reactos/drivers/bus/acpi/acpica/dispatcher/dscontrol.c

   1 /******************************************************************************
   2  *
   3  * Module Name: dscontrol - Support for execution control opcodes -
   4  *                          if/else/while/return
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2017, Intel Corp.
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions, and the following disclaimer,
  17  *    without modification.
  18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19  *    substantially similar to the "NO WARRANTY" disclaimer below
  20  *    ("Disclaimer") and any redistribution must be conditioned upon
  21  *    including a substantially similar Disclaimer requirement for further
  22  *    binary redistribution.
  23  * 3. Neither the names of the above-listed copyright holders nor the names
  24  *    of any contributors may be used to endorse or promote products derived
  25  *    from this software without specific prior written permission.
  26  *
  27  * Alternatively, this software may be distributed under the terms of the
  28  * GNU General Public License ("GPL") version 2 as published by the Free
  29  * Software Foundation.
  30  *
  31  * NO WARRANTY
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42  * POSSIBILITY OF SUCH DAMAGES.
  43  */
  44
  45 #include "acpi.h"
  46 #include "accommon.h"
  47 #include "amlcode.h"
  48 #include "acdispat.h"
  49 #include "acinterp.h"
  50 #include "acdebug.h"
  51
  52 #define _COMPONENT          ACPI_DISPATCHER
  53         ACPI_MODULE_NAME    ("dscontrol")
  54
  55
  56 /*******************************************************************************
  57  *
  58  * FUNCTION:    AcpiDsExecBeginControlOp
  59  *
  60  * PARAMETERS:  WalkList        - The list that owns the walk stack
  61  *              Op              - The control Op
  62  *
  63  * RETURN:      Status
  64  *
  65  * DESCRIPTION: Handles all control ops encountered during control method
  66  *              execution.
  67  *
  68  ******************************************************************************/
  69
  70 ACPI_STATUS
  71 AcpiDsExecBeginControlOp (
  72     ACPI_WALK_STATE         *WalkState,
  73     ACPI_PARSE_OBJECT       *Op)
  74 {
  75     ACPI_STATUS             Status = AE_OK;
  76     ACPI_GENERIC_STATE      *ControlState;
  77
  78
  79     ACPI_FUNCTION_NAME (DsExecBeginControlOp);
  80
  81
  82     ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n",
  83         Op, Op->Common.AmlOpcode, WalkState));
  84
  85     switch (Op->Common.AmlOpcode)
  86     {
  87     case AML_WHILE_OP:
  88         /*
  89          * If this is an additional iteration of a while loop, continue.
  90          * There is no need to allocate a new control state.
  91          */
  92         if (WalkState->ControlState)
  93         {
  94             if (WalkState->ControlState->Control.AmlPredicateStart ==
  95                 (WalkState->ParserState.Aml - 1))
  96             {
  97                 /* Reset the state to start-of-loop */
  98
  99                 WalkState->ControlState->Common.State =
 100                     ACPI_CONTROL_CONDITIONAL_EXECUTING;
 101                 break;
 102             }
 103         }
 104
 105         /*lint -fallthrough */
 106
 107     case AML_IF_OP:
 108         /*
 109          * IF/WHILE: Create a new control state to manage these
 110          * constructs. We need to manage these as a stack, in order
 111          * to handle nesting.
 112          */
 113         ControlState = AcpiUtCreateControlState ();
 114         if (!ControlState)
 115         {
 116             Status = AE_NO_MEMORY;
 117             break;
 118         }
 119         /*
 120          * Save a pointer to the predicate for multiple executions
 121          * of a loop
 122          */
 123         ControlState->Control.AmlPredicateStart =
 124             WalkState->ParserState.Aml - 1;
 125         ControlState->Control.PackageEnd =
 126             WalkState->ParserState.PkgEnd;
 127         ControlState->Control.Opcode =
 128             Op->Common.AmlOpcode;
 129
 130
 131         /* Push the control state on this walk's control stack */
 132
 133         AcpiUtPushGenericState (&WalkState->ControlState, ControlState);
 134         break;
 135
 136     case AML_ELSE_OP:
 137
 138         /* Predicate is in the state object */
 139         /* If predicate is true, the IF was executed, ignore ELSE part */
 140
 141         if (WalkState->LastPredicate)
 142         {
 143             Status = AE_CTRL_TRUE;
 144         }
 145
 146         break;
 147
 148     case AML_RETURN_OP:
 149
 150         break;
 151
 152     default:
 153
 154         break;
 155     }
 156
 157     return (Status);
 158 }
 159
 160
 161 /*******************************************************************************
 162  *
 163  * FUNCTION:    AcpiDsExecEndControlOp
 164  *
 165  * PARAMETERS:  WalkList        - The list that owns the walk stack
 166  *              Op              - The control Op
 167  *
 168  * RETURN:      Status
 169  *
 170  * DESCRIPTION: Handles all control ops encountered during control method
 171  *              execution.
