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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef _LINUX_BITOPS_H3#define _LINUX_BITOPS_H4 5#include <asm/types.h>6#include <linux/bits.h>7#include <linux/typecheck.h>8 9#include <uapi/linux/kernel.h>10 11#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)12#define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))13#define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))14#define BITS_TO_U32(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))15#define BITS_TO_BYTES(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))16 17#define BYTES_TO_BITS(nb) ((nb) * BITS_PER_BYTE)18 19extern unsigned int __sw_hweight8(unsigned int w);20extern unsigned int __sw_hweight16(unsigned int w);21extern unsigned int __sw_hweight32(unsigned int w);22extern unsigned long __sw_hweight64(__u64 w);23 24/*25 * Defined here because those may be needed by architecture-specific static26 * inlines.27 */28 29#include <asm-generic/bitops/generic-non-atomic.h>30 31/*32 * Many architecture-specific non-atomic bitops contain inline asm code and due33 * to that the compiler can't optimize them to compile-time expressions or34 * constants. In contrary, generic_*() helpers are defined in pure C and35 * compilers optimize them just well.36 * Therefore, to make `unsigned long foo = 0; __set_bit(BAR, &foo)` effectively37 * equal to `unsigned long foo = BIT(BAR)`, pick the generic C alternative when38 * the arguments can be resolved at compile time. That expression itself is a39 * constant and doesn't bring any functional changes to the rest of cases.40 * The casts to `uintptr_t` are needed to mitigate `-Waddress` warnings when41 * passing a bitmap from .bss or .data (-> `!!addr` is always true).42 */43#define bitop(op, nr, addr) \44 ((__builtin_constant_p(nr) && \45 __builtin_constant_p((uintptr_t)(addr) != (uintptr_t)NULL) && \46 (uintptr_t)(addr) != (uintptr_t)NULL && \47 __builtin_constant_p(*(const unsigned long *)(addr))) ? \48 const##op(nr, addr) : op(nr, addr))49 50/*51 * The following macros are non-atomic versions of their non-underscored52 * counterparts.53 */54#define __set_bit(nr, addr) bitop(___set_bit, nr, addr)55#define __clear_bit(nr, addr) bitop(___clear_bit, nr, addr)56#define __change_bit(nr, addr) bitop(___change_bit, nr, addr)57#define __test_and_set_bit(nr, addr) bitop(___test_and_set_bit, nr, addr)58#define __test_and_clear_bit(nr, addr) bitop(___test_and_clear_bit, nr, addr)59#define __test_and_change_bit(nr, addr) bitop(___test_and_change_bit, nr, addr)60 61#define test_bit(nr, addr) bitop(_test_bit, nr, addr)62#define test_bit_acquire(nr, addr) bitop(_test_bit_acquire, nr, addr)63 64/*65 * Include this here because some architectures need generic_ffs/fls in66 * scope67 */68#include <asm/bitops.h>69 70/* Check that the bitops prototypes are sane */71#define __check_bitop_pr(name) \72 static_assert(__same_type(arch_##name, generic_##name) && \73 __same_type(const_##name, generic_##name) && \74 __same_type(_##name, generic_##name))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__check_bitop_pr(test_bit_acquire);84 85#undef __check_bitop_pr86 87static inline int get_bitmask_order(unsigned int count)88{89 int order;90 91 order = fls(count);92 return order; /* We could be slightly more clever with -1 here... */93}94 95static __always_inline unsigned long hweight_long(unsigned long w)96{97 return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);98}99 100/**101 * rol64 - rotate a 64-bit value left102 * @word: value to rotate103 * @shift: bits to roll104 */105static inline __u64 rol64(__u64 word, unsigned int shift)106{107 return (word << (shift & 63)) | (word >> ((-shift) & 63));108}109 110/**111 * ror64 - rotate a 64-bit value right112 * @word: value to rotate113 * @shift: bits to roll114 */115static inline __u64 ror64(__u64 word, unsigned int shift)116{117 return (word >> (shift & 63)) | (word << ((-shift) & 63));118}119 120/**121 * rol32 - rotate a 32-bit value left122 * @word: value to rotate123 * @shift: bits to roll124 */125static inline __u32 rol32(__u32 word, unsigned int shift)126{127 return (word << (shift & 31)) | (word >> ((-shift) & 31));128}129 130/**131 * ror32 - rotate a 32-bit value right132 * @word: value to rotate133 * @shift: bits to roll134 */135static inline __u32 ror32(__u32 word, unsigned int shift)136{137 return (word >> (shift & 31)) | (word << ((-shift) & 31));138}139 140/**141 * rol16 - rotate a 16-bit value left142 * @word: value to rotate143 * @shift: bits to roll144 */145static inline __u16 rol16(__u16 word, unsigned int shift)146{147 return (word << (shift & 15)) | (word >> ((-shift) & 15));148}149 150/**151 * ror16 - rotate a 16-bit value right152 * @word: value to rotate153 * @shift: bits to roll154 */155static inline __u16 ror16(__u16 word, unsigned int