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v3.1
  1
  2/******************************************************************************
  3 *
  4 * Module Name: exresolv - AML Interpreter object resolution
  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 "amlcode.h"
 48#include "acdispat.h"
 49#include "acinterp.h"
 50#include "acnamesp.h"
 51
 52#define _COMPONENT          ACPI_EXECUTER
 53ACPI_MODULE_NAME("exresolv")
 54
 55/* Local prototypes */
 56static acpi_status
 57acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
 58				struct acpi_walk_state *walk_state);
 59
 60/*******************************************************************************
 61 *
 62 * FUNCTION:    acpi_ex_resolve_to_value
 63 *
 64 * PARAMETERS:  **stack_ptr         - Points to entry on obj_stack, which can
 65 *                                    be either an (union acpi_operand_object *)
 66 *                                    or an acpi_handle.
 67 *              walk_state          - Current method state
 68 *
 69 * RETURN:      Status
 70 *
 71 * DESCRIPTION: Convert Reference objects to values
 72 *
 73 ******************************************************************************/
 74
 75acpi_status
 76acpi_ex_resolve_to_value(union acpi_operand_object **stack_ptr,
 77			 struct acpi_walk_state *walk_state)
 78{
 79	acpi_status status;
 80
 81	ACPI_FUNCTION_TRACE_PTR(ex_resolve_to_value, stack_ptr);
 82
 83	if (!stack_ptr || !*stack_ptr) {
 84		ACPI_ERROR((AE_INFO, "Internal - null pointer"));
 85		return_ACPI_STATUS(AE_AML_NO_OPERAND);
 86	}
 87
 88	/*
 89	 * The entity pointed to by the stack_ptr can be either
 90	 * 1) A valid union acpi_operand_object, or
 91	 * 2) A struct acpi_namespace_node (named_obj)
 92	 */
 93	if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_OPERAND) {
 94		status = acpi_ex_resolve_object_to_value(stack_ptr, walk_state);
 95		if (ACPI_FAILURE(status)) {
 96			return_ACPI_STATUS(status);
 97		}
 98
 99		if (!*stack_ptr) {
100			ACPI_ERROR((AE_INFO, "Internal - null pointer"));
101			return_ACPI_STATUS(AE_AML_NO_OPERAND);
102		}
103	}
104
105	/*
106	 * Object on the stack may have changed if acpi_ex_resolve_object_to_value()
107	 * was called (i.e., we can't use an _else_ here.)
108	 */
109	if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_NAMED) {
110		status =
111		    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
112						  (struct acpi_namespace_node,
113						   stack_ptr), walk_state);
114		if (ACPI_FAILURE(status)) {
115			return_ACPI_STATUS(status);
116		}
117	}
118
119	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Resolved object %p\n", *stack_ptr));
120	return_ACPI_STATUS(AE_OK);
121}
122
123/*******************************************************************************
124 *
125 * FUNCTION:    acpi_ex_resolve_object_to_value
126 *
127 * PARAMETERS:  stack_ptr       - Pointer to an internal object
128 *              walk_state      - Current method state
129 *
130 * RETURN:      Status
131 *
132 * DESCRIPTION: Retrieve the value from an internal object. The Reference type
133 *              uses the associated AML opcode to determine the value.
