xref: /openbmc/linux/drivers/acpi/acpica/nseval.c (revision aac5987a)
1 /*******************************************************************************
2  *
3  * Module Name: nseval - Object evaluation, includes control method execution
4  *
5  ******************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2017, 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 these fields
63  *                                and more:
64  *                  prefix_node     - Prefix or Method/Object Node to execute
65  *                  relative_path   - Name of method to execute, If NULL, the
66  *                                    Node is the object to execute
67  *                  parameters      - List of parameters to pass to the method,
68  *                                    terminated by NULL. Params itself may be
69  *                                    NULL if no parameters are being passed.
70  *                  parameter_type  - Type of Parameter list
71  *                  return_object   - Where to put method's return value (if
72  *                                    any). If NULL, no value is returned.
73  *                  flags           - ACPI_IGNORE_RETURN_VALUE to delete return
74  *
75  * RETURN:      Status
76  *
77  * DESCRIPTION: Execute a control method or return the current value of an
78  *              ACPI namespace object.
79  *
80  * MUTEX:       Locks interpreter
81  *
82  ******************************************************************************/
83 
84 acpi_status acpi_ns_evaluate(struct acpi_evaluate_info *info)
85 {
86 	acpi_status status;
87 
88 	ACPI_FUNCTION_TRACE(ns_evaluate);
89 
90 	if (!info) {
91 		return_ACPI_STATUS(AE_BAD_PARAMETER);
92 	}
93 
94 	if (!info->node) {
95 		/*
96 		 * Get the actual namespace node for the target object if we
97 		 * need to. Handles these cases:
98 		 *
99 		 * 1) Null node, valid pathname from root (absolute path)
100 		 * 2) Node and valid pathname (path relative to Node)
101 		 * 3) Node, Null pathname
102 		 */
103 		status =
104 		    acpi_ns_get_node(info->prefix_node, info->relative_pathname,
105 				     ACPI_NS_NO_UPSEARCH, &info->node);
106 		if (ACPI_FAILURE(status)) {
107 			return_ACPI_STATUS(status);
108 		}
109 	}
110 
111 	/*
112 	 * For a method alias, we must grab the actual method node so that
113 	 * proper scoping context will be established before execution.
114 	 */
115 	if (acpi_ns_get_type(info->node) == ACPI_TYPE_LOCAL_METHOD_ALIAS) {
116 		info->node =
117 		    ACPI_CAST_PTR(struct acpi_namespace_node,
118 				  info->node->object);
119 	}
120 
121 	/* Complete the info block initialization */
122 
123 	info->return_object = NULL;
124 	info->node_flags = info->node->flags;
125 	info->obj_desc = acpi_ns_get_attached_object(info->node);
126 
127 	ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "%s [%p] Value %p\n",
128 			  info->relative_pathname, info->node,
129 			  acpi_ns_get_attached_object(info->node)));
130 
131 	/* Get info if we have a predefined name (_HID, etc.) */
132 
133 	info->predefined =
134 	    acpi_ut_match_predefined_method(info->node->name.ascii);
135 
136 	/* Get the full pathname to the object, for use in warning messages */
137 
138 	info->full_pathname = acpi_ns_get_normalized_pathname(info->node, TRUE);
139 	if (!info->full_pathname) {
140 		return_ACPI_STATUS(AE_NO_MEMORY);
141 	}
142 
143 	/* Count the number of arguments being passed in */
144 
145 	info->param_count = 0;
146 	if (info->parameters) {
147 		while (info->parameters[info->param_count]) {
148 			info->param_count++;
149 		}
150 
151 		/* Warn on impossible argument count */
152 
153 		if (info->param_count > ACPI_METHOD_NUM_ARGS) {
154 			ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
155 					      ACPI_WARN_ALWAYS,
156 					      "Excess arguments (%u) - using only %u",
157 					      info->param_count,
158 					      ACPI_METHOD_NUM_ARGS));
159 
160 			info->param_count = ACPI_METHOD_NUM_ARGS;
161 		}
162 	}
163 
164 	/*
165 	 * For predefined names: Check that the declared argument count
166 	 * matches the ACPI spec -- otherwise this is a BIOS error.
167 	 */
168 	acpi_ns_check_acpi_compliance(info->full_pathname, info->node,
169 				      info->predefined);
170 
171 	/*
172 	 * For all names: Check that the incoming argument count for
173 	 * this method/object matches the actual ASL/AML definition.
174 	 */
175 	acpi_ns_check_argument_count(info->full_pathname, info->node,
176 				     info->param_count, info->predefined);
177 
178 	/* For predefined names: Typecheck all incoming arguments */
179 
180 	acpi_ns_check_argument_types(info);
181 
182 	/*
183 	 * Three major evaluation cases:
184 	 *
185 	 * 1) Object types that cannot be evaluated by definition
186 	 * 2) The object is a control method -- execute it
187 	 * 3) The object is not a method -- just return it's current value
188 	 */
189 	switch (acpi_ns_get_type(info->node)) {
190 	case ACPI_TYPE_DEVICE:
191 	case ACPI_TYPE_EVENT:
192 	case ACPI_TYPE_MUTEX:
193 	case ACPI_TYPE_REGION:
194 	case ACPI_TYPE_THERMAL:
195 	case ACPI_TYPE_LOCAL_SCOPE:
196 		/*
197 		 * 1) Disallow evaluation of certain object types. For these,
198 		 *    object evaluation is undefined and not supported.
