Merge with 2.4.0-test7.

1 files changed, 1186 insertions, 0 deletions

diff --git a/drivers/net/natsemi.c b/drivers/net/natsemi.c
new file mode 100644
index 000000000..565ddc52b
--- /dev/null
+++ b/drivers/net/natsemi.c
@@ -0,0 +1,1186 @@
+/* natsemi.c: A Linux PCI Ethernet driver for the NatSemi DP83810 series. */
+/*
+	Written/copyright 1999-2000 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.  License for under other terms may be
+	available.  Contact the original author for details.
+
+	The original author may be reached as becker@scyld.com, or at
+	Scyld Computing Corporation
+	410 Severn Ave., Suite 210
+	Annapolis MD 21403
+
+	Support information and updates available at
+	http://www.scyld.com/network/netsemi.html
+*/
+
+/* These identify the driver base version and may not be removed. */
+static const char version1[] =
+"natsemi.c:v1.05 8/7/2000  Written by Donald Becker <becker@scyld.com>\n";
+static const char version2[] =
+"  http://www.scyld.com/network/natsemi.html\n";
+static const char version3[] =
+"  (unofficial 2.4.x kernel port, version 1.0.0, August 10, 2000)\n";
+/* Updated to recommendations in pci-skeleton v2.03. */
+
+/* Automatically extracted configuration info:
+probe-func: natsemi_probe
+config-in: tristate 'National Semiconductor DP83810 series PCI Ethernet support' CONFIG_NATSEMI
+
+c-help-name: National Semiconductor DP83810 series PCI Ethernet support
+c-help-symbol: CONFIG_NATSEMI
+c-help: This driver is for the National Semiconductor DP83810 series,
+c-help: including the 83815 chip.
+c-help: More specific information and updates are available from 
+c-help: http://www.scyld.com/network/natsemi.html
+*/
+
+/* The user-configurable values.
+   These may be modified when a driver module is loaded.*/
+
+static int debug = 1;			/* 1 normal messages, 0 quiet .. 7 verbose. */
+/* Maximum events (Rx packets, etc.) to handle at each interrupt. */
+static int max_interrupt_work = 20;
+static int mtu = 0;
+/* Maximum number of multicast addresses to filter (vs. rx-all-multicast).
+   This chip uses a 512 element hash table based on the Ethernet CRC.  */
+static int multicast_filter_limit = 100;
+
+/* Set the copy breakpoint for the copy-only-tiny-frames scheme.
+   Setting to > 1518 effectively disables this feature. */
+static int rx_copybreak = 0;
+
+/* Used to pass the media type, etc.
+   Both 'options[]' and 'full_duplex[]' should exist for driver
+   interoperability.
+   The media type is usually passed in 'options[]'.
+*/
+#define MAX_UNITS 8		/* More are supported, limit only on options */
+static int options[MAX_UNITS] = {-1, -1, -1, -1, -1, -1, -1, -1};
+static int full_duplex[MAX_UNITS] = {-1, -1, -1, -1, -1, -1, -1, -1};
+
+/* Operational parameters that are set at compile time. */
+
+/* Keep the ring sizes a power of two for compile efficiency.
+   The compiler will convert <unsigned>'%'<2^N> into a bit mask.
+   Making the Tx ring too large decreases the effectiveness of channel
+   bonding and packet priority.
+   There are no ill effects from too-large receive rings. */
+#define TX_RING_SIZE	16
+#define TX_QUEUE_LEN	10		/* Limit ring entries actually used.  */
+#define RX_RING_SIZE	32
+
+/* Operational parameters that usually are not changed. */
+/* Time in jiffies before concluding the transmitter is hung. */
+#define TX_TIMEOUT  (2*HZ)
+
+#define PKT_BUF_SZ		1536			/* Size of each temporary Rx buffer.*/
+
+#if !defined(__OPTIMIZE__)
+#warning  You must compile this file with the correct options!
+#warning  See the last lines of the source file.
+#error You must compile this driver with "-O".
+#endif
+
+/* Include files, designed to support most kernel versions 2.0.0 and later. */
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/malloc.h>
+#include <linux/interrupt.h>
+#include <linux/pci.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <asm/processor.h>		/* Processor type for cache alignment. */
+#include <asm/bitops.h>
+#include <asm/io.h>
+
+/* Condensed operations for readability. */
+#define virt_to_le32desc(addr)  cpu_to_le32(virt_to_bus(addr))
+#define le32desc_to_virt(addr)  bus_to_virt(le32_to_cpu(addr))
+
+MODULE_AUTHOR("Donald Becker <becker@scyld.com>");
+MODULE_DESCRIPTION("National Semiconductor DP83810 series PCI Ethernet driver");
+MODULE_PARM(max_interrupt_work, "i");
+MODULE_PARM(mtu, "i");
+MODULE_PARM(debug, "i");
+MODULE_PARM(rx_copybreak, "i");
+MODULE_PARM(options, "1-" __MODULE_STRING(MAX_UNITS) "i");
+MODULE_PARM(full_duplex, "1-" __MODULE_STRING(MAX_UNITS) "i");
+
+/*
+				Theory of Operation
+
+I. Board Compatibility
+
+This driver is designed for National Semiconductor DP83815 PCI Ethernet NIC.
+It also works with other chips in in the DP83810 series.
+
+II. Board-specific settings
+
+This driver requires the PCI interrupt line to be valid.
+It honors the EEPROM-set values. 
+
+III. Driver operation
+
+IIIa. Ring buffers
+
+This driver uses two statically allocated fixed-size descriptor lists
+formed into rings by a branch from the final descriptor to the beginning of
+the list.  The ring sizes are set at compile time by RX/TX_RING_SIZE.
+The NatSemi design uses a 'next descriptor' pointer that the driver forms
+into a list. 
+
+IIIb/c. Transmit/Receive Structure
+
+This driver uses a zero-copy receive and transmit scheme.
+The driver allocates full frame size skbuffs for the Rx ring buffers at
+open() time and passes the skb->data field to the chip as receive data
+buffers.  When an incoming frame is less than RX_COPYBREAK bytes long,
+a fresh skbuff is allocated and the frame is copied to the new skbuff.
