drivers/acpi/executer/exmisc.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: exmisc - ACPI AML (p-code) execution - specific opcodes
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2008, Intel Corp.
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions, and the following disclaimer,
  17  *    without modification.
  18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19  *    substantially similar to the "NO WARRANTY" disclaimer below
  20  *    ("Disclaimer") and any redistribution must be conditioned upon
  21  *    including a substantially similar Disclaimer requirement for further
  22  *    binary redistribution.
  23  * 3. Neither the names of the above-listed copyright holders nor the names
  24  *    of any contributors may be used to endorse or promote products derived
  25  *    from this software without specific prior written permission.
  26  *
  27  * Alternatively, this software may be distributed under the terms of the
  28  * GNU General Public License ("GPL") version 2 as published by the Free
  29  * Software Foundation.
  30  *
  31  * NO WARRANTY
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42  * POSSIBILITY OF SUCH DAMAGES.
  43  */
  44
  45 #include <acpi/acpi.h>
  46 #include <acpi/acinterp.h>
  47 #include <acpi/amlcode.h>
  48 #include <acpi/amlresrc.h>
  49
  50 #define _COMPONENT          ACPI_EXECUTER
  51 ACPI_MODULE_NAME("exmisc")
  52
  53 /*******************************************************************************
  54  *
  55  * FUNCTION:    acpi_ex_get_object_reference
  56  *
  57  * PARAMETERS:  obj_desc            - Create a reference to this object
  58  *              return_desc         - Where to store the reference
  59  *              walk_state          - Current state
  60  *
  61  * RETURN:      Status
  62  *
  63  * DESCRIPTION: Obtain and return a "reference" to the target object
  64  *              Common code for the ref_of_op and the cond_ref_of_op.
  65  *
  66  ******************************************************************************/
  67 acpi_status
  68 acpi_ex_get_object_reference(union acpi_operand_object *obj_desc,
  69                              union acpi_operand_object **return_desc,
  70                              struct acpi_walk_state *walk_state)
  71 {
  72         union acpi_operand_object *reference_obj;
  73         union acpi_operand_object *referenced_obj;
  74
  75         ACPI_FUNCTION_TRACE_PTR(ex_get_object_reference, obj_desc);
  76
  77         *return_desc = NULL;
  78
  79         switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
  80         case ACPI_DESC_TYPE_OPERAND:
  81
  82                 if (ACPI_GET_OBJECT_TYPE(obj_desc) != ACPI_TYPE_LOCAL_REFERENCE) {
  83                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
  84                 }
  85
  86                 /*
  87                  * Must be a reference to a Local or Arg
  88                  */
  89                 switch (obj_desc->reference.opcode) {
  90                 case AML_LOCAL_OP:
  91                 case AML_ARG_OP:
  92                 case AML_DEBUG_OP:
  93
  94                         /* The referenced object is the pseudo-node for the local/arg */
  95
  96                         referenced_obj = obj_desc->reference.object;
  97                         break;
  98
  99                 default:
 100
 101                         ACPI_ERROR((AE_INFO, "Unknown Reference opcode %X",
 102                                     obj_desc->reference.opcode));
 103                         return_ACPI_STATUS(AE_AML_INTERNAL);
 104                 }
 105                 break;
 106
 107         case ACPI_DESC_TYPE_NAMED:
 108
 109                 /*
 110                  * A named reference that has already been resolved to a Node
 111                  */
 112                 referenced_obj = obj_desc;
 113                 break;
 114
 115         default:
 116
 117                 ACPI_ERROR((AE_INFO, "Invalid descriptor type %X",
 118                             ACPI_GET_DESCRIPTOR_TYPE(obj_desc)));
 119                 return_ACPI_STATUS(AE_TYPE);
 120         }
 121
 122         /* Create a new reference object */
 123
 124         reference_obj =
 125             acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_REFERENCE);
 126         if (!reference_obj) {
 127                 return_ACPI_STATUS(AE_NO_MEMORY);
