xref: /openbmc/linux/drivers/acpi/acpica/nseval.c (revision 0c874100)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /*******************************************************************************
3  *
4  * Module Name: nseval - Object evaluation, includes control method execution
5  *
6  ******************************************************************************/
7 
8 #include <acpi/acpi.h>
9 #include "accommon.h"
10 #include "acparser.h"
11 #include "acinterp.h"
12 #include "acnamesp.h"
13 
14 #define _COMPONENT          ACPI_NAMESPACE
15 ACPI_MODULE_NAME("nseval")
16 
17 /* Local prototypes */
18 static void
19 acpi_ns_exec_module_code(union acpi_operand_object *method_obj,
20 			 struct acpi_evaluate_info *info);
21 
22 /*******************************************************************************
23  *
24  * FUNCTION:    acpi_ns_evaluate
25  *
26  * PARAMETERS:  info            - Evaluation info block, contains these fields
27  *                                and more:
28  *                  prefix_node     - Prefix or Method/Object Node to execute
29  *                  relative_path   - Name of method to execute, If NULL, the
30  *                                    Node is the object to execute
31  *                  parameters      - List of parameters to pass to the method,
32  *                                    terminated by NULL. Params itself may be
33  *                                    NULL if no parameters are being passed.
34  *                  parameter_type  - Type of Parameter list
35  *                  return_object   - Where to put method's return value (if
36  *                                    any). If NULL, no value is returned.
37  *                  flags           - ACPI_IGNORE_RETURN_VALUE to delete return
38  *
39  * RETURN:      Status
40  *
41  * DESCRIPTION: Execute a control method or return the current value of an
42  *              ACPI namespace object.
43  *
44  * MUTEX:       Locks interpreter
45  *
46  ******************************************************************************/
47 
48 acpi_status acpi_ns_evaluate(struct acpi_evaluate_info *info)
49 {
50 	acpi_status status;
51 
52 	ACPI_FUNCTION_TRACE(ns_evaluate);
53 
54 	if (!info) {
55 		return_ACPI_STATUS(AE_BAD_PARAMETER);
56 	}
57 
58 	if (!info->node) {
59 		/*
60 		 * Get the actual namespace node for the target object if we
61 		 * need to. Handles these cases:
62 		 *
63 		 * 1) Null node, valid pathname from root (absolute path)
64 		 * 2) Node and valid pathname (path relative to Node)
65 		 * 3) Node, Null pathname
66 		 */
67 		status =
68 		    acpi_ns_get_node(info->prefix_node, info->relative_pathname,
69 				     ACPI_NS_NO_UPSEARCH, &info->node);
70 		if (ACPI_FAILURE(status)) {
71 			return_ACPI_STATUS(status);
72 		}
73 	}
74 
75 	/*
76 	 * For a method alias, we must grab the actual method node so that
77 	 * proper scoping context will be established before execution.
78 	 */
79 	if (acpi_ns_get_type(info->node) == ACPI_TYPE_LOCAL_METHOD_ALIAS) {
80 		info->node =
81 		    ACPI_CAST_PTR(struct acpi_namespace_node,
82 				  info->node->object);
83 	}
84 
85 	/* Complete the info block initialization */
86 
87 	info->return_object = NULL;
88 	info->node_flags = info->node->flags;
89 	info->obj_desc = acpi_ns_get_attached_object(info->node);
90 
91 	ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "%s [%p] Value %p\n",
92 			  info->relative_pathname, info->node,
93 			  acpi_ns_get_attached_object(info->node)));
94 
95 	/* Get info if we have a predefined name (_HID, etc.) */
96 
97 	info->predefined =
98 	    acpi_ut_match_predefined_method(info->node->name.ascii);
99 
100 	/* Get the full pathname to the object, for use in warning messages */
101 
102 	info->full_pathname = acpi_ns_get_normalized_pathname(info->node, TRUE);
103 	if (!info->full_pathname) {
104 		return_ACPI_STATUS(AE_NO_MEMORY);
105 	}
106 
107 	/* Count the number of arguments being passed in */
108 
109 	info->param_count = 0;
110 	if (info->parameters) {
111 		while (info->parameters[info->param_count]) {
112 			info->param_count++;
113 		}
114 
115 		/* Warn on impossible argument count */
116 
117 		if (info->param_count > ACPI_METHOD_NUM_ARGS) {
118 			ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
119 					      ACPI_WARN_ALWAYS,
120 					      "Excess arguments (%u) - using only %u",
121 					      info->param_count,
122 					      ACPI_METHOD_NUM_ARGS));
123 
124 			info->param_count = ACPI_METHOD_NUM_ARGS;
125 		}
126 	}
127 
128 	/*
129 	 * For predefined names: Check that the declared argument count
130 	 * matches the ACPI spec -- otherwise this is a BIOS error.
