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1 /*******************************************************************************
2  *
3  * Module Name: nseval - Object evaluation, includes control method execution
4  *
5  ******************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2013, 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 /* Local prototypes */
54 static void
55 acpi_ns_exec_module_code(union acpi_operand_object *method_obj,
56 			 struct acpi_evaluate_info *info);
57 
58 /*******************************************************************************
59  *
60  * FUNCTION:    acpi_ns_evaluate
61  *
62  * PARAMETERS:  info            - Evaluation info block, contains:
63  *                  prefix_node     - Prefix or Method/Object Node to execute
64  *                  pathname        - Name of method to execute, If NULL, the
65  *                                    Node is the object to execute
66  *                  parameters      - List of parameters to pass to the method,
67  *                                    terminated by NULL. Params itself may be
68  *                                    NULL if no parameters are being passed.
69  *                  return_object   - Where to put method's return value (if
70  *                                    any). If NULL, no value is returned.
71  *                  parameter_type  - Type of Parameter list
72  *                  return_object   - Where to put method's return value (if
73  *                                    any). If NULL, no value is returned.
74  *                  flags           - ACPI_IGNORE_RETURN_VALUE to delete return
75  *
76  * RETURN:      Status
77  *
78  * DESCRIPTION: Execute a control method or return the current value of an
79  *              ACPI namespace object.
80  *
81  * MUTEX:       Locks interpreter
82  *
83  ******************************************************************************/
84 
acpi_ns_evaluate(struct acpi_evaluate_info * info)85 acpi_status acpi_ns_evaluate(struct acpi_evaluate_info * info)
86 {
87 	acpi_status status;
88 	struct acpi_namespace_node *node;
89 
90 	ACPI_FUNCTION_TRACE(ns_evaluate);
91 
92 	if (!info) {
93 		return_ACPI_STATUS(AE_BAD_PARAMETER);
94 	}
95 
96 	/* Initialize the return value to an invalid object */
97 
98 	info->return_object = NULL;
99 	info->param_count = 0;
100 
101 	if (!info->resolved_node) {
102 		/*
103 		 * Get the actual namespace node for the target object if we need to.
104 		 * Handles these cases:
105 		 *
106 		 * 1) Null node, Pathname (absolute path)
107 		 * 2) Node, Pathname (path relative to Node)
108 		 * 3) Node, Null Pathname
109 		 */
110 		status = acpi_ns_get_node(info->prefix_node, info->pathname,
111 					  ACPI_NS_NO_UPSEARCH,
112 					  &info->resolved_node);
113 		if (ACPI_FAILURE(status)) {
114 			return_ACPI_STATUS(status);
115 		}
116 	}
117 
118 	/*
119 	 * For a method alias, we must grab the actual method node so that proper
120 	 * scoping context will be established before execution.
121 	 */
122 	if (acpi_ns_get_type(info->resolved_node) ==
123 	    ACPI_TYPE_LOCAL_METHOD_ALIAS) {
124 		info->resolved_node =
125 		    ACPI_CAST_PTR(struct acpi_namespace_node,
126 				  info->resolved_node->object);
127 	}
128 
129 	ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "%s [%p] Value %p\n", info->pathname,
130 			  info->resolved_node,
131 			  acpi_ns_get_attached_object(info->resolved_node)));
132 
133 	node = info->resolved_node;
134 
135 	/*
136 	 * Two major cases here:
137 	 *
138 	 * 1) The object is a control method -- execute it
139 	 * 2) The object is not a method -- just return it's current value
140 	 */
141 	if (acpi_ns_get_type(info->resolved_node) == ACPI_TYPE_METHOD) {
142 		/*
143 		 * 1) Object is a control method - execute it
144 		 */
145 
146 		/* Verify that there is a method object associated with this node */
147 
148 		info->obj_desc =
149 		    acpi_ns_get_attached_object(info->resolved_node);
150 		if (!info->obj_desc) {
151 			ACPI_ERROR((AE_INFO,
152 				    "Control method has no attached sub-object"));
153 			return_ACPI_STATUS(AE_NULL_OBJECT);
154 		}
155 
156 		/* Count the number of arguments being passed to the method */
157 
158 		if (info->parameters) {
159 			while (info->parameters[info->param_count]) {
160 				if (info->param_count > ACPI_METHOD_MAX_ARG) {
161 					return_ACPI_STATUS(AE_LIMIT);
162 				}
163 				info->param_count++;
164 			}
165 		}
166 
167 
168 		ACPI_DUMP_PATHNAME(info->resolved_node, "ACPI: Execute Method",
169 				   ACPI_LV_INFO, _COMPONENT);
170 
171 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
172 				  "Method at AML address %p Length %X\n",
173 				  info->obj_desc->method.aml_start + 1,
174 				  info->obj_desc->method.aml_length - 1));
175 
176 		/*
177 		 * Any namespace deletion must acquire both the namespace and
178 		 * interpreter locks to ensure that no thread is using the portion of
179 		 * the namespace that is being deleted.
