pcmcia: CompactFlash driver for PA Semi Electra boards
[pv_ops_mirror.git] / drivers / acpi / executer / exmutex.c
blob6748e3ef09972472d9aeeaeaa1abf639773a77a8
2 /******************************************************************************
4 * Module Name: exmutex - ASL Mutex Acquire/Release functions
6 *****************************************************************************/
8 /*
9 * Copyright (C) 2000 - 2007, 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
14 * are met:
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.
31 * NO WARRANTY
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
35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 * POSSIBILITY OF SUCH DAMAGES.
45 #include <acpi/acpi.h>
46 #include <acpi/acinterp.h>
47 #include <acpi/acevents.h>
49 #define _COMPONENT ACPI_EXECUTER
50 ACPI_MODULE_NAME("exmutex")
52 /* Local prototypes */
53 static void
54 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
55 struct acpi_thread_state *thread);
57 /*******************************************************************************
59 * FUNCTION: acpi_ex_unlink_mutex
61 * PARAMETERS: obj_desc - The mutex to be unlinked
63 * RETURN: None
65 * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
67 ******************************************************************************/
69 void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)
71 struct acpi_thread_state *thread = obj_desc->mutex.owner_thread;
73 if (!thread) {
74 return;
77 /* Doubly linked list */
79 if (obj_desc->mutex.next) {
80 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
83 if (obj_desc->mutex.prev) {
84 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
85 } else {
86 thread->acquired_mutex_list = obj_desc->mutex.next;
90 /*******************************************************************************
92 * FUNCTION: acpi_ex_link_mutex
94 * PARAMETERS: obj_desc - The mutex to be linked
95 * Thread - Current executing thread object
97 * RETURN: None
99 * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
101 ******************************************************************************/
103 static void
104 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
105 struct acpi_thread_state *thread)
107 union acpi_operand_object *list_head;
109 list_head = thread->acquired_mutex_list;
111 /* This object will be the first object in the list */
113 obj_desc->mutex.prev = NULL;
114 obj_desc->mutex.next = list_head;
116 /* Update old first object to point back to this object */
118 if (list_head) {
119 list_head->mutex.prev = obj_desc;
122 /* Update list head */
124 thread->acquired_mutex_list = obj_desc;
127 /*******************************************************************************
129 * FUNCTION: acpi_ex_acquire_mutex
131 * PARAMETERS: time_desc - Timeout integer
132 * obj_desc - Mutex object
133 * walk_state - Current method execution state
135 * RETURN: Status
137 * DESCRIPTION: Acquire an AML mutex
139 ******************************************************************************/
141 acpi_status
142 acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
143 union acpi_operand_object *obj_desc,
144 struct acpi_walk_state *walk_state)
146 acpi_status status;
148 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
150 if (!obj_desc) {
151 return_ACPI_STATUS(AE_BAD_PARAMETER);
154 /* Sanity check: we must have a valid thread ID */
156 if (!walk_state->thread) {
157 ACPI_ERROR((AE_INFO,
158 "Cannot acquire Mutex [%4.4s], null thread info",
159 acpi_ut_get_node_name(obj_desc->mutex.node)));
160 return_ACPI_STATUS(AE_AML_INTERNAL);
164 * Current Sync must be less than or equal to the sync level of the
165 * mutex. This mechanism provides some deadlock prevention
167 if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
168 ACPI_ERROR((AE_INFO,
169 "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%d)",
170 acpi_ut_get_node_name(obj_desc->mutex.node),
171 walk_state->thread->current_sync_level));
172 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
175 /* Support for multiple acquires by the owning thread */
177 if (obj_desc->mutex.owner_thread) {
178 if (obj_desc->mutex.owner_thread->thread_id ==
179 walk_state->thread->thread_id) {
181 * The mutex is already owned by this thread, just increment the
182 * acquisition depth
184 obj_desc->mutex.acquisition_depth++;
185 return_ACPI_STATUS(AE_OK);
189 /* Acquire the mutex, wait if necessary. Special case for Global Lock */
191 if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
192 status =
193 acpi_ev_acquire_global_lock((u16) time_desc->integer.value);
194 } else {
195 status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
196 (u16) time_desc->integer.
197 value);
200 if (ACPI_FAILURE(status)) {
202 /* Includes failure from a timeout on time_desc */
204 return_ACPI_STATUS(status);
207 /* Have the mutex: update mutex and walk info and save the sync_level */
209 obj_desc->mutex.owner_thread = walk_state->thread;
210 obj_desc->mutex.acquisition_depth = 1;
211 obj_desc->mutex.original_sync_level =
212 walk_state->thread->current_sync_level;
214 walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;
216 /* Link the mutex to the current thread for force-unlock at method exit */
218 acpi_ex_link_mutex(obj_desc, walk_state->thread);
219 return_ACPI_STATUS(AE_OK);
222 /*******************************************************************************
224 * FUNCTION: acpi_ex_release_mutex
226 * PARAMETERS: obj_desc - The object descriptor for this op
227 * walk_state - Current method execution state
229 * RETURN: Status
231 * DESCRIPTION: Release a previously acquired Mutex.
