xref: /openbmc/linux/drivers/acpi/acpica/exoparg1.c (revision 4800cd83)
1 
2 /******************************************************************************
3  *
4  * Module Name: exoparg1 - AML execution - opcodes with 1 argument
5  *
6  *****************************************************************************/
7 
8 /*
9  * Copyright (C) 2000 - 2011, 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 "acparser.h"
48 #include "acdispat.h"
49 #include "acinterp.h"
50 #include "amlcode.h"
51 #include "acnamesp.h"
52 
53 #define _COMPONENT          ACPI_EXECUTER
54 ACPI_MODULE_NAME("exoparg1")
55 
56 /*!
57  * Naming convention for AML interpreter execution routines.
58  *
59  * The routines that begin execution of AML opcodes are named with a common
60  * convention based upon the number of arguments, the number of target operands,
61  * and whether or not a value is returned:
62  *
63  *      AcpiExOpcode_xA_yT_zR
64  *
65  * Where:
66  *
67  * xA - ARGUMENTS:    The number of arguments (input operands) that are
68  *                    required for this opcode type (0 through 6 args).
69  * yT - TARGETS:      The number of targets (output operands) that are required
70  *                    for this opcode type (0, 1, or 2 targets).
71  * zR - RETURN VALUE: Indicates whether this opcode type returns a value
72  *                    as the function return (0 or 1).
73  *
74  * The AcpiExOpcode* functions are called via the Dispatcher component with
75  * fully resolved operands.
76 !*/
77 /*******************************************************************************
78  *
79  * FUNCTION:    acpi_ex_opcode_0A_0T_1R
80  *
81  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
82  *
83  * RETURN:      Status
84  *
85  * DESCRIPTION: Execute operator with no operands, one return value
86  *
87  ******************************************************************************/
88 acpi_status acpi_ex_opcode_0A_0T_1R(struct acpi_walk_state *walk_state)
89 {
90 	acpi_status status = AE_OK;
91 	union acpi_operand_object *return_desc = NULL;
92 
93 	ACPI_FUNCTION_TRACE_STR(ex_opcode_0A_0T_1R,
94 				acpi_ps_get_opcode_name(walk_state->opcode));
95 
96 	/* Examine the AML opcode */
97 
98 	switch (walk_state->opcode) {
99 	case AML_TIMER_OP:	/*  Timer () */
100 
101 		/* Create a return object of type Integer */
102 
103 		return_desc =
104 		    acpi_ut_create_integer_object(acpi_os_get_timer());
105 		if (!return_desc) {
106 			status = AE_NO_MEMORY;
107 			goto cleanup;
108 		}
109 		break;
110 
111 	default:		/*  Unknown opcode  */
112 
113 		ACPI_ERROR((AE_INFO, "Unknown AML opcode 0x%X",
114 			    walk_state->opcode));
115 		status = AE_AML_BAD_OPCODE;
116 		break;
117 	}
118 
119       cleanup:
120 
121 	/* Delete return object on error */
122 
123 	if ((ACPI_FAILURE(status)) || walk_state->result_obj) {
124 		acpi_ut_remove_reference(return_desc);
125 		walk_state->result_obj = NULL;
126 	} else {
127 		/* Save the return value */
128 
129 		walk_state->result_obj = return_desc;
130 	}
131 
132 	return_ACPI_STATUS(status);
133 }
134 
135 /*******************************************************************************
136  *
137  * FUNCTION:    acpi_ex_opcode_1A_0T_0R
138  *
139  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
140  *
141  * RETURN:      Status
142  *
143  * DESCRIPTION: Execute Type 1 monadic operator with numeric operand on
144  *              object stack
145  *
146  ******************************************************************************/
147 
148 acpi_status acpi_ex_opcode_1A_0T_0R(struct acpi_walk_state *walk_state)
149 {
150 	union acpi_operand_object **operand = &walk_state->operands[0];
151 	acpi_status status = AE_OK;
152 
153 	ACPI_FUNCTION_TRACE_STR(ex_opcode_1A_0T_0R,
154 				acpi_ps_get_opcode_name(walk_state->opcode));
155 
156 	/* Examine the AML opcode */
157 
158 	switch (walk_state->opcode) {
159 	case AML_RELEASE_OP:	/*  Release (mutex_object) */
160 
161 		status = acpi_ex_release_mutex(operand[0], walk_state);
