drivers/acpi/acpica/dsopcode.c

   1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
   2 /******************************************************************************
   3  *
   4  * Module Name: dsopcode - Dispatcher support for regions and fields
   5  *
   6  * Copyright (C) 2000 - 2020, Intel Corp.
   7  *
   8  *****************************************************************************/
   9
  10 #include <acpi/acpi.h>
  11 #include "accommon.h"
  12 #include "acparser.h"
  13 #include "amlcode.h"
  14 #include "acdispat.h"
  15 #include "acinterp.h"
  16 #include "acnamesp.h"
  17 #include "acevents.h"
  18 #include "actables.h"
  19
  20 #define _COMPONENT          ACPI_DISPATCHER
  21 ACPI_MODULE_NAME("dsopcode")
  22
  23 /* Local prototypes */
  24 static acpi_status
  25 acpi_ds_init_buffer_field(u16 aml_opcode,
  26                           union acpi_operand_object *obj_desc,
  27                           union acpi_operand_object *buffer_desc,
  28                           union acpi_operand_object *offset_desc,
  29                           union acpi_operand_object *length_desc,
  30                           union acpi_operand_object *result_desc);
  31
  32 /*******************************************************************************
  33  *
  34  * FUNCTION:    acpi_ds_initialize_region
  35  *
  36  * PARAMETERS:  obj_handle      - Region namespace node
  37  *
  38  * RETURN:      Status
  39  *
  40  * DESCRIPTION: Front end to ev_initialize_region
  41  *
  42  ******************************************************************************/
  43
  44 acpi_status acpi_ds_initialize_region(acpi_handle obj_handle)
  45 {
  46         union acpi_operand_object *obj_desc;
  47         acpi_status status;
  48
  49         obj_desc = acpi_ns_get_attached_object(obj_handle);
  50
  51         /* Namespace is NOT locked */
  52
  53         status = acpi_ev_initialize_region(obj_desc);
  54         return (status);
  55 }
  56
  57 /*******************************************************************************
  58  *
  59  * FUNCTION:    acpi_ds_init_buffer_field
  60  *
  61  * PARAMETERS:  aml_opcode      - create_xxx_field
  62  *              obj_desc        - buffer_field object
  63  *              buffer_desc     - Host Buffer
  64  *              offset_desc     - Offset into buffer
  65  *              length_desc     - Length of field (CREATE_FIELD_OP only)
  66  *              result_desc     - Where to store the result
  67  *
  68  * RETURN:      Status
  69  *
  70  * DESCRIPTION: Perform actual initialization of a buffer field
  71  *
  72  ******************************************************************************/
  73
  74 static acpi_status
  75 acpi_ds_init_buffer_field(u16 aml_opcode,
  76                           union acpi_operand_object *obj_desc,
  77                           union acpi_operand_object *buffer_desc,
  78                           union acpi_operand_object *offset_desc,
  79                           union acpi_operand_object *length_desc,
  80                           union acpi_operand_object *result_desc)
  81 {
  82         u32 offset;
  83         u32 bit_offset;
  84         u32 bit_count;
  85         u8 field_flags;
  86         acpi_status status;
  87
  88         ACPI_FUNCTION_TRACE_PTR(ds_init_buffer_field, obj_desc);
  89
  90         /* Host object must be a Buffer */
  91
  92         if (buffer_desc->common.type != ACPI_TYPE_BUFFER) {
  93                 ACPI_ERROR((AE_INFO,
  94                             "Target of Create Field is not a Buffer object - %s",
  95                             acpi_ut_get_object_type_name(buffer_desc)));
  96
  97                 status = AE_AML_OPERAND_TYPE;
  98                 goto cleanup;
  99         }
 100
 101         /*
 102          * The last parameter to all of these opcodes (result_desc) started
 103          * out as a name_string, and should therefore now be a NS node
 104          * after resolution in acpi_ex_resolve_operands().
