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))
14 * Include this here because some architectures need generic_ffs/fls in
17 #include <asm/bitops.h>
19 #define for_each_set_bit(bit, addr, size) \
20 for ((bit) = find_first_bit((addr), (size)); \
22 (bit) = find_next_bit((addr), (size), (bit) + 1))
25 #define for_each_bit(bit, addr, size) for_each_set_bit(bit, addr, size)
27 static __inline__ int get_bitmask_order(unsigned int count)
32 return order; /* We could be slightly more clever with -1 here... */
35 static __inline__ int get_count_order(unsigned int count)
39 order = fls(count) - 1;
40 if (count & (count - 1))
45 static inline unsigned long hweight_long(unsigned long w)
47 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
51 * rol32 - rotate a 32-bit value left
52 * @word: value to rotate
53 * @shift: bits to roll
55 static inline __u32 rol32(__u32 word, unsigned int shift)
57 return (word << shift) | (word >> (32 - shift));
61 * ror32 - rotate a 32-bit value right
62 * @word: value to rotate
63 * @shift: bits to roll
65 static inline __u32 ror32(__u32 word, unsigned int shift)
67 return (word >> shift) | (word << (32 - shift));
71 * rol16 - rotate a 16-bit value left
72 * @word: value to rotate
73 * @shift: bits to roll
75 static inline __u16 rol16(__u16 word, unsigned int shift)
77 return (word << shift) | (word >> (16 - shift));
81 * ror16 - rotate a 16-bit value right
82 * @word: value to rotate
83 * @shift: bits to roll
85 static inline __u16 ror16(__u16 word, unsigned int shift)
87 return (word >> shift) | (word << (16 - shift));
91 * rol8 - rotate an 8-bit value left
92 * @word: value to rotate
93 * @shift: bits to roll
95 static inline __u8 rol8(__u8 word, unsigned int shift)
97 return (word << shift) | (word >> (8 - shift));
101 * ror8 - rotate an 8-bit value right
102 * @word: value to rotate
103 * @shift: bits to roll
105 static inline __u8 ror8(__u8 word, unsigned int shift)
107 return (word >> shift) | (word << (8 - shift));
110 static inline unsigned fls_long(unsigned long l)
118 * __ffs64 - find first set bit in a 64 bit word
119 * @word: The 64 bit word
121 * On 64 bit arches this is a synomyn for __ffs
122 * The result is not defined if no bits are set, so check that @word
123 * is non-zero before calling this.
125 static inline unsigned long __ffs64(u64 word)
127 #if BITS_PER_LONG == 32
128 if (((u32)word) == 0UL)
129 return __ffs((u32)(word >> 32)) + 32;
130 #elif BITS_PER_LONG != 64
131 #error BITS_PER_LONG not 32 or 64
133 return __ffs((unsigned long)word);
137 #ifdef CONFIG_GENERIC_FIND_FIRST_BIT
140 * find_first_bit - find the first set bit in a memory region
141 * @addr: The address to start the search at
142 * @size: The maximum size to search
144 * Returns the bit number of the first set bit.
146 extern unsigned long find_first_bit(const unsigned long *addr,
150 * find_first_zero_bit - find the first cleared bit in a memory region
151 * @addr: The address to start the search at
152 * @size: The maximum size to search
154 * Returns the bit number of the first cleared bit.
156 extern unsigned long find_first_zero_bit(const unsigned long *addr,
158 #endif /* CONFIG_GENERIC_FIND_FIRST_BIT */
160 #ifdef CONFIG_GENERIC_FIND_LAST_BIT
162 * find_last_bit - find the last set bit in a memory region
163 * @addr: The address to start the search at
164 * @size: The maximum size to search
166 * Returns the bit number of the first set bit, or size.
168 extern unsigned long find_last_bit(const unsigned long *addr,
170 #endif /* CONFIG_GENERIC_FIND_LAST_BIT */
172 #ifdef CONFIG_GENERIC_FIND_NEXT_BIT
175 * find_next_bit - find the next set bit in a memory region
176 * @addr: The address to base the search on
177 * @offset: The bitnumber to start searching at
178 * @size: The bitmap size in bits
180 extern unsigned long find_next_bit(const unsigned long *addr,
181 unsigned long size, unsigned long offset);
184 * find_next_zero_bit - find the next cleared bit in a memory region
185 * @addr: The address to base the search on
186 * @offset: The bitnumber to start searching at
187 * @size: The bitmap size in bits
190 extern unsigned long find_next_zero_bit(const unsigned long *addr,
192 unsigned long offset);
194 #endif /* CONFIG_GENERIC_FIND_NEXT_BIT */
195 #endif /* __KERNEL__ */