MMIO and gcc re-ordering issue

[Arnd Bergmann]

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.

	Arnd <><