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1
2 /******************************************************************************
3  *
4  * Module Name: exmutex - ASL Mutex Acquire/Release functions
5  *
6  *****************************************************************************/
7
8 /*
9  * Copyright (C) 2000 - 2008, 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 #include <acpi/acpi.h>
46 #include <acpi/acinterp.h>
47 #include <acpi/acevents.h>
48
49 #define _COMPONENT          ACPI_EXECUTER
50 ACPI_MODULE_NAME("exmutex")
51
52 /* Local prototypes */
53 static void
54 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
55                    struct acpi_thread_state *thread);
56
57 /*******************************************************************************
58  *
59  * FUNCTION:    acpi_ex_unlink_mutex
60  *
61  * PARAMETERS:  obj_desc            - The mutex to be unlinked
62  *
63  * RETURN:      None
64  *
65  * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
66  *
67  ******************************************************************************/
68
69 void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)
70 {
71         struct acpi_thread_state *thread = obj_desc->mutex.owner_thread;
72
73         if (!thread) {
74                 return;
75         }
76
77         /* Doubly linked list */
78
79         if (obj_desc->mutex.next) {
80                 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
81         }
82
83         if (obj_desc->mutex.prev) {
84                 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
85         } else {
86                 thread->acquired_mutex_list = obj_desc->mutex.next;
87         }
88 }
89
90 /*******************************************************************************
91  *
92  * FUNCTION:    acpi_ex_link_mutex
93  *
94  * PARAMETERS:  obj_desc        - The mutex to be linked
95  *              Thread          - Current executing thread object
96  *
97  * RETURN:      None
98  *
99  * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
100  *
101  ******************************************************************************/
102
103 static void
104 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
105                    struct acpi_thread_state *thread)
106 {
107         union acpi_operand_object *list_head;
108
109         list_head = thread->acquired_mutex_list;
110
111         /* This object will be the first object in the list */
112
113         obj_desc->mutex.prev = NULL;
114         obj_desc->mutex.next = list_head;
115
116         /* Update old first object to point back to this object */
117
118         if (list_head) {
119                 list_head->mutex.prev = obj_desc;
120         }
121
122         /* Update list head */
123
124         thread->acquired_mutex_list = obj_desc;
125 }
126
127 /*******************************************************************************
128  *
129  * FUNCTION:    acpi_ex_acquire_mutex_object
130  *
131  * PARAMETERS:  time_desc           - Timeout in milliseconds
132  *              obj_desc            - Mutex object
133  *              Thread              - Current thread state
134  *
135  * RETURN:      Status
136  *
137  * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common
138  *              path that supports multiple acquires by the same thread.
139  *
140  * MUTEX:       Interpreter must be locked
141  *
142  * NOTE: This interface is called from three places:
143  * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator
144  * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the
145  *    global lock
146  * 3) From the external interface, acpi_acquire_global_lock
147  *
148  ******************************************************************************/
149
150 acpi_status
151 acpi_ex_acquire_mutex_object(u16 timeout,
152                              union acpi_operand_object *obj_desc,
153                              acpi_thread_id thread_id)
154 {
155         acpi_status status;
156
157         ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc);
158
159         if (!obj_desc) {
160                 return_ACPI_STATUS(AE_BAD_PARAMETER);
161         }
162
163         /* Support for multiple acquires by the owning thread */
164
165         if (obj_desc->mutex.thread_id == thread_id) {
166                 /*
167                  * The mutex is already owned by this thread, just increment the
168                  * acquisition depth
169                  */
170                 obj_desc->mutex.acquisition_depth++;
171                 return_ACPI_STATUS(AE_OK);
172         }
173
174         /* Acquire the mutex, wait if necessary. Special case for Global Lock */
175
176         if (obj_desc == acpi_gbl_global_lock_mutex) {
177                 status = acpi_ev_acquire_global_lock(timeout);
178         } else {
179                 status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
180                                                    timeout);
181         }
182
183         if (ACPI_FAILURE(status)) {
184
185                 /* Includes failure from a timeout on time_desc */
186
187                 return_ACPI_STATUS(status);
188         }
189
190         /* Acquired the mutex: update mutex object */
191
192         obj_desc->mutex.thread_id = thread_id;
193         obj_desc->mutex.acquisition_depth = 1;
194         obj_desc->mutex.original_sync_level = 0;
195         obj_desc->mutex.owner_thread = NULL;    /* Used only for AML Acquire() */
