1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_BITOPS_H
3 #define _LINUX_BITOPS_H
5 #include <linux/bits.h>
7 /* Set bits in the first 'n' bytes when loaded from memory */
9 # define aligned_byte_mask(n) ((1UL << 8*(n))-1)
11 # define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
14 #define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
15 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
17 extern unsigned int __sw_hweight8(unsigned int w);
18 extern unsigned int __sw_hweight16(unsigned int w);
19 extern unsigned int __sw_hweight32(unsigned int w);
20 extern unsigned long __sw_hweight64(__u64 w);
23 * Include this here because some architectures need generic_ffs/fls in
26 #include <asm/bitops.h>
28 #define for_each_set_bit(bit, addr, size) \
29 for ((bit) = find_first_bit((addr), (size)); \
31 (bit) = find_next_bit((addr), (size), (bit) + 1))
33 /* same as for_each_set_bit() but use bit as value to start with */
34 #define for_each_set_bit_from(bit, addr, size) \
35 for ((bit) = find_next_bit((addr), (size), (bit)); \
37 (bit) = find_next_bit((addr), (size), (bit) + 1))
39 #define for_each_clear_bit(bit, addr, size) \
40 for ((bit) = find_first_zero_bit((addr), (size)); \
42 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
44 /* same as for_each_clear_bit() but use bit as value to start with */
45 #define for_each_clear_bit_from(bit, addr, size) \
46 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
48 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
50 static inline int get_bitmask_order(unsigned int count)
55 return order; /* We could be slightly more clever with -1 here... */
58 static __always_inline unsigned long hweight_long(unsigned long w)
60 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
64 * rol64 - rotate a 64-bit value left
65 * @word: value to rotate
66 * @shift: bits to roll
68 static inline __u64 rol64(__u64 word, unsigned int shift)
70 return (word << (shift & 63)) | (word >> ((-shift) & 63));
74 * ror64 - rotate a 64-bit value right
75 * @word: value to rotate
76 * @shift: bits to roll
78 static inline __u64 ror64(__u64 word, unsigned int shift)
80 return (word >> (shift & 63)) | (word << ((-shift) & 63));
84 * rol32 - rotate a 32-bit value left
85 * @word: value to rotate
86 * @shift: bits to roll
88 static inline __u32 rol32(__u32 word, unsigned int shift)
90 return (word << (shift & 31)) | (word >> ((-shift) & 31));
94 * ror32 - rotate a 32-bit value right
95 * @word: value to rotate
96 * @shift: bits to roll
98 static inline __u32 ror32(__u32 word, unsigned int shift)
100 return (word >> (shift & 31)) | (word << ((-shift) & 31));
104 * rol16 - rotate a 16-bit value left
105 * @word: value to rotate
106 * @shift: bits to roll
108 static inline __u16 rol16(__u16 word, unsigned int shift)
110 return (word << (shift & 15)) | (word >> ((-shift) & 15));
114 * ror16 - rotate a 16-bit value right
115 * @word: value to rotate
116 * @shift: bits to roll
118 static inline __u16 ror16(__u16 word, unsigned int shift)
120 return (word >> (shift & 15)) | (word << ((-shift) & 15));
124 * rol8 - rotate an 8-bit value left
125 * @word: value to rotate
126 * @shift: bits to roll
128 static inline __u8 rol8(__u8 word, unsigned int shift)
130 return (word << (shift & 7)) | (word >> ((-shift) & 7));
134 * ror8 - rotate an 8-bit value right
135 * @word: value to rotate
136 * @shift: bits to roll
138 static inline __u8 ror8(__u8 word, unsigned int shift)
140 return (word >> (shift & 7)) | (word << ((-shift) & 7));
144 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
145 * @value: value to sign extend
146 * @index: 0 based bit index (0<=index<32) to sign bit
148 * This is safe to use for 16- and 8-bit types as well.
150 static inline __s32 sign_extend32(__u32 value, int index)
152 __u8 shift = 31 - index;
153 return (__s32)(value << shift) >> shift;
157 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
158 * @value: value to sign extend
159 * @index: 0 based bit index (0<=index<64) to sign bit
161 static inline __s64 sign_extend64(__u64 value, int index)
163 __u8 shift = 63 - index;
164 return (__s64)(value << shift) >> shift;
167 static inline unsigned fls_long(unsigned long l)
174 static inline int get_count_order(unsigned int count)
178 order = fls(count) - 1;
179 if (count & (count - 1))
185 * get_count_order_long - get order after rounding @l up to power of 2
188 * it is same as get_count_order() but with long type parameter
190 static inline int get_count_order_long(unsigned long l)
194 else if (l & (l - 1UL))
195 return (int)fls_long(l);
197 return (int)fls_long(l) - 1;
201 * __ffs64 - find first set bit in a 64 bit word
202 * @word: The 64 bit word
204 * On 64 bit arches this is a synomyn for __ffs
205 * The result is not defined if no bits are set, so check that @word
206 * is non-zero before calling this.
208 static inline unsigned long __ffs64(u64 word)
210 #if BITS_PER_LONG == 32
211 if (((u32)word) == 0UL)
212 return __ffs((u32)(word >> 32)) + 32;
213 #elif BITS_PER_LONG != 64
214 #error BITS_PER_LONG not 32 or 64
216 return __ffs((unsigned long)word);
220 * assign_bit - Assign value to a bit in memory
221 * @nr: the bit to set
222 * @addr: the address to start counting from
223 * @value: the value to assign
225 static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
234 static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
240 __clear_bit(nr, addr);
245 #ifndef set_mask_bits
246 #define set_mask_bits(ptr, mask, bits) \
248 const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \
249 typeof(*(ptr)) old__, new__; \
252 old__ = READ_ONCE(*(ptr)); \
253 new__ = (old__ & ~mask__) | bits__; \
254 } while (cmpxchg(ptr, old__, new__) != old__); \
260 #ifndef bit_clear_unless
261 #define bit_clear_unless(ptr, clear, test) \
263 const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
264 typeof(*(ptr)) old__, new__; \
267 old__ = READ_ONCE(*(ptr)); \
268 new__ = old__ & ~clear__; \
269 } while (!(old__ & test__) && \
270 cmpxchg(ptr, old__, new__) != old__); \
276 #ifndef find_last_bit
278 * find_last_bit - find the last set bit in a memory region
279 * @addr: The address to start the search at
280 * @size: The number of bits to search
282 * Returns the bit number of the last set bit, or size.
284 extern unsigned long find_last_bit(const unsigned long *addr,
288 #endif /* __KERNEL__ */