1 /******************************************************************************
3 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
5 *****************************************************************************/
8 * Copyright (C) 2000 - 2015, Intel Corp.
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54 #define _COMPONENT ACPI_DISPATCHER
55 ACPI_MODULE_NAME ("dsmethod")
57 /* Local prototypes */
60 AcpiDsDetectNamedOpcodes (
61 ACPI_WALK_STATE *WalkState,
62 ACPI_PARSE_OBJECT **OutOp);
65 AcpiDsCreateMethodMutex (
66 ACPI_OPERAND_OBJECT *MethodDesc);
69 /*******************************************************************************
71 * FUNCTION: AcpiDsAutoSerializeMethod
73 * PARAMETERS: Node - Namespace Node of the method
74 * ObjDesc - Method object attached to node
78 * DESCRIPTION: Parse a control method AML to scan for control methods that
79 * need serialization due to the creation of named objects.
81 * NOTE: It is a bit of overkill to mark all such methods serialized, since
82 * there is only a problem if the method actually blocks during execution.
83 * A blocking operation is, for example, a Sleep() operation, or any access
84 * to an operation region. However, it is probably not possible to easily
85 * detect whether a method will block or not, so we simply mark all suspicious
86 * methods as serialized.
88 * NOTE2: This code is essentially a generic routine for parsing a single
91 ******************************************************************************/
94 AcpiDsAutoSerializeMethod (
95 ACPI_NAMESPACE_NODE *Node,
96 ACPI_OPERAND_OBJECT *ObjDesc)
99 ACPI_PARSE_OBJECT *Op = NULL;
100 ACPI_WALK_STATE *WalkState;
103 ACPI_FUNCTION_TRACE_PTR (DsAutoSerializeMethod, Node);
106 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
107 "Method auto-serialization parse [%4.4s] %p\n",
108 AcpiUtGetNodeName (Node), Node));
110 /* Create/Init a root op for the method parse tree */
112 Op = AcpiPsAllocOp (AML_METHOD_OP);
115 return_ACPI_STATUS (AE_NO_MEMORY);
118 AcpiPsSetName (Op, Node->Name.Integer);
119 Op->Common.Node = Node;
121 /* Create and initialize a new walk state */
123 WalkState = AcpiDsCreateWalkState (Node->OwnerId, NULL, NULL, NULL);
127 return_ACPI_STATUS (AE_NO_MEMORY);
130 Status = AcpiDsInitAmlWalk (WalkState, Op, Node, ObjDesc->Method.AmlStart,
131 ObjDesc->Method.AmlLength, NULL, 0);
132 if (ACPI_FAILURE (Status))
134 AcpiDsDeleteWalkState (WalkState);
136 return_ACPI_STATUS (Status);
139 WalkState->DescendingCallback = AcpiDsDetectNamedOpcodes;
141 /* Parse the method, scan for creation of named objects */
143 Status = AcpiPsParseAml (WalkState);
145 AcpiPsDeleteParseTree (Op);
146 return_ACPI_STATUS (Status);
150 /*******************************************************************************
152 * FUNCTION: AcpiDsDetectNamedOpcodes
154 * PARAMETERS: WalkState - Current state of the parse tree walk
155 * OutOp - Unused, required for parser interface
159 * DESCRIPTION: Descending callback used during the loading of ACPI tables.
160 * Currently used to detect methods that must be marked serialized
161 * in order to avoid problems with the creation of named objects.
163 ******************************************************************************/
166 AcpiDsDetectNamedOpcodes (
167 ACPI_WALK_STATE *WalkState,
168 ACPI_PARSE_OBJECT **OutOp)
171 ACPI_FUNCTION_NAME (AcpiDsDetectNamedOpcodes);
174 /* We are only interested in opcodes that create a new name */
176 if (!(WalkState->OpInfo->Flags & (AML_NAMED | AML_CREATE | AML_FIELD)))
182 * At this point, we know we have a Named object opcode.
