xref: /freebsd/sys/dev/virtio/virtqueue.h (revision 6bfca4dcab07dad45a805879d954876b353c0810)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
29 #ifndef _VIRTIO_VIRTQUEUE_H
30 #define _VIRTIO_VIRTQUEUE_H
31 
32 struct virtqueue;
33 struct sglist;
34 
35 /* Device callback for a virtqueue interrupt. */
36 typedef void virtqueue_intr_t(void *);
37 
38 /*
39  * Hint on how long the next interrupt should be postponed. This is
40  * only used when the EVENT_IDX feature is negotiated.
41  */
42 typedef enum {
43 	VQ_POSTPONE_SHORT,
44 	VQ_POSTPONE_LONG,
45 	VQ_POSTPONE_EMPTIED	/* Until all available desc are used. */
46 } vq_postpone_t;
47 
48 #define VIRTQUEUE_MAX_NAME_SZ	32
49 
50 /* One for each virtqueue the device wishes to allocate. */
51 struct vq_alloc_info {
52 	char		   vqai_name[VIRTQUEUE_MAX_NAME_SZ];
53 	int		   vqai_maxindirsz;
54 	virtqueue_intr_t  *vqai_intr;
55 	void		  *vqai_intr_arg;
56 	struct virtqueue **vqai_vq;
57 };
58 
59 #define VQ_ALLOC_INFO_INIT(_i,_nsegs,_intr,_arg,_vqp,_str,...) do {	\
60 	snprintf((_i)->vqai_name, VIRTQUEUE_MAX_NAME_SZ, _str,		\
61 	    ##__VA_ARGS__);						\
62 	(_i)->vqai_maxindirsz = (_nsegs);				\
63 	(_i)->vqai_intr = (_intr);					\
64 	(_i)->vqai_intr_arg = (_arg);					\
65 	(_i)->vqai_vq = (_vqp);						\
66 } while (0)
67 
68 int	 virtqueue_alloc(device_t dev, uint16_t queue, uint16_t size,
69 	     bus_size_t notify_offset, int align, vm_paddr_t highaddr,
70 	     struct vq_alloc_info *info, struct virtqueue **vqp);
71 void	*virtqueue_drain(struct virtqueue *vq, int *last);
72 void	 virtqueue_free(struct virtqueue *vq);
73 int	 virtqueue_reinit(struct virtqueue *vq, uint16_t size);
74 
75 int	 virtqueue_intr_filter(struct virtqueue *vq);
76 void	 virtqueue_intr(struct virtqueue *vq);
77 int	 virtqueue_enable_intr(struct virtqueue *vq);
78 int	 virtqueue_postpone_intr(struct virtqueue *vq, vq_postpone_t hint);
79 void	 virtqueue_disable_intr(struct virtqueue *vq);
80 
81 /* Get physical address of the virtqueue ring. */
82 vm_paddr_t virtqueue_paddr(struct virtqueue *vq);
83 vm_paddr_t virtqueue_desc_paddr(struct virtqueue *vq);
84 vm_paddr_t virtqueue_avail_paddr(struct virtqueue *vq);
85 vm_paddr_t virtqueue_used_paddr(struct virtqueue *vq);
86 
87 uint16_t virtqueue_index(struct virtqueue *vq);
88 bool	 virtqueue_full(struct virtqueue *vq);
89 bool	 virtqueue_empty(struct virtqueue *vq);
90 int	 virtqueue_size(struct virtqueue *vq);
91 int	 virtqueue_nfree(struct virtqueue *vq);
92 int	 virtqueue_nused(struct virtqueue *vq);
93 void	 virtqueue_notify(struct virtqueue *vq);
94 void	 virtqueue_dump(struct virtqueue *vq);
95 
96 int	 virtqueue_enqueue(struct virtqueue *vq, void *cookie,
97 	     struct sglist *sg, int readable, int writable);
98 void	*virtqueue_dequeue(struct virtqueue *vq, uint32_t *len);
99 void	*virtqueue_poll(struct virtqueue *vq, uint32_t *len);
100 
101 #endif /* _VIRTIO_VIRTQUEUE_H */
102