xref: /openbmc/linux/drivers/acpi/acpica/exresolv.c (revision 79f08d9e)
1 /******************************************************************************
2  *
3  * Module Name: exresolv - AML Interpreter object resolution
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2013, 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 "amlcode.h"
47 #include "acdispat.h"
48 #include "acinterp.h"
49 #include "acnamesp.h"
50 
51 #define _COMPONENT          ACPI_EXECUTER
52 ACPI_MODULE_NAME("exresolv")
53 
54 /* Local prototypes */
55 static acpi_status
56 acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
57 				struct acpi_walk_state *walk_state);
58 
59 /*******************************************************************************
60  *
61  * FUNCTION:    acpi_ex_resolve_to_value
62  *
63  * PARAMETERS:  **stack_ptr         - Points to entry on obj_stack, which can
64  *                                    be either an (union acpi_operand_object *)
65  *                                    or an acpi_handle.
66  *              walk_state          - Current method state
67  *
68  * RETURN:      Status
69  *
70  * DESCRIPTION: Convert Reference objects to values
71  *
72  ******************************************************************************/
73 
74 acpi_status
75 acpi_ex_resolve_to_value(union acpi_operand_object **stack_ptr,
76 			 struct acpi_walk_state *walk_state)
77 {
78 	acpi_status status;
79 
80 	ACPI_FUNCTION_TRACE_PTR(ex_resolve_to_value, stack_ptr);
81 
82 	if (!stack_ptr || !*stack_ptr) {
83 		ACPI_ERROR((AE_INFO, "Internal - null pointer"));
84 		return_ACPI_STATUS(AE_AML_NO_OPERAND);
85 	}
86 
87 	/*
88 	 * The entity pointed to by the stack_ptr can be either
89 	 * 1) A valid union acpi_operand_object, or
90 	 * 2) A struct acpi_namespace_node (named_obj)
91 	 */
92 	if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_OPERAND) {
93 		status = acpi_ex_resolve_object_to_value(stack_ptr, walk_state);
94 		if (ACPI_FAILURE(status)) {
95 			return_ACPI_STATUS(status);
96 		}
97 
98 		if (!*stack_ptr) {
99 			ACPI_ERROR((AE_INFO, "Internal - null pointer"));
100 			return_ACPI_STATUS(AE_AML_NO_OPERAND);
101 		}
102 	}
103 
104 	/*
105 	 * Object on the stack may have changed if acpi_ex_resolve_object_to_value()
106 	 * was called (i.e., we can't use an _else_ here.)
107 	 */
108 	if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_NAMED) {
109 		status =
110 		    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
111 						  (struct acpi_namespace_node,
112 						   stack_ptr), walk_state);
113 		if (ACPI_FAILURE(status)) {
114 			return_ACPI_STATUS(status);
115 		}
116 	}
117 
118 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Resolved object %p\n", *stack_ptr));
119 	return_ACPI_STATUS(AE_OK);
120 }
121 
122 /*******************************************************************************
123  *
124  * FUNCTION:    acpi_ex_resolve_object_to_value
125  *
126  * PARAMETERS:  stack_ptr       - Pointer to an internal object
127  *              walk_state      - Current method state
128  *
129  * RETURN:      Status
130  *
131  * DESCRIPTION: Retrieve the value from an internal object. The Reference type
132  *              uses the associated AML opcode to determine the value.
