Pull acpica into release branch
[linux-2.6.git] / drivers / acpi / dispatcher / dswstate.c
1 /******************************************************************************
2  *
3  * Module Name: dswstate - Dispatcher parse tree walk management routines
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2006, R. Byron Moore
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 <acpi/acparser.h>
46 #include <acpi/acdispat.h>
47 #include <acpi/acnamesp.h>
48
49 #define _COMPONENT          ACPI_DISPATCHER
50 ACPI_MODULE_NAME("dswstate")
51
52 /* Local prototypes */
53 #ifdef ACPI_OBSOLETE_FUNCTIONS
54 acpi_status
55 acpi_ds_result_insert(void *object,
56                       u32 index, struct acpi_walk_state *walk_state);
57
58 acpi_status acpi_ds_obj_stack_delete_all(struct acpi_walk_state *walk_state);
59
60 acpi_status
61 acpi_ds_obj_stack_pop_object(union acpi_operand_object **object,
62                              struct acpi_walk_state *walk_state);
63
64 void *acpi_ds_obj_stack_get_value(u32 index,
65                                   struct acpi_walk_state *walk_state);
66 #endif
67
68 #ifdef ACPI_FUTURE_USAGE
69 /*******************************************************************************
70  *
71  * FUNCTION:    acpi_ds_result_remove
72  *
73  * PARAMETERS:  Object              - Where to return the popped object
74  *              Index               - Where to extract the object
75  *              walk_state          - Current Walk state
76  *
77  * RETURN:      Status
78  *
79  * DESCRIPTION: Pop an object off the bottom of this walk's result stack.  In
80  *              other words, this is a FIFO.
81  *
82  ******************************************************************************/
83
84 acpi_status
85 acpi_ds_result_remove(union acpi_operand_object **object,
86                       u32 index, struct acpi_walk_state *walk_state)
87 {
88         union acpi_generic_state *state;
89
90         ACPI_FUNCTION_NAME(ds_result_remove);
91
92         state = walk_state->results;
93         if (!state) {
94                 ACPI_ERROR((AE_INFO, "No result object pushed! State=%p",
95                             walk_state));
96                 return (AE_NOT_EXIST);
97         }
98
99         if (index >= ACPI_OBJ_MAX_OPERAND) {
100                 ACPI_ERROR((AE_INFO,
101                             "Index out of range: %X State=%p Num=%X",
102                             index, walk_state, state->results.num_results));
103         }
104
105         /* Check for a valid result object */
106
107         if (!state->results.obj_desc[index]) {
108                 ACPI_ERROR((AE_INFO,
109                             "Null operand! State=%p #Ops=%X, Index=%X",
110                             walk_state, state->results.num_results, index));
111                 return (AE_AML_NO_RETURN_VALUE);
112         }
113
114         /* Remove the object */
115
116         state->results.num_results--;
117
118         *object = state->results.obj_desc[index];
119         state->results.obj_desc[index] = NULL;
120
121         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
122                           "Obj=%p [%s] Index=%X State=%p Num=%X\n",
123                           *object,
124                           (*object) ? acpi_ut_get_object_type_name(*object) :
125                           "NULL", index, walk_state,
126                           state->results.num_results));
127
128         return (AE_OK);
129 }
130 #endif                          /*  ACPI_FUTURE_USAGE  */
131
132 /*******************************************************************************
133  *
134  * FUNCTION:    acpi_ds_result_pop
135  *
136  * PARAMETERS:  Object              - Where to return the popped object
137  *              walk_state          - Current Walk state
138  *
139  * RETURN:      Status
140  *
141  * DESCRIPTION: Pop an object off the bottom of this walk's result stack.  In
142  *              other words, this is a FIFO.
