On stepping A0/A1 of the 80200, invalidating D-cache by line doesn't
clear the dirty bits, which means that if we invalidate a dirty line,
the dirty data can still be written back to memory later on.

To work around this, dma_inv_range() on these two processors is
implemented as dma_flush_range() (i.e. do a clean D-cache line before
doing the invalidate D-cache line.)  For this, we currently have a
processor ID check in xscale_dma_inv_range(), but a better solution
is to add a separate cache_fns and proc_info for A0/A1 80200.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>