 172  *
 173  ******************************************************************************/
 174
 175 ACPI_STATUS
 176 AcpiDsExecEndControlOp (
 177     ACPI_WALK_STATE         *WalkState,
 178     ACPI_PARSE_OBJECT       *Op)
 179 {
 180     ACPI_STATUS             Status = AE_OK;
 181     ACPI_GENERIC_STATE      *ControlState;
 182
 183
 184     ACPI_FUNCTION_NAME (DsExecEndControlOp);
 185
 186
 187     switch (Op->Common.AmlOpcode)
 188     {
 189     case AML_IF_OP:
 190
 191         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", Op));
 192
 193         /*
 194          * Save the result of the predicate in case there is an
 195          * ELSE to come
 196          */
 197         WalkState->LastPredicate =
 198             (BOOLEAN) WalkState->ControlState->Common.Value;
 199
 200         /*
 201          * Pop the control state that was created at the start
 202          * of the IF and free it
 203          */
 204         ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
 205         AcpiUtDeleteGenericState (ControlState);
 206         break;
 207
 208     case AML_ELSE_OP:
 209
 210         break;
 211
 212     case AML_WHILE_OP:
 213
 214         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", Op));
 215
 216         ControlState = WalkState->ControlState;
 217         if (ControlState->Common.Value)
 218         {
 219             /* Predicate was true, the body of the loop was just executed */
 220
 221             /*
 222              * This loop counter mechanism allows the interpreter to escape
 223              * possibly infinite loops. This can occur in poorly written AML
 224              * when the hardware does not respond within a while loop and the
 225              * loop does not implement a timeout.
 226              */
 227             ControlState->Control.LoopCount++;
 228             if (ControlState->Control.LoopCount > AcpiGbl_MaxLoopIterations)
 229             {
 230                 Status = AE_AML_INFINITE_LOOP;
 231                 break;
 232             }
 233
 234             /*
 235              * Go back and evaluate the predicate and maybe execute the loop
 236              * another time
 237              */
 238             Status = AE_CTRL_PENDING;
 239             WalkState->AmlLastWhile =
 240                 ControlState->Control.AmlPredicateStart;
 241             break;
 242         }
 243
 244         /* Predicate was false, terminate this while loop */
 245
 246         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 247             "[WHILE_OP] termination! Op=%p\n",Op));
 248
 249         /* Pop this control state and free it */
 250
 251         ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
 252         AcpiUtDeleteGenericState (ControlState);
 253         break;
 254
 255     case AML_RETURN_OP:
 256
 257         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 258             "[RETURN_OP] Op=%p Arg=%p\n",Op, Op->Common.Value.Arg));
 259
 260         /*
 261          * One optional operand -- the return value
 262          * It can be either an immediate operand or a result that
 263          * has been bubbled up the tree
 264          */
 265         if (Op->Common.Value.Arg)
 266         {
 267             /* Since we have a real Return(), delete any implicit return */
 268
 269             AcpiDsClearImplicitReturn (WalkState);
 270
 271             /* Return statement has an immediate operand */
 272
 273             Status = AcpiDsCreateOperands (WalkState, Op->Common.Value.Arg);
 274             if (ACPI_FAILURE (Status))
 275             {
 276                 return (Status);
 277             }
 278
 279             /*
 280              * If value being returned is a Reference (such as
 281              * an arg or local), resolve it now because it may
 282              * cease to exist at the end of the method.
