/*

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

	Maintained by Jeff Garzik <jgarzik@mandrakesoft.com>
	Copyright 2000,2001 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 Ringström - Rx interrupt status checking suggestion

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

	Submitting bug reports:

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

		See 8139too.txt for more details.

-----------------------------------------------------------------------------

				Theory of Operation

I. Board Compatibility

This device driver is designed for the RealTek RTL8139 series, the RealTek
Fast Ethernet controllers for PCI and CardBus.  This chip is used on many
low-end boards, sometimes with its markings changed.


II. Board-specific settings

PCI bus devices are configured by the system at boot time, so no jumpers
need to be set on the board.  The system BIOS will assign the
PCI INTA signal to a (preferably otherwise unused) system IRQ line.

III. Driver operation

IIIa. Rx Ring buffers

The receive unit uses a single linear ring buffer rather than the more
common (and more efficient) descriptor-based architecture.  Incoming frames
are sequentially stored into the Rx region, and the host copies them into
skbuffs.

Comment: While it is theoretically possible to process many frames in place,
any delay in Rx processing would cause us to drop frames.  More importantly,
the Linux protocol stack is not designed to operate in this manner.

IIIb. Tx operation

The RTL8139 uses a fixed set of four Tx descriptors in register space.
In a stunningly bad design choice, Tx frames must be 32 bit aligned.  Linux
aligns the IP header on word boundaries, and 14 byte ethernet header means
that almost all frames will need to be copied to an alignment buffer.

IVb. References

http://www.realtek.com.tw/cn/cn.html
http://www.scyld.com/expert/NWay.html

IVc. Errata

1) The RTL-8139 has a serious problem with motherboards which do
posted MMIO writes to PCI space.  This driver works around the
problem by having an MMIO  register write be immediately followed by
an MMIO register read.

*/

#define DRV_NAME	"8139too"
#define DRV_VERSION	"0.9.18-pre4"


#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.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 <asm/io.h>
#include <asm/uaccess.h>

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


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

/* define to 1 to enable copious debugging info */
#undef RTL8139_DEBUG

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


#ifdef 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(!(expr)) {					\
        printk( "Assertion failed! %s,%s,%s,line=%d\n",	\
        #expr,__FILE__,__FUNCTION__,__LINE__);		\
        }
#endif

#define dev_kfree_skb_irq(a)	dev_kfree_skb(a)
#define netif_wake_queue(dev)	do { clear_bit(0, &dev->tbusy); mark_bh(NET_BH); } while (0);
#define netif_stop_queue(dev)	set_bit(0, &dev->tbusy)

static inline void netif_start_queue(struct device *dev)
{
	dev->tbusy = 0;
	dev->interrupt = 0;
	dev->start = 1;
}

#define netif_queue_stopped(dev)	dev->tbusy
#define netif_running(dev)		dev->start
#define dma_addr_t unsigned long

struct resource {
	const char *name;
	unsigned long start, end;
	unsigned long flags;
	struct resource *parent, *sibling, *child;
};

#define IORESOURCE_BITS         0x000000ff      /* Bus-specific bits */
#define IORESOURCE_IO           0x00000100      /* Resource type */
#define IORESOURCE_MEM          0x00000200
#define IORESOURCE_IRQ          0x00000400
#define IORESOURCE_DMA          0x00000800
#define IORESOURCE_PREFETCH     0x00001000      /* No side effects */
#define IORESOURCE_READONLY     0x00002000
#define IORESOURCE_CACHEABLE    0x00004000
#define IORESOURCE_RANGELENGTH  0x00008000
#define IORESOURCE_SHADOWABLE   0x00010000
#define IORESOURCE_UNSET        0x20000000
#define IORESOURCE_AUTO         0x40000000
#define IORESOURCE_BUSY         0x80000000

#define PCI_USES_IO		1
#define PCI_USES_MEM		2
#define PCI_USES_MASTER 	4

static inline unsigned int rtl8139_pci_calc_resource_flags(unsigned int flags)
{
	if (flags & PCI_BASE_ADDRESS_SPACE_IO)
		return IORESOURCE_IO;

	if (flags & PCI_BASE_ADDRESS_MEM_PREFETCH)
		return IORESOURCE_MEM | IORESOURCE_PREFETCH;

	return IORESOURCE_MEM;
}

static void rtl8139_read_pci_resources(struct pci_dev *dev, struct resource *res)
{
	unsigned int pos, reg, next;
	u32 l, sz, tmp;
	u16 cmd;

	/* Disable IO and memory while we fiddle */
	pci_read_config_word(dev, PCI_COMMAND, &cmd);
	tmp = cmd & ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
	pci_write_config_word(dev, PCI_COMMAND, tmp);
	
	for (pos=0; pos<4; pos = next, res++) {
		next = pos+1;
		reg = PCI_BASE_ADDRESS_0 + (pos << 2);
		pci_read_config_dword(dev, reg, &l);
		pci_write_config_dword(dev, reg, ~0);
		pci_read_config_dword(dev, reg, &sz);
		pci_write_config_dword(dev, reg, l);
		if (!sz || sz == 0xffffffff)
			continue;
		if (l == 0xffffffff)
			l = 0;
		if ((l & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_MEMORY) {
			res->start = l & PCI_BASE_ADDRESS_MEM_MASK;
			sz = ~(sz & PCI_BASE_ADDRESS_MEM_MASK);
		} else {
			res->start = l & PCI_BASE_ADDRESS_IO_MASK;
			sz = ~(sz & PCI_BASE_ADDRESS_IO_MASK) & 0xffff;
		}
		res->end = res->start + (unsigned long) sz;
		res->flags |= (l & 0xf) | rtl8139_pci_calc_resource_flags(l);
	}
}

#define rtl8139_pci_resource_start(dev_priv,bar)	((dev_priv)->rtl8139_pci_resource[(bar)].start)
#define rtl8139_pci_resource_end(dev_priv,bar)	((dev_priv)->rtl8139_pci_resource[(bar)].end)
#define rtl8139_pci_resource_flags(dev_priv,bar)	((dev_priv)->rtl8139_pci_resource[(bar)].flags)
#define rtl8139_pci_resource_len(dev_priv,bar) \
	((rtl8139_pci_resource_start((dev_priv),(bar)) == 0 &&	\
	  rtl8139_pci_resource_end((dev_priv),(bar)) ==		\
	  rtl8139_pci_resource_start((dev_priv),(bar))) ? 0 :	\
	  						\
	 (rtl8139_pci_resource_end((dev_priv),(bar)) -		\
	  rtl8139_pci_resource_start((dev_priv),(bar)) + 1))

#define RTL8139_PCI_ANY_ID 0xffff
static inline struct pci_dev *rtl8139_pci_find_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
{
	if (!from)
		from = pci_devices;
	else
		from = from->next;
	while (from && (!(from->vendor == vendor || vendor==RTL8139_PCI_ANY_ID) || !(from->device == device || device==RTL8139_PCI_ANY_ID)))
		from = from->next;
	return from;
}

#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
#define SIOCETHTOOL	0x8946		/* Ethtool interface */
#define SIOCGMIIPHY	0x8947		/* Get address of MII PHY in use. */
#define SIOCGMIIREG	0x8948		/* Read MII PHY register.	*/
#define SIOCSMIIREG	0x8949		/* Write MII PHY register.	*/
#define ETHTOOL_GSET		0x00000001 /* Get settings. */
#define ETHTOOL_SSET		0x00000002 /* Set settings, privileged. */
#define ETHTOOL_GDRVINFO	0x00000003 /* Get driver info. */

/* these strings are set to whatever the driver author decides... */
struct ethtool_drvinfo {
	u32	cmd;
	char	driver[32];	/* driver short name, "tulip", "eepro100" */
	char	version[32];	/* driver version string */
	char	fw_version[32];	/* firmware version string, if applicable */
	char	bus_info[32];	/* Bus info for this interface.  For PCI
				 * devices, use pci_dev->slot_name. */
	char	reserved1[32];
	char	reserved2[32];
};

/* This structure is used in all SIOCxMIIxxx ioctl calls */
struct mii_ioctl_data {
	u16		phy_id;
	u16		reg_num;
	u16		val_in;
	u16		val_out;
};

/* 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 events (Rx packets, etc.) to handle at each interrupt. */
static int max_interrupt_work = 20;

/* 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;

/* Size of the in-memory receive ring. */
#define RX_BUF_LEN_IDX	2	/* 0==8K, 1==16K, 2==32K, 3==64K */
#define RX_BUF_LEN (8192 << RX_BUF_LEN_IDX)
#define RX_BUF_PAD 16
#define RX_BUF_WRAP_PAD 2048 /* spare padding to handle lack of packet wrap */
#define RX_BUF_TOT_LEN (RX_BUF_LEN + RX_BUF_PAD + RX_BUF_WRAP_PAD)
#define RX_EARLY_THRESH 2

/* 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. */
#define RX_FIFO_THRESH	7	/* Rx buffer level before first PCI xfer.  */
#define RX_DMA_BURST	7	/* Maximum PCI burst, '6' is 1024 */
#define TX_DMA_BURST	6	/* Maximum PCI burst, '6' is 1024 */


/* Operational parameters that usually are not changed. */
/* Time in jiffies before concluding the transmitter is hung. */
#define TX_TIMEOUT  (6*HZ)


enum {
	RTL_PCI_64BIT = 0x0100,
	HAS_MII_XCVR = 0x010000,
	HAS_CHIP_XCVR = 0x020000,
	HAS_LNK_CHNG = 0x040000,
};

#define RTL_MIN_IO_SIZE 0x80
#define RTL8139B_IO_SIZE 256

#define RTL8129_CAPS	HAS_MII_XCVR
#define RTL8139_CAPS	HAS_CHIP_XCVR|HAS_LNK_CHNG

typedef enum {
	RTL8139 = 0,
	RTL8139_CB,
	SMC1211TX,
	MPX5030,
	DELTA8139,
	ADDTRON8139,
	DFE538TX,
	RTL8129,
} board_t;


/* indexed by board_t, above */
static struct {
	const char *name;
	u32 hw_flags;
} board_info[] = {
	{ "RealTek RTL8139 Fast Ethernet", RTL8139_CAPS },
	{ "RealTek RTL8139B PCI/CardBus", RTL8139_CAPS },
	{ "SMC1211TX EZCard 10/100 (RealTek RTL8139)", RTL8139_CAPS | (RTL_PCI_64BIT | 2)},
	{ "Accton MPX5030 (RealTek RTL8139)", RTL8139_CAPS | (RTL_PCI_64BIT | 2)},
	{ "Delta Electronics 8139 10/100BaseTX", RTL8139_CAPS },
	{ "Addtron Technolgy 8139 10/100BaseTX", RTL8139_CAPS },
	{ "D-Link DFE-538TX (RealTek RTL8139)", RTL8139_CAPS | (RTL_PCI_64BIT | 1)},
	{ "RealTek RTL8129", RTL8129_CAPS },
};

struct pci_device_id {
	unsigned int vendor, device;
	board_t board;
};

static struct pci_device_id rtl8139_pci_tbl[] = {
	{0x10ec, 0x8139, RTL8139 },
	{0x10ec, 0x8138, RTL8139_CB },
	{0x1113, 0x1211, SMC1211TX },
	{0x1113, 0x1211, MPX5030 },
	{0x1500, 0x1360, DELTA8139 },
	{0x4033, 0x1360, ADDTRON8139 },
	{0x1186, 0x1300, DFE538TX },
#ifdef CONFIG_8139TOO_8129
	{0x10ec, 0x8129, RTL8129 },
#endif
	/* some crazy card report invalid vendor IDs,
	 * catch this. RTL8139_PCI_ANY_ID means match anything
	 * 1KJD 2001-04-08
	 */
	{RTL8139_PCI_ANY_ID, 0x8139, RTL8139 },
	{0,}
};

