1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /*******************************************************************************
3 *
4 * Module Name: dsutils - Dispatcher utilities
5 *
6 ******************************************************************************/
7
8 #include <acpi/acpi.h>
9 #include "accommon.h"
10 #include "acparser.h"
11 #include "amlcode.h"
12 #include "acdispat.h"
13 #include "acinterp.h"
14 #include "acnamesp.h"
15 #include "acdebug.h"
16
17 #define _COMPONENT ACPI_DISPATCHER
18 ACPI_MODULE_NAME("dsutils")
19
20 /*******************************************************************************
21 *
22 * FUNCTION: acpi_ds_clear_implicit_return
23 *
24 * PARAMETERS: walk_state - Current State
25 *
26 * RETURN: None.
27 *
28 * DESCRIPTION: Clear and remove a reference on an implicit return value. Used
29 * to delete "stale" return values (if enabled, the return value
30 * from every operator is saved at least momentarily, in case the
31 * parent method exits.)
32 *
33 ******************************************************************************/
acpi_ds_clear_implicit_return(struct acpi_walk_state * walk_state)34 void acpi_ds_clear_implicit_return(struct acpi_walk_state *walk_state)
35 {
36 ACPI_FUNCTION_NAME(ds_clear_implicit_return);
37
38 /*
39 * Slack must be enabled for this feature
40 */
41 if (!acpi_gbl_enable_interpreter_slack) {
42 return;
43 }
44
45 if (walk_state->implicit_return_obj) {
46 /*
47 * Delete any "stale" implicit return. However, in
48 * complex statements, the implicit return value can be
49 * bubbled up several levels.
50 */
51 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
52 "Removing reference on stale implicit return obj %p\n",
53 walk_state->implicit_return_obj));
54
55 acpi_ut_remove_reference(walk_state->implicit_return_obj);
56 walk_state->implicit_return_obj = NULL;
57 }
58 }
59
60 /*******************************************************************************
61 *
62 * FUNCTION: acpi_ds_do_implicit_return
63 *
64 * PARAMETERS: return_desc - The return value
65 * walk_state - Current State
66 * add_reference - True if a reference should be added to the
67 * return object
68 *
69 * RETURN: TRUE if implicit return enabled, FALSE otherwise
70 *
71 * DESCRIPTION: Implements the optional "implicit return". We save the result
72 * of every ASL operator and control method invocation in case the
73 * parent method exit. Before storing a new return value, we
74 * delete the previous return value.
75 *
76 ******************************************************************************/
77
78 u8
acpi_ds_do_implicit_return(union acpi_operand_object * return_desc,struct acpi_walk_state * walk_state,u8 add_reference)79 acpi_ds_do_implicit_return(union acpi_operand_object *return_desc,
80 struct acpi_walk_state *walk_state, u8 add_reference)
81 {
82 ACPI_FUNCTION_NAME(ds_do_implicit_return);
83
84 /*
85 * Slack must be enabled for this feature, and we must
86 * have a valid return object
87 */
88 if ((!acpi_gbl_enable_interpreter_slack) || (!return_desc)) {
89 return (FALSE);
90 }
91
92 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
93 "Result %p will be implicitly returned; Prev=%p\n",
94 return_desc, walk_state->implicit_return_obj));
95
96 /*
97 * Delete any "stale" implicit return value first. However, in
98 * complex statements, the implicit return value can be
99 * bubbled up several levels, so we don't clear the value if it
100 * is the same as the return_desc.