196
197         return_ACPI_STATUS(AE_OK);
198 }
199
200 /*******************************************************************************
201  *
202  * FUNCTION:    acpi_ex_acquire_mutex
203  *
204  * PARAMETERS:  time_desc           - Timeout integer
205  *              obj_desc            - Mutex object
206  *              walk_state          - Current method execution state
207  *
208  * RETURN:      Status
209  *
210  * DESCRIPTION: Acquire an AML mutex
211  *
212  ******************************************************************************/
213
214 acpi_status
215 acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
216                       union acpi_operand_object *obj_desc,
217                       struct acpi_walk_state *walk_state)
218 {
219         acpi_status status;
220
221         ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
222
223         if (!obj_desc) {
224                 return_ACPI_STATUS(AE_BAD_PARAMETER);
225         }
226
227         /* Must have a valid thread ID */
228
229         if (!walk_state->thread) {
230                 ACPI_ERROR((AE_INFO,
231                             "Cannot acquire Mutex [%4.4s], null thread info",
232                             acpi_ut_get_node_name(obj_desc->mutex.node)));
233                 return_ACPI_STATUS(AE_AML_INTERNAL);
234         }
235
236         /*
237          * Current sync level must be less than or equal to the sync level of the
238          * mutex. This mechanism provides some deadlock prevention
239          */
240         if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
241                 ACPI_ERROR((AE_INFO,
242                             "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%d)",
243                             acpi_ut_get_node_name(obj_desc->mutex.node),
244                             walk_state->thread->current_sync_level));
245                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
246         }
247
248         status = acpi_ex_acquire_mutex_object((u16) time_desc->integer.value,
249                                               obj_desc,
250                                               walk_state->thread->thread_id);
251         if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) {
252
253                 /* Save Thread object, original/current sync levels */
254
255                 obj_desc->mutex.owner_thread = walk_state->thread;
256                 obj_desc->mutex.original_sync_level =
257                     walk_state->thread->current_sync_level;
258                 walk_state->thread->current_sync_level =
259                     obj_desc->mutex.sync_level;
260
261                 /* Link the mutex to the current thread for force-unlock at method exit */
262
263                 acpi_ex_link_mutex(obj_desc, walk_state->thread);
264         }
265
266         return_ACPI_STATUS(status);
267 }
268
269 /*******************************************************************************
270  *
271  * FUNCTION:    acpi_ex_release_mutex_object
272  *
273  * PARAMETERS:  obj_desc            - The object descriptor for this op
274  *
275  * RETURN:      Status
276  *
277  * DESCRIPTION: Release a previously acquired Mutex, low level interface.
278  *              Provides a common path that supports multiple releases (after
279  *              previous multiple acquires) by the same thread.
280  *
281  * MUTEX:       Interpreter must be locked
282  *
283  * NOTE: This interface is called from three places:
284  * 1) From acpi_ex_release_mutex, via an AML Acquire() operator
285  * 2) From acpi_ex_release_global_lock when an AML Field access requires the
286  *    global lock
287  * 3) From the external interface, acpi_release_global_lock
288  *
289  ******************************************************************************/
290
291 acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc)
292 {
293         acpi_status status = AE_OK;
294
295         ACPI_FUNCTION_TRACE(ex_release_mutex_object);
296
297         if (obj_desc->mutex.acquisition_depth == 0) {
298                 return (AE_NOT_ACQUIRED);
299         }
300
301         /* Match multiple Acquires with multiple Releases */
302
303         obj_desc->mutex.acquisition_depth--;
304         if (obj_desc->mutex.acquisition_depth != 0) {
305
306                 /* Just decrement the depth and return */
307
308                 return_ACPI_STATUS(AE_OK);
309         }
310
311         if (obj_desc->mutex.owner_thread) {
312
313                 /* Unlink the mutex from the owner's list */
314
315                 acpi_ex_unlink_mutex(obj_desc);
316                 obj_desc->mutex.owner_thread = NULL;
317         }
318
319         /* Release the mutex, special case for Global Lock */
320
321         if (obj_desc == acpi_gbl_global_lock_mutex) {
322                 status = acpi_ev_release_global_lock();
323         } else {
324                 acpi_os_release_mutex(obj_desc->mutex.os_mutex);
325         }
326
327         /* Clear mutex info */
328
329         obj_desc->mutex.thread_id = NULL;
330         return_ACPI_STATUS(status);
331 }
332
333 /*******************************************************************************
334  *
335  * FUNCTION:    acpi_ex_release_mutex
336  *
337  * PARAMETERS:  obj_desc            - The object descriptor for this op
338  *              walk_state          - Current method execution state
339  *
340  * RETURN:      Status
341  *
342  * DESCRIPTION: Release a previously acquired Mutex.