134 *
135 ******************************************************************************/
136
137static acpi_status
138acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
139				struct acpi_walk_state *walk_state)
140{
141	acpi_status status = AE_OK;
142	union acpi_operand_object *stack_desc;
143	union acpi_operand_object *obj_desc = NULL;
144	u8 ref_type;
145
146	ACPI_FUNCTION_TRACE(ex_resolve_object_to_value);
147
148	stack_desc = *stack_ptr;
149
150	/* This is a union acpi_operand_object    */
151
152	switch (stack_desc->common.type) {
153	case ACPI_TYPE_LOCAL_REFERENCE:
154
155		ref_type = stack_desc->reference.class;
156
157		switch (ref_type) {
158		case ACPI_REFCLASS_LOCAL:
159		case ACPI_REFCLASS_ARG:
160
161			/*
162			 * Get the local from the method's state info
163			 * Note: this increments the local's object reference count
164			 */
165			status = acpi_ds_method_data_get_value(ref_type,
166							       stack_desc->
167							       reference.value,
168							       walk_state,
169							       &obj_desc);
170			if (ACPI_FAILURE(status)) {
171				return_ACPI_STATUS(status);
172			}
173
174			ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
175					  "[Arg/Local %X] ValueObj is %p\n",
176					  stack_desc->reference.value,
177					  obj_desc));
178
179			/*
180			 * Now we can delete the original Reference Object and
181			 * replace it with the resolved value
182			 */
183			acpi_ut_remove_reference(stack_desc);
184			*stack_ptr = obj_desc;
185			break;
186
187		case ACPI_REFCLASS_INDEX:
188
189			switch (stack_desc->reference.target_type) {
190			case ACPI_TYPE_BUFFER_FIELD:
191
192				/* Just return - do not dereference */
193				break;
194
195			case ACPI_TYPE_PACKAGE:
196
197				/* If method call or copy_object - do not dereference */
198
199				if ((walk_state->opcode ==
200				     AML_INT_METHODCALL_OP)
201				    || (walk_state->opcode == AML_COPY_OP)) {
 
202					break;
203				}
204
205				/* Otherwise, dereference the package_index to a package element */
206
207				obj_desc = *stack_desc->reference.where;
208				if (obj_desc) {
209					/*
210					 * Valid object descriptor, copy pointer to return value
211					 * (i.e., dereference the package index)
212					 * Delete the ref object, increment the returned object
213					 */
214					acpi_ut_remove_reference(stack_desc);
215					acpi_ut_add_reference(obj_desc);
216					*stack_ptr = obj_desc;
217				} else {
218					/*
219					 * A NULL object descriptor means an uninitialized element of
220					 * the package, can't dereference it
221					 */
222					ACPI_ERROR((AE_INFO,
223						    "Attempt to dereference an Index to NULL package element Idx=%p",
 
224						    stack_desc));
225					status = AE_AML_UNINITIALIZED_ELEMENT;
226				}
227				break;
228
229			default:
230
231				/* Invalid reference object */
232
233				ACPI_ERROR((AE_INFO,
234					    "Unknown TargetType 0x%X in Index/Reference object %p",
235					    stack_desc->reference.target_type,
236					    stack_desc));
237				status = AE_AML_INTERNAL;
238				break;
239			}
240			break;
241
242		case ACPI_REFCLASS_REFOF:
243		case ACPI_REFCLASS_DEBUG:
244		case ACPI_REFCLASS_TABLE:
245
246			/* Just leave the object as-is, do not dereference */
247
248			break;
249
250		case ACPI_REFCLASS_NAME:	/* Reference to a named object */
251
252			/* Dereference the name */
253
254			if ((stack_desc->reference.node->type ==
255			     ACPI_TYPE_DEVICE)
256			    || (stack_desc->reference.node->type ==
257				ACPI_TYPE_THERMAL)) {
258
259				/* These node types do not have 'real' subobjects */
260
261				*stack_ptr = (void *)stack_desc->reference.node;
262			} else {
263				/* Get the object pointed to by the namespace node */
264
265				*stack_ptr =
266				    (stack_desc->reference.node)->object;
267				acpi_ut_add_reference(*stack_ptr);
268			}
269
270			acpi_ut_remove_reference(stack_desc);
271			break;
272
273		default:
274
275			ACPI_ERROR((AE_INFO,
276				    "Unknown Reference type 0x%X in %p",
277				    ref_type, stack_desc));
278			status = AE_AML_INTERNAL;
279			break;
280		}
281		break;
282
283	case ACPI_TYPE_BUFFER:
284
285		status = acpi_ds_get_buffer_arguments(stack_desc);
286		break;
287
288	case ACPI_TYPE_PACKAGE:
289
290		status = acpi_ds_get_package_arguments(stack_desc);
291		break;
292
293	case ACPI_TYPE_BUFFER_FIELD:
294	case ACPI_TYPE_LOCAL_REGION_FIELD:
295	case ACPI_TYPE_LOCAL_BANK_FIELD:
296	case ACPI_TYPE_LOCAL_INDEX_FIELD:
297
298		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
299				  "FieldRead SourceDesc=%p Type=%X\n",
300				  stack_desc, stack_desc->common.type));
301
302		status =
303		    acpi_ex_read_data_from_field(walk_state, stack_desc,
304						 &obj_desc);
305
306		/* Remove a reference to the original operand, then override */
307
308		acpi_ut_remove_reference(*stack_ptr);
309		*stack_ptr = (void *)obj_desc;
310		break;
311
312	default:
 
313		break;
314	}
315
316	return_ACPI_STATUS(status);
317}
318
319/*******************************************************************************
320 *
321 * FUNCTION:    acpi_ex_resolve_multiple
322 *
323 * PARAMETERS:  walk_state          - Current state (contains AML opcode)
324 *              Operand             - Starting point for resolution
325 *              return_type         - Where the object type is returned
326 *              return_desc         - Where the resolved object is returned
327 *
328 * RETURN:      Status
329 *
330 * DESCRIPTION: Return the base object and type.  Traverse a reference list if
331 *              necessary to get to the base object.
