/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_MATH64_H
#define _LINUX_MATH64_H

#include <linux/types.h>

#ifdef __x86_64__
static inline u64 mul_u64_u64_div64(u64 a, u64 b, u64 c)
{
        u64 q;

        asm ("mulq %2; divq %3" : "=a" (q)
                                : "a" (a), "rm" (b), "rm" (c)
                                : "rdx");

        return q;
}
#define mul_u64_u64_div64 mul_u64_u64_div64
#endif

#ifdef __SIZEOF_INT128__
static inline u64 mul_u64_u32_shr(u64 a, u32 b, unsigned int shift)
{
        return (u64)(((unsigned __int128)a * b) >> shift);
}

#else

#ifdef __i386__
static inline u64 mul_u32_u32(u32 a, u32 b)
{
        u32 high, low;

        asm ("mull %[b]" : "=a" (low), "=d" (high)
                         : [a] "a" (a), [b] "rm" (b) );

        return low | ((u64)high) << 32;
}
#else
static inline u64 mul_u32_u32(u32 a, u32 b)
{
        return (u64)a * b;
}
#endif

static inline u64 mul_u64_u32_shr(u64 a, u32 b, unsigned int shift)
{
        u32 ah, al;
        u64 ret;

        al = a;
        ah = a >> 32;

        ret = mul_u32_u32(al, b) >> shift;
        if (ah)
                ret += mul_u32_u32(ah, b) << (32 - shift);

        return ret;
}

#endif  /* __SIZEOF_INT128__ */

#ifndef mul_u64_u64_div64
static inline u64 mul_u64_u64_div64(u64 a, u64 b, u64 c)
{
        u64 quot, rem;

        quot = a / c;
        rem = a % c;

        return quot * b + (rem * b) / c;
}
#endif

static inline u64 div_u64(u64 dividend, u32 divisor)
{
        return dividend / divisor;
}

#endif /* _LINUX_MATH64_H */