1 /*******************************************************************************
3 * Module Name: dsutils - Dispatcher utilities
5 ******************************************************************************/
8 * Copyright (C) 2000 - 2005, R. Byron Moore
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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.
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
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44 #include <acpi/acpi.h>
45 #include <acpi/acparser.h>
46 #include <acpi/amlcode.h>
47 #include <acpi/acdispat.h>
48 #include <acpi/acinterp.h>
49 #include <acpi/acnamesp.h>
50 #include <acpi/acdebug.h>
52 #define _COMPONENT ACPI_DISPATCHER
53 ACPI_MODULE_NAME("dsutils")
55 /*******************************************************************************
57 * FUNCTION: acpi_ds_clear_implicit_return
59 * PARAMETERS: walk_state - Current State
63 * DESCRIPTION: Clear and remove a reference on an implicit return value. Used
64 * to delete "stale" return values (if enabled, the return value
65 * from every operator is saved at least momentarily, in case the
66 * parent method exits.)
68 ******************************************************************************/
69 void acpi_ds_clear_implicit_return(struct acpi_walk_state *walk_state)
71 ACPI_FUNCTION_NAME("ds_clear_implicit_return");
74 * Slack must be enabled for this feature
76 if (!acpi_gbl_enable_interpreter_slack) {
80 if (walk_state->implicit_return_obj) {
82 * Delete any "stale" implicit return. However, in
83 * complex statements, the implicit return value can be
84 * bubbled up several levels.
86 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
87 "Removing reference on stale implicit return obj %p\n",
88 walk_state->implicit_return_obj));
90 acpi_ut_remove_reference(walk_state->implicit_return_obj);
91 walk_state->implicit_return_obj = NULL;
95 #ifndef ACPI_NO_METHOD_EXECUTION
96 /*******************************************************************************
98 * FUNCTION: acpi_ds_do_implicit_return
100 * PARAMETERS: return_desc - The return value
101 * walk_state - Current State
102 * add_reference - True if a reference should be added to the
105 * RETURN: TRUE if implicit return enabled, FALSE otherwise
107 * DESCRIPTION: Implements the optional "implicit return". We save the result
108 * of every ASL operator and control method invocation in case the
109 * parent method exit. Before storing a new return value, we
110 * delete the previous return value.
112 ******************************************************************************/
115 acpi_ds_do_implicit_return(union acpi_operand_object *return_desc,
116 struct acpi_walk_state *walk_state, u8 add_reference)
118 ACPI_FUNCTION_NAME("ds_do_implicit_return");
121 * Slack must be enabled for this feature, and we must
122 * have a valid return object
124 if ((!acpi_gbl_enable_interpreter_slack) || (!return_desc)) {
128 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
129 "Result %p will be implicitly returned; Prev=%p\n",
130 return_desc, walk_state->implicit_return_obj));
133 * Delete any "stale" implicit return value first. However, in
134 * complex statements, the implicit return value can be
135 * bubbled up several levels, so we don't clear the value if it
136 * is the same as the return_desc.
138 if (walk_state->implicit_return_obj) {
139 if (walk_state->implicit_return_obj == return_desc) {
142 acpi_ds_clear_implicit_return(walk_state);
145 /* Save the implicit return value, add a reference if requested */
147 walk_state->implicit_return_obj = return_desc;
149 acpi_ut_add_reference(return_desc);
155 /*******************************************************************************
157 * FUNCTION: acpi_ds_is_result_used
159 * PARAMETERS: Op - Current Op
160 * walk_state - Current State
162 * RETURN: TRUE if result is used, FALSE otherwise
164 * DESCRIPTION: Check if a result object will be used by the parent
166 ******************************************************************************/
169 acpi_ds_is_result_used(union acpi_parse_object * op,
170 struct acpi_walk_state * walk_state)
172 const struct acpi_opcode_info *parent_info;
174 ACPI_FUNCTION_TRACE_PTR("ds_is_result_used", op);
176 /* Must have both an Op and a Result Object */
179 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Null Op\n"));
184 * We know that this operator is not a
185 * Return() operator (would not come here.) The following code is the
186 * optional support for a so-called "implicit return". Some AML code
187 * assumes that the last value of the method is "implicitly" returned
188 * to the caller. Just save the last result as the return value.
189 * NOTE: this is optional because the ASL language does not actually
190 * support this behavior.
