1
2/******************************************************************************
3 *
4 * Module Name: exmutex - ASL Mutex Acquire/Release functions
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2011, 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#define __EXMUTEX_C__
46
47#include <contrib/dev/acpica/include/acpi.h>
48#include <contrib/dev/acpica/include/accommon.h>
49#include <contrib/dev/acpica/include/acinterp.h>
50#include <contrib/dev/acpica/include/acevents.h>
51
52#define _COMPONENT          ACPI_EXECUTER
53        ACPI_MODULE_NAME    ("exmutex")
54
55/* Local prototypes */
56
57static void
58AcpiExLinkMutex (
59    ACPI_OPERAND_OBJECT     *ObjDesc,
60    ACPI_THREAD_STATE       *Thread);
61
62
63/*******************************************************************************
64 *
65 * FUNCTION:    AcpiExUnlinkMutex
66 *
67 * PARAMETERS:  ObjDesc             - The mutex to be unlinked
68 *
69 * RETURN:      None
70 *
71 * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
72 *
73 ******************************************************************************/
74
75void
76AcpiExUnlinkMutex (
77    ACPI_OPERAND_OBJECT     *ObjDesc)
78{
79    ACPI_THREAD_STATE       *Thread = ObjDesc->Mutex.OwnerThread;
80
81
82    if (!Thread)
83    {
84        return;
85    }
86
87    /* Doubly linked list */
88
89    if (ObjDesc->Mutex.Next)
90    {
91        (ObjDesc->Mutex.Next)->Mutex.Prev = ObjDesc->Mutex.Prev;
92    }
93
94    if (ObjDesc->Mutex.Prev)
95    {
96        (ObjDesc->Mutex.Prev)->Mutex.Next = ObjDesc->Mutex.Next;
97
98        /*
99         * Migrate the previous sync level associated with this mutex to
100         * the previous mutex on the list so that it may be preserved.
101         * This handles the case where several mutexes have been acquired
102         * at the same level, but are not released in opposite order.
103         */
104        (ObjDesc->Mutex.Prev)->Mutex.OriginalSyncLevel =
105            ObjDesc->Mutex.OriginalSyncLevel;
106    }
107    else
108    {
109        Thread->AcquiredMutexList = ObjDesc->Mutex.Next;
110    }
111}
112
113
114/*******************************************************************************
115 *
116 * FUNCTION:    AcpiExLinkMutex
117 *
118 * PARAMETERS:  ObjDesc             - The mutex to be linked
119 *              Thread              - Current executing thread object
120 *
121 * RETURN:      None
122 *
123 * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
124 *
125 ******************************************************************************/
126
127static void
128AcpiExLinkMutex (
129    ACPI_OPERAND_OBJECT     *ObjDesc,
130    ACPI_THREAD_STATE       *Thread)
131{
132    ACPI_OPERAND_OBJECT     *ListHead;
133
134
135    ListHead = Thread->AcquiredMutexList;
136
137    /* This object will be the first object in the list */
138
139    ObjDesc->Mutex.Prev = NULL;
140    ObjDesc->Mutex.Next = ListHead;
141
142    /* Update old first object to point back to this object */
143
144    if (ListHead)
145    {
146        ListHead->Mutex.Prev = ObjDesc;
147    }
148
149    /* Update list head */
150
151    Thread->AcquiredMutexList = ObjDesc;
152}
153
154
155/*******************************************************************************
156 *
157 * FUNCTION:    AcpiExAcquireMutexObject
158 *
159 * PARAMETERS:  Timeout             - Timeout in milliseconds
160 *              ObjDesc             - Mutex object
161 *              ThreadId            - Current thread state
162 *
163 * RETURN:      Status
164 *
165 * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common
166 *              path that supports multiple acquires by the same thread.