183 * Mark the method as serialized. Later code will create a mutex for
184 * this method to enforce serialization.
186 * Note, ACPI_METHOD_IGNORE_SYNC_LEVEL flag means that we will ignore the
187 * Sync Level mechanism for this method, even though it is now serialized.
188 * Otherwise, there can be conflicts with existing ASL code that actually
191 WalkState->MethodDesc->Method.SyncLevel = 0;
192 WalkState->MethodDesc->Method.InfoFlags |=
193 (ACPI_METHOD_SERIALIZED | ACPI_METHOD_IGNORE_SYNC_LEVEL);
195 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
196 "Method serialized [%4.4s] %p - [%s] (%4.4X)\n",
197 WalkState->MethodNode->Name.Ascii, WalkState->MethodNode,
198 WalkState->OpInfo->Name, WalkState->Opcode));
200 /* Abort the parse, no need to examine this method any further */
202 return (AE_CTRL_TERMINATE);
206 /*******************************************************************************
208 * FUNCTION: AcpiDsMethodError
210 * PARAMETERS: Status - Execution status
211 * WalkState - Current state
215 * DESCRIPTION: Called on method error. Invoke the global exception handler if
216 * present, dump the method data if the disassembler is configured
218 * Note: Allows the exception handler to change the status code
220 ******************************************************************************/
225 ACPI_WALK_STATE *WalkState)
227 ACPI_FUNCTION_ENTRY ();
230 /* Ignore AE_OK and control exception codes */
232 if (ACPI_SUCCESS (Status) ||
233 (Status & AE_CODE_CONTROL))
238 /* Invoke the global exception handler */
240 if (AcpiGbl_ExceptionHandler)
242 /* Exit the interpreter, allow handler to execute methods */
244 AcpiExExitInterpreter ();
247 * Handler can map the exception code to anything it wants, including
248 * AE_OK, in which case the executing method will not be aborted.
250 Status = AcpiGbl_ExceptionHandler (Status,
251 WalkState->MethodNode ?
252 WalkState->MethodNode->Name.Integer : 0,
253 WalkState->Opcode, WalkState->AmlOffset, NULL);
254 AcpiExEnterInterpreter ();
257 AcpiDsClearImplicitReturn (WalkState);
259 #ifdef ACPI_DISASSEMBLER
260 if (ACPI_FAILURE (Status))
262 /* Display method locals/args if disassembler is present */
264 AcpiDmDumpMethodInfo (Status, WalkState, WalkState->Op);
272 /*******************************************************************************
274 * FUNCTION: AcpiDsCreateMethodMutex
276 * PARAMETERS: ObjDesc - The method object
280 * DESCRIPTION: Create a mutex object for a serialized control method
282 ******************************************************************************/
285 AcpiDsCreateMethodMutex (
286 ACPI_OPERAND_OBJECT *MethodDesc)
288 ACPI_OPERAND_OBJECT *MutexDesc;
292 ACPI_FUNCTION_TRACE (DsCreateMethodMutex);
295 /* Create the new mutex object */
297 MutexDesc = AcpiUtCreateInternalObject (ACPI_TYPE_MUTEX);
300 return_ACPI_STATUS (AE_NO_MEMORY);
303 /* Create the actual OS Mutex */
305 Status = AcpiOsCreateMutex (&MutexDesc->Mutex.OsMutex);
306 if (ACPI_FAILURE (Status))
308 AcpiUtDeleteObjectDesc (MutexDesc);
309 return_ACPI_STATUS (Status);
312 MutexDesc->Mutex.SyncLevel = MethodDesc->Method.SyncLevel;
313 MethodDesc->Method.Mutex = MutexDesc;
314 return_ACPI_STATUS (AE_OK);
318 /*******************************************************************************
320 * FUNCTION: AcpiDsBeginMethodExecution
322 * PARAMETERS: MethodNode - Node of the method
323 * ObjDesc - The method object
324 * WalkState - current state, NULL if not yet executing
329 * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
330 * increments the thread count, and waits at the method semaphore
331 * for clearance to execute.
