Commits
Ido Schimmel committed d81a6bdb87c
mlxsw: spectrum: Add IEEE 802.1Qbb PFC support Implement the appropriate DCB ops and allow a user to configure certain traffic classes as lossless. The operation configures PFC for both the egress (respecting PFC frames) and ingress (sending PFC frames) parts of the port. At egress, when a PFC frame is received for a PFC enabled priority, then all the priorities mapped to the same TC are stopped. At ingress, the priority group (PG) buffers to which the enabled PFC priorities are mapped are configured to be lossless. PFC frames will be transmitted when the Xoff threshold is crossed. The user-supplied delay parameter is used to determine the PG's size according to the following formula: PG_SIZE = PG_SIZE_LOSSY + delay * CELL_FACTOR + MTU In the worst case scenario the delay will be made up of packets that are all of size CELL_SIZE + 1, which means each packet will require almost twice its true size when buffered in the switch. We therefore multiply this value by the "cell factor", which is close to 2. Another MTU is added in case the transmitting host already started transmitting a maximum length frame when the PFC packet was received. As with PAUSE enabled ports, when the port's MTU is changed both the PGs' size and threshold are adjusted accordingly. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>