v4.19.13 snapshot.
diff --git a/arch/alpha/include/asm/topology.h b/arch/alpha/include/asm/topology.h
new file mode 100644
index 0000000..e6e13a8
--- /dev/null
+++ b/arch/alpha/include/asm/topology.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_ALPHA_TOPOLOGY_H
+#define _ASM_ALPHA_TOPOLOGY_H
+
+#include <linux/smp.h>
+#include <linux/threads.h>
+#include <asm/machvec.h>
+
+#ifdef CONFIG_NUMA
+static inline int cpu_to_node(int cpu)
+{
+ int node;
+
+ if (!alpha_mv.cpuid_to_nid)
+ return 0;
+
+ node = alpha_mv.cpuid_to_nid(cpu);
+
+#ifdef DEBUG_NUMA
+ BUG_ON(node < 0);
+#endif
+
+ return node;
+}
+
+extern struct cpumask node_to_cpumask_map[];
+/* FIXME: This is dumb, recalculating every time. But simple. */
+static const struct cpumask *cpumask_of_node(int node)
+{
+ int cpu;
+
+ if (node == -1)
+ return cpu_all_mask;
+
+ cpumask_clear(&node_to_cpumask_map[node]);
+
+ for_each_online_cpu(cpu) {
+ if (cpu_to_node(cpu) == node)
+ cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
+ }
+
+ return &node_to_cpumask_map[node];
+}
+
+#define cpumask_of_pcibus(bus) (cpu_online_mask)
+
+#endif /* !CONFIG_NUMA */
+# include <asm-generic/topology.h>
+
+#endif /* _ASM_ALPHA_TOPOLOGY_H */