192 (void)acpi_ds_do_implicit_return(walk_state->result_obj, walk_state,
196 * Now determine if the parent will use the result
198 * If there is no parent, or the parent is a scope_op, we are executing
199 * at the method level. An executing method typically has no parent,
200 * since each method is parsed separately. A method invoked externally
201 * via execute_control_method has a scope_op as the parent.
203 if ((!op->common.parent) ||
204 (op->common.parent->common.aml_opcode == AML_SCOPE_OP)) {
205 /* No parent, the return value cannot possibly be used */
207 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
208 "At Method level, result of [%s] not used\n",
209 acpi_ps_get_opcode_name(op->common.
214 /* Get info on the parent. The root_op is AML_SCOPE */
217 acpi_ps_get_opcode_info(op->common.parent->common.aml_opcode);
218 if (parent_info->class == AML_CLASS_UNKNOWN) {
219 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
220 "Unknown parent opcode. Op=%p\n", op));
225 * Decide what to do with the result based on the parent. If
226 * the parent opcode will not use the result, delete the object.
227 * Otherwise leave it as is, it will be deleted when it is used
228 * as an operand later.
230 switch (parent_info->class) {
231 case AML_CLASS_CONTROL:
233 switch (op->common.parent->common.aml_opcode) {
236 /* Never delete the return value associated with a return opcode */
244 * If we are executing the predicate AND this is the predicate op,
245 * we will use the return value
247 if ((walk_state->control_state->common.state ==
248 ACPI_CONTROL_PREDICATE_EXECUTING)
249 && (walk_state->control_state->control.
250 predicate_op == op)) {
256 /* Ignore other control opcodes */
260 /* The general control opcode returns no result */
262 goto result_not_used;
264 case AML_CLASS_CREATE:
267 * These opcodes allow term_arg(s) as operands and therefore
268 * the operands can be method calls. The result is used.
272 case AML_CLASS_NAMED_OBJECT:
274 if ((op->common.parent->common.aml_opcode == AML_REGION_OP) ||
275 (op->common.parent->common.aml_opcode == AML_DATA_REGION_OP)
276 || (op->common.parent->common.aml_opcode == AML_PACKAGE_OP)
277 || (op->common.parent->common.aml_opcode ==
279 || (op->common.parent->common.aml_opcode == AML_BUFFER_OP)
280 || (op->common.parent->common.aml_opcode ==
281 AML_INT_EVAL_SUBTREE_OP)) {
283 * These opcodes allow term_arg(s) as operands and therefore
284 * the operands can be method calls. The result is used.
289 goto result_not_used;
294 * In all other cases. the parent will actually use the return
295 * object, so keep it.
301 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
302 "Result of [%s] used by Parent [%s] Op=%p\n",
303 acpi_ps_get_opcode_name(op->common.aml_opcode),
304 acpi_ps_get_opcode_name(op->common.parent->common.
310 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
311 "Result of [%s] not used by Parent [%s] Op=%p\n",
312 acpi_ps_get_opcode_name(op->common.aml_opcode),
313 acpi_ps_get_opcode_name(op->common.parent->common.
319 /*******************************************************************************
321 * FUNCTION: acpi_ds_delete_result_if_not_used
323 * PARAMETERS: Op - Current parse Op
324 * result_obj - Result of the operation
325 * walk_state - Current state
329 * DESCRIPTION: Used after interpretation of an opcode. If there is an internal
330 * result descriptor, check if the parent opcode will actually use
331 * this result. If not, delete the result now so that it will
332 * not become orphaned.
334 ******************************************************************************/
337 acpi_ds_delete_result_if_not_used(union acpi_parse_object *op,
338 union acpi_operand_object *result_obj,
339 struct acpi_walk_state *walk_state)
341 union acpi_operand_object *obj_desc;
344 ACPI_FUNCTION_TRACE_PTR("ds_delete_result_if_not_used", result_obj);
347 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Null Op\n"));
355 if (!acpi_ds_is_result_used(op, walk_state)) {
356 /* Must pop the result stack (obj_desc should be equal to result_obj) */
358 status = acpi_ds_result_pop(&obj_desc, walk_state);
359 if (ACPI_SUCCESS(status)) {
360 acpi_ut_remove_reference(result_obj);
367 /*******************************************************************************
369 * FUNCTION: acpi_ds_resolve_operands
371 * PARAMETERS: walk_state - Current walk state with operands on stack
375 * DESCRIPTION: Resolve all operands to their values. Used to prepare
376 * arguments to a control method invocation (a call from one
377 * method to another.)
