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