xref: /openbmc/linux/drivers/acpi/acpica/nseval.c (revision 1a59d1b8)
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 	/* Optional object evaluation log */
108 
109 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
110 			      "%-26s:  %s (%s)\n", "   Enter evaluation",
111 			      &info->full_pathname[1],
112 			      acpi_ut_get_type_name(info->node->type)));
113 
114 	/* Count the number of arguments being passed in */
115 
116 	info->param_count = 0;
117 	if (info->parameters) {
118 		while (info->parameters[info->param_count]) {
119 			info->param_count++;
120 		}
121 
122 		/* Warn on impossible argument count */
123 
124 		if (info->param_count > ACPI_METHOD_NUM_ARGS) {
125 			ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
126 					      ACPI_WARN_ALWAYS,
127 					      "Excess arguments (%u) - using only %u",
128 					      info->param_count,
129 					      ACPI_METHOD_NUM_ARGS));
130 
131 			info->param_count = ACPI_METHOD_NUM_ARGS;
132 		}
133 	}
134 
135 	/*
136 	 * For predefined names: Check that the declared argument count
137 	 * matches the ACPI spec -- otherwise this is a BIOS error.
138 	 */
139 	acpi_ns_check_acpi_compliance(info->full_pathname, info->node,
140 				      info->predefined);
141 
142 	/*
143 	 * For all names: Check that the incoming argument count for
144 	 * this method/object matches the actual ASL/AML definition.
145 	 */
146 	acpi_ns_check_argument_count(info->full_pathname, info->node,
147 				     info->param_count, info->predefined);
148 
149 	/* For predefined names: Typecheck all incoming arguments */
150 
151 	acpi_ns_check_argument_types(info);
152 
153 	/*
154 	 * Three major evaluation cases:
155 	 *
156 	 * 1) Object types that cannot be evaluated by definition
157 	 * 2) The object is a control method -- execute it
158 	 * 3) The object is not a method -- just return it's current value
159 	 */
160 	switch (acpi_ns_get_type(info->node)) {
161 	case ACPI_TYPE_ANY:
162 	case ACPI_TYPE_DEVICE:
163 	case ACPI_TYPE_EVENT:
164 	case ACPI_TYPE_MUTEX:
165 	case ACPI_TYPE_REGION:
166 	case ACPI_TYPE_THERMAL:
167 	case ACPI_TYPE_LOCAL_SCOPE:
168 		/*
169 		 * 1) Disallow evaluation of these object types. For these,
170 		 *    object evaluation is undefined.
171 		 */
172 		ACPI_ERROR((AE_INFO,
173 			    "%s: This object type [%s] "
174 			    "never contains data and cannot be evaluated",
175 			    info->full_pathname,
176 			    acpi_ut_get_type_name(info->node->type)));
177 
178 		status = AE_TYPE;
179 		goto cleanup;
180 
181 	case ACPI_TYPE_METHOD:
182 		/*
183 		 * 2) Object is a control method - execute it
184 		 */
185 
186 		/* Verify that there is a method object associated with this node */
187 
188 		if (!info->obj_desc) {
189 			ACPI_ERROR((AE_INFO,
190 				    "%s: Method has no attached sub-object",
191 				    info->full_pathname));
192 			status = AE_NULL_OBJECT;
193 			goto cleanup;
194 		}
195 
196 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
197 				  "**** Execute method [%s] at AML address %p length %X\n",
198 				  info->full_pathname,
199 				  info->obj_desc->method.aml_start + 1,
200 				  info->obj_desc->method.aml_length - 1));
201 
202 		/*
203 		 * Any namespace deletion must acquire both the namespace and
204 		 * interpreter locks to ensure that no thread is using the portion of
205 		 * the namespace that is being deleted.
206 		 *
207 		 * Execute the method via the interpreter. The interpreter is locked
208 		 * here before calling into the AML parser
209 		 */
210 		acpi_ex_enter_interpreter();
211 		status = acpi_ps_execute_method(info);
212 		acpi_ex_exit_interpreter();
213 		break;
214 
215 	default:
216 		/*
217 		 * 3) All other non-method objects -- get the current object value
218 		 */
219 
220 		/*
221 		 * Some objects require additional resolution steps (e.g., the Node
222 		 * may be a field that must be read, etc.) -- we can't just grab
223 		 * the object out of the node.
224 		 *
225 		 * Use resolve_node_to_value() to get the associated value.
