drivers/acpi/acpica/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 "accommon.h"
  47 #include "acinterp.h"
  48 #include "amlcode.h"
  49 #include "amlresrc.h"
  50
  51 #define _COMPONENT          ACPI_EXECUTER
  52 ACPI_MODULE_NAME("exmisc")
  53
  54 /*******************************************************************************
  55  *
  56  * FUNCTION:    acpi_ex_get_object_reference
  57  *
  58  * PARAMETERS:  obj_desc            - Create a reference to this object
  59  *              return_desc         - Where to store the reference
  60  *              walk_state          - Current state
  61  *
  62  * RETURN:      Status
  63  *
  64  * DESCRIPTION: Obtain and return a "reference" to the target object
  65  *              Common code for the ref_of_op and the cond_ref_of_op.
  66  *
  67  ******************************************************************************/
  68 acpi_status
  69 acpi_ex_get_object_reference(union acpi_operand_object *obj_desc,
  70                              union acpi_operand_object **return_desc,
  71                              struct acpi_walk_state *walk_state)
  72 {
  73         union acpi_operand_object *reference_obj;
  74         union acpi_operand_object *referenced_obj;
  75
  76         ACPI_FUNCTION_TRACE_PTR(ex_get_object_reference, obj_desc);
  77
  78         *return_desc = NULL;
  79
  80         switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
  81         case ACPI_DESC_TYPE_OPERAND:
  82
  83                 if (ACPI_GET_OBJECT_TYPE(obj_desc) != ACPI_TYPE_LOCAL_REFERENCE) {
  84                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
  85                 }
  86
  87                 /*
  88                  * Must be a reference to a Local or Arg
  89                  */
  90                 switch (obj_desc->reference.class) {
  91                 case ACPI_REFCLASS_LOCAL:
  92                 case ACPI_REFCLASS_ARG:
  93                 case ACPI_REFCLASS_DEBUG:
  94
  95                         /* The referenced object is the pseudo-node for the local/arg */
  96
  97                         referenced_obj = obj_desc->reference.object;
  98                         break;
  99
 100                 default:
 101
 102                         ACPI_ERROR((AE_INFO, "Unknown Reference Class %2.2X",
 103                                     obj_desc->reference.class));
 104                         return_ACPI_STATUS(AE_AML_INTERNAL);
 105                 }
 106                 break;
 107
 108         case ACPI_DESC_TYPE_NAMED:
 109
 110                 /*
 111                  * A named reference that has already been resolved to a Node
 112                  */
 113                 referenced_obj = obj_desc;
 114                 break;
 115
 116         default:
 117
 118                 ACPI_ERROR((AE_INFO, "Invalid descriptor type %X",
 119                             ACPI_GET_DESCRIPTOR_TYPE(obj_desc)));
 120                 return_ACPI_STATUS(AE_TYPE);
 121         }
 122
 123         /* Create a new reference object */
 124
 125         reference_obj =
 126             acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_REFERENCE);
 127         if (!reference_obj) {
 128                 return_ACPI_STATUS(AE_NO_MEMORY);
 129         }
 130
 131         reference_obj->reference.class = ACPI_REFCLASS_REFOF;
 132         reference_obj->reference.object = referenced_obj;
 133         *return_desc = reference_obj;
 134
 135         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 136                           "Object %p Type [%s], returning Reference %p\n",
 137                           obj_desc, acpi_ut_get_object_type_name(obj_desc),
 138                           *return_desc));
 139
 140         return_ACPI_STATUS(AE_OK);
 141 }
 142
 143 /*******************************************************************************
 144  *
 145  * FUNCTION:    acpi_ex_concat_template
 146  *
 147  * PARAMETERS:  Operand0            - First source object
 148  *              Operand1            - Second source object
 149  *              actual_return_desc  - Where to place the return object
 150  *              walk_state          - Current walk state
 151  *
 152  * RETURN:      Status
 153  *
 154  * DESCRIPTION: Concatenate two resource templates
 155  *
 156  ******************************************************************************/
 157
 158 acpi_status
 159 acpi_ex_concat_template(union acpi_operand_object *operand0,
 160                         union acpi_operand_object *operand1,
 161                         union acpi_operand_object **actual_return_desc,
 162                         struct acpi_walk_state *walk_state)
 163 {
 164         acpi_status status;
 165         union acpi_operand_object *return_desc;
 166         u8 *new_buf;
 167         u8 *end_tag;
 168         acpi_size length0;
 169         acpi_size length1;
 170         acpi_size new_length;
 171
 172         ACPI_FUNCTION_TRACE(ex_concat_template);
 173
 174         /*
 175          * Find the end_tag descriptor in each resource template.
