xref: /freebsd/sys/dev/virtio/virtqueue.h (revision 8d20be1e22095c27faf8fe8b2f0d089739cc742e)
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 /*
45  * Hint on how long the next interrupt should be postponed. This is
46  * only used when the EVENT_IDX feature is negotiated.
47  */
48 typedef enum {
49 	VQ_POSTPONE_SHORT,
50 	VQ_POSTPONE_LONG,
51 	VQ_POSTPONE_EMPTIED	/* Until all available desc are used. */
52 } vq_postpone_t;
53 
54 #define VIRTQUEUE_MAX_NAME_SZ	32
55 
56 /* One for each virtqueue the device wishes to allocate. */
57 struct vq_alloc_info {
58 	char		   vqai_name[VIRTQUEUE_MAX_NAME_SZ];
59 	int		   vqai_maxindirsz;
60 	virtqueue_intr_t  *vqai_intr;
61 	void		  *vqai_intr_arg;
62 	struct virtqueue **vqai_vq;
63 };
64 
65 #define VQ_ALLOC_INFO_INIT(_i,_nsegs,_intr,_arg,_vqp,_str,...) do {	\
66 	snprintf((_i)->vqai_name, VIRTQUEUE_MAX_NAME_SZ, _str,		\
67 	    ##__VA_ARGS__);						\
68 	(_i)->vqai_maxindirsz = (_nsegs);				\
69 	(_i)->vqai_intr = (_intr);					\
70 	(_i)->vqai_intr_arg = (_arg);					\
71 	(_i)->vqai_vq = (_vqp);						\
72 } while (0)
73 
74 uint64_t virtqueue_filter_features(uint64_t features);
75 
76 int	 virtqueue_alloc(device_t dev, uint16_t queue, uint16_t size,
77 	     int align, vm_paddr_t highaddr, struct vq_alloc_info *info,
78 	     struct virtqueue **vqp);
79 void	*virtqueue_drain(struct virtqueue *vq, int *last);
80 void	 virtqueue_free(struct virtqueue *vq);
81 int	 virtqueue_reinit(struct virtqueue *vq, uint16_t size);
82 
83 int	 virtqueue_intr_filter(struct virtqueue *vq);
84 void	 virtqueue_intr(struct virtqueue *vq);
85 int	 virtqueue_enable_intr(struct virtqueue *vq);
86 int	 virtqueue_postpone_intr(struct virtqueue *vq, vq_postpone_t hint);
87 void	 virtqueue_disable_intr(struct virtqueue *vq);
88 
89 /* Get physical address of the virtqueue ring. */
90 vm_paddr_t virtqueue_paddr(struct virtqueue *vq);
91 
92 int	 virtqueue_full(struct virtqueue *vq);
93 int	 virtqueue_empty(struct virtqueue *vq);
94 int	 virtqueue_size(struct virtqueue *vq);
95 int	 virtqueue_nused(struct virtqueue *vq);
96 void	 virtqueue_notify(struct virtqueue *vq);
97 void	 virtqueue_dump(struct virtqueue *vq);
98 
99 int	 virtqueue_enqueue(struct virtqueue *vq, void *cookie,
100 	     struct sglist *sg, int readable, int writable);
101 void	*virtqueue_dequeue(struct virtqueue *vq, uint32_t *len);
102 void	*virtqueue_poll(struct virtqueue *vq, uint32_t *len);
103 
104 #endif /* _VIRTIO_VIRTQUEUE_H */
105