1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_BITOPS_H
3 #define _LINUX_BITOPS_H
6 #include <linux/bits.h>
7 #include <linux/typecheck.h>
9 #include <uapi/linux/kernel.h>
11 /* Set bits in the first 'n' bytes when loaded from memory */
12 #ifdef __LITTLE_ENDIAN
13 # define aligned_byte_mask(n) ((1UL << 8*(n))-1)
15 # define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
18 #define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
19 #define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
20 #define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
21 #define BITS_TO_U32(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
22 #define BITS_TO_BYTES(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))
24 extern unsigned int __sw_hweight8(unsigned int w);
25 extern unsigned int __sw_hweight16(unsigned int w);
26 extern unsigned int __sw_hweight32(unsigned int w);
27 extern unsigned long __sw_hweight64(__u64 w);
30 * Include this here because some architectures need generic_ffs/fls in
33 #include <asm/bitops.h>
35 static inline int get_bitmask_order(unsigned int count)
40 return order; /* We could be slightly more clever with -1 here... */
43 static __always_inline unsigned long hweight_long(unsigned long w)
45 return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);
49 * rol64 - rotate a 64-bit value left
50 * @word: value to rotate
51 * @shift: bits to roll
53 static inline __u64 rol64(__u64 word, unsigned int shift)
55 return (word << (shift & 63)) | (word >> ((-shift) & 63));
59 * ror64 - rotate a 64-bit value right
60 * @word: value to rotate
61 * @shift: bits to roll
63 static inline __u64 ror64(__u64 word, unsigned int shift)
65 return (word >> (shift & 63)) | (word << ((-shift) & 63));
69 * rol32 - rotate a 32-bit value left
70 * @word: value to rotate
71 * @shift: bits to roll
73 static inline __u32 rol32(__u32 word, unsigned int shift)
75 return (word << (shift & 31)) | (word >> ((-shift) & 31));
79 * ror32 - rotate a 32-bit value right
80 * @word: value to rotate
81 * @shift: bits to roll
83 static inline __u32 ror32(__u32 word, unsigned int shift)
85 return (word >> (shift & 31)) | (word << ((-shift) & 31));
89 * rol16 - rotate a 16-bit value left
90 * @word: value to rotate
91 * @shift: bits to roll
93 static inline __u16 rol16(__u16 word, unsigned int shift)
95 return (word << (shift & 15)) | (word >> ((-shift) & 15));
99 * ror16 - rotate a 16-bit value right
100 * @word: value to rotate
101 * @shift: bits to roll
103 static inline __u16 ror16(__u16 word, unsigned int shift)
105 return (word >> (shift & 15)) | (word << ((-shift) & 15));
109 * rol8 - rotate an 8-bit value left
110 * @word: value to rotate
111 * @shift: bits to roll
113 static inline __u8 rol8(__u8 word, unsigned int shift)
115 return (word << (shift & 7)) | (word >> ((-shift) & 7));
119 * ror8 - rotate an 8-bit value right
120 * @word: value to rotate
121 * @shift: bits to roll
123 static inline __u8 ror8(__u8 word, unsigned int shift)
125 return (word >> (shift & 7)) | (word << ((-shift) & 7));
129 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
130 * @value: value to sign extend
131 * @index: 0 based bit index (0<=index<32) to sign bit
133 * This is safe to use for 16- and 8-bit types as well.
135 static __always_inline __s32 sign_extend32(__u32 value, int index)
137 __u8 shift = 31 - index;
138 return (__s32)(value << shift) >> shift;
142 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
143 * @value: value to sign extend
144 * @index: 0 based bit index (0<=index<64) to sign bit
146 static __always_inline __s64 sign_extend64(__u64 value, int index)
148 __u8 shift = 63 - index;
149 return (__s64)(value << shift) >> shift;
152 static inline unsigned fls_long(unsigned long l)
159 static inline int get_count_order(unsigned int count)
168 * get_count_order_long - get order after rounding @l up to power of 2
171 * it is same as get_count_order() but with long type parameter
173 static inline int get_count_order_long(unsigned long l)
177 return (int)fls_long(--l);
181 * __ffs64 - find first set bit in a 64 bit word
182 * @word: The 64 bit word
184 * On 64 bit arches this is a synonym for __ffs
185 * The result is not defined if no bits are set, so check that @word
186 * is non-zero before calling this.
188 static inline unsigned long __ffs64(u64 word)
190 #if BITS_PER_LONG == 32
191 if (((u32)word) == 0UL)
192 return __ffs((u32)(word >> 32)) + 32;
193 #elif BITS_PER_LONG != 64
194 #error BITS_PER_LONG not 32 or 64
196 return __ffs((unsigned long)word);
200 * assign_bit - Assign value to a bit in memory
201 * @nr: the bit to set
202 * @addr: the address to start counting from
203 * @value: the value to assign
205 static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
214 static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
220 __clear_bit(nr, addr);
224 * __ptr_set_bit - Set bit in a pointer's value
225 * @nr: the bit to set
226 * @addr: the address of the pointer variable
230 * __ptr_set_bit(bit, &p);
232 #define __ptr_set_bit(nr, addr) \
234 typecheck_pointer(*(addr)); \
235 __set_bit(nr, (unsigned long *)(addr)); \
239 * __ptr_clear_bit - Clear bit in a pointer's value
240 * @nr: the bit to clear
241 * @addr: the address of the pointer variable
245 * __ptr_clear_bit(bit, &p);
247 #define __ptr_clear_bit(nr, addr) \
249 typecheck_pointer(*(addr)); \
250 __clear_bit(nr, (unsigned long *)(addr)); \
254 * __ptr_test_bit - Test bit in a pointer's value
255 * @nr: the bit to test
256 * @addr: the address of the pointer variable
260 * if (__ptr_test_bit(bit, &p)) {
266 #define __ptr_test_bit(nr, addr) \
268 typecheck_pointer(*(addr)); \
269 test_bit(nr, (unsigned long *)(addr)); \
274 #ifndef set_mask_bits
275 #define set_mask_bits(ptr, mask, bits) \
277 const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \
278 typeof(*(ptr)) old__, new__; \
281 old__ = READ_ONCE(*(ptr)); \
282 new__ = (old__ & ~mask__) | bits__; \
283 } while (cmpxchg(ptr, old__, new__) != old__); \
289 #ifndef bit_clear_unless
290 #define bit_clear_unless(ptr, clear, test) \
292 const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
293 typeof(*(ptr)) old__, new__; \
296 old__ = READ_ONCE(*(ptr)); \
297 new__ = old__ & ~clear__; \
298 } while (!(old__ & test__) && \
299 cmpxchg(ptr, old__, new__) != old__); \
305 #endif /* __KERNEL__ */