[openib-general] CM handling of REJ retry

[Fab Tillier]

The IB spec, section 12.9.8.7 states that the local CID should be changed if
retrying a REQ after receiving a REJ in the REQ Sent or REP Wait state.

The current API seems to require uses to destroy their CID and allocate a
new one before they can retry (i.e. it doesn't support REJ retry).  Do we
want (and is it possible) to have the CM reserve the upper byte (or any
other portion) of the LCID and use it as a revolving counter so users can
just retry a request?  This would limit a system to 2^24 CIDs, which is
probably more then enough.

Thoughts?

- Fab