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 #include <asm-generic/bitops/generic-non-atomic.h> 30 31 /* 32 * Include this here because some architectures need generic_ffs/fls in 33 * scope 34 */ 35 #include <asm/bitops.h> 36 37 /* Check that the bitops prototypes are sane */ 38 #define __check_bitop_pr(name) \ 39 static_assert(__same_type(arch_##name, generic_##name) && \ 40 __same_type(const_##name, generic_##name) && \ 41 __same_type(name, generic_##name)) 42 43 __check_bitop_pr(__set_bit); 44 __check_bitop_pr(__clear_bit); 45 __check_bitop_pr(__change_bit); 46 __check_bitop_pr(__test_and_set_bit); 47 __check_bitop_pr(__test_and_clear_bit); 48 __check_bitop_pr(__test_and_change_bit); 49 __check_bitop_pr(test_bit); 50 51 #undef __check_bitop_pr 52 53 static inline int get_bitmask_order(unsigned int count) 54 { 55 int order; 56 57 order = fls(count); 58 return order; /* We could be slightly more clever with -1 here... */ 59 } 60 61 static __always_inline unsigned long hweight_long(unsigned long w) 62 { 63 return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w); 64 } 65 66 /** 67 * rol64 - rotate a 64-bit value left 68 * @word: value to rotate 69 * @shift: bits to roll 70 */ 71 static inline __u64 rol64(__u64 word, unsigned int shift) 72 { 73 return (word << (shift & 63)) | (word >> ((-shift) & 63)); 74 } 75 76 /** 77 * ror64 - rotate a 64-bit value right 78 * @word: value to rotate 79 * @shift: bits to roll 80 */ 81 static inline __u64 ror64(__u64 word, unsigned int shift) 82 { 83 return (word >> (shift & 63)) | (word << ((-shift) & 63)); 84 } 85 86 /** 87 * rol32 - rotate a 32-bit value left 88 * @word: value to rotate 89 * @shift: bits to roll 90 */ 91 static inline __u32 rol32(__u32 word, unsigned int shift) 92 { 93 return (word << (shift & 31)) | (word >> ((-shift) & 31)); 94 } 95 96 /** 97 * ror32 - rotate a 32-bit value right 98 * @word: value to rotate 99 * @shift: bits to roll 100 */ 101 static inline __u32 ror32(__u32 word, unsigned int shift) 102 { 103 return (word >> (shift & 31)) | (word << ((-shift) & 31)); 104 } 105 106 /** 107 * rol16 - rotate a 16-bit value left 108 * @word: value to rotate 109 * @shift: bits to roll 110 */ 111 static inline __u16 rol16(__u16 word, unsigned int shift) 112 { 113 return (word << (shift & 15)) | (word >> ((-shift) & 15)); 114 } 115 116 /** 117 * ror16 - rotate a 16-bit value right 118 * @word: value to rotate 119 * @shift: bits to roll 120 */ 121 static inline __u16 ror16(__u16 word, unsigned int shift) 122 { 123 return (word >> (shift & 15)) | (word << ((-shift) & 15)); 124 } 125 126 /** 127 * rol8 - rotate an 8-bit value left 128 * @word: value to rotate 129 * @shift: bits to roll 130 */ 131 static inline __u8 rol8(__u8 word, unsigned int shift) 132 { 133 return (word << (shift & 7)) | (word >> ((-shift) & 7)); 134 } 135 136 /** 137 * ror8 - rotate an 8-bit value right 138 * @word: value to rotate 139 * @shift: bits to roll 140 */ 141 static inline __u8 ror8(__u8 word, unsigned int shift) 142 { 143 return (word >> (shift & 7)) | (word << ((-shift) & 7)); 144 } 145 146 /** 147 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit 148 * @value: value to sign extend 149 * @index: 0 based bit index (0<=index<32) to sign bit 150 * 151 * This is safe to use for 16- and 8-bit types as well. 152 */ 153 static __always_inline __s32 sign_extend32(__u32 value, int index) 154 { 155 __u8 shift = 31 - index; 156 return (__s32)(value << shift) >> shift; 157 } 158 159 /** 160 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit 161 * @value: value to sign extend 162 * @index: 0 based bit index (0<=index<64) to sign bit 163 */ 164 static __always_inline __s64 sign_extend64(__u64 value, int index) 165 { 166 __u8 shift = 63 - index; 167 return (__s64)(value << shift) >> shift; 168 } 169 170 static inline unsigned fls_long(unsigned long l) 171 { 172 if (sizeof(l) == 4) 173 return fls(l); 174 return fls64(l); 175 } 176 177 static inline int get_count_order(unsigned int count) 178 { 179 if (count == 0) 180 return -1; 181 182 return fls(--count); 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 */ 191 static inline int get_count_order_long(unsigned long l) 192 { 193 if (l == 0UL) 194 return -1; 195 return (int)fls_long(--l); 196 } 197 198 /** 199 * __ffs64 - find first set bit in a 64 bit word 200 * @word: The 64 bit word 201 * 202 * On 64 bit arches this is a synonym for __ffs 203 * The result is not defined if no bits are set, so check that @word 204 * is non-zero before calling this. 205 */ 206 static inline unsigned long __ffs64(u64 word) 207 { 208 #if BITS_PER_LONG == 32 209 if (((u32)word) == 0UL) 210 return __ffs((u32)(word >> 32)) + 32; 211 #elif BITS_PER_LONG != 64 212 #error BITS_PER_LONG not 32 or 64 213 #endif 214 return __ffs((unsigned long)word); 215 } 216 217 /** 218 * assign_bit - Assign value to a bit in memory 219 * @nr: the bit to set 220 * @addr: the address to start counting from 221 * @value: the value to assign 222 */ 223 static __always_inline void assign_bit(long nr, volatile unsigned long *addr, 224 bool value) 225 { 226 if (value) 227 set_bit(nr, addr); 228 else 229 clear_bit(nr, addr); 230 } 231 232 static __always_inline void __assign_bit(long nr, volatile unsigned long *addr, 233 bool value) 234 { 235 if (value) 236 __set_bit(nr, addr); 237 else 238 __clear_bit(nr, addr); 239 } 240 241 /** 242 * __ptr_set_bit - Set bit in a pointer's value 243 * @nr: the bit to set 244 * @addr: the address of the pointer variable 245 * 246 * Example: 247 * void *p = foo(); 248 * __ptr_set_bit(bit, &p); 249 */ 250 #define __ptr_set_bit(nr, addr) \ 251 ({ \ 252 typecheck_pointer(*(addr)); \ 253 __set_bit(nr, (unsigned long *)(addr)); \ 254 }) 255 256 /** 257 * __ptr_clear_bit - Clear bit in a pointer's value 258 * @nr: the bit to clear 259 * @addr: the address of the pointer variable 260 * 261 * Example: 262 * void *p = foo(); 263 * __ptr_clear_bit(bit, &p); 264 */ 265 #define __ptr_clear_bit(nr, addr) \ 266 ({ \ 267 typecheck_pointer(*(addr)); \ 268 __clear_bit(nr, (unsigned long *)(addr)); \ 269 }) 270 271 /** 272 * __ptr_test_bit - Test bit in a pointer's value 273 * @nr: the bit to test 274 * @addr: the address of the pointer variable 275 * 276 * Example: 277 * void *p = foo(); 278 * if (__ptr_test_bit(bit, &p)) { 279 * ... 280 * } else { 281 * ... 282 * } 283 */ 284 #define __ptr_test_bit(nr, addr) \ 285 ({ \ 286 typecheck_pointer(*(addr)); \ 287 test_bit(nr, (unsigned long *)(addr)); \ 288 }) 289 290 #ifdef __KERNEL__ 291 292 #ifndef set_mask_bits 293 #define set_mask_bits(ptr, mask, bits) \ 294 ({ \ 295 const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \ 296 typeof(*(ptr)) old__, new__; \ 297 \ 298 do { \ 299 old__ = READ_ONCE(*(ptr)); \ 300 new__ = (old__ & ~mask__) | bits__; \ 301 } while (cmpxchg(ptr, old__, new__) != old__); \ 302 \ 303 old__; \ 304 }) 305 #endif 306 307 #ifndef bit_clear_unless 308 #define bit_clear_unless(ptr, clear, test) \ 309 ({ \ 310 const typeof(*(ptr)) clear__ = (clear), test__ = (test);\ 311 typeof(*(ptr)) old__, new__; \ 312 \ 313 do { \ 314 old__ = READ_ONCE(*(ptr)); \ 315 new__ = old__ & ~clear__; \ 316 } while (!(old__ & test__) && \ 317 cmpxchg(ptr, old__, new__) != old__); \ 318 \ 319 !(old__ & test__); \ 320 }) 321 #endif 322 323 #endif /* __KERNEL__ */ 324 #endif 325