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 <linux/types.h>
 31#include <linux/fs.h>
 32#include <asm/byteorder.h>
 33
 34typedef __kernel_ulong_t aio_context_t;
 35
 36enum {
 37	IOCB_CMD_PREAD = 0,
 38	IOCB_CMD_PWRITE = 1,
 39	IOCB_CMD_FSYNC = 2,
 40	IOCB_CMD_FDSYNC = 3,
 41	/* 4 was the experimental IOCB_CMD_PREADX */
 42	IOCB_CMD_POLL = 5,
 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 * IOCB_FLAG_IOPRIO - Set if the "aio_reqprio" member of the "struct iocb"
 54 *                    is valid.
 55 */
 56#define IOCB_FLAG_RESFD		(1 << 0)
 57#define IOCB_FLAG_IOPRIO	(1 << 1)
 58
 59/* read() from /dev/aio returns these structures. */
 60struct io_event {
 61	__u64		data;		/* the data field from the iocb */
 62	__u64		obj;		/* what iocb this event came from */
 63	__s64		res;		/* result code for this event */
 64	__s64		res2;		/* secondary result */
 65};
 66
 67/*
 68 * we always use a 64bit off_t when communicating
 69 * with userland.  its up to libraries to do the
 70 * proper padding and aio_error abstraction
 71 */
 72
 73struct iocb {
 74	/* these are internal to the kernel/libc. */
 75	__u64	aio_data;	/* data to be returned in event's data */
 76
 77#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
 78	__u32	aio_key;	/* the kernel sets aio_key to the req # */
 79	__kernel_rwf_t aio_rw_flags;	/* RWF_* flags */
 80#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
 81	__kernel_rwf_t aio_rw_flags;	/* RWF_* flags */
 82	__u32	aio_key;	/* the kernel sets aio_key to the req # */
 83#else
 84#error edit for your odd byteorder.
 85#endif
 86
 87	/* common fields */
 88	__u16	aio_lio_opcode;	/* see IOCB_CMD_ above */
 89	__s16	aio_reqprio;
 90	__u32	aio_fildes;
 91
 92	__u64	aio_buf;
 93	__u64	aio_nbytes;
 94	__s64	aio_offset;
 95
 96	/* extra parameters */
 97	__u64	aio_reserved2;	/* TODO: use this for a (struct sigevent *) */
 98
 99	/* flags for the "struct iocb" */
100	__u32	aio_flags;
101
102	/*
103	 * if the IOCB_FLAG_RESFD flag of "aio_flags" is set, this is an
104	 * eventfd to signal AIO readiness to
105	 */
106	__u32	aio_resfd;
107}; /* 64 bytes */
108
109#undef IFBIG
110#undef IFLITTLE
111
112#endif /* __LINUX__AIO_ABI_H */