162 		break;
163 
164 	case AML_RESET_OP:	/*  Reset (event_object) */
165 
166 		status = acpi_ex_system_reset_event(operand[0]);
167 		break;
168 
169 	case AML_SIGNAL_OP:	/*  Signal (event_object) */
170 
171 		status = acpi_ex_system_signal_event(operand[0]);
172 		break;
173 
174 	case AML_SLEEP_OP:	/*  Sleep (msec_time) */
175 
176 		status = acpi_ex_system_do_sleep(operand[0]->integer.value);
177 		break;
178 
179 	case AML_STALL_OP:	/*  Stall (usec_time) */
180 
181 		status =
182 		    acpi_ex_system_do_stall((u32) operand[0]->integer.value);
183 		break;
184 
185 	case AML_UNLOAD_OP:	/*  Unload (Handle) */
186 
187 		status = acpi_ex_unload_table(operand[0]);
188 		break;
189 
190 	default:		/*  Unknown opcode  */
191 
192 		ACPI_ERROR((AE_INFO, "Unknown AML opcode 0x%X",
193 			    walk_state->opcode));
194 		status = AE_AML_BAD_OPCODE;
195 		break;
196 	}
197 
198 	return_ACPI_STATUS(status);
199 }
200 
201 /*******************************************************************************
202  *
203  * FUNCTION:    acpi_ex_opcode_1A_1T_0R
204  *
205  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
206  *
207  * RETURN:      Status
208  *
209  * DESCRIPTION: Execute opcode with one argument, one target, and no
210  *              return value.
211  *
212  ******************************************************************************/
213 
214 acpi_status acpi_ex_opcode_1A_1T_0R(struct acpi_walk_state *walk_state)
215 {
216 	acpi_status status = AE_OK;
217 	union acpi_operand_object **operand = &walk_state->operands[0];
218 
219 	ACPI_FUNCTION_TRACE_STR(ex_opcode_1A_1T_0R,
220 				acpi_ps_get_opcode_name(walk_state->opcode));
221 
222 	/* Examine the AML opcode */
223 
224 	switch (walk_state->opcode) {
225 	case AML_LOAD_OP:
226 
227 		status = acpi_ex_load_op(operand[0], operand[1], walk_state);
228 		break;
229 
230 	default:		/* Unknown opcode */
231 
232 		ACPI_ERROR((AE_INFO, "Unknown AML opcode 0x%X",
233 			    walk_state->opcode));
234 		status = AE_AML_BAD_OPCODE;
235 		goto cleanup;
236 	}
237 
238       cleanup:
239 
240 	return_ACPI_STATUS(status);
241 }
242 
243 /*******************************************************************************
244  *
245  * FUNCTION:    acpi_ex_opcode_1A_1T_1R
246  *
247  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
248  *
249  * RETURN:      Status
250  *
251  * DESCRIPTION: Execute opcode with one argument, one target, and a
252  *              return value.
253  *
254  ******************************************************************************/
255 
256 acpi_status acpi_ex_opcode_1A_1T_1R(struct acpi_walk_state *walk_state)
257 {
258 	acpi_status status = AE_OK;
259 	union acpi_operand_object **operand = &walk_state->operands[0];
260 	union acpi_operand_object *return_desc = NULL;
261 	union acpi_operand_object *return_desc2 = NULL;
262 	u32 temp32;
263 	u32 i;
264 	u64 power_of_ten;
265 	u64 digit;
266 
267 	ACPI_FUNCTION_TRACE_STR(ex_opcode_1A_1T_1R,
268 				acpi_ps_get_opcode_name(walk_state->opcode));
269 
270 	/* Examine the AML opcode */
271 
272 	switch (walk_state->opcode) {
273 	case AML_BIT_NOT_OP:
274 	case AML_FIND_SET_LEFT_BIT_OP:
275 	case AML_FIND_SET_RIGHT_BIT_OP:
276 	case AML_FROM_BCD_OP:
277 	case AML_TO_BCD_OP:
278 	case AML_COND_REF_OF_OP:
279 
280 		/* Create a return object of type Integer for these opcodes */
281 
282 		return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
283 		if (!return_desc) {
284 			status = AE_NO_MEMORY;
285 			goto cleanup;
286 		}
287 
288 		switch (walk_state->opcode) {
289 		case AML_BIT_NOT_OP:	/* Not (Operand, Result)  */
290 
291 			return_desc->integer.value = ~operand[0]->integer.value;
292 			break;
293 
294 		case AML_FIND_SET_LEFT_BIT_OP:	/* find_set_left_bit (Operand, Result) */
295 
296 			return_desc->integer.value = operand[0]->integer.value;
297 
298 			/*
299 			 * Acpi specification describes Integer type as a little
300 			 * endian unsigned value, so this boundary condition is valid.