+When the incoming frame is larger, the skbuff is passed directly up the
+protocol stack.  Buffers consumed this way are replaced by newly allocated
+skbuffs in a later phase of receives.
+
+The RX_COPYBREAK value is chosen to trade-off the memory wasted by
+using a full-sized skbuff for small frames vs. the copying costs of larger
+frames.  New boards are typically used in generously configured machines
+and the underfilled buffers have negligible impact compared to the benefit of
+a single allocation size, so the default value of zero results in never
+copying packets.  When copying is done, the cost is usually mitigated by using
+a combined copy/checksum routine.  Copying also preloads the cache, which is
+most useful with small frames.
+
+A subtle aspect of the operation is that unaligned buffers are not permitted
+by the hardware.  Thus the IP header at offset 14 in an ethernet frame isn't
+longword aligned for further processing.  On copies frames are put into the
+skbuff at an offset of "+2", 16-byte aligning the IP header.
+
+IIId. Synchronization
+
+The driver runs as two independent, single-threaded flows of control.  One
+is the send-packet routine, which enforces single-threaded use by the
+dev->tbusy flag.  The other thread is the interrupt handler, which is single
+threaded by the hardware and interrupt handling software.
+
+The send packet thread has partial control over the Tx ring and 'dev->tbusy'
+flag.  It sets the tbusy flag whenever it's queuing a Tx packet. If the next
+queue slot is empty, it clears the tbusy flag when finished otherwise it sets
+the 'lp->tx_full' flag.
+
+The interrupt handler has exclusive control over the Rx ring and records stats
+from the Tx ring.  After reaping the stats, it marks the Tx queue entry as
+empty by incrementing the dirty_tx mark. Iff the 'lp->tx_full' flag is set, it
+clears both the tx_full and tbusy flags.
+
+IV. Notes
+
+NatSemi PCI network controllers are very uncommon.
+
+IVb. References
+
+http://www.scyld.com/expert/100mbps.html
+http://www.scyld.com/expert/NWay.html
+No NatSemi datasheet was publically available at the initial release date.
+
+IVc. Errata
+
+None characterised.
+*/
+
+
+
+enum pcistuff {
+	PCI_USES_IO = 0x01,
+	PCI_USES_MEM = 0x02,
+	PCI_USES_MASTER = 0x04,
+	PCI_ADDR0 = 0x08,
+	PCI_ADDR1 = 0x10,
+};
+
+/* MMIO operations required */
+#define PCI_IOTYPE (PCI_USES_MASTER | PCI_USES_MEM | PCI_ADDR1)
+
+
+/* array of board data directly indexed by pci_tbl[x].driver_data */
+static struct {
+	const char *name;
+	unsigned long flags;
+} natsemi_pci_info[] __devinitdata = {
+	{ "NatSemi DP83815", PCI_IOTYPE },
+};
+
+static struct pci_device_id natsemi_pci_tbl[] __devinitdata = {
+	{ 0x100B, 0x0020, PCI_ANY_ID, PCI_ANY_ID, },
+	{ 0, },
+};
+MODULE_DEVICE_TABLE(pci, natsemi_pci_tbl);
+
+/* Offsets to the device registers.
+   Unlike software-only systems, device drivers interact with complex hardware.
+   It's not useful to define symbolic names for every register bit in the
+   device.
+*/
+enum register_offsets {
+	ChipCmd=0x00, ChipConfig=0x04, EECtrl=0x08, PCIBusCfg=0x0C,
+	IntrStatus=0x10, IntrMask=0x14, IntrEnable=0x18,
+	TxRingPtr=0x20, TxConfig=0x24,
+	RxRingPtr=0x30, RxConfig=0x34,
+	WOLCmd=0x40, PauseCmd=0x44, RxFilterAddr=0x48, RxFilterData=0x4C,
+	BootRomAddr=0x50, BootRomData=0x54, StatsCtrl=0x5C, StatsData=0x60,
+	RxPktErrs=0x60, RxMissed=0x68, RxCRCErrs=0x64,
+};
+
+/* Bit in ChipCmd. */
+enum ChipCmdBits {
+	ChipReset=0x100, RxReset=0x20, TxReset=0x10, RxOff=0x08, RxOn=0x04,
+	TxOff=0x02, TxOn=0x01,
+};
+
+/* Bits in the interrupt status/mask registers. */
+enum intr_status_bits {
+	IntrRxDone=0x0001, IntrRxIntr=0x0002, IntrRxErr=0x0004, IntrRxEarly=0x0008,
+	IntrRxIdle=0x0010, IntrRxOverrun=0x0020,
+	IntrTxDone=0x0040, IntrTxIntr=0x0080, IntrTxErr=0x0100,
+	IntrTxIdle=0x0200, IntrTxOverrun=0x0400,
+	StatsMax=0x0800, LinkChange=0x4000,
+	WOLPkt=0x2000,
+	RxResetDone=0x1000000, TxResetDone=0x2000000,
+	IntrPCIErr=0x00f00000,
+	IntrNormalSummary=0x0251, IntrAbnormalSummary=0xCD20,
+};
+
+/* Bits in the RxMode register. */
+enum rx_mode_bits {
+	AcceptErr=0x20, AcceptRunt=0x10,
+	AcceptBroadcast=0xC0000000,
+	AcceptMulticast=0x00200000, AcceptAllMulticast=0x20000000,
+	AcceptAllPhys=0x10000000, AcceptMyPhys=0x08000000,
+};
+
+/* The Rx and Tx buffer descriptors. */
+/* Note that using only 32 bit fields simplifies conversion to big-endian
+   architectures. */
+struct netdev_desc {
+	u32 next_desc;
+	s32 cmd_status;
+	u32 addr;
+	u32 software_use;
+};
+
+/* Bits in network_desc.status */
+enum desc_status_bits {
+	DescOwn=0x80000000, DescMore=0x40000000, DescIntr=0x20000000,
+	DescNoCRC=0x10000000,
+	DescPktOK=0x08000000, RxTooLong=0x00400000,
+};
+
+#define PRIV_ALIGN	15 	/* Required alignment mask */
+struct netdev_private {
+	/* Descriptor rings first for alignment. */
+	struct netdev_desc rx_ring[RX_RING_SIZE];
+	struct netdev_desc tx_ring[TX_RING_SIZE];
+	/* The addresses of receive-in-place skbuffs. */
+	struct sk_buff* rx_skbuff[RX_RING_SIZE];
+	/* The saved address of a sent-in-place packet/buffer, for later free(). */
+	struct sk_buff* tx_skbuff[TX_RING_SIZE];
