xref: /openbmc/linux/drivers/acpi/acpica/dsopcode.c (revision 3932b9ca)
1 /******************************************************************************
2  *
3  * Module Name: dsopcode - Dispatcher support for regions and fields
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/acpi.h>
45 #include "accommon.h"
46 #include "acparser.h"
47 #include "amlcode.h"
48 #include "acdispat.h"
49 #include "acinterp.h"
50 #include "acnamesp.h"
51 #include "acevents.h"
52 #include "actables.h"
53 
54 #define _COMPONENT          ACPI_DISPATCHER
55 ACPI_MODULE_NAME("dsopcode")
56 
57 /* Local prototypes */
58 static acpi_status
59 acpi_ds_init_buffer_field(u16 aml_opcode,
60 			  union acpi_operand_object *obj_desc,
61 			  union acpi_operand_object *buffer_desc,
62 			  union acpi_operand_object *offset_desc,
63 			  union acpi_operand_object *length_desc,
64 			  union acpi_operand_object *result_desc);
65 
66 /*******************************************************************************
67  *
68  * FUNCTION:    acpi_ds_initialize_region
69  *
70  * PARAMETERS:  obj_handle      - Region namespace node
71  *
72  * RETURN:      Status
73  *
74  * DESCRIPTION: Front end to ev_initialize_region
75  *
76  ******************************************************************************/
77 
78 acpi_status acpi_ds_initialize_region(acpi_handle obj_handle)
79 {
80 	union acpi_operand_object *obj_desc;
81 	acpi_status status;
82 
83 	obj_desc = acpi_ns_get_attached_object(obj_handle);
84 
85 	/* Namespace is NOT locked */
86 
87 	status = acpi_ev_initialize_region(obj_desc, FALSE);
88 	return (status);
89 }
90 
91 /*******************************************************************************
92  *
93  * FUNCTION:    acpi_ds_init_buffer_field
94  *
95  * PARAMETERS:  aml_opcode      - create_xxx_field
96  *              obj_desc        - buffer_field object
97  *              buffer_desc     - Host Buffer
98  *              offset_desc     - Offset into buffer
99  *              length_desc     - Length of field (CREATE_FIELD_OP only)
100  *              result_desc     - Where to store the result
101  *
102  * RETURN:      Status
103  *
104  * DESCRIPTION: Perform actual initialization of a buffer field
105  *
106  ******************************************************************************/
107 
108 static acpi_status
109 acpi_ds_init_buffer_field(u16 aml_opcode,
110 			  union acpi_operand_object *obj_desc,
111 			  union acpi_operand_object *buffer_desc,
112 			  union acpi_operand_object *offset_desc,
113 			  union acpi_operand_object *length_desc,
114 			  union acpi_operand_object *result_desc)
115 {
116 	u32 offset;
117 	u32 bit_offset;
118 	u32 bit_count;
119 	u8 field_flags;
120 	acpi_status status;
121 
122 	ACPI_FUNCTION_TRACE_PTR(ds_init_buffer_field, obj_desc);
123 
124 	/* Host object must be a Buffer */
125 
126 	if (buffer_desc->common.type != ACPI_TYPE_BUFFER) {
127 		ACPI_ERROR((AE_INFO,
128 			    "Target of Create Field is not a Buffer object - %s",
129 			    acpi_ut_get_object_type_name(buffer_desc)));
130 
131 		status = AE_AML_OPERAND_TYPE;
132 		goto cleanup;
133 	}
134 
135 	/*
136 	 * The last parameter to all of these opcodes (result_desc) started
137 	 * out as a name_string, and should therefore now be a NS node
138 	 * after resolution in acpi_ex_resolve_operands().
