1#ifndef _LINUX_MATH64_H 2#define _LINUX_MATH64_H 3 4#include <linux/types.h> 5#include <asm/div64.h> 6 7#if BITS_PER_LONG == 64 8 9/** 10 * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder 11 * 12 * This is commonly provided by 32bit archs to provide an optimized 64bit 13 * divide. 14 */ 15static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) 16{ 17 *remainder = dividend % divisor; 18 return dividend / divisor; 19} 20 21/** 22 * div_s64_rem - signed 64bit divide with 32bit divisor with remainder 23 */ 24static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder) 25{ 26 *remainder = dividend % divisor; 27 return dividend / divisor; 28} 29 30/** 31 * div64_u64 - unsigned 64bit divide with 64bit divisor 32 */ 33static inline u64 div64_u64(u64 dividend, u64 divisor) 34{ 35 return dividend / divisor; 36} 37 38#elif BITS_PER_LONG == 32 39 40#ifndef div_u64_rem 41static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) 42{ 43 *remainder = do_div(dividend, divisor); 44 return dividend; 45} 46#endif 47 48#ifndef div_s64_rem 49extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder); 50#endif 51 52#ifndef div64_u64 53extern u64 div64_u64(u64 dividend, u64 divisor); 54#endif 55 56#endif /* BITS_PER_LONG */ 57 58/** 59 * div_u64 - unsigned 64bit divide with 32bit divisor 60 * 61 * This is the most common 64bit divide and should be used if possible, 62 * as many 32bit archs can optimize this variant better than a full 64bit 63 * divide. 64 */ 65#ifndef div_u64 66static inline u64 div_u64(u64 dividend, u32 divisor) 67{ 68 u32 remainder; 69 return div_u64_rem(dividend, divisor, &remainder); 70} 71#endif 72 73/** 74 * div_s64 - signed 64bit divide with 32bit divisor 75 */ 76#ifndef div_s64 77static inline s64 div_s64(s64 dividend, s32 divisor) 78{ 79 s32 remainder; 80 return div_s64_rem(dividend, divisor, &remainder); 81} 82#endif 83 84u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder); 85 86static __always_inline u32 87__iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder) 88{ 89 u32 ret = 0; 90 91 while (dividend >= divisor) { 92 /* The following asm() prevents the compiler from 93 optimising this loop into a modulo operation. */ 94 asm("" : "+rm"(dividend)); 95 96 dividend -= divisor; 97 ret++; 98 } 99 100 *remainder = dividend; 101 102 return ret; 103} 104 105#endif /* _LINUX_MATH64_H */ 106