[RFC/PATCH 2/12] powerpc: Remove #ifdef ISERIES from __raw_* accessors in io.h

[Arnd Bergmann]

On Tuesday 17 January 2006 05:59, David Gibson wrote:
> > +static inline unsigned char __raw_readb(const volatile void __iomem *addr)
> > +{
> > +     if (firmware_has_feature(FW_FEATURE_ISERIES))
> > +             BUG();  /* raw accessors aren't supported on iSeries
> > */
> 
> BUG_ON() would seem reasonable here..
> 
Actually, I think not. The result of 
firmware_has_features(FW_FEATURE_ISERIES) should normally be
a compile-time constant, so the BUG code gets optimized away.
If you do BUG_ON(), you force the compiler to emit the code for
that anyway, even if it never causes any action to be taken.

	Arnd <><