1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice unmodified, this list of conditions, and the following
12 *    disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#ifndef _VIRTIO_VIRTQUEUE_H
32#define _VIRTIO_VIRTQUEUE_H
33
34struct virtqueue;
35struct sglist;
36
37/* Device callback for a virtqueue interrupt. */
38typedef void virtqueue_intr_t(void *);
39
40/*
41 * Hint on how long the next interrupt should be postponed. This is
42 * only used when the EVENT_IDX feature is negotiated.
43 */
44typedef enum {
45	VQ_POSTPONE_SHORT,
46	VQ_POSTPONE_LONG,
47	VQ_POSTPONE_EMPTIED	/* Until all available desc are used. */
48} vq_postpone_t;
49
50#define VIRTQUEUE_MAX_NAME_SZ	32
51
52/* One for each virtqueue the device wishes to allocate. */
53struct vq_alloc_info {
54	char		   vqai_name[VIRTQUEUE_MAX_NAME_SZ];
55	int		   vqai_maxindirsz;
56	virtqueue_intr_t  *vqai_intr;
57	void		  *vqai_intr_arg;
58	struct virtqueue **vqai_vq;
59};
60
61#define VQ_ALLOC_INFO_INIT(_i,_nsegs,_intr,_arg,_vqp,_str,...) do {	\
62	snprintf((_i)->vqai_name, VIRTQUEUE_MAX_NAME_SZ, _str,		\
63	    ##__VA_ARGS__);						\
64	(_i)->vqai_maxindirsz = (_nsegs);				\
65	(_i)->vqai_intr = (_intr);					\
66	(_i)->vqai_intr_arg = (_arg);					\
67	(_i)->vqai_vq = (_vqp);						\
68} while (0)
69
70int	 virtqueue_alloc(device_t dev, uint16_t queue, uint16_t size,
71	     bus_size_t notify_offset, int align, vm_paddr_t highaddr,
72	     struct vq_alloc_info *info, struct virtqueue **vqp);
73void	*virtqueue_drain(struct virtqueue *vq, int *last);
74void	 virtqueue_free(struct virtqueue *vq);
75int	 virtqueue_reinit(struct virtqueue *vq, uint16_t size);
76
77int	 virtqueue_intr_filter(struct virtqueue *vq);
78void	 virtqueue_intr(struct virtqueue *vq);
79int	 virtqueue_enable_intr(struct virtqueue *vq);
80int	 virtqueue_postpone_intr(struct virtqueue *vq, vq_postpone_t hint);
81void	 virtqueue_disable_intr(struct virtqueue *vq);
82
83/* Get physical address of the virtqueue ring. */
84vm_paddr_t virtqueue_paddr(struct virtqueue *vq);
85vm_paddr_t virtqueue_desc_paddr(struct virtqueue *vq);
86vm_paddr_t virtqueue_avail_paddr(struct virtqueue *vq);
87vm_paddr_t virtqueue_used_paddr(struct virtqueue *vq);
88
89uint16_t virtqueue_index(struct virtqueue *vq);
90int	 virtqueue_full(struct virtqueue *vq);
91int	 virtqueue_empty(struct virtqueue *vq);
92int	 virtqueue_size(struct virtqueue *vq);
93int	 virtqueue_nfree(struct virtqueue *vq);
94int	 virtqueue_nused(struct virtqueue *vq);
95void	 virtqueue_notify(struct virtqueue *vq);
96void	 virtqueue_dump(struct virtqueue *vq);
97
98int	 virtqueue_enqueue(struct virtqueue *vq, void *cookie,
99	     struct sglist *sg, int readable, int writable);
100void	*virtqueue_dequeue(struct virtqueue *vq, uint32_t *len);
101void	*virtqueue_poll(struct virtqueue *vq, uint32_t *len);
102
103#endif /* _VIRTIO_VIRTQUEUE_H */
104