1 /******************************************************************************
2 *
3 * Module Name: exmutex - ASL Mutex Acquire/Release functions
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2013, 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 #include "acinterp.h"
47 #include "acevents.h"
48
49 #define _COMPONENT ACPI_EXECUTER
50 ACPI_MODULE_NAME("exmutex")
51
52 /* Local prototypes */
53 static void
54 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
55 struct acpi_thread_state *thread);
56
57 /*******************************************************************************
58 *
59 * FUNCTION: acpi_ex_unlink_mutex
60 *
61 * PARAMETERS: obj_desc - The mutex to be unlinked
62 *
63 * RETURN: None
64 *
65 * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
66 *
67 ******************************************************************************/
68
acpi_ex_unlink_mutex(union acpi_operand_object * obj_desc)69 void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)
70 {
71 struct acpi_thread_state *thread = obj_desc->mutex.owner_thread;
72
73 if (!thread) {
74 return;
75 }
76
77 /* Doubly linked list */
78
79 if (obj_desc->mutex.next) {
80 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
81 }
82
83 if (obj_desc->mutex.prev) {
84 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
85
86 /*
87 * Migrate the previous sync level associated with this mutex to
88 * the previous mutex on the list so that it may be preserved.
89 * This handles the case where several mutexes have been acquired
90 * at the same level, but are not released in opposite order.
91 */
92 (obj_desc->mutex.prev)->mutex.original_sync_level =
93 obj_desc->mutex.original_sync_level;
94 } else {
95 thread->acquired_mutex_list = obj_desc->mutex.next;
96 }
97 }
98
99 /*******************************************************************************
100 *
101 * FUNCTION: acpi_ex_link_mutex
102 *
103 * PARAMETERS: obj_desc - The mutex to be linked
104 * thread - Current executing thread object
105 *
106 * RETURN: None
107 *
108 * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
109 *
110 ******************************************************************************/
111
112 static void
acpi_ex_link_mutex(union acpi_operand_object * obj_desc,struct acpi_thread_state * thread)113 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
114 struct acpi_thread_state *thread)
115 {
116 union acpi_operand_object *list_head;
117
118 list_head = thread->acquired_mutex_list;
119
120 /* This object will be the first object in the list */
121
122 obj_desc->mutex.prev = NULL;
123 obj_desc->mutex.next = list_head;
124
125 /* Update old first object to point back to this object */
126
127 if (list_head) {
128 list_head->mutex.prev = obj_desc;
129 }
130
131 /* Update list head */
132
133 thread->acquired_mutex_list = obj_desc;
134 }
135
136 /*******************************************************************************
137 *
138 * FUNCTION: acpi_ex_acquire_mutex_object
139 *
140 * PARAMETERS: timeout - Timeout in milliseconds
141 * obj_desc - Mutex object
142 * thread_id - Current thread state
143 *
144 * RETURN: Status
145 *
146 * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common
147 * path that supports multiple acquires by the same thread.
148 *
149 * MUTEX: Interpreter must be locked
150 *
151 * NOTE: This interface is called from three places:
152 * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator
153 * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the
154 * global lock
155 * 3) From the external interface, acpi_acquire_global_lock
156 *
157 ******************************************************************************/
158
159 acpi_status
acpi_ex_acquire_mutex_object(u16 timeout,union acpi_operand_object * obj_desc,acpi_thread_id thread_id)160 acpi_ex_acquire_mutex_object(u16 timeout,
161 union acpi_operand_object *obj_desc,
162 acpi_thread_id thread_id)
163 {
164 acpi_status status;
165
166 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc);
167
168 if (!obj_desc) {
169 return_ACPI_STATUS(AE_BAD_PARAMETER);
170 }
171
172 /* Support for multiple acquires by the owning thread */
173
174 if (obj_desc->mutex.thread_id == thread_id) {
175 /*
176 * The mutex is already owned by this thread, just increment the
177 * acquisition depth
178 */
179 obj_desc->mutex.acquisition_depth++;
180 return_ACPI_STATUS(AE_OK);
181 }
182
183 /* Acquire the mutex, wait if necessary. Special case for Global Lock */
184
185 if (obj_desc == acpi_gbl_global_lock_mutex) {
186 status = acpi_ev_acquire_global_lock(timeout);
187 } else {
188 status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
189 timeout);
190 }
191
192 if (ACPI_FAILURE(status)) {
193
194 /* Includes failure from a timeout on time_desc */
195
196 return_ACPI_STATUS(status);
197 }
198
199 /* Acquired the mutex: update mutex object */
