ACPICA: Update all ACPICA copyrights and signons to 2010
[linux-3.10.git] / drivers / acpi / acpica / dsmthdat.c
1 /*******************************************************************************
2  *
3  * Module Name: dsmthdat - control method arguments and local variables
4  *
5  ******************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2010, 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 "acdispat.h"
47 #include "acnamesp.h"
48 #include "acinterp.h"
49
50 #define _COMPONENT          ACPI_DISPATCHER
51 ACPI_MODULE_NAME("dsmthdat")
52
53 /* Local prototypes */
54 static void
55 acpi_ds_method_data_delete_value(u8 type,
56                                  u32 index, struct acpi_walk_state *walk_state);
57
58 static acpi_status
59 acpi_ds_method_data_set_value(u8 type,
60                               u32 index,
61                               union acpi_operand_object *object,
62                               struct acpi_walk_state *walk_state);
63
64 #ifdef ACPI_OBSOLETE_FUNCTIONS
65 acpi_object_type
66 acpi_ds_method_data_get_type(u16 opcode,
67                              u32 index, struct acpi_walk_state *walk_state);
68 #endif
69
70 /*******************************************************************************
71  *
72  * FUNCTION:    acpi_ds_method_data_init
73  *
74  * PARAMETERS:  walk_state          - Current walk state object
75  *
76  * RETURN:      Status
77  *
78  * DESCRIPTION: Initialize the data structures that hold the method's arguments
79  *              and locals.  The data struct is an array of namespace nodes for
80  *              each - this allows ref_of and de_ref_of to work properly for these
81  *              special data types.
82  *
83  * NOTES:       walk_state fields are initialized to zero by the
84  *              ACPI_ALLOCATE_ZEROED().
85  *
86  *              A pseudo-Namespace Node is assigned to each argument and local
87  *              so that ref_of() can return a pointer to the Node.
88  *
89  ******************************************************************************/
90
91 void acpi_ds_method_data_init(struct acpi_walk_state *walk_state)
92 {
93         u32 i;
94
95         ACPI_FUNCTION_TRACE(ds_method_data_init);
96
97         /* Init the method arguments */
98
99         for (i = 0; i < ACPI_METHOD_NUM_ARGS; i++) {
100                 ACPI_MOVE_32_TO_32(&walk_state->arguments[i].name,
101                                    NAMEOF_ARG_NTE);
102                 walk_state->arguments[i].name.integer |= (i << 24);
103                 walk_state->arguments[i].descriptor_type = ACPI_DESC_TYPE_NAMED;
104                 walk_state->arguments[i].type = ACPI_TYPE_ANY;
105                 walk_state->arguments[i].flags =
106                     ANOBJ_END_OF_PEER_LIST | ANOBJ_METHOD_ARG;
107         }
108
109         /* Init the method locals */
110
111         for (i = 0; i < ACPI_METHOD_NUM_LOCALS; i++) {
112                 ACPI_MOVE_32_TO_32(&walk_state->local_variables[i].name,
113                                    NAMEOF_LOCAL_NTE);
114
115                 walk_state->local_variables[i].name.integer |= (i << 24);
116                 walk_state->local_variables[i].descriptor_type =
117                     ACPI_DESC_TYPE_NAMED;
118                 walk_state->local_variables[i].type = ACPI_TYPE_ANY;
119                 walk_state->local_variables[i].flags =
120                     ANOBJ_END_OF_PEER_LIST | ANOBJ_METHOD_LOCAL;
121         }
122
123         return_VOID;
124 }
125
126 /*******************************************************************************
127  *
128  * FUNCTION:    acpi_ds_method_data_delete_all
129  *
130  * PARAMETERS:  walk_state          - Current walk state object
131  *
132  * RETURN:      None
133  *
134  * DESCRIPTION: Delete method locals and arguments.  Arguments are only
135  *              deleted if this method was called from another method.
