1 /******************************************************************************
2 *
3 * Module Name: exmisc - ACPI AML (p-code) execution - specific opcodes
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2014, Intel Corp.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions, and the following disclaimer,
16 * without modification.
17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 * substantially similar to the "NO WARRANTY" disclaimer below
19 * ("Disclaimer") and any redistribution must be conditioned upon
20 * including a substantially similar Disclaimer requirement for further
21 * binary redistribution.
22 * 3. Neither the names of the above-listed copyright holders nor the names
23 * of any contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * Alternatively, this software may be distributed under the terms of the
27 * GNU General Public License ("GPL") version 2 as published by the Free
28 * Software Foundation.
29 *
30 * NO WARRANTY
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 * POSSIBILITY OF SUCH DAMAGES.
42 */
43
44 #include "acpi.h"
45 #include "accommon.h"
46 #include "acinterp.h"
47 #include "amlcode.h"
48 #include "amlresrc.h"
49
50
51 #define _COMPONENT ACPI_EXECUTER
52 ACPI_MODULE_NAME ("exmisc")
53
54
55 /*******************************************************************************
56 *
57 * FUNCTION: AcpiExGetObjectReference
58 *
59 * PARAMETERS: ObjDesc - Create a reference to this object
60 * ReturnDesc - Where to store the reference
61 * WalkState - Current state
62 *
63 * RETURN: Status
64 *
65 * DESCRIPTION: Obtain and return a "reference" to the target object
66 * Common code for the RefOfOp and the CondRefOfOp.
67 *
68 ******************************************************************************/
69
70 ACPI_STATUS
AcpiExGetObjectReference(ACPI_OPERAND_OBJECT * ObjDesc,ACPI_OPERAND_OBJECT ** ReturnDesc,ACPI_WALK_STATE * WalkState)71 AcpiExGetObjectReference (
72 ACPI_OPERAND_OBJECT *ObjDesc,
73 ACPI_OPERAND_OBJECT **ReturnDesc,
74 ACPI_WALK_STATE *WalkState)
75 {
76 ACPI_OPERAND_OBJECT *ReferenceObj;
77 ACPI_OPERAND_OBJECT *ReferencedObj;
78
79
80 ACPI_FUNCTION_TRACE_PTR (ExGetObjectReference, ObjDesc);
81
82
83 *ReturnDesc = NULL;
84
85 switch (ACPI_GET_DESCRIPTOR_TYPE (ObjDesc))
86 {
87 case ACPI_DESC_TYPE_OPERAND:
88
89 if (ObjDesc->Common.Type != ACPI_TYPE_LOCAL_REFERENCE)
90 {
91 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
92 }
93
94 /*
95 * Must be a reference to a Local or Arg
96 */
97 switch (ObjDesc->Reference.Class)
98 {
99 case ACPI_REFCLASS_LOCAL:
100 case ACPI_REFCLASS_ARG:
101 case ACPI_REFCLASS_DEBUG:
102
103 /* The referenced object is the pseudo-node for the local/arg */
104
105 ReferencedObj = ObjDesc->Reference.Object;
106 break;
107
108 default:
109
110 ACPI_ERROR ((AE_INFO, "Unknown Reference Class 0x%2.2X",
111 ObjDesc->Reference.Class));
112 return_ACPI_STATUS (AE_AML_INTERNAL);
113 }
114 break;
115
116 case ACPI_DESC_TYPE_NAMED:
117 /*
118 * A named reference that has already been resolved to a Node
119 */
120 ReferencedObj = ObjDesc;
121 break;
122
123 default:
124
125 ACPI_ERROR ((AE_INFO, "Invalid descriptor type 0x%X",
126 ACPI_GET_DESCRIPTOR_TYPE (ObjDesc)));
127 return_ACPI_STATUS (AE_TYPE);
128 }
129
130
131 /* Create a new reference object */
132
133 ReferenceObj = AcpiUtCreateInternalObject (ACPI_TYPE_LOCAL_REFERENCE);
134 if (!ReferenceObj)
135 {
136 return_ACPI_STATUS (AE_NO_MEMORY);
137 }
138
139 ReferenceObj->Reference.Class = ACPI_REFCLASS_REFOF;