133  *
134  ******************************************************************************/
135 
136 static acpi_status
137 acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
138 				struct acpi_walk_state *walk_state)
139 {
140 	acpi_status status = AE_OK;
141 	union acpi_operand_object *stack_desc;
142 	union acpi_operand_object *obj_desc = NULL;
143 	u8 ref_type;
144 
145 	ACPI_FUNCTION_TRACE(ex_resolve_object_to_value);
146 
147 	stack_desc = *stack_ptr;
148 
149 	/* This is an object of type union acpi_operand_object */
150 
151 	switch (stack_desc->common.type) {
152 	case ACPI_TYPE_LOCAL_REFERENCE:
153 
154 		ref_type = stack_desc->reference.class;
155 
156 		switch (ref_type) {
157 		case ACPI_REFCLASS_LOCAL:
158 		case ACPI_REFCLASS_ARG:
159 			/*
160 			 * Get the local from the method's state info
161 			 * Note: this increments the local's object reference count
162 			 */
163 			status = acpi_ds_method_data_get_value(ref_type,
164 							       stack_desc->
165 							       reference.value,
166 							       walk_state,
167 							       &obj_desc);
168 			if (ACPI_FAILURE(status)) {
169 				return_ACPI_STATUS(status);
170 			}
171 
172 			ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
173 					  "[Arg/Local %X] ValueObj is %p\n",
174 					  stack_desc->reference.value,
175 					  obj_desc));
176 
177 			/*
178 			 * Now we can delete the original Reference Object and
179 			 * replace it with the resolved value
180 			 */
181 			acpi_ut_remove_reference(stack_desc);
182 			*stack_ptr = obj_desc;
183 			break;
184 
185 		case ACPI_REFCLASS_INDEX:
186 
187 			switch (stack_desc->reference.target_type) {
188 			case ACPI_TYPE_BUFFER_FIELD:
189 
190 				/* Just return - do not dereference */
191 				break;
192 
193 			case ACPI_TYPE_PACKAGE:
194 
195 				/* If method call or copy_object - do not dereference */
196 
197 				if ((walk_state->opcode ==
198 				     AML_INT_METHODCALL_OP)
199 				    || (walk_state->opcode == AML_COPY_OP)) {
200 					break;
201 				}
202 
203 				/* Otherwise, dereference the package_index to a package element */
204 
205 				obj_desc = *stack_desc->reference.where;
206 				if (obj_desc) {
207 					/*
208 					 * Valid object descriptor, copy pointer to return value
209 					 * (i.e., dereference the package index)
210 					 * Delete the ref object, increment the returned object
211 					 */
212 					acpi_ut_remove_reference(stack_desc);
213 					acpi_ut_add_reference(obj_desc);
214 					*stack_ptr = obj_desc;
215 				} else {
216 					/*
217 					 * A NULL object descriptor means an uninitialized element of
218 					 * the package, can't dereference it
219 					 */
220 					ACPI_ERROR((AE_INFO,
221 						    "Attempt to dereference an Index to NULL package element Idx=%p",
222 						    stack_desc));
223 					status = AE_AML_UNINITIALIZED_ELEMENT;
224 				}
225 				break;
226 
227 			default:
228 
229 				/* Invalid reference object */
230 
231 				ACPI_ERROR((AE_INFO,
232 					    "Unknown TargetType 0x%X in Index/Reference object %p",
233 					    stack_desc->reference.target_type,
234 					    stack_desc));
235 				status = AE_AML_INTERNAL;
236 				break;
237 			}
238 			break;
239 
240 		case ACPI_REFCLASS_REFOF:
241 		case ACPI_REFCLASS_DEBUG:
242 		case ACPI_REFCLASS_TABLE:
243 
244 			/* Just leave the object as-is, do not dereference */
245 
246 			break;
247 
248 		case ACPI_REFCLASS_NAME:	/* Reference to a named object */
249 
250 			/* Dereference the name */
251 
252 			if ((stack_desc->reference.node->type ==
253 			     ACPI_TYPE_DEVICE)
254 			    || (stack_desc->reference.node->type ==
255 				ACPI_TYPE_THERMAL)) {
256 
257 				/* These node types do not have 'real' subobjects */
258 
259 				*stack_ptr = (void *)stack_desc->reference.node;
260 			} else {
