xref: /openbmc/linux/drivers/acpi/acpica/utmutex.c (revision 28f65c11)
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 
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 	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 
121 void 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 
158 static 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 
187 static 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 
210 acpi_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 
294 acpi_status acpi_ut_release_mutex(acpi_mutex_handle mutex_id)
295 {
296 	acpi_thread_id this_thread_id;
297 
298 	ACPI_FUNCTION_NAME(ut_release_mutex);
299 
300 	this_thread_id = acpi_os_get_thread_id();
301 
302 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Thread %u releasing Mutex [%s]\n",
303 			  (u32)this_thread_id,
304 			  acpi_ut_get_mutex_name(mutex_id)));
305 
306 	if (mutex_id > ACPI_MAX_MUTEX) {
307 		return (AE_BAD_PARAMETER);
308 	}
309 
310 	/*
311 	 * Mutex must be acquired in order to release it!
312 	 */
313 	if (acpi_gbl_mutex_info[mutex_id].thread_id == ACPI_MUTEX_NOT_ACQUIRED) {
314 		ACPI_ERROR((AE_INFO,
315 			    "Mutex [0x%X] is not acquired, cannot release",
316 			    mutex_id));
317 
318 		return (AE_NOT_ACQUIRED);
319 	}
320 #ifdef ACPI_MUTEX_DEBUG
321 	{
322 		u32 i;
323 		/*
324 		 * Mutex debug code, for internal debugging only.
325 		 *
326 		 * Deadlock prevention.  Check if this thread owns any mutexes of value
327 		 * greater than this one.  If so, the thread has violated the mutex
328 		 * ordering rule.  This indicates a coding error somewhere in
329 		 * the ACPI subsystem code.
330 		 */
331 		for (i = mutex_id; i < ACPI_NUM_MUTEX; i++) {
332 			if (acpi_gbl_mutex_info[i].thread_id == this_thread_id) {
333 				if (i == mutex_id) {
334 					continue;
335 				}
336 
337 				ACPI_ERROR((AE_INFO,
338 					    "Invalid release order: owns [%s], releasing [%s]",
339 					    acpi_ut_get_mutex_name(i),
340 					    acpi_ut_get_mutex_name(mutex_id)));
341 
342 				return (AE_RELEASE_DEADLOCK);
343 			}
344 		}
345 	}
346 #endif
347 
348 	/* Mark unlocked FIRST */
349 
350 	acpi_gbl_mutex_info[mutex_id].thread_id = ACPI_MUTEX_NOT_ACQUIRED;
351 
352 	acpi_os_release_mutex(acpi_gbl_mutex_info[mutex_id].mutex);
353 	return (AE_OK);
354 }
355