xref: /linux/drivers/acpi/acpica/nseval.c (revision d99ff463ecf651437e9e4abe68f331dfb6b5bd9d)
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 /*******************************************************************************
18  *
19  * FUNCTION:    acpi_ns_evaluate
20  *
21  * PARAMETERS:  info            - Evaluation info block, contains these fields
22  *                                and more:
23  *                  prefix_node     - Prefix or Method/Object Node to execute
24  *                  relative_path   - Name of method to execute, If NULL, the
25  *                                    Node is the object to execute
26  *                  parameters      - List of parameters to pass to the method,
27  *                                    terminated by NULL. Params itself may be
28  *                                    NULL if no parameters are being passed.
29  *                  parameter_type  - Type of Parameter list
30  *                  return_object   - Where to put method's return value (if
31  *                                    any). If NULL, no value is returned.
32  *                  flags           - ACPI_IGNORE_RETURN_VALUE to delete return
33  *
34  * RETURN:      Status
35  *
36  * DESCRIPTION: Execute a control method or return the current value of an
37  *              ACPI namespace object.
38  *
39  * MUTEX:       Locks interpreter
40  *
41  ******************************************************************************/
42 acpi_status acpi_ns_evaluate(struct acpi_evaluate_info *info)
43 {
44 	acpi_status status;
45 
46 	ACPI_FUNCTION_TRACE(ns_evaluate);
47 
48 	if (!info) {
49 		return_ACPI_STATUS(AE_BAD_PARAMETER);
50 	}
51 
52 	if (!info->node) {
53 		/*
54 		 * Get the actual namespace node for the target object if we
55 		 * need to. Handles these cases:
56 		 *
57 		 * 1) Null node, valid pathname from root (absolute path)
58 		 * 2) Node and valid pathname (path relative to Node)
59 		 * 3) Node, Null pathname
60 		 */
61 		status =
62 		    acpi_ns_get_node(info->prefix_node, info->relative_pathname,
63 				     ACPI_NS_NO_UPSEARCH, &info->node);
64 		if (ACPI_FAILURE(status)) {
65 			return_ACPI_STATUS(status);
66 		}
67 	}
68 
69 	/*
70 	 * For a method alias, we must grab the actual method node so that
71 	 * proper scoping context will be established before execution.
72 	 */
73 	if (acpi_ns_get_type(info->node) == ACPI_TYPE_LOCAL_METHOD_ALIAS) {
74 		info->node =
75 		    ACPI_CAST_PTR(struct acpi_namespace_node,
76 				  info->node->object);
77 	}
78 
79 	/* Complete the info block initialization */
80 
81 	info->return_object = NULL;
82 	info->node_flags = info->node->flags;
83 	info->obj_desc = acpi_ns_get_attached_object(info->node);
84 
85 	ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "%s [%p] Value %p\n",
86 			  info->relative_pathname, info->node,
87 			  acpi_ns_get_attached_object(info->node)));
88 
89 	/* Get info if we have a predefined name (_HID, etc.) */
90 
91 	info->predefined =
92 	    acpi_ut_match_predefined_method(info->node->name.ascii);
93 
94 	/* Get the full pathname to the object, for use in warning messages */
95 
96 	info->full_pathname = acpi_ns_get_normalized_pathname(info->node, TRUE);
97 	if (!info->full_pathname) {
98 		return_ACPI_STATUS(AE_NO_MEMORY);
99 	}
100 
101 	/* Optional object evaluation log */
102 
103 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
104 			      "%-26s:  %s (%s)\n", "   Enter evaluation",
105 			      &info->full_pathname[1],
106 			      acpi_ut_get_type_name(info->node->type)));
107 
108 	/* Count the number of arguments being passed in */
109 
110 	info->param_count = 0;
111 	if (info->parameters) {
112 		while (info->parameters[info->param_count]) {
113 			info->param_count++;
114 		}
115 
116 		/* Warn on impossible argument count */
117 
118 		if (info->param_count > ACPI_METHOD_NUM_ARGS) {
119 			ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
120 					      ACPI_WARN_ALWAYS,
121 					      "Excess arguments (%u) - using only %u",
122 					      info->param_count,
123 					      ACPI_METHOD_NUM_ARGS));
124 
125 			info->param_count = ACPI_METHOD_NUM_ARGS;
126 		}
127 	}
128 
129 	/*
130 	 * For predefined names: Check that the declared argument count
131 	 * matches the ACPI spec -- otherwise this is a BIOS error.
132 	 */
133 	acpi_ns_check_acpi_compliance(info->full_pathname, info->node,
134 				      info->predefined);
135 
136 	/*
137 	 * For all names: Check that the incoming argument count for
138 	 * this method/object matches the actual ASL/AML definition.
139 	 */
140 	acpi_ns_check_argument_count(info->full_pathname, info->node,
141 				     info->param_count, info->predefined);
142 
143 	/* For predefined names: Typecheck all incoming arguments */
144 
145 	acpi_ns_check_argument_types(info);
146 
147 	/*
148 	 * Three major evaluation cases:
149 	 *
150 	 * 1) Object types that cannot be evaluated by definition
151 	 * 2) The object is a control method -- execute it
152 	 * 3) The object is not a method -- just return it's current value
153 	 */
154 	switch (acpi_ns_get_type(info->node)) {
155 	case ACPI_TYPE_ANY:
156 	case ACPI_TYPE_DEVICE:
157 	case ACPI_TYPE_EVENT:
158 	case ACPI_TYPE_MUTEX:
159 	case ACPI_TYPE_REGION:
160 	case ACPI_TYPE_THERMAL:
161 	case ACPI_TYPE_LOCAL_SCOPE:
162 		/*
163 		 * 1) Disallow evaluation of these object types. For these,
164 		 *    object evaluation is undefined.
