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 <asm/byteorder.h>
32
33typedef __kernel_ulong_t aio_context_t;
34
35enum {
36	IOCB_CMD_PREAD = 0,
37	IOCB_CMD_PWRITE = 1,
38	IOCB_CMD_FSYNC = 2,
39	IOCB_CMD_FDSYNC = 3,
40	/* These two are experimental.
41	 * IOCB_CMD_PREADX = 4,
42	 * IOCB_CMD_POLL = 5,
43	 */
44	IOCB_CMD_NOOP = 6,
45	IOCB_CMD_PREADV = 7,
46	IOCB_CMD_PWRITEV = 8,
47};
48
49/*
50 * Valid flags for the "aio_flags" member of the "struct iocb".
51 *
52 * IOCB_FLAG_RESFD - Set if the "aio_resfd" member of the "struct iocb"
53 *                   is valid.
54 */
55#define IOCB_FLAG_RESFD		(1 << 0)
56
57/* read() from /dev/aio returns these structures. */
58struct io_event {
59	__u64		data;		/* the data field from the iocb */
60	__u64		obj;		/* what iocb this event came from */
61	__s64		res;		/* result code for this event */
62	__s64		res2;		/* secondary result */
63};
64
65#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
66#define PADDED(x,y)	x, y
67#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
68#define PADDED(x,y)	y, x
69#else
70#error edit for your odd byteorder.
71#endif
72
73/*
74 * we always use a 64bit off_t when communicating
75 * with userland.  its up to libraries to do the
76 * proper padding and aio_error abstraction
77 */
78
79struct iocb {
80	/* these are internal to the kernel/libc. */
81	__u64	aio_data;	/* data to be returned in event's data */
82	__u32	PADDED(aio_key, aio_reserved1);
83				/* the kernel sets aio_key to the req # */
84
85	/* common fields */
86	__u16	aio_lio_opcode;	/* see IOCB_CMD_ above */
87	__s16	aio_reqprio;
88	__u32	aio_fildes;
89
90	__u64	aio_buf;
91	__u64	aio_nbytes;
92	__s64	aio_offset;
93
94	/* extra parameters */
95	__u64	aio_reserved2;	/* TODO: use this for a (struct sigevent *) */
96
97	/* flags for the "struct iocb" */
98	__u32	aio_flags;
99
100	/*
101	 * if the IOCB_FLAG_RESFD flag of "aio_flags" is set, this is an
102	 * eventfd to signal AIO readiness to
103	 */
104	__u32	aio_resfd;
105}; /* 64 bytes */
106
107#undef IFBIG
108#undef IFLITTLE
109
110#endif /* __LINUX__AIO_ABI_H */
111
112