uio.h revision 96080 
1/*
2 * Copyright (c) 1982, 1986, 1993, 1994
3 *	The Regents of the University of California.  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, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)uio.h	8.5 (Berkeley) 2/22/94
34 * $FreeBSD: head/sys/sys/uio.h 96080 2002-05-05 22:42:40Z alc $
35 */
36
37#ifndef _SYS_UIO_H_
38#define	_SYS_UIO_H_
39
40/*
41 * XXX
42 * iov_base should be a void *.
43 */
44struct iovec {
45	char	*iov_base;	/* Base address. */
46	size_t	 iov_len;	/* Length. */
47};
48
49enum	uio_rw { UIO_READ, UIO_WRITE };
50
51/* Segment flag values. */
52enum uio_seg {
53	UIO_USERSPACE,		/* from user data space */
54	UIO_SYSSPACE,		/* from system space */
55	UIO_USERISPACE,		/* from user I space */
56	UIO_NOCOPY		/* don't copy, already in object */
57};
58
59#ifdef _KERNEL
60
61struct uio {
62	struct	iovec *uio_iov;
63	int	uio_iovcnt;
64	off_t	uio_offset;
65	int	uio_resid;
66	enum	uio_seg uio_segflg;
67	enum	uio_rw uio_rw;
68	struct	thread *uio_td;
69};
70
71/*
72 * Limits
73 *
74 * N.B.: UIO_MAXIOV must be no less than IOV_MAX from <sys/syslimits.h>
75 * which in turn must be no less than _XOPEN_IOV_MAX from <limits.h>.  If
76 * we ever make this tunable (probably pointless), then IOV_MAX should be
77 * removed from <sys/syslimits.h> and applications would be expected to use
78 * sysconf(3) to find out the correct value, or else assume the worst
79 * (_XOPEN_IOV_MAX).  Perhaps UIO_MAXIOV should be simply defined as
80 * IOV_MAX.
81 */
82#define UIO_MAXIOV	1024		/* max 1K of iov's */
83#define UIO_SMALLIOV	8		/* 8 on stack, else malloc */
84
85struct vm_object;
86
87void	uio_yield(void);
88int	uiomove(caddr_t, int, struct uio *);
89#ifdef ENABLE_VFS_IOOPT		/* Experimental support for zero-copy I/O */
90int	uiomoveco(caddr_t, int, struct uio *, struct vm_object *);
91int	uioread(int, struct uio *, struct vm_object *, int *);
92#endif
93int	copyinfrom(const void *src, void *dst, size_t len, int seg);
94int	copyinstrfrom(const void *src, void *dst, size_t len,
95	    size_t *copied, int seg);
96
97#else /* !_KERNEL */
98
99#include <sys/cdefs.h>
100
101__BEGIN_DECLS
102ssize_t	readv(int, const struct iovec *, int);
103ssize_t	writev(int, const struct iovec *, int);
104__END_DECLS
105
106#endif /* _KERNEL */
107
108#endif /* !_SYS_UIO_H_ */
109