drivers/acpi/executer/exoparg1.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: exoparg1 - AML execution - opcodes with 1 argument
   5  *              $Revision: 145 $
   6  *
   7  *****************************************************************************/
   8
   9 /*
  10  *  Copyright (C) 2000 - 2002, R. Byron Moore
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or
  15  *  (at your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; if not, write to the Free Software
  24  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25  */
  26
  27
  28 #include "acpi.h"
  29 #include "acparser.h"
  30 #include "acdispat.h"
  31 #include "acinterp.h"
  32 #include "amlcode.h"
  33 #include "acnamesp.h"
  34
  35
  36 #define _COMPONENT          ACPI_EXECUTER
  37          ACPI_MODULE_NAME    ("exoparg1")
  38
  39
  40 /*!
  41  * Naming convention for AML interpreter execution routines.
  42  *
  43  * The routines that begin execution of AML opcodes are named with a common
  44  * convention based upon the number of arguments, the number of target operands,
  45  * and whether or not a value is returned:
  46  *
  47  *      AcpiExOpcode_xA_yT_zR
  48  *
  49  * Where:
  50  *
  51  * xA - ARGUMENTS:    The number of arguments (input operands) that are
  52  *                    required for this opcode type (1 through 6 args).
  53  * yT - TARGETS:      The number of targets (output operands) that are required
  54  *                    for this opcode type (0, 1, or 2 targets).
  55  * zR - RETURN VALUE: Indicates whether this opcode type returns a value
  56  *                    as the function return (0 or 1).
  57  *
  58  * The AcpiExOpcode* functions are called via the Dispatcher component with
  59  * fully resolved operands.
  60 !*/
  61
  62 /*******************************************************************************
  63  *
  64  * FUNCTION:    Acpi_ex_opcode_1A_0T_0R
  65  *
  66  * PARAMETERS:  Walk_state          - Current state (contains AML opcode)
  67  *
  68  * RETURN:      Status
  69  *
  70  * DESCRIPTION: Execute Type 1 monadic operator with numeric operand on
  71  *              object stack
  72  *
  73  ******************************************************************************/
  74
  75 acpi_status
  76 acpi_ex_opcode_1A_0T_0R (
  77         acpi_walk_state         *walk_state)
  78 {
  79         acpi_operand_object     **operand = &walk_state->operands[0];
  80         acpi_status             status = AE_OK;
  81
  82
  83         ACPI_FUNCTION_TRACE_STR ("Ex_opcode_1A_0T_0R", acpi_ps_get_opcode_name (walk_state->opcode));
  84
  85
  86         /* Examine the AML opcode */
  87
  88         switch (walk_state->opcode) {
  89         case AML_RELEASE_OP:    /*  Release (Mutex_object) */
  90
  91                 status = acpi_ex_release_mutex (operand[0], walk_state);
  92                 break;
  93
  94
  95         case AML_RESET_OP:      /*  Reset (Event_object) */
  96
  97                 status = acpi_ex_system_reset_event (operand[0]);
  98                 break;
  99
 100
 101         case AML_SIGNAL_OP:     /*  Signal (Event_object) */
 102
 103                 status = acpi_ex_system_signal_event (operand[0]);
 104                 break;
 105
 106
 107         case AML_SLEEP_OP:      /*  Sleep (Msec_time) */
 108
 109                 status = acpi_ex_system_do_suspend ((u32) operand[0]->integer.value);
 110                 break;
 111
 112
 113         case AML_STALL_OP:      /*  Stall (Usec_time) */
 114
 115                 status = acpi_ex_system_do_stall ((u32) operand[0]->integer.value);
 116                 break;
 117
 118
 119         case AML_UNLOAD_OP:     /*  Unload (Handle) */
 120
 121                 status = acpi_ex_unload_table (operand[0]);
 122                 break;
 123
 124
 125         default:                /*  Unknown opcode  */
 126
 127                 ACPI_REPORT_ERROR (("Acpi_ex_opcode_1A_0T_0R: Unknown opcode %X\n",
 128                         walk_state->opcode));
 129                 status = AE_AML_BAD_OPCODE;
 130                 break;
 131         }
 132
 133         return_ACPI_STATUS (status);
 134 }
 135
 136
 137 /*******************************************************************************
 138  *
 139  * FUNCTION:    Acpi_ex_opcode_1A_1T_0R
 140  *
 141  * PARAMETERS:  Walk_state          - Current state (contains AML opcode)
 142  *
 143  * RETURN:      Status
 144  *
 145  * DESCRIPTION: Execute opcode with one argument, one target, and no
 146  *              return value.
