The manual says that it is required and we actually have crash reports
where loads see stale data due to not having membars here.
In one case the networking does:
memset(skb, 0, offsetof(struct sk_buff, truesize));
and then some code later checks skb->nohdr for zero, but it's still
the value that was there before the memset().
Note that arch/sparc64/lib/xor.S already got this right.
Signed-off-by: David S. Miller <davem@davemloft.net>
Happily we have no D-cache aliasing issues on these
chips, so the implementation is very straightforward.
Add a stub in bootup which will be where the patching
calls will be made for niagara/sun4v/hypervisor.
Signed-off-by: David S. Miller <davem@davemloft.net>