333 ******************************************************************************/
336 AcpiDsBeginMethodExecution (
337 ACPI_NAMESPACE_NODE *MethodNode,
338 ACPI_OPERAND_OBJECT *ObjDesc,
339 ACPI_WALK_STATE *WalkState)
341 ACPI_STATUS Status = AE_OK;
344 ACPI_FUNCTION_TRACE_PTR (DsBeginMethodExecution, MethodNode);
349 return_ACPI_STATUS (AE_NULL_ENTRY);
352 /* Prevent wraparound of thread count */
354 if (ObjDesc->Method.ThreadCount == ACPI_UINT8_MAX)
356 ACPI_ERROR ((AE_INFO,
357 "Method reached maximum reentrancy limit (255)"));
358 return_ACPI_STATUS (AE_AML_METHOD_LIMIT);
362 * If this method is serialized, we need to acquire the method mutex.
364 if (ObjDesc->Method.InfoFlags & ACPI_METHOD_SERIALIZED)
367 * Create a mutex for the method if it is defined to be Serialized
368 * and a mutex has not already been created. We defer the mutex creation
369 * until a method is actually executed, to minimize the object count
371 if (!ObjDesc->Method.Mutex)
373 Status = AcpiDsCreateMethodMutex (ObjDesc);
374 if (ACPI_FAILURE (Status))
376 return_ACPI_STATUS (Status);
381 * The CurrentSyncLevel (per-thread) must be less than or equal to
382 * the sync level of the method. This mechanism provides some
383 * deadlock prevention.
385 * If the method was auto-serialized, we just ignore the sync level
386 * mechanism, because auto-serialization of methods can interfere
387 * with ASL code that actually uses sync levels.
389 * Top-level method invocation has no walk state at this point
392 (!(ObjDesc->Method.InfoFlags & ACPI_METHOD_IGNORE_SYNC_LEVEL)) &&
393 (WalkState->Thread->CurrentSyncLevel > ObjDesc->Method.Mutex->Mutex.SyncLevel))
395 ACPI_ERROR ((AE_INFO,
396 "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%u)",
397 AcpiUtGetNodeName (MethodNode),
398 WalkState->Thread->CurrentSyncLevel));
400 return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
404 * Obtain the method mutex if necessary. Do not acquire mutex for a
408 !ObjDesc->Method.Mutex->Mutex.ThreadId ||
409 (WalkState->Thread->ThreadId != ObjDesc->Method.Mutex->Mutex.ThreadId))
412 * Acquire the method mutex. This releases the interpreter if we
413 * block (and reacquires it before it returns)
415 Status = AcpiExSystemWaitMutex (ObjDesc->Method.Mutex->Mutex.OsMutex,
417 if (ACPI_FAILURE (Status))
419 return_ACPI_STATUS (Status);
422 /* Update the mutex and walk info and save the original SyncLevel */
426 ObjDesc->Method.Mutex->Mutex.OriginalSyncLevel =
427 WalkState->Thread->CurrentSyncLevel;
429 ObjDesc->Method.Mutex->Mutex.ThreadId = WalkState->Thread->ThreadId;
430 WalkState->Thread->CurrentSyncLevel = ObjDesc->Method.SyncLevel;
434 ObjDesc->Method.Mutex->Mutex.OriginalSyncLevel =
435 ObjDesc->Method.Mutex->Mutex.SyncLevel;
439 /* Always increase acquisition depth */
441 ObjDesc->Method.Mutex->Mutex.AcquisitionDepth++;
445 * Allocate an Owner ID for this method, only if this is the first thread
446 * to begin concurrent execution. We only need one OwnerId, even if the
447 * method is invoked recursively.