143  *
144  ******************************************************************************/
145
146 acpi_status
147 acpi_ds_result_pop(union acpi_operand_object ** object,
148                    struct acpi_walk_state * walk_state)
149 {
150         acpi_native_uint index;
151         union acpi_generic_state *state;
152
153         ACPI_FUNCTION_NAME(ds_result_pop);
154
155         state = walk_state->results;
156         if (!state) {
157                 return (AE_OK);
158         }
159
160         if (!state->results.num_results) {
161                 ACPI_ERROR((AE_INFO, "Result stack is empty! State=%p",
162                             walk_state));
163                 return (AE_AML_NO_RETURN_VALUE);
164         }
165
166         /* Remove top element */
167
168         state->results.num_results--;
169
170         for (index = ACPI_OBJ_NUM_OPERANDS; index; index--) {
171
172                 /* Check for a valid result object */
173
174                 if (state->results.obj_desc[index - 1]) {
175                         *object = state->results.obj_desc[index - 1];
176                         state->results.obj_desc[index - 1] = NULL;
177
178                         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
179                                           "Obj=%p [%s] Index=%X State=%p Num=%X\n",
180                                           *object,
181                                           (*object) ?
182                                           acpi_ut_get_object_type_name(*object)
183                                           : "NULL", (u32) index - 1, walk_state,
184                                           state->results.num_results));
185
186                         return (AE_OK);
187                 }
188         }
189
190         ACPI_ERROR((AE_INFO, "No result objects! State=%p", walk_state));
191         return (AE_AML_NO_RETURN_VALUE);
192 }
193
194 /*******************************************************************************
195  *
196  * FUNCTION:    acpi_ds_result_pop_from_bottom
197  *
198  * PARAMETERS:  Object              - Where to return the popped object
199  *              walk_state          - Current Walk state
200  *
201  * RETURN:      Status
202  *
203  * DESCRIPTION: Pop an object off the bottom of this walk's result stack.  In
204  *              other words, this is a FIFO.
205  *
206  ******************************************************************************/
207
208 acpi_status
209 acpi_ds_result_pop_from_bottom(union acpi_operand_object ** object,
210                                struct acpi_walk_state * walk_state)
211 {
212         acpi_native_uint index;
213         union acpi_generic_state *state;
214
215         ACPI_FUNCTION_NAME(ds_result_pop_from_bottom);
216
217         state = walk_state->results;
218         if (!state) {
219                 ACPI_ERROR((AE_INFO,
220                             "No result object pushed! State=%p", walk_state));
221                 return (AE_NOT_EXIST);
222         }
223
224         if (!state->results.num_results) {
225                 ACPI_ERROR((AE_INFO, "No result objects! State=%p",
226                             walk_state));
227                 return (AE_AML_NO_RETURN_VALUE);
228         }
229
230         /* Remove Bottom element */
231
232         *object = state->results.obj_desc[0];
233
234         /* Push entire stack down one element */
235
236         for (index = 0; index < state->results.num_results; index++) {
237                 state->results.obj_desc[index] =
238                     state->results.obj_desc[index + 1];
239         }
240
241         state->results.num_results--;
242
243         /* Check for a valid result object */
244
245         if (!*object) {
246                 ACPI_ERROR((AE_INFO,
247                             "Null operand! State=%p #Ops=%X Index=%X",
248                             walk_state, state->results.num_results,
249                             (u32) index));
250                 return (AE_AML_NO_RETURN_VALUE);
251         }
252
253         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] Results=%p State=%p\n",
254                           *object,
255                           (*object) ? acpi_ut_get_object_type_name(*object) :
256                           "NULL", state, walk_state));
257
258         return (AE_OK);
259 }
260
261 /*******************************************************************************
262  *
263  * FUNCTION:    acpi_ds_result_push
264  *
265  * PARAMETERS:  Object              - Where to return the popped object
266  *              walk_state          - Current Walk state
267  *
268  * RETURN:      Status
269  *
270  * DESCRIPTION: Push an object onto the current result stack
271  *
272  ******************************************************************************/
273
274 acpi_status
275 acpi_ds_result_push(union acpi_operand_object * object,
276                     struct acpi_walk_state * walk_state)
277 {
278         union acpi_generic_state *state;
279
280         ACPI_FUNCTION_NAME(ds_result_push);
281
282         state = walk_state->results;
283         if (!state) {
284                 ACPI_ERROR((AE_INFO, "No result stack frame during push"));
285                 return (AE_AML_INTERNAL);
286         }
287
288         if (state->results.num_results == ACPI_OBJ_NUM_OPERANDS) {
289                 ACPI_ERROR((AE_INFO,
290                             "Result stack overflow: Obj=%p State=%p Num=%X",
291                             object, walk_state, state->results.num_results));
292                 return (AE_STACK_OVERFLOW);
293         }
294
295         if (!object) {
296                 ACPI_ERROR((AE_INFO,
297                             "Null Object! Obj=%p State=%p Num=%X",
298                             object, walk_state, state->results.num_results));
299                 return (AE_BAD_PARAMETER);
300         }
301
302         state->results.obj_desc[state->results.num_results] = object;
303         state->results.num_results++;
304
305         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p Num=%X Cur=%X\n",
306                           object,
307                           object ?
