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 - 2010, 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 namespace node in buffer object %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 namespace 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 (buffer_desc->common.type != 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 0x%02X",
 584                             aml_opcode));
 585                 status = AE_AML_BAD_OPCODE;
 586                 goto cleanup;
 587         }
 588
 589         /* Entire field must fit within the current length of the buffer */
 590
 591         if ((bit_offset + bit_count) > (8 * (u32) buffer_desc->buffer.length)) {
 592                 ACPI_ERROR((AE_INFO,
 593                             "Field [%4.4s] at %u exceeds Buffer [%4.4s] size %u (bits)",
 594                             acpi_ut_get_node_name(result_desc),
 595                             bit_offset + bit_count,
 596                             acpi_ut_get_node_name(buffer_desc->buffer.node),
 597                             8 * (u32) buffer_desc->buffer.length));
 598                 status = AE_AML_BUFFER_LIMIT;
 599                 goto cleanup;
 600         }
 601
 602         /*
 603          * Initialize areas of the field object that are common to all fields
 604          * For field_flags, use LOCK_RULE = 0 (NO_LOCK),
 605          * UPDATE_RULE = 0 (UPDATE_PRESERVE)
 606          */
 607         status = acpi_ex_prep_common_field_object(obj_desc, field_flags, 0,
 608                                                   bit_offset, bit_count);
 609         if (ACPI_FAILURE(status)) {
 610                 goto cleanup;
 611         }
 612
 613         obj_desc->buffer_field.buffer_obj = buffer_desc;
 614
 615         /* Reference count for buffer_desc inherits obj_desc count */
 616
 617         buffer_desc->common.reference_count = (u16)
 618             (buffer_desc->common.reference_count +
 619              obj_desc->common.reference_count);
 620
 621       cleanup:
 622
 623         /* Always delete the operands */
 624
 625         acpi_ut_remove_reference(offset_desc);
 626         acpi_ut_remove_reference(buffer_desc);
 627
 628         if (aml_opcode == AML_CREATE_FIELD_OP) {
 629                 acpi_ut_remove_reference(length_desc);
 630         }
 631
 632         /* On failure, delete the result descriptor */
 633
 634         if (ACPI_FAILURE(status)) {
 635                 acpi_ut_remove_reference(result_desc);  /* Result descriptor */
 636         } else {
 637                 /* Now the address and length are valid for this buffer_field */
 638
 639                 obj_desc->buffer_field.flags |= AOPOBJ_DATA_VALID;
 640         }
 641
 642         return_ACPI_STATUS(status);
 643 }
 644
 645 /*******************************************************************************
 646  *
 647  * FUNCTION:    acpi_ds_eval_buffer_field_operands
 648  *
 649  * PARAMETERS:  walk_state      - Current walk
 650  *              Op              - A valid buffer_field Op object
 651  *
 652  * RETURN:      Status
 653  *
 654  * DESCRIPTION: Get buffer_field Buffer and Index
 655  *              Called from acpi_ds_exec_end_op during buffer_field parse tree walk
 656  *
 657  ******************************************************************************/
 658
 659 acpi_status
 660 acpi_ds_eval_buffer_field_operands(struct acpi_walk_state *walk_state,
 661                                    union acpi_parse_object *op)
 662 {
 663         acpi_status status;
 664         union acpi_operand_object *obj_desc;
 665         struct acpi_namespace_node *node;
 666         union acpi_parse_object *next_op;
 667
 668         ACPI_FUNCTION_TRACE_PTR(ds_eval_buffer_field_operands, op);
 669
 670         /*
 671          * This is where we evaluate the address and length fields of the
 672          * create_xxx_field declaration
 673          */
 674         node = op->common.node;
 675
 676         /* next_op points to the op that holds the Buffer */
 677
 678         next_op = op->common.value.arg;
 679
 680         /* Evaluate/create the address and length operands */
 681
 682         status = acpi_ds_create_operands(walk_state, next_op);
 683         if (ACPI_FAILURE(status)) {
 684                 return_ACPI_STATUS(status);
 685         }
 686
 687         obj_desc = acpi_ns_get_attached_object(node);
 688         if (!obj_desc) {
 689                 return_ACPI_STATUS(AE_NOT_EXIST);
 690         }
 691
 692         /* Resolve the operands */
 693
 694         status = acpi_ex_resolve_operands(op->common.aml_opcode,
