xref: /illumos-gate/usr/src/common/acpica/executer/exmutex.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
1 /******************************************************************************
2  *
3  * Module Name: exmutex - ASL Mutex Acquire/Release functions
4  *
5  *****************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2018, Intel Corp.
12  * All rights reserved.
13  *
14  * 2. License
15  *
16  * 2.1. This is your license from Intel Corp. under its intellectual property
17  * rights. You may have additional license terms from the party that provided
18  * you this software, covering your right to use that party's intellectual
19  * property rights.
20  *
21  * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
22  * copy of the source code appearing in this file ("Covered Code") an
23  * irrevocable, perpetual, worldwide license under Intel's copyrights in the
24  * base code distributed originally by Intel ("Original Intel Code") to copy,
25  * make derivatives, distribute, use and display any portion of the Covered
26  * Code in any form, with the right to sublicense such rights; and
27  *
28  * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
29  * license (with the right to sublicense), under only those claims of Intel
30  * patents that are infringed by the Original Intel Code, to make, use, sell,
31  * offer to sell, and import the Covered Code and derivative works thereof
32  * solely to the minimum extent necessary to exercise the above copyright
33  * license, and in no event shall the patent license extend to any additions
34  * to or modifications of the Original Intel Code. No other license or right
35  * is granted directly or by implication, estoppel or otherwise;
36  *
37  * The above copyright and patent license is granted only if the following
38  * conditions are met:
39  *
40  * 3. Conditions
41  *
42  * 3.1. Redistribution of Source with Rights to Further Distribute Source.
43  * Redistribution of source code of any substantial portion of the Covered
44  * Code or modification with rights to further distribute source must include
45  * the above Copyright Notice, the above License, this list of Conditions,
46  * and the following Disclaimer and Export Compliance provision. In addition,
47  * Licensee must cause all Covered Code to which Licensee contributes to
48  * contain a file documenting the changes Licensee made to create that Covered
49  * Code and the date of any change. Licensee must include in that file the
50  * documentation of any changes made by any predecessor Licensee. Licensee
51  * must include a prominent statement that the modification is derived,
52  * directly or indirectly, from Original Intel Code.
53  *
54  * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
55  * Redistribution of source code of any substantial portion of the Covered
56  * Code or modification without rights to further distribute source must
57  * include the following Disclaimer and Export Compliance provision in the
58  * documentation and/or other materials provided with distribution. In
59  * addition, Licensee may not authorize further sublicense of source of any
60  * portion of the Covered Code, and must include terms to the effect that the
61  * license from Licensee to its licensee is limited to the intellectual
62  * property embodied in the software Licensee provides to its licensee, and
63  * not to intellectual property embodied in modifications its licensee may
64  * make.
65  *
66  * 3.3. Redistribution of Executable. Redistribution in executable form of any
67  * substantial portion of the Covered Code or modification must reproduce the
68  * above Copyright Notice, and the following Disclaimer and Export Compliance
69  * provision in the documentation and/or other materials provided with the
70  * distribution.
71  *
72  * 3.4. Intel retains all right, title, and interest in and to the Original
73  * Intel Code.
74  *
75  * 3.5. Neither the name Intel nor any other trademark owned or controlled by
76  * Intel shall be used in advertising or otherwise to promote the sale, use or
77  * other dealings in products derived from or relating to the Covered Code
78  * without prior written authorization from Intel.
79  *
80  * 4. Disclaimer and Export Compliance
81  *
82  * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
83  * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
84  * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
85  * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
86  * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
87  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
88  * PARTICULAR PURPOSE.
89  *
90  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
91  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
92  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
93  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
94  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
95  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
96  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
97  * LIMITED REMEDY.
98  *
99  * 4.3. Licensee shall not export, either directly or indirectly, any of this
100  * software or system incorporating such software without first obtaining any
101  * required license or other approval from the U. S. Department of Commerce or
102  * any other agency or department of the United States Government. In the
103  * event Licensee exports any such software from the United States or
104  * re-exports any such software from a foreign destination, Licensee shall
105  * ensure that the distribution and export/re-export of the software is in
106  * compliance with all laws, regulations, orders, or other restrictions of the
107  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
108  * any of its subsidiaries will export/re-export any technical data, process,
109  * software, or service, directly or indirectly, to any country for which the
110  * United States government or any agency thereof requires an export license,
111  * other governmental approval, or letter of assurance, without first obtaining
112  * such license, approval or letter.
