2 /******************************************************************************
4 * Module Name: exmutex - ASL Mutex Acquire/Release functions
6 *****************************************************************************/
9 * Copyright (C) 2000 - 2006, R. Byron Moore
10 * All rights reserved.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer,
17 * without modification.
18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19 * substantially similar to the "NO WARRANTY" disclaimer below
20 * ("Disclaimer") and any redistribution must be conditioned upon
21 * including a substantially similar Disclaimer requirement for further
22 * binary redistribution.
23 * 3. Neither the names of the above-listed copyright holders nor the names
24 * of any contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
27 * Alternatively, this software may be distributed under the terms of the
28 * GNU General Public License ("GPL") version 2 as published by the Free
29 * Software Foundation.
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
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45 #include <acpi/acpi.h>
46 #include <acpi/acinterp.h>
48 #define _COMPONENT ACPI_EXECUTER
49 ACPI_MODULE_NAME("exmutex")
51 /* Local prototypes */
53 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
54 struct acpi_thread_state *thread);
56 /*******************************************************************************
58 * FUNCTION: acpi_ex_unlink_mutex
60 * PARAMETERS: obj_desc - The mutex to be unlinked
64 * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
66 ******************************************************************************/
68 void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)
70 struct acpi_thread_state *thread = obj_desc->mutex.owner_thread;
76 /* Doubly linked list */
78 if (obj_desc->mutex.next) {
79 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
82 if (obj_desc->mutex.prev) {
83 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
85 thread->acquired_mutex_list = obj_desc->mutex.next;
89 /*******************************************************************************
91 * FUNCTION: acpi_ex_link_mutex
93 * PARAMETERS: obj_desc - The mutex to be linked
94 * Thread - Current executing thread object
98 * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
100 ******************************************************************************/
103 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
104 struct acpi_thread_state *thread)
106 union acpi_operand_object *list_head;
108 list_head = thread->acquired_mutex_list;
110 /* This object will be the first object in the list */
112 obj_desc->mutex.prev = NULL;
113 obj_desc->mutex.next = list_head;
115 /* Update old first object to point back to this object */
118 list_head->mutex.prev = obj_desc;
121 /* Update list head */
123 thread->acquired_mutex_list = obj_desc;
126 /*******************************************************************************
128 * FUNCTION: acpi_ex_acquire_mutex
130 * PARAMETERS: time_desc - Timeout integer
131 * obj_desc - Mutex object
132 * walk_state - Current method execution state
136 * DESCRIPTION: Acquire an AML mutex
138 ******************************************************************************/
141 acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
142 union acpi_operand_object *obj_desc,
143 struct acpi_walk_state *walk_state)
147 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
150 return_ACPI_STATUS(AE_BAD_PARAMETER);
153 /* Sanity check -- we must have a valid thread ID */
155 if (!walk_state->thread) {
157 "Cannot acquire Mutex [%4.4s], null thread info",
158 acpi_ut_get_node_name(obj_desc->mutex.node)));
159 return_ACPI_STATUS(AE_AML_INTERNAL);
163 * Current Sync must be less than or equal to the sync level of the
164 * mutex. This mechanism provides some deadlock prevention
166 if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
168 "Cannot acquire Mutex [%4.4s], incorrect SyncLevel",
169 acpi_ut_get_node_name(obj_desc->mutex.node)));
170 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
173 /* Support for multiple acquires by the owning thread */
175 if (obj_desc->mutex.owner_thread) {
177 /* Special case for Global Lock, allow all threads */
179 if ((obj_desc->mutex.owner_thread->thread_id ==
180 walk_state->thread->thread_id) ||
181 (obj_desc->mutex.semaphore ==
182 acpi_gbl_global_lock_semaphore)) {
184 * The mutex is already owned by this thread,
185 * just increment the acquisition depth
187 obj_desc->mutex.acquisition_depth++;
188 return_ACPI_STATUS(AE_OK);
192 /* Acquire the mutex, wait if necessary */
194 status = acpi_ex_system_acquire_mutex(time_desc, obj_desc);
195 if (ACPI_FAILURE(status)) {
197 /* Includes failure from a timeout on time_desc */
199 return_ACPI_STATUS(status);
202 /* Have the mutex: update mutex and walk info and save the sync_level */
204 obj_desc->mutex.owner_thread = walk_state->thread;
205 obj_desc->mutex.acquisition_depth = 1;
206 obj_desc->mutex.original_sync_level =
207 walk_state->thread->current_sync_level;
209 walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;
211 /* Link the mutex to the current thread for force-unlock at method exit */
213 acpi_ex_link_mutex(obj_desc, walk_state->thread);
215 return_ACPI_STATUS(AE_OK);
218 /*******************************************************************************
220 * FUNCTION: acpi_ex_release_mutex
222 * PARAMETERS: obj_desc - The object descriptor for this op
223 * walk_state - Current method execution state
227 * DESCRIPTION: Release a previously acquired Mutex.
