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![Erik Schmauss](/assets/img/avatar_default.png)
Signed-off-by: Erik Schmauss <erik.schmauss@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
372 lines
9.4 KiB
C
372 lines
9.4 KiB
C
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
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/******************************************************************************
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*
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* Module Name: dscontrol - Support for execution control opcodes -
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* if/else/while/return
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*
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* Copyright (C) 2000 - 2018, Intel Corp.
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*
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*****************************************************************************/
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#include <acpi/acpi.h>
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#include "accommon.h"
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#include "amlcode.h"
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#include "acdispat.h"
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#include "acinterp.h"
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#include "acdebug.h"
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#define _COMPONENT ACPI_DISPATCHER
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ACPI_MODULE_NAME("dscontrol")
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/*******************************************************************************
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*
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* FUNCTION: acpi_ds_exec_begin_control_op
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*
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* PARAMETERS: walk_list - The list that owns the walk stack
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* op - The control Op
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*
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* RETURN: Status
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*
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* DESCRIPTION: Handles all control ops encountered during control method
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* execution.
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*
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******************************************************************************/
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acpi_status
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acpi_ds_exec_begin_control_op(struct acpi_walk_state *walk_state,
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union acpi_parse_object *op)
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{
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acpi_status status = AE_OK;
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union acpi_generic_state *control_state;
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ACPI_FUNCTION_NAME(ds_exec_begin_control_op);
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ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n",
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op, op->common.aml_opcode, walk_state));
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switch (op->common.aml_opcode) {
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case AML_WHILE_OP:
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/*
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* If this is an additional iteration of a while loop, continue.
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* There is no need to allocate a new control state.
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*/
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if (walk_state->control_state) {
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if (walk_state->control_state->control.
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aml_predicate_start ==
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(walk_state->parser_state.aml - 1)) {
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/* Reset the state to start-of-loop */
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walk_state->control_state->common.state =
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ACPI_CONTROL_CONDITIONAL_EXECUTING;
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break;
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}
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}
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/*lint -fallthrough */
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case AML_IF_OP:
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/*
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* IF/WHILE: Create a new control state to manage these
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* constructs. We need to manage these as a stack, in order
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* to handle nesting.
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*/
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control_state = acpi_ut_create_control_state();
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if (!control_state) {
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status = AE_NO_MEMORY;
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break;
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}
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/*
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* Save a pointer to the predicate for multiple executions
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* of a loop
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*/
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control_state->control.aml_predicate_start =
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walk_state->parser_state.aml - 1;
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control_state->control.package_end =
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walk_state->parser_state.pkg_end;
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control_state->control.opcode = op->common.aml_opcode;
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control_state->control.loop_timeout = acpi_os_get_timer() +
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(u64)(acpi_gbl_max_loop_iterations * ACPI_100NSEC_PER_SEC);
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/* Push the control state on this walk's control stack */
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acpi_ut_push_generic_state(&walk_state->control_state,
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control_state);
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break;
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case AML_ELSE_OP:
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/* Predicate is in the state object */
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/* If predicate is true, the IF was executed, ignore ELSE part */
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if (walk_state->last_predicate) {
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status = AE_CTRL_TRUE;
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}
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break;
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case AML_RETURN_OP:
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break;
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default:
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break;
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}
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return (status);
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}
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/*******************************************************************************
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*
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* FUNCTION: acpi_ds_exec_end_control_op
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*
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* PARAMETERS: walk_list - The list that owns the walk stack
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* op - The control Op
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*
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* RETURN: Status
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*
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* DESCRIPTION: Handles all control ops encountered during control method
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* execution.
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*
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******************************************************************************/
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acpi_status
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acpi_ds_exec_end_control_op(struct acpi_walk_state *walk_state,
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union acpi_parse_object *op)
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{
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acpi_status status = AE_OK;
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union acpi_generic_state *control_state;
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ACPI_FUNCTION_NAME(ds_exec_end_control_op);
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switch (op->common.aml_opcode) {
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case AML_IF_OP:
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ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", op));
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/*
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* Save the result of the predicate in case there is an
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* ELSE to come
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*/
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walk_state->last_predicate =
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(u8)walk_state->control_state->common.value;
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/*
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* Pop the control state that was created at the start
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* of the IF and free it
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*/
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control_state =
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acpi_ut_pop_generic_state(&walk_state->control_state);
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acpi_ut_delete_generic_state(control_state);
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break;
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case AML_ELSE_OP:
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break;
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case AML_WHILE_OP:
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ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", op));
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control_state = walk_state->control_state;
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if (control_state->common.value) {
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/* Predicate was true, the body of the loop was just executed */
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/*
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* This infinite loop detection mechanism allows the interpreter
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* to escape possibly infinite loops. This can occur in poorly
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* written AML when the hardware does not respond within a while
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* loop and the loop does not implement a timeout.
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*/
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if (ACPI_TIME_AFTER(acpi_os_get_timer(),
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control_state->control.
