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