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v3.5.6
  1/*******************************************************************************
  2 *
  3 * Module Name: utmutex - local mutex support
  4 *
  5 ******************************************************************************/
  6
  7/*
  8 * Copyright (C) 2000 - 2012, 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
 48ACPI_MODULE_NAME("utmutex")
 49
 50/* Local prototypes */
 51static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id);
 52
 53static 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
 68acpi_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	status = acpi_os_create_lock (&acpi_gbl_gpe_lock);
 87	if (ACPI_FAILURE (status)) {
 88		return_ACPI_STATUS (status);
 89	}
 90
 91	status = acpi_os_create_lock (&acpi_gbl_hardware_lock);
 92	if (ACPI_FAILURE (status)) {
 93		return_ACPI_STATUS (status);
 94	}
 95
 
 
 
 
 
 96	/* Mutex for _OSI support */
 
 97	status = acpi_os_create_mutex(&acpi_gbl_osi_mutex);
 98	if (ACPI_FAILURE(status)) {
 99		return_ACPI_STATUS(status);
100	}
101
102	/* Create the reader/writer lock for namespace access */
103
104	status = acpi_ut_create_rw_lock(&acpi_gbl_namespace_rw_lock);
105	return_ACPI_STATUS(status);
106}
107
108/*******************************************************************************
109 *
110 * FUNCTION:    acpi_ut_mutex_terminate
111 *
112 * PARAMETERS:  None.
113 *
114 * RETURN:      None.
115 *
116 * DESCRIPTION: Delete all of the system mutex objects. This includes mutexes,
117 *              spin locks, and reader/writer locks.
118 *
119 ******************************************************************************/
120
121void acpi_ut_mutex_terminate(void)
122{
123	u32 i;
124
125	ACPI_FUNCTION_TRACE(ut_mutex_terminate);
126
127	/* Delete each predefined mutex object */
128
129	for (i = 0; i < ACPI_NUM_MUTEX; i++) {
130		acpi_ut_delete_mutex(i);
131	}
132
133	acpi_os_delete_mutex(acpi_gbl_osi_mutex);
134
135	/* Delete the spinlocks */
136
137	acpi_os_delete_lock(acpi_gbl_gpe_lock);
138	acpi_os_delete_lock(acpi_gbl_hardware_lock);
 
139
140	/* Delete the reader/writer lock */
141
142	acpi_ut_delete_rw_lock(&acpi_gbl_namespace_rw_lock);
143	return_VOID;
144}
145
146/*******************************************************************************
147 *
148 * FUNCTION:    acpi_ut_create_mutex
149 *
150 * PARAMETERS:  mutex_iD        - ID of the mutex to be created
151 *
152 * RETURN:      Status
153 *
154 * DESCRIPTION: Create a mutex object.
155 *
156 ******************************************************************************/
157
158static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
159{
160	acpi_status status = AE_OK;
161
162	ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
163
164	if (!acpi_gbl_mutex_info[mutex_id].mutex) {
165		status =
166		    acpi_os_create_mutex(&acpi_gbl_mutex_info[mutex_id].mutex);
167		acpi_gbl_mutex_info[mutex_id].thread_id =
168		    ACPI_MUTEX_NOT_ACQUIRED;
169		acpi_gbl_mutex_info[mutex_id].use_count = 0;
170	}
171
172	return_ACPI_STATUS(status);
173}
174
175/*******************************************************************************
176 *
177 * FUNCTION:    acpi_ut_delete_mutex
178 *
179 * PARAMETERS:  mutex_iD        - ID of the mutex to be deleted
180 *
181 * RETURN:      Status
182 *
183 * DESCRIPTION: Delete a mutex object.
184 *
185 ******************************************************************************/
186
187static void acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
188{
189
190	ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
191
192	acpi_os_delete_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
193
194	acpi_gbl_mutex_info[mutex_id].mutex = NULL;
195	acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 
 
196}
197
198/*******************************************************************************
199 *
200 * FUNCTION:    acpi_ut_acquire_mutex
201 *
202 * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
203 *
204 * RETURN:      Status
205 *
206 * DESCRIPTION: Acquire a mutex object.
207 *
208 ******************************************************************************/
209
210acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
211{
212	acpi_status status;
213	acpi_thread_id this_thread_id;
214
215	ACPI_FUNCTION_NAME(ut_acquire_mutex);
216
217	if (mutex_id > ACPI_MAX_MUTEX) {
218		return (AE_BAD_PARAMETER);
219	}
220
221	this_thread_id = acpi_os_get_thread_id();
222
223#ifdef ACPI_MUTEX_DEBUG
224	{
225		u32 i;
226		/*
227		 * Mutex debug code, for internal debugging only.
