1 #ifndef _LINUX_BITOPS_H
2 #define _LINUX_BITOPS_H
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))
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
);
19 * Include this here because some architectures need generic_ffs/fls in
22 #include <asm/bitops.h>
24 #define for_each_set_bit(bit, addr, size) \
25 for ((bit) = find_first_bit((addr), (size)); \
27 (bit) = find_next_bit((addr), (size), (bit) + 1))
29 static __inline__
int get_bitmask_order(unsigned int count
)
34 return order
; /* We could be slightly more clever with -1 here... */
37 static __inline__
int get_count_order(unsigned int count
)
41 order
= fls(count
) - 1;
42 if (count
& (count
- 1))
47 static inline unsigned long hweight_long(unsigned long w
)
49 return sizeof(w
) == 4 ? hweight32(w
) : hweight64(w
);
53 * rol32 - rotate a 32-bit value left
54 * @word: value to rotate
55 * @shift: bits to roll
57 static inline __u32
rol32(__u32 word
, unsigned int shift
)
59 return (word
<< shift
) | (word
>> (32 - shift
));
63 * ror32 - rotate a 32-bit value right
64 * @word: value to rotate
65 * @shift: bits to roll
67 static inline __u32
ror32(__u32 word
, unsigned int shift
)
69 return (word
>> shift
) | (word
<< (32 - shift
));
73 * rol16 - rotate a 16-bit value left
74 * @word: value to rotate
75 * @shift: bits to roll
77 static inline __u16
rol16(__u16 word
, unsigned int shift
)
79 return (word
<< shift
) | (word
>> (16 - shift
));
83 * ror16 - rotate a 16-bit value right
84 * @word: value to rotate
85 * @shift: bits to roll
87 static inline __u16
ror16(__u16 word
, unsigned int shift
)
89 return (word
>> shift
) | (word
<< (16 - shift
));
93 * rol8 - rotate an 8-bit value left
94 * @word: value to rotate
95 * @shift: bits to roll
97 static inline __u8
rol8(__u8 word
, unsigned int shift
)
99 return (word
<< shift
) | (word
>> (8 - shift
));
103 * ror8 - rotate an 8-bit value right
104 * @word: value to rotate
105 * @shift: bits to roll
107 static inline __u8
ror8(__u8 word
, unsigned int shift
)
109 return (word
>> shift
) | (word
<< (8 - shift
));
113 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
114 * @value: value to sign extend
115 * @index: 0 based bit index (0<=index<32) to sign bit
117 static inline __s32
sign_extend32(__u32 value
, int index
)
119 __u8 shift
= 31 - index
;
120 return (__s32
)(value
<< shift
) >> shift
;
123 static inline unsigned fls_long(unsigned long l
)
131 * __ffs64 - find first set bit in a 64 bit word
132 * @word: The 64 bit word
134 * On 64 bit arches this is a synomyn for __ffs
135 * The result is not defined if no bits are set, so check that @word
136 * is non-zero before calling this.
138 static inline unsigned long __ffs64(u64 word
)
140 #if BITS_PER_LONG == 32
141 if (((u32
)word
) == 0UL)
142 return __ffs((u32
)(word
>> 32)) + 32;
143 #elif BITS_PER_LONG != 64
144 #error BITS_PER_LONG not 32 or 64
146 return __ffs((unsigned long)word
);
151 #ifdef CONFIG_GENERIC_FIND_LAST_BIT
153 * find_last_bit - find the last set bit in a memory region
154 * @addr: The address to start the search at
155 * @size: The maximum size to search
157 * Returns the bit number of the first set bit, or size.
159 extern unsigned long find_last_bit(const unsigned long *addr
,
161 #endif /* CONFIG_GENERIC_FIND_LAST_BIT */
163 #endif /* __KERNEL__ */
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