/* The rest of these values should never change. */

static struct device *rtl8139_device_tab[16];
static int rtl8139_device_count = 0;
static int rtl8139_initialized = 0;

/* Symbolic offsets to registers. */
enum RTL8139_registers {
	MAC0 = 0,		/* Ethernet hardware address. */
	MAR0 = 8,		/* Multicast filter. */
	TxStatus0 = 0x10,	/* Transmit status (Four 32bit registers). */
	TxAddr0 = 0x20,		/* Tx descriptors (also four 32bit). */
	RxBuf = 0x30,
	RxEarlyCnt = 0x34,
	RxEarlyStatus = 0x36,
	ChipCmd = 0x37,
	RxBufPtr = 0x38,
	RxBufAddr = 0x3A,
	IntrMask = 0x3C,
	IntrStatus = 0x3E,
	TxConfig = 0x40,
	ChipVersion = 0x43,
	RxConfig = 0x44,
	Timer = 0x48,		/* A general-purpose counter. */
	RxMissed = 0x4C,	/* 24 bits valid, write clears. */
	Cfg9346 = 0x50,
	Config0 = 0x51,
	Config1 = 0x52,
	FlashReg = 0x54,
	MediaStatus = 0x58,
	Config3 = 0x59,
	Config4 = 0x5A,		/* absent on RTL-8139A */
	HltClk = 0x5B,
	MultiIntr = 0x5C,
	TxSummary = 0x60,
	BasicModeCtrl = 0x62,
	BasicModeStatus = 0x64,
	NWayAdvert = 0x66,
	NWayLPAR = 0x68,
	NWayExpansion = 0x6A,
	/* Undocumented registers, but required for proper operation. */
	FIFOTMS = 0x70,		/* FIFO Control and test. */
	CSCR = 0x74,		/* Chip Status and Configuration Register. */
	PARA78 = 0x78,
	PARA7c = 0x7c,		/* Magic transceiver parameter register. */
	Config5 = 0xD8,		/* absent on RTL-8139A */
};

enum ClearBitMasks {
	MultiIntrClear = 0xF000,
	ChipCmdClear = 0xE2,
	Config1Clear = (1<<7)|(1<<6)|(1<<3)|(1<<2)|(1<<1),
};

enum ChipCmdBits {
	CmdReset = 0x10,
	CmdRxEnb = 0x08,
	CmdTxEnb = 0x04,
	RxBufEmpty = 0x01,
};

/* Interrupt register bits, using my own meaningful names. */
enum IntrStatusBits {
	PCIErr = 0x8000,
	PCSTimeout = 0x4000,
	RxFIFOOver = 0x40,
	RxUnderrun = 0x20,
	RxOverflow = 0x10,
	TxErr = 0x08,
	TxOK = 0x04,
	RxErr = 0x02,
	RxOK = 0x01,

	RxAckBits = RxFIFOOver | RxOverflow | RxOK,
};

enum TxStatusBits {
	TxHostOwns = 0x2000,
	TxUnderrun = 0x4000,
	TxStatOK = 0x8000,
	TxOutOfWindow = 0x20000000,
	TxAborted = 0x40000000,
	TxCarrierLost = 0x80000000,
};
enum RxStatusBits {
	RxMulticast = 0x8000,
	RxPhysical = 0x4000,
	RxBroadcast = 0x2000,
	RxBadSymbol = 0x0020,
	RxRunt = 0x0010,
	RxTooLong = 0x0008,
	RxCRCErr = 0x0004,
	RxBadAlign = 0x0002,
	RxStatusOK = 0x0001,
};

/* Bits in RxConfig. */
enum rx_mode_bits {
	AcceptErr = 0x20,
	AcceptRunt = 0x10,
	AcceptBroadcast = 0x08,
	AcceptMulticast = 0x04,
	AcceptMyPhys = 0x02,
	AcceptAllPhys = 0x01,
};

/* Bits in TxConfig. */
enum tx_config_bits {
	TxIFG1 = (1 << 25),	/* Interframe Gap Time */
	TxIFG0 = (1 << 24),	/* Enabling these bits violates IEEE 802.3 */
	TxLoopBack = (1 << 18) | (1 << 17), /* enable loopback test mode */
	TxCRC = (1 << 16),	/* DISABLE appending CRC to end of Tx packets */
	TxClearAbt = (1 << 0),	/* Clear abort (WO) */
	TxDMAShift = 8,		/* DMA burst value (0-7) is shift this many bits */

	TxVersionMask = 0x7C800000, /* mask out version bits 30-26, 23 */
};

/* Bits in Config1 */
enum Config1Bits {
	Cfg1_PM_Enable = 0x01,
	Cfg1_VPD_Enable = 0x02,
	Cfg1_PIO = 0x04,
	Cfg1_MMIO = 0x08,
	LWAKE = 0x10,		/* not on 8139, 8139A */
	Cfg1_Driver_Load = 0x20,
	Cfg1_LED0 = 0x40,
	Cfg1_LED1 = 0x80,
	SLEEP = (1 << 1),	/* only on 8139, 8139A */
	PWRDN = (1 << 0),	/* only on 8139, 8139A */
};

/* Bits in Config4 */
enum Config4Bits {
	LWPTN = (1 << 2),	/* not on 8139, 8139A */
};

enum RxConfigBits {
	/* Early Rx threshold, none or X/16 */
	RxCfgEarlyRxNone = 0,
	RxCfgEarlyRxShift = 24,

	/* rx fifo threshold */
	RxCfgFIFOShift = 13,
	RxCfgFIFONone = (7 << RxCfgFIFOShift),

	/* Max DMA burst */
	RxCfgDMAShift = 8,
	RxCfgDMAUnlimited = (7 << RxCfgDMAShift),

	/* rx ring buffer length */
	RxCfgRcv8K = 0,
	RxCfgRcv16K = (1 << 11),
	RxCfgRcv32K = (1 << 12),
	RxCfgRcv64K = (1 << 11) | (1 << 12),

	/* Disable packet wrap at end of Rx buffer */
	RxNoWrap = (1 << 7),
};


/* Twister tuning parameters from RealTek.
   Completely undocumented, but required to tune bad links. */
enum CSCRBits {
	CSCR_LinkOKBit = 0x0400,
	CSCR_LinkChangeBit = 0x0800,
	CSCR_LinkStatusBits = 0x0f000,
	CSCR_LinkDownOffCmd = 0x003c0,
	CSCR_LinkDownCmd = 0x0f3c0,
};


enum Cfg9346Bits {
	Cfg9346_Lock = 0x00,
	Cfg9346_Unlock = 0xC0,
};


#define PARA78_default	0x78fa8388
#define PARA7c_default	0xcb38de43	/* param[0][3] */
#define PARA7c_xxx		0xcb38de43
static const unsigned long param[4][4] = {
	{0xcb39de43, 0xcb39ce43, 0xfb38de03, 0xcb38de43},
	{0xcb39de43, 0xcb39ce43, 0xcb39ce83, 0xcb39ce83},
	{0xcb39de43, 0xcb39ce43, 0xcb39ce83, 0xcb39ce83},
	{0xbb39de43, 0xbb39ce43, 0xbb39ce83, 0xbb39ce83}
};

struct ring_info {
	struct sk_buff *skb;
};


typedef enum {
	CH_8139 = 0,
	CH_8139_K,
	CH_8139A,
	CH_8139B,
	CH_8130,
	CH_8139C,
} chip_t;

enum chip_flags {
	HasHltClk = (1 << 0),
	HasLWake = (1 << 1),
};


/* directly indexed by chip_t, above */
const static struct {
	const char *name;
	u8 version; /* from RTL8139C docs */
	u32 RxConfigMask; /* should clear the bits supported by this chip */
	u32 flags;
} rtl_chip_info[] = {
	{ "RTL-8139",
	  0x40,
	  0xf0fe0040, /* XXX copied from RTL8139A, verify */
	  HasHltClk,
	},

	{ "RTL-8139 rev K",
	  0x60,
	  0xf0fe0040,
	  HasHltClk,
	},

	{ "RTL-8139A",
	  0x70,
	  0xf0fe0040,
	  HasHltClk, /* XXX undocumented? */
	},

	{ "RTL-8139B",
	  0x78,
	  0xf0fc0040,
	  HasLWake,
	},

	{ "RTL-8130",
	  0x7C,
	  0xf0fe0040, /* XXX copied from RTL8139A, verify */
	  HasLWake,
	},

	{ "RTL-8139C",
	  0x74,
	  0xf0fc0040, /* XXX copied from RTL8139B, verify */
	  HasLWake,
	},

};

struct rtl_extra_stats {
	unsigned long early_rx;
	unsigned long tx_buf_mapped;
	unsigned long tx_timeouts;
};

struct rtl8139_private {
	void *mmio_addr;
	int drv_flags;
	struct pci_dev *pci_dev;
	struct resource rtl8139_pci_resource[4];
	struct net_device_stats stats;
	unsigned char *rx_ring;
	unsigned int cur_rx;	/* Index into the Rx buffer of next Rx pkt. */
	unsigned int tx_flag;
	unsigned long cur_tx;
	unsigned long dirty_tx;
	/* The saved address of a sent-in-place packet/buffer, for skfree(). */
	struct ring_info tx_info[NUM_TX_DESC];
	unsigned char *tx_buf[NUM_TX_DESC];	/* Tx bounce buffers */
	unsigned char *tx_bufs;	/* Tx bounce buffer region. */
	dma_addr_t rx_ring_dma;
	dma_addr_t tx_bufs_dma;
	signed char phys[4];		/* MII device addresses. */
	u16 advertising;					/* NWay media advertisement */
	char twistie, twist_row, twist_col;	/* Twister tune state. */
	unsigned int full_duplex:1;	/* Full-duplex operation requested. */
	unsigned int duplex_lock:1;
	unsigned int default_port:4;	/* Last dev->if_port value. */
	unsigned int media2:4;	/* Secondary monitored media port. */
	unsigned int medialock:1;	/* Don't sense media type. */
	unsigned int mediasense:1;	/* Media sensing in progress. */
	spinlock_t lock;
	chip_t chipset;
	pid_t thr_pid;
	wait_queue_head_t thr_wait;
	struct semaphore thr_exited;
	u32 rx_config;
	struct rtl_extra_stats xstats;
};

