xref: /openbmc/linux/drivers/acpi/acpica/dsfield.c (revision b9b77222)
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 - 2018, 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 #define _COMPONENT          ACPI_DISPATCHER
19 ACPI_MODULE_NAME("dsfield")
20 
21 /* Local prototypes */
22 #ifdef ACPI_ASL_COMPILER
23 #include "acdisasm.h"
24 static acpi_status
25 acpi_ds_create_external_region(acpi_status lookup_status,
26 			       union acpi_parse_object *op,
27 			       char *path,
28 			       struct acpi_walk_state *walk_state,
29 			       struct acpi_namespace_node **node);
30 #endif
31 
32 static acpi_status
33 acpi_ds_get_field_names(struct acpi_create_field_info *info,
34 			struct acpi_walk_state *walk_state,
35 			union acpi_parse_object *arg);
36 
37 #ifdef ACPI_ASL_COMPILER
38 /*******************************************************************************
39  *
40  * FUNCTION:    acpi_ds_create_external_region (iASL Disassembler only)
41  *
42  * PARAMETERS:  lookup_status   - Status from ns_lookup operation
43  *              op              - Op containing the Field definition and args
44  *              path            - Pathname of the region
45  *  `           walk_state      - Current method state
46  *              node            - Where the new region node is returned
47  *
48  * RETURN:      Status
49  *
50  * DESCRIPTION: Add region to the external list if NOT_FOUND. Create a new
51  *              region node/object.
52  *
53  ******************************************************************************/
54 
55 static acpi_status
56 acpi_ds_create_external_region(acpi_status lookup_status,
57 			       union acpi_parse_object *op,
58 			       char *path,
59 			       struct acpi_walk_state *walk_state,
60 			       struct acpi_namespace_node **node)
61 {
62 	acpi_status status;
63 	union acpi_operand_object *obj_desc;
64 
65 	if (lookup_status != AE_NOT_FOUND) {
66 		return (lookup_status);
67 	}
68 
69 	/*
70 	 * Table disassembly:
71 	 * operation_region not found. Generate an External for it, and
72 	 * insert the name into the namespace.
73 	 */
74 	acpi_dm_add_op_to_external_list(op, path, ACPI_TYPE_REGION, 0, 0);
75 
76 	status = acpi_ns_lookup(walk_state->scope_info, path, ACPI_TYPE_REGION,
77 				ACPI_IMODE_LOAD_PASS1, ACPI_NS_SEARCH_PARENT,
78 				walk_state, node);
79 	if (ACPI_FAILURE(status)) {
80 		return (status);
81 	}
82 
83 	/* Must create and install a region object for the new node */
84 
85 	obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_REGION);
86 	if (!obj_desc) {
87 		return (AE_NO_MEMORY);
88 	}
89 
90 	obj_desc->region.node = *node;
91 	status = acpi_ns_attach_object(*node, obj_desc, ACPI_TYPE_REGION);
92 	return (status);
93 }
94 #endif
95 
96 /*******************************************************************************
97  *
98  * FUNCTION:    acpi_ds_create_buffer_field
99  *
100  * PARAMETERS:  op                  - Current parse op (create_XXField)
101  *              walk_state          - Current state
102  *
103  * RETURN:      Status
104  *
105  * DESCRIPTION: Execute the create_field operators:
106  *              create_bit_field_op,
107  *              create_byte_field_op,
108  *              create_word_field_op,
109  *              create_dword_field_op,
110  *              create_qword_field_op,
111  *              create_field_op     (all of which define a field in a buffer)
