xref: /linux/drivers/acpi/acpica/exmisc.c (revision a8fe58cec351c25e09c393bf46117c0c47b5a17c)
1 /******************************************************************************
2  *
3  * Module Name: exmisc - ACPI AML (p-code) execution - specific opcodes
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2016, 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/acpi.h>
45 #include "accommon.h"
46 #include "acinterp.h"
47 #include "amlcode.h"
48 #include "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 (obj_desc->common.type != 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.class) {
90 		case ACPI_REFCLASS_LOCAL:
91 		case ACPI_REFCLASS_ARG:
92 		case ACPI_REFCLASS_DEBUG:
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, "Invalid Reference Class 0x%2.2X",
102 				    obj_desc->reference.class));
103 			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
104 		}
105 		break;
106 
107 	case ACPI_DESC_TYPE_NAMED:
108 		/*
109 		 * A named reference that has already been resolved to a Node
110 		 */
111 		referenced_obj = obj_desc;
112 		break;
113 
114 	default:
115 
116 		ACPI_ERROR((AE_INFO, "Invalid descriptor type 0x%X",
117 			    ACPI_GET_DESCRIPTOR_TYPE(obj_desc)));
118 		return_ACPI_STATUS(AE_TYPE);
119 	}
120 
121 	/* Create a new reference object */
122 
123 	reference_obj =
124 	    acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_REFERENCE);
125 	if (!reference_obj) {
126 		return_ACPI_STATUS(AE_NO_MEMORY);
127 	}
128 
129 	reference_obj->reference.class = ACPI_REFCLASS_REFOF;
130 	reference_obj->reference.object = referenced_obj;
131 	*return_desc = reference_obj;
132 
133 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
134 			  "Object %p Type [%s], returning Reference %p\n",
135 			  obj_desc, acpi_ut_get_object_type_name(obj_desc),
136 			  *return_desc));
137 
138 	return_ACPI_STATUS(AE_OK);
139 }
140 
141 /*******************************************************************************
142  *
143  * FUNCTION:    acpi_ex_concat_template
144  *
145  * PARAMETERS:  operand0            - First source object
146  *              operand1            - Second source object
147  *              actual_return_desc  - Where to place the return object
148  *              walk_state          - Current walk state
149  *
150  * RETURN:      Status
151  *
152  * DESCRIPTION: Concatenate two resource templates
153  *
154  ******************************************************************************/
155 
156 acpi_status
157 acpi_ex_concat_template(union acpi_operand_object *operand0,
158 			union acpi_operand_object *operand1,
159 			union acpi_operand_object **actual_return_desc,
160 			struct acpi_walk_state *walk_state)
161 {
162 	acpi_status status;
163 	union acpi_operand_object *return_desc;
164 	u8 *new_buf;
165 	u8 *end_tag;
166 	acpi_size length0;
167 	acpi_size length1;
168 	acpi_size new_length;
169 
170 	ACPI_FUNCTION_TRACE(ex_concat_template);
171 
172 	/*
173 	 * Find the end_tag descriptor in each resource template.
174 	 * Note1: returned pointers point TO the end_tag, not past it.
175 	 * Note2: zero-length buffers are allowed; treated like one end_tag
176 	 */
177 
178 	/* Get the length of the first resource template */
179 
180 	status = acpi_ut_get_resource_end_tag(operand0, &end_tag);
181 	if (ACPI_FAILURE(status)) {
182 		return_ACPI_STATUS(status);
183 	}
184 
185 	length0 = ACPI_PTR_DIFF(end_tag, operand0->buffer.pointer);
186 
187 	/* Get the length of the second resource template */
188 
189 	status = acpi_ut_get_resource_end_tag(operand1, &end_tag);
190 	if (ACPI_FAILURE(status)) {
191 		return_ACPI_STATUS(status);
192 	}
193 
194 	length1 = ACPI_PTR_DIFF(end_tag, operand1->buffer.pointer);
195 
196 	/* Combine both lengths, minimum size will be 2 for end_tag */
197 
198 	new_length = length0 + length1 + sizeof(struct aml_resource_end_tag);
199 
200 	/* Create a new buffer object for the result (with one end_tag) */
201 
202 	return_desc = acpi_ut_create_buffer_object(new_length);
203 	if (!return_desc) {
204 		return_ACPI_STATUS(AE_NO_MEMORY);
205 	}
206 
207 	/*
208 	 * Copy the templates to the new buffer, 0 first, then 1 follows. One
209 	 * end_tag descriptor is copied from Operand1.
