From: Alexander Duyck <redacted>
Date: Mon, 24 Oct 2016 08:06:07 -0400

This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to
avoid invoking cache line invalidation if the driver will just handle it
via a sync_for_cpu or sync_for_device call.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: Alexander Duyck <redacted>

This is fine for avoiding the flush for performance reasons, but the
chip isn't going to write anything back unless the device wrote into
the area.