/****************************************************************************** * * Module Name: dscontrol - Support for execution control opcodes - * if/else/while/return * *****************************************************************************/ /****************************************************************************** * * 1. Copyright Notice * * Some or all of this work - Copyright (c) 1999 - 2021, 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 "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; } } 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); }