[CPUFREQ] If max_freq got reduced (e.g. by _PPC) a write to sysfs scaling_governor...
[linux-2.6] / drivers / acpi / executer / exresolv.c
1
2 /******************************************************************************
3  *
4  * Module Name: exresolv - AML Interpreter object resolution
5  *
6  *****************************************************************************/
7
8 /*
9  * Copyright (C) 2000 - 2006, R. Byron Moore
10  * All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions, and the following disclaimer,
17  *    without modification.
18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19  *    substantially similar to the "NO WARRANTY" disclaimer below
20  *    ("Disclaimer") and any redistribution must be conditioned upon
21  *    including a substantially similar Disclaimer requirement for further
22  *    binary redistribution.
23  * 3. Neither the names of the above-listed copyright holders nor the names
24  *    of any contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * Alternatively, this software may be distributed under the terms of the
28  * GNU General Public License ("GPL") version 2 as published by the Free
29  * Software Foundation.
30  *
31  * NO WARRANTY
32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42  * POSSIBILITY OF SUCH DAMAGES.
43  */
44
45 #include <acpi/acpi.h>
46 #include <acpi/amlcode.h>
47 #include <acpi/acdispat.h>
48 #include <acpi/acinterp.h>
49 #include <acpi/acnamesp.h>
50 #include <acpi/acparser.h>
51
52 #define _COMPONENT          ACPI_EXECUTER
53 ACPI_MODULE_NAME("exresolv")
54
55 /* Local prototypes */
56 static acpi_status
57 acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
58                                 struct acpi_walk_state *walk_state);
59
60 /*******************************************************************************
61  *
62  * FUNCTION:    acpi_ex_resolve_to_value
63  *
64  * PARAMETERS:  **stack_ptr         - Points to entry on obj_stack, which can
65  *                                    be either an (union acpi_operand_object *)
66  *                                    or an acpi_handle.
67  *              walk_state          - Current method state
68  *
69  * RETURN:      Status
70  *
71  * DESCRIPTION: Convert Reference objects to values
72  *
73  ******************************************************************************/
74
75 acpi_status
76 acpi_ex_resolve_to_value(union acpi_operand_object **stack_ptr,
77                          struct acpi_walk_state *walk_state)
78 {
79         acpi_status status;
80
81         ACPI_FUNCTION_TRACE_PTR("ex_resolve_to_value", stack_ptr);
82
83         if (!stack_ptr || !*stack_ptr) {
84                 ACPI_ERROR((AE_INFO, "Internal - null pointer"));
85                 return_ACPI_STATUS(AE_AML_NO_OPERAND);
86         }
87
88         /*
89          * The entity pointed to by the stack_ptr can be either
90          * 1) A valid union acpi_operand_object, or
91          * 2) A struct acpi_namespace_node (named_obj)
92          */
93         if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_OPERAND) {
94                 status = acpi_ex_resolve_object_to_value(stack_ptr, walk_state);
95                 if (ACPI_FAILURE(status)) {
96                         return_ACPI_STATUS(status);
97                 }
98
99                 if (!*stack_ptr) {
100                         ACPI_ERROR((AE_INFO, "Internal - null pointer"));
101                         return_ACPI_STATUS(AE_AML_NO_OPERAND);
102                 }
103         }
104
105         /*
106          * Object on the stack may have changed if acpi_ex_resolve_object_to_value()
107          * was called (i.e., we can't use an _else_ here.)
108          */
109         if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_NAMED) {
110                 status =
111                     acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
112                                                   (struct acpi_namespace_node,
113                                                    stack_ptr), walk_state);
114                 if (ACPI_FAILURE(status)) {
115                         return_ACPI_STATUS(status);
116                 }
117         }
118
119         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Resolved object %p\n", *stack_ptr));
120         return_ACPI_STATUS(AE_OK);
121 }
122
123 /*******************************************************************************
124  *
125  * FUNCTION:    acpi_ex_resolve_object_to_value
126  *
127  * PARAMETERS:  stack_ptr       - Pointer to an internal object
128  *              walk_state      - Current method state
129  *
130  * RETURN:      Status
131  *
132  * DESCRIPTION: Retrieve the value from an internal object. The Reference type
133  *              uses the associated AML opcode to determine the value.
