ACPICA: Lindent
[linux-2.6.git] / drivers / acpi / utilities / utmutex.c
1 /*******************************************************************************
2  *
3  * Module Name: utmutex - local mutex support
4  *
5  ******************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2007, R. Byron Moore
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43
44 #include <acpi/acpi.h>
45
46 #define _COMPONENT          ACPI_UTILITIES
47 ACPI_MODULE_NAME("utmutex")
48
49 /* Local prototypes */
50 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id);
51
52 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id);
53
54 /*******************************************************************************
55  *
56  * FUNCTION:    acpi_ut_mutex_initialize
57  *
58  * PARAMETERS:  None.
59  *
60  * RETURN:      Status
61  *
62  * DESCRIPTION: Create the system mutex objects.
63  *
64  ******************************************************************************/
65
66 acpi_status acpi_ut_mutex_initialize(void)
67 {
68         u32 i;
69         acpi_status status;
70
71         ACPI_FUNCTION_TRACE(ut_mutex_initialize);
72
73         /*
74          * Create each of the predefined mutex objects
75          */
76         for (i = 0; i < ACPI_NUM_MUTEX; i++) {
77                 status = acpi_ut_create_mutex(i);
78                 if (ACPI_FAILURE(status)) {
79                         return_ACPI_STATUS(status);
80                 }
81         }
82
83         /* Create the spinlocks for use at interrupt level */
84
85         spin_lock_init(acpi_gbl_gpe_lock);
86         spin_lock_init(acpi_gbl_hardware_lock);
87
88         return_ACPI_STATUS(status);
89 }
90
91 /*******************************************************************************
92  *
93  * FUNCTION:    acpi_ut_mutex_terminate
94  *
95  * PARAMETERS:  None.
96  *
97  * RETURN:      None.
98  *
99  * DESCRIPTION: Delete all of the system mutex objects.
100  *
101  ******************************************************************************/
102
103 void acpi_ut_mutex_terminate(void)
104 {
105         u32 i;
106
107         ACPI_FUNCTION_TRACE(ut_mutex_terminate);
108
109         /*
110          * Delete each predefined mutex object
111          */
112         for (i = 0; i < ACPI_NUM_MUTEX; i++) {
113                 (void)acpi_ut_delete_mutex(i);
114         }
115
116         /* Delete the spinlocks */
117
118         acpi_os_delete_lock(acpi_gbl_gpe_lock);
119         acpi_os_delete_lock(acpi_gbl_hardware_lock);
120         return_VOID;
121 }
122
123 /*******************************************************************************
124  *
125  * FUNCTION:    acpi_ut_create_mutex
126  *
127  * PARAMETERS:  mutex_iD        - ID of the mutex to be created
128  *
129  * RETURN:      Status
130  *
131  * DESCRIPTION: Create a mutex object.
132  *
133  ******************************************************************************/
134
135 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
136 {
137         acpi_status status = AE_OK;
138
139         ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
140
141         if (mutex_id > ACPI_MAX_MUTEX) {
142                 return_ACPI_STATUS(AE_BAD_PARAMETER);
143         }
144
145         if (!acpi_gbl_mutex_info[mutex_id].mutex) {
146                 status =
147                     acpi_os_create_mutex(&acpi_gbl_mutex_info[mutex_id].mutex);
148                 acpi_gbl_mutex_info[mutex_id].thread_id =
149                     ACPI_MUTEX_NOT_ACQUIRED;
150                 acpi_gbl_mutex_info[mutex_id].use_count = 0;
151         }
152
153         return_ACPI_STATUS(status);
154 }
155
156 /*******************************************************************************
157  *
158  * FUNCTION:    acpi_ut_delete_mutex
159  *
160  * PARAMETERS:  mutex_iD        - ID of the mutex to be deleted
161  *
162  * RETURN:      Status
163  *
164  * DESCRIPTION: Delete a mutex object.
165  *
166  ******************************************************************************/
167
168 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
169 {
170
171         ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
172
173         if (mutex_id > ACPI_MAX_MUTEX) {
174                 return_ACPI_STATUS(AE_BAD_PARAMETER);
175         }
176
177         acpi_os_delete_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
178
179         acpi_gbl_mutex_info[mutex_id].mutex = NULL;
180         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
181
182         return_ACPI_STATUS(AE_OK);
183 }
184
185 /*******************************************************************************
186  *
187  * FUNCTION:    acpi_ut_acquire_mutex
188  *
189  * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
190  *
191  * RETURN:      Status
192  *
193  * DESCRIPTION: Acquire a mutex object.