+	struct net_device_stats stats;
+	struct timer_list timer;	/* Media monitoring timer. */
+	/* Frequently used values: keep some adjacent for cache effect. */
+	struct pci_dev *pci_dev;
+	struct netdev_desc *rx_head_desc;
+	unsigned int cur_rx, dirty_rx;		/* Producer/consumer ring indices */
+	unsigned int cur_tx, dirty_tx;
+	unsigned int rx_buf_sz;				/* Based on MTU+slack. */
+	unsigned int tx_full:1;				/* The Tx queue is full. */
+	/* These values are keep track of the transceiver/media in use. */
+	unsigned int full_duplex:1;			/* Full-duplex operation requested. */
+	unsigned int duplex_lock:1;
+	unsigned int medialock:1;			/* Do not sense media. */
+	unsigned int default_port:4;		/* Last dev->if_port value. */
+	/* Rx filter. */
+	u32 cur_rx_mode;
+	u32 rx_filter[16];
+	/* FIFO and PCI burst thresholds. */
+	int tx_config, rx_config;
+	/* MII transceiver section. */
+	u16 advertising;					/* NWay media advertisement */
+	
+	unsigned int iosize;
+	spinlock_t lock;
+};
+
+static int  eeprom_read(long ioaddr, int location);
+static int  mdio_read(struct net_device *dev, int phy_id, int location);
+static void mdio_write(struct net_device *dev, int phy_id, int location, int value);
+static int  netdev_open(struct net_device *dev);
+static void check_duplex(struct net_device *dev);
+static void netdev_timer(unsigned long data);
+static void tx_timeout(struct net_device *dev);
+static void init_ring(struct net_device *dev);
+static int  start_tx(struct sk_buff *skb, struct net_device *dev);
+static void intr_handler(int irq, void *dev_instance, struct pt_regs *regs);
+static void netdev_error(struct net_device *dev, int intr_status);
+static int  netdev_rx(struct net_device *dev);
+static void netdev_error(struct net_device *dev, int intr_status);
+static void set_rx_mode(struct net_device *dev);
+static struct net_device_stats *get_stats(struct net_device *dev);
+static int mii_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
+static int  netdev_close(struct net_device *dev);
+
+
+static int __devinit natsemi_probe1 (struct pci_dev *pdev,
+				     const struct pci_device_id *ent)
+{
+	struct net_device *dev;
+	struct netdev_private *np;
+	int i, option, irq = pdev->irq, chip_idx = ent->driver_data;
+	static int find_cnt = -1;
+	static int printed_version;
+	unsigned long ioaddr;
+	const int pcibar = 1; /* PCI base address register */
+
+	if ((debug <= 1) && !printed_version++)
+		printk(KERN_INFO "%s" KERN_INFO "%s" KERN_INFO "%s",
+			version1, version2, version3);
+
+	find_cnt++;
+	option = find_cnt < MAX_UNITS ? options[find_cnt] : 0;
+	ioaddr = pci_resource_start(pdev, pcibar);
+	
+	if (pci_enable_device(pdev))
+		return -EIO;
+	if (natsemi_pci_info[chip_idx].flags & PCI_USES_MASTER)
+		pci_set_master(pdev);
+
+	dev = init_etherdev(NULL, sizeof (struct netdev_private));
+	if (!dev)
+		return -ENOMEM;
+
+	{
+		void *mmio;
+		if (request_mem_region(ioaddr, pci_resource_len (pdev, pcibar),
+				       dev->name) == NULL) {
+			unregister_netdev(dev);
+			kfree(dev);
+			return -EBUSY;
+		}
+		mmio = ioremap (ioaddr, pci_resource_len (pdev, pcibar));
+		if (!mmio) {
+			release_mem_region(ioaddr, pci_resource_len (pdev, pcibar));
+			unregister_netdev(dev);
+			kfree(dev);
+			return -ENOMEM;
+		}
+		ioaddr = (unsigned long) mmio;
+	}
+
+	printk(KERN_INFO "%s: %s at 0x%lx, ",
+		   dev->name, natsemi_pci_info[chip_idx].name, ioaddr);
+
+	for (i = 0; i < 3; i++)
+		((u16 *)dev->dev_addr)[i] = be16_to_cpu(eeprom_read(ioaddr, i + 7));
+	for (i = 0; i < 5; i++)
+			printk("%2.2x:", dev->dev_addr[i]);
+	printk("%2.2x, IRQ %d.\n", dev->dev_addr[i], irq);
+
+#if ! defined(final_version) /* Dump the EEPROM contents during development. */
+	if (debug > 4)
+		for (i = 0; i < 64; i++)
+			printk("%4.4x%s",
+				   eeprom_read(ioaddr, i), i % 16 != 15 ? " " : "\n");
+#endif
+
+	/* Reset the chip to erase previous misconfiguration. */
+	writel(ChipReset, ioaddr + ChipCmd);
+
+	dev->base_addr = ioaddr;
+	dev->irq = irq;
+
+	np = dev->priv;
+
+	np->pci_dev = pdev;
+	pdev->driver_data = dev;
+	np->iosize = pci_resource_len(pdev, pcibar);
+
+	if (dev->mem_start)
+		option = dev->mem_start;
+
+	/* The lower four bits are the media type. */
+	if (option > 0) {
+		if (option & 0x200)
+			np->full_duplex = 1;
+		np->default_port = option & 15;
+		if (np->default_port)
+			np->medialock = 1;
+	}
+	if (find_cnt < MAX_UNITS  &&  full_duplex[find_cnt] > 0)
+		np->full_duplex = 1;
+
+	if (np->full_duplex)
+		np->duplex_lock = 1;
+
+	/* The chip-specific entries in the device structure. */
+	dev->open = &netdev_open;
+	dev->hard_start_xmit = &start_tx;
+	dev->stop = &netdev_close;
+	dev->get_stats = &get_stats;
+	dev->set_multicast_list = &set_rx_mode;
+	dev->do_ioctl = &mii_ioctl;
+	dev->tx_timeout = &tx_timeout;
+	dev->watchdog_timeo = TX_TIMEOUT;
+
+	if (mtu)
+		dev->mtu = mtu;
+
+	np->advertising = readl(ioaddr + 0x90);
+	printk(KERN_INFO "%s: Transceiver status 0x%4.4x advertising %4.4x.\n",
+		   dev->name, (int)readl(ioaddr + 0x84), np->advertising);
+
+	return 0;
+}
+
+
+/* Read the EEPROM and MII Management Data I/O (MDIO) interfaces.
