xref: /openbmc/linux/drivers/acpi/acpica/exresolv.c (revision d9fd5a71)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: exresolv - AML Interpreter object resolution
5  *
6  * Copyright (C) 2000 - 2021, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12 #include "amlcode.h"
13 #include "acdispat.h"
14 #include "acinterp.h"
15 #include "acnamesp.h"
16 
17 #define _COMPONENT          ACPI_EXECUTER
18 ACPI_MODULE_NAME("exresolv")
19 
20 /* Local prototypes */
21 static acpi_status
22 acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
23 				struct acpi_walk_state *walk_state);
24 
25 /*******************************************************************************
26  *
27  * FUNCTION:    acpi_ex_resolve_to_value
28  *
29  * PARAMETERS:  **stack_ptr         - Points to entry on obj_stack, which can
30  *                                    be either an (union acpi_operand_object *)
31  *                                    or an acpi_handle.
32  *              walk_state          - Current method state
33  *
34  * RETURN:      Status
35  *
36  * DESCRIPTION: Convert Reference objects to values
37  *
38  ******************************************************************************/
39 
40 acpi_status
41 acpi_ex_resolve_to_value(union acpi_operand_object **stack_ptr,
42 			 struct acpi_walk_state *walk_state)
43 {
44 	acpi_status status;
45 
46 	ACPI_FUNCTION_TRACE_PTR(ex_resolve_to_value, stack_ptr);
47 
48 	if (!stack_ptr || !*stack_ptr) {
49 		ACPI_ERROR((AE_INFO, "Internal - null pointer"));
50 		return_ACPI_STATUS(AE_AML_NO_OPERAND);
51 	}
52 
53 	/*
54 	 * The entity pointed to by the stack_ptr can be either
55 	 * 1) A valid union acpi_operand_object, or
56 	 * 2) A struct acpi_namespace_node (named_obj)
57 	 */
58 	if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_OPERAND) {
59 		status = acpi_ex_resolve_object_to_value(stack_ptr, walk_state);
60 		if (ACPI_FAILURE(status)) {
61 			return_ACPI_STATUS(status);
62 		}
63 
64 		if (!*stack_ptr) {
65 			ACPI_ERROR((AE_INFO, "Internal - null pointer"));
66 			return_ACPI_STATUS(AE_AML_NO_OPERAND);
67 		}
68 	}
69 
70 	/*
71 	 * Object on the stack may have changed if acpi_ex_resolve_object_to_value()
72 	 * was called (i.e., we can't use an _else_ here.)
73 	 */
74 	if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_NAMED) {
75 		status =
76 		    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
77 						  (struct acpi_namespace_node,
78 						   stack_ptr), walk_state);
79 		if (ACPI_FAILURE(status)) {
80 			return_ACPI_STATUS(status);
81 		}
82 	}
83 
84 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Resolved object %p\n", *stack_ptr));
85 	return_ACPI_STATUS(AE_OK);
86 }
87 
88 /*******************************************************************************
89  *
90  * FUNCTION:    acpi_ex_resolve_object_to_value
91  *
92  * PARAMETERS:  stack_ptr       - Pointer to an internal object
93  *              walk_state      - Current method state
94  *
95  * RETURN:      Status
96  *
97  * DESCRIPTION: Retrieve the value from an internal object. The Reference type
98  *              uses the associated AML opcode to determine the value.