165 		 */
166 		ACPI_ERROR((AE_INFO,
167 			    "%s: This object type [%s] "
168 			    "never contains data and cannot be evaluated",
169 			    info->full_pathname,
170 			    acpi_ut_get_type_name(info->node->type)));
171 
172 		status = AE_TYPE;
173 		goto cleanup;
174 
175 	case ACPI_TYPE_METHOD:
176 		/*
177 		 * 2) Object is a control method - execute it
178 		 */
179 
180 		/* Verify that there is a method object associated with this node */
181 
182 		if (!info->obj_desc) {
183 			ACPI_ERROR((AE_INFO,
184 				    "%s: Method has no attached sub-object",
185 				    info->full_pathname));
186 			status = AE_NULL_OBJECT;
187 			goto cleanup;
188 		}
189 
190 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
191 				  "**** Execute method [%s] at AML address %p length %X\n",
192 				  info->full_pathname,
193 				  info->obj_desc->method.aml_start + 1,
194 				  info->obj_desc->method.aml_length - 1));
195 
196 		/*
197 		 * Any namespace deletion must acquire both the namespace and
198 		 * interpreter locks to ensure that no thread is using the portion of
199 		 * the namespace that is being deleted.
200 		 *
201 		 * Execute the method via the interpreter. The interpreter is locked
202 		 * here before calling into the AML parser
203 		 */
204 		acpi_ex_enter_interpreter();
205 		status = acpi_ps_execute_method(info);
206 		acpi_ex_exit_interpreter();
207 		break;
208 
209 	default:
210 		/*
211 		 * 3) All other non-method objects -- get the current object value
212 		 */
213 
214 		/*
215 		 * Some objects require additional resolution steps (e.g., the Node
216 		 * may be a field that must be read, etc.) -- we can't just grab
217 		 * the object out of the node.
218 		 *
219 		 * Use resolve_node_to_value() to get the associated value.
220 		 *
221 		 * NOTE: we can get away with passing in NULL for a walk state because
222 		 * the Node is guaranteed to not be a reference to either a method
223 		 * local or a method argument (because this interface is never called
224 		 * from a running method.)
225 		 *
226 		 * Even though we do not directly invoke the interpreter for object
227 		 * resolution, we must lock it because we could access an op_region.
228 		 * The op_region access code assumes that the interpreter is locked.
229 		 */
230 		acpi_ex_enter_interpreter();
231 
232 		/* TBD: resolve_node_to_value has a strange interface, fix */
233 
234 		info->return_object =
235 		    ACPI_CAST_PTR(union acpi_operand_object, info->node);
236 
237 		status =
238 		    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
239 						  (struct acpi_namespace_node,
240 						   &info->return_object), NULL);
241 		acpi_ex_exit_interpreter();
242 
243 		if (ACPI_FAILURE(status)) {
244 			info->return_object = NULL;
245 			goto cleanup;
246 		}
247 
248 		ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "Returned object %p [%s]\n",
249 				  info->return_object,
250 				  acpi_ut_get_object_type_name(info->
251 							       return_object)));
252 
253 		status = AE_CTRL_RETURN_VALUE;	/* Always has a "return value" */
254 		break;
255 	}
256 
257 	/*
258 	 * For predefined names, check the return value against the ACPI
259 	 * specification. Some incorrect return value types are repaired.
260 	 */
261 	(void)acpi_ns_check_return_value(info->node, info, info->param_count,
262 					 status, &info->return_object);
263 
264 	/* Check if there is a return value that must be dealt with */
265 
266 	if (status == AE_CTRL_RETURN_VALUE) {
267 
268 		/* If caller does not want the return value, delete it */
269 
270 		if (info->flags & ACPI_IGNORE_RETURN_VALUE) {
271 			acpi_ut_remove_reference(info->return_object);
272 			info->return_object = NULL;
273 		}
274 
275 		/* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
276 
277 		status = AE_OK;
278 	} else if (ACPI_FAILURE(status)) {
279 
280 		/* If return_object exists, delete it */
281 
282 		if (info->return_object) {
283 			acpi_ut_remove_reference(info->return_object);
284 			info->return_object = NULL;
285 		}
286 	}
287 
288 	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
289 			  "*** Completed evaluation of object %s ***\n",
290 			  info->relative_pathname));
291 
292 cleanup:
293 	/* Optional object evaluation log */
294 
295 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
296 			      "%-26s:  %s\n", "   Exit evaluation",
297 			      &info->full_pathname[1]));
298 
299 	/*
300 	 * Namespace was unlocked by the handling acpi_ns* function, so we
301 	 * just free the pathname and return
302 	 */
303 	ACPI_FREE(info->full_pathname);
304 	info->full_pathname = NULL;
305 	return_ACPI_STATUS(status);
306 }
307