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v3.1
  1/******************************************************************************
  2 *
  3 * Module Name: dswstate - Dispatcher parse tree walk management routines
  4 *
  5 *****************************************************************************/
  6
  7/*
  8 * Copyright (C) 2000 - 2011, 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 "acdispat.h"
 48#include "acnamesp.h"
 49
 50#define _COMPONENT          ACPI_DISPATCHER
 51ACPI_MODULE_NAME("dswstate")
 52
 53  /* Local prototypes */
 54static acpi_status acpi_ds_result_stack_push(struct acpi_walk_state *ws);
 55static acpi_status acpi_ds_result_stack_pop(struct acpi_walk_state *ws);
 
 56
 57/*******************************************************************************
 58 *
 59 * FUNCTION:    acpi_ds_result_pop
 60 *
 61 * PARAMETERS:  Object              - Where to return the popped object
 62 *              walk_state          - Current Walk state
 63 *
 64 * RETURN:      Status
 65 *
 66 * DESCRIPTION: Pop an object off the top of this walk's result stack
 67 *
 68 ******************************************************************************/
 69
 70acpi_status
 71acpi_ds_result_pop(union acpi_operand_object **object,
 72		   struct acpi_walk_state *walk_state)
 73{
 74	u32 index;
 75	union acpi_generic_state *state;
 76	acpi_status status;
 77
 78	ACPI_FUNCTION_NAME(ds_result_pop);
 79
 80	state = walk_state->results;
 81
 82	/* Incorrect state of result stack */
 83
 84	if (state && !walk_state->result_count) {
 85		ACPI_ERROR((AE_INFO, "No results on result stack"));
 86		return (AE_AML_INTERNAL);
 87	}
 88
 89	if (!state && walk_state->result_count) {
 90		ACPI_ERROR((AE_INFO, "No result state for result stack"));
 91		return (AE_AML_INTERNAL);
 92	}
 93
 94	/* Empty result stack */
 95
 96	if (!state) {
 97		ACPI_ERROR((AE_INFO, "Result stack is empty! State=%p",
 98			    walk_state));
 99		return (AE_AML_NO_RETURN_VALUE);
100	}
101
102	/* Return object of the top element and clean that top element result stack */
103
104	walk_state->result_count--;
105	index = (u32)walk_state->result_count % ACPI_RESULTS_FRAME_OBJ_NUM;
106
107	*object = state->results.obj_desc[index];
108	if (!*object) {
109		ACPI_ERROR((AE_INFO,
110			    "No result objects on result stack, State=%p",
111			    walk_state));
112		return (AE_AML_NO_RETURN_VALUE);
113	}
114
115	state->results.obj_desc[index] = NULL;
116	if (index == 0) {
117		status = acpi_ds_result_stack_pop(walk_state);
118		if (ACPI_FAILURE(status)) {
119			return (status);
120		}
121	}
122
123	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
124			  "Obj=%p [%s] Index=%X State=%p Num=%X\n", *object,
125			  acpi_ut_get_object_type_name(*object),
126			  index, walk_state, walk_state->result_count));
127
128	return (AE_OK);
129}
130
131/*******************************************************************************
132 *
133 * FUNCTION:    acpi_ds_result_push
134 *
135 * PARAMETERS:  Object              - Where to return the popped object
136 *              walk_state          - Current Walk state
137 *
138 * RETURN:      Status
139 *
140 * DESCRIPTION: Push an object onto the current result stack
141 *
142 ******************************************************************************/
143
144acpi_status
145acpi_ds_result_push(union acpi_operand_object * object,
146		    struct acpi_walk_state * walk_state)
147{
148	union acpi_generic_state *state;
149	acpi_status status;
150	u32 index;
151
152	ACPI_FUNCTION_NAME(ds_result_push);
153
154	if (walk_state->result_count > walk_state->result_size) {
155		ACPI_ERROR((AE_INFO, "Result stack is full"));
156		return (AE_AML_INTERNAL);
157	} else if (walk_state->result_count == walk_state->result_size) {
158
159		/* Extend the result stack */
160
161		status = acpi_ds_result_stack_push(walk_state);
162		if (ACPI_FAILURE(status)) {
163			ACPI_ERROR((AE_INFO,
164				    "Failed to extend the result stack"));
165			return (status);
166		}
167	}
168
169	if (!(walk_state->result_count < walk_state->result_size)) {
170		ACPI_ERROR((AE_INFO, "No free elements in result stack"));
171		return (AE_AML_INTERNAL);
172	}
173
174	state = walk_state->results;
175	if (!state) {
176		ACPI_ERROR((AE_INFO, "No result stack frame during push"));
177		return (AE_AML_INTERNAL);
178	}
179
180	if (!object) {
181		ACPI_ERROR((AE_INFO,
182			    "Null Object! Obj=%p State=%p Num=%u",
183			    object, walk_state, walk_state->result_count));
184		return (AE_BAD_PARAMETER);
185	}
186
187	/* Assign the address of object to the top free element of result stack */
188
189	index = (u32)walk_state->result_count % ACPI_RESULTS_FRAME_OBJ_NUM;
190	state->results.obj_desc[index] = object;
191	walk_state->result_count++;
192
193	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p Num=%X Cur=%X\n",
194			  object,
195			  acpi_ut_get_object_type_name((union
196							acpi_operand_object *)
197						       object), walk_state,
198			  walk_state->result_count,
199			  walk_state->current_result));
200
201	return (AE_OK);
202}
203
204/*******************************************************************************
205 *
206 * FUNCTION:    acpi_ds_result_stack_push
207 *
208 * PARAMETERS:  walk_state          - Current Walk state
209 *
210 * RETURN:      Status
211 *
212 * DESCRIPTION: Push an object onto the walk_state result stack
213 *
214 ******************************************************************************/
215
216static acpi_status acpi_ds_result_stack_push(struct acpi_walk_state *walk_state)
