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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 1 | #ifndef __LINUX_UIO_H |
| 2 | #define __LINUX_UIO_H |
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| 3 | |||
| 4 | #include <linux/compiler.h> |
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| 5 | #include <linux/types.h> |
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| 6 | |||
| 7 | /* |
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| 8 | * Berkeley style UIO structures - Alan Cox 1994. |
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| 9 | * |
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| 10 | * This program is free software; you can redistribute it and/or |
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| 11 | * modify it under the terms of the GNU General Public License |
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| 12 | * as published by the Free Software Foundation; either version |
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| 13 | * 2 of the License, or (at your option) any later version. |
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| 14 | */ |
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| 15 | |||
| 16 | |||
| 17 | /* A word of warning: Our uio structure will clash with the C library one (which is now obsolete). Remove the C |
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| 18 | library one from sys/uio.h if you have a very old library set */ |
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| 19 | |||
| 20 | struct iovec |
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| 21 | { |
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| 22 | void __user *iov_base; /* BSD uses caddr_t (1003.1g requires void *) */ |
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| 23 | __kernel_size_t iov_len; /* Must be size_t (1003.1g) */ |
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| 24 | }; |
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| 25 | |||
| 26 | /* |
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| 27 | * UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1) |
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| 28 | */ |
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| 29 | |||
| 30 | #define UIO_FASTIOV 8 |
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| 31 | #define UIO_MAXIOV 1024 |
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| 32 | #if 0 |
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| 33 | #define UIO_MAXIOV 16 /* Maximum iovec's in one operation |
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| 34 | 16 matches BSD */ |
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| 35 | /* Beg pardon: BSD has 1024 --ANK */ |
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| 36 | #endif |
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| 37 | |||
| 38 | /* |
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| 39 | * Total number of bytes covered by an iovec. |
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| 40 | * |
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| 41 | * NOTE that it is not safe to use this function until all the iovec's |
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| 42 | * segment lengths have been validated. Because the individual lengths can |
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| 43 | * overflow a size_t when added together. |
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| 44 | */ |
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| 45 | static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs) |
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| 46 | { |
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| 47 | unsigned long seg; |
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| 48 | size_t ret = 0; |
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| 49 | |||
| 50 | for (seg = 0; seg < nr_segs; seg++) |
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| 51 | ret += iov[seg].iov_len; |
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| 52 | return ret; |
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| 53 | } |
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| 54 | |||
| 55 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to); |
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| 56 | |||
| 57 | #endif |