xref: /openbmc/linux/drivers/acpi/acpica/utmutex.c (revision 30614cf3)
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
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 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 
127 void 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 
165 static 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 
194 static 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 
219 acpi_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 
303 acpi_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 }
361