patch-2.4.10 linux/drivers/net/ns83820.c

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diff -u --recursive --new-file v2.4.9/linux/drivers/net/ns83820.c linux/drivers/net/ns83820.c
@@ -0,0 +1,1428 @@
+#define VERSION "0.11"
+/* ns83820.c by Benjamin LaHaise <bcrl@redhat.com>
+ *
+ * $Revision: 1.34.2.2 $
+ *
+ * Copyright 2001 Benjamin LaHaise.
+ * Copyright 2001 Red Hat.
+ *
+ * Mmmm, chocolate vanilla mocha...
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *
+ * ChangeLog
+ * =========
+ *	20010414	0.1 - created
+ *	20010622	0.2 - basic rx and tx.
+ *	20010711	0.3 - added duplex and link state detection support.
+ *	20010713	0.4 - zero copy, no hangs.
+ *			0.5 - 64 bit dma support (davem will hate me for this)
+ *			    - disable jumbo frames to avoid tx hangs
+ *			    - work around tx deadlocks on my 1.02 card via
+ *			      fiddling with TXCFG
+ *	20010810	0.6 - use pci dma api for ringbuffers, work on ia64
+ *	20010816	0.7 - misc cleanups
+ *	20010826	0.8 - fix critical zero copy bugs
+ *			0.9 - internal experiment
+ *	20010827	0.10 - fix ia64 unaligned access.
+ *	20010906	0.11 - accept all packets with checksum errors as
+ *			       otherwise fragments get lost
+			     - fix >> 32 bugs
+ *
+ * Driver Overview
+ * ===============
+ *
+ * This driver was originally written for the National Semiconductor
+ * 83820 chip, a 10/100/1000 Mbps 64 bit PCI ethernet NIC.  Hopefully
+ * this code will turn out to be a) clean, b) correct, and c) fast.
+ * With that in mind, I'm aiming to split the code up as much as
+ * reasonably possible.  At present there are X major sections that
+ * break down into a) packet receive, b) packet transmit, c) link
+ * management, d) initialization and configuration.  Where possible,
+ * these code paths are designed to run in parallel.
+ *
+ * This driver has been tested and found to work with the following
+ * cards (in no particular order):
+ *
+ *	Cameo		SOHO-GA2000T	SOHO-GA2500T
+ *	D-Link		DGE-500T
+ *	PureData	PDP8023Z-TG
+ *	SMC		SMC9462TX
+ *
+ * Reports of success or failure would be greatly appreciated.
+ */
+//#define dprintk		printk
+#define dprintk(x...)		do { } while (0)
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/delay.h>
+#include <linux/smp_lock.h>
+#include <linux/tqueue.h>
+#include <linux/init.h>
+#include <linux/ip.h>	/* for iph */
+#include <linux/in.h>	/* for IPPROTO_... */
+#include <linux/eeprom.h>
+#include <linux/compiler.h>
+//#include <linux/skbrefill.h>
+
+#include <asm/io.h>
+
+/* Dprintk is used for more interesting debug events */
+#undef Dprintk
+#define	Dprintk			dprintk
+
+#ifdef CONFIG_HIGHMEM64G
+#define USE_64BIT_ADDR
+#elif defined(__ia64__)
+#define USE_64BIT_ADDR
+#endif
+
+/* Tell davem to fix the pci dma api.  Grrr. */
+/* stolen from acenic.c */
+#ifdef CONFIG_HIGHMEM
+#if defined(CONFIG_X86)
+#define DMAADDR_OFFSET  0
+#if defined(CONFIG_HIGHMEM64G)
+typedef u64 dmaaddr_high_t;
+#else
+typedef u32 dmaaddr_high_t;
+#endif
+#elif defined(CONFIG_PPC)
+#define DMAADDR_OFFSET PCI_DRAM_OFFSET
+typedef unsigned long dmaaddr_high_t;
+#endif
+
+static inline dmaaddr_high_t
+pci_map_single_high(struct pci_dev *hwdev, struct page *page,
+		    int offset, size_t size, int dir)
+{
+	u64 phys;
+	phys = page - mem_map;
+	phys <<= PAGE_SHIFT;
+	phys += offset;
+	phys += DMAADDR_OFFSET;
+	return phys;
+}
+#else
+
+typedef unsigned long dmaaddr_high_t;
+
+static inline dmaaddr_high_t
+pci_map_single_high(struct pci_dev *hwdev, struct page *page,
+		    int offset, size_t size, int dir)
+{
+	return pci_map_single(hwdev, page_address(page) + offset, size, dir);
+}
+#endif
+
+/* tunables */
+#define RX_BUF_SIZE	6144	/* 8192 */
+#define NR_RX_DESC	256
+
+#define NR_TX_DESC	256
+
+/* register defines */
+#define CFGCS		0x04
+