112  *
113  ******************************************************************************/
114 
115 acpi_status
116 acpi_ds_create_buffer_field(union acpi_parse_object *op,
117 			    struct acpi_walk_state *walk_state)
118 {
119 	union acpi_parse_object *arg;
120 	struct acpi_namespace_node *node;
121 	acpi_status status;
122 	union acpi_operand_object *obj_desc;
123 	union acpi_operand_object *second_desc = NULL;
124 	u32 flags;
125 
126 	ACPI_FUNCTION_TRACE(ds_create_buffer_field);
127 
128 	/*
129 	 * Get the name_string argument (name of the new buffer_field)
130 	 */
131 	if (op->common.aml_opcode == AML_CREATE_FIELD_OP) {
132 
133 		/* For create_field, name is the 4th argument */
134 
135 		arg = acpi_ps_get_arg(op, 3);
136 	} else {
137 		/* For all other create_XXXField operators, name is the 3rd argument */
138 
139 		arg = acpi_ps_get_arg(op, 2);
140 	}
141 
142 	if (!arg) {
143 		return_ACPI_STATUS(AE_AML_NO_OPERAND);
144 	}
145 
146 	if (walk_state->deferred_node) {
147 		node = walk_state->deferred_node;
148 		status = AE_OK;
149 	} else {
150 		/* Execute flag should always be set when this function is entered */
151 
152 		if (!(walk_state->parse_flags & ACPI_PARSE_EXECUTE)) {
153 			ACPI_ERROR((AE_INFO, "Parse execute mode is not set"));
154 			return_ACPI_STATUS(AE_AML_INTERNAL);
155 		}
156 
157 		/* Creating new namespace node, should not already exist */
158 
159 		flags = ACPI_NS_NO_UPSEARCH | ACPI_NS_DONT_OPEN_SCOPE |
160 		    ACPI_NS_ERROR_IF_FOUND;
161 
162 		/*
163 		 * Mark node temporary if we are executing a normal control
164 		 * method. (Don't mark if this is a module-level code method)
165 		 */
166 		if (walk_state->method_node &&
167 		    !(walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL)) {
168 			flags |= ACPI_NS_TEMPORARY;
169 		}
170 
171 		/* Enter the name_string into the namespace */
172 
173 		status = acpi_ns_lookup(walk_state->scope_info,
174 					arg->common.value.string, ACPI_TYPE_ANY,
175 					ACPI_IMODE_LOAD_PASS1, flags,
176 					walk_state, &node);
177 		if (ACPI_FAILURE(status)) {
178 			ACPI_ERROR_NAMESPACE(walk_state->scope_info,
179 					     arg->common.value.string, status);
180 			return_ACPI_STATUS(status);
181 		}
182 	}
183 
184 	/*
185 	 * We could put the returned object (Node) on the object stack for later,
186 	 * but for now, we will put it in the "op" object that the parser uses,
187 	 * so we can get it again at the end of this scope.
188 	 */
189 	op->common.node = node;
190 
191 	/*
192 	 * If there is no object attached to the node, this node was just created
193 	 * and we need to create the field object. Otherwise, this was a lookup
194 	 * of an existing node and we don't want to create the field object again.
195 	 */
196 	obj_desc = acpi_ns_get_attached_object(node);
197 	if (obj_desc) {
198 		return_ACPI_STATUS(AE_OK);
199 	}
200 
201 	/*
202 	 * The Field definition is not fully parsed at this time.
203 	 * (We must save the address of the AML for the buffer and index operands)
204 	 */
205 
206 	/* Create the buffer field object */
207 
208 	obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_BUFFER_FIELD);
209 	if (!obj_desc) {
210 		status = AE_NO_MEMORY;
211 		goto cleanup;
212 	}
213 
214 	/*
215 	 * Remember location in AML stream of the field unit opcode and operands
216 	 * -- since the buffer and index operands must be evaluated.
