Linux kernel mirror (for testing)
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linux
1#ifndef _LINUX_BITOPS_H
2#define _LINUX_BITOPS_H
3#include <asm/types.h>
4
5#ifdef __KERNEL__
6#define BIT(nr) (1UL << (nr))
7#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
8#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
9#define BITS_PER_BYTE 8
10#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
11#endif
12
13/*
14 * Include this here because some architectures need generic_ffs/fls in
15 * scope
16 */
17#include <asm/bitops.h>
18
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
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
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
43static inline unsigned long hweight_long(unsigned long w)
44{
45 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
46}
47
48/**
49 * rol32 - rotate a 32-bit value left
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
58/**
59 * ror32 - rotate a 32-bit value right
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
68/**
69 * rol16 - rotate a 16-bit value left
70 * @word: value to rotate
71 * @shift: bits to roll
72 */
73static inline __u16 rol16(__u16 word, unsigned int shift)
74{
75 return (word << shift) | (word >> (16 - shift));
76}
77
78/**
79 * ror16 - rotate a 16-bit value right
80 * @word: value to rotate
81 * @shift: bits to roll
82 */
83static inline __u16 ror16(__u16 word, unsigned int shift)
84{
85 return (word >> shift) | (word << (16 - shift));
86}
87
88/**
89 * rol8 - rotate an 8-bit value left
90 * @word: value to rotate
91 * @shift: bits to roll
92 */
93static inline __u8 rol8(__u8 word, unsigned int shift)
94{
95 return (word << shift) | (word >> (8 - shift));
96}
97
98/**
99 * ror8 - rotate an 8-bit value right
100 * @word: value to rotate
101 * @shift: bits to roll
102 */
103static inline __u8 ror8(__u8 word, unsigned int shift)
104{
105 return (word >> shift) | (word << (8 - shift));
106}
107
108static inline unsigned fls_long(unsigned long l)
109{
110 if (sizeof(l) == 4)
111 return fls(l);
112 return fls64(l);
113}
114
115/**
116 * __ffs64 - find first set bit in a 64 bit word
117 * @word: The 64 bit word
118 *
119 * On 64 bit arches this is a synomyn for __ffs
120 * The result is not defined if no bits are set, so check that @word
121 * is non-zero before calling this.
122 */
123static inline unsigned long __ffs64(u64 word)
124{
125#if BITS_PER_LONG == 32
126 if (((u32)word) == 0UL)
127 return __ffs((u32)(word >> 32)) + 32;
128#elif BITS_PER_LONG != 64
129#error BITS_PER_LONG not 32 or 64
130#endif
131 return __ffs((unsigned long)word);
132}
133
134#ifdef __KERNEL__
135#ifdef CONFIG_GENERIC_FIND_FIRST_BIT
136
137/**
138 * find_first_bit - find the first set bit in a memory region
139 * @addr: The address to start the search at
140 * @size: The maximum size to search
141 *
142 * Returns the bit number of the first set bit.
143 */
144extern unsigned long find_first_bit(const unsigned long *addr,
145 unsigned long size);
146
147/**
148 * find_first_zero_bit - find the first cleared bit in a memory region
149 * @addr: The address to start the search at
150 * @size: The maximum size to search
151 *
152 * Returns the bit number of the first cleared bit.
153 */
154extern unsigned long find_first_zero_bit(const unsigned long *addr,
155 unsigned long size);
156#endif /* CONFIG_GENERIC_FIND_FIRST_BIT */
157
158#ifdef CONFIG_GENERIC_FIND_LAST_BIT
159/**
160 * find_last_bit - find the last set bit in a memory region
161 * @addr: The address to start the search at
162 * @size: The maximum size to search
163 *
164 * Returns the bit number of the first set bit, or size.
165 */
166extern unsigned long find_last_bit(const unsigned long *addr,
167 unsigned long size);
168#endif /* CONFIG_GENERIC_FIND_LAST_BIT */
169
170#ifdef CONFIG_GENERIC_FIND_NEXT_BIT
171
172/**
173 * find_next_bit - find the next set bit in a memory region
174 * @addr: The address to base the search on
175 * @offset: The bitnumber to start searching at
176 * @size: The bitmap size in bits
177 */
178extern unsigned long find_next_bit(const unsigned long *addr,
179 unsigned long size, unsigned long offset);
180
181/**
182 * find_next_zero_bit - find the next cleared bit in a memory region
183 * @addr: The address to base the search on
184 * @offset: The bitnumber to start searching at
185 * @size: The bitmap size in bits
186 */
187
188extern unsigned long find_next_zero_bit(const unsigned long *addr,
189 unsigned long size,
190 unsigned long offset);
191
192#endif /* CONFIG_GENERIC_FIND_NEXT_BIT */
193#endif /* __KERNEL__ */
194#endif