1. 08 Feb, 2008 1 commit
    • Jack Morgenstein's avatar
      IB/mlx4: Use multiple WQ blocks to post smaller send WQEs · ea54b10c
      Jack Morgenstein authored
      ConnectX HCA supports shrinking WQEs, so that a single work request
      can be made of multiple units of wqe_shift.  This way, WRs can differ
      in size, and do not have to be a power of 2 in size, saving memory and
      speeding up send WR posting.  Unfortunately, if we do this then the
      wqe_index field in CQEs can't be used to look up the WR ID anymore, so
      our implementation does this only if selective signaling is off.
      
      Further, on 32-bit platforms, we can't use vmap() to make the QP
      buffer virtually contigious. Thus we have to use constant-sized WRs to
      make sure a WR is always fully within a single page-sized chunk.
      
      Finally, we use WRs with the NOP opcode to avoid wrapping around the
      queue buffer in the middle of posting a WR, and we set the
      NoErrorCompletion bit to avoid getting completions with error for NOP
      WRs.  However, NEC is only supported starting with firmware 2.2.232,
      so we use constant-sized WRs for older firmware.  And, since MLX QPs
      only support SEND, we use constant-sized WRs in this case.
      
      When stamping during NOP posting, do stamping following setting of the
      NOP WQE valid bit.
      Signed-off-by: default avatarMichael S. Tsirkin <mst@dev.mellanox.co.il>
      Signed-off-by: default avatarJack Morgenstein <jackm@dev.mellanox.co.il>
      Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
      ea54b10c
  2. 07 Feb, 2008 3 commits
  3. 05 Feb, 2008 36 commits