1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_BITOPS_H
3 #define _LINUX_BITOPS_H
5 #include <linux/bits.h>
7 #define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
8 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
10 extern unsigned int __sw_hweight8(unsigned int w);
11 extern unsigned int __sw_hweight16(unsigned int w);
12 extern unsigned int __sw_hweight32(unsigned int w);
13 extern unsigned long __sw_hweight64(__u64 w);
16 * Include this here because some architectures need generic_ffs/fls in
19 #include <asm/bitops.h>
21 #define for_each_set_bit(bit, addr, size) \
22 for ((bit) = find_first_bit((addr), (size)); \
24 (bit) = find_next_bit((addr), (size), (bit) + 1))
26 /* same as for_each_set_bit() but use bit as value to start with */
27 #define for_each_set_bit_from(bit, addr, size) \
28 for ((bit) = find_next_bit((addr), (size), (bit)); \
30 (bit) = find_next_bit((addr), (size), (bit) + 1))
32 #define for_each_clear_bit(bit, addr, size) \
33 for ((bit) = find_first_zero_bit((addr), (size)); \
35 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
37 /* same as for_each_clear_bit() but use bit as value to start with */
38 #define for_each_clear_bit_from(bit, addr, size) \
39 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
41 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
43 static inline int get_bitmask_order(unsigned int count)
48 return order; /* We could be slightly more clever with -1 here... */
51 static __always_inline unsigned long hweight_long(unsigned long w)
53 return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);
57 * rol64 - rotate a 64-bit value left
58 * @word: value to rotate
59 * @shift: bits to roll
61 static inline __u64 rol64(__u64 word, unsigned int shift)
63 return (word << (shift & 63)) | (word >> ((-shift) & 63));
67 * ror64 - rotate a 64-bit value right
68 * @word: value to rotate
69 * @shift: bits to roll
71 static inline __u64 ror64(__u64 word, unsigned int shift)
73 return (word >> (shift & 63)) | (word << ((-shift) & 63));
77 * rol32 - rotate a 32-bit value left
78 * @word: value to rotate
79 * @shift: bits to roll
81 static inline __u32 rol32(__u32 word, unsigned int shift)
83 return (word << (shift & 31)) | (word >> ((-shift) & 31));
87 * ror32 - rotate a 32-bit value right
88 * @word: value to rotate
89 * @shift: bits to roll
91 static inline __u32 ror32(__u32 word, unsigned int shift)
93 return (word >> (shift & 31)) | (word << ((-shift) & 31));
97 * rol16 - rotate a 16-bit value left
98 * @word: value to rotate
99 * @shift: bits to roll
101 static inline __u16 rol16(__u16 word, unsigned int shift)
103 return (word << (shift & 15)) | (word >> ((-shift) & 15));
107 * ror16 - rotate a 16-bit value right
108 * @word: value to rotate
109 * @shift: bits to roll
111 static inline __u16 ror16(__u16 word, unsigned int shift)
113 return (word >> (shift & 15)) | (word << ((-shift) & 15));
117 * rol8 - rotate an 8-bit value left
118 * @word: value to rotate
119 * @shift: bits to roll
121 static inline __u8 rol8(__u8 word, unsigned int shift)
123 return (word << (shift & 7)) | (word >> ((-shift) & 7));
127 * ror8 - rotate an 8-bit value right
128 * @word: value to rotate
129 * @shift: bits to roll
131 static inline __u8 ror8(__u8 word, unsigned int shift)
133 return (word >> (shift & 7)) | (word << ((-shift) & 7));
137 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
138 * @value: value to sign extend
139 * @index: 0 based bit index (0<=index<32) to sign bit
141 * This is safe to use for 16- and 8-bit types as well.
143 static inline __s32 sign_extend32(__u32 value, int index)
145 __u8 shift = 31 - index;
146 return (__s32)(value << shift) >> shift;
150 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
151 * @value: value to sign extend
152 * @index: 0 based bit index (0<=index<64) to sign bit
154 static inline __s64 sign_extend64(__u64 value, int index)
156 __u8 shift = 63 - index;
157 return (__s64)(value << shift) >> shift;
160 static inline unsigned fls_long(unsigned long l)
167 static inline int get_count_order(unsigned int count)
171 order = fls(count) - 1;
172 if (count & (count - 1))
178 * get_count_order_long - get order after rounding @l up to power of 2
181 * it is same as get_count_order() but with long type parameter
183 static inline int get_count_order_long(unsigned long l)
187 else if (l & (l - 1UL))
188 return (int)fls_long(l);
190 return (int)fls_long(l) - 1;
194 * __ffs64 - find first set bit in a 64 bit word
195 * @word: The 64 bit word
197 * On 64 bit arches this is a synomyn for __ffs
198 * The result is not defined if no bits are set, so check that @word
199 * is non-zero before calling this.
201 static inline unsigned long __ffs64(u64 word)
203 #if BITS_PER_LONG == 32
204 if (((u32)word) == 0UL)
205 return __ffs((u32)(word >> 32)) + 32;
206 #elif BITS_PER_LONG != 64
207 #error BITS_PER_LONG not 32 or 64
209 return __ffs((unsigned long)word);
213 * assign_bit - Assign value to a bit in memory
214 * @nr: the bit to set
215 * @addr: the address to start counting from
216 * @value: the value to assign
218 static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
227 static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
233 __clear_bit(nr, addr);
238 #ifndef set_mask_bits
239 #define set_mask_bits(ptr, mask, bits) \
241 const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \
242 typeof(*(ptr)) old__, new__; \
245 old__ = READ_ONCE(*(ptr)); \
246 new__ = (old__ & ~mask__) | bits__; \
247 } while (cmpxchg(ptr, old__, new__) != old__); \
253 #ifndef bit_clear_unless
254 #define bit_clear_unless(ptr, _clear, _test) \
256 const typeof(*ptr) clear = (_clear), test = (_test); \
257 typeof(*ptr) old, new; \
260 old = READ_ONCE(*ptr); \
261 new = old & ~clear; \
262 } while (!(old & test) && \
263 cmpxchg(ptr, old, new) != old); \
269 #ifndef find_last_bit
271 * find_last_bit - find the last set bit in a memory region
272 * @addr: The address to start the search at
273 * @size: The number of bits to search
275 * Returns the bit number of the last set bit, or size.
277 extern unsigned long find_last_bit(const unsigned long *addr,
281 #endif /* __KERNEL__ */