 695                                           ACPI_WALK_OPERANDS, walk_state);
 696         if (ACPI_FAILURE(status)) {
 697                 ACPI_ERROR((AE_INFO, "(%s) bad operand(s), status 0x%X",
 698                             acpi_ps_get_opcode_name(op->common.aml_opcode),
 699                             status));
 700
 701                 return_ACPI_STATUS(status);
 702         }
 703
 704         /* Initialize the Buffer Field */
 705
 706         if (op->common.aml_opcode == AML_CREATE_FIELD_OP) {
 707
 708                 /* NOTE: Slightly different operands for this opcode */
 709
 710                 status =
 711                     acpi_ds_init_buffer_field(op->common.aml_opcode, obj_desc,
 712                                               walk_state->operands[0],
 713                                               walk_state->operands[1],
 714                                               walk_state->operands[2],
 715                                               walk_state->operands[3]);
 716         } else {
 717                 /* All other, create_xxx_field opcodes */
 718
 719                 status =
 720                     acpi_ds_init_buffer_field(op->common.aml_opcode, obj_desc,
 721                                               walk_state->operands[0],
 722                                               walk_state->operands[1], NULL,
 723                                               walk_state->operands[2]);
 724         }
 725
 726         return_ACPI_STATUS(status);
 727 }
 728
 729 /*******************************************************************************
 730  *
 731  * FUNCTION:    acpi_ds_eval_region_operands
 732  *
 733  * PARAMETERS:  walk_state      - Current walk
 734  *              Op              - A valid region Op object
 735  *
 736  * RETURN:      Status
 737  *
 738  * DESCRIPTION: Get region address and length
 739  *              Called from acpi_ds_exec_end_op during op_region parse tree walk
 740  *
 741  ******************************************************************************/
 742
 743 acpi_status
 744 acpi_ds_eval_region_operands(struct acpi_walk_state *walk_state,
 745                              union acpi_parse_object *op)
 746 {
 747         acpi_status status;
 748         union acpi_operand_object *obj_desc;
 749         union acpi_operand_object *operand_desc;
 750         struct acpi_namespace_node *node;
 751         union acpi_parse_object *next_op;
 752
 753         ACPI_FUNCTION_TRACE_PTR(ds_eval_region_operands, op);
 754
 755         /*
 756          * This is where we evaluate the address and length fields of the
 757          * op_region declaration
 758          */
 759         node = op->common.node;
 760
 761         /* next_op points to the op that holds the space_iD */
 762
 763         next_op = op->common.value.arg;
 764
 765         /* next_op points to address op */
 766
 767         next_op = next_op->common.next;
 768
 769         /* Evaluate/create the address and length operands */
 770
 771         status = acpi_ds_create_operands(walk_state, next_op);
 772         if (ACPI_FAILURE(status)) {
 773                 return_ACPI_STATUS(status);
 774         }
 775
 776         /* Resolve the length and address operands to numbers */
 777
 778         status = acpi_ex_resolve_operands(op->common.aml_opcode,
 779                                           ACPI_WALK_OPERANDS, walk_state);
 780         if (ACPI_FAILURE(status)) {
 781                 return_ACPI_STATUS(status);
 782         }
 783
 784         obj_desc = acpi_ns_get_attached_object(node);
 785         if (!obj_desc) {
 786                 return_ACPI_STATUS(AE_NOT_EXIST);
 787         }
 788
 789         /*
 790          * Get the length operand and save it
 791          * (at Top of stack)
 792          */
 793         operand_desc = walk_state->operands[walk_state->num_operands - 1];
 794
 795         obj_desc->region.length = (u32) operand_desc->integer.value;
 796         acpi_ut_remove_reference(operand_desc);
 797
 798         /*
 799          * Get the address and save it
 800          * (at top of stack - 1)
 801          */
 802         operand_desc = walk_state->operands[walk_state->num_operands - 2];
 803
 804         obj_desc->region.address = (acpi_physical_address)
 805             operand_desc->integer.value;
 806         acpi_ut_remove_reference(operand_desc);
 807
 808         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "RgnObj %p Addr %8.8X%8.8X Len %X\n",
 809                           obj_desc,