261 				/* Get the object pointed to by the namespace node */
262 
263 				*stack_ptr =
264 				    (stack_desc->reference.node)->object;
265 				acpi_ut_add_reference(*stack_ptr);
266 			}
267 
268 			acpi_ut_remove_reference(stack_desc);
269 			break;
270 
271 		default:
272 
273 			ACPI_ERROR((AE_INFO,
274 				    "Unknown Reference type 0x%X in %p",
275 				    ref_type, stack_desc));
276 			status = AE_AML_INTERNAL;
277 			break;
278 		}
279 		break;
280 
281 	case ACPI_TYPE_BUFFER:
282 
283 		status = acpi_ds_get_buffer_arguments(stack_desc);
284 		break;
285 
286 	case ACPI_TYPE_PACKAGE:
287 
288 		status = acpi_ds_get_package_arguments(stack_desc);
289 		break;
290 
291 	case ACPI_TYPE_BUFFER_FIELD:
292 	case ACPI_TYPE_LOCAL_REGION_FIELD:
293 	case ACPI_TYPE_LOCAL_BANK_FIELD:
294 	case ACPI_TYPE_LOCAL_INDEX_FIELD:
295 
296 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
297 				  "FieldRead SourceDesc=%p Type=%X\n",
298 				  stack_desc, stack_desc->common.type));
299 
300 		status =
301 		    acpi_ex_read_data_from_field(walk_state, stack_desc,
302 						 &obj_desc);
303 
304 		/* Remove a reference to the original operand, then override */
305 
306 		acpi_ut_remove_reference(*stack_ptr);
307 		*stack_ptr = (void *)obj_desc;
308 		break;
309 
310 	default:
311 
312 		break;
313 	}
314 
315 	return_ACPI_STATUS(status);
316 }
317 
318 /*******************************************************************************
319  *
320  * FUNCTION:    acpi_ex_resolve_multiple
321  *
322  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
323  *              operand             - Starting point for resolution
324  *              return_type         - Where the object type is returned
325  *              return_desc         - Where the resolved object is returned
326  *
327  * RETURN:      Status
328  *
329  * DESCRIPTION: Return the base object and type. Traverse a reference list if
330  *              necessary to get to the base object.
331  *
332  ******************************************************************************/
333 
334 acpi_status
335 acpi_ex_resolve_multiple(struct acpi_walk_state *walk_state,
336 			 union acpi_operand_object *operand,
337 			 acpi_object_type * return_type,
338 			 union acpi_operand_object **return_desc)
339 {
340 	union acpi_operand_object *obj_desc = (void *)operand;
341 	struct acpi_namespace_node *node;
342 	acpi_object_type type;
343 	acpi_status status;
344 
345 	ACPI_FUNCTION_TRACE(acpi_ex_resolve_multiple);
346 
347 	/* Operand can be either a namespace node or an operand descriptor */
348 
349 	switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
350 	case ACPI_DESC_TYPE_OPERAND:
351 
352 		type = obj_desc->common.type;
353 		break;
354 
355 	case ACPI_DESC_TYPE_NAMED:
356 
357 		type = ((struct acpi_namespace_node *)obj_desc)->type;
358 		obj_desc =
359 		    acpi_ns_get_attached_object((struct acpi_namespace_node *)
360 						obj_desc);
361 
362 		/* If we had an Alias node, use the attached object for type info */
363 
364 		if (type == ACPI_TYPE_LOCAL_ALIAS) {
365 			type = ((struct acpi_namespace_node *)obj_desc)->type;
366 			obj_desc =
367 			    acpi_ns_get_attached_object((struct
368 							 acpi_namespace_node *)
369 							obj_desc);
370 		}
371 		break;
372 
373 	default:
374 		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
375 	}
376 
377 	/* If type is anything other than a reference, we are done */
378 
379 	if (type != ACPI_TYPE_LOCAL_REFERENCE) {
380 		goto exit;
381 	}
382 
383 	/*
384 	 * For reference objects created via the ref_of, Index, or Load/load_table
385 	 * operators, we need to get to the base object (as per the ACPI
386 	 * specification of the object_type and size_of operators). This means
387 	 * traversing the list of possibly many nested references.