228		 *
229		 * Deadlock prevention.  Check if this thread owns any mutexes of value
230		 * greater than or equal to this one.  If so, the thread has violated
231		 * the mutex ordering rule.  This indicates a coding error somewhere in
232		 * the ACPI subsystem code.
233		 */
234		for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
235			if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
236				if (i == mutex_id) {
237					ACPI_ERROR((AE_INFO,
238						    "Mutex [%s] already acquired by this thread [%u]",
239						    acpi_ut_get_mutex_name
240						    (mutex_id),
241						    (u32)this_thread_id));
242
243					return (AE_ALREADY_ACQUIRED);
244				}
245
246				ACPI_ERROR((AE_INFO,
247					    "Invalid acquire order: Thread %u owns [%s], wants [%s]",
248					    (u32)this_thread_id,
249					    acpi_ut_get_mutex_name(i),
250					    acpi_ut_get_mutex_name(mutex_id)));
251
252				return (AE_ACQUIRE_DEADLOCK);
253			}
254		}
255	}
256#endif
257
258	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
259			  "Thread %u attempting to acquire Mutex [%s]\n",
260			  (u32)this_thread_id,
261			  acpi_ut_get_mutex_name(mutex_id)));
262
263	status = acpi_os_acquire_mutex(acpi_gbl_mutex_info[mutex_id].mutex,
264				       ACPI_WAIT_FOREVER);
265	if (ACPI_SUCCESS(status)) {
266		ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
267				  "Thread %u acquired Mutex [%s]\n",
268				  (u32)this_thread_id,
269				  acpi_ut_get_mutex_name(mutex_id)));
270
271		acpi_gbl_mutex_info[mutex_id].use_count++;
272		acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
273	} else {
274		ACPI_EXCEPTION((AE_INFO, status,
275				"Thread %u could not acquire Mutex [0x%X]",
276				(u32)this_thread_id, mutex_id));
277	}
278
279	return (status);
280}
281
282/*******************************************************************************
283 *
284 * FUNCTION:    acpi_ut_release_mutex
285 *
286 * PARAMETERS:  mutex_iD        - ID of the mutex to be released
287 *
288 * RETURN:      Status
289 *
290 * DESCRIPTION: Release a mutex object.
291 *
292 ******************************************************************************/
293
294acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
295{
296	ACPI_FUNCTION_NAME(ut_release_mutex);
297
298	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Thread %u releasing Mutex [%s]\n",
299			  (u32)acpi_os_get_thread_id(),
300			  acpi_ut_get_mutex_name(mutex_id)));
301
302	if (mutex_id > ACPI_MAX_MUTEX) {
303		return (AE_BAD_PARAMETER);
304	}
305
306	/*
307	 * Mutex must be acquired in order to release it!
308	 */
309	if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
310		ACPI_ERROR((AE_INFO,
311			    "Mutex [0x%X] is not acquired, cannot release",
312			    mutex_id));
313
314		return (AE_NOT_ACQUIRED);
315	}
316#ifdef ACPI_MUTEX_DEBUG
317	{
318		u32 i;
319		/*
320		 * Mutex debug code, for internal debugging only.
321		 *
322		 * Deadlock prevention.  Check if this thread owns any mutexes of value
323		 * greater than this one.  If so, the thread has violated the mutex
324		 * ordering rule.  This indicates a coding error somewhere in
325		 * the ACPI subsystem code.
