#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); |