Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : #ifndef _LINUX_BITOPS_H
3 : #define _LINUX_BITOPS_H
4 :
5 : #include <asm/types.h>
6 : #include <linux/bits.h>
7 :
8 : #include <uapi/linux/kernel.h>
9 :
10 : /* Set bits in the first 'n' bytes when loaded from memory */
11 : #ifdef __LITTLE_ENDIAN
12 : # define aligned_byte_mask(n) ((1UL << 8*(n))-1)
13 : #else
14 : # define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
15 : #endif
16 :
17 : #define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
18 : #define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
19 : #define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
20 : #define BITS_TO_U32(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
21 : #define BITS_TO_BYTES(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))
22 :
23 : extern unsigned int __sw_hweight8(unsigned int w);
24 : extern unsigned int __sw_hweight16(unsigned int w);
25 : extern unsigned int __sw_hweight32(unsigned int w);
26 : extern unsigned long __sw_hweight64(__u64 w);
27 :
28 : /*
29 : * Include this here because some architectures need generic_ffs/fls in
30 : * scope
31 : */
32 : #include <asm/bitops.h>
33 :
34 : #define for_each_set_bit(bit, addr, size) \
35 : for ((bit) = find_first_bit((addr), (size)); \
36 : (bit) < (size); \
37 : (bit) = find_next_bit((addr), (size), (bit) + 1))
38 :
39 : /* same as for_each_set_bit() but use bit as value to start with */
40 : #define for_each_set_bit_from(bit, addr, size) \
41 : for ((bit) = find_next_bit((addr), (size), (bit)); \
42 : (bit) < (size); \
43 : (bit) = find_next_bit((addr), (size), (bit) + 1))
44 :
45 : #define for_each_clear_bit(bit, addr, size) \
46 : for ((bit) = find_first_zero_bit((addr), (size)); \
47 : (bit) < (size); \
48 : (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
49 :
50 : /* same as for_each_clear_bit() but use bit as value to start with */
51 : #define for_each_clear_bit_from(bit, addr, size) \
52 : for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
53 : (bit) < (size); \
54 : (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
55 :
56 : /**
57 : * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits
58 : * @start: bit offset to start search and to store the current iteration offset
59 : * @clump: location to store copy of current 8-bit clump
60 : * @bits: bitmap address to base the search on
61 : * @size: bitmap size in number of bits
62 : */
63 : #define for_each_set_clump8(start, clump, bits, size) \
64 : for ((start) = find_first_clump8(&(clump), (bits), (size)); \
65 : (start) < (size); \
66 : (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8))
67 :
68 : static inline int get_bitmask_order(unsigned int count)
69 : {
70 : int order;
71 :
72 : order = fls(count);
73 : return order; /* We could be slightly more clever with -1 here... */
74 : }
75 :
76 390 : static __always_inline unsigned long hweight_long(unsigned long w)
77 : {
78 390 : return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);
79 : }
80 :
81 : /**
82 : * rol64 - rotate a 64-bit value left
83 : * @word: value to rotate
84 : * @shift: bits to roll
85 : */
86 303493 : static inline __u64 rol64(__u64 word, unsigned int shift)
87 : {
88 112234 : return (word << (shift & 63)) | (word >> ((-shift) & 63));
89 : }
90 :
91 : /**
92 : * ror64 - rotate a 64-bit value right
93 : * @word: value to rotate
94 : * @shift: bits to roll
95 : */
96 : static inline __u64 ror64(__u64 word, unsigned int shift)
97 : {
98 : return (word >> (shift & 63)) | (word << ((-shift) & 63));
99 : }
100 :
101 : /**
102 : * rol32 - rotate a 32-bit value left
103 : * @word: value to rotate
104 : * @shift: bits to roll
105 : */
106 105448722 : static inline __u32 rol32(__u32 word, unsigned int shift)
107 : {
108 56970318 : return (word << (shift & 31)) | (word >> ((-shift) & 31));
109 : }
110 :
111 : /**
112 : * ror32 - rotate a 32-bit value right
113 : * @word: value to rotate
114 : * @shift: bits to roll
115 : */
116 40 : static inline __u32 ror32(__u32 word, unsigned int shift)
117 : {
118 40 : return (word >> (shift & 31)) | (word << ((-shift) & 31));
119 : }
120 :
121 : /**
122 : * rol16 - rotate a 16-bit value left
123 : * @word: value to rotate
124 : * @shift: bits to roll
125 : */
126 : static inline __u16 rol16(__u16 word, unsigned int shift)
127 : {
128 : return (word << (shift & 15)) | (word >> ((-shift) & 15));
129 : }
130 :
131 : /**
132 : * ror16 - rotate a 16-bit value right
133 : * @word: value to rotate
134 : * @shift: bits to roll
135 : */
136 : static inline __u16 ror16(__u16 word, unsigned int shift)
137 : {
138 : return (word >> (shift & 15)) | (word << ((-shift) & 15));
139 : }
140 :
141 : /**
142 : * rol8 - rotate an 8-bit value left
143 : * @word: value to rotate
144 : * @shift: bits to roll
145 : */
146 : static inline __u8 rol8(__u8 word, unsigned int shift)
147 : {
148 : return (word << (shift & 7)) | (word >> ((-shift) & 7));
149 : }
150 :
151 : /**
152 : * ror8 - rotate an 8-bit value right
153 : * @word: value to rotate
154 : * @shift: bits to roll
155 : */
156 : static inline __u8 ror8(__u8 word, unsigned int shift)
157 : {
158 : return (word >> (shift & 7)) | (word << ((-shift) & 7));
159 : }
160 :
161 : /**
162 : * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
163 : * @value: value to sign extend
164 : * @index: 0 based bit index (0<=index<32) to sign bit
165 : *
166 : * This is safe to use for 16- and 8-bit types as well.