134  *
135  ******************************************************************************/
136
137 static acpi_status
138 acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
139                                 struct acpi_walk_state *walk_state)
140 {
141         acpi_status status = AE_OK;
142         union acpi_operand_object *stack_desc;
143         void *temp_node;
144         union acpi_operand_object *obj_desc;
145         u16 opcode;
146
147         ACPI_FUNCTION_TRACE("ex_resolve_object_to_value");
148
149         stack_desc = *stack_ptr;
150
151         /* This is an union acpi_operand_object    */
152
153         switch (ACPI_GET_OBJECT_TYPE(stack_desc)) {
154         case ACPI_TYPE_LOCAL_REFERENCE:
155
156                 opcode = stack_desc->reference.opcode;
157
158                 switch (opcode) {
159                 case AML_NAME_OP:
160
161                         /*
162                          * Convert name reference to a namespace node
163                          * Then, acpi_ex_resolve_node_to_value can be used to get the value
164                          */
165                         temp_node = stack_desc->reference.object;
166
167                         /* Delete the Reference Object */
168
169                         acpi_ut_remove_reference(stack_desc);
170
171                         /* Return the namespace node */
172
173                         (*stack_ptr) = temp_node;
174                         break;
175
176                 case AML_LOCAL_OP:
177                 case AML_ARG_OP:
178
179                         /*
180                          * Get the local from the method's state info
181                          * Note: this increments the local's object reference count
182                          */
183                         status = acpi_ds_method_data_get_value(opcode,
184                                                                stack_desc->
185                                                                reference.offset,
186                                                                walk_state,
187                                                                &obj_desc);
188                         if (ACPI_FAILURE(status)) {
189                                 return_ACPI_STATUS(status);
190                         }
191
192                         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
193                                           "[Arg/Local %X] value_obj is %p\n",
194                                           stack_desc->reference.offset,
195                                           obj_desc));
196
197                         /*
198                          * Now we can delete the original Reference Object and
199                          * replace it with the resolved value
200                          */
201                         acpi_ut_remove_reference(stack_desc);
202                         *stack_ptr = obj_desc;
203                         break;
204
205                 case AML_INDEX_OP:
206
207                         switch (stack_desc->reference.target_type) {
208                         case ACPI_TYPE_BUFFER_FIELD:
209
210                                 /* Just return - leave the Reference on the stack */
211                                 break;
212
213                         case ACPI_TYPE_PACKAGE:
214
215                                 obj_desc = *stack_desc->reference.where;
216                                 if (obj_desc) {
217                                         /*
218                                          * Valid obj descriptor, copy pointer to return value
219                                          * (i.e., dereference the package index)
220                                          * Delete the ref object, increment the returned object
221                                          */
222                                         acpi_ut_remove_reference(stack_desc);
223                                         acpi_ut_add_reference(obj_desc);
224                                         *stack_ptr = obj_desc;
225                                 } else {
226                                         /*
227                                          * A NULL object descriptor means an unitialized element of
228                                          * the package, can't dereference it
229                                          */
230                                         ACPI_ERROR((AE_INFO,
231                                                     "Attempt to deref an Index to NULL pkg element Idx=%p",
232                                                     stack_desc));
233                                         status = AE_AML_UNINITIALIZED_ELEMENT;
234                                 }
235                                 break;
236
237                         default:
238
239                                 /* Invalid reference object */
240
241                                 ACPI_ERROR((AE_INFO,
242                                             "Unknown target_type %X in Index/Reference obj %p",
243                                             stack_desc->reference.target_type,
244                                             stack_desc));
245                                 status = AE_AML_INTERNAL;
246                                 break;
247                         }
248                         break;
249
250                 case AML_REF_OF_OP:
251                 case AML_DEBUG_OP:
252                 case AML_LOAD_OP:
253
254                         /* Just leave the object as-is */
255
256                         break;
257
258                 case AML_INT_NAMEPATH_OP:       /* Reference to a named object */
259
260                         /* Get the object pointed to by the namespace node */
261
262                         *stack_ptr = (stack_desc->reference.node)->object;
263                         acpi_ut_add_reference(*stack_ptr);
264                         acpi_ut_remove_reference(stack_desc);
265                         break;
266
267                 default:
268
269                         ACPI_ERROR((AE_INFO,
270                                     "Unknown Reference opcode %X (%s) in %p",
271                                     opcode, acpi_ps_get_opcode_name(opcode),
272                                     stack_desc));
273                         status = AE_AML_INTERNAL;
