Re: Kernel 2.6.12-rc6-mm1 & Chelsio driver

[Scott Bardone <sbardone@chelsio.com>]

We modify the existing Linux TCP stack to add "hooks" so that our card can 
perform TCP offload and HW based checksum, thus making it possible to see high 
throughput with multiple connections and low CPU utilization.

We add 2 source files to the kernel, toedev.c and offload.c. We also modify 
neighbor.c, tcp.c, tcp_diag.c, tcp_ipv4.c, tcp_timer.c to add functions for our 
TOE capabilities so that the offloaded packet can be sent to our hardware 
(offload) path instead of going through the software (TCP stack) path.

Our processing engine is an ASIC with a HW based TCP stack which processes 
packets with Chelsio's CPL messages (Chelsio Protocol Language). I would not 
consider it a derived work.

-Scott


Christoph Hellwig wrote:
> On Tue, Jun 07, 2005 at 07:19:46PM -0700, Scott Bardone wrote:
> 
>>We currently don't have the TOE API in the Linux kernel so the TOE 
>>functionality does not exist, therefore you can only use the Chelsio 
>>modified 2.6.6 kernel for TOE.
> 
> 
> Care to explain what modifications you do, and whether or not you consider
> your card firmware a derived work of the TCP stack because of them?
>