drivers/dma-buf/dma-fence-chain.c

3  * fence-chain: chain fences together in a timeline
10 #include <linux/dma-fence-chain.h>
16  * @chain: chain node to get the previous node from
19  * chain node.
21 static struct dma_fence *dma_fence_chain_get_prev(struct dma_fence_chain *chain)
26 	prev = dma_fence_get_rcu_safe(&chain->prev);
32  * dma_fence_chain_walk - chain walking function
33  * @fence: current chain node
35  * Walk the chain to the next node. Returns the next fence or NULL if we are at
36  * the end of the chain. Garbage collects chain nodes which are already
41 	struct dma_fence_chain *chain, *prev_chain;
44 	chain = to_dma_fence_chain(fence);
45 	if (!chain) {
50 	while ((prev = dma_fence_chain_get_prev(chain))) {
65 		tmp = unrcu_pointer(cmpxchg(&chain->prev, RCU_INITIALIZER(prev),
80  * dma_fence_chain_find_seqno - find fence chain node by seqno
81  * @pfence: pointer to the chain node where to start
84  * Advance the fence pointer to the chain node which will signal this sequence
87  * Returns EINVAL if the fence is not a chain node or the sequence number has
92 	struct dma_fence_chain *chain;
97 	chain = to_dma_fence_chain(*pfence);
98 	if (!chain || chain->base.seqno < seqno)
101 	dma_fence_chain_for_each(*pfence, &chain->base) {
102 		if ((*pfence)->context != chain->base.context ||
106 	dma_fence_put(&chain->base);
124 	struct dma_fence_chain *chain;
126 	chain = container_of(work, typeof(*chain), work);
129 	if (!dma_fence_chain_enable_signaling(&chain->base))
131 		dma_fence_signal(&chain->base);
132 	dma_fence_put(&chain->base);
137 	struct dma_fence_chain *chain;
139 	chain = container_of(cb, typeof(*chain), cb);
140 	init_irq_work(&chain->work, dma_fence_chain_irq_work);
141 	irq_work_queue(&chain->work);
180 	struct dma_fence_chain *chain = to_dma_fence_chain(fence);
183 	/* Manually unlink the chain as much as possible to avoid recursion
186 	while ((prev = rcu_dereference_protected(chain->prev, true))) {
199 		chain->prev = prev_chain->prev;
205 	dma_fence_put(chain->fence);
232  * dma_fence_chain_init - initialize a fence chain
233  * @chain: the chain node to initialize
236  * @seqno: the sequence number to use for the fence chain
238  * Initialize a new chain node and either start a new chain or add the node to
239  * the existing chain of the previous fence.
241 void dma_fence_chain_init(struct dma_fence_chain *chain,
249 	spin_lock_init(&chain->lock);
250 	rcu_assign_pointer(chain->prev, prev);
251 	chain->fence = fence;
252 	chain->prev_seqno = 0;
254 	/* Try to reuse the context of the previous chain node. */
257 		chain->prev_seqno = prev->seqno;
265 	dma_fence_init(&chain->base, &dma_fence_chain_ops,
266 		       &chain->lock, context, seqno);