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 * $FreeBSD$ 33 */ 34 35 /* 36 * A scatter/gather list describes a group of physical address ranges. 37 * Each physical address range consists of a starting address and a 38 * length. 39 */ 40 41 #ifndef __SGLIST_H__ 42 #define __SGLIST_H__ 43 44 #include <sys/refcount.h> 45 46 struct sglist_seg { 47 vm_paddr_t ss_paddr; 48 size_t ss_len; 49 }; 50 51 struct sglist { 52 struct sglist_seg *sg_segs; 53 u_int sg_refs; 54 u_short sg_nseg; 55 u_short sg_maxseg; 56 }; 57 58 struct bio; 59 struct mbuf; 60 struct uio; 61 62 static __inline void 63 sglist_init(struct sglist *sg, u_short maxsegs, struct sglist_seg *segs) 64 { 65 66 sg->sg_segs = segs; 67 sg->sg_nseg = 0; 68 sg->sg_maxseg = maxsegs; 69 refcount_init(&sg->sg_refs, 1); 70 } 71 72 static __inline void 73 sglist_reset(struct sglist *sg) 74 { 75 76 sg->sg_nseg = 0; 77 } 78 79 static __inline struct sglist * 80 sglist_hold(struct sglist *sg) 81 { 82 83 refcount_acquire(&sg->sg_refs); 84 return (sg); 85 } 86 87 struct sglist *sglist_alloc(int nsegs, int mflags); 88 int sglist_append(struct sglist *sg, void *buf, size_t len); 89 int sglist_append_bio(struct sglist *sg, struct bio *bp); 90 int sglist_append_mbuf(struct sglist *sg, struct mbuf *m0); 91 int sglist_append_mbuf_epg(struct sglist *sg, struct mbuf *m0, size_t off, 92 size_t len); 93 int sglist_append_phys(struct sglist *sg, vm_paddr_t paddr, 94 size_t len); 95 int sglist_append_sglist(struct sglist *sg, struct sglist *source, 96 size_t offset, size_t length); 97 int sglist_append_uio(struct sglist *sg, struct uio *uio); 98 int sglist_append_user(struct sglist *sg, void *buf, size_t len, 99 struct thread *td); 100 int sglist_append_vmpages(struct sglist *sg, vm_page_t *m, size_t pgoff, 101 size_t len); 102 struct sglist *sglist_build(void *buf, size_t len, int mflags); 103 struct sglist *sglist_clone(struct sglist *sg, int mflags); 104 int sglist_consume_uio(struct sglist *sg, struct uio *uio, size_t resid); 105 int sglist_count(void *buf, size_t len); 106 int sglist_count_mbuf_epg(struct mbuf *m, size_t off, size_t len); 107 int sglist_count_vmpages(vm_page_t *m, size_t pgoff, size_t len); 108 void sglist_free(struct sglist *sg); 109 int sglist_join(struct sglist *first, struct sglist *second); 110 size_t sglist_length(struct sglist *sg); 111 int sglist_slice(struct sglist *original, struct sglist **slice, 112 size_t offset, size_t length, int mflags); 113 int sglist_split(struct sglist *original, struct sglist **head, 114 size_t length, int mflags); 115 116 #endif /* !__SGLIST_H__ */ 117