 105          */
 106         if (ACPI_GET_DESCRIPTOR_TYPE(result_desc) != ACPI_DESC_TYPE_NAMED) {
 107                 ACPI_ERROR((AE_INFO,
 108                             "(%s) destination not a NS Node [%s]",
 109                             acpi_ps_get_opcode_name(aml_opcode),
 110                             acpi_ut_get_descriptor_name(result_desc)));
 111
 112                 status = AE_AML_OPERAND_TYPE;
 113                 goto cleanup;
 114         }
 115
 116         offset = (u32) offset_desc->integer.value;
 117
 118         /*
 119          * Setup the Bit offsets and counts, according to the opcode
 120          */
 121         switch (aml_opcode) {
 122         case AML_CREATE_FIELD_OP:
 123
 124                 /* Offset is in bits, count is in bits */
 125
 126                 field_flags = AML_FIELD_ACCESS_BYTE;
 127                 bit_offset = offset;
 128                 bit_count = (u32) length_desc->integer.value;
 129
 130                 /* Must have a valid (>0) bit count */
 131
 132                 if (bit_count == 0) {
 133                         ACPI_BIOS_ERROR((AE_INFO,
 134                                          "Attempt to CreateField of length zero"));
 135                         status = AE_AML_OPERAND_VALUE;
 136                         goto cleanup;
 137                 }
 138                 break;
 139
 140         case AML_CREATE_BIT_FIELD_OP:
 141
 142                 /* Offset is in bits, Field is one bit */
 143
 144                 bit_offset = offset;
 145                 bit_count = 1;
 146                 field_flags = AML_FIELD_ACCESS_BYTE;
 147                 break;
 148
 149         case AML_CREATE_BYTE_FIELD_OP:
 150
 151                 /* Offset is in bytes, field is one byte */
 152
 153                 bit_offset = 8 * offset;
 154                 bit_count = 8;
 155                 field_flags = AML_FIELD_ACCESS_BYTE;
 156                 break;
 157
 158         case AML_CREATE_WORD_FIELD_OP:
 159
 160                 /* Offset is in bytes, field is one word */
 161
 162                 bit_offset = 8 * offset;
 163                 bit_count = 16;
 164                 field_flags = AML_FIELD_ACCESS_WORD;
 165                 break;
 166
 167         case AML_CREATE_DWORD_FIELD_OP:
 168
 169                 /* Offset is in bytes, field is one dword */
 170
 171                 bit_offset = 8 * offset;
 172                 bit_count = 32;
 173                 field_flags = AML_FIELD_ACCESS_DWORD;
 174                 break;
 175
 176         case AML_CREATE_QWORD_FIELD_OP:
 177
 178                 /* Offset is in bytes, field is one qword */
 179
 180                 bit_offset = 8 * offset;
 181                 bit_count = 64;
 182                 field_flags = AML_FIELD_ACCESS_QWORD;
 183                 break;
 184
 185         default:
 186
 187                 ACPI_ERROR((AE_INFO,
 188                             "Unknown field creation opcode 0x%02X",
 189                             aml_opcode));
 190                 status = AE_AML_BAD_OPCODE;
 191                 goto cleanup;
 192         }
 193
 194         /* Entire field must fit within the current length of the buffer */
 195
 196         if ((bit_offset + bit_count) > (8 * (u32)buffer_desc->buffer.length)) {
 197                 status = AE_AML_BUFFER_LIMIT;
 198                 ACPI_BIOS_EXCEPTION((AE_INFO, status,
 199                                      "Field [%4.4s] at bit offset/length %u/%u "
 200                                      "exceeds size of target Buffer (%u bits)",
 201                                      acpi_ut_get_node_name(result_desc),
 202                                      bit_offset, bit_count,
 203                                      8 * (u32)buffer_desc->buffer.length));
 204                 goto cleanup;
 205         }
 206
 207         /*
 208          * Initialize areas of the field object that are common to all fields
 209          * For field_flags, use LOCK_RULE = 0 (NO_LOCK),
 210          * UPDATE_RULE = 0 (UPDATE_PRESERVE)
 211          */
 212         status =
 213             acpi_ex_prep_common_field_object(obj_desc, field_flags, 0,
 214                                              bit_offset, bit_count);
 215         if (ACPI_FAILURE(status)) {
 216                 goto cleanup;
 217         }
 218
 219         obj_desc->buffer_field.buffer_obj = buffer_desc;
 220         obj_desc->buffer_field.is_create_field =
