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