iommu_dma_alloc_iova
iova = iommu_dma_alloc_iova(domain, iova_len, dma_get_mask(dev), dev);
addr = iommu_dma_alloc_iova(domain,
iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
iova = iommu_dma_alloc_iova(domain, size, dma_mask, dev);
iova = iommu_dma_alloc_iova(domain, size, dev->coherent_dma_mask, dev);