Commit | Line | Data |
---|---|---|
b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _LINUX_BITOPS_H |
3 | #define _LINUX_BITOPS_H | |
aa6159ab | 4 | |
1da177e4 | 5 | #include <asm/types.h> |
8bd9cb51 | 6 | #include <linux/bits.h> |
cb0f8003 | 7 | #include <linux/typecheck.h> |
1da177e4 | 8 | |
aa6159ab AS |
9 | #include <uapi/linux/kernel.h> |
10 | ||
f5a1a536 AS |
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 | ||
0bddc1bd | 18 | #define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE) |
aa6159ab AS |
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)) | |
10ef6b0d | 23 | |
4677d4a5 BP |
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 | ||
e69eb9c4 AL |
29 | /* |
30 | * Defined here because those may be needed by architecture-specific static | |
31 | * inlines. | |
32 | */ | |
33 | ||
0e862838 AL |
34 | #include <asm-generic/bitops/generic-non-atomic.h> |
35 | ||
b03fc117 AL |
36 | /* |
37 | * Many architecture-specific non-atomic bitops contain inline asm code and due | |
38 | * to that the compiler can't optimize them to compile-time expressions or | |
39 | * constants. In contrary, generic_*() helpers are defined in pure C and | |
40 | * compilers optimize them just well. | |
41 | * Therefore, to make `unsigned long foo = 0; __set_bit(BAR, &foo)` effectively | |
42 | * equal to `unsigned long foo = BIT(BAR)`, pick the generic C alternative when | |
43 | * the arguments can be resolved at compile time. That expression itself is a | |
44 | * constant and doesn't bring any functional changes to the rest of cases. | |
45 | * The casts to `uintptr_t` are needed to mitigate `-Waddress` warnings when | |
46 | * passing a bitmap from .bss or .data (-> `!!addr` is always true). | |
47 | */ | |
e69eb9c4 | 48 | #define bitop(op, nr, addr) \ |
b03fc117 AL |
49 | ((__builtin_constant_p(nr) && \ |
50 | __builtin_constant_p((uintptr_t)(addr) != (uintptr_t)NULL) && \ | |
51 | (uintptr_t)(addr) != (uintptr_t)NULL && \ | |
52 | __builtin_constant_p(*(const unsigned long *)(addr))) ? \ | |
53 | const##op(nr, addr) : op(nr, addr)) | |
e69eb9c4 AL |
54 | |
55 | #define __set_bit(nr, addr) bitop(___set_bit, nr, addr) | |
56 | #define __clear_bit(nr, addr) bitop(___clear_bit, nr, addr) | |
57 | #define __change_bit(nr, addr) bitop(___change_bit, nr, addr) | |
58 | #define __test_and_set_bit(nr, addr) bitop(___test_and_set_bit, nr, addr) | |
59 | #define __test_and_clear_bit(nr, addr) bitop(___test_and_clear_bit, nr, addr) | |
60 | #define __test_and_change_bit(nr, addr) bitop(___test_and_change_bit, nr, addr) | |
61 | #define test_bit(nr, addr) bitop(_test_bit, nr, addr) | |
8238b457 | 62 | #define test_bit_acquire(nr, addr) bitop(_test_bit_acquire, nr, addr) |
e69eb9c4 | 63 | |
1da177e4 LT |
64 | /* |
65 | * Include this here because some architectures need generic_ffs/fls in | |
66 | * scope | |
67 | */ | |
68 | #include <asm/bitops.h> | |
69 | ||
0e862838 AL |
70 | /* Check that the bitops prototypes are sane */ |
71 | #define __check_bitop_pr(name) \ | |
72 | static_assert(__same_type(arch_##name, generic_##name) && \ | |
bb7379bf | 73 | __same_type(const_##name, generic_##name) && \ |
e69eb9c4 | 74 | __same_type(_##name, generic_##name)) |
0e862838 AL |
75 | |
76 | __check_bitop_pr(__set_bit); | |
77 | __check_bitop_pr(__clear_bit); | |