 128         }
 129
 130         reference_obj->reference.opcode = AML_REF_OF_OP;
 131         reference_obj->reference.object = referenced_obj;
 132         *return_desc = reference_obj;
 133
 134         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 135                           "Object %p Type [%s], returning Reference %p\n",
 136                           obj_desc, acpi_ut_get_object_type_name(obj_desc),
 137                           *return_desc));
 138
 139         return_ACPI_STATUS(AE_OK);
 140 }
 141
 142 /*******************************************************************************
 143  *
 144  * FUNCTION:    acpi_ex_concat_template
 145  *
 146  * PARAMETERS:  Operand0            - First source object
 147  *              Operand1            - Second source object
 148  *              actual_return_desc  - Where to place the return object
 149  *              walk_state          - Current walk state
 150  *
 151  * RETURN:      Status
 152  *
 153  * DESCRIPTION: Concatenate two resource templates
 154  *
 155  ******************************************************************************/
 156
 157 acpi_status
 158 acpi_ex_concat_template(union acpi_operand_object *operand0,
 159                         union acpi_operand_object *operand1,
 160                         union acpi_operand_object **actual_return_desc,
 161                         struct acpi_walk_state *walk_state)
 162 {
 163         acpi_status status;
 164         union acpi_operand_object *return_desc;
 165         u8 *new_buf;
 166         u8 *end_tag;
 167         acpi_size length0;
 168         acpi_size length1;
 169         acpi_size new_length;
 170
 171         ACPI_FUNCTION_TRACE(ex_concat_template);
 172
 173         /*
 174          * Find the end_tag descriptor in each resource template.
 175          * Note1: returned pointers point TO the end_tag, not past it.
 176          * Note2: zero-length buffers are allowed; treated like one end_tag
 177          */
 178
 179         /* Get the length of the first resource template */
 180
 181         status = acpi_ut_get_resource_end_tag(operand0, &end_tag);
 182         if (ACPI_FAILURE(status)) {
 183                 return_ACPI_STATUS(status);
 184         }
 185
 186         length0 = ACPI_PTR_DIFF(end_tag, operand0->buffer.pointer);
 187
 188         /* Get the length of the second resource template */
 189
 190         status = acpi_ut_get_resource_end_tag(operand1, &end_tag);
 191         if (ACPI_FAILURE(status)) {
 192                 return_ACPI_STATUS(status);
 193         }
 194
 195         length1 = ACPI_PTR_DIFF(end_tag, operand1->buffer.pointer);
 196
 197         /* Combine both lengths, minimum size will be 2 for end_tag */
 198
 199         new_length = length0 + length1 + sizeof(struct aml_resource_end_tag);
 200
 201         /* Create a new buffer object for the result (with one end_tag) */
 202
 203         return_desc = acpi_ut_create_buffer_object(new_length);
 204         if (!return_desc) {
 205                 return_ACPI_STATUS(AE_NO_MEMORY);
 206         }
 207
 208         /*
 209          * Copy the templates to the new buffer, 0 first, then 1 follows. One
 210          * end_tag descriptor is copied from Operand1.
 211          */
 212         new_buf = return_desc->buffer.pointer;
 213         ACPI_MEMCPY(new_buf, operand0->buffer.pointer, length0);
 214         ACPI_MEMCPY(new_buf + length0, operand1->buffer.pointer, length1);
 215
 216         /* Insert end_tag and set the checksum to zero, means "ignore checksum" */
 217
 218         new_buf[new_length - 1] = 0;
 219         new_buf[new_length - 2] = ACPI_RESOURCE_NAME_END_TAG | 1;
 220
 221         /* Return the completed resource template */
 222
 223         *actual_return_desc = return_desc;
 224         return_ACPI_STATUS(AE_OK);
 225 }
 226
 227 /*******************************************************************************
 228  *
 229  * FUNCTION:    acpi_ex_do_concatenate
 230  *
 231  * PARAMETERS:  Operand0            - First source object
 232  *              Operand1            - Second source object
 233  *              actual_return_desc  - Where to place the return object
 234  *              walk_state          - Current walk state
 235  *
 236  * RETURN:      Status
 237  *
 238  * DESCRIPTION: Concatenate two objects OF THE SAME TYPE.
