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)  in dma_fence_chain_get_prev()  argument
26 	prev = dma_fence_get_rcu_safe(&chain->prev);  in dma_fence_chain_get_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;  in dma_fence_chain_walk()  local
44 	chain = to_dma_fence_chain(fence);  in dma_fence_chain_walk()
45 	if (!chain) {  in dma_fence_chain_walk()
50 	while ((prev = dma_fence_chain_get_prev(chain))) {  in dma_fence_chain_walk()
65 		tmp = unrcu_pointer(cmpxchg(&chain->prev, RCU_INITIALIZER(prev),  in dma_fence_chain_walk()
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;  in dma_fence_chain_find_seqno()  local
97 	chain = to_dma_fence_chain(*pfence);  in dma_fence_chain_find_seqno()
98 	if (!chain || chain->base.seqno < seqno)  in dma_fence_chain_find_seqno()
101 	dma_fence_chain_for_each(*pfence, &chain->base) {  in dma_fence_chain_find_seqno()
102 		if ((*pfence)->context != chain->base.context ||  in dma_fence_chain_find_seqno()
106 	dma_fence_put(&chain->base);  in dma_fence_chain_find_seqno()
124 	struct dma_fence_chain *chain;  in dma_fence_chain_irq_work()  local
126 	chain = container_of(work, typeof(*chain), work);  in dma_fence_chain_irq_work()
129 	if (!dma_fence_chain_enable_signaling(&chain->base))  in dma_fence_chain_irq_work()
131 		dma_fence_signal(&chain->base);  in dma_fence_chain_irq_work()
132 	dma_fence_put(&chain->base);  in dma_fence_chain_irq_work()
137 	struct dma_fence_chain *chain;  in dma_fence_chain_cb()  local
139 	chain = container_of(cb, typeof(*chain), cb);  in dma_fence_chain_cb()
140 	init_irq_work(&chain->work, dma_fence_chain_irq_work);  in dma_fence_chain_cb()
141 	irq_work_queue(&chain->work);  in dma_fence_chain_cb()
180 	struct dma_fence_chain *chain = to_dma_fence_chain(fence);  in dma_fence_chain_release()  local
183 	/* Manually unlink the chain as much as possible to avoid recursion  in dma_fence_chain_release()
186 	while ((prev = rcu_dereference_protected(chain->prev, true))) {  in dma_fence_chain_release()
199 		chain->prev = prev_chain->prev;  in dma_fence_chain_release()
205 	dma_fence_put(chain->fence);  in dma_fence_chain_release()
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,  in dma_fence_chain_init()  argument
249 	spin_lock_init(&chain->lock);  in dma_fence_chain_init()
250 	rcu_assign_pointer(chain->prev, prev);  in dma_fence_chain_init()
251 	chain->fence = fence;  in dma_fence_chain_init()
252 	chain->prev_seqno = 0;  in dma_fence_chain_init()
254 	/* Try to reuse the context of the previous chain node. */  in dma_fence_chain_init()
257 		chain->prev_seqno = prev->seqno;  in dma_fence_chain_init()
265 	dma_fence_init(&chain->base, &dma_fence_chain_ops,  in dma_fence_chain_init()
266 		       &chain->lock, context, seqno);  in dma_fence_chain_init()