8139too.c

/*

	8139too.c: A RealTek RTL-8139 Fast Ethernet driver for Linux.

	Maintained by Jeff Garzik <jgarzik@pobox.com>
	Copyright 2000-2002 Jeff Garzik

	Much code comes from Donald Becker's rtl8139.c driver,
	versions 1.13 and older.  This driver was originally based
	on rtl8139.c version 1.07.  Header of rtl8139.c version 1.13:

	-----<snip>-----

        	Written 1997-2001 by Donald Becker.
		This software may be used and distributed according to the
		terms of the GNU General Public License (GPL), incorporated
		herein by reference.  Drivers based on or derived from this
		code fall under the GPL and must retain the authorship,
		copyright and license notice.  This file is not a complete
		program and may only be used when the entire operating
		system is licensed under the GPL.

		This driver is for boards based on the RTL8129 and RTL8139
		PCI ethernet chips.

		The author may be reached as becker@scyld.com, or C/O Scyld
		Computing Corporation 410 Severn Ave., Suite 210 Annapolis
		MD 21403

		Support and updates available at
		http://www.scyld.com/network/rtl8139.html

		Twister-tuning table provided by Kinston
		<shangh@realtek.com.tw>.

	-----<snip>-----

	This software may be used and distributed according to the terms
	of the GNU General Public License, incorporated herein by reference.

	Contributors:

		Donald Becker - he wrote the original driver, kudos to him!
		(but please don't e-mail him for support, this isn't his driver)

		Tigran Aivazian - bug fixes, skbuff free cleanup

		Martin Mares - suggestions for PCI cleanup

		David S. Miller - PCI DMA and softnet updates

		Ernst Gill - fixes ported from BSD driver

		Daniel Kobras - identified specific locations of
			posted MMIO write bugginess

		Gerard Sharp - bug fix, testing and feedback

		David Ford - Rx ring wrap fix

		Dan DeMaggio - swapped RTL8139 cards with me, and allowed me
		to find and fix a crucial bug on older chipsets.

		Donald Becker/Chris Butterworth/Marcus Westergren -
		Noticed various Rx packet size-related buglets.

		Santiago Garcia Mantinan - testing and feedback

		Jens David - 2.2.x kernel backports

		Martin Dennett - incredibly helpful insight on undocumented
		features of the 8139 chips

		Jean-Jacques Michel - bug fix

		Tobias Ringstrm - Rx interrupt status checking suggestion

		Andrew Morton - Clear blocked signals, avoid
		buffer overrun setting current->comm.

		Kalle Olavi Niemitalo - Wake-on-LAN ioctls

		Robert Kuebel - Save kernel thread from dying on any signal.

	Submitting bug reports:

		"rtl8139-diag -mmmaaavvveefN" output
		enable RTL8139_DEBUG below, and look at 'dmesg' or kernel log

*/

#define DRV_NAME	"8139too"
#define DRV_VERSION	"0.9.27"


#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/compiler.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/delay.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/completion.h>
#include <linux/crc32.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/irq.h>

#define RTL8139_DRIVER_NAME   DRV_NAME " Fast Ethernet driver " DRV_VERSION
#define PFX DRV_NAME ": "

/* Default Message level */
#define RTL8139_DEF_MSG_ENABLE   (NETIF_MSG_DRV   | \
                                 NETIF_MSG_PROBE  | \
                                 NETIF_MSG_LINK)


/* enable PIO instead of MMIO, if CONFIG_8139TOO_PIO is selected */
#ifdef CONFIG_8139TOO_PIO
#define USE_IO_OPS 1
#endif

/* define to 1, 2 or 3 to enable copious debugging info */
#define RTL8139_DEBUG 0

/* define to 1 to disable lightweight runtime debugging checks */
#undef RTL8139_NDEBUG


#if RTL8139_DEBUG
/* note: prints function name for you */
#  define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt, __FUNCTION__ , ## args)
#else
#  define DPRINTK(fmt, args...)
#endif

#ifdef RTL8139_NDEBUG
#  define assert(expr) do {} while (0)
#else
#  define assert(expr) \
        if(unlikely(!(expr))) {				        \
        printk(KERN_ERR "Assertion failed! %s,%s,%s,line=%d\n",	\
        #expr,__FILE__,__FUNCTION__,__LINE__);		        \
        }
#endif


/* A few user-configurable values. */
/* media options */
#define MAX_UNITS 8
static int media[MAX_UNITS] = {-1, -1, -1, -1, -1, -1, -1, -1};
static int full_duplex[MAX_UNITS] = {-1, -1, -1, -1, -1, -1, -1, -1};

/* Maximum number of multicast addresses to filter (vs. Rx-all-multicast).
   The RTL chips use a 64 element hash table based on the Ethernet CRC.  */
static int multicast_filter_limit = 32;

/* bitmapped message enable number */
static int debug = -1;

/*
 * Receive ring size 
 * Warning: 64K ring has hardware issues and may lock up.
 */
#if defined(CONFIG_SH_DREAMCAST)
#define RX_BUF_IDX	1	/* 16K ring */
#else
#define RX_BUF_IDX	2	/* 32K ring */
#endif
#define RX_BUF_LEN	(8192 << RX_BUF_IDX)
#define RX_BUF_PAD	16
#define RX_BUF_WRAP_PAD 2048 /* spare padding to handle lack of packet wrap */

#if RX_BUF_LEN == 65536
#define RX_BUF_TOT_LEN	RX_BUF_LEN
#else
#define RX_BUF_TOT_LEN	(RX_BUF_LEN + RX_BUF_PAD + RX_BUF_WRAP_PAD)
#endif

/* Number of Tx descriptor registers. */
#define NUM_TX_DESC	4

/* max supported ethernet frame size -- must be at least (dev->mtu+14+4).*/
#define MAX_ETH_FRAME_SIZE	1536

/* Size of the Tx bounce buffers -- must be at least (dev->mtu+14+4). */
#define TX_BUF_SIZE	MAX_ETH_FRAME_SIZE
#define TX_BUF_TOT_LEN	(TX_BUF_SIZE * NUM_TX_DESC)

/* PCI Tuning Parameters
   Threshold is bytes transferred to chip before transmission starts. */
#define TX_FIFO_THRESH 256	/* In bytes, rounded down to 32 byte units. */

/* The following settings are log_2(bytes)-4:  0 == 16 bytes .. 6==1024, 7==end of packet. */