 239  *
 240  ******************************************************************************/
 241
 242 acpi_status
 243 acpi_ex_do_concatenate(union acpi_operand_object *operand0,
 244                        union acpi_operand_object *operand1,
 245                        union acpi_operand_object **actual_return_desc,
 246                        struct acpi_walk_state *walk_state)
 247 {
 248         union acpi_operand_object *local_operand1 = operand1;
 249         union acpi_operand_object *return_desc;
 250         char *new_buf;
 251         acpi_status status;
 252
 253         ACPI_FUNCTION_TRACE(ex_do_concatenate);
 254
 255         /*
 256          * Convert the second operand if necessary.  The first operand
 257          * determines the type of the second operand, (See the Data Types
 258          * section of the ACPI specification.)  Both object types are
 259          * guaranteed to be either Integer/String/Buffer by the operand
 260          * resolution mechanism.
 261          */
 262         switch (ACPI_GET_OBJECT_TYPE(operand0)) {
 263         case ACPI_TYPE_INTEGER:
 264                 status =
 265                     acpi_ex_convert_to_integer(operand1, &local_operand1, 16);
 266                 break;
 267
 268         case ACPI_TYPE_STRING:
 269                 status = acpi_ex_convert_to_string(operand1, &local_operand1,
 270                                                    ACPI_IMPLICIT_CONVERT_HEX);
 271                 break;
 272
 273         case ACPI_TYPE_BUFFER:
 274                 status = acpi_ex_convert_to_buffer(operand1, &local_operand1);
 275                 break;
 276
 277         default:
 278                 ACPI_ERROR((AE_INFO, "Invalid object type: %X",
 279                             ACPI_GET_OBJECT_TYPE(operand0)));
 280                 status = AE_AML_INTERNAL;
 281         }
 282
 283         if (ACPI_FAILURE(status)) {
 284                 goto cleanup;
 285         }
 286
 287         /*
 288          * Both operands are now known to be the same object type
 289          * (Both are Integer, String, or Buffer), and we can now perform the
 290          * concatenation.
 291          */
 292
 293         /*
 294          * There are three cases to handle:
 295          *
 296          * 1) Two Integers concatenated to produce a new Buffer
 297          * 2) Two Strings concatenated to produce a new String
 298          * 3) Two Buffers concatenated to produce a new Buffer
 299          */
 300         switch (ACPI_GET_OBJECT_TYPE(operand0)) {
 301         case ACPI_TYPE_INTEGER:
 302
 303                 /* Result of two Integers is a Buffer */
 304                 /* Need enough buffer space for two integers */
 305
 306                 return_desc = acpi_ut_create_buffer_object((acpi_size)
 307                                                            ACPI_MUL_2
 308                                                            (acpi_gbl_integer_byte_width));
 309                 if (!return_desc) {
 310                         status = AE_NO_MEMORY;
 311                         goto cleanup;
 312                 }
 313
 314                 new_buf = (char *)return_desc->buffer.pointer;
 315
 316                 /* Copy the first integer, LSB first */
 317
 318                 ACPI_MEMCPY(new_buf, &operand0->integer.value,
 319                             acpi_gbl_integer_byte_width);
 320
 321                 /* Copy the second integer (LSB first) after the first */
 322
 323                 ACPI_MEMCPY(new_buf + acpi_gbl_integer_byte_width,
 324                             &local_operand1->integer.value,
 325                             acpi_gbl_integer_byte_width);
 326                 break;
 327
 328         case ACPI_TYPE_STRING:
 329
 330                 /* Result of two Strings is a String */
 331
 332                 return_desc = acpi_ut_create_string_object((acpi_size)
 333                                                            (operand0->string.
 334                                                             length +
 335                                                             local_operand1->
 336                                                             string.length));
 337                 if (!return_desc) {
 338                         status = AE_NO_MEMORY;
 339                         goto cleanup;
 340                 }
 341
 342                 new_buf = return_desc->string.pointer;
 343
 344                 /* Concatenate the strings */
 345
 346                 ACPI_STRCPY(new_buf, operand0->string.pointer);
 347                 ACPI_STRCPY(new_buf + operand0->string.length,
 348                             local_operand1->string.pointer);
 349                 break;
 350
 351         case ACPI_TYPE_BUFFER:
 352
 353                 /* Result of two Buffers is a Buffer */
 354
 355                 return_desc = acpi_ut_create_buffer_object((acpi_size)
 356                                                            (operand0->buffer.
