>> +static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
>> +{
>> + union {
>> + u64 v64;
>> + u32 v32[2];
>> + } d = { dividend };
>> + u32 upper;
>> +
>> + upper = d.v32[1];
>> + d.v32[1] = 0;
>> + if (upper >= divisor) {
>> + d.v32[1] = upper / divisor;
>> + upper %= divisor;
>> + }
>> + asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) :
>> + "rm" (divisor), "0" (d.v32[0]), "1" (upper));
>> + return d.v64;
>> +}
>
>Why aren't you using the simple one from include/linux/math64.h ?
Cant't use div_u64() in math64.h directly, because that will cause ld error.
Even in 64-bit environment, arch/x86/boot/*.o will be built as 32-bit
binary. In 64-bit binary, the dividend is handled as 64-bit value,
that's OK, but in 32-bit binary, that's wrong. So it's necessary
to separate the dividend to upper and lower in 32-bit binary.
That's why copy the needed div_u64() here.
So, when copying kstrtoull(), we should copy div_u64().
When trying to include lib/kstrtox.c, even if other error in make period
are solved, we will also meet this error. We should also copy div_u64
also. And then cover the math64.h in boot/string.c, and hanlde the other
error and warining who comes together.
So just like Baoquan said, it's a good choice to use simple_strtoull()
for now.
Thanks,
Chao Fan
>
>Rest looks ok.
>
>--
>Regards/Gruss,
> Boris.
>
>Good mailing practices for 400: avoid top-posting and trim the reply.
>
>