 810                           ACPI_FORMAT_NATIVE_UINT(obj_desc->region.address),
 811                           obj_desc->region.length));
 812
 813         /* Now the address and length are valid for this opregion */
 814
 815         obj_desc->region.flags |= AOPOBJ_DATA_VALID;
 816
 817         return_ACPI_STATUS(status);
 818 }
 819
 820 /*******************************************************************************
 821  *
 822  * FUNCTION:    acpi_ds_eval_table_region_operands
 823  *
 824  * PARAMETERS:  walk_state      - Current walk
 825  *              Op              - A valid region Op object
 826  *
 827  * RETURN:      Status
 828  *
 829  * DESCRIPTION: Get region address and length
 830  *              Called from acpi_ds_exec_end_op during data_table_region parse tree walk
 831  *
 832  ******************************************************************************/
 833
 834 acpi_status
 835 acpi_ds_eval_table_region_operands(struct acpi_walk_state *walk_state,
 836                                    union acpi_parse_object *op)
 837 {
 838         acpi_status status;
 839         union acpi_operand_object *obj_desc;
 840         union acpi_operand_object **operand;
 841         struct acpi_namespace_node *node;
 842         union acpi_parse_object *next_op;
 843         u32 table_index;
 844         struct acpi_table_header *table;
 845
 846         ACPI_FUNCTION_TRACE_PTR(ds_eval_table_region_operands, op);
 847
 848         /*
 849          * This is where we evaluate the signature_string and oem_iDString
 850          * and oem_table_iDString of the data_table_region declaration
 851          */
 852         node = op->common.node;
 853
 854         /* next_op points to signature_string op */
 855
 856         next_op = op->common.value.arg;
 857
 858         /*
 859          * Evaluate/create the signature_string and oem_iDString
 860          * and oem_table_iDString operands
 861          */
 862         status = acpi_ds_create_operands(walk_state, next_op);
 863         if (ACPI_FAILURE(status)) {
 864                 return_ACPI_STATUS(status);
 865         }
 866
 867         /*
 868          * Resolve the signature_string and oem_iDString
 869          * and oem_table_iDString operands
 870          */
 871         status = acpi_ex_resolve_operands(op->common.aml_opcode,
 872                                           ACPI_WALK_OPERANDS, walk_state);
 873         if (ACPI_FAILURE(status)) {
 874                 return_ACPI_STATUS(status);
 875         }
 876
 877         operand = &walk_state->operands[0];
 878
 879         /* Find the ACPI table */
 880
 881         status = acpi_tb_find_table(operand[0]->string.pointer,
 882                                     operand[1]->string.pointer,
 883                                     operand[2]->string.pointer, &table_index);
 884         if (ACPI_FAILURE(status)) {
 885                 return_ACPI_STATUS(status);
 886         }
 887
 888         acpi_ut_remove_reference(operand[0]);
 889         acpi_ut_remove_reference(operand[1]);
 890         acpi_ut_remove_reference(operand[2]);
 891
 892         status = acpi_get_table_by_index(table_index, &table);
 893         if (ACPI_FAILURE(status)) {
 894                 return_ACPI_STATUS(status);
 895         }
 896
 897         obj_desc = acpi_ns_get_attached_object(node);
 898         if (!obj_desc) {
 899                 return_ACPI_STATUS(AE_NOT_EXIST);
 900         }
 901
 902         obj_desc->region.address =
 903             (acpi_physical_address) ACPI_TO_INTEGER(table);
 904         obj_desc->region.length = table->length;
 905
 906         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "RgnObj %p Addr %8.8X%8.8X Len %X\n",
 907                           obj_desc,
 908                           ACPI_FORMAT_NATIVE_UINT(obj_desc->region.address),
 909                           obj_desc->region.length));
 910
 911         /* Now the address and length are valid for this opregion */
 912
 913         obj_desc->region.flags |= AOPOBJ_DATA_VALID;
 914
 915         return_ACPI_STATUS(status);
 916 }
 917
 918 /*******************************************************************************
 919  *
 920  * FUNCTION:    acpi_ds_eval_data_object_operands
 921  *
 922  * PARAMETERS:  walk_state      - Current walk
 923  *              Op              - A valid data_object Op object
 924  *              obj_desc        - data_object
 925  *
 926  * RETURN:      Status
 927  *
 928  * DESCRIPTION: Get the operands and complete the following data object types:
 929  *              Buffer, Package.