99  *
100  ******************************************************************************/
101 
102 static acpi_status
103 acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
104 				struct acpi_walk_state *walk_state)
105 {
106 	acpi_status status = AE_OK;
107 	union acpi_operand_object *stack_desc;
108 	union acpi_operand_object *obj_desc = NULL;
109 	u8 ref_type;
110 
111 	ACPI_FUNCTION_TRACE(ex_resolve_object_to_value);
112 
113 	stack_desc = *stack_ptr;
114 
115 	/* This is an object of type union acpi_operand_object */
116 
117 	switch (stack_desc->common.type) {
118 	case ACPI_TYPE_LOCAL_REFERENCE:
119 
120 		ref_type = stack_desc->reference.class;
121 
122 		switch (ref_type) {
123 		case ACPI_REFCLASS_LOCAL:
124 		case ACPI_REFCLASS_ARG:
125 			/*
126 			 * Get the local from the method's state info
127 			 * Note: this increments the local's object reference count
128 			 */
129 			status = acpi_ds_method_data_get_value(ref_type,
130 							       stack_desc->
131 							       reference.value,
132 							       walk_state,
133 							       &obj_desc);
134 			if (ACPI_FAILURE(status)) {
135 				return_ACPI_STATUS(status);
136 			}
137 
138 			ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
139 					  "[Arg/Local %X] ValueObj is %p\n",
140 					  stack_desc->reference.value,
141 					  obj_desc));
142 
143 			/*
144 			 * Now we can delete the original Reference Object and
145 			 * replace it with the resolved value
146 			 */
147 			acpi_ut_remove_reference(stack_desc);
148 			*stack_ptr = obj_desc;
149 			break;
150 
151 		case ACPI_REFCLASS_INDEX:
152 
153 			switch (stack_desc->reference.target_type) {
154 			case ACPI_TYPE_BUFFER_FIELD:
155 
156 				/* Just return - do not dereference */
157 				break;
158 
159 			case ACPI_TYPE_PACKAGE:
160 
161 				/* If method call or copy_object - do not dereference */
162 
163 				if ((walk_state->opcode ==
164 				     AML_INT_METHODCALL_OP)
165 				    || (walk_state->opcode ==
166 					AML_COPY_OBJECT_OP)) {
167 					break;
168 				}
169 
170 				/* Otherwise, dereference the package_index to a package element */
171 
172 				obj_desc = *stack_desc->reference.where;
173 				if (obj_desc) {
174 					/*
175 					 * Valid object descriptor, copy pointer to return value
176 					 * (i.e., dereference the package index)
177 					 * Delete the ref object, increment the returned object
178 					 */
179 					acpi_ut_add_reference(obj_desc);
180 					*stack_ptr = obj_desc;
181 				} else {
182 					/*
183 					 * A NULL object descriptor means an uninitialized element of
184 					 * the package, can't dereference it
185 					 */
186 					ACPI_ERROR((AE_INFO,
187 						    "Attempt to dereference an Index to "
188 						    "NULL package element Idx=%p",
189 						    stack_desc));
190 					status = AE_AML_UNINITIALIZED_ELEMENT;
191 				}
192 				break;
193 
194 			default:
195 
196 				/* Invalid reference object */
197 
198 				ACPI_ERROR((AE_INFO,
199 					    "Unknown TargetType 0x%X in Index/Reference object %p",
200 					    stack_desc->reference.target_type,
201 					    stack_desc));
202 				status = AE_AML_INTERNAL;
203 				break;
204 			}
205 			break;
206 
207 		case ACPI_REFCLASS_REFOF:
208 		case ACPI_REFCLASS_DEBUG:
209 		case ACPI_REFCLASS_TABLE:
210 
211 			/* Just leave the object as-is, do not dereference */
212 
213 			break;
214 
215 		case ACPI_REFCLASS_NAME:	/* Reference to a named object */
216 
217 			/* Dereference the name */
218 
219 			if ((stack_desc->reference.node->type ==
220 			     ACPI_TYPE_DEVICE)
221 			    || (stack_desc->reference.node->type ==
222 				ACPI_TYPE_THERMAL)) {
223 
224 				/* These node types do not have 'real' subobjects */
225 
226 				*stack_ptr = (void *)stack_desc->reference.node;
227 			} else {
228 				/* Get the object pointed to by the namespace node */
229 
230 				*stack_ptr =
231 				    (stack_desc->reference.node)->object;
232 				acpi_ut_add_reference(*stack_ptr);
233 			}
234 
235 			acpi_ut_remove_reference(stack_desc);
236 			break;
237 
238 		default:
239 
240 			ACPI_ERROR((AE_INFO,
241 				    "Unknown Reference type 0x%X in %p",
242 				    ref_type, stack_desc));
243 			status = AE_AML_INTERNAL;
244 			break;
245 		}
246 		break;
247 
248 	case ACPI_TYPE_BUFFER:
249 
250 		status = acpi_ds_get_buffer_arguments(stack_desc);
251 		break;
252 
253 	case ACPI_TYPE_PACKAGE:
254 
255 		status = acpi_ds_get_package_arguments(stack_desc);
256 		break;
257 
258 	case ACPI_TYPE_BUFFER_FIELD:
259 	case ACPI_TYPE_LOCAL_REGION_FIELD:
260 	case ACPI_TYPE_LOCAL_BANK_FIELD:
261 	case ACPI_TYPE_LOCAL_INDEX_FIELD:
262 
263 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
264 				  "FieldRead SourceDesc=%p Type=%X\n",
265 				  stack_desc, stack_desc->common.type));
266 
267 		status =
268 		    acpi_ex_read_data_from_field(walk_state, stack_desc,
269 						 &obj_desc);
270 
271 		/* Remove a reference to the original operand, then override */
272 
273 		acpi_ut_remove_reference(*stack_ptr);
274 		*stack_ptr = (void *)obj_desc;
275 		break;
276 
277 	default:
278 
279 		break;
280 	}
281 
282 	return_ACPI_STATUS(status);
283 }
284 
285 /*******************************************************************************
286  *
287  * FUNCTION:    acpi_ex_resolve_multiple
288  *
289  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
290  *              operand             - Starting point for resolution
291  *              return_type         - Where the object type is returned
292  *              return_desc         - Where the resolved object is returned
293  *
294  * RETURN:      Status
295  *
296  * DESCRIPTION: Return the base object and type. Traverse a reference list if
297  *              necessary to get to the base object.
