Rev 5056 | Details | Compare with Previous | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
3391 | Serge | 1 | /************************************************************************** |
2 | * |
||
3 | * Copyright (c) 2007-2009 VMware, Inc., Palo Alto, CA., USA |
||
4 | * All Rights Reserved. |
||
5 | * |
||
6 | * Permission is hereby granted, free of charge, to any person obtaining a |
||
7 | * copy of this software and associated documentation files (the |
||
8 | * "Software"), to deal in the Software without restriction, including |
||
9 | * without limitation the rights to use, copy, modify, merge, publish, |
||
10 | * distribute, sub license, and/or sell copies of the Software, and to |
||
11 | * permit persons to whom the Software is furnished to do so, subject to |
||
12 | * the following conditions: |
||
13 | * |
||
14 | * The above copyright notice and this permission notice (including the |
||
15 | * next paragraph) shall be included in all copies or substantial portions |
||
16 | * of the Software. |
||
17 | * |
||
18 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
||
19 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
||
20 | * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
||
21 | * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, |
||
22 | * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
||
23 | * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
||
24 | * USE OR OTHER DEALINGS IN THE SOFTWARE. |
||
25 | * |
||
26 | **************************************************************************/ |
||
27 | /* |
||
28 | * Authors: Thomas Hellstrom |
||
29 | */ |
||
30 | |||
31 | /** @file ttm_lock.h |
||
32 | * This file implements a simple replacement for the buffer manager use |
||
33 | * of the DRM heavyweight hardware lock. |
||
34 | * The lock is a read-write lock. Taking it in read mode and write mode |
||
35 | * is relatively fast, and intended for in-kernel use only. |
||
36 | * |
||
37 | * The vt mode is used only when there is a need to block all |
||
38 | * user-space processes from validating buffers. |
||
39 | * It's allowed to leave kernel space with the vt lock held. |
||
40 | * If a user-space process dies while having the vt-lock, |
||
41 | * it will be released during the file descriptor release. The vt lock |
||
42 | * excludes write lock and read lock. |
||
43 | * |
||
44 | * The suspend mode is used to lock out all TTM users when preparing for |
||
45 | * and executing suspend operations. |
||
46 | * |
||
47 | */ |
||
48 | |||
49 | #ifndef _TTM_LOCK_H_ |
||
50 | #define _TTM_LOCK_H_ |
||
51 | |||
52 | #include |
||
53 | #include |
||
6082 | serge | 54 | #include |
3391 | Serge | 55 | |
56 | /** |
||
57 | * struct ttm_lock |
||
58 | * |
||
59 | * @base: ttm base object used solely to release the lock if the client |
||
60 | * holding the lock dies. |
||
61 | * @queue: Queue for processes waiting for lock change-of-status. |
||
62 | * @lock: Spinlock protecting some lock members. |
||
63 | * @rw: Read-write lock counter. Protected by @lock. |
||
64 | * @flags: Lock state. Protected by @lock. |
||
65 | * @kill_takers: Boolean whether to kill takers of the lock. |
||
66 | * @signal: Signal to send when kill_takers is true. |
||
67 | */ |
||
68 | |||
69 | struct ttm_lock { |
||
70 | struct ttm_base_object base; |
||
71 | wait_queue_head_t queue; |
||
72 | spinlock_t lock; |
||
73 | int32_t rw; |
||
74 | uint32_t flags; |
||
75 | bool kill_takers; |
||
76 | int signal; |
||
77 | struct ttm_object_file *vt_holder; |
||
78 | }; |
||
79 | |||
80 | |||
81 | /** |
||
82 | * ttm_lock_init |
||
83 | * |
||
84 | * @lock: Pointer to a struct ttm_lock |
||
85 | * Initializes the lock. |
||
86 | */ |
||
87 | extern void ttm_lock_init(struct ttm_lock *lock); |
||
88 | |||
89 | /** |
||
90 | * ttm_read_unlock |
||
91 | * |
||
92 | * @lock: Pointer to a struct ttm_lock |
||
93 | * |
||
94 | * Releases a read lock. |
||
95 | */ |
||
96 | extern void ttm_read_unlock(struct ttm_lock *lock); |
||
97 | |||
98 | /** |
||
99 | * ttm_read_lock |
||
100 | * |
||
101 | * @lock: Pointer to a struct ttm_lock |
||
102 | * @interruptible: Interruptible sleeping while waiting for a lock. |
||
103 | * |
||
104 | * Takes the lock in read mode. |
||
105 | * Returns: |
||
106 | * -ERESTARTSYS If interrupted by a signal and interruptible is true. |
||
107 | */ |
||
108 | extern int ttm_read_lock(struct ttm_lock *lock, bool interruptible); |
||
109 | |||
110 | /** |
||
111 | * ttm_read_trylock |
||
112 | * |
||
113 | * @lock: Pointer to a struct ttm_lock |
||
114 | * @interruptible: Interruptible sleeping while waiting for a lock. |
||
115 | * |
||
116 | * Tries to take the lock in read mode. If the lock is already held |
