1 /*******************************************************************************
3 * Module Name: nseval - Object evaluation, includes control method execution
5 ******************************************************************************/
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44 #include <acpi/acpi.h>
45 #include <acpi/acparser.h>
46 #include <acpi/acinterp.h>
47 #include <acpi/acnamesp.h>
49 #define _COMPONENT ACPI_NAMESPACE
50 ACPI_MODULE_NAME("nseval")
52 /*******************************************************************************
54 * FUNCTION: acpi_ns_evaluate
56 * PARAMETERS: Info - Evaluation info block, contains:
57 * prefix_node - Prefix or Method/Object Node to execute
58 * Pathname - Name of method to execute, If NULL, the
59 * Node is the object to execute
60 * Parameters - List of parameters to pass to the method,
61 * terminated by NULL. Params itself may be
62 * NULL if no parameters are being passed.
63 * return_object - Where to put method's return value (if
64 * any). If NULL, no value is returned.
65 * parameter_type - Type of Parameter list
66 * return_object - Where to put method's return value (if
67 * any). If NULL, no value is returned.
68 * Flags - ACPI_IGNORE_RETURN_VALUE to delete return
72 * DESCRIPTION: Execute a control method or return the current value of an
73 * ACPI namespace object.
75 * MUTEX: Locks interpreter
77 ******************************************************************************/
78 acpi_status
acpi_ns_evaluate(struct acpi_evaluate_info
* info
)
81 struct acpi_namespace_node
*node
;
83 ACPI_FUNCTION_TRACE(ns_evaluate
);
86 return_ACPI_STATUS(AE_BAD_PARAMETER
);
89 /* Initialize the return value to an invalid object */
91 info
->return_object
= NULL
;
92 info
->param_count
= 0;
95 * Get the actual namespace node for the target object. Handles these cases:
97 * 1) Null node, Pathname (absolute path)
98 * 2) Node, Pathname (path relative to Node)
99 * 3) Node, Null Pathname
101 status
= acpi_ns_get_node(info
->prefix_node
, info
->pathname
,
102 ACPI_NS_NO_UPSEARCH
, &info
->resolved_node
);
103 if (ACPI_FAILURE(status
)) {
104 return_ACPI_STATUS(status
);
108 * For a method alias, we must grab the actual method node so that proper
109 * scoping context will be established before execution.
111 if (acpi_ns_get_type(info
->resolved_node
) ==
112 ACPI_TYPE_LOCAL_METHOD_ALIAS
) {
113 info
->resolved_node
=
114 ACPI_CAST_PTR(struct acpi_namespace_node
,
115 info
->resolved_node
->object
);
118 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
, "%s [%p] Value %p\n", info
->pathname
,
120 acpi_ns_get_attached_object(info
->resolved_node
)));
122 node
= info
->resolved_node
;
125 * Two major cases here:
127 * 1) The object is a control method -- execute it
128 * 2) The object is not a method -- just return it's current value
130 if (acpi_ns_get_type(info
->resolved_node
) == ACPI_TYPE_METHOD
) {
132 * 1) Object is a control method - execute it
135 /* Verify that there is a method object associated with this node */
138 acpi_ns_get_attached_object(info
->resolved_node
);
139 if (!info
->obj_desc
) {
141 "Control method has no attached sub-object"));
142 return_ACPI_STATUS(AE_NULL_OBJECT
);
145 /* Count the number of arguments being passed to the method */
147 if (info
->parameters
) {
148 while (info
->parameters
[info
->param_count
]) {
149 if (info
->param_count
> ACPI_METHOD_MAX_ARG
) {
150 return_ACPI_STATUS(AE_LIMIT
);
157 ACPI_DUMP_PATHNAME(info
->resolved_node
, "Execute Method:",
158 ACPI_LV_INFO
, _COMPONENT
);
160 ACPI_DEBUG_PRINT((ACPI_DB_EXEC
,
161 "Method at AML address %p Length %X\n",
162 info
->obj_desc
->method
.aml_start
+ 1,
163 info
->obj_desc
->method
.aml_length
- 1));
166 * Any namespace deletion must acquire both the namespace and
167 * interpreter locks to ensure that no thread is using the portion of
168 * the namespace that is being deleted.
170 * Execute the method via the interpreter. The interpreter is locked
171 * here before calling into the AML parser
173 acpi_ex_enter_interpreter();
174 status
= acpi_ps_execute_method(info
);
175 acpi_ex_exit_interpreter();
178 * 2) Object is not a method, return its current value
180 * Disallow certain object types. For these, "evaluation" is undefined.
182 switch (info
->resolved_node
->type
) {
183 case ACPI_TYPE_DEVICE
:
184 case ACPI_TYPE_EVENT
:
185 case ACPI_TYPE_MUTEX
:
186 case ACPI_TYPE_REGION
:
187 case ACPI_TYPE_THERMAL
:
188 case ACPI_TYPE_LOCAL_SCOPE
:
191 "[%4.4s] Evaluation of object type [%s] is not supported",
192 info
->resolved_node
->name
.ascii
,
193 acpi_ut_get_type_name(info
->resolved_node
->
196 return_ACPI_STATUS(AE_TYPE
);
203 * Objects require additional resolution steps (e.g., the Node may be
204 * a field that must be read, etc.) -- we can't just grab the object
207 * Use resolve_node_to_value() to get the associated value.
209 * NOTE: we can get away with passing in NULL for a walk state because
210 * resolved_node is guaranteed to not be a reference to either a method
211 * local or a method argument (because this interface is never called
212 * from a running method.)
214 * Even though we do not directly invoke the interpreter for object
215 * resolution, we must lock it because we could access an opregion.
216 * The opregion access code assumes that the interpreter is locked.
218 acpi_ex_enter_interpreter();
220 /* Function has a strange interface */
223 acpi_ex_resolve_node_to_value(&info
->resolved_node
, NULL
);
224 acpi_ex_exit_interpreter();
227 * If acpi_ex_resolve_node_to_value() succeeded, the return value was placed
230 if (ACPI_SUCCESS(status
)) {
231 status
= AE_CTRL_RETURN_VALUE
;
232 info
->return_object
=
233 ACPI_CAST_PTR(union acpi_operand_object
,
234 info
->resolved_node
);
236 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
237 "Returning object %p [%s]\n",
239 acpi_ut_get_object_type_name(info
->
245 * Check input argument count against the ASL-defined count for a method.
246 * Also check predefined names: argument count and return value against
247 * the ACPI specification. Some incorrect return value types are repaired.
249 (void)acpi_ns_check_predefined_names(node
, info
->param_count
,
250 status
, &info
->return_object
);
252 /* Check if there is a return value that must be dealt with */
254 if (status
== AE_CTRL_RETURN_VALUE
) {
256 /* If caller does not want the return value, delete it */
258 if (info
->flags
& ACPI_IGNORE_RETURN_VALUE
) {
259 acpi_ut_remove_reference(info
->return_object
);
260 info
->return_object
= NULL
;
263 /* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
268 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
269 "*** Completed evaluation of object %s ***\n",
273 * Namespace was unlocked by the handling acpi_ns* function, so we
276 return_ACPI_STATUS(status
);