298  *
299  ******************************************************************************/
300 
301 acpi_status
302 acpi_ex_resolve_multiple(struct acpi_walk_state *walk_state,
303 			 union acpi_operand_object *operand,
304 			 acpi_object_type *return_type,
305 			 union acpi_operand_object **return_desc)
306 {
307 	union acpi_operand_object *obj_desc = ACPI_CAST_PTR(void, operand);
308 	struct acpi_namespace_node *node =
309 	    ACPI_CAST_PTR(struct acpi_namespace_node, operand);
310 	acpi_object_type type;
311 	acpi_status status;
312 
313 	ACPI_FUNCTION_TRACE(acpi_ex_resolve_multiple);
314 
315 	/* Operand can be either a namespace node or an operand descriptor */
316 
317 	switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
318 	case ACPI_DESC_TYPE_OPERAND:
319 
320 		type = obj_desc->common.type;
321 		break;
322 
323 	case ACPI_DESC_TYPE_NAMED:
324 
325 		type = ((struct acpi_namespace_node *)obj_desc)->type;
326 		obj_desc = acpi_ns_get_attached_object(node);
327 
328 		/* If we had an Alias node, use the attached object for type info */
329 
330 		if (type == ACPI_TYPE_LOCAL_ALIAS) {
331 			type = ((struct acpi_namespace_node *)obj_desc)->type;
332 			obj_desc = acpi_ns_get_attached_object((struct
333 								acpi_namespace_node
334 								*)obj_desc);
335 		}
336 
337 		switch (type) {
338 		case ACPI_TYPE_DEVICE:
339 		case ACPI_TYPE_THERMAL:
340 
341 			/* These types have no attached subobject */
342 			break;
343 
344 		default:
345 
346 			/* All other types require a subobject */
347 
348 			if (!obj_desc) {
349 				ACPI_ERROR((AE_INFO,
350 					    "[%4.4s] Node is unresolved or uninitialized",
351 					    acpi_ut_get_node_name(node)));
352 				return_ACPI_STATUS(AE_AML_UNINITIALIZED_NODE);
353 			}
354 			break;
355 		}
356 		break;
357 
358 	default:
359 		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
360 	}
361 
362 	/* If type is anything other than a reference, we are done */
363 
364 	if (type != ACPI_TYPE_LOCAL_REFERENCE) {
365 		goto exit;
366 	}
367 
368 	/*
369 	 * For reference objects created via the ref_of, Index, or Load/load_table
370 	 * operators, we need to get to the base object (as per the ACPI
371 	 * specification of the object_type and size_of operators). This means
372 	 * traversing the list of possibly many nested references.
