mirror of
https://github.com/torvalds/linux.git
synced 2024-11-17 17:41:44 +00:00
f8b0dfd152
Open MPI, Intel MPI and other applications don't respect the iWARP requirement that the client (active) side of the connection send the first RDMA message. This class of application connection setup is called peer-to-peer. Typically once the connection is setup, _both_ sides want to send data. This patch enables supporting peer-to-peer over the chelsio RNIC by enforcing this iWARP requirement in the driver itself as part of RDMA connection setup. Connection setup is extended, when the peer2peer module option is 1, such that the MPA initiator will send a 0B Read (the RTR) just after connection setup. The MPA responder will suspend SQ processing until the RTR message is received and reply-to. In the longer term, this will be handled in a standardized way by enhancing the MPA negotiation so peers can indicate whether they want/need the RTR and what type of RTR (0B read, 0B write, or 0B send) should be sent. This will be done by standardizing a few bits of the private data in order to negotiate all this. However this patch enables peer-to-peer applications now and allows most of the required firmware and driver changes to be done and tested now. Design: - Add a module option, peer2peer, to enable this mode. - New firmware support for peer-to-peer mode: - a new bit in the rdma_init WR to tell it to do peer-2-peer and what form of RTR message to send or expect. - process _all_ preposted recvs before moving the connection into rdma mode. - passive side: defer completing the rdma_init WR until all pre-posted recvs are processed. Suspend SQ processing until the RTR is received. - active side: expect and process the 0B read WR on offload TX queue. Defer completing the rdma_init WR until all pre-posted recvs are processed. Suspend SQ processing until the 0B read WR is processed from the offload TX queue. - If peer2peer is set, driver posts 0B read request on offload TX queue just after posting the rdma_init WR to the offload TX queue. - Add CQ poll logic to ignore unsolicitied read responses. Signed-off-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Roland Dreier <rolandd@cisco.com> |
||
|---|---|---|
| .. | ||
| core | ||
| hw | ||
| ulp | ||
| Kconfig | ||
| Makefile | ||