140 ReferenceObj->Reference.Object = ReferencedObj;
141 *ReturnDesc = ReferenceObj;
142
143 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
144 "Object %p Type [%s], returning Reference %p\n",
145 ObjDesc, AcpiUtGetObjectTypeName (ObjDesc), *ReturnDesc));
146
147 return_ACPI_STATUS (AE_OK);
148 }
149
150
151 /*******************************************************************************
152 *
153 * FUNCTION: AcpiExConcatTemplate
154 *
155 * PARAMETERS: Operand0 - First source object
156 * Operand1 - Second source object
157 * ActualReturnDesc - Where to place the return object
158 * WalkState - Current walk state
159 *
160 * RETURN: Status
161 *
162 * DESCRIPTION: Concatenate two resource templates
163 *
164 ******************************************************************************/
165
166 ACPI_STATUS
AcpiExConcatTemplate(ACPI_OPERAND_OBJECT * Operand0,ACPI_OPERAND_OBJECT * Operand1,ACPI_OPERAND_OBJECT ** ActualReturnDesc,ACPI_WALK_STATE * WalkState)167 AcpiExConcatTemplate (
168 ACPI_OPERAND_OBJECT *Operand0,
169 ACPI_OPERAND_OBJECT *Operand1,
170 ACPI_OPERAND_OBJECT **ActualReturnDesc,
171 ACPI_WALK_STATE *WalkState)
172 {
173 ACPI_STATUS Status;
174 ACPI_OPERAND_OBJECT *ReturnDesc;
175 UINT8 *NewBuf;
176 UINT8 *EndTag;
177 ACPI_SIZE Length0;
178 ACPI_SIZE Length1;
179 ACPI_SIZE NewLength;
180
181
182 ACPI_FUNCTION_TRACE (ExConcatTemplate);
183
184
185 /*
186 * Find the EndTag descriptor in each resource template.
187 * Note1: returned pointers point TO the EndTag, not past it.
188 * Note2: zero-length buffers are allowed; treated like one EndTag
189 */
190
191 /* Get the length of the first resource template */
192
193 Status = AcpiUtGetResourceEndTag (Operand0, &EndTag);
194 if (ACPI_FAILURE (Status))
195 {
196 return_ACPI_STATUS (Status);
197 }
198
199 Length0 = ACPI_PTR_DIFF (EndTag, Operand0->Buffer.Pointer);
200
201 /* Get the length of the second resource template */
202
203 Status = AcpiUtGetResourceEndTag (Operand1, &EndTag);
204 if (ACPI_FAILURE (Status))
205 {
206 return_ACPI_STATUS (Status);
207 }
208
209 Length1 = ACPI_PTR_DIFF (EndTag, Operand1->Buffer.Pointer);
210
211 /* Combine both lengths, minimum size will be 2 for EndTag */
212
213 NewLength = Length0 + Length1 + sizeof (AML_RESOURCE_END_TAG);
214
215 /* Create a new buffer object for the result (with one EndTag) */
216
217 ReturnDesc = AcpiUtCreateBufferObject (NewLength);
218 if (!ReturnDesc)
219 {
220 return_ACPI_STATUS (AE_NO_MEMORY);
221 }
222
223 /*
224 * Copy the templates to the new buffer, 0 first, then 1 follows. One
225 * EndTag descriptor is copied from Operand1.
226 */
227 NewBuf = ReturnDesc->Buffer.Pointer;
228 ACPI_MEMCPY (NewBuf, Operand0->Buffer.Pointer, Length0);
229 ACPI_MEMCPY (NewBuf + Length0, Operand1->Buffer.Pointer, Length1);
230
231 /* Insert EndTag and set the checksum to zero, means "ignore checksum" */
232
233 NewBuf[NewLength - 1] = 0;
234 NewBuf[NewLength - 2] = ACPI_RESOURCE_NAME_END_TAG | 1;
235
236 /* Return the completed resource template */
237
238 *ActualReturnDesc = ReturnDesc;
239 return_ACPI_STATUS (AE_OK);
240 }
241
242
243 /*******************************************************************************
244 *
245 * FUNCTION: AcpiExDoConcatenate
246 *
247 * PARAMETERS: Operand0 - First source object
248 * Operand1 - Second source object
249 * ActualReturnDesc - Where to place the return object
250 * WalkState - Current walk state
251 *
252 * RETURN: Status
253 *
254 * DESCRIPTION: Concatenate two objects OF THE SAME TYPE.