373 	 */
374 	while (obj_desc->common.type == ACPI_TYPE_LOCAL_REFERENCE) {
375 		switch (obj_desc->reference.class) {
376 		case ACPI_REFCLASS_REFOF:
377 		case ACPI_REFCLASS_NAME:
378 
379 			/* Dereference the reference pointer */
380 
381 			if (obj_desc->reference.class == ACPI_REFCLASS_REFOF) {
382 				node = obj_desc->reference.object;
383 			} else {	/* AML_INT_NAMEPATH_OP */
384 
385 				node = obj_desc->reference.node;
386 			}
387 
388 			/* All "References" point to a NS node */
389 
390 			if (ACPI_GET_DESCRIPTOR_TYPE(node) !=
391 			    ACPI_DESC_TYPE_NAMED) {
392 				ACPI_ERROR((AE_INFO,
393 					    "Not a namespace node %p [%s]",
394 					    node,
395 					    acpi_ut_get_descriptor_name(node)));
396 				return_ACPI_STATUS(AE_AML_INTERNAL);
397 			}
398 
399 			/* Get the attached object */
400 
401 			obj_desc = acpi_ns_get_attached_object(node);
402 			if (!obj_desc) {
403 
404 				/* No object, use the NS node type */
405 
406 				type = acpi_ns_get_type(node);
407 				goto exit;
408 			}
409 
410 			/* Check for circular references */
411 
412 			if (obj_desc == operand) {
413 				return_ACPI_STATUS(AE_AML_CIRCULAR_REFERENCE);
414 			}
415 			break;
416 
417 		case ACPI_REFCLASS_INDEX:
418 
419 			/* Get the type of this reference (index into another object) */
420 
421 			type = obj_desc->reference.target_type;
422 			if (type != ACPI_TYPE_PACKAGE) {
423 				goto exit;
424 			}
425 
426 			/*
427 			 * The main object is a package, we want to get the type
428 			 * of the individual package element that is referenced by
429 			 * the index.
430 			 *
431 			 * This could of course in turn be another reference object.
432 			 */
433 			obj_desc = *(obj_desc->reference.where);
434 			if (!obj_desc) {
435 
436 				/* NULL package elements are allowed */
437 
438 				type = 0;	/* Uninitialized */
439 				goto exit;
440 			}
441 			break;
442 
443 		case ACPI_REFCLASS_TABLE:
444 
445 			type = ACPI_TYPE_DDB_HANDLE;
446 			goto exit;
447 
448 		case ACPI_REFCLASS_LOCAL:
449 		case ACPI_REFCLASS_ARG:
450 
451 			if (return_desc) {
452 				status =
453 				    acpi_ds_method_data_get_value(obj_desc->
454 								  reference.
455 								  class,
456 								  obj_desc->
457 								  reference.
458 								  value,
459 								  walk_state,
460 								  &obj_desc);
461 				if (ACPI_FAILURE(status)) {
462 					return_ACPI_STATUS(status);
463 				}
464 				acpi_ut_remove_reference(obj_desc);
465 			} else {
466 				status =
467 				    acpi_ds_method_data_get_node(obj_desc->
468 								 reference.
469 								 class,
470 								 obj_desc->
471 								 reference.
472 								 value,
473 								 walk_state,
474 								 &node);
475 				if (ACPI_FAILURE(status)) {
476 					return_ACPI_STATUS(status);
477 				}
478 
479 				obj_desc = acpi_ns_get_attached_object(node);
480 				if (!obj_desc) {
481 					type = ACPI_TYPE_ANY;
482 					goto exit;
483 				}
484 			}
485 			break;
486 
487 		case ACPI_REFCLASS_DEBUG:
488 
489 			/* The Debug Object is of type "DebugObject" */
490 
491 			type = ACPI_TYPE_DEBUG_OBJECT;
492 			goto exit;
493 
494 		default:
495 
496 			ACPI_ERROR((AE_INFO,
497 				    "Unknown Reference Class 0x%2.2X",
498 				    obj_desc->reference.class));
499 			return_ACPI_STATUS(AE_AML_INTERNAL);
500 		}
501 	}
502 
503 	/*
504 	 * Now we are guaranteed to have an object that has not been created
505 	 * via the ref_of or Index operators.
506 	 */
507 	type = obj_desc->common.type;
508 
509 exit:
510 	/* Convert internal types to external types */
511 
512 	switch (type) {
513 	case ACPI_TYPE_LOCAL_REGION_FIELD:
514 	case ACPI_TYPE_LOCAL_BANK_FIELD:
515 	case ACPI_TYPE_LOCAL_INDEX_FIELD:
516 
517 		type = ACPI_TYPE_FIELD_UNIT;
518 		break;
519 
520 	case ACPI_TYPE_LOCAL_SCOPE:
521 
522 		/* Per ACPI Specification, Scope is untyped */
523 
524 		type = ACPI_TYPE_ANY;
525 		break;
526 
527 	default:
528 
529 		/* No change to Type required */
530 
531 		break;
532 	}
533 
534 	*return_type = type;
535 	if (return_desc) {
536 		*return_desc = obj_desc;
537 	}
538 	return_ACPI_STATUS(AE_OK);
539 }
540