#define RTL8139_AUTHOR "Jeff Garzik <jgarzik@mandrakesoft.com>"
MODULE_AUTHOR (RTL8139_AUTHOR);
MODULE_DESCRIPTION ("RealTek RTL-8139 Fast Ethernet driver");
MODULE_PARM (multicast_filter_limit, "i");
MODULE_PARM (max_interrupt_work, "i");
MODULE_PARM (media, "1-" __MODULE_STRING(MAX_UNITS) "i");
MODULE_PARM (full_duplex, "1-" __MODULE_STRING(MAX_UNITS) "i");
MODULE_PARM_DESC (multicast_filter_limit, "8139too maximum number of filtered multicast addresses");
MODULE_PARM_DESC (max_interrupt_work, "8139too maximum events handled per interrupt");
MODULE_PARM_DESC (media, "8139too: Bits 4+9: force full duplex, bit 5: 100Mbps");
MODULE_PARM_DESC (full_duplex, "8139too: Force full duplex for board(s) (1)");

static int read_eeprom (void *ioaddr, int location, int addr_len);
static int rtl8139_open (struct device *dev);
static int mdio_read (struct device *dev, int phy_id, int location);
static void mdio_write (struct device *dev, int phy_id, int location,
			int val);
static int rtl8139_thread (void *data);
static void rtl8139_tx_timeout (struct device *dev);
static void rtl8139_init_ring (struct device *dev);
static int rtl8139_start_xmit (struct sk_buff *skb,
			       struct device *dev);
static void rtl8139_interrupt (int irq, void *dev_instance,
			       struct pt_regs *regs);
static int rtl8139_close (struct device *dev);
static int netdev_ioctl (struct device *dev, struct ifreq *rq, int cmd);
static struct net_device_stats *rtl8139_get_stats (struct device *dev);
static inline u32 ether_crc (int length, unsigned char *data);
static void rtl8139_set_rx_mode (struct device *dev);
static void rtl8139_hw_start (struct device *dev);

#ifdef USE_IO_OPS

#define RTL_R8(reg)		inb (((unsigned long)ioaddr) + (reg))
#define RTL_R16(reg)		inw (((unsigned long)ioaddr) + (reg))
#define RTL_R32(reg)		((unsigned long) inl (((unsigned long)ioaddr) + (reg)))
#define RTL_W8(reg, val8)	outb ((val8), ((unsigned long)ioaddr) + (reg))
#define RTL_W16(reg, val16)	outw ((val16), ((unsigned long)ioaddr) + (reg))
#define RTL_W32(reg, val32)	outl ((val32), ((unsigned long)ioaddr) + (reg))
#define RTL_W8_F		RTL_W8
#define RTL_W16_F		RTL_W16
#define RTL_W32_F		RTL_W32
#undef readb
#undef readw
#undef readl
#undef writeb
#undef writew
#undef writel
#define readb(addr) inb((unsigned long)(addr))
#define readw(addr) inw((unsigned long)(addr))
#define readl(addr) inl((unsigned long)(addr))
#define writeb(val,addr) outb((val),(unsigned long)(addr))
#define writew(val,addr) outw((val),(unsigned long)(addr))
#define writel(val,addr) outl((val),(unsigned long)(addr))

#else

/* write MMIO register, with flush */
/* Flush avoids rtl8139 bug w/ posted MMIO writes */
#define RTL_W8_F(reg, val8)	do { writeb ((val8), ioaddr + (reg)); readb (ioaddr + (reg)); } while (0)
#define RTL_W16_F(reg, val16)	do { writew ((val16), ioaddr + (reg)); readw (ioaddr + (reg)); } while (0)
#define RTL_W32_F(reg, val32)	do { writel ((val32), ioaddr + (reg)); readl (ioaddr + (reg)); } while (0)


#define MMIO_FLUSH_AUDIT_COMPLETE 1
#if MMIO_FLUSH_AUDIT_COMPLETE

/* write MMIO register */
#define RTL_W8(reg, val8)	writeb ((val8), ioaddr + (reg))
#define RTL_W16(reg, val16)	writew ((val16), ioaddr + (reg))
#define RTL_W32(reg, val32)	writel ((val32), ioaddr + (reg))

#else

/* write MMIO register, then flush */
#define RTL_W8		RTL_W8_F
#define RTL_W16		RTL_W16_F
#define RTL_W32		RTL_W32_F

#endif /* MMIO_FLUSH_AUDIT_COMPLETE */

/* read MMIO register */
#define RTL_R8(reg)		readb (ioaddr + (reg))
#define RTL_R16(reg)		readw (ioaddr + (reg))
#define RTL_R32(reg)		((unsigned long) readl (ioaddr + (reg)))

#endif /* USE_IO_OPS */


static const u16 rtl8139_intr_mask =
	PCIErr | PCSTimeout | RxUnderrun | RxOverflow | RxFIFOOver |
	TxErr | TxOK | RxErr | RxOK;

static const unsigned int rtl8139_rx_config =
	  (RX_EARLY_THRESH << RxCfgEarlyRxShift) | RxCfgRcv32K | RxNoWrap |
	  (RX_FIFO_THRESH << RxCfgFIFOShift) |
	  (RX_DMA_BURST << RxCfgDMAShift);


static void __rtl8139_cleanup_dev (struct device *dev)
{
	struct rtl8139_private *tp;
	struct pci_dev *pdev;

	assert (dev != NULL);
	assert (dev->priv != NULL);

	tp = dev->priv;
	assert (tp->pci_dev != NULL);
	pdev = tp->pci_dev;

#ifndef USE_IO_OPS
	if (tp->mmio_addr)
		iounmap (tp->mmio_addr);
#endif /* !USE_IO_OPS */

#ifndef RTL8139_NDEBUG
	/* poison memory before freeing */
	memset (dev, 0xBC,
		sizeof (struct device) +
		sizeof (struct rtl8139_private));
#endif /* RTL8139_NDEBUG */

	kfree (dev);
}


static void rtl8139_chip_reset (void *ioaddr)
{
	int i;

	/* Soft reset the chip. */
	RTL_W8 (ChipCmd, CmdReset);

	/* Check that the chip has finished the reset. */
	for (i = 1000; i > 0; i--) {
		barrier();
		if ((RTL_R8 (ChipCmd) & CmdReset) == 0)
			break;
		udelay (10);
	}
}


static int rtl8139_init_board (struct pci_dev *pdev,
					 struct device **dev_out,
					 u32 hwflags)
{
	void *ioaddr;
	struct device *dev;
	struct rtl8139_private *tp;
	u8 tmp8;
	int rc;
	unsigned int i;
	u32 pio_start, pio_end, pio_flags, pio_len;
	unsigned long mmio_start, mmio_end, mmio_flags, mmio_len;
	unsigned short pci_command, new_command;
	u32 tmp;

	DPRINTK ("ENTER\n");

	assert (pdev != NULL);

	*dev_out = NULL;

	/* dev and dev->priv zeroed in init_etherdev */
	dev = init_etherdev (NULL, sizeof (*tp));
	if (dev == NULL) {
		printk (KERN_ERR PFX "Unable to alloc new ethernet device\n");
		DPRINTK ("EXIT, returning -ENOMEM\n");
		return -ENOMEM;
	}
	tp = dev->priv;
	tp->pci_dev = pdev;

	rtl8139_read_pci_resources(pdev, &tp->rtl8139_pci_resource[0]);

	pio_start = rtl8139_pci_resource_start (tp, 0);
	pio_end = rtl8139_pci_resource_end (tp, 0);
	pio_flags = rtl8139_pci_resource_flags (tp, 0);
	pio_len = rtl8139_pci_resource_len (tp, 0);

	mmio_start = rtl8139_pci_resource_start (tp, 1);
	mmio_end = rtl8139_pci_resource_end (tp, 1);
	mmio_flags = rtl8139_pci_resource_flags (tp, 1);
	mmio_len = rtl8139_pci_resource_len (tp, 1);
#ifdef __alpha__
	/* handle 64 bit address space mapping */
	if (hwflags & RTL_PCI_64BIT) {
		u32 pci_ext64;
		pcibios_read_config_dword(PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn),
				((hwflags & 0x0f) << 2) + 0x10, &pci_ext64);
		pio_start |= (unsigned long) pci_ext64 << 32;
		pio_end |= (unsigned long) pci_ext64 << 32;
		mmio_start |= (unsigned long) pci_ext64 << 32;
		mmio_end |= (unsigned long) pci_ext64 << 32;
	}
#endif

	/* set this immediately, we need to know before
	 * we talk to the chip directly */
	DPRINTK("PIO region size at 0x%08lx == 0x%02X\n", (unsigned long) pio_start, pio_len);
	DPRINTK("MMIO region size at 0x%08lx == 0x%02lX\n", (unsigned long) mmio_start, mmio_len);

#ifdef USE_IO_OPS
	/* make sure PCI base addr 0 is PIO */
	if (!(pio_flags & IORESOURCE_IO)) {
		printk (KERN_ERR PFX "8139too: region #0 not a PIO resource, aborting\n");
		rc = -ENODEV;
		goto err_out;
	}
	/* check for weird/broken PCI region reporting */
	if (pio_len < RTL_MIN_IO_SIZE) {
		printk (KERN_ERR PFX "8139too: Invalid PCI I/O region size(s), aborting\n");
		rc = -ENODEV;
		goto err_out;
	}
#else
  	/* make sure PCI base addr 1 is MMIO */
  	if (!(mmio_flags & IORESOURCE_MEM)) {
		printk (KERN_ERR PFX "8139too: region #1 not an MMIO resource, aborting\n");
		rc = -ENODEV;
		goto err_out;
	}
	if (mmio_len < RTL_MIN_IO_SIZE) {
		printk (KERN_ERR PFX "8139too: Invalid PCI mem region size(s), aborting\n");
		rc = -ENODEV;
		goto err_out;
	}
#endif
	request_region(pio_start, pio_len, dev->name);
	
	pci_set_master (pdev);

#ifdef USE_IO_OPS
	ioaddr = (void *) pio_start;
	dev->base_addr = pio_start;
#else
	/* ioremap MMIO region */
	ioaddr = ioremap_nocache(mmio_start, mmio_len);	
	if (ioaddr == NULL) {
		printk (KERN_ERR PFX "cannot remap MMIO, aborting\n");
		rc = -EIO;
		goto err_out;
	}
	dev->base_addr = (long) ioaddr;
#endif /* USE_IO_OPS */
	tp->mmio_addr = ioaddr;

	/* Activate the card: fix for brain-damaged Win98 BIOSes. */
	pci_read_config_word(pdev,  PCI_COMMAND, &pci_command);
	new_command = pci_command | PCI_USES_IO | PCI_USES_MEM | PCI_USES_MASTER;
	if (pci_command != new_command)
		pci_write_config_word(pdev, PCI_COMMAND, new_command);

	/* Bring old chips out of low-power mode. */
	RTL_W8 (HltClk, 'R');

	/* check for missing/broken hardware */
	if (RTL_R32 (TxConfig) == 0xFFFFFFFF) {
		printk (KERN_ERR PFX "slot %u: Chip not responding, ignoring board\n",
			PCI_SLOT(pdev->devfn));
		rc = -EIO;
		goto err_out;
	}