+   The EEPROM code is for the common 93c06/46 EEPROMs with 6 bit addresses. */
+
+/* Delay between EEPROM clock transitions.
+   No extra delay is needed with 33Mhz PCI, but future 66Mhz access may need
+   a delay.  Note that pre-2.0.34 kernels had a cache-alignment bug that
+   made udelay() unreliable.
+   The old method of using an ISA access as a delay, __SLOW_DOWN_IO__, is
+   depricated.
+*/
+#define eeprom_delay(ee_addr)	readl(ee_addr)
+
+enum EEPROM_Ctrl_Bits {
+	EE_ShiftClk=0x04, EE_DataIn=0x01, EE_ChipSelect=0x08, EE_DataOut=0x02,
+};
+#define EE_Write0 (EE_ChipSelect)
+#define EE_Write1 (EE_ChipSelect | EE_DataIn)
+
+/* The EEPROM commands include the alway-set leading bit. */
+enum EEPROM_Cmds {
+	EE_WriteCmd=(5 << 6), EE_ReadCmd=(6 << 6), EE_EraseCmd=(7 << 6),
+};
+
+static int eeprom_read(long addr, int location)
+{
+	int i;
+	int retval = 0;
+	int ee_addr = addr + EECtrl;
+	int read_cmd = location | EE_ReadCmd;
+	writel(EE_Write0, ee_addr);
+
+	/* Shift the read command bits out. */
+	for (i = 10; i >= 0; i--) {
+		short dataval = (read_cmd & (1 << i)) ? EE_Write1 : EE_Write0;
+		writel(dataval, ee_addr);
+		eeprom_delay(ee_addr);
+		writel(dataval | EE_ShiftClk, ee_addr);
+		eeprom_delay(ee_addr);
+	}
+	writel(EE_ChipSelect, ee_addr);
+
+	for (i = 16; i > 0; i--) {
+		writel(EE_ChipSelect | EE_ShiftClk, ee_addr);
+		eeprom_delay(ee_addr);
+		retval = (retval << 1) | ((readl(ee_addr) & EE_DataOut) ? 1 : 0);
+		writel(EE_ChipSelect, ee_addr);
+		eeprom_delay(ee_addr);
+	}
+
+	/* Terminate the EEPROM access. */
+	writel(EE_Write0, ee_addr);
+	writel(0, ee_addr);
+	return retval;
+}
+
+/*  MII transceiver control section.
+	The 83815 series has an internal transceiver, and we present the
+	management registers as if they were MII connected. */
+
+static int mdio_read(struct net_device *dev, int phy_id, int location)
+{
+	if (phy_id == 1 && location < 32)
+		return readl(dev->base_addr + 0x80 + (location<<2)) & 0xffff;
+	else
+		return 0xffff;
+}
+
+static void mdio_write(struct net_device *dev, int phy_id, int location, int value)
+{
+	if (phy_id == 1 && location < 32)
+		writew(value, dev->base_addr + 0x80 + (location<<2));
+}
+
+
+static int netdev_open(struct net_device *dev)
+{
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+	long ioaddr = dev->base_addr;
+	int i;
+
+	/* Do we need to reset the chip??? */
+
+	MOD_INC_USE_COUNT;
+
+	if (request_irq(dev->irq, &intr_handler, SA_SHIRQ, dev->name, dev)) {
+		MOD_DEC_USE_COUNT;
+		return -EAGAIN;
+	}
+
+	if (debug > 1)
+		printk(KERN_DEBUG "%s: netdev_open() irq %d.\n",
+			   dev->name, dev->irq);
+
+	init_ring(dev);
+
+	writel(virt_to_bus(np->rx_ring), ioaddr + RxRingPtr);
+	writel(virt_to_bus(np->tx_ring), ioaddr + TxRingPtr);
+
+	for (i = 0; i < 6; i += 2) {
+		writel(i, ioaddr + RxFilterAddr);
+		writew(dev->dev_addr[i] + (dev->dev_addr[i+1] << 8),
+			   ioaddr + RxFilterData);
+	}
+
+	/* Initialize other registers. */
+	/* Configure the PCI bus bursts and FIFO thresholds. */
+	/* Configure for standard, in-spec Ethernet. */
+	np->tx_config = 0x10800802;
+	writel(np->tx_config, ioaddr + TxConfig);
+	np->rx_config = 0x0020;
+	writel(np->rx_config, ioaddr + RxConfig);
+
+	if (dev->if_port == 0)
+		dev->if_port = np->default_port;
+
+	netif_start_queue(dev);
+
+	check_duplex(dev);
+	set_rx_mode(dev);
+
+	/* Enable interrupts by setting the interrupt mask. */
+	writel(IntrNormalSummary | IntrAbnormalSummary | 0x1f, ioaddr + IntrMask);
+	writel(1, ioaddr + IntrEnable);
+
+	writel(RxOn | TxOn, ioaddr + ChipCmd);
+	writel(4, ioaddr + StatsCtrl); 					/* Clear Stats */
+
+	if (debug > 2)
+		printk(KERN_DEBUG "%s: Done netdev_open(), status: %x.\n",
+			   dev->name, (int)readl(ioaddr + ChipCmd));
+
+	/* Set the timer to check for link beat. */
+	init_timer(&np->timer);
+	np->timer.expires = jiffies + 3*HZ;
+	np->timer.data = (unsigned long)dev;
+	np->timer.function = &netdev_timer;				/* timer handler */
+	add_timer(&np->timer);
+
+	return 0;
+}
+
+static void check_duplex(struct net_device *dev)
+{
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+	long ioaddr = dev->base_addr;
+	int duplex;
+
+	if (np->duplex_lock)
+		return;
+	duplex = readl(ioaddr + ChipConfig) & 0x20000000 ? 1 : 0;
+	if (np->full_duplex != duplex) {
+		np->full_duplex = duplex;
+		if (debug)
