math64: New DIV_U64_ROUND_CLOSEST helper

Provide DIV_U64_ROUND_CLOSEST helper which uses div_u64 to perform
division rounded to the closest integer using unsigned 64bit
dividend and unsigned 32bit divisor.

Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/20220219152818.4319-2-kabel@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pali Rohár 2022-02-19 16:28:13 +01:00 committed by Greg Kroah-Hartman
parent 679875d1d8
commit 2c861b73a2

View File

@ -300,6 +300,19 @@ u64 mul_u64_u64_div_u64(u64 a, u64 mul, u64 div);
#define DIV64_U64_ROUND_CLOSEST(dividend, divisor) \
({ u64 _tmp = (divisor); div64_u64((dividend) + _tmp / 2, _tmp); })
/*
* DIV_U64_ROUND_CLOSEST - unsigned 64bit divide with 32bit divisor rounded to nearest integer
* @dividend: unsigned 64bit dividend
* @divisor: unsigned 32bit divisor
*
* Divide unsigned 64bit dividend by unsigned 32bit divisor
* and round to closest integer.
*
* Return: dividend / divisor rounded to nearest integer
*/
#define DIV_U64_ROUND_CLOSEST(dividend, divisor) \
({ u32 _tmp = (divisor); div_u64((u64)(dividend) + _tmp / 2, _tmp); })
/*
* DIV_S64_ROUND_CLOSEST - signed 64bit divide with 32bit divisor rounded to nearest integer
* @dividend: signed 64bit dividend