274                         break;
275                 }
276                 break;
277
278         case ACPI_TYPE_BUFFER:
279
280                 status = acpi_ds_get_buffer_arguments(stack_desc);
281                 break;
282
283         case ACPI_TYPE_PACKAGE:
284
285                 status = acpi_ds_get_package_arguments(stack_desc);
286                 break;
287
288                 /* These cases may never happen here, but just in case.. */
289
290         case ACPI_TYPE_BUFFER_FIELD:
291         case ACPI_TYPE_LOCAL_REGION_FIELD:
292         case ACPI_TYPE_LOCAL_BANK_FIELD:
293         case ACPI_TYPE_LOCAL_INDEX_FIELD:
294
295                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
296                                   "field_read source_desc=%p Type=%X\n",
297                                   stack_desc,
298                                   ACPI_GET_OBJECT_TYPE(stack_desc)));
299
300                 status =
301                     acpi_ex_read_data_from_field(walk_state, stack_desc,
302                                                  &obj_desc);
303                 *stack_ptr = (void *)obj_desc;
304                 break;
305
306         default:
307                 break;
308         }
309
310         return_ACPI_STATUS(status);
311 }
312
313 /*******************************************************************************
314  *
315  * FUNCTION:    acpi_ex_resolve_multiple
316  *
317  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
318  *              Operand             - Starting point for resolution
319  *              return_type         - Where the object type is returned
320  *              return_desc         - Where the resolved object is returned
321  *
322  * RETURN:      Status
323  *
324  * DESCRIPTION: Return the base object and type.  Traverse a reference list if
325  *              necessary to get to the base object.
326  *
327  ******************************************************************************/
328
329 acpi_status
330 acpi_ex_resolve_multiple(struct acpi_walk_state *walk_state,
331                          union acpi_operand_object *operand,
332                          acpi_object_type * return_type,
333                          union acpi_operand_object **return_desc)
334 {
335         union acpi_operand_object *obj_desc = (void *)operand;
336         struct acpi_namespace_node *node;
337         acpi_object_type type;
338         acpi_status status;
339
340         ACPI_FUNCTION_TRACE("acpi_ex_resolve_multiple");
341
342         /* Operand can be either a namespace node or an operand descriptor */
343
344         switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
345         case ACPI_DESC_TYPE_OPERAND:
346                 type = obj_desc->common.type;
347                 break;
348
349         case ACPI_DESC_TYPE_NAMED:
350                 type = ((struct acpi_namespace_node *)obj_desc)->type;
351                 obj_desc =
352                     acpi_ns_get_attached_object((struct acpi_namespace_node *)
353                                                 obj_desc);
354
355                 /* If we had an Alias node, use the attached object for type info */
356
357                 if (type == ACPI_TYPE_LOCAL_ALIAS) {
358                         type = ((struct acpi_namespace_node *)obj_desc)->type;
359                         obj_desc =
360                             acpi_ns_get_attached_object((struct
361                                                          acpi_namespace_node *)
362                                                         obj_desc);
363                 }
364                 break;
365
366         default:
367                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
368         }
369
370         /* If type is anything other than a reference, we are done */
371
372         if (type != ACPI_TYPE_LOCAL_REFERENCE) {
373                 goto exit;
374         }
375
376         /*
377          * For reference objects created via the ref_of or Index operators,
378          * we need to get to the base object (as per the ACPI specification
379          * of the object_type and size_of operators). This means traversing
380          * the list of possibly many nested references.
381          */
382         while (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REFERENCE) {
383                 switch (obj_desc->reference.opcode) {
384                 case AML_REF_OF_OP:
385
386                         /* Dereference the reference pointer */
387
388                         node = obj_desc->reference.object;
389
390                         /* All "References" point to a NS node */
391
392                         if (ACPI_GET_DESCRIPTOR_TYPE(node) !=
393                             ACPI_DESC_TYPE_NAMED) {
394                                 ACPI_ERROR((AE_INFO, "Not a NS node %p [%s]",
395                                             node,
396                                             acpi_ut_get_descriptor_name(node)));
397                                 return_ACPI_STATUS(AE_AML_INTERNAL);
398                         }
399
400                         /* Get the attached object */
401
402                         obj_desc = acpi_ns_get_attached_object(node);
403                         if (!obj_desc) {
404                                 /* No object, use the NS node type */
405
406                                 type = acpi_ns_get_type(node);
407                                 goto exit;
408                         }
409
410                         /* Check for circular references */
411
412                         if (obj_desc == operand) {
413                                 return_ACPI_STATUS(AE_AML_CIRCULAR_REFERENCE);
414                         }
415                         break;
416
417                 case AML_INDEX_OP:
418
419                         /* Get the type of this reference (index into another object) */
420
421                         type = obj_desc->reference.target_type;
422                         if (type != ACPI_TYPE_PACKAGE) {
423                                 goto exit;
424                         }
425
426                         /*
427                          * The main object is a package, we want to get the type
428                          * of the individual package element that is referenced by
429                          * the index.
