/******************************************************************************
*
* Module Name: dscontrol - Support for execution control opcodes -
* if/else/while/return
*
*****************************************************************************/
/******************************************************************************
*
* 1. Copyright Notice
*
* Some or all of this work - Copyright (c) 1999 - 2011, Intel Corp.
* All rights reserved.
*
* 2. License
*
* 2.1. This is your license from Intel Corp. under its intellectual property
* rights. You may have additional license terms from the party that provided
* you this software, covering your right to use that party's intellectual
* property rights.
*
* 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
* copy of the source code appearing in this file ("Covered Code") an
* irrevocable, perpetual, worldwide license under Intel's copyrights in the
* base code distributed originally by Intel ("Original Intel Code") to copy,
* make derivatives, distribute, use and display any portion of the Covered
* Code in any form, with the right to sublicense such rights; and
*
* 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
* license (with the right to sublicense), under only those claims of Intel
* patents that are infringed by the Original Intel Code, to make, use, sell,
* offer to sell, and import the Covered Code and derivative works thereof
* solely to the minimum extent necessary to exercise the above copyright
* license, and in no event shall the patent license extend to any additions
* to or modifications of the Original Intel Code. No other license or right
* is granted directly or by implication, estoppel or otherwise;
*
* The above copyright and patent license is granted only if the following
* conditions are met:
*
* 3. Conditions
*
* 3.1. Redistribution of Source with Rights to Further Distribute Source.
* Redistribution of source code of any substantial portion of the Covered
* Code or modification with rights to further distribute source must include
* the above Copyright Notice, the above License, this list of Conditions,
* and the following Disclaimer and Export Compliance provision. In addition,
* Licensee must cause all Covered Code to which Licensee contributes to
* contain a file documenting the changes Licensee made to create that Covered
* Code and the date of any change. Licensee must include in that file the
* documentation of any changes made by any predecessor Licensee. Licensee
* must include a prominent statement that the modification is derived,
* directly or indirectly, from Original Intel Code.
*
* 3.2. Redistribution of Source with no Rights to Further Distribute Source.
* Redistribution of source code of any substantial portion of the Covered
* Code or modification without rights to further distribute source must
* include the following Disclaimer and Export Compliance provision in the
* documentation and/or other materials provided with distribution. In
* addition, Licensee may not authorize further sublicense of source of any
* portion of the Covered Code, and must include terms to the effect that the
* license from Licensee to its licensee is limited to the intellectual
* property embodied in the software Licensee provides to its licensee, and
* not to intellectual property embodied in modifications its licensee may
* make.
*
* 3.3. Redistribution of Executable. Redistribution in executable form of any
* substantial portion of the Covered Code or modification must reproduce the
* above Copyright Notice, and the following Disclaimer and Export Compliance
* provision in the documentation and/or other materials provided with the
* distribution.
*
* 3.4. Intel retains all right, title, and interest in and to the Original
* Intel Code.
*
* 3.5. Neither the name Intel nor any other trademark owned or controlled by
* Intel shall be used in advertising or otherwise to promote the sale, use or
* other dealings in products derived from or relating to the Covered Code
* without prior written authorization from Intel.
*
* 4. Disclaimer and Export Compliance
*
* 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
* HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
* IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
* INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
* UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
* IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
* PARTICULAR PURPOSE.
*
* 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
* OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
* COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
* SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
* CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
* HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
* SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
* LIMITED REMEDY.
*
* 4.3. Licensee shall not export, either directly or indirectly, any of this
* software or system incorporating such software without first obtaining any
* required license or other approval from the U. S. Department of Commerce or
* any other agency or department of the United States Government. In the
* event Licensee exports any such software from the United States or
* re-exports any such software from a foreign destination, Licensee shall
* ensure that the distribution and export/re-export of the software is in
* compliance with all laws, regulations, orders, or other restrictions of the
* U.S. Export Administration Regulations. Licensee agrees that neither it nor
* any of its subsidiaries will export/re-export any technical data, process,
* software, or service, directly or indirectly, to any country for which the
* United States government or any agency thereof requires an export license,
* other governmental approval, or letter of assurance, without first obtaining
* such license, approval or letter.
*
*****************************************************************************/
#define __DSCONTROL_C__
#include "acpi.h"
#include "accommon.h"
#include "amlcode.h"
#include "acdispat.h"
#include "acinterp.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 > ACPI_MAX_LOOP_ITERATIONS)
{
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:
/*
* Set the single-step flag. This will cause the debugger (if present)
* to break to the console within the AML debugger at the start of the
* next AML instruction.
*/
ACPI_DEBUGGER_EXEC (
AcpiGbl_CmSingleStep = TRUE);
ACPI_DEBUGGER_EXEC (
AcpiOsPrintf ("**break** Executed AML BreakPoint opcode\n"));
/* 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);
}