113  *
114  *****************************************************************************
115  *
116  * Alternatively, you may choose to be licensed under the terms of the
117  * following license:
118  *
119  * Redistribution and use in source and binary forms, with or without
120  * modification, are permitted provided that the following conditions
121  * are met:
122  * 1. Redistributions of source code must retain the above copyright
123  *    notice, this list of conditions, and the following disclaimer,
124  *    without modification.
125  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
126  *    substantially similar to the "NO WARRANTY" disclaimer below
127  *    ("Disclaimer") and any redistribution must be conditioned upon
128  *    including a substantially similar Disclaimer requirement for further
129  *    binary redistribution.
130  * 3. Neither the names of the above-listed copyright holders nor the names
131  *    of any contributors may be used to endorse or promote products derived
132  *    from this software without specific prior written permission.
133  *
134  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
135  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
136  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
137  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
138  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
139  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
140  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
141  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
142  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
143  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
144  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
145  *
146  * Alternatively, you may choose to be licensed under the terms of the
147  * GNU General Public License ("GPL") version 2 as published by the Free
148  * Software Foundation.
149  *
150  *****************************************************************************/
151 
152 #include "acpi.h"
153 #include "accommon.h"
154 #include "acinterp.h"
155 #include "acevents.h"
156 
157 #define _COMPONENT          ACPI_EXECUTER
158         ACPI_MODULE_NAME    ("exmutex")
159 
160 /* Local prototypes */
161 
162 static void
163 AcpiExLinkMutex (
164     ACPI_OPERAND_OBJECT     *ObjDesc,
165     ACPI_THREAD_STATE       *Thread);
166 
167 
168 /*******************************************************************************
169  *
170  * FUNCTION:    AcpiExUnlinkMutex
171  *
172  * PARAMETERS:  ObjDesc             - The mutex to be unlinked
173  *
174  * RETURN:      None
175  *
176  * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
177  *
178  ******************************************************************************/
179 
180 void
181 AcpiExUnlinkMutex (
182     ACPI_OPERAND_OBJECT     *ObjDesc)
183 {
184     ACPI_THREAD_STATE       *Thread = ObjDesc->Mutex.OwnerThread;
185 
186 
187     if (!Thread)
188     {
189         return;
190     }
191 
192     /* Doubly linked list */
193 
194     if (ObjDesc->Mutex.Next)
195     {
196         (ObjDesc->Mutex.Next)->Mutex.Prev = ObjDesc->Mutex.Prev;
197     }
198 
199     if (ObjDesc->Mutex.Prev)
200     {
201         (ObjDesc->Mutex.Prev)->Mutex.Next = ObjDesc->Mutex.Next;
202 
203         /*
204          * Migrate the previous sync level associated with this mutex to
205          * the previous mutex on the list so that it may be preserved.
206          * This handles the case where several mutexes have been acquired
207          * at the same level, but are not released in opposite order.
208          */
209         (ObjDesc->Mutex.Prev)->Mutex.OriginalSyncLevel =
210             ObjDesc->Mutex.OriginalSyncLevel;
211     }
212     else
213     {
214         Thread->AcquiredMutexList = ObjDesc->Mutex.Next;
215     }
216 }
217 
218 
219 /*******************************************************************************
220  *
221  * FUNCTION:    AcpiExLinkMutex
222  *
223  * PARAMETERS:  ObjDesc             - The mutex to be linked
224  *              Thread              - Current executing thread object
225  *
226  * RETURN:      None
227  *
228  * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
229  *
230  ******************************************************************************/
231 
232 static void
233 AcpiExLinkMutex (
234     ACPI_OPERAND_OBJECT     *ObjDesc,
235     ACPI_THREAD_STATE       *Thread)
236 {
237     ACPI_OPERAND_OBJECT     *ListHead;
238 
239 
240     ListHead = Thread->AcquiredMutexList;
241 
242     /* This object will be the first object in the list */
243 
244     ObjDesc->Mutex.Prev = NULL;
245     ObjDesc->Mutex.Next = ListHead;
246 
247     /* Update old first object to point back to this object */
248 
249     if (ListHead)
250     {
251         ListHead->Mutex.Prev = ObjDesc;
252     }
253 
254     /* Update list head */
255 
256     Thread->AcquiredMutexList = ObjDesc;
257 }
258 
259 
260 /*******************************************************************************
261  *
262  * FUNCTION:    AcpiExAcquireMutexObject
263  *
264  * PARAMETERS:  Timeout             - Timeout in milliseconds
265  *              ObjDesc             - Mutex object
266  *              ThreadId            - Current thread state
267  *
268  * RETURN:      Status
269  *
270  * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common
271  *              path that supports multiple acquires by the same thread.
