LXR linux/include/linux/aio

   1/* include/linux/aio_abi.h
   2 *
   3 * Copyright 2000,2001,2002 Red Hat.
   4 *
   5 * Written by Benjamin LaHaise <bcrl@kvack.org>
   6 *
   7 * Distribute under the terms of the GPLv2 (see ../../COPYING) or under 
   8 * the following terms.
   9 *
  10 * Permission to use, copy, modify, and distribute this software and its
  11 * documentation is hereby granted, provided that the above copyright
  12 * notice appears in all copies.  This software is provided without any
  13 * warranty, express or implied.  Red Hat makes no representations about
  14 * the suitability of this software for any purpose.
  15 *
  16 * IN NO EVENT SHALL RED HAT BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
  17 * SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF
  18 * THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF RED HAT HAS BEEN ADVISED
  19 * OF THE POSSIBILITY OF SUCH DAMAGE.
  20 *
  21 * RED HAT DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  23 * PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND
  24 * RED HAT HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
  25 * ENHANCEMENTS, OR MODIFICATIONS.
  26 */
  27#ifndef __LINUX__AIO_ABI_H
  28#define __LINUX__AIO_ABI_H
  29
  30#include <asm/byteorder.h>
  31
  32typedef unsigned long   aio_context_t;
  33
  34enum {
  35        IOCB_CMD_PREAD = 0,
  36        IOCB_CMD_PWRITE = 1,
  37        IOCB_CMD_FSYNC = 2,
  38        IOCB_CMD_FDSYNC = 3,
  39        /* These two are experimental.
  40         * IOCB_CMD_PREADX = 4,
  41         * IOCB_CMD_POLL = 5,
  42         */
  43        IOCB_CMD_NOOP = 6,
  44        IOCB_CMD_PREADV = 7,
  45        IOCB_CMD_PWRITEV = 8,
  46};
  47
  48/*
  49 * Valid flags for the "aio_flags" member of the "struct iocb".
  50 *
  51 * IOCB_FLAG_RESFD - Set if the "aio_resfd" member of the "struct iocb"
  52 *                   is valid.
  53 */
  54#define IOCB_FLAG_RESFD         (1 << 0)
  55
  56/* read() from /dev/aio returns these structures. */
  57struct io_event {
  58        __u64           data;           /* the data field from the iocb */
  59        __u64           obj;            /* what iocb this event came from */
  60        __s64           res;            /* result code for this event */
  61        __s64           res2;           /* secondary result */
  62};
  63
  64#if defined(__LITTLE_ENDIAN)
  65#define PADDED(x,y)     x, y
  66#elif defined(__BIG_ENDIAN)
  67#define PADDED(x,y)     y, x
  68#else
  69#error edit for your odd byteorder.
  70#endif
  71
  72/*
  73 * we always use a 64bit off_t when communicating
  74 * with userland.  its up to libraries to do the
  75 * proper padding and aio_error abstraction
  76 */
  77
  78struct iocb {
  79        /* these are internal to the kernel/libc. */
  80        __u64   aio_data;       /* data to be returned in event's data */
  81        __u32   PADDED(aio_key, aio_reserved1);
  82                                /* the kernel sets aio_key to the req # */
  83
  84        /* common fields */
  85        __u16   aio_lio_opcode; /* see IOCB_CMD_ above */
  86        __s16   aio_reqprio;
  87        __u32   aio_fildes;
  88
  89        __u64   aio_buf;
  90        __u64   aio_nbytes;
  91        __s64   aio_offset;
  92
  93        /* extra parameters */
  94        __u64   aio_reserved2;  /* TODO: use this for a (struct sigevent *) */
  95
  96        /* flags for the "struct iocb" */
  97        __u32   aio_flags;
  98
  99        /*
 100         * if the IOCB_FLAG_RESFD flag of "aio_flags" is set, this is an
 101         * eventfd to signal AIO readiness to
 102         */
 103        __u32   aio_resfd;
 104}; /* 64 bytes */
 105
 106#undef IFBIG
 107#undef IFLITTLE
 108
 109#endif /* __LINUX__AIO_ABI_H */
 110
 111