139 	 */
140 	if (ACPI_GET_DESCRIPTOR_TYPE(result_desc) != ACPI_DESC_TYPE_NAMED) {
141 		ACPI_ERROR((AE_INFO,
142 			    "(%s) destination not a NS Node [%s]",
143 			    acpi_ps_get_opcode_name(aml_opcode),
144 			    acpi_ut_get_descriptor_name(result_desc)));
145 
146 		status = AE_AML_OPERAND_TYPE;
147 		goto cleanup;
148 	}
149 
150 	offset = (u32) offset_desc->integer.value;
151 
152 	/*
153 	 * Setup the Bit offsets and counts, according to the opcode
154 	 */
155 	switch (aml_opcode) {
156 	case AML_CREATE_FIELD_OP:
157 
158 		/* Offset is in bits, count is in bits */
159 
160 		field_flags = AML_FIELD_ACCESS_BYTE;
161 		bit_offset = offset;
162 		bit_count = (u32) length_desc->integer.value;
163 
164 		/* Must have a valid (>0) bit count */
165 
166 		if (bit_count == 0) {
167 			ACPI_ERROR((AE_INFO,
168 				    "Attempt to CreateField of length zero"));
169 			status = AE_AML_OPERAND_VALUE;
170 			goto cleanup;
171 		}
172 		break;
173 
174 	case AML_CREATE_BIT_FIELD_OP:
175 
176 		/* Offset is in bits, Field is one bit */
177 
178 		bit_offset = offset;
179 		bit_count = 1;
180 		field_flags = AML_FIELD_ACCESS_BYTE;
181 		break;
182 
183 	case AML_CREATE_BYTE_FIELD_OP:
184 
185 		/* Offset is in bytes, field is one byte */
186 
187 		bit_offset = 8 * offset;
188 		bit_count = 8;
189 		field_flags = AML_FIELD_ACCESS_BYTE;
190 		break;
191 
192 	case AML_CREATE_WORD_FIELD_OP:
193 
194 		/* Offset is in bytes, field is one word */
195 
196 		bit_offset = 8 * offset;
197 		bit_count = 16;
198 		field_flags = AML_FIELD_ACCESS_WORD;
199 		break;
200 
201 	case AML_CREATE_DWORD_FIELD_OP:
202 
203 		/* Offset is in bytes, field is one dword */
204 
205 		bit_offset = 8 * offset;
206 		bit_count = 32;
207 		field_flags = AML_FIELD_ACCESS_DWORD;
208 		break;
209 
210 	case AML_CREATE_QWORD_FIELD_OP:
211 
212 		/* Offset is in bytes, field is one qword */
213 
214 		bit_offset = 8 * offset;
215 		bit_count = 64;
216 		field_flags = AML_FIELD_ACCESS_QWORD;
217 		break;
218 
219 	default:
220 
221 		ACPI_ERROR((AE_INFO,
222 			    "Unknown field creation opcode 0x%02X",
223 			    aml_opcode));
224 		status = AE_AML_BAD_OPCODE;
225 		goto cleanup;
226 	}
227 
228 	/* Entire field must fit within the current length of the buffer */
229 
230 	if ((bit_offset + bit_count) > (8 * (u32) buffer_desc->buffer.length)) {
231 		ACPI_ERROR((AE_INFO,
232 			    "Field [%4.4s] at %u exceeds Buffer [%4.4s] size %u (bits)",
233 			    acpi_ut_get_node_name(result_desc),
234 			    bit_offset + bit_count,
235 			    acpi_ut_get_node_name(buffer_desc->buffer.node),
236 			    8 * (u32) buffer_desc->buffer.length));
237 		status = AE_AML_BUFFER_LIMIT;
238 		goto cleanup;
239 	}
240 
241 	/*
242 	 * Initialize areas of the field object that are common to all fields
243 	 * For field_flags, use LOCK_RULE = 0 (NO_LOCK),
244 	 * UPDATE_RULE = 0 (UPDATE_PRESERVE)
245 	 */
246 	status = acpi_ex_prep_common_field_object(obj_desc, field_flags, 0,
247 						  bit_offset, bit_count);
248 	if (ACPI_FAILURE(status)) {
249 		goto cleanup;
250 	}
251 
252 	obj_desc->buffer_field.buffer_obj = buffer_desc;
253 
254 	/* Reference count for buffer_desc inherits obj_desc count */
255 
256 	buffer_desc->common.reference_count = (u16)
257 	    (buffer_desc->common.reference_count +
258 	     obj_desc->common.reference_count);
259 
260 cleanup:
261 
262 	/* Always delete the operands */
263 
264 	acpi_ut_remove_reference(offset_desc);
265 	acpi_ut_remove_reference(buffer_desc);
266 
267 	if (aml_opcode == AML_CREATE_FIELD_OP) {
268 		acpi_ut_remove_reference(length_desc);
269 	}
270 
271 	/* On failure, delete the result descriptor */
272 
273 	if (ACPI_FAILURE(status)) {
274 		acpi_ut_remove_reference(result_desc);	/* Result descriptor */
275 	} else {