 147  *
 148  ******************************************************************************/
 149
 150 acpi_status
 151 acpi_ex_opcode_1A_1T_0R (
 152         acpi_walk_state         *walk_state)
 153 {
 154         acpi_status             status = AE_OK;
 155         acpi_operand_object     **operand = &walk_state->operands[0];
 156
 157
 158         ACPI_FUNCTION_TRACE_STR ("Ex_opcode_1A_1T_0R", acpi_ps_get_opcode_name (walk_state->opcode));
 159
 160
 161         /* Examine the AML opcode */
 162
 163         switch (walk_state->opcode) {
 164         case AML_LOAD_OP:
 165
 166                 status = acpi_ex_load_op (operand[0], operand[1], walk_state);
 167                 break;
 168
 169         default:                        /* Unknown opcode */
 170
 171                 ACPI_REPORT_ERROR (("Acpi_ex_opcode_1A_1T_0R: Unknown opcode %X\n",
 172                         walk_state->opcode));
 173                 status = AE_AML_BAD_OPCODE;
 174                 goto cleanup;
 175         }
 176
 177
 178 cleanup:
 179
 180         return_ACPI_STATUS (status);
 181 }
 182
 183
 184 /*******************************************************************************
 185  *
 186  * FUNCTION:    Acpi_ex_opcode_1A_1T_1R
 187  *
 188  * PARAMETERS:  Walk_state          - Current state (contains AML opcode)
 189  *
 190  * RETURN:      Status
 191  *
 192  * DESCRIPTION: Execute opcode with one argument, one target, and a
 193  *              return value.
 194  *
 195  ******************************************************************************/
 196
 197 acpi_status
 198 acpi_ex_opcode_1A_1T_1R (
 199         acpi_walk_state         *walk_state)
 200 {
 201         acpi_status             status = AE_OK;
 202         acpi_operand_object     **operand = &walk_state->operands[0];
 203         acpi_operand_object     *return_desc = NULL;
 204         acpi_operand_object     *return_desc2 = NULL;
 205         u32                     temp32;
 206         u32                     i;
 207         u32                     j;
 208         acpi_integer            digit;
 209
 210
 211         ACPI_FUNCTION_TRACE_STR ("Ex_opcode_1A_1T_1R", acpi_ps_get_opcode_name (walk_state->opcode));
 212
 213
 214         /* Examine the AML opcode */
 215
 216         switch (walk_state->opcode) {
 217         case AML_BIT_NOT_OP:
 218         case AML_FIND_SET_LEFT_BIT_OP:
 219         case AML_FIND_SET_RIGHT_BIT_OP:
 220         case AML_FROM_BCD_OP:
 221         case AML_TO_BCD_OP:
 222         case AML_COND_REF_OF_OP:
 223
 224                 /* Create a return object of type Integer for these opcodes */
 225
 226                 return_desc = acpi_ut_create_internal_object (ACPI_TYPE_INTEGER);
 227                 if (!return_desc) {
 228                         status = AE_NO_MEMORY;
 229                         goto cleanup;
 230                 }
 231
 232                 switch (walk_state->opcode) {
 233                 case AML_BIT_NOT_OP:            /* Not (Operand, Result)  */
 234
 235                         return_desc->integer.value = ~operand[0]->integer.value;
 236                         break;
 237
 238
 239                 case AML_FIND_SET_LEFT_BIT_OP:  /* Find_set_left_bit (Operand, Result) */
 240
 241                         return_desc->integer.value = operand[0]->integer.value;
 242
 243                         /*
 244                          * Acpi specification describes Integer type as a little
 245                          * endian unsigned value, so this boundary condition is valid.
 246                          */
 247                         for (temp32 = 0; return_desc->integer.value && temp32 < ACPI_INTEGER_BIT_SIZE; ++temp32) {
 248                                 return_desc->integer.value >>= 1;
 249                         }
 250
 251                         return_desc->integer.value = temp32;
 252                         break;
 253
 254
 255                 case AML_FIND_SET_RIGHT_BIT_OP: /* Find_set_right_bit (Operand, Result) */
 256
 257                         return_desc->integer.value = operand[0]->integer.value;
 258
 259                         /*
 260                          * The Acpi specification describes Integer type as a little
 261                          * endian unsigned value, so this boundary condition is valid.
