xref: /linux/drivers/acpi/acpica/dsfield.c (revision 44f57d78)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: dsfield - Dispatcher field routines
5  *
6  * Copyright (C) 2000 - 2019, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12 #include "amlcode.h"
13 #include "acdispat.h"
14 #include "acinterp.h"
15 #include "acnamesp.h"
16 #include "acparser.h"
17 
18 #ifdef ACPI_EXEC_APP
19 #include "aecommon.h"
20 #endif
21 
22 #define _COMPONENT          ACPI_DISPATCHER
23 ACPI_MODULE_NAME("dsfield")
24 
25 /* Local prototypes */
26 #ifdef ACPI_ASL_COMPILER
27 #include "acdisasm.h"
28 static acpi_status
29 acpi_ds_create_external_region(acpi_status lookup_status,
30 			       union acpi_parse_object *op,
31 			       char *path,
32 			       struct acpi_walk_state *walk_state,
33 			       struct acpi_namespace_node **node);
34 #endif
35 
36 static acpi_status
37 acpi_ds_get_field_names(struct acpi_create_field_info *info,
38 			struct acpi_walk_state *walk_state,
39 			union acpi_parse_object *arg);
40 
41 #ifdef ACPI_ASL_COMPILER
42 /*******************************************************************************
43  *
44  * FUNCTION:    acpi_ds_create_external_region (iASL Disassembler only)
45  *
46  * PARAMETERS:  lookup_status   - Status from ns_lookup operation
47  *              op              - Op containing the Field definition and args
48  *              path            - Pathname of the region
49  *  `           walk_state      - Current method state
50  *              node            - Where the new region node is returned
51  *
52  * RETURN:      Status
53  *
54  * DESCRIPTION: Add region to the external list if NOT_FOUND. Create a new
55  *              region node/object.
56  *
57  ******************************************************************************/
58 
59 static acpi_status
60 acpi_ds_create_external_region(acpi_status lookup_status,
61 			       union acpi_parse_object *op,
62 			       char *path,
63 			       struct acpi_walk_state *walk_state,
64 			       struct acpi_namespace_node **node)
65 {
66 	acpi_status status;
67 	union acpi_operand_object *obj_desc;
68 
69 	if (lookup_status != AE_NOT_FOUND) {
70 		return (lookup_status);
71 	}
72 
73 	/*
74 	 * Table disassembly:
75 	 * operation_region not found. Generate an External for it, and
76 	 * insert the name into the namespace.
77 	 */
78 	acpi_dm_add_op_to_external_list(op, path, ACPI_TYPE_REGION, 0, 0);
79 
80 	status = acpi_ns_lookup(walk_state->scope_info, path, ACPI_TYPE_REGION,
81 				ACPI_IMODE_LOAD_PASS1, ACPI_NS_SEARCH_PARENT,
82 				walk_state, node);
83 	if (ACPI_FAILURE(status)) {
84 		return (status);
85 	}
86 
87 	/* Must create and install a region object for the new node */
88 
89 	obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_REGION);
90 	if (!obj_desc) {
91 		return (AE_NO_MEMORY);
92 	}
93 
94 	obj_desc->region.node = *node;
95 	status = acpi_ns_attach_object(*node, obj_desc, ACPI_TYPE_REGION);
96 	return (status);
97 }
98 #endif
99 
100 /*******************************************************************************
101  *
102  * FUNCTION:    acpi_ds_create_buffer_field
103  *
104  * PARAMETERS:  op                  - Current parse op (create_XXField)
105  *              walk_state          - Current state
106  *
107  * RETURN:      Status
108  *
109  * DESCRIPTION: Execute the create_field operators:
110  *              create_bit_field_op,
111  *              create_byte_field_op,
112  *              create_word_field_op,
113  *              create_dword_field_op,
114  *              create_qword_field_op,
115  *              create_field_op     (all of which define a field in a buffer)
116  *
117  ******************************************************************************/
118 
119 acpi_status
120 acpi_ds_create_buffer_field(union acpi_parse_object *op,
121 			    struct acpi_walk_state *walk_state)
122 {
123 	union acpi_parse_object *arg;
124 	struct acpi_namespace_node *node;
125 	acpi_status status;
126 	union acpi_operand_object *obj_desc;
127 	union acpi_operand_object *second_desc = NULL;