101 */
102 if (walk_state->implicit_return_obj) {
103 if (walk_state->implicit_return_obj == return_desc) {
104 return (TRUE);
105 }
106 acpi_ds_clear_implicit_return(walk_state);
107 }
108
109 /* Save the implicit return value, add a reference if requested */
110
111 walk_state->implicit_return_obj = return_desc;
112 if (add_reference) {
113 acpi_ut_add_reference(return_desc);
114 }
115
116 return (TRUE);
117 }
118
119 /*******************************************************************************
120 *
121 * FUNCTION: acpi_ds_is_result_used
122 *
123 * PARAMETERS: op - Current Op
124 * walk_state - Current State
125 *
126 * RETURN: TRUE if result is used, FALSE otherwise
127 *
128 * DESCRIPTION: Check if a result object will be used by the parent
129 *
130 ******************************************************************************/
131
132 u8
acpi_ds_is_result_used(union acpi_parse_object * op,struct acpi_walk_state * walk_state)133 acpi_ds_is_result_used(union acpi_parse_object * op,
134 struct acpi_walk_state * walk_state)
135 {
136 const struct acpi_opcode_info *parent_info;
137
138 ACPI_FUNCTION_TRACE_PTR(ds_is_result_used, op);
139
140 /* Must have both an Op and a Result Object */
141
142 if (!op) {
143 ACPI_ERROR((AE_INFO, "Null Op"));
144 return_UINT8(TRUE);
145 }
146
147 /*
148 * We know that this operator is not a
149 * Return() operator (would not come here.) The following code is the
150 * optional support for a so-called "implicit return". Some AML code
151 * assumes that the last value of the method is "implicitly" returned
152 * to the caller. Just save the last result as the return value.
153 * NOTE: this is optional because the ASL language does not actually
154 * support this behavior.
155 */
156 (void)acpi_ds_do_implicit_return(walk_state->result_obj, walk_state,
157 TRUE);
158
159 /*
160 * Now determine if the parent will use the result
161 *
162 * If there is no parent, or the parent is a scope_op, we are executing
163 * at the method level. An executing method typically has no parent,
164 * since each method is parsed separately. A method invoked externally
165 * via execute_control_method has a scope_op as the parent.
166 */
167 if ((!op->common.parent) ||
168 (op->common.parent->common.aml_opcode == AML_SCOPE_OP)) {
169
170 /* No parent, the return value cannot possibly be used */
171
172 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
173 "At Method level, result of [%s] not used\n",
174 acpi_ps_get_opcode_name(op->common.
175 aml_opcode)));
176 return_UINT8(FALSE);
177 }
178
179 /* Get info on the parent. The root_op is AML_SCOPE */
180
181 parent_info =
182 acpi_ps_get_opcode_info(op->common.parent->common.aml_opcode);
183 if (parent_info->class == AML_CLASS_UNKNOWN) {
184 ACPI_ERROR((AE_INFO, "Unknown parent opcode Op=%p", op));
185 return_UINT8(FALSE);
186 }
187
188 /*
189 * Decide what to do with the result based on the parent. If
190 * the parent opcode will not use the result, delete the object.
191 * Otherwise leave it as is, it will be deleted when it is used
192 * as an operand later.
193 */
194 switch (parent_info->class) {
195 case AML_CLASS_CONTROL:
196
197 switch (op->common.parent->common.aml_opcode) {
198 case AML_RETURN_OP:
199
200 /* Never delete the return value associated with a return opcode */
201
202 goto result_used;
203
204 case AML_IF_OP:
205 case AML_WHILE_OP:
206 /*
207 * If we are executing the predicate AND this is the predicate op,
208 * we will use the return value
209 */
210 if ((walk_state->control_state->common.state ==
211 ACPI_CONTROL_PREDICATE_EXECUTING) &&
212 (walk_state->control_state->control.predicate_op ==
213 op)) {
214 goto result_used;
215 }
216 break;
217
218 default:
219
220 /* Ignore other control opcodes */
221
222 break;
223 }
224
225 /* The general control opcode returns no result */
226
227 goto result_not_used;
228
229 case AML_CLASS_CREATE:
230 /*
231 * These opcodes allow term_arg(s) as operands and therefore
232 * the operands can be method calls. The result is used.
