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