> It appears that my problem boils down to a single host page of memory > that is mapped for dma, and the dma address returned by dma_map_sg() > is _not_ 64KB aligned. Here is an example:
> My first question is: Is there an assumption or requirement in linux > that dma_addressess should have the same alignment as the host address > they are mapped to? IE the rdma core is mapping the entire 64KB page, > but the mapping doesn't begin on a 64KB page boundary. I don't think this is explicitly documented anywhere, but it certainly seems that we want the bus address to be page-aligned in this case. For mthca/mlx4 at least, we tell the adapter what the host page size is (so that it knows how to align doorbell pages etc) and I think this sort of thing would confuse the HW. - R. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