167 *
168 * MUTEX:       Interpreter must be locked
169 *
170 * NOTE: This interface is called from three places:
171 * 1) From AcpiExAcquireMutex, via an AML Acquire() operator
172 * 2) From AcpiExAcquireGlobalLock when an AML Field access requires the
173 *    global lock
174 * 3) From the external interface, AcpiAcquireGlobalLock
175 *
176 ******************************************************************************/
177
178ACPI_STATUS
179AcpiExAcquireMutexObject (
180    UINT16                  Timeout,
181    ACPI_OPERAND_OBJECT     *ObjDesc,
182    ACPI_THREAD_ID          ThreadId)
183{
184    ACPI_STATUS             Status;
185
186
187    ACPI_FUNCTION_TRACE_PTR (ExAcquireMutexObject, ObjDesc);
188
189
190    if (!ObjDesc)
191    {
192        return_ACPI_STATUS (AE_BAD_PARAMETER);
193    }
194
195    /* Support for multiple acquires by the owning thread */
196
197    if (ObjDesc->Mutex.ThreadId == ThreadId)
198    {
199        /*
200         * The mutex is already owned by this thread, just increment the
201         * acquisition depth
202         */
203        ObjDesc->Mutex.AcquisitionDepth++;
204        return_ACPI_STATUS (AE_OK);
205    }
206
207    /* Acquire the mutex, wait if necessary. Special case for Global Lock */
208
209    if (ObjDesc == AcpiGbl_GlobalLockMutex)
210    {
211        Status = AcpiEvAcquireGlobalLock (Timeout);
212    }
213    else
214    {
215        Status = AcpiExSystemWaitMutex (ObjDesc->Mutex.OsMutex,
216                    Timeout);
217    }
218
219    if (ACPI_FAILURE (Status))
220    {
221        /* Includes failure from a timeout on TimeDesc */
222
223        return_ACPI_STATUS (Status);
224    }
225
226    /* Acquired the mutex: update mutex object */
227
228    ObjDesc->Mutex.ThreadId = ThreadId;
229    ObjDesc->Mutex.AcquisitionDepth = 1;
230    ObjDesc->Mutex.OriginalSyncLevel = 0;
231    ObjDesc->Mutex.OwnerThread = NULL;      /* Used only for AML Acquire() */
232
233    return_ACPI_STATUS (AE_OK);
234}
235
236
237/*******************************************************************************
238 *
239 * FUNCTION:    AcpiExAcquireMutex
240 *
241 * PARAMETERS:  TimeDesc            - Timeout integer
242 *              ObjDesc             - Mutex object
243 *              WalkState           - Current method execution state
244 *
245 * RETURN:      Status
246 *
247 * DESCRIPTION: Acquire an AML mutex
248 *
249 ******************************************************************************/
250
251ACPI_STATUS
252AcpiExAcquireMutex (
253    ACPI_OPERAND_OBJECT     *TimeDesc,
254    ACPI_OPERAND_OBJECT     *ObjDesc,
255    ACPI_WALK_STATE         *WalkState)
256{
257    ACPI_STATUS             Status;
258
259
260    ACPI_FUNCTION_TRACE_PTR (ExAcquireMutex, ObjDesc);
261
262
263    if (!ObjDesc)
264    {
265        return_ACPI_STATUS (AE_BAD_PARAMETER);
266    }
267
268    /* Must have a valid thread state struct */
269
270    if (!WalkState->Thread)
271    {
272        ACPI_ERROR ((AE_INFO,
273            "Cannot acquire Mutex [%4.4s], null thread info",
274            AcpiUtGetNodeName (ObjDesc->Mutex.Node)));
275        return_ACPI_STATUS (AE_AML_INTERNAL);
276    }
277
278    /*
279     * Current sync level must be less than or equal to the sync level of the
280     * mutex. This mechanism provides some deadlock prevention
281     */
282    if (WalkState->Thread->CurrentSyncLevel > ObjDesc->Mutex.SyncLevel)
283    {
284        ACPI_ERROR ((AE_INFO,
285            "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%u)",
286            AcpiUtGetNodeName (ObjDesc->Mutex.Node),
287            WalkState->Thread->CurrentSyncLevel));
288        return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
289    }
290
291    Status = AcpiExAcquireMutexObject ((UINT16) TimeDesc->Integer.Value,
292                ObjDesc, WalkState->Thread->ThreadId);
293    if (ACPI_SUCCESS (Status) && ObjDesc->Mutex.AcquisitionDepth == 1)
294    {
295        /* Save Thread object, original/current sync levels */
296
297        ObjDesc->Mutex.OwnerThread = WalkState->Thread;
298        ObjDesc->Mutex.OriginalSyncLevel = WalkState->Thread->CurrentSyncLevel;
299        WalkState->Thread->CurrentSyncLevel = ObjDesc->Mutex.SyncLevel;
300
301        /* Link the mutex to the current thread for force-unlock at method exit */
302
303        AcpiExLinkMutex (ObjDesc, WalkState->Thread);
304    }
305
306    return_ACPI_STATUS (Status);
307}
308
309
310/*******************************************************************************
311 *
312 * FUNCTION:    AcpiExReleaseMutexObject
313 *
314 * PARAMETERS:  ObjDesc             - The object descriptor for this op
315 *
316 * RETURN:      Status
317 *
318 * DESCRIPTION: Release a previously acquired Mutex, low level interface.
