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 "acpi.h"
48 #include "accommon.h"
49 #include "acinterp.h"
50 #include "acevents.h"
51
52 #define _COMPONENT ACPI_EXECUTER
53 ACPI_MODULE_NAME ("exmutex")
54
55 /* Local prototypes */
56
57 static void
58 AcpiExLinkMutex (
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
75 void
76 AcpiExUnlinkMutex (
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
127 static void
128 AcpiExLinkMutex (
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
178 ACPI_STATUS
179 AcpiExAcquireMutexObject (
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
251 ACPI_STATUS
252 AcpiExAcquireMutex (
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
332 ACPI_STATUS
333 AcpiExReleaseMutexObject (
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
396 ACPI_STATUS
397 AcpiExReleaseMutex (
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
510 void
511 AcpiExReleaseAllMutexes (
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 }