136  *
137  ******************************************************************************/
138
139 void acpi_ds_method_data_delete_all(struct acpi_walk_state *walk_state)
140 {
141         u32 index;
142
143         ACPI_FUNCTION_TRACE(ds_method_data_delete_all);
144
145         /* Detach the locals */
146
147         for (index = 0; index < ACPI_METHOD_NUM_LOCALS; index++) {
148                 if (walk_state->local_variables[index].object) {
149                         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Deleting Local%d=%p\n",
150                                           index,
151                                           walk_state->local_variables[index].
152                                           object));
153
154                         /* Detach object (if present) and remove a reference */
155
156                         acpi_ns_detach_object(&walk_state->
157                                               local_variables[index]);
158                 }
159         }
160
161         /* Detach the arguments */
162
163         for (index = 0; index < ACPI_METHOD_NUM_ARGS; index++) {
164                 if (walk_state->arguments[index].object) {
165                         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Deleting Arg%d=%p\n",
166                                           index,
167                                           walk_state->arguments[index].object));
168
169                         /* Detach object (if present) and remove a reference */
170
171                         acpi_ns_detach_object(&walk_state->arguments[index]);
172                 }
173         }
174
175         return_VOID;
176 }
177
178 /*******************************************************************************
179  *
180  * FUNCTION:    acpi_ds_method_data_init_args
181  *
182  * PARAMETERS:  *Params         - Pointer to a parameter list for the method
183  *              max_param_count - The arg count for this method
184  *              walk_state      - Current walk state object
185  *
186  * RETURN:      Status
187  *
188  * DESCRIPTION: Initialize arguments for a method.  The parameter list is a list
189  *              of ACPI operand objects, either null terminated or whose length
190  *              is defined by max_param_count.
191  *
192  ******************************************************************************/
193
194 acpi_status
195 acpi_ds_method_data_init_args(union acpi_operand_object **params,
196                               u32 max_param_count,
197                               struct acpi_walk_state *walk_state)
198 {
199         acpi_status status;
200         u32 index = 0;
201
202         ACPI_FUNCTION_TRACE_PTR(ds_method_data_init_args, params);
203
204         if (!params) {
205                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
206                                   "No param list passed to method\n"));
207                 return_ACPI_STATUS(AE_OK);
208         }
209
210         /* Copy passed parameters into the new method stack frame */
211
212         while ((index < ACPI_METHOD_NUM_ARGS) &&
213                (index < max_param_count) && params[index]) {
214                 /*
215                  * A valid parameter.
216                  * Store the argument in the method/walk descriptor.
217                  * Do not copy the arg in order to implement call by reference
218                  */
219                 status = acpi_ds_method_data_set_value(ACPI_REFCLASS_ARG, index,
220                                                        params[index],
221                                                        walk_state);
222                 if (ACPI_FAILURE(status)) {
223                         return_ACPI_STATUS(status);
224                 }
225
226                 index++;
227         }
228
229         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%d args passed to method\n", index));
230         return_ACPI_STATUS(AE_OK);
231 }
232
233 /*******************************************************************************
234  *
235  * FUNCTION:    acpi_ds_method_data_get_node
236  *
237  * PARAMETERS:  Type                - Either ACPI_REFCLASS_LOCAL or
238  *                                    ACPI_REFCLASS_ARG
239  *              Index               - Which Local or Arg whose type to get
240  *              walk_state          - Current walk state object
241  *              Node                - Where the node is returned.
242  *
243  * RETURN:      Status and node
244  *
245  * DESCRIPTION: Get the Node associated with a local or arg.
