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 17 extern unsigned int __sw_hweight8(unsigned int w); 18 extern unsigned int __sw_hweight16(unsigned int w); 19 extern unsigned int __sw_hweight32(unsigned int w); 20 extern unsigned long __sw_hweight64(__u64 w); 21 22 /* 23 * Include this here because some architectures need generic_ffs/fls in 24 * scope 25 */ 26 #include <asm/bitops.h> 27 28 #define for_each_set_bit(bit, addr, size) \ 29 for ((bit) = find_first_bit((addr), (size)); \ 30 (bit) < (size); \ 31 (bit) = find_next_bit((addr), (size), (bit) + 1)) 32 33 /* same as for_each_set_bit() but use bit as value to start with */ 34 #define for_each_set_bit_from(bit, addr, size) \ 35 for ((bit) = find_next_bit((addr), (size), (bit)); \ 36 (bit) < (size); \ 37 (bit) = find_next_bit((addr), (size), (bit) + 1)) 38 39 #define for_each_clear_bit(bit, addr, size) \ 40 for ((bit) = find_first_zero_bit((addr), (size)); \ 41 (bit) < (size); \ 42 (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) 43 44 /* same as for_each_clear_bit() but use bit as value to start with */ 45 #define for_each_clear_bit_from(bit, addr, size) \ 46 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \ 47 (bit) < (size); \ 48 (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) 49 50 /** 51 * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits 52 * @start: bit offset to start search and to store the current iteration offset 53 * @clump: location to store copy of current 8-bit clump 54 * @bits: bitmap address to base the search on 55 * @size: bitmap size in number of bits 56 */ 57 #define for_each_set_clump8(start, clump, bits, size) \ 58 for ((start) = find_first_clump8(&(clump), (bits), (size)); \ 59 (start) < (size); \ 60 (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8)) 61 62 static inline int get_bitmask_order(unsigned int count) 63 { 64 int order; 65 66 order = fls(count); 67 return order; /* We could be slightly more clever with -1 here... */ 68 } 69 70 static __always_inline unsigned long hweight_long(unsigned long w) 71 { 72 return sizeof(w) == 4 ? hweight32(w) : hweight64(w); 73 } 74 75 /** 76 * rol64 - rotate a 64-bit value left 77 * @word: value to rotate 78 * @shift: bits to roll 79 */ 80 static inline __u64 rol64(__u64 word, unsigned int shift) 81 { 82 return (word << (shift & 63)) | (word >> ((-shift) & 63)); 83 } 84 85 /** 86 * ror64 - rotate a 64-bit value right 87 * @word: value to rotate 88 * @shift: bits to roll 89 */ 90 static inline __u64 ror64(__u64 word, unsigned int shift) 91 { 92 return (word >> (shift & 63)) | (word << ((-shift) & 63)); 93 } 94 95 /** 96 * rol32 - rotate a 32-bit value left 97 * @word: value to rotate 98 * @shift: bits to roll 99 */ 100 static inline __u32 rol32(__u32 word, unsigned int shift) 101 { 102 return (word << (shift & 31)) | (word >> ((-shift) & 31)); 103 } 104 105 /** 106 * ror32 - rotate a 32-bit value right 107 * @word: value to rotate 108 * @shift: bits to roll 109 */ 110 static inline __u32 ror32(__u32 word, unsigned int shift) 111 { 112 return (word >> (shift & 31)) | (word << ((-shift) & 31)); 113 } 114 115 /** 116 * rol16 - rotate a 16-bit value left 117 * @word: value to rotate 118 * @shift: bits to roll 119 */ 120 static inline __u16 rol16(__u16 word, unsigned int shift) 121 { 122 return (word << (shift & 15)) | (word >> ((-shift) & 15)); 123 } 124 125 /** 126 * ror16 - rotate a 16-bit value right 127 * @word: value to rotate 128 * @shift: bits to roll 129 */ 130 static inline __u16 ror16(__u16 word, unsigned int shift) 131 { 132 return (word >> (shift & 15)) | (word << ((-shift) & 15)); 133 } 134 135 /** 136 * rol8 - rotate an 8-bit value left 137 * @word: value to rotate 138 * @shift: bits to roll 139 */ 140 static inline __u8 rol8(__u8 word, unsigned int shift) 141 { 142 return (word << (shift & 7)) | (word >> ((-shift) & 7)); 143 } 144 145 /** 146 * ror8 - rotate an 8-bit value right 147 * @word: value to rotate 148 * @shift: bits to roll 149 */ 150 static inline __u8 ror8(__u8 word, unsigned int shift) 151 { 152 return (word >> (shift & 7)) | (word << ((-shift) & 7)); 153 } 154 155 /** 156 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit 157 * @value: value to sign extend 158 * @index: 0 based bit index (0<=index<32) to sign bit 159 * 160 * This is safe to use for 16- and 8-bit types as well. 161 */ 162 static inline __s32 sign_extend32(__u32 value, int index) 163 { 164 __u8 shift = 31 - index; 165 return (__s32)(value << shift) >> shift; 166 } 167 168 /** 169 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit 170 * @value: value to sign extend 171 * @index: 0 based bit index (0<=index<64) to sign bit 172 */ 173 static inline __s64 sign_extend64(__u64 value, int index) 174 { 175 __u8 shift = 63 - index; 176 return (__s64)(value << shift) >> shift; 177 } 178 179 static inline unsigned fls_long(unsigned long l) 180 { 181 if (sizeof(l) == 4) 182 return fls(l); 183 return fls64(l); 184 } 185 186 static inline int get_count_order(unsigned int count) 187 { 188 int order; 189 190 order = fls(count) - 1; 191 if (count & (count - 1)) 192 order++; 193 return order; 194 } 195 196 /** 197 * get_count_order_long - get order after rounding @l up to power of 2 198 * @l: parameter 199 * 200 * it is same as get_count_order() but with long type parameter 201 */ 202 static inline int get_count_order_long(unsigned long l) 203 { 204 if (l == 0UL) 205 return -1; 206 else if (l & (l - 1UL)) 207 return (int)fls_long(l); 208 else 209 return (int)fls_long(l) - 1; 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