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loop_timeout)) {
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status = AE_AML_LOOP_TIMEOUT;
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break;
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}
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/*
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* Go back and evaluate the predicate and maybe execute the loop
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* another time
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*/
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status = AE_CTRL_PENDING;
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walk_state->aml_last_while =
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control_state->control.aml_predicate_start;
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break;
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}
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/* Predicate was false, terminate this while loop */
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ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
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"[WHILE_OP] termination! Op=%p\n", op));
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/* Pop this control state and free it */
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control_state =
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acpi_ut_pop_generic_state(&walk_state->control_state);
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acpi_ut_delete_generic_state(control_state);
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break;
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case AML_RETURN_OP:
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ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
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"[RETURN_OP] Op=%p Arg=%p\n", op,
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op->common.value.arg));
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/*
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* One optional operand -- the return value
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* It can be either an immediate operand or a result that
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* has been bubbled up the tree
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*/
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if (op->common.value.arg) {
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/* Since we have a real Return(), delete any implicit return */
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acpi_ds_clear_implicit_return(walk_state);
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/* Return statement has an immediate operand */
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status =
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acpi_ds_create_operands(walk_state,
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op->common.value.arg);
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if (ACPI_FAILURE(status)) {
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return (status);
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}
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/*
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* If value being returned is a Reference (such as
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* an arg or local), resolve it now because it may
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* cease to exist at the end of the method.
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*/
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status =
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acpi_ex_resolve_to_value(&walk_state->operands[0],
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walk_state);
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if (ACPI_FAILURE(status)) {
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return (status);
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}
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/*
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* Get the return value and save as the last result
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* value. This is the only place where walk_state->return_desc
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* is set to anything other than zero!
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*/
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walk_state->return_desc = walk_state->operands[0];
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} else if (walk_state->result_count) {
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/* Since we have a real Return(), delete any implicit return */
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acpi_ds_clear_implicit_return(walk_state);
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/*
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* The return value has come from a previous calculation.
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*
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* If value being returned is a Reference (such as
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* an arg or local), resolve it now because it may
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* cease to exist at the end of the method.
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*
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* Allow references created by the Index operator to return
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* unchanged.
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*/
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if ((ACPI_GET_DESCRIPTOR_TYPE
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(walk_state->results->results.obj_desc[0]) ==
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ACPI_DESC_TYPE_OPERAND)
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&& ((walk_state->results->results.obj_desc[0])->
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common.type == ACPI_TYPE_LOCAL_REFERENCE)
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&& ((walk_state->results->results.obj_desc[0])->
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reference.class != ACPI_REFCLASS_INDEX)) {
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status =
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acpi_ex_resolve_to_value(&walk_state->
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results->results.
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obj_desc[0],
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walk_state);
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if (ACPI_FAILURE(status)) {
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return (status);
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}
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}
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walk_state->return_desc =
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walk_state->results->results.obj_desc[0];
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} else {
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/* No return operand */
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if (walk_state->num_operands) {
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acpi_ut_remove_reference(walk_state->
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operands[0]);
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}
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walk_state->operands[0] = NULL;
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walk_state->num_operands = 0;
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walk_state->return_desc = NULL;
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}
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ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
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"Completed RETURN_OP State=%p, RetVal=%p\n",
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walk_state, walk_state->return_desc));
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/* End the control method execution right now */
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status = AE_CTRL_TERMINATE;
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break;
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case AML_NOOP_OP:
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/* Just do nothing! */
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break;
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case AML_BREAKPOINT_OP:
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acpi_db_signal_break_point(walk_state);
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/* Call to the OSL in case OS wants a piece of the action */
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status = acpi_os_signal(ACPI_SIGNAL_BREAKPOINT,
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"Executed AML Breakpoint opcode");
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break;
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case AML_BREAK_OP:
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case AML_CONTINUE_OP: /* ACPI 2.0 */
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/* Pop and delete control states until we find a while */
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while (walk_state->control_state &&
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(walk_state->control_state->control.opcode !=
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AML_WHILE_OP)) {
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control_state =
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acpi_ut_pop_generic_state(&walk_state->
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control_state);
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acpi_ut_delete_generic_state(control_state);
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}
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/* No while found? */
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if (!walk_state->control_state) {
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return (AE_AML_NO_WHILE);
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}
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/* Was: walk_state->aml_last_while = walk_state->control_state->Control.aml_predicate_start; */
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walk_state->aml_last_while =
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walk_state->control_state->control.package_end;
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/* Return status depending on opcode */
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if (op->common.aml_opcode == AML_BREAK_OP) {
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status = AE_CTRL_BREAK;
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} else {
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status = AE_CTRL_CONTINUE;
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}
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break;
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default:
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ACPI_ERROR((AE_INFO, "Unknown control opcode=0x%X Op=%p",
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op->common.aml_opcode, op));
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status = AE_AML_BAD_OPCODE;
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break;
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}
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return (status);
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}
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