319 *              Provides a common path that supports multiple releases (after
320 *              previous multiple acquires) by the same thread.
321 *
322 * MUTEX:       Interpreter must be locked
323 *
324 * NOTE: This interface is called from three places:
325 * 1) From AcpiExReleaseMutex, via an AML Acquire() operator
326 * 2) From AcpiExReleaseGlobalLock when an AML Field access requires the
327 *    global lock
328 * 3) From the external interface, AcpiReleaseGlobalLock
329 *
330 ******************************************************************************/
331
332ACPI_STATUS
333AcpiExReleaseMutexObject (
334    ACPI_OPERAND_OBJECT     *ObjDesc)
335{
336    ACPI_STATUS             Status = AE_OK;
337
338
339    ACPI_FUNCTION_TRACE (ExReleaseMutexObject);
340
341
342    if (ObjDesc->Mutex.AcquisitionDepth == 0)
343    {
344        return (AE_NOT_ACQUIRED);
345    }
346
347    /* Match multiple Acquires with multiple Releases */
348
349    ObjDesc->Mutex.AcquisitionDepth--;
350    if (ObjDesc->Mutex.AcquisitionDepth != 0)
351    {
352        /* Just decrement the depth and return */
353
354        return_ACPI_STATUS (AE_OK);
355    }
356
357    if (ObjDesc->Mutex.OwnerThread)
358    {
359        /* Unlink the mutex from the owner's list */
360
361        AcpiExUnlinkMutex (ObjDesc);
362        ObjDesc->Mutex.OwnerThread = NULL;
363    }
364
365    /* Release the mutex, special case for Global Lock */
366
367    if (ObjDesc == AcpiGbl_GlobalLockMutex)
368    {
369        Status = AcpiEvReleaseGlobalLock ();
370    }
371    else
372    {
373        AcpiOsReleaseMutex (ObjDesc->Mutex.OsMutex);
374    }
375
376    /* Clear mutex info */
377
378    ObjDesc->Mutex.ThreadId = 0;
379    return_ACPI_STATUS (Status);
380}
381
382
383/*******************************************************************************
384 *
385 * FUNCTION:    AcpiExReleaseMutex
386 *
387 * PARAMETERS:  ObjDesc             - The object descriptor for this op
388 *              WalkState           - Current method execution state
389 *
390 * RETURN:      Status
391 *
392 * DESCRIPTION: Release a previously acquired Mutex.
393 *
394 ******************************************************************************/
395
396ACPI_STATUS
397AcpiExReleaseMutex (
398    ACPI_OPERAND_OBJECT     *ObjDesc,
399    ACPI_WALK_STATE         *WalkState)
400{
401    ACPI_STATUS             Status = AE_OK;
402    UINT8                   PreviousSyncLevel;
403    ACPI_THREAD_STATE       *OwnerThread;
404
405
406    ACPI_FUNCTION_TRACE (ExReleaseMutex);
407
408
409    if (!ObjDesc)
410    {
411        return_ACPI_STATUS (AE_BAD_PARAMETER);
412    }
413
414    OwnerThread = ObjDesc->Mutex.OwnerThread;
415
416    /* The mutex must have been previously acquired in order to release it */
417
418    if (!OwnerThread)
419    {
420        ACPI_ERROR ((AE_INFO,
421            "Cannot release Mutex [%4.4s], not acquired",
422            AcpiUtGetNodeName (ObjDesc->Mutex.Node)));
423        return_ACPI_STATUS (AE_AML_MUTEX_NOT_ACQUIRED);
424    }
425
426    /* Must have a valid thread ID */
427
428    if (!WalkState->Thread)
429    {
430        ACPI_ERROR ((AE_INFO,
431            "Cannot release Mutex [%4.4s], null thread info",
432            AcpiUtGetNodeName (ObjDesc->Mutex.Node)));
433        return_ACPI_STATUS (AE_AML_INTERNAL);
434    }
435
436    /*
437     * The Mutex is owned, but this thread must be the owner.
