1 /*
2 * SPDX-License-Identifier: MIT
3 *
4 * i915_sw_fence.h - library routines for N:M synchronisation points
5 *
6 * Copyright (C) 2016 Intel Corporation
7 */
8
9 #ifndef _I915_SW_FENCE_H_
10 #define _I915_SW_FENCE_H_
11
12 #include <linux/dma-fence.h>
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_resv;
20 struct i915_sw_fence;
21
22 enum i915_sw_fence_notify {
23 FENCE_COMPLETE,
24 FENCE_FREE
25 };
26
27 typedef int (*i915_sw_fence_notify_t)(struct i915_sw_fence *,
28 enum i915_sw_fence_notify state);
29
30 struct i915_sw_fence {
31 wait_queue_head_t wait;
32 i915_sw_fence_notify_t fn;
33 #ifdef CONFIG_DRM_I915_SW_FENCE_CHECK_DAG
34 unsigned long flags;
35 #endif
36 atomic_t pending;
37 int error;
38 };
39
40 #define I915_SW_FENCE_CHECKED_BIT 0 /* used internally for DAG checking */
41
42 void __i915_sw_fence_init(struct i915_sw_fence *fence,
43 i915_sw_fence_notify_t fn,
44 const char *name,
45 struct lock_class_key *key);
46 #ifdef CONFIG_LOCKDEP
47 #define i915_sw_fence_init(fence, fn) \
48 do { \
49 static struct lock_class_key __key; \
50 \
51 __i915_sw_fence_init((fence), (fn), #fence, &__key); \
52 } while (0)
53 #else
54 #define i915_sw_fence_init(fence, fn) \
55 __i915_sw_fence_init((fence), (fn), NULL, NULL)
56 #endif
57
58 void i915_sw_fence_reinit(struct i915_sw_fence *fence);
59
60 #ifdef CONFIG_DRM_I915_SW_FENCE_DEBUG_OBJECTS
61 void i915_sw_fence_fini(struct i915_sw_fence *fence);
62 #else
i915_sw_fence_fini(struct i915_sw_fence * fence)63 static inline void i915_sw_fence_fini(struct i915_sw_fence *fence) {}
64 #endif
65
66 void i915_sw_fence_commit(struct i915_sw_fence *fence);
67
68 int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
69 struct i915_sw_fence *after,
70 wait_queue_entry_t *wq);
71 int i915_sw_fence_await_sw_fence_gfp(struct i915_sw_fence *fence,
72 struct i915_sw_fence *after,
73 gfp_t gfp);
74
75 struct i915_sw_dma_fence_cb {
76 struct dma_fence_cb base;
77 struct i915_sw_fence *fence;
78 };
79
80 int __i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
81 struct dma_fence *dma,
82 struct i915_sw_dma_fence_cb *cb);
83 int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
84 struct dma_fence *dma,
85 unsigned long timeout,
86 gfp_t gfp);
87
88 int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
89 struct dma_resv *resv,
90 const struct dma_fence_ops *exclude,
91 bool write,
92 unsigned long timeout,
93 gfp_t gfp);
94
95 bool i915_sw_fence_await(struct i915_sw_fence *fence);
96 void i915_sw_fence_complete(struct i915_sw_fence *fence);
97
i915_sw_fence_signaled(const struct i915_sw_fence * fence)98 static inline bool i915_sw_fence_signaled(const struct i915_sw_fence *fence)
99 {
100 return atomic_read(&fence->pending) <= 0;
101 }
102
i915_sw_fence_done(const struct i915_sw_fence * fence)103 static inline bool i915_sw_fence_done(const struct i915_sw_fence *fence)
104 {
105 return atomic_read(&fence->pending) < 0;
106 }
107
i915_sw_fence_wait(struct i915_sw_fence * fence)108 static inline void i915_sw_fence_wait(struct i915_sw_fence *fence)
109 {
110 wait_event(fence->wait, i915_sw_fence_done(fence));
111 }
112
113 static inline void
i915_sw_fence_set_error_once(struct i915_sw_fence * fence,int error)114 i915_sw_fence_set_error_once(struct i915_sw_fence *fence, int error)
115 {
116 if (unlikely(error))
117 cmpxchg(&fence->error, 0, error);
118 }
119
120 #endif /* _I915_SW_FENCE_H_ */
121