1 /* nicstar.c v0.22 Jawaid Bazyar (bazyar@hypermall.com)
2 * nicstar.c, M. Welsh (matt.welsh@cl.cam.ac.uk)
3 *
4 * Hacked October, 1997 by Jawaid Bazyar, Interlink Advertising Services Inc.
5 * http://www.hypermall.com/
6 * 10/1/97 - commented out CFG_PHYIE bit - we don't care when the PHY
7 * interrupts us (except possibly for removal/insertion of the cable?)
8 * 10/4/97 - began heavy inline documentation of the code. Corrected typos
9 * and spelling mistakes.
10 * 10/5/97 - added code to handle PHY interrupts, disable PHY on
11 * loss of link, and correctly re-enable PHY when link is
12 * re-established. (put back CFG_PHYIE)
13 *
14 * Modified to work with the IDT7721 nicstar -- AAL5 (tested) only.
15 *
16 * R. D. Rechenmacher <ron@fnal.gov>, Aug. 6, 1997 $Revision: 1.1 $ $Date: 1999/08/20 11:00:11 $
17 *
18 * Linux driver for the IDT77201 NICStAR PCI ATM controller.
19 * PHY component is expected to be 155 Mbps S/UNI-Lite or IDT 77155;
20 * see init_nicstar() for PHY initialization to change this. This driver
21 * expects the Linux ATM stack to support scatter-gather lists
22 * (skb->atm.iovcnt != 0) for Rx skb's passed to vcc->push.
23 *
24 * Implementing minimal-copy of received data:
25 * IDT always receives data into a small buffer, then large buffers
26 * as needed. This means that data must always be copied to create
27 * the linear buffer needed by most non-ATM protocol stacks (e.g. IP)
28 * Fix is simple: make large buffers large enough to hold entire
29 * SDU, and leave <small_buffer_data> bytes empty at the start. Then
30 * copy small buffer contents to head of large buffer.
31 * Trick is to avoid fragmenting Linux, due to need for a lot of large
32 * buffers. This is done by 2 things:
33 * 1) skb->destructor / skb->atm.recycle_buffer
34 * combined, allow nicstar_free_rx_skb to be called to
35 * recycle large data buffers
36 * 2) skb_clone of received buffers
37 * See nicstar_free_rx_skb and linearize_buffer for implementation
38 * details.
39 *
40 *
41 *
42 * Copyright (c) 1996 University of Cambridge Computer Laboratory
43 *
44 * This program is free software; you can redistribute it and/or modify
45 * it under the terms of the GNU General Public License as published by
46 * the Free Software Foundation; either version 2 of the License, or
47 * (at your option) any later version.
48 *
49 * This program is distributed in the hope that it will be useful,
50 * but WITHOUT ANY WARRANTY; without even the implied warranty of
51 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
52 * GNU General Public License for more details.
53 *
54 * You should have received a copy of the GNU General Public License
55 * along with this program; if not, write to the Free Software
56 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
57 *
58 * M. Welsh, 6 July 1996
59 *
60 *
61 */
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.