276 		/* Now the address and length are valid for this buffer_field */
277 
278 		obj_desc->buffer_field.flags |= AOPOBJ_DATA_VALID;
279 	}
280 
281 	return_ACPI_STATUS(status);
282 }
283 
284 /*******************************************************************************
285  *
286  * FUNCTION:    acpi_ds_eval_buffer_field_operands
287  *
288  * PARAMETERS:  walk_state      - Current walk
289  *              op              - A valid buffer_field Op object
290  *
291  * RETURN:      Status
292  *
293  * DESCRIPTION: Get buffer_field Buffer and Index
294  *              Called from acpi_ds_exec_end_op during buffer_field parse tree walk
295  *
296  ******************************************************************************/
297 
298 acpi_status
299 acpi_ds_eval_buffer_field_operands(struct acpi_walk_state *walk_state,
300 				   union acpi_parse_object *op)
301 {
302 	acpi_status status;
303 	union acpi_operand_object *obj_desc;
304 	struct acpi_namespace_node *node;
305 	union acpi_parse_object *next_op;
306 
307 	ACPI_FUNCTION_TRACE_PTR(ds_eval_buffer_field_operands, op);
308 
309 	/*
310 	 * This is where we evaluate the address and length fields of the
311 	 * create_xxx_field declaration
312 	 */
313 	node = op->common.node;
314 
315 	/* next_op points to the op that holds the Buffer */
316 
317 	next_op = op->common.value.arg;
318 
319 	/* Evaluate/create the address and length operands */
320 
321 	status = acpi_ds_create_operands(walk_state, next_op);
322 	if (ACPI_FAILURE(status)) {
323 		return_ACPI_STATUS(status);
324 	}
325 
326 	obj_desc = acpi_ns_get_attached_object(node);
327 	if (!obj_desc) {
328 		return_ACPI_STATUS(AE_NOT_EXIST);
329 	}
330 
331 	/* Resolve the operands */
332 
333 	status = acpi_ex_resolve_operands(op->common.aml_opcode,
334 					  ACPI_WALK_OPERANDS, walk_state);
335 	if (ACPI_FAILURE(status)) {
336 		ACPI_ERROR((AE_INFO, "(%s) bad operand(s), status 0x%X",
337 			    acpi_ps_get_opcode_name(op->common.aml_opcode),
338 			    status));
339 
340 		return_ACPI_STATUS(status);
341 	}
342 
343 	/* Initialize the Buffer Field */
344 
345 	if (op->common.aml_opcode == AML_CREATE_FIELD_OP) {
346 
347 		/* NOTE: Slightly different operands for this opcode */
348 
349 		status =
350 		    acpi_ds_init_buffer_field(op->common.aml_opcode, obj_desc,
351 					      walk_state->operands[0],
352 					      walk_state->operands[1],
353 					      walk_state->operands[2],
354 					      walk_state->operands[3]);
355 	} else {
356 		/* All other, create_xxx_field opcodes */
357 
358 		status =
359 		    acpi_ds_init_buffer_field(op->common.aml_opcode, obj_desc,
360 					      walk_state->operands[0],
361 					      walk_state->operands[1], NULL,
362 					      walk_state->operands[2]);
363 	}
364 
365 	return_ACPI_STATUS(status);
366 }
367 
368 /*******************************************************************************
369  *
370  * FUNCTION:    acpi_ds_eval_region_operands
371  *
372  * PARAMETERS:  walk_state      - Current walk
373  *              op              - A valid region Op object
374  *
375  * RETURN:      Status
376  *
377  * DESCRIPTION: Get region address and length
378  *              Called from acpi_ds_exec_end_op during op_region parse tree walk
379  *
380  ******************************************************************************/
381 
382 acpi_status
383 acpi_ds_eval_region_operands(struct acpi_walk_state *walk_state,
384 			     union acpi_parse_object *op)
385 {
386 	acpi_status status;
387 	union acpi_operand_object *obj_desc;
388 	union acpi_operand_object *operand_desc;
389 	struct acpi_namespace_node *node;
390 	union acpi_parse_object *next_op;
391 
392 	ACPI_FUNCTION_TRACE_PTR(ds_eval_region_operands, op);
393 
394 	/*
395 	 * This is where we evaluate the address and length fields of the
396 	 * op_region declaration
