1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_BITOPS_H
3 #define _LINUX_BITOPS_H
7 #define BIT(nr) (1UL << (nr))
8 #define BIT_ULL(nr) (1ULL << (nr))
9 #define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
10 #define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
11 #define BIT_ULL_MASK(nr) (1ULL << ((nr) % BITS_PER_LONG_LONG))
12 #define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG)
13 #define BITS_PER_BYTE 8
14 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
18 * Create a contiguous bitmask starting at bit position @l and ending at
19 * position @h. For example
20 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
22 #define GENMASK(h, l) \
23 (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
25 #define GENMASK_ULL(h, l) \
26 (((~0ULL) - (1ULL << (l)) + 1) & \
27 (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
29 extern unsigned int __sw_hweight8(unsigned int w
);
30 extern unsigned int __sw_hweight16(unsigned int w
);
31 extern unsigned int __sw_hweight32(unsigned int w
);
32 extern unsigned long __sw_hweight64(__u64 w
);
35 * Include this here because some architectures need generic_ffs/fls in
38 #include <asm/bitops.h>
40 #define for_each_set_bit(bit, addr, size) \
41 for ((bit) = find_first_bit((addr), (size)); \
43 (bit) = find_next_bit((addr), (size), (bit) + 1))
45 /* same as for_each_set_bit() but use bit as value to start with */
46 #define for_each_set_bit_from(bit, addr, size) \
47 for ((bit) = find_next_bit((addr), (size), (bit)); \
49 (bit) = find_next_bit((addr), (size), (bit) + 1))
51 #define for_each_clear_bit(bit, addr, size) \
52 for ((bit) = find_first_zero_bit((addr), (size)); \
54 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
56 /* same as for_each_clear_bit() but use bit as value to start with */
57 #define for_each_clear_bit_from(bit, addr, size) \
58 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
60 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
62 static inline int get_bitmask_order(unsigned int count
)
67 return order
; /* We could be slightly more clever with -1 here... */
70 static __always_inline
unsigned long hweight_long(unsigned long w
)
72 return sizeof(w
) == 4 ? hweight32(w
) : hweight64(w
);
76 * rol64 - rotate a 64-bit value left
77 * @word: value to rotate
78 * @shift: bits to roll
80 static inline __u64
rol64(__u64 word
, unsigned int shift
)
82 return (word
<< shift
) | (word
>> (64 - shift
));
86 * ror64 - rotate a 64-bit value right
87 * @word: value to rotate
88 * @shift: bits to roll
90 static inline __u64
ror64(__u64 word
, unsigned int shift
)
92 return (word
>> shift
) | (word
<< (64 - shift
));
96 * rol32 - rotate a 32-bit value left
97 * @word: value to rotate
98 * @shift: bits to roll
100 static inline __u32
rol32(__u32 word
, unsigned int shift
)
102 return (word
<< shift
) | (word
>> ((-shift
) & 31));
106 * ror32 - rotate a 32-bit value right
107 * @word: value to rotate
108 * @shift: bits to roll
110 static inline __u32
ror32(__u32 word
, unsigned int shift
)
112 return (word
>> shift
) | (word
<< (32 - shift
));
116 * rol16 - rotate a 16-bit value left
117 * @word: value to rotate
118 * @shift: bits to roll
120 static inline __u16
rol16(__u16 word
, unsigned int shift
)
122 return (word
<< shift
) | (word
>> (16 - shift
));
126 * ror16 - rotate a 16-bit value right
127 * @word: value to rotate
128 * @shift: bits to roll
130 static inline __u16
ror16(__u16 word
, unsigned int shift
)
132 return (word
>> shift
) | (word
<< (16 - shift
));
136 * rol8 - rotate an 8-bit value left
137 * @word: value to rotate
138 * @shift: bits to roll
140 static inline __u8
rol8(__u8 word
, unsigned int shift
)
142 return (word
<< shift
) | (word
>> (8 - shift
));
146 * ror8 - rotate an 8-bit value right
147 * @word: value to rotate
148 * @shift: bits to roll
150 static inline __u8
ror8(__u8 word
, unsigned int shift
)
152 return (word
>> shift
) | (word
<< (8 - shift
));
156 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
157 * @value: value to sign extend
158 * @index: 0 based bit index (0<=index<32) to sign bit
160 * This is safe to use for 16- and 8-bit types as well.
162 static inline __s32
sign_extend32(__u32 value
, int index
)
164 __u8 shift
= 31 - index
;
165 return (__s32
)(value
<< shift
) >> shift
;
169 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
170 * @value: value to sign extend
171 * @index: 0 based bit index (0<=index<64) to sign bit
173 static inline __s64
sign_extend64(__u64 value
, int index
)
175 __u8 shift
= 63 - index
;
176 return (__s64
)(value
<< shift
) >> shift
;
179 static inline unsigned fls_long(unsigned long l
)
186 static inline int get_count_order(unsigned int count
)
190 order
= fls(count
) - 1;
191 if (count
& (count
- 1))
197 * get_count_order_long - get order after rounding @l up to power of 2
200 * it is same as get_count_order() but with long type parameter
202 static inline int get_count_order_long(unsigned long l
)
206 else if (l
& (l
- 1UL))
207 return (int)fls_long(l
);
209 return (int)fls_long(l
) - 1;
213 * __ffs64 - find first set bit in a 64 bit word
214 * @word: The 64 bit word
216 * On 64 bit arches this is a synomyn for __ffs
217 * The result is not defined if no bits are set, so check that @word
218 * is non-zero before calling this.
220 static inline unsigned long __ffs64(u64 word
)
222 #if BITS_PER_LONG == 32
223 if (((u32
)word
) == 0UL)
224 return __ffs((u32
)(word
>> 32)) + 32;
225 #elif BITS_PER_LONG != 64
226 #error BITS_PER_LONG not 32 or 64
228 return __ffs((unsigned long)word
);
232 * assign_bit - Assign value to a bit in memory
233 * @nr: the bit to set
234 * @addr: the address to start counting from
235 * @value: the value to assign
237 static __always_inline
void assign_bit(long nr
, volatile unsigned long *addr
,
246 static __always_inline
void __assign_bit(long nr
, volatile unsigned long *addr
,
252 __clear_bit(nr
, addr
);
257 #ifndef set_mask_bits
258 #define set_mask_bits(ptr, _mask, _bits) \
260 const typeof(*ptr) mask = (_mask), bits = (_bits); \
261 typeof(*ptr) old, new; \
264 old = READ_ONCE(*ptr); \
265 new = (old & ~mask) | bits; \
266 } while (cmpxchg(ptr, old, new) != old); \
272 #ifndef bit_clear_unless
273 #define bit_clear_unless(ptr, _clear, _test) \
275 const typeof(*ptr) clear = (_clear), test = (_test); \
276 typeof(*ptr) old, new; \
279 old = READ_ONCE(*ptr); \
280 new = old & ~clear; \
281 } while (!(old & test) && \
282 cmpxchg(ptr, old, new) != old); \
288 #ifndef find_last_bit
290 * find_last_bit - find the last set bit in a memory region
291 * @addr: The address to start the search at
292 * @size: The number of bits to search
294 * Returns the bit number of the last set bit, or size.
296 extern unsigned long find_last_bit(const unsigned long *addr
,
300 #endif /* __KERNEL__ */