128 	u32 flags;
129 
130 	ACPI_FUNCTION_TRACE(ds_create_buffer_field);
131 
132 	/*
133 	 * Get the name_string argument (name of the new buffer_field)
134 	 */
135 	if (op->common.aml_opcode == AML_CREATE_FIELD_OP) {
136 
137 		/* For create_field, name is the 4th argument */
138 
139 		arg = acpi_ps_get_arg(op, 3);
140 	} else {
141 		/* For all other create_XXXField operators, name is the 3rd argument */
142 
143 		arg = acpi_ps_get_arg(op, 2);
144 	}
145 
146 	if (!arg) {
147 		return_ACPI_STATUS(AE_AML_NO_OPERAND);
148 	}
149 
150 	if (walk_state->deferred_node) {
151 		node = walk_state->deferred_node;
152 		status = AE_OK;
153 	} else {
154 		/* Execute flag should always be set when this function is entered */
155 
156 		if (!(walk_state->parse_flags & ACPI_PARSE_EXECUTE)) {
157 			ACPI_ERROR((AE_INFO, "Parse execute mode is not set"));
158 			return_ACPI_STATUS(AE_AML_INTERNAL);
159 		}
160 
161 		/* Creating new namespace node, should not already exist */
162 
163 		flags = ACPI_NS_NO_UPSEARCH | ACPI_NS_DONT_OPEN_SCOPE |
164 		    ACPI_NS_ERROR_IF_FOUND;
165 
166 		/*
167 		 * Mark node temporary if we are executing a normal control
168 		 * method. (Don't mark if this is a module-level code method)
169 		 */
170 		if (walk_state->method_node &&
171 		    !(walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL)) {
172 			flags |= ACPI_NS_TEMPORARY;
173 		}
174 
175 		/* Enter the name_string into the namespace */
176 
177 		status = acpi_ns_lookup(walk_state->scope_info,
178 					arg->common.value.string, ACPI_TYPE_ANY,
179 					ACPI_IMODE_LOAD_PASS1, flags,
180 					walk_state, &node);
181 		if (ACPI_FAILURE(status)) {
182 			ACPI_ERROR_NAMESPACE(walk_state->scope_info,
183 					     arg->common.value.string, status);
184 			return_ACPI_STATUS(status);
185 		}
186 	}
187 
188 	/*
189 	 * We could put the returned object (Node) on the object stack for later,
190 	 * but for now, we will put it in the "op" object that the parser uses,
191 	 * so we can get it again at the end of this scope.
192 	 */
193 	op->common.node = node;
194 
195 	/*
196 	 * If there is no object attached to the node, this node was just created
197 	 * and we need to create the field object. Otherwise, this was a lookup
198 	 * of an existing node and we don't want to create the field object again.
199 	 */
200 	obj_desc = acpi_ns_get_attached_object(node);
201 	if (obj_desc) {
202 		return_ACPI_STATUS(AE_OK);
203 	}
204 
205 	/*
206 	 * The Field definition is not fully parsed at this time.
207 	 * (We must save the address of the AML for the buffer and index operands)
208 	 */
209 
210 	/* Create the buffer field object */
211 
212 	obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_BUFFER_FIELD);
213 	if (!obj_desc) {
214 		status = AE_NO_MEMORY;
215 		goto cleanup;
216 	}
217 
218 	/*
219 	 * Remember location in AML stream of the field unit opcode and operands
220 	 * -- since the buffer and index operands must be evaluated.
221 	 */
222 	second_desc = obj_desc->common.next_object;
223 	second_desc->extra.aml_start = op->named.data;
224 	second_desc->extra.aml_length = op->named.length;
225 	obj_desc->buffer_field.node = node;
226 
227 	/* Attach constructed field descriptors to parent node */
228 
229 	status = acpi_ns_attach_object(node, obj_desc, ACPI_TYPE_BUFFER_FIELD);
230 	if (ACPI_FAILURE(status)) {
231 		goto cleanup;
232 	}
233 
234 cleanup:
235 
236 	/* Remove local reference to the object */
237 
238 	acpi_ut_remove_reference(obj_desc);
239 	return_ACPI_STATUS(status);
240 }
241 
242 /*******************************************************************************
243  *
244  * FUNCTION:    acpi_ds_get_field_names
245  *
246  * PARAMETERS:  info            - create_field info structure
247  *  `           walk_state      - Current method state
248  *              arg             - First parser arg for the field name list
249  *
250  * RETURN:      Status
251  *
252  * DESCRIPTION: Process all named fields in a field declaration. Names are
253  *              entered into the namespace.