 930  *
 931  ******************************************************************************/
 932
 933 acpi_status
 934 acpi_ds_eval_data_object_operands(struct acpi_walk_state *walk_state,
 935                                   union acpi_parse_object *op,
 936                                   union acpi_operand_object *obj_desc)
 937 {
 938         acpi_status status;
 939         union acpi_operand_object *arg_desc;
 940         u32 length;
 941
 942         ACPI_FUNCTION_TRACE(ds_eval_data_object_operands);
 943
 944         /* The first operand (for all of these data objects) is the length */
 945
 946         /*
 947          * Set proper index into operand stack for acpi_ds_obj_stack_push
 948          * invoked inside acpi_ds_create_operand.
 949          */
 950         walk_state->operand_index = walk_state->num_operands;
 951
 952         status = acpi_ds_create_operand(walk_state, op->common.value.arg, 1);
 953         if (ACPI_FAILURE(status)) {
 954                 return_ACPI_STATUS(status);
 955         }
 956
 957         status = acpi_ex_resolve_operands(walk_state->opcode,
 958                                           &(walk_state->
 959                                             operands[walk_state->num_operands -
 960                                                      1]), walk_state);
 961         if (ACPI_FAILURE(status)) {
 962                 return_ACPI_STATUS(status);
 963         }
 964
 965         /* Extract length operand */
 966
 967         arg_desc = walk_state->operands[walk_state->num_operands - 1];
 968         length = (u32) arg_desc->integer.value;
 969
 970         /* Cleanup for length operand */
 971
 972         status = acpi_ds_obj_stack_pop(1, walk_state);
 973         if (ACPI_FAILURE(status)) {
 974                 return_ACPI_STATUS(status);
 975         }
 976
 977         acpi_ut_remove_reference(arg_desc);
 978
 979         /*
 980          * Create the actual data object
 981          */
 982         switch (op->common.aml_opcode) {
 983         case AML_BUFFER_OP:
 984
 985                 status =
 986                     acpi_ds_build_internal_buffer_obj(walk_state, op, length,
 987                                                       &obj_desc);
 988                 break;
 989
 990         case AML_PACKAGE_OP:
 991         case AML_VAR_PACKAGE_OP:
 992
 993                 status =
 994                     acpi_ds_build_internal_package_obj(walk_state, op, length,
 995                                                        &obj_desc);
 996                 break;
 997
 998         default:
 999                 return_ACPI_STATUS(AE_AML_BAD_OPCODE);
1000         }
1001
1002         if (ACPI_SUCCESS(status)) {
1003                 /*
1004                  * Return the object in the walk_state, unless the parent is a package -
1005                  * in this case, the return object will be stored in the parse tree
1006                  * for the package.