180 		 *
181 		 * Execute the method via the interpreter. The interpreter is locked
182 		 * here before calling into the AML parser
183 		 */
184 		acpi_ex_enter_interpreter();
185 		status = acpi_ps_execute_method(info);
186 		acpi_ex_exit_interpreter();
187 	} else {
188 		/*
189 		 * 2) Object is not a method, return its current value
190 		 *
191 		 * Disallow certain object types. For these, "evaluation" is undefined.
192 		 */
193 		switch (info->resolved_node->type) {
194 		case ACPI_TYPE_DEVICE:
195 		case ACPI_TYPE_EVENT:
196 		case ACPI_TYPE_MUTEX:
197 		case ACPI_TYPE_REGION:
198 		case ACPI_TYPE_THERMAL:
199 		case ACPI_TYPE_LOCAL_SCOPE:
200 
201 			ACPI_ERROR((AE_INFO,
202 				    "[%4.4s] Evaluation of object type [%s] is not supported",
203 				    info->resolved_node->name.ascii,
204 				    acpi_ut_get_type_name(info->resolved_node->
205 							  type)));
206 
207 			return_ACPI_STATUS(AE_TYPE);
208 
209 		default:
210 			break;
211 		}
212 
213 		/*
214 		 * Objects require additional resolution steps (e.g., the Node may be
215 		 * a field that must be read, etc.) -- we can't just grab the object
216 		 * out of the node.
217 		 *
218 		 * Use resolve_node_to_value() to get the associated value.
219 		 *
220 		 * NOTE: we can get away with passing in NULL for a walk state because
221 		 * resolved_node is guaranteed to not be a reference to either a method
222 		 * local or a method argument (because this interface is never called
223 		 * from a running method.)
224 		 *
225 		 * Even though we do not directly invoke the interpreter for object
226 		 * resolution, we must lock it because we could access an opregion.
227 		 * The opregion access code assumes that the interpreter is locked.
228 		 */
229 		acpi_ex_enter_interpreter();
230 
231 		/* Function has a strange interface */
232 
233 		status =
234 		    acpi_ex_resolve_node_to_value(&info->resolved_node, NULL);
235 		acpi_ex_exit_interpreter();
236 
237 		/*
238 		 * If acpi_ex_resolve_node_to_value() succeeded, the return value was placed
239 		 * in resolved_node.
240 		 */
241 		if (ACPI_SUCCESS(status)) {
242 			status = AE_CTRL_RETURN_VALUE;
243 			info->return_object =
244 			    ACPI_CAST_PTR(union acpi_operand_object,
245 					  info->resolved_node);
246 
247 			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
248 					  "Returning object %p [%s]\n",
249 					  info->return_object,
250 					  acpi_ut_get_object_type_name(info->
251 								       return_object)));
252 		}
253 	}
254 
255 	/*
256 	 * Check input argument count against the ASL-defined count for a method.
257 	 * Also check predefined names: argument count and return value against
258 	 * the ACPI specification. Some incorrect return value types are repaired.
259 	 */
260 	(void)acpi_ns_check_predefined_names(node, info->param_count,
261 		status, &info->return_object);
262 
263 	/* Check if there is a return value that must be dealt with */
264 
265 	if (status == AE_CTRL_RETURN_VALUE) {
266 
267 		/* If caller does not want the return value, delete it */
268 
269 		if (info->flags & ACPI_IGNORE_RETURN_VALUE) {
270 			acpi_ut_remove_reference(info->return_object);
271 			info->return_object = NULL;
272 		}
273 
274 		/* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
275 
276 		status = AE_OK;
277 	}
278 
279 	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
280 			  "*** Completed evaluation of object %s ***\n",
281 			  info->pathname));
282 
283 	/*
284 	 * Namespace was unlocked by the handling acpi_ns* function, so we
285 	 * just return
286 	 */
287 	return_ACPI_STATUS(status);
288 }
289 
290 /*******************************************************************************
291  *
292  * FUNCTION:    acpi_ns_exec_module_code_list
293  *
294  * PARAMETERS:  None
295  *
296  * RETURN:      None. Exceptions during method execution are ignored, since
297  *              we cannot abort a table load.
298  *
299  * DESCRIPTION: Execute all elements of the global module-level code list.
300  *              Each element is executed as a single control method.
