Re: [PATCH] HPET driver

From: Andrew Morton
Date: Mon May 17 2004 - 18:33:16 EST


Jeff Garzik <jgarzik@xxxxxxxxx> 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.
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