xref: /openbmc/linux/drivers/gpu/drm/msm/msm_fence.c (revision 16b0314a)
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 #include <linux/dma-fence.h>
8 
9 #include "msm_drv.h"
10 #include "msm_fence.h"
11 
12 
13 struct msm_fence_context *
14 msm_fence_context_alloc(struct drm_device *dev, volatile uint32_t *fenceptr,
15 		const char *name)
16 {
17 	struct msm_fence_context *fctx;
18 
19 	fctx = kzalloc(sizeof(*fctx), GFP_KERNEL);
20 	if (!fctx)
21 		return ERR_PTR(-ENOMEM);
22 
23 	fctx->dev = dev;
24 	strncpy(fctx->name, name, sizeof(fctx->name));
25 	fctx->context = dma_fence_context_alloc(1);
26 	fctx->fenceptr = fenceptr;
27 	spin_lock_init(&fctx->spinlock);
28 
29 	return fctx;
30 }
31 
32 void msm_fence_context_free(struct msm_fence_context *fctx)
33 {
34 	kfree(fctx);
35 }
36 
37 static inline bool fence_completed(struct msm_fence_context *fctx, uint32_t fence)
38 {
39 	/*
40 	 * Note: Check completed_fence first, as fenceptr is in a write-combine
41 	 * mapping, so it will be more expensive to read.
42 	 */
43 	return (int32_t)(fctx->completed_fence - fence) >= 0 ||
44 		(int32_t)(*fctx->fenceptr - fence) >= 0;
45 }
46 
47 /* called from workqueue */
48 void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence)
49 {
50 	spin_lock(&fctx->spinlock);
51 	fctx->completed_fence = max(fence, fctx->completed_fence);
52 	spin_unlock(&fctx->spinlock);
53 }
54 
55 struct msm_fence {
56 	struct dma_fence base;
57 	struct msm_fence_context *fctx;
58 };
59 
60 static inline struct msm_fence *to_msm_fence(struct dma_fence *fence)
61 {
62 	return container_of(fence, struct msm_fence, base);
63 }
64 
65 static const char *msm_fence_get_driver_name(struct dma_fence *fence)
66 {
67 	return "msm";
68 }
69 
70 static const char *msm_fence_get_timeline_name(struct dma_fence *fence)
71 {
72 	struct msm_fence *f = to_msm_fence(fence);
73 	return f->fctx->name;
74 }
75 
76 static bool msm_fence_signaled(struct dma_fence *fence)
77 {
78 	struct msm_fence *f = to_msm_fence(fence);
79 	return fence_completed(f->fctx, f->base.seqno);
80 }
81 
82 static const struct dma_fence_ops msm_fence_ops = {
83 	.get_driver_name = msm_fence_get_driver_name,
84 	.get_timeline_name = msm_fence_get_timeline_name,
85 	.signaled = msm_fence_signaled,
86 };
87 
88 struct dma_fence *
89 msm_fence_alloc(struct msm_fence_context *fctx)
90 {
91 	struct msm_fence *f;
92 
93 	f = kzalloc(sizeof(*f), GFP_KERNEL);
94 	if (!f)
95 		return ERR_PTR(-ENOMEM);
96 
97 	f->fctx = fctx;
98 
99 	dma_fence_init(&f->base, &msm_fence_ops, &fctx->spinlock,
100 		       fctx->context, ++fctx->last_fence);
101 
102 	return &f->base;
103 }
104