1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2008 Yahoo!, Inc.
5 * All rights reserved.
6 * Written by: John Baldwin <jhb@FreeBSD.org>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following 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 * 3. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
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 u_int sg_refs;
52 u_short sg_nseg;
53 u_short sg_maxseg;
54};
55
56struct bio;
57struct mbuf;
58struct thread;
59struct uio;
60
61static __inline void
62sglist_init(struct sglist *sg, u_short maxsegs, struct sglist_seg *segs)
63{
64
65 sg->sg_segs = segs;
66 sg->sg_nseg = 0;
67 sg->sg_maxseg = maxsegs;
68 refcount_init(&sg->sg_refs, 1);
69}
70
71static __inline void
72sglist_reset(struct sglist *sg)
73{
74
75 sg->sg_nseg = 0;
76}
77
78static __inline struct sglist *
79sglist_hold(struct sglist *sg)
80{
81
82 refcount_acquire(&sg->sg_refs);
83 return (sg);
84}
85
86struct sglist *sglist_alloc(int nsegs, int mflags);
87int sglist_append(struct sglist *sg, void *buf, size_t len);
88int sglist_append_bio(struct sglist *sg, struct bio *bp);
89int sglist_append_mbuf(struct sglist *sg, struct mbuf *m0);
90int sglist_append_mbuf_epg(struct sglist *sg, struct mbuf *m0, size_t off,
91 size_t len);
92int sglist_append_phys(struct sglist *sg, vm_paddr_t paddr,
93 size_t len);
94int sglist_append_sglist(struct sglist *sg, struct sglist *source,
95 size_t offset, size_t length);
96int sglist_append_single_mbuf(struct sglist *sg, struct mbuf *m);
97int sglist_append_uio(struct sglist *sg, struct uio *uio);
98int sglist_append_user(struct sglist *sg, void *buf, size_t len,
99 struct thread *td);
100int sglist_append_vmpages(struct sglist *sg, vm_page_t *m, size_t pgoff,
101 size_t len);
102struct sglist *sglist_build(void *buf, size_t len, int mflags);
103struct sglist *sglist_clone(struct sglist *sg, int mflags);
104int sglist_consume_uio(struct sglist *sg, struct uio *uio, size_t resid);
105int sglist_count(void *buf, size_t len);
106int sglist_count_mbuf_epg(struct mbuf *m, size_t off, size_t len);
107int sglist_count_vmpages(vm_page_t *m, size_t pgoff, size_t len);
108void sglist_free(struct sglist *sg);
109int sglist_join(struct sglist *first, struct sglist *second);
110size_t sglist_length(struct sglist *sg);
111int sglist_slice(struct sglist *original, struct sglist **slice,
112 size_t offset, size_t length, int mflags);
113int sglist_split(struct sglist *original, struct sglist **head,
114 size_t length, int mflags);
115
116#endif /* !__SGLIST_H__ */