[mirror_ubuntu-zesty-kernel.git] / drivers / acpi / namespace / nseval.c

/*******************************************************************************
 *
 * Module Name: nseval - Object evaluation interfaces -- includes control
 *                       method lookup and execution.
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2005, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */


#include <acpi/acpi.h>
#include <acpi/acparser.h>
#include <acpi/acinterp.h>
#include <acpi/acnamesp.h>


#define _COMPONENT          ACPI_NAMESPACE
	 ACPI_MODULE_NAME    ("nseval")


/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_evaluate_relative
 *
 * PARAMETERS:  Pathname            - Name of method to execute, If NULL, the
 *                                    handle is the object to execute
 *              Info                - Method info block
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Find and execute the requested method using the handle as a
 *              scope
 *
 * MUTEX:       Locks Namespace
 *
 ******************************************************************************/

acpi_status
acpi_ns_evaluate_relative (
	char                            *pathname,
	struct acpi_parameter_info      *info)
{
	acpi_status                     status;
	struct acpi_namespace_node      *node = NULL;
	union acpi_generic_state        *scope_info;
	char                            *internal_path = NULL;


	ACPI_FUNCTION_TRACE ("ns_evaluate_relative");


	/*
	 * Must have a valid object handle
	 */
	if (!info || !info->node) {
		return_ACPI_STATUS (AE_BAD_PARAMETER);
	}

	/* Build an internal name string for the method */

	status = acpi_ns_internalize_name (pathname, &internal_path);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	scope_info = acpi_ut_create_generic_state ();
	if (!scope_info) {
		goto cleanup1;
	}

	/* Get the prefix handle and Node */

	status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE (status)) {
		goto cleanup;
	}

	info->node = acpi_ns_map_handle_to_node (info->node);
	if (!info->node) {
		(void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
		status = AE_BAD_PARAMETER;
		goto cleanup;
	}

	/* Lookup the name in the namespace */

	scope_info->scope.node = info->node;
	status = acpi_ns_lookup (scope_info, internal_path, ACPI_TYPE_ANY,
			 ACPI_IMODE_EXECUTE, ACPI_NS_NO_UPSEARCH, NULL,
			 &node);

	(void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);

	if (ACPI_FAILURE (status)) {
		ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "Object [%s] not found [%s]\n",
			pathname, acpi_format_exception (status)));
		goto cleanup;
	}

	/*
	 * Now that we have a handle to the object, we can attempt to evaluate it.
	 */
	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "%s [%p] Value %p\n",
		pathname, node, acpi_ns_get_attached_object (node)));

	info->node = node;
	status = acpi_ns_evaluate_by_handle (info);

	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "*** Completed eval of object %s ***\n",
		pathname));

cleanup:
	acpi_ut_delete_generic_state (scope_info);

cleanup1:
	ACPI_MEM_FREE (internal_path);
	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_evaluate_by_name
 *
 * PARAMETERS:  Pathname            - Fully qualified pathname to the object
 *              Info                - Contains:
 *                  return_object   - Where to put method's return value (if
 *                                    any).  If NULL, no value is returned.
 *                  Params          - List of parameters to pass to the method,
 *                                    terminated by NULL.  Params itself may be
 *                                    NULL if no parameters are being passed.
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Find and execute the requested method passing the given
 *              parameters
 *
 * MUTEX:       Locks Namespace
 *
 ******************************************************************************/

acpi_status
acpi_ns_evaluate_by_name (
	char                            *pathname,
	struct acpi_parameter_info      *info)
{
	acpi_status                     status;
	char                            *internal_path = NULL;


	ACPI_FUNCTION_TRACE ("ns_evaluate_by_name");


	/* Build an internal name string for the method */

	status = acpi_ns_internalize_name (pathname, &internal_path);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE (status)) {
		goto cleanup;
	}

	/* Lookup the name in the namespace */

	status = acpi_ns_lookup (NULL, internal_path, ACPI_TYPE_ANY,
			 ACPI_IMODE_EXECUTE, ACPI_NS_NO_UPSEARCH, NULL,
			 &info->node);

