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
18struct completion;
19struct dma_fence;
20struct dma_fence_ops;
21struct reservation_object;
22
23struct 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
34enum i915_sw_fence_notify {
35	FENCE_COMPLETE,
36	FENCE_FREE
37};
38
39typedef 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
43void __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)				\
49do {								\
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
59void i915_sw_fence_commit(struct i915_sw_fence *fence);
60
61int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
62				 struct i915_sw_fence *after,
63				 wait_queue_t *wq);
64int i915_sw_fence_await_sw_fence_gfp(struct i915_sw_fence *fence,
65				     struct i915_sw_fence *after,
66				     gfp_t gfp);
67int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
68				  struct dma_fence *dma,
69				  unsigned long timeout,
70				  gfp_t gfp);
71int 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
78static inline bool i915_sw_fence_signaled(const struct i915_sw_fence *fence)
79{
80	return atomic_read(&fence->pending) <= 0;
81}
82
83static inline bool i915_sw_fence_done(const struct i915_sw_fence *fence)
84{
85	return atomic_read(&fence->pending) < 0;
86}
87
88static 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_ */