ia64/linux-2.6.18-xen.hg

view drivers/acpi/utilities/utmutex.c @ 0:831230e53067

Import 2.6.18 from kernel.org tarball.
author Ian Campbell <ian.campbell@xensource.com>
date Wed Apr 11 14:15:44 2007 +0100 (2007-04-11)
parents
children
line source
1 /*******************************************************************************
2 *
3 * Module Name: utmutex - local mutex support
4 *
5 ******************************************************************************/
7 /*
8 * Copyright (C) 2000 - 2006, 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 */
44 #include <acpi/acpi.h>
46 #define _COMPONENT ACPI_UTILITIES
47 ACPI_MODULE_NAME("utmutex")
49 /* Local prototypes */
50 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id);
52 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id);
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 ******************************************************************************/
66 acpi_status acpi_ut_mutex_initialize(void)
67 {
68 u32 i;
69 acpi_status status;
71 ACPI_FUNCTION_TRACE(ut_mutex_initialize);
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 }
83 /* Create the spinlocks for use at interrupt level */
85 spin_lock_init(acpi_gbl_gpe_lock);
86 spin_lock_init(acpi_gbl_hardware_lock);
88 return_ACPI_STATUS(status);
89 }
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 ******************************************************************************/
103 void acpi_ut_mutex_terminate(void)
104 {
105 u32 i;
107 ACPI_FUNCTION_TRACE(ut_mutex_terminate);
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 }
116 /* Delete the spinlocks */
118 acpi_os_delete_lock(acpi_gbl_gpe_lock);
119 acpi_os_delete_lock(acpi_gbl_hardware_lock);
120 return_VOID;
121 }
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 ******************************************************************************/
135 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
136 {
137 acpi_status status = AE_OK;
139 ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
141 if (mutex_id > ACPI_MAX_MUTEX) {
142 return_ACPI_STATUS(AE_BAD_PARAMETER);
143 }
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 }
153 return_ACPI_STATUS(status);
154 }
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 ******************************************************************************/
168 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
169 {
171 ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
173 if (mutex_id > ACPI_MAX_MUTEX) {
174 return_ACPI_STATUS(AE_BAD_PARAMETER);
175 }
177 acpi_os_delete_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
179 acpi_gbl_mutex_info[mutex_id].mutex = NULL;
180 acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
182 return_ACPI_STATUS(AE_OK);
183 }
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 ******************************************************************************/
197 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
198 {
199 acpi_status status;
200 acpi_thread_id this_thread_id;
202 ACPI_FUNCTION_NAME(ut_acquire_mutex);
204 if (mutex_id > ACPI_MAX_MUTEX) {
205 return (AE_BAD_PARAMETER);
206 }
208 this_thread_id = acpi_os_get_thread_id();
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));
230 return (AE_ALREADY_ACQUIRED);
231 }
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)));
239 return (AE_ACQUIRE_DEADLOCK);
240 }
241 }
242 }
243 #endif
245 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
246 "Thread %X attempting to acquire Mutex [%s]\n",
247 (u32) this_thread_id, acpi_ut_get_mutex_name(mutex_id)));
249 status = acpi_os_acquire_mutex(acpi_gbl_mutex_info[mutex_id].mutex,
250 ACPI_WAIT_FOREVER);
251 if (ACPI_SUCCESS(status)) {
252 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
253 "Thread %X acquired Mutex [%s]\n",
254 (u32) this_thread_id,
255 acpi_ut_get_mutex_name(mutex_id)));
257 acpi_gbl_mutex_info[mutex_id].use_count++;
258 acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
259 } else {
260 ACPI_EXCEPTION((AE_INFO, status,
261 "Thread %X could not acquire Mutex [%X]",
262 (u32) this_thread_id, mutex_id));
263 }
265 return (status);
266 }
268 /*******************************************************************************
269 *
270 * FUNCTION: acpi_ut_release_mutex
271 *
272 * PARAMETERS: mutex_iD - ID of the mutex to be released
273 *
274 * RETURN: Status
275 *
276 * DESCRIPTION: Release a mutex object.
277 *
278 ******************************************************************************/
280 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
281 {
282 acpi_thread_id this_thread_id;
284 ACPI_FUNCTION_NAME(ut_release_mutex);
286 this_thread_id = acpi_os_get_thread_id();
287 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
288 "Thread %X releasing Mutex [%s]\n", (u32) this_thread_id,
289 acpi_ut_get_mutex_name(mutex_id)));
291 if (mutex_id > ACPI_MAX_MUTEX) {
292 return (AE_BAD_PARAMETER);
293 }
295 /*
296 * Mutex must be acquired in order to release it!
297 */
298 if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
299 ACPI_ERROR((AE_INFO,
300 "Mutex [%X] is not acquired, cannot release",
301 mutex_id));
303 return (AE_NOT_ACQUIRED);
304 }
305 #ifdef ACPI_MUTEX_DEBUG
306 {
307 u32 i;
308 /*
309 * Mutex debug code, for internal debugging only.
310 *
311 * Deadlock prevention. Check if this thread owns any mutexes of value
312 * greater than this one. If so, the thread has violated the mutex
313 * ordering rule. This indicates a coding error somewhere in
314 * the ACPI subsystem code.
315 */
316 for (i = mutex_id; i < ACPI_MAX_MUTEX; i++) {
317 if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
318 if (i == mutex_id) {
319 continue;
320 }
322 ACPI_ERROR((AE_INFO,
323 "Invalid release order: owns [%s], releasing [%s]",
324 acpi_ut_get_mutex_name(i),
325 acpi_ut_get_mutex_name(mutex_id)));
327 return (AE_RELEASE_DEADLOCK);
328 }
329 }
330 }
331 #endif
333 /* Mark unlocked FIRST */
335 acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
337 acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
338 return (AE_OK);
339 }