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
18struct completion;
19struct dma_resv;
20struct i915_sw_fence;
21
22enum i915_sw_fence_notify {
23 FENCE_COMPLETE,
24 FENCE_FREE
25};
26
27typedef int (*i915_sw_fence_notify_t)(struct i915_sw_fence *,
28 enum i915_sw_fence_notify state);
29
30struct 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
42void __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) \
48do { \
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) \
56do { \
57 BUILD_BUG_ON((fn) == NULL); \
58 __i915_sw_fence_init((fence), (fn), NULL, NULL); \
59} while (0)
60#endif
61
62void i915_sw_fence_reinit(struct i915_sw_fence *fence);
63
64#ifdef CONFIG_DRM_I915_SW_FENCE_DEBUG_OBJECTS
65void i915_sw_fence_fini(struct i915_sw_fence *fence);
66#else
67static inline void i915_sw_fence_fini(struct i915_sw_fence *fence) {}
68#endif
69
70void i915_sw_fence_commit(struct i915_sw_fence *fence);
71
72int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
73 struct i915_sw_fence *after,
74 wait_queue_entry_t *wq);
75int i915_sw_fence_await_sw_fence_gfp(struct i915_sw_fence *fence,
76 struct i915_sw_fence *after,
77 gfp_t gfp);
78
79struct i915_sw_dma_fence_cb {
80 struct dma_fence_cb base;
81 struct i915_sw_fence *fence;
82};
83
84int __i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
85 struct dma_fence *dma,
86 struct i915_sw_dma_fence_cb *cb);
87int 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
92int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
93 struct dma_resv *resv,
94 bool write,
95 unsigned long timeout,
96 gfp_t gfp);
97
98bool i915_sw_fence_await(struct i915_sw_fence *fence);
99void i915_sw_fence_complete(struct i915_sw_fence *fence);
100
101static inline bool i915_sw_fence_signaled(const struct i915_sw_fence *fence)
102{
103 return atomic_read(v: &fence->pending) <= 0;
104}
105
106static inline bool i915_sw_fence_done(const struct i915_sw_fence *fence)
107{
108 return atomic_read(v: &fence->pending) < 0;
109}
110
111static inline void i915_sw_fence_wait(struct i915_sw_fence *fence)
112{
113 wait_event(fence->wait, i915_sw_fence_done(fence));
114}
115
116static inline void
117i915_sw_fence_set_error_once(struct i915_sw_fence *fence, int error)
118{
119 if (unlikely(error))
120 cmpxchg(&fence->error, 0, error);
121}
122
123#endif /* _I915_SW_FENCE_H_ */
124