| /****************************************************************************** |
| * |
| * Module Name: dscontrol - Support for execution control opcodes - |
| * if/else/while/return |
| * |
| *****************************************************************************/ |
| |
| /* |
| * Copyright (C) 2000 - 2020, 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. |
| * |
| * 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; |
| 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); |
| } |
