ACPI: NUMA: map pxms to low node ids

pxms are mapped to low node ids to maintain generic kernel use of
functions such as pxm_to_node() that are used to determine device
affinity.  Otherwise, there is no pxm-to-node and node-to-pxm matching
rule for x86_64 users of NUMA emulation where a single pxm may be bound
to multiple NUMA nodes.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/numa.c

@@ -61,8 +61,10 @@ int node_to_pxm(int node)
 
 void __acpi_map_pxm_to_node(int pxm, int node)
 {
-	pxm_to_node_map[pxm] = node;
-	node_to_pxm_map[node] = pxm;
+	if (pxm_to_node_map[pxm] == NUMA_NO_NODE || node < pxm_to_node_map[pxm])
+		pxm_to_node_map[pxm] = node;
+	if (node_to_pxm_map[node] == PXM_INVAL || pxm < node_to_pxm_map[node])
+		node_to_pxm_map[node] = pxm;
 }
 
 int acpi_map_pxm_to_node(int pxm)