Implement the HCALLs to do more than one TCE setup or invalidation at a
time on pSeries LPAR.  Previous implementation did one hypervisor call per
setup or teardown, resulting in significant overhead.

A simple test of "time dd if=/dev/sda of=/dev/null bs=128k" shows the
amount of system time go down by about 5% by using the multi-tce calls.
Signed-off-by: Olof Johansson <olof@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>