301 			 */
302 			for (temp32 = 0; return_desc->integer.value &&
303 			     temp32 < ACPI_INTEGER_BIT_SIZE; ++temp32) {
304 				return_desc->integer.value >>= 1;
305 			}
306 
307 			return_desc->integer.value = temp32;
308 			break;
309 
310 		case AML_FIND_SET_RIGHT_BIT_OP:	/* find_set_right_bit (Operand, Result) */
311 
312 			return_desc->integer.value = operand[0]->integer.value;
313 
314 			/*
315 			 * The Acpi specification describes Integer type as a little
316 			 * endian unsigned value, so this boundary condition is valid.
317 			 */
318 			for (temp32 = 0; return_desc->integer.value &&
319 			     temp32 < ACPI_INTEGER_BIT_SIZE; ++temp32) {
320 				return_desc->integer.value <<= 1;
321 			}
322 
323 			/* Since the bit position is one-based, subtract from 33 (65) */
324 
325 			return_desc->integer.value =
326 			    temp32 ==
327 			    0 ? 0 : (ACPI_INTEGER_BIT_SIZE + 1) - temp32;
328 			break;
329 
330 		case AML_FROM_BCD_OP:	/* from_bcd (BCDValue, Result) */
331 
332 			/*
333 			 * The 64-bit ACPI integer can hold 16 4-bit BCD characters
334 			 * (if table is 32-bit, integer can hold 8 BCD characters)
335 			 * Convert each 4-bit BCD value
336 			 */
337 			power_of_ten = 1;
338 			return_desc->integer.value = 0;
339 			digit = operand[0]->integer.value;
340 
341 			/* Convert each BCD digit (each is one nybble wide) */
342 
343 			for (i = 0;
344 			     (i < acpi_gbl_integer_nybble_width) && (digit > 0);
345 			     i++) {
346 
347 				/* Get the least significant 4-bit BCD digit */
348 
349 				temp32 = ((u32) digit) & 0xF;
350 
351 				/* Check the range of the digit */
352 
353 				if (temp32 > 9) {
354 					ACPI_ERROR((AE_INFO,
355 						    "BCD digit too large (not decimal): 0x%X",
356 						    temp32));
357 
358 					status = AE_AML_NUMERIC_OVERFLOW;
359 					goto cleanup;
360 				}
361 
362 				/* Sum the digit into the result with the current power of 10 */
363 
364 				return_desc->integer.value +=
365 				    (((u64) temp32) * power_of_ten);
366 
367 				/* Shift to next BCD digit */
368 
369 				digit >>= 4;
370 
371 				/* Next power of 10 */
372 
373 				power_of_ten *= 10;
374 			}
375 			break;
376 
377 		case AML_TO_BCD_OP:	/* to_bcd (Operand, Result) */
378 
379 			return_desc->integer.value = 0;
380 			digit = operand[0]->integer.value;
381 
382 			/* Each BCD digit is one nybble wide */
383 
384 			for (i = 0;
385 			     (i < acpi_gbl_integer_nybble_width) && (digit > 0);
386 			     i++) {
387 				(void)acpi_ut_short_divide(digit, 10, &digit,
388 							   &temp32);
389 
390 				/*
391 				 * Insert the BCD digit that resides in the
392 				 * remainder from above
393 				 */
394 				return_desc->integer.value |=
395 				    (((u64) temp32) << ACPI_MUL_4(i));
396 			}
397 
398 			/* Overflow if there is any data left in Digit */
399 
400 			if (digit > 0) {
401 				ACPI_ERROR((AE_INFO,
402 					    "Integer too large to convert to BCD: 0x%8.8X%8.8X",
403 					    ACPI_FORMAT_UINT64(operand[0]->
404 							       integer.value)));
405 				status = AE_AML_NUMERIC_OVERFLOW;
406 				goto cleanup;
407 			}
408 			break;
409 
410 		case AML_COND_REF_OF_OP:	/* cond_ref_of (source_object, Result) */
411 
412 			/*
413 			 * This op is a little strange because the internal return value is
414 			 * different than the return value stored in the result descriptor
415 			 * (There are really two return values)
416 			 */
417 			if ((struct acpi_namespace_node *)operand[0] ==