217{
218	union acpi_generic_state *state;
219
220	ACPI_FUNCTION_NAME(ds_result_stack_push);
221
222	/* Check for stack overflow */
223
224	if (((u32) walk_state->result_size + ACPI_RESULTS_FRAME_OBJ_NUM) >
225	    ACPI_RESULTS_OBJ_NUM_MAX) {
226		ACPI_ERROR((AE_INFO, "Result stack overflow: State=%p Num=%u",
227			    walk_state, walk_state->result_size));
228		return (AE_STACK_OVERFLOW);
229	}
230
231	state = acpi_ut_create_generic_state();
232	if (!state) {
233		return (AE_NO_MEMORY);
234	}
235
236	state->common.descriptor_type = ACPI_DESC_TYPE_STATE_RESULT;
237	acpi_ut_push_generic_state(&walk_state->results, state);
238
239	/* Increase the length of the result stack by the length of frame */
240
241	walk_state->result_size += ACPI_RESULTS_FRAME_OBJ_NUM;
242
243	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Results=%p State=%p\n",
244			  state, walk_state));
245
246	return (AE_OK);
247}
248
249/*******************************************************************************
250 *
251 * FUNCTION:    acpi_ds_result_stack_pop
252 *
253 * PARAMETERS:  walk_state          - Current Walk state
254 *
255 * RETURN:      Status
256 *
257 * DESCRIPTION: Pop an object off of the walk_state result stack
258 *
259 ******************************************************************************/
260
261static acpi_status acpi_ds_result_stack_pop(struct acpi_walk_state *walk_state)
262{
263	union acpi_generic_state *state;
264
265	ACPI_FUNCTION_NAME(ds_result_stack_pop);
266
267	/* Check for stack underflow */
268
269	if (walk_state->results == NULL) {
270		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
271				  "Result stack underflow - State=%p\n",
272				  walk_state));
273		return (AE_AML_NO_OPERAND);
274	}
275
276	if (walk_state->result_size < ACPI_RESULTS_FRAME_OBJ_NUM) {
277		ACPI_ERROR((AE_INFO, "Insufficient result stack size"));
278		return (AE_AML_INTERNAL);
279	}
280
281	state = acpi_ut_pop_generic_state(&walk_state->results);
282	acpi_ut_delete_generic_state(state);
283
284	/* Decrease the length of result stack by the length of frame */
285
286	walk_state->result_size -= ACPI_RESULTS_FRAME_OBJ_NUM;
287
288	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
289			  "Result=%p RemainingResults=%X State=%p\n",
290			  state, walk_state->result_count, walk_state));
291
292	return (AE_OK);
293}
294
295/*******************************************************************************
296 *
297 * FUNCTION:    acpi_ds_obj_stack_push
298 *
299 * PARAMETERS:  Object              - Object to push
300 *              walk_state          - Current Walk state
301 *
302 * RETURN:      Status
303 *
304 * DESCRIPTION: Push an object onto this walk's object/operand stack
305 *
306 ******************************************************************************/
307
308acpi_status
309acpi_ds_obj_stack_push(void *object, struct acpi_walk_state * walk_state)
310{
311	ACPI_FUNCTION_NAME(ds_obj_stack_push);
312
313	/* Check for stack overflow */
314
315	if (walk_state->num_operands >= ACPI_OBJ_NUM_OPERANDS) {
316		ACPI_ERROR((AE_INFO,
317			    "Object stack overflow! Obj=%p State=%p #Ops=%u",
318			    object, walk_state, walk_state->num_operands));
319		return (AE_STACK_OVERFLOW);
320	}
321
322	/* Put the object onto the stack */
323
324	walk_state->operands[walk_state->operand_index] = object;
325	walk_state->num_operands++;
326
327	/* For the usual order of filling the operand stack */
328
329	walk_state->operand_index++;
330
331	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p #Ops=%X\n",
332			  object,
333			  acpi_ut_get_object_type_name((union
334							acpi_operand_object *)
335						       object), walk_state,
336			  walk_state->num_operands));
337
338	return (AE_OK);
339}
340
341/*******************************************************************************
342 *
343 * FUNCTION:    acpi_ds_obj_stack_pop
344 *
345 * PARAMETERS:  pop_count           - Number of objects/entries to pop
346 *              walk_state          - Current Walk state
347 *
348 * RETURN:      Status
349 *
350 * DESCRIPTION: Pop this walk's object stack.  Objects on the stack are NOT
351 *              deleted by this routine.
352 *
353 ******************************************************************************/
354
355acpi_status
356acpi_ds_obj_stack_pop(u32 pop_count, struct acpi_walk_state * walk_state)
357{
358	u32 i;
359
360	ACPI_FUNCTION_NAME(ds_obj_stack_pop);
361
362	for (i = 0; i < pop_count; i++) {
363
364		/* Check for stack underflow */
365
366		if (walk_state->num_operands == 0) {
367			ACPI_ERROR((AE_INFO,
368				    "Object stack underflow! Count=%X State=%p #Ops=%u",
369				    pop_count, walk_state,
370				    walk_state->num_operands));
371			return (AE_STACK_UNDERFLOW);
372		}
373
374		/* Just set the stack entry to null */
375
376		walk_state->num_operands--;
377		walk_state->operands[walk_state->num_operands] = NULL;
378	}
379
380	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Count=%X State=%p #Ops=%u\n",
381			  pop_count, walk_state, walk_state->num_operands));
382
383	return (AE_OK);
384}
385
386/*******************************************************************************
387 *
388 * FUNCTION:    acpi_ds_obj_stack_pop_and_delete
389 *
390 * PARAMETERS:  pop_count           - Number of objects/entries to pop
391 *              walk_state          - Current Walk state
392 *
393 * RETURN:      Status
394 *
395 * DESCRIPTION: Pop this walk's object stack and delete each object that is
396 *              popped off.
