1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /*******************************************************************************
4 * Module Name: dsutils - Dispatcher utilities
6 ******************************************************************************/
17 #define _COMPONENT ACPI_DISPATCHER
18 ACPI_MODULE_NAME("dsutils")
20 /*******************************************************************************
22 * FUNCTION: acpi_ds_clear_implicit_return
24 * PARAMETERS: walk_state - Current State
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.)
33 ******************************************************************************/
34 void acpi_ds_clear_implicit_return(struct acpi_walk_state *walk_state)
36 ACPI_FUNCTION_NAME(ds_clear_implicit_return);
39 * Slack must be enabled for this feature
41 if (!acpi_gbl_enable_interpreter_slack) {
45 if (walk_state->implicit_return_obj) {
47 * Delete any "stale" implicit return. However, in
48 * complex statements, the implicit return value can be
49 * bubbled up several levels.
51 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
52 "Removing reference on stale implicit return obj %p\n",
53 walk_state->implicit_return_obj));
55 acpi_ut_remove_reference(walk_state->implicit_return_obj);
56 walk_state->implicit_return_obj = NULL;
60 #ifndef ACPI_NO_METHOD_EXECUTION
61 /*******************************************************************************
63 * FUNCTION: acpi_ds_do_implicit_return
65 * PARAMETERS: return_desc - The return value
66 * walk_state - Current State
67 * add_reference - True if a reference should be added to the
70 * RETURN: TRUE if implicit return enabled, FALSE otherwise
72 * DESCRIPTION: Implements the optional "implicit return". We save the result
73 * of every ASL operator and control method invocation in case the
74 * parent method exit. Before storing a new return value, we
75 * delete the previous return value.
77 ******************************************************************************/
80 acpi_ds_do_implicit_return(union acpi_operand_object *return_desc,
81 struct acpi_walk_state *walk_state, u8 add_reference)
83 ACPI_FUNCTION_NAME(ds_do_implicit_return);
86 * Slack must be enabled for this feature, and we must
87 * have a valid return object
89 if ((!acpi_gbl_enable_interpreter_slack) || (!return_desc)) {
93 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
94 "Result %p will be implicitly returned; Prev=%p\n",
95 return_desc, walk_state->implicit_return_obj));
98 * Delete any "stale" implicit return value first. However, in
99 * complex statements, the implicit return value can be
100 * bubbled up several levels, so we don't clear the value if it
101 * is the same as the return_desc.
103 if (walk_state->implicit_return_obj) {
104 if (walk_state->implicit_return_obj == return_desc) {
107 acpi_ds_clear_implicit_return(walk_state);
110 /* Save the implicit return value, add a reference if requested */
112 walk_state->implicit_return_obj = return_desc;
114 acpi_ut_add_reference(return_desc);
120 /*******************************************************************************
122 * FUNCTION: acpi_ds_is_result_used
124 * PARAMETERS: op - Current Op
125 * walk_state - Current State
127 * RETURN: TRUE if result is used, FALSE otherwise
129 * DESCRIPTION: Check if a result object will be used by the parent
131 ******************************************************************************/
134 acpi_ds_is_result_used(union acpi_parse_object * op,
135 struct acpi_walk_state * walk_state)
137 const struct acpi_opcode_info *parent_info;
139 ACPI_FUNCTION_TRACE_PTR(ds_is_result_used, op);
141 /* Must have both an Op and a Result Object */
144 ACPI_ERROR((AE_INFO, "Null Op"));
149 * We know that this operator is not a
150 * Return() operator (would not come here.) The following code is the
151 * optional support for a so-called "implicit return". Some AML code
152 * assumes that the last value of the method is "implicitly" returned
153 * to the caller. Just save the last result as the return value.
154 * NOTE: this is optional because the ASL language does not actually
155 * support this behavior.
157 (void)acpi_ds_do_implicit_return(walk_state->result_obj, walk_state,
161 * Now determine if the parent will use the result
163 * If there is no parent, or the parent is a scope_op, we are executing
164 * at the method level. An executing method typically has no parent,
165 * since each method is parsed separately. A method invoked externally
166 * via execute_control_method has a scope_op as the parent.