	/* identify chip attached to board */
	tmp = RTL_R8 (ChipVersion);
	for (i = ARRAY_SIZE (rtl_chip_info) - 1; i >= 0; i--)
		if (tmp == rtl_chip_info[i].version) {
			tp->chipset = i;
			goto match;
		}

	/* if unknown chip, assume array element #0, original RTL-8139 in this case */
	printk (KERN_DEBUG PFX "PCI device %08lX: unknown chip version, assuming RTL-8139\n",
		(unsigned long) pdev);
	printk (KERN_DEBUG PFX "PCI device %08lX: TxConfig = 0x%lx\n", (unsigned long) pdev, RTL_R32 (TxConfig));
	tp->chipset = 0;

match:
	DPRINTK ("chipset id (%d) == index %d, '%s'\n",
		tmp,
		tp->chipset,
		rtl_chip_info[tp->chipset].name);

	if (tp->chipset >= CH_8139B) {
		u8 new_tmp8 = tmp8 = RTL_R8 (Config1);
		DPRINTK("PCI PM wakeup\n");
		if ((rtl_chip_info[tp->chipset].flags & HasLWake) &&
		    (tmp8 & LWAKE))
			new_tmp8 &= ~LWAKE;
		new_tmp8 |= Cfg1_PM_Enable;
		if (new_tmp8 != tmp8) {
			RTL_W8 (Cfg9346, Cfg9346_Unlock);
			RTL_W8 (Config1, tmp8);
			RTL_W8 (Cfg9346, Cfg9346_Lock);
		}
		if (rtl_chip_info[tp->chipset].flags & HasLWake) {
			tmp8 = RTL_R8 (Config4);
			if (tmp8 & LWPTN)
				RTL_W8 (Config4, tmp8 & ~LWPTN);
		}
	} else {
		DPRINTK("Old chip wakeup\n");
		tmp8 = RTL_R8 (Config1);
		tmp8 &= ~(SLEEP | PWRDN);
		RTL_W8 (Config1, tmp8);
	}

	rtl8139_chip_reset (ioaddr);

	DPRINTK ("EXIT, returning 0\n");
	*dev_out = dev;
	return 0;

err_out:
	__rtl8139_cleanup_dev (dev);
	DPRINTK ("EXIT, returning %d\n", rc);
	return rc;
}

static int rtl8139_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
{
	struct device *dev = NULL;
	struct rtl8139_private *tp;
	int i, addr_len, option;
	void *ioaddr;
	static int board_idx = -1;

	DPRINTK ("ENTER\n");

	assert (pdev != NULL);
	assert (ent != NULL);

	board_idx++;

	i = rtl8139_init_board (pdev, &dev, board_info[ent->board].hw_flags);
	if (i < 0) {
		DPRINTK ("EXIT, returning %d\n", i);
		return i;
	}

	tp = dev->priv;
	ioaddr = tp->mmio_addr;

	assert (ioaddr != NULL);
	assert (dev != NULL);
	assert (tp != NULL);

	addr_len = read_eeprom (ioaddr, 0, 8) == 0x8129 ? 8 : 6;
	for (i = 0; i < 3; i++)
		((u16 *) (dev->dev_addr))[i] =
		    le16_to_cpu (read_eeprom (ioaddr, i + 7, addr_len));

	/* The Rtl8139-specific entries in the device structure. */
	dev->open = rtl8139_open;
	dev->hard_start_xmit = rtl8139_start_xmit;
	dev->stop = rtl8139_close;
	dev->get_stats = rtl8139_get_stats;
	dev->set_multicast_list = rtl8139_set_rx_mode;
	dev->do_ioctl = netdev_ioctl;

	dev->irq = pdev->irq;

	/* dev->priv/tp zeroed and aligned in init_etherdev */
	tp = dev->priv;

	/* note: tp->chipset set in rtl8139_init_board */
	tp->drv_flags = board_info[ent->board].hw_flags;
	tp->mmio_addr = ioaddr;
	spin_lock_init (&tp->lock);
	init_waitqueue_head (&tp->thr_wait);
	init_MUTEX_LOCKED (&tp->thr_exited);

	if (rtl8139_device_count == 0) {
		printk (KERN_INFO "%s: " RTL8139_DRIVER_NAME " " RTL8139_AUTHOR "\n", dev->name);
		printk (KERN_INFO "%s: Linux-2.2 bug reports to Jens David <dg1kjd@afthd.tu-darmstadt.de>\n", dev->name);
	}
	
	printk (KERN_INFO "%s: %s board found at 0x%lx, IRQ %d\n",
		dev->name, board_info[ent->board].name,
		dev->base_addr, dev->irq);

	printk (KERN_INFO "%s: Chip is '%s' - MAC address '%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x'.\n",
		dev->name,
		rtl_chip_info[tp->chipset].name,
		dev->dev_addr[0], dev->dev_addr[1],
		dev->dev_addr[2], dev->dev_addr[3],
		dev->dev_addr[4], dev->dev_addr[5]);

	/* Find the connected MII xcvrs.
	   Doing this in open() would allow detecting external xcvrs later, but
	   takes too much time. */
#ifdef CONFIG_8139TOO_8129
	if (tp->drv_flags & HAS_MII_XCVR) {
		int phy, phy_idx = 0;
		for (phy = 0; phy < 32 && phy_idx < sizeof(tp->phys); phy++) {
			int mii_status = mdio_read(dev, phy, 1);
			if (mii_status != 0xffff  &&  mii_status != 0x0000) {
				u16 advertising = mdio_read(dev, phy, 4);
				tp->phys[phy_idx++] = phy;
				printk(KERN_INFO "%s: MII transceiver %d status 0x%4.4x "
					   "advertising %4.4x.\n",
					   dev->name, phy, mii_status, advertising);
			}
		}
		if (phy_idx == 0) {
			printk(KERN_INFO "%s: No MII transceivers found!  Assuming SYM "
				   "transceiver.\n",
				   dev->name);
			tp->phys[0] = 32;
		}
	} else
#endif
		tp->phys[0] = 32;

	/* The lower four bits are the media type. */
	option = (board_idx >= MAX_UNITS) ? 0 : media[board_idx];
	if (option > 0) {
		tp->full_duplex = (option & 0x210) ? 1 : 0;
		tp->default_port = option & 0xFF;
		if (tp->default_port)
			tp->medialock = 1;
	}
	if (board_idx < MAX_UNITS  &&  full_duplex[board_idx] > 0)
		tp->full_duplex = full_duplex[board_idx];
	if (tp->full_duplex) {
		printk(KERN_INFO "%s: Media type forced to Full Duplex.\n", dev->name);
		/* Changing the MII-advertised media because might prevent
		   re-connection. */
		tp->duplex_lock = 1;
	}
	if (tp->default_port) {
		printk(KERN_INFO "  Forcing %dMbs %s-duplex operation.\n",
			   (option & 0x20 ? 100 : 10),
			   (option & 0x10 ? "full" : "half"));
		mdio_write(dev, tp->phys[0], 0,
				   ((option & 0x20) ? 0x2000 : 0) | 	/* 100mbps? */
				   ((option & 0x10) ? 0x0100 : 0)); /* Full duplex? */
	}

	rtl8139_device_tab[rtl8139_device_count++] = dev;
	/* Put the chip into low-power mode. */
	if (rtl_chip_info[tp->chipset].flags & HasHltClk)
		RTL_W8 (HltClk, 'H');	/* 'R' would leave the clock running. */

	DPRINTK ("EXIT - returning 0\n");
	return 0;
}

static void rtl8139_remove_one (struct device *dev)
{
	struct pci_dev *pdev;
	struct rtl8139_private *np;

	DPRINTK ("ENTER\n");

	assert (dev != NULL);

	np = (struct rtl8139_private *) (dev->priv);
	assert (np != NULL);

	pdev = np->pci_dev;
	assert (pdev != NULL);

	unregister_netdev (dev);

	__rtl8139_cleanup_dev (dev);

	DPRINTK ("EXIT\n");
}


/* Serial EEPROM section. */

/*  EEPROM_Ctrl bits. */
#define EE_SHIFT_CLK	0x04	/* EEPROM shift clock. */
#define EE_CS			0x08	/* EEPROM chip select. */
#define EE_DATA_WRITE	0x02	/* EEPROM chip data in. */
#define EE_WRITE_0		0x00
#define EE_WRITE_1		0x02
#define EE_DATA_READ	0x01	/* EEPROM chip data out. */
#define EE_ENB			(0x80 | EE_CS)

/* Delay between EEPROM clock transitions.
   No extra delay is needed with 33Mhz PCI, but 66Mhz may change this.
 */

#define eeprom_delay()	readl(ee_addr)

/* The EEPROM commands include the alway-set leading bit. */
#define EE_WRITE_CMD	(5)
#define EE_READ_CMD		(6)
#define EE_ERASE_CMD	(7)

static int read_eeprom (void *ioaddr, int location, int addr_len)
{
	int i;
	unsigned retval = 0;
	void *ee_addr = ioaddr + Cfg9346;
	int read_cmd = location | (EE_READ_CMD << addr_len);

	DPRINTK ("ENTER\n");

	writeb (EE_ENB & ~EE_CS, ee_addr);
	writeb (EE_ENB, ee_addr);
	eeprom_delay ();

	/* Shift the read command bits out. */
	for (i = 4 + addr_len; i >= 0; i--) {
		int dataval = (read_cmd & (1 << i)) ? EE_DATA_WRITE : 0;
		writeb (EE_ENB | dataval, ee_addr);
		eeprom_delay ();
		writeb (EE_ENB | dataval | EE_SHIFT_CLK, ee_addr);
		eeprom_delay ();
	}
	writeb (EE_ENB, ee_addr);
	eeprom_delay ();

	for (i = 16; i > 0; i--) {
		writeb (EE_ENB | EE_SHIFT_CLK, ee_addr);
		eeprom_delay ();
		retval =
		    (retval << 1) | ((readb (ee_addr) & EE_DATA_READ) ? 1 :
				     0);
		writeb (EE_ENB, ee_addr);
		eeprom_delay ();
	}

	/* Terminate the EEPROM access. */
	writeb (~EE_CS, ee_addr);
	eeprom_delay ();

	DPRINTK ("EXIT - returning %d\n", retval);
	return retval;
}

/* MII serial management: mostly bogus for now. */
/* Read and write the MII management registers using software-generated
   serial MDIO protocol.
   The maximum data clock rate is 2.5 Mhz.  The minimum timing is usually
   met by back-to-back PCI I/O cycles, but we insert a delay to avoid
   "overclocking" issues. */
#define MDIO_DIR		0x80
#define MDIO_DATA_OUT	0x04
#define MDIO_DATA_IN	0x02
#define MDIO_CLK		0x01
#define MDIO_WRITE0 (MDIO_DIR)
#define MDIO_WRITE1 (MDIO_DIR | MDIO_DATA_OUT)

#define mdio_delay(mdio_addr)	readb(mdio_addr)


static char mii_2_8139_map[8] = {
	BasicModeCtrl,
	BasicModeStatus,
	0,
	0,
	NWayAdvert,
	NWayLPAR,
	NWayExpansion,
	0
};

