Re: [PATCH] HPET driver

[Andrew Morton <akpm@osdl.org>]

Jeff Garzik <jgarzik@pobox.com> wrote:
>
> Andrew Morton wrote:
> > +static inline u64 readq(void *addr)
> > +{
> > +	return readl(addr) | (((u64)readl(addr + 4)) << 32);
> > +}
> > +
> > +static inline void writeq(u64 v, void *addr)
> > +{
> > +	writel(v & 0xffffffff, addr);
> > +	writel(v >> 32, addr + 4);
> > +}
> 
> 
> Seems sane, though I wonder about two things:
> 
> * better home is probably asm-generic

It's only applicable to 32-bit machines.  I thik I'd prefer to let the
various arch maintainers decide if this is an appropriate implementation.

> * It seems to me that a poorly-written writel() macro might prefer some 
> guarantee that it's argument is pre-cast to u32.  I dunno if this is 
> just paranoia or not.

That could be an issue if other architectures were to use this
particular implementation.  I'll stick the typecasts in there anyway.