+			printk(KERN_INFO "%s: Setting %s-duplex based on negotiated link"
+				   " capability.\n", dev->name,
+				   duplex ? "full" : "half");
+		if (duplex) {
+			np->rx_config |= 0x10000000;
+			np->tx_config |= 0xC0000000;
+		} else {
+			np->rx_config &= ~0x10000000;
+			np->tx_config &= ~0xC0000000;
+		}
+		writew(np->tx_config, ioaddr + TxConfig);
+		writew(np->rx_config, ioaddr + RxConfig);
+	}
+}
+
+static void netdev_timer(unsigned long data)
+{
+	struct net_device *dev = (struct net_device *)data;
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+	long ioaddr = dev->base_addr;
+	int next_tick = 60*HZ;
+
+	if (debug > 3)
+		printk(KERN_DEBUG "%s: Media selection timer tick, status %8.8x.\n",
+			   dev->name, (int)readl(ioaddr + IntrStatus));
+	check_duplex(dev);
+	np->timer.expires = jiffies + next_tick;
+	add_timer(&np->timer);
+}
+
+static void tx_timeout(struct net_device *dev)
+{
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+	long ioaddr = dev->base_addr;
+
+	printk(KERN_WARNING "%s: Transmit timed out, status %8.8x,"
+		   " resetting...\n", dev->name, (int)readl(ioaddr + TxRingPtr));
+
+#ifndef __alpha__
+	{
+		int i;
+		printk(KERN_DEBUG "  Rx ring %8.8x: ", (int)np->rx_ring);
+		for (i = 0; i < RX_RING_SIZE; i++)
+			printk(" %8.8x", (unsigned int)np->rx_ring[i].cmd_status);
+		printk("\n"KERN_DEBUG"  Tx ring %8.8x: ", (int)np->tx_ring);
+		for (i = 0; i < TX_RING_SIZE; i++)
+			printk(" %4.4x", np->tx_ring[i].cmd_status);
+		printk("\n");
+	}
+#endif
+
+	/* Perhaps we should reinitialize the hardware here. */
+	dev->if_port = 0;
+	/* Stop and restart the chip's Tx processes . */
+
+	/* Trigger an immediate transmit demand. */
+
+	dev->trans_start = jiffies;
+	np->stats.tx_errors++;
+	return;
+}
+
+
+/* Initialize the Rx and Tx rings, along with various 'dev' bits. */
+static void init_ring(struct net_device *dev)
+{
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+	int i;
+
+	np->tx_full = 0;
+	np->cur_rx = np->cur_tx = 0;
+	np->dirty_rx = np->dirty_tx = 0;
+
+	np->rx_buf_sz = (dev->mtu <= 1500 ? PKT_BUF_SZ : dev->mtu + 32);
+	np->rx_head_desc = &np->rx_ring[0];
+
+	/* Initialize all Rx descriptors. */
+	for (i = 0; i < RX_RING_SIZE; i++) {
+		np->rx_ring[i].next_desc = virt_to_le32desc(&np->rx_ring[i+1]);
+		np->rx_ring[i].cmd_status = DescOwn;
+		np->rx_skbuff[i] = 0;
+	}
+	/* Mark the last entry as wrapping the ring. */
+	np->rx_ring[i-1].next_desc = virt_to_le32desc(&np->rx_ring[0]);
+
+	/* Fill in the Rx buffers.  Handle allocation failure gracefully. */
+	for (i = 0; i < RX_RING_SIZE; i++) {
+		struct sk_buff *skb = dev_alloc_skb(np->rx_buf_sz);
+		np->rx_skbuff[i] = skb;
+		if (skb == NULL)
+			break;
+		skb->dev = dev;			/* Mark as being used by this device. */
+		np->rx_ring[i].addr = virt_to_le32desc(skb->tail);
+		np->rx_ring[i].cmd_status =
+			cpu_to_le32(DescIntr | np->rx_buf_sz);
+	}
+	np->dirty_rx = (unsigned int)(i - RX_RING_SIZE);
+
+	for (i = 0; i < TX_RING_SIZE; i++) {
+		np->tx_skbuff[i] = 0;
+		np->tx_ring[i].next_desc = virt_to_le32desc(&np->tx_ring[i+1]);
+		np->tx_ring[i].cmd_status = 0;
+	}
+	np->tx_ring[i-1].next_desc = virt_to_le32desc(&np->tx_ring[0]);
+	return;
+}
+
+static int start_tx(struct sk_buff *skb, struct net_device *dev)
+{
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+	unsigned entry;
+
+	/* Note: Ordering is important here, set the field with the
+	   "ownership" bit last, and only then increment cur_tx. */
+
+	/* Calculate the next Tx descriptor entry. */
+	entry = np->cur_tx % TX_RING_SIZE;
+
+	np->tx_skbuff[entry] = skb;
+
+	np->tx_ring[entry].addr = virt_to_le32desc(skb->data);
+	np->tx_ring[entry].cmd_status = cpu_to_le32(DescOwn|DescIntr | skb->len);
+	np->cur_tx++;
+
+	/* StrongARM: Explicitly cache flush np->tx_ring and skb->data,skb->len. */
+
+	if (np->cur_tx - np->dirty_tx >= TX_QUEUE_LEN - 1) {
+		np->tx_full = 1;
+		netif_stop_queue(dev);
+	}
+	/* Wake the potentially-idle transmit channel. */
+	writel(TxOn, dev->base_addr + ChipCmd);
+
+	dev->trans_start = jiffies;
+
+	if (debug > 4) {
+		printk(KERN_DEBUG "%s: Transmit frame #%d queued in slot %d.\n",
+			   dev->name, np->cur_tx, entry);
+	}
+	return 0;
+}
+
+/* The interrupt handler does all of the Rx thread work and cleans up
+   after the Tx thread. */
+static void intr_handler(int irq, void *dev_instance, struct pt_regs *rgs)
