1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
4 * Module Name: exmutex - ASL Mutex Acquire/Release functions
6 * Copyright (C) 2000 - 2020, Intel Corp.
8 *****************************************************************************/
10 #include <acpi/acpi.h>
15 #define _COMPONENT ACPI_EXECUTER
16 ACPI_MODULE_NAME("exmutex")
18 /* Local prototypes */
20 acpi_ex_link_mutex(union acpi_operand_object
*obj_desc
,
21 struct acpi_thread_state
*thread
);
23 /*******************************************************************************
25 * FUNCTION: acpi_ex_unlink_mutex
27 * PARAMETERS: obj_desc - The mutex to be unlinked
31 * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
33 ******************************************************************************/
35 void acpi_ex_unlink_mutex(union acpi_operand_object
*obj_desc
)
37 struct acpi_thread_state
*thread
= obj_desc
->mutex
.owner_thread
;
43 /* Doubly linked list */
45 if (obj_desc
->mutex
.next
) {
46 (obj_desc
->mutex
.next
)->mutex
.prev
= obj_desc
->mutex
.prev
;
49 if (obj_desc
->mutex
.prev
) {
50 (obj_desc
->mutex
.prev
)->mutex
.next
= obj_desc
->mutex
.next
;
53 * Migrate the previous sync level associated with this mutex to
54 * the previous mutex on the list so that it may be preserved.
55 * This handles the case where several mutexes have been acquired
56 * at the same level, but are not released in opposite order.
58 (obj_desc
->mutex
.prev
)->mutex
.original_sync_level
=
59 obj_desc
->mutex
.original_sync_level
;
61 thread
->acquired_mutex_list
= obj_desc
->mutex
.next
;
65 /*******************************************************************************
67 * FUNCTION: acpi_ex_link_mutex
69 * PARAMETERS: obj_desc - The mutex to be linked
70 * thread - Current executing thread object
74 * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
76 ******************************************************************************/
79 acpi_ex_link_mutex(union acpi_operand_object
*obj_desc
,
80 struct acpi_thread_state
*thread
)
82 union acpi_operand_object
*list_head
;
84 list_head
= thread
->acquired_mutex_list
;
86 /* This object will be the first object in the list */
88 obj_desc
->mutex
.prev
= NULL
;
89 obj_desc
->mutex
.next
= list_head
;
91 /* Update old first object to point back to this object */
94 list_head
->mutex
.prev
= obj_desc
;
97 /* Update list head */
99 thread
->acquired_mutex_list
= obj_desc
;
102 /*******************************************************************************
104 * FUNCTION: acpi_ex_acquire_mutex_object
106 * PARAMETERS: timeout - Timeout in milliseconds
107 * obj_desc - Mutex object
108 * thread_id - Current thread state
112 * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common
113 * path that supports multiple acquires by the same thread.
