From cd15b048445d0a54f7147c35a86c5a16ef231554 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 11 Feb 2014 11:32:38 +1100 Subject: 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 --- arch/powerpc/include/asm/iommu.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/powerpc/include/asm/iommu.h') diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h index f7a8036..42632c7 100644 --- a/arch/powerpc/include/asm/iommu.h +++ b/arch/powerpc/include/asm/iommu.h @@ -77,6 +77,7 @@ struct iommu_table { #ifdef CONFIG_IOMMU_API struct iommu_group *it_group; #endif + void (*set_bypass)(struct iommu_table *tbl, bool enable); }; /* Pure 2^n version of get_order */ -- cgit v1.1