IOMMU Updates for Linux v4.13 This update comes with: * Support for lockless operation in the ARM io-pgtable code. This is an important step to solve the scalability problems in the common dma-iommu code for ARM * Some Errata workarounds for ARM SMMU implemenations * Rewrite of the deferred IO/TLB flush code in the AMD IOMMU driver. The code suffered from very high flush rates, with the new implementation the flush rate is down to ~1% of what it was before * Support for amd_iommu=off when booting with kexec. Problem here was that the IOMMU driver bailed out early without disabling the iommu hardware, if it was enabled in the old kernel * The Rockchip IOMMU driver is now available on ARM64 * Align the return value of the iommu_ops->device_group call-backs to not miss error values * Preempt-disable optimizations in the Intel VT-d and common IOVA code to help Linux-RT * Various other small cleanups and fixes