1 /******************************************************************************
3 * Module Name: dscontrol - Support for execution control opcodes -
6 *****************************************************************************/
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45 #include <contrib/dev/acpica/include/acpi.h>
46 #include <contrib/dev/acpica/include/accommon.h>
47 #include <contrib/dev/acpica/include/amlcode.h>
48 #include <contrib/dev/acpica/include/acdispat.h>
49 #include <contrib/dev/acpica/include/acinterp.h>
50 #include <contrib/dev/acpica/include/acdebug.h>
52 #define _COMPONENT ACPI_DISPATCHER
53 ACPI_MODULE_NAME ("dscontrol")
56 /*******************************************************************************
58 * FUNCTION: AcpiDsExecBeginControlOp
60 * PARAMETERS: WalkList - The list that owns the walk stack
65 * DESCRIPTION: Handles all control ops encountered during control method
68 ******************************************************************************/
71 AcpiDsExecBeginControlOp (
72 ACPI_WALK_STATE *WalkState,
73 ACPI_PARSE_OBJECT *Op)
75 ACPI_STATUS Status = AE_OK;
76 ACPI_GENERIC_STATE *ControlState;
79 ACPI_FUNCTION_NAME (DsExecBeginControlOp);
82 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n",
83 Op, Op->Common.AmlOpcode, WalkState));
85 switch (Op->Common.AmlOpcode)
89 * If this is an additional iteration of a while loop, continue.
90 * There is no need to allocate a new control state.
92 if (WalkState->ControlState)
94 if (WalkState->ControlState->Control.AmlPredicateStart ==
95 (WalkState->ParserState.Aml - 1))
97 /* Reset the state to start-of-loop */
99 WalkState->ControlState->Common.State =
100 ACPI_CONTROL_CONDITIONAL_EXECUTING;
105 /*lint -fallthrough */
109 * IF/WHILE: Create a new control state to manage these
110 * constructs. We need to manage these as a stack, in order
113 ControlState = AcpiUtCreateControlState ();
116 Status = AE_NO_MEMORY;
120 * Save a pointer to the predicate for multiple executions
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;
131 /* Push the control state on this walk's control stack */
133 AcpiUtPushGenericState (&WalkState->ControlState, ControlState);
138 /* Predicate is in the state object */
139 /* If predicate is true, the IF was executed, ignore ELSE part */
141 if (WalkState->LastPredicate)
143 Status = AE_CTRL_TRUE;
161 /*******************************************************************************
163 * FUNCTION: AcpiDsExecEndControlOp
165 * PARAMETERS: WalkList - The list that owns the walk stack
166 * Op - The control Op
170 * DESCRIPTION: Handles all control ops encountered during control method
173 ******************************************************************************/
176 AcpiDsExecEndControlOp (
177 ACPI_WALK_STATE *WalkState,
178 ACPI_PARSE_OBJECT *Op)
180 ACPI_STATUS Status = AE_OK;
181 ACPI_GENERIC_STATE *ControlState;
184 ACPI_FUNCTION_NAME (DsExecEndControlOp);
187 switch (Op->Common.AmlOpcode)
191 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", Op));
194 * Save the result of the predicate in case there is an
197 WalkState->LastPredicate =
198 (BOOLEAN) WalkState->ControlState->Common.Value;
201 * Pop the control state that was created at the start
202 * of the IF and free it
204 ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
205 AcpiUtDeleteGenericState (ControlState);
214 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", Op));
216 ControlState = WalkState->ControlState;
217 if (ControlState->Common.Value)
219 /* Predicate was true, the body of the loop was just executed */
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.
227 ControlState->Control.LoopCount++;
228 if (ControlState->Control.LoopCount > AcpiGbl_MaxLoopIterations)
230 Status = AE_AML_INFINITE_LOOP;
235 * Go back and evaluate the predicate and maybe execute the loop
238 Status = AE_CTRL_PENDING;
239 WalkState->AmlLastWhile =
240 ControlState->Control.AmlPredicateStart;
244 /* Predicate was false, terminate this while loop */
246 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
247 "[WHILE_OP] termination! Op=%p\n",Op));
249 /* Pop this control state and free it */
251 ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
252 AcpiUtDeleteGenericState (ControlState);
257 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
258 "[RETURN_OP] Op=%p Arg=%p\n",Op, Op->Common.Value.Arg));
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
265 if (Op->Common.Value.Arg)
267 /* Since we have a real Return(), delete any implicit return */
269 AcpiDsClearImplicitReturn (WalkState);
271 /* Return statement has an immediate operand */
273 Status = AcpiDsCreateOperands (WalkState, Op->Common.Value.Arg);
274 if (ACPI_FAILURE (Status))
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.
284 Status = AcpiExResolveToValue (
285 &WalkState->Operands [0], WalkState);
286 if (ACPI_FAILURE (Status))
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!
296 WalkState->ReturnDesc = WalkState->Operands[0];
298 else if (WalkState->ResultCount)
300 /* Since we have a real Return(), delete any implicit return */
302 AcpiDsClearImplicitReturn (WalkState);
305 * The return value has come from a previous calculation.
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.
311 * Allow references created by the Index operator to return
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))
321 Status = AcpiExResolveToValue (
322 &WalkState->Results->Results.ObjDesc [0], WalkState);
323 if (ACPI_FAILURE (Status))
329 WalkState->ReturnDesc = WalkState->Results->Results.ObjDesc [0];
333 /* No return operand */
335 if (WalkState->NumOperands)
337 AcpiUtRemoveReference (WalkState->Operands [0]);
340 WalkState->Operands[0] = NULL;
341 WalkState->NumOperands = 0;
342 WalkState->ReturnDesc = NULL;
346 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
347 "Completed RETURN_OP State=%p, RetVal=%p\n",
348 WalkState, WalkState->ReturnDesc));
350 /* End the control method execution right now */
352 Status = AE_CTRL_TERMINATE;
357 /* Just do nothing! */
361 case AML_BREAK_POINT_OP:
363 AcpiDbSignalBreakPoint (WalkState);
365 /* Call to the OSL in case OS wants a piece of the action */
367 Status = AcpiOsSignal (ACPI_SIGNAL_BREAKPOINT,
368 "Executed AML Breakpoint opcode");
372 case AML_CONTINUE_OP: /* ACPI 2.0 */
374 /* Pop and delete control states until we find a while */
376 while (WalkState->ControlState &&
377 (WalkState->ControlState->Control.Opcode != AML_WHILE_OP))
379 ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
380 AcpiUtDeleteGenericState (ControlState);
383 /* No while found? */
385 if (!WalkState->ControlState)
387 return (AE_AML_NO_WHILE);
390 /* Was: WalkState->AmlLastWhile = WalkState->ControlState->Control.AmlPredicateStart; */
392 WalkState->AmlLastWhile =
393 WalkState->ControlState->Control.PackageEnd;
395 /* Return status depending on opcode */
397 if (Op->Common.AmlOpcode == AML_BREAK_OP)
399 Status = AE_CTRL_BREAK;
403 Status = AE_CTRL_CONTINUE;
409 ACPI_ERROR ((AE_INFO, "Unknown control opcode=0x%X Op=%p",
410 Op->Common.AmlOpcode, Op));
412 Status = AE_AML_BAD_OPCODE;