 176          * Note1: returned pointers point TO the end_tag, not past it.
 177          * Note2: zero-length buffers are allowed; treated like one end_tag
 178          */
 179
 180         /* Get the length of the first resource template */
 181
 182         status = acpi_ut_get_resource_end_tag(operand0, &end_tag);
 183         if (ACPI_FAILURE(status)) {
 184                 return_ACPI_STATUS(status);
 185         }
 186
 187         length0 = ACPI_PTR_DIFF(end_tag, operand0->buffer.pointer);
 188
 189         /* Get the length of the second resource template */
 190
 191         status = acpi_ut_get_resource_end_tag(operand1, &end_tag);
 192         if (ACPI_FAILURE(status)) {
 193                 return_ACPI_STATUS(status);
 194         }
 195
 196         length1 = ACPI_PTR_DIFF(end_tag, operand1->buffer.pointer);
 197
 198         /* Combine both lengths, minimum size will be 2 for end_tag */
 199
 200         new_length = length0 + length1 + sizeof(struct aml_resource_end_tag);
 201
 202         /* Create a new buffer object for the result (with one end_tag) */
 203
 204         return_desc = acpi_ut_create_buffer_object(new_length);
 205         if (!return_desc) {
 206                 return_ACPI_STATUS(AE_NO_MEMORY);
 207         }
 208
 209         /*
 210          * Copy the templates to the new buffer, 0 first, then 1 follows. One
 211          * end_tag descriptor is copied from Operand1.
 212          */
 213         new_buf = return_desc->buffer.pointer;
 214         ACPI_MEMCPY(new_buf, operand0->buffer.pointer, length0);
 215         ACPI_MEMCPY(new_buf + length0, operand1->buffer.pointer, length1);
 216
 217         /* Insert end_tag and set the checksum to zero, means "ignore checksum" */
 218
 219         new_buf[new_length - 1] = 0;
 220         new_buf[new_length - 2] = ACPI_RESOURCE_NAME_END_TAG | 1;
 221
 222         /* Return the completed resource template */
 223
 224         *actual_return_desc = return_desc;
 225         return_ACPI_STATUS(AE_OK);
 226 }
 227
 228 /*******************************************************************************
 229  *
 230  * FUNCTION:    acpi_ex_do_concatenate
 231  *
 232  * PARAMETERS:  Operand0            - First source object
 233  *              Operand1            - Second source object
 234  *              actual_return_desc  - Where to place the return object
 235  *              walk_state          - Current walk state
 236  *
 237  * RETURN:      Status
 238  *
 239  * DESCRIPTION: Concatenate two objects OF THE SAME TYPE.
 240  *
 241  ******************************************************************************/
 242
 243 acpi_status
 244 acpi_ex_do_concatenate(union acpi_operand_object *operand0,
 245                        union acpi_operand_object *operand1,
 246                        union acpi_operand_object **actual_return_desc,
 247                        struct acpi_walk_state *walk_state)
 248 {
 249         union acpi_operand_object *local_operand1 = operand1;
 250         union acpi_operand_object *return_desc;
 251         char *new_buf;
 252         acpi_status status;
 253
 254         ACPI_FUNCTION_TRACE(ex_do_concatenate);
 255
 256         /*
 257          * Convert the second operand if necessary.  The first operand
 258          * determines the type of the second operand, (See the Data Types
 259          * section of the ACPI specification.)  Both object types are
 260          * guaranteed to be either Integer/String/Buffer by the operand
 261          * resolution mechanism.