1007                  */
1008                 if ((!op->common.parent) ||
1009                     ((op->common.parent->common.aml_opcode != AML_PACKAGE_OP) &&
1010                      (op->common.parent->common.aml_opcode !=
1011                       AML_VAR_PACKAGE_OP)
1012                      && (op->common.parent->common.aml_opcode != AML_NAME_OP))) {
1013                         walk_state->result_obj = obj_desc;
1014                 }
1015         }
1016
1017         return_ACPI_STATUS(status);
1018 }
1019
1020 /*******************************************************************************
1021  *
1022  * FUNCTION:    acpi_ds_eval_bank_field_operands
1023  *
1024  * PARAMETERS:  walk_state      - Current walk
1025  *              Op              - A valid bank_field Op object
1026  *
1027  * RETURN:      Status
1028  *
1029  * DESCRIPTION: Get bank_field bank_value
1030  *              Called from acpi_ds_exec_end_op during bank_field parse tree walk
1031  *
1032  ******************************************************************************/
1033
1034 acpi_status
1035 acpi_ds_eval_bank_field_operands(struct acpi_walk_state *walk_state,
1036                                  union acpi_parse_object *op)
1037 {
1038         acpi_status status;
1039         union acpi_operand_object *obj_desc;
1040         union acpi_operand_object *operand_desc;
1041         struct acpi_namespace_node *node;
1042         union acpi_parse_object *next_op;
1043         union acpi_parse_object *arg;
1044
1045         ACPI_FUNCTION_TRACE_PTR(ds_eval_bank_field_operands, op);
1046
1047         /*
1048          * This is where we evaluate the bank_value field of the
1049          * bank_field declaration
1050          */
1051
1052         /* next_op points to the op that holds the Region */
1053
1054         next_op = op->common.value.arg;
1055
1056         /* next_op points to the op that holds the Bank Register */
1057
1058         next_op = next_op->common.next;
1059
1060         /* next_op points to the op that holds the Bank Value */
1061
1062         next_op = next_op->common.next;
1063
1064         /*
1065          * Set proper index into operand stack for acpi_ds_obj_stack_push
1066          * invoked inside acpi_ds_create_operand.
1067          *
1068          * We use walk_state->Operands[0] to store the evaluated bank_value
1069          */
1070         walk_state->operand_index = 0;
1071
1072         status = acpi_ds_create_operand(walk_state, next_op, 0);
1073         if (ACPI_FAILURE(status)) {
1074                 return_ACPI_STATUS(status);
1075         }
1076
1077         status = acpi_ex_resolve_to_value(&walk_state->operands[0], walk_state);
1078         if (ACPI_FAILURE(status)) {
1079                 return_ACPI_STATUS(status);
1080         }
1081
1082         ACPI_DUMP_OPERANDS(ACPI_WALK_OPERANDS,
1083                            acpi_ps_get_opcode_name(op->common.aml_opcode), 1);
1084         /*
1085          * Get the bank_value operand and save it
1086          * (at Top of stack)
1087          */
1088         operand_desc = walk_state->operands[0];
1089
1090         /* Arg points to the start Bank Field */
1091
1092         arg = acpi_ps_get_arg(op, 4);
1093         while (arg) {
1094
1095                 /* Ignore OFFSET and ACCESSAS terms here */
1096
1097                 if (arg->common.aml_opcode == AML_INT_NAMEDFIELD_OP) {
1098                         node = arg->common.node;
1099
1100                         obj_desc = acpi_ns_get_attached_object(node);
1101                         if (!obj_desc) {
1102                                 return_ACPI_STATUS(AE_NOT_EXIST);
1103                         }
1104
1105                         obj_desc->bank_field.value =
1106                             (u32) operand_desc->integer.value;
1107                 }
1108
1109                 /* Move to next field in the list */
1110
1111                 arg = arg->common.next;
1112         }
1113
1114         acpi_ut_remove_reference(operand_desc);
1115         return_ACPI_STATUS(status);
1116 }
1117
1118 /*******************************************************************************
1119  *
1120  * FUNCTION:    acpi_ds_exec_begin_control_op
1121  *
1122  * PARAMETERS:  walk_list       - The list that owns the walk stack
1123  *              Op              - The control Op
1124  *
1125  * RETURN:      Status
1126  *
1127  * DESCRIPTION: Handles all control ops encountered during control method
1128  *              execution.
