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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-02-11 04:32:38 +0400
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-02-11 09:07:37 +0400
commitcd15b048445d0a54f7147c35a86c5a16ef231554 (patch)
tree80c7e63624143adc5d453106ec13f445438c6135 /arch/powerpc/include/asm/iommu.h
parentea961a828fe7250e954f086d74d9323c3d44c3e4 (diff)
downloadlinux-cd15b048445d0a54f7147c35a86c5a16ef231554.tar.xz
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 <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/include/asm/iommu.h')
-rw-r--r--arch/powerpc/include/asm/iommu.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index f7a8036579b5..42632c7a2a4e 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 */