aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/bitops.h
blob: 40d54731de7e0b9fb6b44ebf7db983ea58fc1ac2 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
#ifndef _LINUX_BITOPS_H
#define _LINUX_BITOPS_H
#include <asm/types.h>

#ifdef	__KERNEL__
#define BIT(nr)			(1UL << (nr))
#define BIT_MASK(nr)		(1UL << ((nr) % BITS_PER_LONG))
#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
#define BITS_TO_LONGS(nr)	DIV_ROUND_UP(nr, BITS_PER_LONG)
#define BITS_PER_BYTE		8
#endif

/*
 * Include this here because some architectures need generic_ffs/fls in
 * scope
 */
#include <asm/bitops.h>

#define for_each_bit(bit, addr, size) \
	for ((bit) = find_first_bit((addr), (size)); \
	     (bit) < (size); \
	     (bit) = find_next_bit((addr), (size), (bit) + 1))


static __inline__ int get_bitmask_order(unsigned int count)
{
	int order;
	
	order = fls(count);
	return order;	/* We could be slightly more clever with -1 here... */
}

static __inline__ int get_count_order(unsigned int count)
{
	int order;
	
	order = fls(count) - 1;
	if (count & (count - 1))
		order++;
	return order;
}

static inline unsigned long hweight_long(unsigned long w)
{
	return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
}

/**
 * rol32 - rotate a 32-bit value left
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u32 rol32(__u32 word, unsigned int shift)
{
	return (word << shift) | (word >> (32 - shift));
}

/**
 * ror32 - rotate a 32-bit value right
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u32 ror32(__u32 word, unsigned int shift)
{
	return (word >> shift) | (word << (32 - shift));
}

/**
 * rol16 - rotate a 16-bit value left
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u16 rol16(__u16 word, unsigned int shift)
{
	return (word << shift) | (word >> (16 - shift));
}

/**
 * ror16 - rotate a 16-bit value right
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u16 ror16(__u16 word, unsigned int shift)
{
	return (word >> shift) | (word << (16 - shift));
}

/**
 * rol8 - rotate an 8-bit value left
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u8 rol8(__u8 word, unsigned int shift)
{
	return (word << shift) | (word >> (8 - shift));
}

/**
 * ror8 - rotate an 8-bit value right
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u8 ror8(__u8 word, unsigned int shift)
{
	return (word >> shift) | (word << (8 - shift));
}

static inline unsigned fls_long(unsigned long l)
{
	if (sizeof(l) == 4)
		return fls(l);
	return fls64(l);
}

#endif