254  *
255  ******************************************************************************/
256 
257 static acpi_status
258 acpi_ds_get_field_names(struct acpi_create_field_info *info,
259 			struct acpi_walk_state *walk_state,
260 			union acpi_parse_object *arg)
261 {
262 	acpi_status status;
263 	u64 position;
264 	union acpi_parse_object *child;
265 
266 #ifdef ACPI_EXEC_APP
267 	u64 value = 0;
268 	union acpi_operand_object *result_desc;
269 	union acpi_operand_object *obj_desc;
270 	char *name_path;
271 #endif
272 
273 	ACPI_FUNCTION_TRACE_PTR(ds_get_field_names, info);
274 
275 	/* First field starts at bit zero */
276 
277 	info->field_bit_position = 0;
278 
279 	/* Process all elements in the field list (of parse nodes) */
280 
281 	while (arg) {
282 		/*
283 		 * Four types of field elements are handled:
284 		 * 1) name - Enters a new named field into the namespace
285 		 * 2) offset - specifies a bit offset
286 		 * 3) access_as - changes the access mode/attributes
287 		 * 4) connection - Associate a resource template with the field
288 		 */
289 		switch (arg->common.aml_opcode) {
290 		case AML_INT_RESERVEDFIELD_OP:
291 
292 			position = (u64)info->field_bit_position +
293 			    (u64)arg->common.value.size;
294 
295 			if (position > ACPI_UINT32_MAX) {
296 				ACPI_ERROR((AE_INFO,
297 					    "Bit offset within field too large (> 0xFFFFFFFF)"));
298 				return_ACPI_STATUS(AE_SUPPORT);
299 			}
300 
301 			info->field_bit_position = (u32) position;
302 			break;
303 
304 		case AML_INT_ACCESSFIELD_OP:
305 		case AML_INT_EXTACCESSFIELD_OP:
306 			/*
307 			 * Get new access_type, access_attribute, and access_length fields
308 			 * -- to be used for all field units that follow, until the
309 			 * end-of-field or another access_as keyword is encountered.
310 			 * NOTE. These three bytes are encoded in the integer value
311 			 * of the parseop for convenience.
312 			 *
313 			 * In field_flags, preserve the flag bits other than the
314 			 * ACCESS_TYPE bits.
315 			 */
316 
317 			/* access_type (byte_acc, word_acc, etc.) */
318 
319 			info->field_flags = (u8)
320 			    ((info->
321 			      field_flags & ~(AML_FIELD_ACCESS_TYPE_MASK)) |
322 			     ((u8)((u32)(arg->common.value.integer & 0x07))));
323 
324 			/* access_attribute (attrib_quick, attrib_byte, etc.) */
325 
326 			info->attribute = (u8)
327 			    ((arg->common.value.integer >> 8) & 0xFF);
328 
329 			/* access_length (for serial/buffer protocols) */
330 
331 			info->access_length = (u8)
332 			    ((arg->common.value.integer >> 16) & 0xFF);
333 			break;
334 
335 		case AML_INT_CONNECTION_OP:
336 			/*
337 			 * Clear any previous connection. New connection is used for all
338 			 * fields that follow, similar to access_as
339 			 */
340 			info->resource_buffer = NULL;
341 			info->connection_node = NULL;
342 			info->pin_number_index = 0;
343 
344 			/*
345 			 * A Connection() is either an actual resource descriptor (buffer)
346 			 * or a named reference to a resource template
347 			 */
348 			child = arg->common.value.arg;
349 			if (child->common.aml_opcode == AML_INT_BYTELIST_OP) {
350 				info->resource_buffer = child->named.data;
351 				info->resource_length =
352 				    (u16)child->named.value.integer;
353 			} else {
354 				/* Lookup the Connection() namepath, it should already exist */
355 
356 				status = acpi_ns_lookup(walk_state->scope_info,
357 							child->common.value.
