44  * Lock ioctl.
52  * Add the current task to the lock wait queue, and attempt to take to lock.
57 	struct drm_lock *lock = data;  in drm_lock()  local
63 	if (lock->context == DRM_KERNEL_CONTEXT) {  in drm_lock()
65 			  task_pid_nr(current), lock->context);  in drm_lock()
69 	DRM_DEBUG("%d (pid %d) requests lock (0x%08x), flags = 0x%08x\n",  in drm_lock()
70 		  lock->context, task_pid_nr(current),  in drm_lock()
71 		  master->lock.hw_lock->lock, lock->flags);  in drm_lock()
74 		if (lock->context < 0)  in drm_lock()
77 	add_wait_queue(&master->lock.lock_queue, &entry);  in drm_lock()
78 	spin_lock_bh(&master->lock.spinlock);  in drm_lock()
79 	master->lock.user_waiters++;  in drm_lock()
80 	spin_unlock_bh(&master->lock.spinlock);  in drm_lock()
84 		if (!master->lock.hw_lock) {  in drm_lock()
90 		if (drm_lock_take(&master->lock, lock->context)) {  in drm_lock()
91 			master->lock.file_priv = file_priv;  in drm_lock()
92 			master->lock.lock_time = jiffies;  in drm_lock()
94 			break;	/* Got lock */  in drm_lock()
106 	spin_lock_bh(&master->lock.spinlock);  in drm_lock()
107 	master->lock.user_waiters--;  in drm_lock()
108 	spin_unlock_bh(&master->lock.spinlock);  in drm_lock()
110 	remove_wait_queue(&master->lock.lock_queue, &entry);  in drm_lock()
112 	DRM_DEBUG("%d %s\n", lock->context,  in drm_lock()
113 		  ret ? "interrupted" : "has lock");  in drm_lock()
125 		dev->sigdata.context = lock->context;  in drm_lock()
126 		dev->sigdata.lock = master->lock.hw_lock;  in drm_lock()
130 	if (dev->driver->dma_quiescent && (lock->flags & _DRM_LOCK_QUIESCENT))  in drm_lock()
134 				  lock->context);  in drm_lock()
151  * Transfer and free the lock.
155 	struct drm_lock *lock = data;  in drm_unlock()  local
158 	if (lock->context == DRM_KERNEL_CONTEXT) {  in drm_unlock()
160 			  task_pid_nr(current), lock->context);  in drm_unlock()
166 	if (drm_lock_free(&master->lock, lock->context)) {  in drm_unlock()
175  * Take the heavyweight lock.
177  * \param lock lock pointer.
179  * \return one if the lock is held, or zero otherwise.
181  * Attempt to mark the lock as held by the given context, via the \p cmpxchg instruction.
188 	volatile unsigned int *lock = &lock_data->hw_lock->lock;  in drm_lock_take()  local
192 		old = *lock;  in drm_lock_take()
200 		prev = cmpxchg(lock, old, new);  in drm_lock_take()
207 				DRM_ERROR("%d holds heavyweight lock\n",  in drm_lock_take()
215 		/* Have lock */  in drm_lock_take()
222  * This takes a lock forcibly and hands it to context.	Should ONLY be used
223  * inside *_unlock to give lock to kernel before calling *_dma_schedule.
226  * \param lock lock pointer.
230  * Resets the lock file pointer.
231  * Marks the lock as held by the given context, via the \p cmpxchg instruction.
237 	volatile unsigned int *lock = &lock_data->hw_lock->lock;  in drm_lock_transfer()  local
241 		old = *lock;  in drm_lock_transfer()
243 		prev = cmpxchg(lock, old, new);  in drm_lock_transfer()
249  * Free lock.
252  * \param lock lock.
255  * Resets the lock file pointer.
256  * Marks the lock as not held, via the \p cmpxchg instruction. Wakes any task
257  * waiting on the lock queue.
262 	volatile unsigned int *lock = &lock_data->hw_lock->lock;  in drm_lock_free()  local
274 		old = *lock;  in drm_lock_free()
276 		prev = cmpxchg(lock, old, new);  in drm_lock_free()
280 		DRM_ERROR("%d freed heavyweight lock held by %d\n",  in drm_lock_free()
292  * If the lock is not held, then let the signal proceed as usual.  If the lock
304 	/* Allow signal delivery if lock isn't held */  in drm_notifier()
305 	if (!s->lock || !_DRM_LOCK_IS_HELD(s->lock->lock)  in drm_notifier()
306 	    || _DRM_LOCKING_CONTEXT(s->lock->lock) != s->context)  in drm_notifier()
312 		old = s->lock->lock;  in drm_notifier()
314 		prev = cmpxchg(&s->lock->lock, old, new);  in drm_notifier()
320  * This function returns immediately and takes the hw lock
324  * This guarantees that the kernel will _eventually_ have the lock _unless_ it is held
325  * by a blocked process. (In the latter case an explicit wait for the hardware lock would cause
354 	volatile unsigned int *lock = &lock_data->hw_lock->lock;  in drm_idlelock_release()  local
360 				old = *lock;  in drm_idlelock_release()
361 				prev = cmpxchg(lock, old, DRM_KERNEL_CONTEXT);  in drm_idlelock_release()
374 	return (file_priv->lock_count && master->lock.hw_lock &&  in drm_i_have_hw_lock()
375 		_DRM_LOCK_IS_HELD(master->lock.hw_lock->lock) &&  in drm_i_have_hw_lock()
376 		master->lock.file_priv == file_priv);  in drm_i_have_hw_lock()