332 *
333 ******************************************************************************/
334
335acpi_status
336acpi_ex_resolve_multiple(struct acpi_walk_state *walk_state,
337			 union acpi_operand_object *operand,
338			 acpi_object_type * return_type,
339			 union acpi_operand_object **return_desc)
340{
341	union acpi_operand_object *obj_desc = (void *)operand;
342	struct acpi_namespace_node *node;
 
343	acpi_object_type type;
344	acpi_status status;
345
346	ACPI_FUNCTION_TRACE(acpi_ex_resolve_multiple);
347
348	/* Operand can be either a namespace node or an operand descriptor */
349
350	switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
351	case ACPI_DESC_TYPE_OPERAND:
 
352		type = obj_desc->common.type;
353		break;
354
355	case ACPI_DESC_TYPE_NAMED:
 
356		type = ((struct acpi_namespace_node *)obj_desc)->type;
357		obj_desc =
358		    acpi_ns_get_attached_object((struct acpi_namespace_node *)
359						obj_desc);
360
361		/* If we had an Alias node, use the attached object for type info */
362
363		if (type == ACPI_TYPE_LOCAL_ALIAS) {
364			type = ((struct acpi_namespace_node *)obj_desc)->type;
365			obj_desc =
366			    acpi_ns_get_attached_object((struct
367							 acpi_namespace_node *)
368							obj_desc);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
369		}
370		break;
371
372	default:
373		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
374	}
375
376	/* If type is anything other than a reference, we are done */
377
378	if (type != ACPI_TYPE_LOCAL_REFERENCE) {
379		goto exit;
380	}
381
382	/*
383	 * For reference objects created via the ref_of, Index, or Load/load_table
384	 * operators, we need to get to the base object (as per the ACPI
385	 * specification of the object_type and size_of operators). This means
386	 * traversing the list of possibly many nested references.
387	 */
388	while (obj_desc->common.type == ACPI_TYPE_LOCAL_REFERENCE) {
389		switch (obj_desc->reference.class) {
390		case ACPI_REFCLASS_REFOF:
391		case ACPI_REFCLASS_NAME:
392
393			/* Dereference the reference pointer */
394
395			if (obj_desc->reference.class == ACPI_REFCLASS_REFOF) {
396				node = obj_desc->reference.object;
397			} else {	/* AML_INT_NAMEPATH_OP */
398
399				node = obj_desc->reference.node;
400			}
401
402			/* All "References" point to a NS node */
403
404			if (ACPI_GET_DESCRIPTOR_TYPE(node) !=
405			    ACPI_DESC_TYPE_NAMED) {
406				ACPI_ERROR((AE_INFO,
407					    "Not a namespace node %p [%s]",
408					    node,
409					    acpi_ut_get_descriptor_name(node)));
410				return_ACPI_STATUS(AE_AML_INTERNAL);
411			}
412
413			/* Get the attached object */
414
415			obj_desc = acpi_ns_get_attached_object(node);
416			if (!obj_desc) {
417
418				/* No object, use the NS node type */
419
420				type = acpi_ns_get_type(node);
421				goto exit;
422			}
423
424			/* Check for circular references */
425
426			if (obj_desc == operand) {
427				return_ACPI_STATUS(AE_AML_CIRCULAR_REFERENCE);
428			}
429			break;
430
431		case ACPI_REFCLASS_INDEX:
432
433			/* Get the type of this reference (index into another object) */
434
435			type = obj_desc->reference.target_type;
436			if (type != ACPI_TYPE_PACKAGE) {
437				goto exit;
438			}
439
440			/*
441			 * The main object is a package, we want to get the type
442			 * of the individual package element that is referenced by
443			 * the index.
