Merge branch 'master' into gfs2

[powerpc.git] / Documentation / x86_64 / boot-options.txt

diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt
index 4303e0c..74b77f9 100644 (file)
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -199,6 +199,11 @@ IOMMU
    allowed  overwrite iommu off workarounds for specific chipsets.
    soft         Use software bounce buffering (default for Intel machines)
    noaperture Don't touch the aperture for AGP.
+   allowdac Allow DMA >4GB
+           When off all DMA over >4GB is forced through an IOMMU or bounce
+           buffering.
+   nodac    Forbid DMA >4GB
+   panic    Always panic when IOMMU overflows
 
   swiotlb=pages[,force]