REORDERING PCP FLOWS AS THEY ARE ASSIGNED TO VIRTUAL CHANNELS

摘要

A Network Flow Processor (NFP) integrated circuit receives, via each of a plurality of physical MAC ports, PCP (Priority Code Point) flows. The NFP also maintains, for each of a plurality of virtual channels, a linked list of buffers. There is one port enqueue engine for each physical MAC port. For each PCP flow received via the physical MAC port associated with a port enqueue engine, the engine causes frame data of the flow to be loaded into one particular linked list of buffers. Each engine has a lookup table circuit that is configurable so that the relative priorities of the PCP flows are reordered as the PCP flows are assigned to virtual channels. A PCP flow with a higher PCP value can be assigned to a lower priority virtual channel, whereas a PCP flow with a lower PCP value can be assigned to a higher priority virtual channel.

主权项

1. A method comprising:
(a) receiving configuration information onto a Media Access Control (MAC) layer interface circuit of a Network Flow Processor (NFP) integrated circuit, wherein the configuration information includes port definition configuration information and Priority Code Point (PCP) remap information, wherein the PCP remap information includes a plurality of portions; (b) using the port definition configuration information to configure the MAC layer interface circuit to include a first number of physical MAC ports, wherein the MAC layer interface circuit can alternatively be configured by the other port definition configuration information into another configuration that includes another number of physical MAC ports; (c) receiving a plurality of PCP flows of ethernet frames via the physical MAC ports onto the NFP integrated circuit, wherein all the frames of a PCP flow are received via the same physical MAC port and wherein all of the frames of the PCP flow have the same PCP value, wherein a first PCP flow received via a physical MAC port has a larger PCP value as compared to a second PCP flow received via the same physical MAC port that has a smaller PCP value; (d) storing each respective portion of the PCP remap information in association with a corresponding respective one of the physical MAC ports; and (e) for each frame received via a particular physical MAC port using the PCP value of the frame and the portion of the PCP remap information associated with the physical MAC port to assign the frame to one of a second number of virtual channels, wherein a first of the virtual channels is a higher priority channel through the NFP integrated circuit as compared to second of the virtual channels that is of a lower priority, wherein the assigning of (e) involves assigning the first PCP flow to the second virtual channel and assigning the second PCP flow to the first virtual channel, wherein the first number multiplied by eight is greater than the second number.