linux-imx

/*

 * 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.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, see the file COPYING, or write

 * to the Free Software Foundation, Inc.

 */

​

#include <linux/export.h>

#include <linux/libgcc.h>

​

#define W_TYPE_SIZE 32

​

#define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))

#define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))

#define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))

​

/* If we still don't have umul_ppmm, define it using plain C.  */

#if !defined(umul_ppmm)

#define umul_ppmm(w1, w0, u, v)                     \

    do {                                \

        unsigned long __x0, __x1, __x2, __x3;           \

        unsigned short __ul, __vl, __uh, __vh;          \

                                    \

        __ul = __ll_lowpart(u);                 \

        __uh = __ll_highpart(u);                \

        __vl = __ll_lowpart(v);                 \

        __vh = __ll_highpart(v);                \

                                    \

        __x0 = (unsigned long) __ul * __vl;         \

        __x1 = (unsigned long) __ul * __vh;         \

        __x2 = (unsigned long) __uh * __vl;         \

        __x3 = (unsigned long) __uh * __vh;         \

                                    \

        __x1 += __ll_highpart(__x0); /* this can't give carry */\

        __x1 += __x2; /* but this indeed can */         \

        if (__x1 < __x2) /* did we get it? */           \

        __x3 += __ll_B; /* yes, add it in the proper pos */ \

                                    \

        (w1) = __x3 + __ll_highpart(__x1);          \

        (w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\

    } while (0)

#endif

​

#if !defined(__umulsidi3)

#define __umulsidi3(u, v) ({                \

    DWunion __w;                    \

    umul_ppmm(__w.s.high, __w.s.low, u, v);     \

    __w.ll;                     \

    })

#endif

​

long long notrace __muldi3(long long u, long long v)

{

    const DWunion uu = {.ll = u};

    const DWunion vv = {.ll = v};

    DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};

​

    w.s.high += ((unsigned long) uu.s.low * (unsigned long) vv.s.high

        + (unsigned long) uu.s.high * (unsigned long) vv.s.low);

​

    return w.ll;

}

EXPORT_SYMBOL(__muldi3);