1129  *
1130  ******************************************************************************/
1131
1132 acpi_status
1133 acpi_ds_exec_begin_control_op(struct acpi_walk_state *walk_state,
1134                               union acpi_parse_object *op)
1135 {
1136         acpi_status status = AE_OK;
1137         union acpi_generic_state *control_state;
1138
1139         ACPI_FUNCTION_NAME(ds_exec_begin_control_op);
1140
1141         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n", op,
1142                           op->common.aml_opcode, walk_state));
1143
1144         switch (op->common.aml_opcode) {
1145         case AML_WHILE_OP:
1146
1147                 /*
1148                  * If this is an additional iteration of a while loop, continue.
1149                  * There is no need to allocate a new control state.
1150                  */
1151                 if (walk_state->control_state) {
1152                         if (walk_state->control_state->control.aml_predicate_start
1153                                 == (walk_state->parser_state.aml - 1)) {
1154
1155                                 /* Reset the state to start-of-loop */
1156
1157                                 walk_state->control_state->common.state =
1158                                     ACPI_CONTROL_CONDITIONAL_EXECUTING;
1159                                 break;
1160                         }
1161                 }
1162
1163                 /*lint -fallthrough */
1164
1165         case AML_IF_OP:
1166
1167                 /*
1168                  * IF/WHILE: Create a new control state to manage these
1169                  * constructs. We need to manage these as a stack, in order
1170                  * to handle nesting.
1171                  */
1172                 control_state = acpi_ut_create_control_state();
1173                 if (!control_state) {
1174                         status = AE_NO_MEMORY;
1175                         break;
1176                 }
1177                 /*
1178                  * Save a pointer to the predicate for multiple executions
1179                  * of a loop
1180                  */
1181                 control_state->control.aml_predicate_start =
1182                     walk_state->parser_state.aml - 1;
1183                 control_state->control.package_end =
1184                     walk_state->parser_state.pkg_end;
1185                 control_state->control.opcode = op->common.aml_opcode;
1186
1187                 /* Push the control state on this walk's control stack */
1188
1189                 acpi_ut_push_generic_state(&walk_state->control_state,
1190                                            control_state);
1191                 break;
1192
1193         case AML_ELSE_OP:
1194
1195                 /* Predicate is in the state object */
1196                 /* If predicate is true, the IF was executed, ignore ELSE part */
1197
1198                 if (walk_state->last_predicate) {
1199                         status = AE_CTRL_TRUE;
1200                 }
1201
1202                 break;
1203
1204         case AML_RETURN_OP:
1205
1206                 break;
1207
1208         default:
1209                 break;
1210         }
1211
1212         return (status);
1213 }
1214
1215 /*******************************************************************************
1216  *
1217  * FUNCTION:    acpi_ds_exec_end_control_op
1218  *
1219  * PARAMETERS:  walk_list       - The list that owns the walk stack
1220  *              Op              - The control Op
1221  *
1222  * RETURN:      Status
1223  *
1224  * DESCRIPTION: Handles all control ops encountered during control method
1225  *              execution.
