blob: fcb4ce682c6fae37d71aa6138007b51cd0d8a2b3 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <asm/div64.h>
#include <linux/reciprocal_div.h>
#include <linux/export.h>
/*
* For a description of the algorithm please have a look at
* include/linux/reciprocal_div.h
*/
struct reciprocal_value reciprocal_value(u32 d)
{
struct reciprocal_value R;
u64 m;
int l;
l = fls(d - 1);
m = ((1ULL << 32) * ((1ULL << l) - d));
do_div(m, d);
++m;
R.m = (u32)m;
R.sh1 = min(l, 1);
R.sh2 = max(l - 1, 0);
return R;
}
EXPORT_SYMBOL(reciprocal_value);