AFAICS you need stronger barriers though; {w,r,}mb(),
to prevent _any_ reordering of those memory accesses,
not just the compiler-generated ones.
My impression was that the eieio used by iobarrier would be sufficient
for that, as we're not trying to synchronize between accesses to
different types of memory. Is sync really required here?
For accesses to main system memory, eieio only orders
writes, not reads, so iobarrier_r() doesn't do what
you want; and iobarrier_w() isn't meant to be used for
main memory access ordering either.
Also, it is better to not use powerpc-specific interfaces
in a device driver if you don't have a strong reason to.
Segher
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html