 283              */
 284             Status = AcpiExResolveToValue (
 285                 &WalkState->Operands [0], WalkState);
 286             if (ACPI_FAILURE (Status))
 287             {
 288                 return (Status);
 289             }
 290
 291             /*
 292              * Get the return value and save as the last result
 293              * value. This is the only place where WalkState->ReturnDesc
 294              * is set to anything other than zero!
 295              */
 296             WalkState->ReturnDesc = WalkState->Operands[0];
 297         }
 298         else if (WalkState->ResultCount)
 299         {
 300             /* Since we have a real Return(), delete any implicit return */
 301
 302             AcpiDsClearImplicitReturn (WalkState);
 303
 304             /*
 305              * The return value has come from a previous calculation.
 306              *
 307              * If value being returned is a Reference (such as
 308              * an arg or local), resolve it now because it may
 309              * cease to exist at the end of the method.
 310              *
 311              * Allow references created by the Index operator to return
 312              * unchanged.
 313              */
 314             if ((ACPI_GET_DESCRIPTOR_TYPE (WalkState->Results->Results.ObjDesc[0]) ==
 315                     ACPI_DESC_TYPE_OPERAND) &&
 316                 ((WalkState->Results->Results.ObjDesc [0])->Common.Type ==
 317                     ACPI_TYPE_LOCAL_REFERENCE) &&
 318                 ((WalkState->Results->Results.ObjDesc [0])->Reference.Class !=
 319                     ACPI_REFCLASS_INDEX))
 320             {
 321                 Status = AcpiExResolveToValue (
 322                     &WalkState->Results->Results.ObjDesc [0], WalkState);
 323                 if (ACPI_FAILURE (Status))
 324                 {
 325                     return (Status);
 326                 }
 327             }
 328
 329             WalkState->ReturnDesc = WalkState->Results->Results.ObjDesc [0];
 330         }
 331         else
 332         {
 333             /* No return operand */
 334
 335             if (WalkState->NumOperands)
 336             {
 337                 AcpiUtRemoveReference (WalkState->Operands [0]);
 338             }
 339
 340             WalkState->Operands[0] = NULL;
 341             WalkState->NumOperands = 0;
 342             WalkState->ReturnDesc = NULL;
 343         }
 344
 345
 346         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 347             "Completed RETURN_OP State=%p, RetVal=%p\n",
 348             WalkState, WalkState->ReturnDesc));
 349
 350         /* End the control method execution right now */
 351
 352         Status = AE_CTRL_TERMINATE;
 353         break;
 354
 355     case AML_NOOP_OP:
 356
 357         /* Just do nothing! */
 358
 359         break;
 360
 361     case AML_BREAK_POINT_OP:
 362
 363         AcpiDbSignalBreakPoint (WalkState);
 364
 365         /* Call to the OSL in case OS wants a piece of the action */
 366
 367         Status = AcpiOsSignal (ACPI_SIGNAL_BREAKPOINT,
 368             "Executed AML Breakpoint opcode");
 369         break;
 370
 371     case AML_BREAK_OP:
 372     case AML_CONTINUE_OP: /* ACPI 2.0 */
 373
 374         /* Pop and delete control states until we find a while */
 375
 376         while (WalkState->ControlState &&
 377                 (WalkState->ControlState->Control.Opcode != AML_WHILE_OP))
 378         {
 379             ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
 380             AcpiUtDeleteGenericState (ControlState);
 381         }
 382
 383         /* No while found? */
 384
 385         if (!WalkState->ControlState)
 386         {
 387             return (AE_AML_NO_WHILE);
 388         }
 389
 390         /* Was: WalkState->AmlLastWhile = WalkState->ControlState->Control.AmlPredicateStart; */
 391
 392         WalkState->AmlLastWhile =
 393             WalkState->ControlState->Control.PackageEnd;
 394
 395         /* Return status depending on opcode */
 396
 397         if (Op->Common.AmlOpcode == AML_BREAK_OP)
 398         {
 399             Status = AE_CTRL_BREAK;
 400         }
 401         else
 402         {
 403             Status = AE_CTRL_CONTINUE;
 404         }
 405         break;
 406
 407     default:
 408
 409         ACPI_ERROR ((AE_INFO, "Unknown control opcode=0x%X Op=%p",
 410             Op->Common.AmlOpcode, Op));
 411
 412         Status = AE_AML_BAD_OPCODE;
 413         break;
 414     }
 415
 416     return (Status);
 417 }