1226  *
1227  ******************************************************************************/
1228
1229 acpi_status
1230 acpi_ds_exec_end_control_op(struct acpi_walk_state * walk_state,
1231                             union acpi_parse_object * op)
1232 {
1233         acpi_status status = AE_OK;
1234         union acpi_generic_state *control_state;
1235
1236         ACPI_FUNCTION_NAME(ds_exec_end_control_op);
1237
1238         switch (op->common.aml_opcode) {
1239         case AML_IF_OP:
1240
1241                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", op));
1242
1243                 /*
1244                  * Save the result of the predicate in case there is an
1245                  * ELSE to come
1246                  */
1247                 walk_state->last_predicate =
1248                     (u8) walk_state->control_state->common.value;
1249
1250                 /*
1251                  * Pop the control state that was created at the start
1252                  * of the IF and free it
1253                  */
1254                 control_state =
1255                     acpi_ut_pop_generic_state(&walk_state->control_state);
1256                 acpi_ut_delete_generic_state(control_state);
1257                 break;
1258
1259         case AML_ELSE_OP:
1260
1261                 break;
1262
1263         case AML_WHILE_OP:
1264
1265                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", op));
1266
1267                 control_state = walk_state->control_state;
1268                 if (control_state->common.value) {
1269
1270                         /* Predicate was true, the body of the loop was just executed */
1271
1272                         /*
1273                          * This loop counter mechanism allows the interpreter to escape
1274                          * possibly infinite loops. This can occur in poorly written AML
1275                          * when the hardware does not respond within a while loop and the
1276                          * loop does not implement a timeout.
1277                          */
1278                         control_state->control.loop_count++;
1279                         if (control_state->control.loop_count >
1280                                 ACPI_MAX_LOOP_ITERATIONS) {
1281                                 status = AE_AML_INFINITE_LOOP;
1282                                 break;
1283                         }
1284
1285                         /*
1286                          * Go back and evaluate the predicate and maybe execute the loop
1287                          * another time
1288                          */
1289                         status = AE_CTRL_PENDING;
1290                         walk_state->aml_last_while =
1291                             control_state->control.aml_predicate_start;
1292                         break;
1293                 }
1294
1295                 /* Predicate was false, terminate this while loop */
1296
1297                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
1298                                   "[WHILE_OP] termination! Op=%p\n", op));
1299
1300                 /* Pop this control state and free it */
1301
1302                 control_state =
1303                     acpi_ut_pop_generic_state(&walk_state->control_state);
1304                 acpi_ut_delete_generic_state(control_state);
1305                 break;
1306
1307         case AML_RETURN_OP:
1308
1309                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
1310                                   "[RETURN_OP] Op=%p Arg=%p\n", op,
1311                                   op->common.value.arg));
1312
1313                 /*
1314                  * One optional operand -- the return value
1315                  * It can be either an immediate operand or a result that
1316                  * has been bubbled up the tree
1317                  */
1318                 if (op->common.value.arg) {
1319
1320                         /* Since we have a real Return(), delete any implicit return */
1321
1322                         acpi_ds_clear_implicit_return(walk_state);
1323
1324                         /* Return statement has an immediate operand */
1325
1326                         status =
1327                             acpi_ds_create_operands(walk_state,
1328                                                     op->common.value.arg);
1329                         if (ACPI_FAILURE(status)) {
1330                                 return (status);
1331                         }
1332
1333                         /*
1334                          * If value being returned is a Reference (such as
1335                          * an arg or local), resolve it now because it may
1336                          * cease to exist at the end of the method.
1337                          */
1338                         status =
1339                             acpi_ex_resolve_to_value(&walk_state->operands[0],
1340                                                      walk_state);
1341                         if (ACPI_FAILURE(status)) {
1342                                 return (status);
1343                         }
1344
1345                         /*
1346                          * Get the return value and save as the last result
1347                          * value.  This is the only place where walk_state->return_desc
1348                          * is set to anything other than zero!
1349                          */
1350                         walk_state->return_desc = walk_state->operands[0];
1351                 } else if (walk_state->result_count) {
1352
1353                         /* Since we have a real Return(), delete any implicit return */
1354
1355                         acpi_ds_clear_implicit_return(walk_state);
1356
1357                         /*
1358                          * The return value has come from a previous calculation.
1359                          *
1360                          * If value being returned is a Reference (such as
1361                          * an arg or local), resolve it now because it may
1362                          * cease to exist at the end of the method.
1363                          *
1364                          * Allow references created by the Index operator to return unchanged.
