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 #include <linux/typecheck.h>
8
9 #include <uapi/linux/kernel.h>
10
11 /* Set bits in the first 'n' bytes when loaded from memory */
12 #ifdef __LITTLE_ENDIAN
13 # define aligned_byte_mask(n) ((1UL << 8*(n))-1)
14 #else
15 # define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
16 #endif
17
18 #define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
19 #define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
20 #define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
21 #define BITS_TO_U32(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
22 #define BITS_TO_BYTES(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))
23
24 extern unsigned int __sw_hweight8(unsigned int w);
25 extern unsigned int __sw_hweight16(unsigned int w);
26 extern unsigned int __sw_hweight32(unsigned int w);
27 extern unsigned long __sw_hweight64(__u64 w);
28
29 /*
30 * Include this here because some architectures need generic_ffs/fls in
31 * scope
32 */
33 #include <asm/bitops.h>
34
get_bitmask_order(unsigned int count)35 static inline int get_bitmask_order(unsigned int count)
36 {
37 int order;
38
39 order = fls(count);
40 return order; /* We could be slightly more clever with -1 here... */
41 }
42
hweight_long(unsigned long w)43 static __always_inline unsigned long hweight_long(unsigned long w)
44 {
45 return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);
46 }
47
48 /**
49 * rol64 - rotate a 64-bit value left
50 * @word: value to rotate
51 * @shift: bits to roll
52 */
rol64(__u64 word,unsigned int shift)53 static inline __u64 rol64(__u64 word, unsigned int shift)
54 {
55 return (word << (shift & 63)) | (word >> ((-shift) & 63));
56 }
57
58 /**
59 * ror64 - rotate a 64-bit value right
60 * @word: value to rotate
61 * @shift: bits to roll
62 */
ror64(__u64 word,unsigned int shift)63 static inline __u64 ror64(__u64 word, unsigned int shift)
64 {
65 return (word >> (shift & 63)) | (word << ((-shift) & 63));
66 }
67
68 /**
69 * rol32 - rotate a 32-bit value left
70 * @word: value to rotate
71 * @shift: bits to roll
72 */
rol32(__u32 word,unsigned int shift)73 static inline __u32 rol32(__u32 word, unsigned int shift)
74 {
75 return (word << (shift & 31)) | (word >> ((-shift) & 31));
76 }
77
78 /**
79 * ror32 - rotate a 32-bit value right
80 * @word: value to rotate
81 * @shift: bits to roll
82 */
ror32(__u32 word,unsigned int shift)83 static inline __u32 ror32(__u32 word, unsigned int shift)
84 {
85 return (word >> (shift & 31)) | (word << ((-shift) & 31));
86 }
87
88 /**
89 * rol16 - rotate a 16-bit value left
90 * @word: value to rotate
91 * @shift: bits to roll
92 */
rol16(__u16 word,unsigned int shift)93 static inline __u16 rol16(__u16 word, unsigned int shift)
94 {
95 return (word << (shift & 15)) | (word >> ((-shift) & 15));
96 }
97
98 /**
99 * ror16 - rotate a 16-bit value right
100 * @word: value to rotate
101 * @shift: bits to roll
102 */
ror16(__u16 word,unsigned int shift)103 static inline __u16 ror16(__u16 word, unsigned int shift)
104 {
105 return (word >> (shift & 15)) | (word << ((-shift) & 15));
106 }
107
108 /**
109 * rol8 - rotate an 8-bit value left
110 * @word: value to rotate
111 * @shift: bits to roll
112 */
rol8(__u8 word,unsigned int shift)113 static inline __u8 rol8(__u8 word, unsigned int shift)
114 {
115 return (word << (shift & 7)) | (word >> ((-shift) & 7));
116 }
117
118 /**
119 * ror8 - rotate an 8-bit value right
120 * @word: value to rotate
121 * @shift: bits to roll
122 */
ror8(__u8 word,unsigned int shift)123 static inline __u8 ror8(__u8 word, unsigned int shift)
124 {
125 return (word >> (shift & 7)) | (word << ((-shift) & 7));
126 }
127
128 /**
129 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
130 * @value: value to sign extend
131 * @index: 0 based bit index (0<=index<32) to sign bit
132 *
133 * This is safe to use for 16- and 8-bit types as well.