+{
+	struct net_device *dev = (struct net_device *)dev_instance;
+	struct netdev_private *np;
+	long ioaddr;
+	int boguscnt = max_interrupt_work;
+
+#ifndef final_version			/* Can never occur. */
+	if (dev == NULL) {
+		printk (KERN_ERR "Netdev interrupt handler(): IRQ %d for unknown "
+				"device.\n", irq);
+		return;
+	}
+#endif
+
+	ioaddr = dev->base_addr;
+	np = (struct netdev_private *)dev->priv;
+
+	if (!spin_trylock(&np->lock))
+		return;
+
+	do {
+		u32 intr_status = readl(ioaddr + IntrStatus);
+
+		/* Acknowledge all of the current interrupt sources ASAP. */
+		writel(intr_status & 0x000ffff, ioaddr + IntrStatus);
+
+		if (debug > 4)
+			printk(KERN_DEBUG "%s: Interrupt, status %4.4x.\n",
+				   dev->name, intr_status);
+
+		if (intr_status == 0)
+			break;
+
+		if (intr_status & (IntrRxDone | IntrRxIntr))
+			netdev_rx(dev);
+
+		for (; np->cur_tx - np->dirty_tx > 0; np->dirty_tx++) {
+			int entry = np->dirty_tx % TX_RING_SIZE;
+			if (np->tx_ring[entry].cmd_status & cpu_to_le32(DescOwn))
+				break;
+			if (np->tx_ring[entry].cmd_status & cpu_to_le32(0x08000000)) {
+				np->stats.tx_packets++;
+#if LINUX_VERSION_CODE > 0x20127
+				np->stats.tx_bytes += np->tx_skbuff[entry]->len;
+#endif
+			} else {			/* Various Tx errors */
+				int tx_status = le32_to_cpu(np->tx_ring[entry].cmd_status);
+				if (tx_status & 0x04010000) np->stats.tx_aborted_errors++;
+				if (tx_status & 0x02000000) np->stats.tx_fifo_errors++;
+				if (tx_status & 0x01000000) np->stats.tx_carrier_errors++;
+				if (tx_status & 0x00200000) np->stats.tx_window_errors++;
+				np->stats.tx_errors++;
+			}
+			/* Free the original skb. */
+			dev_kfree_skb(np->tx_skbuff[entry]);
+			np->tx_skbuff[entry] = 0;
+		}
+		if (np->tx_full
+			&& np->cur_tx - np->dirty_tx < TX_QUEUE_LEN - 4) {
+			/* The ring is no longer full, wake queue. */
+			np->tx_full = 0;
+			netif_wake_queue(dev);
+		}
+
+		/* Abnormal error summary/uncommon events handlers. */
+		if (intr_status & IntrAbnormalSummary)
+			netdev_error(dev, intr_status);
+
+		if (--boguscnt < 0) {
+			printk(KERN_WARNING "%s: Too much work at interrupt, "
+				   "status=0x%4.4x.\n",
+				   dev->name, intr_status);
+			break;
+		}
+	} while (1);
+
+	if (debug > 3)
+		printk(KERN_DEBUG "%s: exiting interrupt, status=%#4.4x.\n",
+			   dev->name, (int)readl(ioaddr + IntrStatus));
+
+#ifndef final_version
+	/* Code that should never be run!  Perhaps remove after testing.. */
+	{
+		static int stopit = 10;
+		if (!netif_running(dev)  &&  --stopit < 0) {
+			printk(KERN_ERR "%s: Emergency stop, looping startup interrupt.\n",
+				   dev->name);
+			free_irq(irq, dev);
+		}
+	}
+#endif
+
+	spin_unlock(&np->lock);
+}
+
+/* This routine is logically part of the interrupt handler, but separated
+   for clarity and better register allocation. */
+static int netdev_rx(struct net_device *dev)
+{
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+	int entry = np->cur_rx % RX_RING_SIZE;
+	int boguscnt = np->dirty_rx + RX_RING_SIZE - np->cur_rx;
+	s32 desc_status = le32_to_cpu(np->rx_head_desc->cmd_status);
+
+	/* If the driver owns the next entry it's a new packet. Send it up. */
+	while (desc_status < 0) {        /* e.g. & DescOwn */
+		if (debug > 4)
+			printk(KERN_DEBUG "  In netdev_rx() entry %d status was %8.8x.\n",
+				   entry, desc_status);
+		if (--boguscnt < 0)
+			break;
+		if ((desc_status & (DescMore|DescPktOK|RxTooLong)) != DescPktOK) {
+			if (desc_status & DescMore) {
+				printk(KERN_WARNING "%s: Oversized(?) Ethernet frame spanned "
+					   "multiple buffers, entry %#x status %x.\n",
+					   dev->name, np->cur_rx, desc_status);
+				np->stats.rx_length_errors++;
+			} else {
+				/* There was a error. */
+				if (debug > 2)
+					printk(KERN_DEBUG "  netdev_rx() Rx error was %8.8x.\n",
+						   desc_status);
+				np->stats.rx_errors++;
+				if (desc_status & 0x06000000) np->stats.rx_over_errors++;
+				if (desc_status & 0x00600000) np->stats.rx_length_errors++;
+				if (desc_status & 0x00140000) np->stats.rx_frame_errors++;
+				if (desc_status & 0x00080000) np->stats.rx_crc_errors++;
+			}
+		} else {
+			struct sk_buff *skb;
+			int pkt_len = (desc_status & 0x0fff) - 4; 	/* Omit CRC size. */
+			/* Check if the packet is long enough to accept without copying
