// SPDX-License-Identifier: GPL-2.0#include <linux/bitops.h>#include <linux/bug.h>#include <linux/export.h>#include <linux/limits.h>#include <linux/math.h>#include <linux/minmax.h>#include <linux/types.h> #include <linux/reciprocal_div.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); struct reciprocal_value_adv reciprocal_value_adv(u32 d, u8 prec){	struct reciprocal_value_adv R;	u32 l, post_shift;	u64 mhigh, mlow; 	/* ceil(log2(d)) */	l = fls(d - 1);	/* NOTE: mlow/mhigh could overflow u64 when l == 32. This case needs to	 * be handled before calling "reciprocal_value_adv", please see the	 * comment at include/linux/reciprocal_div.h.	 */	WARN(l == 32,	     "ceil(log2(0x%08x)) == 32, %s doesn't support such divisor",	     d, __func__);	post_shift = l;	mlow = 1ULL << (32 + l);	do_div(mlow, d);	mhigh = (1ULL << (32 + l)) + (1ULL << (32 + l - prec));	do_div(mhigh, d); 	for (; post_shift > 0; post_shift--) {		u64 lo = mlow >> 1, hi = mhigh >> 1; 		if (lo >= hi)			break; 		mlow = lo;		mhigh = hi;	} 	R.m = (u32)mhigh;	R.sh = post_shift;	R.exp = l;	R.is_wide_m = mhigh > U32_MAX; 	return R;}EXPORT_SYMBOL(reciprocal_value_adv);