1365                          */
1366                         if ((ACPI_GET_DESCRIPTOR_TYPE
1367                              (walk_state->results->results.obj_desc[0]) ==
1368                              ACPI_DESC_TYPE_OPERAND)
1369                             && ((walk_state->results->results.obj_desc[0])->
1370                                 common.type == ACPI_TYPE_LOCAL_REFERENCE)
1371                             && ((walk_state->results->results.obj_desc[0])->
1372                                 reference.class != ACPI_REFCLASS_INDEX)) {
1373                                 status =
1374                                     acpi_ex_resolve_to_value(&walk_state->
1375                                                              results->results.
1376                                                              obj_desc[0],
1377                                                              walk_state);
1378                                 if (ACPI_FAILURE(status)) {
1379                                         return (status);
1380                                 }
1381                         }
1382
1383                         walk_state->return_desc =
1384                             walk_state->results->results.obj_desc[0];
1385                 } else {
1386                         /* No return operand */
1387
1388                         if (walk_state->num_operands) {
1389                                 acpi_ut_remove_reference(walk_state->
1390                                                          operands[0]);
1391                         }
1392
1393                         walk_state->operands[0] = NULL;
1394                         walk_state->num_operands = 0;
1395                         walk_state->return_desc = NULL;
1396                 }
1397
1398                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
1399                                   "Completed RETURN_OP State=%p, RetVal=%p\n",
1400                                   walk_state, walk_state->return_desc));
1401
1402                 /* End the control method execution right now */
1403
1404                 status = AE_CTRL_TERMINATE;
1405                 break;
1406
1407         case AML_NOOP_OP:
1408
1409                 /* Just do nothing! */
1410                 break;
1411
1412         case AML_BREAK_POINT_OP:
1413
1414                 /*
1415                  * Set the single-step flag. This will cause the debugger (if present)
1416                  * to break to the console within the AML debugger at the start of the
1417                  * next AML instruction.
1418                  */
1419                 ACPI_DEBUGGER_EXEC(acpi_gbl_cm_single_step = TRUE);
1420                 ACPI_DEBUGGER_EXEC(acpi_os_printf
1421                                    ("**break** Executed AML BreakPoint opcode\n"));
1422
1423                 /* Call to the OSL in case OS wants a piece of the action */
1424
1425                 status = acpi_os_signal(ACPI_SIGNAL_BREAKPOINT,
1426                                         "Executed AML Breakpoint opcode");
1427                 break;
1428
1429         case AML_BREAK_OP:
1430         case AML_CONTINUE_OP:   /* ACPI 2.0 */
1431
1432                 /* Pop and delete control states until we find a while */
1433
1434                 while (walk_state->control_state &&
1435                        (walk_state->control_state->control.opcode !=
1436                         AML_WHILE_OP)) {
1437                         control_state =
1438                             acpi_ut_pop_generic_state(&walk_state->
1439                                                       control_state);
1440                         acpi_ut_delete_generic_state(control_state);
1441                 }
1442
1443                 /* No while found? */
1444
1445                 if (!walk_state->control_state) {
1446                         return (AE_AML_NO_WHILE);
1447                 }
1448
1449                 /* Was: walk_state->aml_last_while = walk_state->control_state->Control.aml_predicate_start; */
1450
1451                 walk_state->aml_last_while =
1452                     walk_state->control_state->control.package_end;
1453
1454                 /* Return status depending on opcode */
1455
1456                 if (op->common.aml_opcode == AML_BREAK_OP) {
1457                         status = AE_CTRL_BREAK;
1458                 } else {
1459                         status = AE_CTRL_CONTINUE;
1460                 }
1461                 break;
1462
1463         default:
1464
1465                 ACPI_ERROR((AE_INFO, "Unknown control opcode=0x%X Op=%p",
1466                             op->common.aml_opcode, op));
1467
1468                 status = AE_AML_BAD_OPCODE;
1469                 break;
1470         }
1471
1472         return (status);
1473 }