- mmtimer: add support for the use of hardware timers on SGI SHubs (sn
  subarch) via the posix timer interface.

- Allows the scheduling of up to 3 hardware interrupts per node to
  deliver signals to processes running on those nodes.

- Periodic timers in user space capable of supporting intervals down to
  10us (<10us supported but will usually result in excessive overruns).

- Scheduling accuracy of 40ns.  (However, typically it takes at least a
  few usecs for an interrupt to be forwarded to a signal in user space.)

- Add missing SHub information to include/asm-ia64/sn/shub_mmr.h

- Reserve timer interrupt used in include/asm-ia64/sn/intr.h
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>