1 | // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 |
2 | /****************************************************************************** |
3 | * |
4 | * Module Name: exmutex - ASL Mutex Acquire/Release functions |
5 | * |
6 | * Copyright (C) 2000 - 2023, Intel Corp. |
7 | * |
8 | *****************************************************************************/ |
9 | |
10 | #include <acpi/acpi.h> |
11 | #include "accommon.h" |
12 | #include "acinterp.h" |
13 | #include "acevents.h" |
14 | |
15 | #define _COMPONENT ACPI_EXECUTER |
16 | ACPI_MODULE_NAME("exmutex" ) |
17 | |
18 | /* Local prototypes */ |
19 | static void |
20 | acpi_ex_link_mutex(union acpi_operand_object *obj_desc, |
21 | struct acpi_thread_state *thread); |
22 | |
23 | /******************************************************************************* |
24 | * |
25 | * FUNCTION: acpi_ex_unlink_mutex |
26 | * |
27 | * PARAMETERS: obj_desc - The mutex to be unlinked |
28 | * |
29 | * RETURN: None |
30 | * |
31 | * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list |
32 | * |
33 | ******************************************************************************/ |
34 | |
35 | void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc) |
36 | { |
37 | struct acpi_thread_state *thread = obj_desc->mutex.owner_thread; |
38 | |
39 | if (!thread) { |
40 | return; |
41 | } |
42 | |
43 | /* Doubly linked list */ |
44 | |
45 | if (obj_desc->mutex.next) { |
46 | (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev; |
47 | } |
48 | |
49 | if (obj_desc->mutex.prev) { |
50 | (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next; |
51 | |
52 | /* |
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. |
57 | */ |
58 | (obj_desc->mutex.prev)->mutex.original_sync_level = |
59 | obj_desc->mutex.original_sync_level; |
60 | } else { |
61 | thread->acquired_mutex_list = obj_desc->mutex.next; |
62 | } |
63 | } |
64 | |
65 | /******************************************************************************* |
66 | * |
67 | * FUNCTION: acpi_ex_link_mutex |
68 | * |
69 | * PARAMETERS: obj_desc - The mutex to be linked |
70 | * thread - Current executing thread object |
71 | * |
72 | * RETURN: None |
73 | * |
74 | * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk |
75 | * |
76 | ******************************************************************************/ |
77 | |
78 | static void |
79 | acpi_ex_link_mutex(union acpi_operand_object *obj_desc, |
80 | struct acpi_thread_state *thread) |
81 | { |
82 | union acpi_operand_object *list_head; |
83 | |
84 | list_head = thread->acquired_mutex_list; |
85 | |
86 | /* This object will be the first object in the list */ |
87 | |
88 | obj_desc->mutex.prev = NULL; |
89 | obj_desc->mutex.next = list_head; |
90 | |
91 | /* Update old first object to point back to this object */ |
92 | |
93 | if (list_head) { |
94 | list_head->mutex.prev = obj_desc; |
95 | } |
96 | |
97 | /* Update list head */ |
98 | |
99 | thread->acquired_mutex_list = obj_desc; |
100 | } |
101 | |
102 | /******************************************************************************* |
103 | * |
104 | * FUNCTION: acpi_ex_acquire_mutex_object |
105 | * |
106 | * PARAMETERS: timeout - Timeout in milliseconds |
107 | * obj_desc - Mutex object |
108 | * thread_id - Current thread state |
109 | * |
110 | * RETURN: Status |
111 | * |
112 | * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common |
113 | * path that supports multiple acquires by the same thread. |
114 | * |
115 | * MUTEX: Interpreter must be locked |
116 | * |
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 |
120 | * global lock |
121 | * 3) From the external interface, acpi_acquire_global_lock |
122 | * |
123 | ******************************************************************************/ |
124 | |
125 | acpi_status |
126 | acpi_ex_acquire_mutex_object(u16 timeout, |
127 | union acpi_operand_object *obj_desc, |
128 | acpi_thread_id thread_id) |
129 | { |
130 | acpi_status status; |
131 | |
132 | ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc); |
133 | |
134 | if (!obj_desc) { |
135 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
136 | } |
137 | |
138 | /* Support for multiple acquires by the owning thread */ |
139 | |
140 | if (obj_desc->mutex.thread_id == thread_id) { |
141 | /* |
142 | * The mutex is already owned by this thread, just increment the |
143 | * acquisition depth |
144 | */ |
145 | obj_desc->mutex.acquisition_depth++; |
146 | return_ACPI_STATUS(AE_OK); |
147 | } |
148 | |
149 | /* Acquire the mutex, wait if necessary. Special case for Global Lock */ |
150 | |