134 */
sign_extend32(__u32 value,int index)135 static __always_inline __s32 sign_extend32(__u32 value, int index)
136 {
137 __u8 shift = 31 - index;
138 return (__s32)(value << shift) >> shift;
139 }
140
141 /**
142 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
143 * @value: value to sign extend
144 * @index: 0 based bit index (0<=index<64) to sign bit
145 */
sign_extend64(__u64 value,int index)146 static __always_inline __s64 sign_extend64(__u64 value, int index)
147 {
148 __u8 shift = 63 - index;
149 return (__s64)(value << shift) >> shift;
150 }
151
fls_long(unsigned long l)152 static inline unsigned fls_long(unsigned long l)
153 {
154 if (sizeof(l) == 4)
155 return fls(l);
156 return fls64(l);
157 }
158
get_count_order(unsigned int count)159 static inline int get_count_order(unsigned int count)
160 {
161 if (count == 0)
162 return -1;
163
164 return fls(--count);
165 }
166
167 /**
168 * get_count_order_long - get order after rounding @l up to power of 2
169 * @l: parameter
170 *
171 * it is same as get_count_order() but with long type parameter
172 */
get_count_order_long(unsigned long l)173 static inline int get_count_order_long(unsigned long l)
174 {
175 if (l == 0UL)
176 return -1;
177 return (int)fls_long(--l);
178 }
179
180 /**
181 * __ffs64 - find first set bit in a 64 bit word
182 * @word: The 64 bit word
183 *
184 * On 64 bit arches this is a synonym for __ffs
185 * The result is not defined if no bits are set, so check that @word
186 * is non-zero before calling this.
187 */
__ffs64(u64 word)188 static inline unsigned long __ffs64(u64 word)
189 {
190 #if BITS_PER_LONG == 32
191 if (((u32)word) == 0UL)
192 return __ffs((u32)(word >> 32)) + 32;
193 #elif BITS_PER_LONG != 64
194 #error BITS_PER_LONG not 32 or 64
195 #endif
196 return __ffs((unsigned long)word);
197 }
198
199 /**
200 * assign_bit - Assign value to a bit in memory
201 * @nr: the bit to set
202 * @addr: the address to start counting from
203 * @value: the value to assign
204 */
assign_bit(long nr,volatile unsigned long * addr,bool value)205 static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
206 bool value)
207 {
208 if (value)
209 set_bit(nr, addr);
210 else
211 clear_bit(nr, addr);
212 }
213
__assign_bit(long nr,volatile unsigned long * addr,bool value)214 static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
215 bool value)
216 {
217 if (value)
218 __set_bit(nr, addr);
219 else
220 __clear_bit(nr, addr);
221 }
222
223 /**
224 * __ptr_set_bit - Set bit in a pointer's value
225 * @nr: the bit to set
226 * @addr: the address of the pointer variable
227 *
228 * Example:
229 * void *p = foo();
230 * __ptr_set_bit(bit, &p);
231 */
232 #define __ptr_set_bit(nr, addr) \
233 ({ \
234 typecheck_pointer(*(addr)); \
235 __set_bit(nr, (unsigned long *)(addr)); \
236 })
237
238 /**
239 * __ptr_clear_bit - Clear bit in a pointer's value
240 * @nr: the bit to clear
241 * @addr: the address of the pointer variable
242 *
243 * Example:
244 * void *p = foo();
245 * __ptr_clear_bit(bit, &p);
246 */
247 #define __ptr_clear_bit(nr, addr) \
248 ({ \
249 typecheck_pointer(*(addr)); \
250 __clear_bit(nr, (unsigned long *)(addr)); \
251 })
252
253 /**
254 * __ptr_test_bit - Test bit in a pointer's value
255 * @nr: the bit to test
256 * @addr: the address of the pointer variable
257 *
258 * Example:
259 * void *p = foo();
260 * if (__ptr_test_bit(bit, &p)) {
261 * ...
262 * } else {
263 * ...
264 * }
265 */
266 #define __ptr_test_bit(nr, addr) \
267 ({ \
268 typecheck_pointer(*(addr)); \
269 test_bit(nr, (unsigned long *)(addr)); \
270 })
271
272 #ifdef __KERNEL__
273
274 #ifndef set_mask_bits
275 #define set_mask_bits(ptr, mask, bits) \
276 ({ \
277 const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \
278 typeof(*(ptr)) old__, new__; \
279 \
280 do { \
281 old__ = READ_ONCE(*(ptr)); \
282 new__ = (old__ & ~mask__) | bits__; \
283 } while (cmpxchg(ptr, old__, new__) != old__); \
284 \
285 old__; \
286 })
287 #endif
288
289 #ifndef bit_clear_unless
290 #define bit_clear_unless(ptr, clear, test) \
291 ({ \
292 const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
293 typeof(*(ptr)) old__, new__; \
294 \
295 do { \
296 old__ = READ_ONCE(*(ptr)); \
297 new__ = old__ & ~clear__; \
298 } while (!(old__ & test__) && \
299 cmpxchg(ptr, old__, new__) != old__); \
300 \
301 !(old__ & test__); \
302 })
303 #endif
304
305 #endif /* __KERNEL__ */
306 #endif
307