444			 *
445			 * This could of course in turn be another reference object.
446			 */
447			obj_desc = *(obj_desc->reference.where);
448			if (!obj_desc) {
449
450				/* NULL package elements are allowed */
451
452				type = 0;	/* Uninitialized */
453				goto exit;
454			}
455			break;
456
457		case ACPI_REFCLASS_TABLE:
458
459			type = ACPI_TYPE_DDB_HANDLE;
460			goto exit;
461
462		case ACPI_REFCLASS_LOCAL:
463		case ACPI_REFCLASS_ARG:
464
465			if (return_desc) {
466				status =
467				    acpi_ds_method_data_get_value(obj_desc->
468								  reference.
469								  class,
470								  obj_desc->
471								  reference.
472								  value,
473								  walk_state,
474								  &obj_desc);
475				if (ACPI_FAILURE(status)) {
476					return_ACPI_STATUS(status);
477				}
478				acpi_ut_remove_reference(obj_desc);
479			} else {
480				status =
481				    acpi_ds_method_data_get_node(obj_desc->
482								 reference.
483								 class,
484								 obj_desc->
485								 reference.
486								 value,
487								 walk_state,
488								 &node);
489				if (ACPI_FAILURE(status)) {
490					return_ACPI_STATUS(status);
491				}
492
493				obj_desc = acpi_ns_get_attached_object(node);
494				if (!obj_desc) {
495					type = ACPI_TYPE_ANY;
496					goto exit;
497				}
498			}
499			break;
500
501		case ACPI_REFCLASS_DEBUG:
502
503			/* The Debug Object is of type "DebugObject" */
504
505			type = ACPI_TYPE_DEBUG_OBJECT;
506			goto exit;
507
508		default:
509
510			ACPI_ERROR((AE_INFO,
511				    "Unknown Reference Class 0x%2.2X",
512				    obj_desc->reference.class));
513			return_ACPI_STATUS(AE_AML_INTERNAL);
514		}
515	}
516
517	/*
518	 * Now we are guaranteed to have an object that has not been created
519	 * via the ref_of or Index operators.
520	 */
521	type = obj_desc->common.type;
522
523      exit:
524	/* Convert internal types to external types */
525
526	switch (type) {
527	case ACPI_TYPE_LOCAL_REGION_FIELD:
528	case ACPI_TYPE_LOCAL_BANK_FIELD:
529	case ACPI_TYPE_LOCAL_INDEX_FIELD:
530
531		type = ACPI_TYPE_FIELD_UNIT;
532		break;
533
534	case ACPI_TYPE_LOCAL_SCOPE:
535
536		/* Per ACPI Specification, Scope is untyped */
537
538		type = ACPI_TYPE_ANY;
539		break;
540
541	default:
 
542		/* No change to Type required */
 
543		break;
544	}
545
546	*return_type = type;
547	if (return_desc) {
548		*return_desc = obj_desc;
549	}
550	return_ACPI_STATUS(AE_OK);
551}
v5.9
  1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
  2/******************************************************************************
  3 *
  4 * Module Name: exresolv - AML Interpreter object resolution
  5 *
  6 * Copyright (C) 2000 - 2020, 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
 17#define _COMPONENT          ACPI_EXECUTER
 18ACPI_MODULE_NAME("exresolv")
 19
 20/* Local prototypes */
 21static acpi_status
 22acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
 23				struct acpi_walk_state *walk_state);
 24
 25/*******************************************************************************
 26 *
 27 * FUNCTION:    acpi_ex_resolve_to_value
 28 *
 29 * PARAMETERS:  **stack_ptr         - Points to entry on obj_stack, which can
 30 *                                    be either an (union acpi_operand_object *)
 31 *                                    or an acpi_handle.