168 if ((!op->common.parent) ||
169 (op->common.parent->common.aml_opcode == AML_SCOPE_OP)) {
171 /* No parent, the return value cannot possibly be used */
173 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
174 "At Method level, result of [%s] not used\n",
175 acpi_ps_get_opcode_name(op->common.
180 /* Get info on the parent. The root_op is AML_SCOPE */
183 acpi_ps_get_opcode_info(op->common.parent->common.aml_opcode);
184 if (parent_info->class == AML_CLASS_UNKNOWN) {
185 ACPI_ERROR((AE_INFO, "Unknown parent opcode Op=%p", op));
190 * Decide what to do with the result based on the parent. If
191 * the parent opcode will not use the result, delete the object.
192 * Otherwise leave it as is, it will be deleted when it is used
193 * as an operand later.
195 switch (parent_info->class) {
196 case AML_CLASS_CONTROL:
198 switch (op->common.parent->common.aml_opcode) {
201 /* Never delete the return value associated with a return opcode */
208 * If we are executing the predicate AND this is the predicate op,
209 * we will use the return value
211 if ((walk_state->control_state->common.state ==
212 ACPI_CONTROL_PREDICATE_EXECUTING) &&
213 (walk_state->control_state->control.predicate_op ==
221 /* Ignore other control opcodes */
226 /* The general control opcode returns no result */
228 goto result_not_used;
230 case AML_CLASS_CREATE:
232 * These opcodes allow term_arg(s) as operands and therefore
233 * the operands can be method calls. The result is used.
237 case AML_CLASS_NAMED_OBJECT:
239 if ((op->common.parent->common.aml_opcode == AML_REGION_OP) ||
240 (op->common.parent->common.aml_opcode == AML_DATA_REGION_OP)
241 || (op->common.parent->common.aml_opcode == AML_PACKAGE_OP)
242 || (op->common.parent->common.aml_opcode == AML_BUFFER_OP)
243 || (op->common.parent->common.aml_opcode ==
244 AML_VARIABLE_PACKAGE_OP)
245 || (op->common.parent->common.aml_opcode ==
246 AML_INT_EVAL_SUBTREE_OP)
247 || (op->common.parent->common.aml_opcode ==
248 AML_BANK_FIELD_OP)) {
250 * These opcodes allow term_arg(s) as operands and therefore
251 * the operands can be method calls. The result is used.
256 goto result_not_used;
260 * In all other cases. the parent will actually use the return
261 * object, so keep it.
267 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
268 "Result of [%s] used by Parent [%s] Op=%p\n",
269 acpi_ps_get_opcode_name(op->common.aml_opcode),
270 acpi_ps_get_opcode_name(op->common.parent->common.
276 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
277 "Result of [%s] not used by Parent [%s] Op=%p\n",
278 acpi_ps_get_opcode_name(op->common.aml_opcode),
279 acpi_ps_get_opcode_name(op->common.parent->common.
285 /*******************************************************************************
287 * FUNCTION: acpi_ds_delete_result_if_not_used
289 * PARAMETERS: op - Current parse Op
290 * result_obj - Result of the operation
291 * walk_state - Current state
295 * DESCRIPTION: Used after interpretation of an opcode. If there is an internal
296 * result descriptor, check if the parent opcode will actually use
297 * this result. If not, delete the result now so that it will
298 * not become orphaned.
300 ******************************************************************************/
303 acpi_ds_delete_result_if_not_used(union acpi_parse_object *op,
304 union acpi_operand_object *result_obj,
305 struct acpi_walk_state *walk_state)
307 union acpi_operand_object *obj_desc;
310 ACPI_FUNCTION_TRACE_PTR(ds_delete_result_if_not_used, result_obj);
313 ACPI_ERROR((AE_INFO, "Null Op"));
321 if (!acpi_ds_is_result_used(op, walk_state)) {
323 /* Must pop the result stack (obj_desc should be equal to result_obj) */
325 status = acpi_ds_result_pop(&obj_desc, walk_state);
326 if (ACPI_SUCCESS(status)) {
327 acpi_ut_remove_reference(result_obj);
334 /*******************************************************************************
336 * FUNCTION: acpi_ds_resolve_operands
338 * PARAMETERS: walk_state - Current walk state with operands on stack
342 * DESCRIPTION: Resolve all operands to their values. Used to prepare
343 * arguments to a control method invocation (a call from one
344 * method to another.)