246  *
247  ******************************************************************************/
248
249 acpi_status
250 acpi_ds_method_data_get_node(u8 type,
251                              u32 index,
252                              struct acpi_walk_state *walk_state,
253                              struct acpi_namespace_node **node)
254 {
255         ACPI_FUNCTION_TRACE(ds_method_data_get_node);
256
257         /*
258          * Method Locals and Arguments are supported
259          */
260         switch (type) {
261         case ACPI_REFCLASS_LOCAL:
262
263                 if (index > ACPI_METHOD_MAX_LOCAL) {
264                         ACPI_ERROR((AE_INFO,
265                                     "Local index %d is invalid (max %d)",
266                                     index, ACPI_METHOD_MAX_LOCAL));
267                         return_ACPI_STATUS(AE_AML_INVALID_INDEX);
268                 }
269
270                 /* Return a pointer to the pseudo-node */
271
272                 *node = &walk_state->local_variables[index];
273                 break;
274
275         case ACPI_REFCLASS_ARG:
276
277                 if (index > ACPI_METHOD_MAX_ARG) {
278                         ACPI_ERROR((AE_INFO,
279                                     "Arg index %d is invalid (max %d)",
280                                     index, ACPI_METHOD_MAX_ARG));
281                         return_ACPI_STATUS(AE_AML_INVALID_INDEX);
282                 }
283
284                 /* Return a pointer to the pseudo-node */
285
286                 *node = &walk_state->arguments[index];
287                 break;
288
289         default:
290                 ACPI_ERROR((AE_INFO, "Type %d is invalid", type));
291                 return_ACPI_STATUS(AE_TYPE);
292         }
293
294         return_ACPI_STATUS(AE_OK);
295 }
296
297 /*******************************************************************************
298  *
299  * FUNCTION:    acpi_ds_method_data_set_value
300  *
301  * PARAMETERS:  Type                - Either ACPI_REFCLASS_LOCAL or
302  *                                    ACPI_REFCLASS_ARG
303  *              Index               - Which Local or Arg to get
304  *              Object              - Object to be inserted into the stack entry
305  *              walk_state          - Current walk state object
306  *
307  * RETURN:      Status
308  *
309  * DESCRIPTION: Insert an object onto the method stack at entry Opcode:Index.
310  *              Note: There is no "implicit conversion" for locals.
311  *
312  ******************************************************************************/
313
314 static acpi_status
315 acpi_ds_method_data_set_value(u8 type,
316                               u32 index,
317                               union acpi_operand_object *object,
318                               struct acpi_walk_state *walk_state)
319 {
320         acpi_status status;
321         struct acpi_namespace_node *node;
322
323         ACPI_FUNCTION_TRACE(ds_method_data_set_value);
324
325         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
326                           "NewObj %p Type %2.2X, Refs=%d [%s]\n", object,
327                           type, object->common.reference_count,
328                           acpi_ut_get_type_name(object->common.type)));
329
330         /* Get the namespace node for the arg/local */
331
332         status = acpi_ds_method_data_get_node(type, index, walk_state, &node);
333         if (ACPI_FAILURE(status)) {
334                 return_ACPI_STATUS(status);
335         }
336
337         /*
338          * Increment ref count so object can't be deleted while installed.
339          * NOTE: We do not copy the object in order to preserve the call by
340          * reference semantics of ACPI Control Method invocation.
341          * (See ACPI Specification 2.0_c)
342          */
343         acpi_ut_add_reference(object);
344
345         /* Install the object */
346
347         node->object = object;
348         return_ACPI_STATUS(status);
349 }
350
351 /*******************************************************************************
352  *
353  * FUNCTION:    acpi_ds_method_data_get_value
354  *
355  * PARAMETERS:  Type                - Either ACPI_REFCLASS_LOCAL or
356  *                                    ACPI_REFCLASS_ARG
357  *              Index               - Which local_var or argument to get
358  *              walk_state          - Current walk state object
359  *              dest_desc           - Where Arg or Local value is returned
360  *
361  * RETURN:      Status
362  *
363  * DESCRIPTION: Retrieve value of selected Arg or Local for this method
364  *              Used only in acpi_ex_resolve_to_value().
