[openib-general] Re: ib_mad.h ib_mad_post_send PCI mapping

Roland Dreier roland at topspin.com
Tue Sep 7 10:20:04 PDT 2004


    Hal> I have another ib_mad_post_send question relative to PCI
    Hal> mapping. Is it correct to assume that like ib_post_send that
    Hal> any PCI mapping (and cache synchronization) is to be
    Hal> performed in the client rather than in ib_mad_post_send
    Hal> itself ?

    Sean> Not entirely sure what you mean here.  Are you asking if the
    Sean> buffers are registered with the HCA?  If so, then my
    Sean> assumption is that the client did this.

Actually I think Hal is asking who calls pci_map()/pci_unmap() (I
think the plan for memory registration is just for the MAD layer to
register all of RAM or use the reserved L_Key).

I agree that it makes sense for the consumer to do the PCI mapping
since that allows consumers to do thinks like allocate MADs with
pci_pool_alloc() and avoid calling pci_map at all.

 - R.



More information about the general mailing list