Apparatus and method for accelerated page link list processing in a packet processor operating at wirespeed
View Patent ↗A packet processor has a packet memory manager configured to store a page walk link list, receive a descriptor and initiate a page walk through the page walk link list in response to the descriptor and without a prompt from transmit direct memory access circuitry. The packet memory manager is configured to receive an indicator of a single page packet and read a new packet in response to the indicator without waiting to obtain page state associated with the page of the single page packet.
1. A packet processor, comprising:
a packet memory manager configured to
store a page walk link list;
receive a descriptor;
initiate a page walk through the page walk link list in response to the descriptor and without a prompt from transmit direct memory access circuitry;
guarantee that the state of a first page of a packet is written by the time the descriptor of the packet is received;
apply a first latency to a second page of the packet, wherein the first latency is the difference between the latency of a packet processor ingress port to fill a full page with packet data and the maximum latency of a control block issuing a descriptor; and
apply a second latency to each additional page of the packet, wherein the second latency is the latency of the packet processor ingress port to fill a full page with packet data.
2. The packet processor of claim 1 wherein the packet memory manager is further configured to
receive an indicator of a single page packet; and
read a new packet in response to the indicator without waiting to obtain page state associated with the page of the single page packet.
3. The packet processor of claim 2 wherein the indictor is a single bit.
4. A packet processor, comprising:
a packet memory manager configured to
receive an indicator of a single page packet;
read a new packet in response to the indicator without waiting to obtain page state associated with the page of the single page packet;
guarantee that the state of a first page of a packet is written by the time a descriptor of the packet is received;
apply a first latency to a second page of the packet, wherein the first latency is the difference between the latency of a packet processor ingress port to fill a full page with packet data and the maximum latency of a control block issuing a descriptor; and
apply a second latency to each additional page of the packet, wherein the second latency is the latency of the packet processor ingress port to fill a full page with packet data.
5. The packet processor of claim 4 wherein the indictor is a single bit.
6. The packet processor of claim 4 , wherein the packet memory manager is further configured to
store a page walk link list;
receive a descriptor; and
initiate a page walk through the page walk link list in response to the descriptor and without a prompt from transmit direct memory access circuitry.
7. A packet processor, comprising:
a packet memory manager configured for cut-through operation so as to
guarantee that the state of a first page of a packet is written by the time the descriptor of the packet is received;
apply a first latency to a second page of the packet, wherein the first latency is the difference between the latency of a packet processor ingress port to fill a full page with packet data and the maximum latency of a control block issuing a descriptor; and
apply a second latency to each additional page of the packet, wherein the second latency is the latency of the packet processor ingress port to fill a full page with packet data.
8. The packet processor of claim 7 wherein the packet memory manager is further configured to
store a page walk link list;
receive a descriptor; and
initiate a page walk through the page walk link list in response to the descriptor and without a prompt from transmit direct memory access circuitry.
9. The packet processor of claim 7 wherein the packet memory manager is further configured to
receive an indicator of a single page packet; and
read a new packet in response to the indicator without waiting to obtain the page state associated with the page of the single page packet.
10. The packet processor of claim 9 wherein the indictor is a single bit.