Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | #ifndef __LINUX_UIO_H |
2 | #define __LINUX_UIO_H | |
3 | ||
4 | #include <linux/compiler.h> | |
5 | #include <linux/types.h> | |
6 | ||
7 | /* | |
8 | * Berkeley style UIO structures - Alan Cox 1994. | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or (at your option) any later version. | |
14 | */ | |
15 | ||
16 | ||
17 | /* A word of warning: Our uio structure will clash with the C library one (which is now obsolete). Remove the C | |
18 | library one from sys/uio.h if you have a very old library set */ | |
19 | ||
20 | struct iovec | |
21 | { | |
22 | void __user *iov_base; /* BSD uses caddr_t (1003.1g requires void *) */ | |
23 | __kernel_size_t iov_len; /* Must be size_t (1003.1g) */ | |
24 | }; | |
25 | ||
26 | #ifdef __KERNEL__ | |
27 | ||
28 | struct kvec { | |
29 | void *iov_base; /* and that should *never* hold a userland pointer */ | |
30 | size_t iov_len; | |
31 | }; | |
32 | ||
33 | #endif | |
34 | ||
35 | /* | |
36 | * UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1) | |
37 | */ | |
38 | ||
39 | #define UIO_FASTIOV 8 | |
40 | #define UIO_MAXIOV 1024 | |
41 | #if 0 | |
42 | #define UIO_MAXIOV 16 /* Maximum iovec's in one operation | |
43 | 16 matches BSD */ | |
44 | /* Beg pardon: BSD has 1024 --ANK */ | |
45 | #endif | |
46 | ||
47 | /* | |
48 | * Total number of bytes covered by an iovec. | |
49 | * | |
50 | * NOTE that it is not safe to use this function until all the iovec's | |
51 | * segment lengths have been validated. Because the individual lengths can | |
52 | * overflow a size_t when added together. | |
53 | */ | |
54 | static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs) | |
55 | { | |
56 | unsigned long seg; | |
57 | size_t ret = 0; | |
58 | ||
59 | for (seg = 0; seg < nr_segs; seg++) | |
60 | ret += iov[seg].iov_len; | |
61 | return ret; | |
62 | } | |
63 | ||
64 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to); | |
65 | ||
66 | #endif |