358 							name, ACPI_TYPE_ANY,
359 							ACPI_IMODE_EXECUTE,
360 							ACPI_NS_DONT_OPEN_SCOPE,
361 							walk_state,
362 							&info->connection_node);
363 				if (ACPI_FAILURE(status)) {
364 					ACPI_ERROR_NAMESPACE(walk_state->
365 							     scope_info,
366 							     child->common.
367 							     value.name,
368 							     status);
369 					return_ACPI_STATUS(status);
370 				}
371 			}
372 			break;
373 
374 		case AML_INT_NAMEDFIELD_OP:
375 
376 			/* Lookup the name, it should already exist */
377 
378 			status = acpi_ns_lookup(walk_state->scope_info,
379 						(char *)&arg->named.name,
380 						info->field_type,
381 						ACPI_IMODE_EXECUTE,
382 						ACPI_NS_DONT_OPEN_SCOPE,
383 						walk_state, &info->field_node);
384 			if (ACPI_FAILURE(status)) {
385 				ACPI_ERROR_NAMESPACE(walk_state->scope_info,
386 						     (char *)&arg->named.name,
387 						     status);
388 				return_ACPI_STATUS(status);
389 			} else {
390 				arg->common.node = info->field_node;
391 				info->field_bit_length = arg->common.value.size;
392 
393 				/*
394 				 * If there is no object attached to the node, this node was
395 				 * just created and we need to create the field object.
396 				 * Otherwise, this was a lookup of an existing node and we
397 				 * don't want to create the field object again.
398 				 */
399 				if (!acpi_ns_get_attached_object
400 				    (info->field_node)) {
401 					status = acpi_ex_prep_field_value(info);
402 					if (ACPI_FAILURE(status)) {
403 						return_ACPI_STATUS(status);
404 					}
405 #ifdef ACPI_EXEC_APP
406 					name_path =
407 					    acpi_ns_get_external_pathname(info->
408 									  field_node);
409 					obj_desc =
410 					    acpi_ut_create_integer_object
411 					    (value);
412 					if (ACPI_SUCCESS
413 					    (ae_lookup_init_file_entry
414 					     (name_path, &value))) {
415 						acpi_ex_write_data_to_field
416 						    (obj_desc,
417 						     acpi_ns_get_attached_object
418 						     (info->field_node),
419 						     &result_desc);
420 					}
421 					acpi_ut_remove_reference(obj_desc);
422 					ACPI_FREE(name_path);
423 #endif
424 				}
425 			}
426 
427 			/* Keep track of bit position for the next field */
428 
429 			position = (u64)info->field_bit_position +
430 			    (u64)arg->common.value.size;
431 
432 			if (position > ACPI_UINT32_MAX) {
433 				ACPI_ERROR((AE_INFO,
434 					    "Field [%4.4s] bit offset too large (> 0xFFFFFFFF)",
435 					    ACPI_CAST_PTR(char,
436 							  &info->field_node->
437 							  name)));
438 				return_ACPI_STATUS(AE_SUPPORT);
439 			}
440 
441 			info->field_bit_position += info->field_bit_length;
442 			info->pin_number_index++;	/* Index relative to previous Connection() */
443 			break;
444 
445 		default:
446 
447 			ACPI_ERROR((AE_INFO,
448 				    "Invalid opcode in field list: 0x%X",
449 				    arg->common.aml_opcode));
450 			return_ACPI_STATUS(AE_AML_BAD_OPCODE);
451 		}
452 
453 		arg = arg->common.next;
454 	}
455 
456 	return_ACPI_STATUS(AE_OK);
457 }
458 
459 /*******************************************************************************
460  *
461  * FUNCTION:    acpi_ds_create_field
462  *
463  * PARAMETERS:  op              - Op containing the Field definition and args
464  *              region_node     - Object for the containing Operation Region
465  *  `           walk_state      - Current method state
466  *
467  * RETURN:      Status
468  *
469  * DESCRIPTION: Create a new field in the specified operation region
