Re: MMIO and gcc re-ordering issue

Arnd Bergmann
2008-05-29T07:10:57Z

On Wednesday 28 May 2008, Benjamin Herrenschmidt wrote:
> On Tue, 2008-05-27 at 14:55 -0700, Linus Torvalds wrote:
> >
> > On Wed, 28 May 2008, Benjamin Herrenschmidt wrote:
> > >
> > > A problem with __raw_ though is that they -also- don't do byteswap,
> >
> > Well, that's why there is __readl() and __raw_readl(), no?
>
> As I replied to somebody else, __readl() is news to me :-) we dont' have
> those on powerpc.
>

It's not exactly a well-established interface. Only five architectures
define these functions, and there is not a single user in the kernel
source outside of these architecture's io.h files.