• Sean Hefty's avatar
    [IB] Fix MAD layer DMA mappings to avoid touching data buffer once mapped · 34816ad9
    Sean Hefty authored
    The MAD layer was violating the DMA API by touching data buffers used
    for sends after the DMA mapping was done.  This causes problems on
    non-cache-coherent architectures, because the device doing DMA won't
    see updates to the payload buffers that exist only in the CPU cache.
    Fix this by having all MAD consumers use ib_create_send_mad() to
    allocate their send buffers, and moving the DMA mapping into the MAD
    layer so it can be done just before calling send (and after any
    modifications of the send buffer by the MAD layer).
    Tested on a non-cache-coherent PowerPC 440SPe system.
    Signed-off-by: default avatarSean Hefty <sean.hefty@intel.com>
    Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>