397 	 */
398 	node = op->common.node;
399 
400 	/* next_op points to the op that holds the space_ID */
401 
402 	next_op = op->common.value.arg;
403 
404 	/* next_op points to address op */
405 
406 	next_op = next_op->common.next;
407 
408 	/* Evaluate/create the address and length operands */
409 
410 	status = acpi_ds_create_operands(walk_state, next_op);
411 	if (ACPI_FAILURE(status)) {
412 		return_ACPI_STATUS(status);
413 	}
414 
415 	/* Resolve the length and address operands to numbers */
416 
417 	status = acpi_ex_resolve_operands(op->common.aml_opcode,
418 					  ACPI_WALK_OPERANDS, walk_state);
419 	if (ACPI_FAILURE(status)) {
420 		return_ACPI_STATUS(status);
421 	}
422 
423 	obj_desc = acpi_ns_get_attached_object(node);
424 	if (!obj_desc) {
425 		return_ACPI_STATUS(AE_NOT_EXIST);
426 	}
427 
428 	/*
429 	 * Get the length operand and save it
430 	 * (at Top of stack)
431 	 */
432 	operand_desc = walk_state->operands[walk_state->num_operands - 1];
433 
434 	obj_desc->region.length = (u32) operand_desc->integer.value;
435 	acpi_ut_remove_reference(operand_desc);
436 
437 	/*
438 	 * Get the address and save it
439 	 * (at top of stack - 1)
440 	 */
441 	operand_desc = walk_state->operands[walk_state->num_operands - 2];
442 
443 	obj_desc->region.address = (acpi_physical_address)
444 	    operand_desc->integer.value;
445 	acpi_ut_remove_reference(operand_desc);
446 
447 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "RgnObj %p Addr %8.8X%8.8X Len %X\n",
448 			  obj_desc,
449 			  ACPI_FORMAT_NATIVE_UINT(obj_desc->region.address),
450 			  obj_desc->region.length));
451 
452 	/* Now the address and length are valid for this opregion */
453 
454 	obj_desc->region.flags |= AOPOBJ_DATA_VALID;
455 
456 	return_ACPI_STATUS(status);
457 }
458 
459 /*******************************************************************************
460  *
461  * FUNCTION:    acpi_ds_eval_table_region_operands
462  *
463  * PARAMETERS:  walk_state      - Current walk
464  *              op              - A valid region Op object
465  *
466  * RETURN:      Status
467  *
468  * DESCRIPTION: Get region address and length.
469  *              Called from acpi_ds_exec_end_op during data_table_region parse
470  *              tree walk.
471  *
472  ******************************************************************************/
473 
474 acpi_status
475 acpi_ds_eval_table_region_operands(struct acpi_walk_state *walk_state,
476 				   union acpi_parse_object *op)
477 {
478 	acpi_status status;
479 	union acpi_operand_object *obj_desc;
480 	union acpi_operand_object **operand;
481 	struct acpi_namespace_node *node;
482 	union acpi_parse_object *next_op;
483 	u32 table_index;
484 	struct acpi_table_header *table;
485 
486 	ACPI_FUNCTION_TRACE_PTR(ds_eval_table_region_operands, op);
487 
488 	/*
489 	 * This is where we evaluate the Signature string, oem_id string,
490 	 * and oem_table_id string of the Data Table Region declaration
491 	 */
492 	node = op->common.node;
493 
494 	/* next_op points to Signature string op */
495 
496 	next_op = op->common.value.arg;
497 
498 	/*
499 	 * Evaluate/create the Signature string, oem_id string,
500 	 * and oem_table_id string operands
501 	 */
502 	status = acpi_ds_create_operands(walk_state, next_op);
503 	if (ACPI_FAILURE(status)) {
504 		return_ACPI_STATUS(status);
505 	}
506 
507 	/*
508 	 * Resolve the Signature string, oem_id string,
509 	 * and oem_table_id string operands
510 	 */
511 	status = acpi_ex_resolve_operands(op->common.aml_opcode,
512 					  ACPI_WALK_OPERANDS, walk_state);
513 	if (ACPI_FAILURE(status)) {
514 		return_ACPI_STATUS(status);
515 	}
516 
517 	operand = &walk_state->operands[0];
518 
519 	/* Find the ACPI table */
520 
521 	status = acpi_tb_find_table(operand[0]->string.pointer,