255 *
256 ******************************************************************************/
257
258 ACPI_STATUS
AcpiExDoConcatenate(ACPI_OPERAND_OBJECT * Operand0,ACPI_OPERAND_OBJECT * Operand1,ACPI_OPERAND_OBJECT ** ActualReturnDesc,ACPI_WALK_STATE * WalkState)259 AcpiExDoConcatenate (
260 ACPI_OPERAND_OBJECT *Operand0,
261 ACPI_OPERAND_OBJECT *Operand1,
262 ACPI_OPERAND_OBJECT **ActualReturnDesc,
263 ACPI_WALK_STATE *WalkState)
264 {
265 ACPI_OPERAND_OBJECT *LocalOperand1 = Operand1;
266 ACPI_OPERAND_OBJECT *ReturnDesc;
267 char *NewBuf;
268 ACPI_STATUS Status;
269
270
271 ACPI_FUNCTION_TRACE (ExDoConcatenate);
272
273
274 /*
275 * Convert the second operand if necessary. The first operand
276 * determines the type of the second operand, (See the Data Types
277 * section of the ACPI specification.) Both object types are
278 * guaranteed to be either Integer/String/Buffer by the operand
279 * resolution mechanism.
280 */
281 switch (Operand0->Common.Type)
282 {
283 case ACPI_TYPE_INTEGER:
284
285 Status = AcpiExConvertToInteger (Operand1, &LocalOperand1, 16);
286 break;
287
288 case ACPI_TYPE_STRING:
289
290 Status = AcpiExConvertToString (Operand1, &LocalOperand1,
291 ACPI_IMPLICIT_CONVERT_HEX);
292 break;
293
294 case ACPI_TYPE_BUFFER:
295
296 Status = AcpiExConvertToBuffer (Operand1, &LocalOperand1);
297 break;
298
299 default:
300
301 ACPI_ERROR ((AE_INFO, "Invalid object type: 0x%X",
302 Operand0->Common.Type));
303 Status = AE_AML_INTERNAL;
304 }
305
306 if (ACPI_FAILURE (Status))
307 {
308 goto Cleanup;
309 }
310
311 /*
312 * Both operands are now known to be the same object type
313 * (Both are Integer, String, or Buffer), and we can now perform the
314 * concatenation.
315 */
316
317 /*
318 * There are three cases to handle:
319 *
320 * 1) Two Integers concatenated to produce a new Buffer
321 * 2) Two Strings concatenated to produce a new String
322 * 3) Two Buffers concatenated to produce a new Buffer
323 */
324 switch (Operand0->Common.Type)
325 {
326 case ACPI_TYPE_INTEGER:
327
328 /* Result of two Integers is a Buffer */
329 /* Need enough buffer space for two integers */
330
331 ReturnDesc = AcpiUtCreateBufferObject ((ACPI_SIZE)
332 ACPI_MUL_2 (AcpiGbl_IntegerByteWidth));
333 if (!ReturnDesc)
334 {
335 Status = AE_NO_MEMORY;
336 goto Cleanup;
337 }
338
339 NewBuf = (char *) ReturnDesc->Buffer.Pointer;
340
341 /* Copy the first integer, LSB first */
342
343 ACPI_MEMCPY (NewBuf, &Operand0->Integer.Value,
344 AcpiGbl_IntegerByteWidth);
345
346 /* Copy the second integer (LSB first) after the first */
347
348 ACPI_MEMCPY (NewBuf + AcpiGbl_IntegerByteWidth,
349 &LocalOperand1->Integer.Value,
350 AcpiGbl_IntegerByteWidth);
351 break;
352
353 case ACPI_TYPE_STRING:
354
355 /* Result of two Strings is a String */
356
357 ReturnDesc = AcpiUtCreateStringObject (
358 ((ACPI_SIZE) Operand0->String.Length +
359 LocalOperand1->String.Length));
360 if (!ReturnDesc)
361 {
362 Status = AE_NO_MEMORY;
363 goto Cleanup;
364 }
365
366 NewBuf = ReturnDesc->String.Pointer;
367
368 /* Concatenate the strings */
369
370 ACPI_STRCPY (NewBuf, Operand0->String.Pointer);
371 ACPI_STRCPY (NewBuf + Operand0->String.Length,
