[IA64] Fix build breakage

In commit 0ac0c0d0
cpusets: randomize node rotor used in cpuset_mem_spread_node()

Jack Steiner fixed a problem with too many small tasks being
assigned to node 0. Copy his code to ia64 to avoid build error.

    arch/ia64/kernel/smpboot.c:641: error: ‘cpu_to_node_map’ undeclared (first use in this function)

In commit 3bccd996
numa: ia64: use generic percpu var numa_node_id() implementation

Lee Schermerhorn added some set_numa_node() calls - but these
only work on CONFIG_NUMA=y configurations. Surround the calls
with #ifdef CONFIG_NUMA
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/smpboot.c

@@ -390,11 +390,13 @@ smp_callin (void)
 
 	fix_b0_for_bsp();
 
+#ifdef CONFIG_NUMA
 	/*
 	 * numa_node_id() works after this.
 	 */
 	set_numa_node(cpu_to_node_map[cpuid]);
 	set_numa_mem(local_memory_node(cpu_to_node_map[cpuid]));
+#endif
 
 	ipi_call_lock_irq();
 	spin_lock(&vector_lock);
@@ -638,7 +640,9 @@ void __devinit smp_prepare_boot_cpu(void)
 {
 	cpu_set(smp_processor_id(), cpu_online_map);
 	cpu_set(smp_processor_id(), cpu_callin_map);
+#ifdef CONFIG_NUMA
 	set_numa_node(cpu_to_node_map[smp_processor_id()]);
+#endif
 	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 	paravirt_post_smp_prepare_boot_cpu();
 }

arch/ia64/mm/numa.c

@@ -17,6 +17,7 @@
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/module.h>
+#include <linux/random.h>
 #include <asm/mmzone.h>
 #include <asm/numa.h>
 
@@ -50,6 +51,22 @@ paddr_to_nid(unsigned long paddr)
 	return (i < num_node_memblks) ? node_memblk[i].nid : (num_node_memblks ? -1 : 0);
 }
 
+/*
+ * Return the bit number of a random bit set in the nodemask.
+ *   (returns -1 if nodemask is empty)
+ */
+int __node_random(const nodemask_t *maskp)
+{
+	int w, bit = -1;
+
+	w = nodes_weight(*maskp);
+	if (w)
+		bit = bitmap_ord_to_pos(maskp->bits,
+			get_random_int() % w, MAX_NUMNODES);
+	return bit;
+}
+EXPORT_SYMBOL(__node_random);
+
 #if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
 /*
  * Because of holes evaluate on section limits.