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- /******************************************************************************
- *
- * Module Name: dscontrol - Support for execution control opcodes -
- * if/else/while/return
- *
- *****************************************************************************/
- /*
- * Copyright (C) 2000 - 2015, Intel Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions, and the following disclaimer,
- * without modification.
- * 2. Redistributions in binary form must reproduce at minimum a disclaimer
- * substantially similar to the "NO WARRANTY" disclaimer below
- * ("Disclaimer") and any redistribution must be conditioned upon
- * including a substantially similar Disclaimer requirement for further
- * binary redistribution.
- * 3. Neither the names of the above-listed copyright holders nor the names
- * of any contributors may be used to endorse or promote products derived
- * from this software without specific prior written permission.
- *
- * Alternatively, this software may be distributed under the terms of the
- * GNU General Public License ("GPL") version 2 as published by the Free
- * Software Foundation.
- *
- * NO WARRANTY
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
- * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGES.
- */
- #include "acpi.h"
- #include "accommon.h"
- #include "amlcode.h"
- #include "acdispat.h"
- #include "acinterp.h"
- #include "acdebug.h"
- #define _COMPONENT ACPI_DISPATCHER
- ACPI_MODULE_NAME ("dscontrol")
- /*******************************************************************************
- *
- * FUNCTION: AcpiDsExecBeginControlOp
- *
- * PARAMETERS: WalkList - The list that owns the walk stack
- * Op - The control Op
- *
- * RETURN: Status
- *
- * DESCRIPTION: Handles all control ops encountered during control method
- * execution.
- *
- ******************************************************************************/
- ACPI_STATUS
- AcpiDsExecBeginControlOp (
- ACPI_WALK_STATE *WalkState,
- ACPI_PARSE_OBJECT *Op)
- {
- ACPI_STATUS Status = AE_OK;
- ACPI_GENERIC_STATE *ControlState;
- ACPI_FUNCTION_NAME (DsExecBeginControlOp);
- ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n",
- Op, Op->Common.AmlOpcode, WalkState));
- switch (Op->Common.AmlOpcode)
- {
- case AML_WHILE_OP:
- /*
- * If this is an additional iteration of a while loop, continue.
- * There is no need to allocate a new control state.
- */
- if (WalkState->ControlState)
- {
- if (WalkState->ControlState->Control.AmlPredicateStart ==
- (WalkState->ParserState.Aml - 1))
- {
- /* Reset the state to start-of-loop */
- WalkState->ControlState->Common.State =
- ACPI_CONTROL_CONDITIONAL_EXECUTING;
- break;
- }
- }
- /*lint -fallthrough */
- case AML_IF_OP:
- /*
- * IF/WHILE: Create a new control state to manage these
- * constructs. We need to manage these as a stack, in order
- * to handle nesting.
- */
- ControlState = AcpiUtCreateControlState ();
- if (!ControlState)
- {
- Status = AE_NO_MEMORY;
- break;
- }
- /*
- * Save a pointer to the predicate for multiple executions
- * of a loop
- */
- ControlState->Control.AmlPredicateStart =
- WalkState->ParserState.Aml - 1;
- ControlState->Control.PackageEnd =
- WalkState->ParserState.PkgEnd;
- ControlState->Control.Opcode =
- Op->Common.AmlOpcode;
- /* Push the control state on this walk's control stack */
- AcpiUtPushGenericState (&WalkState->ControlState, ControlState);
- break;
- case AML_ELSE_OP:
- /* Predicate is in the state object */
- /* If predicate is true, the IF was executed, ignore ELSE part */
- if (WalkState->LastPredicate)
- {
- Status = AE_CTRL_TRUE;
- }
- break;
- case AML_RETURN_OP:
- break;
- default:
- break;
- }
- return (Status);
- }
- /*******************************************************************************
- *
- * FUNCTION: AcpiDsExecEndControlOp
- *
- * PARAMETERS: WalkList - The list that owns the walk stack
- * Op - The control Op
- *
- * RETURN: Status
- *
- * DESCRIPTION: Handles all control ops encountered during control method
- * execution.
- *
- ******************************************************************************/
- ACPI_STATUS
- AcpiDsExecEndControlOp (
- ACPI_WALK_STATE *WalkState,
- ACPI_PARSE_OBJECT *Op)
- {
- ACPI_STATUS Status = AE_OK;
- ACPI_GENERIC_STATE *ControlState;
- ACPI_FUNCTION_NAME (DsExecEndControlOp);
- switch (Op->Common.AmlOpcode)
- {
- case AML_IF_OP:
- ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", Op));
- /*
- * Save the result of the predicate in case there is an
- * ELSE to come
- */
- WalkState->LastPredicate =
- (BOOLEAN) WalkState->ControlState->Common.Value;
- /*
- * Pop the control state that was created at the start
- * of the IF and free it
- */
- ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
- AcpiUtDeleteGenericState (ControlState);
- break;
- case AML_ELSE_OP:
- break;
- case AML_WHILE_OP:
- ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", Op));
- ControlState = WalkState->ControlState;
- if (ControlState->Common.Value)
- {
- /* Predicate was true, the body of the loop was just executed */
- /*
- * This loop counter mechanism allows the interpreter to escape
- * possibly infinite loops. This can occur in poorly written AML
- * when the hardware does not respond within a while loop and the
- * loop does not implement a timeout.