 262          */
 263         switch (ACPI_GET_OBJECT_TYPE(operand0)) {
 264         case ACPI_TYPE_INTEGER:
 265                 status =
 266                     acpi_ex_convert_to_integer(operand1, &local_operand1, 16);
 267                 break;
 268
 269         case ACPI_TYPE_STRING:
 270                 status = acpi_ex_convert_to_string(operand1, &local_operand1,
 271                                                    ACPI_IMPLICIT_CONVERT_HEX);
 272                 break;
 273
 274         case ACPI_TYPE_BUFFER:
 275                 status = acpi_ex_convert_to_buffer(operand1, &local_operand1);
 276                 break;
 277
 278         default:
 279                 ACPI_ERROR((AE_INFO, "Invalid object type: %X",
 280                             ACPI_GET_OBJECT_TYPE(operand0)));
 281                 status = AE_AML_INTERNAL;
 282         }
 283
 284         if (ACPI_FAILURE(status)) {
 285                 goto cleanup;
 286         }
 287
 288         /*
 289          * Both operands are now known to be the same object type
 290          * (Both are Integer, String, or Buffer), and we can now perform the
 291          * concatenation.
 292          */
 293
 294         /*
 295          * There are three cases to handle:
 296          *
 297          * 1) Two Integers concatenated to produce a new Buffer
 298          * 2) Two Strings concatenated to produce a new String
 299          * 3) Two Buffers concatenated to produce a new Buffer
 300          */
 301         switch (ACPI_GET_OBJECT_TYPE(operand0)) {
 302         case ACPI_TYPE_INTEGER:
 303
 304                 /* Result of two Integers is a Buffer */
 305                 /* Need enough buffer space for two integers */
 306
 307                 return_desc = acpi_ut_create_buffer_object((acpi_size)
 308                                                            ACPI_MUL_2
 309                                                            (acpi_gbl_integer_byte_width));
 310                 if (!return_desc) {
 311                         status = AE_NO_MEMORY;
 312                         goto cleanup;
 313                 }
 314
 315                 new_buf = (char *)return_desc->buffer.pointer;
 316
 317                 /* Copy the first integer, LSB first */
 318
 319                 ACPI_MEMCPY(new_buf, &operand0->integer.value,
 320                             acpi_gbl_integer_byte_width);
 321
 322                 /* Copy the second integer (LSB first) after the first */
 323
 324                 ACPI_MEMCPY(new_buf + acpi_gbl_integer_byte_width,
 325                             &local_operand1->integer.value,
 326                             acpi_gbl_integer_byte_width);
 327                 break;
 328
 329         case ACPI_TYPE_STRING:
 330
 331                 /* Result of two Strings is a String */
 332
 333                 return_desc = acpi_ut_create_string_object(((acpi_size)
 334                                                             operand0->string.
 335                                                             length +
 336                                                             local_operand1->
 337                                                             string.length));
 338                 if (!return_desc) {
 339                         status = AE_NO_MEMORY;
 340                         goto cleanup;
 341                 }
 342
 343                 new_buf = return_desc->string.pointer;
 344
 345                 /* Concatenate the strings */
 346
 347                 ACPI_STRCPY(new_buf, operand0->string.pointer);
 348                 ACPI_STRCPY(new_buf + operand0->string.length,
 349                             local_operand1->string.pointer);
 350                 break;
 351
 352         case ACPI_TYPE_BUFFER:
 353
 354                 /* Result of two Buffers is a Buffer */
 355
 356                 return_desc = acpi_ut_create_buffer_object(((acpi_size)
 357                                                             operand0->buffer.
