comedi/include/asm/div64.h

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/***************************************************************************
                                  asm/div64.h
                             -------------------

    copyright            : (C) 2002 by Frank Mori Hess
    email                : fmhess@users.sourceforge.net
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef _DIV64_COMPAT_H
#define _DIV64_COMPAT_H

#include <linux/version.h>

#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 4, 0)

static inline u64 my_ull_div(u64 numerator, unsigned long denominator)
{
        u32 value;
        u64 remainder, temp, answer = 0;
        unsigned int shift;
        static const u32 max_u32 = 0xffffffff;

        remainder = numerator;

        while (remainder >= denominator) {
                shift = 0;
                numerator = remainder;
                // shift most significant bits into 32 bit variable
                while (numerator > max_u32) {
                        numerator >>= 1;
                        shift++;
                }
                if (numerator < denominator) {
                        shift--;
                        value = 1;
                } else {
                        value = numerator;
                        value /= denominator;
                }
                temp = ((u64) value) << shift;
                answer += temp;
                remainder -= temp * denominator;
        }

        return answer;
}

#define do_div(n, base) ((n) = my_ull_div(n, base))

#else

#include_next <asm/div64.h>

#endif

#endif // _DIV64_COMPAT_H