Merge branch 'acpica' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux...
[linux-3.10.git] / drivers / acpi / acpica / utmutex.c
1 /*******************************************************************************
2  *
3  * Module Name: utmutex - local mutex support
4  *
5  ******************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2011, Intel Corp.
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 #include "accommon.h"
46
47 #define _COMPONENT          ACPI_UTILITIES
48 ACPI_MODULE_NAME("utmutex")
49
50 /* Local prototypes */
51 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id);
52
53 static void acpi_ut_delete_mutex(acpi_mutex_handle mutex_id);
54
55 /*******************************************************************************
56  *
57  * FUNCTION:    acpi_ut_mutex_initialize
58  *
59  * PARAMETERS:  None.
60  *
61  * RETURN:      Status
62  *
63  * DESCRIPTION: Create the system mutex objects. This includes mutexes,
64  *              spin locks, and reader/writer locks.
65  *
66  ******************************************************************************/
67
68 acpi_status acpi_ut_mutex_initialize(void)
69 {
70         u32 i;
71         acpi_status status;
72
73         ACPI_FUNCTION_TRACE(ut_mutex_initialize);
74
75         /* Create each of the predefined mutex objects */
76
77         for (i = 0; i < ACPI_NUM_MUTEX; i++) {
78                 status = acpi_ut_create_mutex(i);
79                 if (ACPI_FAILURE(status)) {
80                         return_ACPI_STATUS(status);
81                 }
82         }
83
84         /* Create the spinlocks for use at interrupt level */
85
86         spin_lock_init(acpi_gbl_gpe_lock);
87         spin_lock_init(acpi_gbl_hardware_lock);
88         spin_lock_init(acpi_ev_global_lock_pending_lock);
89
90         /* Mutex for _OSI support */
91         status = acpi_os_create_mutex(&acpi_gbl_osi_mutex);
92         if (ACPI_FAILURE(status)) {
93                 return_ACPI_STATUS(status);
94         }
95
96         /* Create the reader/writer lock for namespace access */
97
98         status = acpi_ut_create_rw_lock(&acpi_gbl_namespace_rw_lock);
99         return_ACPI_STATUS(status);
100 }
101
102 /*******************************************************************************
103  *
104  * FUNCTION:    acpi_ut_mutex_terminate
105  *
106  * PARAMETERS:  None.
107  *
108  * RETURN:      None.
109  *
110  * DESCRIPTION: Delete all of the system mutex objects. This includes mutexes,
111  *              spin locks, and reader/writer locks.
112  *
113  ******************************************************************************/
114
115 void acpi_ut_mutex_terminate(void)
116 {
117         u32 i;
118
119         ACPI_FUNCTION_TRACE(ut_mutex_terminate);
120
121         /* Delete each predefined mutex object */
122
123         for (i = 0; i < ACPI_NUM_MUTEX; i++) {
124                 acpi_ut_delete_mutex(i);
125         }
126
127         acpi_os_delete_mutex(acpi_gbl_osi_mutex);
128
129         /* Delete the spinlocks */
130
131         acpi_os_delete_lock(acpi_gbl_gpe_lock);
132         acpi_os_delete_lock(acpi_gbl_hardware_lock);
133
134         /* Delete the reader/writer lock */
135
136         acpi_ut_delete_rw_lock(&acpi_gbl_namespace_rw_lock);
137         return_VOID;
138 }
139
140 /*******************************************************************************
141  *
142  * FUNCTION:    acpi_ut_create_mutex
143  *
144  * PARAMETERS:  mutex_iD        - ID of the mutex to be created
145  *
146  * RETURN:      Status
147  *
148  * DESCRIPTION: Create a mutex object.
149  *
150  ******************************************************************************/
151
152 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
153 {
154         acpi_status status = AE_OK;
155
156         ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
157
158         if (!acpi_gbl_mutex_info[mutex_id].mutex) {
159                 status =
160                     acpi_os_create_mutex(&acpi_gbl_mutex_info[mutex_id].mutex);
161                 acpi_gbl_mutex_info[mutex_id].thread_id =
162                     ACPI_MUTEX_NOT_ACQUIRED;
163                 acpi_gbl_mutex_info[mutex_id].use_count = 0;
164         }
165
166         return_ACPI_STATUS(status);
167 }
168
169 /*******************************************************************************
170  *
171  * FUNCTION:    acpi_ut_delete_mutex
172  *
173  * PARAMETERS:  mutex_iD        - ID of the mutex to be deleted
174  *
175  * RETURN:      Status
176  *
177  * DESCRIPTION: Delete a mutex object.
178  *
179  ******************************************************************************/
180
181 static void acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
182 {
183
184         ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
185
186         acpi_os_delete_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
187
188         acpi_gbl_mutex_info[mutex_id].mutex = NULL;
189         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
190 }
191
192 /*******************************************************************************
193  *
194  * FUNCTION:    acpi_ut_acquire_mutex
195  *
196  * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
197  *
198  * RETURN:      Status
199  *
200  * DESCRIPTION: Acquire a mutex object.
