diff --git a/src/soc/amd/stoneyridge/include/soc/northbridge.h b/src/soc/amd/stoneyridge/include/soc/northbridge.h
index 13d7d36270..5984637787 100644
--- a/src/soc/amd/stoneyridge/include/soc/northbridge.h
+++ b/src/soc/amd/stoneyridge/include/soc/northbridge.h
@@ -20,6 +20,11 @@
 #include <arch/io.h>
 #include <device/device.h>
 
+/* D18F1 - Address Map Registers */
+#define D18F1_DRAM_HOLE		0xf0
+# define DRAM_HOIST_VALID	(1 << 1)
+# define DRAM_HOLE_VALID	(1 << 0)
+
 void cpu_bus_scan(device_t dev);
 void domain_enable_resources(device_t dev);
 void domain_read_resources(device_t dev);