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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - include/linux/bitops.h
1 #ifndef _LINUX_BITOPS_H
2 #define _LINUX_BITOPS_H
6 #define BIT(nr) (1UL << (nr))
7 #define BIT_ULL(nr) (1ULL << (nr))
8 #define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
9 #define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
10 #define BIT_ULL_MASK(nr) (1ULL << ((nr) % BITS_PER_LONG_LONG))
11 #define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG)
12 #define BITS_PER_BYTE 8
13 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
17 * Create a contiguous bitmask starting at bit position @l and ending at
18 * position @h. For example
19 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
21 #define GENMASK(h, l) \
22 (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
24 #define GENMASK_ULL(h, l) \
25 (((~0ULL) - (1ULL << (l)) + 1) & \
26 (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
28 extern unsigned int __sw_hweight8(unsigned int w
);
29 extern unsigned int __sw_hweight16(unsigned int w
);
30 extern unsigned int __sw_hweight32(unsigned int w
);
31 extern unsigned long __sw_hweight64(__u64 w
);
34 * Include this here because some architectures need generic_ffs/fls in
37 #include <asm/bitops.h>
39 #define for_each_set_bit(bit, addr, size) \
40 for ((bit) = find_first_bit((addr), (size)); \
42 (bit) = find_next_bit((addr), (size), (bit) + 1))
44 /* same as for_each_set_bit() but use bit as value to start with */
45 #define for_each_set_bit_from(bit, addr, size) \
46 for ((bit) = find_next_bit((addr), (size), (bit)); \
48 (bit) = find_next_bit((addr), (size), (bit) + 1))
50 #define for_each_clear_bit(bit, addr, size) \
51 for ((bit) = find_first_zero_bit((addr), (size)); \
53 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
55 /* same as for_each_clear_bit() but use bit as value to start with */
56 #define for_each_clear_bit_from(bit, addr, size) \
57 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
59 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
61 static inline int get_bitmask_order(unsigned int count
)
66 return order
; /* We could be slightly more clever with -1 here... */
69 static __always_inline
unsigned long hweight_long(unsigned long w
)
71 return sizeof(w
) == 4 ? hweight32(w
) : hweight64(w
);
75 * rol64 - rotate a 64-bit value left
76 * @word: value to rotate
77 * @shift: bits to roll
79 static inline __u64
rol64(__u64 word
, unsigned int shift
)
81 return (word
<< shift
) | (word
>> (64 - shift
));
85 * ror64 - rotate a 64-bit value right
86 * @word: value to rotate
87 * @shift: bits to roll
89 static inline __u64
ror64(__u64 word
, unsigned int shift
)
91 return (word
>> shift
) | (word
<< (64 - shift
));
95 * rol32 - rotate a 32-bit value left
96 * @word: value to rotate
97 * @shift: bits to roll
99 static inline __u32
rol32(__u32 word
, unsigned int shift
)
101 return (word
<< shift
) | (word
>> ((-shift
) & 31));
105 * ror32 - rotate a 32-bit value right
106 * @word: value to rotate
107 * @shift: bits to roll
109 static inline __u32
ror32(__u32 word
, unsigned int shift
)
111 return (word
>> shift
) | (word
<< (32 - shift
));
115 * rol16 - rotate a 16-bit value left
116 * @word: value to rotate
117 * @shift: bits to roll
119 static inline __u16
rol16(__u16 word
, unsigned int shift
)
121 return (word
<< shift
) | (word
>> (16 - shift
));
125 * ror16 - rotate a 16-bit value right
126 * @word: value to rotate
127 * @shift: bits to roll
129 static inline __u16
ror16(__u16 word
, unsigned int shift
)
131 return (word
>> shift
) | (word
<< (16 - shift
));
135 * rol8 - rotate an 8-bit value left
136 * @word: value to rotate
137 * @shift: bits to roll
139 static inline __u8
rol8(__u8 word
, unsigned int shift
)
141 return (word
<< shift
) | (word
>> (8 - shift
));
145 * ror8 - rotate an 8-bit value right
146 * @word: value to rotate
147 * @shift: bits to roll
149 static inline __u8
ror8(__u8 word
, unsigned int shift
)
151 return (word
>> shift
) | (word
<< (8 - shift
));
155 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
156 * @value: value to sign extend
157 * @index: 0 based bit index (0<=index<32) to sign bit
159 * This is safe to use for 16- and 8-bit types as well.
161 static inline __s32
sign_extend32(__u32 value
, int index
)
163 __u8 shift
= 31 - index
;
164 return (__s32
)(value
<< shift
) >> shift
;
168 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
169 * @value: value to sign extend
170 * @index: 0 based bit index (0<=index<64) to sign bit
172 static inline __s64
sign_extend64(__u64 value
, int index
)
174 __u8 shift
= 63 - index
;
175 return (__s64
)(value
<< shift
) >> shift
;
178 static inline unsigned fls_long(unsigned long l
)
185 static inline int get_count_order(unsigned int count
)
189 order
= fls(count
) - 1;
190 if (count
& (count
- 1))
196 * get_count_order_long - get order after rounding @l up to power of 2
199 * it is same as get_count_order() but with long type parameter
201 static inline int get_count_order_long(unsigned long l
)
205 else if (l
& (l
- 1UL))
206 return (int)fls_long(l
);
208 return (int)fls_long(l
) - 1;
212 * __ffs64 - find first set bit in a 64 bit word
213 * @word: The 64 bit word
215 * On 64 bit arches this is a synomyn for __ffs
216 * The result is not defined if no bits are set, so check that @word
217 * is non-zero before calling this.
219 static inline unsigned long __ffs64(u64 word
)
221 #if BITS_PER_LONG == 32
222 if (((u32
)word
) == 0UL)
223 return __ffs((u32
)(word
>> 32)) + 32;
224 #elif BITS_PER_LONG != 64
225 #error BITS_PER_LONG not 32 or 64
227 return __ffs((unsigned long)word
);
232 #ifndef set_mask_bits
233 #define set_mask_bits(ptr, _mask, _bits) \
235 const typeof(*ptr) mask = (_mask), bits = (_bits); \
236 typeof(*ptr) old, new; \
239 old = ACCESS_ONCE(*ptr); \
240 new = (old & ~mask) | bits; \
241 } while (cmpxchg(ptr, old, new) != old); \
247 #ifndef bit_clear_unless
248 #define bit_clear_unless(ptr, _clear, _test) \
250 const typeof(*ptr) clear = (_clear), test = (_test); \
251 typeof(*ptr) old, new; \
254 old = ACCESS_ONCE(*ptr); \
255 new = old & ~clear; \
256 } while (!(old & test) && \
257 cmpxchg(ptr, old, new) != old); \
263 #ifndef find_last_bit
265 * find_last_bit - find the last set bit in a memory region
266 * @addr: The address to start the search at
267 * @size: The number of bits to search
269 * Returns the bit number of the last set bit, or size.
271 extern unsigned long find_last_bit(const unsigned long *addr
,
275 #endif /* __KERNEL__ */