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