131 	 */
132 	acpi_ns_check_acpi_compliance(info->full_pathname, info->node,
133 				      info->predefined);
134 
135 	/*
136 	 * For all names: Check that the incoming argument count for
137 	 * this method/object matches the actual ASL/AML definition.
138 	 */
139 	acpi_ns_check_argument_count(info->full_pathname, info->node,
140 				     info->param_count, info->predefined);
141 
142 	/* For predefined names: Typecheck all incoming arguments */
143 
144 	acpi_ns_check_argument_types(info);
145 
146 	/*
147 	 * Three major evaluation cases:
148 	 *
149 	 * 1) Object types that cannot be evaluated by definition
150 	 * 2) The object is a control method -- execute it
151 	 * 3) The object is not a method -- just return it's current value
152 	 */
153 	switch (acpi_ns_get_type(info->node)) {
154 	case ACPI_TYPE_ANY:
155 	case ACPI_TYPE_DEVICE:
156 	case ACPI_TYPE_EVENT:
157 	case ACPI_TYPE_MUTEX:
158 	case ACPI_TYPE_REGION:
159 	case ACPI_TYPE_THERMAL:
160 	case ACPI_TYPE_LOCAL_SCOPE:
161 		/*
162 		 * 1) Disallow evaluation of these object types. For these,
163 		 *    object evaluation is undefined.
164 		 */
165 		ACPI_ERROR((AE_INFO,
166 			    "%s: This object type [%s] "
167 			    "never contains data and cannot be evaluated",
168 			    info->full_pathname,
169 			    acpi_ut_get_type_name(info->node->type)));
170 
171 		status = AE_TYPE;
172 		goto cleanup;
173 
174 	case ACPI_TYPE_METHOD:
175 		/*
176 		 * 2) Object is a control method - execute it
177 		 */
178 
179 		/* Verify that there is a method object associated with this node */
180 
181 		if (!info->obj_desc) {
182 			ACPI_ERROR((AE_INFO,
183 				    "%s: Method has no attached sub-object",
184 				    info->full_pathname));
185 			status = AE_NULL_OBJECT;
186 			goto cleanup;
187 		}
188 
189 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
190 				  "**** Execute method [%s] at AML address %p length %X\n",
191 				  info->full_pathname,
192 				  info->obj_desc->method.aml_start + 1,
193 				  info->obj_desc->method.aml_length - 1));
194 
195 		/*
196 		 * Any namespace deletion must acquire both the namespace and
197 		 * interpreter locks to ensure that no thread is using the portion of
198 		 * the namespace that is being deleted.
199 		 *
200 		 * Execute the method via the interpreter. The interpreter is locked
201 		 * here before calling into the AML parser
202 		 */
203 		acpi_ex_enter_interpreter();
204 		status = acpi_ps_execute_method(info);
205 		acpi_ex_exit_interpreter();
206 		break;
207 
208 	default:
209 		/*
210 		 * 3) All other non-method objects -- get the current object value
211 		 */
212 
213 		/*
214 		 * Some objects require additional resolution steps (e.g., the Node
215 		 * may be a field that must be read, etc.) -- we can't just grab
216 		 * the object 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 		 * the 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 op_region.
