xen/numa: prepare NUMA setup code for unit testing

Introduce __XEN__ guards to differentiate between hypervisor vs unit test
builds.  Also move numa_set_node() so it's outside the __XEN__ guards.  No
functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>

xen/common/numa.c

@@ -4,6 +4,7 @@
  * Adapted for Xen: Ryan Harper <ryanh@us.ibm.com>
  */
 
+#ifdef __XEN__
 #include <xen/init.h>
 #include <xen/keyhandler.h>
 #include <xen/mm.h>
@@ -13,6 +14,7 @@
 #include <xen/pfn.h>
 #include <xen/sched.h>
 #include <xen/softirq.h>
+#endif /* __XEN__ */
 
 static nodemask_t __initdata processor_nodes_parsed;
 static nodemask_t __initdata memory_nodes_parsed;
@@ -561,6 +563,12 @@ void __init numa_init_array(void)
     }
 }
 
+void numa_set_node(unsigned int cpu, nodeid_t node)
+{
+    cpu_to_node[cpu] = node;
+}
+
+#ifdef __XEN__
 #ifdef CONFIG_NUMA_EMU
 static unsigned int __initdata numa_fake;
 
@@ -661,11 +669,6 @@ void numa_add_cpu(unsigned int cpu)
     cpumask_set_cpu(cpu, &node_to_cpumask[cpu_to_node(cpu)]);
 }
 
-void numa_set_node(unsigned int cpu, nodeid_t node)
-{
-    cpu_to_node[cpu] = node;
-}
-
 /* [numa=off] */
 static int __init cf_check numa_setup(const char *opt)
 {
@@ -830,3 +833,4 @@ static int __init cf_check register_numa_trigger(void)
     return 0;
 }
 __initcall(register_numa_trigger);
+#endif /* __XEN__ */