470  *
471  ******************************************************************************/
472 
473 acpi_status
474 acpi_ds_create_field(union acpi_parse_object *op,
475 		     struct acpi_namespace_node *region_node,
476 		     struct acpi_walk_state *walk_state)
477 {
478 	acpi_status status;
479 	union acpi_parse_object *arg;
480 	struct acpi_create_field_info info;
481 
482 	ACPI_FUNCTION_TRACE_PTR(ds_create_field, op);
483 
484 	/* First arg is the name of the parent op_region (must already exist) */
485 
486 	arg = op->common.value.arg;
487 
488 	if (!region_node) {
489 		status =
490 		    acpi_ns_lookup(walk_state->scope_info,
491 				   arg->common.value.name, ACPI_TYPE_REGION,
492 				   ACPI_IMODE_EXECUTE, ACPI_NS_SEARCH_PARENT,
493 				   walk_state, &region_node);
494 #ifdef ACPI_ASL_COMPILER
495 		status = acpi_ds_create_external_region(status, arg,
496 							arg->common.value.name,
497 							walk_state,
498 							&region_node);
499 #endif
500 		if (ACPI_FAILURE(status)) {
501 			ACPI_ERROR_NAMESPACE(walk_state->scope_info,
502 					     arg->common.value.name, status);
503 			return_ACPI_STATUS(status);
504 		}
505 	}
506 
507 	memset(&info, 0, sizeof(struct acpi_create_field_info));
508 
509 	/* Second arg is the field flags */
510 
511 	arg = arg->common.next;
512 	info.field_flags = (u8) arg->common.value.integer;
513 	info.attribute = 0;
514 
515 	/* Each remaining arg is a Named Field */
516 
517 	info.field_type = ACPI_TYPE_LOCAL_REGION_FIELD;
518 	info.region_node = region_node;
519 
520 	status = acpi_ds_get_field_names(&info, walk_state, arg->common.next);
521 	if (info.region_node->object->region.space_id ==
522 	    ACPI_ADR_SPACE_PLATFORM_COMM
523 	    && !(region_node->object->field.internal_pcc_buffer =
524 		 ACPI_ALLOCATE_ZEROED(info.region_node->object->region.
525 				      length))) {
526 		return_ACPI_STATUS(AE_NO_MEMORY);
527 	}
528 	return_ACPI_STATUS(status);
529 }
530 
531 /*******************************************************************************
532  *
533  * FUNCTION:    acpi_ds_init_field_objects
534  *
535  * PARAMETERS:  op              - Op containing the Field definition and args
536  *  `           walk_state      - Current method state
537  *
538  * RETURN:      Status
539  *
540  * DESCRIPTION: For each "Field Unit" name in the argument list that is
541  *              part of the field declaration, enter the name into the
542  *              namespace.
543  *
544  ******************************************************************************/
545 
546 acpi_status
547 acpi_ds_init_field_objects(union acpi_parse_object *op,
548 			   struct acpi_walk_state *walk_state)
549 {
550 	acpi_status status;
551 	union acpi_parse_object *arg = NULL;
552 	struct acpi_namespace_node *node;
553 	u8 type = 0;
554 	u32 flags;
555 
556 	ACPI_FUNCTION_TRACE_PTR(ds_init_field_objects, op);
557 
558 	/* Execute flag should always be set when this function is entered */
559 
560 	if (!(walk_state->parse_flags & ACPI_PARSE_EXECUTE)) {
561 		if (walk_state->parse_flags & ACPI_PARSE_DEFERRED_OP) {
562 
563 			/* bank_field Op is deferred, just return OK */
564 
565 			return_ACPI_STATUS(AE_OK);
566 		}
567 
568 		ACPI_ERROR((AE_INFO, "Parse deferred mode is not set"));
569 		return_ACPI_STATUS(AE_AML_INTERNAL);
570 	}
571 
572 	/*
573 	 * Get the field_list argument for this opcode. This is the start of the
574 	 * list of field elements.
