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1 : : /* SPDX-License-Identifier: GPL-2.0-only */ 2 : : /* 3 : : * fence-chain: chain fences together in a timeline 4 : : * 5 : : * Copyright (C) 2018 Advanced Micro Devices, Inc. 6 : : * Authors: 7 : : * Christian König <christian.koenig@amd.com> 8 : : */ 9 : : 10 : : #ifndef __LINUX_DMA_FENCE_CHAIN_H 11 : : #define __LINUX_DMA_FENCE_CHAIN_H 12 : : 13 : : #include <linux/dma-fence.h> 14 : : #include <linux/irq_work.h> 15 : : 16 : : /** 17 : : * struct dma_fence_chain - fence to represent an node of a fence chain 18 : : * @base: fence base class 19 : : * @lock: spinlock for fence handling 20 : : * @prev: previous fence of the chain 21 : : * @prev_seqno: original previous seqno before garbage collection 22 : : * @fence: encapsulated fence 23 : : * @cb: callback structure for signaling 24 : : * @work: irq work item for signaling 25 : : */ 26 : : struct dma_fence_chain { 27 : : struct dma_fence base; 28 : : spinlock_t lock; 29 : : struct dma_fence __rcu *prev; 30 : : u64 prev_seqno; 31 : : struct dma_fence *fence; 32 : : struct dma_fence_cb cb; 33 : : struct irq_work work; 34 : : }; 35 : : 36 : : extern const struct dma_fence_ops dma_fence_chain_ops; 37 : : 38 : : /** 39 : : * to_dma_fence_chain - cast a fence to a dma_fence_chain 40 : : * @fence: fence to cast to a dma_fence_array 41 : : * 42 : : * Returns NULL if the fence is not a dma_fence_chain, 43 : : * or the dma_fence_chain otherwise. 44 : : */ 45 : : static inline struct dma_fence_chain * 46 : 0 : to_dma_fence_chain(struct dma_fence *fence) 47 : : { 48 [ # # # # : 0 : if (!fence || fence->ops != &dma_fence_chain_ops) # # # # # # # # # # # # # # # # # # # # # # # # # # ] 49 : 0 : return NULL; 50 : : 51 : : return container_of(fence, struct dma_fence_chain, base); 52 : : } 53 : : 54 : : /** 55 : : * dma_fence_chain_for_each - iterate over all fences in chain 56 : : * @iter: current fence 57 : : * @head: starting point 58 : : * 59 : : * Iterate over all fences in the chain. We keep a reference to the current 60 : : * fence while inside the loop which must be dropped when breaking out. 61 : : */ 62 : : #define dma_fence_chain_for_each(iter, head) \ 63 : : for (iter = dma_fence_get(head); iter; \ 64 : : iter = dma_fence_chain_walk(iter)) 65 : : 66 : : struct dma_fence *dma_fence_chain_walk(struct dma_fence *fence); 67 : : int dma_fence_chain_find_seqno(struct dma_fence **pfence, uint64_t seqno); 68 : : void dma_fence_chain_init(struct dma_fence_chain *chain, 69 : : struct dma_fence *prev, 70 : : struct dma_fence *fence, 71 : : uint64_t seqno); 72 : : 73 : : #endif /* __LINUX_DMA_FENCE_CHAIN_H */