210 	 */
211 	new_buf = return_desc->buffer.pointer;
212 	memcpy(new_buf, operand0->buffer.pointer, length0);
213 	memcpy(new_buf + length0, operand1->buffer.pointer, length1);
214 
215 	/* Insert end_tag and set the checksum to zero, means "ignore checksum" */
216 
217 	new_buf[new_length - 1] = 0;
218 	new_buf[new_length - 2] = ACPI_RESOURCE_NAME_END_TAG | 1;
219 
220 	/* Return the completed resource template */
221 
222 	*actual_return_desc = return_desc;
223 	return_ACPI_STATUS(AE_OK);
224 }
225 
226 /*******************************************************************************
227  *
228  * FUNCTION:    acpi_ex_do_concatenate
229  *
230  * PARAMETERS:  operand0            - First source object
231  *              operand1            - Second source object
232  *              actual_return_desc  - Where to place the return object
233  *              walk_state          - Current walk state
234  *
235  * RETURN:      Status
236  *
237  * DESCRIPTION: Concatenate two objects OF THE SAME TYPE.
238  *
239  ******************************************************************************/
240 
241 acpi_status
242 acpi_ex_do_concatenate(union acpi_operand_object *operand0,
243 		       union acpi_operand_object *operand1,
244 		       union acpi_operand_object **actual_return_desc,
245 		       struct acpi_walk_state *walk_state)
246 {
247 	union acpi_operand_object *local_operand1 = operand1;
248 	union acpi_operand_object *return_desc;
249 	char *new_buf;
250 	const char *type_string;
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 (operand0->common.type) {
263 	case ACPI_TYPE_INTEGER:
264 
265 		status =
266 		    acpi_ex_convert_to_integer(operand1, &local_operand1, 16);
267 		break;
268 
269 	case ACPI_TYPE_STRING:
270 		/*
271 		 * Per the ACPI spec, Concatenate only supports int/str/buf.
272 		 * However, we support all objects here as an extension.
273 		 * This improves the usefulness of the Printf() macro.
274 		 * 12/2015.
275 		 */
276 		switch (operand1->common.type) {
277 		case ACPI_TYPE_INTEGER:
278 		case ACPI_TYPE_STRING:
279 		case ACPI_TYPE_BUFFER:
280 
281 			status =
282 			    acpi_ex_convert_to_string(operand1, &local_operand1,
283 						      ACPI_IMPLICIT_CONVERT_HEX);
284 			break;
285 
286 		default:
287 			/*
288 			 * Just emit a string containing the object type.
289 			 */
290 			type_string =
291 			    acpi_ut_get_type_name(operand1->common.type);
292 
293 			local_operand1 = acpi_ut_create_string_object(((acpi_size) strlen(type_string) + 9));	/* 9 For "[Object]" */
294 			if (!local_operand1) {
295 				status = AE_NO_MEMORY;
296 				goto cleanup;
297 			}
298 
299 			strcpy(local_operand1->string.pointer, "[");
300 			strcat(local_operand1->string.pointer, type_string);
301 			strcat(local_operand1->string.pointer, " Object]");
302 			status = AE_OK;
303 			break;
304 		}
305 		break;
306 
307 	case ACPI_TYPE_BUFFER:
308 
309 		status = acpi_ex_convert_to_buffer(operand1, &local_operand1);
310 		break;
311 
312 	default:
313 
314 		ACPI_ERROR((AE_INFO, "Invalid object type: 0x%X",
315 			    operand0->common.type));
316 		status = AE_AML_INTERNAL;
317 	}
318 
319 	if (ACPI_FAILURE(status)) {
320 		goto cleanup;
321 	}
322 
323 	/*
324 	 * Both operands are now known to be the same object type
325 	 * (Both are Integer, String, or Buffer), and we can now perform the
326 	 * concatenation.
327 	 */
328 
329 	/*
330 	 * There are three cases to handle:
331 	 *
332 	 * 1) Two Integers concatenated to produce a new Buffer
333 	 * 2) Two Strings concatenated to produce a new String
334 	 * 3) Two Buffers concatenated to produce a new Buffer
335 	 */
336 	switch (operand0->common.type) {
337 	case ACPI_TYPE_INTEGER:
338 
339 		/* Result of two Integers is a Buffer */
340 		/* Need enough buffer space for two integers */
341 
342 		return_desc = acpi_ut_create_buffer_object((acpi_size)
343 							   ACPI_MUL_2
344 							   (acpi_gbl_integer_byte_width));
345 		if (!return_desc) {
346 			status = AE_NO_MEMORY;
347 			goto cleanup;
348 		}
349 
350 		new_buf = (char *)return_desc->buffer.pointer;
351 
352 		/* Copy the first integer, LSB first */
353 
354 		memcpy(new_buf, &operand0->integer.value,
355 		       acpi_gbl_integer_byte_width);
356 
357 		/* Copy the second integer (LSB first) after the first */
358 
359 		memcpy(new_buf + acpi_gbl_integer_byte_width,
360 		       &local_operand1->integer.value,
361 		       acpi_gbl_integer_byte_width);
362 		break;
363 
364 	case ACPI_TYPE_STRING:
365 
366 		/* Result of two Strings is a String */
367 
368 		return_desc = acpi_ut_create_string_object(((acpi_size)
369 							    operand0->string.
