/* include/linux/aio_abi.h
*
* Copyright 2000,2001,2002 Red Hat.
*
* Written by Benjamin LaHaise <[email protected]>
*
* Distribute under the terms of the GPLv2 (see ../../COPYING) or under
* the following terms.
*
* Permission to use, copy, modify, and distribute this software and its
* documentation is hereby granted, provided that the above copyright
* notice appears in all copies. This software is provided without any
* warranty, express or implied. Red Hat makes no representations about
* the suitability of this software for any purpose.
*
* IN NO EVENT SHALL RED HAT BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
* SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF
* THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF RED HAT HAS BEEN ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* RED HAT DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND
* RED HAT HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
* ENHANCEMENTS, OR MODIFICATIONS.
*/
#ifndef __LINUX__AIO_ABI_H
#define __LINUX__AIO_ABI_H

#include <linux/types.h>
#include <asm/byteorder.h>

typedef __kernel_ulong_t aio_context_t;

enum {
IOCB_CMD_PREAD = 0,
IOCB_CMD_PWRITE = 1,
IOCB_CMD_FSYNC = 2,
IOCB_CMD_FDSYNC = 3,
/* These two are experimental.
* IOCB_CMD_PREADX = 4,
* IOCB_CMD_POLL = 5,
*/
IOCB_CMD_NOOP = 6,
IOCB_CMD_PREADV = 7,
IOCB_CMD_PWRITEV = 8,
};

/*
* Valid flags for the "aio_flags" member of the "struct iocb".
*
* IOCB_FLAG_RESFD - Set if the "aio_resfd" member of the "struct iocb"
* is valid.
*/
#define IOCB_FLAG_RESFD (1 << 0)

/* read() from /dev/aio returns these structures. */
struct io_event {
__u64 data; /* the data field from the iocb */
__u64 obj; /* what iocb this event came from */
__s64 res; /* result code for this event */
__s64 res2; /* secondary result */
};

#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
#define PADDED(x,y) x, y
#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
#define PADDED(x,y) y, x
#else
#error edit for your odd byteorder.
#endif

/*
* we always use a 64bit off_t when communicating
* with userland. its up to libraries to do the
* proper padding and aio_error abstraction
*/

struct iocb {
/* these are internal to the kernel/libc. */
__u64 aio_data; /* data to be returned in event's data */
__u32 PADDED(aio_key, aio_reserved1);
/* the kernel sets aio_key to the req # */

/* common fields */
__u16 aio_lio_opcode; /* see IOCB_CMD_ above */
__s16 aio_reqprio;
__u32 aio_fildes;

__u64 aio_buf;
__u64 aio_nbytes;
__s64 aio_offset;

/* extra parameters */
__u64 aio_reserved2; /* TODO: use this for a (struct sigevent *) */

/* flags for the "struct iocb" */
__u32 aio_flags;

/*
* if the IOCB_FLAG_RESFD flag of "aio_flags" is set, this is an
* eventfd to signal AIO readiness to
*/
__u32 aio_resfd;
}; /* 64 bytes */

#undef IFBIG
#undef IFLITTLE

#endif /* __LINUX__AIO_ABI_H */