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  */
18 struct 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 
57 struct msm_fence_context * msm_fence_context_alloc(struct drm_device *dev,
58 		volatile uint32_t *fenceptr, const char *name);
59 void msm_fence_context_free(struct msm_fence_context *fctx);
60 
61 bool msm_fence_completed(struct msm_fence_context *fctx, uint32_t fence);
62 void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence);
63 
64 struct dma_fence * msm_fence_alloc(struct msm_fence_context *fctx);
65 
66 static inline bool
fence_before(uint32_t a,uint32_t b)67 fence_before(uint32_t a, uint32_t b)
68 {
69    return (int32_t)(a - b) < 0;
70 }
71 
72 static inline bool
fence_after(uint32_t a,uint32_t b)73 fence_after(uint32_t a, uint32_t b)
74 {
75    return (int32_t)(a - b) > 0;
76 }
77 
78 #endif
79