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,
44 			  i915_sw_fence_notify_t fn,
45 			  const char *name,
46 			  struct lock_class_key *key);
47 #ifdef CONFIG_LOCKDEP
48 #define i915_sw_fence_init(fence, fn)				\
49 do {								\
50 	static struct lock_class_key __key;			\
51 								\
52 	__i915_sw_fence_init((fence), (fn), #fence, &__key);	\
53 } while (0)
54 #else
55 #define i915_sw_fence_init(fence, fn)				\
56 	__i915_sw_fence_init((fence), (fn), NULL, NULL)
57 #endif
58 
59 void i915_sw_fence_commit(struct i915_sw_fence *fence);
60 
61 int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
62 				 struct i915_sw_fence *after,
63 				 wait_queue_t *wq);
64 int i915_sw_fence_await_sw_fence_gfp(struct i915_sw_fence *fence,
65 				     struct i915_sw_fence *after,
66 				     gfp_t gfp);
67 int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
68 				  struct dma_fence *dma,
69 				  unsigned long timeout,
70 				  gfp_t gfp);
71 int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
72 				    struct reservation_object *resv,
73 				    const struct dma_fence_ops *exclude,
74 				    bool write,
75 				    unsigned long timeout,
76 				    gfp_t gfp);
77 
78 static inline bool i915_sw_fence_signaled(const struct i915_sw_fence *fence)
79 {
80 	return atomic_read(&fence->pending) <= 0;
81 }
82 
83 static inline bool i915_sw_fence_done(const struct i915_sw_fence *fence)
84 {
85 	return atomic_read(&fence->pending) < 0;
86 }
87 
88 static inline void i915_sw_fence_wait(struct i915_sw_fence *fence)
89 {
90 	wait_event(fence->wait, i915_sw_fence_done(fence));
91 }
92 
93 #endif /* _I915_SW_FENCE_H_ */
94