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 * Defined here because those may be needed by architecture-specific static 31 * inlines. 32 */ 33 34 #include <asm-generic/bitops/generic-non-atomic.h> 35 36 #define bitop(op, nr, addr) \ 37 op(nr, addr) 38 39 #define __set_bit(nr, addr) bitop(___set_bit, nr, addr) 40 #define __clear_bit(nr, addr) bitop(___clear_bit, nr, addr) 41 #define __change_bit(nr, addr) bitop(___change_bit, nr, addr) 42 #define __test_and_set_bit(nr, addr) bitop(___test_and_set_bit, nr, addr) 43 #define __test_and_clear_bit(nr, addr) bitop(___test_and_clear_bit, nr, addr) 44 #define __test_and_change_bit(nr, addr) bitop(___test_and_change_bit, nr, addr) 45 #define test_bit(nr, addr) bitop(_test_bit, nr, addr) 46 47 /* 48 * Include this here because some architectures need generic_ffs/fls in 49 * scope 50 */ 51 #include <asm/bitops.h> 52 53 /* Check that the bitops prototypes are sane */ 54 #define __check_bitop_pr(name) \ 55 static_assert(__same_type(arch_##name, generic_##name) && \ 56 __same_type(const_##name, generic_##name) && \ 57 __same_type(_##name, generic_##name)) 58 59 __check_bitop_pr(__set_bit); 60 __check_bitop_pr(__clear_bit); 61 __check_bitop_pr(__change_bit); 62 __check_bitop_pr(__test_and_set_bit); 63 __check_bitop_pr(__test_and_clear_bit); 64 __check_bitop_pr(__test_and_change_bit); 65 __check_bitop_pr(test_bit); 66 67 #undef __check_bitop_pr 68 69 static inline int get_bitmask_order(unsigned int count) 70 { 71 int order; 72 73 order = fls(count); 74 return order; /* We could be slightly more clever with -1 here... */ 75 } 76 77 static __always_inline unsigned long hweight_long(unsigned long w) 78 { 79 return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w); 80 } 81 82 /** 83 * rol64 - rotate a 64-bit value left 84 * @word: value to rotate 85 * @shift: bits to roll 86 */ 87 static inline __u64 rol64(__u64 word, unsigned int shift) 88 { 89 return (word << (shift & 63)) | (word >> ((-shift) & 63)); 90 } 91 92 /** 93 * ror64 - rotate a 64-bit value right 94 * @word: value to rotate 95 * @shift: bits to roll 96 */ 97 static inline __u64 ror64(__u64 word, unsigned int shift) 98 { 99 return (word >> (shift & 63)) | (word << ((-shift) & 63)); 100 } 101 102 /** 103 * rol32 - rotate a 32-bit value left 104 * @word: value to rotate 105 * @shift: bits to roll 106 */ 107 static inline __u32 rol32(__u32 word, unsigned int shift) 108 { 109 return (word << (shift & 31)) | (word >> ((-shift) & 31)); 110 } 111 112 /** 113 * ror32 - rotate a 32-bit value right 114 * @word: value to rotate 115 * @shift: bits to roll 116 */ 117 static inline __u32 ror32(__u32 word, unsigned int shift) 118 { 119 return (word >> (shift & 31)) | (word << ((-shift) & 31)); 120 } 121 122 /** 123 * rol16 - rotate a 16-bit value left 124 * @word: value to rotate 125 * @shift: bits to roll 126 */ 127 static inline __u16 rol16(__u16 word, unsigned int shift) 128 { 129 return (word << (shift & 15)) | (word >> ((-shift) & 15)); 130 } 131 132 /** 133 * ror16 - rotate a 16-bit value right 134 * @word: value to rotate 135 * @shift: bits to roll 136 */ 137 static inline __u16 ror16(__u16 word, unsigned int shift) 138 { 139 return (word >> (shift & 15)) | (word << ((-shift) & 15)); 140 } 141 142 /** 143 * rol8 - rotate an 8-bit value left 144 * @word: value to rotate 145 * @shift: bits to roll 146 */ 147 static inline __u8 rol8(__u8 word, unsigned int shift) 148 { 149 return (word << (shift & 7)) | (word >> ((-shift) & 7)); 150 } 151 152 /** 153 * ror8 - rotate an 8-bit value right 154 * @word: value to rotate 155 * @shift: bits to roll 156 */ 157 static inline __u8 ror8(__u8 word, unsigned int shift) 158 { 159 return (word >> (shift & 7)) | (word << ((-shift) & 7)); 160 } 161 162 /** 163 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit 164 * @value: value to sign extend 165 * @index: 0 based bit index (0<=index<32) to sign bit 166 * 167 * This is safe to use for 16- and 8-bit types as well. 168 */ 169 static __always_inline __s32 sign_extend32(__u32 value, int index) 170 { 171 __u8 shift = 31 - index; 172 return (__s32)(value << shift) >> shift; 173 } 174 175 /** 176 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit 177 * @value: value to sign extend 178 * @index: 0 based bit index (0<=index<64) to sign bit 179 */ 180 static __always_inline __s64 sign_extend64(__u64 value, int index) 181 { 182 __u8 shift = 63 - index; 183 return (__s64)(value << shift) >> shift; 184 } 185 186 static inline unsigned fls_long(unsigned long l) 187 { 188 if (sizeof(l) == 4) 189 return fls(l); 190 return fls64(l); 191 } 192 193 static inline int get_count_order(unsigned int count) 194 { 195 if (count == 0) 196 return -1; 197 198 return fls(--count); 199 } 200 201 /** 202 * get_count_order_long - get order after rounding @l up to power of 2 203 * @l: parameter 204 * 205 * it is same as get_count_order() but with long type parameter 206 */ 207 static inline int get_count_order_long(unsigned long l) 208 { 209 if (l == 0UL) 210 return -1; 211 return (int)fls_long(--l); 212 } 213 214 /** 215 * __ffs64 - find first set bit in a 64 bit word 216 * @word: The 64 bit word 217 * 218 * On 64 bit arches this is a synonym for __ffs 219 * The result is not defined if no bits are set, so check that @word 220 * is non-zero before calling this. 221 */ 222 static inline unsigned long __ffs64(u64 word) 223 { 224 #if BITS_PER_LONG == 32 225 if (((u32)word) == 0UL) 226 return __ffs((u32)(word >> 32)) + 32; 227 #elif BITS_PER_LONG != 64 228 #error BITS_PER_LONG not 32 or 64 229 #endif 230 return __ffs((unsigned long)word); 231 } 232 233 /** 234 * assign_bit - Assign value to a bit in memory 235 * @nr: the bit to set 236 * @addr: the address to start counting from 237 * @value: the value to assign 238 */ 239 static __always_inline void assign_bit(long nr, volatile unsigned long *addr, 240 bool value) 241 { 242 if (value) 243 set_bit(nr, addr); 244 else 245 clear_bit(nr, addr); 246 } 247 248 static __always_inline void __assign_bit(long nr, volatile unsigned long *addr, 249 bool value) 250 { 251 if (value) 252 __set_bit(nr, addr); 253 else 254 __clear_bit(nr, addr); 255 } 256 257 /** 258 * __ptr_set_bit - Set bit in a pointer's value 259 * @nr: the bit to set 260 * @addr: the address of the pointer variable 261 * 262 * Example: 263 * void *p = foo(); 264 * __ptr_set_bit(bit, &p); 265 */ 266 #define __ptr_set_bit(nr, addr) \ 267 ({ \ 268 typecheck_pointer(*(addr)); \ 269 __set_bit(nr, (unsigned long *)(addr)); \ 270 }) 271 272 /** 273 * __ptr_clear_bit - Clear bit in a pointer's value 274 * @nr: the bit to clear 275 * @addr: the address of the pointer variable 276 * 277 * Example: 278 * void *p = foo(); 279 * __ptr_clear_bit(bit, &p); 280 */ 281 #define __ptr_clear_bit(nr, addr) \ 282 ({ \ 283 typecheck_pointer(*(addr)); \ 284 __clear_bit(nr, (unsigned long *)(addr)); \ 285 }) 286 287 /** 288 * __ptr_test_bit - Test bit in a pointer's value 289 * @nr: the bit to test 290 * @addr: the address of the pointer variable 291 * 292 * Example: 293 * void *p = foo(); 294 * if (__ptr_test_bit(bit, &p)) { 295 * ... 296 * } else { 297 * ... 298 * } 299 */ 300 #define __ptr_test_bit(nr, addr) \ 301 ({ \ 302 typecheck_pointer(*(addr)); \ 303 test_bit(nr, (unsigned long *)(addr)); \ 304 }) 305 306 #ifdef __KERNEL__ 307 308 #ifndef set_mask_bits 309 #define set_mask_bits(ptr, mask, bits) \ 310 ({ \ 311 const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \ 312 typeof(*(ptr)) old__, new__; \ 313 \ 314 do { \ 315 old__ = READ_ONCE(*(ptr)); \ 316 new__ = (old__ & ~mask__) | bits__; \ 317 } while (cmpxchg(ptr, old__, new__) != old__); \ 318 \ 319 old__; \ 320 }) 321 #endif 322 323 #ifndef bit_clear_unless 324 #define bit_clear_unless(ptr, clear, test) \ 325 ({ \ 326 const typeof(*(ptr)) clear__ = (clear), test__ = (test);\ 327 typeof(*(ptr)) old__, new__; \ 328 \ 329 do { \ 330 old__ = READ_ONCE(*(ptr)); \ 331 new__ = old__ & ~clear__; \ 332 } while (!(old__ & test__) && \ 333 cmpxchg(ptr, old__, new__) != old__); \ 334 \ 335 !(old__ & test__); \ 336 }) 337 #endif 338 339 #endif /* __KERNEL__ */ 340 #endif 341