575 	 */
576 	switch (walk_state->opcode) {
577 	case AML_FIELD_OP:
578 
579 		arg = acpi_ps_get_arg(op, 2);
580 		type = ACPI_TYPE_LOCAL_REGION_FIELD;
581 		break;
582 
583 	case AML_BANK_FIELD_OP:
584 
585 		arg = acpi_ps_get_arg(op, 4);
586 		type = ACPI_TYPE_LOCAL_BANK_FIELD;
587 		break;
588 
589 	case AML_INDEX_FIELD_OP:
590 
591 		arg = acpi_ps_get_arg(op, 3);
592 		type = ACPI_TYPE_LOCAL_INDEX_FIELD;
593 		break;
594 
595 	default:
596 
597 		return_ACPI_STATUS(AE_BAD_PARAMETER);
598 	}
599 
600 	/* Creating new namespace node(s), should not already exist */
601 
602 	flags = ACPI_NS_NO_UPSEARCH | ACPI_NS_DONT_OPEN_SCOPE |
603 	    ACPI_NS_ERROR_IF_FOUND;
604 
605 	/*
606 	 * Mark node(s) temporary if we are executing a normal control
607 	 * method. (Don't mark if this is a module-level code method)
608 	 */
609 	if (walk_state->method_node &&
610 	    !(walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL)) {
611 		flags |= ACPI_NS_TEMPORARY;
612 	}
613 #ifdef ACPI_EXEC_APP
614 	flags |= ACPI_NS_OVERRIDE_IF_FOUND;
615 #endif
616 	/*
617 	 * Walk the list of entries in the field_list
618 	 * Note: field_list can be of zero length. In this case, Arg will be NULL.
619 	 */
620 	while (arg) {
621 		/*
622 		 * Ignore OFFSET/ACCESSAS/CONNECTION terms here; we are only interested
623 		 * in the field names in order to enter them into the namespace.
624 		 */
625 		if (arg->common.aml_opcode == AML_INT_NAMEDFIELD_OP) {
626 			status = acpi_ns_lookup(walk_state->scope_info,
627 						(char *)&arg->named.name, type,
628 						ACPI_IMODE_LOAD_PASS1, flags,
629 						walk_state, &node);
630 			if (ACPI_FAILURE(status)) {
631 				ACPI_ERROR_NAMESPACE(walk_state->scope_info,
632 						     (char *)&arg->named.name,
633 						     status);
634 				if (status != AE_ALREADY_EXISTS) {
635 					return_ACPI_STATUS(status);
636 				}
637 
638 				/* Name already exists, just ignore this error */
639 
640 				status = AE_OK;
641 			}
642 
643 			arg->common.node = node;
644 		}
645 
646 		/* Get the next field element in the list */
647 
648 		arg = arg->common.next;
649 	}
650 
651 	return_ACPI_STATUS(AE_OK);
652 }
653 
654 /*******************************************************************************
655  *
656  * FUNCTION:    acpi_ds_create_bank_field
657  *
658  * PARAMETERS:  op              - Op containing the Field definition and args
659  *              region_node     - Object for the containing Operation Region
660  *              walk_state      - Current method state
661  *
662  * RETURN:      Status
663  *
664  * DESCRIPTION: Create a new bank field in the specified operation region
665  *
666  ******************************************************************************/
667 
668 acpi_status
669 acpi_ds_create_bank_field(union acpi_parse_object *op,
670 			  struct acpi_namespace_node *region_node,
671 			  struct acpi_walk_state *walk_state)
672 {
673 	acpi_status status;
674 	union acpi_parse_object *arg;
675 	struct acpi_create_field_info info;
676 
677 	ACPI_FUNCTION_TRACE_PTR(ds_create_bank_field, op);
678 
679 	/* First arg is the name of the parent op_region (must already exist) */
680 
681 	arg = op->common.value.arg;
682 	if (!region_node) {
683 		status =
684 		    acpi_ns_lookup(walk_state->scope_info,
685 				   arg->common.value.name, ACPI_TYPE_REGION,
686 				   ACPI_IMODE_EXECUTE, ACPI_NS_SEARCH_PARENT,
687 				   walk_state, &region_node);
688 #ifdef ACPI_ASL_COMPILER
689 		status = acpi_ds_create_external_region(status, arg,
690 							arg->common.value.name,
691 							walk_state,
692 							&region_node);
693 #endif
694 		if (ACPI_FAILURE(status)) {
695 			ACPI_ERROR_NAMESPACE(walk_state->scope_info,
696 					     arg->common.value.name, status);
697 			return_ACPI_STATUS(status);
698 		}
699 	}
700 
701 	/* Second arg is the Bank Register (Field) (must already exist) */
702 
