Index: head/sys/dev/ofw/ofw_cpu.c
===================================================================
--- head/sys/dev/ofw/ofw_cpu.c
+++ head/sys/dev/ofw/ofw_cpu.c
@@ -244,6 +244,7 @@
 static int
 ofw_cpu_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
 {
+	struct ofw_cpulist_softc *psc;
 	struct ofw_cpu_softc *sc;
 
 	sc = device_get_softc(dev);
@@ -258,6 +259,16 @@
 			return (0);
 		}
 		break;
+	case CPU_IVAR_CPUID_SIZE:
+		psc = device_get_softc(device_get_parent(dev));
+		*result = psc->sc_addr_cells;
+		return (0);
+	case CPU_IVAR_CPUID:
+		if (sc->sc_reg_valid) {
+			*result = (uintptr_t)sc->sc_reg;
+			return (0);
+		}
+		break;
 	}
 
 	return (ENOENT);
Index: head/sys/sys/cpu.h
===================================================================
--- head/sys/sys/cpu.h
+++ head/sys/sys/cpu.h
@@ -37,6 +37,8 @@
 
 #define CPU_IVAR_PCPU		1
 #define CPU_IVAR_NOMINAL_MHZ	2
+#define CPU_IVAR_CPUID_SIZE	3
+#define CPU_IVAR_CPUID		4
 
 static __inline struct pcpu *cpu_get_pcpu(device_t dev)
 {
@@ -54,6 +56,20 @@
 	return ((int32_t)v);
 }
 
+static __inline const uint32_t *cpu_get_cpuid(device_t dev, size_t *count)
+{
+	uintptr_t v = 0;
+	if (BUS_READ_IVAR(device_get_parent(dev), dev,
+	    CPU_IVAR_CPUID_SIZE, &v) != 0)
+		return (NULL);
+	*count = (size_t)v;
+
+	if (BUS_READ_IVAR(device_get_parent(dev), dev,
+	    CPU_IVAR_CPUID, &v) != 0)
+		return (NULL);
+	return ((const uint32_t *)v);
+}
+
 /*
  * CPU frequency control interface.
  */