 358                                                             length +
 359                                                             local_operand1->
 360                                                             buffer.length));
 361                 if (!return_desc) {
 362                         status = AE_NO_MEMORY;
 363                         goto cleanup;
 364                 }
 365
 366                 new_buf = (char *)return_desc->buffer.pointer;
 367
 368                 /* Concatenate the buffers */
 369
 370                 ACPI_MEMCPY(new_buf, operand0->buffer.pointer,
 371                             operand0->buffer.length);
 372                 ACPI_MEMCPY(new_buf + operand0->buffer.length,
 373                             local_operand1->buffer.pointer,
 374                             local_operand1->buffer.length);
 375                 break;
 376
 377         default:
 378
 379                 /* Invalid object type, should not happen here */
 380
 381                 ACPI_ERROR((AE_INFO, "Invalid object type: %X",
 382                             ACPI_GET_OBJECT_TYPE(operand0)));
 383                 status = AE_AML_INTERNAL;
 384                 goto cleanup;
 385         }
 386
 387         *actual_return_desc = return_desc;
 388
 389       cleanup:
 390         if (local_operand1 != operand1) {
 391                 acpi_ut_remove_reference(local_operand1);
 392         }
 393         return_ACPI_STATUS(status);
 394 }
 395
 396 /*******************************************************************************
 397  *
 398  * FUNCTION:    acpi_ex_do_math_op
 399  *
 400  * PARAMETERS:  Opcode              - AML opcode
 401  *              Integer0            - Integer operand #0
 402  *              Integer1            - Integer operand #1
 403  *
 404  * RETURN:      Integer result of the operation
 405  *
 406  * DESCRIPTION: Execute a math AML opcode. The purpose of having all of the
 407  *              math functions here is to prevent a lot of pointer dereferencing
 408  *              to obtain the operands.
 409  *
 410  ******************************************************************************/
 411
 412 acpi_integer
 413 acpi_ex_do_math_op(u16 opcode, acpi_integer integer0, acpi_integer integer1)
 414 {
 415
 416         ACPI_FUNCTION_ENTRY();
 417
 418         switch (opcode) {
 419         case AML_ADD_OP:        /* Add (Integer0, Integer1, Result) */
 420
 421                 return (integer0 + integer1);
 422
 423         case AML_BIT_AND_OP:    /* And (Integer0, Integer1, Result) */
 424
 425                 return (integer0 & integer1);
 426
 427         case AML_BIT_NAND_OP:   /* NAnd (Integer0, Integer1, Result) */
 428
 429                 return (~(integer0 & integer1));
 430
 431         case AML_BIT_OR_OP:     /* Or (Integer0, Integer1, Result) */
 432
 433                 return (integer0 | integer1);
 434
 435         case AML_BIT_NOR_OP:    /* NOr (Integer0, Integer1, Result) */
 436
 437                 return (~(integer0 | integer1));
 438
 439         case AML_BIT_XOR_OP:    /* XOr (Integer0, Integer1, Result) */
 440
 441                 return (integer0 ^ integer1);
 442
 443         case AML_MULTIPLY_OP:   /* Multiply (Integer0, Integer1, Result) */
 444
 445                 return (integer0 * integer1);
 446
 447         case AML_SHIFT_LEFT_OP: /* shift_left (Operand, shift_count, Result) */
 448
 449                 /*
 450                  * We need to check if the shiftcount is larger than the integer bit
 451                  * width since the behavior of this is not well-defined in the C language.
 452                  */
 453                 if (integer1 >= acpi_gbl_integer_bit_width) {
 454                         return (0);
 455                 }
 456                 return (integer0 << integer1);
 457
 458         case AML_SHIFT_RIGHT_OP:        /* shift_right (Operand, shift_count, Result) */
 459
 460                 /*
 461                  * We need to check if the shiftcount is larger than the integer bit
 462                  * width since the behavior of this is not well-defined in the C language.
 463                  */
 464                 if (integer1 >= acpi_gbl_integer_bit_width) {
 465                         return (0);
 466                 }
 467                 return (integer0 >> integer1);
 468
 469         case AML_SUBTRACT_OP:   /* Subtract (Integer0, Integer1, Result) */
 470
 471                 return (integer0 - integer1);
 472
 473         default:
 474
 475                 return (0);
 476         }
 477 }
 478
 479 /*******************************************************************************
 480  *
 481  * FUNCTION:    acpi_ex_do_logical_numeric_op
 482  *
 483  * PARAMETERS:  Opcode              - AML opcode
 484  *              Integer0            - Integer operand #0
 485  *              Integer1            - Integer operand #1
 486  *              logical_result      - TRUE/FALSE result of the operation
 487  *
 488  * RETURN:      Status
 489  *
 490  * DESCRIPTION: Execute a logical "Numeric" AML opcode. For these Numeric
 491  *              operators (LAnd and LOr), both operands must be integers.
