diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 50680a59a2ff..557763487a1a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3061,7 +3061,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			controller if no parameter or 1 is given or disable
 			it if 0 is given (See Documentation/cgroups/memory.txt)
 
-	swiotlb=	[IA-64] Number of I/O TLB slabs
+	swiotlb=	[ARM,IA-64,PPC,MIPS,X86]
+			Format: { <int> | force }
+			<int> -- Number of I/O TLB slabs
+			force -- force using of bounce buffers even if they
+			         wouldn't be automatically used by the kernel
 
 	switches=	[HW,M68k]