388 	 */
389 	while (obj_desc->common.type == ACPI_TYPE_LOCAL_REFERENCE) {
390 		switch (obj_desc->reference.class) {
391 		case ACPI_REFCLASS_REFOF:
392 		case ACPI_REFCLASS_NAME:
393 
394 			/* Dereference the reference pointer */
395 
396 			if (obj_desc->reference.class == ACPI_REFCLASS_REFOF) {
397 				node = obj_desc->reference.object;
398 			} else {	/* AML_INT_NAMEPATH_OP */
399 
400 				node = obj_desc->reference.node;
401 			}
402 
403 			/* All "References" point to a NS node */
404 
405 			if (ACPI_GET_DESCRIPTOR_TYPE(node) !=
406 			    ACPI_DESC_TYPE_NAMED) {
407 				ACPI_ERROR((AE_INFO,
408 					    "Not a namespace node %p [%s]",
409 					    node,
410 					    acpi_ut_get_descriptor_name(node)));
411 				return_ACPI_STATUS(AE_AML_INTERNAL);
412 			}
413 
414 			/* Get the attached object */
415 
416 			obj_desc = acpi_ns_get_attached_object(node);
417 			if (!obj_desc) {
418 
419 				/* No object, use the NS node type */
420 
421 				type = acpi_ns_get_type(node);
422 				goto exit;
423 			}
424 
425 			/* Check for circular references */
426 
427 			if (obj_desc == operand) {
428 				return_ACPI_STATUS(AE_AML_CIRCULAR_REFERENCE);
429 			}
430 			break;
431 
432 		case ACPI_REFCLASS_INDEX:
433 
434 			/* Get the type of this reference (index into another object) */
435 
436 			type = obj_desc->reference.target_type;
437 			if (type != ACPI_TYPE_PACKAGE) {
438 				goto exit;
439 			}
440 
441 			/*
442 			 * The main object is a package, we want to get the type
443 			 * of the individual package element that is referenced by
444 			 * the index.
445 			 *
446 			 * This could of course in turn be another reference object.
447 			 */
448 			obj_desc = *(obj_desc->reference.where);
449 			if (!obj_desc) {
450 
451 				/* NULL package elements are allowed */
452 
453 				type = 0;	/* Uninitialized */
454 				goto exit;
455 			}
456 			break;
457 
458 		case ACPI_REFCLASS_TABLE:
459 
460 			type = ACPI_TYPE_DDB_HANDLE;
461 			goto exit;
462 
463 		case ACPI_REFCLASS_LOCAL:
464 		case ACPI_REFCLASS_ARG:
465 
466 			if (return_desc) {
467 				status =
468 				    acpi_ds_method_data_get_value(obj_desc->
469 								  reference.
470 								  class,
471 								  obj_desc->
472 								  reference.
473 								  value,
474 								  walk_state,
475 								  &obj_desc);
476 				if (ACPI_FAILURE(status)) {
477 					return_ACPI_STATUS(status);
478 				}
479 				acpi_ut_remove_reference(obj_desc);
480 			} else {
481 				status =
482 				    acpi_ds_method_data_get_node(obj_desc->
483 								 reference.
484 								 class,
485 								 obj_desc->
486 								 reference.
487 								 value,
488 								 walk_state,
489 								 &node);
490 				if (ACPI_FAILURE(status)) {
491 					return_ACPI_STATUS(status);
492 				}
493 
494 				obj_desc = acpi_ns_get_attached_object(node);
495 				if (!obj_desc) {
496 					type = ACPI_TYPE_ANY;
497 					goto exit;
498 				}
499 			}
500 			break;
501 
502 		case ACPI_REFCLASS_DEBUG:
503 
504 			/* The Debug Object is of type "DebugObject" */
505 
506 			type = ACPI_TYPE_DEBUG_OBJECT;
507 			goto exit;
508 
509 		default:
510 
511 			ACPI_ERROR((AE_INFO,
512 				    "Unknown Reference Class 0x%2.2X",
513 				    obj_desc->reference.class));
514 			return_ACPI_STATUS(AE_AML_INTERNAL);
515 		}
516 	}
517 
518 	/*
519 	 * Now we are guaranteed to have an object that has not been created
520 	 * via the ref_of or Index operators.
521 	 */
522 	type = obj_desc->common.type;
523 
524 exit:
525 	/* Convert internal types to external types */
526 
527 	switch (type) {
528 	case ACPI_TYPE_LOCAL_REGION_FIELD:
529 	case ACPI_TYPE_LOCAL_BANK_FIELD:
530 	case ACPI_TYPE_LOCAL_INDEX_FIELD:
531 
532 		type = ACPI_TYPE_FIELD_UNIT;
533 		break;
534 
535 	case ACPI_TYPE_LOCAL_SCOPE:
536 
537 		/* Per ACPI Specification, Scope is untyped */
538 
539 		type = ACPI_TYPE_ANY;
540 		break;
541 
542 	default:
543 
544 		/* No change to Type required */
545 
546 		break;
547 	}
548 
549 	*return_type = type;
550 	if (return_desc) {
551 		*return_desc = obj_desc;
552 	}
553 	return_ACPI_STATUS(AE_OK);
554 }
555