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 #define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
8 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
9
10 extern unsigned int __sw_hweight8(unsigned int w);
11 extern unsigned int __sw_hweight16(unsigned int w);
12 extern unsigned int __sw_hweight32(unsigned int w);
13 extern unsigned long __sw_hweight64(__u64 w);
14
15 /*
16 * Include this here because some architectures need generic_ffs/fls in
17 * scope
18 */
19 #include <asm/bitops.h>
20
21 #define for_each_set_bit(bit, addr, size) \
22 for ((bit) = find_first_bit((addr), (size)); \
23 (bit) < (size); \
24 (bit) = find_next_bit((addr), (size), (bit) + 1))
25
26 /* same as for_each_set_bit() but use bit as value to start with */
27 #define for_each_set_bit_from(bit, addr, size) \
28 for ((bit) = find_next_bit((addr), (size), (bit)); \
29 (bit) < (size); \
30 (bit) = find_next_bit((addr), (size), (bit) + 1))
31
32 #define for_each_clear_bit(bit, addr, size) \
33 for ((bit) = find_first_zero_bit((addr), (size)); \
34 (bit) < (size); \
35 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
36
37 /* same as for_each_clear_bit() but use bit as value to start with */
38 #define for_each_clear_bit_from(bit, addr, size) \
39 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
40 (bit) < (size); \
41 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
42
get_bitmask_order(unsigned int count)43 static inline int get_bitmask_order(unsigned int count)
44 {
45 int order;
46
47 order = fls(count);
48 return order; /* We could be slightly more clever with -1 here... */
49 }
50
hweight_long(unsigned long w)51 static __always_inline unsigned long hweight_long(unsigned long w)
52 {
53 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
54 }
55
56 /**
57 * rol64 - rotate a 64-bit value left
58 * @word: value to rotate
59 * @shift: bits to roll
60 */
rol64(__u64 word,unsigned int shift)61 static inline __u64 rol64(__u64 word, unsigned int shift)
62 {
63 return (word << (shift & 63)) | (word >> ((-shift) & 63));
64 }
65
66 /**
67 * ror64 - rotate a 64-bit value right
68 * @word: value to rotate
69 * @shift: bits to roll
70 */
ror64(__u64 word,unsigned int shift)71 static inline __u64 ror64(__u64 word, unsigned int shift)
72 {
73 return (word >> (shift & 63)) | (word << ((-shift) & 63));
74 }
75
76 /**
77 * rol32 - rotate a 32-bit value left
78 * @word: value to rotate
79 * @shift: bits to roll
80 */
rol32(__u32 word,unsigned int shift)81 static inline __u32 rol32(__u32 word, unsigned int shift)
82 {
83 return (word << (shift & 31)) | (word >> ((-shift) & 31));
84 }
85
86 /**
87 * ror32 - rotate a 32-bit value right
88 * @word: value to rotate
89 * @shift: bits to roll
90 */
ror32(__u32 word,unsigned int shift)91 static inline __u32 ror32(__u32 word, unsigned int shift)
92 {
93 return (word >> (shift & 31)) | (word << ((-shift) & 31));
94 }
95
96 /**
97 * rol16 - rotate a 16-bit value left
98 * @word: value to rotate
99 * @shift: bits to roll
100 */
rol16(__u16 word,unsigned int shift)101 static inline __u16 rol16(__u16 word, unsigned int shift)
102 {
103 return (word << (shift & 15)) | (word >> ((-shift) & 15));
104 }
105
106 /**
107 * ror16 - rotate a 16-bit value right
108 * @word: value to rotate
109 * @shift: bits to roll
110 */
ror16(__u16 word,unsigned int shift)111 static inline __u16 ror16(__u16 word, unsigned int shift)
112 {
113 return (word >> (shift & 15)) | (word << ((-shift) & 15));
114 }
115
116 /**
117 * rol8 - rotate an 8-bit value left
118 * @word: value to rotate
119 * @shift: bits to roll
120 */
rol8(__u8 word,unsigned int shift)121 static inline __u8 rol8(__u8 word, unsigned int shift)
122 {
123 return (word << (shift & 7)) | (word >> ((-shift) & 7));
124 }
125
126 /**
127 * ror8 - rotate an 8-bit value right
128 * @word: value to rotate
129 * @shift: bits to roll
130 */
ror8(__u8 word,unsigned int shift)131 static inline __u8 ror8(__u8 word, unsigned int shift)
132 {
133 return (word >> (shift & 7)) | (word << ((-shift) & 7));
134 }
135
136 /**
137 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
138 * @value: value to sign extend
139 * @index: 0 based bit index (0<=index<32) to sign bit
140 *
141 * This is safe to use for 16- and 8-bit types as well.
