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_gpu_fence(x) \
31 container_of(x, struct virtio_gpu_fence, f)
32
33static const char *virtio_gpu_get_driver_name(struct dma_fence *f)
34{
35 return "virtio_gpu";
36}
37
38static const char *virtio_gpu_get_timeline_name(struct dma_fence *f)
39{
40 return "controlq";
41}
42
43static bool virtio_gpu_fence_signaled(struct dma_fence *f)
44{
45 /* leaked fence outside driver before completing
46 * initialization with virtio_gpu_fence_emit.
47 */
48 WARN_ON_ONCE(f->seqno == 0);
49 return false;
50}
51
52static void virtio_gpu_fence_value_str(struct dma_fence *f, char *str, int size)
53{
54 snprintf(buf: str, size, fmt: "[%llu, %llu]", f->context, f->seqno);
55}
56
57static void virtio_gpu_timeline_value_str(struct dma_fence *f, char *str,
58 int size)
59{
60 struct virtio_gpu_fence *fence = to_virtio_gpu_fence(f);
61
62 snprintf(buf: str, size, fmt: "%llu",
63 (u64)atomic64_read(v: &fence->drv->last_fence_id));
64}
65
66static const struct dma_fence_ops virtio_gpu_fence_ops = {
67 .get_driver_name = virtio_gpu_get_driver_name,
68 .get_timeline_name = virtio_gpu_get_timeline_name,
69 .signaled = virtio_gpu_fence_signaled,
70 .fence_value_str = virtio_gpu_fence_value_str,
71 .timeline_value_str = virtio_gpu_timeline_value_str,
72};
73
74struct virtio_gpu_fence *virtio_gpu_fence_alloc(struct virtio_gpu_device *vgdev,
75 uint64_t base_fence_ctx,
76 uint32_t ring_idx)
77{
78 uint64_t fence_context = base_fence_ctx + ring_idx;
79 struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
80 struct virtio_gpu_fence *fence = kzalloc(size: sizeof(struct virtio_gpu_fence),
81 GFP_KERNEL);
82
83 if (!fence)
84 return fence;
85
86 fence->drv = drv;
87 fence->ring_idx = ring_idx;
88 fence->emit_fence_info = !(base_fence_ctx == drv->context);
89
90 /* This only partially initializes the fence because the seqno is
91 * unknown yet. The fence must not be used outside of the driver
92 * until virtio_gpu_fence_emit is called.
93 */
94
95 dma_fence_init(fence: &fence->f, ops: &virtio_gpu_fence_ops, lock: &drv->lock,
96 context: fence_context, seqno: 0);
97
98 return fence;
99}
100
101void virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev,
102 struct virtio_gpu_ctrl_hdr *cmd_hdr,
103 struct virtio_gpu_fence *fence)
104{
105 struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
106 unsigned long irq_flags;
107
108 spin_lock_irqsave(&drv->lock, irq_flags);
109 fence->fence_id = fence->f.seqno = ++drv->current_fence_id;
110 dma_fence_get(fence: &fence->f);
111 list_add_tail(new: &fence->node, head: &drv->fences);
112 spin_unlock_irqrestore(lock: &drv->lock, flags: irq_flags);
113
114 trace_dma_fence_emit(fence: &fence->f);
115
116 cmd_hdr->flags |= cpu_to_le32(VIRTIO_GPU_FLAG_FENCE);
117 cmd_hdr->fence_id = cpu_to_le64(fence->fence_id);
118
119 /* Only currently defined fence param. */
120 if (fence->emit_fence_info) {
121 cmd_hdr->flags |=
122 cpu_to_le32(VIRTIO_GPU_FLAG_INFO_RING_IDX);
123 cmd_hdr->ring_idx = (u8)fence->ring_idx;
124 }
125}
126
127void virtio_gpu_fence_event_process(struct virtio_gpu_device *vgdev,
128 u64 fence_id)
129{
130 struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
131 struct virtio_gpu_fence *signaled, *curr, *tmp;
132 unsigned long irq_flags;
133
134 spin_lock_irqsave(&drv->lock, irq_flags);
135 atomic64_set(v: &vgdev->fence_drv.last_fence_id, i: fence_id);
136 list_for_each_entry_safe(curr, tmp, &drv->fences, node) {
137 if (fence_id != curr->fence_id)
138 continue;
139
140 signaled = curr;
141
142 /*
143 * Signal any fences with a strictly smaller sequence number
144 * than the current signaled fence.
145 */
146 list_for_each_entry_safe(curr, tmp, &drv->fences, node) {
147 /* dma-fence contexts must match */
148 if (signaled->f.context != curr->f.context)
149 continue;
150
151 if (!dma_fence_is_later(f1: &signaled->f, f2: &curr->f))
152 continue;
153
154 dma_fence_signal_locked(fence: &curr->f);
155 if (curr->e) {
156 drm_send_event(dev: vgdev->ddev, e: &curr->e->base);
157 curr->e = NULL;
158 }
159
160 list_del(entry: &curr->node);
161 dma_fence_put(fence: &curr->f);
162 }
163
164 dma_fence_signal_locked(fence: &signaled->f);
165 if (signaled->e) {
166 drm_send_event(dev: vgdev->ddev, e: &signaled->e->base);
167 signaled->e = NULL;
168 }
169
170 list_del(entry: &signaled->node);
171 dma_fence_put(fence: &signaled->f);
172 break;
173 }
174 spin_unlock_irqrestore(lock: &drv->lock, flags: irq_flags);
175}
176

source code of linux/drivers/gpu/drm/virtio/virtgpu_fence.c