shift)156{157 return (word >> (shift & 15)) | (word << ((-shift) & 15));158}159 160/**161 * rol8 - rotate an 8-bit value left162 * @word: value to rotate163 * @shift: bits to roll164 */165static inline __u8 rol8(__u8 word, unsigned int shift)166{167 return (word << (shift & 7)) | (word >> ((-shift) & 7));168}169 170/**171 * ror8 - rotate an 8-bit value right172 * @word: value to rotate173 * @shift: bits to roll174 */175static inline __u8 ror8(__u8 word, unsigned int shift)176{177 return (word >> (shift & 7)) | (word << ((-shift) & 7));178}179 180/**181 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit182 * @value: value to sign extend183 * @index: 0 based bit index (0<=index<32) to sign bit184 *185 * This is safe to use for 16- and 8-bit types as well.186 */187static __always_inline __s32 sign_extend32(__u32 value, int index)188{189 __u8 shift = 31 - index;190 return (__s32)(value << shift) >> shift;191}192 193/**194 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit195 * @value: value to sign extend196 * @index: 0 based bit index (0<=index<64) to sign bit197 */198static __always_inline __s64 sign_extend64(__u64 value, int index)199{200 __u8 shift = 63 - index;201 return (__s64)(value << shift) >> shift;202}203 204static inline unsigned int fls_long(unsigned long l)205{206 if (sizeof(l) == 4)207 return fls(l);208 return fls64(l);209}210 211static inline int get_count_order(unsigned int count)212{213 if (count == 0)214 return -1;215 216 return fls(--count);217}218 219/**220 * get_count_order_long - get order after rounding @l up to power of 2221 * @l: parameter222 *223 * it is same as get_count_order() but with long type parameter224 */225static inline int get_count_order_long(unsigned long l)226{227 if (l == 0UL)228 return -1;229 return (int)fls_long(--l);230}231 232/**233 * __ffs64 - find first set bit in a 64 bit word234 * @word: The 64 bit word235 *236 * On 64 bit arches this is a synonym for __ffs237 * The result is not defined if no bits are set, so check that @word238 * is non-zero before calling this.239 */240static inline unsigned int __ffs64(u64 word)241{242#if BITS_PER_LONG == 32243 if (((u32)word) == 0UL)244 return __ffs((u32)(word >> 32)) + 32;245#elif BITS_PER_LONG != 64246#error BITS_PER_LONG not 32 or 64247#endif248 return __ffs((unsigned long)word);249}250 251/**252 * fns - find N'th set bit in a word253 * @word: The word to search254 * @n: Bit to find255 */256static inline unsigned int fns(unsigned long word, unsigned int n)257{258 while (word && n--)259 word &= word - 1;260 261 return word ? __ffs(word) : BITS_PER_LONG;262}263 264/**265 * assign_bit - Assign value to a bit in memory266 * @nr: the bit to set267 * @addr: the address to start counting from268 * @value: the value to assign269 */270#define assign_bit(nr, addr, value) \271 ((value) ? set_bit((nr), (addr)) : clear_bit((nr), (addr)))272 273#define __assign_bit(nr, addr, value) \274 ((value) ? __set_bit((nr), (addr)) : __clear_bit((nr), (addr)))275 276/**277 * __ptr_set_bit - Set bit in a pointer's value278 * @nr: the bit to set279 * @addr: the address of the pointer variable280 *281 * Example:282 * void *p = foo();283 * __ptr_set_bit(bit, &p);284 */285#define __ptr_set_bit(nr, addr) \286 ({ \287 typecheck_pointer(*(addr)); \288 __set_bit(nr, (unsigned long *)(addr)); \289 })290 291/**292 * __ptr_clear_bit - Clear bit in a pointer's value293 * @nr: the bit to clear294 * @addr: the address of the pointer variable295 *296 * Example:297 * void *p = foo();298 * __ptr_clear_bit(bit, &p);299 */300#define __ptr_clear_bit(nr, addr) \301 ({ \302 typecheck_pointer(*(addr)); \303 __clear_bit(nr, (unsigned long *)(addr)); \304 })305 306/**307 * __ptr_test_bit - Test bit in a pointer's value308 * @nr: the bit to test309 * @addr: the address of the pointer variable310 *311 * Example:312 * void *p = foo();313 * if (__ptr_test_bit(bit, &p)) {314 * ...315 * } else {316 * ...317 * }318 */319#define __ptr_test_bit(nr, addr) \320 ({ \321 typecheck_pointer(*(addr)); \322 test_bit(nr, (unsigned long *)(addr)); \323 })324 325#ifdef __KERNEL__326 327#ifndef set_mask_bits328#define set_mask_bits(ptr, mask, bits) \329({ \330 const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \331 typeof(*(ptr)) old__, new__; \332 \333 old__ = READ_ONCE(*(ptr)); \334 do { \335 new__ = (old__ & ~mask__) | bits__; \336 } while (!try_cmpxchg(ptr, &old__, new__)); \337 \338 old__; \339})340#endif341 342#ifndef bit_clear_unless343#define bit_clear_unless(ptr, clear, test) \344({ \345 const typeof(*(ptr)) clear__ = (clear), test__ = (test);\346 typeof(*(ptr)) old__, new__; \347 \348 old__ = READ_ONCE(*(ptr)); \349 do { \350 if (old__ & test__) \351 break; \352 new__ = old__ & ~clear__; \353 } while (!try_cmpxchg(ptr, &old__, new__)); \354 \355 !(old__ & test__); \356})357#endif358 359#endif /* __KERNEL__ */360#endif361