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 
34 typedef __kernel_ulong_t aio_context_t;
35 
36 enum {
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. */
60 struct 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 
73 struct 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 */
113 
114