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