272  *
273  * MUTEX:       Interpreter must be locked
274  *
275  * NOTE: This interface is called from three places:
276  * 1) From AcpiExAcquireMutex, via an AML Acquire() operator
277  * 2) From AcpiExAcquireGlobalLock when an AML Field access requires the
278  *    global lock
279  * 3) From the external interface, AcpiAcquireGlobalLock
280  *
281  ******************************************************************************/
282 
283 ACPI_STATUS
284 AcpiExAcquireMutexObject (
285     UINT16                  Timeout,
286     ACPI_OPERAND_OBJECT     *ObjDesc,
287     ACPI_THREAD_ID          ThreadId)
288 {
289     ACPI_STATUS             Status;
290 
291 
292     ACPI_FUNCTION_TRACE_PTR (ExAcquireMutexObject, ObjDesc);
293 
294 
295     if (!ObjDesc)
296     {
297         return_ACPI_STATUS (AE_BAD_PARAMETER);
298     }
299 
300     /* Support for multiple acquires by the owning thread */
301 
302     if (ObjDesc->Mutex.ThreadId == ThreadId)
303     {
304         /*
305          * The mutex is already owned by this thread, just increment the
306          * acquisition depth
307          */
308         ObjDesc->Mutex.AcquisitionDepth++;
309         return_ACPI_STATUS (AE_OK);
310     }
311 
312     /* Acquire the mutex, wait if necessary. Special case for Global Lock */
313 
314     if (ObjDesc == AcpiGbl_GlobalLockMutex)
315     {
316         Status = AcpiEvAcquireGlobalLock (Timeout);
317     }
318     else
319     {
320         Status = AcpiExSystemWaitMutex (ObjDesc->Mutex.OsMutex, Timeout);
321     }
322 
323     if (ACPI_FAILURE (Status))
324     {
325         /* Includes failure from a timeout on TimeDesc */
326 
327         return_ACPI_STATUS (Status);
328     }
329 
330     /* Acquired the mutex: update mutex object */
331 
332     ObjDesc->Mutex.ThreadId = ThreadId;
333     ObjDesc->Mutex.AcquisitionDepth = 1;
334     ObjDesc->Mutex.OriginalSyncLevel = 0;
335     ObjDesc->Mutex.OwnerThread = NULL;      /* Used only for AML Acquire() */
336 
337     return_ACPI_STATUS (AE_OK);
338 }
339 
340 
341 /*******************************************************************************
342  *
343  * FUNCTION:    AcpiExAcquireMutex
344  *
345  * PARAMETERS:  TimeDesc            - Timeout integer
346  *              ObjDesc             - Mutex object
347  *              WalkState           - Current method execution state
348  *
349  * RETURN:      Status
350  *
351  * DESCRIPTION: Acquire an AML mutex
352  *
353  ******************************************************************************/
354 
355 ACPI_STATUS
356 AcpiExAcquireMutex (
357     ACPI_OPERAND_OBJECT     *TimeDesc,
358     ACPI_OPERAND_OBJECT     *ObjDesc,
359     ACPI_WALK_STATE         *WalkState)
360 {
361     ACPI_STATUS             Status;
362 
363 
364     ACPI_FUNCTION_TRACE_PTR (ExAcquireMutex, ObjDesc);
365 
366 
367     if (!ObjDesc)
368     {
369         return_ACPI_STATUS (AE_BAD_PARAMETER);
370     }
371 
372     /* Must have a valid thread state struct */
373 
374     if (!WalkState->Thread)
375     {
376         ACPI_ERROR ((AE_INFO,
377             "Cannot acquire Mutex [%4.4s], null thread info",
378             AcpiUtGetNodeName (ObjDesc->Mutex.Node)));
379         return_ACPI_STATUS (AE_AML_INTERNAL);
380     }
381 
382     /*
383      * Current sync level must be less than or equal to the sync level
384      * of the mutex. This mechanism provides some deadlock prevention.