370 							    length +
371 							    local_operand1->
372 							    string.length));
373 		if (!return_desc) {
374 			status = AE_NO_MEMORY;
375 			goto cleanup;
376 		}
377 
378 		new_buf = return_desc->string.pointer;
379 
380 		/* Concatenate the strings */
381 
382 		strcpy(new_buf, operand0->string.pointer);
383 		strcat(new_buf, local_operand1->string.pointer);
384 		break;
385 
386 	case ACPI_TYPE_BUFFER:
387 
388 		/* Result of two Buffers is a Buffer */
389 
390 		return_desc = acpi_ut_create_buffer_object(((acpi_size)
391 							    operand0->buffer.
392 							    length +
393 							    local_operand1->
394 							    buffer.length));
395 		if (!return_desc) {
396 			status = AE_NO_MEMORY;
397 			goto cleanup;
398 		}
399 
400 		new_buf = (char *)return_desc->buffer.pointer;
401 
402 		/* Concatenate the buffers */
403 
404 		memcpy(new_buf, operand0->buffer.pointer,
405 		       operand0->buffer.length);
406 		memcpy(new_buf + operand0->buffer.length,
407 		       local_operand1->buffer.pointer,
408 		       local_operand1->buffer.length);
409 		break;
410 
411 	default:
412 
413 		/* Invalid object type, should not happen here */
414 
415 		ACPI_ERROR((AE_INFO, "Invalid object type: 0x%X",
416 			    operand0->common.type));
417 		status = AE_AML_INTERNAL;
418 		goto cleanup;
419 	}
420 
421 	*actual_return_desc = return_desc;
422 
423 cleanup:
424 	if (local_operand1 != operand1) {
425 		acpi_ut_remove_reference(local_operand1);
426 	}
427 	return_ACPI_STATUS(status);
428 }
429 
430 /*******************************************************************************
431  *
432  * FUNCTION:    acpi_ex_do_math_op
433  *
434  * PARAMETERS:  opcode              - AML opcode
435  *              integer0            - Integer operand #0
436  *              integer1            - Integer operand #1
437  *
438  * RETURN:      Integer result of the operation
439  *
440  * DESCRIPTION: Execute a math AML opcode. The purpose of having all of the
441  *              math functions here is to prevent a lot of pointer dereferencing
442  *              to obtain the operands.
443  *
444  ******************************************************************************/
445 
446 u64 acpi_ex_do_math_op(u16 opcode, u64 integer0, u64 integer1)
447 {
448 
449 	ACPI_FUNCTION_ENTRY();
450 
451 	switch (opcode) {
452 	case AML_ADD_OP:	/* Add (Integer0, Integer1, Result) */
453 
454 		return (integer0 + integer1);
455 
456 	case AML_BIT_AND_OP:	/* And (Integer0, Integer1, Result) */
457 
458 		return (integer0 & integer1);
459 
460 	case AML_BIT_NAND_OP:	/* NAnd (Integer0, Integer1, Result) */
461 
462 		return (~(integer0 & integer1));
463 
464 	case AML_BIT_OR_OP:	/* Or (Integer0, Integer1, Result) */
465 
466 		return (integer0 | integer1);
467 
468 	case AML_BIT_NOR_OP:	/* NOr (Integer0, Integer1, Result) */
469 
470 		return (~(integer0 | integer1));
471 
472 	case AML_BIT_XOR_OP:	/* XOr (Integer0, Integer1, Result) */
473 
474 		return (integer0 ^ integer1);
475 
476 	case AML_MULTIPLY_OP:	/* Multiply (Integer0, Integer1, Result) */
477 
478 		return (integer0 * integer1);
479 
480 	case AML_SHIFT_LEFT_OP:	/* shift_left (Operand, shift_count, Result) */
481 
482 		/*
483 		 * We need to check if the shiftcount is larger than the integer bit
484 		 * width since the behavior of this is not well-defined in the C language.
