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);
142 * Calculate the number of arguments being passed to the method
145 info->param_count = 0;
146 if (info->parameters) {
147 while (info->parameters[info->param_count])
152 * Warning if too few or too many arguments have been passed by the
153 * caller. We don't want to abort here with an error because an
154 * incorrect number of arguments may not cause the method to fail.
155 * However, the method will fail if there are too few arguments passed
156 * and the method attempts to use one of the missing ones.
159 if (info->param_count < info->obj_desc->method.param_count) {
160 ACPI_WARNING((AE_INFO,
161 "Insufficient arguments - "
162 "method [%4.4s] needs %d, found %d",
163 acpi_ut_get_node_name(info->resolved_node),
164 info->obj_desc->method.param_count,
166 } else if (info->param_count >
167 info->obj_desc->method.param_count) {
168 ACPI_WARNING((AE_INFO,
169 "Excess arguments - "
170 "method [%4.4s] needs %d, found %d",
171 acpi_ut_get_node_name(info->
173 info->obj_desc->method.param_count,
177 ACPI_DUMP_PATHNAME(info->resolved_node, "Execute Method:",
178 ACPI_LV_INFO, _COMPONENT);
180 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
181 "Method at AML address %p Length %X\n",
182 info->obj_desc->method.aml_start + 1,
183 info->obj_desc->method.aml_length - 1));
186 * Any namespace deletion must acquire both the namespace and
187 * interpreter locks to ensure that no thread is using the portion of
188 * the namespace that is being deleted.
190 * Execute the method via the interpreter. The interpreter is locked
191 * here before calling into the AML parser
193 acpi_ex_enter_interpreter();
194 status = acpi_ps_execute_method(info);
195 acpi_ex_exit_interpreter();
198 * 2) Object is not a method, return its current value
200 * Disallow certain object types. For these, "evaluation" is undefined.
202 switch (info->resolved_node->type) {
203 case ACPI_TYPE_DEVICE:
204 case ACPI_TYPE_EVENT:
205 case ACPI_TYPE_MUTEX:
206 case ACPI_TYPE_REGION:
207 case ACPI_TYPE_THERMAL:
208 case ACPI_TYPE_LOCAL_SCOPE:
211 "[%4.4s] Evaluation of object type [%s] is not supported",
212 info->resolved_node->name.ascii,
213 acpi_ut_get_type_name(info->resolved_node->
216 return_ACPI_STATUS(AE_TYPE);
223 * Objects require additional resolution steps (e.g., the Node may be
224 * a field that must be read, etc.) -- we can't just grab the object
227 * Use resolve_node_to_value() to get the associated value.
229 * NOTE: we can get away with passing in NULL for a walk state because
230 * resolved_node is guaranteed to not be a reference to either a method
231 * local or a method argument (because this interface is never called
232 * from a running method.)
234 * Even though we do not directly invoke the interpreter for object
235 * resolution, we must lock it because we could access an opregion.
236 * The opregion access code assumes that the interpreter is locked.
238 acpi_ex_enter_interpreter();
240 /* Function has a strange interface */
243 acpi_ex_resolve_node_to_value(&info->resolved_node, NULL);
244 acpi_ex_exit_interpreter();
247 * If acpi_ex_resolve_node_to_value() succeeded, the return value was placed
250 if (ACPI_SUCCESS(status)) {
251 status = AE_CTRL_RETURN_VALUE;
252 info->return_object =
253 ACPI_CAST_PTR(union acpi_operand_object,
254 info->resolved_node);
256 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
257 "Returning object %p [%s]\n",
259 acpi_ut_get_object_type_name(info->
265 * Check if there is a return value that must be dealt with
267 if (status == AE_CTRL_RETURN_VALUE) {
269 /* If caller does not want the return value, delete it */
271 if (info->flags & ACPI_IGNORE_RETURN_VALUE) {
272 acpi_ut_remove_reference(info->return_object);
273 info->return_object = NULL;
276 /* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
281 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
282 "*** Completed evaluation of object %s ***\n",
286 * Namespace was unlocked by the handling acpi_ns* function, so we
289 return_ACPI_STATUS(status);