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