 492  *
 493  *              Note: cleanest machine code seems to be produced by the code
 494  *              below, rather than using statements of the form:
 495  *                  Result = (Integer0 && Integer1);
 496  *
 497  ******************************************************************************/
 498
 499 acpi_status
 500 acpi_ex_do_logical_numeric_op(u16 opcode,
 501                               acpi_integer integer0,
 502                               acpi_integer integer1, u8 * logical_result)
 503 {
 504         acpi_status status = AE_OK;
 505         u8 local_result = FALSE;
 506
 507         ACPI_FUNCTION_TRACE(ex_do_logical_numeric_op);
 508
 509         switch (opcode) {
 510         case AML_LAND_OP:       /* LAnd (Integer0, Integer1) */
 511
 512                 if (integer0 && integer1) {
 513                         local_result = TRUE;
 514                 }
 515                 break;
 516
 517         case AML_LOR_OP:        /* LOr (Integer0, Integer1) */
 518
 519                 if (integer0 || integer1) {
 520                         local_result = TRUE;
 521                 }
 522                 break;
 523
 524         default:
 525                 status = AE_AML_INTERNAL;
 526                 break;
 527         }
 528
 529         /* Return the logical result and status */
 530
 531         *logical_result = local_result;
 532         return_ACPI_STATUS(status);
 533 }
 534
 535 /*******************************************************************************
 536  *
 537  * FUNCTION:    acpi_ex_do_logical_op
 538  *
 539  * PARAMETERS:  Opcode              - AML opcode
 540  *              Operand0            - operand #0
 541  *              Operand1            - operand #1
 542  *              logical_result      - TRUE/FALSE result of the operation
 543  *
 544  * RETURN:      Status
 545  *
 546  * DESCRIPTION: Execute a logical AML opcode. The purpose of having all of the
 547  *              functions here is to prevent a lot of pointer dereferencing
 548  *              to obtain the operands and to simplify the generation of the
 549  *              logical value. For the Numeric operators (LAnd and LOr), both
 550  *              operands must be integers. For the other logical operators,
 551  *              operands can be any combination of Integer/String/Buffer. The
 552  *              first operand determines the type to which the second operand
 553  *              will be converted.
 554  *
 555  *              Note: cleanest machine code seems to be produced by the code
 556  *              below, rather than using statements of the form:
 557  *                  Result = (Operand0 == Operand1);
 558  *
 559  ******************************************************************************/
 560
 561 acpi_status
 562 acpi_ex_do_logical_op(u16 opcode,
 563                       union acpi_operand_object *operand0,
 564                       union acpi_operand_object *operand1, u8 * logical_result)
 565 {
 566         union acpi_operand_object *local_operand1 = operand1;
 567         acpi_integer integer0;
 568         acpi_integer integer1;
 569         u32 length0;
 570         u32 length1;
 571         acpi_status status = AE_OK;
 572         u8 local_result = FALSE;
 573         int compare;
 574
 575         ACPI_FUNCTION_TRACE(ex_do_logical_op);
 576
 577         /*
 578          * Convert the second operand if necessary.  The first operand
 579          * determines the type of the second operand, (See the Data Types
 580          * section of the ACPI 3.0+ specification.)  Both object types are
 581          * guaranteed to be either Integer/String/Buffer by the operand
 582          * resolution mechanism.
