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