217 	 */
218 	second_desc = obj_desc->common.next_object;
219 	second_desc->extra.aml_start = op->named.data;
220 	second_desc->extra.aml_length = op->named.length;
221 	obj_desc->buffer_field.node = node;
222 
223 	/* Attach constructed field descriptors to parent node */
224 
225 	status = acpi_ns_attach_object(node, obj_desc, ACPI_TYPE_BUFFER_FIELD);
226 	if (ACPI_FAILURE(status)) {
227 		goto cleanup;
228 	}
229 
230 cleanup:
231 
232 	/* Remove local reference to the object */
233 
234 	acpi_ut_remove_reference(obj_desc);
235 	return_ACPI_STATUS(status);
236 }
237 
238 /*******************************************************************************
239  *
240  * FUNCTION:    acpi_ds_get_field_names
241  *
242  * PARAMETERS:  info            - create_field info structure
243  *  `           walk_state      - Current method state
244  *              arg             - First parser arg for the field name list
245  *
246  * RETURN:      Status
247  *
248  * DESCRIPTION: Process all named fields in a field declaration. Names are
249  *              entered into the namespace.
250  *
251  ******************************************************************************/
252 
253 static acpi_status
254 acpi_ds_get_field_names(struct acpi_create_field_info *info,
255 			struct acpi_walk_state *walk_state,
256 			union acpi_parse_object *arg)
257 {
258 	acpi_status status;
259 	u64 position;
260 	union acpi_parse_object *child;
261 
262 	ACPI_FUNCTION_TRACE_PTR(ds_get_field_names, info);
263 
264 	/* First field starts at bit zero */
265 
266 	info->field_bit_position = 0;
267 
268 	/* Process all elements in the field list (of parse nodes) */
269 
270 	while (arg) {
271 		/*
272 		 * Four types of field elements are handled:
273 		 * 1) name - Enters a new named field into the namespace
274 		 * 2) offset - specifies a bit offset
275 		 * 3) access_as - changes the access mode/attributes
276 		 * 4) connection - Associate a resource template with the field
277 		 */
278 		switch (arg->common.aml_opcode) {
279 		case AML_INT_RESERVEDFIELD_OP:
280 
281 			position = (u64)info->field_bit_position +
282 			    (u64)arg->common.value.size;
283 
284 			if (position > ACPI_UINT32_MAX) {
285 				ACPI_ERROR((AE_INFO,
286 					    "Bit offset within field too large (> 0xFFFFFFFF)"));
287 				return_ACPI_STATUS(AE_SUPPORT);
288 			}
289 
290 			info->field_bit_position = (u32) position;
291 			break;
292 
293 		case AML_INT_ACCESSFIELD_OP:
294 		case AML_INT_EXTACCESSFIELD_OP:
295 			/*
296 			 * Get new access_type, access_attribute, and access_length fields
297 			 * -- to be used for all field units that follow, until the
298 			 * end-of-field or another access_as keyword is encountered.
299 			 * NOTE. These three bytes are encoded in the integer value
300 			 * of the parseop for convenience.
301 			 *
302 			 * In field_flags, preserve the flag bits other than the
303 			 * ACCESS_TYPE bits.
304 			 */
305 
306 			/* access_type (byte_acc, word_acc, etc.) */
307 
308 			info->field_flags = (u8)
309 			    ((info->
310 			      field_flags & ~(AML_FIELD_ACCESS_TYPE_MASK)) |
311 			     ((u8)((u32)(arg->common.value.integer & 0x07))));
312 
313 			/* access_attribute (attrib_quick, attrib_byte, etc.) */
314 
315 			info->attribute = (u8)
316 			    ((arg->common.value.integer >> 8) & 0xFF);
317 
318 			/* access_length (for serial/buffer protocols) */
319 
320 			info->access_length = (u8)
321 			    ((arg->common.value.integer >> 16) & 0xFF);
322 			break;
323 
324 		case AML_INT_CONNECTION_OP:
325 			/*
326 			 * Clear any previous connection. New connection is used for all
327 			 * fields that follow, similar to access_as
328 			 */
329 			info->resource_buffer = NULL;
330 			info->connection_node = NULL;
331 			info->pin_number_index = 0;
332 
333 			/*
334 			 * A Connection() is either an actual resource descriptor (buffer)
335 			 * or a named reference to a resource template
336 			 */
337 			child = arg->common.value.arg;
338 			if (child->common.aml_opcode == AML_INT_BYTELIST_OP) {
339 				info->resource_buffer = child->named.data;
340 				info->resource_length =
341 				    (u16)child->named.value.integer;
342 			} else {
343 				/* Lookup the Connection() namepath, it should already exist */
344 
345 				status = acpi_ns_lookup(walk_state->scope_info,
346 							child->common.value.