308                           acpi_ut_get_object_type_name((union
309                                                         acpi_operand_object *)
310                                                        object) : "NULL",
311                           walk_state, state->results.num_results,
312                           walk_state->current_result));
313
314         return (AE_OK);
315 }
316
317 /*******************************************************************************
318  *
319  * FUNCTION:    acpi_ds_result_stack_push
320  *
321  * PARAMETERS:  walk_state          - Current Walk state
322  *
323  * RETURN:      Status
324  *
325  * DESCRIPTION: Push an object onto the walk_state result stack.
326  *
327  ******************************************************************************/
328
329 acpi_status acpi_ds_result_stack_push(struct acpi_walk_state * walk_state)
330 {
331         union acpi_generic_state *state;
332
333         ACPI_FUNCTION_NAME(ds_result_stack_push);
334
335         state = acpi_ut_create_generic_state();
336         if (!state) {
337                 return (AE_NO_MEMORY);
338         }
339
340         state->common.descriptor_type = ACPI_DESC_TYPE_STATE_RESULT;
341         acpi_ut_push_generic_state(&walk_state->results, state);
342
343         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Results=%p State=%p\n",
344                           state, walk_state));
345
346         return (AE_OK);
347 }
348
349 /*******************************************************************************
350  *
351  * FUNCTION:    acpi_ds_result_stack_pop
352  *
353  * PARAMETERS:  walk_state          - Current Walk state
354  *
355  * RETURN:      Status
356  *
357  * DESCRIPTION: Pop an object off of the walk_state result stack.
358  *
359  ******************************************************************************/
360
361 acpi_status acpi_ds_result_stack_pop(struct acpi_walk_state * walk_state)
362 {
363         union acpi_generic_state *state;
364
365         ACPI_FUNCTION_NAME(ds_result_stack_pop);
366
367         /* Check for stack underflow */
368
369         if (walk_state->results == NULL) {
370                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Underflow - State=%p\n",
371                                   walk_state));
372                 return (AE_AML_NO_OPERAND);
373         }
374
375         state = acpi_ut_pop_generic_state(&walk_state->results);
376
377         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
378                           "Result=%p RemainingResults=%X State=%p\n",
379                           state, state->results.num_results, walk_state));
380
381         acpi_ut_delete_generic_state(state);
382
383         return (AE_OK);
384 }
385
386 /*******************************************************************************
387  *
388  * FUNCTION:    acpi_ds_obj_stack_push
389  *
390  * PARAMETERS:  Object              - Object to push
391  *              walk_state          - Current Walk state
392  *
393  * RETURN:      Status
394  *
395  * DESCRIPTION: Push an object onto this walk's object/operand stack
396  *
397  ******************************************************************************/
398
399 acpi_status
400 acpi_ds_obj_stack_push(void *object, struct acpi_walk_state * walk_state)
401 {
402         ACPI_FUNCTION_NAME(ds_obj_stack_push);
403
404         /* Check for stack overflow */
405
406         if (walk_state->num_operands >= ACPI_OBJ_NUM_OPERANDS) {
407                 ACPI_ERROR((AE_INFO,
408                             "Object stack overflow! Obj=%p State=%p #Ops=%X",
409                             object, walk_state, walk_state->num_operands));
410                 return (AE_STACK_OVERFLOW);
411         }
412
413         /* Put the object onto the stack */
414
415         walk_state->operands[walk_state->num_operands] = object;
416         walk_state->num_operands++;
417
418         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p #Ops=%X\n",
419                           object,
420                           acpi_ut_get_object_type_name((union
421                                                         acpi_operand_object *)
422                                                        object), walk_state,
423                           walk_state->num_operands));
424
425         return (AE_OK);
426 }
427
428 /*******************************************************************************
429  *
430  * FUNCTION:    acpi_ds_obj_stack_pop
431  *
432  * PARAMETERS:  pop_count           - Number of objects/entries to pop
433  *              walk_state          - Current Walk state
434  *
435  * RETURN:      Status
436  *
437  * DESCRIPTION: Pop this walk's object stack.  Objects on the stack are NOT
438  *              deleted by this routine.
