add swiotlb support to arm32

Christoph Hellwig
2019-07-09T14:27:05Z

Hi Russell,

This series adds swiotlb support to the 32-bit arm port to ensure
platforms with LPAE support can support DMA mapping for all devices
using 32-bit dma masks, just like we do on other ports that support
> 32-bit physical addressing and don't have an iommu.