	(void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);

	if (ACPI_FAILURE (status)) {
		ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
			"Object at [%s] was not found, status=%.4X\n",
			pathname, status));
		goto cleanup;
	}

	/*
	 * Now that we have a handle to the object, we can attempt to evaluate it.
	 */
	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "%s [%p] Value %p\n",
		pathname, info->node, acpi_ns_get_attached_object (info->node)));

	status = acpi_ns_evaluate_by_handle (info);

	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "*** Completed eval of object %s ***\n",
		pathname));


cleanup:

	/* Cleanup */

	if (internal_path) {
		ACPI_MEM_FREE (internal_path);
	}

	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_evaluate_by_handle
 *
 * PARAMETERS:  Handle              - Method Node to execute
 *              Params              - List of parameters to pass to the method,
 *                                    terminated by NULL.  Params itself may be
 *                                    NULL if no parameters are being passed.
 *              param_type          - Type of Parameter list
 *              return_object       - Where to put method's return value (if
 *                                    any).  If NULL, no value is returned.
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Execute the requested method passing the given parameters
 *
 * MUTEX:       Locks Namespace
 *
 ******************************************************************************/

acpi_status
acpi_ns_evaluate_by_handle (
	struct acpi_parameter_info      *info)
{
	acpi_status                     status;


	ACPI_FUNCTION_TRACE ("ns_evaluate_by_handle");


	/* Check if namespace has been initialized */

	if (!acpi_gbl_root_node) {
		return_ACPI_STATUS (AE_NO_NAMESPACE);
	}

	/* Parameter Validation */

	if (!info) {
		return_ACPI_STATUS (AE_BAD_PARAMETER);
	}

	/* Initialize the return value to an invalid object */

	info->return_object = NULL;

	/* Get the prefix handle and Node */

	status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	info->node = acpi_ns_map_handle_to_node (info->node);
	if (!info->node) {
		(void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
		return_ACPI_STATUS (AE_BAD_PARAMETER);
	}

	/*
	 * For a method alias, we must grab the actual method node so that proper
	 * scoping context will be established before execution.
	 */
	if (acpi_ns_get_type (info->node) == ACPI_TYPE_LOCAL_METHOD_ALIAS) {
		info->node = ACPI_CAST_PTR (struct acpi_namespace_node, info->node->object);
	}

	/*
	 * Two major cases here:
	 * 1) The object is an actual control method -- execute it.
	 * 2) The object is not a method -- just return it's current value
	 *
	 * In both cases, the namespace is unlocked by the acpi_ns* procedure
	 */
	if (acpi_ns_get_type (info->node) == ACPI_TYPE_METHOD) {
		/*
		 * Case 1) We have an actual control method to execute
		 */
		status = acpi_ns_execute_control_method (info);
	}
	else {
		/*
		 * Case 2) Object is NOT a method, just return its current value
		 */
		status = acpi_ns_get_object_value (info);
	}

	/*
	 * Check if there is a return value on the stack that must be dealt with
	 */
	if (status == AE_CTRL_RETURN_VALUE) {
		/* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */

		status = AE_OK;
	}

	/*
	 * Namespace was unlocked by the handling acpi_ns* function, so we
	 * just return
	 */
	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_execute_control_method
 *
 * PARAMETERS:  Info            - Method info block (w/params)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Execute the requested method passing the given parameters
 *
 * MUTEX:       Assumes namespace is locked
 *
 ******************************************************************************/

acpi_status
acpi_ns_execute_control_method (
	struct acpi_parameter_info      *info)
{
	acpi_status                     status;
	union acpi_operand_object       *obj_desc;


	ACPI_FUNCTION_TRACE ("ns_execute_control_method");


	/* Verify that there is a method associated with this object */

	obj_desc = acpi_ns_get_attached_object (info->node);
	if (!obj_desc) {
		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "No attached method object\n"));

		(void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
		return_ACPI_STATUS (AE_NULL_OBJECT);
	}

	ACPI_DUMP_PATHNAME (info->node, "Execute Method:",
		ACPI_LV_INFO, _COMPONENT);

	ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Method at AML address %p Length %X\n",
		obj_desc->method.aml_start + 1, obj_desc->method.aml_length - 1));

	/*
	 * Unlock the namespace before execution.  This allows namespace access
	 * via the external Acpi* interfaces while a method is being executed.
	 * However, any namespace deletion must acquire both the namespace and
	 * interpreter locks to ensure that no thread is using the portion of the
	 * namespace that is being deleted.
	 */
	status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	/*
	 * Execute the method via the interpreter.  The interpreter is locked
	 * here before calling into the AML parser
	 */
	status = acpi_ex_enter_interpreter ();
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	status = acpi_psx_execute (info);
	acpi_ex_exit_interpreter ();

	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_object_value
 *
 * PARAMETERS:  Info            - Method info block (w/params)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Return the current value of the object
 *
 * MUTEX:       Assumes namespace is locked, leaves namespace unlocked
 *
 ******************************************************************************/

acpi_status
acpi_ns_get_object_value (
	struct acpi_parameter_info      *info)
{
	acpi_status                     status = AE_OK;
	struct acpi_namespace_node      *resolved_node = info->node;


	ACPI_FUNCTION_TRACE ("ns_get_object_value");


	/*
	 * Objects require additional resolution steps (e.g., the Node may be a
	 * field that must be read, etc.) -- we can't just grab the object out of
	 * the node.
	 */

	/*
	 * Use resolve_node_to_value() to get the associated value. This call always
	 * deletes obj_desc (allocated above).
	 *
	 * NOTE: we can get away with passing in NULL for a walk state because
	 * obj_desc is guaranteed to not be a reference to either a method local or
	 * a method argument (because this interface can only be called from the
	 * acpi_evaluate external interface, never called from a running method.)
	 *
	 * Even though we do not directly invoke the interpreter for this, we must
	 * enter it because we could access an opregion. The opregion access code
	 * assumes that the interpreter is locked.
	 *
	 * We must release the namespace lock before entering the intepreter.
	 */
	status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	status = acpi_ex_enter_interpreter ();
	if (ACPI_SUCCESS (status)) {
		status = acpi_ex_resolve_node_to_value (&resolved_node, NULL);
		/*
		 * If acpi_ex_resolve_node_to_value() succeeded, the return value was placed
		 * in resolved_node.
		 */
		acpi_ex_exit_interpreter ();

		if (ACPI_SUCCESS (status)) {
			status = AE_CTRL_RETURN_VALUE;
			info->return_object = ACPI_CAST_PTR
					 (union acpi_operand_object, resolved_node);
			ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "Returning object %p [%s]\n",
				info->return_object,
				acpi_ut_get_object_type_name (info->return_object)));
		}
	}

