/* nicstar.c  v0.22  Jawaid Bazyar (bazyar@hypermall.com)
   * nicstar.c, M. Welsh (matt.welsh@cl.cam.ac.uk)
   *
   * Hacked October, 1997 by Jawaid Bazyar, Interlink Advertising Services Inc.
   * 	http://www.hypermall.com/
   * 10/1/97 - commented out CFG_PHYIE bit - we don't care when the PHY
   *	interrupts us (except possibly for removal/insertion of the cable?)
   * 10/4/97 - began heavy inline documentation of the code. Corrected typos
   *	and spelling mistakes.
   * 10/5/97 - added code to handle PHY interrupts, disable PHY on
   *	loss of link, and correctly re-enable PHY when link is
   *	re-established. (put back CFG_PHYIE)
   *
   *   Modified to work with the IDT7721 nicstar -- AAL5 (tested) only.
   *

   * R. D. Rechenmacher <ron@fnal.gov>, Aug. 6, 1997

   *
   * Linux driver for the IDT77201 NICStAR PCI ATM controller.
   * 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
   *
   *
   */