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