343  *
344  ******************************************************************************/
345
346 acpi_status
347 acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
348                       struct acpi_walk_state *walk_state)
349 {
350         acpi_status status = AE_OK;
351
352         ACPI_FUNCTION_TRACE(ex_release_mutex);
353
354         if (!obj_desc) {
355                 return_ACPI_STATUS(AE_BAD_PARAMETER);
356         }
357
358         /* The mutex must have been previously acquired in order to release it */
359
360         if (!obj_desc->mutex.owner_thread) {
361                 ACPI_ERROR((AE_INFO,
362                             "Cannot release Mutex [%4.4s], not acquired",
363                             acpi_ut_get_node_name(obj_desc->mutex.node)));
364                 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
365         }
366
367         /*
368          * The Mutex is owned, but this thread must be the owner.
369          * Special case for Global Lock, any thread can release
370          */
371         if ((obj_desc->mutex.owner_thread->thread_id !=
372              walk_state->thread->thread_id)
373             && (obj_desc != acpi_gbl_global_lock_mutex)) {
374                 ACPI_ERROR((AE_INFO,
375                             "Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
376                             (unsigned long)walk_state->thread->thread_id,
377                             acpi_ut_get_node_name(obj_desc->mutex.node),
378                             (unsigned long)obj_desc->mutex.owner_thread->
379                             thread_id));
380                 return_ACPI_STATUS(AE_AML_NOT_OWNER);
381         }
382
383         /* Must have a valid thread ID */
384
385         if (!walk_state->thread) {
386                 ACPI_ERROR((AE_INFO,
387                             "Cannot release Mutex [%4.4s], null thread info",
388                             acpi_ut_get_node_name(obj_desc->mutex.node)));
389                 return_ACPI_STATUS(AE_AML_INTERNAL);
390         }
391
392         /*
393          * The sync level of the mutex must be less than or equal to the current
394          * sync level
395          */
396         if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
397                 ACPI_ERROR((AE_INFO,
398                             "Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %d current %d",
399                             acpi_ut_get_node_name(obj_desc->mutex.node),
400                             obj_desc->mutex.sync_level,
401                             walk_state->thread->current_sync_level));
402                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
403         }
404
405         status = acpi_ex_release_mutex_object(obj_desc);
406
407         if (obj_desc->mutex.acquisition_depth == 0) {
408
409                 /* Restore the original sync_level */
410
411                 walk_state->thread->current_sync_level =
412                     obj_desc->mutex.original_sync_level;
413         }
414         return_ACPI_STATUS(status);
415 }
416
417 /*******************************************************************************
418  *
419  * FUNCTION:    acpi_ex_release_all_mutexes
420  *
421  * PARAMETERS:  Thread          - Current executing thread object
422  *
423  * RETURN:      Status
424  *
425  * DESCRIPTION: Release all mutexes held by this thread
426  *
427  * NOTE: This function is called as the thread is exiting the interpreter.
428  * Mutexes are not released when an individual control method is exited, but
429  * only when the parent thread actually exits the interpreter. This allows one
430  * method to acquire a mutex, and a different method to release it, as long as
431  * this is performed underneath a single parent control method.
432  *
433  ******************************************************************************/
434
435 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
436 {
437         union acpi_operand_object *next = thread->acquired_mutex_list;
438         union acpi_operand_object *obj_desc;
439
440         ACPI_FUNCTION_ENTRY();
441
442         /* Traverse the list of owned mutexes, releasing each one */
443
444         while (next) {
445                 obj_desc = next;
446                 next = obj_desc->mutex.next;
447
448                 obj_desc->mutex.prev = NULL;
449                 obj_desc->mutex.next = NULL;
450                 obj_desc->mutex.acquisition_depth = 0;
451
452                 /* Release the mutex, special case for Global Lock */
453
454                 if (obj_desc == acpi_gbl_global_lock_mutex) {
455
456                         /* Ignore errors */
457
458                         (void)acpi_ev_release_global_lock();
459                 } else {
460                         acpi_os_release_mutex(obj_desc->mutex.os_mutex);
461                 }
462
463                 /* Mark mutex unowned */
464
465                 obj_desc->mutex.owner_thread = NULL;
466                 obj_desc->mutex.thread_id = NULL;
467
468                 /* Update Thread sync_level (Last mutex is the important one) */
469
470                 thread->current_sync_level =
471                     obj_desc->mutex.original_sync_level;
472         }
473 }