#ifdef CONFIG_8139TOO_8129
/* Syncronize the MII management interface by shifting 32 one bits out. */
static void mdio_sync (void *mdio_addr)
{
	int i;

	DPRINTK ("ENTER\n");

	for (i = 32; i >= 0; i--) {
		writeb (MDIO_WRITE1, mdio_addr);
		mdio_delay (mdio_addr);
		writeb (MDIO_WRITE1 | MDIO_CLK, mdio_addr);
		mdio_delay (mdio_addr);
	}

	DPRINTK ("EXIT\n");
}
#endif

static int mdio_read (struct device *dev, int phy_id, int location)
{
	struct rtl8139_private *tp = dev->priv;
	int retval = 0;
#ifdef CONFIG_8139TOO_8129
	int i;
	void *mdio_addr = tp->mmio_addr + Config4;
	int mii_cmd = (0xf6 << 10) | (phy_id << 5) | location;
#endif

	DPRINTK ("ENTER\n");

	if (phy_id > 31) {	/* Really a 8139.  Use internal registers. */
		DPRINTK ("EXIT after directly using 8139 internal regs\n");
		return location < 8 && mii_2_8139_map[location] ?
		    readw (tp->mmio_addr + mii_2_8139_map[location]) : 0;
	}

#ifdef CONFIG_8139TOO_8129
	mdio_sync (mdio_addr);
	/* Shift the read command bits out. */
	for (i = 15; i >= 0; i--) {
		int dataval = (mii_cmd & (1 << i)) ? MDIO_DATA_OUT : 0;

		writeb (MDIO_DIR | dataval, mdio_addr);
		mdio_delay (mdio_addr);
		writeb (MDIO_DIR | dataval | MDIO_CLK, mdio_addr);
		mdio_delay (mdio_addr);
	}

	/* Read the two transition, 16 data, and wire-idle bits. */
	for (i = 19; i > 0; i--) {
		writeb (0, mdio_addr);
		mdio_delay (mdio_addr);
		retval = (retval << 1) | ((readb (mdio_addr) & MDIO_DATA_IN) ? 1 : 0);
		writeb (MDIO_CLK, mdio_addr);
		mdio_delay (mdio_addr);
	}
#endif

	DPRINTK ("EXIT, returning %d\n", (retval >> 1) & 0xffff);
	return (retval >> 1) & 0xffff;
}


static void mdio_write (struct device *dev, int phy_id, int location,
			int value)
{
	struct rtl8139_private *tp = dev->priv;
#ifdef CONFIG_8139TOO_8129
	int i;
	void *mdio_addr = tp->mmio_addr + Config4;
	int mii_cmd = (0x5002 << 16) | (phy_id << 23) | (location << 18) | value;
#endif

	DPRINTK ("ENTER\n");

	if (phy_id > 31) {	/* Really a 8139.  Use internal registers. */
		void *ioaddr = tp->mmio_addr;
		if (location == 0) {
			RTL_W8 (Cfg9346, Cfg9346_Unlock);
			RTL_W16 (BasicModeCtrl, value);
			RTL_W8 (Cfg9346, Cfg9346_Lock);
		} else if (location < 8 && mii_2_8139_map[location])
			RTL_W16 (mii_2_8139_map[location], value);
		return;
	}

#ifdef CONFIG_8139TOO_8129
	mdio_sync (mdio_addr);

	/* Shift the command bits out. */
	for (i = 31; i >= 0; i--) {
		int dataval =
		    (mii_cmd & (1 << i)) ? MDIO_WRITE1 : MDIO_WRITE0;
		writeb (dataval, mdio_addr);
		mdio_delay (mdio_addr);
		writeb (dataval | MDIO_CLK, mdio_addr);
		mdio_delay (mdio_addr);
	}
	/* Clear out extra bits. */
	for (i = 2; i > 0; i--) {
		writeb (0, mdio_addr);
		mdio_delay (mdio_addr);
		writeb (MDIO_CLK, mdio_addr);
		mdio_delay (mdio_addr);
	}
#endif
}


static int rtl8139_open (struct device *dev)
{
	struct rtl8139_private *tp = dev->priv;
	int retval;
#ifdef RTL8139_DEBUG
	void *ioaddr = tp->mmio_addr;
#endif

	DPRINTK ("ENTER\n");

	MOD_INC_USE_COUNT;

	retval = request_irq (dev->irq, rtl8139_interrupt, SA_SHIRQ, dev->name, dev);
	if (retval) {
		DPRINTK ("EXIT, returning %d\n", retval);
		MOD_DEC_USE_COUNT;
		return retval;
	}

	tp->tx_bufs = kmalloc(TX_BUF_TOT_LEN, GFP_KERNEL | GFP_DMA);
	tp->tx_bufs_dma = virt_to_bus(tp->tx_bufs);
	tp->rx_ring = kmalloc(RX_BUF_TOT_LEN, GFP_KERNEL | GFP_DMA);
	tp->rx_ring_dma = virt_to_bus(tp->rx_ring);

	if (tp->tx_bufs == NULL || tp->rx_ring == NULL) {
		free_irq(dev->irq, dev);

		if (tp->tx_bufs) kfree(tp->tx_bufs);
		if (tp->rx_ring) kfree(tp->rx_ring);

		DPRINTK ("EXIT, returning -ENOMEM\n");
		MOD_DEC_USE_COUNT;
		return -ENOMEM;

	}

	tp->full_duplex = tp->duplex_lock;
	tp->tx_flag = (TX_FIFO_THRESH << 11) & 0x003f0000;
	tp->twistie = 1;

	rtl8139_init_ring (dev);
	rtl8139_hw_start (dev);

	DPRINTK ("%s: rtl8139_open() ioaddr %#lx IRQ %d"
			" GP Pins %2.2x %s-duplex.\n",
			dev->name, (unsigned long) tp->mmio_addr,
			dev->irq, RTL_R8 (MediaStatus),
			tp->full_duplex ? "full" : "half");

	tp->thr_pid = kernel_thread (rtl8139_thread, dev, CLONE_FS | CLONE_FILES);
	if (tp->thr_pid < 0)
		printk (KERN_WARNING "%s: unable to start kernel thread\n",
			dev->name);

	DPRINTK ("EXIT, returning 0\n");
	return 0;
}


static void rtl_check_media (struct device *dev)
{
	struct rtl8139_private *tp = dev->priv;

	DPRINTK("ENTER\n");
	
	if (tp->phys[0] >= 0) {
		u16 mii_reg5 = mdio_read(dev, tp->phys[0], 5);
		if (mii_reg5 == 0xffff)
			;					/* Not there */
		else if ((mii_reg5 & 0x0100) == 0x0100
				 || (mii_reg5 & 0x00C0) == 0x0040)
			tp->full_duplex = 1;

		printk (KERN_INFO"%s: Setting %s%s-duplex based on"
				" auto-negotiated partner ability %4.4x.\n",
		        dev->name, mii_reg5 == 0 ? "" :
				(mii_reg5 & 0x0180) ? "100mbps " : "10mbps ",
			tp->full_duplex ? "full" : "half", mii_reg5);
	}
}

/* Start the hardware at open or resume. */
static void rtl8139_hw_start (struct device *dev)
{
	struct rtl8139_private *tp = dev->priv;
	void *ioaddr = tp->mmio_addr;
	u32 i;
	u8 tmp;

	DPRINTK ("ENTER\n");

	/* Bring old chips out of low-power mode. */
	if (rtl_chip_info[tp->chipset].flags & HasHltClk)
		RTL_W8 (HltClk, 'R');

	rtl8139_chip_reset (ioaddr);

	/* unlock Config[01234] and BMCR register writes */
	RTL_W8_F (Cfg9346, Cfg9346_Unlock);
	/* Restore our idea of the MAC address. */
	RTL_W32_F (MAC0 + 0, cpu_to_le32 (*(u32 *) (dev->dev_addr + 0)));
	RTL_W32_F (MAC0 + 4, cpu_to_le32 (*(u32 *) (dev->dev_addr + 4)));

	/* Must enable Tx/Rx before setting transfer thresholds! */
	RTL_W8 (ChipCmd, CmdRxEnb | CmdTxEnb);

	tp->rx_config = rtl8139_rx_config | AcceptBroadcast | AcceptMyPhys;
	RTL_W32 (RxConfig, tp->rx_config);

	/* Check this value: the documentation for IFG contradicts ifself. */
	RTL_W32 (TxConfig, (TX_DMA_BURST << TxDMAShift));

	tp->cur_rx = 0;
	
	rtl_check_media (dev);

	if (tp->chipset >= CH_8139B) {
		/* disable magic packet scanning, which is enabled
		 * when PM is enabled in Config1 */
		RTL_W8 (Config3, RTL_R8 (Config3) & ~(1<<5));
	}

	DPRINTK("init buffer addresses\n");

	/* Lock Config[01234] and BMCR register writes */
	RTL_W8 (Cfg9346, Cfg9346_Lock);

	/* init Rx ring buffer DMA address */
	RTL_W32_F (RxBuf, tp->rx_ring_dma);

	/* init Tx buffer DMA addresses */
	for (i = 0; i < NUM_TX_DESC; i++)
		RTL_W32_F (TxAddr0 + (i * 4), tp->tx_bufs_dma + (tp->tx_buf[i] - tp->tx_bufs));

	RTL_W32 (RxMissed, 0);

	rtl8139_set_rx_mode (dev);

	/* no early-rx interrupts */
	RTL_W16 (MultiIntr, RTL_R16 (MultiIntr) & MultiIntrClear);

	/* make sure RxTx has started */
	tmp = RTL_R8 (ChipCmd);
	if ((!(tmp & CmdRxEnb)) || (!(tmp & CmdTxEnb)))
		RTL_W8 (ChipCmd, CmdRxEnb | CmdTxEnb);

	/* Enable all known interrupts by setting the interrupt mask. */
	RTL_W16 (IntrMask, rtl8139_intr_mask);

	netif_start_queue (dev);

	DPRINTK ("EXIT\n");
}


/* Initialize the Rx and Tx rings, along with various 'dev' bits. */
static void rtl8139_init_ring (struct device *dev)
{
	struct rtl8139_private *tp = dev->priv;
	int i;

	DPRINTK ("ENTER\n");

	tp->cur_rx = 0;
	tp->cur_tx = 0;
	tp->dirty_tx = 0;

	for (i = 0; i < NUM_TX_DESC; i++) {
		tp->tx_info[i].skb = NULL;
		tp->tx_buf[i] = &tp->tx_bufs[i * TX_BUF_SIZE];
	}

	DPRINTK ("EXIT\n");
}


/* This must be global for CONFIG_8139TOO_TUNE_TWISTER case */
static int next_tick = 3 * HZ;

#ifndef CONFIG_8139TOO_TUNE_TWISTER
static inline void rtl8139_tune_twister (struct device *dev,
				  struct rtl8139_private *tp) {}
#else
static void rtl8139_tune_twister (struct device *dev,
				  struct rtl8139_private *tp)
{
	int linkcase;
	void *ioaddr = tp->mmio_addr;

	DPRINTK ("ENTER\n");