 221             aml_opcode == AML_CREATE_FIELD_OP;
 222
 223         /* Reference count for buffer_desc inherits obj_desc count */
 224
 225         buffer_desc->common.reference_count = (u16)
 226             (buffer_desc->common.reference_count +
 227              obj_desc->common.reference_count);
 228
 229 cleanup:
 230
 231         /* Always delete the operands */
 232
 233         acpi_ut_remove_reference(offset_desc);
 234         acpi_ut_remove_reference(buffer_desc);
 235
 236         if (aml_opcode == AML_CREATE_FIELD_OP) {
 237                 acpi_ut_remove_reference(length_desc);
 238         }
 239
 240         /* On failure, delete the result descriptor */
 241
 242         if (ACPI_FAILURE(status)) {
 243                 acpi_ut_remove_reference(result_desc);  /* Result descriptor */
 244         } else {
 245                 /* Now the address and length are valid for this buffer_field */
 246
 247                 obj_desc->buffer_field.flags |= AOPOBJ_DATA_VALID;
 248         }
 249
 250         return_ACPI_STATUS(status);
 251 }
 252
 253 /*******************************************************************************
 254  *
 255  * FUNCTION:    acpi_ds_eval_buffer_field_operands
 256  *
 257  * PARAMETERS:  walk_state      - Current walk
 258  *              op              - A valid buffer_field Op object
 259  *
 260  * RETURN:      Status
 261  *
 262  * DESCRIPTION: Get buffer_field Buffer and Index
 263  *              Called from acpi_ds_exec_end_op during buffer_field parse tree walk
 264  *
 265  ******************************************************************************/
 266
 267 acpi_status
 268 acpi_ds_eval_buffer_field_operands(struct acpi_walk_state *walk_state,
 269                                    union acpi_parse_object *op)
 270 {
 271         acpi_status status;
 272         union acpi_operand_object *obj_desc;
 273         struct acpi_namespace_node *node;
 274         union acpi_parse_object *next_op;
 275
 276         ACPI_FUNCTION_TRACE_PTR(ds_eval_buffer_field_operands, op);
 277
 278         /*
 279          * This is where we evaluate the address and length fields of the
 280          * create_xxx_field declaration
 281          */
 282         node = op->common.node;
 283
 284         /* next_op points to the op that holds the Buffer */
 285
 286         next_op = op->common.value.arg;
 287
 288         /* Evaluate/create the address and length operands */
 289
 290         status = acpi_ds_create_operands(walk_state, next_op);
 291         if (ACPI_FAILURE(status)) {
 292                 return_ACPI_STATUS(status);
 293         }
 294
 295         obj_desc = acpi_ns_get_attached_object(node);
 296         if (!obj_desc) {
 297                 return_ACPI_STATUS(AE_NOT_EXIST);
 298         }
 299
 300         /* Resolve the operands */
 301
 302         status =
 303             acpi_ex_resolve_operands(op->common.aml_opcode, ACPI_WALK_OPERANDS,
 304                                      walk_state);
 305         if (ACPI_FAILURE(status)) {
 306                 ACPI_ERROR((AE_INFO, "(%s) bad operand(s), status 0x%X",
 307                             acpi_ps_get_opcode_name(op->common.aml_opcode),
 308                             status));
 309
 310                 return_ACPI_STATUS(status);
 311         }
 312
 313         /* Initialize the Buffer Field */
 314
 315         if (op->common.aml_opcode == AML_CREATE_FIELD_OP) {
 316
 317                 /* NOTE: Slightly different operands for this opcode */
 318
 319                 status =
 320                     acpi_ds_init_buffer_field(op->common.aml_opcode, obj_desc,
 321                                               walk_state->operands[0],
 322                                               walk_state->operands[1],
 323                                               walk_state->operands[2],
 324                                               walk_state->operands[3]);
 325         } else {
 326                 /* All other, create_xxx_field opcodes */
 327
 328                 status =
 329                     acpi_ds_init_buffer_field(op->common.aml_opcode, obj_desc,
 330                                               walk_state->operands[0],
 331                                               walk_state->operands[1], NULL,
 332                                               walk_state->operands[2]);
 333         }
 334
 335         return_ACPI_STATUS(status);
 336 }
 337