+			   to a minimally-sized skbuff. */
+			if (pkt_len < rx_copybreak
+				&& (skb = dev_alloc_skb(pkt_len + 2)) != NULL) {
+				skb->dev = dev;
+				skb_reserve(skb, 2);	/* 16 byte align the IP header */
+#if HAS_IP_COPYSUM
+				eth_copy_and_sum(skb, np->rx_skbuff[entry]->tail, pkt_len, 0);
+				skb_put(skb, pkt_len);
+#else
+				memcpy(skb_put(skb, pkt_len), np->rx_skbuff[entry]->tail,
+					   pkt_len);
+#endif
+			} else {
+				char *temp = skb_put(skb = np->rx_skbuff[entry], pkt_len);
+				np->rx_skbuff[entry] = NULL;
+#ifndef final_version				/* Remove after testing. */
+				if (le32desc_to_virt(np->rx_ring[entry].addr) != temp)
+					printk(KERN_ERR "%s: Internal fault: The skbuff addresses "
+						   "do not match in netdev_rx: %p vs. %p / %p.\n",
+						   dev->name,
+						   le32desc_to_virt(np->rx_ring[entry].addr),
+						   skb->head, temp);
+#endif
+			}
+#ifndef final_version				/* Remove after testing. */
+			/* You will want this info for the initial debug. */
+			if (debug > 5)
+				printk(KERN_DEBUG "  Rx data %2.2x:%2.2x:%2.2x:%2.2x:%2.2x:"
+					   "%2.2x %2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x %2.2x%2.2x "
+					   "%d.%d.%d.%d.\n",
+					   skb->data[0], skb->data[1], skb->data[2], skb->data[3],
+					   skb->data[4], skb->data[5], skb->data[6], skb->data[7],
+					   skb->data[8], skb->data[9], skb->data[10],
+					   skb->data[11], skb->data[12], skb->data[13],
+					   skb->data[14], skb->data[15], skb->data[16],
+					   skb->data[17]);
+#endif
+			skb->protocol = eth_type_trans(skb, dev);
+			/* W/ hardware checksum: skb->ip_summed = CHECKSUM_UNNECESSARY; */
+			netif_rx(skb);
+			dev->last_rx = jiffies;
+			np->stats.rx_packets++;
+#if LINUX_VERSION_CODE > 0x20127
+			np->stats.rx_bytes += pkt_len;
+#endif
+		}
+		entry = (++np->cur_rx) % RX_RING_SIZE;
+		np->rx_head_desc = &np->rx_ring[entry];
+		desc_status = le32_to_cpu(np->rx_head_desc->cmd_status);
+	}
+
+	/* Refill the Rx ring buffers. */
+	for (; np->cur_rx - np->dirty_rx > 0; np->dirty_rx++) {
+		struct sk_buff *skb;
+		entry = np->dirty_rx % RX_RING_SIZE;
+		if (np->rx_skbuff[entry] == NULL) {
+			skb = dev_alloc_skb(np->rx_buf_sz);
+			np->rx_skbuff[entry] = skb;
+			if (skb == NULL)
+				break;				/* Better luck next round. */
+			skb->dev = dev;			/* Mark as being used by this device. */
+			np->rx_ring[entry].addr = virt_to_le32desc(skb->tail);
+		}
+		np->rx_ring[entry].cmd_status =
+			cpu_to_le32(DescIntr | np->rx_buf_sz);
+	}
+
+	/* Restart Rx engine if stopped. */
+	writel(RxOn, dev->base_addr + ChipCmd);
+	return 0;
+}
+
+static void netdev_error(struct net_device *dev, int intr_status)
+{
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+	long ioaddr = dev->base_addr;
+
+	if (intr_status & LinkChange) {
+		printk(KERN_NOTICE "%s: Link changed: Autonegotiation advertising"
+			   " %4.4x  partner %4.4x.\n", dev->name,
+			   (int)readl(ioaddr + 0x90), (int)readl(ioaddr + 0x94));
+		check_duplex(dev);
+	}
+	if (intr_status & StatsMax) {
+		get_stats(dev);
+	}
+	if ((intr_status & ~(LinkChange|StatsMax|RxResetDone|TxResetDone|0x83ff))
+		&& debug)
+		printk(KERN_ERR "%s: Something Wicked happened! %4.4x.\n",
+			   dev->name, intr_status);
+	/* Hmmmmm, it's not clear how to recover from PCI faults. */
+	if (intr_status & IntrPCIErr) {
+		np->stats.tx_fifo_errors++;
+		np->stats.rx_fifo_errors++;
+	}
+}
+
+static struct net_device_stats *get_stats(struct net_device *dev)
+{
+	long ioaddr = dev->base_addr;
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+
+	/* We should lock this segment of code for SMP eventually, although
+	   the vulnerability window is very small and statistics are
+	   non-critical. */
+	/* The chip only need report frame silently dropped. */
+	np->stats.rx_crc_errors	+= readl(ioaddr + RxCRCErrs);
+	np->stats.rx_missed_errors	+= readl(ioaddr + RxMissed);
+
+	return &np->stats;
+}
+
+/* The little-endian AUTODIN II ethernet CRC calculations.
+   A big-endian version is also available.
+   This is slow but compact code.  Do not use this routine for bulk data,
+   use a table-based routine instead.
+   This is common code and should be moved to net/core/crc.c.
+   Chips may use the upper or lower CRC bits, and may reverse and/or invert
+   them.  Select the endian-ness that results in minimal calculations.
