Merge Question on asm-ppc*/rwsem.h

[Paul Mackerras]

Jon Loeliger writes:

> Which begs the question, what is the "else smp_wmb();" clause
> really doing for us in the ppc32 case, and can we either
> get rid of it, or is it safe to add to the ppc64 case?

I think the difference is that the atomic ops that return a value also
have include a barrier on ppc64, but don't on ppc32 (although they
probably should).  IOW I think the merged case should follow ppc64
here.

Paul.