151 | if (obj_desc == acpi_gbl_global_lock_mutex) { |
152 | status = acpi_ev_acquire_global_lock(timeout); |
153 | } else { |
154 | status = |
155 | acpi_ex_system_wait_mutex(mutex: obj_desc->mutex.os_mutex, |
156 | timeout); |
157 | } |
158 | |
159 | if (ACPI_FAILURE(status)) { |
160 | |
161 | /* Includes failure from a timeout on time_desc */ |
162 | |
163 | return_ACPI_STATUS(status); |
164 | } |
165 | |
166 | /* Acquired the mutex: update mutex object */ |
167 | |
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() */ |
172 | |
173 | return_ACPI_STATUS(AE_OK); |
174 | } |
175 | |
176 | /******************************************************************************* |
177 | * |
178 | * FUNCTION: acpi_ex_acquire_mutex |
179 | * |
180 | * PARAMETERS: time_desc - Timeout integer |
181 | * obj_desc - Mutex object |
182 | * walk_state - Current method execution state |
183 | * |
184 | * RETURN: Status |
185 | * |
186 | * DESCRIPTION: Acquire an AML mutex |
187 | * |
188 | ******************************************************************************/ |
189 | |
190 | acpi_status |
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) |
194 | { |
195 | acpi_status status; |
196 | |
197 | ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc); |
198 | |
199 | if (!obj_desc) { |
200 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
201 | } |
202 | |
203 | /* Must have a valid thread state struct */ |
204 | |
205 | if (!walk_state->thread) { |
206 | ACPI_ERROR((AE_INFO, |
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); |
210 | } |
211 | |
212 | /* |
213 | * Current sync level must be less than or equal to the sync level |
214 | * of the mutex. This mechanism provides some deadlock prevention. |
215 | */ |
216 | if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) { |
217 | ACPI_ERROR((AE_INFO, |
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); |
223 | } |
224 | |
225 | ACPI_DEBUG_PRINT((ACPI_DB_EXEC, |
226 | "Acquiring: Mutex SyncLevel %u, Thread SyncLevel %u, " |
227 | "Depth %u TID %p\n" , |
228 | obj_desc->mutex.sync_level, |
229 | walk_state->thread->current_sync_level, |
230 | obj_desc->mutex.acquisition_depth, |
231 | walk_state->thread)); |
232 | |
233 | status = acpi_ex_acquire_mutex_object(timeout: (u16)time_desc->integer.value, |
234 | obj_desc, |
235 | thread_id: walk_state->thread->thread_id); |
236 | |
237 | if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) { |
238 | |
239 | /* Save Thread object, original/current sync levels */ |
240 | |
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; |
246 | |
247 | /* Link the mutex to the current thread for force-unlock at method exit */ |
248 | |
249 | acpi_ex_link_mutex(obj_desc, thread: walk_state->thread); |
250 | } |
251 | |
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)); |
257 | |
258 | return_ACPI_STATUS(status); |
259 | } |
260 | |
261 | /******************************************************************************* |
262 | * |
263 | * FUNCTION: acpi_ex_release_mutex_object |
264 | * |
265 | * PARAMETERS: obj_desc - The object descriptor for this op |
266 | * |
267 | * RETURN: Status |
268 | * |
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. |
272 | * |
273 | * MUTEX: Interpreter must be locked |
274 | * |
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 |
278 | * global lock |
279 | * 3) From the external interface, acpi_release_global_lock |
280 | * |
281 | ******************************************************************************/ |
282 | |
283 | acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc) |
284 | { |
285 | acpi_status status = AE_OK; |
286 | |
287 | ACPI_FUNCTION_TRACE(ex_release_mutex_object); |
288 | |
289 | if (obj_desc->mutex.acquisition_depth == 0) { |
290 | return_ACPI_STATUS(AE_NOT_ACQUIRED); |
291 | } |
292 | |
293 | /* Match multiple Acquires with multiple Releases */ |
294 | |
295 | obj_desc->mutex.acquisition_depth--; |
296 | if (obj_desc->mutex.acquisition_depth != 0) { |
297 | |
298 | /* Just decrement the depth and return */ |
299 | |
300 | return_ACPI_STATUS(AE_OK); |
301 | } |
302 | |
303 | if (obj_desc->mutex.owner_thread) { |
304 | |
305 | /* Unlink the mutex from the owner's list */ |
306 | |
307 | acpi_ex_unlink_mutex(obj_desc); |
308 | obj_desc->mutex.owner_thread = NULL; |
309 | } |
310 | |
311 | /* Release the mutex, special case for Global Lock */ |
312 | |
313 | if (obj_desc == acpi_gbl_global_lock_mutex) { |
314 | status = acpi_ev_release_global_lock(); |
315 | } else { |
316 | acpi_os_release_mutex(obj_desc->mutex.os_mutex); |
317 | } |
318 | |
319 | /* Clear mutex info */ |
320 | |
