1 /*
2  * Copyright (C) 2015 Red Hat, Inc.
3  * All Rights Reserved.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining
6  * a copy of this software and associated documentation files (the
7  * "Software"), to deal in the Software without restriction, including
8  * without limitation the rights to use, copy, modify, merge, publish,
9  * distribute, sublicense, and/or sell copies of the Software, and to
10  * permit persons to whom the Software is furnished to do so, subject to
11  * the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the
14  * next paragraph) shall be included in all copies or substantial
15  * portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
20  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24  */
25 
26 #include <trace/events/dma_fence.h>
27 
28 #include "virtgpu_drv.h"
29 
30 static const char *virtio_get_driver_name(struct dma_fence *f)
31 {
32 	return "virtio_gpu";
33 }
34 
35 static const char *virtio_get_timeline_name(struct dma_fence *f)
36 {
37 	return "controlq";
38 }
39 
40 bool virtio_fence_signaled(struct dma_fence *f)
41 {
42 	struct virtio_gpu_fence *fence = to_virtio_fence(f);
43 
44 	if (WARN_ON_ONCE(fence->f.seqno == 0))
45 		/* leaked fence outside driver before completing
46 		 * initialization with virtio_gpu_fence_emit */
47 		return false;
48 	if (atomic64_read(&fence->drv->last_seq) >= fence->f.seqno)
49 		return true;
50 	return false;
51 }
52 
53 static void virtio_fence_value_str(struct dma_fence *f, char *str, int size)
54 {
55 	snprintf(str, size, "%llu", f->seqno);
56 }
57 
58 static void virtio_timeline_value_str(struct dma_fence *f, char *str, int size)
59 {
60 	struct virtio_gpu_fence *fence = to_virtio_fence(f);
61 
62 	snprintf(str, size, "%llu", (u64)atomic64_read(&fence->drv->last_seq));
63 }
64 
65 static const struct dma_fence_ops virtio_fence_ops = {
66 	.get_driver_name     = virtio_get_driver_name,
67 	.get_timeline_name   = virtio_get_timeline_name,
68 	.signaled            = virtio_fence_signaled,
69 	.fence_value_str     = virtio_fence_value_str,
70 	.timeline_value_str  = virtio_timeline_value_str,
71 };
72 
73 struct virtio_gpu_fence *virtio_gpu_fence_alloc(struct virtio_gpu_device *vgdev)
74 {
75 	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
76 	struct virtio_gpu_fence *fence = kzalloc(sizeof(struct virtio_gpu_fence),
77 							GFP_KERNEL);
78 	if (!fence)
79 		return fence;
80 
81 	fence->drv = drv;
82 
83 	/* This only partially initializes the fence because the seqno is
84 	 * unknown yet.  The fence must not be used outside of the driver
85 	 * until virtio_gpu_fence_emit is called.
86 	 */
87 	dma_fence_init(&fence->f, &virtio_fence_ops, &drv->lock, drv->context, 0);
88 
89 	return fence;
90 }
91 
92 void virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev,
93 			  struct virtio_gpu_ctrl_hdr *cmd_hdr,
94 			  struct virtio_gpu_fence *fence)
95 {
96 	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
97 	unsigned long irq_flags;
98 
99 	spin_lock_irqsave(&drv->lock, irq_flags);
100 	fence->f.seqno = ++drv->sync_seq;
101 	dma_fence_get(&fence->f);
102 	list_add_tail(&fence->node, &drv->fences);
103 	spin_unlock_irqrestore(&drv->lock, irq_flags);
104 
105 	trace_dma_fence_emit(&fence->f);
106 
107 	cmd_hdr->flags |= cpu_to_le32(VIRTIO_GPU_FLAG_FENCE);
108 	cmd_hdr->fence_id = cpu_to_le64(fence->f.seqno);
109 }
110 
111 void virtio_gpu_fence_event_process(struct virtio_gpu_device *vgdev,
112 				    u64 last_seq)
113 {
114 	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
115 	struct virtio_gpu_fence *fence, *tmp;
116 	unsigned long irq_flags;
117 
118 	spin_lock_irqsave(&drv->lock, irq_flags);
119 	atomic64_set(&vgdev->fence_drv.last_seq, last_seq);
120 	list_for_each_entry_safe(fence, tmp, &drv->fences, node) {
121 		if (last_seq < fence->f.seqno)
122 			continue;
123 		dma_fence_signal_locked(&fence->f);
124 		list_del(&fence->node);
125 		dma_fence_put(&fence->f);
126 	}
127 	spin_unlock_irqrestore(&drv->lock, irq_flags);
128 }
129