1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_BITOPS_H 3 #define _LINUX_BITOPS_H 4 #include <asm/types.h> 5 #include <linux/bits.h> 6 7 /* Set bits in the first 'n' bytes when loaded from memory */ 8 #ifdef __LITTLE_ENDIAN 9 # define aligned_byte_mask(n) ((1UL << 8*(n))-1) 10 #else 11 # define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n))) 12 #endif 13 14 #define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE) 15 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(long)) 16 #define BITS_TO_U64(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(u64)) 17 #define BITS_TO_U32(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(u32)) 18 #define BITS_TO_BYTES(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(char)) 19 20 extern unsigned int __sw_hweight8(unsigned int w); 21 extern unsigned int __sw_hweight16(unsigned int w); 22 extern unsigned int __sw_hweight32(unsigned int w); 23 extern unsigned long __sw_hweight64(__u64 w); 24 25 /* 26 * Include this here because some architectures need generic_ffs/fls in 27 * scope 28 */ 29 #include <asm/bitops.h> 30 31 #define for_each_set_bit(bit, addr, size) \ 32 for ((bit) = find_first_bit((addr), (size)); \ 33 (bit) < (size); \ 34 (bit) = find_next_bit((addr), (size), (bit) + 1)) 35 36 /* same as for_each_set_bit() but use bit as value to start with */ 37 #define for_each_set_bit_from(bit, addr, size) \ 38 for ((bit) = find_next_bit((addr), (size), (bit)); \ 39 (bit) < (size); \ 40 (bit) = find_next_bit((addr), (size), (bit) + 1)) 41 42 #define for_each_clear_bit(bit, addr, size) \ 43 for ((bit) = find_first_zero_bit((addr), (size)); \ 44 (bit) < (size); \ 45 (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) 46 47 /* same as for_each_clear_bit() but use bit as value to start with */ 48 #define for_each_clear_bit_from(bit, addr, size) \ 49 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \ 50 (bit) < (size); \ 51 (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) 52 53 /** 54 * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits 55 * @start: bit offset to start search and to store the current iteration offset 56 * @clump: location to store copy of current 8-bit clump 57 * @bits: bitmap address to base the search on 58 * @size: bitmap size in number of bits 59 */ 60 #define for_each_set_clump8(start, clump, bits, size) \ 61 for ((start) = find_first_clump8(&(clump), (bits), (size)); \ 62 (start) < (size); \ 63 (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8)) 64 65 static inline int get_bitmask_order(unsigned int count) 66 { 67 int order; 68 69 order = fls(count); 70 return order; /* We could be slightly more clever with -1 here... */ 71 } 72 73 static __always_inline unsigned long hweight_long(unsigned long w) 74 { 75 return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w); 76 } 77 78 /** 79 * rol64 - rotate a 64-bit value left 80 * @word: value to rotate 81 * @shift: bits to roll 82 */ 83 static inline __u64 rol64(__u64 word, unsigned int shift) 84 { 85 return (word << (shift & 63)) | (word >> ((-shift) & 63)); 86 } 87 88 /** 89 * ror64 - rotate a 64-bit value right 90 * @word: value to rotate 91 * @shift: bits to roll 92 */ 93 static inline __u64 ror64(__u64 word, unsigned int shift) 94 { 95 return (word >> (shift & 63)) | (word << ((-shift) & 63)); 96 } 97 98 /** 99 * rol32 - rotate a 32-bit value left 100 * @word: value to rotate 101 * @shift: bits to roll 102 */ 103 static inline __u32 rol32(__u32 word, unsigned int shift) 104 { 105 return (word << (shift & 31)) | (word >> ((-shift) & 31)); 106 } 107 108 /** 109 * ror32 - rotate a 32-bit value right 110 * @word: value to rotate 111 * @shift: bits to roll 112 */ 113 static inline __u32 ror32(__u32 word, unsigned int shift) 114 { 115 return (word >> (shift & 31)) | (word << ((-shift) & 31)); 116 } 117 118 /** 119 * rol16 - rotate a 16-bit value left 120 * @word: value to rotate 121 * @shift: bits to roll 122 */ 123 static inline __u16 rol16(__u16 word, unsigned int shift) 124 { 125 return (word << (shift & 15)) | (word >> ((-shift) & 15)); 126 } 127 128 /** 129 * ror16 - rotate a 16-bit value right 130 * @word: value to rotate 131 * @shift: bits to roll 132 */ 133 static inline __u16 ror16(__u16 word, unsigned