372 LocalOperand1->String.Pointer);
373 break;
374
375 case ACPI_TYPE_BUFFER:
376
377 /* Result of two Buffers is a Buffer */
378
379 ReturnDesc = AcpiUtCreateBufferObject (
380 ((ACPI_SIZE) Operand0->Buffer.Length +
381 LocalOperand1->Buffer.Length));
382 if (!ReturnDesc)
383 {
384 Status = AE_NO_MEMORY;
385 goto Cleanup;
386 }
387
388 NewBuf = (char *) ReturnDesc->Buffer.Pointer;
389
390 /* Concatenate the buffers */
391
392 ACPI_MEMCPY (NewBuf, Operand0->Buffer.Pointer,
393 Operand0->Buffer.Length);
394 ACPI_MEMCPY (NewBuf + Operand0->Buffer.Length,
395 LocalOperand1->Buffer.Pointer,
396 LocalOperand1->Buffer.Length);
397 break;
398
399 default:
400
401 /* Invalid object type, should not happen here */
402
403 ACPI_ERROR ((AE_INFO, "Invalid object type: 0x%X",
404 Operand0->Common.Type));
405 Status =AE_AML_INTERNAL;
406 goto Cleanup;
407 }
408
409 *ActualReturnDesc = ReturnDesc;
410
411 Cleanup:
412 if (LocalOperand1 != Operand1)
413 {
414 AcpiUtRemoveReference (LocalOperand1);
415 }
416 return_ACPI_STATUS (Status);
417 }
418
419
420 /*******************************************************************************
421 *
422 * FUNCTION: AcpiExDoMathOp
423 *
424 * PARAMETERS: Opcode - AML opcode
425 * Integer0 - Integer operand #0
426 * Integer1 - Integer operand #1
427 *
428 * RETURN: Integer result of the operation
429 *
430 * DESCRIPTION: Execute a math AML opcode. The purpose of having all of the
431 * math functions here is to prevent a lot of pointer dereferencing
432 * to obtain the operands.
433 *
434 ******************************************************************************/
435
436 UINT64
AcpiExDoMathOp(UINT16 Opcode,UINT64 Integer0,UINT64 Integer1)437 AcpiExDoMathOp (
438 UINT16 Opcode,
439 UINT64 Integer0,
440 UINT64 Integer1)
441 {
442
443 ACPI_FUNCTION_ENTRY ();
444
445
446 switch (Opcode)
447 {
448 case AML_ADD_OP: /* Add (Integer0, Integer1, Result) */
449
450 return (Integer0 + Integer1);
451
452 case AML_BIT_AND_OP: /* And (Integer0, Integer1, Result) */
453
454 return (Integer0 & Integer1);
455
456 case AML_BIT_NAND_OP: /* NAnd (Integer0, Integer1, Result) */
457
458 return (~(Integer0 & Integer1));
459
460 case AML_BIT_OR_OP: /* Or (Integer0, Integer1, Result) */
461
462 return (Integer0 | Integer1);
463
464 case AML_BIT_NOR_OP: /* NOr (Integer0, Integer1, Result) */
465
466 return (~(Integer0 | Integer1));
467
468 case AML_BIT_XOR_OP: /* XOr (Integer0, Integer1, Result) */
469
470 return (Integer0 ^ Integer1);
471
472 case AML_MULTIPLY_OP: /* Multiply (Integer0, Integer1, Result) */
473
474 return (Integer0 * Integer1);
475
476 case AML_SHIFT_LEFT_OP: /* ShiftLeft (Operand, ShiftCount, Result)*/
477
478 /*
479 * We need to check if the shiftcount is larger than the integer bit
480 * width since the behavior of this is not well-defined in the C language.
481 */
482 if (Integer1 >= AcpiGbl_IntegerBitWidth)
483 {
484 return (0);
485 }
486 return (Integer0 << Integer1);
487
488 case AML_SHIFT_RIGHT_OP: /* ShiftRight (Operand, ShiftCount, Result) */
489
490 /*
491 * We need to check if the shiftcount is larger than the integer bit
492 * width since the behavior of this is not well-defined in the C language.