347 							name, ACPI_TYPE_ANY,
348 							ACPI_IMODE_EXECUTE,
349 							ACPI_NS_DONT_OPEN_SCOPE,
350 							walk_state,
351 							&info->connection_node);
352 				if (ACPI_FAILURE(status)) {
353 					ACPI_ERROR_NAMESPACE(walk_state->
354 							     scope_info,
355 							     child->common.
356 							     value.name,
357 							     status);
358 					return_ACPI_STATUS(status);
359 				}
360 			}
361 			break;
362 
363 		case AML_INT_NAMEDFIELD_OP:
364 
365 			/* Lookup the name, it should already exist */
366 
367 			status = acpi_ns_lookup(walk_state->scope_info,
368 						(char *)&arg->named.name,
369 						info->field_type,
370 						ACPI_IMODE_EXECUTE,
371 						ACPI_NS_DONT_OPEN_SCOPE,
372 						walk_state, &info->field_node);
373 			if (ACPI_FAILURE(status)) {
374 				ACPI_ERROR_NAMESPACE(walk_state->scope_info,
375 						     (char *)&arg->named.name,
376 						     status);
377 				return_ACPI_STATUS(status);
378 			} else {
379 				arg->common.node = info->field_node;
380 				info->field_bit_length = arg->common.value.size;
381 
382 				/*
383 				 * If there is no object attached to the node, this node was
384 				 * just created and we need to create the field object.
385 				 * Otherwise, this was a lookup of an existing node and we
386 				 * don't want to create the field object again.
387 				 */
388 				if (!acpi_ns_get_attached_object
389 				    (info->field_node)) {
390 					status = acpi_ex_prep_field_value(info);
391 					if (ACPI_FAILURE(status)) {
392 						return_ACPI_STATUS(status);
393 					}
394 				}
395 			}
396 
397 			/* Keep track of bit position for the next field */
398 
399 			position = (u64)info->field_bit_position +
400 			    (u64)arg->common.value.size;
401 
402 			if (position > ACPI_UINT32_MAX) {
403 				ACPI_ERROR((AE_INFO,
404 					    "Field [%4.4s] bit offset too large (> 0xFFFFFFFF)",
405 					    ACPI_CAST_PTR(char,
406 							  &info->field_node->
407 							  name)));
408 				return_ACPI_STATUS(AE_SUPPORT);
409 			}
410 
411 			info->field_bit_position += info->field_bit_length;
412 			info->pin_number_index++;	/* Index relative to previous Connection() */
413 			break;
414 
415 		default:
416 
417 			ACPI_ERROR((AE_INFO,
418 				    "Invalid opcode in field list: 0x%X",
419 				    arg->common.aml_opcode));
420 			return_ACPI_STATUS(AE_AML_BAD_OPCODE);
421 		}
422 
423 		arg = arg->common.next;
424 	}
425 
426 	return_ACPI_STATUS(AE_OK);
427 }
428 
429 /*******************************************************************************
430  *
431  * FUNCTION:    acpi_ds_create_field
432  *
433  * PARAMETERS:  op              - Op containing the Field definition and args
434  *              region_node     - Object for the containing Operation Region
435  *  `           walk_state      - Current method state
436  *
437  * RETURN:      Status
438  *
439  * DESCRIPTION: Create a new field in the specified operation region
440  *
441  ******************************************************************************/
442 
443 acpi_status
444 acpi_ds_create_field(union acpi_parse_object *op,
445 		     struct acpi_namespace_node *region_node,
446 		     struct acpi_walk_state *walk_state)
447 {
448 	acpi_status status;
449 	union acpi_parse_object *arg;
450 	struct acpi_create_field_info info;
451 
452 	ACPI_FUNCTION_TRACE_PTR(ds_create_field, op);
453 
454 	/* First arg is the name of the parent op_region (must already exist) */
455 
456 	arg = op->common.value.arg;
457 
458 	if (!region_node) {
459 		status =
460 		    acpi_ns_lookup(walk_state->scope_info,
461 				   arg->common.value.name, ACPI_TYPE_REGION,
