xref: /openbmc/linux/drivers/acpi/acpica/utmutex.c (revision b627b4ed)
1 /*******************************************************************************
2  *
3  * Module Name: utmutex - local mutex support
4  *
5  ******************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2008, 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 acpi_status 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 
89 	/* Create the reader/writer lock for namespace access */
90 
91 	status = acpi_ut_create_rw_lock(&acpi_gbl_namespace_rw_lock);
92 	return_ACPI_STATUS(status);
93 }
94 
95 /*******************************************************************************
96  *
97  * FUNCTION:    acpi_ut_mutex_terminate
98  *
99  * PARAMETERS:  None.
100  *
101  * RETURN:      None.
102  *
103  * DESCRIPTION: Delete all of the system mutex objects. This includes mutexes,
104  *              spin locks, and reader/writer locks.
105  *
106  ******************************************************************************/
107 
108 void acpi_ut_mutex_terminate(void)
109 {
110 	u32 i;
111 
112 	ACPI_FUNCTION_TRACE(ut_mutex_terminate);
113 
114 	/* Delete each predefined mutex object */
115 
116 	for (i = 0; i < ACPI_NUM_MUTEX; i++) {
117 		(void)acpi_ut_delete_mutex(i);
118 	}
119 
120 	/* Delete the spinlocks */
121 
122 	acpi_os_delete_lock(acpi_gbl_gpe_lock);
123 	acpi_os_delete_lock(acpi_gbl_hardware_lock);
124 
125 	/* Delete the reader/writer lock */
126 
127 	acpi_ut_delete_rw_lock(&acpi_gbl_namespace_rw_lock);
128 	return_VOID;
129 }
130 
131 /*******************************************************************************
132  *
133  * FUNCTION:    acpi_ut_create_mutex
134  *
135  * PARAMETERS:  mutex_iD        - ID of the mutex to be created
136  *
137  * RETURN:      Status
138  *
139  * DESCRIPTION: Create a mutex object.
140  *
141  ******************************************************************************/
142 
143 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
144 {
145 	acpi_status status = AE_OK;
146 
147 	ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
148 
149 	if (mutex_id > ACPI_MAX_MUTEX) {
150 		return_ACPI_STATUS(AE_BAD_PARAMETER);
151 	}
152 
153 	if (!acpi_gbl_mutex_info[mutex_id].mutex) {
154 		status =
155 		    acpi_os_create_mutex(&acpi_gbl_mutex_info[mutex_id].mutex);
156 		acpi_gbl_mutex_info[mutex_id].thread_id =
157 		    ACPI_MUTEX_NOT_ACQUIRED;
158 		acpi_gbl_mutex_info[mutex_id].use_count = 0;
159 	}
160 
161 	return_ACPI_STATUS(status);
162 }
163 
164 /*******************************************************************************
165  *
166  * FUNCTION:    acpi_ut_delete_mutex
167  *
168  * PARAMETERS:  mutex_iD        - ID of the mutex to be deleted
169  *
170  * RETURN:      Status
171  *
172  * DESCRIPTION: Delete a mutex object.
173  *
174  ******************************************************************************/
175 
176 static acpi_status acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
177 {
178 
179 	ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
180 
181 	if (mutex_id > ACPI_MAX_MUTEX) {
182 		return_ACPI_STATUS(AE_BAD_PARAMETER);
183 	}
184 
185 	acpi_os_delete_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
186 
187 	acpi_gbl_mutex_info[mutex_id].mutex = NULL;
188 	acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
189 
190 	return_ACPI_STATUS(AE_OK);
191 }
192 
193 /*******************************************************************************
194  *
195  * FUNCTION:    acpi_ut_acquire_mutex
196  *
197  * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
198  *
199  * RETURN:      Status
200  *
201  * DESCRIPTION: Acquire a mutex object.
202  *
203  ******************************************************************************/
204 
205 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
206 {
207 	acpi_status status;
208 	acpi_thread_id this_thread_id;
209 
210 	ACPI_FUNCTION_NAME(ut_acquire_mutex);
211 
212 	if (mutex_id > ACPI_MAX_MUTEX) {
213 		return (AE_BAD_PARAMETER);
214 	}
215 
216 	this_thread_id = acpi_os_get_thread_id();
217 
218 #ifdef ACPI_MUTEX_DEBUG
219 	{
220 		u32 i;
221 		/*
222 		 * Mutex debug code, for internal debugging only.
