On Mon, Jun 24, 2019 at 10:53:38AM -0600, Logan Gunthorpe wrote: > > It is only a very narrow case where you can take shortcuts with > > dma_addr_t, and I don't think shortcuts like are are appropriate for > > the mainline kernel.. > > I don't think it's that narrow and it opens up a lot of avenues for > system design that people are wanting to go. If your high speed data > path can avoid the root complex and CPU, you can design a system which a > much smaller CPU and fewer lanes directed at the CPU. I mean the shortcut that something generates dma_addr_t for Device A and then passes it to Device B - that is too hacky for mainline. Sounded like this series does generate the dma_addr for the correct device.. Jason