229 ******************************************************************************/
232 acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
233 struct acpi_walk_state *walk_state)
237 ACPI_FUNCTION_TRACE(ex_release_mutex);
240 return_ACPI_STATUS(AE_BAD_PARAMETER);
243 /* The mutex must have been previously acquired in order to release it */
245 if (!obj_desc->mutex.owner_thread) {
247 "Cannot release Mutex [%4.4s], not acquired",
248 acpi_ut_get_node_name(obj_desc->mutex.node)));
249 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
252 /* Sanity check -- we must have a valid thread ID */
254 if (!walk_state->thread) {
256 "Cannot release Mutex [%4.4s], null thread info",
257 acpi_ut_get_node_name(obj_desc->mutex.node)));
258 return_ACPI_STATUS(AE_AML_INTERNAL);
262 * The Mutex is owned, but this thread must be the owner.
263 * Special case for Global Lock, any thread can release
265 if ((obj_desc->mutex.owner_thread->thread_id !=
266 walk_state->thread->thread_id)
267 && (obj_desc->mutex.semaphore != acpi_gbl_global_lock_semaphore)) {
269 "Thread %X cannot release Mutex [%4.4s] acquired by thread %X",
270 walk_state->thread->thread_id,
271 acpi_ut_get_node_name(obj_desc->mutex.node),
272 obj_desc->mutex.owner_thread->thread_id));
273 return_ACPI_STATUS(AE_AML_NOT_OWNER);
277 * The sync level of the mutex must be less than or
278 * equal to the current sync level
280 if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
282 "Cannot release Mutex [%4.4s], incorrect SyncLevel",
283 acpi_ut_get_node_name(obj_desc->mutex.node)));
284 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
287 /* Match multiple Acquires with multiple Releases */
289 obj_desc->mutex.acquisition_depth--;
290 if (obj_desc->mutex.acquisition_depth != 0) {
292 /* Just decrement the depth and return */
294 return_ACPI_STATUS(AE_OK);
297 /* Unlink the mutex from the owner's list */
299 acpi_ex_unlink_mutex(obj_desc);
301 /* Release the mutex */
303 status = acpi_ex_system_release_mutex(obj_desc);
305 /* Update the mutex and walk state, restore sync_level before acquire */
307 obj_desc->mutex.owner_thread = NULL;
308 walk_state->thread->current_sync_level =
309 obj_desc->mutex.original_sync_level;
311 return_ACPI_STATUS(status);
314 /*******************************************************************************
316 * FUNCTION: acpi_ex_release_all_mutexes
318 * PARAMETERS: Thread - Current executing thread object
322 * DESCRIPTION: Release all mutexes held by this thread
324 ******************************************************************************/
326 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
328 union acpi_operand_object *next = thread->acquired_mutex_list;
329 union acpi_operand_object *this;
332 ACPI_FUNCTION_ENTRY();
334 /* Traverse the list of owned mutexes, releasing each one */
338 next = this->mutex.next;
340 this->mutex.acquisition_depth = 1;
341 this->mutex.prev = NULL;
342 this->mutex.next = NULL;
344 /* Release the mutex */
346 status = acpi_ex_system_release_mutex(this);
347 if (ACPI_FAILURE(status)) {
351 /* Mark mutex unowned */
353 this->mutex.owner_thread = NULL;
355 /* Update Thread sync_level (Last mutex is the important one) */
357 thread->current_sync_level = this->mutex.original_sync_level;