xref: /freebsd/sys/dev/virtio/virtqueue.h (revision cc759c1995237364b02829feb9e5fdd1e6ed2c5b)
1 /*-
2  * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef _VIRTIO_VIRTQUEUE_H
30 #define _VIRTIO_VIRTQUEUE_H
31 
32 struct virtqueue;
33 struct sglist;
34 
35 /* Support for indirect buffer descriptors. */
36 #define VIRTIO_RING_F_INDIRECT_DESC	(1 << 28)
37 
38 /* Support to suppress interrupt until specific index is reached. */
39 #define VIRTIO_RING_F_EVENT_IDX		(1 << 29)
40 
41 /* Device callback for a virtqueue interrupt. */
42 typedef void virtqueue_intr_t(void *);
43 
44 #define VIRTQUEUE_MAX_NAME_SZ	32
45 
46 /* One for each virtqueue the device wishes to allocate. */
47 struct vq_alloc_info {
48 	char		   vqai_name[VIRTQUEUE_MAX_NAME_SZ];
49 	int		   vqai_maxindirsz;
50 	virtqueue_intr_t  *vqai_intr;
51 	void		  *vqai_intr_arg;
52 	struct virtqueue **vqai_vq;
53 };
54 
55 #define VQ_ALLOC_INFO_INIT(_i,_nsegs,_intr,_arg,_vqp,_str,...) do {	\
56 	snprintf((_i)->vqai_name, VIRTQUEUE_MAX_NAME_SZ, _str,		\
57 	    ##__VA_ARGS__);						\
58 	(_i)->vqai_maxindirsz = (_nsegs);				\
59 	(_i)->vqai_intr = (_intr);					\
60 	(_i)->vqai_intr_arg = (_arg);					\
61 	(_i)->vqai_vq = (_vqp);						\
62 } while (0)
63 
64 uint64_t virtqueue_filter_features(uint64_t features);
65 
66 int	 virtqueue_alloc(device_t dev, uint16_t queue, uint16_t size,
67 	     int align, vm_paddr_t highaddr, struct vq_alloc_info *info,
68 	     struct virtqueue **vqp);
69 void	*virtqueue_drain(struct virtqueue *vq, int *last);
70 void	 virtqueue_free(struct virtqueue *vq);
71 int	 virtqueue_reinit(struct virtqueue *vq, uint16_t size);
72 
73 int	 virtqueue_intr_filter(struct virtqueue *vq);
74 void	 virtqueue_intr(struct virtqueue *vq);
75 int	 virtqueue_enable_intr(struct virtqueue *vq);
76 int	 virtqueue_postpone_intr(struct virtqueue *vq);
77 void	 virtqueue_disable_intr(struct virtqueue *vq);
78 
79 /* Get physical address of the virtqueue ring. */
80 vm_paddr_t virtqueue_paddr(struct virtqueue *vq);
81 
82 int	 virtqueue_full(struct virtqueue *vq);
83 int	 virtqueue_empty(struct virtqueue *vq);
84 int	 virtqueue_size(struct virtqueue *vq);
85 int	 virtqueue_nused(struct virtqueue *vq);
86 void	 virtqueue_notify(struct virtqueue *vq);
87 void	 virtqueue_dump(struct virtqueue *vq);
88 
89 int	 virtqueue_enqueue(struct virtqueue *vq, void *cookie,
90 	     struct sglist *sg, int readable, int writable);
91 void	*virtqueue_dequeue(struct virtqueue *vq, uint32_t *len);
92 void	*virtqueue_poll(struct virtqueue *vq, uint32_t *len);
93 
94 #endif /* _VIRTIO_VIRTQUEUE_H */
95