From: Benjamin Herrenschmidt Date: Tue, 11 Feb 2014 00:32:38 +0000 (+1100) Subject: powerpc/powernv: Add iommu DMA bypass support for IODA2 X-Git-Tag: v3.14-rc3~32^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cd15b048445d0a54f7147c35a86c5a16ef231554;p=pandora-kernel.git powerpc/powernv: Add iommu DMA bypass support for IODA2 This patch adds the support for to create a direct iommu "bypass" window on IODA2 bridges (such as Power8) allowing to bypass iommu page translation completely for 64-bit DMA capable devices, thus significantly improving DMA performances. Additionally, this adds a hook to the struct iommu_table so that the IOMMU API / VFIO can disable the bypass when external ownership is requested, since in that case, the device will be used by an environment such as userspace or a KVM guest which must not be allowed to bypass translations. Signed-off-by: Benjamin Herrenschmidt --- Reading git-diff-tree failed