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_ */