drm/ttm/ttm_lock.h

33  * of the DRM heavyweight hardware lock.
34  * The lock is a read-write lock. Taking it in read mode and write mode
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.
44  * The suspend mode is used to lock out all TTM users when preparing for
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.
72 	spinlock_t lock;  member
84  * @lock: Pointer to a struct ttm_lock
85  * Initializes the lock.
87 extern void ttm_lock_init(struct ttm_lock *lock);
92  * @lock: Pointer to a struct ttm_lock
94  * Releases a read lock.
96 extern void ttm_read_unlock(struct ttm_lock *lock);
101  * @lock: Pointer to a struct ttm_lock
102  * @interruptible: Interruptible sleeping while waiting for a lock.
104  * Takes the lock in read mode.
108 extern int ttm_read_lock(struct ttm_lock *lock, bool interruptible);
113  * @lock: Pointer to a struct ttm_lock
114  * @interruptible: Interruptible sleeping while waiting for a lock.
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
122  * -EBUSY The lock was already held in write mode.
125 extern int ttm_read_trylock(struct ttm_lock *lock, bool interruptible);
130  * @lock: Pointer to a struct ttm_lock
132  * Releases a write lock.
134 extern void ttm_write_unlock(struct ttm_lock *lock);
139  * @lock: Pointer to a struct ttm_lock
140  * @interruptible: Interruptible sleeping while waiting for a lock.
142  * Takes the lock in write mode.
146 extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible);
151  * @lock: Pointer to a struct ttm_lock
153  * Downgrades a write lock to a read lock.
155 extern void ttm_lock_downgrade(struct ttm_lock *lock);
160  * @lock: Pointer to a struct ttm_lock
162  * Takes the lock in suspend mode. Excludes read and write mode.
164 extern void ttm_suspend_lock(struct ttm_lock *lock);
169  * @lock: Pointer to a struct ttm_lock
171  * Releases a suspend lock
173 extern void ttm_suspend_unlock(struct ttm_lock *lock);
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.
182  * Takes the lock in vt mode.
187 extern int ttm_vt_lock(struct ttm_lock *lock, bool interruptible,
193  * @lock: Pointer to a struct ttm_lock
195  * Releases a vt lock.
197  * -EINVAL If the lock was not held.
199 extern int ttm_vt_unlock(struct ttm_lock *lock);
204  * @lock: Pointer to a struct ttm_lock
206  * Releases a write lock.
208 extern void ttm_write_unlock(struct ttm_lock *lock);
213  * @lock: Pointer to a struct ttm_lock
214  * @interruptible: Interruptible sleeping while waiting for a lock.
216  * Takes the lock in write mode.
220 extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible);
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.
229  * The kill-when-taking-lock functionality is used to kill processes that keep
232  * - X server takes lock in write mode.
235  * - X server releases the lock on file release.
236  * - Another dri client wants to render, takes the lock and is killed.
239 static inline void ttm_lock_set_kill(struct ttm_lock *lock, bool val,  in ttm_lock_set_kill()  argument
242 	lock->kill_takers = val;  in ttm_lock_set_kill()
244 		lock->signal = signal;  in ttm_lock_set_kill()