194  *
195  ******************************************************************************/
196
197 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
198 {
199         acpi_status status;
200         acpi_thread_id this_thread_id;
201
202         ACPI_FUNCTION_NAME(ut_acquire_mutex);
203
204         if (mutex_id > ACPI_MAX_MUTEX) {
205                 return (AE_BAD_PARAMETER);
206         }
207
208         this_thread_id = acpi_os_get_thread_id();
209
210 #ifdef ACPI_MUTEX_DEBUG
211         {
212                 u32 i;
213                 /*
214                  * Mutex debug code, for internal debugging only.
215                  *
216                  * Deadlock prevention.  Check if this thread owns any mutexes of value
217                  * greater than or equal to this one.  If so, the thread has violated
218                  * the mutex ordering rule.  This indicates a coding error somewhere in
219                  * the ACPI subsystem code.
220                  */
221                 for (i = mutex_id; i < ACPI_MAX_MUTEX; i++) {
222                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
223                                 if (i == mutex_id) {
224                                         ACPI_ERROR((AE_INFO,
225                                                     "Mutex [%s] already acquired by this thread [%X]",
226                                                     acpi_ut_get_mutex_name
227                                                     (mutex_id),
228                                                     this_thread_id));
229
230                                         return (AE_ALREADY_ACQUIRED);
231                                 }
232
233                                 ACPI_ERROR((AE_INFO,
234                                             "Invalid acquire order: Thread %X owns [%s], wants [%s]",
235                                             this_thread_id,
236                                             acpi_ut_get_mutex_name(i),
237                                             acpi_ut_get_mutex_name(mutex_id)));
238
239                                 return (AE_ACQUIRE_DEADLOCK);
240                         }
241                 }
242         }
243 #endif
244
245         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
246                           "Thread %lX attempting to acquire Mutex [%s]\n",
247                           (unsigned long)this_thread_id,
248                           acpi_ut_get_mutex_name(mutex_id)));
249
250         status = acpi_os_acquire_mutex(acpi_gbl_mutex_info[mutex_id].mutex,
251                                        ACPI_WAIT_FOREVER);
252         if (ACPI_SUCCESS(status)) {
253                 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
254                                   "Thread %lX acquired Mutex [%s]\n",
255                                   (unsigned long)this_thread_id,
256                                   acpi_ut_get_mutex_name(mutex_id)));
257
258                 acpi_gbl_mutex_info[mutex_id].use_count++;
259                 acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
260         } else {
261                 ACPI_EXCEPTION((AE_INFO, status,
262                                 "Thread %lX could not acquire Mutex [%X]",
263                                 (unsigned long)this_thread_id, mutex_id));
264         }
265
266         return (status);
267 }
268
269 /*******************************************************************************
270  *
271  * FUNCTION:    acpi_ut_release_mutex
272  *
273  * PARAMETERS:  mutex_iD        - ID of the mutex to be released
274  *
275  * RETURN:      Status
276  *
277  * DESCRIPTION: Release a mutex object.
278  *
279  ******************************************************************************/
280
281 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
282 {
283         acpi_thread_id this_thread_id;
284
285         ACPI_FUNCTION_NAME(ut_release_mutex);
286
287         this_thread_id = acpi_os_get_thread_id();
288         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
289                           "Thread %lX releasing Mutex [%s]\n",
290                           (unsigned long)this_thread_id,
291                           acpi_ut_get_mutex_name(mutex_id)));
292
293         if (mutex_id > ACPI_MAX_MUTEX) {
294                 return (AE_BAD_PARAMETER);
295         }
296
297         /*
298          * Mutex must be acquired in order to release it!
299          */
300         if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
301                 ACPI_ERROR((AE_INFO,
302                             "Mutex [%X] is not acquired, cannot release",
303                             mutex_id));
304
305                 return (AE_NOT_ACQUIRED);
306         }
307 #ifdef ACPI_MUTEX_DEBUG
308         {
309                 u32 i;
310                 /*
311                  * Mutex debug code, for internal debugging only.
312                  *
313                  * Deadlock prevention.  Check if this thread owns any mutexes of value
314                  * greater than this one.  If so, the thread has violated the mutex
315                  * ordering rule.  This indicates a coding error somewhere in
316                  * the ACPI subsystem code.
317                  */
318                 for (i = mutex_id; i < ACPI_MAX_MUTEX; i++) {
319                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
320                                 if (i == mutex_id) {
321                                         continue;
322                                 }
323
324                                 ACPI_ERROR((AE_INFO,
325                                             "Invalid release order: owns [%s], releasing [%s]",
326                                             acpi_ut_get_mutex_name(i),
327                                             acpi_ut_get_mutex_name(mutex_id)));
328
329                                 return (AE_RELEASE_DEADLOCK);
330                         }
331                 }
332         }
333 #endif
334
335         /* Mark unlocked FIRST */
336
337         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
338
339         acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
340         return (AE_OK);
341 }