321 | obj_desc->mutex.thread_id = 0; |
322 | return_ACPI_STATUS(status); |
323 | } |
324 | |
325 | /******************************************************************************* |
326 | * |
327 | * FUNCTION: acpi_ex_release_mutex |
328 | * |
329 | * PARAMETERS: obj_desc - The object descriptor for this op |
330 | * walk_state - Current method execution state |
331 | * |
332 | * RETURN: Status |
333 | * |
334 | * DESCRIPTION: Release a previously acquired Mutex. |
335 | * |
336 | ******************************************************************************/ |
337 | |
338 | acpi_status |
339 | acpi_ex_release_mutex(union acpi_operand_object *obj_desc, |
340 | struct acpi_walk_state *walk_state) |
341 | { |
342 | u8 previous_sync_level; |
343 | struct acpi_thread_state *owner_thread; |
344 | acpi_status status = AE_OK; |
345 | |
346 | ACPI_FUNCTION_TRACE(ex_release_mutex); |
347 | |
348 | if (!obj_desc) { |
349 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
350 | } |
351 | |
352 | owner_thread = obj_desc->mutex.owner_thread; |
353 | |
354 | /* The mutex must have been previously acquired in order to release it */ |
355 | |
356 | if (!owner_thread) { |
357 | ACPI_ERROR((AE_INFO, |
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); |
361 | } |
362 | |
363 | /* Must have a valid thread ID */ |
364 | |
365 | if (!walk_state->thread) { |
366 | ACPI_ERROR((AE_INFO, |
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); |
370 | } |
371 | |
372 | /* |
373 | * The Mutex is owned, but this thread must be the owner. |
374 | * Special case for Global Lock, any thread can release |
375 | */ |
376 | if ((owner_thread->thread_id != walk_state->thread->thread_id) && |
377 | (obj_desc != acpi_gbl_global_lock_mutex)) { |
378 | ACPI_ERROR((AE_INFO, |
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); |
384 | } |
385 | |
386 | /* |
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. |
392 | */ |
393 | if (obj_desc->mutex.sync_level != owner_thread->current_sync_level) { |
394 | ACPI_ERROR((AE_INFO, |
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); |
401 | } |
402 | |
403 | /* |
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. |
407 | */ |
408 | previous_sync_level = |
409 | owner_thread->acquired_mutex_list->mutex.original_sync_level; |
410 | |
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, |
416 | previous_sync_level, |
417 | obj_desc->mutex.acquisition_depth, |
418 | walk_state->thread)); |
419 | |
420 | status = acpi_ex_release_mutex_object(obj_desc); |
421 | if (ACPI_FAILURE(status)) { |
422 | return_ACPI_STATUS(status); |
423 | } |
424 | |
425 | if (obj_desc->mutex.acquisition_depth == 0) { |
426 | |
427 | /* Restore the previous sync_level */ |
428 | |
429 | owner_thread->current_sync_level = previous_sync_level; |
430 | } |
431 | |
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, |
437 | previous_sync_level, |
438 | obj_desc->mutex.acquisition_depth)); |
439 | |
440 | return_ACPI_STATUS(status); |
441 | } |
442 | |
443 | /******************************************************************************* |
444 | * |
445 | * FUNCTION: acpi_ex_release_all_mutexes |
446 | * |
447 | * PARAMETERS: thread - Current executing thread object |
448 | * |
449 | * RETURN: Status |
450 | * |
451 | * DESCRIPTION: Release all mutexes held by this thread |
452 | * |
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. |
458 | * |
459 | ******************************************************************************/ |
460 | |
461 | void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread) |
462 | { |
463 | union acpi_operand_object *next = thread->acquired_mutex_list; |
464 | union acpi_operand_object *obj_desc; |
465 | |
466 | ACPI_FUNCTION_TRACE(ex_release_all_mutexes); |
467 | |
468 | /* Traverse the list of owned mutexes, releasing each one */ |
469 | |
470 | while (next) { |
471 | obj_desc = next; |
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)); |
477 | |
478 | /* Release the mutex, special case for Global Lock */ |
479 | |
480 | if (obj_desc == acpi_gbl_global_lock_mutex) { |
481 | |
482 | /* Ignore errors */ |
483 | |
484 | (void)acpi_ev_release_global_lock(); |
485 | } else { |
486 | acpi_os_release_mutex(obj_desc->mutex.os_mutex); |
487 | } |
488 | |
489 | /* Update Thread sync_level (Last mutex is the important one) */ |
490 | |
491 | thread->current_sync_level = |
492 | obj_desc->mutex.original_sync_level; |
493 | |
494 | /* Mark mutex unowned */ |
495 | |
496 | next = obj_desc->mutex.next; |
497 | |
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; |
503 | } |
504 | |
505 | return_VOID; |
506 | } |
507 | |