	/* This is a complicated state machine to configure the "twister" for
	   impedance/echos based on the cable length.
	   All of this is magic and undocumented.
	 */
	switch (tp->twistie) {
	case 1:
		if (RTL_R16 (CSCR) & CSCR_LinkOKBit) {
			/* We have link beat, let us tune the twister. */
			RTL_W16 (CSCR, CSCR_LinkDownOffCmd);
			tp->twistie = 2;	/* Change to state 2. */
			next_tick = HZ / 10;
		} else {
			/* Just put in some reasonable defaults for when beat returns. */
			RTL_W16 (CSCR, CSCR_LinkDownCmd);
			RTL_W32 (FIFOTMS, 0x20);	/* Turn on cable test mode. */
			RTL_W32 (PARA78, PARA78_default);
			RTL_W32 (PARA7c, PARA7c_default);
			tp->twistie = 0;	/* Bail from future actions. */
		}
		break;
	case 2:
		/* Read how long it took to hear the echo. */
		linkcase = RTL_R16 (CSCR) & CSCR_LinkStatusBits;
		if (linkcase == 0x7000)
			tp->twist_row = 3;
		else if (linkcase == 0x3000)
			tp->twist_row = 2;
		else if (linkcase == 0x1000)
			tp->twist_row = 1;
		else
			tp->twist_row = 0;
		tp->twist_col = 0;
		tp->twistie = 3;	/* Change to state 2. */
		next_tick = HZ / 10;
		break;
	case 3:
		/* Put out four tuning parameters, one per 100msec. */
		if (tp->twist_col == 0)
			RTL_W16 (FIFOTMS, 0);
		RTL_W32 (PARA7c, param[(int) tp->twist_row]
			 [(int) tp->twist_col]);
		next_tick = HZ / 10;
		if (++tp->twist_col >= 4) {
			/* For short cables we are done.
			   For long cables (row == 3) check for mistune. */
			tp->twistie =
			    (tp->twist_row == 3) ? 4 : 0;
		}
		break;
	case 4:
		/* Special case for long cables: check for mistune. */
		if ((RTL_R16 (CSCR) &
		     CSCR_LinkStatusBits) == 0x7000) {
			tp->twistie = 0;
			break;
		} else {
			RTL_W32 (PARA7c, 0xfb38de03);
			tp->twistie = 5;
			next_tick = HZ / 10;
		}
		break;
	case 5:
		/* Retune for shorter cable (column 2). */
		RTL_W32 (FIFOTMS, 0x20);
		RTL_W32 (PARA78, PARA78_default);
		RTL_W32 (PARA7c, PARA7c_default);
		RTL_W32 (FIFOTMS, 0x00);
		tp->twist_row = 2;
		tp->twist_col = 0;
		tp->twistie = 3;
		next_tick = HZ / 10;
		break;

	default:
		/* do nothing */
		break;
	}

	DPRINTK ("EXIT\n");
}
#endif /* CONFIG_8139TOO_TUNE_TWISTER */


static inline void rtl8139_thread_iter (struct device *dev,
					struct rtl8139_private *tp,
					void *ioaddr)
{
	int mii_reg5;

	mii_reg5 = mdio_read (dev, tp->phys[0], 5);

	if (!tp->duplex_lock && mii_reg5 != 0xffff) {
		int duplex = (mii_reg5 & 0x0100)
		    || (mii_reg5 & 0x01C0) == 0x0040;
		if (tp->full_duplex != duplex) {
			tp->full_duplex = duplex;

			if (mii_reg5) {
				printk (KERN_INFO
					"%s: Setting %s-duplex based on MII #%d link"
					" partner ability of %4.4x.\n",
					dev->name,
					tp->full_duplex ? "full" : "half",
					tp->phys[0], mii_reg5);
			} else {
				printk(KERN_INFO"%s: media is unconnected, link down, or incompatible connection\n",
				       dev->name);
			}
#if 0
			RTL_W8 (Cfg9346, Cfg9346_Unlock);
			RTL_W8 (Config1, tp->full_duplex ? 0x60 : 0x20);
			RTL_W8 (Cfg9346, Cfg9346_Lock);
#endif
		}
	}

	next_tick = HZ * 60;

	rtl8139_tune_twister (dev, tp);

	DPRINTK ("%s: Media selection tick, Link partner %4.4x.\n",
		 dev->name, RTL_R16 (NWayLPAR));
	DPRINTK ("%s:  Other registers are IntMask %4.4x IntStatus %4.4x"
		 " RxStatus %4.4lx.\n", dev->name,
		 RTL_R16 (IntrMask),
		 RTL_R16 (IntrStatus),
		 RTL_R32 (RxEarlyStatus));
	DPRINTK ("%s:  Chip config %2.2x %2.2x.\n",
		 dev->name, RTL_R8 (Config0),
		 RTL_R8 (Config1));
}


static int rtl8139_thread (void *data)
{
	struct device *dev = (struct device *) data;
	struct rtl8139_private *tp = (struct rtl8139_private *) dev->priv;
	unsigned long timeout;

	exit_files(current);
	daemonize ();
	spin_lock_irq(&current->sigmask_lock);
	sigemptyset(&current->blocked);
	recalc_sigpending(current);
	spin_unlock_irq(&current->sigmask_lock);

	strncpy (current->comm, dev->name, sizeof(current->comm) - 1);
	current->comm[sizeof(current->comm) - 1] = '\0';

	while (1) {
		rtl8139_thread_iter (dev, tp, tp->mmio_addr);
		timeout = next_tick;
		do {
			timeout = interruptible_sleep_on_timeout (&tp->thr_wait, timeout);
		} while (!signal_pending (current) && (timeout > 0));

		if (signal_pending (current))
			break;

		rtnl_lock ();
		rtnl_unlock ();
	}

	up (&tp->thr_exited);
	return 0;
}


static void rtl8139_tx_clear (struct rtl8139_private *tp)
{
	int i;

	tp->cur_tx = 0;
	tp->dirty_tx = 0;

	/* Dump the unsent Tx packets. */
	for (i = 0; i < NUM_TX_DESC; i++) {
		struct ring_info *rp = &tp->tx_info[i];
		if (rp->skb) {
			dev_kfree_skb (rp->skb);
			rp->skb = NULL;
			tp->stats.tx_dropped++;
		}
	}
}


static void rtl8139_tx_timeout (struct device *dev)
{
	struct rtl8139_private *tp = dev->priv;
	void *ioaddr = tp->mmio_addr;
	int i;
	u8 tmp8;
	unsigned long flags;

	DPRINTK ("%s: Transmit timeout, status %2.2x %4.4x "
		 "media %2.2x.\n", dev->name,
		 RTL_R8 (ChipCmd),
		 RTL_R16 (IntrStatus),
		 RTL_R8 (MediaStatus));

	tp->xstats.tx_timeouts++;

	/* disable Tx ASAP, if not already */
	tmp8 = RTL_R8 (ChipCmd);
	if (tmp8 & CmdTxEnb)
		RTL_W8 (ChipCmd, CmdRxEnb);

	/* Disable interrupts by clearing the interrupt mask. */
	RTL_W16 (IntrMask, 0x0000);

	/* Emit info to figure out what went wrong. */
	printk (KERN_DEBUG "%s: Tx queue start entry %ld  dirty entry %ld.\n",
		dev->name, tp->cur_tx, tp->dirty_tx);
	for (i = 0; i < NUM_TX_DESC; i++)
		printk (KERN_DEBUG "%s:  Tx descriptor %d is %8.8lx.%s\n",
			dev->name, i, RTL_R32 (TxStatus0 + (i * 4)),
			i == tp->dirty_tx % NUM_TX_DESC ?
				" (queue head)" : "");

	/* Stop a shared interrupt from scavenging while we are. */
	spin_lock_irqsave (&tp->lock, flags);
	rtl8139_tx_clear (tp);
	spin_unlock_irqrestore (&tp->lock, flags);

	/* ...and finally, reset everything */
	rtl8139_hw_start (dev);

	netif_wake_queue (dev);
}


static int rtl8139_start_xmit (struct sk_buff *skb, struct device *dev)
{
	struct rtl8139_private *tp = dev->priv;
	void *ioaddr = tp->mmio_addr;
	unsigned int entry;
	u32 dma_addr;

	if (dev->tbusy) {
		/* If this happens network layer tells us we're broken. */
		if (jiffies - dev->trans_start > TX_TIMEOUT) {
			rtl8139_tx_timeout(dev);
			if (skb) kfree_skb(skb);
			return 0;
		}
	}
	mb();

	/* Calculate the next Tx descriptor entry. */
	entry = tp->cur_tx % NUM_TX_DESC;

	assert (tp->tx_info[entry].skb == NULL);

	tp->tx_info[entry].skb = skb;
	if ((long) skb->data & 3) {	/* Must use alignment buffer. */
		/* tp->tx_info[entry].mapping = 0; */
		memcpy (tp->tx_buf[entry], skb->data, skb->len);
		dma_addr = tp->tx_bufs_dma + (tp->tx_buf[entry] - tp->tx_bufs);
	} else {
		dma_addr = virt_to_bus(skb->data);
	}

	/* Note: the chip doesn't have auto-pad! */
	spin_lock_irq(&tp->lock);
	RTL_W32_F (TxAddr0 + (entry * 4), dma_addr);
	RTL_W32_F (TxStatus0 + (entry * sizeof (u32)),
		   tp->tx_flag | (skb->len >= ETH_ZLEN ? skb->len : ETH_ZLEN));
	spin_unlock_irq(&tp->lock);

	dev->trans_start = jiffies;

	tp->cur_tx++;
	mb();
	if ((tp->cur_tx - NUM_TX_DESC) == tp->dirty_tx)
		netif_stop_queue (dev);

	DPRINTK ("%s: Queued Tx packet at %p size %u to slot %d.\n",
		 dev->name, skb->data, skb->len, entry);

	return 0;
}


static void rtl8139_tx_interrupt (struct device *dev,
					 struct rtl8139_private *tp,
					 void *ioaddr)
{
	unsigned long dirty_tx, tx_left;

	assert (dev != NULL);
	assert (tp != NULL);
	assert (ioaddr != NULL);

	dirty_tx = tp->dirty_tx;
	tx_left = tp->cur_tx - dirty_tx;
	while (tx_left > 0) {
		int entry = dirty_tx % NUM_TX_DESC;
		int txstatus;

		txstatus = RTL_R32 (TxStatus0 + (entry * sizeof (u32)));

		if (!(txstatus & (TxStatOK | TxUnderrun | TxAborted)))
			break;	/* It still hasn't been Txed */

