACPI_FUNCTION_NAME(ds_exec_begin_control_op);
1139
1140         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n", op,
1141                           op->common.aml_opcode, walk_state));
1142
1143         switch (op->common.aml_opcode) {
1144         case AML_WHILE_OP:
1145
1146                 /*
1147                  * If this is an additional iteration of a while loop, continue.
1148                  * There is no need to allocate a new control state.
1149                  */
1150                 if (walk_state->control_state) {
1151                         if (walk_state->control_state->control.aml_predicate_start
1152                                 == (walk_state->parser_state.aml - 1)) {
1153
1154                                 /* Reset the state to start-of-loop */
1155
1156                                 walk_state->control_state->common.state =
1157                                     ACPI_CONTROL_CONDITIONAL_EXECUTING;
1158                                 break;
1159                         }
1160                 }
1161
1162                 /*lint -fallthrough */
1163
1164         case AML_IF_OP:
1165
1166                 /*
1167                  * IF/WHILE: Create a new control state to manage these
1168                  * constructs. We need to manage these as a stack, in order
1169                  * to handle nesting.
1170                  */
1171                 control_state = acpi_ut_create_control_state();
1172                 if (!control_state) {
1173                         status = AE_NO_MEMORY;
1174                         break;
1175                 }
1176                 /*
1177                  * Save a pointer to the predicate for multiple executions
1178                  * of a loop
1179                  */
1180                 control_state->control.aml_predicate_start =
1181                     walk_state->parser_state.aml - 1;
1182                 control_state->control.package_end =
1183                     walk_state->parser_state.pkg_end;
1184                 control_state->control.opcode = op->common.aml_opcode;
1185
1186                 /* Push the control state on this walk's control stack */
1187
1188                 acpi_ut_push_generic_state(&walk_state->control_state,
1189                                            control_state);
1190                 break;
1191
1192         case AML_ELSE_OP:
1193
1194                 /* Predicate is in the state object */
1195                 /* If predicate is true, the IF was executed, ignore ELSE part */
1196
1197                 if (walk_state->last_predicate) {
1198                         status = AE_CTRL_TRUE;
1199                 }
1200
1201                 break;
1202
1203         case AML_RETURN_OP:
1204
1205                 break;
1206
1207         default:
1208                 break;
1209         }
1210
1211         return (status);
1212 }
1213
1214 /*******************************************************************************
1215  *
1216  * FUNCTION:    acpi_ds_exec_end_control_op
1217  *
1218  * PARAMETERS:  walk_list       - The list that owns the walk stack
1219  *              Op              - The control Op
1220  *
1221  * RETURN:      Status
1222  *
1223  * DESCRIPTION: Handles all control ops encountered during control method
1224  *              execution.
1225  *
1226  ******************************************************************************/
1227
1228 acpi_status
1229 acpi_ds_exec_end_control_op(struct acpi_walk_state * walk_state,
1230                             union acpi_parse_object * op)
1231 {
1232         acpi_status status = AE_OK;
1233         union acpi_generic_state *control_state;
1234
1235         ACPI_FUNCTION_NAME(ds_exec_end_control_op);
1236
1237         switch (op->common.aml_opcode) {
1238         case AML_IF_OP:
1239
1240                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", op));
1241
1242                 /*
1243                  * Save the result of the predicate in case there is an
1244                  * ELSE to come
1245                  */
1246                 walk_state->last_predicate =
1247                     (u8) walk_state->control_state->common.value;
1248
1249                 /*
1250                  * Pop the control state that was created at the start
1251                  * of the IF and free it
1252                  */
1253                 control_state =
1254                     acpi_ut_pop_generic_state(&walk_state->control_state);
1255                 acpi_ut_delete_generic_state(control_state);
1256                 break;
1257
1258         case AML_ELSE_OP:
1259
1260                 break;
1261
1262         case AML_WHILE_OP:
1263
1264                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", op));
1265
1266                 control_state = walk_state->control_state;
1267                 if (control_state->common.value) {
1268
1269                         /* Predicate was true, the body of the loop was just executed */
1270
1271                         /*
1272                          * This loop counter mechanism allows the interpreter to escape
1273                          * possibly infinite loops. This can occur in poorly written AML
1274                          * when the hardware does not respond within a while loop and the
1275                          * loop does not implement a timeout.
1276                          */
1277                         control_state->control.loop_count++;
1278                         if (control_state->control.loop_count >
1279                                 ACPI_MAX_LOOP_ITERATIONS) {
1280                                 status = AE_AML_INFINITE_LOOP;
1281                                 break;
1282                         }
1283
1284                         /*
1285                          * Go back and evaluate the predicate and maybe execute the loop
1286                          * another time
1287                          */
1288                         status = AE_CTRL_PENDING;
1289                         walk_state->aml_last_while =
1290                             control_state->control.aml_predicate_start;
1291                         break;
1292                 }
1293
1294                 /* Predicate was false, terminate this while loop */
1295
1296                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
1297                                   "[WHILE_OP] termination! Op=%p\n", op));
1298
1299                 /* Pop this control state and free it */
1300
1301                 control_state =
1302                     acpi_ut_pop_generic_state(&walk_state->control_state);
1303                 acpi_ut_delete_generic_state(control_state);
1304                 break;
1305
1306         case AML_RETURN_OP:
1307
1308                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
1309                                   "[RETURN_OP] Op=%p Arg=%p\n", op,
1310                                   op->common.value.arg));
1311
1312                 /*
1313                  * One optional operand -- the return value
1314                  * It can be either an immediate operand or a result that
1315                  * has been bubbled up the tree
1316                  */
1317                 if (op->common.value.arg) {
1318
1319                         /* Since we have a real Return(), delete any implicit return */
1320
1321                         acpi_ds_clear_implicit_return(walk_state);
1322
1323                         /* Return statement has an immediate operand */
1324
1325                         status =
1326                             acpi_ds_create_operands(walk_state,
1327                                                     op->common.value.arg);
1328                         if (ACPI_FAILURE(status)) {
1329                                 return (status);
1330                         }
1331
1332                         /*
1333                          * If value being returned is a Reference (such as
1334                          * an arg or local), resolve it now because it may
1335                          * cease to exist at the end of the method.