522 				    operand[1]->string.pointer,
523 				    operand[2]->string.pointer, &table_index);
524 	if (ACPI_FAILURE(status)) {
525 		return_ACPI_STATUS(status);
526 	}
527 
528 	acpi_ut_remove_reference(operand[0]);
529 	acpi_ut_remove_reference(operand[1]);
530 	acpi_ut_remove_reference(operand[2]);
531 
532 	status = acpi_get_table_by_index(table_index, &table);
533 	if (ACPI_FAILURE(status)) {
534 		return_ACPI_STATUS(status);
535 	}
536 
537 	obj_desc = acpi_ns_get_attached_object(node);
538 	if (!obj_desc) {
539 		return_ACPI_STATUS(AE_NOT_EXIST);
540 	}
541 
542 	obj_desc->region.address =
543 	    (acpi_physical_address) ACPI_TO_INTEGER(table);
544 	obj_desc->region.length = table->length;
545 
546 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "RgnObj %p Addr %8.8X%8.8X Len %X\n",
547 			  obj_desc,
548 			  ACPI_FORMAT_NATIVE_UINT(obj_desc->region.address),
549 			  obj_desc->region.length));
550 
551 	/* Now the address and length are valid for this opregion */
552 
553 	obj_desc->region.flags |= AOPOBJ_DATA_VALID;
554 
555 	return_ACPI_STATUS(status);
556 }
557 
558 /*******************************************************************************
559  *
560  * FUNCTION:    acpi_ds_eval_data_object_operands
561  *
562  * PARAMETERS:  walk_state      - Current walk
563  *              op              - A valid data_object Op object
564  *              obj_desc        - data_object
565  *
566  * RETURN:      Status
567  *
568  * DESCRIPTION: Get the operands and complete the following data object types:
569  *              Buffer, Package.
570  *
571  ******************************************************************************/
572 
573 acpi_status
574 acpi_ds_eval_data_object_operands(struct acpi_walk_state *walk_state,
575 				  union acpi_parse_object *op,
576 				  union acpi_operand_object *obj_desc)
577 {
578 	acpi_status status;
579 	union acpi_operand_object *arg_desc;
580 	u32 length;
581 
582 	ACPI_FUNCTION_TRACE(ds_eval_data_object_operands);
583 
584 	/* The first operand (for all of these data objects) is the length */
585 
586 	/*
587 	 * Set proper index into operand stack for acpi_ds_obj_stack_push
588 	 * invoked inside acpi_ds_create_operand.
589 	 */
590 	walk_state->operand_index = walk_state->num_operands;
591 
592 	status = acpi_ds_create_operand(walk_state, op->common.value.arg, 1);
593 	if (ACPI_FAILURE(status)) {
594 		return_ACPI_STATUS(status);
595 	}
596 
597 	status = acpi_ex_resolve_operands(walk_state->opcode,
598 					  &(walk_state->
599 					    operands[walk_state->num_operands -
600 						     1]), walk_state);
601 	if (ACPI_FAILURE(status)) {
602 		return_ACPI_STATUS(status);
603 	}
604 
605 	/* Extract length operand */
606 
607 	arg_desc = walk_state->operands[walk_state->num_operands - 1];
608 	length = (u32) arg_desc->integer.value;
609 
610 	/* Cleanup for length operand */
611 
612 	status = acpi_ds_obj_stack_pop(1, walk_state);
613 	if (ACPI_FAILURE(status)) {
614 		return_ACPI_STATUS(status);
615 	}
616 
617 	acpi_ut_remove_reference(arg_desc);
618 
619 	/*
620 	 * Create the actual data object
621 	 */
622 	switch (op->common.aml_opcode) {
623 	case AML_BUFFER_OP:
624 
625 		status =
626 		    acpi_ds_build_internal_buffer_obj(walk_state, op, length,
627 						      &obj_desc);
628 		break;
629 
630 	case AML_PACKAGE_OP:
631 	case AML_VAR_PACKAGE_OP:
632 
633 		status =
634 		    acpi_ds_build_internal_package_obj(walk_state, op, length,
635 						       &obj_desc);
636 		break;
637 
638 	default:
639 
640 		return_ACPI_STATUS(AE_AML_BAD_OPCODE);
641 	}
642 
643 	if (ACPI_SUCCESS(status)) {
644 		/*
645 		 * Return the object in the walk_state, unless the parent is a package -
646 		 * in this case, the return object will be stored in the parse tree
647 		 * for the package.