233 */
234 goto result_used;
235
236 case AML_CLASS_NAMED_OBJECT:
237
238 if ((op->common.parent->common.aml_opcode == AML_REGION_OP) ||
239 (op->common.parent->common.aml_opcode == AML_DATA_REGION_OP)
240 || (op->common.parent->common.aml_opcode == AML_PACKAGE_OP)
241 || (op->common.parent->common.aml_opcode == AML_BUFFER_OP)
242 || (op->common.parent->common.aml_opcode ==
243 AML_VARIABLE_PACKAGE_OP)
244 || (op->common.parent->common.aml_opcode ==
245 AML_INT_EVAL_SUBTREE_OP)
246 || (op->common.parent->common.aml_opcode ==
247 AML_BANK_FIELD_OP)) {
248 /*
249 * These opcodes allow term_arg(s) as operands and therefore
250 * the operands can be method calls. The result is used.
251 */
252 goto result_used;
253 }
254
255 goto result_not_used;
256
257 default:
258 /*
259 * In all other cases. the parent will actually use the return
260 * object, so keep it.
261 */
262 goto result_used;
263 }
264
265 result_used:
266 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
267 "Result of [%s] used by Parent [%s] Op=%p\n",
268 acpi_ps_get_opcode_name(op->common.aml_opcode),
269 acpi_ps_get_opcode_name(op->common.parent->common.
270 aml_opcode), op));
271
272 return_UINT8(TRUE);
273
274 result_not_used:
275 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
276 "Result of [%s] not used by Parent [%s] Op=%p\n",
277 acpi_ps_get_opcode_name(op->common.aml_opcode),
278 acpi_ps_get_opcode_name(op->common.parent->common.
279 aml_opcode), op));
280
281 return_UINT8(FALSE);
282 }
283
284 /*******************************************************************************
285 *
286 * FUNCTION: acpi_ds_delete_result_if_not_used
287 *
288 * PARAMETERS: op - Current parse Op
289 * result_obj - Result of the operation
290 * walk_state - Current state
291 *
292 * RETURN: Status
293 *
294 * DESCRIPTION: Used after interpretation of an opcode. If there is an internal
295 * result descriptor, check if the parent opcode will actually use
296 * this result. If not, delete the result now so that it will
297 * not become orphaned.
298 *
299 ******************************************************************************/
300
301 void
acpi_ds_delete_result_if_not_used(union acpi_parse_object * op,union acpi_operand_object * result_obj,struct acpi_walk_state * walk_state)302 acpi_ds_delete_result_if_not_used(union acpi_parse_object *op,
303 union acpi_operand_object *result_obj,
304 struct acpi_walk_state *walk_state)
305 {
306 union acpi_operand_object *obj_desc;
307 acpi_status status;
308
309 ACPI_FUNCTION_TRACE_PTR(ds_delete_result_if_not_used, result_obj);
310
311 if (!op) {
312 ACPI_ERROR((AE_INFO, "Null Op"));
313 return_VOID;
314 }
315
316 if (!result_obj) {
317 return_VOID;
318 }
319
320 if (!acpi_ds_is_result_used(op, walk_state)) {
321
322 /* Must pop the result stack (obj_desc should be equal to result_obj) */
323
324 status = acpi_ds_result_pop(&obj_desc, walk_state);
325 if (ACPI_SUCCESS(status)) {
326 acpi_ut_remove_reference(result_obj);
327 }
328 }
329
330 return_VOID;
331 }
332
333 /*******************************************************************************
334 *
335 * FUNCTION: acpi_ds_resolve_operands
336 *
337 * PARAMETERS: walk_state - Current walk state with operands on stack
338 *
339 * RETURN: Status
340 *
341 * DESCRIPTION: Resolve all operands to their values. Used to prepare
342 * arguments to a control method invocation (a call from one
343 * method to another.)
344 *
345 ******************************************************************************/
346
acpi_ds_resolve_operands(struct acpi_walk_state * walk_state)347 acpi_status acpi_ds_resolve_operands(struct acpi_walk_state *walk_state)
348 {
349 u32 i;
350 acpi_status status = AE_OK;
351
352 ACPI_FUNCTION_TRACE_PTR(ds_resolve_operands, walk_state);
353
354 /*
355 * Attempt to resolve each of the valid operands
356 * Method arguments are passed by reference, not by value. This means
357 * that the actual objects are passed, not copies of the objects.