439  *
440  ******************************************************************************/
441
442 acpi_status
443 acpi_ds_obj_stack_pop(u32 pop_count, struct acpi_walk_state * walk_state)
444 {
445         u32 i;
446
447         ACPI_FUNCTION_NAME(ds_obj_stack_pop);
448
449         for (i = 0; i < pop_count; i++) {
450
451                 /* Check for stack underflow */
452
453                 if (walk_state->num_operands == 0) {
454                         ACPI_ERROR((AE_INFO,
455                                     "Object stack underflow! Count=%X State=%p #Ops=%X",
456                                     pop_count, walk_state,
457                                     walk_state->num_operands));
458                         return (AE_STACK_UNDERFLOW);
459                 }
460
461                 /* Just set the stack entry to null */
462
463                 walk_state->num_operands--;
464                 walk_state->operands[walk_state->num_operands] = NULL;
465         }
466
467         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Count=%X State=%p #Ops=%X\n",
468                           pop_count, walk_state, walk_state->num_operands));
469
470         return (AE_OK);
471 }
472
473 /*******************************************************************************
474  *
475  * FUNCTION:    acpi_ds_obj_stack_pop_and_delete
476  *
477  * PARAMETERS:  pop_count           - Number of objects/entries to pop
478  *              walk_state          - Current Walk state
479  *
480  * RETURN:      Status
481  *
482  * DESCRIPTION: Pop this walk's object stack and delete each object that is
483  *              popped off.
484  *
485  ******************************************************************************/
486
487 acpi_status
488 acpi_ds_obj_stack_pop_and_delete(u32 pop_count,
489                                  struct acpi_walk_state * walk_state)
490 {
491         u32 i;
492         union acpi_operand_object *obj_desc;
493
494         ACPI_FUNCTION_NAME(ds_obj_stack_pop_and_delete);
495
496         for (i = 0; i < pop_count; i++) {
497
498                 /* Check for stack underflow */
499
500                 if (walk_state->num_operands == 0) {
501                         ACPI_ERROR((AE_INFO,
502                                     "Object stack underflow! Count=%X State=%p #Ops=%X",
503                                     pop_count, walk_state,
504                                     walk_state->num_operands));
505                         return (AE_STACK_UNDERFLOW);
506                 }
507
508                 /* Pop the stack and delete an object if present in this stack entry */
509
510                 walk_state->num_operands--;
511                 obj_desc = walk_state->operands[walk_state->num_operands];
512                 if (obj_desc) {
513                         acpi_ut_remove_reference(walk_state->
514                                                  operands[walk_state->
515                                                           num_operands]);
516                         walk_state->operands[walk_state->num_operands] = NULL;
517                 }
518         }
519
520         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Count=%X State=%p #Ops=%X\n",
521                           pop_count, walk_state, walk_state->num_operands));
522
523         return (AE_OK);
524 }
525
526 /*******************************************************************************
527  *
528  * FUNCTION:    acpi_ds_get_current_walk_state
529  *
530  * PARAMETERS:  Thread          - Get current active state for this Thread
531  *
532  * RETURN:      Pointer to the current walk state
533  *
534  * DESCRIPTION: Get the walk state that is at the head of the list (the "current"
535  *              walk state.)
