ia64/pv_ops/xen: paravirtualize ivt.S for xen.

paravirtualize ivt.S for xen by multi compile.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/xen/Makefile b/arch/ia64/xen/Makefile
index 7cb4247..5c87e4a7 100644
--- a/arch/ia64/xen/Makefile
+++ b/arch/ia64/xen/Makefile
@@ -2,5 +2,19 @@
 # Makefile for Xen components
 #
 
-obj-y := hypercall.o xensetup.o xen_pv_ops.o \
+obj-y := hypercall.o xenivt.o xensetup.o xen_pv_ops.o \
 	 hypervisor.o xencomm.o xcom_hcall.o grant-table.o
+
+AFLAGS_xenivt.o += -D__IA64_ASM_PARAVIRTUALIZED_XEN
+
+# xen multi compile
+ASM_PARAVIRT_MULTI_COMPILE_SRCS = ivt.S
+ASM_PARAVIRT_OBJS = $(addprefix xen-,$(ASM_PARAVIRT_MULTI_COMPILE_SRCS:.S=.o))
+obj-y += $(ASM_PARAVIRT_OBJS)
+define paravirtualized_xen
+AFLAGS_$(1) += -D__IA64_ASM_PARAVIRTUALIZED_XEN
+endef
+$(foreach o,$(ASM_PARAVIRT_OBJS),$(eval $(call paravirtualized_xen,$(o))))
+
+$(obj)/xen-%.o: $(src)/../kernel/%.S FORCE
+	$(call if_changed_dep,as_o_S)