358 */
359 for (i = 0; i < walk_state->num_operands; i++) {
360 status =
361 acpi_ex_resolve_to_value(&walk_state->operands[i],
362 walk_state);
363 if (ACPI_FAILURE(status)) {
364 break;
365 }
366 }
367
368 return_ACPI_STATUS(status);
369 }
370
371 /*******************************************************************************
372 *
373 * FUNCTION: acpi_ds_clear_operands
374 *
375 * PARAMETERS: walk_state - Current walk state with operands on stack
376 *
377 * RETURN: None
378 *
379 * DESCRIPTION: Clear all operands on the current walk state operand stack.
380 *
381 ******************************************************************************/
382
acpi_ds_clear_operands(struct acpi_walk_state * walk_state)383 void acpi_ds_clear_operands(struct acpi_walk_state *walk_state)
384 {
385 u32 i;
386
387 ACPI_FUNCTION_TRACE_PTR(ds_clear_operands, walk_state);
388
389 /* Remove a reference on each operand on the stack */
390
391 for (i = 0; i < walk_state->num_operands; i++) {
392 /*
393 * Remove a reference to all operands, including both
394 * "Arguments" and "Targets".
395 */
396 acpi_ut_remove_reference(walk_state->operands[i]);
397 walk_state->operands[i] = NULL;
398 }
399
400 walk_state->num_operands = 0;
401 return_VOID;
402 }
403
404 /*******************************************************************************
405 *
406 * FUNCTION: acpi_ds_create_operand
407 *
408 * PARAMETERS: walk_state - Current walk state
409 * arg - Parse object for the argument
410 * arg_index - Which argument (zero based)
411 *
412 * RETURN: Status
413 *
414 * DESCRIPTION: Translate a parse tree object that is an argument to an AML
415 * opcode to the equivalent interpreter object. This may include
416 * looking up a name or entering a new name into the internal
417 * namespace.
418 *
419 ******************************************************************************/
420
421 acpi_status
acpi_ds_create_operand(struct acpi_walk_state * walk_state,union acpi_parse_object * arg,u32 arg_index)422 acpi_ds_create_operand(struct acpi_walk_state *walk_state,
423 union acpi_parse_object *arg, u32 arg_index)
424 {
425 acpi_status status = AE_OK;
426 char *name_string;
427 u32 name_length;
428 union acpi_operand_object *obj_desc;
429 union acpi_parse_object *parent_op;
430 u16 opcode;
431 acpi_interpreter_mode interpreter_mode;
432 const struct acpi_opcode_info *op_info;
433
434 ACPI_FUNCTION_TRACE_PTR(ds_create_operand, arg);
435
436 /* A valid name must be looked up in the namespace */
437
438 if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
439 (arg->common.value.string) &&
440 !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
441 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n",
442 arg));
443
444 /* Get the entire name string from the AML stream */
445
446 status = acpi_ex_get_name_string(ACPI_TYPE_ANY,
447 arg->common.value.buffer,
448 &name_string, &name_length);
449
450 if (ACPI_FAILURE(status)) {
451 return_ACPI_STATUS(status);
452 }
453
454 /* All prefixes have been handled, and the name is in name_string */
455
456 /*
457 * Special handling for buffer_field declarations. This is a deferred
458 * opcode that unfortunately defines the field name as the last
459 * parameter instead of the first. We get here when we are performing
460 * the deferred execution, so the actual name of the field is already
461 * in the namespace. We don't want to attempt to look it up again
462 * because we may be executing in a different scope than where the
463 * actual opcode exists.