536  *
537  ******************************************************************************/
538
539 struct acpi_walk_state *acpi_ds_get_current_walk_state(struct acpi_thread_state
540                                                        *thread)
541 {
542         ACPI_FUNCTION_NAME(ds_get_current_walk_state);
543
544         if (!thread) {
545                 return (NULL);
546         }
547
548         ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "Current WalkState %p\n",
549                           thread->walk_state_list));
550
551         return (thread->walk_state_list);
552 }
553
554 /*******************************************************************************
555  *
556  * FUNCTION:    acpi_ds_push_walk_state
557  *
558  * PARAMETERS:  walk_state      - State to push
559  *              Thread          - Thread state object
560  *
561  * RETURN:      None
562  *
563  * DESCRIPTION: Place the Thread state at the head of the state list.
564  *
565  ******************************************************************************/
566
567 void
568 acpi_ds_push_walk_state(struct acpi_walk_state *walk_state,
569                         struct acpi_thread_state *thread)
570 {
571         ACPI_FUNCTION_TRACE(ds_push_walk_state);
572
573         walk_state->next = thread->walk_state_list;
574         thread->walk_state_list = walk_state;
575
576         return_VOID;
577 }
578
579 /*******************************************************************************
580  *
581  * FUNCTION:    acpi_ds_pop_walk_state
582  *
583  * PARAMETERS:  Thread      - Current thread state
584  *
585  * RETURN:      A walk_state object popped from the thread's stack
586  *
587  * DESCRIPTION: Remove and return the walkstate object that is at the head of
588  *              the walk stack for the given walk list.  NULL indicates that
589  *              the list is empty.
590  *
591  ******************************************************************************/
592
593 struct acpi_walk_state *acpi_ds_pop_walk_state(struct acpi_thread_state *thread)
594 {
595         struct acpi_walk_state *walk_state;
596
597         ACPI_FUNCTION_TRACE(ds_pop_walk_state);
598
599         walk_state = thread->walk_state_list;
600
601         if (walk_state) {
602
603                 /* Next walk state becomes the current walk state */
604
605                 thread->walk_state_list = walk_state->next;
606
607                 /*
608                  * Don't clear the NEXT field, this serves as an indicator
609                  * that there is a parent WALK STATE
610                  * Do Not: walk_state->Next = NULL;
611                  */
612         }
613
614         return_PTR(walk_state);
615 }
616
617 /*******************************************************************************
618  *
619  * FUNCTION:    acpi_ds_create_walk_state
620  *
621  * PARAMETERS:  owner_id        - ID for object creation
622  *              Origin          - Starting point for this walk
623  *              method_desc     - Method object
624  *              Thread          - Current thread state
625  *
626  * RETURN:      Pointer to the new walk state.
627  *
628  * DESCRIPTION: Allocate and initialize a new walk state.  The current walk
629  *              state is set to this new state.
630  *
631  ******************************************************************************/
632
633 struct acpi_walk_state *acpi_ds_create_walk_state(acpi_owner_id owner_id,
634                                                   union acpi_parse_object
635                                                   *origin,
636                                                   union acpi_operand_object
637                                                   *method_desc,
638                                                   struct acpi_thread_state
639                                                   *thread)
640 {
641         struct acpi_walk_state *walk_state;
642         acpi_status status;
643
644         ACPI_FUNCTION_TRACE(ds_create_walk_state);
645
646         walk_state = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_walk_state));
647         if (!walk_state) {
648                 return_PTR(NULL);
649         }
650
651         walk_state->descriptor_type = ACPI_DESC_TYPE_WALK;
652         walk_state->method_desc = method_desc;
653         walk_state->owner_id = owner_id;
654         walk_state->origin = origin;
655         walk_state->thread = thread;
656
657         walk_state->parser_state.start_op = origin;
658
659         /* Init the method args/local */
660
661 #if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))
662         acpi_ds_method_data_init(walk_state);
663 #endif
664
665         /* Create an initial result stack entry */
666
667         status = acpi_ds_result_stack_push(walk_state);
668         if (ACPI_FAILURE(status)) {
669                 ACPI_FREE(walk_state);
670                 return_PTR(NULL);
671         }
672
673         /* Put the new state at the head of the walk list */
674
675         if (thread) {
676                 acpi_ds_push_walk_state(walk_state, thread);
677         }
678
679         return_PTR(walk_state);
680 }
681
682 /*******************************************************************************
683  *
684  * FUNCTION:    acpi_ds_init_aml_walk
685  *
686  * PARAMETERS:  walk_state      - New state to be initialized
687  *              Op              - Current parse op
688  *              method_node     - Control method NS node, if any
689  *              aml_start       - Start of AML
690  *              aml_length      - Length of AML
691  *              Info            - Method info block (params, etc.)