142 */
sign_extend32(__u32 value,int index)143 static inline __s32 sign_extend32(__u32 value, int index)
144 {
145 __u8 shift = 31 - index;
146 return (__s32)(value << shift) >> shift;
147 }
148
149 /**
150 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
151 * @value: value to sign extend
152 * @index: 0 based bit index (0<=index<64) to sign bit
153 */
sign_extend64(__u64 value,int index)154 static inline __s64 sign_extend64(__u64 value, int index)
155 {
156 __u8 shift = 63 - index;
157 return (__s64)(value << shift) >> shift;
158 }
159
fls_long(unsigned long l)160 static inline unsigned fls_long(unsigned long l)
161 {
162 if (sizeof(l) == 4)
163 return fls(l);
164 return fls64(l);
165 }
166
get_count_order(unsigned int count)167 static inline int get_count_order(unsigned int count)
168 {
169 int order;
170
171 order = fls(count) - 1;
172 if (count & (count - 1))
173 order++;
174 return order;
175 }
176
177 /**
178 * get_count_order_long - get order after rounding @l up to power of 2
179 * @l: parameter
180 *
181 * it is same as get_count_order() but with long type parameter
182 */
get_count_order_long(unsigned long l)183 static inline int get_count_order_long(unsigned long l)
184 {
185 if (l == 0UL)
186 return -1;
187 else if (l & (l - 1UL))
188 return (int)fls_long(l);
189 else
190 return (int)fls_long(l) - 1;
191 }
192
193 /**
194 * __ffs64 - find first set bit in a 64 bit word
195 * @word: The 64 bit word
196 *
197 * On 64 bit arches this is a synomyn for __ffs
198 * The result is not defined if no bits are set, so check that @word
199 * is non-zero before calling this.
200 */
__ffs64(u64 word)201 static inline unsigned long __ffs64(u64 word)
202 {
203 #if BITS_PER_LONG == 32
204 if (((u32)word) == 0UL)
205 return __ffs((u32)(word >> 32)) + 32;
206 #elif BITS_PER_LONG != 64
207 #error BITS_PER_LONG not 32 or 64
208 #endif
209 return __ffs((unsigned long)word);
210 }
211
212 #ifdef __KERNEL__
213
214 #ifndef set_mask_bits
215 #define set_mask_bits(ptr, _mask, _bits) \
216 ({ \
217 const typeof(*ptr) mask = (_mask), bits = (_bits); \
218 typeof(*ptr) old, new; \
219 \
220 do { \
221 old = ACCESS_ONCE(*ptr); \
222 new = (old & ~mask) | bits; \
223 } while (cmpxchg(ptr, old, new) != old); \
224 \
225 new; \
226 })
227 #endif
228
229 #ifndef bit_clear_unless
230 #define bit_clear_unless(ptr, _clear, _test) \
231 ({ \
232 const typeof(*ptr) clear = (_clear), test = (_test); \
233 typeof(*ptr) old, new; \
234 \
235 do { \
236 old = ACCESS_ONCE(*ptr); \
237 new = old & ~clear; \
238 } while (!(old & test) && \
239 cmpxchg(ptr, old, new) != old); \
240 \
241 !(old & test); \
242 })
243 #endif
244
245 #ifndef find_last_bit
246 /**
247 * find_last_bit - find the last set bit in a memory region
248 * @addr: The address to start the search at
249 * @size: The number of bits to search
250 *
251 * Returns the bit number of the last set bit, or size.
252 */
253 extern unsigned long find_last_bit(const unsigned long *addr,
254 unsigned long size);
255 #endif
256
257 #endif /* __KERNEL__ */
258 #endif
259