	/* Namespace is unlocked */

	return_ACPI_STATUS (status);
}
Commit	Line	Data
1da177e4 LT	1	/*******************************************************************************
	2	*
	3	* Module Name: nseval - Object evaluation interfaces -- includes control
	4	* method lookup and execution.
	5	*
	6	******************************************************************************/
	7
	8	/*
	9	* Copyright (C) 2000 - 2005, 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
	46	#include <acpi/acpi.h>
	47	#include <acpi/acparser.h>
	48	#include <acpi/acinterp.h>
	49	#include <acpi/acnamesp.h>
	50
	51
	52	#define _COMPONENT ACPI_NAMESPACE
	53	ACPI_MODULE_NAME ("nseval")
	54
	55
	56	/*******************************************************************************
	57	*
	58	* FUNCTION: acpi_ns_evaluate_relative
	59	*
	60	* PARAMETERS: Pathname - Name of method to execute, If NULL, the
	61	* handle is the object to execute
	62	* Info - Method info block
	63	*
	64	* RETURN: Status
65	*
66	* DESCRIPTION: Find and execute the requested method using the handle as a
67	* scope
68	*
69	* MUTEX: Locks Namespace
70	*
71	******************************************************************************/
72
73	acpi_status
74	acpi_ns_evaluate_relative (
75	char *pathname,
76	struct acpi_parameter_info *info)
77	{
78	acpi_status status;
79	struct acpi_namespace_node *node = NULL;
80	union acpi_generic_state *scope_info;
81	char *internal_path = NULL;
82
83
84	ACPI_FUNCTION_TRACE ("ns_evaluate_relative");
85
86
87	/*
88	* Must have a valid object handle
89	*/
90	if (!info \|\| !info->node) {
91	return_ACPI_STATUS (AE_BAD_PARAMETER);
92	}
93
94	/* Build an internal name string for the method */
95
96	status = acpi_ns_internalize_name (pathname, &internal_path);
97	if (ACPI_FAILURE (status)) {
98	return_ACPI_STATUS (status);
99	}
100
101	scope_info = acpi_ut_create_generic_state ();
102	if (!scope_info) {
103	goto cleanup1;
104	}
105
106	/* Get the prefix handle and Node */
107
108	status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
109	if (ACPI_FAILURE (status)) {
110	goto cleanup;
111	}
112
113	info->node = acpi_ns_map_handle_to_node (info->node);
114	if (!info->node) {
115	(void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
116	status = AE_BAD_PARAMETER;
117	goto cleanup;
118	}
119
120	/* Lookup the name in the namespace */
121
122	scope_info->scope.node = info->node;
123	status = acpi_ns_lookup (scope_info, internal_path, ACPI_TYPE_ANY,
124	ACPI_IMODE_EXECUTE, ACPI_NS_NO_UPSEARCH, NULL,
125	&node);
126
127	(void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
128
129	if (ACPI_FAILURE (status)) {
130	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "Object [%s] not found [%s]\n",
131	pathname, acpi_format_exception (status)));
132	goto cleanup;
133	}
134
135	/*
136	* Now that we have a handle to the object, we can attempt to evaluate it.
137	*/
138	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "%s [%p] Value %p\n",
139	pathname, node, acpi_ns_get_attached_object (node)));
140
141	info->node = node;
142	status = acpi_ns_evaluate_by_handle (info);
143
144	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "* Completed eval of object %s *\n",
145	pathname));
146
147	cleanup:
148	acpi_ut_delete_generic_state (scope_info);
149
150	cleanup1:
151	ACPI_MEM_FREE (internal_path);
152	return_ACPI_STATUS (status);
153	}
154
155
156	/*******************************************************************************
157	*
158	* FUNCTION: acpi_ns_evaluate_by_name
159	*
160	* PARAMETERS: Pathname - Fully qualified pathname to the object
161	* Info - Contains:
162	* return_object - Where to put method's return value (if
163	* any). If NULL, no value is returned.
164	* Params - List of parameters to pass to the method,
165	* terminated by NULL. Params itself may be
166	* NULL if no parameters are being passed.
167	*
168	* RETURN: Status
169	*
170	* DESCRIPTION: Find and execute the requested method passing the given
171	* parameters
172	*
173	* MUTEX: Locks Namespace
174	*
175	******************************************************************************/
176
177	acpi_status
178	acpi_ns_evaluate_by_name (
179	char *pathname,
180	struct acpi_parameter_info *info)
181	{
182	acpi_status status;
183	char *internal_path = NULL;
184
185
186	ACPI_FUNCTION_TRACE ("ns_evaluate_by_name");
187
188
189	/* Build an internal name string for the method */
190
