1 /* SPDX-License-Identifier: MIT */
2 
3 /*
4  * Copyright © 2019 Intel Corporation
5  */
6 
7 #ifndef I915_SW_FENCE_WORK_H
8 #define I915_SW_FENCE_WORK_H
9 
10 #include <linux/dma-fence.h>
11 #include <linux/spinlock.h>
12 #include <linux/workqueue.h>
13 
14 #include "i915_sw_fence.h"
15 
16 struct dma_fence_work;
17 
18 struct dma_fence_work_ops {
19 	const char *name;
20 	int (*work)(struct dma_fence_work *f);
21 	void (*release)(struct dma_fence_work *f);
22 };
23 
24 struct dma_fence_work {
25 	struct dma_fence dma;
26 	spinlock_t lock;
27 
28 	struct i915_sw_fence chain;
29 	struct i915_sw_dma_fence_cb cb;
30 
31 	struct work_struct work;
32 	const struct dma_fence_work_ops *ops;
33 };
34 
35 enum {
36 	DMA_FENCE_WORK_IMM = DMA_FENCE_FLAG_USER_BITS,
37 };
38 
39 void dma_fence_work_init(struct dma_fence_work *f,
40 			 const struct dma_fence_work_ops *ops);
41 int dma_fence_work_chain(struct dma_fence_work *f, struct dma_fence *signal);
42 
43 static inline void dma_fence_work_commit(struct dma_fence_work *f)
44 {
45 	i915_sw_fence_commit(&f->chain);
46 }
47 
48 /**
49  * dma_fence_work_commit_imm: Commit the fence, and if possible execute locally.
50  * @f: the fenced worker
51  *
52  * Instead of always scheduling a worker to execute the callback (see
53  * dma_fence_work_commit()), we try to execute the callback immediately in
54  * the local context. It is required that the fence be committed before it
55  * is published, and that no other threads try to tamper with the number
56  * of asynchronous waits on the fence (or else the callback will be
57  * executed in the wrong context, i.e. not the callers).
58  */
59 static inline void dma_fence_work_commit_imm(struct dma_fence_work *f)
60 {
61 	if (atomic_read(&f->chain.pending) <= 1)
62 		__set_bit(DMA_FENCE_WORK_IMM, &f->dma.flags);
63 
64 	dma_fence_work_commit(f);
65 }
66 
67 #endif /* I915_SW_FENCE_WORK_H */
68