1 files changed, 17 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6accd360da73..b2361667839f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -772,6 +772,23 @@ and is between 256 and 4096 characters. It is defined in the file
 
         inttest=        [IA64]
 
+        intel_iommu=    [DMAR] Intel IOMMU driver (DMAR) option
+                off
+                        Disable intel iommu driver.
+                igfx_off [Default Off]
+                        By default, gfx is mapped as normal device. If a gfx
+                        device has a dedicated DMAR unit, the DMAR unit is
+                        bypassed by not enabling DMAR with this option. In
+                        this case, gfx device will use physical address for
+                        DMA.
+                forcedac [x86_64]
+                        With this option iommu will not optimize to look
+                        for io virtual address below 32 bit forcing dual
+                        address cycle on pci bus for cards supporting greater
+                        than 32 bit addressing. The default is to look
+                        for translation below 32 bit and if not available
+                        then look in the higher range.
+
         io7=            [HW] IO7 for Marvel based alpha systems
                         See comment before marvel_specify_io7 in
                         arch/alpha/kernel/core_marvel.c.