346 ******************************************************************************/
348 acpi_status acpi_ds_resolve_operands(struct acpi_walk_state *walk_state)
351 acpi_status status = AE_OK;
353 ACPI_FUNCTION_TRACE_PTR(ds_resolve_operands, walk_state);
356 * Attempt to resolve each of the valid operands
357 * Method arguments are passed by reference, not by value. This means
358 * that the actual objects are passed, not copies of the objects.
360 for (i = 0; i < walk_state->num_operands; i++) {
362 acpi_ex_resolve_to_value(&walk_state->operands[i],
364 if (ACPI_FAILURE(status)) {
369 return_ACPI_STATUS(status);
372 /*******************************************************************************
374 * FUNCTION: acpi_ds_clear_operands
376 * PARAMETERS: walk_state - Current walk state with operands on stack
380 * DESCRIPTION: Clear all operands on the current walk state operand stack.
382 ******************************************************************************/
384 void acpi_ds_clear_operands(struct acpi_walk_state *walk_state)
388 ACPI_FUNCTION_TRACE_PTR(ds_clear_operands, walk_state);
390 /* Remove a reference on each operand on the stack */
392 for (i = 0; i < walk_state->num_operands; i++) {
394 * Remove a reference to all operands, including both
395 * "Arguments" and "Targets".
397 acpi_ut_remove_reference(walk_state->operands[i]);
398 walk_state->operands[i] = NULL;
401 walk_state->num_operands = 0;
406 /*******************************************************************************
408 * FUNCTION: acpi_ds_create_operand
410 * PARAMETERS: walk_state - Current walk state
411 * arg - Parse object for the argument
412 * arg_index - Which argument (zero based)
416 * DESCRIPTION: Translate a parse tree object that is an argument to an AML
417 * opcode to the equivalent interpreter object. This may include
418 * looking up a name or entering a new name into the internal
421 ******************************************************************************/
424 acpi_ds_create_operand(struct acpi_walk_state *walk_state,
425 union acpi_parse_object *arg, u32 arg_index)
427 acpi_status status = AE_OK;
430 union acpi_operand_object *obj_desc;
431 union acpi_parse_object *parent_op;
433 acpi_interpreter_mode interpreter_mode;
434 const struct acpi_opcode_info *op_info;
436 ACPI_FUNCTION_TRACE_PTR(ds_create_operand, arg);
438 /* A valid name must be looked up in the namespace */
440 if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
441 (arg->common.value.string) &&
442 !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
443 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n",
446 /* Get the entire name string from the AML stream */
448 status = acpi_ex_get_name_string(ACPI_TYPE_ANY,
449 arg->common.value.buffer,
450 &name_string, &name_length);
452 if (ACPI_FAILURE(status)) {
453 return_ACPI_STATUS(status);
456 /* All prefixes have been handled, and the name is in name_string */
459 * Special handling for buffer_field declarations. This is a deferred
460 * opcode that unfortunately defines the field name as the last
461 * parameter instead of the first. We get here when we are performing
462 * the deferred execution, so the actual name of the field is already
463 * in the namespace. We don't want to attempt to look it up again
464 * because we may be executing in a different scope than where the
465 * actual opcode exists.
467 if ((walk_state->deferred_node) &&
468 (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD)
469 && (arg_index == (u32)
470 ((walk_state->opcode == AML_CREATE_FIELD_OP) ? 3 : 2))) {
472 ACPI_CAST_PTR(union acpi_operand_object,
473 walk_state->deferred_node);
475 } else { /* All other opcodes */
478 * Differentiate between a namespace "create" operation
479 * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
480 * IMODE_EXECUTE) in order to support the creation of
481 * namespace objects during the execution of control methods.
483 parent_op = arg->common.parent;
485 acpi_ps_get_opcode_info(parent_op->common.
488 if ((op_info->flags & AML_NSNODE) &&
489 (parent_op->common.aml_opcode !=
490 AML_INT_METHODCALL_OP)
491 && (parent_op->common.aml_opcode != AML_REGION_OP)
492 && (parent_op->common.aml_opcode !=
493 AML_INT_NAMEPATH_OP)) {
495 /* Enter name into namespace if not found */
497 interpreter_mode = ACPI_IMODE_LOAD_PASS2;
499 /* Return a failure if name not found */
501 interpreter_mode = ACPI_IMODE_EXECUTE;
505 acpi_ns_lookup(walk_state->scope_info, name_string,
506 ACPI_TYPE_ANY, interpreter_mode,
507 ACPI_NS_SEARCH_PARENT |
508 ACPI_NS_DONT_OPEN_SCOPE, walk_state,
509 ACPI_CAST_INDIRECT_PTR(struct
513 * The only case where we pass through (ignore) a NOT_FOUND
514 * error is for the cond_ref_of opcode.
