mlx4: Add ref counting to port MAC table for RoCE
The IB side of RoCE requires the MAC table index of the MAC address used by its QPs. To obtain the real MAC index, the IB side registers the MAC (increasing its ref count, and also returning the real MAC index) during the modify-qp sequence. This protects against the ETH side deleting or modifying that MAC table entry while the QP is active. Note that until the modify-qp command returns success, the MAC and VLAN information only has "candidate" status. If the modify-qp succeeds, the "candidate" info is promoted to the operational MAC/VLAN info for the qp. If the modify fails, the candidate MAC/VLAN is unregistered, and the old qp info is preserved. The patch is a bit complex, because there are multiple qp transitions where the primary-path information may be modified: INIT-to-RTR, and SQD-to-SQD. Similarly for the alternate path information. Therefore the code must handle cases where path information has already been entered into the QP context by previous qp transitions. For the MAC address, the success logic is as follows: 1. If there was no previous MAC, simply move the candidate MAC information to the operational information, and reset the candidate MAC info. 2. If there was a previous MAC, unregister it. Then move the MAC information from candidate to operational, and reset the candidate info (as in 1. above). The MAC address failure logic is the same for all cases: - Unregister the candidate MAC, and reset the candidate MAC info. For Vlan registration, the logic is similar. Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Showing
Please register or sign in to comment