From 7d3b03ce7bff9d39ebaee1bb8de1968c4434b883 Mon Sep 17 00:00:00 2001 From: "Keshavamurthy, Anil S" Date: Sun, 21 Oct 2007 16:41:53 -0700 Subject: Intel IOMMU: Intel iommu cmdline option - forcedac Introduce intel_iommu=forcedac commandline option. This option is helpful to verify the pci device capability of handling physical dma'able address greater than 4G. Signed-off-by: Anil S Keshavamurthy Cc: Andi Kleen Cc: Peter Zijlstra Cc: Muli Ben-Yehuda Cc: "Siddha, Suresh B" Cc: Arjan van de Ven Cc: Ashok Raj Cc: "David S. Miller" Cc: Christoph Lameter Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-parameters.txt | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 8157417724a..b2361667839 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -781,6 +781,13 @@ and is between 256 and 4096 characters. It is defined in the file 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 -- cgit v1.2.3