[openib-general] mthca and DDR not hidden

Tue Oct 5 08:53:10 PDT 2004

    Michael> Actually saw some mail on lkml the other day about a 64
    Michael> bit system where memory is fragmented - PCI at 0 and
    Michael> actual memory near -1.  Anyway, Tavor is likely not only
    Michael> device with restrictions on maximum region size?

Right, that's why there's pci_set_dma_mask() etc.

    Michael> Are you saying consumer shall play with IOMMU? But then
    Michael> PCI addresses of memory will change each time consumer
    Michael> does this and you wont be able to use your default
    Michael> region?

Not "play with IOMMU" but use pci_map_single() etc.  The PCI address
may change but as long as it is in the low 0xffffffffffffffff part of
memory we're fine.

 - Roland