 32 *              walk_state          - Current method state
 33 *
 34 * RETURN:      Status
 35 *
 36 * DESCRIPTION: Convert Reference objects to values
 37 *
 38 ******************************************************************************/
 39
 40acpi_status
 41acpi_ex_resolve_to_value(union acpi_operand_object **stack_ptr,
 42			 struct acpi_walk_state *walk_state)
 43{
 44	acpi_status status;
 45
 46	ACPI_FUNCTION_TRACE_PTR(ex_resolve_to_value, stack_ptr);
 47
 48	if (!stack_ptr || !*stack_ptr) {
 49		ACPI_ERROR((AE_INFO, "Internal - null pointer"));
 50		return_ACPI_STATUS(AE_AML_NO_OPERAND);
 51	}
 52
 53	/*
 54	 * The entity pointed to by the stack_ptr can be either
 55	 * 1) A valid union acpi_operand_object, or
 56	 * 2) A struct acpi_namespace_node (named_obj)
 57	 */
 58	if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_OPERAND) {
 59		status = acpi_ex_resolve_object_to_value(stack_ptr, walk_state);
 60		if (ACPI_FAILURE(status)) {
 61			return_ACPI_STATUS(status);
 62		}
 63
 64		if (!*stack_ptr) {
 65			ACPI_ERROR((AE_INFO, "Internal - null pointer"));
 66			return_ACPI_STATUS(AE_AML_NO_OPERAND);
 67		}
 68	}
 69
 70	/*
 71	 * Object on the stack may have changed if acpi_ex_resolve_object_to_value()
 72	 * was called (i.e., we can't use an _else_ here.)
 73	 */
 74	if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_NAMED) {
 75		status =
 76		    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
 77						  (struct acpi_namespace_node,
 78						   stack_ptr), walk_state);
 79		if (ACPI_FAILURE(status)) {
 80			return_ACPI_STATUS(status);
 81		}
 82	}
 83
 84	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Resolved object %p\n", *stack_ptr));
 85	return_ACPI_STATUS(AE_OK);
 86}
 87
 88/*******************************************************************************
 89 *
 90 * FUNCTION:    acpi_ex_resolve_object_to_value
 91 *
 92 * PARAMETERS:  stack_ptr       - Pointer to an internal object
 93 *              walk_state      - Current method state
 94 *
 95 * RETURN:      Status
 96 *
 97 * DESCRIPTION: Retrieve the value from an internal object. The Reference type
 98 *              uses the associated AML opcode to determine the value.