418 			    acpi_gbl_root_node) {
419 				/*
420 				 * This means that the object does not exist in the namespace,
421 				 * return FALSE
422 				 */
423 				return_desc->integer.value = 0;
424 				goto cleanup;
425 			}
426 
427 			/* Get the object reference, store it, and remove our reference */
428 
429 			status = acpi_ex_get_object_reference(operand[0],
430 							      &return_desc2,
431 							      walk_state);
432 			if (ACPI_FAILURE(status)) {
433 				goto cleanup;
434 			}
435 
436 			status =
437 			    acpi_ex_store(return_desc2, operand[1], walk_state);
438 			acpi_ut_remove_reference(return_desc2);
439 
440 			/* The object exists in the namespace, return TRUE */
441 
442 			return_desc->integer.value = ACPI_UINT64_MAX;
443 			goto cleanup;
444 
445 		default:
446 			/* No other opcodes get here */
447 			break;
448 		}
449 		break;
450 
451 	case AML_STORE_OP:	/* Store (Source, Target) */
452 
453 		/*
454 		 * A store operand is typically a number, string, buffer or lvalue
455 		 * Be careful about deleting the source object,
456 		 * since the object itself may have been stored.
457 		 */
458 		status = acpi_ex_store(operand[0], operand[1], walk_state);
459 		if (ACPI_FAILURE(status)) {
460 			return_ACPI_STATUS(status);
461 		}
462 
463 		/* It is possible that the Store already produced a return object */
464 
465 		if (!walk_state->result_obj) {
466 			/*
467 			 * Normally, we would remove a reference on the Operand[0]
468 			 * parameter; But since it is being used as the internal return
469 			 * object (meaning we would normally increment it), the two
470 			 * cancel out, and we simply don't do anything.
471 			 */
472 			walk_state->result_obj = operand[0];
473 			walk_state->operands[0] = NULL;	/* Prevent deletion */
474 		}
475 		return_ACPI_STATUS(status);
476 
477 		/*
478 		 * ACPI 2.0 Opcodes
479 		 */
480 	case AML_COPY_OP:	/* Copy (Source, Target) */
481 
482 		status =
483 		    acpi_ut_copy_iobject_to_iobject(operand[0], &return_desc,
484 						    walk_state);
485 		break;
486 
487 	case AML_TO_DECSTRING_OP:	/* to_decimal_string (Data, Result) */
488 
489 		status = acpi_ex_convert_to_string(operand[0], &return_desc,
490 						   ACPI_EXPLICIT_CONVERT_DECIMAL);
491 		if (return_desc == operand[0]) {
492 
493 			/* No conversion performed, add ref to handle return value */
494 			acpi_ut_add_reference(return_desc);
495 		}
496 		break;
497 
498 	case AML_TO_HEXSTRING_OP:	/* to_hex_string (Data, Result) */
499 
500 		status = acpi_ex_convert_to_string(operand[0], &return_desc,
501 						   ACPI_EXPLICIT_CONVERT_HEX);
502 		if (return_desc == operand[0]) {
503 
504 			/* No conversion performed, add ref to handle return value */
505 			acpi_ut_add_reference(return_desc);
506 		}
507 		break;
508 
509 	case AML_TO_BUFFER_OP:	/* to_buffer (Data, Result) */
510 
511 		status = acpi_ex_convert_to_buffer(operand[0], &return_desc);
512 		if (return_desc == operand[0]) {
513 
514 			/* No conversion performed, add ref to handle return value */
515 			acpi_ut_add_reference(return_desc);
516 		}
517 		break;
518 
519 	case AML_TO_INTEGER_OP:	/* to_integer (Data, Result) */
520 
521 		status = acpi_ex_convert_to_integer(operand[0], &return_desc,
522 						    ACPI_ANY_BASE);
523 		if (return_desc == operand[0]) {
524 
525 			/* No conversion performed, add ref to handle return value */
526 			acpi_ut_add_reference(return_desc);
527 		}
528 		break;
529 
530 	case AML_SHIFT_LEFT_BIT_OP:	/* shift_left_bit (Source, bit_num) */
