[openib-general] [RFC] [PATCH 0/2] for 2.6.21/OFED1.2: add IB multicast support

[Sean Hefty]

The IB SA tracks multicast join/leave requests on a per port basis.
In order to support multiple users of the same multicast group from
the same port, we need to perform local reference counting on each
of the nodes.

Add an ib_multicast module to perform reference counting of multicast
join/leave requests, and modify ib_ipoib to use the new module.

Also extend the rdma_cm to support multicast communication.  A new
port space is added to the rdma_cm that allows joining the multicast
groups used by ipoib, or multicast groups can be joined using the
existing RDMA UDP port space.  The newly added RDMA_PS_IPOIB port
space also allows for unicast operations.

All changes are available through my rdma-dev.git tree (multicast branch);
although, that tree contains a collection of development patches.
Equivalent changes to the userspace librdmacm are also available in my
librdmacm.git tree.  Assuming that there are no issues after a code
review, I would like OFED 1.2 to rebase the multicast patches based
on the latest changes.  (The changes are also available in my
multicast-sa_cache branch.)

It is also my intent to create a 1.2 branch in my librdmacm.git tree as
a starting point for a release of the librdmacm.  (There are 1.0 and 1.1
branches there already, which are left from the initial svn conversion
to git.)

Signed-off-by: Sean Hefty <sean.hefty at intel.com>