xref: /openbmc/linux/drivers/gpu/drm/msm/msm_fence.c (revision 8e774e02)
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, const char *name)
15 {
16 	struct msm_fence_context *fctx;
17 
18 	fctx = kzalloc(sizeof(*fctx), GFP_KERNEL);
19 	if (!fctx)
20 		return ERR_PTR(-ENOMEM);
21 
22 	fctx->dev = dev;
23 	strncpy(fctx->name, name, sizeof(fctx->name));
24 	fctx->context = dma_fence_context_alloc(1);
25 	init_waitqueue_head(&fctx->event);
26 	spin_lock_init(&fctx->spinlock);
27 
28 	return fctx;
29 }
30 
31 void msm_fence_context_free(struct msm_fence_context *fctx)
32 {
33 	kfree(fctx);
34 }
35 
36 static inline bool fence_completed(struct msm_fence_context *fctx, uint32_t fence)
37 {
38 	return (int32_t)(fctx->completed_fence - fence) >= 0;
39 }
40 
41 /* legacy path for WAIT_FENCE ioctl: */
42 int msm_wait_fence(struct msm_fence_context *fctx, uint32_t fence,
43 		ktime_t *timeout, bool interruptible)
44 {
45 	int ret;
46 
47 	if (fence > fctx->last_fence) {
48 		DRM_ERROR("%s: waiting on invalid fence: %u (of %u)\n",
49 				fctx->name, fence, fctx->last_fence);
50 		return -EINVAL;
51 	}
52 
53 	if (!timeout) {
54 		/* no-wait: */
55 		ret = fence_completed(fctx, fence) ? 0 : -EBUSY;
56 	} else {
57 		unsigned long remaining_jiffies = timeout_to_jiffies(timeout);
58 
59 		if (interruptible)
60 			ret = wait_event_interruptible_timeout(fctx->event,
61 				fence_completed(fctx, fence),
62 				remaining_jiffies);
63 		else
64 			ret = wait_event_timeout(fctx->event,
65 				fence_completed(fctx, fence),
66 				remaining_jiffies);
67 
68 		if (ret == 0) {
69 			DBG("timeout waiting for fence: %u (completed: %u)",
70 					fence, fctx->completed_fence);
71 			ret = -ETIMEDOUT;
72 		} else if (ret != -ERESTARTSYS) {
73 			ret = 0;
74 		}
75 	}
76 
77 	return ret;
78 }
79 
80 /* called from workqueue */
81 void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence)
82 {
83 	spin_lock(&fctx->spinlock);
84 	fctx->completed_fence = max(fence, fctx->completed_fence);
85 	spin_unlock(&fctx->spinlock);
86 
87 	wake_up_all(&fctx->event);
88 }
89 
90 struct msm_fence {
91 	struct dma_fence base;
92 	struct msm_fence_context *fctx;
93 };
94 
95 static inline struct msm_fence *to_msm_fence(struct dma_fence *fence)
96 {
97 	return container_of(fence, struct msm_fence, base);
98 }
99 
100 static const char *msm_fence_get_driver_name(struct dma_fence *fence)
101 {
102 	return "msm";
103 }
104 
105 static const char *msm_fence_get_timeline_name(struct dma_fence *fence)
106 {
107 	struct msm_fence *f = to_msm_fence(fence);
108 	return f->fctx->name;
109 }
110 
111 static bool msm_fence_signaled(struct dma_fence *fence)
112 {
113 	struct msm_fence *f = to_msm_fence(fence);
114 	return fence_completed(f->fctx, f->base.seqno);
115 }
116 
117 static const struct dma_fence_ops msm_fence_ops = {
118 	.get_driver_name = msm_fence_get_driver_name,
119 	.get_timeline_name = msm_fence_get_timeline_name,
120 	.signaled = msm_fence_signaled,
121 };
122 
123 struct dma_fence *
124 msm_fence_alloc(struct msm_fence_context *fctx)
125 {
126 	struct msm_fence *f;
127 
128 	f = kzalloc(sizeof(*f), GFP_KERNEL);
129 	if (!f)
130 		return ERR_PTR(-ENOMEM);
131 
132 	f->fctx = fctx;
133 
134 	dma_fence_init(&f->base, &msm_fence_ops, &fctx->spinlock,
135 		       fctx->context, ++fctx->last_fence);
136 
137 	return &f->base;
138 }
139