115 * MUTEX: Interpreter must be locked
117 * NOTE: This interface is called from three places:
118 * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator
119 * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the
121 * 3) From the external interface, acpi_acquire_global_lock
123 ******************************************************************************/
126 acpi_ex_acquire_mutex_object(u16 timeout
,
127 union acpi_operand_object
*obj_desc
,
128 acpi_thread_id thread_id
)
132 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object
, obj_desc
);
135 return_ACPI_STATUS(AE_BAD_PARAMETER
);
138 /* Support for multiple acquires by the owning thread */
140 if (obj_desc
->mutex
.thread_id
== thread_id
) {
142 * The mutex is already owned by this thread, just increment the
145 obj_desc
->mutex
.acquisition_depth
++;
146 return_ACPI_STATUS(AE_OK
);
149 /* Acquire the mutex, wait if necessary. Special case for Global Lock */
151 if (obj_desc
== acpi_gbl_global_lock_mutex
) {
152 status
= acpi_ev_acquire_global_lock(timeout
);
155 acpi_ex_system_wait_mutex(obj_desc
->mutex
.os_mutex
,
159 if (ACPI_FAILURE(status
)) {
161 /* Includes failure from a timeout on time_desc */
163 return_ACPI_STATUS(status
);
166 /* Acquired the mutex: update mutex object */
168 obj_desc
->mutex
.thread_id
= thread_id
;
169 obj_desc
->mutex
.acquisition_depth
= 1;
170 obj_desc
->mutex
.original_sync_level
= 0;
171 obj_desc
->mutex
.owner_thread
= NULL
; /* Used only for AML Acquire() */
173 return_ACPI_STATUS(AE_OK
);
176 /*******************************************************************************
178 * FUNCTION: acpi_ex_acquire_mutex
180 * PARAMETERS: time_desc - Timeout integer
181 * obj_desc - Mutex object
182 * walk_state - Current method execution state
186 * DESCRIPTION: Acquire an AML mutex
188 ******************************************************************************/
191 acpi_ex_acquire_mutex(union acpi_operand_object
*time_desc
,
192 union acpi_operand_object
*obj_desc
,
193 struct acpi_walk_state
*walk_state
)
197 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex
, obj_desc
);
200 return_ACPI_STATUS(AE_BAD_PARAMETER
);
203 /* Must have a valid thread state struct */
205 if (!walk_state
->thread
) {
207 "Cannot acquire Mutex [%4.4s], null thread info",
208 acpi_ut_get_node_name(obj_desc
->mutex
.node
)));
209 return_ACPI_STATUS(AE_AML_INTERNAL
);
213 * Current sync level must be less than or equal to the sync level
214 * of the mutex. This mechanism provides some deadlock prevention.
216 if (walk_state
->thread
->current_sync_level
> obj_desc
->mutex
.sync_level
) {
218 "Cannot acquire Mutex [%4.4s], "
219 "current SyncLevel is too large (%u)",
220 acpi_ut_get_node_name(obj_desc
->mutex
.node
),
221 walk_state
->thread
->current_sync_level
));
222 return_ACPI_STATUS(AE_AML_MUTEX_ORDER
);
225 ACPI_DEBUG_PRINT((ACPI_DB_EXEC
,
226 "Acquiring: Mutex SyncLevel %u, Thread SyncLevel %u, "
228 obj_desc
->mutex
.sync_level
,
229 walk_state
->thread
->current_sync_level
,
230 obj_desc
->mutex
.acquisition_depth
,
231 walk_state
->thread
));
233 status
= acpi_ex_acquire_mutex_object((u16
)time_desc
->integer
.value
,
235 walk_state
->thread
->thread_id
);
237 if (ACPI_SUCCESS(status
) && obj_desc
->mutex
.acquisition_depth
== 1) {
239 /* Save Thread object, original/current sync levels */
241 obj_desc
->mutex
.owner_thread
= walk_state
->thread
;
242 obj_desc
->mutex
.original_sync_level
=
243 walk_state
->thread
->current_sync_level
;
244 walk_state
->thread
->current_sync_level
=
245 obj_desc
->mutex
.sync_level
;
247 /* Link the mutex to the current thread for force-unlock at method exit */
249 acpi_ex_link_mutex(obj_desc
, walk_state
->thread
);
252 ACPI_DEBUG_PRINT((ACPI_DB_EXEC
,
253 "Acquired: Mutex SyncLevel %u, Thread SyncLevel %u, Depth %u\n",
254 obj_desc
->mutex
.sync_level
,
255 walk_state
->thread
->current_sync_level
,
256 obj_desc
->mutex
.acquisition_depth
));
258 return_ACPI_STATUS(status
);
261 /*******************************************************************************
263 * FUNCTION: acpi_ex_release_mutex_object
265 * PARAMETERS: obj_desc - The object descriptor for this op
269 * DESCRIPTION: Release a previously acquired Mutex, low level interface.
270 * Provides a common path that supports multiple releases (after
271 * previous multiple acquires) by the same thread.
