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 BUILD_BUG_ON((fn) == NULL); \
52 __i915_sw_fence_init((fence), (fn), #fence, &__key); \
53 } while (0)
54 #else
55 #define i915_sw_fence_init(fence, fn) \
56 do { \
57 BUILD_BUG_ON((fn) == NULL); \
58 __i915_sw_fence_init((fence), (fn), NULL, NULL); \
59 } while (0)
60 #endif
61
62 void i915_sw_fence_reinit(struct i915_sw_fence *fence);
63
64 #ifdef CONFIG_DRM_I915_SW_FENCE_DEBUG_OBJECTS
65 void i915_sw_fence_fini(struct i915_sw_fence *fence);
66 #else
i915_sw_fence_fini(struct i915_sw_fence * fence)67 static inline void i915_sw_fence_fini(struct i915_sw_fence *fence) {}
68 #endif
69
70 void i915_sw_fence_commit(struct i915_sw_fence *fence);
71
72 int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
73 struct i915_sw_fence *after,
74 wait_queue_entry_t *wq);
75 int i915_sw_fence_await_sw_fence_gfp(struct i915_sw_fence *fence,
76 struct i915_sw_fence *after,
77 gfp_t gfp);
78
79 struct i915_sw_dma_fence_cb {
80 struct dma_fence_cb base;
81 struct i915_sw_fence *fence;
82 };
83
84 int __i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
85 struct dma_fence *dma,
86 struct i915_sw_dma_fence_cb *cb);
87 int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
88 struct dma_fence *dma,
89 unsigned long timeout,
90 gfp_t gfp);
91
92 int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
93 struct dma_resv *resv,
94 const struct dma_fence_ops *exclude,
95 bool write,
96 unsigned long timeout,
97 gfp_t gfp);
98
99 bool i915_sw_fence_await(struct i915_sw_fence *fence);
100 void i915_sw_fence_complete(struct i915_sw_fence *fence);
101
i915_sw_fence_signaled(const struct i915_sw_fence * fence)102 static inline bool i915_sw_fence_signaled(const struct i915_sw_fence *fence)
103 {
104 return atomic_read(&fence->pending) <= 0;
105 }
106
i915_sw_fence_done(const struct i915_sw_fence * fence)107 static inline bool i915_sw_fence_done(const struct i915_sw_fence *fence)
108 {
109 return atomic_read(&fence->pending) < 0;
110 }
111
i915_sw_fence_wait(struct i915_sw_fence * fence)112 static inline void i915_sw_fence_wait(struct i915_sw_fence *fence)
113 {
114 wait_event(fence->wait, i915_sw_fence_done(fence));
115 }
116
117 static inline void
i915_sw_fence_set_error_once(struct i915_sw_fence * fence,int error)118 i915_sw_fence_set_error_once(struct i915_sw_fence *fence, int error)
119 {
120 if (unlikely(error))
121 cmpxchg(&fence->error, 0, error);
122 }
123
124 #endif /* _I915_SW_FENCE_H_ */
125