1#ifndef _LINUX_MATH64_H 2#define _LINUX_MATH64_H 3 4#include <div64.h> 5#include <linux/bitops.h> 6#include <linux/types.h> 7 8#if BITS_PER_LONG == 64 9 10#define div64_long(x, y) div64_s64((x), (y)) 11#define div64_ul(x, y) div64_u64((x), (y)) 12 13/** 14 * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder 15 * 16 * This is commonly provided by 32bit archs to provide an optimized 64bit 17 * divide. 18 */ 19static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) 20{ 21 *remainder = dividend % divisor; 22 return dividend / divisor; 23} 24 25/** 26 * div_s64_rem - signed 64bit divide with 32bit divisor with remainder 27 */ 28static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder) 29{ 30 *remainder = dividend % divisor; 31 return dividend / divisor; 32} 33 34/** 35 * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder 36 */ 37static inline u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder) 38{ 39 *remainder = dividend % divisor; 40 return dividend / divisor; 41} 42 43/** 44 * div64_u64 - unsigned 64bit divide with 64bit divisor 45 */ 46static inline u64 div64_u64(u64 dividend, u64 divisor) 47{ 48 return dividend / divisor; 49} 50 51#define DIV64_U64_ROUND_UP(ll, d) \ 52 ({ u64 _tmp = (d); div64_u64((ll) + _tmp - 1, _tmp); }) 53 54/** 55 * div64_s64 - signed 64bit divide with 64bit divisor 56 */ 57static inline s64 div64_s64(s64 dividend, s64 divisor) 58{ 59 return dividend / divisor; 60} 61 62#elif BITS_PER_LONG == 32 63 64#define div64_long(x, y) div_s64((x), (y)) 65#define div64_ul(x, y) div_u64((x), (y)) 66 67#ifndef div_u64_rem 68static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) 69{ 70 *remainder = do_div(dividend, divisor); 71 return dividend; 72} 73#endif 74 75#ifndef div_s64_rem 76extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder); 77#endif 78 79#ifndef div64_u64_rem 80extern u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder); 81#endif 82 83#ifndef div64_u64 84extern u64 div64_u64(u64 dividend, u64 divisor); 85#endif 86 87#ifndef div64_s64 88extern s64 div64_s64(s64 dividend, s64 divisor); 89#endif 90 91#endif /* BITS_PER_LONG */ 92 93/** 94 * div_u64 - unsigned 64bit divide with 32bit divisor 95 * 96 * This is the most common 64bit divide and should be used if possible, 97 * as many 32bit archs can optimize this variant better than a full 64bit 98 * divide. 99 */ 100#ifndef div_u64 101static inline u64 div_u64(u64 dividend, u32 divisor) 102{ 103 u32 remainder; 104 return div_u64_rem(dividend, divisor, &remainder); 105} 106#endif 107 108/** 109 * div_s64 - signed 64bit divide with 32bit divisor 110 */ 111#ifndef div_s64 112static inline s64 div_s64(s64 dividend, s32 divisor) 113{ 114 s32 remainder; 115 return div_s64_rem(dividend, divisor, &remainder); 116} 117#endif 118 119u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder); 120 121static __always_inline u32 122__iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder) 123{ 124 u32 ret = 0; 125 126 while (dividend >= divisor) { 127 /* The following asm() prevents the compiler from 128 optimising this loop into a modulo operation. */ 129 asm("" : "+rm"(dividend)); 130 131 dividend -= divisor; 132 ret++; 133 } 134 135 *remainder = dividend; 136 137 return ret; 138} 139 140#ifndef mul_u32_u32 141/* 142 * Many a GCC version messes this up and generates a 64x64 mult :-( 143 */ 144static inline u64 mul_u32_u32(u32 a, u32 b) 145{ 146 return (u64)a * b; 147} 148#endif 149 150#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__) 151 152#ifndef mul_u64_u32_shr 153static inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift) 154{ 155 return (u64)(((unsigned __int128)a * mul) >> shift); 156} 157#endif /* mul_u64_u32_shr */ 158 159#ifndef mul_u64_u64_shr 160static inline u64 mul_u64_u64_shr(u64 a, u64 mul, unsigned int shift) 161{ 162 return (u64)(((unsigned __int128)a * mul) >> shift); 163} 164#endif /* mul_u64_u64_shr */ 165 166#else 167 168#ifndef mul_u64_u32_shr 169static inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift) 170{ 171 u32 ah, al; 172 u64 ret; 173 174 al = a; 175 ah = a >> 32; 176 177 ret = mul_u32_u32(al, mul) >> shift; 178 if (ah) 179 ret += mul_u32_u32(ah, mul) << (32 - shift); 180 181 return ret; 182} 183#endif /* mul_u64_u32_shr */ 184 185#ifndef mul_u64_u64_shr 186static inline u64 mul_u64_u64_shr(u64 a, u64 b, unsigned int shift) 187{ 188 union { 189 u64 ll; 190 struct { 191#ifdef __BIG_ENDIAN 192 u32 high, low; 193#else 194 u32 low, high; 195#endif 196 } l; 197 } rl, rm, rn, rh, a0, b0; 198 u64 c; 199 200 a0.ll = a; 201 b0.ll = b; 202 203 rl.ll = mul_u32_u32(a0.l.low, b0.l.low); 204 rm.ll = mul_u32_u32(a0.l.low, b0.l.high); 205 rn.ll = mul_u32_u32(a0.l.high, b0.l.low); 206 rh.ll = mul_u32_u32(a0.l.high, b0.l.high); 207 208 /* 209 * Each of these lines computes a 64-bit intermediate result into "c", 210 * starting at bits 32-95. The low 32-bits go into the result of the 211 * multiplication, the high 32-bits are carried into the next step. 212 */ 213 rl.l.high = c = (u64)rl.l.high + rm.l.low + rn.l.low; 214 rh.l.low = c = (c >> 32) + rm.l.high + rn.l.high + rh.l.low; 215 rh.l.high = (c >> 32) + rh.l.high; 216 217 /* 218 * The 128-bit result of the multiplication is in rl.ll and rh.ll, 219 * shift it right and throw away the high part of the result. 220 */ 221 if (shift == 0) 222 return rl.ll; 223 if (shift < 64) 224 return (rl.ll >> shift) | (rh.ll << (64 - shift)); 225 return rh.ll >> (shift & 63); 226} 227#endif /* mul_u64_u64_shr */ 228 229#endif 230 231#ifndef mul_u64_u32_div 232static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor) 233{ 234 union { 235 u64 ll; 236 struct { 237#ifdef __BIG_ENDIAN 238 u32 high, low; 239#else 240 u32 low, high; 241#endif 242 } l; 243 } u, rl, rh; 244 245 u.ll = a; 246 rl.ll = mul_u32_u32(u.l.low, mul); 247 rh.ll = mul_u32_u32(u.l.high, mul) + rl.l.high; 248 249 /* Bits 32-63 of the result will be in rh.l.low. */ 250 rl.l.high = do_div(rh.ll, divisor); 251 252 /* Bits 0-31 of the result will be in rl.l.low. */ 253 do_div(rl.ll, divisor); 254 255 rl.l.high = rh.l.low; 256 return rl.ll; 257} 258#endif /* mul_u64_u32_div */ 259 260#endif /* _LINUX_MATH64_H */ 261