||
117 | * in write mode, the function will return -EBUSY. If the lock is held |
||
118 | * in vt or suspend mode, the function will sleep until these modes |
||
119 | * are unlocked. |
||
120 | * |
||
121 | * Returns: |
||
122 | * -EBUSY The lock was already held in write mode. |
||
123 | * -ERESTARTSYS If interrupted by a signal and interruptible is true. |
||
124 | */ |
||
125 | extern int ttm_read_trylock(struct ttm_lock *lock, bool interruptible); |
||
126 | |||
127 | /** |
||
128 | * ttm_write_unlock |
||
129 | * |
||
130 | * @lock: Pointer to a struct ttm_lock |
||
131 | * |
||
132 | * Releases a write lock. |
||
133 | */ |
||
134 | extern void ttm_write_unlock(struct ttm_lock *lock); |
||
135 | |||
136 | /** |
||
137 | * ttm_write_lock |
||
138 | * |
||
139 | * @lock: Pointer to a struct ttm_lock |
||
140 | * @interruptible: Interruptible sleeping while waiting for a lock. |
||
141 | * |
||
142 | * Takes the lock in write mode. |
||
143 | * Returns: |
||
144 | * -ERESTARTSYS If interrupted by a signal and interruptible is true. |
||
145 | */ |
||
146 | extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible); |
||
147 | |||
148 | /** |
||
149 | * ttm_lock_downgrade |
||
150 | * |
||
151 | * @lock: Pointer to a struct ttm_lock |
||
152 | * |
||
153 | * Downgrades a write lock to a read lock. |
||
154 | */ |
||
155 | extern void ttm_lock_downgrade(struct ttm_lock *lock); |
||
156 | |||
157 | /** |
||
158 | * ttm_suspend_lock |
||
159 | * |
||
160 | * @lock: Pointer to a struct ttm_lock |
||
161 | * |
||
162 | * Takes the lock in suspend mode. Excludes read and write mode. |
||
163 | */ |
||
164 | extern void ttm_suspend_lock(struct ttm_lock *lock); |
||
165 | |||
166 | /** |
||
167 | * ttm_suspend_unlock |
||
168 | * |
||
169 | * @lock: Pointer to a struct ttm_lock |
||
170 | * |
||
171 | * Releases a suspend lock |
||
172 | */ |
||
173 | extern void ttm_suspend_unlock(struct ttm_lock *lock); |
||
174 | |||
175 | /** |
||
176 | * ttm_vt_lock |
||
177 | * |
||
178 | * @lock: Pointer to a struct ttm_lock |
||
179 | * @interruptible: Interruptible sleeping while waiting for a lock. |
||
180 | * @tfile: Pointer to a struct ttm_object_file to register the lock with. |
||
181 | * |
||
182 | * Takes the lock in vt mode. |
||
183 | * Returns: |
||
184 | * -ERESTARTSYS If interrupted by a signal and interruptible is true. |
||
185 | * -ENOMEM: Out of memory when locking. |
||
186 | */ |
||
187 | extern int ttm_vt_lock(struct ttm_lock *lock, bool interruptible, |
||
188 | struct ttm_object_file *tfile); |
||
189 | |||
190 | /** |
||
191 | * ttm_vt_unlock |
||
192 | * |
||
193 | * @lock: Pointer to a struct ttm_lock |
||
194 | * |
||
195 | * Releases a vt lock. |
||
196 | * Returns: |
||
197 | * -EINVAL If the lock was not held. |
||
198 | */ |
||
199 | extern int ttm_vt_unlock(struct ttm_lock *lock); |
||
200 | |||
201 | /** |
||
202 | * ttm_write_unlock |
||
203 | * |
||
204 | * @lock: Pointer to a struct ttm_lock |
||
205 | * |
||
206 | * Releases a write lock. |
||
207 | */ |
||
208 | extern void ttm_write_unlock(struct ttm_lock *lock); |
||
209 | |||
210 | /** |
||
211 | * ttm_write_lock |
||
212 | * |
||
213 | * @lock: Pointer to a struct ttm_lock |
||
214 | * @interruptible: Interruptible sleeping while waiting for a lock. |
||
215 | * |
||
216 | * Takes the lock in write mode. |
||
217 | * Returns: |
||
218 | * -ERESTARTSYS If interrupted by a signal and interruptible is true. |
||
219 | */ |
||
220 | extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible); |
||
221 | |||
222 | /** |
||
223 | * ttm_lock_set_kill |
||
224 | * |
||
225 | * @lock: Pointer to a struct ttm_lock |
||
226 | * @val: Boolean whether to kill processes taking the lock. |
||
227 | * @signal: Signal to send to the process taking the lock. |
||
228 | * |
||
229 | * The kill-when-taking-lock functionality is used to kill processes that keep |
||
230 | * on using the TTM functionality when its resources has been taken down, for |
||
231 | * example when the X server exits. A typical sequence would look like this: |
||
232 | * - X server takes lock in write mode. |
||
233 | * - ttm_lock_set_kill() is called with @val set to true. |
||
234 | * - As part of X server exit, TTM resources are taken down. |
||
235 | * - X server releases the lock on file release. |
||
236 | * - Another dri client wants to render, takes the lock and is killed. |
||
237 | * |
||
238 | */ |
||
239 | static inline void ttm_lock_set_kill(struct ttm_lock *lock, bool val, |
||
240 | int signal) |
||
241 | { |
||
242 | lock->kill_takers = val; |
||
243 | if (val) |
||
244 | lock->signal = signal; |
||
245 | } |
||
246 | |||
247 | #endif |