648 		 */
649 		if ((!op->common.parent) ||
650 		    ((op->common.parent->common.aml_opcode != AML_PACKAGE_OP) &&
651 		     (op->common.parent->common.aml_opcode !=
652 		      AML_VAR_PACKAGE_OP)
653 		     && (op->common.parent->common.aml_opcode !=
654 			 AML_NAME_OP))) {
655 			walk_state->result_obj = obj_desc;
656 		}
657 	}
658 
659 	return_ACPI_STATUS(status);
660 }
661 
662 /*******************************************************************************
663  *
664  * FUNCTION:    acpi_ds_eval_bank_field_operands
665  *
666  * PARAMETERS:  walk_state      - Current walk
667  *              op              - A valid bank_field Op object
668  *
669  * RETURN:      Status
670  *
671  * DESCRIPTION: Get bank_field bank_value
672  *              Called from acpi_ds_exec_end_op during bank_field parse tree walk
673  *
674  ******************************************************************************/
675 
676 acpi_status
677 acpi_ds_eval_bank_field_operands(struct acpi_walk_state *walk_state,
678 				 union acpi_parse_object *op)
679 {
680 	acpi_status status;
681 	union acpi_operand_object *obj_desc;
682 	union acpi_operand_object *operand_desc;
683 	struct acpi_namespace_node *node;
684 	union acpi_parse_object *next_op;
685 	union acpi_parse_object *arg;
686 
687 	ACPI_FUNCTION_TRACE_PTR(ds_eval_bank_field_operands, op);
688 
689 	/*
690 	 * This is where we evaluate the bank_value field of the
691 	 * bank_field declaration
692 	 */
693 
694 	/* next_op points to the op that holds the Region */
695 
696 	next_op = op->common.value.arg;
697 
698 	/* next_op points to the op that holds the Bank Register */
699 
700 	next_op = next_op->common.next;
701 
702 	/* next_op points to the op that holds the Bank Value */
703 
704 	next_op = next_op->common.next;
705 
706 	/*
707 	 * Set proper index into operand stack for acpi_ds_obj_stack_push
708 	 * invoked inside acpi_ds_create_operand.
709 	 *
710 	 * We use walk_state->Operands[0] to store the evaluated bank_value
711 	 */
712 	walk_state->operand_index = 0;
713 
714 	status = acpi_ds_create_operand(walk_state, next_op, 0);
715 	if (ACPI_FAILURE(status)) {
716 		return_ACPI_STATUS(status);
717 	}
718 
719 	status = acpi_ex_resolve_to_value(&walk_state->operands[0], walk_state);
720 	if (ACPI_FAILURE(status)) {
721 		return_ACPI_STATUS(status);
722 	}
723 
724 	ACPI_DUMP_OPERANDS(ACPI_WALK_OPERANDS,
725 			   acpi_ps_get_opcode_name(op->common.aml_opcode), 1);
726 	/*
727 	 * Get the bank_value operand and save it
728 	 * (at Top of stack)
729 	 */
730 	operand_desc = walk_state->operands[0];
731 
732 	/* Arg points to the start Bank Field */
733 
734 	arg = acpi_ps_get_arg(op, 4);
735 	while (arg) {
736 
737 		/* Ignore OFFSET and ACCESSAS terms here */
738 
739 		if (arg->common.aml_opcode == AML_INT_NAMEDFIELD_OP) {
740 			node = arg->common.node;
741 
742 			obj_desc = acpi_ns_get_attached_object(node);
743 			if (!obj_desc) {
744 				return_ACPI_STATUS(AE_NOT_EXIST);
745 			}
746 
747 			obj_desc->bank_field.value =
748 			    (u32) operand_desc->integer.value;
749 		}
750 
751 		/* Move to next field in the list */
752 
753 		arg = arg->common.next;
754 	}
755 
756 	acpi_ut_remove_reference(operand_desc);
757 	return_ACPI_STATUS(status);
758 }
759