493 */
494 if (Integer1 >= AcpiGbl_IntegerBitWidth)
495 {
496 return (0);
497 }
498 return (Integer0 >> Integer1);
499
500 case AML_SUBTRACT_OP: /* Subtract (Integer0, Integer1, Result) */
501
502 return (Integer0 - Integer1);
503
504 default:
505
506 return (0);
507 }
508 }
509
510
511 /*******************************************************************************
512 *
513 * FUNCTION: AcpiExDoLogicalNumericOp
514 *
515 * PARAMETERS: Opcode - AML opcode
516 * Integer0 - Integer operand #0
517 * Integer1 - Integer operand #1
518 * LogicalResult - TRUE/FALSE result of the operation
519 *
520 * RETURN: Status
521 *
522 * DESCRIPTION: Execute a logical "Numeric" AML opcode. For these Numeric
523 * operators (LAnd and LOr), both operands must be integers.
524 *
525 * Note: cleanest machine code seems to be produced by the code
526 * below, rather than using statements of the form:
527 * Result = (Integer0 && Integer1);
528 *
529 ******************************************************************************/
530
531 ACPI_STATUS
AcpiExDoLogicalNumericOp(UINT16 Opcode,UINT64 Integer0,UINT64 Integer1,BOOLEAN * LogicalResult)532 AcpiExDoLogicalNumericOp (
533 UINT16 Opcode,
534 UINT64 Integer0,
535 UINT64 Integer1,
536 BOOLEAN *LogicalResult)
537 {
538 ACPI_STATUS Status = AE_OK;
539 BOOLEAN LocalResult = FALSE;
540
541
542 ACPI_FUNCTION_TRACE (ExDoLogicalNumericOp);
543
544
545 switch (Opcode)
546 {
547 case AML_LAND_OP: /* LAnd (Integer0, Integer1) */
548
549 if (Integer0 && Integer1)
550 {
551 LocalResult = TRUE;
552 }
553 break;
554
555 case AML_LOR_OP: /* LOr (Integer0, Integer1) */
556
557 if (Integer0 || Integer1)
558 {
559 LocalResult = TRUE;
560 }
561 break;
562
563 default:
564
565 Status = AE_AML_INTERNAL;
566 break;
567 }
568
569 /* Return the logical result and status */
570
571 *LogicalResult = LocalResult;
572 return_ACPI_STATUS (Status);
573 }
574
575
576 /*******************************************************************************
577 *
578 * FUNCTION: AcpiExDoLogicalOp
579 *
580 * PARAMETERS: Opcode - AML opcode
581 * Operand0 - operand #0
582 * Operand1 - operand #1
583 * LogicalResult - TRUE/FALSE result of the operation
584 *
585 * RETURN: Status
586 *
587 * DESCRIPTION: Execute a logical AML opcode. The purpose of having all of the
588 * functions here is to prevent a lot of pointer dereferencing
589 * to obtain the operands and to simplify the generation of the
590 * logical value. For the Numeric operators (LAnd and LOr), both
591 * operands must be integers. For the other logical operators,
592 * operands can be any combination of Integer/String/Buffer. The
593 * first operand determines the type to which the second operand
594 * will be converted.
595 *
596 * Note: cleanest machine code seems to be produced by the code
597 * below, rather than using statements of the form:
598 * Result = (Operand0 == Operand1);
599 *
600 ******************************************************************************/
601
602 ACPI_STATUS
AcpiExDoLogicalOp(UINT16 Opcode,ACPI_OPERAND_OBJECT * Operand0,ACPI_OPERAND_OBJECT * Operand1,BOOLEAN * LogicalResult)603 AcpiExDoLogicalOp (
604 UINT16 Opcode,
605 ACPI_OPERAND_OBJECT *Operand0,
606 ACPI_OPERAND_OBJECT *Operand1,
607 BOOLEAN *LogicalResult)
608 {
609 ACPI_OPERAND_OBJECT *LocalOperand1 = Operand1;
610 UINT64 Integer0;
611 UINT64 Integer1;
612 UINT32 Length0;
613 UINT32 Length1;
614 ACPI_STATUS Status = AE_OK;
615 BOOLEAN LocalResult = FALSE;
616 int Compare;
617
618
619 ACPI_FUNCTION_TRACE (ExDoLogicalOp);
620
621
622 /*
623 * Convert the second operand if necessary. The first operand
624 * determines the type of the second operand, (See the Data Types
625 * section of the ACPI 3.0+ specification.) Both object types are
626 * guaranteed to be either Integer/String/Buffer by the operand
627 * resolution mechanism.