 99 *
100 ******************************************************************************/
101
102static acpi_status
103acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
104				struct acpi_walk_state *walk_state)
105{
106	acpi_status status = AE_OK;
107	union acpi_operand_object *stack_desc;
108	union acpi_operand_object *obj_desc = NULL;
109	u8 ref_type;
110
111	ACPI_FUNCTION_TRACE(ex_resolve_object_to_value);
112
113	stack_desc = *stack_ptr;
114
115	/* This is an object of type union acpi_operand_object */
116
117	switch (stack_desc->common.type) {
118	case ACPI_TYPE_LOCAL_REFERENCE:
119
120		ref_type = stack_desc->reference.class;
121
122		switch (ref_type) {
123		case ACPI_REFCLASS_LOCAL:
124		case ACPI_REFCLASS_ARG:
 
125			/*
126			 * Get the local from the method's state info
127			 * Note: this increments the local's object reference count
128			 */
129			status = acpi_ds_method_data_get_value(ref_type,
130							       stack_desc->
131							       reference.value,
132							       walk_state,
133							       &obj_desc);
134			if (ACPI_FAILURE(status)) {
135				return_ACPI_STATUS(status);
136			}
137
138			ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
139					  "[Arg/Local %X] ValueObj is %p\n",
140					  stack_desc->reference.value,
141					  obj_desc));
142
143			/*
144			 * Now we can delete the original Reference Object and
145			 * replace it with the resolved value
146			 */
147			acpi_ut_remove_reference(stack_desc);
148			*stack_ptr = obj_desc;
149			break;
150
151		case ACPI_REFCLASS_INDEX:
152
153			switch (stack_desc->reference.target_type) {
154			case ACPI_TYPE_BUFFER_FIELD:
155
156				/* Just return - do not dereference */
157				break;
158
159			case ACPI_TYPE_PACKAGE:
160
161				/* If method call or copy_object - do not dereference */
162
163				if ((walk_state->opcode ==
164				     AML_INT_METHODCALL_OP)
165				    || (walk_state->opcode ==
166					AML_COPY_OBJECT_OP)) {
167					break;
168				}
169
170				/* Otherwise, dereference the package_index to a package element */
171
172				obj_desc = *stack_desc->reference.where;
173				if (obj_desc) {
174					/*
175					 * Valid object descriptor, copy pointer to return value
176					 * (i.e., dereference the package index)
177					 * Delete the ref object, increment the returned object
178					 */
 
179					acpi_ut_add_reference(obj_desc);
180					*stack_ptr = obj_desc;
181				} else {
182					/*
183					 * A NULL object descriptor means an uninitialized element of
184					 * the package, can't dereference it
185					 */
186					ACPI_ERROR((AE_INFO,
187						    "Attempt to dereference an Index to "
188						    "NULL package element Idx=%p",
189						    stack_desc));
190					status = AE_AML_UNINITIALIZED_ELEMENT;
191				}
192				break;
193
194			default:
195
196				/* Invalid reference object */
197
198				ACPI_ERROR((AE_INFO,
199					    "Unknown TargetType 0x%X in Index/Reference object %p",
200					    stack_desc->reference.target_type,
201					    stack_desc));
202				status = AE_AML_INTERNAL;
203				break;
204			}
205			break;
206
207		case ACPI_REFCLASS_REFOF:
208		case ACPI_REFCLASS_DEBUG:
209		case ACPI_REFCLASS_TABLE:
210
211			/* Just leave the object as-is, do not dereference */
212
213			break;
214
215		case ACPI_REFCLASS_NAME:	/* Reference to a named object */
216
217			/* Dereference the name */
218
219			if ((stack_desc->reference.node->type ==
220			     ACPI_TYPE_DEVICE)
221			    || (stack_desc->reference.node->type ==
222				ACPI_TYPE_THERMAL)) {
223
224				/* These node types do not have 'real' subobjects */
225
226				*stack_ptr = (void *)stack_desc->reference.node;
227			} else {
228				/* Get the object pointed to by the namespace node */
229
230				*stack_ptr =
231				    (stack_desc->reference.node)->object;
232				acpi_ut_add_reference(*stack_ptr);
233			}
234
235			acpi_ut_remove_reference(stack_desc);
236			break;
237
238		default:
239
240			ACPI_ERROR((AE_INFO,
241				    "Unknown Reference type 0x%X in %p",
242				    ref_type, stack_desc));
243			status = AE_AML_INTERNAL;
244			break;
245		}
246		break;
247
248	case ACPI_TYPE_BUFFER:
249
250		status = acpi_ds_get_buffer_arguments(stack_desc);
251		break;
252
253	case ACPI_TYPE_PACKAGE:
254
255		status = acpi_ds_get_package_arguments(stack_desc);
256		break;
257
258	case ACPI_TYPE_BUFFER_FIELD:
259	case ACPI_TYPE_LOCAL_REGION_FIELD:
260	case ACPI_TYPE_LOCAL_BANK_FIELD:
261	case ACPI_TYPE_LOCAL_INDEX_FIELD:
262
263		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
264				  "FieldRead SourceDesc=%p Type=%X\n",
265				  stack_desc, stack_desc->common.type));
266
267		status =
268		    acpi_ex_read_data_from_field(walk_state, stack_desc,
269						 &obj_desc);
270
271		/* Remove a reference to the original operand, then override */
272
273		acpi_ut_remove_reference(*stack_ptr);
274		*stack_ptr = (void *)obj_desc;
275		break;
276
277	default:
278
279		break;
280	}
281
282	return_ACPI_STATUS(status);
283}
284
285/*******************************************************************************
286 *
287 * FUNCTION:    acpi_ex_resolve_multiple
288 *
289 * PARAMETERS:  walk_state          - Current state (contains AML opcode)
290 *              operand             - Starting point for resolution
291 *              return_type         - Where the object type is returned
292 *              return_desc         - Where the resolved object is returned
293 *
294 * RETURN:      Status
295 *
296 * DESCRIPTION: Return the base object and type. Traverse a reference list if
297 *              necessary to get to the base object.
