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Merge branch 'for-2.6.37/drivers' into for-linus
[mirror_ubuntu-bionic-kernel.git] / include / linux / bitops.h
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 extern unsigned int __sw_hweight8(unsigned int w);
14 extern unsigned int __sw_hweight16(unsigned int w);
15 extern unsigned int __sw_hweight32(unsigned int w);
16 extern unsigned long __sw_hweight64(__u64 w);
17
18 /*
19 * Include this here because some architectures need generic_ffs/fls in
20 * scope
21 */
22 #include <asm/bitops.h>
23
24 #define for_each_set_bit(bit, addr, size) \
25 for ((bit) = find_first_bit((addr), (size)); \
26 (bit) < (size); \
27 (bit) = find_next_bit((addr), (size), (bit) + 1))
28
29 static __inline__ int get_bitmask_order(unsigned int count)
30 {
31 int order;
32
33 order = fls(count);
34 return order; /* We could be slightly more clever with -1 here... */
35 }
36
37 static __inline__ int get_count_order(unsigned int count)
38 {
39 int order;
40
41 order = fls(count) - 1;
42 if (count & (count - 1))
43 order++;
44 return order;
45 }
46
47 static inline unsigned long hweight_long(unsigned long w)
48 {
49 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
50 }
51
52 /**
53 * rol32 - rotate a 32-bit value left
54 * @word: value to rotate
55 * @shift: bits to roll
56 */
57 static inline __u32 rol32(__u32 word, unsigned int shift)
58 {
59 return (word << shift) | (word >> (32 - shift));
60 }
61
62 /**
63 * ror32 - rotate a 32-bit value right
64 * @word: value to rotate
65 * @shift: bits to roll
66 */
67 static inline __u32 ror32(__u32 word, unsigned int shift)
68 {
69 return (word >> shift) | (word << (32 - shift));
70 }
71
72 /**
73 * rol16 - rotate a 16-bit value left
74 * @word: value to rotate
75 * @shift: bits to roll
76 */
77 static inline __u16 rol16(__u16 word, unsigned int shift)
78 {
79 return (word << shift) | (word >> (16 - shift));
80 }
81
82 /**
83 * ror16 - rotate a 16-bit value right
84 * @word: value to rotate
85 * @shift: bits to roll
86 */
87 static inline __u16 ror16(__u16 word, unsigned int shift)
88 {
89 return (word >> shift) | (word << (16 - shift));
90 }
91
92 /**
93 * rol8 - rotate an 8-bit value left
94 * @word: value to rotate
95 * @shift: bits to roll
96 */
97 static inline __u8 rol8(__u8 word, unsigned int shift)
98 {
99 return (word << shift) | (word >> (8 - shift));
100 }
101
102 /**
103 * ror8 - rotate an 8-bit value right
104 * @word: value to rotate
105 * @shift: bits to roll
106 */
107 static inline __u8 ror8(__u8 word, unsigned int shift)
108 {
109 return (word >> shift) | (word << (8 - shift));
110 }
111
112 static inline unsigned fls_long(unsigned long l)
113 {
114 if (sizeof(l) == 4)
115 return fls(l);
116 return fls64(l);
117 }
118
119 /**
120 * __ffs64 - find first set bit in a 64 bit word
121 * @word: The 64 bit word
122 *
123 * On 64 bit arches this is a synomyn for __ffs
124 * The result is not defined if no bits are set, so check that @word
125 * is non-zero before calling this.
126 */
127 static inline unsigned long __ffs64(u64 word)
128 {
129 #if BITS_PER_LONG == 32
130 if (((u32)word) == 0UL)
131 return __ffs((u32)(word >> 32)) + 32;
132 #elif BITS_PER_LONG != 64
133 #error BITS_PER_LONG not 32 or 64
134 #endif
135 return __ffs((unsigned long)word);
136 }
137
138 #ifdef __KERNEL__
139
140 #ifdef CONFIG_GENERIC_FIND_LAST_BIT
141 /**
142 * find_last_bit - find the last set bit in a memory region
143 * @addr: The address to start the search at
144 * @size: The maximum size to search
145 *
146 * Returns the bit number of the first set bit, or size.
147 */
148 extern unsigned long find_last_bit(const unsigned long *addr,
149 unsigned long size);
150 #endif /* CONFIG_GENERIC_FIND_LAST_BIT */
151
152 #endif /* __KERNEL__ */
153 #endif