385      */
386     if (WalkState->Thread->CurrentSyncLevel > ObjDesc->Mutex.SyncLevel)
387     {
388         ACPI_ERROR ((AE_INFO,
389             "Cannot acquire Mutex [%4.4s], "
390             "current SyncLevel is too large (%u)",
391             AcpiUtGetNodeName (ObjDesc->Mutex.Node),
392             WalkState->Thread->CurrentSyncLevel));
393         return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
394     }
395 
396     ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
397         "Acquiring: Mutex SyncLevel %u, Thread SyncLevel %u, "
398         "Depth %u TID %p\n",
399         ObjDesc->Mutex.SyncLevel, WalkState->Thread->CurrentSyncLevel,
400         ObjDesc->Mutex.AcquisitionDepth, WalkState->Thread));
401 
402     Status = AcpiExAcquireMutexObject ((UINT16) TimeDesc->Integer.Value,
403         ObjDesc, WalkState->Thread->ThreadId);
404 
405     if (ACPI_SUCCESS (Status) && ObjDesc->Mutex.AcquisitionDepth == 1)
406     {
407         /* Save Thread object, original/current sync levels */
408 
409         ObjDesc->Mutex.OwnerThread = WalkState->Thread;
410         ObjDesc->Mutex.OriginalSyncLevel =
411             WalkState->Thread->CurrentSyncLevel;
412         WalkState->Thread->CurrentSyncLevel =
413             ObjDesc->Mutex.SyncLevel;
414 
415         /* Link the mutex to the current thread for force-unlock at method exit */
416 
417         AcpiExLinkMutex (ObjDesc, WalkState->Thread);
418     }
419 
420     ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
421         "Acquired: Mutex SyncLevel %u, Thread SyncLevel %u, Depth %u\n",
422         ObjDesc->Mutex.SyncLevel, WalkState->Thread->CurrentSyncLevel,
423         ObjDesc->Mutex.AcquisitionDepth));
424 
425     return_ACPI_STATUS (Status);
426 }
427 
428 
429 /*******************************************************************************
430  *
431  * FUNCTION:    AcpiExReleaseMutexObject
432  *
433  * PARAMETERS:  ObjDesc             - The object descriptor for this op
434  *
435  * RETURN:      Status
436  *
437  * DESCRIPTION: Release a previously acquired Mutex, low level interface.
438  *              Provides a common path that supports multiple releases (after
439  *              previous multiple acquires) by the same thread.
440  *
441  * MUTEX:       Interpreter must be locked
442  *
443  * NOTE: This interface is called from three places:
444  * 1) From AcpiExReleaseMutex, via an AML Acquire() operator
445  * 2) From AcpiExReleaseGlobalLock when an AML Field access requires the
446  *    global lock
447  * 3) From the external interface, AcpiReleaseGlobalLock
448  *
449  ******************************************************************************/
450 
451 ACPI_STATUS
452 AcpiExReleaseMutexObject (
453     ACPI_OPERAND_OBJECT     *ObjDesc)
454 {
455     ACPI_STATUS             Status = AE_OK;
456 
457 
458     ACPI_FUNCTION_TRACE (ExReleaseMutexObject);
459 
460 
461     if (ObjDesc->Mutex.AcquisitionDepth == 0)
462     {
463         return_ACPI_STATUS (AE_NOT_ACQUIRED);
464     }
465 
466     /* Match multiple Acquires with multiple Releases */
467 
468     ObjDesc->Mutex.AcquisitionDepth--;
469     if (ObjDesc->Mutex.AcquisitionDepth != 0)
470     {
471         /* Just decrement the depth and return */
472 
473         return_ACPI_STATUS (AE_OK);
474     }
475 
476     if (ObjDesc->Mutex.OwnerThread)
477     {
478         /* Unlink the mutex from the owner's list */
479 
480         AcpiExUnlinkMutex (ObjDesc);
481         ObjDesc->Mutex.OwnerThread = NULL;
482     }
483 
484     /* Release the mutex, special case for Global Lock */
485 
486     if (ObjDesc == AcpiGbl_GlobalLockMutex)
487     {
488         Status = AcpiEvReleaseGlobalLock ();
489     }
490     else
491     {
492         AcpiOsReleaseMutex (ObjDesc->Mutex.OsMutex);
493     }
494 
495     /* Clear mutex info */
496 
497     ObjDesc->Mutex.ThreadId = 0;
498     return_ACPI_STATUS (Status);
499 }
500 
501 
502 /*******************************************************************************
503  *
504  * FUNCTION:    AcpiExReleaseMutex
505  *
506  * PARAMETERS:  ObjDesc             - The object descriptor for this op
507  *              WalkState           - Current method execution state
508  *
509  * RETURN:      Status
510  *
511  * DESCRIPTION: Release a previously acquired Mutex.