 357                                                             length +
 358                                                             local_operand1->
 359                                                             buffer.length));
 360                 if (!return_desc) {
 361                         status = AE_NO_MEMORY;
 362                         goto cleanup;
 363                 }
 364
 365                 new_buf = (char *)return_desc->buffer.pointer;
 366
 367                 /* Concatenate the buffers */
 368
 369                 ACPI_MEMCPY(new_buf, operand0->buffer.pointer,
 370                             operand0->buffer.length);
 371                 ACPI_MEMCPY(new_buf + operand0->buffer.length,
 372                             local_operand1->buffer.pointer,
 373                             local_operand1->buffer.length);
 374                 break;
 375
 376         default:
 377
 378                 /* Invalid object type, should not happen here */
 379
 380                 ACPI_ERROR((AE_INFO, "Invalid object type: %X",
 381                             ACPI_GET_OBJECT_TYPE(operand0)));
 382                 status = AE_AML_INTERNAL;
 383                 goto cleanup;
 384         }
 385
 386         *actual_return_desc = return_desc;
 387
 388       cleanup:
 389         if (local_operand1 != operand1) {
 390                 acpi_ut_remove_reference(local_operand1);
 391         }
 392         return_ACPI_STATUS(status);
 393 }
 394
 395 /*******************************************************************************
 396  *
 397  * FUNCTION:    acpi_ex_do_math_op
 398  *
 399  * PARAMETERS:  Opcode              - AML opcode
 400  *              Integer0            - Integer operand #0
 401  *              Integer1            - Integer operand #1
 402  *
 403  * RETURN:      Integer result of the operation
 404  *
 405  * DESCRIPTION: Execute a math AML opcode. The purpose of having all of the
 406  *              math functions here is to prevent a lot of pointer dereferencing
 407  *              to obtain the operands.
 408  *
 409  ******************************************************************************/
 410
 411 acpi_integer
 412 acpi_ex_do_math_op(u16 opcode, acpi_integer integer0, acpi_integer integer1)
 413 {
 414
 415         ACPI_FUNCTION_ENTRY();
 416
 417         switch (opcode) {
 418         case AML_ADD_OP:        /* Add (Integer0, Integer1, Result) */
 419
 420                 return (integer0 + integer1);
 421
 422         case AML_BIT_AND_OP:    /* And (Integer0, Integer1, Result) */
 423
 424                 return (integer0 & integer1);
 425
 426         case AML_BIT_NAND_OP:   /* NAnd (Integer0, Integer1, Result) */
 427
 428                 return (~(integer0 & integer1));
 429
 430         case AML_BIT_OR_OP:     /* Or (Integer0, Integer1, Result) */
 431
 432                 return (integer0 | integer1);
 433
 434         case AML_BIT_NOR_OP:    /* NOr (Integer0, Integer1, Result) */
 435
 436                 return (~(integer0 | integer1));
 437
 438         case AML_BIT_XOR_OP:    /* XOr (Integer0, Integer1, Result) */
 439
 440                 return (integer0 ^ integer1);
 441
 442         case AML_MULTIPLY_OP:   /* Multiply (Integer0, Integer1, Result) */
 443
 444                 return (integer0 * integer1);
 445
 446         case AML_SHIFT_LEFT_OP: /* shift_left (Operand, shift_count, Result) */
 447
 448                 /*
 449                  * We need to check if the shiftcount is larger than the integer bit
 450                  * width since the behavior of this is not well-defined in the C language.
 451                  */
 452                 if (integer1 >= acpi_gbl_integer_bit_width) {
 453                         return (0);
 454                 }
 455                 return (integer0 << integer1);
 456
 457         case AML_SHIFT_RIGHT_OP:        /* shift_right (Operand, shift_count, Result) */
 458
 459                 /*
 460                  * We need to check if the shiftcount is larger than the integer bit
 461                  * width since the behavior of this is not well-defined in the C language.
 462                  */
 463                 if (integer1 >= acpi_gbl_integer_bit_width) {
 464                         return (0);
 465                 }
 466                 return (integer0 >> integer1);
 467
 468         case AML_SUBTRACT_OP:   /* Subtract (Integer0, Integer1, Result) */
 469
 470                 return (integer0 - integer1);
 471
 472         default:
 473
 474                 return (0);
 475         }
 476 }
 477
 478 /*******************************************************************************
 479  *
 480  * FUNCTION:    acpi_ex_do_logical_numeric_op
 481  *
 482  * PARAMETERS:  Opcode              - AML opcode
 483  *              Integer0            - Integer operand #0
 484  *              Integer1            - Integer operand #1
 485  *              logical_result      - TRUE/FALSE result of the operation
 486  *
 487  * RETURN:      Status
 488  *
 489  * DESCRIPTION: Execute a logical "Numeric" AML opcode. For these Numeric
 490  *              operators (LAnd and LOr), both operands must be integers.
