This patch is originally from Jake Moilanen <moilanen@austin.ibm.com>,
substantially modified by me.

On PPC64 systems with a hypervisor, we can't set the Data Address Breakpoint
Register (DABR) directly, we have to do it through a hypervisor call.
Signed-off-by: Jake Moilanen <moilanen@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>