linuxkpi: math.h: Add mul_u64_u32_div and mul_u64_u32_shr

[manu]

Summary

Needed by drm-kmod.

Obtained from: OpenBSD
Sponsored by: Beckhoff Automation GmbH & Co. KG

[• hselasky]

sys/compat/linuxkpi/common/include/linux/math64.h

106

This looks wrong and may overflow! Do it like shown below instead, and implement mul_u64_u64_div() at the same time:

static inline uint64_t
mul_u64_u64_div(uint64_t num, uint64_t mul, uint64_t div)
{
       const uint64_t rem = num % div;

       return (num / div) * mul + (rem * mul) / div;
}

[bz]

sys/compat/linuxkpi/common/include/linux/math64.h

106

In any case, BSD style is putting the return (value) in ().

[manu]

Fix mul_u64_u64_div

[• hselasky]

sys/compat/linuxkpi/common/include/linux/math64.h

104

x->num and y->rem

[manu]

Fix var names.

[• hselasky]

Looks good.

sys/compat/linuxkpi/common/include/linux/math64.h

108

Maybe add ()'s