226 		 *
227 		 * NOTE: we can get away with passing in NULL for a walk state because
228 		 * the Node is guaranteed to not be a reference to either a method
229 		 * local or a method argument (because this interface is never called
230 		 * from a running method.)
231 		 *
232 		 * Even though we do not directly invoke the interpreter for object
233 		 * resolution, we must lock it because we could access an op_region.
234 		 * The op_region access code assumes that the interpreter is locked.
235 		 */
236 		acpi_ex_enter_interpreter();
237 
238 		/* TBD: resolve_node_to_value has a strange interface, fix */
239 
240 		info->return_object =
241 		    ACPI_CAST_PTR(union acpi_operand_object, info->node);
242 
243 		status =
244 		    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
245 						  (struct acpi_namespace_node,
246 						   &info->return_object), NULL);
247 		acpi_ex_exit_interpreter();
248 
249 		if (ACPI_FAILURE(status)) {
250 			info->return_object = NULL;
251 			goto cleanup;
252 		}
253 
254 		ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "Returned object %p [%s]\n",
255 				  info->return_object,
256 				  acpi_ut_get_object_type_name(info->
257 							       return_object)));
258 
259 		status = AE_CTRL_RETURN_VALUE;	/* Always has a "return value" */
260 		break;
261 	}
262 
263 	/*
264 	 * For predefined names, check the return value against the ACPI
265 	 * specification. Some incorrect return value types are repaired.
266 	 */
267 	(void)acpi_ns_check_return_value(info->node, info, info->param_count,
268 					 status, &info->return_object);
269 
270 	/* Check if there is a return value that must be dealt with */
271 
272 	if (status == AE_CTRL_RETURN_VALUE) {
273 
274 		/* If caller does not want the return value, delete it */
275 
276 		if (info->flags & ACPI_IGNORE_RETURN_VALUE) {
277 			acpi_ut_remove_reference(info->return_object);
278 			info->return_object = NULL;
279 		}
280 
281 		/* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
282 
283 		status = AE_OK;
284 	} else if (ACPI_FAILURE(status)) {
285 
286 		/* If return_object exists, delete it */
287 
288 		if (info->return_object) {
289 			acpi_ut_remove_reference(info->return_object);
290 			info->return_object = NULL;
291 		}
292 	}
293 
294 	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
295 			  "*** Completed evaluation of object %s ***\n",
296 			  info->relative_pathname));
297 
298 cleanup:
299 	/* Optional object evaluation log */
300 
301 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
302 			      "%-26s:  %s\n", "   Exit evaluation",
303 			      &info->full_pathname[1]));
304 
305 	/*
306 	 * Namespace was unlocked by the handling acpi_ns* function, so we
307 	 * just free the pathname and return
308 	 */
309 	ACPI_FREE(info->full_pathname);
310 	info->full_pathname = NULL;
311 	return_ACPI_STATUS(status);
312 }
313 
314 /*******************************************************************************
315  *
316  * FUNCTION:    acpi_ns_exec_module_code_list
317  *
318  * PARAMETERS:  None
319  *
320  * RETURN:      None. Exceptions during method execution are ignored, since
321  *              we cannot abort a table load.
322  *
323  * DESCRIPTION: Execute all elements of the global module-level code list.
324  *              Each element is executed as a single control method.
325  *
326  * NOTE: With this option enabled, each block of detected executable AML
327  * code that is outside of any control method is wrapped with a temporary
328  * control method object and placed on a global list. The methods on this
329  * list are executed below.
330  *
331  * This function executes the module-level code for all tables only after
332  * all of the tables have been loaded. It is a legacy option and is
333  * not compatible with other ACPI implementations. See acpi_ns_load_table.
334  *
335  * This function will be removed when the legacy option is removed.
