1 /******************************************************************************
3 * Module Name: dscontrol - Support for execution control opcodes -
6 *****************************************************************************/
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45 #define __DSCONTROL_C__
47 #include <contrib/dev/acpica/include/acpi.h>
48 #include <contrib/dev/acpica/include/accommon.h>
49 #include <contrib/dev/acpica/include/amlcode.h>
50 #include <contrib/dev/acpica/include/acdispat.h>
51 #include <contrib/dev/acpica/include/acinterp.h>
53 #define _COMPONENT ACPI_DISPATCHER
54 ACPI_MODULE_NAME ("dscontrol")
57 /*******************************************************************************
59 * FUNCTION: AcpiDsExecBeginControlOp
61 * PARAMETERS: WalkList - The list that owns the walk stack
66 * DESCRIPTION: Handles all control ops encountered during control method
69 ******************************************************************************/
72 AcpiDsExecBeginControlOp (
73 ACPI_WALK_STATE *WalkState,
74 ACPI_PARSE_OBJECT *Op)
76 ACPI_STATUS Status = AE_OK;
77 ACPI_GENERIC_STATE *ControlState;
80 ACPI_FUNCTION_NAME (DsExecBeginControlOp);
83 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n",
84 Op, Op->Common.AmlOpcode, WalkState));
86 switch (Op->Common.AmlOpcode)
91 * If this is an additional iteration of a while loop, continue.
92 * There is no need to allocate a new control state.
94 if (WalkState->ControlState)
96 if (WalkState->ControlState->Control.AmlPredicateStart ==
97 (WalkState->ParserState.Aml - 1))
99 /* Reset the state to start-of-loop */
101 WalkState->ControlState->Common.State =
102 ACPI_CONTROL_CONDITIONAL_EXECUTING;
107 /*lint -fallthrough */
112 * IF/WHILE: Create a new control state to manage these
113 * constructs. We need to manage these as a stack, in order
116 ControlState = AcpiUtCreateControlState ();
119 Status = AE_NO_MEMORY;
123 * Save a pointer to the predicate for multiple executions
126 ControlState->Control.AmlPredicateStart = WalkState->ParserState.Aml - 1;
127 ControlState->Control.PackageEnd = WalkState->ParserState.PkgEnd;
128 ControlState->Control.Opcode = 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;
160 /*******************************************************************************
162 * FUNCTION: AcpiDsExecEndControlOp
164 * PARAMETERS: WalkList - The list that owns the walk stack
165 * Op - The control Op
169 * DESCRIPTION: Handles all control ops encountered during control method
172 ******************************************************************************/
175 AcpiDsExecEndControlOp (
176 ACPI_WALK_STATE *WalkState,
177 ACPI_PARSE_OBJECT *Op)
179 ACPI_STATUS Status = AE_OK;
180 ACPI_GENERIC_STATE *ControlState;
183 ACPI_FUNCTION_NAME (DsExecEndControlOp);
186 switch (Op->Common.AmlOpcode)
190 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", Op));
193 * Save the result of the predicate in case there is an
196 WalkState->LastPredicate =
197 (BOOLEAN) WalkState->ControlState->Common.Value;
200 * Pop the control state that was created at the start
201 * of the IF and free it
203 ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
204 AcpiUtDeleteGenericState (ControlState);
215 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", Op));
217 ControlState = WalkState->ControlState;
218 if (ControlState->Common.Value)
220 /* Predicate was true, the body of the loop was just executed */
223 * This loop counter mechanism allows the interpreter to escape
224 * possibly infinite loops. This can occur in poorly written AML
225 * when the hardware does not respond within a while loop and the
226 * loop does not implement a timeout.
228 ControlState->Control.LoopCount++;
229 if (ControlState->Control.LoopCount > ACPI_MAX_LOOP_ITERATIONS)
231 Status = AE_AML_INFINITE_LOOP;
236 * Go back and evaluate the predicate and maybe execute the loop
239 Status = AE_CTRL_PENDING;
240 WalkState->AmlLastWhile = 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);
258 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
259 "[RETURN_OP] Op=%p Arg=%p\n",Op, Op->Common.Value.Arg));
262 * One optional operand -- the return value
263 * It can be either an immediate operand or a result that
264 * has been bubbled up the tree
266 if (Op->Common.Value.Arg)
268 /* Since we have a real Return(), delete any implicit return */
270 AcpiDsClearImplicitReturn (WalkState);
272 /* Return statement has an immediate operand */
274 Status = AcpiDsCreateOperands (WalkState, Op->Common.Value.Arg);
275 if (ACPI_FAILURE (Status))
281 * If value being returned is a Reference (such as
282 * an arg or local), resolve it now because it may
283 * cease to exist at the end of the method.
285 Status = AcpiExResolveToValue (&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]) == ACPI_DESC_TYPE_OPERAND) &&
315 ((WalkState->Results->Results.ObjDesc [0])->Common.Type == ACPI_TYPE_LOCAL_REFERENCE) &&
316 ((WalkState->Results->Results.ObjDesc [0])->Reference.Class != ACPI_REFCLASS_INDEX))
318 Status = AcpiExResolveToValue (&WalkState->Results->Results.ObjDesc [0], WalkState);
319 if (ACPI_FAILURE (Status))
325 WalkState->ReturnDesc = WalkState->Results->Results.ObjDesc [0];
329 /* No return operand */
331 if (WalkState->NumOperands)
333 AcpiUtRemoveReference (WalkState->Operands [0]);
336 WalkState->Operands [0] = NULL;
337 WalkState->NumOperands = 0;
338 WalkState->ReturnDesc = NULL;
342 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
343 "Completed RETURN_OP State=%p, RetVal=%p\n",
344 WalkState, WalkState->ReturnDesc));
346 /* End the control method execution right now */
348 Status = AE_CTRL_TERMINATE;
354 /* Just do nothing! */
358 case AML_BREAK_POINT_OP:
361 * Set the single-step flag. This will cause the debugger (if present)
362 * to break to the console within the AML debugger at the start of the
363 * next AML instruction.
366 AcpiGbl_CmSingleStep = TRUE);
368 AcpiOsPrintf ("**break** Executed AML BreakPoint opcode\n"));
370 /* Call to the OSL in case OS wants a piece of the action */
372 Status = AcpiOsSignal (ACPI_SIGNAL_BREAKPOINT,
373 "Executed AML Breakpoint opcode");
378 case AML_CONTINUE_OP: /* ACPI 2.0 */
381 /* Pop and delete control states until we find a while */
383 while (WalkState->ControlState &&
384 (WalkState->ControlState->Control.Opcode != AML_WHILE_OP))
386 ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
387 AcpiUtDeleteGenericState (ControlState);
390 /* No while found? */
392 if (!WalkState->ControlState)
394 return (AE_AML_NO_WHILE);
397 /* Was: WalkState->AmlLastWhile = WalkState->ControlState->Control.AmlPredicateStart; */
399 WalkState->AmlLastWhile = WalkState->ControlState->Control.PackageEnd;
401 /* Return status depending on opcode */
403 if (Op->Common.AmlOpcode == AML_BREAK_OP)
405 Status = AE_CTRL_BREAK;
409 Status = AE_CTRL_CONTINUE;
416 ACPI_ERROR ((AE_INFO, "Unknown control opcode=0x%X Op=%p",
417 Op->Common.AmlOpcode, Op));
419 Status = AE_AML_BAD_OPCODE;