aboutsummaryrefslogtreecommitdiffstats
path: root/tools/include/asm-generic/bitops/find.h
blob: 6481fd11012a9e471ae305d1627a72f7ffea8414 (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
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _TOOLS_LINUX_ASM_GENERIC_BITOPS_FIND_H_
#define _TOOLS_LINUX_ASM_GENERIC_BITOPS_FIND_H_

extern unsigned long _find_next_bit(const unsigned long *addr1,
		const unsigned long *addr2, unsigned long nbits,
		unsigned long start, unsigned long invert, unsigned long le);
extern unsigned long _find_first_bit(const unsigned long *addr, unsigned long size);
extern unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size);
extern unsigned long _find_last_bit(const unsigned long *addr, unsigned long size);

#ifndef find_next_bit
/**
 * find_next_bit - find the next set bit in a memory region
 * @addr: The address to base the search on
 * @offset: The bitnumber to start searching at
 * @size: The bitmap size in bits
 *
 * Returns the bit number for the next set bit
 * If no bits are set, returns @size.
 */
static inline
unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
			    unsigned long offset)
{
	if (small_const_nbits(size)) {
		unsigned long val;

		if (unlikely(offset >= size))
			return size;

		val = *addr & GENMASK(size - 1, offset);
		return val ? __ffs(val) : size;
	}

	return _find_next_bit(addr, NULL, size, offset, 0UL, 0);
}
#endif

#ifndef find_next_and_bit
/**
 * find_next_and_bit - find the next set bit in both memory regions
 * @addr1: The first address to base the search on
 * @addr2: The second address to base the search on
 * @offset: The bitnumber to start searching at
 * @size: The bitmap size in bits
 *
 * Returns the bit number for the next set bit
 * If no bits are set, returns @size.
 */
static inline
unsigned long find_next_and_bit(const unsigned long *addr1,
		const unsigned long *addr2, unsigned long size,
		unsigned long offset)
{
	if (small_const_nbits(size)) {
		unsigned long val;

		if (unlikely(offset >= size))
			return size;

		val = *addr1 & *addr2 & GENMASK(size - 1, offset);
		return val ? __ffs(val) : size;
	}

	return _find_next_bit(addr1, addr2, size, offset, 0UL, 0);
}
#endif

#ifndef find_next_zero_bit
/**
 * find_next_zero_bit - find the next cleared bit in a memory region
 * @addr: The address to base the search on
 * @offset: The bitnumber to start searching at
 * @size: The bitmap size in bits
 *
 * Returns the bit number of the next zero bit
 * If no bits are zero, returns @size.
 */
static inline
unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
				 unsigned long offset)
{
	if (small_const_nbits(size)) {
		unsigned long val;

		if (unlikely(offset >= size))
			return size;

		val = *addr | ~GENMASK(size - 1, offset);
		return val == ~0UL ? size : ffz(val);
	}

	return _find_next_bit(addr, NULL, size, offset, ~0UL, 0);
}
#endif

#ifndef find_first_bit

/**
 * find_first_bit - find the first set bit in a memory region
 * @addr: The address to start the search at
 * @size: The maximum number of bits to search
 *
 * Returns the bit number of the first set bit.
 * If no bits are set, returns @size.
 */
static inline
unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
{
	if (small_const_nbits(size)) {
		unsigned long val = *addr & GENMASK(size - 1, 0);

		return val ? __ffs(val) : size;
	}

	return _find_first_bit(addr, size);
}

#endif /* find_first_bit */

#ifndef find_first_zero_bit

/**
 * find_first_zero_bit - find the first cleared bit in a memory region
 * @addr: The address to start the search at
 * @size: The maximum number of bits to search
 *
 * Returns the bit number of the first cleared bit.
 * If no bits are zero, returns @size.
 */
static inline
unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
{
	if (small_const_nbits(size)) {
		unsigned long val = *addr | ~GENMASK(size - 1, 0);

		return val == ~0UL ? size : ffz(val);
	}

	return _find_first_zero_bit(addr, size);
}
#endif

#endif /*_TOOLS_LINUX_ASM_GENERIC_BITOPS_FIND_H_ */