include/linux/dma-resv.h

2  * Header file for reservations for dma-buf and ttm
5  * Copyright (C) 2012-2013 Canonical Ltd
11  * Thomas Hellstrom <thellstrom-at-vmware-dot-com>
16  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
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43 #include <linux/dma-fence.h>
53  * enum dma_resv_usage - how the fences from a dma_resv obj are used
81 	 * that is when the resource is known to be locked down in place by
120  * dma_resv_usage_rw - helper for implicit sync
139  * struct dma_resv - a reservation object manages fences for a buffer
144  * One use is to synchronize cross-driver access to a struct dma_buf, either for
147  * in-depth discussion.
182  * struct dma_resv_iter - current position into the dma_resv fences
225  * dma_resv_iter_begin - initialize a dma_resv_iter object
234 	cursor->obj = obj;  in dma_resv_iter_begin()
235 	cursor->usage = usage;  in dma_resv_iter_begin()
236 	cursor->fence = NULL;  in dma_resv_iter_begin()
240  * dma_resv_iter_end - cleanup a dma_resv_iter object
248 	dma_fence_put(cursor->fence);  in dma_resv_iter_end()
252  * dma_resv_iter_usage - Return the usage of the current fence
260 	return cursor->fence_usage;  in dma_resv_iter_usage()
264  * dma_resv_iter_is_restarted - test if this is the first fence after a restart
271 	return cursor->is_restarted;  in dma_resv_iter_is_restarted()
275  * dma_resv_for_each_fence_unlocked - unlocked fence iterator
294  * dma_resv_for_each_fence - fence iterator
311 #define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base)
312 #define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base)
321  * dma_resv_lock - lock the reservation object
330  * As the reservation object may be locked by multiple parties in an
333  * object may be locked by itself by passing NULL as @ctx.
335  * When a die situation is indicated by returning -EDEADLK all locks held by
345 	return ww_mutex_lock(&obj->lock, ctx);  in dma_resv_lock()
349  * dma_resv_lock_interruptible - lock the reservation object
358  * As the reservation object may be locked by multiple parties in an
361  * object may be locked by itself by passing NULL as @ctx.
363  * When a die situation is indicated by returning -EDEADLK all locks held by
372 	return ww_mutex_lock_interruptible(&obj->lock, ctx);  in dma_resv_lock_interruptible()
376  * dma_resv_lock_slow - slowpath lock the reservation object
389 	ww_mutex_lock_slow(&obj->lock, ctx);  in dma_resv_lock_slow()
393  * dma_resv_lock_slow_interruptible - slowpath lock the reservation
405 	return ww_mutex_lock_slow_interruptible(&obj->lock, ctx);  in dma_resv_lock_slow_interruptible()
409  * dma_resv_trylock - trylock the reservation object
424 	return ww_mutex_trylock(&obj->lock, NULL);  in dma_resv_trylock()
428  * dma_resv_is_locked - is the reservation object locked
431  * Returns true if the mutex is locked, false if unlocked.
435 	return ww_mutex_is_locked(&obj->lock);  in dma_resv_is_locked()
439  * dma_resv_locking_ctx - returns the context used to lock the object
443  * was used or the object is not locked at all.
452 	return READ_ONCE(obj->lock.ctx);  in dma_resv_locking_ctx()
456  * dma_resv_unlock - unlock the reservation object
464 	ww_mutex_unlock(&obj->lock);  in dma_resv_unlock()