Method and apparatus for a configurable packet routing, buffering and scheduling scheme to optimize throughput with deadlock prevention in SRIO-to-PCIe bridges

摘要

A method and apparatus for a configurable packet routing, buffering and scheduling scheme to optimize throughput with deadlock prevention in SRIO-to-PCIe Bridges have been described. A single level enqueue method with dynamic buffering and dequeuing based on packet re-ordering is disclosed. Single level packet routing and scheduling to meet SRIO and PCIe rules to enqueue packets based on FType/TType is disclosed. Backpressure based on ingress watermarks for different packet types is disclosed. Use of a circular-reorder queue (CRQ) for both ingress and egress allows packet reordering and packet passing.

主权项

1. A method for bridging between a Serial RapidIO® (SRIO) port and a PCI Express® (PCIe) port, the method comprising:
keeping track of arrival times for all packets received at an ingress port, said ingress port selected from the group consisting of said Serial RapidIO® (SRIO) port and said PCI Express® (PCIe) port, said ingress port having a dequeue block, and said ingress port operatively coupled to a plurality of virtual output queues; selecting said plurality of virtual output queues for storing said all packets based on packet priority, packet critical request flow, and packet flow identification; generating an ingress backpressure wherein the ingress backpressure is based on user configurable watermarks for user defined one or more packet types and for each of said Serial RapidIO® (SRIO) port and said PCI Express® (PCIe) port; placing said all packets received at said ingress port in a circular-reorder queue, said circular-reorder queue having a last-free-location pointer to a first open location in said circular-reorder queue, a next-to-send-location pointer to a first occupied location in said circular-reorder queue, a first-free-location pointer to a second open location in said circular-reorder queue, a last-packet-enqueued-location pointer to a second occupied location in said circular-reorder queue, and wherein said circular-reorder queue stores an acknowledgement identification for each of said all packets received at said ingress port; and dequeuing said circular-reorder queue.