diff --git a/arch/powerpc/kernel/firmware.c b/arch/powerpc/kernel/firmware.c
index 1679a70bbcad..6b1f4271eb53 100644
--- a/arch/powerpc/kernel/firmware.c
+++ b/arch/powerpc/kernel/firmware.c
@@ -17,5 +17,5 @@
 
 #include <asm/firmware.h>
 
-unsigned long powerpc_firmware_features;
+unsigned long powerpc_firmware_features __read_mostly;
 EXPORT_SYMBOL_GPL(powerpc_firmware_features);