365  *
366  ******************************************************************************/
367
368 acpi_status
369 acpi_ds_method_data_get_value(u8 type,
370                               u32 index,
371                               struct acpi_walk_state *walk_state,
372                               union acpi_operand_object **dest_desc)
373 {
374         acpi_status status;
375         struct acpi_namespace_node *node;
376         union acpi_operand_object *object;
377
378         ACPI_FUNCTION_TRACE(ds_method_data_get_value);
379
380         /* Validate the object descriptor */
381
382         if (!dest_desc) {
383                 ACPI_ERROR((AE_INFO, "Null object descriptor pointer"));
384                 return_ACPI_STATUS(AE_BAD_PARAMETER);
385         }
386
387         /* Get the namespace node for the arg/local */
388
389         status = acpi_ds_method_data_get_node(type, index, walk_state, &node);
390         if (ACPI_FAILURE(status)) {
391                 return_ACPI_STATUS(status);
392         }
393
394         /* Get the object from the node */
395
396         object = node->object;
397
398         /* Examine the returned object, it must be valid. */
399
400         if (!object) {
401                 /*
402                  * Index points to uninitialized object.
403                  * This means that either 1) The expected argument was
404                  * not passed to the method, or 2) A local variable
405                  * was referenced by the method (via the ASL)
406                  * before it was initialized.  Either case is an error.
407                  */
408
409                 /* If slack enabled, init the local_x/arg_x to an Integer of value zero */
410
411                 if (acpi_gbl_enable_interpreter_slack) {
412                         object = acpi_ut_create_integer_object((u64) 0);
413                         if (!object) {
414                                 return_ACPI_STATUS(AE_NO_MEMORY);
415                         }
416
417                         node->object = object;
418                 }
419
420                 /* Otherwise, return the error */
421
422                 else
423                         switch (type) {
424                         case ACPI_REFCLASS_ARG:
425
426                                 ACPI_ERROR((AE_INFO,
427                                             "Uninitialized Arg[%d] at node %p",
428                                             index, node));
429
430                                 return_ACPI_STATUS(AE_AML_UNINITIALIZED_ARG);
431
432                         case ACPI_REFCLASS_LOCAL:
433
434                                 /*
435                                  * No error message for this case, will be trapped again later to
436                                  * detect and ignore cases of Store(local_x,local_x)
437                                  */
438                                 return_ACPI_STATUS(AE_AML_UNINITIALIZED_LOCAL);
439
440                         default:
441
442                                 ACPI_ERROR((AE_INFO,
443                                             "Not a Arg/Local opcode: %X",
444                                             type));
445                                 return_ACPI_STATUS(AE_AML_INTERNAL);
446                         }
447         }
448
449         /*
450          * The Index points to an initialized and valid object.
451          * Return an additional reference to the object
452          */
453         *dest_desc = object;
454         acpi_ut_add_reference(object);
455
456         return_ACPI_STATUS(AE_OK);
457 }
458
459 /*******************************************************************************
460  *
461  * FUNCTION:    acpi_ds_method_data_delete_value
462  *
463  * PARAMETERS:  Type                - Either ACPI_REFCLASS_LOCAL or
464  *                                    ACPI_REFCLASS_ARG
465  *              Index               - Which local_var or argument to delete
466  *              walk_state          - Current walk state object
467  *
468  * RETURN:      None
469  *
470  * DESCRIPTION: Delete the entry at Opcode:Index.  Inserts
471  *              a null into the stack slot after the object is deleted.
472  *
473  ******************************************************************************/
474
475 static void
476 acpi_ds_method_data_delete_value(u8 type,
477                                  u32 index, struct acpi_walk_state *walk_state)
478 {
479         acpi_status status;
480         struct acpi_namespace_node *node;
481         union acpi_operand_object *object;
482
483         ACPI_FUNCTION_TRACE(ds_method_data_delete_value);
484
485         /* Get the namespace node for the arg/local */
486
487         status = acpi_ds_method_data_get_node(type, index, walk_state, &node);
488         if (ACPI_FAILURE(status)) {
489                 return_VOID;
490         }
491
492         /* Get the associated object */
493
494         object = acpi_ns_get_attached_object(node);
495
496         /*
497          * Undefine the Arg or Local by setting its descriptor
498          * pointer to NULL. Locals/Args can contain both
499          * ACPI_OPERAND_OBJECTS and ACPI_NAMESPACE_NODEs
500          */
501         node->object = NULL;
502
503         if ((object) &&
504             (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_OPERAND)) {
505                 /*
506                  * There is a valid object.