 262                          */
 263                         for (temp32 = 0; return_desc->integer.value && temp32 < ACPI_INTEGER_BIT_SIZE; ++temp32) {
 264                                 return_desc->integer.value <<= 1;
 265                         }
 266
 267                         /* Since the bit position is one-based, subtract from 33 (65) */
 268
 269                         return_desc->integer.value = temp32 == 0 ? 0 : (ACPI_INTEGER_BIT_SIZE + 1) - temp32;
 270                         break;
 271
 272
 273                 case AML_FROM_BCD_OP:           /* From_bcd (BCDValue, Result) */
 274
 275                         /*
 276                          * The 64-bit ACPI integer can hold 16 4-bit BCD integers
 277                          */
 278                         return_desc->integer.value = 0;
 279                         for (i = 0; i < ACPI_MAX_BCD_DIGITS; i++) {
 280                                 /* Get one BCD digit */
 281
 282                                 digit = (acpi_integer) ((operand[0]->integer.value >> (i * 4)) & 0xF);
 283
 284                                 /* Check the range of the digit */
 285
 286                                 if (digit > 9) {
 287                                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "BCD digit too large: %d\n",
 288                                                 (u32) digit));
 289                                         status = AE_AML_NUMERIC_OVERFLOW;
 290                                         goto cleanup;
 291                                 }
 292
 293                                 if (digit > 0) {
 294                                         /* Sum into the result with the appropriate power of 10 */
 295
 296                                         for (j = 0; j < i; j++) {
 297                                                 digit *= 10;
 298                                         }
 299
 300                                         return_desc->integer.value += digit;
 301                                 }
 302                         }
 303                         break;
 304
 305
 306                 case AML_TO_BCD_OP:             /* To_bcd (Operand, Result) */
 307
 308                         if (operand[0]->integer.value > ACPI_MAX_BCD_VALUE) {
 309                                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "BCD overflow: %8.8X%8.8X\n",
 310                                         ACPI_HIDWORD(operand[0]->integer.value),
 311                                         ACPI_LODWORD(operand[0]->integer.value)));
 312                                 status = AE_AML_NUMERIC_OVERFLOW;
 313                                 goto cleanup;
 314                         }
 315
 316                         return_desc->integer.value = 0;
 317                         for (i = 0; i < ACPI_MAX_BCD_DIGITS; i++) {
 318                                 /* Divide by nth factor of 10 */
 319
 320                                 temp32 = 0;
 321                                 digit = operand[0]->integer.value;
 322                                 for (j = 0; j < i; j++) {
 323                                         (void) acpi_ut_short_divide (&digit, 10, &digit, &temp32);
 324                                 }
 325
 326                                 /* Create the BCD digit from the remainder above */
 327
 328                                 if (digit > 0) {
 329                                         return_desc->integer.value += ((acpi_integer) temp32 << (i * 4));
 330                                 }
 331                         }
 332                         break;
 333
 334
 335                 case AML_COND_REF_OF_OP:        /* Cond_ref_of (Source_object, Result) */
 336
 337                         /*
 338                          * This op is a little strange because the internal return value is
 339                          * different than the return value stored in the result descriptor
 340                          * (There are really two return values)
 341                          */
 342                         if ((acpi_namespace_node *) operand[0] == acpi_gbl_root_node) {
 343                                 /*
 344                                  * This means that the object does not exist in the namespace,
 345                                  * return FALSE
 346                                  */
 347                                 return_desc->integer.value = 0;
 348
 349                                 /*
 350                                  * Must delete the result descriptor since there is no reference
 351                                  * being returned
 352                                  */
 353                                 acpi_ut_remove_reference (operand[1]);
 354                                 goto cleanup;
 355                         }
 356
 357                         /* Get the object reference, store it, and remove our reference */
 358
 359                         status = acpi_ex_get_object_reference (operand[0], &return_desc2, walk_state);
 360                         if (ACPI_FAILURE (status)) {
 361                                 goto cleanup;
 362                         }
 363
 364                         status = acpi_ex_store (return_desc2, operand[1], walk_state);
 365                         acpi_ut_remove_reference (return_desc2);
 366
 367                         /* The object exists in the namespace, return TRUE */
 368
 369                         return_desc->integer.value = ACPI_INTEGER_MAX;
 370                         goto cleanup;
 371
 372
 373                 default:
 374                         /* No other opcodes get here */
 375                         break;
 376                 }
 377                 break;
 378
 379
 380         case AML_STORE_OP:              /* Store (Source, Target) */
 381
 382                 /*
 383                  * A store operand is typically a number, string, buffer or lvalue
 384                  * Be careful about deleting the source object,
 385                  * since the object itself may have been stored.