int shift) 134 { 135 return (word >> (shift & 15)) | (word << ((-shift) & 15)); 136 } 137 138 /** 139 * rol8 - rotate an 8-bit value left 140 * @word: value to rotate 141 * @shift: bits to roll 142 */ 143 static inline __u8 rol8(__u8 word, unsigned int shift) 144 { 145 return (word << (shift & 7)) | (word >> ((-shift) & 7)); 146 } 147 148 /** 149 * ror8 - rotate an 8-bit value right 150 * @word: value to rotate 151 * @shift: bits to roll 152 */ 153 static inline __u8 ror8(__u8 word, unsigned int shift) 154 { 155 return (word >> (shift & 7)) | (word << ((-shift) & 7)); 156 } 157 158 /** 159 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit 160 * @value: value to sign extend 161 * @index: 0 based bit index (0<=index<32) to sign bit 162 * 163 * This is safe to use for 16- and 8-bit types as well. 164 */ 165 static __always_inline __s32 sign_extend32(__u32 value, int index) 166 { 167 __u8 shift = 31 - index; 168 return (__s32)(value << shift) >> shift; 169 } 170 171 /** 172 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit 173 * @value: value to sign extend 174 * @index: 0 based bit index (0<=index<64) to sign bit 175 */ 176 static __always_inline __s64 sign_extend64(__u64 value, int index) 177 { 178 __u8 shift = 63 - index; 179 return (__s64)(value << shift) >> shift; 180 } 181 182 static inline unsigned fls_long(unsigned long l) 183 { 184 if (sizeof(l) == 4) 185 return fls(l); 186 return fls64(l); 187 } 188 189 static inline int get_count_order(unsigned int count) 190 { 191 int order; 192 193 order = fls(count) - 1; 194 if (count & (count - 1)) 195 order++; 196 return order; 197 } 198 199 /** 200 * get_count_order_long - get order after rounding @l up to power of 2 201 * @l: parameter 202 * 203 * it is same as get_count_order() but with long type parameter 204 */ 205 static inline int get_count_order_long(unsigned long l) 206 { 207 if (l == 0UL) 208 return -1; 209 return (int)fls_long(--l); 210 } 211 212 /** 213 * __ffs64 - find first set bit in a 64 bit word 214 * @word: The 64 bit word 215 * 216 * On 64 bit arches this is a synomyn for __ffs 217 * The result is not defined if no bits are set, so check that @word 218 * is non-zero before calling this. 219 */ 220 static inline unsigned long __ffs64(u64 word) 221 { 222 #if BITS_PER_LONG == 32 223 if (((u32)word) == 0UL) 224 return __ffs((u32)(word >> 32)) + 32; 225 #elif BITS_PER_LONG != 64 226 #error BITS_PER_LONG not 32 or 64 227 #endif 228 return __ffs((unsigned long)word); 229 } 230 231 /** 232 * assign_bit - Assign value to a bit in memory 233 * @nr: the bit to set 234 * @addr: the address to start counting from 235 * @value: the value to assign 236 */ 237 static __always_inline void assign_bit(long nr, volatile unsigned long *addr, 238 bool value) 239 { 240 if (value) 241 set_bit(nr, addr); 242 else 243 clear_bit(nr, addr); 244 } 245 246 static __always_inline void __assign_bit(long nr, volatile unsigned long *addr, 247 bool value) 248 { 249 if (value) 250 __set_bit(nr, addr); 251 else 252 __clear_bit(nr, addr); 253 } 254 255 #ifdef __KERNEL__ 256 257 #ifndef set_mask_bits 258 #define set_mask_bits(ptr, mask, bits) \ 259 ({ \ 260 const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \ 261 typeof(*(ptr)) old__, new__; \ 262 \ 263 do { \ 264 old__ = READ_ONCE(*(ptr)); \ 265 new__ = (old__ & ~mask__) | bits__; \ 266 } while (cmpxchg(ptr, old__, new__) != old__); \ 267 \ 268 old__; \ 269 }) 270 #endif 271 272 #ifndef bit_clear_unless 273 #define bit_clear_unless(ptr, clear, test) \ 274 ({ \ 275 const typeof(*(ptr)) clear__ = (clear), test__ = (test);\ 276 typeof(*(ptr)) old__, new__; \ 277 \ 278 do { \ 279 old__ = READ_ONCE(*(ptr)); \ 280 new__ = old__ & ~clear__; \ 281 } while (!(old__ & test__) && \ 282 cmpxchg(ptr, old__, new__) != old__); \ 283 \ 284 !(old__ & test__); \ 285 }) 286 #endif 287 288 #ifndef find_last_bit 289 /** 290 * find_last_bit - find the last set bit in a memory region 291 * @addr: The address to start the search at 292 * @size: The number of bits to search 293 * 294 * Returns the bit number of the last set bit, or size. 295 */ 296 extern unsigned long find_last_bit(const unsigned long *addr, 297 unsigned long size); 298 #endif 299 300 #endif /* __KERNEL__ */ 301 #endif 302