531 	case AML_SHIFT_RIGHT_BIT_OP:	/* shift_right_bit (Source, bit_num) */
532 
533 		/* These are two obsolete opcodes */
534 
535 		ACPI_ERROR((AE_INFO,
536 			    "%s is obsolete and not implemented",
537 			    acpi_ps_get_opcode_name(walk_state->opcode)));
538 		status = AE_SUPPORT;
539 		goto cleanup;
540 
541 	default:		/* Unknown opcode */
542 
543 		ACPI_ERROR((AE_INFO, "Unknown AML opcode 0x%X",
544 			    walk_state->opcode));
545 		status = AE_AML_BAD_OPCODE;
546 		goto cleanup;
547 	}
548 
549 	if (ACPI_SUCCESS(status)) {
550 
551 		/* Store the return value computed above into the target object */
552 
553 		status = acpi_ex_store(return_desc, operand[1], walk_state);
554 	}
555 
556       cleanup:
557 
558 	/* Delete return object on error */
559 
560 	if (ACPI_FAILURE(status)) {
561 		acpi_ut_remove_reference(return_desc);
562 	}
563 
564 	/* Save return object on success */
565 
566 	else if (!walk_state->result_obj) {
567 		walk_state->result_obj = return_desc;
568 	}
569 
570 	return_ACPI_STATUS(status);
571 }
572 
573 /*******************************************************************************
574  *
575  * FUNCTION:    acpi_ex_opcode_1A_0T_1R
576  *
577  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
578  *
579  * RETURN:      Status
580  *
581  * DESCRIPTION: Execute opcode with one argument, no target, and a return value
582  *
583  ******************************************************************************/
584 
585 acpi_status acpi_ex_opcode_1A_0T_1R(struct acpi_walk_state *walk_state)
586 {
587 	union acpi_operand_object **operand = &walk_state->operands[0];
588 	union acpi_operand_object *temp_desc;
589 	union acpi_operand_object *return_desc = NULL;
590 	acpi_status status = AE_OK;
591 	u32 type;
592 	u64 value;
593 
594 	ACPI_FUNCTION_TRACE_STR(ex_opcode_1A_0T_1R,
595 				acpi_ps_get_opcode_name(walk_state->opcode));
596 
597 	/* Examine the AML opcode */
598 
599 	switch (walk_state->opcode) {
600 	case AML_LNOT_OP:	/* LNot (Operand) */
601 
602 		return_desc = acpi_ut_create_integer_object((u64) 0);
603 		if (!return_desc) {
604 			status = AE_NO_MEMORY;
605 			goto cleanup;
606 		}
607 
608 		/*
609 		 * Set result to ONES (TRUE) if Value == 0.  Note:
610 		 * return_desc->Integer.Value is initially == 0 (FALSE) from above.
611 		 */
612 		if (!operand[0]->integer.value) {
613 			return_desc->integer.value = ACPI_UINT64_MAX;
614 		}
615 		break;
616 
617 	case AML_DECREMENT_OP:	/* Decrement (Operand)  */
618 	case AML_INCREMENT_OP:	/* Increment (Operand)  */
619 
620 		/*
621 		 * Create a new integer.  Can't just get the base integer and
622 		 * increment it because it may be an Arg or Field.
623 		 */
624 		return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
625 		if (!return_desc) {
626 			status = AE_NO_MEMORY;
627 			goto cleanup;
628 		}
629 
630 		/*
631 		 * Since we are expecting a Reference operand, it can be either a
632 		 * NS Node or an internal object.
633 		 */
634 		temp_desc = operand[0];
635 		if (ACPI_GET_DESCRIPTOR_TYPE(temp_desc) ==
636 		    ACPI_DESC_TYPE_OPERAND) {
637 
638 			/* Internal reference object - prevent deletion */
639 
640 			acpi_ut_add_reference(temp_desc);
641 		}
642 
643 		/*
644 		 * Convert the Reference operand to an Integer (This removes a
645 		 * reference on the Operand[0] object)
646 		 *
647 		 * NOTE:  We use LNOT_OP here in order to force resolution of the
648 		 * reference operand to an actual integer.
