xref: /freebsd/sys/dev/virtio/virtqueue.h (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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 
34 struct virtqueue;
35 struct sglist;
36 
37 /* Device callback for a virtqueue interrupt. */
38 typedef 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  */
44 typedef 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. */
53 struct 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 
70 int	 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);
73 void	*virtqueue_drain(struct virtqueue *vq, int *last);
74 void	 virtqueue_free(struct virtqueue *vq);
75 int	 virtqueue_reinit(struct virtqueue *vq, uint16_t size);
76 
77 int	 virtqueue_intr_filter(struct virtqueue *vq);
78 void	 virtqueue_intr(struct virtqueue *vq);
79 int	 virtqueue_enable_intr(struct virtqueue *vq);
80 int	 virtqueue_postpone_intr(struct virtqueue *vq, vq_postpone_t hint);
81 void	 virtqueue_disable_intr(struct virtqueue *vq);
82 
83 /* Get physical address of the virtqueue ring. */
84 vm_paddr_t virtqueue_paddr(struct virtqueue *vq);
85 vm_paddr_t virtqueue_desc_paddr(struct virtqueue *vq);
86 vm_paddr_t virtqueue_avail_paddr(struct virtqueue *vq);
87 vm_paddr_t virtqueue_used_paddr(struct virtqueue *vq);
88 
89 uint16_t virtqueue_index(struct virtqueue *vq);
90 int	 virtqueue_full(struct virtqueue *vq);
91 int	 virtqueue_empty(struct virtqueue *vq);
92 int	 virtqueue_size(struct virtqueue *vq);
93 int	 virtqueue_nfree(struct virtqueue *vq);
94 int	 virtqueue_nused(struct virtqueue *vq);
95 void	 virtqueue_notify(struct virtqueue *vq);
96 void	 virtqueue_dump(struct virtqueue *vq);
97 
98 int	 virtqueue_enqueue(struct virtqueue *vq, void *cookie,
99 	     struct sglist *sg, int readable, int writable);
100 void	*virtqueue_dequeue(struct virtqueue *vq, uint32_t *len);
101 void	*virtqueue_poll(struct virtqueue *vq, uint32_t *len);
102 
103 #endif /* _VIRTIO_VIRTQUEUE_H */
104