aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/bitops.h
blob: 638165f571dacedf7455f0bc9d87e3390b8ee781 (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
#ifndef _LINUX_BITOPS_H
#define _LINUX_BITOPS_H
#include <asm/types.h>

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

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));
}

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

#endif