xref: /openbmc/linux/drivers/acpi/acpica/utmutex.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1 /*******************************************************************************
2  *
3  * Module Name: utmutex - local mutex support
4  *
5  ******************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2010, 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 
89 	/* Mutex for _OSI support */
90 	status = acpi_os_create_mutex(&acpi_gbl_osi_mutex);
91 	if (ACPI_FAILURE(status)) {
92 		return_ACPI_STATUS(status);
93 	}
94 
95 	/* Create the reader/writer lock for namespace access */
96 
97 	status = acpi_ut_create_rw_lock(&acpi_gbl_namespace_rw_lock);
98 	return_ACPI_STATUS(status);
99 }
100 
101 /*******************************************************************************
102  *
103  * FUNCTION:    acpi_ut_mutex_terminate
104  *
105  * PARAMETERS:  None.
106  *
107  * RETURN:      None.
108  *
109  * DESCRIPTION: Delete all of the system mutex objects. This includes mutexes,
110  *              spin locks, and reader/writer locks.
111  *
112  ******************************************************************************/
113 
114 void acpi_ut_mutex_terminate(void)
115 {
116 	u32 i;
117 
118 	ACPI_FUNCTION_TRACE(ut_mutex_terminate);
119 
120 	/* Delete each predefined mutex object */
121 
122 	for (i = 0; i < ACPI_NUM_MUTEX; i++) {
123 		acpi_ut_delete_mutex(i);
124 	}
125 
126 	acpi_os_delete_mutex(acpi_gbl_osi_mutex);
127 
128 	/* Delete the spinlocks */
129 
130 	acpi_os_delete_lock(acpi_gbl_gpe_lock);
131 	acpi_os_delete_lock(acpi_gbl_hardware_lock);
132 
133 	/* Delete the reader/writer lock */
134 
135 	acpi_ut_delete_rw_lock(&acpi_gbl_namespace_rw_lock);
136 	return_VOID;
137 }
138 
139 /*******************************************************************************
140  *
141  * FUNCTION:    acpi_ut_create_mutex
142  *
143  * PARAMETERS:  mutex_iD        - ID of the mutex to be created
144  *
145  * RETURN:      Status
146  *
147  * DESCRIPTION: Create a mutex object.
148  *
149  ******************************************************************************/
150 
151 static acpi_status acpi_ut_create_mutex(acpi_mutex_handle mutex_id)
152 {
153 	acpi_status status = AE_OK;
154 
155 	ACPI_FUNCTION_TRACE_U32(ut_create_mutex, mutex_id);
156 
157 	if (!acpi_gbl_mutex_info[mutex_id].mutex) {
158 		status =
159 		    acpi_os_create_mutex(&acpi_gbl_mutex_info[mutex_id].mutex);
160 		acpi_gbl_mutex_info[mutex_id].thread_id =
161 		    ACPI_MUTEX_NOT_ACQUIRED;
162 		acpi_gbl_mutex_info[mutex_id].use_count = 0;
163 	}
164 
165 	return_ACPI_STATUS(status);
166 }
167 
168 /*******************************************************************************
169  *
170  * FUNCTION:    acpi_ut_delete_mutex
171  *
172  * PARAMETERS:  mutex_iD        - ID of the mutex to be deleted
173  *
174  * RETURN:      Status
175  *
176  * DESCRIPTION: Delete a mutex object.
177  *
178  ******************************************************************************/
179 
180 static void acpi_ut_delete_mutex(acpi_mutex_handle mutex_id)
181 {
182 
183 	ACPI_FUNCTION_TRACE_U32(ut_delete_mutex, mutex_id);
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 
191 /*******************************************************************************
192  *
193  * FUNCTION:    acpi_ut_acquire_mutex
194  *
195  * PARAMETERS:  mutex_iD        - ID of the mutex to be acquired
196  *
197  * RETURN:      Status
198  *
199  * DESCRIPTION: Acquire a mutex object.
200  *
201  ******************************************************************************/
202 
203 acpi_status acpi_ut_acquire_mutex(acpi_mutex_handle mutex_id)
204 {
205 	acpi_status status;
206 	acpi_thread_id this_thread_id;
207 
208 	ACPI_FUNCTION_NAME(ut_acquire_mutex);
209 
210 	if (mutex_id > ACPI_MAX_MUTEX) {
211 		return (AE_BAD_PARAMETER);
212 	}
213 
214 	this_thread_id = acpi_os_get_thread_id();
215 
216 #ifdef ACPI_MUTEX_DEBUG
217 	{
218 		u32 i;
219 		/*
220 		 * Mutex debug code, for internal debugging only.
