FreeBSD/Linux Kernel Cross Reference
sys/contrib/dev/acpica/components/dispatcher/dscontrol.c

     /******************************************************************************
      *
      * Module Name: dscontrol - Support for execution control opcodes -
      *                          if/else/while/return
      *
      *****************************************************************************/
     
     /******************************************************************************
      *
     * 1. Copyright Notice
     *
     * Some or all of this work - Copyright (c) 1999 - 2022, 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.
    *
    *****************************************************************************
    *
    * Alternatively, you may choose to be licensed under the terms of the
    * following license:
    *
    * 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.
    *
    * 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 MERCHANTABILITY AND FITNESS FOR
    * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    * 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 DAMAGE.
    *
    * Alternatively, you may choose to be licensed under the terms of the
    * GNU General Public License ("GPL") version 2 as published by the Free
    * Software Foundation.
    *
    *****************************************************************************/
   
   #include <contrib/dev/acpica/include/acpi.h>
   #include <contrib/dev/acpica/include/accommon.h>
   #include <contrib/dev/acpica/include/amlcode.h>
   #include <contrib/dev/acpica/include/acdispat.h>
   #include <contrib/dev/acpica/include/acinterp.h>
   #include <contrib/dev/acpica/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;
               }
           }
   
           ACPI_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;
           ControlState->Control.LoopTimeout = AcpiOsGetTimer () +
              ((UINT64) AcpiGbl_MaxLoopIterations * ACPI_100NSEC_PER_SEC);
   
           /* 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 infinite loop detection 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.
                */
               if (ACPI_TIME_AFTER (AcpiOsGetTimer (),
                       ControlState->Control.LoopTimeout))
               {
                   Status = AE_AML_LOOP_TIMEOUT;
                   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_BREAKPOINT_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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