diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index f149217..b667217 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -23,6 +23,7 @@
 #include <asm/setup.h>
 #include <asm/page.h>
 #include <asm/smp_plat.h>
+#include <asm/system_info.h>
 #include <asm/mach/arch.h>
 #include <asm/mach-types.h>
 
@@ -81,48 +82,64 @@ void __init arm_dt_init_cpu_maps(void)
 	static u32 tmp_map[NR_CPUS] __initdata = {
 				[0 ... NR_CPUS-1] = UINT_MAX };
 	struct device_node *cpu, *cpus;
-	u32 i, j, cpuidx = 1;
+	u32 i, j, ac, cpuidx = 1;
 	u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
-
+	int len;
 	bool bootcpu_valid = false;
+
 	cpus = of_find_node_by_path("/cpus");
 
-	if (!cpus)
+	if (!cpus || ((cpu_architecture() < CPU_ARCH_ARMv7) && !is_smp()))
 		return;
 
+	if (WARN_ON(of_property_read_u32(cpus, "#address-cells", &ac)))
+		ac = of_n_addr_cells(cpus);
+
 	for_each_child_of_node(cpus, cpu) {
-		u32 hwid;
+		u64 hwid64;
+		u32 hwid32;
+		const __be32 *prop;
 
 		pr_debug(" * %s...\n", cpu->full_name);
 		/*
-		 * A device tree containing CPU nodes with missing "reg"
-		 * properties is considered invalid to build the
-		 * cpu_logical_map.
+		 * A CPU node with missing or wrong "reg" property is
+		 * considered invalid to build a cpu_logical_map entry.
 		 */
-		if (of_property_read_u32(cpu, "reg", &hwid)) {
-			pr_debug(" * %s missing reg property\n",
-				     cpu->full_name);
-			return;
+		prop = of_get_property(cpu, "reg", &len);
+		if (!prop || len < (ac * sizeof(*prop))) {
+			WARN(1, " * %s node missing/wrong reg property, skipped\n",
+				cpu->full_name);
+				goto next;
 		}
-
 		/*
-		 * 8 MSBs must be set to 0 in the DT since the reg property
-		 * defines the MPIDR[23:0].
+		 * Always read reg as u64 value.
+		 * For dts with #address-cells == 1 hwid64[63:32]
+		 * will be set to 0 by of_read_number.
+		 * Toss away the top 32 bits and store value in hwid32.
+		 */
+		hwid32 = hwid64 = of_read_number(prop, ac);
+		/*
+		 * hwid64[63:24] must be always be 0 since the reg
+		 * property defines the MPIDR[23:0] bits regardless
+		 * of the cpus node #address-cells value.
 		 */
-		if (hwid & ~MPIDR_HWID_BITMASK)
-			return;
+		if (hwid64 & ~MPIDR_HWID_BITMASK) {
+			WARN(1, " * %s node reg[63:24] must be 0 on 32-bit dts, got %#016llx, skipped\n",
+				cpu->full_name, hwid64);
+			goto next;
+		}
 
 		/*
 		 * Duplicate MPIDRs are a recipe for disaster.
 		 * Scan all initialized entries and check for
-		 * duplicates. If any is found just bail out.
+		 * duplicates. If any is found just ignore the CPU.
 		 * temp values were initialized to UINT_MAX
 		 * to avoid matching valid MPIDR[23:0] values.
 		 */
 		for (j = 0; j < cpuidx; j++)
-			if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg "
-						     "properties in the DT\n"))
-				return;
+			if (WARN(tmp_map[j] == hwid32, " * %s node duplicate cpu reg property, skipped\n",
+						       cpu->full_name))
+				goto next;
 
 		/*
 		 * Build a stashed array of MPIDR values. Numbering scheme
@@ -133,26 +150,27 @@ void __init arm_dt_init_cpu_maps(void)
 		 * logical map built from DT is validated and can be used
 		 * to override the map created in smp_setup_processor_id().
 		 */
-		if (hwid == mpidr) {
+		if (hwid32 == mpidr) {
 			i = 0;
 			bootcpu_valid = true;
 		} else {
 			i = cpuidx++;
 		}
 
-		if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than "
-					       "max cores %u, capping them\n",
-					       cpuidx, nr_cpu_ids)) {
+		if (WARN_ONCE(cpuidx > nr_cpu_ids, "DT cpu %u nodes greater than max cores %u, capping them\n",
+						    cpuidx, nr_cpu_ids)) {
 			cpuidx = nr_cpu_ids;
-			break;
+			goto next;
 		}
 
-		tmp_map[i] = hwid;
+		tmp_map[i] = hwid32;
+next:	;
 	}
-
-	if (WARN(!bootcpu_valid, "DT missing boot CPU MPIDR[23:0], "
-				 "fall back to default cpu_logical_map\n"))
-		return;
+	/*
+	 * A DT missing the boot CPU MPIDR is a really bad omen
+	 * Flag it up as such and force firmware/dtb updates
+	 */
+	BUG_ON(!bootcpu_valid);
 
 	/*
 	 * Since the boot CPU node contains proper data, and all nodes have