464 */
465 if ((walk_state->deferred_node) &&
466 (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD)
467 && (arg_index == (u32)
468 ((walk_state->opcode == AML_CREATE_FIELD_OP) ? 3 : 2))) {
469 obj_desc =
470 ACPI_CAST_PTR(union acpi_operand_object,
471 walk_state->deferred_node);
472 status = AE_OK;
473 } else { /* All other opcodes */
474
475 /*
476 * Differentiate between a namespace "create" operation
477 * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
478 * IMODE_EXECUTE) in order to support the creation of
479 * namespace objects during the execution of control methods.
480 */
481 parent_op = arg->common.parent;
482 op_info =
483 acpi_ps_get_opcode_info(parent_op->common.
484 aml_opcode);
485
486 if ((op_info->flags & AML_NSNODE) &&
487 (parent_op->common.aml_opcode !=
488 AML_INT_METHODCALL_OP)
489 && (parent_op->common.aml_opcode != AML_REGION_OP)
490 && (parent_op->common.aml_opcode !=
491 AML_INT_NAMEPATH_OP)) {
492
493 /* Enter name into namespace if not found */
494
495 interpreter_mode = ACPI_IMODE_LOAD_PASS2;
496 } else {
497 /* Return a failure if name not found */
498
499 interpreter_mode = ACPI_IMODE_EXECUTE;
500 }
501
502 status =
503 acpi_ns_lookup(walk_state->scope_info, name_string,
504 ACPI_TYPE_ANY, interpreter_mode,
505 ACPI_NS_SEARCH_PARENT |
506 ACPI_NS_DONT_OPEN_SCOPE, walk_state,
507 ACPI_CAST_INDIRECT_PTR(struct
508 acpi_namespace_node,
509 &obj_desc));
510 /*
511 * The only case where we pass through (ignore) a NOT_FOUND
512 * error is for the cond_ref_of opcode.
513 */
514 if (status == AE_NOT_FOUND) {
515 if (parent_op->common.aml_opcode ==
516 AML_CONDITIONAL_REF_OF_OP) {
517 /*
518 * For the Conditional Reference op, it's OK if
519 * the name is not found; We just need a way to
520 * indicate this to the interpreter, set the
521 * object to the root
522 */
523 obj_desc =
524 ACPI_CAST_PTR(union
525 acpi_operand_object,
526 acpi_gbl_root_node);
527 status = AE_OK;
528 } else if (parent_op->common.aml_opcode ==
529 AML_EXTERNAL_OP) {
530 /*
531 * This opcode should never appear here. It is used only
532 * by AML disassemblers and is surrounded by an If(0)
533 * by the ASL compiler.
534 *
535 * Therefore, if we see it here, it is a serious error.
536 */
537 status = AE_AML_BAD_OPCODE;
538 } else {
539 /*
540 * We just plain didn't find it -- which is a
541 * very serious error at this point
542 */
543 status = AE_AML_NAME_NOT_FOUND;
544 }
545 }
546
547 if (ACPI_FAILURE(status)) {
548 ACPI_ERROR_NAMESPACE(walk_state->scope_info,
549 name_string, status);
550 }
551 }
552
553 /* Free the namestring created above */
554
555 ACPI_FREE(name_string);
556
557 /* Check status from the lookup */
558
559 if (ACPI_FAILURE(status)) {
560 return_ACPI_STATUS(status);
561 }
562
563 /* Put the resulting object onto the current object stack */
564
565 status = acpi_ds_obj_stack_push(obj_desc, walk_state);
566 if (ACPI_FAILURE(status)) {
567 return_ACPI_STATUS(status);
568 }
569
570 acpi_db_display_argument_object(obj_desc, walk_state);
571 } else {
572 /* Check for null name case */
573
574 if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
575 !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
576 /*
577 * If the name is null, this means that this is an
578 * optional result parameter that was not specified
579 * in the original ASL. Create a Zero Constant for a
580 * placeholder. (Store to a constant is a Noop.)
