ACPICA: hide private headers
[linux-2.6.git] / drivers / acpi / acpica / nseval.c
1 /*******************************************************************************
2  *
3  * Module Name: nseval - Object evaluation, includes control method execution
4  *
5  ******************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2008, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acparser.h"
47 #include "acinterp.h"
48 #include "acnamesp.h"
49
50 #define _COMPONENT          ACPI_NAMESPACE
51 ACPI_MODULE_NAME("nseval")
52
53 /*******************************************************************************
54  *
55  * FUNCTION:    acpi_ns_evaluate
56  *
57  * PARAMETERS:  Info            - Evaluation info block, contains:
58  *                  prefix_node     - Prefix or Method/Object Node to execute
59  *                  Pathname        - Name of method to execute, If NULL, the
60  *                                    Node is the object to execute
61  *                  Parameters      - List of parameters to pass to the method,
62  *                                    terminated by NULL. Params itself may be
63  *                                    NULL if no parameters are being passed.
64  *                  return_object   - Where to put method's return value (if
65  *                                    any). If NULL, no value is returned.
66  *                  parameter_type  - Type of Parameter list
67  *                  return_object   - Where to put method's return value (if
68  *                                    any). If NULL, no value is returned.
69  *                  Flags           - ACPI_IGNORE_RETURN_VALUE to delete return
70  *
71  * RETURN:      Status
72  *
73  * DESCRIPTION: Execute a control method or return the current value of an
74  *              ACPI namespace object.
75  *
76  * MUTEX:       Locks interpreter
77  *
78  ******************************************************************************/
79 acpi_status acpi_ns_evaluate(struct acpi_evaluate_info * info)
80 {
81         acpi_status status;
82         struct acpi_namespace_node *node;
83
84         ACPI_FUNCTION_TRACE(ns_evaluate);
85
86         if (!info) {
87                 return_ACPI_STATUS(AE_BAD_PARAMETER);
88         }
89
90         /* Initialize the return value to an invalid object */
91
92         info->return_object = NULL;
93         info->param_count = 0;
94
95         /*
96          * Get the actual namespace node for the target object. Handles these cases:
97          *
98          * 1) Null node, Pathname (absolute path)
99          * 2) Node, Pathname (path relative to Node)
100          * 3) Node, Null Pathname
101          */
102         status = acpi_ns_get_node(info->prefix_node, info->pathname,
103                                   ACPI_NS_NO_UPSEARCH, &info->resolved_node);
104         if (ACPI_FAILURE(status)) {
105                 return_ACPI_STATUS(status);
106         }
107
108         /*
109          * For a method alias, we must grab the actual method node so that proper
110          * scoping context will be established before execution.
111          */
112         if (acpi_ns_get_type(info->resolved_node) ==
113             ACPI_TYPE_LOCAL_METHOD_ALIAS) {
114                 info->resolved_node =
115                     ACPI_CAST_PTR(struct acpi_namespace_node,
116                                   info->resolved_node->object);
117         }
118
119         ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "%s [%p] Value %p\n", info->pathname,
120                           info->resolved_node,
121                           acpi_ns_get_attached_object(info->resolved_node)));
122
123         node = info->resolved_node;
124
125         /*
126          * Two major cases here:
127          *
128          * 1) The object is a control method -- execute it
129          * 2) The object is not a method -- just return it's current value
130          */
131         if (acpi_ns_get_type(info->resolved_node) == ACPI_TYPE_METHOD) {
132                 /*
133                  * 1) Object is a control method - execute it
134                  */
135
136                 /* Verify that there is a method object associated with this node */
137
138                 info->obj_desc =
139                     acpi_ns_get_attached_object(info->resolved_node);
140                 if (!info->obj_desc) {
141                         ACPI_ERROR((AE_INFO,
142                                     "Control method has no attached sub-object"));
143                         return_ACPI_STATUS(AE_NULL_OBJECT);
144                 }
145
146                 /* Count the number of arguments being passed to the method */
147
148                 if (info->parameters) {
149                         while (info->parameters[info->param_count]) {
150                                 if (info->param_count > ACPI_METHOD_MAX_ARG) {
151                                         return_ACPI_STATUS(AE_LIMIT);
152                                 }
153                                 info->param_count++;
154                         }
155                 }
156
157
158                 ACPI_DUMP_PATHNAME(info->resolved_node, "Execute Method:",
159                                    ACPI_LV_INFO, _COMPONENT);
160
161                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
162                                   "Method at AML address %p Length %X\n",
163                                   info->obj_desc->method.aml_start + 1,
164                                   info->obj_desc->method.aml_length - 1));
165
166                 /*
167                  * Any namespace deletion must acquire both the namespace and
168                  * interpreter locks to ensure that no thread is using the portion of
169                  * the namespace that is being deleted.