516 if (status == AE_NOT_FOUND) {
517 if (parent_op->common.aml_opcode ==
518 AML_CONDITIONAL_REF_OF_OP) {
520 * For the Conditional Reference op, it's OK if
521 * the name is not found; We just need a way to
522 * indicate this to the interpreter, set the
530 } else if (parent_op->common.aml_opcode ==
533 * This opcode should never appear here. It is used only
534 * by AML disassemblers and is surrounded by an If(0)
535 * by the ASL compiler.
537 * Therefore, if we see it here, it is a serious error.
539 status = AE_AML_BAD_OPCODE;
542 * We just plain didn't find it -- which is a
543 * very serious error at this point
545 status = AE_AML_NAME_NOT_FOUND;
549 if (ACPI_FAILURE(status)) {
550 ACPI_ERROR_NAMESPACE(walk_state->scope_info,
551 name_string, status);
555 /* Free the namestring created above */
557 ACPI_FREE(name_string);
559 /* Check status from the lookup */
561 if (ACPI_FAILURE(status)) {
562 return_ACPI_STATUS(status);
565 /* Put the resulting object onto the current object stack */
567 status = acpi_ds_obj_stack_push(obj_desc, walk_state);
568 if (ACPI_FAILURE(status)) {
569 return_ACPI_STATUS(status);
572 acpi_db_display_argument_object(obj_desc, walk_state);
574 /* Check for null name case */
576 if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
577 !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
579 * If the name is null, this means that this is an
580 * optional result parameter that was not specified
581 * in the original ASL. Create a Zero Constant for a
582 * placeholder. (Store to a constant is a Noop.)
584 opcode = AML_ZERO_OP; /* Has no arguments! */
586 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
587 "Null namepath: Arg=%p\n", arg));
589 opcode = arg->common.aml_opcode;
592 /* Get the object type of the argument */
594 op_info = acpi_ps_get_opcode_info(opcode);
595 if (op_info->object_type == ACPI_TYPE_INVALID) {
596 return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
599 if ((op_info->flags & AML_HAS_RETVAL) ||
600 (arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
602 * Use value that was already previously returned
603 * by the evaluation of this argument
605 status = acpi_ds_result_pop(&obj_desc, walk_state);
606 if (ACPI_FAILURE(status)) {
608 * Only error is underflow, and this indicates
609 * a missing or null operand!
611 ACPI_EXCEPTION((AE_INFO, status,
612 "Missing or null operand"));
613 return_ACPI_STATUS(status);
616 /* Create an ACPI_INTERNAL_OBJECT for the argument */
619 acpi_ut_create_internal_object(op_info->
622 return_ACPI_STATUS(AE_NO_MEMORY);
625 /* Initialize the new object */
628 acpi_ds_init_object_from_op(walk_state, arg, opcode,
630 if (ACPI_FAILURE(status)) {
631 acpi_ut_delete_object_desc(obj_desc);
632 return_ACPI_STATUS(status);
636 /* Put the operand object on the object stack */
638 status = acpi_ds_obj_stack_push(obj_desc, walk_state);
639 if (ACPI_FAILURE(status)) {
640 return_ACPI_STATUS(status);
643 acpi_db_display_argument_object(obj_desc, walk_state);
646 return_ACPI_STATUS(AE_OK);
649 /*******************************************************************************
651 * FUNCTION: acpi_ds_create_operands
653 * PARAMETERS: walk_state - Current state
654 * first_arg - First argument of a parser argument tree
658 * DESCRIPTION: Convert an operator's arguments from a parse tree format to
659 * namespace objects and place those argument object on the object
660 * stack in preparation for evaluation by the interpreter.
