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))
51 * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits
52 * @start: bit offset to start search and to store the current iteration offset
53 * @clump: location to store copy of current 8-bit clump
54 * @bits: bitmap address to base the search on
55 * @size: bitmap size in number of bits
57 #define for_each_set_clump8(start, clump, bits, size) \
58 for ((start) = find_first_clump8(&(clump), (bits), (size)); \
60 (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8))
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 & 63)) | (word >> ((-shift) & 63));
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 & 63)) | (word << ((-shift) & 63));
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 & 31)) | (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 & 31)) | (word << ((-shift) & 31));
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 & 15)) | (word >> ((-shift) & 15));
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 & 15)) | (word << ((-shift) & 15));
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 & 7)) | (word >> ((-shift) & 7));
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 & 7)) | (word << ((-shift) & 7));
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__ */