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 
acpi_ut_mutex_initialize(void)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 
acpi_ut_mutex_terminate(void)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 
acpi_ut_create_mutex(acpi_mutex_handle mutex_id)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 
acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)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 
acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)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 
acpi_ut_release_mutex(acpi_mutex_handle mutex_id)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 }
349