191	status = acpi_ns_internalize_name (pathname, &internal_path);
192	if (ACPI_FAILURE (status)) {
193	return_ACPI_STATUS (status);
194	}
195
196	status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
197	if (ACPI_FAILURE (status)) {
198	goto cleanup;
199	}
200
201	/* Lookup the name in the namespace */
202
203	status = acpi_ns_lookup (NULL, internal_path, ACPI_TYPE_ANY,
204	ACPI_IMODE_EXECUTE, ACPI_NS_NO_UPSEARCH, NULL,
205	&info->node);
206
207	(void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
208
209	if (ACPI_FAILURE (status)) {
210	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
211	"Object at [%s] was not found, status=%.4X\n",
212	pathname, status));
213	goto cleanup;
214	}
215
216	/*
217	* Now that we have a handle to the object, we can attempt to evaluate it.
218	*/
219	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "%s [%p] Value %p\n",
220	pathname, info->node, acpi_ns_get_attached_object (info->node)));
221
222	status = acpi_ns_evaluate_by_handle (info);
223
224	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "* Completed eval of object %s *\n",
225	pathname));
226
227
228	cleanup:
229
230	/* Cleanup */
231
232	if (internal_path) {
233	ACPI_MEM_FREE (internal_path);
234	}
235
236	return_ACPI_STATUS (status);
237	}
238
239
240	/*******************************************************************************
241	*
242	* FUNCTION: acpi_ns_evaluate_by_handle
243	*
244	* PARAMETERS: Handle - Method Node to execute
245	* Params - List of parameters to pass to the method,
246	* terminated by NULL. Params itself may be
247	* NULL if no parameters are being passed.
248	* param_type - Type of Parameter list
249	* return_object - Where to put method's return value (if
250	* any). If NULL, no value is returned.
251	*
252	* RETURN: Status
253	*
254	* DESCRIPTION: Execute the requested method passing the given parameters
255	*
256	* MUTEX: Locks Namespace
257	*
258	******************************************************************************/
259
260	acpi_status
261	acpi_ns_evaluate_by_handle (
262	struct acpi_parameter_info *info)
263	{
264	acpi_status status;
265
266
267	ACPI_FUNCTION_TRACE ("ns_evaluate_by_handle");
268
269
270	/* Check if namespace has been initialized */
271
272	if (!acpi_gbl_root_node) {
273	return_ACPI_STATUS (AE_NO_NAMESPACE);
274	}
275
276	/* Parameter Validation */
277
278	if (!info) {
279	return_ACPI_STATUS (AE_BAD_PARAMETER);
280	}
281
282	/* Initialize the return value to an invalid object */
283
284	info->return_object = NULL;
285
286	/* Get the prefix handle and Node */
287
288	status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
289	if (ACPI_FAILURE (status)) {
290	return_ACPI_STATUS (status);
291	}
292
293	info->node = acpi_ns_map_handle_to_node (info->node);
294	if (!info->node) {
295	(void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
296	return_ACPI_STATUS (AE_BAD_PARAMETER);
297	}
298
299	/*
300	* For a method alias, we must grab the actual method node so that proper
301	* scoping context will be established before execution.
302	*/
303	if (acpi_ns_get_type (info->node) == ACPI_TYPE_LOCAL_METHOD_ALIAS) {
304	info->node = ACPI_CAST_PTR (struct acpi_namespace_node, info->node->object);
305	}
306
307	/*
308	* Two major cases here:
309	* 1) The object is an actual control method -- execute it.
310	* 2) The object is not a method -- just return it's current value
311	*
312	* In both cases, the namespace is unlocked by the acpi_ns* procedure
313	*/
314	if (acpi_ns_get_type (info->node) == ACPI_TYPE_METHOD) {
315	/*
316	* Case 1) We have an actual control method to execute
317	*/
318	status = acpi_ns_execute_control_method (info);
319	}
320	else {
321	/*
322	* Case 2) Object is NOT a method, just return its current value
323	*/
324	status = acpi_ns_get_object_value (info);
325	}
326
327	/*
328	* Check if there is a return value on the stack that must be dealt with
329	*/
330	if (status == AE_CTRL_RETURN_VALUE) {
331	/* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
332
333	status = AE_OK;
334	}
335
336	/*
337	* Namespace was unlocked by the handling acpi_ns* function, so we
338	* just return
339	*/
340	return_ACPI_STATUS (status);
341	}
342
343
344	/*******************************************************************************
345	*
346	* FUNCTION: acpi_ns_execute_control_method
347	*
348	* PARAMETERS: Info - Method info block (w/params)
349	*
350	* RETURN: Status