692  *              pass_number     - 1, 2, or 3
693  *
694  * RETURN:      Status
695  *
696  * DESCRIPTION: Initialize a walk state for a pass 1 or 2 parse tree walk
697  *
698  ******************************************************************************/
699
700 acpi_status
701 acpi_ds_init_aml_walk(struct acpi_walk_state *walk_state,
702                       union acpi_parse_object *op,
703                       struct acpi_namespace_node *method_node,
704                       u8 * aml_start,
705                       u32 aml_length,
706                       struct acpi_evaluate_info *info, u8 pass_number)
707 {
708         acpi_status status;
709         struct acpi_parse_state *parser_state = &walk_state->parser_state;
710         union acpi_parse_object *extra_op;
711
712         ACPI_FUNCTION_TRACE(ds_init_aml_walk);
713
714         walk_state->parser_state.aml =
715             walk_state->parser_state.aml_start = aml_start;
716         walk_state->parser_state.aml_end =
717             walk_state->parser_state.pkg_end = aml_start + aml_length;
718
719         /* The next_op of the next_walk will be the beginning of the method */
720
721         walk_state->next_op = NULL;
722         walk_state->pass_number = pass_number;
723
724         if (info) {
725                 if (info->parameter_type == ACPI_PARAM_GPE) {
726                         walk_state->gpe_event_info =
727                             ACPI_CAST_PTR(struct acpi_gpe_event_info,
728                                           info->parameters);
729                 } else {
730                         walk_state->params = info->parameters;
731                         walk_state->caller_return_desc = &info->return_object;
732                 }
733         }
734
735         status = acpi_ps_init_scope(&walk_state->parser_state, op);
736         if (ACPI_FAILURE(status)) {
737                 return_ACPI_STATUS(status);
738         }
739
740         if (method_node) {
741                 walk_state->parser_state.start_node = method_node;
742                 walk_state->walk_type = ACPI_WALK_METHOD;
743                 walk_state->method_node = method_node;
744                 walk_state->method_desc =
745                     acpi_ns_get_attached_object(method_node);
746
747                 /* Push start scope on scope stack and make it current  */
748
749                 status =
750                     acpi_ds_scope_stack_push(method_node, ACPI_TYPE_METHOD,
751                                              walk_state);
752                 if (ACPI_FAILURE(status)) {
753                         return_ACPI_STATUS(status);
754                 }
755
756                 /* Init the method arguments */
757
758                 status = acpi_ds_method_data_init_args(walk_state->params,
759                                                        ACPI_METHOD_NUM_ARGS,
760                                                        walk_state);
761                 if (ACPI_FAILURE(status)) {
762                         return_ACPI_STATUS(status);
763                 }
764         } else {
765                 /*
766                  * Setup the current scope.
767                  * Find a Named Op that has a namespace node associated with it.
768                  * search upwards from this Op.  Current scope is the first
769                  * Op with a namespace node.