 386                  */
 387                 status = acpi_ex_store (operand[0], operand[1], walk_state);
 388                 if (ACPI_FAILURE (status)) {
 389                         return_ACPI_STATUS (status);
 390                 }
 391
 392                 if (!walk_state->result_obj) {
 393                         /*
 394                          * Normally, we would remove a reference on the Operand[0] parameter;
 395                          * But since it is being used as the internal return object
 396                          * (meaning we would normally increment it), the two cancel out,
 397                          * and we simply don't do anything.
 398                          */
 399                         walk_state->result_obj = operand[0];
 400                         walk_state->operands[0] = NULL; /* Prevent deletion */
 401                 }
 402                 return_ACPI_STATUS (status);
 403
 404
 405         /*
 406          * ACPI 2.0 Opcodes
 407          */
 408         case AML_COPY_OP:               /* Copy (Source, Target) */
 409
 410                 status = acpi_ut_copy_iobject_to_iobject (operand[0], &return_desc, walk_state);
 411                 break;
 412
 413
 414         case AML_TO_DECSTRING_OP:       /* To_decimal_string (Data, Result) */
 415
 416                 status = acpi_ex_convert_to_string (operand[0], &return_desc, 10, ACPI_UINT32_MAX, walk_state);
 417                 break;
 418
 419
 420         case AML_TO_HEXSTRING_OP:       /* To_hex_string (Data, Result) */
 421
 422                 status = acpi_ex_convert_to_string (operand[0], &return_desc, 16, ACPI_UINT32_MAX, walk_state);
 423                 break;
 424
 425
 426         case AML_TO_BUFFER_OP:          /* To_buffer (Data, Result) */
 427
 428                 status = acpi_ex_convert_to_buffer (operand[0], &return_desc, walk_state);
 429                 break;
 430
 431
 432         case AML_TO_INTEGER_OP:         /* To_integer (Data, Result) */
 433
 434                 status = acpi_ex_convert_to_integer (operand[0], &return_desc, walk_state);
 435                 break;
 436
 437
 438         case AML_SHIFT_LEFT_BIT_OP:     /*  Shift_left_bit (Source, Bit_num) */
 439         case AML_SHIFT_RIGHT_BIT_OP:    /*  Shift_right_bit (Source, Bit_num) */
 440
 441                 /*
 442                  * These are two obsolete opcodes
 443                  */
 444                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "%s is obsolete and not implemented\n",
 445                                   acpi_ps_get_opcode_name (walk_state->opcode)));
 446                 status = AE_SUPPORT;
 447                 goto cleanup;
 448
 449
 450         default:                        /* Unknown opcode */
 451
 452                 ACPI_REPORT_ERROR (("Acpi_ex_opcode_1A_1T_1R: Unknown opcode %X\n",
 453                         walk_state->opcode));
 454                 status = AE_AML_BAD_OPCODE;
 455                 goto cleanup;
 456         }
 457
 458         /*
 459          * Store the return value computed above into the target object
 460          */
 461         status = acpi_ex_store (return_desc, operand[1], walk_state);
 462
 463
 464 cleanup:
 465
 466         if (!walk_state->result_obj) {
 467                 walk_state->result_obj = return_desc;
 468         }
 469
 470         /* Delete return object on error */
 471
 472         if (ACPI_FAILURE (status)) {
 473                 acpi_ut_remove_reference (return_desc);
 474         }
 475
 476         return_ACPI_STATUS (status);
 477 }
 478
 479
 480 /*******************************************************************************
 481  *
 482  * FUNCTION:    Acpi_ex_opcode_1A_0T_1R
 483  *
 484  * PARAMETERS:  Walk_state          - Current state (contains AML opcode)
 485  *
 486  * RETURN:      Status
 487  *
 488  * DESCRIPTION: Execute opcode with one argument, no target, and a return value
 489  *
 490  ******************************************************************************/
 491
 492 acpi_status
 493 acpi_ex_opcode_1A_0T_1R (
 494         acpi_walk_state         *walk_state)
 495 {
 496         acpi_operand_object     **operand = &walk_state->operands[0];