649 		 */
650 		status =
651 		    acpi_ex_resolve_operands(AML_LNOT_OP, &temp_desc,
652 					     walk_state);
653 		if (ACPI_FAILURE(status)) {
654 			ACPI_EXCEPTION((AE_INFO, status,
655 					"While resolving operands for [%s]",
656 					acpi_ps_get_opcode_name(walk_state->
657 								opcode)));
658 
659 			goto cleanup;
660 		}
661 
662 		/*
663 		 * temp_desc is now guaranteed to be an Integer object --
664 		 * Perform the actual increment or decrement
665 		 */
666 		if (walk_state->opcode == AML_INCREMENT_OP) {
667 			return_desc->integer.value =
668 			    temp_desc->integer.value + 1;
669 		} else {
670 			return_desc->integer.value =
671 			    temp_desc->integer.value - 1;
672 		}
673 
674 		/* Finished with this Integer object */
675 
676 		acpi_ut_remove_reference(temp_desc);
677 
678 		/*
679 		 * Store the result back (indirectly) through the original
680 		 * Reference object
681 		 */
682 		status = acpi_ex_store(return_desc, operand[0], walk_state);
683 		break;
684 
685 	case AML_TYPE_OP:	/* object_type (source_object) */
686 
687 		/*
688 		 * Note: The operand is not resolved at this point because we want to
689 		 * get the associated object, not its value.  For example, we don't
690 		 * want to resolve a field_unit to its value, we want the actual
691 		 * field_unit object.
692 		 */
693 
694 		/* Get the type of the base object */
695 
696 		status =
697 		    acpi_ex_resolve_multiple(walk_state, operand[0], &type,
698 					     NULL);
699 		if (ACPI_FAILURE(status)) {
700 			goto cleanup;
701 		}
702 
703 		/* Allocate a descriptor to hold the type. */
704 
705 		return_desc = acpi_ut_create_integer_object((u64) type);
706 		if (!return_desc) {
707 			status = AE_NO_MEMORY;
708 			goto cleanup;
709 		}
710 		break;
711 
712 	case AML_SIZE_OF_OP:	/* size_of (source_object) */
713 
714 		/*
715 		 * Note: The operand is not resolved at this point because we want to
716 		 * get the associated object, not its value.
717 		 */
718 
719 		/* Get the base object */
720 
721 		status = acpi_ex_resolve_multiple(walk_state,
722 						  operand[0], &type,
723 						  &temp_desc);
724 		if (ACPI_FAILURE(status)) {
725 			goto cleanup;
726 		}
727 
728 		/*
729 		 * The type of the base object must be integer, buffer, string, or
730 		 * package.  All others are not supported.
731 		 *
732 		 * NOTE: Integer is not specifically supported by the ACPI spec,
733 		 * but is supported implicitly via implicit operand conversion.
734 		 * rather than bother with conversion, we just use the byte width
735 		 * global (4 or 8 bytes).
736 		 */
737 		switch (type) {
738 		case ACPI_TYPE_INTEGER:
739 			value = acpi_gbl_integer_byte_width;
740 			break;
741 
742 		case ACPI_TYPE_STRING:
743 			value = temp_desc->string.length;
744 			break;
745 
746 		case ACPI_TYPE_BUFFER:
747 
748 			/* Buffer arguments may not be evaluated at this point */
749 
750 			status = acpi_ds_get_buffer_arguments(temp_desc);
751 			value = temp_desc->buffer.length;
752 			break;
753 
754 		case ACPI_TYPE_PACKAGE:
755 
756 			/* Package arguments may not be evaluated at this point */
757 
758 			status = acpi_ds_get_package_arguments(temp_desc);
759 			value = temp_desc->package.count;
760 			break;
761 
762 		default:
763 			ACPI_ERROR((AE_INFO,
764 				    "Operand must be Buffer/Integer/String/Package - found type %s",
765 				    acpi_ut_get_type_name(type)));
766 			status = AE_AML_OPERAND_TYPE;
767 			goto cleanup;
768 		}
769 
770 		if (ACPI_FAILURE(status)) {
771 			goto cleanup;
772 		}
773 
774 		/*
775 		 * Now that we have the size of the object, create a result
776 		 * object to hold the value
777 		 */
778 		return_desc = acpi_ut_create_integer_object(value);
779 		if (!return_desc) {
780 			status = AE_NO_MEMORY;