397 *
398 ******************************************************************************/
399
400void
401acpi_ds_obj_stack_pop_and_delete(u32 pop_count,
402				 struct acpi_walk_state *walk_state)
403{
404	s32 i;
405	union acpi_operand_object *obj_desc;
406
407	ACPI_FUNCTION_NAME(ds_obj_stack_pop_and_delete);
408
409	if (pop_count == 0) {
410		return;
411	}
412
413	for (i = (s32) pop_count - 1; i >= 0; i--) {
414		if (walk_state->num_operands == 0) {
415			return;
416		}
417
418		/* Pop the stack and delete an object if present in this stack entry */
419
420		walk_state->num_operands--;
421		obj_desc = walk_state->operands[i];
422		if (obj_desc) {
423			acpi_ut_remove_reference(walk_state->operands[i]);
424			walk_state->operands[i] = NULL;
425		}
426	}
427
428	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Count=%X State=%p #Ops=%X\n",
429			  pop_count, walk_state, walk_state->num_operands));
430}
431
432/*******************************************************************************
433 *
434 * FUNCTION:    acpi_ds_get_current_walk_state
435 *
436 * PARAMETERS:  Thread          - Get current active state for this Thread
437 *
438 * RETURN:      Pointer to the current walk state
439 *
440 * DESCRIPTION: Get the walk state that is at the head of the list (the "current"
441 *              walk state.)
442 *
443 ******************************************************************************/
444
445struct acpi_walk_state *acpi_ds_get_current_walk_state(struct acpi_thread_state
446						       *thread)
447{
448	ACPI_FUNCTION_NAME(ds_get_current_walk_state);
449
450	if (!thread) {
451		return (NULL);
452	}
453
454	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "Current WalkState %p\n",
455			  thread->walk_state_list));
456
457	return (thread->walk_state_list);
458}
459
460/*******************************************************************************
461 *
462 * FUNCTION:    acpi_ds_push_walk_state
463 *
464 * PARAMETERS:  walk_state      - State to push
465 *              Thread          - Thread state object
466 *
467 * RETURN:      None
468 *
469 * DESCRIPTION: Place the Thread state at the head of the state list
470 *
471 ******************************************************************************/
472
473void
474acpi_ds_push_walk_state(struct acpi_walk_state *walk_state,
475			struct acpi_thread_state *thread)
476{
477	ACPI_FUNCTION_TRACE(ds_push_walk_state);
478
479	walk_state->next = thread->walk_state_list;
480	thread->walk_state_list = walk_state;
481
482	return_VOID;
483}
484
485/*******************************************************************************
486 *
487 * FUNCTION:    acpi_ds_pop_walk_state
488 *
489 * PARAMETERS:  Thread      - Current thread state
490 *
491 * RETURN:      A walk_state object popped from the thread's stack
492 *
493 * DESCRIPTION: Remove and return the walkstate object that is at the head of
494 *              the walk stack for the given walk list.  NULL indicates that
495 *              the list is empty.
496 *
497 ******************************************************************************/
498
499struct acpi_walk_state *acpi_ds_pop_walk_state(struct acpi_thread_state *thread)
500{
501	struct acpi_walk_state *walk_state;
502
503	ACPI_FUNCTION_TRACE(ds_pop_walk_state);
504
505	walk_state = thread->walk_state_list;
506
507	if (walk_state) {
508
509		/* Next walk state becomes the current walk state */
510
511		thread->walk_state_list = walk_state->next;
512
513		/*
514		 * Don't clear the NEXT field, this serves as an indicator
515		 * that there is a parent WALK STATE
516		 * Do Not: walk_state->Next = NULL;
517		 */
518	}
519
520	return_PTR(walk_state);
521}
522
523/*******************************************************************************
524 *
525 * FUNCTION:    acpi_ds_create_walk_state
526 *
527 * PARAMETERS:  owner_id        - ID for object creation
528 *              Origin          - Starting point for this walk
529 *              method_desc     - Method object
530 *              Thread          - Current thread state
531 *
532 * RETURN:      Pointer to the new walk state.
533 *
534 * DESCRIPTION: Allocate and initialize a new walk state.  The current walk
535 *              state is set to this new state.
536 *
537 ******************************************************************************/
538
539struct acpi_walk_state *acpi_ds_create_walk_state(acpi_owner_id owner_id, union acpi_parse_object
540						  *origin, union acpi_operand_object
541						  *method_desc, struct acpi_thread_state
 
 
 
542						  *thread)
543{
544	struct acpi_walk_state *walk_state;
545
546	ACPI_FUNCTION_TRACE(ds_create_walk_state);
547
548	walk_state = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_walk_state));
549	if (!walk_state) {
550		return_PTR(NULL);
551	}
552
553	walk_state->descriptor_type = ACPI_DESC_TYPE_WALK;
554	walk_state->method_desc = method_desc;
555	walk_state->owner_id = owner_id;
556	walk_state->origin = origin;
557	walk_state->thread = thread;
558
559	walk_state->parser_state.start_op = origin;
560
561	/* Init the method args/local */
562
563#if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))
564	acpi_ds_method_data_init(walk_state);
565#endif
566
567	/* Put the new state at the head of the walk list */
568
569	if (thread) {
570		acpi_ds_push_walk_state(walk_state, thread);
571	}
572
573	return_PTR(walk_state);
574}
575
576/*******************************************************************************
577 *
578 * FUNCTION:    acpi_ds_init_aml_walk
579 *
580 * PARAMETERS:  walk_state      - New state to be initialized
581 *              Op              - Current parse op
582 *              method_node     - Control method NS node, if any
583 *              aml_start       - Start of AML
584 *              aml_length      - Length of AML
585 *              Info            - Method info block (params, etc.)