78 | __check_bitop_pr(__change_bit); | |
79 | __check_bitop_pr(__test_and_set_bit); | |
80 | __check_bitop_pr(__test_and_clear_bit); | |
81 | __check_bitop_pr(__test_and_change_bit); | |
82 | __check_bitop_pr(test_bit); | |
83 | ||
84 | #undef __check_bitop_pr | |
85 | ||
1a1d48a4 | 86 | static inline int get_bitmask_order(unsigned int count) |
1da177e4 LT |
87 | { |
88 | int order; | |
9f41699e | 89 | |
1da177e4 LT |
90 | order = fls(count); |
91 | return order; /* We could be slightly more clever with -1 here... */ | |
92 | } | |
93 | ||
1a1d48a4 | 94 | static __always_inline unsigned long hweight_long(unsigned long w) |
1da177e4 | 95 | { |
bd93f003 | 96 | return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w); |
1da177e4 LT |
97 | } |
98 | ||
f2ea0f5f AD |
99 | /** |
100 | * rol64 - rotate a 64-bit value left | |
101 | * @word: value to rotate | |
102 | * @shift: bits to roll | |
103 | */ | |
104 | static inline __u64 rol64(__u64 word, unsigned int shift) | |
105 | { | |
ef4d6f6b | 106 | return (word << (shift & 63)) | (word >> ((-shift) & 63)); |
f2ea0f5f AD |
107 | } |
108 | ||
109 | /** | |
110 | * ror64 - rotate a 64-bit value right | |
111 | * @word: value to rotate | |
112 | * @shift: bits to roll | |
113 | */ | |
114 | static inline __u64 ror64(__u64 word, unsigned int shift) | |
115 | { | |
ef4d6f6b | 116 | return (word >> (shift & 63)) | (word << ((-shift) & 63)); |
f2ea0f5f AD |
117 | } |
118 | ||
45f8bde0 | 119 | /** |
1da177e4 | 120 | * rol32 - rotate a 32-bit value left |
1da177e4 LT |
121 | * @word: value to rotate |
122 | * @shift: bits to roll | |
123 | */ | |
124 | static inline __u32 rol32(__u32 word, unsigned int shift) | |
125 | { | |
ef4d6f6b | 126 | return (word << (shift & 31)) | (word >> ((-shift) & 31)); |
1da177e4 LT |
127 | } |
128 | ||
45f8bde0 | 129 | /** |
1da177e4 | 130 | * ror32 - rotate a 32-bit value right |
1da177e4 LT |
131 | * @word: value to rotate |
132 | * @shift: bits to roll | |
133 | */ | |
134 | static inline __u32 ror32(__u32 word, unsigned int shift) | |
135 | { | |
ef4d6f6b | 136 | return (word >> (shift & 31)) | (word << ((-shift) & 31)); |
1da177e4 LT |
137 | } |
138 | ||
3afe3925 HH |
139 | /** |
140 | * rol16 - rotate a 16-bit value left | |
141 | * @word: value to rotate | |
142 | * @shift: bits to roll | |
143 | */ | |
144 | static inline __u16 rol16(__u16 word, unsigned int shift) | |
145 | { | |
ef4d6f6b | 146 | return (word << (shift & 15)) | (word >> ((-shift) & 15)); |
3afe3925 HH |
147 | } |
148 | ||
149 | /** | |
150 | * ror16 - rotate a 16-bit value right | |
151 | * @word: value to rotate | |
152 | * @shift: bits to roll | |
153 | */ | |
154 | static inline __u16 ror16(__u16 word, unsigned int shift) | |
155 | { | |
ef4d6f6b | 156 | return (word >> (shift & 15)) | (word << ((-shift) & 15)); |
3afe3925 HH |
157 | } |
158 | ||
159 | /** | |
160 | * rol8 - rotate an 8-bit value left | |
161 | * @word: value to rotate | |
162 | * @shift: bits to roll | |
163 | */ | |
164 | static inline __u8 rol8(__u8 word, unsigned int shift) | |
165 | { | |
ef4d6f6b | 166 | return (word << (shift & 7)) | (word >> ((-shift) & 7)); |
3afe3925 HH |
167 | } |
168 | ||
169 | /** | |
170 | * ror8 - rotate an 8-bit value right | |
171 | * @word: value to rotate | |
172 | * @shift: bits to roll | |
173 | */ | |