273 * MUTEX: Interpreter must be locked
275 * NOTE: This interface is called from three places:
276 * 1) From acpi_ex_release_mutex, via an AML Acquire() operator
277 * 2) From acpi_ex_release_global_lock when an AML Field access requires the
279 * 3) From the external interface, acpi_release_global_lock
281 ******************************************************************************/
283 acpi_status
acpi_ex_release_mutex_object(union acpi_operand_object
*obj_desc
)
285 acpi_status status
= AE_OK
;
287 ACPI_FUNCTION_TRACE(ex_release_mutex_object
);
289 if (obj_desc
->mutex
.acquisition_depth
== 0) {
290 return_ACPI_STATUS(AE_NOT_ACQUIRED
);
293 /* Match multiple Acquires with multiple Releases */
295 obj_desc
->mutex
.acquisition_depth
--;
296 if (obj_desc
->mutex
.acquisition_depth
!= 0) {
298 /* Just decrement the depth and return */
300 return_ACPI_STATUS(AE_OK
);
303 if (obj_desc
->mutex
.owner_thread
) {
305 /* Unlink the mutex from the owner's list */
307 acpi_ex_unlink_mutex(obj_desc
);
308 obj_desc
->mutex
.owner_thread
= NULL
;
311 /* Release the mutex, special case for Global Lock */
313 if (obj_desc
== acpi_gbl_global_lock_mutex
) {
314 status
= acpi_ev_release_global_lock();
316 acpi_os_release_mutex(obj_desc
->mutex
.os_mutex
);
319 /* Clear mutex info */
321 obj_desc
->mutex
.thread_id
= 0;
322 return_ACPI_STATUS(status
);
325 /*******************************************************************************
327 * FUNCTION: acpi_ex_release_mutex
329 * PARAMETERS: obj_desc - The object descriptor for this op
330 * walk_state - Current method execution state
334 * DESCRIPTION: Release a previously acquired Mutex.
336 ******************************************************************************/
339 acpi_ex_release_mutex(union acpi_operand_object
*obj_desc
,
340 struct acpi_walk_state
*walk_state
)
342 u8 previous_sync_level
;
343 struct acpi_thread_state
*owner_thread
;
344 acpi_status status
= AE_OK
;
346 ACPI_FUNCTION_TRACE(ex_release_mutex
);
349 return_ACPI_STATUS(AE_BAD_PARAMETER
);
352 owner_thread
= obj_desc
->mutex
.owner_thread
;
354 /* The mutex must have been previously acquired in order to release it */
358 "Cannot release Mutex [%4.4s], not acquired",
359 acpi_ut_get_node_name(obj_desc
->mutex
.node
)));
360 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED
);
363 /* Must have a valid thread ID */
365 if (!walk_state
->thread
) {
367 "Cannot release Mutex [%4.4s], null thread info",
368 acpi_ut_get_node_name(obj_desc
->mutex
.node
)));
369 return_ACPI_STATUS(AE_AML_INTERNAL
);
373 * The Mutex is owned, but this thread must be the owner.
374 * Special case for Global Lock, any thread can release
376 if ((owner_thread
->thread_id
!= walk_state
->thread
->thread_id
) &&
377 (obj_desc
!= acpi_gbl_global_lock_mutex
)) {
379 "Thread %u cannot release Mutex [%4.4s] acquired by thread %u",
380 (u32
)walk_state
->thread
->thread_id
,
381 acpi_ut_get_node_name(obj_desc
->mutex
.node
),
382 (u32
)owner_thread
->thread_id
));
383 return_ACPI_STATUS(AE_AML_NOT_OWNER
);
387 * The sync level of the mutex must be equal to the current sync level. In
388 * other words, the current level means that at least one mutex at that
389 * level is currently being held. Attempting to release a mutex of a
390 * different level can only mean that the mutex ordering rule is being
391 * violated. This behavior is clarified in ACPI 4.0 specification.
