drm2/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.
71 	struct mtx lock;
83  * @lock: Pointer to a struct ttm_lock
84  * Initializes the lock.
86 extern void ttm_lock_init(struct ttm_lock *lock);
91  * @lock: Pointer to a struct ttm_lock
93  * Releases a read lock.
95 extern void ttm_read_unlock(struct ttm_lock *lock);
100  * @lock: Pointer to a struct ttm_lock
101  * @interruptible: Interruptible sleeping while waiting for a lock.
103  * Takes the lock in read mode.
107 extern int ttm_read_lock(struct ttm_lock *lock, bool interruptible);
112  * @lock: Pointer to a struct ttm_lock
113  * @interruptible: Interruptible sleeping while waiting for a lock.
115  * Tries to take the lock in read mode. If the lock is already held
116  * in write mode, the function will return -EBUSY. If the lock is held
121  * -EBUSY The lock was already held in write mode.
124 extern int ttm_read_trylock(struct ttm_lock *lock, bool interruptible);
129  * @lock: Pointer to a struct ttm_lock
131  * Downgrades a write lock to a read lock.
133 extern void ttm_lock_downgrade(struct ttm_lock *lock);
138  * @lock: Pointer to a struct ttm_lock
140  * Takes the lock in suspend mode. Excludes read and write mode.
142 extern void ttm_suspend_lock(struct ttm_lock *lock);
147  * @lock: Pointer to a struct ttm_lock
149  * Releases a suspend lock
151 extern void ttm_suspend_unlock(struct ttm_lock *lock);
156  * @lock: Pointer to a struct ttm_lock
157  * @interruptible: Interruptible sleeping while waiting for a lock.
158  * @tfile: Pointer to a struct ttm_object_file to register the lock with.
160  * Takes the lock in vt mode.
165 extern int ttm_vt_lock(struct ttm_lock *lock, bool interruptible,
171  * @lock: Pointer to a struct ttm_lock
173  * Releases a vt lock.
175  * -EINVAL If the lock was not held.
177 extern int ttm_vt_unlock(struct ttm_lock *lock);
182  * @lock: Pointer to a struct ttm_lock
184  * Releases a write lock.
186 extern void ttm_write_unlock(struct ttm_lock *lock);
191  * @lock: Pointer to a struct ttm_lock
192  * @interruptible: Interruptible sleeping while waiting for a lock.
194  * Takes the lock in write mode.
198 extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible);
200 void ttm_write_lock_downgrade(struct ttm_lock *lock);
205  * @lock: Pointer to a struct ttm_lock
206  * @val: Boolean whether to kill processes taking the lock.
207  * @signal: Signal to send to the process taking the lock.
209  * The kill-when-taking-lock functionality is used to kill processes that keep
212  * - X server takes lock in write mode.
215  * - X server releases the lock on file release.
216  * - Another dri client wants to render, takes the lock and is killed.
219 static inline void ttm_lock_set_kill(struct ttm_lock *lock, bool val,
222 	lock->kill_takers = val;
224 		lock->signal = signal;