430                          *
431                          * This could of course in turn be another reference object.
432                          */
433                         obj_desc = *(obj_desc->reference.where);
434                         if (!obj_desc) {
435                                 /* NULL package elements are allowed */
436
437                                 type = 0;       /* Uninitialized */
438                                 goto exit;
439                         }
440                         break;
441
442                 case AML_INT_NAMEPATH_OP:
443
444                         /* Dereference the reference pointer */
445
446                         node = obj_desc->reference.node;
447
448                         /* All "References" point to a NS node */
449
450                         if (ACPI_GET_DESCRIPTOR_TYPE(node) !=
451                             ACPI_DESC_TYPE_NAMED) {
452                                 ACPI_ERROR((AE_INFO, "Not a NS node %p [%s]",
453                                             node,
454                                             acpi_ut_get_descriptor_name(node)));
455                                 return_ACPI_STATUS(AE_AML_INTERNAL);
456                         }
457
458                         /* Get the attached object */
459
460                         obj_desc = acpi_ns_get_attached_object(node);
461                         if (!obj_desc) {
462                                 /* No object, use the NS node type */
463
464                                 type = acpi_ns_get_type(node);
465                                 goto exit;
466                         }
467
468                         /* Check for circular references */
469
470                         if (obj_desc == operand) {
471                                 return_ACPI_STATUS(AE_AML_CIRCULAR_REFERENCE);
472                         }
473                         break;
474
475                 case AML_LOCAL_OP:
476                 case AML_ARG_OP:
477
478                         if (return_desc) {
479                                 status =
480                                     acpi_ds_method_data_get_value(obj_desc->
481                                                                   reference.
482                                                                   opcode,
483                                                                   obj_desc->
484                                                                   reference.
485                                                                   offset,
486                                                                   walk_state,
487                                                                   &obj_desc);
488                                 if (ACPI_FAILURE(status)) {
489                                         return_ACPI_STATUS(status);
490                                 }
491                                 acpi_ut_remove_reference(obj_desc);
492                         } else {
493                                 status =
494                                     acpi_ds_method_data_get_node(obj_desc->
495                                                                  reference.
496                                                                  opcode,
497                                                                  obj_desc->
498                                                                  reference.
499                                                                  offset,
500                                                                  walk_state,
501                                                                  &node);
502                                 if (ACPI_FAILURE(status)) {
503                                         return_ACPI_STATUS(status);
504                                 }
505
506                                 obj_desc = acpi_ns_get_attached_object(node);
507                                 if (!obj_desc) {
508                                         type = ACPI_TYPE_ANY;
509                                         goto exit;
510                                 }
511                         }
512                         break;
513
514                 case AML_DEBUG_OP:
515
516                         /* The Debug Object is of type "debug_object" */
517
518                         type = ACPI_TYPE_DEBUG_OBJECT;
519                         goto exit;
520
521                 default:
522
523                         ACPI_ERROR((AE_INFO,
524                                     "Unknown Reference subtype %X",
525                                     obj_desc->reference.opcode));
526                         return_ACPI_STATUS(AE_AML_INTERNAL);
527                 }
528         }
529
530         /*
531          * Now we are guaranteed to have an object that has not been created
532          * via the ref_of or Index operators.
533          */
534         type = ACPI_GET_OBJECT_TYPE(obj_desc);
535
536       exit:
537         /* Convert internal types to external types */
538
539         switch (type) {
540         case ACPI_TYPE_LOCAL_REGION_FIELD:
541         case ACPI_TYPE_LOCAL_BANK_FIELD:
542         case ACPI_TYPE_LOCAL_INDEX_FIELD:
543
544                 type = ACPI_TYPE_FIELD_UNIT;
545                 break;
546
547         case ACPI_TYPE_LOCAL_SCOPE:
548
549                 /* Per ACPI Specification, Scope is untyped */
550
551                 type = ACPI_TYPE_ANY;
552                 break;
553
554         default:
555                 /* No change to Type required */
556                 break;
557         }
558
559         *return_type = type;
560         if (return_desc) {
561                 *return_desc = obj_desc;
562         }
563         return_ACPI_STATUS(AE_OK);
564 }