449 if (!ObjDesc->Method.OwnerId)
451 Status = AcpiUtAllocateOwnerId (&ObjDesc->Method.OwnerId);
452 if (ACPI_FAILURE (Status))
459 * Increment the method parse tree thread count since it has been
460 * reentered one more time (even if it is the same thread)
462 ObjDesc->Method.ThreadCount++;
464 return_ACPI_STATUS (Status);
468 /* On error, must release the method mutex (if present) */
470 if (ObjDesc->Method.Mutex)
472 AcpiOsReleaseMutex (ObjDesc->Method.Mutex->Mutex.OsMutex);
474 return_ACPI_STATUS (Status);
478 /*******************************************************************************
480 * FUNCTION: AcpiDsCallControlMethod
482 * PARAMETERS: Thread - Info for this thread
483 * ThisWalkState - Current walk state
484 * Op - Current Op to be walked
488 * DESCRIPTION: Transfer execution to a called control method
490 ******************************************************************************/
493 AcpiDsCallControlMethod (
494 ACPI_THREAD_STATE *Thread,
495 ACPI_WALK_STATE *ThisWalkState,
496 ACPI_PARSE_OBJECT *Op)
499 ACPI_NAMESPACE_NODE *MethodNode;
500 ACPI_WALK_STATE *NextWalkState = NULL;
501 ACPI_OPERAND_OBJECT *ObjDesc;
502 ACPI_EVALUATE_INFO *Info;
506 ACPI_FUNCTION_TRACE_PTR (DsCallControlMethod, ThisWalkState);
508 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Calling method %p, currentstate=%p\n",
509 ThisWalkState->PrevOp, ThisWalkState));
512 * Get the namespace entry for the control method we are about to call
514 MethodNode = ThisWalkState->MethodCallNode;
517 return_ACPI_STATUS (AE_NULL_ENTRY);
520 ObjDesc = AcpiNsGetAttachedObject (MethodNode);
523 return_ACPI_STATUS (AE_NULL_OBJECT);
526 /* Init for new method, possibly wait on method mutex */
528 Status = AcpiDsBeginMethodExecution (MethodNode, ObjDesc,
530 if (ACPI_FAILURE (Status))
532 return_ACPI_STATUS (Status);
535 /* Begin method parse/execution. Create a new walk state */
537 NextWalkState = AcpiDsCreateWalkState (ObjDesc->Method.OwnerId,
538 NULL, ObjDesc, Thread);
541 Status = AE_NO_MEMORY;
546 * The resolved arguments were put on the previous walk state's operand
547 * stack. Operands on the previous walk state stack always
548 * start at index 0. Also, null terminate the list of arguments
550 ThisWalkState->Operands [ThisWalkState->NumOperands] = NULL;
553 * Allocate and initialize the evaluation information block
554 * TBD: this is somewhat inefficient, should change interface to
555 * DsInitAmlWalk. For now, keeps this struct off the CPU stack
557 Info = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_EVALUATE_INFO));
560 Status = AE_NO_MEMORY;
564 Info->Parameters = &ThisWalkState->Operands[0];
566 Status = AcpiDsInitAmlWalk (NextWalkState, NULL, MethodNode,
567 ObjDesc->Method.AmlStart, ObjDesc->Method.AmlLength,
568 Info, ACPI_IMODE_EXECUTE);
571 if (ACPI_FAILURE (Status))
577 * Delete the operands on the previous walkstate operand stack
578 * (they were copied to new objects)
580 for (i = 0; i < ObjDesc->Method.ParamCount; i++)
582 AcpiUtRemoveReference (ThisWalkState->Operands [i]);
583 ThisWalkState->Operands [i] = NULL;
586 /* Clear the operand stack */
588 ThisWalkState->NumOperands = 0;
590 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
591 "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
592 MethodNode->Name.Ascii, NextWalkState));
594 /* Invoke an internal method if necessary */
596 if (ObjDesc->Method.InfoFlags & ACPI_METHOD_INTERNAL_ONLY)
598 Status = ObjDesc->Method.Dispatch.Implementation (NextWalkState);
601 Status = AE_CTRL_TERMINATE;
605 return_ACPI_STATUS (Status);
610 /* On error, we must terminate the method properly */
612 AcpiDsTerminateControlMethod (ObjDesc, NextWalkState);
615 AcpiDsDeleteWalkState (NextWalkState);
618 return_ACPI_STATUS (Status);
622 /*******************************************************************************
624 * FUNCTION: AcpiDsRestartControlMethod
626 * PARAMETERS: WalkState - State for preempted method (caller)
627 * ReturnDesc - Return value from the called method
631 * DESCRIPTION: Restart a method that was preempted by another (nested) method
632 * invocation. Handle the return value (if any) from the callee.