221 		 *
222 		 * Deadlock prevention.  Check if this thread owns any mutexes of value
223 		 * greater than or equal to this one.  If so, the thread has violated
224 		 * the mutex ordering rule.  This indicates a coding error somewhere in
225 		 * the ACPI subsystem code.
226 		 */
227 		for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
228 			if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
229 				if (i == mutex_id) {
230 					ACPI_ERROR((AE_INFO,
231 						    "Mutex [%s] already acquired by this thread [%u]",
232 						    acpi_ut_get_mutex_name
233 						    (mutex_id),
234 						    (u32)this_thread_id));
235 
236 					return (AE_ALREADY_ACQUIRED);
237 				}
238 
239 				ACPI_ERROR((AE_INFO,
240 					    "Invalid acquire order: Thread %u owns [%s], wants [%s]",
241 					    (u32)this_thread_id,
242 					    acpi_ut_get_mutex_name(i),
243 					    acpi_ut_get_mutex_name(mutex_id)));
244 
245 				return (AE_ACQUIRE_DEADLOCK);
246 			}
247 		}
248 	}
249 #endif
250 
251 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
252 			  "Thread %u attempting to acquire Mutex [%s]\n",
253 			  (u32)this_thread_id,
254 			  acpi_ut_get_mutex_name(mutex_id)));
255 
256 	status = acpi_os_acquire_mutex(acpi_gbl_mutex_info[mutex_id].mutex,
257 				       ACPI_WAIT_FOREVER);
258 	if (ACPI_SUCCESS(status)) {
259 		ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
260 				  "Thread %u acquired Mutex [%s]\n",
261 				  (u32)this_thread_id,
262 				  acpi_ut_get_mutex_name(mutex_id)));
263 
264 		acpi_gbl_mutex_info[mutex_id].use_count++;
265 		acpi_gbl_mutex_info[mutex_id].thread_id = this_thread_id;
266 	} else {
267 		ACPI_EXCEPTION((AE_INFO, status,
268 				"Thread %u could not acquire Mutex [0x%X]",
269 				(u32)this_thread_id, mutex_id));
270 	}
271 
272 	return (status);
273 }
274 
275 /*******************************************************************************
276  *
277  * FUNCTION:    acpi_ut_release_mutex
278  *
279  * PARAMETERS:  mutex_iD        - ID of the mutex to be released
280  *
281  * RETURN:      Status
282  *
283  * DESCRIPTION: Release a mutex object.
284  *
285  ******************************************************************************/
286 
287 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
288 {
289 	acpi_thread_id this_thread_id;
290 
291 	ACPI_FUNCTION_NAME(ut_release_mutex);
292 
293 	this_thread_id = acpi_os_get_thread_id();
294 
295 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Thread %u releasing Mutex [%s]\n",
296 			  (u32)this_thread_id,
297 			  acpi_ut_get_mutex_name(mutex_id)));
298 
299 	if (mutex_id > ACPI_MAX_MUTEX) {
300 		return (AE_BAD_PARAMETER);
301 	}
302 
303 	/*
304 	 * Mutex must be acquired in order to release it!
305 	 */
306 	if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
307 		ACPI_ERROR((AE_INFO,
308 			    "Mutex [0x%X] is not acquired, cannot release",
309 			    mutex_id));
310 
311 		return (AE_NOT_ACQUIRED);
312 	}
313 #ifdef ACPI_MUTEX_DEBUG
314 	{
315 		u32 i;
316 		/*
317 		 * Mutex debug code, for internal debugging only.
318 		 *
319 		 * Deadlock prevention.  Check if this thread owns any mutexes of value
320 		 * greater than this one.  If so, the thread has violated the mutex
321 		 * ordering rule.  This indicates a coding error somewhere in
322 		 * the ACPI subsystem code.
323 		 */
324 		for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
325 			if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
326 				if (i == mutex_id) {
327 					continue;
328 				}
329 
330 				ACPI_ERROR((AE_INFO,
331 					    "Invalid release order: owns [%s], releasing [%s]",
332 					    acpi_ut_get_mutex_name(i),
333 					    acpi_ut_get_mutex_name(mutex_id)));
334 
335 				return (AE_RELEASE_DEADLOCK);
336 			}
337 		}
338 	}
339 #endif
340 
341 	/* Mark unlocked FIRST */
342 
343 	acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
344 
345 	acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
346 	return (AE_OK);
347 }
348