233 ******************************************************************************/
235 acpi_status
236 acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
237 struct acpi_walk_state *walk_state)
239 acpi_status status = AE_OK;
241 ACPI_FUNCTION_TRACE(ex_release_mutex);
243 if (!obj_desc) {
244 return_ACPI_STATUS(AE_BAD_PARAMETER);
247 /* The mutex must have been previously acquired in order to release it */
249 if (!obj_desc->mutex.owner_thread) {
250 ACPI_ERROR((AE_INFO,
251 "Cannot release Mutex [%4.4s], not acquired",
252 acpi_ut_get_node_name(obj_desc->mutex.node)));
253 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
256 /* Sanity check: we must have a valid thread ID */
258 if (!walk_state->thread) {
259 ACPI_ERROR((AE_INFO,
260 "Cannot release Mutex [%4.4s], null thread info",
261 acpi_ut_get_node_name(obj_desc->mutex.node)));
262 return_ACPI_STATUS(AE_AML_INTERNAL);
266 * The Mutex is owned, but this thread must be the owner.
267 * Special case for Global Lock, any thread can release
269 if ((obj_desc->mutex.owner_thread->thread_id !=
270 walk_state->thread->thread_id)
271 && (obj_desc->mutex.os_mutex != acpi_gbl_global_lock_mutex)) {
272 ACPI_ERROR((AE_INFO,
273 "Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
274 (unsigned long)walk_state->thread->thread_id,
275 acpi_ut_get_node_name(obj_desc->mutex.node),
276 (unsigned long)obj_desc->mutex.owner_thread->
277 thread_id));
278 return_ACPI_STATUS(AE_AML_NOT_OWNER);
282 * The sync level of the mutex must be less than or equal to the current
283 * sync level
285 if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
286 ACPI_ERROR((AE_INFO,
287 "Cannot release Mutex [%4.4s], incorrect SyncLevel",
288 acpi_ut_get_node_name(obj_desc->mutex.node)));
289 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
292 /* Match multiple Acquires with multiple Releases */
294 obj_desc->mutex.acquisition_depth--;
295 if (obj_desc->mutex.acquisition_depth != 0) {
297 /* Just decrement the depth and return */
299 return_ACPI_STATUS(AE_OK);
302 /* Unlink the mutex from the owner's list */
304 acpi_ex_unlink_mutex(obj_desc);
306 /* Release the mutex, special case for Global Lock */
308 if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
309 status = acpi_ev_release_global_lock();
310 } else {
311 acpi_os_release_mutex(obj_desc->mutex.os_mutex);
314 /* Update the mutex and restore sync_level */
316 obj_desc->mutex.owner_thread = NULL;
317 walk_state->thread->current_sync_level =
318 obj_desc->mutex.original_sync_level;
320 return_ACPI_STATUS(status);
323 /*******************************************************************************
325 * FUNCTION: acpi_ex_release_all_mutexes
327 * PARAMETERS: Thread - Current executing thread object
329 * RETURN: Status
331 * DESCRIPTION: Release all mutexes held by this thread
333 * NOTE: This function is called as the thread is exiting the interpreter.
334 * Mutexes are not released when an individual control method is exited, but
335 * only when the parent thread actually exits the interpreter. This allows one
336 * method to acquire a mutex, and a different method to release it, as long as
337 * this is performed underneath a single parent control method.
339 ******************************************************************************/
341 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
343 union acpi_operand_object *next = thread->acquired_mutex_list;
344 union acpi_operand_object *obj_desc;
346 ACPI_FUNCTION_ENTRY();
348 /* Traverse the list of owned mutexes, releasing each one */
350 while (next) {
351 obj_desc = next;
352 next = obj_desc->mutex.next;
354 obj_desc->mutex.prev = NULL;
355 obj_desc->mutex.next = NULL;
356 obj_desc->mutex.acquisition_depth = 0;
358 /* Release the mutex, special case for Global Lock */
360 if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
362 /* Ignore errors */
364 (void)acpi_ev_release_global_lock();
365 } else {
366 acpi_os_release_mutex(obj_desc->mutex.os_mutex);
369 /* Mark mutex unowned */
371 obj_desc->mutex.owner_thread = NULL;
373 /* Update Thread sync_level (Last mutex is the important one) */
375 thread->current_sync_level =
376 obj_desc->mutex.original_sync_level;