298 *
299 ******************************************************************************/
300
301acpi_status
302acpi_ex_resolve_multiple(struct acpi_walk_state *walk_state,
303			 union acpi_operand_object *operand,
304			 acpi_object_type *return_type,
305			 union acpi_operand_object **return_desc)
306{
307	union acpi_operand_object *obj_desc = ACPI_CAST_PTR(void, operand);
308	struct acpi_namespace_node *node =
309	    ACPI_CAST_PTR(struct acpi_namespace_node, operand);
310	acpi_object_type type;
311	acpi_status status;
312
313	ACPI_FUNCTION_TRACE(acpi_ex_resolve_multiple);
314
315	/* Operand can be either a namespace node or an operand descriptor */
316
317	switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
318	case ACPI_DESC_TYPE_OPERAND:
319
320		type = obj_desc->common.type;
321		break;
322
323	case ACPI_DESC_TYPE_NAMED:
324
325		type = ((struct acpi_namespace_node *)obj_desc)->type;
326		obj_desc = acpi_ns_get_attached_object(node);
 
 
327
328		/* If we had an Alias node, use the attached object for type info */
329
330		if (type == ACPI_TYPE_LOCAL_ALIAS) {
331			type = ((struct acpi_namespace_node *)obj_desc)->type;
332			obj_desc = acpi_ns_get_attached_object((struct
333								acpi_namespace_node
334								*)obj_desc);
335		}
336
337		switch (type) {
338		case ACPI_TYPE_DEVICE:
339		case ACPI_TYPE_THERMAL:
340
341			/* These types have no attached subobject */
342			break;
343
344		default:
345
346			/* All other types require a subobject */
347
348			if (!obj_desc) {
349				ACPI_ERROR((AE_INFO,
350					    "[%4.4s] Node is unresolved or uninitialized",
351					    acpi_ut_get_node_name(node)));
352				return_ACPI_STATUS(AE_AML_UNINITIALIZED_NODE);
353			}
354			break;
355		}
356		break;
357
358	default:
359		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
360	}
361
362	/* If type is anything other than a reference, we are done */
363
364	if (type != ACPI_TYPE_LOCAL_REFERENCE) {
365		goto exit;
366	}
367
368	/*
369	 * For reference objects created via the ref_of, Index, or Load/load_table
370	 * operators, we need to get to the base object (as per the ACPI
371	 * specification of the object_type and size_of operators). This means
372	 * traversing the list of possibly many nested references.