167 : */
168 0 : static __always_inline __s32 sign_extend32(__u32 value, int index)
169 : {
170 0 : __u8 shift = 31 - index;
171 0 : return (__s32)(value << shift) >> shift;
172 : }
173 :
174 : /**
175 : * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
176 : * @value: value to sign extend
177 : * @index: 0 based bit index (0<=index<64) to sign bit
178 : */
179 0 : static __always_inline __s64 sign_extend64(__u64 value, int index)
180 : {
181 0 : __u8 shift = 63 - index;
182 0 : return (__s64)(value << shift) >> shift;
183 : }
184 :
185 645 : static inline unsigned fls_long(unsigned long l)
186 : {
187 645 : if (sizeof(l) == 4)
188 : return fls(l);
189 645 : return fls64(l);
190 : }
191 :
192 24 : static inline int get_count_order(unsigned int count)
193 : {
194 24 : if (count == 0)
195 : return -1;
196 :
197 8 : return fls(--count);
198 : }
199 :
200 : /**
201 : * get_count_order_long - get order after rounding @l up to power of 2
202 : * @l: parameter
203 : *
204 : * it is same as get_count_order() but with long type parameter
205 : */
206 2 : static inline int get_count_order_long(unsigned long l)
207 : {
208 2 : if (l == 0UL)
209 : return -1;
210 2 : return (int)fls_long(--l);
211 : }
212 :
213 : /**
214 : * __ffs64 - find first set bit in a 64 bit word
215 : * @word: The 64 bit word
216 : *
217 : * On 64 bit arches this is a synonym for __ffs
218 : * The result is not defined if no bits are set, so check that @word
219 : * is non-zero before calling this.
220 : */
221 1 : static inline unsigned long __ffs64(u64 word)
222 : {
223 : #if BITS_PER_LONG == 32
224 : if (((u32)word) == 0UL)
225 : return __ffs((u32)(word >> 32)) + 32;
226 : #elif BITS_PER_LONG != 64
227 : #error BITS_PER_LONG not 32 or 64
228 : #endif
229 1 : return __ffs((unsigned long)word);
230 : }
231 :
232 : /**
233 : * assign_bit - Assign value to a bit in memory
234 : * @nr: the bit to set
235 : * @addr: the address to start counting from
236 : * @value: the value to assign
237 : */
238 271 : static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
239 : bool value)
240 : {
241 271 : if (value)
242 136 : set_bit(nr, addr);
243 : else
244 135 : clear_bit(nr, addr);
245 : }
246 :
247 : static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
248 : bool value)
249 : {
250 : if (value)
251 : __set_bit(nr, addr);
252 : else
253 : __clear_bit(nr, addr);
254 : }
255 :
256 : #ifdef __KERNEL__
257 :
258 : #ifndef set_mask_bits
259 : #define set_mask_bits(ptr, mask, bits) \
260 : ({ \
261 : const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \
262 : typeof(*(ptr)) old__, new__; \
263 : \
264 : do { \
265 : old__ = READ_ONCE(*(ptr)); \
266 : new__ = (old__ & ~mask__) | bits__; \
267 : } while (cmpxchg(ptr, old__, new__) != old__); \
268 : \
269 : old__; \
270 : })
271 : #endif
272 :
273 : #ifndef bit_clear_unless
274 : #define bit_clear_unless(ptr, clear, test) \
275 : ({ \
276 : const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
277 : typeof(*(ptr)) old__, new__; \
278 : \
279 : do { \
280 : old__ = READ_ONCE(*(ptr)); \
281 : new__ = old__ & ~clear__; \
282 : } while (!(old__ & test__) && \
283 : cmpxchg(ptr, old__, new__) != old__); \
284 : \
285 : !(old__ & test__); \
286 : })
287 : #endif
288 :
289 : #ifndef find_last_bit
290 : /**
291 : * find_last_bit - find the last set bit in a memory region
292 : * @addr: The address to start the search at
293 : * @size: The number of bits to search
294 : *
295 : * Returns the bit number of the last set bit, or size.
296 : */
297 : extern unsigned long find_last_bit(const unsigned long *addr,
298 : unsigned long size);
299 : #endif
300 :
301 : #endif /* __KERNEL__ */
302 : #endif
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