379 ******************************************************************************/
381 acpi_status acpi_ds_resolve_operands(struct acpi_walk_state *walk_state)
384 acpi_status status = AE_OK;
386 ACPI_FUNCTION_TRACE_PTR("ds_resolve_operands", walk_state);
389 * Attempt to resolve each of the valid operands
390 * Method arguments are passed by reference, not by value. This means
391 * that the actual objects are passed, not copies of the objects.
393 for (i = 0; i < walk_state->num_operands; i++) {
395 acpi_ex_resolve_to_value(&walk_state->operands[i],
397 if (ACPI_FAILURE(status)) {
402 return_ACPI_STATUS(status);
405 /*******************************************************************************
407 * FUNCTION: acpi_ds_clear_operands
409 * PARAMETERS: walk_state - Current walk state with operands on stack
413 * DESCRIPTION: Clear all operands on the current walk state operand stack.
415 ******************************************************************************/
417 void acpi_ds_clear_operands(struct acpi_walk_state *walk_state)
421 ACPI_FUNCTION_TRACE_PTR("ds_clear_operands", walk_state);
423 /* Remove a reference on each operand on the stack */
425 for (i = 0; i < walk_state->num_operands; i++) {
427 * Remove a reference to all operands, including both
428 * "Arguments" and "Targets".
430 acpi_ut_remove_reference(walk_state->operands[i]);
431 walk_state->operands[i] = NULL;
434 walk_state->num_operands = 0;
439 /*******************************************************************************
441 * FUNCTION: acpi_ds_create_operand
443 * PARAMETERS: walk_state - Current walk state
444 * Arg - Parse object for the argument
445 * arg_index - Which argument (zero based)
449 * DESCRIPTION: Translate a parse tree object that is an argument to an AML
450 * opcode to the equivalent interpreter object. This may include
451 * looking up a name or entering a new name into the internal
454 ******************************************************************************/
457 acpi_ds_create_operand(struct acpi_walk_state *walk_state,
458 union acpi_parse_object *arg, u32 arg_index)
460 acpi_status status = AE_OK;
463 union acpi_operand_object *obj_desc;
464 union acpi_parse_object *parent_op;
466 acpi_interpreter_mode interpreter_mode;
467 const struct acpi_opcode_info *op_info;
469 ACPI_FUNCTION_TRACE_PTR("ds_create_operand", arg);
471 /* A valid name must be looked up in the namespace */
473 if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
474 (arg->common.value.string)) {
475 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n",
478 /* Get the entire name string from the AML stream */
481 acpi_ex_get_name_string(ACPI_TYPE_ANY,
482 arg->common.value.buffer,
483 &name_string, &name_length);
485 if (ACPI_FAILURE(status)) {
486 return_ACPI_STATUS(status);
489 /* All prefixes have been handled, and the name is in name_string */
492 * Special handling for buffer_field declarations. This is a deferred
493 * opcode that unfortunately defines the field name as the last
494 * parameter instead of the first. We get here when we are performing
495 * the deferred execution, so the actual name of the field is already
496 * in the namespace. We don't want to attempt to look it up again
497 * because we may be executing in a different scope than where the
498 * actual opcode exists.
500 if ((walk_state->deferred_node) &&
501 (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD)
502 && (arg_index != 0)) {
504 ACPI_CAST_PTR(union acpi_operand_object,
505 walk_state->deferred_node);
507 } else { /* All other opcodes */
510 * Differentiate between a namespace "create" operation
511 * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
512 * IMODE_EXECUTE) in order to support the creation of
513 * namespace objects during the execution of control methods.
515 parent_op = arg->common.parent;
517 acpi_ps_get_opcode_info(parent_op->common.
519 if ((op_info->flags & AML_NSNODE)
520 && (parent_op->common.aml_opcode !=
521 AML_INT_METHODCALL_OP)
522 && (parent_op->common.aml_opcode != AML_REGION_OP)
523 && (parent_op->common.aml_opcode !=
524 AML_INT_NAMEPATH_OP)) {
525 /* Enter name into namespace if not found */
527 interpreter_mode = ACPI_IMODE_LOAD_PASS2;
529 /* Return a failure if name not found */
531 interpreter_mode = ACPI_IMODE_EXECUTE;
535 acpi_ns_lookup(walk_state->scope_info, name_string,
536 ACPI_TYPE_ANY, interpreter_mode,
537 ACPI_NS_SEARCH_PARENT |
538 ACPI_NS_DONT_OPEN_SCOPE, walk_state,
539 ACPI_CAST_INDIRECT_PTR(struct
543 * The only case where we pass through (ignore) a NOT_FOUND
544 * error is for the cond_ref_of opcode.
