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))
16 #define BITS_TO_U64(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
17 #define BITS_TO_U32(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
18 #define BITS_TO_BYTES(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(char))
20 extern unsigned int __sw_hweight8(unsigned int w);
21 extern unsigned int __sw_hweight16(unsigned int w);
22 extern unsigned int __sw_hweight32(unsigned int w);
23 extern unsigned long __sw_hweight64(__u64 w);
26 * Include this here because some architectures need generic_ffs/fls in
29 #include <asm/bitops.h>
31 #define for_each_set_bit(bit, addr, size) \
32 for ((bit) = find_first_bit((addr), (size)); \
34 (bit) = find_next_bit((addr), (size), (bit) + 1))
36 /* same as for_each_set_bit() but use bit as value to start with */
37 #define for_each_set_bit_from(bit, addr, size) \
38 for ((bit) = find_next_bit((addr), (size), (bit)); \
40 (bit) = find_next_bit((addr), (size), (bit) + 1))
42 #define for_each_clear_bit(bit, addr, size) \
43 for ((bit) = find_first_zero_bit((addr), (size)); \
45 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
47 /* same as for_each_clear_bit() but use bit as value to start with */
48 #define for_each_clear_bit_from(bit, addr, size) \
49 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
51 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
54 * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits
55 * @start: bit offset to start search and to store the current iteration offset
56 * @clump: location to store copy of current 8-bit clump
57 * @bits: bitmap address to base the search on
58 * @size: bitmap size in number of bits
60 #define for_each_set_clump8(start, clump, bits, size) \
61 for ((start) = find_first_clump8(&(clump), (bits), (size)); \
63 (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8))
65 static inline int get_bitmask_order(unsigned int count)
70 return order; /* We could be slightly more clever with -1 here... */
73 static __always_inline unsigned long hweight_long(unsigned long w)
75 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
79 * rol64 - rotate a 64-bit value left
80 * @word: value to rotate
81 * @shift: bits to roll
83 static inline __u64 rol64(__u64 word, unsigned int shift)
85 return (word << (shift & 63)) | (word >> ((-shift) & 63));
89 * ror64 - rotate a 64-bit value right
90 * @word: value to rotate
91 * @shift: bits to roll
93 static inline __u64 ror64(__u64 word, unsigned int shift)
95 return (word >> (shift & 63)) | (word << ((-shift) & 63));
99 * rol32 - rotate a 32-bit value left
100 * @word: value to rotate
101 * @shift: bits to roll
103 static inline __u32 rol32(__u32 word, unsigned int shift)
105 return (word << (shift & 31)) | (word >> ((-shift) & 31));
109 * ror32 - rotate a 32-bit value right
110 * @word: value to rotate
111 * @shift: bits to roll
113 static inline __u32 ror32(__u32 word, unsigned int shift)
115 return (word >> (shift & 31)) | (word << ((-shift) & 31));
119 * rol16 - rotate a 16-bit value left
120 * @word: value to rotate
121 * @shift: bits to roll
123 static inline __u16 rol16(__u16 word, unsigned int shift)
125 return (word << (shift & 15)) | (word >> ((-shift) & 15));
129 * ror16 - rotate a 16-bit value right
130 * @word: value to rotate
131 * @shift: bits to roll
133 static inline __u16 ror16(__u16 word, unsigned int shift)
135 return (word >> (shift & 15)) | (word << ((-shift) & 15));
139 * rol8 - rotate an 8-bit value left
140 * @word: value to rotate
141 * @shift: bits to roll
143 static inline __u8 rol8(__u8 word, unsigned int shift)
145 return (word << (shift & 7)) | (word >> ((-shift) & 7));
149 * ror8 - rotate an 8-bit value right
150 * @word: value to rotate
151 * @shift: bits to roll
153 static inline __u8 ror8(__u8 word, unsigned int shift)
155 return (word >> (shift & 7)) | (word << ((-shift) & 7));
159 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
160 * @value: value to sign extend
161 * @index: 0 based bit index (0<=index<32) to sign bit
163 * This is safe to use for 16- and 8-bit types as well.
165 static __always_inline __s32 sign_extend32(__u32 value, int index)
167 __u8 shift = 31 - index;
168 return (__s32)(value << shift) >> shift;
172 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
173 * @value: value to sign extend
174 * @index: 0 based bit index (0<=index<64) to sign bit
176 static __always_inline __s64 sign_extend64(__u64 value, int index)
178 __u8 shift = 63 - index;
179 return (__s64)(value << shift) >> shift;
182 static inline unsigned fls_long(unsigned long l)
189 static inline int get_count_order(unsigned int count)
193 order = fls(count) - 1;
194 if (count & (count - 1))
200 * get_count_order_long - get order after rounding @l up to power of 2
203 * it is same as get_count_order() but with long type parameter
205 static inline int get_count_order_long(unsigned long l)
209 else if (l & (l - 1UL))
210 return (int)fls_long(l);
212 return (int)fls_long(l) - 1;
216 * __ffs64 - find first set bit in a 64 bit word
217 * @word: The 64 bit word
219 * On 64 bit arches this is a synomyn for __ffs
220 * The result is not defined if no bits are set, so check that @word
221 * is non-zero before calling this.
223 static inline unsigned long __ffs64(u64 word)
225 #if BITS_PER_LONG == 32
226 if (((u32)word) == 0UL)
227 return __ffs((u32)(word >> 32)) + 32;
228 #elif BITS_PER_LONG != 64
229 #error BITS_PER_LONG not 32 or 64
231 return __ffs((unsigned long)word);
235 * assign_bit - Assign value to a bit in memory
236 * @nr: the bit to set
237 * @addr: the address to start counting from
238 * @value: the value to assign
240 static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
249 static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
255 __clear_bit(nr, addr);
260 #ifndef set_mask_bits
261 #define set_mask_bits(ptr, mask, bits) \
263 const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \
264 typeof(*(ptr)) old__, new__; \
267 old__ = READ_ONCE(*(ptr)); \
268 new__ = (old__ & ~mask__) | bits__; \
269 } while (cmpxchg(ptr, old__, new__) != old__); \
275 #ifndef bit_clear_unless
276 #define bit_clear_unless(ptr, clear, test) \
278 const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
279 typeof(*(ptr)) old__, new__; \
282 old__ = READ_ONCE(*(ptr)); \
283 new__ = old__ & ~clear__; \
284 } while (!(old__ & test__) && \
285 cmpxchg(ptr, old__, new__) != old__); \
291 #ifndef find_last_bit
293 * find_last_bit - find the last set bit in a memory region
294 * @addr: The address to start the search at
295 * @size: The number of bits to search
297 * Returns the bit number of the last set bit, or size.
299 extern unsigned long find_last_bit(const unsigned long *addr,
303 #endif /* __KERNEL__ */