770                  */
771                 extra_op = parser_state->start_op;
772                 while (extra_op && !extra_op->common.node) {
773                         extra_op = extra_op->common.parent;
774                 }
775
776                 if (!extra_op) {
777                         parser_state->start_node = NULL;
778                 } else {
779                         parser_state->start_node = extra_op->common.node;
780                 }
781
782                 if (parser_state->start_node) {
783
784                         /* Push start scope on scope stack and make it current  */
785
786                         status =
787                             acpi_ds_scope_stack_push(parser_state->start_node,
788                                                      parser_state->start_node->
789                                                      type, walk_state);
790                         if (ACPI_FAILURE(status)) {
791                                 return_ACPI_STATUS(status);
792                         }
793                 }
794         }
795
796         status = acpi_ds_init_callbacks(walk_state, pass_number);
797         return_ACPI_STATUS(status);
798 }
799
800 /*******************************************************************************
801  *
802  * FUNCTION:    acpi_ds_delete_walk_state
803  *
804  * PARAMETERS:  walk_state      - State to delete
805  *
806  * RETURN:      Status
807  *
808  * DESCRIPTION: Delete a walk state including all internal data structures
809  *
810  ******************************************************************************/
811
812 void acpi_ds_delete_walk_state(struct acpi_walk_state *walk_state)
813 {
814         union acpi_generic_state *state;
815
816         ACPI_FUNCTION_TRACE_PTR(ds_delete_walk_state, walk_state);
817
818         if (!walk_state) {
819                 return;
820         }
821
822         if (walk_state->descriptor_type != ACPI_DESC_TYPE_WALK) {
823                 ACPI_ERROR((AE_INFO, "%p is not a valid walk state",
824                             walk_state));
825                 return;
826         }
827
828         /* There should not be any open scopes */
829
830         if (walk_state->parser_state.scope) {
831                 ACPI_ERROR((AE_INFO, "%p walk still has a scope list",
832                             walk_state));
833                 acpi_ps_cleanup_scope(&walk_state->parser_state);
834         }
835
836         /* Always must free any linked control states */
837
838         while (walk_state->control_state) {
839                 state = walk_state->control_state;
840                 walk_state->control_state = state->common.next;
841
842                 acpi_ut_delete_generic_state(state);
843         }
844
845         /* Always must free any linked parse states */
846
847         while (walk_state->scope_info) {
848                 state = walk_state->scope_info;
849                 walk_state->scope_info = state->common.next;
850
851                 acpi_ut_delete_generic_state(state);
852         }
853
854         /* Always must free any stacked result states */
855
856         while (walk_state->results) {
857                 state = walk_state->results;
858                 walk_state->results = state->common.next;
859
860                 acpi_ut_delete_generic_state(state);
861         }
862
863         ACPI_FREE(walk_state);
864         return_VOID;
865 }
866
867 #ifdef ACPI_OBSOLETE_FUNCTIONS
868 /*******************************************************************************
869  *
870  * FUNCTION:    acpi_ds_result_insert
871  *
872  * PARAMETERS:  Object              - Object to push
873  *              Index               - Where to insert the object
874  *              walk_state          - Current Walk state
875  *
876  * RETURN:      Status
877  *
878  * DESCRIPTION: Insert an object onto this walk's result stack
879  *
880  ******************************************************************************/
881
882 acpi_status
883 acpi_ds_result_insert(void *object,
884                       u32 index, struct acpi_walk_state *walk_state)
885 {
886         union acpi_generic_state *state;
887
888         ACPI_FUNCTION_NAME(ds_result_insert);
889
890         state = walk_state->results;
891         if (!state) {
892                 ACPI_ERROR((AE_INFO, "No result object pushed! State=%p",
893                             walk_state));
894                 return (AE_NOT_EXIST);
895         }
896
897         if (index >= ACPI_OBJ_NUM_OPERANDS) {
898                 ACPI_ERROR((AE_INFO,
899                             "Index out of range: %X Obj=%p State=%p Num=%X",
900                             index, object, walk_state,
901                             state->results.num_results));
902                 return (AE_BAD_PARAMETER);
903         }
904
905         if (!object) {
906                 ACPI_ERROR((AE_INFO,
907                             "Null Object! Index=%X Obj=%p State=%p Num=%X",
908                             index, object, walk_state,
909                             state->results.num_results));
910                 return (AE_BAD_PARAMETER);
911         }
912
913         state->results.obj_desc[index] = object;
914         state->results.num_results++;
915
916         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
917                           "Obj=%p [%s] State=%p Num=%X Cur=%X\n",
918                           object,
919                           object ?
920                           acpi_ut_get_object_type_name((union
921                                                         acpi_operand_object *)
922                                                        object) : "NULL",
923                           walk_state, state->results.num_results,
924                           walk_state->current_result));
925
926         return (AE_OK);
927 }
928
929 /*******************************************************************************
930  *
931  * FUNCTION:    acpi_ds_obj_stack_delete_all
932  *
933  * PARAMETERS:  walk_state          - Current Walk state
934  *
935  * RETURN:      Status
936  *
937  * DESCRIPTION: Clear the object stack by deleting all objects that are on it.