485 		 */
486 		if (integer1 >= acpi_gbl_integer_bit_width) {
487 			return (0);
488 		}
489 		return (integer0 << integer1);
490 
491 	case AML_SHIFT_RIGHT_OP:	/* shift_right (Operand, shift_count, Result) */
492 
493 		/*
494 		 * We need to check if the shiftcount is larger than the integer bit
495 		 * width since the behavior of this is not well-defined in the C language.
496 		 */
497 		if (integer1 >= acpi_gbl_integer_bit_width) {
498 			return (0);
499 		}
500 		return (integer0 >> integer1);
501 
502 	case AML_SUBTRACT_OP:	/* Subtract (Integer0, Integer1, Result) */
503 
504 		return (integer0 - integer1);
505 
506 	default:
507 
508 		return (0);
509 	}
510 }
511 
512 /*******************************************************************************
513  *
514  * FUNCTION:    acpi_ex_do_logical_numeric_op
515  *
516  * PARAMETERS:  opcode              - AML opcode
517  *              integer0            - Integer operand #0
518  *              integer1            - Integer operand #1
519  *              logical_result      - TRUE/FALSE result of the operation
520  *
521  * RETURN:      Status
522  *
523  * DESCRIPTION: Execute a logical "Numeric" AML opcode. For these Numeric
524  *              operators (LAnd and LOr), both operands must be integers.
525  *
526  *              Note: cleanest machine code seems to be produced by the code
527  *              below, rather than using statements of the form:
528  *                  Result = (Integer0 && Integer1);
529  *
530  ******************************************************************************/
531 
532 acpi_status
533 acpi_ex_do_logical_numeric_op(u16 opcode,
534 			      u64 integer0, u64 integer1, u8 *logical_result)
535 {
536 	acpi_status status = AE_OK;
537 	u8 local_result = FALSE;
538 
539 	ACPI_FUNCTION_TRACE(ex_do_logical_numeric_op);
540 
541 	switch (opcode) {
542 	case AML_LAND_OP:	/* LAnd (Integer0, Integer1) */
543 
544 		if (integer0 && integer1) {
545 			local_result = TRUE;
546 		}
547 		break;
548 
549 	case AML_LOR_OP:	/* LOr (Integer0, Integer1) */
550 
551 		if (integer0 || integer1) {
552 			local_result = TRUE;
553 		}
554 		break;
555 
556 	default:
557 
558 		status = AE_AML_INTERNAL;
559 		break;
560 	}
561 
562 	/* Return the logical result and status */
563 
564 	*logical_result = local_result;
565 	return_ACPI_STATUS(status);
566 }
567 
568 /*******************************************************************************
569  *
570  * FUNCTION:    acpi_ex_do_logical_op
571  *
572  * PARAMETERS:  opcode              - AML opcode
573  *              operand0            - operand #0
574  *              operand1            - operand #1
575  *              logical_result      - TRUE/FALSE result of the operation
576  *
577  * RETURN:      Status
578  *
579  * DESCRIPTION: Execute a logical AML opcode. The purpose of having all of the
580  *              functions here is to prevent a lot of pointer dereferencing
581  *              to obtain the operands and to simplify the generation of the
582  *              logical value. For the Numeric operators (LAnd and LOr), both
583  *              operands must be integers. For the other logical operators,
584  *              operands can be any combination of Integer/String/Buffer. The
585  *              first operand determines the type to which the second operand
586  *              will be converted.
587  *
588  *              Note: cleanest machine code seems to be produced by the code
589  *              below, rather than using statements of the form:
590  *                  Result = (Operand0 == Operand1);
591  *
592  ******************************************************************************/
593 
594 acpi_status
595 acpi_ex_do_logical_op(u16 opcode,
596 		      union acpi_operand_object *operand0,
597 		      union acpi_operand_object *operand1, u8 * logical_result)
598 {
599 	union acpi_operand_object *local_operand1 = operand1;
600 	u64 integer0;
601 	u64 integer1;
602 	u32 length0;
603 	u32 length1;
604 	acpi_status status = AE_OK;
605 	u8 local_result = FALSE;
606 	int compare;
607 
608 	ACPI_FUNCTION_TRACE(ex_do_logical_op);
609 
610 	/*
611 	 * Convert the second operand if necessary. The first operand
612 	 * determines the type of the second operand, (See the Data Types
613 	 * section of the ACPI 3.0+ specification.)  Both object types are
614 	 * guaranteed to be either Integer/String/Buffer by the operand
615 	 * resolution mechanism.
