1 /*
2  * i915_sw_fence.h - library routines for N:M synchronisation points
3  *
4  * Copyright (C) 2016 Intel Corporation
5  *
6  * This file is released under the GPLv2.
7  *
8  */
9 
10 #ifndef _I915_SW_FENCE_H_
11 #define _I915_SW_FENCE_H_
12 
13 #include <linux/gfp.h>
14 #include <linux/kref.h>
15 #include <linux/notifier.h> /* for NOTIFY_DONE */
16 #include <linux/wait.h>
17 
18 struct completion;
19 struct dma_fence;
20 struct dma_fence_ops;
21 struct reservation_object;
22 
23 struct i915_sw_fence {
24 	wait_queue_head_t wait;
25 	unsigned long flags;
26 	struct kref kref;
27 	atomic_t pending;
28 };
29 
30 #define I915_SW_FENCE_CHECKED_BIT	0 /* used internally for DAG checking */
31 #define I915_SW_FENCE_PRIVATE_BIT	1 /* available for use by owner */
32 #define I915_SW_FENCE_MASK		(~3)
33 
34 enum i915_sw_fence_notify {
35 	FENCE_COMPLETE,
36 	FENCE_FREE
37 };
38 
39 typedef int (*i915_sw_fence_notify_t)(struct i915_sw_fence *,
40 				      enum i915_sw_fence_notify state);
41 #define __i915_sw_fence_call __aligned(4)
42 
43 void i915_sw_fence_init(struct i915_sw_fence *fence, i915_sw_fence_notify_t fn);
44 void i915_sw_fence_commit(struct i915_sw_fence *fence);
45 
46 int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
47 				 struct i915_sw_fence *after,
48 				 wait_queue_t *wq);
49 int i915_sw_fence_await_sw_fence_gfp(struct i915_sw_fence *fence,
50 				     struct i915_sw_fence *after,
51 				     gfp_t gfp);
52 int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
53 				  struct dma_fence *dma,
54 				  unsigned long timeout,
55 				  gfp_t gfp);
56 int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
57 				    struct reservation_object *resv,
58 				    const struct dma_fence_ops *exclude,
59 				    bool write,
60 				    unsigned long timeout,
61 				    gfp_t gfp);
62 
63 static inline bool i915_sw_fence_done(const struct i915_sw_fence *fence)
64 {
65 	return atomic_read(&fence->pending) < 0;
66 }
67 
68 static inline void i915_sw_fence_wait(struct i915_sw_fence *fence)
69 {
70 	wait_event(fence->wait, i915_sw_fence_done(fence));
71 }
72 
73 #endif /* _I915_SW_FENCE_H_ */
74