Older UltraSPARC-III chips have a P-Cache bug that makes us disable it
by default at boot time.

However, this does hurt performance substantially, particularly with
memcpy(), and the bug is _incredibly_ obscure.  I have never seen it
triggered in practice, ever.

So provide a "-P" boot option that forces the P-Cache on.  It taints
the kernel, so if it does trigger and cause some data corruption or
OOPS, we will find out in the logs that this option was on when it
happened.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!