938  *              Should be used with great care, if at all!
939  *
940  ******************************************************************************/
941
942 acpi_status acpi_ds_obj_stack_delete_all(struct acpi_walk_state * walk_state)
943 {
944         u32 i;
945
946         ACPI_FUNCTION_TRACE_PTR(ds_obj_stack_delete_all, walk_state);
947
948         /* The stack size is configurable, but fixed */
949
950         for (i = 0; i < ACPI_OBJ_NUM_OPERANDS; i++) {
951                 if (walk_state->operands[i]) {
952                         acpi_ut_remove_reference(walk_state->operands[i]);
953                         walk_state->operands[i] = NULL;
954                 }
955         }
956
957         return_ACPI_STATUS(AE_OK);
958 }
959
960 /*******************************************************************************
961  *
962  * FUNCTION:    acpi_ds_obj_stack_pop_object
963  *
964  * PARAMETERS:  Object              - Where to return the popped object
965  *              walk_state          - Current Walk state
966  *
967  * RETURN:      Status
968  *
969  * DESCRIPTION: Pop this walk's object stack.  Objects on the stack are NOT
970  *              deleted by this routine.
971  *
972  ******************************************************************************/
973
974 acpi_status
975 acpi_ds_obj_stack_pop_object(union acpi_operand_object **object,
976                              struct acpi_walk_state *walk_state)
977 {
978         ACPI_FUNCTION_NAME(ds_obj_stack_pop_object);
979
980         /* Check for stack underflow */
981
982         if (walk_state->num_operands == 0) {
983                 ACPI_ERROR((AE_INFO,
984                             "Missing operand/stack empty! State=%p #Ops=%X",
985                             walk_state, walk_state->num_operands));
986                 *object = NULL;
987                 return (AE_AML_NO_OPERAND);
988         }
989
990         /* Pop the stack */
991
992         walk_state->num_operands--;
993
994         /* Check for a valid operand */
995
996         if (!walk_state->operands[walk_state->num_operands]) {
997                 ACPI_ERROR((AE_INFO,
998                             "Null operand! State=%p #Ops=%X",
999                             walk_state, walk_state->num_operands));
1000                 *object = NULL;
1001                 return (AE_AML_NO_OPERAND);
1002         }
1003
1004         /* Get operand and set stack entry to null */
1005
1006         *object = walk_state->operands[walk_state->num_operands];
1007         walk_state->operands[walk_state->num_operands] = NULL;
1008
1009         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p #Ops=%X\n",
1010                           *object, acpi_ut_get_object_type_name(*object),
1011                           walk_state, walk_state->num_operands));
1012
1013         return (AE_OK);
1014 }
1015
1016 /*******************************************************************************
1017  *
1018  * FUNCTION:    acpi_ds_obj_stack_get_value
1019  *
1020  * PARAMETERS:  Index               - Stack index whose value is desired.  Based
1021  *                                    on the top of the stack (index=0 == top)
1022  *              walk_state          - Current Walk state
1023  *
1024  * RETURN:      Pointer to the requested operand
1025  *
1026  * DESCRIPTION: Retrieve an object from this walk's operand stack.  Index must
1027  *              be within the range of the current stack pointer.
1028  *
1029  ******************************************************************************/
1030
1031 void *acpi_ds_obj_stack_get_value(u32 index, struct acpi_walk_state *walk_state)
1032 {
1033
1034         ACPI_FUNCTION_TRACE_PTR(ds_obj_stack_get_value, walk_state);
1035
1036         /* Can't do it if the stack is empty */
1037
1038         if (walk_state->num_operands == 0) {
1039                 return_PTR(NULL);
1040         }
1041
1042         /* or if the index is past the top of the stack */
1043
1044         if (index > (walk_state->num_operands - (u32) 1)) {
1045                 return_PTR(NULL);
1046         }
1047
1048         return_PTR(walk_state->
1049                    operands[(acpi_native_uint) (walk_state->num_operands - 1) -
1050                             index]);
1051 }
1052 #endif