[RFC PATCH] riscv/locking: Strengthen spin_lock() and spin_unlock()

[Peter Zijlstra]

On Thu, Feb 22, 2018 at 10:13:17AM -0800, Paul E. McKenney wrote:
> So we have something that is not all that rare in the Linux kernel
> community, namely two conflicting more-or-less concurrent changes.
> This clearly needs to be resolved, either by us not strengthening the
> Linux-kernel memory model in the way we were planning to or by you
> strengthening RISC-V to be no weaker than PowerPC for these sorts of
> externally viewed release-acquire situations.
> 
> Other thoughts?

Like said in the other email, I would _much_ prefer to not go weaker
than PPC, I find that PPC is already painfully weak at times.