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
)
82 ACPI_FUNCTION_TRACE(ns_evaluate
);
85 return_ACPI_STATUS(AE_BAD_PARAMETER
);
88 /* Initialize the return value to an invalid object */
90 info
->return_object
= NULL
;
93 * Get the actual namespace node for the target object. Handles these cases:
95 * 1) Null node, Pathname (absolute path)
96 * 2) Node, Pathname (path relative to Node)
97 * 3) Node, Null Pathname
99 status
= acpi_ns_get_node(info
->prefix_node
, info
->pathname
,
100 ACPI_NS_NO_UPSEARCH
, &info
->resolved_node
);
101 if (ACPI_FAILURE(status
)) {
102 return_ACPI_STATUS(status
);
106 * For a method alias, we must grab the actual method node so that proper
107 * scoping context will be established before execution.
109 if (acpi_ns_get_type(info
->resolved_node
) ==
110 ACPI_TYPE_LOCAL_METHOD_ALIAS
) {
111 info
->resolved_node
=
112 ACPI_CAST_PTR(struct acpi_namespace_node
,
113 info
->resolved_node
->object
);
116 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
, "%s [%p] Value %p\n", info
->pathname
,
118 acpi_ns_get_attached_object(info
->resolved_node
)));
121 * Two major cases here:
123 * 1) The object is a control method -- execute it
124 * 2) The object is not a method -- just return it's current value
126 if (acpi_ns_get_type(info
->resolved_node
) == ACPI_TYPE_METHOD
) {
128 * 1) Object is a control method - execute it
131 /* Verify that there is a method object associated with this node */
134 acpi_ns_get_attached_object(info
->resolved_node
);
135 if (!info
->obj_desc
) {
137 "Control method has no attached sub-object"));
138 return_ACPI_STATUS(AE_NULL_OBJECT
);
141 ACPI_DUMP_PATHNAME(info
->resolved_node
, "Execute Method:",
142 ACPI_LV_INFO
, _COMPONENT
);
144 ACPI_DEBUG_PRINT((ACPI_DB_EXEC
,
145 "Method at AML address %p Length %X\n",
146 info
->obj_desc
->method
.aml_start
+ 1,
147 info
->obj_desc
->method
.aml_length
- 1));
150 * Any namespace deletion must acquire both the namespace and
151 * interpreter locks to ensure that no thread is using the portion of
152 * the namespace that is being deleted.
154 * Execute the method via the interpreter. The interpreter is locked
155 * here before calling into the AML parser
157 acpi_ex_enter_interpreter();
158 status
= acpi_ps_execute_method(info
);
159 acpi_ex_exit_interpreter();
162 * 2) Object is not a method, return its current value
166 * Objects require additional resolution steps (e.g., the Node may be
167 * a field that must be read, etc.) -- we can't just grab the object
170 * Use resolve_node_to_value() to get the associated value.
172 * NOTE: we can get away with passing in NULL for a walk state because
173 * resolved_node is guaranteed to not be a reference to either a method
174 * local or a method argument (because this interface is never called
175 * from a running method.)
177 * Even though we do not directly invoke the interpreter for object
178 * resolution, we must lock it because we could access an opregion.
179 * The opregion access code assumes that the interpreter is locked.
181 acpi_ex_enter_interpreter();
183 /* Function has a strange interface */
186 acpi_ex_resolve_node_to_value(&info
->resolved_node
, NULL
);
187 acpi_ex_exit_interpreter();
190 * If acpi_ex_resolve_node_to_value() succeeded, the return value was placed
193 if (ACPI_SUCCESS(status
)) {
194 status
= AE_CTRL_RETURN_VALUE
;
195 info
->return_object
=
196 ACPI_CAST_PTR(union acpi_operand_object
,
197 info
->resolved_node
);
199 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
200 "Returning object %p [%s]\n",
202 acpi_ut_get_object_type_name(info
->
208 * Check if there is a return value that must be dealt with
210 if (status
== AE_CTRL_RETURN_VALUE
) {
212 /* If caller does not want the return value, delete it */
214 if (info
->flags
& ACPI_IGNORE_RETURN_VALUE
) {
215 acpi_ut_remove_reference(info
->return_object
);
216 info
->return_object
= NULL
;
219 /* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
224 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
225 "*** Completed evaluation of object %s ***\n",
229 * Namespace was unlocked by the handling acpi_ns* function, so we
232 return_ACPI_STATUS(status
);