 491  *
 492  *              Note: cleanest machine code seems to be produced by the code
 493  *              below, rather than using statements of the form:
 494  *                  Result = (Integer0 && Integer1);
 495  *
 496  ******************************************************************************/
 497
 498 acpi_status
 499 acpi_ex_do_logical_numeric_op(u16 opcode,
 500                               acpi_integer integer0,
 501                               acpi_integer integer1, u8 * logical_result)
 502 {
 503         acpi_status status = AE_OK;
 504         u8 local_result = FALSE;
 505
 506         ACPI_FUNCTION_TRACE(ex_do_logical_numeric_op);
 507
 508         switch (opcode) {
 509         case AML_LAND_OP:       /* LAnd (Integer0, Integer1) */
 510
 511                 if (integer0 && integer1) {
 512                         local_result = TRUE;
 513                 }
 514                 break;
 515
 516         case AML_LOR_OP:        /* LOr (Integer0, Integer1) */
 517
 518                 if (integer0 || integer1) {
 519                         local_result = TRUE;
 520                 }
 521                 break;
 522
 523         default:
 524                 status = AE_AML_INTERNAL;
 525                 break;
 526         }
 527
 528         /* Return the logical result and status */
 529
 530         *logical_result = local_result;
 531         return_ACPI_STATUS(status);
 532 }
 533
 534 /*******************************************************************************
 535  *
 536  * FUNCTION:    acpi_ex_do_logical_op
 537  *
 538  * PARAMETERS:  Opcode              - AML opcode
 539  *              Operand0            - operand #0
 540  *              Operand1            - operand #1
 541  *              logical_result      - TRUE/FALSE result of the operation
 542  *
 543  * RETURN:      Status
 544  *
 545  * DESCRIPTION: Execute a logical AML opcode. The purpose of having all of the
 546  *              functions here is to prevent a lot of pointer dereferencing
 547  *              to obtain the operands and to simplify the generation of the
 548  *              logical value. For the Numeric operators (LAnd and LOr), both
 549  *              operands must be integers. For the other logical operators,
 550  *              operands can be any combination of Integer/String/Buffer. The
 551  *              first operand determines the type to which the second operand
 552  *              will be converted.
 553  *
 554  *              Note: cleanest machine code seems to be produced by the code
 555  *              below, rather than using statements of the form:
 556  *                  Result = (Operand0 == Operand1);
 557  *
 558  ******************************************************************************/
 559
 560 acpi_status
 561 acpi_ex_do_logical_op(u16 opcode,
 562                       union acpi_operand_object *operand0,
 563                       union acpi_operand_object *operand1, u8 * logical_result)
 564 {
 565         union acpi_operand_object *local_operand1 = operand1;
 566         acpi_integer integer0;
 567         acpi_integer integer1;
 568         u32 length0;
 569         u32 length1;
 570         acpi_status status = AE_OK;
 571         u8 local_result = FALSE;
 572         int compare;
 573
 574         ACPI_FUNCTION_TRACE(ex_do_logical_op);
 575
 576         /*
 577          * Convert the second operand if necessary.  The first operand
 578          * determines the type of the second operand, (See the Data Types
 579          * section of the ACPI 3.0+ specification.)  Both object types are
 580          * guaranteed to be either Integer/String/Buffer by the operand
 581          * resolution mechanism.
