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 #define to_virtio_fence(x) \
31 	container_of(x, struct virtio_gpu_fence, f)
32 
33 static const char *virtio_get_driver_name(struct dma_fence *f)
34 {
35 	return "virtio_gpu";
36 }
37 
38 static const char *virtio_get_timeline_name(struct dma_fence *f)
39 {
40 	return "controlq";
41 }
42 
43 static bool virtio_fence_signaled(struct dma_fence *f)
44 {
45 	struct virtio_gpu_fence *fence = to_virtio_fence(f);
46 
47 	if (WARN_ON_ONCE(fence->f.seqno == 0))
48 		/* leaked fence outside driver before completing
49 		 * initialization with virtio_gpu_fence_emit */
50 		return false;
51 	if (atomic64_read(&fence->drv->last_fence_id) >= fence->f.seqno)
52 		return true;
53 	return false;
54 }
55 
56 static void virtio_fence_value_str(struct dma_fence *f, char *str, int size)
57 {
58 	snprintf(str, size, "%llu", f->seqno);
59 }
60 
61 static void virtio_timeline_value_str(struct dma_fence *f, char *str, int size)
62 {
63 	struct virtio_gpu_fence *fence = to_virtio_fence(f);
64 
65 	snprintf(str, size, "%llu",
66 		 (u64)atomic64_read(&fence->drv->last_fence_id));
67 }
68 
69 static const struct dma_fence_ops virtio_fence_ops = {
70 	.get_driver_name     = virtio_get_driver_name,
71 	.get_timeline_name   = virtio_get_timeline_name,
72 	.signaled            = virtio_fence_signaled,
73 	.fence_value_str     = virtio_fence_value_str,
74 	.timeline_value_str  = virtio_timeline_value_str,
75 };
76 
77 struct virtio_gpu_fence *virtio_gpu_fence_alloc(struct virtio_gpu_device *vgdev)
78 {
79 	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
80 	struct virtio_gpu_fence *fence = kzalloc(sizeof(struct virtio_gpu_fence),
81 							GFP_KERNEL);
82 	if (!fence)
83 		return fence;
84 
85 	fence->drv = drv;
86 
87 	/* This only partially initializes the fence because the seqno is
88 	 * unknown yet.  The fence must not be used outside of the driver
89 	 * until virtio_gpu_fence_emit is called.
90 	 */
91 	dma_fence_init(&fence->f, &virtio_fence_ops, &drv->lock, drv->context, 0);
92 
93 	return fence;
94 }
95 
96 void virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev,
97 			  struct virtio_gpu_ctrl_hdr *cmd_hdr,
98 			  struct virtio_gpu_fence *fence)
99 {
100 	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
101 	unsigned long irq_flags;
102 
103 	spin_lock_irqsave(&drv->lock, irq_flags);
104 	fence->f.seqno = ++drv->current_fence_id;
105 	dma_fence_get(&fence->f);
106 	list_add_tail(&fence->node, &drv->fences);
107 	spin_unlock_irqrestore(&drv->lock, irq_flags);
108 
109 	trace_dma_fence_emit(&fence->f);
110 
111 	cmd_hdr->flags |= cpu_to_le32(VIRTIO_GPU_FLAG_FENCE);
112 	cmd_hdr->fence_id = cpu_to_le64(fence->f.seqno);
113 }
114 
115 void virtio_gpu_fence_event_process(struct virtio_gpu_device *vgdev,
116 				    u64 fence_id)
117 {
118 	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
119 	struct virtio_gpu_fence *fence, *tmp;
120 	unsigned long irq_flags;
121 
122 	spin_lock_irqsave(&drv->lock, irq_flags);
123 	atomic64_set(&vgdev->fence_drv.last_fence_id, fence_id);
124 	list_for_each_entry_safe(fence, tmp, &drv->fences, node) {
125 		if (fence_id < fence->f.seqno)
126 			continue;
127 		dma_fence_signal_locked(&fence->f);
128 		list_del(&fence->node);
129 		dma_fence_put(&fence->f);
130 	}
131 	spin_unlock_irqrestore(&drv->lock, irq_flags);
132 }
133