326		 */
327		for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
328			if (acpi_gbl_mutex_info[i].thread_id ==
329			    acpi_os_get_thread_id()) {
330				if (i == mutex_id) {
331					continue;
332				}
333
334				ACPI_ERROR((AE_INFO,
335					    "Invalid release order: owns [%s], releasing [%s]",
336					    acpi_ut_get_mutex_name(i),
337					    acpi_ut_get_mutex_name(mutex_id)));
338
339				return (AE_RELEASE_DEADLOCK);
340			}
341		}
342	}
343#endif
344
345	/* Mark unlocked FIRST */
346
347	acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
348
349	acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
350	return (AE_OK);
351}
v3.15
  1/*******************************************************************************
  2 *
  3 * Module Name: utmutex - local mutex support
  4 *
  5 ******************************************************************************/
  6
  7/*
  8 * Copyright (C) 2000 - 2014, 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
 48ACPI_MODULE_NAME("utmutex")
 49
 50/* Local prototypes */
 51static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id);
 52
 53static 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
 68acpi_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 or for speed */
 85
 86	status = acpi_os_create_lock (&acpi_gbl_gpe_lock);
 87	if (ACPI_FAILURE (status)) {
 88		return_ACPI_STATUS (status);
 89	}
 90
 91	status = acpi_os_create_lock (&acpi_gbl_hardware_lock);
 92	if (ACPI_FAILURE (status)) {
 93		return_ACPI_STATUS (status);
 94	}
 95
 96	status = acpi_os_create_lock(&acpi_gbl_reference_count_lock);
 97	if (ACPI_FAILURE(status)) {
 98		return_ACPI_STATUS(status);
 99	}
100
101	/* Mutex for _OSI support */
102
103	status = acpi_os_create_mutex(&acpi_gbl_osi_mutex);
104	if (ACPI_FAILURE(status)) {
105		return_ACPI_STATUS(status);
106	}
107
108	/* Create the reader/writer lock for namespace access */
109
110	status = acpi_ut_create_rw_lock(&acpi_gbl_namespace_rw_lock);
111	return_ACPI_STATUS(status);
112}
113
114/*******************************************************************************
115 *
116 * FUNCTION:    acpi_ut_mutex_terminate
117 *
118 * PARAMETERS:  None.
119 *
120 * RETURN:      None.
121 *
122 * DESCRIPTION: Delete all of the system mutex objects. This includes mutexes,
123 *              spin locks, and reader/writer locks.
124 *
125 ******************************************************************************/
126
127void acpi_ut_mutex_terminate(void)
128{
129	u32 i;
130
131	ACPI_FUNCTION_TRACE(ut_mutex_terminate);
132
133	/* Delete each predefined mutex object */
134
135	for (i = 0; i < ACPI_NUM_MUTEX; i++) {
136		acpi_ut_delete_mutex(i);
137	}
138
139	acpi_os_delete_mutex(acpi_gbl_osi_mutex);
140
141	/* Delete the spinlocks */
142
143	acpi_os_delete_lock(acpi_gbl_gpe_lock);
144	acpi_os_delete_lock(acpi_gbl_hardware_lock);
145	acpi_os_delete_lock(acpi_gbl_reference_count_lock);
146
147	/* Delete the reader/writer lock */
148
149	acpi_ut_delete_rw_lock(&acpi_gbl_namespace_rw_lock);
150	return_VOID;
151}
152
153/*******************************************************************************
154 *
155 * FUNCTION:    acpi_ut_create_mutex
156 *
157 * PARAMETERS:  mutex_ID        - ID of the mutex to be created
158 *
159 * RETURN:      Status
160 *
161 * DESCRIPTION: Create a mutex object.
162 *
163 ******************************************************************************/
164
165static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
166{
167	acpi_status status = AE_OK;
168
169	ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
170
171	if (!acpi_gbl_mutex_info[mutex_id].mutex) {
172		status =
173		    acpi_os_create_mutex(&acpi_gbl_mutex_info[mutex_id].mutex);
174		acpi_gbl_mutex_info[mutex_id].thread_id =
175		    ACPI_MUTEX_NOT_ACQUIRED;
176		acpi_gbl_mutex_info[mutex_id].use_count = 0;
177	}
178
179	return_ACPI_STATUS(status);
180}
181
182/*******************************************************************************
183 *
184 * FUNCTION:    acpi_ut_delete_mutex
185 *
186 * PARAMETERS:  mutex_ID        - ID of the mutex to be deleted
187 *
188 * RETURN:      Status
189 *
190 * DESCRIPTION: Delete a mutex object.
191 *
192 ******************************************************************************/
193
194static void acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
195{
196
197	ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
198
199	acpi_os_delete_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
200
201	acpi_gbl_mutex_info[mutex_id].mutex = NULL;
202	acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
203
204	return_VOID;
205}
206
207/*******************************************************************************
208 *
209 * FUNCTION:    acpi_ut_acquire_mutex
210 *
211 * PARAMETERS:  mutex_ID        - ID of the mutex to be acquired
212 *
213 * RETURN:      Status
214 *
215 * DESCRIPTION: Acquire a mutex object.
