[IA64] SN: Add support for CPU disable

Add additional support for CPU disable on SN platforms.
Correctly setup the smp_affinity mask for I/O error IRQs.
Restrict the use of the feature to Altix 4000 and 450 systems
running with a CPU disable capable PROM, and do not allow disabling
of CPU 0.

Signed-off-by: John Keller <jpk@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/sn/pci/tioca_provider.c b/arch/ia64/sn/pci/tioca_provider.c
index d798dd4..ef048a6 100644
--- a/arch/ia64/sn/pci/tioca_provider.c
+++ b/arch/ia64/sn/pci/tioca_provider.c
@@ -654,6 +654,8 @@
 		       __FUNCTION__, SGI_TIOCA_ERROR,
 		       (int)tioca_common->ca_common.bs_persist_busnum);
 
+	sn_set_err_irq_affinity(SGI_TIOCA_ERROR);
+
 	/* Setup locality information */
 	controller->node = tioca_kern->ca_closest_node;
 	return tioca_common;