634 ******************************************************************************/
637 AcpiDsRestartControlMethod (
638 ACPI_WALK_STATE *WalkState,
639 ACPI_OPERAND_OBJECT *ReturnDesc)
642 int SameAsImplicitReturn;
645 ACPI_FUNCTION_TRACE_PTR (DsRestartControlMethod, WalkState);
648 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
649 "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
650 AcpiUtGetNodeName (WalkState->MethodNode),
651 WalkState->MethodCallOp, ReturnDesc));
653 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
654 " ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
655 WalkState->ReturnUsed,
656 WalkState->Results, WalkState));
658 /* Did the called method return a value? */
662 /* Is the implicit return object the same as the return desc? */
664 SameAsImplicitReturn = (WalkState->ImplicitReturnObj == ReturnDesc);
666 /* Are we actually going to use the return value? */
668 if (WalkState->ReturnUsed)
670 /* Save the return value from the previous method */
672 Status = AcpiDsResultPush (ReturnDesc, WalkState);
673 if (ACPI_FAILURE (Status))
675 AcpiUtRemoveReference (ReturnDesc);
676 return_ACPI_STATUS (Status);
680 * Save as THIS method's return value in case it is returned
681 * immediately to yet another method
683 WalkState->ReturnDesc = ReturnDesc;
687 * The following code is the optional support for the so-called
688 * "implicit return". Some AML code assumes that the last value of the
689 * method is "implicitly" returned to the caller, in the absence of an
690 * explicit return value.
692 * Just save the last result of the method as the return value.
694 * NOTE: this is optional because the ASL language does not actually
695 * support this behavior.
697 else if (!AcpiDsDoImplicitReturn (ReturnDesc, WalkState, FALSE) ||
698 SameAsImplicitReturn)
701 * Delete the return value if it will not be used by the
702 * calling method or remove one reference if the explicit return
703 * is the same as the implicit return value.
705 AcpiUtRemoveReference (ReturnDesc);
709 return_ACPI_STATUS (AE_OK);
713 /*******************************************************************************
715 * FUNCTION: AcpiDsTerminateControlMethod
717 * PARAMETERS: MethodDesc - Method object
718 * WalkState - State associated with the method
722 * DESCRIPTION: Terminate a control method. Delete everything that the method
723 * created, delete all locals and arguments, and delete the parse
726 * MUTEX: Interpreter is locked
728 ******************************************************************************/
731 AcpiDsTerminateControlMethod (
732 ACPI_OPERAND_OBJECT *MethodDesc,
733 ACPI_WALK_STATE *WalkState)
736 ACPI_FUNCTION_TRACE_PTR (DsTerminateControlMethod, WalkState);
739 /* MethodDesc is required, WalkState is optional */
748 /* Delete all arguments and locals */
750 AcpiDsMethodDataDeleteAll (WalkState);
753 * If method is serialized, release the mutex and restore the
754 * current sync level for this thread
756 if (MethodDesc->Method.Mutex)
758 /* Acquisition Depth handles recursive calls */
760 MethodDesc->Method.Mutex->Mutex.AcquisitionDepth--;
761 if (!MethodDesc->Method.Mutex->Mutex.AcquisitionDepth)
763 WalkState->Thread->CurrentSyncLevel =
764 MethodDesc->Method.Mutex->Mutex.OriginalSyncLevel;
766 AcpiOsReleaseMutex (MethodDesc->Method.Mutex->Mutex.OsMutex);
767 MethodDesc->Method.Mutex->Mutex.ThreadId = 0;
772 * Delete any namespace objects created anywhere within the
773 * namespace by the execution of this method. Unless:
774 * 1) This method is a module-level executable code method, in which
775 * case we want make the objects permanent.
