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/*

 * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>

 *

 * Based on former do_div() implementation from asm-parisc/div64.h:

 *      Copyright (C) 1999 Hewlett-Packard Co

 *      Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>

 *

 *

 * Generic C version of 64bit/32bit division and modulo, with

 * 64bit result and 32bit remainder.

 *

 * The fast case for (n>>32 == 0) is handled inline by do_div().

 *

 * Code generated for this function might be very inefficient

 * for some CPUs. __div64_32() can be overridden by linking arch-specific

 * assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S.

 */

#include <linux/types.h>

#include <linux/module.h>

#include <asm/div64.h>

/* Not needed on 64bit architectures */

#if BITS_PER_LONG == 32

uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)

{

        uint64_t rem = *n;

        uint64_t b = base;

        uint64_t res, d = 1;

        uint32_t high = rem >> 32;

        /* Reduce the thing a bit first */

        res = 0;

        if (high >= base) {

                high /= base;

                res = (uint64_t) high << 32;

                rem -= (uint64_t) (high*base) << 32;

        }

        while ((int64_t)b > 0 && b < rem) {

                b = b+b;

                d = d+d;

        }

        do {

                if (rem >= b) {

                        rem -= b;

                        res += d;

                }

                b >>= 1;

                d >>= 1;

        } while (d);

        *n = res;

        return rem;

}

EXPORT_SYMBOL(__div64_32);

/* 64bit divisor, dividend and result. dynamic precision */

uint64_t div64_64(uint64_t dividend, uint64_t divisor)

{

        uint32_t high, d;

        high = divisor >> 32;

        if (high) {

                unsigned int shift = fls(high);

                d = divisor >> shift;

                dividend >>= shift;

        } else

                d = divisor;

        do_div(dividend, d);

        return dividend;

}

EXPORT_SYMBOL(div64_64);

#endif /* BITS_PER_LONG == 32 */