662 ******************************************************************************/
665 acpi_ds_create_operands(struct acpi_walk_state *walk_state,
666 union acpi_parse_object *first_arg)
668 acpi_status status = AE_OK;
669 union acpi_parse_object *arg;
670 union acpi_parse_object *arguments[ACPI_OBJ_NUM_OPERANDS];
672 u32 index = walk_state->num_operands;
675 ACPI_FUNCTION_TRACE_PTR(ds_create_operands, first_arg);
677 /* Get all arguments in the list */
681 if (index >= ACPI_OBJ_NUM_OPERANDS) {
682 return_ACPI_STATUS(AE_BAD_DATA);
685 arguments[index] = arg;
686 walk_state->operands[index] = NULL;
688 /* Move on to next argument, if any */
690 arg = arg->common.next;
695 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
696 "NumOperands %d, ArgCount %d, Index %d\n",
697 walk_state->num_operands, arg_count, index));
699 /* Create the interpreter arguments, in reverse order */
702 for (i = 0; i < arg_count; i++) {
703 arg = arguments[index];
704 walk_state->operand_index = (u8)index;
706 status = acpi_ds_create_operand(walk_state, arg, index);
707 if (ACPI_FAILURE(status)) {
711 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
712 "Created Arg #%u (%p) %u args total\n",
713 index, arg, arg_count));
717 return_ACPI_STATUS(status);
721 * We must undo everything done above; meaning that we must
722 * pop everything off of the operand stack and delete those
725 acpi_ds_obj_stack_pop_and_delete(arg_count, walk_state);
727 ACPI_EXCEPTION((AE_INFO, status, "While creating Arg %u", index));
728 return_ACPI_STATUS(status);
731 /*****************************************************************************
733 * FUNCTION: acpi_ds_evaluate_name_path
735 * PARAMETERS: walk_state - Current state of the parse tree walk,
736 * the opcode of current operation should be
737 * AML_INT_NAMEPATH_OP
741 * DESCRIPTION: Translate the -name_path- parse tree object to the equivalent
742 * interpreter object, convert it to value, if needed, duplicate
743 * it, if needed, and push it onto the current result stack.
745 ****************************************************************************/
747 acpi_status acpi_ds_evaluate_name_path(struct acpi_walk_state *walk_state)
749 acpi_status status = AE_OK;
750 union acpi_parse_object *op = walk_state->op;
751 union acpi_operand_object **operand = &walk_state->operands[0];
752 union acpi_operand_object *new_obj_desc;
755 ACPI_FUNCTION_TRACE_PTR(ds_evaluate_name_path, walk_state);
757 if (!op->common.parent) {
759 /* This happens after certain exception processing */
764 if ((op->common.parent->common.aml_opcode == AML_PACKAGE_OP) ||
765 (op->common.parent->common.aml_opcode == AML_VARIABLE_PACKAGE_OP) ||
766 (op->common.parent->common.aml_opcode == AML_REF_OF_OP)) {
768 /* TBD: Should we specify this feature as a bit of op_info->Flags of these opcodes? */
773 status = acpi_ds_create_operand(walk_state, op, 0);
774 if (ACPI_FAILURE(status)) {
778 if (op->common.flags & ACPI_PARSEOP_TARGET) {
779 new_obj_desc = *operand;
783 type = (*operand)->common.type;
785 status = acpi_ex_resolve_to_value(operand, walk_state);
786 if (ACPI_FAILURE(status)) {
790 if (type == ACPI_TYPE_INTEGER) {
792 /* It was incremented by acpi_ex_resolve_to_value */
794 acpi_ut_remove_reference(*operand);
797 acpi_ut_copy_iobject_to_iobject(*operand, &new_obj_desc,
799 if (ACPI_FAILURE(status)) {
804 * The object either was anew created or is
805 * a Namespace node - don't decrement it.
807 new_obj_desc = *operand;
810 /* Cleanup for name-path operand */
812 status = acpi_ds_obj_stack_pop(1, walk_state);
813 if (ACPI_FAILURE(status)) {
814 walk_state->result_obj = new_obj_desc;
820 walk_state->result_obj = new_obj_desc;
822 status = acpi_ds_result_push(walk_state->result_obj, walk_state);
823 if (ACPI_SUCCESS(status)) {
825 /* Force to take it from stack */
827 op->common.flags |= ACPI_PARSEOP_IN_STACK;
832 return_ACPI_STATUS(status);