373	 */
374	while (obj_desc->common.type == ACPI_TYPE_LOCAL_REFERENCE) {
375		switch (obj_desc->reference.class) {
376		case ACPI_REFCLASS_REFOF:
377		case ACPI_REFCLASS_NAME:
378
379			/* Dereference the reference pointer */
380
381			if (obj_desc->reference.class == ACPI_REFCLASS_REFOF) {
382				node = obj_desc->reference.object;
383			} else {	/* AML_INT_NAMEPATH_OP */
384
385				node = obj_desc->reference.node;
386			}
387
388			/* All "References" point to a NS node */
389
390			if (ACPI_GET_DESCRIPTOR_TYPE(node) !=
391			    ACPI_DESC_TYPE_NAMED) {
392				ACPI_ERROR((AE_INFO,
393					    "Not a namespace node %p [%s]",
394					    node,
395					    acpi_ut_get_descriptor_name(node)));
396				return_ACPI_STATUS(AE_AML_INTERNAL);
397			}
398
399			/* Get the attached object */
400
401			obj_desc = acpi_ns_get_attached_object(node);
402			if (!obj_desc) {
403
404				/* No object, use the NS node type */
405
406				type = acpi_ns_get_type(node);
407				goto exit;
408			}
409
410			/* Check for circular references */
411
412			if (obj_desc == operand) {
413				return_ACPI_STATUS(AE_AML_CIRCULAR_REFERENCE);
414			}
415			break;
416
417		case ACPI_REFCLASS_INDEX:
418
419			/* Get the type of this reference (index into another object) */
420
421			type = obj_desc->reference.target_type;
422			if (type != ACPI_TYPE_PACKAGE) {
423				goto exit;
424			}
425
426			/*
427			 * The main object is a package, we want to get the type
428			 * of the individual package element that is referenced by
429			 * the index.
430			 *
431			 * This could of course in turn be another reference object.
432			 */
433			obj_desc = *(obj_desc->reference.where);
434			if (!obj_desc) {
435
436				/* NULL package elements are allowed */
437
438				type = 0;	/* Uninitialized */
439				goto exit;
440			}
441			break;
442
443		case ACPI_REFCLASS_TABLE:
444
445			type = ACPI_TYPE_DDB_HANDLE;
446			goto exit;
447
448		case ACPI_REFCLASS_LOCAL:
449		case ACPI_REFCLASS_ARG:
450
451			if (return_desc) {
452				status =
453				    acpi_ds_method_data_get_value(obj_desc->
454								  reference.
455								  class,
456								  obj_desc->
457								  reference.
458								  value,
459								  walk_state,
460								  &obj_desc);
461				if (ACPI_FAILURE(status)) {
462					return_ACPI_STATUS(status);
463				}
464				acpi_ut_remove_reference(obj_desc);
465			} else {
466				status =
467				    acpi_ds_method_data_get_node(obj_desc->
468								 reference.
469								 class,
470								 obj_desc->
471								 reference.
472								 value,
473								 walk_state,
474								 &node);
475				if (ACPI_FAILURE(status)) {
476					return_ACPI_STATUS(status);
477				}
478
479				obj_desc = acpi_ns_get_attached_object(node);
480				if (!obj_desc) {
481					type = ACPI_TYPE_ANY;
482					goto exit;
483				}
484			}
485			break;
486
487		case ACPI_REFCLASS_DEBUG:
488
489			/* The Debug Object is of type "DebugObject" */
490
491			type = ACPI_TYPE_DEBUG_OBJECT;
492			goto exit;
493
494		default:
495
496			ACPI_ERROR((AE_INFO,
497				    "Unknown Reference Class 0x%2.2X",
498				    obj_desc->reference.class));
499			return_ACPI_STATUS(AE_AML_INTERNAL);
500		}
501	}
502
503	/*
504	 * Now we are guaranteed to have an object that has not been created
505	 * via the ref_of or Index operators.
506	 */
507	type = obj_desc->common.type;
508
509exit:
510	/* Convert internal types to external types */
511
512	switch (type) {
513	case ACPI_TYPE_LOCAL_REGION_FIELD:
514	case ACPI_TYPE_LOCAL_BANK_FIELD:
515	case ACPI_TYPE_LOCAL_INDEX_FIELD:
516
517		type = ACPI_TYPE_FIELD_UNIT;
518		break;
519
520	case ACPI_TYPE_LOCAL_SCOPE:
521
522		/* Per ACPI Specification, Scope is untyped */
523
524		type = ACPI_TYPE_ANY;
525		break;
526
527	default:
528
529		/* No change to Type required */
530
531		break;
532	}
533
534	*return_type = type;
535	if (return_desc) {
536		*return_desc = obj_desc;
537	}
538	return_ACPI_STATUS(AE_OK);
539}