216 *
217 ******************************************************************************/
218
219acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
220{
221	acpi_status status;
222	acpi_thread_id this_thread_id;
223
224	ACPI_FUNCTION_NAME(ut_acquire_mutex);
225
226	if (mutex_id > ACPI_MAX_MUTEX) {
227		return (AE_BAD_PARAMETER);
228	}
229
230	this_thread_id = acpi_os_get_thread_id();
231
232#ifdef ACPI_MUTEX_DEBUG
233	{
234		u32 i;
235		/*
236		 * Mutex debug code, for internal debugging only.
237		 *
238		 * Deadlock prevention. Check if this thread owns any mutexes of value
239		 * greater than or equal to this one. If so, the thread has violated
240		 * the mutex ordering rule. This indicates a coding error somewhere in
241		 * the ACPI subsystem code.
242		 */
243		for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
244			if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
245				if (i == mutex_id) {
246					ACPI_ERROR((AE_INFO,
247						    "Mutex [%s] already acquired by this thread [%u]",
248						    acpi_ut_get_mutex_name
249						    (mutex_id),
250						    (u32)this_thread_id));
251
252					return (AE_ALREADY_ACQUIRED);
253				}
254
255				ACPI_ERROR((AE_INFO,
256					    "Invalid acquire order: Thread %u owns [%s], wants [%s]",
257					    (u32)this_thread_id,
258					    acpi_ut_get_mutex_name(i),
259					    acpi_ut_get_mutex_name(mutex_id)));
260
261				return (AE_ACQUIRE_DEADLOCK);
262			}
263		}
264	}
265#endif
266
267	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
268			  "Thread %u attempting to acquire Mutex [%s]\n",
269			  (u32)this_thread_id,
270			  acpi_ut_get_mutex_name(mutex_id)));
271
272	status = acpi_os_acquire_mutex(acpi_gbl_mutex_info[mutex_id].mutex,
273				       ACPI_WAIT_FOREVER);
274	if (ACPI_SUCCESS(status)) {
275		ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
276				  "Thread %u acquired Mutex [%s]\n",
277				  (u32)this_thread_id,
278				  acpi_ut_get_mutex_name(mutex_id)));
279
280		acpi_gbl_mutex_info[mutex_id].use_count++;
281		acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
282	} else {
283		ACPI_EXCEPTION((AE_INFO, status,
284				"Thread %u could not acquire Mutex [0x%X]",
285				(u32)this_thread_id, mutex_id));
286	}
287
288	return (status);
289}
290
291/*******************************************************************************
292 *
293 * FUNCTION:    acpi_ut_release_mutex
294 *
295 * PARAMETERS:  mutex_ID        - ID of the mutex to be released
296 *
297 * RETURN:      Status
298 *
299 * DESCRIPTION: Release a mutex object.
300 *
301 ******************************************************************************/
302
303acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
304{
305	ACPI_FUNCTION_NAME(ut_release_mutex);
306
307	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Thread %u releasing Mutex [%s]\n",
308			  (u32)acpi_os_get_thread_id(),
309			  acpi_ut_get_mutex_name(mutex_id)));
310
311	if (mutex_id > ACPI_MAX_MUTEX) {
312		return (AE_BAD_PARAMETER);
313	}
314
315	/*
316	 * Mutex must be acquired in order to release it!
317	 */
318	if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
319		ACPI_ERROR((AE_INFO,
320			    "Mutex [0x%X] is not acquired, cannot release",
321			    mutex_id));
322
323		return (AE_NOT_ACQUIRED);
324	}
325#ifdef ACPI_MUTEX_DEBUG
326	{
327		u32 i;
328		/*
329		 * Mutex debug code, for internal debugging only.
330		 *
331		 * Deadlock prevention. Check if this thread owns any mutexes of value
332		 * greater than this one. If so, the thread has violated the mutex
333		 * ordering rule. This indicates a coding error somewhere in
334		 * the ACPI subsystem code.
335		 */
336		for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
337			if (acpi_gbl_mutex_info[i].thread_id ==
338			    acpi_os_get_thread_id()) {
339				if (i == mutex_id) {
340					continue;
341				}
342
343				ACPI_ERROR((AE_INFO,
344					    "Invalid release order: owns [%s], releasing [%s]",
345					    acpi_ut_get_mutex_name(i),
346					    acpi_ut_get_mutex_name(mutex_id)));
347
348				return (AE_RELEASE_DEADLOCK);
349			}
350		}
351	}
352#endif
353
354	/* Mark unlocked FIRST */
355
356	acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
357
358	acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
359	return (AE_OK);
360}