On Fri, Mar 11, 2016 at 01:58:46PM +0100, Niklas S?derlund wrote: > Without an IOMMU this is easy since the phys_addr_t and dma_addr_t are > the same and no special care is needed. However if you have a IOMMU you > need to map the DMA slave phys_addr_t to a dma_addr_t using something > like this. Is it not very similar to dma_map_single() where one maps > processor virtual memory (instead if MMIO) so that it can be used with > DMA slaves?
It's similar, but I don't think this actually works as a general case as there are quite a few places that expect to be able to have a struct page for a physical address. We'd at least need a very careful audit for that case.