		/* Note: TxCarrierLost is always asserted at 100mbps. */
		if (txstatus & (TxOutOfWindow | TxAborted)) {
			/* There was an major error, log it. */
			DPRINTK ("%s: Transmit error, Tx status %8.8x.\n",
				 dev->name, txstatus);
			tp->stats.tx_errors++;
			if (txstatus & TxAborted) {
				tp->stats.tx_aborted_errors++;
				RTL_W32_F (TxConfig, TxClearAbt | (TX_DMA_BURST << TxDMAShift));
			}
			if (txstatus & TxCarrierLost)
				tp->stats.tx_carrier_errors++;
			if (txstatus & TxOutOfWindow)
				tp->stats.tx_window_errors++;
#ifdef ETHER_STATS
			if ((txstatus & 0x0f000000) == 0x0f000000)
				tp->stats.collisions16++;
#endif
		} else {
			if (txstatus & TxUnderrun) {
				/* Add 64 to the Tx FIFO threshold. */
				if (tp->tx_flag < 0x00300000)
					tp->tx_flag += 0x00020000;
				tp->stats.tx_fifo_errors++;
			}
			tp->stats.collisions += (txstatus >> 24) & 15;
			tp->stats.tx_bytes += txstatus & 0x7ff;
			tp->stats.tx_packets++;
		}
		dev_kfree_skb_irq (tp->tx_info[entry].skb);
		tp->tx_info[entry].skb = NULL;

		dirty_tx++;
		tx_left--;
	}

#ifndef RTL8139_NDEBUG
	if (tp->cur_tx - dirty_tx > NUM_TX_DESC) {
		printk (KERN_ERR "%s: Out-of-sync dirty pointer, %ld vs. %ld.\n",
		        dev->name, dirty_tx, tp->cur_tx);
		dirty_tx += NUM_TX_DESC;
	}
#endif /* RTL8139_NDEBUG */

	/* only wake the queue if we did work, and the queue is stopped */
	if (tp->dirty_tx != dirty_tx) {
		tp->dirty_tx = dirty_tx;
		mb();
		if (netif_queue_stopped (dev))
			netif_wake_queue (dev);
	}
}


/* TODO: clean this up!  Rx reset need not be this intensive */
static void rtl8139_rx_err (u32 rx_status, struct device *dev,
			    struct rtl8139_private *tp, void *ioaddr)
{
	u8 tmp8;
	int tmp_work = 1000;

	DPRINTK ("%s: Ethernet frame had errors, status %8.8x.\n",
	         dev->name, rx_status);
	if (rx_status & RxTooLong) {
		DPRINTK ("%s: Oversized Ethernet frame, status %4.4x!\n",
			 dev->name, rx_status);
		/* A.C.: The chip hangs here. */
	}
	tp->stats.rx_errors++;
	if (rx_status & (RxBadSymbol | RxBadAlign))
		tp->stats.rx_frame_errors++;
	if (rx_status & (RxRunt | RxTooLong))
		tp->stats.rx_length_errors++;
	if (rx_status & RxCRCErr)
		tp->stats.rx_crc_errors++;
	/* Reset the receiver, based on RealTek recommendation. (Bug?) */
	tp->cur_rx = 0;

	/* disable receive */
	RTL_W8 (ChipCmd, CmdTxEnb);

	/* A.C.: Reset the multicast list. */
	rtl8139_set_rx_mode (dev);

	/* XXX potentially temporary hack to
	 * restart hung receiver */
	while (--tmp_work > 0) {
		barrier();
		tmp8 = RTL_R8 (ChipCmd);
		if ((tmp8 & CmdRxEnb) && (tmp8 & CmdTxEnb))
			break;
		RTL_W8 (ChipCmd, CmdRxEnb | CmdTxEnb);
	}

	/* G.S.: Re-enable receiver */
	/* XXX temporary hack to work around receiver hang */
	rtl8139_set_rx_mode (dev);

	if (tmp_work <= 0)
		printk (KERN_WARNING PFX "tx/rx enable wait too long\n");
}


static void rtl8139_rx_interrupt (struct device *dev,
				  struct rtl8139_private *tp, void *ioaddr)
{
	unsigned char *rx_ring;
	u16 cur_rx;

	assert (dev != NULL);
	assert (tp != NULL);
	assert (ioaddr != NULL);

	rx_ring = tp->rx_ring;
	cur_rx = tp->cur_rx;

	DPRINTK ("%s: In rtl8139_rx(), current %4.4x BufAddr %4.4x,"
		 " free to %4.4x, Cmd %2.2x.\n", dev->name, cur_rx,
		 RTL_R16 (RxBufAddr),
		 RTL_R16 (RxBufPtr), RTL_R8 (ChipCmd));

	while ((RTL_R8 (ChipCmd) & RxBufEmpty) == 0) {
		int ring_offset = cur_rx % RX_BUF_LEN;
		u32 rx_status;
		unsigned int rx_size;
		unsigned int pkt_size;
		struct sk_buff *skb;

		rmb();
		
		/* read size+status of next frame from DMA ring buffer */
		rx_status = le32_to_cpu (*(u32 *) (rx_ring + ring_offset));
		rx_size = rx_status >> 16;
		pkt_size = rx_size - 4;

		DPRINTK ("%s:  rtl8139_rx() status %4.4x, size %4.4x,"
			 " cur %4.4x.\n", dev->name, rx_status,
			 rx_size, cur_rx);
#if RTL8139_DEBUG > 2
		{
			int i;
			DPRINTK ("%s: Frame contents ", dev->name);
			for (i = 0; i < 70; i++)
				printk (" %2.2x",
					rx_ring[ring_offset + i]);
			printk (".\n");
		}
#endif

		if (rx_size == 0xfff0) { /* Early Rx in progress */
			tp->xstats.early_rx++;
			break;
		}

		/* If Rx err or invalid rx_size/rx_status received
		 * (which happens if we get lost in the ring),
		 * Rx process gets reset, so we abort any further
		 * Rx processing.
		 */
		if ((rx_size > (MAX_ETH_FRAME_SIZE+4)) ||
		    (rx_size < 8) ||
		    (!(rx_status & RxStatusOK))) {
			rtl8139_rx_err (rx_status, dev, tp, ioaddr);
			return;
		}

		/* Malloc up new buffer, compatible with net-2e. */
		/* Omit the four octet CRC from the length. */

		/* TODO: consider allocating skb's outside of
		 * interrupt context, both to speed interrupt processing,
		 * and also to reduce the chances of having to
		 * drop packets here under memory pressure.
		 */

		skb = dev_alloc_skb (pkt_size + 2);
		if (skb) {
			skb->dev = dev;
			skb_reserve (skb, 2);	/* 16 byte align the IP fields. */

			eth_copy_and_sum (skb, &rx_ring[ring_offset + 4], pkt_size, 0);
			skb_put (skb, pkt_size);

			skb->protocol = eth_type_trans (skb, dev);
			netif_rx (skb);
			mark_bh(NET_BH);
			tp->stats.rx_bytes += pkt_size ;
			dev->last_rx = jiffies;
			tp->stats.rx_packets++;
		} else {
			printk (KERN_WARNING
				"%s: Memory squeeze, dropping packet.\n",
				dev->name);
			tp->stats.rx_dropped++;
		}

		cur_rx = (cur_rx + rx_size + 4 + 3) & ~3;
		RTL_W16 (RxBufPtr, cur_rx - 16);

		if (RTL_R16 (IntrStatus) & RxAckBits)
			RTL_W16_F (IntrStatus, RxAckBits);
	}

	DPRINTK ("%s: Done rtl8139_rx(), current %4.4x BufAddr %4.4x,"
		 " free to %4.4x, Cmd %2.2x.\n", dev->name, cur_rx,
		 RTL_R16 (RxBufAddr),
		 RTL_R16 (RxBufPtr), RTL_R8 (ChipCmd));

	tp->cur_rx = cur_rx;

	if ((RTL_R8 (ChipCmd) & RxBufEmpty) &&
	    (RTL_R16 (IntrStatus) & RxAckBits))
		RTL_W16_F (IntrStatus, RxAckBits);
}


static void rtl8139_weird_interrupt (struct device *dev,
				     struct rtl8139_private *tp,
				     void *ioaddr,
				     int status, int link_changed)
{
	DPRINTK ("%s: Abnormal interrupt, status %8.8x.\n",
		 dev->name, status);

	assert (dev != NULL);
	assert (tp != NULL);
	assert (ioaddr != NULL);

	/* Update the error count. */
	tp->stats.rx_missed_errors += RTL_R32 (RxMissed);
	RTL_W32 (RxMissed, 0);

	if ((status & RxUnderrun) && link_changed &&
	    (tp->drv_flags & HAS_LNK_CHNG)) {
		/* Really link-change on new chips. */
		int lpar = RTL_R16 (NWayLPAR);
		int duplex = (lpar & 0x0100) || (lpar & 0x01C0) == 0x0040
				|| tp->duplex_lock;
		if (tp->full_duplex != duplex) {
			tp->full_duplex = duplex;
#if 0
			RTL_W8 (Cfg9346, Cfg9346_Unlock);
			RTL_W8 (Config1, tp->full_duplex ? 0x60 : 0x20);
			RTL_W8 (Cfg9346, Cfg9346_Lock);
#endif
		}
		status &= ~RxUnderrun;
	}

	/* XXX along with rtl8139_rx_err, are we double-counting errors? */
	if (status &
	    (RxUnderrun | RxOverflow | RxErr | RxFIFOOver))
		tp->stats.rx_errors++;

	if (status & (PCSTimeout))
		tp->stats.rx_length_errors++;
	if (status & (RxUnderrun | RxFIFOOver))
		tp->stats.rx_fifo_errors++;
	if (status & PCIErr) {
		u16 pci_cmd_status;
		pci_read_config_word (tp->pci_dev, PCI_STATUS, &pci_cmd_status);

		printk (KERN_ERR "%s: PCI Bus error %4.4x.\n",
			dev->name, pci_cmd_status);
	}
}


/* The interrupt handler does all of the Rx thread work and cleans up
   after the Tx thread. */
static void rtl8139_interrupt (int irq, void *dev_instance,
			       struct pt_regs *regs)
{
	struct device *dev = (struct device *) dev_instance;
	struct rtl8139_private *tp = dev->priv;
	int boguscnt = max_interrupt_work;
	void *ioaddr = tp->mmio_addr;
	int ackstat, status;
	int link_changed = 0; /* avoid bogus "uninit" warning */

	spin_lock (&tp->lock);

	do {
		status = RTL_R16 (IntrStatus);

		/* h/w no longer present (hotplug?) or major error, bail */
		if (status == 0xFFFF)
			break;

		/* Acknowledge all of the current interrupt sources ASAP, but
		   an first get an additional status bit from CSCR. */
		if (status & RxUnderrun)
			link_changed = RTL_R16 (CSCR) & CSCR_LinkChangeBit;

		/* The chip takes special action when we clear RxAckBits,
		 * so we clear them later in rtl8139_rx_interrupt
		 */
		ackstat = status & ~RxAckBits;
		RTL_W16 (IntrStatus, ackstat);

		DPRINTK ("%s: interrupt  status=%#4.4x ackstat=%#4.4x new intstat=%#4.4x.\n",
			 dev->name, ackstat, status, RTL_R16 (IntrStatus));

		if ((status &
		     (PCIErr | PCSTimeout | RxUnderrun | RxOverflow |
		      RxFIFOOver | TxErr | TxOK | RxErr | RxOK)) == 0)
			break;

		if (netif_running (dev) && (status & RxAckBits))
			rtl8139_rx_interrupt (dev, tp, ioaddr);

