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