581 */
582 opcode = AML_ZERO_OP; /* Has no arguments! */
583
584 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
585 "Null namepath: Arg=%p\n", arg));
586 } else {
587 opcode = arg->common.aml_opcode;
588 }
589
590 /* Get the object type of the argument */
591
592 op_info = acpi_ps_get_opcode_info(opcode);
593 if (op_info->object_type == ACPI_TYPE_INVALID) {
594 return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
595 }
596
597 if ((op_info->flags & AML_HAS_RETVAL) ||
598 (arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
599 /*
600 * Use value that was already previously returned
601 * by the evaluation of this argument
602 */
603 status = acpi_ds_result_pop(&obj_desc, walk_state);
604 if (ACPI_FAILURE(status)) {
605 /*
606 * Only error is underflow, and this indicates
607 * a missing or null operand!
608 */
609 ACPI_EXCEPTION((AE_INFO, status,
610 "Missing or null operand"));
611 return_ACPI_STATUS(status);
612 }
613 } else {
614 /* Create an ACPI_INTERNAL_OBJECT for the argument */
615
616 obj_desc =
617 acpi_ut_create_internal_object(op_info->
618 object_type);
619 if (!obj_desc) {
620 return_ACPI_STATUS(AE_NO_MEMORY);
621 }
622
623 /* Initialize the new object */
624
625 status =
626 acpi_ds_init_object_from_op(walk_state, arg, opcode,
627 &obj_desc);
628 if (ACPI_FAILURE(status)) {
629 acpi_ut_delete_object_desc(obj_desc);
630 return_ACPI_STATUS(status);
631 }
632 }
633
634 /* Put the operand object on the object stack */
635
636 status = acpi_ds_obj_stack_push(obj_desc, walk_state);
637 if (ACPI_FAILURE(status)) {
638 return_ACPI_STATUS(status);
639 }
640
641 acpi_db_display_argument_object(obj_desc, walk_state);
642 }
643
644 return_ACPI_STATUS(AE_OK);
645 }
646
647 /*******************************************************************************
648 *
649 * FUNCTION: acpi_ds_create_operands
650 *
651 * PARAMETERS: walk_state - Current state
652 * first_arg - First argument of a parser argument tree
653 *
654 * RETURN: Status
655 *
656 * DESCRIPTION: Convert an operator's arguments from a parse tree format to
657 * namespace objects and place those argument object on the object
658 * stack in preparation for evaluation by the interpreter.
659 *
660 ******************************************************************************/
661
662 acpi_status
acpi_ds_create_operands(struct acpi_walk_state * walk_state,union acpi_parse_object * first_arg)663 acpi_ds_create_operands(struct acpi_walk_state *walk_state,
664 union acpi_parse_object *first_arg)
665 {
666 acpi_status status = AE_OK;
667 union acpi_parse_object *arg;
668 union acpi_parse_object *arguments[ACPI_OBJ_NUM_OPERANDS];
669 u32 arg_count = 0;
670 u32 index = walk_state->num_operands;
671 u32 i;
672
673 ACPI_FUNCTION_TRACE_PTR(ds_create_operands, first_arg);
674
675 /* Get all arguments in the list */
676
677 arg = first_arg;
678 while (arg) {
679 if (index >= ACPI_OBJ_NUM_OPERANDS) {
680 return_ACPI_STATUS(AE_BAD_DATA);
681 }
682
683 arguments[index] = arg;
684 walk_state->operands[index] = NULL;
685
686 /* Move on to next argument, if any */
687
688 arg = arg->common.next;
689 arg_count++;
690 index++;
691 }
692
693 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
694 "NumOperands %d, ArgCount %d, Index %d\n",
695 walk_state->num_operands, arg_count, index));
696
697 /* Create the interpreter arguments, in reverse order */
698
699 index--;
700 for (i = 0; i < arg_count; i++) {
701 arg = arguments[index];
702 walk_state->operand_index = (u8)index;
703
704 status = acpi_ds_create_operand(walk_state, arg, index);
705 if (ACPI_FAILURE(status)) {
706 goto cleanup;
707 }
708
709 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
710 "Created Arg #%u (%p) %u args total\n",
711 index, arg, arg_count));
712 index--;
713 }
714
715 return_ACPI_STATUS(status);
716
717 cleanup:
718 /*
719 * We must undo everything done above; meaning that we must
720 * pop everything off of the operand stack and delete those
721 * objects
722 */
723 acpi_ds_obj_stack_pop_and_delete(arg_count, walk_state);
724
725 ACPI_EXCEPTION((AE_INFO, status, "While creating Arg %u", index));
726 return_ACPI_STATUS(status);
727 }
728
729 /*****************************************************************************
730 *
731 * FUNCTION: acpi_ds_evaluate_name_path
732 *
733 * PARAMETERS: walk_state - Current state of the parse tree walk,
734 * the opcode of current operation should be
735 * AML_INT_NAMEPATH_OP
736 *
737 * RETURN: Status
738 *
739 * DESCRIPTION: Translate the -name_path- parse tree object to the equivalent
740 * interpreter object, convert it to value, if needed, duplicate
741 * it, if needed, and push it onto the current result stack.
