Merge git://git.infradead.org/users/dwmw2/iommu-2.6.32

* git://git.infradead.org/users/dwmw2/iommu-2.6.32:
  intel-iommu: Support PCIe hot-plug
  intel-iommu: Obey coherent_dma_mask for alloc_coherent on passthrough
  intel-iommu: Check for 'DMAR at zero' BIOS error earlier.