 338 /*******************************************************************************
 339  *
 340  * FUNCTION:    acpi_ds_eval_region_operands
 341  *
 342  * PARAMETERS:  walk_state      - Current walk
 343  *              op              - A valid region Op object
 344  *
 345  * RETURN:      Status
 346  *
 347  * DESCRIPTION: Get region address and length
 348  *              Called from acpi_ds_exec_end_op during op_region parse tree walk
 349  *
 350  ******************************************************************************/
 351
 352 acpi_status
 353 acpi_ds_eval_region_operands(struct acpi_walk_state *walk_state,
 354                              union acpi_parse_object *op)
 355 {
 356         acpi_status status;
 357         union acpi_operand_object *obj_desc;
 358         union acpi_operand_object *operand_desc;
 359         struct acpi_namespace_node *node;
 360         union acpi_parse_object *next_op;
 361         acpi_adr_space_type space_id;
 362
 363         ACPI_FUNCTION_TRACE_PTR(ds_eval_region_operands, op);
 364
 365         /*
 366          * This is where we evaluate the address and length fields of the
 367          * op_region declaration
 368          */
 369         node = op->common.node;
 370
 371         /* next_op points to the op that holds the space_ID */
 372
 373         next_op = op->common.value.arg;
 374         space_id = (acpi_adr_space_type)next_op->common.value.integer;
 375
 376         /* next_op points to address op */
 377
 378         next_op = next_op->common.next;
 379
 380         /* Evaluate/create the address and length operands */
 381
 382         status = acpi_ds_create_operands(walk_state, next_op);
 383         if (ACPI_FAILURE(status)) {
 384                 return_ACPI_STATUS(status);
 385         }
 386
 387         /* Resolve the length and address operands to numbers */
 388
 389         status =
 390             acpi_ex_resolve_operands(op->common.aml_opcode, ACPI_WALK_OPERANDS,
 391                                      walk_state);
 392         if (ACPI_FAILURE(status)) {
 393                 return_ACPI_STATUS(status);
 394         }
 395
 396         obj_desc = acpi_ns_get_attached_object(node);
 397         if (!obj_desc) {
 398                 return_ACPI_STATUS(AE_NOT_EXIST);
 399         }
 400
 401         /*
 402          * Get the length operand and save it
 403          * (at Top of stack)
 404          */
 405         operand_desc = walk_state->operands[walk_state->num_operands - 1];
 406
 407         obj_desc->region.length = (u32) operand_desc->integer.value;
 408         acpi_ut_remove_reference(operand_desc);
 409
 410         /* A zero-length operation region is unusable. Just warn */
 411
 412         if (!obj_desc->region.length
 413             && (space_id < ACPI_NUM_PREDEFINED_REGIONS)) {
 414                 ACPI_WARNING((AE_INFO,
 415                               "Operation Region [%4.4s] has zero length (SpaceId %X)",
 416                               node->name.ascii, space_id));
 417         }
 418
 419         /*
 420          * Get the address and save it
 421          * (at top of stack - 1)
 422          */
 423         operand_desc = walk_state->operands[walk_state->num_operands - 2];
 424
 425         obj_desc->region.address = (acpi_physical_address)
 426             operand_desc->integer.value;
 427         acpi_ut_remove_reference(operand_desc);
 428
 429         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "RgnObj %p Addr %8.8X%8.8X Len %X\n",
 430                           obj_desc,
 431                           ACPI_FORMAT_UINT64(obj_desc->region.address),
 432                           obj_desc->region.length));
 433
 434         status = acpi_ut_add_address_range(obj_desc->region.space_id,
 435                                            obj_desc->region.address,
 436                                            obj_desc->region.length, node);
 437
 438         /* Now the address and length are valid for this opregion */
 439
 440         obj_desc->region.flags |= AOPOBJ_DATA_VALID;
 441         return_ACPI_STATUS(status);
 442 }
 443
 444 /*******************************************************************************
 445  *
 446  * FUNCTION:    acpi_ds_eval_table_region_operands
 447  *
 448  * PARAMETERS:  walk_state      - Current walk
 449  *              op              - A valid region Op object
 450  *
 451  * RETURN:      Status
 452  *
 453  * DESCRIPTION: Get region address and length.
