1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2022 Advanced Micro Devices, Inc. 4 * Authors: 5 * Christian König <christian.koenig@amd.com> 6 */ 7 8 #ifndef __LINUX_DMA_FENCE_UNWRAP_H 9 #define __LINUX_DMA_FENCE_UNWRAP_H 10 11 struct dma_fence; 12 13 /** 14 * struct dma_fence_unwrap - cursor into the container structure 15 * 16 * Should be used with dma_fence_unwrap_for_each() iterator macro. 17 */ 18 struct dma_fence_unwrap { 19 /** 20 * @chain: potential dma_fence_chain, but can be other fence as well 21 */ 22 struct dma_fence *chain; 23 /** 24 * @array: potential dma_fence_array, but can be other fence as well 25 */ 26 struct dma_fence *array; 27 /** 28 * @index: last returned index if @array is really a dma_fence_array 29 */ 30 unsigned int index; 31 }; 32 33 struct dma_fence *dma_fence_unwrap_first(struct dma_fence *head, 34 struct dma_fence_unwrap *cursor); 35 struct dma_fence *dma_fence_unwrap_next(struct dma_fence_unwrap *cursor); 36 37 /** 38 * dma_fence_unwrap_for_each - iterate over all fences in containers 39 * @fence: current fence 40 * @cursor: current position inside the containers 41 * @head: starting point for the iterator 42 * 43 * Unwrap dma_fence_chain and dma_fence_array containers and deep dive into all 44 * potential fences in them. If @head is just a normal fence only that one is 45 * returned. 46 */ 47 #define dma_fence_unwrap_for_each(fence, cursor, head) \ 48 for (fence = dma_fence_unwrap_first(head, cursor); fence; \ 49 fence = dma_fence_unwrap_next(cursor)) 50 51 struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences, 52 struct dma_fence **fences, 53 struct dma_fence_unwrap *cursors); 54 55 /** 56 * dma_fence_unwrap_merge - unwrap and merge fences 57 * 58 * All fences given as parameters are unwrapped and merged back together as flat 59 * dma_fence_array. Useful if multiple containers need to be merged together. 60 * 61 * Implemented as a macro to allocate the necessary arrays on the stack and 62 * account the stack frame size to the caller. 63 * 64 * Returns NULL on memory allocation failure, a dma_fence object representing 65 * all the given fences otherwise. 66 */ 67 #define dma_fence_unwrap_merge(...) \ 68 ({ \ 69 struct dma_fence *__f[] = { __VA_ARGS__ }; \ 70 struct dma_fence_unwrap __c[ARRAY_SIZE(__f)]; \ 71 \ 72 __dma_fence_unwrap_merge(ARRAY_SIZE(__f), __f, __c); \ 73 }) 74 75 #endif 76