+*/
+static unsigned const ethernet_polynomial_le = 0xedb88320U;
+static inline unsigned ether_crc_le(int length, unsigned char *data)
+{
+	unsigned int crc = 0xffffffff;	/* Initial value. */
+	while(--length >= 0) {
+		unsigned char current_octet = *data++;
+		int bit;
+		for (bit = 8; --bit >= 0; current_octet >>= 1) {
+			if ((crc ^ current_octet) & 1) {
+				crc >>= 1;
+				crc ^= ethernet_polynomial_le;
+			} else
+				crc >>= 1;
+		}
+	}
+	return crc;
+}
+
+static void set_rx_mode(struct net_device *dev)
+{
+	long ioaddr = dev->base_addr;
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+	u16 mc_filter[32];			/* Multicast hash filter */
+	u32 rx_mode;
+
+	if (dev->flags & IFF_PROMISC) {			/* Set promiscuous. */
+		/* Unconditionally log net taps. */
+		printk(KERN_NOTICE "%s: Promiscuous mode enabled.\n", dev->name);
+		rx_mode = AcceptBroadcast | AcceptAllMulticast | AcceptAllPhys
+			| AcceptMyPhys;
+	} else if ((dev->mc_count > multicast_filter_limit)
+			   ||  (dev->flags & IFF_ALLMULTI)) {
+		rx_mode = AcceptBroadcast | AcceptAllMulticast | AcceptMyPhys;
+	} else {
+		struct dev_mc_list *mclist;
+		int i;
+		memset(mc_filter, 0, sizeof(mc_filter));
+		for (i = 0, mclist = dev->mc_list; mclist && i < dev->mc_count;
+			 i++, mclist = mclist->next) {
+			set_bit(ether_crc_le(ETH_ALEN, mclist->dmi_addr) & 0x1ff,
+					mc_filter);
+		}
+		rx_mode = AcceptBroadcast | AcceptMulticast | AcceptMyPhys;
+		for (i = 0; i < 32; i++) {
+			writew(0x200 + (i<<1), ioaddr + RxFilterAddr);
+			writew(cpu_to_be16(mc_filter[i]), ioaddr + RxFilterData);
+		}
+	}
+	writel(rx_mode, ioaddr + RxFilterAddr);
+	np->cur_rx_mode = rx_mode;
+}
+
+static int mii_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
+{
+	u16 *data = (u16 *)&rq->ifr_data;
+
+	switch(cmd) {
+	case SIOCDEVPRIVATE:		/* Get the address of the PHY in use. */
+		data[0] = 1;
+		/* Fall Through */
+	case SIOCDEVPRIVATE+1:		/* Read the specified MII register. */
+		data[3] = mdio_read(dev, data[0] & 0x1f, data[1] & 0x1f);
+		return 0;
+	case SIOCDEVPRIVATE+2:		/* Write the specified MII register */
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		mdio_write(dev, data[0] & 0x1f, data[1] & 0x1f, data[2]);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int netdev_close(struct net_device *dev)
+{
+	long ioaddr = dev->base_addr;
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+	int i;
+
+	netif_stop_queue(dev);
+
+	if (debug > 1) {
+		printk(KERN_DEBUG "%s: Shutting down ethercard, status was %4.4x "
+			   "Int %2.2x.\n",
+			   dev->name, (int)readl(ioaddr + ChipCmd),
+			   (int)readl(ioaddr + IntrStatus));
+		printk(KERN_DEBUG "%s: Queue pointers were Tx %d / %d,  Rx %d / %d.\n",
+			   dev->name, np->cur_tx, np->dirty_tx, np->cur_rx, np->dirty_rx);
+	}
+
+	/* Disable interrupts using the mask. */
+	writel(0, ioaddr + IntrMask);
+	writel(0, ioaddr + IntrEnable);
+	writel(2, ioaddr + StatsCtrl); 					/* Freeze Stats */
+
+	/* Stop the chip's Tx and Rx processes. */
+	writel(RxOff | TxOff, ioaddr + ChipCmd);
+
+	del_timer_sync(&np->timer);
+
+#ifdef __i386__
+	if (debug > 2) {
+		printk("\n"KERN_DEBUG"  Tx ring at %8.8x:\n",
+			   (int)virt_to_bus(np->tx_ring));
+		for (i = 0; i < TX_RING_SIZE; i++)
+			printk(" #%d desc. %8.8x %8.8x.\n",
+				   i, np->tx_ring[i].cmd_status, np->tx_ring[i].addr);
+		printk("\n"KERN_DEBUG "  Rx ring %8.8x:\n",
+			   (int)virt_to_bus(np->rx_ring));
+		for (i = 0; i < RX_RING_SIZE; i++) {
+			printk(KERN_DEBUG " #%d desc. %8.8x %8.8x\n",
+				   i, np->rx_ring[i].cmd_status, np->rx_ring[i].addr);
+		}
+	}
+#endif /* __i386__ debugging only */
+
+	free_irq(dev->irq, dev);
+
+	/* Free all the skbuffs in the Rx queue. */
+	for (i = 0; i < RX_RING_SIZE; i++) {
+		np->rx_ring[i].cmd_status = 0;
+		np->rx_ring[i].addr = 0xBADF00D0; /* An invalid address. */
+		if (np->rx_skbuff[i]) {
+#if LINUX_VERSION_CODE < 0x20100
+			np->rx_skbuff[i]->free = 1;
+#endif
+			dev_kfree_skb(np->rx_skbuff[i]);
+		}
+		np->rx_skbuff[i] = 0;
+	}
+	for (i = 0; i < TX_RING_SIZE; i++) {
+		if (np->tx_skbuff[i])
+			dev_kfree_skb(np->tx_skbuff[i]);
+		np->tx_skbuff[i] = 0;
+	}
+
+#if 0
+	writel(0x0200, ioaddr + ChipConfig); /* Power down Xcvr. */
+#endif
+
+	MOD_DEC_USE_COUNT;
+
+	return 0;
+}
+
+
+static void __devexit natsemi_remove1 (struct pci_dev *pdev)
+{
+	struct net_device *dev = pdev->driver_data;
+	struct netdev_private *np = (struct netdev_private *)dev->priv;
+
+	unregister_netdev (dev);
+	release_mem_region(dev->base_addr, np->iosize);
+	iounmap ((char *) dev->base_addr);
+	kfree (dev);
+}
+
+static struct pci_driver natsemi_driver = {
+	name:		"natsemi",
+	id_table:	natsemi_pci_tbl,
+	probe:		natsemi_probe1,
+	remove:		natsemi_remove1,
+};
+
+static int __init natsemi_init_mod (void)
+{
+	if (debug > 1)
+		printk(KERN_INFO "%s" KERN_INFO "%s" KERN_INFO "%s",
+			version1, version2, version3);
+
+	return pci_module_init (&natsemi_driver);
+}
+
+static void __exit natsemi_exit_mod (void)
+{
+	pci_unregister_driver (&natsemi_driver);
+}
+
+module_init(natsemi_init_mod);
+module_exit(natsemi_exit_mod);
+