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_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_LONG)
10 #define BITS_PER_BYTE 8
14 * Include this here because some architectures need generic_ffs/fls in
17 #include <asm/bitops.h>
19 #define for_each_bit(bit, addr, size) \
20 for ((bit) = find_first_bit((addr), (size)); \
22 (bit) = find_next_bit((addr), (size), (bit) + 1))
25 static __inline__ int get_bitmask_order(unsigned int count)
30 return order; /* We could be slightly more clever with -1 here... */
33 static __inline__ int get_count_order(unsigned int count)
37 order = fls(count) - 1;
38 if (count & (count - 1))
43 static inline unsigned long hweight_long(unsigned long w)
45 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
49 * rol32 - rotate a 32-bit value left
50 * @word: value to rotate
51 * @shift: bits to roll
53 static inline __u32 rol32(__u32 word, unsigned int shift)
55 return (word << shift) | (word >> (32 - shift));
59 * ror32 - rotate a 32-bit value right
60 * @word: value to rotate
61 * @shift: bits to roll
63 static inline __u32 ror32(__u32 word, unsigned int shift)
65 return (word >> shift) | (word << (32 - shift));
69 * rol16 - rotate a 16-bit value left
70 * @word: value to rotate
71 * @shift: bits to roll
73 static inline __u16 rol16(__u16 word, unsigned int shift)
75 return (word << shift) | (word >> (16 - shift));
79 * ror16 - rotate a 16-bit value right
80 * @word: value to rotate
81 * @shift: bits to roll
83 static inline __u16 ror16(__u16 word, unsigned int shift)
85 return (word >> shift) | (word << (16 - shift));
89 * rol8 - rotate an 8-bit value left
90 * @word: value to rotate
91 * @shift: bits to roll
93 static inline __u8 rol8(__u8 word, unsigned int shift)
95 return (word << shift) | (word >> (8 - shift));
99 * ror8 - rotate an 8-bit value right
100 * @word: value to rotate
101 * @shift: bits to roll
103 static inline __u8 ror8(__u8 word, unsigned int shift)
105 return (word >> shift) | (word << (8 - shift));
108 static inline unsigned fls_long(unsigned long l)
116 #ifdef CONFIG_GENERIC_FIND_NEXT_BIT
117 extern unsigned long __find_next_bit(const unsigned long *addr,
118 unsigned long size, unsigned long offset);
121 * find_next_bit - find the next set bit in a memory region
122 * @addr: The address to base the search on
123 * @offset: The bitnumber to start searching at
124 * @size: The bitmap size in bits
126 static __always_inline unsigned long
127 find_next_bit(const unsigned long *addr, unsigned long size,
128 unsigned long offset)
132 /* Avoid a function call if the bitmap size is a constant */
133 /* and not bigger than BITS_PER_LONG. */
135 /* insert a sentinel so that __ffs returns size if there */
136 /* are no set bits in the bitmap */
137 if (__builtin_constant_p(size) && (size < BITS_PER_LONG)) {
138 value = (*addr) & ((~0ul) << offset);
139 value |= (1ul << size);
143 /* the result of __ffs(0) is undefined, so it needs to be */
144 /* handled separately */
145 if (__builtin_constant_p(size) && (size == BITS_PER_LONG)) {
146 value = (*addr) & ((~0ul) << offset);
147 return (value == 0) ? BITS_PER_LONG : __ffs(value);
150 /* size is not constant or too big */
151 return __find_next_bit(addr, size, offset);
154 extern unsigned long __find_next_zero_bit(const unsigned long *addr,
155 unsigned long size, unsigned long offset);
158 * find_next_zero_bit - find the next cleared bit in a memory region
159 * @addr: The address to base the search on
160 * @offset: The bitnumber to start searching at
161 * @size: The bitmap size in bits
163 static __always_inline unsigned long
164 find_next_zero_bit(const unsigned long *addr, unsigned long size,
165 unsigned long offset)
169 /* Avoid a function call if the bitmap size is a constant */
170 /* and not bigger than BITS_PER_LONG. */
172 /* insert a sentinel so that __ffs returns size if there */
173 /* are no set bits in the bitmap */
174 if (__builtin_constant_p(size) && (size < BITS_PER_LONG)) {
175 value = (~(*addr)) & ((~0ul) << offset);
176 value |= (1ul << size);
180 /* the result of __ffs(0) is undefined, so it needs to be */
181 /* handled separately */
182 if (__builtin_constant_p(size) && (size == BITS_PER_LONG)) {
183 value = (~(*addr)) & ((~0ul) << offset);
184 return (value == 0) ? BITS_PER_LONG : __ffs(value);
187 /* size is not constant or too big */
188 return __find_next_zero_bit(addr, size, offset);
190 #endif /* CONFIG_GENERIC_FIND_NEXT_BIT */
191 #endif /* __KERNEL__ */