586 *              pass_number     - 1, 2, or 3
587 *
588 * RETURN:      Status
589 *
590 * DESCRIPTION: Initialize a walk state for a pass 1 or 2 parse tree walk
591 *
592 ******************************************************************************/
593
594acpi_status
595acpi_ds_init_aml_walk(struct acpi_walk_state *walk_state,
596		      union acpi_parse_object *op,
597		      struct acpi_namespace_node *method_node,
598		      u8 * aml_start,
599		      u32 aml_length,
600		      struct acpi_evaluate_info *info, u8 pass_number)
601{
602	acpi_status status;
603	struct acpi_parse_state *parser_state = &walk_state->parser_state;
604	union acpi_parse_object *extra_op;
605
606	ACPI_FUNCTION_TRACE(ds_init_aml_walk);
607
608	walk_state->parser_state.aml =
609	    walk_state->parser_state.aml_start = aml_start;
610	walk_state->parser_state.aml_end =
611	    walk_state->parser_state.pkg_end = aml_start + aml_length;
612
613	/* The next_op of the next_walk will be the beginning of the method */
614
615	walk_state->next_op = NULL;
616	walk_state->pass_number = pass_number;
617
618	if (info) {
619		walk_state->params = info->parameters;
620		walk_state->caller_return_desc = &info->return_object;
621	}
622
623	status = acpi_ps_init_scope(&walk_state->parser_state, op);
624	if (ACPI_FAILURE(status)) {
625		return_ACPI_STATUS(status);
626	}
627
628	if (method_node) {
629		walk_state->parser_state.start_node = method_node;
630		walk_state->walk_type = ACPI_WALK_METHOD;
631		walk_state->method_node = method_node;
632		walk_state->method_desc =
633		    acpi_ns_get_attached_object(method_node);
634
635		/* Push start scope on scope stack and make it current  */
636
637		status =
638		    acpi_ds_scope_stack_push(method_node, ACPI_TYPE_METHOD,
639					     walk_state);
640		if (ACPI_FAILURE(status)) {
641			return_ACPI_STATUS(status);
642		}
643
644		/* Init the method arguments */
645
646		status = acpi_ds_method_data_init_args(walk_state->params,
647						       ACPI_METHOD_NUM_ARGS,
648						       walk_state);
649		if (ACPI_FAILURE(status)) {
650			return_ACPI_STATUS(status);
651		}
652	} else {
653		/*
654		 * Setup the current scope.
655		 * Find a Named Op that has a namespace node associated with it.
656		 * search upwards from this Op.  Current scope is the first
657		 * Op with a namespace node.
658		 */
659		extra_op = parser_state->start_op;
660		while (extra_op && !extra_op->common.node) {
661			extra_op = extra_op->common.parent;
662		}
663
664		if (!extra_op) {
665			parser_state->start_node = NULL;
666		} else {
667			parser_state->start_node = extra_op->common.node;
668		}
669
670		if (parser_state->start_node) {
671
672			/* Push start scope on scope stack and make it current  */
673
674			status =
675			    acpi_ds_scope_stack_push(parser_state->start_node,
676						     parser_state->start_node->
677						     type, walk_state);
678			if (ACPI_FAILURE(status)) {
679				return_ACPI_STATUS(status);
680			}
681		}
682	}
683
684	status = acpi_ds_init_callbacks(walk_state, pass_number);
685	return_ACPI_STATUS(status);
686}
687
688/*******************************************************************************
689 *
690 * FUNCTION:    acpi_ds_delete_walk_state
691 *
692 * PARAMETERS:  walk_state      - State to delete
693 *
694 * RETURN:      Status
695 *
696 * DESCRIPTION: Delete a walk state including all internal data structures
697 *
698 ******************************************************************************/
699
700void acpi_ds_delete_walk_state(struct acpi_walk_state *walk_state)
701{
702	union acpi_generic_state *state;
703
704	ACPI_FUNCTION_TRACE_PTR(ds_delete_walk_state, walk_state);
705
706	if (!walk_state) {
707		return;
708	}
709
710	if (walk_state->descriptor_type != ACPI_DESC_TYPE_WALK) {
711		ACPI_ERROR((AE_INFO, "%p is not a valid walk state",
712			    walk_state));
713		return;
714	}
715
716	/* There should not be any open scopes */
717
718	if (walk_state->parser_state.scope) {
719		ACPI_ERROR((AE_INFO, "%p walk still has a scope list",
720			    walk_state));
721		acpi_ps_cleanup_scope(&walk_state->parser_state);
722	}
723
724	/* Always must free any linked control states */
725
726	while (walk_state->control_state) {
727		state = walk_state->control_state;
728		walk_state->control_state = state->common.next;
729
730		acpi_ut_delete_generic_state(state);
731	}
732
733	/* Always must free any linked parse states */
734
735	while (walk_state->scope_info) {
736		state = walk_state->scope_info;
737		walk_state->scope_info = state->common.next;
738
739		acpi_ut_delete_generic_state(state);
740	}
741
742	/* Always must free any stacked result states */
743
744	while (walk_state->results) {
745		state = walk_state->results;
746		walk_state->results = state->common.next;
747
748		acpi_ut_delete_generic_state(state);
749	}
750
751	ACPI_FREE(walk_state);
752	return_VOID;
753}
v4.6
  1/******************************************************************************
  2 *
  3 * Module Name: dswstate - Dispatcher parse tree walk management routines
  4 *
  5 *****************************************************************************/
  6
  7/*
  8 * Copyright (C) 2000 - 2016, 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 "acdispat.h"
 48#include "acnamesp.h"
 49
 50#define _COMPONENT          ACPI_DISPATCHER