301  *
302  ******************************************************************************/
303 
acpi_ns_exec_module_code_list(void)304 void acpi_ns_exec_module_code_list(void)
305 {
306 	union acpi_operand_object *prev;
307 	union acpi_operand_object *next;
308 	struct acpi_evaluate_info *info;
309 	u32 method_count = 0;
310 
311 	ACPI_FUNCTION_TRACE(ns_exec_module_code_list);
312 
313 	/* Exit now if the list is empty */
314 
315 	next = acpi_gbl_module_code_list;
316 	if (!next) {
317 		return_VOID;
318 	}
319 
320 	/* Allocate the evaluation information block */
321 
322 	info = ACPI_ALLOCATE(sizeof(struct acpi_evaluate_info));
323 	if (!info) {
324 		return_VOID;
325 	}
326 
327 	/* Walk the list, executing each "method" */
328 
329 	while (next) {
330 		prev = next;
331 		next = next->method.mutex;
332 
333 		/* Clear the link field and execute the method */
334 
335 		prev->method.mutex = NULL;
336 		acpi_ns_exec_module_code(prev, info);
337 		method_count++;
338 
339 		/* Delete the (temporary) method object */
340 
341 		acpi_ut_remove_reference(prev);
342 	}
343 
344 	ACPI_INFO((AE_INFO,
345 		   "Executed %u blocks of module-level executable AML code",
346 		   method_count));
347 
348 	ACPI_FREE(info);
349 	acpi_gbl_module_code_list = NULL;
350 	return_VOID;
351 }
352 
353 /*******************************************************************************
354  *
355  * FUNCTION:    acpi_ns_exec_module_code
356  *
357  * PARAMETERS:  method_obj          - Object container for the module-level code
358  *              info                - Info block for method evaluation
359  *
360  * RETURN:      None. Exceptions during method execution are ignored, since
361  *              we cannot abort a table load.
362  *
363  * DESCRIPTION: Execute a control method containing a block of module-level
364  *              executable AML code. The control method is temporarily
365  *              installed to the root node, then evaluated.
366  *
367  ******************************************************************************/
368 
369 static void
acpi_ns_exec_module_code(union acpi_operand_object * method_obj,struct acpi_evaluate_info * info)370 acpi_ns_exec_module_code(union acpi_operand_object *method_obj,
371 			 struct acpi_evaluate_info *info)
372 {
373 	union acpi_operand_object *parent_obj;
374 	struct acpi_namespace_node *parent_node;
375 	acpi_object_type type;
376 	acpi_status status;
377 
378 	ACPI_FUNCTION_TRACE(ns_exec_module_code);
379 
380 	/*
381 	 * Get the parent node. We cheat by using the next_object field
382 	 * of the method object descriptor.
383 	 */
384 	parent_node = ACPI_CAST_PTR(struct acpi_namespace_node,
385 				    method_obj->method.next_object);
386 	type = acpi_ns_get_type(parent_node);
387 
388 	/*
389 	 * Get the region handler and save it in the method object. We may need
390 	 * this if an operation region declaration causes a _REG method to be run.
391 	 *
392 	 * We can't do this in acpi_ps_link_module_code because
393 	 * acpi_gbl_root_node->Object is NULL at PASS1.
394 	 */
395 	if ((type == ACPI_TYPE_DEVICE) && parent_node->object) {
396 		method_obj->method.dispatch.handler =
397 		    parent_node->object->device.handler;
398 	}
399 
400 	/* Must clear next_object (acpi_ns_attach_object needs the field) */
401 
402 	method_obj->method.next_object = NULL;
403 
404 	/* Initialize the evaluation information block */
405 
406 	ACPI_MEMSET(info, 0, sizeof(struct acpi_evaluate_info));
407 	info->prefix_node = parent_node;
408 
409 	/*
410 	 * Get the currently attached parent object. Add a reference, because the
411 	 * ref count will be decreased when the method object is installed to
412 	 * the parent node.
413 	 */
414 	parent_obj = acpi_ns_get_attached_object(parent_node);
415 	if (parent_obj) {
416 		acpi_ut_add_reference(parent_obj);
417 	}
418 
419 	/* Install the method (module-level code) in the parent node */
420 
421 	status = acpi_ns_attach_object(parent_node, method_obj,
422 				       ACPI_TYPE_METHOD);
423 	if (ACPI_FAILURE(status)) {
424 		goto exit;
425 	}
426 
427 	/* Execute the parent node as a control method */
428 
429 	status = acpi_ns_evaluate(info);
430 
431 	ACPI_DEBUG_PRINT((ACPI_DB_INIT, "Executed module-level code at %p\n",
432 			  method_obj->method.aml_start));
433 
434 	/* Delete a possible implicit return value (in slack mode) */
435 
436 	if (info->return_object) {
437 		acpi_ut_remove_reference(info->return_object);
438 	}
439 
440 	/* Detach the temporary method object */
441 
442 	acpi_ns_detach_object(parent_node);
443 
444 	/* Restore the original parent object */
445 
446 	if (parent_obj) {
447 		status = acpi_ns_attach_object(parent_node, parent_obj, type);
448 	} else {
449 		parent_node->type = (u8)type;
450 	}
451 
452       exit:
453 	if (parent_obj) {
454 		acpi_ut_remove_reference(parent_obj);
455 	}
456 	return_VOID;
457 }
458