1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * Copyright (C) 2013-2016 Red Hat
 4 * Author: Rob Clark <robdclark@gmail.com>
 5 */
 6
 7#ifndef __MSM_FENCE_H__
 8#define __MSM_FENCE_H__
 9
10#include "msm_drv.h"
11
12/**
13 * struct msm_fence_context - fence context for gpu
14 *
15 * Each ringbuffer has a single fence context, with the GPU writing an
16 * incrementing fence seqno at the end of each submit
17 */
18struct msm_fence_context {
19	struct drm_device *dev;
20	/** name: human readable name for fence timeline */
21	char name[32];
22	/** context: see dma_fence_context_alloc() */
23	unsigned context;
24	/** index: similar to context, but local to msm_fence_context's */
25	unsigned index;
26
27	/**
28	 * last_fence:
29	 *
30	 * Last assigned fence, incremented each time a fence is created
31	 * on this fence context.  If last_fence == completed_fence,
32	 * there is no remaining pending work
33	 */
34	uint32_t last_fence;
35
36	/**
37	 * completed_fence:
38	 *
39	 * The last completed fence, updated from the CPU after interrupt
40	 * from GPU
41	 */
42	uint32_t completed_fence;
43
44	/**
45	 * fenceptr:
46	 *
47	 * The address that the GPU directly writes with completed fence
48	 * seqno.  This can be ahead of completed_fence.  We can peek at
49	 * this to see if a fence has already signaled but the CPU hasn't
50	 * gotten around to handling the irq and updating completed_fence
51	 */
52	volatile uint32_t *fenceptr;
53
54	spinlock_t spinlock;
55};
56
57struct msm_fence_context * msm_fence_context_alloc(struct drm_device *dev,
58		volatile uint32_t *fenceptr, const char *name);
59void msm_fence_context_free(struct msm_fence_context *fctx);
60
61bool msm_fence_completed(struct msm_fence_context *fctx, uint32_t fence);
62void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence);
63
64struct dma_fence * msm_fence_alloc(struct msm_fence_context *fctx);
65
66static inline bool
67fence_before(uint32_t a, uint32_t b)
68{
69   return (int32_t)(a - b) < 0;
70}
71
72static inline bool
73fence_after(uint32_t a, uint32_t b)
74{
75   return (int32_t)(a - b) > 0;
76}
77
78#endif