 51ACPI_MODULE_NAME("dswstate")
 52
 53  /* Local prototypes */
 54static acpi_status
 55acpi_ds_result_stack_push(struct acpi_walk_state *walk_state);
 56static acpi_status acpi_ds_result_stack_pop(struct acpi_walk_state *walk_state);
 57
 58/*******************************************************************************
 59 *
 60 * FUNCTION:    acpi_ds_result_pop
 61 *
 62 * PARAMETERS:  object              - Where to return the popped object
 63 *              walk_state          - Current Walk state
 64 *
 65 * RETURN:      Status
 66 *
 67 * DESCRIPTION: Pop an object off the top of this walk's result stack
 68 *
 69 ******************************************************************************/
 70
 71acpi_status
 72acpi_ds_result_pop(union acpi_operand_object **object,
 73		   struct acpi_walk_state *walk_state)
 74{
 75	u32 index;
 76	union acpi_generic_state *state;
 77	acpi_status status;
 78
 79	ACPI_FUNCTION_NAME(ds_result_pop);
 80
 81	state = walk_state->results;
 82
 83	/* Incorrect state of result stack */
 84
 85	if (state && !walk_state->result_count) {
 86		ACPI_ERROR((AE_INFO, "No results on result stack"));
 87		return (AE_AML_INTERNAL);
 88	}
 89
 90	if (!state && walk_state->result_count) {
 91		ACPI_ERROR((AE_INFO, "No result state for result stack"));
 92		return (AE_AML_INTERNAL);
 93	}
 94
 95	/* Empty result stack */
 96
 97	if (!state) {
 98		ACPI_ERROR((AE_INFO, "Result stack is empty! State=%p",
 99			    walk_state));
100		return (AE_AML_NO_RETURN_VALUE);
101	}
102
103	/* Return object of the top element and clean that top element result stack */
104
105	walk_state->result_count--;
106	index = (u32)walk_state->result_count % ACPI_RESULTS_FRAME_OBJ_NUM;
107
108	*object = state->results.obj_desc[index];
109	if (!*object) {
110		ACPI_ERROR((AE_INFO,
111			    "No result objects on result stack, State=%p",
112			    walk_state));
113		return (AE_AML_NO_RETURN_VALUE);
114	}
115
116	state->results.obj_desc[index] = NULL;
117	if (index == 0) {
118		status = acpi_ds_result_stack_pop(walk_state);
119		if (ACPI_FAILURE(status)) {
120			return (status);
121		}
122	}
123
124	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
125			  "Obj=%p [%s] Index=%X State=%p Num=%X\n", *object,
126			  acpi_ut_get_object_type_name(*object),
127			  index, walk_state, walk_state->result_count));
128
129	return (AE_OK);
130}
131
132/*******************************************************************************
133 *
134 * FUNCTION:    acpi_ds_result_push
135 *
136 * PARAMETERS:  object              - Where to return the popped object
137 *              walk_state          - Current Walk state
138 *
139 * RETURN:      Status
140 *
141 * DESCRIPTION: Push an object onto the current result stack
142 *
143 ******************************************************************************/
144
145acpi_status
146acpi_ds_result_push(union acpi_operand_object * object,
147		    struct acpi_walk_state * walk_state)
148{
149	union acpi_generic_state *state;
150	acpi_status status;
151	u32 index;
152
153	ACPI_FUNCTION_NAME(ds_result_push);
154
155	if (walk_state->result_count > walk_state->result_size) {
156		ACPI_ERROR((AE_INFO, "Result stack is full"));
157		return (AE_AML_INTERNAL);
158	} else if (walk_state->result_count == walk_state->result_size) {
159
160		/* Extend the result stack */
161
162		status = acpi_ds_result_stack_push(walk_state);
163		if (ACPI_FAILURE(status)) {
164			ACPI_ERROR((AE_INFO,
165				    "Failed to extend the result stack"));
166			return (status);
167		}
168	}
169
170	if (!(walk_state->result_count < walk_state->result_size)) {
171		ACPI_ERROR((AE_INFO, "No free elements in result stack"));
172		return (AE_AML_INTERNAL);
173	}
174
175	state = walk_state->results;
176	if (!state) {
177		ACPI_ERROR((AE_INFO, "No result stack frame during push"));
178		return (AE_AML_INTERNAL);
179	}
180
181	if (!object) {
182		ACPI_ERROR((AE_INFO,
183			    "Null Object! Obj=%p State=%p Num=%u",
184			    object, walk_state, walk_state->result_count));
185		return (AE_BAD_PARAMETER);
186	}
187
188	/* Assign the address of object to the top free element of result stack */
189
190	index = (u32)walk_state->result_count % ACPI_RESULTS_FRAME_OBJ_NUM;
191	state->results.obj_desc[index] = object;
192	walk_state->result_count++;
193
194	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p Num=%X Cur=%X\n",
195			  object,
196			  acpi_ut_get_object_type_name((union
197							acpi_operand_object *)
198						       object), walk_state,
199			  walk_state->result_count,
200			  walk_state->current_result));
201
202	return (AE_OK);
203}
204
205/*******************************************************************************
206 *
207 * FUNCTION:    acpi_ds_result_stack_push
208 *
209 * PARAMETERS:  walk_state          - Current Walk state
210 *
211 * RETURN:      Status
212 *
213 * DESCRIPTION: Push an object onto the walk_state result stack
214 *
215 ******************************************************************************/
216
217static acpi_status acpi_ds_result_stack_push(struct acpi_walk_state *walk_state)
218{
219	union acpi_generic_state *state;
220
221	ACPI_FUNCTION_NAME(ds_result_stack_push);
222
223	/* Check for stack overflow */
224
225	if (((u32) walk_state->result_size + ACPI_RESULTS_FRAME_OBJ_NUM) >