462 				   ACPI_IMODE_EXECUTE, ACPI_NS_SEARCH_PARENT,
463 				   walk_state, &region_node);
464 #ifdef ACPI_ASL_COMPILER
465 		status = acpi_ds_create_external_region(status, arg,
466 							arg->common.value.name,
467 							walk_state,
468 							&region_node);
469 #endif
470 		if (ACPI_FAILURE(status)) {
471 			ACPI_ERROR_NAMESPACE(walk_state->scope_info,
472 					     arg->common.value.name, status);
473 			return_ACPI_STATUS(status);
474 		}
475 	}
476 
477 	memset(&info, 0, sizeof(struct acpi_create_field_info));
478 
479 	/* Second arg is the field flags */
480 
481 	arg = arg->common.next;
482 	info.field_flags = (u8) arg->common.value.integer;
483 	info.attribute = 0;
484 
485 	/* Each remaining arg is a Named Field */
486 
487 	info.field_type = ACPI_TYPE_LOCAL_REGION_FIELD;
488 	info.region_node = region_node;
489 
490 	status = acpi_ds_get_field_names(&info, walk_state, arg->common.next);
491 	return_ACPI_STATUS(status);
492 }
493 
494 /*******************************************************************************
495  *
496  * FUNCTION:    acpi_ds_init_field_objects
497  *
498  * PARAMETERS:  op              - Op containing the Field definition and args
499  *  `           walk_state      - Current method state
500  *
501  * RETURN:      Status
502  *
503  * DESCRIPTION: For each "Field Unit" name in the argument list that is
504  *              part of the field declaration, enter the name into the
505  *              namespace.
506  *
507  ******************************************************************************/
508 
509 acpi_status
510 acpi_ds_init_field_objects(union acpi_parse_object *op,
511 			   struct acpi_walk_state *walk_state)
512 {
513 	acpi_status status;
514 	union acpi_parse_object *arg = NULL;
515 	struct acpi_namespace_node *node;
516 	u8 type = 0;
517 	u32 flags;
518 
519 	ACPI_FUNCTION_TRACE_PTR(ds_init_field_objects, op);
520 
521 	/* Execute flag should always be set when this function is entered */
522 
523 	if (!(walk_state->parse_flags & ACPI_PARSE_EXECUTE)) {
524 		if (walk_state->parse_flags & ACPI_PARSE_DEFERRED_OP) {
525 
526 			/* bank_field Op is deferred, just return OK */
527 
528 			return_ACPI_STATUS(AE_OK);
529 		}
530 
531 		ACPI_ERROR((AE_INFO, "Parse deferred mode is not set"));
532 		return_ACPI_STATUS(AE_AML_INTERNAL);
533 	}
534 
535 	/*
536 	 * Get the field_list argument for this opcode. This is the start of the
537 	 * list of field elements.
538 	 */
539 	switch (walk_state->opcode) {
540 	case AML_FIELD_OP:
541 
542 		arg = acpi_ps_get_arg(op, 2);
543 		type = ACPI_TYPE_LOCAL_REGION_FIELD;
544 		break;
545 
546 	case AML_BANK_FIELD_OP:
547 
548 		arg = acpi_ps_get_arg(op, 4);
549 		type = ACPI_TYPE_LOCAL_BANK_FIELD;
550 		break;
551 
552 	case AML_INDEX_FIELD_OP:
553 
554 		arg = acpi_ps_get_arg(op, 3);
555 		type = ACPI_TYPE_LOCAL_INDEX_FIELD;
556 		break;
557 
558 	default:
559 
560 		return_ACPI_STATUS(AE_BAD_PARAMETER);
561 	}
562 
563 	/* Creating new namespace node(s), should not already exist */
564 
565 	flags = ACPI_NS_NO_UPSEARCH | ACPI_NS_DONT_OPEN_SCOPE |
566 	    ACPI_NS_ERROR_IF_FOUND;
567 
568 	/*
569 	 * Mark node(s) temporary if we are executing a normal control
570 	 * method. (Don't mark if this is a module-level code method)
571 	 */
572 	if (walk_state->method_node &&
573 	    !(walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL)) {
574 		flags |= ACPI_NS_TEMPORARY;
575 	}
576 
577 	/*
578 	 * Walk the list of entries in the field_list
579 	 * Note: field_list can be of zero length. In this case, Arg will be NULL.
