iommu: remove fullflush and nofullflush in IOMMU generic option

This patch against tip/x86/iommu virtually reverts
2842e5bf3115193f05dc9dac20f940e7abf44c1a. But just reverting the
commit breaks AMD IOMMU so this patch also includes some fixes.

The above commit adds new two options to x86 IOMMU generic kernel boot
options, fullflush and nofullflush. But such change that affects all
the IOMMUs needs more discussion (all IOMMU parties need the chance to
discuss it):

http://lkml.org/lkml/2008/9/19/106

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 40066ce..040ce30 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -284,6 +284,11 @@
 			isolate - enable device isolation (each device, as far
 			          as possible, will get its own protection
 			          domain)
+			fullflush - enable flushing of IO/TLB entries when
+				    they are unmapped. Otherwise they are
+				    flushed before they will be reused, which
+				    is a lot of faster
+
 	amd_iommu_size= [HW,X86-64]
 			Define the size of the aperture for the AMD IOMMU
 			driver. Possible values are:
@@ -893,10 +898,6 @@
 		nomerge
 		forcesac
 		soft
-		fullflush
-			Flush IO/TLB at every deallocation
-		nofullflush
-			Flush IO/TLB only when addresses are reused (default)
 
 
 	intel_iommu=	[DMAR] Intel IOMMU driver (DMAR) option