336  *
337  ******************************************************************************/
338 
339 void acpi_ns_exec_module_code_list(void)
340 {
341 	union acpi_operand_object *prev;
342 	union acpi_operand_object *next;
343 	struct acpi_evaluate_info *info;
344 	u32 method_count = 0;
345 
346 	ACPI_FUNCTION_TRACE(ns_exec_module_code_list);
347 
348 	/* Exit now if the list is empty */
349 
350 	next = acpi_gbl_module_code_list;
351 	if (!next) {
352 		ACPI_DEBUG_PRINT((ACPI_DB_INIT_NAMES,
353 				  "Legacy MLC block list is empty\n"));
354 
355 		return_VOID;
356 	}
357 
358 	/* Allocate the evaluation information block */
359 
360 	info = ACPI_ALLOCATE(sizeof(struct acpi_evaluate_info));
361 	if (!info) {
362 		return_VOID;
363 	}
364 
365 	/* Walk the list, executing each "method" */
366 
367 	while (next) {
368 		prev = next;
369 		next = next->method.mutex;
370 
371 		/* Clear the link field and execute the method */
372 
373 		prev->method.mutex = NULL;
374 		acpi_ns_exec_module_code(prev, info);
375 		method_count++;
376 
377 		/* Delete the (temporary) method object */
378 
379 		acpi_ut_remove_reference(prev);
380 	}
381 
382 	ACPI_INFO(("Executed %u blocks of module-level executable AML code",
383 		   method_count));
384 
385 	ACPI_FREE(info);
386 	acpi_gbl_module_code_list = NULL;
387 	return_VOID;
388 }
389 
390 /*******************************************************************************
391  *
392  * FUNCTION:    acpi_ns_exec_module_code
393  *
394  * PARAMETERS:  method_obj          - Object container for the module-level code
395  *              info                - Info block for method evaluation
396  *
397  * RETURN:      None. Exceptions during method execution are ignored, since
398  *              we cannot abort a table load.
399  *
400  * DESCRIPTION: Execute a control method containing a block of module-level
401  *              executable AML code. The control method is temporarily
402  *              installed to the root node, then evaluated.
403  *
404  ******************************************************************************/
405 
406 static void
407 acpi_ns_exec_module_code(union acpi_operand_object *method_obj,
408 			 struct acpi_evaluate_info *info)
409 {
410 	union acpi_operand_object *parent_obj;
411 	struct acpi_namespace_node *parent_node;
412 	acpi_object_type type;
413 	acpi_status status;
414 
415 	ACPI_FUNCTION_TRACE(ns_exec_module_code);
416 
417 	/*
418 	 * Get the parent node. We cheat by using the next_object field
419 	 * of the method object descriptor.
420 	 */
421 	parent_node =
422 	    ACPI_CAST_PTR(struct acpi_namespace_node,
423 				    method_obj->method.next_object);
424 	type = acpi_ns_get_type(parent_node);
425 
426 	/*
427 	 * Get the region handler and save it in the method object. We may need
428 	 * this if an operation region declaration causes a _REG method to be run.
429 	 *
430 	 * We can't do this in acpi_ps_link_module_code because
431 	 * acpi_gbl_root_node->Object is NULL at PASS1.
432 	 */
433 	if ((type == ACPI_TYPE_DEVICE) && parent_node->object) {
434 		method_obj->method.dispatch.handler =
435 		    parent_node->object->device.handler;
436 	}
437 
438 	/* Must clear next_object (acpi_ns_attach_object needs the field) */
439 
440 	method_obj->method.next_object = NULL;
441 
442 	/* Initialize the evaluation information block */
443 
444 	memset(info, 0, sizeof(struct acpi_evaluate_info));
445 	info->prefix_node = parent_node;
446 
447 	/*
448 	 * Get the currently attached parent object. Add a reference,
449 	 * because the ref count will be decreased when the method object
450 	 * is installed to the parent node.
451 	 */
452 	parent_obj = acpi_ns_get_attached_object(parent_node);
453 	if (parent_obj) {
454 		acpi_ut_add_reference(parent_obj);
455 	}
456 
457 	/* Install the method (module-level code) in the parent node */
458 
459 	status =
460 	    acpi_ns_attach_object(parent_node, method_obj, ACPI_TYPE_METHOD);
461 	if (ACPI_FAILURE(status)) {
462 		goto exit;
463 	}
464 
465 	/* Execute the parent node as a control method */
466 
467 	status = acpi_ns_evaluate(info);
468 
469 	ACPI_DEBUG_PRINT((ACPI_DB_INIT_NAMES,
470 			  "Executed module-level code at %p\n",
471 			  method_obj->method.aml_start));
472 
473 	/* Delete a possible implicit return value (in slack mode) */
474 
475 	if (info->return_object) {
476 		acpi_ut_remove_reference(info->return_object);
477 	}
478 
479 	/* Detach the temporary method object */
480 
481 	acpi_ns_detach_object(parent_node);
482 
483 	/* Restore the original parent object */
484 
485 	if (parent_obj) {
486 		status = acpi_ns_attach_object(parent_node, parent_obj, type);
487 	} else {
488 		parent_node->type = (u8)type;
489 	}
490 
491 exit:
492 	if (parent_obj) {
493 		acpi_ut_remove_reference(parent_obj);
494 	}
495 	return_VOID;
496 }
497