507                  * Decrement the reference count by one to balance the
508                  * increment when the object was stored.
509                  */
510                 acpi_ut_remove_reference(object);
511         }
512
513         return_VOID;
514 }
515
516 /*******************************************************************************
517  *
518  * FUNCTION:    acpi_ds_store_object_to_local
519  *
520  * PARAMETERS:  Type                - Either ACPI_REFCLASS_LOCAL or
521  *                                    ACPI_REFCLASS_ARG
522  *              Index               - Which Local or Arg to set
523  *              obj_desc            - Value to be stored
524  *              walk_state          - Current walk state
525  *
526  * RETURN:      Status
527  *
528  * DESCRIPTION: Store a value in an Arg or Local.  The obj_desc is installed
529  *              as the new value for the Arg or Local and the reference count
530  *              for obj_desc is incremented.
531  *
532  ******************************************************************************/
533
534 acpi_status
535 acpi_ds_store_object_to_local(u8 type,
536                               u32 index,
537                               union acpi_operand_object *obj_desc,
538                               struct acpi_walk_state *walk_state)
539 {
540         acpi_status status;
541         struct acpi_namespace_node *node;
542         union acpi_operand_object *current_obj_desc;
543         union acpi_operand_object *new_obj_desc;
544
545         ACPI_FUNCTION_TRACE(ds_store_object_to_local);
546         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Type=%2.2X Index=%d Obj=%p\n",
547                           type, index, obj_desc));
548
549         /* Parameter validation */
550
551         if (!obj_desc) {
552                 return_ACPI_STATUS(AE_BAD_PARAMETER);
553         }
554
555         /* Get the namespace node for the arg/local */
556
557         status = acpi_ds_method_data_get_node(type, index, walk_state, &node);
558         if (ACPI_FAILURE(status)) {
559                 return_ACPI_STATUS(status);
560         }
561
562         current_obj_desc = acpi_ns_get_attached_object(node);
563         if (current_obj_desc == obj_desc) {
564                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p already installed!\n",
565                                   obj_desc));
566                 return_ACPI_STATUS(status);
567         }
568
569         /*
570          * If the reference count on the object is more than one, we must
571          * take a copy of the object before we store.  A reference count
572          * of exactly 1 means that the object was just created during the
573          * evaluation of an expression, and we can safely use it since it
574          * is not used anywhere else.
575          */
576         new_obj_desc = obj_desc;
577         if (obj_desc->common.reference_count > 1) {
578                 status =
579                     acpi_ut_copy_iobject_to_iobject(obj_desc, &new_obj_desc,
580                                                     walk_state);
581                 if (ACPI_FAILURE(status)) {
582                         return_ACPI_STATUS(status);
583                 }
584         }
585
586         /*
587          * If there is an object already in this slot, we either
588          * have to delete it, or if this is an argument and there
589          * is an object reference stored there, we have to do
590          * an indirect store!
591          */
592         if (current_obj_desc) {
593                 /*
594                  * Check for an indirect store if an argument
595                  * contains an object reference (stored as an Node).
596                  * We don't allow this automatic dereferencing for
597                  * locals, since a store to a local should overwrite
598                  * anything there, including an object reference.
599                  *
600                  * If both Arg0 and Local0 contain ref_of (Local4):
601                  *
602                  * Store (1, Arg0)             - Causes indirect store to local4
603                  * Store (1, Local0)           - Stores 1 in local0, overwriting
604                  *                                  the reference to local4
605                  * Store (1, de_refof (Local0)) - Causes indirect store to local4
606                  *
607                  * Weird, but true.