703 	arg = arg->common.next;
704 	status =
705 	    acpi_ns_lookup(walk_state->scope_info, arg->common.value.string,
706 			   ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
707 			   ACPI_NS_SEARCH_PARENT, walk_state,
708 			   &info.register_node);
709 	if (ACPI_FAILURE(status)) {
710 		ACPI_ERROR_NAMESPACE(walk_state->scope_info,
711 				     arg->common.value.string, status);
712 		return_ACPI_STATUS(status);
713 	}
714 
715 	/*
716 	 * Third arg is the bank_value
717 	 * This arg is a term_arg, not a constant
718 	 * It will be evaluated later, by acpi_ds_eval_bank_field_operands
719 	 */
720 	arg = arg->common.next;
721 
722 	/* Fourth arg is the field flags */
723 
724 	arg = arg->common.next;
725 	info.field_flags = (u8) arg->common.value.integer;
726 
727 	/* Each remaining arg is a Named Field */
728 
729 	info.field_type = ACPI_TYPE_LOCAL_BANK_FIELD;
730 	info.region_node = region_node;
731 
732 	/*
733 	 * Use Info.data_register_node to store bank_field Op
734 	 * It's safe because data_register_node will never be used when create
735 	 * bank field \we store aml_start and aml_length in the bank_field Op for
736 	 * late evaluation. Used in acpi_ex_prep_field_value(Info)
737 	 *
738 	 * TBD: Or, should we add a field in struct acpi_create_field_info, like
739 	 * "void *ParentOp"?
740 	 */
741 	info.data_register_node = (struct acpi_namespace_node *)op;
742 
743 	status = acpi_ds_get_field_names(&info, walk_state, arg->common.next);
744 	return_ACPI_STATUS(status);
745 }
746 
747 /*******************************************************************************
748  *
749  * FUNCTION:    acpi_ds_create_index_field
750  *
751  * PARAMETERS:  op              - Op containing the Field definition and args
752  *              region_node     - Object for the containing Operation Region
753  *  `           walk_state      - Current method state
754  *
755  * RETURN:      Status
756  *
757  * DESCRIPTION: Create a new index field in the specified operation region
758  *
759  ******************************************************************************/
760 
761 acpi_status
762 acpi_ds_create_index_field(union acpi_parse_object *op,
763 			   struct acpi_namespace_node *region_node,
764 			   struct acpi_walk_state *walk_state)
765 {
766 	acpi_status status;
767 	union acpi_parse_object *arg;
768 	struct acpi_create_field_info info;
769 
770 	ACPI_FUNCTION_TRACE_PTR(ds_create_index_field, op);
771 
772 	/* First arg is the name of the Index register (must already exist) */
773 
774 	arg = op->common.value.arg;
775 	status =
776 	    acpi_ns_lookup(walk_state->scope_info, arg->common.value.string,
777 			   ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
778 			   ACPI_NS_SEARCH_PARENT, walk_state,
779 			   &info.register_node);
780 	if (ACPI_FAILURE(status)) {
781 		ACPI_ERROR_NAMESPACE(walk_state->scope_info,
782 				     arg->common.value.string, status);
783 		return_ACPI_STATUS(status);
784 	}
785 
786 	/* Second arg is the data register (must already exist) */
787 
788 	arg = arg->common.next;
789 	status =
790 	    acpi_ns_lookup(walk_state->scope_info, arg->common.value.string,
791 			   ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
792 			   ACPI_NS_SEARCH_PARENT, walk_state,
793 			   &info.data_register_node);
794 	if (ACPI_FAILURE(status)) {
795 		ACPI_ERROR_NAMESPACE(walk_state->scope_info,
796 				     arg->common.value.string, status);
797 		return_ACPI_STATUS(status);
798 	}
799 
800 	/* Next arg is the field flags */
801 
802 	arg = arg->common.next;
803 	info.field_flags = (u8) arg->common.value.integer;
804 
805 	/* Each remaining arg is a Named Field */
806 
807 	info.field_type = ACPI_TYPE_LOCAL_INDEX_FIELD;
808 	info.region_node = region_node;
809 
810 	status = acpi_ds_get_field_names(&info, walk_state, arg->common.next);
811 	return_ACPI_STATUS(status);
812 }
813