 454  *              Called from acpi_ds_exec_end_op during data_table_region parse
 455  *              tree walk.
 456  *
 457  ******************************************************************************/
 458
 459 acpi_status
 460 acpi_ds_eval_table_region_operands(struct acpi_walk_state *walk_state,
 461                                    union acpi_parse_object *op)
 462 {
 463         acpi_status status;
 464         union acpi_operand_object *obj_desc;
 465         union acpi_operand_object **operand;
 466         struct acpi_namespace_node *node;
 467         union acpi_parse_object *next_op;
 468         struct acpi_table_header *table;
 469         u32 table_index;
 470
 471         ACPI_FUNCTION_TRACE_PTR(ds_eval_table_region_operands, op);
 472
 473         /*
 474          * This is where we evaluate the Signature string, oem_id string,
 475          * and oem_table_id string of the Data Table Region declaration
 476          */
 477         node = op->common.node;
 478
 479         /* next_op points to Signature string op */
 480
 481         next_op = op->common.value.arg;
 482
 483         /*
 484          * Evaluate/create the Signature string, oem_id string,
 485          * and oem_table_id string operands
 486          */
 487         status = acpi_ds_create_operands(walk_state, next_op);
 488         if (ACPI_FAILURE(status)) {
 489                 return_ACPI_STATUS(status);
 490         }
 491
 492         operand = &walk_state->operands[0];
 493
 494         /*
 495          * Resolve the Signature string, oem_id string,
 496          * and oem_table_id string operands
 497          */
 498         status =
 499             acpi_ex_resolve_operands(op->common.aml_opcode, ACPI_WALK_OPERANDS,
 500                                      walk_state);
 501         if (ACPI_FAILURE(status)) {
 502                 goto cleanup;
 503         }
 504
 505         /* Find the ACPI table */
 506
 507         status = acpi_tb_find_table(operand[0]->string.pointer,
 508                                     operand[1]->string.pointer,
 509                                     operand[2]->string.pointer, &table_index);
 510         if (ACPI_FAILURE(status)) {
 511                 if (status == AE_NOT_FOUND) {
 512                         ACPI_ERROR((AE_INFO,
 513                                     "ACPI Table [%4.4s] OEM:(%s, %s) not found in RSDT/XSDT",
 514                                     operand[0]->string.pointer,
 515                                     operand[1]->string.pointer,
 516                                     operand[2]->string.pointer));
 517                 }
 518                 goto cleanup;
 519         }
 520
 521         status = acpi_get_table_by_index(table_index, &table);
 522         if (ACPI_FAILURE(status)) {
 523                 goto cleanup;
 524         }
 525
 526         obj_desc = acpi_ns_get_attached_object(node);
 527         if (!obj_desc) {
 528                 status = AE_NOT_EXIST;
 529                 goto cleanup;
 530         }
 531
 532         obj_desc->region.address = ACPI_PTR_TO_PHYSADDR(table);
 533         obj_desc->region.length = table->length;
 534
 535         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "RgnObj %p Addr %8.8X%8.8X Len %X\n",
 536                           obj_desc,
 537                           ACPI_FORMAT_UINT64(obj_desc->region.address),
 538                           obj_desc->region.length));
 539
 540         /* Now the address and length are valid for this opregion */
 541
 542         obj_desc->region.flags |= AOPOBJ_DATA_VALID;
 543
 544 cleanup:
 545         acpi_ut_remove_reference(operand[0]);
 546         acpi_ut_remove_reference(operand[1]);
 547         acpi_ut_remove_reference(operand[2]);
 548
 549         return_ACPI_STATUS(status);
 550 }
 551
 552 /*******************************************************************************
 553  *
 554  * FUNCTION:    acpi_ds_eval_data_object_operands
 555  *
 556  * PARAMETERS:  walk_state      - Current walk
 557  *              op              - A valid data_object Op object
 558  *              obj_desc        - data_object
 559  *
 560  * RETURN:      Status
 561  *
 562  * DESCRIPTION: Get the operands and complete the following data object types:
 563  *              Buffer, Package.