226	    ACPI_RESULTS_OBJ_NUM_MAX) {
227		ACPI_ERROR((AE_INFO, "Result stack overflow: State=%p Num=%u",
228			    walk_state, walk_state->result_size));
229		return (AE_STACK_OVERFLOW);
230	}
231
232	state = acpi_ut_create_generic_state();
233	if (!state) {
234		return (AE_NO_MEMORY);
235	}
236
237	state->common.descriptor_type = ACPI_DESC_TYPE_STATE_RESULT;
238	acpi_ut_push_generic_state(&walk_state->results, state);
239
240	/* Increase the length of the result stack by the length of frame */
241
242	walk_state->result_size += ACPI_RESULTS_FRAME_OBJ_NUM;
243
244	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Results=%p State=%p\n",
245			  state, walk_state));
246
247	return (AE_OK);
248}
249
250/*******************************************************************************
251 *
252 * FUNCTION:    acpi_ds_result_stack_pop
253 *
254 * PARAMETERS:  walk_state          - Current Walk state
255 *
256 * RETURN:      Status
257 *
258 * DESCRIPTION: Pop an object off of the walk_state result stack
259 *
260 ******************************************************************************/
261
262static acpi_status acpi_ds_result_stack_pop(struct acpi_walk_state *walk_state)
263{
264	union acpi_generic_state *state;
265
266	ACPI_FUNCTION_NAME(ds_result_stack_pop);
267
268	/* Check for stack underflow */
269
270	if (walk_state->results == NULL) {
271		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
272				  "Result stack underflow - State=%p\n",
273				  walk_state));
274		return (AE_AML_NO_OPERAND);
275	}
276
277	if (walk_state->result_size < ACPI_RESULTS_FRAME_OBJ_NUM) {
278		ACPI_ERROR((AE_INFO, "Insufficient result stack size"));
279		return (AE_AML_INTERNAL);
280	}
281
282	state = acpi_ut_pop_generic_state(&walk_state->results);
283	acpi_ut_delete_generic_state(state);
284
285	/* Decrease the length of result stack by the length of frame */
286
287	walk_state->result_size -= ACPI_RESULTS_FRAME_OBJ_NUM;
288
289	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
290			  "Result=%p RemainingResults=%X State=%p\n",
291			  state, walk_state->result_count, walk_state));
292
293	return (AE_OK);
294}
295
296/*******************************************************************************
297 *
298 * FUNCTION:    acpi_ds_obj_stack_push
299 *
300 * PARAMETERS:  object              - Object to push
301 *              walk_state          - Current Walk state
302 *
303 * RETURN:      Status
304 *
305 * DESCRIPTION: Push an object onto this walk's object/operand stack
306 *
307 ******************************************************************************/
308
309acpi_status
310acpi_ds_obj_stack_push(void *object, struct acpi_walk_state * walk_state)
311{
312	ACPI_FUNCTION_NAME(ds_obj_stack_push);
313
314	/* Check for stack overflow */
315
316	if (walk_state->num_operands >= ACPI_OBJ_NUM_OPERANDS) {
317		ACPI_ERROR((AE_INFO,
318			    "Object stack overflow! Obj=%p State=%p #Ops=%u",
319			    object, walk_state, walk_state->num_operands));
320		return (AE_STACK_OVERFLOW);
321	}
322
323	/* Put the object onto the stack */
324
325	walk_state->operands[walk_state->operand_index] = object;
326	walk_state->num_operands++;
327
328	/* For the usual order of filling the operand stack */
329
330	walk_state->operand_index++;
331
332	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p #Ops=%X\n",
333			  object,
334			  acpi_ut_get_object_type_name((union
335							acpi_operand_object *)
336						       object), walk_state,
337			  walk_state->num_operands));
338
339	return (AE_OK);
340}
341
342/*******************************************************************************
343 *
344 * FUNCTION:    acpi_ds_obj_stack_pop
345 *
346 * PARAMETERS:  pop_count           - Number of objects/entries to pop
347 *              walk_state          - Current Walk state
348 *
349 * RETURN:      Status
350 *
351 * DESCRIPTION: Pop this walk's object stack. Objects on the stack are NOT
352 *              deleted by this routine.
353 *
354 ******************************************************************************/
355
356acpi_status
357acpi_ds_obj_stack_pop(u32 pop_count, struct acpi_walk_state * walk_state)
358{
359	u32 i;
360
361	ACPI_FUNCTION_NAME(ds_obj_stack_pop);
362
363	for (i = 0; i < pop_count; i++) {
364
365		/* Check for stack underflow */
366
367		if (walk_state->num_operands == 0) {
368			ACPI_ERROR((AE_INFO,
369				    "Object stack underflow! Count=%X State=%p #Ops=%u",
370				    pop_count, walk_state,
371				    walk_state->num_operands));
372			return (AE_STACK_UNDERFLOW);
373		}
374
375		/* Just set the stack entry to null */
376
377		walk_state->num_operands--;
378		walk_state->operands[walk_state->num_operands] = NULL;
379	}
380
381	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Count=%X State=%p #Ops=%u\n",
382			  pop_count, walk_state, walk_state->num_operands));
383
384	return (AE_OK);
385}
386
387/*******************************************************************************
388 *
389 * FUNCTION:    acpi_ds_obj_stack_pop_and_delete
390 *
391 * PARAMETERS:  pop_count           - Number of objects/entries to pop
392 *              walk_state          - Current Walk state
393 *
394 * RETURN:      Status
395 *
396 * DESCRIPTION: Pop this walk's object stack and delete each object that is
397 *              popped off.
