xref: /openbmc/linux/drivers/gpu/drm/msm/msm_fence.c (revision e3b9f1e8)
1 /*
2  * Copyright (C) 2013-2016 Red Hat
3  * Author: Rob Clark <robdclark@gmail.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include <linux/dma-fence.h>
19 
20 #include "msm_drv.h"
21 #include "msm_fence.h"
22 
23 
24 struct msm_fence_context *
25 msm_fence_context_alloc(struct drm_device *dev, const char *name)
26 {
27 	struct msm_fence_context *fctx;
28 
29 	fctx = kzalloc(sizeof(*fctx), GFP_KERNEL);
30 	if (!fctx)
31 		return ERR_PTR(-ENOMEM);
32 
33 	fctx->dev = dev;
34 	strncpy(fctx->name, name, sizeof(fctx->name));
35 	fctx->context = dma_fence_context_alloc(1);
36 	init_waitqueue_head(&fctx->event);
37 	spin_lock_init(&fctx->spinlock);
38 
39 	return fctx;
40 }
41 
42 void msm_fence_context_free(struct msm_fence_context *fctx)
43 {
44 	kfree(fctx);
45 }
46 
47 static inline bool fence_completed(struct msm_fence_context *fctx, uint32_t fence)
48 {
49 	return (int32_t)(fctx->completed_fence - fence) >= 0;
50 }
51 
52 /* legacy path for WAIT_FENCE ioctl: */
53 int msm_wait_fence(struct msm_fence_context *fctx, uint32_t fence,
54 		ktime_t *timeout, bool interruptible)
55 {
56 	int ret;
57 
58 	if (fence > fctx->last_fence) {
59 		DRM_ERROR("%s: waiting on invalid fence: %u (of %u)\n",
60 				fctx->name, fence, fctx->last_fence);
61 		return -EINVAL;
62 	}
63 
64 	if (!timeout) {
65 		/* no-wait: */
66 		ret = fence_completed(fctx, fence) ? 0 : -EBUSY;
67 	} else {
68 		unsigned long remaining_jiffies = timeout_to_jiffies(timeout);
69 
70 		if (interruptible)
71 			ret = wait_event_interruptible_timeout(fctx->event,
72 				fence_completed(fctx, fence),
73 				remaining_jiffies);
74 		else
75 			ret = wait_event_timeout(fctx->event,
76 				fence_completed(fctx, fence),
77 				remaining_jiffies);
78 
79 		if (ret == 0) {
80 			DBG("timeout waiting for fence: %u (completed: %u)",
81 					fence, fctx->completed_fence);
82 			ret = -ETIMEDOUT;
83 		} else if (ret != -ERESTARTSYS) {
84 			ret = 0;
85 		}
86 	}
87 
88 	return ret;
89 }
90 
91 /* called from workqueue */
92 void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence)
93 {
94 	spin_lock(&fctx->spinlock);
95 	fctx->completed_fence = max(fence, fctx->completed_fence);
96 	spin_unlock(&fctx->spinlock);
97 
98 	wake_up_all(&fctx->event);
99 }
100 
101 struct msm_fence {
102 	struct dma_fence base;
103 	struct msm_fence_context *fctx;
104 };
105 
106 static inline struct msm_fence *to_msm_fence(struct dma_fence *fence)
107 {
108 	return container_of(fence, struct msm_fence, base);
109 }
110 
111 static const char *msm_fence_get_driver_name(struct dma_fence *fence)
112 {
113 	return "msm";
114 }
115 
116 static const char *msm_fence_get_timeline_name(struct dma_fence *fence)
117 {
118 	struct msm_fence *f = to_msm_fence(fence);
119 	return f->fctx->name;
120 }
121 
122 static bool msm_fence_enable_signaling(struct dma_fence *fence)
123 {
124 	return true;
125 }
126 
127 static bool msm_fence_signaled(struct dma_fence *fence)
128 {
129 	struct msm_fence *f = to_msm_fence(fence);
130 	return fence_completed(f->fctx, f->base.seqno);
131 }
132 
133 static const struct dma_fence_ops msm_fence_ops = {
134 	.get_driver_name = msm_fence_get_driver_name,
135 	.get_timeline_name = msm_fence_get_timeline_name,
136 	.enable_signaling = msm_fence_enable_signaling,
137 	.signaled = msm_fence_signaled,
138 	.wait = dma_fence_default_wait,
139 	.release = dma_fence_free,
140 };
141 
142 struct dma_fence *
143 msm_fence_alloc(struct msm_fence_context *fctx)
144 {
145 	struct msm_fence *f;
146 
147 	f = kzalloc(sizeof(*f), GFP_KERNEL);
148 	if (!f)
149 		return ERR_PTR(-ENOMEM);
150 
151 	f->fctx = fctx;
152 
153 	dma_fence_init(&f->base, &msm_fence_ops, &fctx->spinlock,
154 		       fctx->context, ++fctx->last_fence);
155 
156 	return &f->base;
157 }
158