781 			goto cleanup;
782 		}
783 		break;
784 
785 	case AML_REF_OF_OP:	/* ref_of (source_object) */
786 
787 		status =
788 		    acpi_ex_get_object_reference(operand[0], &return_desc,
789 						 walk_state);
790 		if (ACPI_FAILURE(status)) {
791 			goto cleanup;
792 		}
793 		break;
794 
795 	case AML_DEREF_OF_OP:	/* deref_of (obj_reference | String) */
796 
797 		/* Check for a method local or argument, or standalone String */
798 
799 		if (ACPI_GET_DESCRIPTOR_TYPE(operand[0]) ==
800 		    ACPI_DESC_TYPE_NAMED) {
801 			temp_desc =
802 			    acpi_ns_get_attached_object((struct
803 							 acpi_namespace_node *)
804 							operand[0]);
805 			if (temp_desc
806 			    && ((temp_desc->common.type == ACPI_TYPE_STRING)
807 				|| (temp_desc->common.type ==
808 				    ACPI_TYPE_LOCAL_REFERENCE))) {
809 				operand[0] = temp_desc;
810 				acpi_ut_add_reference(temp_desc);
811 			} else {
812 				status = AE_AML_OPERAND_TYPE;
813 				goto cleanup;
814 			}
815 		} else {
816 			switch ((operand[0])->common.type) {
817 			case ACPI_TYPE_LOCAL_REFERENCE:
818 				/*
819 				 * This is a deref_of (local_x | arg_x)
820 				 *
821 				 * Must resolve/dereference the local/arg reference first
822 				 */
823 				switch (operand[0]->reference.class) {
824 				case ACPI_REFCLASS_LOCAL:
825 				case ACPI_REFCLASS_ARG:
826 
827 					/* Set Operand[0] to the value of the local/arg */
828 
829 					status =
830 					    acpi_ds_method_data_get_value
831 					    (operand[0]->reference.class,
832 					     operand[0]->reference.value,
833 					     walk_state, &temp_desc);
834 					if (ACPI_FAILURE(status)) {
835 						goto cleanup;
836 					}
837 
838 					/*
839 					 * Delete our reference to the input object and
840 					 * point to the object just retrieved
841 					 */
842 					acpi_ut_remove_reference(operand[0]);
843 					operand[0] = temp_desc;
844 					break;
845 
846 				case ACPI_REFCLASS_REFOF:
847 
848 					/* Get the object to which the reference refers */
849 
850 					temp_desc =
851 					    operand[0]->reference.object;
852 					acpi_ut_remove_reference(operand[0]);
853 					operand[0] = temp_desc;
854 					break;
855 
856 				default:
857 
858 					/* Must be an Index op - handled below */
859 					break;
860 				}
861 				break;
862 
863 			case ACPI_TYPE_STRING:
864 				break;
865 
866 			default:
867 				status = AE_AML_OPERAND_TYPE;
868 				goto cleanup;
869 			}
870 		}
871 
872 		if (ACPI_GET_DESCRIPTOR_TYPE(operand[0]) !=
873 		    ACPI_DESC_TYPE_NAMED) {
874 			if ((operand[0])->common.type == ACPI_TYPE_STRING) {
875 				/*
876 				 * This is a deref_of (String). The string is a reference
877 				 * to a named ACPI object.
878 				 *
879 				 * 1) Find the owning Node
880 				 * 2) Dereference the node to an actual object. Could be a
881 				 *    Field, so we need to resolve the node to a value.
882 				 */
883 				status =
884 				    acpi_ns_get_node(walk_state->scope_info->
885 						     scope.node,
886 						     operand[0]->string.pointer,
887 						     ACPI_NS_SEARCH_PARENT,
888 						     ACPI_CAST_INDIRECT_PTR
889 						     (struct
890 						      acpi_namespace_node,
891 						      &return_desc));
892 				if (ACPI_FAILURE(status)) {
893 					goto cleanup;
894 				}
895 
896 				status =
897 				    acpi_ex_resolve_node_to_value
898 				    (ACPI_CAST_INDIRECT_PTR
899 				     (struct acpi_namespace_node, &return_desc),
900 				     walk_state);
901 				goto cleanup;
902 			}
903 		}
904 
905 		/* Operand[0] may have changed from the code above */
906 
907 		if (ACPI_GET_DESCRIPTOR_TYPE(operand[0]) ==
908 		    ACPI_DESC_TYPE_NAMED) {
909 			/*
910 			 * This is a deref_of (object_reference)
911 			 * Get the actual object from the Node (This is the dereference).