393 if (obj_desc
->mutex
.sync_level
!= owner_thread
->current_sync_level
) {
395 "Cannot release Mutex [%4.4s], SyncLevel mismatch: "
396 "mutex %u current %u",
397 acpi_ut_get_node_name(obj_desc
->mutex
.node
),
398 obj_desc
->mutex
.sync_level
,
399 walk_state
->thread
->current_sync_level
));
400 return_ACPI_STATUS(AE_AML_MUTEX_ORDER
);
404 * Get the previous sync_level from the head of the acquired mutex list.
405 * This handles the case where several mutexes at the same level have been
406 * acquired, but are not released in reverse order.
408 previous_sync_level
=
409 owner_thread
->acquired_mutex_list
->mutex
.original_sync_level
;
411 ACPI_DEBUG_PRINT((ACPI_DB_EXEC
,
412 "Releasing: Object SyncLevel %u, Thread SyncLevel %u, "
413 "Prev SyncLevel %u, Depth %u TID %p\n",
414 obj_desc
->mutex
.sync_level
,
415 walk_state
->thread
->current_sync_level
,
417 obj_desc
->mutex
.acquisition_depth
,
418 walk_state
->thread
));
420 status
= acpi_ex_release_mutex_object(obj_desc
);
421 if (ACPI_FAILURE(status
)) {
422 return_ACPI_STATUS(status
);
425 if (obj_desc
->mutex
.acquisition_depth
== 0) {
427 /* Restore the previous sync_level */
429 owner_thread
->current_sync_level
= previous_sync_level
;
432 ACPI_DEBUG_PRINT((ACPI_DB_EXEC
,
433 "Released: Object SyncLevel %u, Thread SyncLevel, %u, "
434 "Prev SyncLevel %u, Depth %u\n",
435 obj_desc
->mutex
.sync_level
,
436 walk_state
->thread
->current_sync_level
,
438 obj_desc
->mutex
.acquisition_depth
));
440 return_ACPI_STATUS(status
);
443 /*******************************************************************************
445 * FUNCTION: acpi_ex_release_all_mutexes
447 * PARAMETERS: thread - Current executing thread object
451 * DESCRIPTION: Release all mutexes held by this thread
453 * NOTE: This function is called as the thread is exiting the interpreter.
454 * Mutexes are not released when an individual control method is exited, but
455 * only when the parent thread actually exits the interpreter. This allows one
456 * method to acquire a mutex, and a different method to release it, as long as
457 * this is performed underneath a single parent control method.
459 ******************************************************************************/
461 void acpi_ex_release_all_mutexes(struct acpi_thread_state
*thread
)
463 union acpi_operand_object
*next
= thread
->acquired_mutex_list
;
464 union acpi_operand_object
*obj_desc
;
466 ACPI_FUNCTION_TRACE(ex_release_all_mutexes
);
468 /* Traverse the list of owned mutexes, releasing each one */
472 ACPI_DEBUG_PRINT((ACPI_DB_EXEC
,
473 "Mutex [%4.4s] force-release, SyncLevel %u Depth %u\n",
474 obj_desc
->mutex
.node
->name
.ascii
,
475 obj_desc
->mutex
.sync_level
,
476 obj_desc
->mutex
.acquisition_depth
));
478 /* Release the mutex, special case for Global Lock */
480 if (obj_desc
== acpi_gbl_global_lock_mutex
) {
484 (void)acpi_ev_release_global_lock();
486 acpi_os_release_mutex(obj_desc
->mutex
.os_mutex
);
489 /* Update Thread sync_level (Last mutex is the important one) */
491 thread
->current_sync_level
=
492 obj_desc
->mutex
.original_sync_level
;
494 /* Mark mutex unowned */
496 next
= obj_desc
->mutex
.next
;
498 obj_desc
->mutex
.prev
= NULL
;
499 obj_desc
->mutex
.next
= NULL
;
500 obj_desc
->mutex
.acquisition_depth
= 0;
501 obj_desc
->mutex
.owner_thread
= NULL
;
502 obj_desc
->mutex
.thread_id
= 0;