1336                          */
1337                         status =
1338                             acpi_ex_resolve_to_value(&walk_state->operands[0],
1339                                                      walk_state);
1340                         if (ACPI_FAILURE(status)) {
1341                                 return (status);
1342                         }
1343
1344                         /*
1345                          * Get the return value and save as the last result
1346                          * value.  This is the only place where walk_state->return_desc
1347                          * is set to anything other than zero!
1348                          */
1349                         walk_state->return_desc = walk_state->operands[0];
1350                 } else if (walk_state->result_count) {
1351
1352                         /* Since we have a real Return(), delete any implicit return */
1353
1354                         acpi_ds_clear_implicit_return(walk_state);
1355
1356                         /*
1357                          * The return value has come from a previous calculation.
1358                          *
1359                          * If value being returned is a Reference (such as
1360                          * an arg or local), resolve it now because it may
1361                          * cease to exist at the end of the method.
1362                          *
1363                          * Allow references created by the Index operator to return unchanged.
1364                          */
1365                         if ((ACPI_GET_DESCRIPTOR_TYPE
1366                              (walk_state->results->results.obj_desc[0]) ==
1367                              ACPI_DESC_TYPE_OPERAND)
1368                             &&
1369                             (ACPI_GET_OBJECT_TYPE
1370                              (walk_state->results->results.obj_desc[0]) ==
1371                              ACPI_TYPE_LOCAL_REFERENCE)
1372                             && ((walk_state->results->results.obj_desc[0])->
1373                                 reference.class != ACPI_REFCLASS_INDEX)) {
1374                                 status =
1375                                     acpi_ex_resolve_to_value(&walk_state->
1376                                                              results->results.
1377                                                              obj_desc[0],
1378                                                              walk_state);
1379                                 if (ACPI_FAILURE(status)) {
1380                                         return (status);
1381                                 }
1382                         }
1383
1384                         walk_state->return_desc =
1385                             walk_state->results->results.obj_desc[0];
1386                 } else {
1387                         /* No return operand */
1388
1389                         if (walk_state->num_operands) {
1390                                 acpi_ut_remove_reference(walk_state->
1391                                                          operands[0]);
1392                         }
1393
1394                         walk_state->operands[0] = NULL;
1395                         walk_state->num_operands = 0;
1396                         walk_state->return_desc = NULL;
1397                 }
1398
1399                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
1400                                   "Completed RETURN_OP State=%p, RetVal=%p\n",
1401                                   walk_state, walk_state->return_desc));
1402
1403                 /* End the control method execution right now */
1404
1405                 status = AE_CTRL_TERMINATE;
1406                 break;
1407
1408         case AML_NOOP_OP:
1409
1410                 /* Just do nothing! */
1411                 break;
1412
1413         case AML_BREAK_POINT_OP:
1414
1415                 /* Call up to the OS service layer to handle this */
1416
1417                 status =
1418                     acpi_os_signal(ACPI_SIGNAL_BREAKPOINT,
1419                                    "Executed AML Breakpoint opcode");
1420
1421                 /* If and when it returns, all done. */
1422
1423                 break;
1424
1425         case AML_BREAK_OP:
1426         case AML_CONTINUE_OP:   /* ACPI 2.0 */
1427
1428                 /* Pop and delete control states until we find a while */
1429
1430                 while (walk_state->control_state &&
1431                        (walk_state->control_state->control.opcode !=
1432                         AML_WHILE_OP)) {
1433                         control_state =
1434                             acpi_ut_pop_generic_state(&walk_state->
1435                                                       control_state);
1436                         acpi_ut_delete_generic_state(control_state);
1437                 }
1438
1439                 /* No while found? */
1440
1441                 if (!walk_state->control_state) {
1442                         return (AE_AML_NO_WHILE);
1443                 }
1444
1445                 /* Was: walk_state->aml_last_while = walk_state->control_state->Control.aml_predicate_start; */
1446
1447                 walk_state->aml_last_while =
1448                     walk_state->control_state->control.package_end;
1449
1450                 /* Return status depending on opcode */
1451
1452                 if (op->common.aml_opcode == AML_BREAK_OP) {
1453                         status = AE_CTRL_BREAK;
1454                 } else {
1455                         status = AE_CTRL_CONTINUE;
1456                 }
1457                 break;
1458
1459         default:
1460
1461                 ACPI_ERROR((AE_INFO, "Unknown control opcode=%X Op=%p",
1462                             op->common.aml_opcode, op));
1463
1464                 status = AE_AML_BAD_OPCODE;
1465                 break;
1466         }
1467
1468         return (status);
1469 }