174 | static inline __u8 ror8(__u8 word, unsigned int shift) | |
175 | { | |
ef4d6f6b | 176 | return (word >> (shift & 7)) | (word << ((-shift) & 7)); |
3afe3925 | 177 | } |
7919a57b AH |
178 | |
179 | /** | |
180 | * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit | |
181 | * @value: value to sign extend | |
182 | * @index: 0 based bit index (0<=index<32) to sign bit | |
e2eb53aa MK |
183 | * |
184 | * This is safe to use for 16- and 8-bit types as well. | |
7919a57b | 185 | */ |
f80ac98a | 186 | static __always_inline __s32 sign_extend32(__u32 value, int index) |
7919a57b AH |
187 | { |
188 | __u8 shift = 31 - index; | |
189 | return (__s32)(value << shift) >> shift; | |
190 | } | |
3afe3925 | 191 | |
48e203e2 MK |
192 | /** |
193 | * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit | |
194 | * @value: value to sign extend | |
195 | * @index: 0 based bit index (0<=index<64) to sign bit | |
196 | */ | |
f80ac98a | 197 | static __always_inline __s64 sign_extend64(__u64 value, int index) |
48e203e2 MK |
198 | { |
199 | __u8 shift = 63 - index; | |
200 | return (__s64)(value << shift) >> shift; | |
201 | } | |
202 | ||
962749af AM |
203 | static inline unsigned fls_long(unsigned long l) |
204 | { | |
205 | if (sizeof(l) == 4) | |
206 | return fls(l); | |
207 | return fls64(l); | |
208 | } | |
209 | ||
252e5c6e | 210 | static inline int get_count_order(unsigned int count) |
211 | { | |
004fba1a WY |
212 | if (count == 0) |
213 | return -1; | |
252e5c6e | 214 | |
004fba1a | 215 | return fls(--count); |
252e5c6e | 216 | } |
217 | ||
218 | /** | |
219 | * get_count_order_long - get order after rounding @l up to power of 2 | |
220 | * @l: parameter | |
221 | * | |
222 | * it is same as get_count_order() but with long type parameter | |
223 | */ | |
224 | static inline int get_count_order_long(unsigned long l) | |
225 | { | |
226 | if (l == 0UL) | |
227 | return -1; | |
a9eb6370 | 228 | return (int)fls_long(--l); |
252e5c6e | 229 | } |
230 | ||
952043ac SW |
231 | /** |
232 | * __ffs64 - find first set bit in a 64 bit word | |
233 | * @word: The 64 bit word | |
234 | * | |
4945cca2 | 235 | * On 64 bit arches this is a synonym for __ffs |
952043ac SW |
236 | * The result is not defined if no bits are set, so check that @word |
237 | * is non-zero before calling this. | |
238 | */ | |
239 | static inline unsigned long __ffs64(u64 word) | |
240 | { | |
241 | #if BITS_PER_LONG == 32 | |
242 | if (((u32)word) == 0UL) | |
243 | return __ffs((u32)(word >> 32)) + 32; | |
244 | #elif BITS_PER_LONG != 64 | |
245 | #error BITS_PER_LONG not 32 or 64 | |
246 | #endif | |
247 | return __ffs((unsigned long)word); | |
248 | } | |
249 | ||
3cea8d47 YN |
250 | /** |
251 | * fns - find N'th set bit in a word | |
252 | * @word: The word to search | |
253 | * @n: Bit to find | |
254 | */ | |
255 | static inline unsigned long fns(unsigned long word, unsigned int n) | |
256 | { | |
257 | unsigned int bit; | |
258 | ||
259 | while (word) { | |
260 | bit = __ffs(word); | |
261 | if (n-- == 0) | |
262 | return bit; | |
263 | __clear_bit(bit, &word); | |
264 | } | |
265 | ||
266 | return BITS_PER_LONG; | |
267 | } | |
268 | ||
5307e2ad LW |
269 | /** |
270 | * assign_bit - Assign value to a bit in memory | |
271 | * @nr: the bit to set | |
272 | * @addr: the address to start counting from | |