199 		 */
200 		ACPI_ERROR((AE_INFO,
201 			    "%s: Evaluation of object type [%s] is not supported",
202 			    info->full_pathname,
203 			    acpi_ut_get_type_name(info->node->type)));
204 
205 		status = AE_TYPE;
206 		goto cleanup;
207 
208 	case ACPI_TYPE_METHOD:
209 		/*
210 		 * 2) Object is a control method - execute it
211 		 */
212 
213 		/* Verify that there is a method object associated with this node */
214 
215 		if (!info->obj_desc) {
216 			ACPI_ERROR((AE_INFO,
217 				    "%s: Method has no attached sub-object",
218 				    info->full_pathname));
219 			status = AE_NULL_OBJECT;
220 			goto cleanup;
221 		}
222 
223 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
224 				  "**** Execute method [%s] at AML address %p length %X\n",
225 				  info->full_pathname,
226 				  info->obj_desc->method.aml_start + 1,
227 				  info->obj_desc->method.aml_length - 1));
228 
229 		/*
230 		 * Any namespace deletion must acquire both the namespace and
231 		 * interpreter locks to ensure that no thread is using the portion of
232 		 * the namespace that is being deleted.
233 		 *
234 		 * Execute the method via the interpreter. The interpreter is locked
235 		 * here before calling into the AML parser
236 		 */
237 		acpi_ex_enter_interpreter();
238 		status = acpi_ps_execute_method(info);
239 		acpi_ex_exit_interpreter();
240 		break;
241 
242 	default:
243 		/*
244 		 * 3) All other non-method objects -- get the current object value
245 		 */
246 
247 		/*
248 		 * Some objects require additional resolution steps (e.g., the Node
249 		 * may be a field that must be read, etc.) -- we can't just grab
250 		 * the object out of the node.
251 		 *
252 		 * Use resolve_node_to_value() to get the associated value.
253 		 *
254 		 * NOTE: we can get away with passing in NULL for a walk state because
255 		 * the Node is guaranteed to not be a reference to either a method
256 		 * local or a method argument (because this interface is never called
257 		 * from a running method.)
258 		 *
259 		 * Even though we do not directly invoke the interpreter for object
260 		 * resolution, we must lock it because we could access an op_region.
261 		 * The op_region access code assumes that the interpreter is locked.
262 		 */
263 		acpi_ex_enter_interpreter();
264 
265 		/* TBD: resolve_node_to_value has a strange interface, fix */
266 
267 		info->return_object =
268 		    ACPI_CAST_PTR(union acpi_operand_object, info->node);
269 
270 		status =
271 		    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
272 						  (struct acpi_namespace_node,
273 						   &info->return_object), NULL);
274 		acpi_ex_exit_interpreter();
275 
276 		if (ACPI_FAILURE(status)) {
277 			info->return_object = NULL;
278 			goto cleanup;
279 		}
280 
281 		ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "Returned object %p [%s]\n",
282 				  info->return_object,
283 				  acpi_ut_get_object_type_name(info->
284 							       return_object)));
285 
286 		status = AE_CTRL_RETURN_VALUE;	/* Always has a "return value" */
287 		break;
288 	}
289 
290 	/*
291 	 * For predefined names, check the return value against the ACPI
292 	 * specification. Some incorrect return value types are repaired.
293 	 */
294 	(void)acpi_ns_check_return_value(info->node, info, info->param_count,
295 					 status, &info->return_object);
296 
297 	/* Check if there is a return value that must be dealt with */
298 
299 	if (status == AE_CTRL_RETURN_VALUE) {
300 
301 		/* If caller does not want the return value, delete it */
302 
303 		if (info->flags & ACPI_IGNORE_RETURN_VALUE) {
304 			acpi_ut_remove_reference(info->return_object);
305 			info->return_object = NULL;
306 		}
307 
308 		/* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
309 
310 		status = AE_OK;
311 	}
312 
313 	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
314 			  "*** Completed evaluation of object %s ***\n",
315 			  info->relative_pathname));
316 
317 cleanup:
318 	/*
319 	 * Namespace was unlocked by the handling acpi_ns* function, so we
320 	 * just free the pathname and return
321 	 */
322 	ACPI_FREE(info->full_pathname);
323 	info->full_pathname = NULL;
324 	return_ACPI_STATUS(status);
325 }
326 
327 /*******************************************************************************
328  *
329  * FUNCTION:    acpi_ns_exec_module_code_list
330  *
331  * PARAMETERS:  None
332  *
333  * RETURN:      None. Exceptions during method execution are ignored, since
334  *              we cannot abort a table load.
335  *
336  * DESCRIPTION: Execute all elements of the global module-level code list.
337  *              Each element is executed as a single control method.