227 		 * The op_region access code assumes that the interpreter is locked.
228 		 */
229 		acpi_ex_enter_interpreter();
230 
231 		/* TBD: resolve_node_to_value has a strange interface, fix */
232 
233 		info->return_object =
234 		    ACPI_CAST_PTR(union acpi_operand_object, info->node);
235 
236 		status =
237 		    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
238 						  (struct acpi_namespace_node,
239 						   &info->return_object), NULL);
240 		acpi_ex_exit_interpreter();
241 
242 		if (ACPI_FAILURE(status)) {
243 			info->return_object = NULL;
244 			goto cleanup;
245 		}
246 
247 		ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "Returned object %p [%s]\n",
248 				  info->return_object,
249 				  acpi_ut_get_object_type_name(info->
250 							       return_object)));
251 
252 		status = AE_CTRL_RETURN_VALUE;	/* Always has a "return value" */
253 		break;
254 	}
255 
256 	/*
257 	 * For predefined names, check the return value against the ACPI
258 	 * specification. Some incorrect return value types are repaired.
259 	 */
260 	(void)acpi_ns_check_return_value(info->node, info, 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 	} else if (ACPI_FAILURE(status)) {
278 
279 		/* If return_object exists, delete it */
280 
281 		if (info->return_object) {
282 			acpi_ut_remove_reference(info->return_object);
283 			info->return_object = NULL;
284 		}
285 	}
286 
287 	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
288 			  "*** Completed evaluation of object %s ***\n",
289 			  info->relative_pathname));
290 
291 cleanup:
292 	/*
293 	 * Namespace was unlocked by the handling acpi_ns* function, so we
294 	 * just free the pathname and return
295 	 */
296 	ACPI_FREE(info->full_pathname);
297 	info->full_pathname = NULL;
298 	return_ACPI_STATUS(status);
299 }
300 
301 /*******************************************************************************
302  *
303  * FUNCTION:    acpi_ns_exec_module_code_list
304  *
305  * PARAMETERS:  None
306  *
307  * RETURN:      None. Exceptions during method execution are ignored, since
308  *              we cannot abort a table load.
309  *
310  * DESCRIPTION: Execute all elements of the global module-level code list.
311  *              Each element is executed as a single control method.
312  *
313  * NOTE: With this option enabled, each block of detected executable AML
314  * code that is outside of any control method is wrapped with a temporary
315  * control method object and placed on a global list. The methods on this
316  * list are executed below.
317  *
318  * This function executes the module-level code for all tables only after
319  * all of the tables have been loaded. It is a legacy option and is
320  * not compatible with other ACPI implementations. See acpi_ns_load_table.
321  *
322  * This function will be removed when the legacy option is removed.
323  *
324  ******************************************************************************/
325 
326 void acpi_ns_exec_module_code_list(void)
327 {
328 	union acpi_operand_object *prev;
329 	union acpi_operand_object *next;
330 	struct acpi_evaluate_info *info;
331 	u32 method_count = 0;
332 
333 	ACPI_FUNCTION_TRACE(ns_exec_module_code_list);
334 
335 	/* Exit now if the list is empty */
336 
337 	next = acpi_gbl_module_code_list;
338 	if (!next) {
339 		ACPI_DEBUG_PRINT((ACPI_DB_INIT_NAMES,
340 				  "Legacy MLC block list is empty\n"));
341 
342 		return_VOID;
343 	}
344 
345 	/* Allocate the evaluation information block */
346 
347 	info = ACPI_ALLOCATE(sizeof(struct acpi_evaluate_info));
348 	if (!info) {
349 		return_VOID;
350 	}
351 
352 	/* Walk the list, executing each "method" */
353 
354 	while (next) {
355 		prev = next;
356 		next = next->method.mutex;
357 
358 		/* Clear the link field and execute the method */
359 
360 		prev->method.mutex = NULL;
361 		acpi_ns_exec_module_code(prev, info);
362 		method_count++;
363 
364 		/* Delete the (temporary) method object */
365 
366 		acpi_ut_remove_reference(prev);
367 	}
368 
369 	ACPI_INFO(("Executed %u blocks of module-level executable AML code",
370 		   method_count));
371 
372 	ACPI_FREE(info);
373 	acpi_gbl_module_code_list = NULL;
374 	return_VOID;
375 }
376 
377 /*******************************************************************************
378  *
379  * FUNCTION:    acpi_ns_exec_module_code
380  *
381  * PARAMETERS:  method_obj          - Object container for the module-level code
382  *              info                - Info block for method evaluation
383  *
384  * RETURN:      None. Exceptions during method execution are ignored, since
385  *              we cannot abort a table load.