- */
- ControlState->Control.LoopCount++;
- if (ControlState->Control.LoopCount > AcpiGbl_MaxLoopIterations)
- {
- Status = AE_AML_INFINITE_LOOP;
- break;
- }
- /*
- * Go back and evaluate the predicate and maybe execute the loop
- * another time
- */
- Status = AE_CTRL_PENDING;
- WalkState->AmlLastWhile =
- ControlState->Control.AmlPredicateStart;
- break;
- }
- /* Predicate was false, terminate this while loop */
- ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
- "[WHILE_OP] termination! Op=%p\n",Op));
- /* Pop this control state and free it */
- ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
- AcpiUtDeleteGenericState (ControlState);
- break;
- case AML_RETURN_OP:
- ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
- "[RETURN_OP] Op=%p Arg=%p\n",Op, Op->Common.Value.Arg));
- /*
- * One optional operand -- the return value
- * It can be either an immediate operand or a result that
- * has been bubbled up the tree
- */
- if (Op->Common.Value.Arg)
- {
- /* Since we have a real Return(), delete any implicit return */
- AcpiDsClearImplicitReturn (WalkState);
- /* Return statement has an immediate operand */
- Status = AcpiDsCreateOperands (WalkState, Op->Common.Value.Arg);
- if (ACPI_FAILURE (Status))
- {
- return (Status);
- }
- /*
- * If value being returned is a Reference (such as
- * an arg or local), resolve it now because it may
- * cease to exist at the end of the method.
- */
- Status = AcpiExResolveToValue (
- &WalkState->Operands [0], WalkState);
- if (ACPI_FAILURE (Status))
- {
- return (Status);
- }
- /*
- * Get the return value and save as the last result
- * value. This is the only place where WalkState->ReturnDesc
- * is set to anything other than zero!
- */
- WalkState->ReturnDesc = WalkState->Operands[0];
- }
- else if (WalkState->ResultCount)
- {
- /* Since we have a real Return(), delete any implicit return */
- AcpiDsClearImplicitReturn (WalkState);
- /*
- * The return value has come from a previous calculation.
- *
- * If value being returned is a Reference (such as
- * an arg or local), resolve it now because it may
- * cease to exist at the end of the method.
- *
- * Allow references created by the Index operator to return
- * unchanged.
- */
- if ((ACPI_GET_DESCRIPTOR_TYPE (WalkState->Results->Results.ObjDesc[0]) ==
- ACPI_DESC_TYPE_OPERAND) &&
- ((WalkState->Results->Results.ObjDesc [0])->Common.Type ==
- ACPI_TYPE_LOCAL_REFERENCE) &&
- ((WalkState->Results->Results.ObjDesc [0])->Reference.Class !=
- ACPI_REFCLASS_INDEX))
- {
- Status = AcpiExResolveToValue (
- &WalkState->Results->Results.ObjDesc [0], WalkState);
- if (ACPI_FAILURE (Status))
- {
- return (Status);
- }
- }
- WalkState->ReturnDesc = WalkState->Results->Results.ObjDesc [0];
- }
- else
- {
- /* No return operand */
- if (WalkState->NumOperands)
- {
- AcpiUtRemoveReference (WalkState->Operands [0]);
- }
- WalkState->Operands[0] = NULL;
- WalkState->NumOperands = 0;
- WalkState->ReturnDesc = NULL;
- }
- ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
- "Completed RETURN_OP State=%p, RetVal=%p\n",
- WalkState, WalkState->ReturnDesc));
- /* End the control method execution right now */
- Status = AE_CTRL_TERMINATE;
- break;
- case AML_NOOP_OP:
- /* Just do nothing! */
- break;
- case AML_BREAK_POINT_OP:
- AcpiDbSignalBreakPoint (WalkState);
- /* Call to the OSL in case OS wants a piece of the action */
- Status = AcpiOsSignal (ACPI_SIGNAL_BREAKPOINT,
- "Executed AML Breakpoint opcode");
- break;
- case AML_BREAK_OP:
- case AML_CONTINUE_OP: /* ACPI 2.0 */
- /* Pop and delete control states until we find a while */
- while (WalkState->ControlState &&
- (WalkState->ControlState->Control.Opcode != AML_WHILE_OP))
- {
- ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
- AcpiUtDeleteGenericState (ControlState);
- }
- /* No while found? */
- if (!WalkState->ControlState)
- {
- return (AE_AML_NO_WHILE);
- }
- /* Was: WalkState->AmlLastWhile = WalkState->ControlState->Control.AmlPredicateStart; */
- WalkState->AmlLastWhile =
- WalkState->ControlState->Control.PackageEnd;
- /* Return status depending on opcode */
- if (Op->Common.AmlOpcode == AML_BREAK_OP)
- {
- Status = AE_CTRL_BREAK;
- }
- else
- {
- Status = AE_CTRL_CONTINUE;
- }
- break;
- default:
- ACPI_ERROR ((AE_INFO, "Unknown control opcode=0x%X Op=%p",
- Op->Common.AmlOpcode, Op));
- Status = AE_AML_BAD_OPCODE;
- break;
- }
- return (Status);
- }
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