 564  *
 565  ******************************************************************************/
 566
 567 acpi_status
 568 acpi_ds_eval_data_object_operands(struct acpi_walk_state *walk_state,
 569                                   union acpi_parse_object *op,
 570                                   union acpi_operand_object *obj_desc)
 571 {
 572         acpi_status status;
 573         union acpi_operand_object *arg_desc;
 574         u32 length;
 575
 576         ACPI_FUNCTION_TRACE(ds_eval_data_object_operands);
 577
 578         /* The first operand (for all of these data objects) is the length */
 579
 580         /*
 581          * Set proper index into operand stack for acpi_ds_obj_stack_push
 582          * invoked inside acpi_ds_create_operand.
 583          */
 584         walk_state->operand_index = walk_state->num_operands;
 585
 586         /* Ignore if child is not valid */
 587
 588         if (!op->common.value.arg) {
 589                 ACPI_ERROR((AE_INFO,
 590                             "Missing child while evaluating opcode %4.4X, Op %p",
 591                             op->common.aml_opcode, op));
 592                 return_ACPI_STATUS(AE_OK);
 593         }
 594
 595         status = acpi_ds_create_operand(walk_state, op->common.value.arg, 1);
 596         if (ACPI_FAILURE(status)) {
 597                 return_ACPI_STATUS(status);
 598         }
 599
 600         status = acpi_ex_resolve_operands(walk_state->opcode,
 601                                           &(walk_state->
 602                                             operands[walk_state->num_operands -
 603                                                      1]), walk_state);
 604         if (ACPI_FAILURE(status)) {
 605                 return_ACPI_STATUS(status);
 606         }
 607
 608         /* Extract length operand */
 609
 610         arg_desc = walk_state->operands[walk_state->num_operands - 1];
 611         length = (u32) arg_desc->integer.value;
 612
 613         /* Cleanup for length operand */
 614
 615         status = acpi_ds_obj_stack_pop(1, walk_state);
 616         if (ACPI_FAILURE(status)) {
 617                 return_ACPI_STATUS(status);
 618         }
 619
 620         acpi_ut_remove_reference(arg_desc);
 621
 622         /*
 623          * Create the actual data object
 624          */
 625         switch (op->common.aml_opcode) {
 626         case AML_BUFFER_OP:
 627
 628                 status =
 629                     acpi_ds_build_internal_buffer_obj(walk_state, op, length,
 630                                                       &obj_desc);
 631                 break;
 632
 633         case AML_PACKAGE_OP:
 634         case AML_VARIABLE_PACKAGE_OP:
 635
 636                 status =
 637                     acpi_ds_build_internal_package_obj(walk_state, op, length,
 638                                                        &obj_desc);
 639                 break;
 640
 641         default:
 642
 643                 return_ACPI_STATUS(AE_AML_BAD_OPCODE);
 644         }
 645
 646         if (ACPI_SUCCESS(status)) {
 647                 /*
 648                  * Return the object in the walk_state, unless the parent is a package -
 649                  * in this case, the return object will be stored in the parse tree
 650                  * for the package.