616 	 */
617 	switch (operand0->common.type) {
618 	case ACPI_TYPE_INTEGER:
619 
620 		status =
621 		    acpi_ex_convert_to_integer(operand1, &local_operand1, 16);
622 		break;
623 
624 	case ACPI_TYPE_STRING:
625 
626 		status =
627 		    acpi_ex_convert_to_string(operand1, &local_operand1,
628 					      ACPI_IMPLICIT_CONVERT_HEX);
629 		break;
630 
631 	case ACPI_TYPE_BUFFER:
632 
633 		status = acpi_ex_convert_to_buffer(operand1, &local_operand1);
634 		break;
635 
636 	default:
637 
638 		status = AE_AML_INTERNAL;
639 		break;
640 	}
641 
642 	if (ACPI_FAILURE(status)) {
643 		goto cleanup;
644 	}
645 
646 	/*
647 	 * Two cases: 1) Both Integers, 2) Both Strings or Buffers
648 	 */
649 	if (operand0->common.type == ACPI_TYPE_INTEGER) {
650 		/*
651 		 * 1) Both operands are of type integer
652 		 *    Note: local_operand1 may have changed above
653 		 */
654 		integer0 = operand0->integer.value;
655 		integer1 = local_operand1->integer.value;
656 
657 		switch (opcode) {
658 		case AML_LEQUAL_OP:	/* LEqual (Operand0, Operand1) */
659 
660 			if (integer0 == integer1) {
661 				local_result = TRUE;
662 			}
663 			break;
664 
665 		case AML_LGREATER_OP:	/* LGreater (Operand0, Operand1) */
666 
667 			if (integer0 > integer1) {
668 				local_result = TRUE;
669 			}
670 			break;
671 
672 		case AML_LLESS_OP:	/* LLess (Operand0, Operand1) */
673 
674 			if (integer0 < integer1) {
675 				local_result = TRUE;
676 			}
677 			break;
678 
679 		default:
680 
681 			status = AE_AML_INTERNAL;
682 			break;
683 		}
684 	} else {
685 		/*
686 		 * 2) Both operands are Strings or both are Buffers
687 		 *    Note: Code below takes advantage of common Buffer/String
688 		 *          object fields. local_operand1 may have changed above. Use
689 		 *          memcmp to handle nulls in buffers.
690 		 */
691 		length0 = operand0->buffer.length;
692 		length1 = local_operand1->buffer.length;
693 
694 		/* Lexicographic compare: compare the data bytes */
695 
696 		compare = memcmp(operand0->buffer.pointer,
697 				 local_operand1->buffer.pointer,
698 				 (length0 > length1) ? length1 : length0);
699 
700 		switch (opcode) {
701 		case AML_LEQUAL_OP:	/* LEqual (Operand0, Operand1) */
702 
703 			/* Length and all bytes must be equal */
704 
705 			if ((length0 == length1) && (compare == 0)) {
706 
707 				/* Length and all bytes match ==> TRUE */
708 
709 				local_result = TRUE;
710 			}
711 			break;
712 
713 		case AML_LGREATER_OP:	/* LGreater (Operand0, Operand1) */
714 
715 			if (compare > 0) {
716 				local_result = TRUE;
717 				goto cleanup;	/* TRUE */
718 			}
719 			if (compare < 0) {
720 				goto cleanup;	/* FALSE */
721 			}
722 
723 			/* Bytes match (to shortest length), compare lengths */
724 
725 			if (length0 > length1) {
726 				local_result = TRUE;
727 			}
728 			break;
729 
730 		case AML_LLESS_OP:	/* LLess (Operand0, Operand1) */
731 
732 			if (compare > 0) {
733 				goto cleanup;	/* FALSE */
734 			}
735 			if (compare < 0) {
736 				local_result = TRUE;
737 				goto cleanup;	/* TRUE */
738 			}
739 
740 			/* Bytes match (to shortest length), compare lengths */
741 
742 			if (length0 < length1) {
743 				local_result = TRUE;
744 			}
745 			break;
746 
747 		default:
748 
749 			status = AE_AML_INTERNAL;
750 			break;
751 		}
752 	}
753 
754 cleanup:
755 
756 	/* New object was created if implicit conversion performed - delete */
757 
758 	if (local_operand1 != operand1) {
759 		acpi_ut_remove_reference(local_operand1);
760 	}
761 
762 	/* Return the logical result and status */
763 
764 	*logical_result = local_result;
765 	return_ACPI_STATUS(status);
766 }
767