776 * 2) There are other threads executing the method, in which case we
777 * will wait until the last thread has completed.
779 if (!(MethodDesc->Method.InfoFlags & ACPI_METHOD_MODULE_LEVEL) &&
780 (MethodDesc->Method.ThreadCount == 1))
782 /* Delete any direct children of (created by) this method */
784 AcpiNsDeleteNamespaceSubtree (WalkState->MethodNode);
787 * Delete any objects that were created by this method
788 * elsewhere in the namespace (if any were created).
789 * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
790 * deletion such that we don't have to perform an entire
791 * namespace walk for every control method execution.
793 if (MethodDesc->Method.InfoFlags & ACPI_METHOD_MODIFIED_NAMESPACE)
795 AcpiNsDeleteNamespaceByOwner (MethodDesc->Method.OwnerId);
796 MethodDesc->Method.InfoFlags &= ~ACPI_METHOD_MODIFIED_NAMESPACE;
801 /* Decrement the thread count on the method */
803 if (MethodDesc->Method.ThreadCount)
805 MethodDesc->Method.ThreadCount--;
809 ACPI_ERROR ((AE_INFO,
810 "Invalid zero thread count in method"));
813 /* Are there any other threads currently executing this method? */
815 if (MethodDesc->Method.ThreadCount)
818 * Additional threads. Do not release the OwnerId in this case,
819 * we immediately reuse it for the next thread executing this method
821 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
822 "*** Completed execution of one thread, %u threads remaining\n",
823 MethodDesc->Method.ThreadCount));
827 /* This is the only executing thread for this method */
830 * Support to dynamically change a method from NotSerialized to
831 * Serialized if it appears that the method is incorrectly written and
832 * does not support multiple thread execution. The best example of this
833 * is if such a method creates namespace objects and blocks. A second
834 * thread will fail with an AE_ALREADY_EXISTS exception.
836 * This code is here because we must wait until the last thread exits
837 * before marking the method as serialized.
839 if (MethodDesc->Method.InfoFlags & ACPI_METHOD_SERIALIZED_PENDING)
844 "Marking method %4.4s as Serialized because of AE_ALREADY_EXISTS error",
845 WalkState->MethodNode->Name.Ascii));
849 * Method tried to create an object twice and was marked as
850 * "pending serialized". The probable cause is that the method
851 * cannot handle reentrancy.
853 * The method was created as NotSerialized, but it tried to create
854 * a named object and then blocked, causing the second thread
855 * entrance to begin and then fail. Workaround this problem by
856 * marking the method permanently as Serialized when the last
859 MethodDesc->Method.InfoFlags &= ~ACPI_METHOD_SERIALIZED_PENDING;
860 MethodDesc->Method.InfoFlags |=
861 (ACPI_METHOD_SERIALIZED | ACPI_METHOD_IGNORE_SYNC_LEVEL);
862 MethodDesc->Method.SyncLevel = 0;
865 /* No more threads, we can free the OwnerId */
867 if (!(MethodDesc->Method.InfoFlags & ACPI_METHOD_MODULE_LEVEL))
869 AcpiUtReleaseOwnerId (&MethodDesc->Method.OwnerId);