/* * fence-chain: chain fences together in a timeline * * Copyright (C) 2018 Advanced Micro Devices, Inc. * Authors: * Christian König <christian.koenig@amd.com> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. */ #ifndef __LINUX_DMA_FENCE_CHAIN_H #define __LINUX_DMA_FENCE_CHAIN_H #include <linux/dma-fence.h> #include <linux/irq_work.h> /** * struct dma_fence_chain - fence to represent an node of a fence chain * @base: fence base class * @lock: spinlock for fence handling * @prev: previous fence of the chain * @prev_seqno: original previous seqno before garbage collection * @fence: encapsulated fence * @cb: callback structure for signaling * @work: irq work item for signaling */ struct dma_fence_chain { struct dma_fence base; spinlock_t lock; struct dma_fence __rcu *prev; u64 prev_seqno; struct dma_fence *fence; struct dma_fence_cb cb; struct irq_work work; }; extern const struct dma_fence_ops dma_fence_chain_ops; /** * to_dma_fence_chain - cast a fence to a dma_fence_chain * @fence: fence to cast to a dma_fence_array * * Returns NULL if the fence is not a dma_fence_chain, * or the dma_fence_chain otherwise. */ static inline struct dma_fence_chain * to_dma_fence_chain(struct dma_fence *fence) { if (!fence || fence->ops != &dma_fence_chain_ops) return NULL; return container_of(fence, struct dma_fence_chain, base); } /** * dma_fence_chain_for_each - iterate over all fences in chain * @iter: current fence * @head: starting point * * Iterate over all fences in the chain. We keep a reference to the current * fence while inside the loop which must be dropped when breaking out. */ #define dma_fence_chain_for_each(iter, head) \ for (iter = dma_fence_get(head); iter; \ iter = dma_fence_chain_walk(iter)) struct dma_fence *dma_fence_chain_walk(struct dma_fence *fence); int dma_fence_chain_find_seqno(struct dma_fence **pfence, uint64_t seqno); void dma_fence_chain_init(struct dma_fence_chain *chain, struct dma_fence *prev, struct dma_fence *fence, uint64_t seqno); #endif /* __LINUX_DMA_FENCE_CHAIN_H */