200
201 obj_desc->mutex.thread_id = thread_id;
202 obj_desc->mutex.acquisition_depth = 1;
203 obj_desc->mutex.original_sync_level = 0;
204 obj_desc->mutex.owner_thread = NULL; /* Used only for AML Acquire() */
205
206 return_ACPI_STATUS(AE_OK);
207 }
208
209 /*******************************************************************************
210 *
211 * FUNCTION: acpi_ex_acquire_mutex
212 *
213 * PARAMETERS: time_desc - Timeout integer
214 * obj_desc - Mutex object
215 * walk_state - Current method execution state
216 *
217 * RETURN: Status
218 *
219 * DESCRIPTION: Acquire an AML mutex
220 *
221 ******************************************************************************/
222
223 acpi_status
acpi_ex_acquire_mutex(union acpi_operand_object * time_desc,union acpi_operand_object * obj_desc,struct acpi_walk_state * walk_state)224 acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
225 union acpi_operand_object *obj_desc,
226 struct acpi_walk_state *walk_state)
227 {
228 acpi_status status;
229
230 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
231
232 if (!obj_desc) {
233 return_ACPI_STATUS(AE_BAD_PARAMETER);
234 }
235
236 /* Must have a valid thread state struct */
237
238 if (!walk_state->thread) {
239 ACPI_ERROR((AE_INFO,
240 "Cannot acquire Mutex [%4.4s], null thread info",
241 acpi_ut_get_node_name(obj_desc->mutex.node)));
242 return_ACPI_STATUS(AE_AML_INTERNAL);
243 }
244
245 /*
246 * Current sync level must be less than or equal to the sync level of the
247 * mutex. This mechanism provides some deadlock prevention
248 */
249 if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
250 ACPI_ERROR((AE_INFO,
251 "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%u)",
252 acpi_ut_get_node_name(obj_desc->mutex.node),
253 walk_state->thread->current_sync_level));
254 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
255 }
256
257 status = acpi_ex_acquire_mutex_object((u16) time_desc->integer.value,
258 obj_desc,
259 walk_state->thread->thread_id);
260 if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) {
261
262 /* Save Thread object, original/current sync levels */
263
264 obj_desc->mutex.owner_thread = walk_state->thread;
265 obj_desc->mutex.original_sync_level =
266 walk_state->thread->current_sync_level;
267 walk_state->thread->current_sync_level =
268 obj_desc->mutex.sync_level;
269
270 /* Link the mutex to the current thread for force-unlock at method exit */
271
272 acpi_ex_link_mutex(obj_desc, walk_state->thread);
273 }
274
275 return_ACPI_STATUS(status);
276 }
277
278 /*******************************************************************************
279 *
280 * FUNCTION: acpi_ex_release_mutex_object
281 *
282 * PARAMETERS: obj_desc - The object descriptor for this op
283 *
284 * RETURN: Status
285 *
286 * DESCRIPTION: Release a previously acquired Mutex, low level interface.
287 * Provides a common path that supports multiple releases (after
288 * previous multiple acquires) by the same thread.
289 *
290 * MUTEX: Interpreter must be locked
291 *
292 * NOTE: This interface is called from three places:
293 * 1) From acpi_ex_release_mutex, via an AML Acquire() operator
294 * 2) From acpi_ex_release_global_lock when an AML Field access requires the
295 * global lock
296 * 3) From the external interface, acpi_release_global_lock
297 *
298 ******************************************************************************/
299
acpi_ex_release_mutex_object(union acpi_operand_object * obj_desc)300 acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc)
301 {
302 acpi_status status = AE_OK;
303
304 ACPI_FUNCTION_TRACE(ex_release_mutex_object);
305
306 if (obj_desc->mutex.acquisition_depth == 0) {
307 return_ACPI_STATUS(AE_NOT_ACQUIRED);
308 }
309
310 /* Match multiple Acquires with multiple Releases */
311
312 obj_desc->mutex.acquisition_depth--;
313 if (obj_desc->mutex.acquisition_depth != 0) {
314
315 /* Just decrement the depth and return */
316
317 return_ACPI_STATUS(AE_OK);
318 }
319
320 if (obj_desc->mutex.owner_thread) {
321
322 /* Unlink the mutex from the owner's list */
323
324 acpi_ex_unlink_mutex(obj_desc);
325 obj_desc->mutex.owner_thread = NULL;
326 }
327
328 /* Release the mutex, special case for Global Lock */
329
330 if (obj_desc == acpi_gbl_global_lock_mutex) {
331 status = acpi_ev_release_global_lock();
332 } else {
333 acpi_os_release_mutex(obj_desc->mutex.os_mutex);
334 }
335
336 /* Clear mutex info */
337
338 obj_desc->mutex.thread_id = 0;
339 return_ACPI_STATUS(status);
340 }
341
342 /*******************************************************************************
343 *
344 * FUNCTION: acpi_ex_release_mutex
345 *
346 * PARAMETERS: obj_desc - The object descriptor for this op
347 * walk_state - Current method execution state
348 *
349 * RETURN: Status
350 *
351 * DESCRIPTION: Release a previously acquired Mutex.