512  *
513  ******************************************************************************/
514 
515 ACPI_STATUS
516 AcpiExReleaseMutex (
517     ACPI_OPERAND_OBJECT     *ObjDesc,
518     ACPI_WALK_STATE         *WalkState)
519 {
520     UINT8                   PreviousSyncLevel;
521     ACPI_THREAD_STATE       *OwnerThread;
522     ACPI_STATUS             Status = AE_OK;
523 
524 
525     ACPI_FUNCTION_TRACE (ExReleaseMutex);
526 
527 
528     if (!ObjDesc)
529     {
530         return_ACPI_STATUS (AE_BAD_PARAMETER);
531     }
532 
533     OwnerThread = ObjDesc->Mutex.OwnerThread;
534 
535     /* The mutex must have been previously acquired in order to release it */
536 
537     if (!OwnerThread)
538     {
539         ACPI_ERROR ((AE_INFO,
540             "Cannot release Mutex [%4.4s], not acquired",
541             AcpiUtGetNodeName (ObjDesc->Mutex.Node)));
542         return_ACPI_STATUS (AE_AML_MUTEX_NOT_ACQUIRED);
543     }
544 
545     /* Must have a valid thread ID */
546 
547     if (!WalkState->Thread)
548     {
549         ACPI_ERROR ((AE_INFO,
550             "Cannot release Mutex [%4.4s], null thread info",
551             AcpiUtGetNodeName (ObjDesc->Mutex.Node)));
552         return_ACPI_STATUS (AE_AML_INTERNAL);
553     }
554 
555     /*
556      * The Mutex is owned, but this thread must be the owner.
557      * Special case for Global Lock, any thread can release
558      */
559     if ((OwnerThread->ThreadId != WalkState->Thread->ThreadId) &&
560         (ObjDesc != AcpiGbl_GlobalLockMutex))
561     {
562         ACPI_ERROR ((AE_INFO,
563             "Thread %u cannot release Mutex [%4.4s] acquired by thread %u",
564             (UINT32) WalkState->Thread->ThreadId,
565             AcpiUtGetNodeName (ObjDesc->Mutex.Node),
566             (UINT32) OwnerThread->ThreadId));
567         return_ACPI_STATUS (AE_AML_NOT_OWNER);
568     }
569 
570     /*
571      * The sync level of the mutex must be equal to the current sync level. In
572      * other words, the current level means that at least one mutex at that
573      * level is currently being held. Attempting to release a mutex of a
574      * different level can only mean that the mutex ordering rule is being
575      * violated. This behavior is clarified in ACPI 4.0 specification.
576      */
577     if (ObjDesc->Mutex.SyncLevel != OwnerThread->CurrentSyncLevel)
578     {
579         ACPI_ERROR ((AE_INFO,
580             "Cannot release Mutex [%4.4s], SyncLevel mismatch: "
581             "mutex %u current %u",
582             AcpiUtGetNodeName (ObjDesc->Mutex.Node),
583             ObjDesc->Mutex.SyncLevel, WalkState->Thread->CurrentSyncLevel));
584         return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
585     }
586 
587     /*
588      * Get the previous SyncLevel from the head of the acquired mutex list.
