Cisco Cisco IPICS Release 2.1 Licensing Information

* PHY component is expected to be 155 Mbps S/UNI-Lite or IDT 77155;

* see init_nicstar() for PHY initialization to change this. This driver

* expects the Linux ATM stack to support scatter-gather lists

* (skb->atm.iovcnt != 0) for Rx skb's passed to vcc->push.

*

* Implementing minimal-copy of received data:

*   IDT always receives data into a small buffer, then large buffers

*     as needed. This means that data must always be copied to create

*     the linear buffer needed by most non-ATM protocol stacks (e.g. IP)

*     Fix is simple: make large buffers large enough to hold entire

*     SDU, and leave <small_buffer_data> bytes empty at the start. Then

*     copy small buffer contents to head of large buffer.

*   Trick is to avoid fragmenting Linux, due to need for a lot of large

*     buffers. This is done by 2 things:

*       1) skb->destructor / skb->atm.recycle_buffer

*            combined, allow nicstar_free_rx_skb to be called to

*            recycle large data buffers

*       2) skb_clone of received buffers

*   See nicstar_free_rx_skb and linearize_buffer for implementation

*     details.

*

*

*

* Copyright (c) 1996 University of Cambridge Computer Laboratory

*

*   This program is free software; you can redistribute it and/or modify

*   it under the terms of the GNU General Public License as published by

*   the Free Software Foundation; either version 2 of the License, or

*   (at your option) any later version.

*

*   This program is distributed in the hope that it will be useful,

*   but WITHOUT ANY WARRANTY; without even the implied warranty of

*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

*   GNU General Public License for more details.

*

*   You should have received a copy of the GNU General Public License

*   along with this program; if not, write to the Free Software

*   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*

* M. Welsh, 6 July 1996

*

*

*/

Code in this directory written at the IDA Supercomputing Research Center

carries the following copyright and license.

 

   Copyright 1993 United States Government as represented by the

   Director, National Security Agency.  This software may be used