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;
20
21struct i915_sw_fence {
22	wait_queue_head_t wait;
23	unsigned long flags;
24	atomic_t pending;
25	int error;
26};
27
28#define I915_SW_FENCE_CHECKED_BIT	0 /* used internally for DAG checking */
29#define I915_SW_FENCE_PRIVATE_BIT	1 /* available for use by owner */
30#define I915_SW_FENCE_MASK		(~3)
31
32enum i915_sw_fence_notify {
33	FENCE_COMPLETE,
34	FENCE_FREE
35};
36
37typedef int (*i915_sw_fence_notify_t)(struct i915_sw_fence *,
38				      enum i915_sw_fence_notify state);
39#define __i915_sw_fence_call __aligned(4)
40
41void __i915_sw_fence_init(struct i915_sw_fence *fence,
42			  i915_sw_fence_notify_t fn,
43			  const char *name,
44			  struct lock_class_key *key);
45#ifdef CONFIG_LOCKDEP
46#define i915_sw_fence_init(fence, fn)				\
47do {								\
48	static struct lock_class_key __key;			\
49								\
50	__i915_sw_fence_init((fence), (fn), #fence, &__key);	\
51} while (0)
52#else
53#define i915_sw_fence_init(fence, fn)				\
54	__i915_sw_fence_init((fence), (fn), NULL, NULL)
55#endif
56
57void i915_sw_fence_reinit(struct i915_sw_fence *fence);
58
59#ifdef CONFIG_DRM_I915_SW_FENCE_DEBUG_OBJECTS
60void i915_sw_fence_fini(struct i915_sw_fence *fence);
61#else
62static inline void i915_sw_fence_fini(struct i915_sw_fence *fence) {}
63#endif
64
65void i915_sw_fence_commit(struct i915_sw_fence *fence);
66
67int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
68				 struct i915_sw_fence *after,
69				 wait_queue_entry_t *wq);
70int i915_sw_fence_await_sw_fence_gfp(struct i915_sw_fence *fence,
71				     struct i915_sw_fence *after,
72				     gfp_t gfp);
73
74struct i915_sw_dma_fence_cb {
75	struct dma_fence_cb base;
76	struct i915_sw_fence *fence;
77};
78
79int __i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
80				    struct dma_fence *dma,
81				    struct i915_sw_dma_fence_cb *cb);
82int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
83				  struct dma_fence *dma,
84				  unsigned long timeout,
85				  gfp_t gfp);
86
87int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
88				    struct dma_resv *resv,
89				    const struct dma_fence_ops *exclude,
90				    bool write,
91				    unsigned long timeout,
92				    gfp_t gfp);
93
94bool i915_sw_fence_await(struct i915_sw_fence *fence);
95void i915_sw_fence_complete(struct i915_sw_fence *fence);
96
97static inline bool i915_sw_fence_signaled(const struct i915_sw_fence *fence)
98{
99	return atomic_read(&fence->pending) <= 0;
100}
101
102static inline bool i915_sw_fence_done(const struct i915_sw_fence *fence)
103{
104	return atomic_read(&fence->pending) < 0;
105}
106
107static inline void i915_sw_fence_wait(struct i915_sw_fence *fence)
108{
109	wait_event(fence->wait, i915_sw_fence_done(fence));
110}
111
112static inline void
113i915_sw_fence_set_error_once(struct i915_sw_fence *fence, int error)
114{
115	if (unlikely(error))
116		cmpxchg(&fence->error, 0, error);
117}
118
119#endif /* _I915_SW_FENCE_H_ */
120