398 *
399 ******************************************************************************/
400
401void
402acpi_ds_obj_stack_pop_and_delete(u32 pop_count,
403				 struct acpi_walk_state *walk_state)
404{
405	s32 i;
406	union acpi_operand_object *obj_desc;
407
408	ACPI_FUNCTION_NAME(ds_obj_stack_pop_and_delete);
409
410	if (pop_count == 0) {
411		return;
412	}
413
414	for (i = (s32) pop_count - 1; i >= 0; i--) {
415		if (walk_state->num_operands == 0) {
416			return;
417		}
418
419		/* Pop the stack and delete an object if present in this stack entry */
420
421		walk_state->num_operands--;
422		obj_desc = walk_state->operands[i];
423		if (obj_desc) {
424			acpi_ut_remove_reference(walk_state->operands[i]);
425			walk_state->operands[i] = NULL;
426		}
427	}
428
429	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Count=%X State=%p #Ops=%X\n",
430			  pop_count, walk_state, walk_state->num_operands));
431}
432
433/*******************************************************************************
434 *
435 * FUNCTION:    acpi_ds_get_current_walk_state
436 *
437 * PARAMETERS:  thread          - Get current active state for this Thread
438 *
439 * RETURN:      Pointer to the current walk state
440 *
441 * DESCRIPTION: Get the walk state that is at the head of the list (the "current"
442 *              walk state.)
443 *
444 ******************************************************************************/
445
446struct acpi_walk_state *acpi_ds_get_current_walk_state(struct acpi_thread_state
447						       *thread)
448{
449	ACPI_FUNCTION_NAME(ds_get_current_walk_state);
450
451	if (!thread) {
452		return (NULL);
453	}
454
455	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "Current WalkState %p\n",
456			  thread->walk_state_list));
457
458	return (thread->walk_state_list);
459}
460
461/*******************************************************************************
462 *
463 * FUNCTION:    acpi_ds_push_walk_state
464 *
465 * PARAMETERS:  walk_state      - State to push
466 *              thread          - Thread state object
467 *
468 * RETURN:      None
469 *
470 * DESCRIPTION: Place the Thread state at the head of the state list
471 *
472 ******************************************************************************/
473
474void
475acpi_ds_push_walk_state(struct acpi_walk_state *walk_state,
476			struct acpi_thread_state *thread)
477{
478	ACPI_FUNCTION_TRACE(ds_push_walk_state);
479
480	walk_state->next = thread->walk_state_list;
481	thread->walk_state_list = walk_state;
482
483	return_VOID;
484}
485
486/*******************************************************************************
487 *
488 * FUNCTION:    acpi_ds_pop_walk_state
489 *
490 * PARAMETERS:  thread      - Current thread state
491 *
492 * RETURN:      A walk_state object popped from the thread's stack
493 *
494 * DESCRIPTION: Remove and return the walkstate object that is at the head of
495 *              the walk stack for the given walk list. NULL indicates that
496 *              the list is empty.
497 *
498 ******************************************************************************/
499
500struct acpi_walk_state *acpi_ds_pop_walk_state(struct acpi_thread_state *thread)
501{
502	struct acpi_walk_state *walk_state;
503
504	ACPI_FUNCTION_TRACE(ds_pop_walk_state);
505
506	walk_state = thread->walk_state_list;
507
508	if (walk_state) {
509
510		/* Next walk state becomes the current walk state */
511
512		thread->walk_state_list = walk_state->next;
513
514		/*
515		 * Don't clear the NEXT field, this serves as an indicator
516		 * that there is a parent WALK STATE
517		 * Do Not: walk_state->Next = NULL;
518		 */
519	}
520
521	return_PTR(walk_state);
522}
523
524/*******************************************************************************
525 *
526 * FUNCTION:    acpi_ds_create_walk_state
527 *
528 * PARAMETERS:  owner_id        - ID for object creation
529 *              origin          - Starting point for this walk
530 *              method_desc     - Method object
531 *              thread          - Current thread state
532 *
533 * RETURN:      Pointer to the new walk state.
534 *
535 * DESCRIPTION: Allocate and initialize a new walk state. The current walk
536 *              state is set to this new state.
537 *
538 ******************************************************************************/
539
540struct acpi_walk_state *acpi_ds_create_walk_state(acpi_owner_id owner_id,
541						  union acpi_parse_object
542						  *origin,
543						  union acpi_operand_object
544						  *method_desc,
545						  struct acpi_thread_state
546						  *thread)
547{
548	struct acpi_walk_state *walk_state;
549
550	ACPI_FUNCTION_TRACE(ds_create_walk_state);
551
552	walk_state = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_walk_state));
553	if (!walk_state) {
554		return_PTR(NULL);
555	}
556
557	walk_state->descriptor_type = ACPI_DESC_TYPE_WALK;
558	walk_state->method_desc = method_desc;
559	walk_state->owner_id = owner_id;
560	walk_state->origin = origin;
561	walk_state->thread = thread;
562
563	walk_state->parser_state.start_op = origin;
564
565	/* Init the method args/local */
566
567#if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))
568	acpi_ds_method_data_init(walk_state);
569#endif
570
571	/* Put the new state at the head of the walk list */
572
573	if (thread) {
574		acpi_ds_push_walk_state(walk_state, thread);
575	}
576
577	return_PTR(walk_state);
578}
579
580/*******************************************************************************
581 *
582 * FUNCTION:    acpi_ds_init_aml_walk
583 *
584 * PARAMETERS:  walk_state      - New state to be initialized
585 *              op              - Current parse op
586 *              method_node     - Control method NS node, if any
587 *              aml_start       - Start of AML
588 *              aml_length      - Length of AML
589 *              info            - Method info block (params, etc.)
