Re: [PATCH 2 of 2] __raw_memcpy_toio32 for x86_64

From: Andi Kleen
Date: Wed Jan 11 2006 - 20:32:50 EST


On Thursday 12 January 2006 02:27, Bryan O'Sullivan wrote:

> > > +__raw_memcpy_toio32:
> > > + movl %edx,%ecx
> > > + shrl $1,%ecx
> >
> > 1? If it's called memcpy it should get a byte argument, no? If not
> > name it something else, otherwise everybody will be confused.
>
> It's called toio32 for a reason :-)
>
> Also, the kernel doc clearly states its purpose.

I think it's deeply wrong to reuse names of standard functions with different
arguments. Either pass bytes or give it some other name.

> > movsq? I thought you wanted 32bit IO?
>
> The northbridge will split qword writes into pairs of dword writes.

That sounds like a very chipset specific assumption. Is that safe
to make? If yes you would need to document it clearly. But most likely
it's not a good idea to do this. Even if it works right now it would
be another death trap for the next user.

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/