diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/math64.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/include/linux/math64.h b/include/linux/math64.h index 44282ec7b682..6e8b5b270ffe 100644 --- a/include/linux/math64.h +++ b/include/linux/math64.h @@ -214,4 +214,33 @@ static inline u64 mul_u64_u64_shr(u64 a, u64 b, unsigned int shift) #endif +#ifndef mul_u64_u32_div +static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor) +{ + union { + u64 ll; + struct { +#ifdef __BIG_ENDIAN + u32 high, low; +#else + u32 low, high; +#endif + } l; + } u, rl, rh; + + u.ll = a; + rl.ll = (u64)u.l.low * mul; + rh.ll = (u64)u.l.high * mul + rl.l.high; + + /* Bits 32-63 of the result will be in rh.l.low. */ + rl.l.high = do_div(rh.ll, divisor); + + /* Bits 0-31 of the result will be in rl.l.low. */ + do_div(rl.ll, divisor); + + rl.l.high = rh.l.low; + return rl.ll; +} +#endif /* mul_u64_u32_div */ + #endif /* _LINUX_MATH64_H */ |