590 *              pass_number     - 1, 2, or 3
591 *
592 * RETURN:      Status
593 *
594 * DESCRIPTION: Initialize a walk state for a pass 1 or 2 parse tree walk
595 *
596 ******************************************************************************/
597
598acpi_status
599acpi_ds_init_aml_walk(struct acpi_walk_state *walk_state,
600		      union acpi_parse_object *op,
601		      struct acpi_namespace_node *method_node,
602		      u8 * aml_start,
603		      u32 aml_length,
604		      struct acpi_evaluate_info *info, u8 pass_number)
605{
606	acpi_status status;
607	struct acpi_parse_state *parser_state = &walk_state->parser_state;
608	union acpi_parse_object *extra_op;
609
610	ACPI_FUNCTION_TRACE(ds_init_aml_walk);
611
612	walk_state->parser_state.aml =
613	    walk_state->parser_state.aml_start = aml_start;
614	walk_state->parser_state.aml_end =
615	    walk_state->parser_state.pkg_end = aml_start + aml_length;
616
617	/* The next_op of the next_walk will be the beginning of the method */
618
619	walk_state->next_op = NULL;
620	walk_state->pass_number = pass_number;
621
622	if (info) {
623		walk_state->params = info->parameters;
624		walk_state->caller_return_desc = &info->return_object;
625	}
626
627	status = acpi_ps_init_scope(&walk_state->parser_state, op);
628	if (ACPI_FAILURE(status)) {
629		return_ACPI_STATUS(status);
630	}
631
632	if (method_node) {
633		walk_state->parser_state.start_node = method_node;
634		walk_state->walk_type = ACPI_WALK_METHOD;
635		walk_state->method_node = method_node;
636		walk_state->method_desc =
637		    acpi_ns_get_attached_object(method_node);
638
639		/* Push start scope on scope stack and make it current  */
640
641		status =
642		    acpi_ds_scope_stack_push(method_node, ACPI_TYPE_METHOD,
643					     walk_state);
644		if (ACPI_FAILURE(status)) {
645			return_ACPI_STATUS(status);
646		}
647
648		/* Init the method arguments */
649
650		status = acpi_ds_method_data_init_args(walk_state->params,
651						       ACPI_METHOD_NUM_ARGS,
652						       walk_state);
653		if (ACPI_FAILURE(status)) {
654			return_ACPI_STATUS(status);
655		}
656	} else {
657		/*
658		 * Setup the current scope.
659		 * Find a Named Op that has a namespace node associated with it.
660		 * search upwards from this Op. Current scope is the first
661		 * Op with a namespace node.
662		 */
663		extra_op = parser_state->start_op;
664		while (extra_op && !extra_op->common.node) {
665			extra_op = extra_op->common.parent;
666		}
667
668		if (!extra_op) {
669			parser_state->start_node = NULL;
670		} else {
671			parser_state->start_node = extra_op->common.node;
672		}
673
674		if (parser_state->start_node) {
675
676			/* Push start scope on scope stack and make it current  */
677
678			status =
679			    acpi_ds_scope_stack_push(parser_state->start_node,
680						     parser_state->start_node->
681						     type, walk_state);
682			if (ACPI_FAILURE(status)) {
683				return_ACPI_STATUS(status);
684			}
685		}
686	}
687
688	status = acpi_ds_init_callbacks(walk_state, pass_number);
689	return_ACPI_STATUS(status);
690}
691
692/*******************************************************************************
693 *
694 * FUNCTION:    acpi_ds_delete_walk_state
695 *
696 * PARAMETERS:  walk_state      - State to delete
697 *
698 * RETURN:      Status
699 *
700 * DESCRIPTION: Delete a walk state including all internal data structures
701 *
702 ******************************************************************************/
703
704void acpi_ds_delete_walk_state(struct acpi_walk_state *walk_state)
705{
706	union acpi_generic_state *state;
707
708	ACPI_FUNCTION_TRACE_PTR(ds_delete_walk_state, walk_state);
709
710	if (!walk_state) {
711		return_VOID;
712	}
713
714	if (walk_state->descriptor_type != ACPI_DESC_TYPE_WALK) {
715		ACPI_ERROR((AE_INFO, "%p is not a valid walk state",
716			    walk_state));
717		return_VOID;
718	}
719
720	/* There should not be any open scopes */
721
722	if (walk_state->parser_state.scope) {
723		ACPI_ERROR((AE_INFO, "%p walk still has a scope list",
724			    walk_state));
725		acpi_ps_cleanup_scope(&walk_state->parser_state);
726	}
727
728	/* Always must free any linked control states */
729
730	while (walk_state->control_state) {
731		state = walk_state->control_state;
732		walk_state->control_state = state->common.next;
733
734		acpi_ut_delete_generic_state(state);
735	}
736
737	/* Always must free any linked parse states */
738
739	while (walk_state->scope_info) {
740		state = walk_state->scope_info;
741		walk_state->scope_info = state->common.next;
742
743		acpi_ut_delete_generic_state(state);
744	}
745
746	/* Always must free any stacked result states */
747
748	while (walk_state->results) {
749		state = walk_state->results;
750		walk_state->results = state->common.next;
751
752		acpi_ut_delete_generic_state(state);
753	}
754
755	ACPI_FREE(walk_state);
756	return_VOID;
757}