170                  *
171                  * Execute the method via the interpreter. The interpreter is locked
172                  * here before calling into the AML parser
173                  */
174                 acpi_ex_enter_interpreter();
175                 status = acpi_ps_execute_method(info);
176                 acpi_ex_exit_interpreter();
177         } else {
178                 /*
179                  * 2) Object is not a method, return its current value
180                  *
181                  * Disallow certain object types. For these, "evaluation" is undefined.
182                  */
183                 switch (info->resolved_node->type) {
184                 case ACPI_TYPE_DEVICE:
185                 case ACPI_TYPE_EVENT:
186                 case ACPI_TYPE_MUTEX:
187                 case ACPI_TYPE_REGION:
188                 case ACPI_TYPE_THERMAL:
189                 case ACPI_TYPE_LOCAL_SCOPE:
190
191                         ACPI_ERROR((AE_INFO,
192                                     "[%4.4s] Evaluation of object type [%s] is not supported",
193                                     info->resolved_node->name.ascii,
194                                     acpi_ut_get_type_name(info->resolved_node->
195                                                           type)));
196
197                         return_ACPI_STATUS(AE_TYPE);
198
199                 default:
200                         break;
201                 }
202
203                 /*
204                  * Objects require additional resolution steps (e.g., the Node may be
205                  * a field that must be read, etc.) -- we can't just grab the object
206                  * out of the node.
207                  *
208                  * Use resolve_node_to_value() to get the associated value.
209                  *
210                  * NOTE: we can get away with passing in NULL for a walk state because
211                  * resolved_node is guaranteed to not be a reference to either a method
212                  * local or a method argument (because this interface is never called
213                  * from a running method.)
214                  *
215                  * Even though we do not directly invoke the interpreter for object
216                  * resolution, we must lock it because we could access an opregion.
217                  * The opregion access code assumes that the interpreter is locked.
218                  */
219                 acpi_ex_enter_interpreter();
220
221                 /* Function has a strange interface */
222
223                 status =
224                     acpi_ex_resolve_node_to_value(&info->resolved_node, NULL);
225                 acpi_ex_exit_interpreter();
226
227                 /*
228                  * If acpi_ex_resolve_node_to_value() succeeded, the return value was placed
229                  * in resolved_node.
230                  */
231                 if (ACPI_SUCCESS(status)) {
232                         status = AE_CTRL_RETURN_VALUE;
233                         info->return_object =
234                             ACPI_CAST_PTR(union acpi_operand_object,
235                                           info->resolved_node);
236
237                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
238                                           "Returning object %p [%s]\n",
239                                           info->return_object,
240                                           acpi_ut_get_object_type_name(info->
241                                                                        return_object)));
242                 }
243         }
244
245         /*
246          * Check input argument count against the ASL-defined count for a method.
247          * Also check predefined names: argument count and return value against
248          * the ACPI specification. Some incorrect return value types are repaired.
249          */
250         (void)acpi_ns_check_predefined_names(node, info->param_count,
251                 status, &info->return_object);
252
253         /* Check if there is a return value that must be dealt with */
254
255         if (status == AE_CTRL_RETURN_VALUE) {
256
257                 /* If caller does not want the return value, delete it */
258
259                 if (info->flags & ACPI_IGNORE_RETURN_VALUE) {
260                         acpi_ut_remove_reference(info->return_object);
261                         info->return_object = NULL;
262                 }
263
264                 /* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
265
266                 status = AE_OK;
267         }
268
269         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
270                           "*** Completed evaluation of object %s ***\n",
271                           info->pathname));
272
273         /*
274          * Namespace was unlocked by the handling acpi_ns* function, so we
275          * just return
276          */
277         return_ACPI_STATUS(status);
278 }