 497         acpi_operand_object     *temp_desc;
 498         acpi_operand_object     *return_desc = NULL;
 499         acpi_status             status = AE_OK;
 500         u32                     type;
 501         acpi_integer            value;
 502
 503
 504         ACPI_FUNCTION_TRACE_STR ("Ex_opcode_1A_0T_0R", acpi_ps_get_opcode_name (walk_state->opcode));
 505
 506
 507         /* Examine the AML opcode */
 508
 509         switch (walk_state->opcode) {
 510         case AML_LNOT_OP:               /* LNot (Operand) */
 511
 512                 return_desc = acpi_ut_create_internal_object (ACPI_TYPE_INTEGER);
 513                 if (!return_desc) {
 514                         status = AE_NO_MEMORY;
 515                         goto cleanup;
 516                 }
 517
 518                 return_desc->integer.value = !operand[0]->integer.value;
 519                 break;
 520
 521
 522         case AML_DECREMENT_OP:          /* Decrement (Operand)  */
 523         case AML_INCREMENT_OP:          /* Increment (Operand)  */
 524
 525                 /*
 526                  * Since we are expecting a Reference operand, it
 527                  * can be either a NS Node or an internal object.
 528                  */
 529                 return_desc = operand[0];
 530                 if (ACPI_GET_DESCRIPTOR_TYPE (operand[0]) == ACPI_DESC_TYPE_OPERAND) {
 531                         /* Internal reference object - prevent deletion */
 532
 533                         acpi_ut_add_reference (return_desc);
 534                 }
 535
 536                 /*
 537                  * Convert the Return_desc Reference to a Number
 538                  * (This removes a reference on the Return_desc object)
 539                  */
 540                 status = acpi_ex_resolve_operands (AML_LNOT_OP, &return_desc, walk_state);
 541                 if (ACPI_FAILURE (status)) {
 542                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "%s: bad operand(s) %s\n",
 543                                 acpi_ps_get_opcode_name (walk_state->opcode), acpi_format_exception(status)));
 544
 545                         goto cleanup;
 546                 }
 547
 548                 /*
 549                  * Return_desc is now guaranteed to be an Integer object
 550                  * Do the actual increment or decrement
 551                  */
 552                 if (AML_INCREMENT_OP == walk_state->opcode) {
 553                         return_desc->integer.value++;
 554                 }
 555                 else {
 556                         return_desc->integer.value--;
 557                 }
 558
 559                 /* Store the result back in the original descriptor */
 560
 561                 status = acpi_ex_store (return_desc, operand[0], walk_state);
 562                 break;
 563
 564
 565         case AML_TYPE_OP:               /* Object_type (Source_object) */
 566
 567                 /* Get the type of the base object */
 568
 569                 status = acpi_ex_resolve_multiple (walk_state, operand[0], &type, NULL);
 570                 if (ACPI_FAILURE (status)) {
 571                         goto cleanup;
 572                 }
 573
 574                 /* Allocate a descriptor to hold the type. */
 575
 576                 return_desc = acpi_ut_create_internal_object (ACPI_TYPE_INTEGER);
 577                 if (!return_desc) {
 578                         status = AE_NO_MEMORY;
 579                         goto cleanup;
 580                 }
 581
 582                 return_desc->integer.value = type;
 583                 break;
 584
 585
 586         case AML_SIZE_OF_OP:            /* Size_of (Source_object) */
 587
 588                 /* Get the base object */
 589
 590                 status = acpi_ex_resolve_multiple (walk_state, operand[0], &type, &temp_desc);
 591                 if (ACPI_FAILURE (status)) {
 592                         goto cleanup;
 593                 }
 594
 595                 /*
 596                  * Type is guaranteed to be a buffer, string, or package at this
 597                  * point (even if the original operand was an object reference, it
 598                  * will be resolved and typechecked during operand resolution.)