273 | * @value: the value to assign | |
274 | */ | |
275 | static __always_inline void assign_bit(long nr, volatile unsigned long *addr, | |
276 | bool value) | |
277 | { | |
278 | if (value) | |
279 | set_bit(nr, addr); | |
280 | else | |
281 | clear_bit(nr, addr); | |
282 | } | |
283 | ||
284 | static __always_inline void __assign_bit(long nr, volatile unsigned long *addr, | |
285 | bool value) | |
286 | { | |
287 | if (value) | |
288 | __set_bit(nr, addr); | |
289 | else | |
290 | __clear_bit(nr, addr); | |
291 | } | |
292 | ||
cb0f8003 KKD |
293 | /** |
294 | * __ptr_set_bit - Set bit in a pointer's value | |
295 | * @nr: the bit to set | |
296 | * @addr: the address of the pointer variable | |
297 | * | |
298 | * Example: | |
299 | * void *p = foo(); | |
300 | * __ptr_set_bit(bit, &p); | |
301 | */ | |
302 | #define __ptr_set_bit(nr, addr) \ | |
303 | ({ \ | |
304 | typecheck_pointer(*(addr)); \ | |
305 | __set_bit(nr, (unsigned long *)(addr)); \ | |
306 | }) | |
307 | ||
308 | /** | |
309 | * __ptr_clear_bit - Clear bit in a pointer's value | |
310 | * @nr: the bit to clear | |
311 | * @addr: the address of the pointer variable | |
312 | * | |
313 | * Example: | |
314 | * void *p = foo(); | |
315 | * __ptr_clear_bit(bit, &p); | |
316 | */ | |
317 | #define __ptr_clear_bit(nr, addr) \ | |
318 | ({ \ | |
319 | typecheck_pointer(*(addr)); \ | |
320 | __clear_bit(nr, (unsigned long *)(addr)); \ | |
321 | }) | |
322 | ||
323 | /** | |
324 | * __ptr_test_bit - Test bit in a pointer's value | |
325 | * @nr: the bit to test | |
326 | * @addr: the address of the pointer variable | |
327 | * | |
328 | * Example: | |
329 | * void *p = foo(); | |
330 | * if (__ptr_test_bit(bit, &p)) { | |
331 | * ... | |
332 | * } else { | |
333 | * ... | |
334 | * } | |
335 | */ | |
336 | #define __ptr_test_bit(nr, addr) \ | |
337 | ({ \ | |
338 | typecheck_pointer(*(addr)); \ | |
339 | test_bit(nr, (unsigned long *)(addr)); \ | |
340 | }) | |
341 | ||
64970b68 | 342 | #ifdef __KERNEL__ |
77b9bd9c | 343 | |
00a1a053 | 344 | #ifndef set_mask_bits |
18127429 | 345 | #define set_mask_bits(ptr, mask, bits) \ |
00a1a053 | 346 | ({ \ |
18127429 MS |
347 | const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \ |
348 | typeof(*(ptr)) old__, new__; \ | |
00a1a053 | 349 | \ |
e1d7c760 | 350 | old__ = READ_ONCE(*(ptr)); \ |
00a1a053 | 351 | do { \ |
18127429 | 352 | new__ = (old__ & ~mask__) | bits__; \ |
e1d7c760 | 353 | } while (!try_cmpxchg(ptr, &old__, new__)); \ |
00a1a053 | 354 | \ |
1db604f6 | 355 | old__; \ |
00a1a053 TT |
356 | }) |
357 | #endif | |
358 | ||
85ad1d13 | 359 | #ifndef bit_clear_unless |
edfa8728 | 360 | #define bit_clear_unless(ptr, clear, test) \ |
85ad1d13 | 361 | ({ \ |
edfa8728 MS |
362 | const typeof(*(ptr)) clear__ = (clear), test__ = (test);\ |
363 | typeof(*(ptr)) old__, new__; \ | |
85ad1d13 | 364 | \ |
e1d7c760 | 365 | old__ = READ_ONCE(*(ptr)); \ |
85ad1d13 | 366 | do { \ |
e1d7c760 UB |
367 | if (old__ & test__) \ |
368 | break; \ | |
edfa8728 | 369 | new__ = old__ & ~clear__; \ |
e1d7c760 | 370 | } while (!try_cmpxchg(ptr, &old__, new__)); \ |
85ad1d13 | 371 | \ |
edfa8728 | 372 | !(old__ & test__); \ |
85ad1d13 GJ |
373 | }) |
374 | #endif | |
375 | ||
64970b68 | 376 | #endif /* __KERNEL__ */ |
1da177e4 | 377 | #endif |