223 		 *
224 		 * Deadlock prevention.  Check if this thread owns any mutexes of value
225 		 * greater than or equal to this one.  If so, the thread has violated
226 		 * the mutex ordering rule.  This indicates a coding error somewhere in
227 		 * the ACPI subsystem code.
228 		 */
229 		for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
230 			if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
231 				if (i == mutex_id) {
232 					ACPI_ERROR((AE_INFO,
233 						    "Mutex [%s] already acquired by this thread [%X]",
234 						    acpi_ut_get_mutex_name
235 						    (mutex_id),
236 						    this_thread_id));
237 
238 					return (AE_ALREADY_ACQUIRED);
239 				}
240 
241 				ACPI_ERROR((AE_INFO,
242 					    "Invalid acquire order: Thread %X owns [%s], wants [%s]",
243 					    this_thread_id,
244 					    acpi_ut_get_mutex_name(i),
245 					    acpi_ut_get_mutex_name(mutex_id)));
246 
247 				return (AE_ACQUIRE_DEADLOCK);
248 			}
249 		}
250 	}
251 #endif
252 
253 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
254 			  "Thread %lX attempting to acquire Mutex [%s]\n",
255 			  (unsigned long)this_thread_id,
256 			  acpi_ut_get_mutex_name(mutex_id)));
257 
258 	status = acpi_os_acquire_mutex(acpi_gbl_mutex_info[mutex_id].mutex,
259 				       ACPI_WAIT_FOREVER);
260 	if (ACPI_SUCCESS(status)) {
261 		ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
262 				  "Thread %lX acquired Mutex [%s]\n",
263 				  (unsigned long)this_thread_id,
264 				  acpi_ut_get_mutex_name(mutex_id)));
265 
266 		acpi_gbl_mutex_info[mutex_id].use_count++;
267 		acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
268 	} else {
269 		ACPI_EXCEPTION((AE_INFO, status,
270 				"Thread %lX could not acquire Mutex [%X]",
271 				(unsigned long)this_thread_id, mutex_id));
272 	}
273 
274 	return (status);
275 }
276 
277 /*******************************************************************************
278  *
279  * FUNCTION:    acpi_ut_release_mutex
280  *
281  * PARAMETERS:  mutex_iD        - ID of the mutex to be released
282  *
283  * RETURN:      Status
284  *
285  * DESCRIPTION: Release a mutex object.
286  *
287  ******************************************************************************/
288 
289 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
290 {
291 	acpi_thread_id this_thread_id;
292 
293 	ACPI_FUNCTION_NAME(ut_release_mutex);
294 
295 	this_thread_id = acpi_os_get_thread_id();
296 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
297 			  "Thread %lX releasing Mutex [%s]\n",
298 			  (unsigned long)this_thread_id,
299 			  acpi_ut_get_mutex_name(mutex_id)));
300 
301 	if (mutex_id > ACPI_MAX_MUTEX) {
302 		return (AE_BAD_PARAMETER);
303 	}
304 
305 	/*
306 	 * Mutex must be acquired in order to release it!
307 	 */
308 	if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
309 		ACPI_ERROR((AE_INFO,
310 			    "Mutex [%X] is not acquired, cannot release",
311 			    mutex_id));
312 
313 		return (AE_NOT_ACQUIRED);
314 	}
315 #ifdef ACPI_MUTEX_DEBUG
316 	{
317 		u32 i;
318 		/*
319 		 * Mutex debug code, for internal debugging only.
320 		 *
321 		 * Deadlock prevention.  Check if this thread owns any mutexes of value
322 		 * greater than this one.  If so, the thread has violated the mutex
323 		 * ordering rule.  This indicates a coding error somewhere in
324 		 * the ACPI subsystem code.
325 		 */
326 		for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
327 			if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
328 				if (i == mutex_id) {
329 					continue;
330 				}
331 
332 				ACPI_ERROR((AE_INFO,
333 					    "Invalid release order: owns [%s], releasing [%s]",
334 					    acpi_ut_get_mutex_name(i),
335 					    acpi_ut_get_mutex_name(mutex_id)));
336 
337 				return (AE_RELEASE_DEADLOCK);
338 			}
339 		}
340 	}
341 #endif
342 
343 	/* Mark unlocked FIRST */
344 
345 	acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
346 
347 	acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
348 	return (AE_OK);
349 }
350