[PATCH] Document Linux's memory barriers [try #4]

[Alan Cox]

On Fri, Mar 10, 2006 at 10:34:53AM +1100, Paul Mackerras wrote:
> MMIO accesses are done under a spinlock, and that if your driver is
> missing them then that is a bug.  I don't think it makes sense to say
> that mmiowb is required "on some systems".

Agreed. But if it is missing it may not be a bug. It depends what the lock
actually protects.