386  *
387  * DESCRIPTION: Execute a control method containing a block of module-level
388  *              executable AML code. The control method is temporarily
389  *              installed to the root node, then evaluated.
390  *
391  ******************************************************************************/
392 
393 static void
394 acpi_ns_exec_module_code(union acpi_operand_object *method_obj,
395 			 struct acpi_evaluate_info *info)
396 {
397 	union acpi_operand_object *parent_obj;
398 	struct acpi_namespace_node *parent_node;
399 	acpi_object_type type;
400 	acpi_status status;
401 
402 	ACPI_FUNCTION_TRACE(ns_exec_module_code);
403 
404 	/*
405 	 * Get the parent node. We cheat by using the next_object field
406 	 * of the method object descriptor.
407 	 */
408 	parent_node =
409 	    ACPI_CAST_PTR(struct acpi_namespace_node,
410 				    method_obj->method.next_object);
411 	type = acpi_ns_get_type(parent_node);
412 
413 	/*
414 	 * Get the region handler and save it in the method object. We may need
415 	 * this if an operation region declaration causes a _REG method to be run.
416 	 *
417 	 * We can't do this in acpi_ps_link_module_code because
418 	 * acpi_gbl_root_node->Object is NULL at PASS1.
419 	 */
420 	if ((type == ACPI_TYPE_DEVICE) && parent_node->object) {
421 		method_obj->method.dispatch.handler =
422 		    parent_node->object->device.handler;
423 	}
424 
425 	/* Must clear next_object (acpi_ns_attach_object needs the field) */
426 
427 	method_obj->method.next_object = NULL;
428 
429 	/* Initialize the evaluation information block */
430 
431 	memset(info, 0, sizeof(struct acpi_evaluate_info));
432 	info->prefix_node = parent_node;
433 
434 	/*
435 	 * Get the currently attached parent object. Add a reference,
436 	 * because the ref count will be decreased when the method object
437 	 * is installed to the parent node.
438 	 */
439 	parent_obj = acpi_ns_get_attached_object(parent_node);
440 	if (parent_obj) {
441 		acpi_ut_add_reference(parent_obj);
442 	}
443 
444 	/* Install the method (module-level code) in the parent node */
445 
446 	status =
447 	    acpi_ns_attach_object(parent_node, method_obj, ACPI_TYPE_METHOD);
448 	if (ACPI_FAILURE(status)) {
449 		goto exit;
450 	}
451 
452 	/* Execute the parent node as a control method */
453 
454 	status = acpi_ns_evaluate(info);
455 
456 	ACPI_DEBUG_PRINT((ACPI_DB_INIT_NAMES,
457 			  "Executed module-level code at %p\n",
458 			  method_obj->method.aml_start));
459 
460 	/* Delete a possible implicit return value (in slack mode) */
461 
462 	if (info->return_object) {
463 		acpi_ut_remove_reference(info->return_object);
464 	}
465 
466 	/* Detach the temporary method object */
467 
468 	acpi_ns_detach_object(parent_node);
469 
470 	/* Restore the original parent object */
471 
472 	if (parent_obj) {
473 		status = acpi_ns_attach_object(parent_node, parent_obj, type);
474 	} else {
475 		parent_node->type = (u8)type;
476 	}
477 
478 exit:
479 	if (parent_obj) {
480 		acpi_ut_remove_reference(parent_obj);
481 	}
482 	return_VOID;
483 }
484