		/* Check uncommon events with one test. */
		if (status & (PCIErr | PCSTimeout | RxUnderrun | RxOverflow |
		  	      RxFIFOOver | TxErr | RxErr))
			rtl8139_weird_interrupt (dev, tp, ioaddr,
						 status, link_changed);

		if (netif_running (dev) && (status & (TxOK | TxErr)))
			rtl8139_tx_interrupt (dev, tp, ioaddr);

		boguscnt--;
	} while (boguscnt > 0);

	if (boguscnt <= 0) {
		printk (KERN_WARNING "%s: Too much work at interrupt, "
			"IntrStatus=0x%4.4x.\n", dev->name, status);

		/* Clear all interrupt sources. */
		RTL_W16 (IntrStatus, 0xffff);
	}

	spin_unlock (&tp->lock);

	DPRINTK ("%s: exiting interrupt, intr_status=%#4.4x.\n",
		 dev->name, RTL_R16 (IntrStatus));
}


static int rtl8139_close (struct device *dev)
{
	struct rtl8139_private *tp = dev->priv;
	void *ioaddr = tp->mmio_addr;
	int ret = 0;
	int i;
	unsigned long flags;

	DPRINTK ("ENTER\n");

	netif_stop_queue (dev);
	dev->start = 0;
	if (tp->thr_pid >= 0) {
		ret = kill_proc (tp->thr_pid, SIGTERM, 1);
		if (ret) {
			printk (KERN_ERR "%s: unable to signal thread\n", dev->name);
			return ret;
		}
		down (&tp->thr_exited);
	}

	DPRINTK ("%s: Shutting down ethercard, status was 0x%4.4x.\n",
			dev->name, RTL_R16 (IntrStatus));

	spin_lock_irqsave (&tp->lock, flags);

	/* Stop the chip's Tx and Rx DMA processes. */
	RTL_W8 (ChipCmd, 0);

	/* Disable interrupts by clearing the interrupt mask. */
	RTL_W16 (IntrMask, 0);

	/* Update the error counts. */
	tp->stats.rx_missed_errors += RTL_R32 (RxMissed);
	RTL_W32 (RxMissed, 0);

	spin_unlock_irqrestore (&tp->lock, flags);

	synchronize_irq ();
	free_irq (dev->irq, dev);

	rtl8139_tx_clear (tp);

	for (i = 0; i < NUM_TX_DESC; i++) {
		struct sk_buff *skb = tp->tx_info[i].skb;

		if (skb) {
			dev_kfree_skb (skb);
			DPRINTK("PCI unmap?\n");
		}
		tp->tx_info[i].skb = NULL;
	}

	kfree(tp->rx_ring);
	kfree(tp->tx_bufs);
	tp->rx_ring = NULL;
	tp->tx_bufs = NULL;

	/* Green! Put the chip in low-power mode. */
	RTL_W8 (Cfg9346, Cfg9346_Unlock);

	if (rtl_chip_info[tp->chipset].flags & HasHltClk)
		RTL_W8 (HltClk, 'H');	/* 'R' would leave the clock running. */

	MOD_DEC_USE_COUNT;
	DPRINTK ("EXIT\n");
	return 0;
}


static int netdev_ethtool_ioctl (struct device *dev, void *useraddr)
{
	struct rtl8139_private *np = dev->priv;
	u32 ethcmd;

	if (copy_from_user (&ethcmd, useraddr, sizeof (ethcmd)))
		return -EFAULT;

	switch (ethcmd) {
	case ETHTOOL_GDRVINFO:
		{
			struct ethtool_drvinfo info = { ETHTOOL_GDRVINFO };
			strcpy (info.driver, DRV_NAME);
			strcpy (info.version, DRV_VERSION);
			sprintf(info.bus_info, "PCI slot #%u", PCI_SLOT(np->pci_dev->devfn));
			if (copy_to_user (useraddr, &info, sizeof (info)))
				return -EFAULT;
			return 0;
		}

	default:
		break;
	}

	return -EOPNOTSUPP;
}

static int netdev_ioctl (struct device *dev, struct ifreq *rq, int cmd)
{
	struct rtl8139_private *tp = dev->priv;
	struct mii_ioctl_data *data = (struct mii_ioctl_data *)&rq->ifr_data;
	int rc = 0;
	int phy = tp->phys[0] & 0x3f;

	DPRINTK ("ENTER\n");

#ifdef notdef
	data->phy_id &= 0x1f;
	data->reg_num &= 0x1f;
#endif

	switch (cmd) {
	case SIOCETHTOOL:
		return netdev_ethtool_ioctl(dev, (void *) rq->ifr_data);

	case SIOCGMIIPHY:	/* Get the address of the PHY in use. */
	case SIOCDEVPRIVATE:	/* binary compat, remove in 2.5 */
		data->phy_id = phy;
		/* Fall Through */

	case SIOCGMIIREG:	/* Read the specified MII register. */
	case SIOCDEVPRIVATE+1:	/* binary compat, remove in 2.5 */
		data->val_out = mdio_read (dev, data->phy_id, data->reg_num);
		break;

	case SIOCSMIIREG:	/* Write the specified MII register */
	case SIOCDEVPRIVATE+2:	/* binary compat, remove in 2.5 */
		if (!capable (CAP_NET_ADMIN)) {
			rc = -EPERM;
			break;
		}

		if (data->phy_id == phy) {
			u16 value = data->val_in;
			switch (data->reg_num) {
			case 0:
				/* Check for autonegotiation on or reset. */
				tp->medialock = (value & 0x9000) ? 0 : 1;
				if (tp->medialock)
					tp->full_duplex = (value & 0x0100) ? 1 : 0;
				break;
			case 4: /* tp->advertising = value; */ break;
			}
		}
		mdio_write(dev, data->phy_id, data->reg_num, data->val_in);
		break;

	default:
		rc = -EOPNOTSUPP;
		break;
	}

	DPRINTK ("EXIT, returning %d\n", rc);
	return rc;
}


static struct net_device_stats *rtl8139_get_stats (struct device *dev)
{
	struct rtl8139_private *tp = dev->priv;
	void *ioaddr = tp->mmio_addr;
	unsigned long flags;

	DPRINTK ("ENTER\n");

	if (netif_running(dev)) {
		spin_lock_irqsave (&tp->lock, flags);
		tp->stats.rx_missed_errors += RTL_R32 (RxMissed);
		RTL_W32 (RxMissed, 0);
		spin_unlock_irqrestore (&tp->lock, flags);
	}

	DPRINTK ("EXIT\n");
	return &tp->stats;
}

/* Set or clear the multicast filter for this adaptor.
   This routine is not state sensitive and need not be SMP locked. */

static unsigned const ethernet_polynomial = 0x04c11db7U;
static inline u32 ether_crc (int length, unsigned char *data)
{
	int crc = -1;

	DPRINTK ("ENTER\n");

	while (--length >= 0) {
		unsigned char current_octet = *data++;
		int bit;
		for (bit = 0; bit < 8; bit++, current_octet >>= 1)
			crc = (crc << 1) ^ ((crc < 0) ^ (current_octet & 1) ?
			     ethernet_polynomial : 0);
	}

	DPRINTK ("EXIT, returning %u\n", crc);
	return crc;
}


static void rtl8139_set_rx_mode (struct device *dev)
{
	struct rtl8139_private *tp = dev->priv;
	void *ioaddr = tp->mmio_addr;
	unsigned long flags;
	u32 mc_filter[2];	/* Multicast hash filter */
	int i, rx_mode;
	u32 tmp;

	DPRINTK ("ENTER\n");

	DPRINTK ("%s:   rtl8139_set_rx_mode(%4.4x) done -- Rx config %8.8lx.\n",
			dev->name, dev->flags, RTL_R32 (RxConfig));

	/* Note: do not reorder, GCC is clever about common statements. */
	if (dev->flags & IFF_PROMISC) {
		/* Unconditionally log net taps. */
		printk (KERN_NOTICE "%s: Promiscuous mode enabled.\n",
			dev->name);
		rx_mode =
		    AcceptBroadcast | AcceptMulticast | AcceptMyPhys |
		    AcceptAllPhys;
		mc_filter[1] = mc_filter[0] = 0xffffffff;
	} else if ((dev->mc_count > multicast_filter_limit)
		   || (dev->flags & IFF_ALLMULTI)) {
		/* Too many to filter perfectly -- accept all multicasts. */
		rx_mode = AcceptBroadcast | AcceptMulticast | AcceptMyPhys;
		mc_filter[1] = mc_filter[0] = 0xffffffff;
	} else {
		struct dev_mc_list *mclist;
		rx_mode = AcceptBroadcast | AcceptMyPhys;
		mc_filter[1] = mc_filter[0] = 0;
		for (i = 0, mclist = dev->mc_list; mclist && i < dev->mc_count;
		     i++, mclist = mclist->next) {
			int bit_nr = ether_crc(ETH_ALEN, mclist->dmi_addr) >> 26;

			mc_filter[bit_nr >> 5] |= cpu_to_le32(1 << (bit_nr & 31));
			rx_mode |= AcceptMulticast;
		}
	}

	spin_lock_irqsave (&tp->lock, flags);

	/* We can safely update without stopping the chip. */
	tmp = rtl8139_rx_config | rx_mode;
	if (tp->rx_config != tmp) {
		RTL_W32 (RxConfig, tmp);
		tp->rx_config = tmp;
	}
	RTL_W32_F (MAR0 + 0, mc_filter[0]);
	RTL_W32_F (MAR0 + 4, mc_filter[1]);

	spin_unlock_irqrestore (&tp->lock, flags);

	DPRINTK ("EXIT\n");
}


int rtl8139_init(void)
{
	struct pci_dev *pcidev;
	struct pci_device_id *pdid;
	struct rtl8139_private *tp;
	int i, initialized;

	if (rtl8139_initialized) return -ENODEV;
	for (pdid=&rtl8139_pci_tbl[0]; pdid->vendor != 0; pdid++) {
		for (pcidev = rtl8139_pci_find_device(pdid->vendor, pdid->device, NULL); pcidev != NULL; pcidev = rtl8139_pci_find_device(pdid->vendor, pdid->device, pcidev)) {
			initialized = 0;
			for (i=0; i<rtl8139_device_count; i++) {
				tp = (struct rtl8139_private *) rtl8139_device_tab[i]->priv;
				if (tp->pci_dev == pcidev)
					initialized = 1;
			}
			if (!initialized)
				if (rtl8139_init_one(pcidev, pdid) != 0)
					printk(KERN_ERR "Error initializing PCI device %08lX.\n", (unsigned long) pcidev);
		}
	}
	rtl8139_initialized++;
	return (rtl8139_device_count > 0 ? 0 : -ENODEV);
}

void rtl8139_cleanup(void)
{
	int i;
	
	for (i=0; i<rtl8139_device_count; i++) {
		rtl8139_remove_one(rtl8139_device_tab[i]);
	}
	return;
}

/* ------------------------------------------------------------------------- */

#ifdef MODULE

int init_module(void)
{
	return rtl8139_init();
}

void cleanup_module(void)
{
	rtl8139_cleanup();
	return;
}

#else

int rtl8139too_probe(struct device *dev)
{
	return rtl8139_init();
}

#endif