589      * This handles the case where several mutexes at the same level have been
590      * acquired, but are not released in reverse order.
591      */
592     PreviousSyncLevel =
593         OwnerThread->AcquiredMutexList->Mutex.OriginalSyncLevel;
594 
595     ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
596         "Releasing: Object SyncLevel %u, Thread SyncLevel %u, "
597         "Prev SyncLevel %u, Depth %u TID %p\n",
598         ObjDesc->Mutex.SyncLevel, WalkState->Thread->CurrentSyncLevel,
599         PreviousSyncLevel, ObjDesc->Mutex.AcquisitionDepth,
600         WalkState->Thread));
601 
602     Status = AcpiExReleaseMutexObject (ObjDesc);
603     if (ACPI_FAILURE (Status))
604     {
605         return_ACPI_STATUS (Status);
606     }
607 
608     if (ObjDesc->Mutex.AcquisitionDepth == 0)
609     {
610         /* Restore the previous SyncLevel */
611 
612         OwnerThread->CurrentSyncLevel = PreviousSyncLevel;
613     }
614 
615     ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
616         "Released: Object SyncLevel %u, Thread SyncLevel, %u, "
617         "Prev SyncLevel %u, Depth %u\n",
618         ObjDesc->Mutex.SyncLevel, WalkState->Thread->CurrentSyncLevel,
619         PreviousSyncLevel, ObjDesc->Mutex.AcquisitionDepth));
620 
621     return_ACPI_STATUS (Status);
622 }
623 
624 
625 /*******************************************************************************
626  *
627  * FUNCTION:    AcpiExReleaseAllMutexes
628  *
629  * PARAMETERS:  Thread              - Current executing thread object
630  *
631  * RETURN:      Status
632  *
633  * DESCRIPTION: Release all mutexes held by this thread
634  *
635  * NOTE: This function is called as the thread is exiting the interpreter.
636  * Mutexes are not released when an individual control method is exited, but
637  * only when the parent thread actually exits the interpreter. This allows one
638  * method to acquire a mutex, and a different method to release it, as long as
639  * this is performed underneath a single parent control method.
640  *
641  ******************************************************************************/
642 
643 void
644 AcpiExReleaseAllMutexes (
645     ACPI_THREAD_STATE       *Thread)
646 {
647     ACPI_OPERAND_OBJECT     *Next = Thread->AcquiredMutexList;
648     ACPI_OPERAND_OBJECT     *ObjDesc;
649 
650 
651     ACPI_FUNCTION_TRACE (ExReleaseAllMutexes);
652 
653 
654     /* Traverse the list of owned mutexes, releasing each one */
655 
656     while (Next)
657     {
658         ObjDesc = Next;
659         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
660             "Mutex [%4.4s] force-release, SyncLevel %u Depth %u\n",
661             ObjDesc->Mutex.Node->Name.Ascii, ObjDesc->Mutex.SyncLevel,
662             ObjDesc->Mutex.AcquisitionDepth));
663 
664         /* Release the mutex, special case for Global Lock */
665 
666         if (ObjDesc == AcpiGbl_GlobalLockMutex)
667         {
668             /* Ignore errors */
669 
670             (void) AcpiEvReleaseGlobalLock ();
671         }
672         else
673         {
674             AcpiOsReleaseMutex (ObjDesc->Mutex.OsMutex);
675         }
676 
677         /* Update Thread SyncLevel (Last mutex is the important one) */
678 
679         Thread->CurrentSyncLevel = ObjDesc->Mutex.OriginalSyncLevel;
680 
681         /* Mark mutex unowned */
682 
683         Next = ObjDesc->Mutex.Next;
684 
685         ObjDesc->Mutex.Prev = NULL;
686         ObjDesc->Mutex.Next = NULL;
687         ObjDesc->Mutex.AcquisitionDepth = 0;
688         ObjDesc->Mutex.OwnerThread = NULL;
689         ObjDesc->Mutex.ThreadId = 0;
690     }
691 
692     return_VOID;
693 }
694