Merge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6
[linux-2.6-block.git] / include / linux / bitops.h
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1da177e4
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1#ifndef _LINUX_BITOPS_H
2#define _LINUX_BITOPS_H
3#include <asm/types.h>
4
d05be13b 5#ifdef __KERNEL__
93043ece 6#define BIT(nr) (1UL << (nr))
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7#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
8#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
14ed9d23 9#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_LONG)
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10#define BITS_PER_BYTE 8
11#endif
12
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13/*
14 * Include this here because some architectures need generic_ffs/fls in
15 * scope
16 */
17#include <asm/bitops.h>
18
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19#define for_each_bit(bit, addr, size) \
20 for ((bit) = find_first_bit((addr), (size)); \
21 (bit) < (size); \
22 (bit) = find_next_bit((addr), (size), (bit) + 1))
23
24
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25static __inline__ int get_bitmask_order(unsigned int count)
26{
27 int order;
28
29 order = fls(count);
30 return order; /* We could be slightly more clever with -1 here... */
31}
32
94605eff
SS
33static __inline__ int get_count_order(unsigned int count)
34{
35 int order;
36
37 order = fls(count) - 1;
38 if (count & (count - 1))
39 order++;
40 return order;
41}
42
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43static inline unsigned long hweight_long(unsigned long w)
44{
e9bebd6f 45 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
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46}
47
45f8bde0 48/**
1da177e4 49 * rol32 - rotate a 32-bit value left
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50 * @word: value to rotate
51 * @shift: bits to roll
52 */
53static inline __u32 rol32(__u32 word, unsigned int shift)
54{
55 return (word << shift) | (word >> (32 - shift));
56}
57
45f8bde0 58/**
1da177e4 59 * ror32 - rotate a 32-bit value right
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60 * @word: value to rotate
61 * @shift: bits to roll
62 */
63static inline __u32 ror32(__u32 word, unsigned int shift)
64{
65 return (word >> shift) | (word << (32 - shift));
66}
67
962749af
AM
68static inline unsigned fls_long(unsigned long l)
69{
70 if (sizeof(l) == 4)
71 return fls(l);
72 return fls64(l);
73}
74
1da177e4 75#endif