351	*
352	* DESCRIPTION: Execute the requested method passing the given parameters
353	*
354	* MUTEX: Assumes namespace is locked
355	*
356	******************************************************************************/
357
358	acpi_status
359	acpi_ns_execute_control_method (
360	struct acpi_parameter_info *info)
361	{
362	acpi_status status;
363	union acpi_operand_object *obj_desc;
364
365
366	ACPI_FUNCTION_TRACE ("ns_execute_control_method");
367
368
369	/* Verify that there is a method associated with this object */
370
371	obj_desc = acpi_ns_get_attached_object (info->node);
372	if (!obj_desc) {
373	ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "No attached method object\n"));
374
375	(void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
376	return_ACPI_STATUS (AE_NULL_OBJECT);
377	}
378
379	ACPI_DUMP_PATHNAME (info->node, "Execute Method:",
380	ACPI_LV_INFO, _COMPONENT);
381
382	ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Method at AML address %p Length %X\n",
383	obj_desc->method.aml_start + 1, obj_desc->method.aml_length - 1));
384
385	/*
386	* Unlock the namespace before execution. This allows namespace access
387	* via the external Acpi* interfaces while a method is being executed.
388	* However, any namespace deletion must acquire both the namespace and
389	* interpreter locks to ensure that no thread is using the portion of the
390	* namespace that is being deleted.
391	*/
392	status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
393	if (ACPI_FAILURE (status)) {
394	return_ACPI_STATUS (status);
395	}
396
397	/*
398	* Execute the method via the interpreter. The interpreter is locked
399	* here before calling into the AML parser
400	*/
401	status = acpi_ex_enter_interpreter ();
402	if (ACPI_FAILURE (status)) {
403	return_ACPI_STATUS (status);
404	}
405
406	status = acpi_psx_execute (info);
407	acpi_ex_exit_interpreter ();
408
409	return_ACPI_STATUS (status);
410	}
411
412
413	/*******************************************************************************
414	*
415	* FUNCTION: acpi_ns_get_object_value
416	*
417	* PARAMETERS: Info - Method info block (w/params)
418	*
419	* RETURN: Status
420	*
421	* DESCRIPTION: Return the current value of the object
422	*
423	* MUTEX: Assumes namespace is locked, leaves namespace unlocked
424	*
425	******************************************************************************/
426
427	acpi_status
428	acpi_ns_get_object_value (
429	struct acpi_parameter_info *info)
430	{
431	acpi_status status = AE_OK;
432	struct acpi_namespace_node *resolved_node = info->node;
433
434
435	ACPI_FUNCTION_TRACE ("ns_get_object_value");
436
437
438	/*
439	* Objects require additional resolution steps (e.g., the Node may be a
440	* field that must be read, etc.) -- we can't just grab the object out of
441	* the node.
442	*/
443
444	/*
445	* Use resolve_node_to_value() to get the associated value. This call always
446	* deletes obj_desc (allocated above).
447	*
448	* NOTE: we can get away with passing in NULL for a walk state because
449	* obj_desc is guaranteed to not be a reference to either a method local or
450	* a method argument (because this interface can only be called from the
451	* acpi_evaluate external interface, never called from a running method.)
452	*
453	* Even though we do not directly invoke the interpreter for this, we must
454	* enter it because we could access an opregion. The opregion access code
455	* assumes that the interpreter is locked.
456	*
457	* We must release the namespace lock before entering the intepreter.
458	*/
459	status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
460	if (ACPI_FAILURE (status)) {
461	return_ACPI_STATUS (status);
462	}
463
464	status = acpi_ex_enter_interpreter ();
465	if (ACPI_SUCCESS (status)) {
466	status = acpi_ex_resolve_node_to_value (&resolved_node, NULL);
467	/*
468	* If acpi_ex_resolve_node_to_value() succeeded, the return value was placed
469	* in resolved_node.
470	*/
471	acpi_ex_exit_interpreter ();
472
473	if (ACPI_SUCCESS (status)) {
474	status = AE_CTRL_RETURN_VALUE;
475	info->return_object = ACPI_CAST_PTR
476	(union acpi_operand_object, resolved_node);
477	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "Returning object %p [%s]\n",
478	info->return_object,
479	acpi_ut_get_object_type_name (info->return_object)));
480	}
481	}
482
483	/* Namespace is unlocked */
484
485	return_ACPI_STATUS (status);
486	}
487