438     * Special case for Global Lock, any thread can release
439     */
440    if ((OwnerThread->ThreadId != WalkState->Thread->ThreadId) &&
441        (ObjDesc != AcpiGbl_GlobalLockMutex))
442    {
443        ACPI_ERROR ((AE_INFO,
444            "Thread %u cannot release Mutex [%4.4s] acquired by thread %u",
445            (UINT32) WalkState->Thread->ThreadId,
446            AcpiUtGetNodeName (ObjDesc->Mutex.Node),
447            (UINT32) OwnerThread->ThreadId));
448        return_ACPI_STATUS (AE_AML_NOT_OWNER);
449    }
450
451    /*
452     * The sync level of the mutex must be equal to the current sync level. In
453     * other words, the current level means that at least one mutex at that
454     * level is currently being held. Attempting to release a mutex of a
455     * different level can only mean that the mutex ordering rule is being
456     * violated. This behavior is clarified in ACPI 4.0 specification.
457     */
458    if (ObjDesc->Mutex.SyncLevel != OwnerThread->CurrentSyncLevel)
459    {
460        ACPI_ERROR ((AE_INFO,
461            "Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %u current %u",
462            AcpiUtGetNodeName (ObjDesc->Mutex.Node),
463            ObjDesc->Mutex.SyncLevel, WalkState->Thread->CurrentSyncLevel));
464        return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
465    }
466
467    /*
468     * Get the previous SyncLevel from the head of the acquired mutex list.
469     * This handles the case where several mutexes at the same level have been
470     * acquired, but are not released in reverse order.
471     */
472    PreviousSyncLevel =
473        OwnerThread->AcquiredMutexList->Mutex.OriginalSyncLevel;
474
475    Status = AcpiExReleaseMutexObject (ObjDesc);
476    if (ACPI_FAILURE (Status))
477    {
478        return_ACPI_STATUS (Status);
479    }
480
481    if (ObjDesc->Mutex.AcquisitionDepth == 0)
482    {
483        /* Restore the previous SyncLevel */
484
485        OwnerThread->CurrentSyncLevel = PreviousSyncLevel;
486    }
487
488    return_ACPI_STATUS (Status);
489}
490
491
492/*******************************************************************************
493 *
494 * FUNCTION:    AcpiExReleaseAllMutexes
495 *
496 * PARAMETERS:  Thread              - Current executing thread object
497 *
498 * RETURN:      Status
499 *
500 * DESCRIPTION: Release all mutexes held by this thread
501 *
502 * NOTE: This function is called as the thread is exiting the interpreter.
503 * Mutexes are not released when an individual control method is exited, but
504 * only when the parent thread actually exits the interpreter. This allows one
505 * method to acquire a mutex, and a different method to release it, as long as
506 * this is performed underneath a single parent control method.
507 *
508 ******************************************************************************/
509
510void
511AcpiExReleaseAllMutexes (
512    ACPI_THREAD_STATE       *Thread)
513{
514    ACPI_OPERAND_OBJECT     *Next = Thread->AcquiredMutexList;
515    ACPI_OPERAND_OBJECT     *ObjDesc;
516
517
518    ACPI_FUNCTION_ENTRY ();
519
520
521    /* Traverse the list of owned mutexes, releasing each one */
522
523    while (Next)
524    {
525        ObjDesc = Next;
526        Next = ObjDesc->Mutex.Next;
527
528        ObjDesc->Mutex.Prev = NULL;
529        ObjDesc->Mutex.Next = NULL;
530        ObjDesc->Mutex.AcquisitionDepth = 0;
531
532        /* Release the mutex, special case for Global Lock */
533
534        if (ObjDesc == AcpiGbl_GlobalLockMutex)
535        {
536            /* Ignore errors */
537
538            (void) AcpiEvReleaseGlobalLock ();
539        }
540        else
541        {
542            AcpiOsReleaseMutex (ObjDesc->Mutex.OsMutex);
543        }
544
545        /* Mark mutex unowned */
546
547        ObjDesc->Mutex.OwnerThread = NULL;
548        ObjDesc->Mutex.ThreadId = 0;
549
550        /* Update Thread SyncLevel (Last mutex is the important one) */
551
552        Thread->CurrentSyncLevel = ObjDesc->Mutex.OriginalSyncLevel;
553    }
554}
555