 651                  */
 652                 if ((!op->common.parent) ||
 653                     ((op->common.parent->common.aml_opcode != AML_PACKAGE_OP) &&
 654                      (op->common.parent->common.aml_opcode !=
 655                       AML_VARIABLE_PACKAGE_OP)
 656                      && (op->common.parent->common.aml_opcode !=
 657                          AML_NAME_OP))) {
 658                         walk_state->result_obj = obj_desc;
 659                 }
 660         }
 661
 662         return_ACPI_STATUS(status);
 663 }
 664
 665 /*******************************************************************************
 666  *
 667  * FUNCTION:    acpi_ds_eval_bank_field_operands
 668  *
 669  * PARAMETERS:  walk_state      - Current walk
 670  *              op              - A valid bank_field Op object
 671  *
 672  * RETURN:      Status
 673  *
 674  * DESCRIPTION: Get bank_field bank_value
 675  *              Called from acpi_ds_exec_end_op during bank_field parse tree walk
 676  *
 677  ******************************************************************************/
 678
 679 acpi_status
 680 acpi_ds_eval_bank_field_operands(struct acpi_walk_state *walk_state,
 681                                  union acpi_parse_object *op)
 682 {
 683         acpi_status status;
 684         union acpi_operand_object *obj_desc;
 685         union acpi_operand_object *operand_desc;
 686         struct acpi_namespace_node *node;
 687         union acpi_parse_object *next_op;
 688         union acpi_parse_object *arg;
 689
 690         ACPI_FUNCTION_TRACE_PTR(ds_eval_bank_field_operands, op);
 691
 692         /*
 693          * This is where we evaluate the bank_value field of the
 694          * bank_field declaration
 695          */
 696
 697         /* next_op points to the op that holds the Region */
 698
 699         next_op = op->common.value.arg;
 700
 701         /* next_op points to the op that holds the Bank Register */
 702
 703         next_op = next_op->common.next;
 704
 705         /* next_op points to the op that holds the Bank Value */
 706
 707         next_op = next_op->common.next;
 708
 709         /*
 710          * Set proper index into operand stack for acpi_ds_obj_stack_push
 711          * invoked inside acpi_ds_create_operand.
 712          *
 713          * We use walk_state->Operands[0] to store the evaluated bank_value
 714          */
 715         walk_state->operand_index = 0;
 716
 717         status = acpi_ds_create_operand(walk_state, next_op, 0);
 718         if (ACPI_FAILURE(status)) {
 719                 return_ACPI_STATUS(status);
 720         }
 721
 722         status = acpi_ex_resolve_to_value(&walk_state->operands[0], walk_state);
 723         if (ACPI_FAILURE(status)) {
 724                 return_ACPI_STATUS(status);
 725         }
 726
 727         ACPI_DUMP_OPERANDS(ACPI_WALK_OPERANDS,
 728                            acpi_ps_get_opcode_name(op->common.aml_opcode), 1);
 729         /*
 730          * Get the bank_value operand and save it
 731          * (at Top of stack)
 732          */
 733         operand_desc = walk_state->operands[0];
 734
 735         /* Arg points to the start Bank Field */
 736
 737         arg = acpi_ps_get_arg(op, 4);
 738         while (arg) {
 739
 740                 /* Ignore OFFSET and ACCESSAS terms here */
 741
 742                 if (arg->common.aml_opcode == AML_INT_NAMEDFIELD_OP) {
 743                         node = arg->common.node;
 744
 745                         obj_desc = acpi_ns_get_attached_object(node);
 746                         if (!obj_desc) {
 747                                 return_ACPI_STATUS(AE_NOT_EXIST);
 748                         }
 749
 750                         obj_desc->bank_field.value =
 751                             (u32) operand_desc->integer.value;
 752                 }
 753
 754                 /* Move to next field in the list */
 755
 756                 arg = arg->common.next;
 757         }
 758
 759         acpi_ut_remove_reference(operand_desc);
 760         return_ACPI_STATUS(status);
 761 }