Use DMA API instead of architecture internal functions like __cpuc_flush_dcache_area() etc. The biggest difficulty here is that dma_map and _sync calls require some struct device, while there is no real 1:1 relation between an IOMMU domain and some device. To overcome this, a simple platform device is registered for each allocated IOMMU domain. With this patch, this driver can be used on both ARM and ARM64 platforms, such as RK3288 and RK3399 respectively. Signed-off-by: Shunqian Zheng <zhengsq@rock-chips.com> Signed-off-by: Tomasz Figa <tfiga@chromium.org> Signed-off-by: Joerg Roedel <jroedel@suse.de>