546 if (status == AE_NOT_FOUND) {
547 if (parent_op->common.aml_opcode ==
548 AML_COND_REF_OF_OP) {
550 * For the Conditional Reference op, it's OK if
551 * the name is not found; We just need a way to
552 * indicate this to the interpreter, set the
562 * We just plain didn't find it -- which is a
563 * very serious error at this point
565 status = AE_AML_NAME_NOT_FOUND;
569 if (ACPI_FAILURE(status)) {
570 ACPI_REPORT_NSERROR(name_string, status);
574 /* Free the namestring created above */
576 ACPI_MEM_FREE(name_string);
578 /* Check status from the lookup */
580 if (ACPI_FAILURE(status)) {
581 return_ACPI_STATUS(status);
584 /* Put the resulting object onto the current object stack */
586 status = acpi_ds_obj_stack_push(obj_desc, walk_state);
587 if (ACPI_FAILURE(status)) {
588 return_ACPI_STATUS(status);
590 ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object
591 (obj_desc, walk_state));
593 /* Check for null name case */
595 if (arg->common.aml_opcode == AML_INT_NAMEPATH_OP) {
597 * If the name is null, this means that this is an
598 * optional result parameter that was not specified
599 * in the original ASL. Create a Zero Constant for a
600 * placeholder. (Store to a constant is a Noop.)
602 opcode = AML_ZERO_OP; /* Has no arguments! */
604 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
605 "Null namepath: Arg=%p\n", arg));
607 opcode = arg->common.aml_opcode;
610 /* Get the object type of the argument */
612 op_info = acpi_ps_get_opcode_info(opcode);
613 if (op_info->object_type == ACPI_TYPE_INVALID) {
614 return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
617 if (op_info->flags & AML_HAS_RETVAL) {
618 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
619 "Argument previously created, already stacked \n"));
621 ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object
623 operands[walk_state->num_operands -
627 * Use value that was already previously returned
628 * by the evaluation of this argument
631 acpi_ds_result_pop_from_bottom(&obj_desc,
633 if (ACPI_FAILURE(status)) {
635 * Only error is underflow, and this indicates
636 * a missing or null operand!
638 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
639 "Missing or null operand, %s\n",
640 acpi_format_exception
642 return_ACPI_STATUS(status);
645 /* Create an ACPI_INTERNAL_OBJECT for the argument */
648 acpi_ut_create_internal_object(op_info->
651 return_ACPI_STATUS(AE_NO_MEMORY);
654 /* Initialize the new object */
657 acpi_ds_init_object_from_op(walk_state, arg, opcode,
659 if (ACPI_FAILURE(status)) {
660 acpi_ut_delete_object_desc(obj_desc);
661 return_ACPI_STATUS(status);
665 /* Put the operand object on the object stack */
667 status = acpi_ds_obj_stack_push(obj_desc, walk_state);
668 if (ACPI_FAILURE(status)) {
669 return_ACPI_STATUS(status);
672 ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object
673 (obj_desc, walk_state));
676 return_ACPI_STATUS(AE_OK);
679 /*******************************************************************************
681 * FUNCTION: acpi_ds_create_operands
683 * PARAMETERS: walk_state - Current state
684 * first_arg - First argument of a parser argument tree
688 * DESCRIPTION: Convert an operator's arguments from a parse tree format to
689 * namespace objects and place those argument object on the object
690 * stack in preparation for evaluation by the interpreter.
692 ******************************************************************************/
695 acpi_ds_create_operands(struct acpi_walk_state *walk_state,
696 union acpi_parse_object *first_arg)
698 acpi_status status = AE_OK;
699 union acpi_parse_object *arg;
702 ACPI_FUNCTION_TRACE_PTR("ds_create_operands", first_arg);
704 /* For all arguments in the list... */
708 status = acpi_ds_create_operand(walk_state, arg, arg_count);
709 if (ACPI_FAILURE(status)) {
713 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
714 "Arg #%d (%p) done, Arg1=%p\n", arg_count,
717 /* Move on to next argument, if any */
719 arg = arg->common.next;
723 return_ACPI_STATUS(status);
727 * We must undo everything done above; meaning that we must
728 * pop everything off of the operand stack and delete those
731 (void)acpi_ds_obj_stack_pop_and_delete(arg_count, walk_state);
733 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "While creating Arg %d - %s\n",
734 (arg_count + 1), acpi_format_exception(status)));
735 return_ACPI_STATUS(status);