1/*-
2 * Copyright (c) 2008 Yahoo!, Inc.
3 * All rights reserved.
4 * Written by: John Baldwin <jhb@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following 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 * 3. Neither the name of the author nor the names of any co-contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $FreeBSD: stable/11/sys/sys/sglist.h 345039 2019-03-11 22:48:51Z jhb $
31 */
32
33/*
34 * A scatter/gather list describes a group of physical address ranges.
35 * Each physical address range consists of a starting address and a
36 * length.
37 */
38
39#ifndef __SGLIST_H__
40#define	__SGLIST_H__
41
42#include <sys/refcount.h>
43
44struct sglist_seg {
45	vm_paddr_t	ss_paddr;
46	size_t		ss_len;
47};
48
49struct sglist {
50	struct sglist_seg *sg_segs;
51	int		sg_refs;
52	u_short		sg_nseg;
53	u_short		sg_maxseg;
54};
55
56struct bio;
57struct mbuf;
58struct uio;
59
60static __inline void
61sglist_init(struct sglist *sg, u_short maxsegs, struct sglist_seg *segs)
62{
63
64	sg->sg_segs = segs;
65	sg->sg_nseg = 0;
66	sg->sg_maxseg = maxsegs;
67	refcount_init(&sg->sg_refs, 1);
68}
69
70static __inline void
71sglist_reset(struct sglist *sg)
72{
73
74	sg->sg_nseg = 0;
75}
76
77static __inline struct sglist *
78sglist_hold(struct sglist *sg)
79{
80
81	refcount_acquire(&sg->sg_refs);
82	return (sg);
83}
84
85struct sglist *sglist_alloc(int nsegs, int mflags);
86int	sglist_append(struct sglist *sg, void *buf, size_t len);
87int	sglist_append_bio(struct sglist *sg, struct bio *bp);
88int	sglist_append_mbuf(struct sglist *sg, struct mbuf *m0);
89int	sglist_append_phys(struct sglist *sg, vm_paddr_t paddr,
90	    size_t len);
91int	sglist_append_sglist(struct sglist *sg, struct sglist *source,
92	    size_t offset, size_t length);
93int	sglist_append_uio(struct sglist *sg, struct uio *uio);
94int	sglist_append_user(struct sglist *sg, void *buf, size_t len,
95	    struct thread *td);
96int	sglist_append_vmpages(struct sglist *sg, vm_page_t *m, size_t pgoff,
97	    size_t len);
98struct sglist *sglist_build(void *buf, size_t len, int mflags);
99struct sglist *sglist_clone(struct sglist *sg, int mflags);
100int	sglist_consume_uio(struct sglist *sg, struct uio *uio, size_t resid);
101int	sglist_count(void *buf, size_t len);
102int	sglist_count_vmpages(vm_page_t *m, size_t pgoff, size_t len);
103void	sglist_free(struct sglist *sg);
104int	sglist_join(struct sglist *first, struct sglist *second);
105size_t	sglist_length(struct sglist *sg);
106int	sglist_slice(struct sglist *original, struct sglist **slice,
107	    size_t offset, size_t length, int mflags);
108int	sglist_split(struct sglist *original, struct sglist **head,
109	    size_t length, int mflags);
110
111#endif	/* !__SGLIST_H__ */
112