x86/amd-iommu: Add amd_iommu=off command line option

This patch adds a command line option to tell the AMD IOMMU
driver to not initialize any IOMMU it finds.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 839b21b0699a..0c6c56076d19 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -324,6 +324,8 @@ and is between 256 and 4096 characters. It is defined in the file
                                     they are unmapped. Otherwise they are
                                     flushed before they will be reused, which
                                     is a lot of faster
+                        off       - do not initialize any AMD IOMMU found in
+                                    the system
 
         amijoy.map=     [HW,JOY] Amiga joystick support
                         Map of devices attached to JOY0DAT and JOY1DAT