 599                  */
 600                 switch (type) {
 601                 case ACPI_TYPE_BUFFER:
 602                         value = temp_desc->buffer.length;
 603                         break;
 604
 605                 case ACPI_TYPE_STRING:
 606                         value = temp_desc->string.length;
 607                         break;
 608
 609                 case ACPI_TYPE_PACKAGE:
 610                         value = temp_desc->package.count;
 611                         break;
 612
 613                 default:
 614                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Size_of, Not Buf/Str/Pkg - found type %s\n",
 615                                 acpi_ut_get_type_name (type)));
 616                         status = AE_AML_OPERAND_TYPE;
 617                         goto cleanup;
 618                 }
 619
 620                 /*
 621                  * Now that we have the size of the object, create a result
 622                  * object to hold the value
 623                  */
 624                 return_desc = acpi_ut_create_internal_object (ACPI_TYPE_INTEGER);
 625                 if (!return_desc) {
 626                         status = AE_NO_MEMORY;
 627                         goto cleanup;
 628                 }
 629
 630                 return_desc->integer.value = value;
 631                 break;
 632
 633
 634         case AML_REF_OF_OP:             /* Ref_of (Source_object) */
 635
 636                 status = acpi_ex_get_object_reference (operand[0], &return_desc, walk_state);
 637                 if (ACPI_FAILURE (status)) {
 638                         goto cleanup;
 639                 }
 640                 break;
 641
 642
 643         case AML_DEREF_OF_OP:           /* Deref_of (Obj_reference | String) */
 644
 645                 /* Check for a method local or argument, or standalone String */
 646
 647                 if (ACPI_GET_DESCRIPTOR_TYPE (operand[0]) != ACPI_DESC_TYPE_NAMED) {
 648                         switch (ACPI_GET_OBJECT_TYPE (operand[0])) {
 649                         case ACPI_TYPE_LOCAL_REFERENCE:
 650                                 /*
 651                                  * This is a Deref_of (Local_x | Arg_x)
 652                                  *
 653                                  * Must resolve/dereference the local/arg reference first
 654                                  */
 655                                 switch (operand[0]->reference.opcode) {
 656                                 case AML_LOCAL_OP:
 657                                 case AML_ARG_OP:
 658
 659                                         /* Set Operand[0] to the value of the local/arg */
 660
 661                                         status = acpi_ds_method_data_get_value (operand[0]->reference.opcode,
 662                                                          operand[0]->reference.offset, walk_state, &temp_desc);
 663                                         if (ACPI_FAILURE (status)) {
 664                                                 goto cleanup;
 665                                         }
 666
 667                                         /*
 668                                          * Delete our reference to the input object and
 669                                          * point to the object just retrieved
 670                                          */
 671                                         acpi_ut_remove_reference (operand[0]);
 672                                         operand[0] = temp_desc;
 673                                         break;
 674
 675                                 case AML_REF_OF_OP:
 676
 677                                         /* Get the object to which the reference refers */
 678
 679                                         temp_desc = operand[0]->reference.object;
 680                                         acpi_ut_remove_reference (operand[0]);
 681                                         operand[0] = temp_desc;
 682                                         break;
 683
 684                                 default:
 685
 686                                         /* Must be an Index op - handled below */
 687                                         break;
 688                                 }
 689                                 break;
 690
 691
 692                         case ACPI_TYPE_STRING:
 693
 694                                 /*
 695                                  * This is a Deref_of (String). The string is a reference to a named ACPI object.
 696                                  *
 697                                  * 1) Find the owning Node
 698                                  * 2) Dereference the node to an actual object.  Could be a Field, so we nee
 699                                  *    to resolve the node to a value.
 700                                  */
 701                                 status = acpi_ns_get_node_by_path (operand[0]->string.pointer,
 702                                                   walk_state->scope_info->scope.node, ACPI_NS_SEARCH_PARENT,
 703                                                   ACPI_CAST_INDIRECT_PTR (acpi_namespace_node, &return_desc));
 704                                 if (ACPI_FAILURE (status)) {
 705                                         goto cleanup;
 706                                 }
 707
 708                                 status = acpi_ex_resolve_node_to_value (
 709                                                   ACPI_CAST_INDIRECT_PTR (acpi_namespace_node, &return_desc), walk_state);
 710                                 goto cleanup;
 711
 712
 713                         default:
 714
 715                                 status = AE_AML_OPERAND_TYPE;
 716                                 goto cleanup;
 717                         }
 718                 }
 719
 720                 /* Operand[0] may have changed from the code above */
 721
 722                 if (ACPI_GET_DESCRIPTOR_TYPE (operand[0]) == ACPI_DESC_TYPE_NAMED) {
 723                         /*
 724                          * This is a Deref_of (Object_reference)
 725                          * Get the actual object from the Node (This is the dereference).
