include/linux/aio_abi.h

   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
  32 typedef unsigned long   aio_context_t;
  33
  34 enum {
  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. */
  57 struct 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
  78 struct 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