742 *
743 ****************************************************************************/
744
acpi_ds_evaluate_name_path(struct acpi_walk_state * walk_state)745 acpi_status acpi_ds_evaluate_name_path(struct acpi_walk_state *walk_state)
746 {
747 acpi_status status = AE_OK;
748 union acpi_parse_object *op = walk_state->op;
749 union acpi_operand_object **operand = &walk_state->operands[0];
750 union acpi_operand_object *new_obj_desc;
751 u8 type;
752
753 ACPI_FUNCTION_TRACE_PTR(ds_evaluate_name_path, walk_state);
754
755 if (!op->common.parent) {
756
757 /* This happens after certain exception processing */
758
759 goto exit;
760 }
761
762 if ((op->common.parent->common.aml_opcode == AML_PACKAGE_OP) ||
763 (op->common.parent->common.aml_opcode == AML_VARIABLE_PACKAGE_OP) ||
764 (op->common.parent->common.aml_opcode == AML_REF_OF_OP)) {
765
766 /* TBD: Should we specify this feature as a bit of op_info->Flags of these opcodes? */
767
768 goto exit;
769 }
770
771 status = acpi_ds_create_operand(walk_state, op, 0);
772 if (ACPI_FAILURE(status)) {
773 goto exit;
774 }
775
776 if (op->common.flags & ACPI_PARSEOP_TARGET) {
777 new_obj_desc = *operand;
778 goto push_result;
779 }
780
781 type = (*operand)->common.type;
782
783 status = acpi_ex_resolve_to_value(operand, walk_state);
784 if (ACPI_FAILURE(status)) {
785 goto exit;
786 }
787
788 if (type == ACPI_TYPE_INTEGER) {
789
790 /* It was incremented by acpi_ex_resolve_to_value */
791
792 acpi_ut_remove_reference(*operand);
793
794 status =
795 acpi_ut_copy_iobject_to_iobject(*operand, &new_obj_desc,
796 walk_state);
797 if (ACPI_FAILURE(status)) {
798 goto exit;
799 }
800 } else {
801 /*
802 * The object either was anew created or is
803 * a Namespace node - don't decrement it.
804 */
805 new_obj_desc = *operand;
806 }
807
808 /* Cleanup for name-path operand */
809
810 status = acpi_ds_obj_stack_pop(1, walk_state);
811 if (ACPI_FAILURE(status)) {
812 walk_state->result_obj = new_obj_desc;
813 goto exit;
814 }
815
816 push_result:
817
818 walk_state->result_obj = new_obj_desc;
819
820 status = acpi_ds_result_push(walk_state->result_obj, walk_state);
821 if (ACPI_SUCCESS(status)) {
822
823 /* Force to take it from stack */
824
825 op->common.flags |= ACPI_PARSEOP_IN_STACK;
826 }
827
828 exit:
829
830 return_ACPI_STATUS(status);
831 }
832