352 *
353 ******************************************************************************/
354
355 acpi_status
acpi_ex_release_mutex(union acpi_operand_object * obj_desc,struct acpi_walk_state * walk_state)356 acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
357 struct acpi_walk_state *walk_state)
358 {
359 acpi_status status = AE_OK;
360 u8 previous_sync_level;
361 struct acpi_thread_state *owner_thread;
362
363 ACPI_FUNCTION_TRACE(ex_release_mutex);
364
365 if (!obj_desc) {
366 return_ACPI_STATUS(AE_BAD_PARAMETER);
367 }
368
369 owner_thread = obj_desc->mutex.owner_thread;
370
371 /* The mutex must have been previously acquired in order to release it */
372
373 if (!owner_thread) {
374 ACPI_ERROR((AE_INFO,
375 "Cannot release Mutex [%4.4s], not acquired",
376 acpi_ut_get_node_name(obj_desc->mutex.node)));
377 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
378 }
379
380 /* Must have a valid thread ID */
381
382 if (!walk_state->thread) {
383 ACPI_ERROR((AE_INFO,
384 "Cannot release Mutex [%4.4s], null thread info",
385 acpi_ut_get_node_name(obj_desc->mutex.node)));
386 return_ACPI_STATUS(AE_AML_INTERNAL);
387 }
388
389 /*
390 * The Mutex is owned, but this thread must be the owner.
391 * Special case for Global Lock, any thread can release
392 */
393 if ((owner_thread->thread_id != walk_state->thread->thread_id) &&
394 (obj_desc != acpi_gbl_global_lock_mutex)) {
395 ACPI_ERROR((AE_INFO,
396 "Thread %u cannot release Mutex [%4.4s] acquired by thread %u",
397 (u32)walk_state->thread->thread_id,
398 acpi_ut_get_node_name(obj_desc->mutex.node),
399 (u32)owner_thread->thread_id));
400 return_ACPI_STATUS(AE_AML_NOT_OWNER);
401 }
402
403 /*
404 * The sync level of the mutex must be equal to the current sync level. In
405 * other words, the current level means that at least one mutex at that
406 * level is currently being held. Attempting to release a mutex of a
407 * different level can only mean that the mutex ordering rule is being
408 * violated. This behavior is clarified in ACPI 4.0 specification.
409 */
410 if (obj_desc->mutex.sync_level != owner_thread->current_sync_level) {
411 ACPI_ERROR((AE_INFO,
412 "Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %u current %u",
413 acpi_ut_get_node_name(obj_desc->mutex.node),
414 obj_desc->mutex.sync_level,
415 walk_state->thread->current_sync_level));
416 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
417 }
418
419 /*
420 * Get the previous sync_level from the head of the acquired mutex list.
421 * This handles the case where several mutexes at the same level have been
422 * acquired, but are not released in reverse order.
423 */
424 previous_sync_level =
425 owner_thread->acquired_mutex_list->mutex.original_sync_level;
426
427 status = acpi_ex_release_mutex_object(obj_desc);
428 if (ACPI_FAILURE(status)) {
429 return_ACPI_STATUS(status);
430 }
431
432 if (obj_desc->mutex.acquisition_depth == 0) {
433
434 /* Restore the previous sync_level */
435
436 owner_thread->current_sync_level = previous_sync_level;
437 }
438
439 return_ACPI_STATUS(status);
440 }
441
442 /*******************************************************************************
443 *
444 * FUNCTION: acpi_ex_release_all_mutexes
445 *
446 * PARAMETERS: thread - Current executing thread object
447 *
448 * RETURN: Status
449 *
450 * DESCRIPTION: Release all mutexes held by this thread
451 *
452 * NOTE: This function is called as the thread is exiting the interpreter.
453 * Mutexes are not released when an individual control method is exited, but
454 * only when the parent thread actually exits the interpreter. This allows one
455 * method to acquire a mutex, and a different method to release it, as long as
456 * this is performed underneath a single parent control method.
457 *
458 ******************************************************************************/
459
acpi_ex_release_all_mutexes(struct acpi_thread_state * thread)460 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
461 {
462 union acpi_operand_object *next = thread->acquired_mutex_list;
463 union acpi_operand_object *obj_desc;
464
465 ACPI_FUNCTION_NAME(ex_release_all_mutexes);
466
467 /* Traverse the list of owned mutexes, releasing each one */
468
469 while (next) {
470 obj_desc = next;
471 next = obj_desc->mutex.next;
472
473 obj_desc->mutex.prev = NULL;
474 obj_desc->mutex.next = NULL;
475 obj_desc->mutex.acquisition_depth = 0;
476
477 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
478 "Force-releasing held mutex: %p\n",
479 obj_desc));
480
481 /* Release the mutex, special case for Global Lock */
482
483 if (obj_desc == acpi_gbl_global_lock_mutex) {
484
485 /* Ignore errors */
486
487 (void)acpi_ev_release_global_lock();
488 } else {
489 acpi_os_release_mutex(obj_desc->mutex.os_mutex);
490 }
491
492 /* Mark mutex unowned */
493
494 obj_desc->mutex.owner_thread = NULL;
495 obj_desc->mutex.thread_id = 0;
496
497 /* Update Thread sync_level (Last mutex is the important one) */
498
499 thread->current_sync_level =
500 obj_desc->mutex.original_sync_level;
501 }
502 }
503