608                  */
609                 if (type == ACPI_REFCLASS_ARG) {
610                         /*
611                          * If we have a valid reference object that came from ref_of(),
612                          * do the indirect store
613                          */
614                         if ((ACPI_GET_DESCRIPTOR_TYPE(current_obj_desc) ==
615                              ACPI_DESC_TYPE_OPERAND)
616                             && (current_obj_desc->common.type ==
617                                 ACPI_TYPE_LOCAL_REFERENCE)
618                             && (current_obj_desc->reference.class ==
619                                 ACPI_REFCLASS_REFOF)) {
620                                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
621                                                   "Arg (%p) is an ObjRef(Node), storing in node %p\n",
622                                                   new_obj_desc,
623                                                   current_obj_desc));
624
625                                 /*
626                                  * Store this object to the Node (perform the indirect store)
627                                  * NOTE: No implicit conversion is performed, as per the ACPI
628                                  * specification rules on storing to Locals/Args.
629                                  */
630                                 status =
631                                     acpi_ex_store_object_to_node(new_obj_desc,
632                                                                  current_obj_desc->
633                                                                  reference.
634                                                                  object,
635                                                                  walk_state,
636                                                                  ACPI_NO_IMPLICIT_CONVERSION);
637
638                                 /* Remove local reference if we copied the object above */
639
640                                 if (new_obj_desc != obj_desc) {
641                                         acpi_ut_remove_reference(new_obj_desc);
642                                 }
643                                 return_ACPI_STATUS(status);
644                         }
645                 }
646
647                 /* Delete the existing object before storing the new one */
648
649                 acpi_ds_method_data_delete_value(type, index, walk_state);
650         }
651
652         /*
653          * Install the Obj descriptor (*new_obj_desc) into
654          * the descriptor for the Arg or Local.
655          * (increments the object reference count by one)
656          */
657         status =
658             acpi_ds_method_data_set_value(type, index, new_obj_desc,
659                                           walk_state);
660
661         /* Remove local reference if we copied the object above */
662
663         if (new_obj_desc != obj_desc) {
664                 acpi_ut_remove_reference(new_obj_desc);
665         }
666
667         return_ACPI_STATUS(status);
668 }
669
670 #ifdef ACPI_OBSOLETE_FUNCTIONS
671 /*******************************************************************************
672  *
673  * FUNCTION:    acpi_ds_method_data_get_type
674  *
675  * PARAMETERS:  Opcode              - Either AML_LOCAL_OP or AML_ARG_OP
676  *              Index               - Which Local or Arg whose type to get
677  *              walk_state          - Current walk state object
678  *
679  * RETURN:      Data type of current value of the selected Arg or Local
680  *
681  * DESCRIPTION: Get the type of the object stored in the Local or Arg
682  *
683  ******************************************************************************/
684
685 acpi_object_type
686 acpi_ds_method_data_get_type(u16 opcode,
687                              u32 index, struct acpi_walk_state *walk_state)
688 {
689         acpi_status status;
690         struct acpi_namespace_node *node;
691         union acpi_operand_object *object;
692
693         ACPI_FUNCTION_TRACE(ds_method_data_get_type);
694
695         /* Get the namespace node for the arg/local */
696
697         status = acpi_ds_method_data_get_node(opcode, index, walk_state, &node);
698         if (ACPI_FAILURE(status)) {
699                 return_VALUE((ACPI_TYPE_NOT_FOUND));
700         }
701
702         /* Get the object */
703
704         object = acpi_ns_get_attached_object(node);
705         if (!object) {
706
707                 /* Uninitialized local/arg, return TYPE_ANY */
708
709                 return_VALUE(ACPI_TYPE_ANY);
710         }
711
712         /* Get the object type */
713
714         return_VALUE(object->type);
715 }
716 #endif