912 			 * This case may only happen when a local_x or arg_x is
913 			 * dereferenced above.
914 			 */
915 			return_desc = acpi_ns_get_attached_object((struct
916 								   acpi_namespace_node
917 								   *)
918 								  operand[0]);
919 			acpi_ut_add_reference(return_desc);
920 		} else {
921 			/*
922 			 * This must be a reference object produced by either the
923 			 * Index() or ref_of() operator
924 			 */
925 			switch (operand[0]->reference.class) {
926 			case ACPI_REFCLASS_INDEX:
927 
928 				/*
929 				 * The target type for the Index operator must be
930 				 * either a Buffer or a Package
931 				 */
932 				switch (operand[0]->reference.target_type) {
933 				case ACPI_TYPE_BUFFER_FIELD:
934 
935 					temp_desc =
936 					    operand[0]->reference.object;
937 
938 					/*
939 					 * Create a new object that contains one element of the
940 					 * buffer -- the element pointed to by the index.
941 					 *
942 					 * NOTE: index into a buffer is NOT a pointer to a
943 					 * sub-buffer of the main buffer, it is only a pointer to a
944 					 * single element (byte) of the buffer!
945 					 *
946 					 * Since we are returning the value of the buffer at the
947 					 * indexed location, we don't need to add an additional
948 					 * reference to the buffer itself.
949 					 */
950 					return_desc =
951 					    acpi_ut_create_integer_object((u64)
952 									  temp_desc->
953 									  buffer.
954 									  pointer
955 									  [operand
956 									   [0]->
957 									   reference.
958 									   value]);
959 					if (!return_desc) {
960 						status = AE_NO_MEMORY;
961 						goto cleanup;
962 					}
963 					break;
964 
965 				case ACPI_TYPE_PACKAGE:
966 
967 					/*
968 					 * Return the referenced element of the package.  We must
969 					 * add another reference to the referenced object, however.
970 					 */
971 					return_desc =
972 					    *(operand[0]->reference.where);
973 					if (return_desc) {
974 						acpi_ut_add_reference
975 						    (return_desc);
976 					}
977 					break;
978 
979 				default:
980 
981 					ACPI_ERROR((AE_INFO,
982 						    "Unknown Index TargetType 0x%X in reference object %p",
983 						    operand[0]->reference.
984 						    target_type, operand[0]));
985 					status = AE_AML_OPERAND_TYPE;
986 					goto cleanup;
987 				}
988 				break;
989 
990 			case ACPI_REFCLASS_REFOF:
991 
992 				return_desc = operand[0]->reference.object;
993 
994 				if (ACPI_GET_DESCRIPTOR_TYPE(return_desc) ==
995 				    ACPI_DESC_TYPE_NAMED) {
996 					return_desc =
997 					    acpi_ns_get_attached_object((struct
998 									 acpi_namespace_node
999 									 *)
1000 									return_desc);
1001 				}
1002 
1003 				/* Add another reference to the object! */
1004 
1005 				acpi_ut_add_reference(return_desc);
1006 				break;
1007 
1008 			default:
1009 				ACPI_ERROR((AE_INFO,
1010 					    "Unknown class in reference(%p) - 0x%2.2X",
1011 					    operand[0],
1012 					    operand[0]->reference.class));
1013 
1014 				status = AE_TYPE;
1015 				goto cleanup;
1016 			}
1017 		}
1018 		break;
1019 
1020 	default:
1021 
1022 		ACPI_ERROR((AE_INFO, "Unknown AML opcode 0x%X",
1023 			    walk_state->opcode));
1024 		status = AE_AML_BAD_OPCODE;
1025 		goto cleanup;
1026 	}
1027 
1028       cleanup:
1029 
1030 	/* Delete return object on error */
1031 
1032 	if (ACPI_FAILURE(status)) {
1033 		acpi_ut_remove_reference(return_desc);
1034 	}
1035 
1036 	/* Save return object on success */
1037 
1038 	else {
1039 		walk_state->result_obj = return_desc;
1040 	}
1041 
1042 	return_ACPI_STATUS(status);
1043 }
1044