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(str, size, "[%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(str, size, "%llu",
 63		 (u64)atomic64_read(&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{
 76	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
 77	struct virtio_gpu_fence *fence = kzalloc(sizeof(struct virtio_gpu_fence),
 78							GFP_KERNEL);
 79	if (!fence)
 80		return fence;
 81
 82	fence->drv = drv;
 83
 84	/* This only partially initializes the fence because the seqno is
 85	 * unknown yet.  The fence must not be used outside of the driver
 86	 * until virtio_gpu_fence_emit is called.
 87	 */
 88	dma_fence_init(&fence->f, &virtio_gpu_fence_ops, &drv->lock, drv->context,
 89		       0);
 90
 91	return fence;
 92}
 93
 94void virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev,
 95			  struct virtio_gpu_ctrl_hdr *cmd_hdr,
 96			  struct virtio_gpu_fence *fence)
 97{
 98	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
 99	unsigned long irq_flags;
100
101	spin_lock_irqsave(&drv->lock, irq_flags);
102	fence->fence_id = fence->f.seqno = ++drv->current_fence_id;
103	dma_fence_get(&fence->f);
104	list_add_tail(&fence->node, &drv->fences);
105	spin_unlock_irqrestore(&drv->lock, irq_flags);
106
107	trace_dma_fence_emit(&fence->f);
108
109	cmd_hdr->flags |= cpu_to_le32(VIRTIO_GPU_FLAG_FENCE);
110	cmd_hdr->fence_id = cpu_to_le64(fence->fence_id);
111}
112
113void virtio_gpu_fence_event_process(struct virtio_gpu_device *vgdev,
114				    u64 fence_id)
115{
116	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
117	struct virtio_gpu_fence *signaled, *curr, *tmp;
118	unsigned long irq_flags;
119
120	spin_lock_irqsave(&drv->lock, irq_flags);
121	atomic64_set(&vgdev->fence_drv.last_fence_id, fence_id);
122	list_for_each_entry_safe(curr, tmp, &drv->fences, node) {
123		if (fence_id != curr->fence_id)
124			continue;
125
126		signaled = curr;
127
128		/*
129		 * Signal any fences with a strictly smaller sequence number
130		 * than the current signaled fence.
131		 */
132		list_for_each_entry_safe(curr, tmp, &drv->fences, node) {
133			/* dma-fence contexts must match */
134			if (signaled->f.context != curr->f.context)
135				continue;
136
137			if (!dma_fence_is_later(&signaled->f, &curr->f))
138				continue;
139
140			dma_fence_signal_locked(&curr->f);
141			list_del(&curr->node);
142			dma_fence_put(&curr->f);
143		}
144
145		dma_fence_signal_locked(&signaled->f);
146		list_del(&signaled->node);
147		dma_fence_put(&signaled->f);
148		break;
149	}
150	spin_unlock_irqrestore(&drv->lock, irq_flags);
151}