diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index ec94f906ea43a7dd6729a518d852d8e9879480ed..d5839179ec770f0134f24bf4c34ac85752feb8b9 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -43,20 +43,9 @@
 #define DBG(...)
 
 static int novmerge;
-static int protect4gb = 1;
 
 static void __iommu_free(struct iommu_table *, dma_addr_t, unsigned int);
 
-static int __init setup_protect4gb(char *str)
-{
-	if (strcmp(str, "on") == 0)
-		protect4gb = 1;
-	else if (strcmp(str, "off") == 0)
-		protect4gb = 0;
-
-	return 1;
-}
-
 static int __init setup_iommu(char *str)
 {
 	if (!strcmp(str, "novmerge"))
@@ -66,7 +55,6 @@ static int __init setup_iommu(char *str)
 	return 1;
 }
 
-__setup("protect4gb=", setup_protect4gb);
 __setup("iommu=", setup_iommu);
 
 static unsigned long iommu_range_alloc(struct device *dev,