628 */
629 switch (Operand0->Common.Type)
630 {
631 case ACPI_TYPE_INTEGER:
632
633 Status = AcpiExConvertToInteger (Operand1, &LocalOperand1, 16);
634 break;
635
636 case ACPI_TYPE_STRING:
637
638 Status = AcpiExConvertToString (Operand1, &LocalOperand1,
639 ACPI_IMPLICIT_CONVERT_HEX);
640 break;
641
642 case ACPI_TYPE_BUFFER:
643
644 Status = AcpiExConvertToBuffer (Operand1, &LocalOperand1);
645 break;
646
647 default:
648
649 Status = AE_AML_INTERNAL;
650 break;
651 }
652
653 if (ACPI_FAILURE (Status))
654 {
655 goto Cleanup;
656 }
657
658 /*
659 * Two cases: 1) Both Integers, 2) Both Strings or Buffers
660 */
661 if (Operand0->Common.Type == ACPI_TYPE_INTEGER)
662 {
663 /*
664 * 1) Both operands are of type integer
665 * Note: LocalOperand1 may have changed above
666 */
667 Integer0 = Operand0->Integer.Value;
668 Integer1 = LocalOperand1->Integer.Value;
669
670 switch (Opcode)
671 {
672 case AML_LEQUAL_OP: /* LEqual (Operand0, Operand1) */
673
674 if (Integer0 == Integer1)
675 {
676 LocalResult = TRUE;
677 }
678 break;
679
680 case AML_LGREATER_OP: /* LGreater (Operand0, Operand1) */
681
682 if (Integer0 > Integer1)
683 {
684 LocalResult = TRUE;
685 }
686 break;
687
688 case AML_LLESS_OP: /* LLess (Operand0, Operand1) */
689
690 if (Integer0 < Integer1)
691 {
692 LocalResult = TRUE;
693 }
694 break;
695
696 default:
697
698 Status = AE_AML_INTERNAL;
699 break;
700 }
701 }
702 else
703 {
704 /*
705 * 2) Both operands are Strings or both are Buffers
706 * Note: Code below takes advantage of common Buffer/String
707 * object fields. LocalOperand1 may have changed above. Use
708 * memcmp to handle nulls in buffers.
709 */
710 Length0 = Operand0->Buffer.Length;
711 Length1 = LocalOperand1->Buffer.Length;
712
713 /* Lexicographic compare: compare the data bytes */
714
715 Compare = ACPI_MEMCMP (Operand0->Buffer.Pointer,
716 LocalOperand1->Buffer.Pointer,
717 (Length0 > Length1) ? Length1 : Length0);
718
719 switch (Opcode)
720 {
721 case AML_LEQUAL_OP: /* LEqual (Operand0, Operand1) */
722
723 /* Length and all bytes must be equal */
724
725 if ((Length0 == Length1) &&
726 (Compare == 0))
727 {
728 /* Length and all bytes match ==> TRUE */
729
730 LocalResult = TRUE;
731 }
732 break;
733
734 case AML_LGREATER_OP: /* LGreater (Operand0, Operand1) */
735
736 if (Compare > 0)
737 {
738 LocalResult = TRUE;
739 goto Cleanup; /* TRUE */
740 }
741 if (Compare < 0)
742 {
743 goto Cleanup; /* FALSE */
744 }
745
746 /* Bytes match (to shortest length), compare lengths */
747
748 if (Length0 > Length1)
749 {
750 LocalResult = TRUE;
751 }
752 break;
753
754 case AML_LLESS_OP: /* LLess (Operand0, Operand1) */
755
756 if (Compare > 0)
757 {
758 goto Cleanup; /* FALSE */
759 }
760 if (Compare < 0)
761 {
762 LocalResult = TRUE;
763 goto Cleanup; /* TRUE */
764 }
765
766 /* Bytes match (to shortest length), compare lengths */
767
768 if (Length0 < Length1)
769 {
770 LocalResult = TRUE;
771 }
772 break;
773
774 default:
775
776 Status = AE_AML_INTERNAL;
777 break;
778 }
779 }
780
781 Cleanup:
782
783 /* New object was created if implicit conversion performed - delete */
784
785 if (LocalOperand1 != Operand1)
786 {
787 AcpiUtRemoveReference (LocalOperand1);
788 }
789
790 /* Return the logical result and status */
791
792 *LogicalResult = LocalResult;
793 return_ACPI_STATUS (Status);
794 }
795