 726                          * -- This case may only happen when a Local_x or Arg_x is dereferenced above.
 727                          */
 728                         return_desc = acpi_ns_get_attached_object ((acpi_namespace_node *) operand[0]);
 729                 }
 730                 else {
 731                         /*
 732                          * This must be a reference object produced by either the Index() or
 733                          * Ref_of() operator
 734                          */
 735                         switch (operand[0]->reference.opcode) {
 736                         case AML_INDEX_OP:
 737
 738                                 /*
 739                                  * The target type for the Index operator must be
 740                                  * either a Buffer or a Package
 741                                  */
 742                                 switch (operand[0]->reference.target_type) {
 743                                 case ACPI_TYPE_BUFFER_FIELD:
 744
 745                                         temp_desc = operand[0]->reference.object;
 746
 747                                         /*
 748                                          * Create a new object that contains one element of the
 749                                          * buffer -- the element pointed to by the index.
 750                                          *
 751                                          * NOTE: index into a buffer is NOT a pointer to a
 752                                          * sub-buffer of the main buffer, it is only a pointer to a
 753                                          * single element (byte) of the buffer!
 754                                          */
 755                                         return_desc = acpi_ut_create_internal_object (ACPI_TYPE_INTEGER);
 756                                         if (!return_desc) {
 757                                                 status = AE_NO_MEMORY;
 758                                                 goto cleanup;
 759                                         }
 760
 761                                         /*
 762                                          * Since we are returning the value of the buffer at the
 763                                          * indexed location, we don't need to add an additional
 764                                          * reference to the buffer itself.
 765                                          */
 766                                         return_desc->integer.value =
 767                                                 temp_desc->buffer.pointer[operand[0]->reference.offset];
 768                                         break;
 769
 770
 771                                 case ACPI_TYPE_PACKAGE:
 772
 773                                         /*
 774                                          * Return the referenced element of the package.  We must add
 775                                          * another reference to the referenced object, however.
 776                                          */
 777                                         return_desc = *(operand[0]->reference.where);
 778                                         if (!return_desc) {
 779                                                 /*
 780                                                  * We can't return a NULL dereferenced value.  This is
 781                                                  * an uninitialized package element and is thus a
 782                                                  * severe error.
 783                                                  */
 784                                                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "NULL package element obj %p\n",
 785                                                         operand[0]));
 786                                                 status = AE_AML_UNINITIALIZED_ELEMENT;
 787                                                 goto cleanup;
 788                                         }
 789
 790                                         acpi_ut_add_reference (return_desc);
 791                                         break;
 792
 793
 794                                 default:
 795
 796                                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Unknown Index Target_type %X in obj %p\n",
 797                                                 operand[0]->reference.target_type, operand[0]));
 798                                         status = AE_AML_OPERAND_TYPE;
 799                                         goto cleanup;
 800                                 }
 801                                 break;
 802
 803
 804                         case AML_REF_OF_OP:
 805
 806                                 return_desc = operand[0]->reference.object;
 807
 808                                 if (ACPI_GET_DESCRIPTOR_TYPE (return_desc) == ACPI_DESC_TYPE_NAMED) {
 809
 810                                         return_desc = acpi_ns_get_attached_object ((acpi_namespace_node *) return_desc);
 811                                 }
 812
 813                                 /* Add another reference to the object! */
 814
 815                                 acpi_ut_add_reference (return_desc);
 816                                 break;
 817
 818
 819                         default:
 820                                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Unknown opcode in ref(%p) - %X\n",
 821                                         operand[0], operand[0]->reference.opcode));
 822
 823                                 status = AE_TYPE;
 824                                 goto cleanup;
 825                         }
 826                 }
 827                 break;
 828
 829
 830         default:
 831
 832                 ACPI_REPORT_ERROR (("Acpi_ex_opcode_1A_0T_1R: Unknown opcode %X\n",
 833                         walk_state->opcode));
 834                 status = AE_AML_BAD_OPCODE;
 835                 goto cleanup;
 836         }
 837
 838
 839 cleanup:
 840
 841         /* Delete return object on error */
 842
 843         if (ACPI_FAILURE (status)) {
 844                 acpi_ut_remove_reference (return_desc);
 845         }
 846
 847         walk_state->result_obj = return_desc;
 848         return_ACPI_STATUS (status);
 849 }
 850