 583          */
 584         switch (ACPI_GET_OBJECT_TYPE(operand0)) {
 585         case ACPI_TYPE_INTEGER:
 586                 status =
 587                     acpi_ex_convert_to_integer(operand1, &local_operand1, 16);
 588                 break;
 589
 590         case ACPI_TYPE_STRING:
 591                 status = acpi_ex_convert_to_string(operand1, &local_operand1,
 592                                                    ACPI_IMPLICIT_CONVERT_HEX);
 593                 break;
 594
 595         case ACPI_TYPE_BUFFER:
 596                 status = acpi_ex_convert_to_buffer(operand1, &local_operand1);
 597                 break;
 598
 599         default:
 600                 status = AE_AML_INTERNAL;
 601                 break;
 602         }
 603
 604         if (ACPI_FAILURE(status)) {
 605                 goto cleanup;
 606         }
 607
 608         /*
 609          * Two cases: 1) Both Integers, 2) Both Strings or Buffers
 610          */
 611         if (ACPI_GET_OBJECT_TYPE(operand0) == ACPI_TYPE_INTEGER) {
 612                 /*
 613                  * 1) Both operands are of type integer
 614                  *    Note: local_operand1 may have changed above
 615                  */
 616                 integer0 = operand0->integer.value;
 617                 integer1 = local_operand1->integer.value;
 618
 619                 switch (opcode) {
 620                 case AML_LEQUAL_OP:     /* LEqual (Operand0, Operand1) */
 621
 622                         if (integer0 == integer1) {
 623                                 local_result = TRUE;
 624                         }
 625                         break;
 626
 627                 case AML_LGREATER_OP:   /* LGreater (Operand0, Operand1) */
 628
 629                         if (integer0 > integer1) {
 630                                 local_result = TRUE;
 631                         }
 632                         break;
 633
 634                 case AML_LLESS_OP:      /* LLess (Operand0, Operand1) */
 635
 636                         if (integer0 < integer1) {
 637                                 local_result = TRUE;
 638                         }
 639                         break;
 640
 641                 default:
 642                         status = AE_AML_INTERNAL;
 643                         break;
 644                 }
 645         } else {
 646                 /*
 647                  * 2) Both operands are Strings or both are Buffers
 648                  *    Note: Code below takes advantage of common Buffer/String
 649                  *          object fields. local_operand1 may have changed above. Use
 650                  *          memcmp to handle nulls in buffers.
 651                  */
 652                 length0 = operand0->buffer.length;
 653                 length1 = local_operand1->buffer.length;
 654
 655                 /* Lexicographic compare: compare the data bytes */
 656
 657                 compare = ACPI_MEMCMP(operand0->buffer.pointer,
 658                                       local_operand1->buffer.pointer,
 659                                       (length0 > length1) ? length1 : length0);
 660
 661                 switch (opcode) {
 662                 case AML_LEQUAL_OP:     /* LEqual (Operand0, Operand1) */
 663
 664                         /* Length and all bytes must be equal */
 665
 666                         if ((length0 == length1) && (compare == 0)) {
 667
 668                                 /* Length and all bytes match ==> TRUE */
 669
 670                                 local_result = TRUE;
 671                         }
 672                         break;
 673
 674                 case AML_LGREATER_OP:   /* LGreater (Operand0, Operand1) */
 675
 676                         if (compare > 0) {
 677                                 local_result = TRUE;
 678                                 goto cleanup;   /* TRUE */
 679                         }
 680                         if (compare < 0) {
 681                                 goto cleanup;   /* FALSE */
 682                         }
 683
 684                         /* Bytes match (to shortest length), compare lengths */
 685
 686                         if (length0 > length1) {
 687                                 local_result = TRUE;
 688                         }
 689                         break;
 690
 691                 case AML_LLESS_OP:      /* LLess (Operand0, Operand1) */
 692
 693                         if (compare > 0) {
 694                                 goto cleanup;   /* FALSE */
 695                         }
 696                         if (compare < 0) {
 697                                 local_result = TRUE;
 698                                 goto cleanup;   /* TRUE */
 699                         }
 700
 701                         /* Bytes match (to shortest length), compare lengths */
 702
 703                         if (length0 < length1) {
 704                                 local_result = TRUE;
 705                         }
 706                         break;
 707
 708                 default:
 709                         status = AE_AML_INTERNAL;
 710                         break;
 711                 }
 712         }
 713
 714       cleanup:
 715
 716         /* New object was created if implicit conversion performed - delete */
 717
 718         if (local_operand1 != operand1) {
 719                 acpi_ut_remove_reference(local_operand1);
 720         }
 721
 722         /* Return the logical result and status */
 723
 724         *logical_result = local_result;
 725         return_ACPI_STATUS(status);
 726 }