 582          */
 583         switch (ACPI_GET_OBJECT_TYPE(operand0)) {
 584         case ACPI_TYPE_INTEGER:
 585                 status =
 586                     acpi_ex_convert_to_integer(operand1, &local_operand1, 16);
 587                 break;
 588
 589         case ACPI_TYPE_STRING:
 590                 status = acpi_ex_convert_to_string(operand1, &local_operand1,
 591                                                    ACPI_IMPLICIT_CONVERT_HEX);
 592                 break;
 593
 594         case ACPI_TYPE_BUFFER:
 595                 status = acpi_ex_convert_to_buffer(operand1, &local_operand1);
 596                 break;
 597
 598         default:
 599                 status = AE_AML_INTERNAL;
 600                 break;
 601         }
 602
 603         if (ACPI_FAILURE(status)) {
 604                 goto cleanup;
 605         }
 606
 607         /*
 608          * Two cases: 1) Both Integers, 2) Both Strings or Buffers
 609          */
 610         if (ACPI_GET_OBJECT_TYPE(operand0) == ACPI_TYPE_INTEGER) {
 611                 /*
 612                  * 1) Both operands are of type integer
 613                  *    Note: local_operand1 may have changed above
 614                  */
 615                 integer0 = operand0->integer.value;
 616                 integer1 = local_operand1->integer.value;
 617
 618                 switch (opcode) {
 619                 case AML_LEQUAL_OP:     /* LEqual (Operand0, Operand1) */
 620
 621                         if (integer0 == integer1) {
 622                                 local_result = TRUE;
 623                         }
 624                         break;
 625
 626                 case AML_LGREATER_OP:   /* LGreater (Operand0, Operand1) */
 627
 628                         if (integer0 > integer1) {
 629                                 local_result = TRUE;
 630                         }
 631                         break;
 632
 633                 case AML_LLESS_OP:      /* LLess (Operand0, Operand1) */
 634
 635                         if (integer0 < integer1) {
 636                                 local_result = TRUE;
 637                         }
 638                         break;
 639
 640                 default:
 641                         status = AE_AML_INTERNAL;
 642                         break;
 643                 }
 644         } else {
 645                 /*
 646                  * 2) Both operands are Strings or both are Buffers
 647                  *    Note: Code below takes advantage of common Buffer/String
 648                  *          object fields. local_operand1 may have changed above. Use
 649                  *          memcmp to handle nulls in buffers.
 650                  */
 651                 length0 = operand0->buffer.length;
 652                 length1 = local_operand1->buffer.length;
 653
 654                 /* Lexicographic compare: compare the data bytes */
 655
 656                 compare = ACPI_MEMCMP(operand0->buffer.pointer,
 657                                       local_operand1->buffer.pointer,
 658                                       (length0 > length1) ? length1 : length0);
 659
 660                 switch (opcode) {
 661                 case AML_LEQUAL_OP:     /* LEqual (Operand0, Operand1) */
 662
 663                         /* Length and all bytes must be equal */
 664
 665                         if ((length0 == length1) && (compare == 0)) {
 666
 667                                 /* Length and all bytes match ==> TRUE */
 668
 669                                 local_result = TRUE;
 670                         }
 671                         break;
 672
 673                 case AML_LGREATER_OP:   /* LGreater (Operand0, Operand1) */
 674
 675                         if (compare > 0) {
 676                                 local_result = TRUE;
 677                                 goto cleanup;   /* TRUE */
 678                         }
 679                         if (compare < 0) {
 680                                 goto cleanup;   /* FALSE */
 681                         }
 682
 683                         /* Bytes match (to shortest length), compare lengths */
 684
 685                         if (length0 > length1) {
 686                                 local_result = TRUE;
 687                         }
 688                         break;
 689
 690                 case AML_LLESS_OP:      /* LLess (Operand0, Operand1) */
 691
 692                         if (compare > 0) {
 693                                 goto cleanup;   /* FALSE */
 694                         }
 695                         if (compare < 0) {
 696                                 local_result = TRUE;
 697                                 goto cleanup;   /* TRUE */
 698                         }
 699
 700                         /* Bytes match (to shortest length), compare lengths */
 701
 702                         if (length0 < length1) {
 703                                 local_result = TRUE;
 704                         }
 705                         break;
 706
 707                 default:
 708                         status = AE_AML_INTERNAL;
 709                         break;
 710                 }
 711         }
 712
 713       cleanup:
 714
 715         /* New object was created if implicit conversion performed - delete */
 716
 717         if (local_operand1 != operand1) {
 718                 acpi_ut_remove_reference(local_operand1);
 719         }
 720
 721         /* Return the logical result and status */
 722
 723         *logical_result = local_result;
 724         return_ACPI_STATUS(status);
 725 }