580 	 */
581 	while (arg) {
582 		/*
583 		 * Ignore OFFSET/ACCESSAS/CONNECTION terms here; we are only interested
584 		 * in the field names in order to enter them into the namespace.
585 		 */
586 		if (arg->common.aml_opcode == AML_INT_NAMEDFIELD_OP) {
587 			status = acpi_ns_lookup(walk_state->scope_info,
588 						(char *)&arg->named.name, type,
589 						ACPI_IMODE_LOAD_PASS1, flags,
590 						walk_state, &node);
591 			if (ACPI_FAILURE(status)) {
592 				ACPI_ERROR_NAMESPACE(walk_state->scope_info,
593 						     (char *)&arg->named.name,
594 						     status);
595 				if (status != AE_ALREADY_EXISTS) {
596 					return_ACPI_STATUS(status);
597 				}
598 
599 				/* Name already exists, just ignore this error */
600 
601 				status = AE_OK;
602 			}
603 
604 			arg->common.node = node;
605 		}
606 
607 		/* Get the next field element in the list */
608 
609 		arg = arg->common.next;
610 	}
611 
612 	return_ACPI_STATUS(AE_OK);
613 }
614 
615 /*******************************************************************************
616  *
617  * FUNCTION:    acpi_ds_create_bank_field
618  *
619  * PARAMETERS:  op              - Op containing the Field definition and args
620  *              region_node     - Object for the containing Operation Region
621  *              walk_state      - Current method state
622  *
623  * RETURN:      Status
624  *
625  * DESCRIPTION: Create a new bank field in the specified operation region
626  *
627  ******************************************************************************/
628 
629 acpi_status
630 acpi_ds_create_bank_field(union acpi_parse_object *op,
631 			  struct acpi_namespace_node *region_node,
632 			  struct acpi_walk_state *walk_state)
633 {
634 	acpi_status status;
635 	union acpi_parse_object *arg;
636 	struct acpi_create_field_info info;
637 
638 	ACPI_FUNCTION_TRACE_PTR(ds_create_bank_field, op);
639 
640 	/* First arg is the name of the parent op_region (must already exist) */
641 
642 	arg = op->common.value.arg;
643 	if (!region_node) {
644 		status =
645 		    acpi_ns_lookup(walk_state->scope_info,
646 				   arg->common.value.name, ACPI_TYPE_REGION,
647 				   ACPI_IMODE_EXECUTE, ACPI_NS_SEARCH_PARENT,
648 				   walk_state, &region_node);
649 #ifdef ACPI_ASL_COMPILER
650 		status = acpi_ds_create_external_region(status, arg,
651 							arg->common.value.name,
652 							walk_state,
653 							&region_node);
654 #endif
655 		if (ACPI_FAILURE(status)) {
656 			ACPI_ERROR_NAMESPACE(walk_state->scope_info,
657 					     arg->common.value.name, status);
658 			return_ACPI_STATUS(status);
659 		}
660 	}
661 
662 	/* Second arg is the Bank Register (Field) (must already exist) */
663 
664 	arg = arg->common.next;
665 	status =
666 	    acpi_ns_lookup(walk_state->scope_info, arg->common.value.string,
667 			   ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
668 			   ACPI_NS_SEARCH_PARENT, walk_state,
669 			   &info.register_node);
670 	if (ACPI_FAILURE(status)) {
671 		ACPI_ERROR_NAMESPACE(walk_state->scope_info,
672 				     arg->common.value.string, status);
673 		return_ACPI_STATUS(status);
674 	}
675 
676 	/*
677 	 * Third arg is the bank_value
678 	 * This arg is a term_arg, not a constant
679 	 * It will be evaluated later, by acpi_ds_eval_bank_field_operands