338  *
339  ******************************************************************************/
340 
341 void acpi_ns_exec_module_code_list(void)
342 {
343 	union acpi_operand_object *prev;
344 	union acpi_operand_object *next;
345 	struct acpi_evaluate_info *info;
346 	u32 method_count = 0;
347 
348 	ACPI_FUNCTION_TRACE(ns_exec_module_code_list);
349 
350 	/* Exit now if the list is empty */
351 
352 	next = acpi_gbl_module_code_list;
353 	if (!next) {
354 		return_VOID;
355 	}
356 
357 	/* Allocate the evaluation information block */
358 
359 	info = ACPI_ALLOCATE(sizeof(struct acpi_evaluate_info));
360 	if (!info) {
361 		return_VOID;
362 	}
363 
364 	/* Walk the list, executing each "method" */
365 
366 	while (next) {
367 		prev = next;
368 		next = next->method.mutex;
369 
370 		/* Clear the link field and execute the method */
371 
372 		prev->method.mutex = NULL;
373 		acpi_ns_exec_module_code(prev, info);
374 		method_count++;
375 
376 		/* Delete the (temporary) method object */
377 
378 		acpi_ut_remove_reference(prev);
379 	}
380 
381 	ACPI_INFO(("Executed %u blocks of module-level executable AML code",
382 		   method_count));
383 
384 	ACPI_FREE(info);
385 	acpi_gbl_module_code_list = NULL;
386 	return_VOID;
387 }
388 
389 /*******************************************************************************
390  *
391  * FUNCTION:    acpi_ns_exec_module_code
392  *
393  * PARAMETERS:  method_obj          - Object container for the module-level code
394  *              info                - Info block for method evaluation
395  *
396  * RETURN:      None. Exceptions during method execution are ignored, since
397  *              we cannot abort a table load.
398  *
399  * DESCRIPTION: Execute a control method containing a block of module-level
400  *              executable AML code. The control method is temporarily
401  *              installed to the root node, then evaluated.
402  *
403  ******************************************************************************/
404 
405 static void
406 acpi_ns_exec_module_code(union acpi_operand_object *method_obj,
407 			 struct acpi_evaluate_info *info)
408 {
409 	union acpi_operand_object *parent_obj;
410 	struct acpi_namespace_node *parent_node;
411 	acpi_object_type type;
412 	acpi_status status;
413 
414 	ACPI_FUNCTION_TRACE(ns_exec_module_code);
415 
416 	/*
417 	 * Get the parent node. We cheat by using the next_object field
418 	 * of the method object descriptor.
419 	 */
420 	parent_node =
421 	    ACPI_CAST_PTR(struct acpi_namespace_node,
422 				    method_obj->method.next_object);
423 	type = acpi_ns_get_type(parent_node);
424 
425 	/*
426 	 * Get the region handler and save it in the method object. We may need
427 	 * this if an operation region declaration causes a _REG method to be run.
428 	 *
429 	 * We can't do this in acpi_ps_link_module_code because
430 	 * acpi_gbl_root_node->Object is NULL at PASS1.
431 	 */
432 	if ((type == ACPI_TYPE_DEVICE) && parent_node->object) {
433 		method_obj->method.dispatch.handler =
434 		    parent_node->object->device.handler;
435 	}
436 
437 	/* Must clear next_object (acpi_ns_attach_object needs the field) */
438 
439 	method_obj->method.next_object = NULL;
440 
441 	/* Initialize the evaluation information block */
442 
443 	memset(info, 0, sizeof(struct acpi_evaluate_info));
444 	info->prefix_node = parent_node;
445 
446 	/*
447 	 * Get the currently attached parent object. Add a reference,
448 	 * because the ref count will be decreased when the method object
449 	 * is installed to the parent node.
450 	 */
451 	parent_obj = acpi_ns_get_attached_object(parent_node);
452 	if (parent_obj) {
453 		acpi_ut_add_reference(parent_obj);
454 	}
455 
456 	/* Install the method (module-level code) in the parent node */
457 
458 	status =
459 	    acpi_ns_attach_object(parent_node, method_obj, ACPI_TYPE_METHOD);
460 	if (ACPI_FAILURE(status)) {
461 		goto exit;
462 	}
463 
464 	/* Execute the parent node as a control method */
465 
466 	status = acpi_ns_evaluate(info);
467 
468 	ACPI_DEBUG_PRINT((ACPI_DB_INIT_NAMES,
469 			  "Executed module-level code at %p\n",
470 			  method_obj->method.aml_start));
471 
472 	/* Delete a possible implicit return value (in slack mode) */
473 
474 	if (info->return_object) {
475 		acpi_ut_remove_reference(info->return_object);
476 	}
477 
478 	/* Detach the temporary method object */
479 
480 	acpi_ns_detach_object(parent_node);
481 
482 	/* Restore the original parent object */
483 
484 	if (parent_obj) {
485 		status = acpi_ns_attach_object(parent_node, parent_obj, type);
486 	} else {
487 		parent_node->type = (u8)type;
488 	}
489 
490 exit:
491 	if (parent_obj) {
492 		acpi_ut_remove_reference(parent_obj);
493 	}
494 	return_VOID;
495 }
496