201  *
202  ******************************************************************************/
203
204 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
205 {
206         acpi_status status;
207         acpi_thread_id this_thread_id;
208
209         ACPI_FUNCTION_NAME(ut_acquire_mutex);
210
211         if (mutex_id > ACPI_MAX_MUTEX) {
212                 return (AE_BAD_PARAMETER);
213         }
214
215         this_thread_id = acpi_os_get_thread_id();
216
217 #ifdef ACPI_MUTEX_DEBUG
218         {
219                 u32 i;
220                 /*
221                  * Mutex debug code, for internal debugging only.
222                  *
223                  * Deadlock prevention.  Check if this thread owns any mutexes of value
224                  * greater than or equal to this one.  If so, the thread has violated
225                  * the mutex ordering rule.  This indicates a coding error somewhere in
226                  * the ACPI subsystem code.
227                  */
228                 for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
229                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
230                                 if (i == mutex_id) {
231                                         ACPI_ERROR((AE_INFO,
232                                                     "Mutex [%s] already acquired by this thread [%u]",
233                                                     acpi_ut_get_mutex_name
234                                                     (mutex_id),
235                                                     (u32)this_thread_id));
236
237                                         return (AE_ALREADY_ACQUIRED);
238                                 }
239
240                                 ACPI_ERROR((AE_INFO,
241                                             "Invalid acquire order: Thread %u owns [%s], wants [%s]",
242                                             (u32)this_thread_id,
243                                             acpi_ut_get_mutex_name(i),
244                                             acpi_ut_get_mutex_name(mutex_id)));
245
246                                 return (AE_ACQUIRE_DEADLOCK);
247                         }
248                 }
249         }
250 #endif
251
252         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
253                           "Thread %u attempting to acquire Mutex [%s]\n",
254                           (u32)this_thread_id,
255                           acpi_ut_get_mutex_name(mutex_id)));
256
257         status = acpi_os_acquire_mutex(acpi_gbl_mutex_info[mutex_id].mutex,
258                                        ACPI_WAIT_FOREVER);
259         if (ACPI_SUCCESS(status)) {
260                 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
261                                   "Thread %u acquired Mutex [%s]\n",
262                                   (u32)this_thread_id,
263                                   acpi_ut_get_mutex_name(mutex_id)));
264
265                 acpi_gbl_mutex_info[mutex_id].use_count++;
266                 acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
267         } else {
268                 ACPI_EXCEPTION((AE_INFO, status,
269                                 "Thread %u could not acquire Mutex [0x%X]",
270                                 (u32)this_thread_id, mutex_id));
271         }
272
273         return (status);
274 }
275
276 /*******************************************************************************
277  *
278  * FUNCTION:    acpi_ut_release_mutex
279  *
280  * PARAMETERS:  mutex_iD        - ID of the mutex to be released
281  *
282  * RETURN:      Status
283  *
284  * DESCRIPTION: Release a mutex object.
285  *
286  ******************************************************************************/
287
288 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
289 {
290         acpi_thread_id this_thread_id;
291
292         ACPI_FUNCTION_NAME(ut_release_mutex);
293
294         this_thread_id = acpi_os_get_thread_id();
295
296         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Thread %u releasing Mutex [%s]\n",
297                           (u32)this_thread_id,
298                           acpi_ut_get_mutex_name(mutex_id)));
299
300         if (mutex_id > ACPI_MAX_MUTEX) {
301                 return (AE_BAD_PARAMETER);
302         }
303
304         /*
305          * Mutex must be acquired in order to release it!
306          */
307         if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
308                 ACPI_ERROR((AE_INFO,
309                             "Mutex [0x%X] is not acquired, cannot release",
310                             mutex_id));
311
312                 return (AE_NOT_ACQUIRED);
313         }
314 #ifdef ACPI_MUTEX_DEBUG
315         {
316                 u32 i;
317                 /*
318                  * Mutex debug code, for internal debugging only.
319                  *
320                  * Deadlock prevention.  Check if this thread owns any mutexes of value
321                  * greater than this one.  If so, the thread has violated the mutex
322                  * ordering rule.  This indicates a coding error somewhere in
323                  * the ACPI subsystem code.
324                  */
325                 for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
326                         if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
327                                 if (i == mutex_id) {
328                                         continue;
329                                 }
330
331                                 ACPI_ERROR((AE_INFO,
332                                             "Invalid release order: owns [%s], releasing [%s]",
333                                             acpi_ut_get_mutex_name(i),
334                                             acpi_ut_get_mutex_name(mutex_id)));
335
336                                 return (AE_RELEASE_DEADLOCK);
337                         }
338                 }
339         }
340 #endif
341
342         /* Mark unlocked FIRST */
343
344         acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
345
346         acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
347         return (AE_OK);
348 }