680 	 */
681 	arg = arg->common.next;
682 
683 	/* Fourth arg is the field flags */
684 
685 	arg = arg->common.next;
686 	info.field_flags = (u8) arg->common.value.integer;
687 
688 	/* Each remaining arg is a Named Field */
689 
690 	info.field_type = ACPI_TYPE_LOCAL_BANK_FIELD;
691 	info.region_node = region_node;
692 
693 	/*
694 	 * Use Info.data_register_node to store bank_field Op
695 	 * It's safe because data_register_node will never be used when create
696 	 * bank field \we store aml_start and aml_length in the bank_field Op for
697 	 * late evaluation. Used in acpi_ex_prep_field_value(Info)
698 	 *
699 	 * TBD: Or, should we add a field in struct acpi_create_field_info, like
700 	 * "void *ParentOp"?
701 	 */
702 	info.data_register_node = (struct acpi_namespace_node *)op;
703 
704 	status = acpi_ds_get_field_names(&info, walk_state, arg->common.next);
705 	return_ACPI_STATUS(status);
706 }
707 
708 /*******************************************************************************
709  *
710  * FUNCTION:    acpi_ds_create_index_field
711  *
712  * PARAMETERS:  op              - Op containing the Field definition and args
713  *              region_node     - Object for the containing Operation Region
714  *  `           walk_state      - Current method state
715  *
716  * RETURN:      Status
717  *
718  * DESCRIPTION: Create a new index field in the specified operation region
719  *
720  ******************************************************************************/
721 
722 acpi_status
723 acpi_ds_create_index_field(union acpi_parse_object *op,
724 			   struct acpi_namespace_node *region_node,
725 			   struct acpi_walk_state *walk_state)
726 {
727 	acpi_status status;
728 	union acpi_parse_object *arg;
729 	struct acpi_create_field_info info;
730 
731 	ACPI_FUNCTION_TRACE_PTR(ds_create_index_field, op);
732 
733 	/* First arg is the name of the Index register (must already exist) */
734 
735 	arg = op->common.value.arg;
736 	status =
737 	    acpi_ns_lookup(walk_state->scope_info, arg->common.value.string,
738 			   ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
739 			   ACPI_NS_SEARCH_PARENT, walk_state,
740 			   &info.register_node);
741 	if (ACPI_FAILURE(status)) {
742 		ACPI_ERROR_NAMESPACE(walk_state->scope_info,
743 				     arg->common.value.string, status);
744 		return_ACPI_STATUS(status);
745 	}
746 
747 	/* Second arg is the data register (must already exist) */
748 
749 	arg = arg->common.next;
750 	status =
751 	    acpi_ns_lookup(walk_state->scope_info, arg->common.value.string,
752 			   ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
753 			   ACPI_NS_SEARCH_PARENT, walk_state,
754 			   &info.data_register_node);
755 	if (ACPI_FAILURE(status)) {
756 		ACPI_ERROR_NAMESPACE(walk_state->scope_info,
757 				     arg->common.value.string, status);
758 		return_ACPI_STATUS(status);
759 	}
760 
761 	/* Next arg is the field flags */
762 
763 	arg = arg->common.next;
764 	info.field_flags = (u8) arg->common.value.integer;
765 
766 	/* Each remaining arg is a Named Field */
767 
768 	info.field_type = ACPI_TYPE_LOCAL_INDEX_FIELD;
769 	info.region_node = region_node;
770 
771 	status = acpi_ds_get_field_names(&info, walk_state, arg->common.next);
772 	return_ACPI_STATUS(status);
773 }
774