[IA64] Implement smp_call_function_mask for ia64

This interface provides more flexible functionality for smp
infrastructure ... e.g. KVM frequently needs to operate on
a subset of cpus.

Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/include/asm-ia64/smp.h b/include/asm-ia64/smp.h
index 4fa733d..ec5f355 100644
--- a/include/asm-ia64/smp.h
+++ b/include/asm-ia64/smp.h
@@ -38,6 +38,9 @@
 	return lid.f.id << 8 | lid.f.eid;
 }
 
+extern int smp_call_function_mask(cpumask_t mask, void (*func)(void *),
+				  void *info, int wait);
+
 #define hard_smp_processor_id()		ia64_get_lid()
 
 #ifdef CONFIG_SMP