sys/sys/uio.h

   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: src/sys/sys/uio.h,v 1.11.2.1 2001/09/28 16:58:35 dillon Exp $
  35  * $DragonFly: src/sys/sys/uio.h,v 1.14 2006/05/27 20:17:17 dillon Exp $
  36  */
  37
  38 #ifndef _SYS_UIO_H_
  39 #define _SYS_UIO_H_
  40
  41 #include <sys/_iovec.h>
  42
  43 #ifndef _SYS_TYPES_H_
  44 #include <sys/types.h>
  45 #endif
  46 #ifndef _SYS_PARAM_H_
  47 #include <sys/param.h>
  48 #endif
  49 #ifndef _SYS_MALLOC_H_
  50 #include <sys/malloc.h>         /* Needed to inline iovec_free(). */
  51 #endif
  52
  53 enum    uio_rw { UIO_READ, UIO_WRITE };
  54
  55 /* Segment flag values. */
  56 enum uio_seg {
  57         UIO_USERSPACE,          /* from user data space */
  58         UIO_SYSSPACE,           /* from system space */
  59         UIO_NOCOPY              /* don't copy, already in object */
  60 };
  61
  62 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
  63
  64 /*
  65  * uio_td is primarily used for USERSPACE transfers, but some devices
  66  * like ttys may also use it to get at the process.
  67  *
  68  * NOTE: uio_resid: Previously used int and FreeBSD decided to use ssize_t,
  69  *       but after reviewing use cases and in particular the fact that the
  70  *       iov uses an unsigned quantity, DragonFly will use the (unsigned)
  71  *       size_t.
  72  */
  73 struct uio {
  74         struct  iovec *uio_iov;
  75         int     uio_iovcnt;
  76         off_t   uio_offset;
  77         size_t  uio_resid;
  78         enum    uio_seg uio_segflg;
  79         enum    uio_rw uio_rw;
  80         struct  thread *uio_td;
  81 };
  82
  83 /*
  84  * Limits
  85  */
  86 #define UIO_MAXIOV      1024            /* max 1K of iov's */
  87 #define UIO_SMALLIOV    8               /* 8 on stack, else malloc */
  88
  89 #endif
  90
  91 #if defined(_KERNEL)
  92
  93 struct vm_object;
  94 struct vm_page;
  95
  96 void    uio_yield (void);
  97 int     uiomove (caddr_t, size_t, struct uio *);
  98 int     uiomovez (size_t, struct uio *);
  99 int     uiomove_frombuf (void *buf, size_t buflen, struct uio *uio);
 100 int     uiomove_fromphys(struct vm_page *ma[], vm_offset_t offset,
 101                             size_t n, struct uio *uio);
 102 int     uioread (int, struct uio *, struct vm_object *, int *);
 103 int     iovec_copyin(struct iovec *, struct iovec **, struct iovec *,
 104                             size_t, size_t *);
 105
 106 /*
 107  * MPSAFE
 108  */
 109 static __inline void
 110 iovec_free(struct iovec **kiov, struct iovec *siov)
 111 {
 112         if (*kiov != siov) {
 113                 FREE(*kiov, M_IOV);
 114                 *kiov = NULL;
 115         }
 116 }
 117
 118 #else /* !_KERNEL */
 119
 120 #include <sys/cdefs.h>
 121
 122 __BEGIN_DECLS
 123 ssize_t readv(int, const struct iovec *, int);
 124 ssize_t writev(int, const struct iovec *, int);
 125 ssize_t preadv(int, const struct iovec *, int, off_t);
 126 ssize_t pwritev(int, const struct iovec *, int, off_t);
 127 __END_DECLS
 128
 129 #endif /* _KERNEL */
 130
 131 #endif /* !_SYS_UIO_H_ */