/* include/linux/aio_abi.h

   *
   * Copyright 2000,2001,2002 Red Hat.
   *
   * Written by Benjamin LaHaise <bcrl@kvack.org>
   *
   * 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 unsigned long	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(__LITTLE_ENDIAN)
  #define PADDED(x,y)	x, y
  #elif 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 */