+#define CR_TXE		0x00000001
+#define CR_TXD		0x00000002
+#define CR_RXE		0x00000004
+#define CR_RXD		0x00000008
+#define CR_TXR		0x00000010
+#define CR_RXR		0x00000020
+#define CR_SWI		0x00000080
+#define CR_RST		0x00000100
+
+#define PTSCR_EEBIST_EN	0x00000002
+#define PTSCR_EELOAD_EN	0x00000004
+
+#define ISR_TXDESC3	0x40000000
+#define ISR_TXDESC2	0x20000000
+#define ISR_TXDESC1	0x10000000
+#define ISR_TXDESC0	0x08000000
+#define ISR_RXDESC3	0x04000000
+#define ISR_RXDESC2	0x02000000
+#define ISR_RXDESC1	0x01000000
+#define ISR_RXDESC0	0x00800000
+#define ISR_TXRCMP	0x00400000
+#define ISR_RXRCMP	0x00200000
+#define ISR_DPERR	0x00100000
+#define ISR_SSERR	0x00080000
+#define ISR_RMABT	0x00040000
+#define ISR_RTABT	0x00020000
+#define ISR_RXSOVR	0x00010000
+#define ISR_HIBINT	0x00008000
+#define ISR_PHY		0x00004000
+#define ISR_PME		0x00002000
+#define ISR_SWI		0x00001000
+#define ISR_MIB		0x00000800
+#define ISR_TXURN	0x00000400
+#define ISR_TXIDLE	0x00000200
+#define ISR_TXERR	0x00000100
+#define ISR_TXDESC	0x00000080
+#define ISR_TXOK	0x00000040
+#define ISR_RXORN	0x00000020
+#define ISR_RXIDLE	0x00000010
+#define ISR_RXEARLY	0x00000008
+#define ISR_RXERR	0x00000004
+#define ISR_RXDESC	0x00000002
+#define ISR_RXOK	0x00000001
+
+#define TXCFG_CSI	0x80000000
+#define TXCFG_HBI	0x40000000
+#define TXCFG_MLB	0x20000000
+#define TXCFG_ATP	0x10000000
+#define TXCFG_ECRETRY	0x00800000
+#define TXCFG_BRST_DIS	0x00080000
+#define TXCFG_MXDMA1024	0x00000000
+#define TXCFG_MXDMA512	0x00700000
+#define TXCFG_MXDMA256	0x00600000
+#define TXCFG_MXDMA128	0x00500000
+#define TXCFG_MXDMA64	0x00400000
+#define TXCFG_MXDMA32	0x00300000
+#define TXCFG_MXDMA16	0x00200000
+#define TXCFG_MXDMA8	0x00100000
+
+#define CFG_LNKSTS	0x80000000
+#define CFG_SPDSTS	0x60000000
+#define CFG_SPDSTS1	0x40000000
+#define CFG_SPDSTS0	0x20000000
+#define CFG_DUPSTS	0x10000000
+#define CFG_TBI_EN	0x01000000
+#define CFG_MODE_1000	0x00400000
+#define CFG_PINT_CTL	0x001c0000
+#define CFG_PINT_DUPSTS	0x00100000
+#define CFG_PINT_LNKSTS	0x00080000
+#define CFG_PINT_SPDSTS	0x00040000
+#define CFG_TMRTEST	0x00020000
+#define CFG_MRM_DIS	0x00010000
+#define CFG_MWI_DIS	0x00008000
+#define CFG_T64ADDR	0x00004000
+#define CFG_PCI64_DET	0x00002000
+#define CFG_DATA64_EN	0x00001000
+#define CFG_M64ADDR	0x00000800
+#define CFG_PHY_RST	0x00000400
+#define CFG_PHY_DIS	0x00000200
+#define CFG_EXTSTS_EN	0x00000100
+#define CFG_REQALG	0x00000080
+#define CFG_SB		0x00000040
+#define CFG_POW		0x00000020
+#define CFG_EXD		0x00000010
+#define CFG_PESEL	0x00000008
+#define CFG_BROM_DIS	0x00000004
+#define CFG_EXT_125	0x00000002
+#define CFG_BEM		0x00000001
+
+#define EXTSTS_UDPPKT	0x00200000
+#define EXTSTS_TCPPKT	0x00080000
+#define EXTSTS_IPPKT	0x00020000
+
+#define SPDSTS_POLARITY	(CFG_SPDSTS1 | CFG_SPDSTS0 | CFG_DUPSTS)
+
+#define MIBC_MIBS	0x00000008
+#define MIBC_ACLR	0x00000004
+#define MIBC_FRZ	0x00000002
+#define MIBC_WRN	0x00000001
+
+#define RXCFG_AEP	0x80000000
+#define RXCFG_ARP	0x40000000
+#define RXCFG_STRIPCRC	0x20000000
+#define RXCFG_RX_FD	0x10000000
+#define RXCFG_ALP	0x08000000
+#define RXCFG_AIRL	0x04000000
+#define RXCFG_MXDMA	0x00700000
+#define RXCFG_MXDMA0	0x00100000
+#define RXCFG_MXDMA64	0x00600000
+#define RXCFG_DRTH	0x0000003e
+#define RXCFG_DRTH0	0x00000002
+
+#define RFCR_RFEN	0x80000000
+#define RFCR_AAB	0x40000000
+#define RFCR_AAM	0x20000000
+#define RFCR_AAU	0x10000000
+#define RFCR_APM	0x08000000
+#define RFCR_APAT	0x07800000
+#define RFCR_APAT3	0x04000000
+#define RFCR_APAT2	0x02000000
+#define RFCR_APAT1	0x01000000
+#define RFCR_APAT0	0x00800000
+#define RFCR_AARP	0x00400000
+#define RFCR_MHEN	0x00200000
+#define RFCR_UHEN	0x00100000
+#define RFCR_ULM	0x00080000
+
+#define VRCR_RUDPE	0x00000080
+#define VRCR_RTCPE	0x00000040
+#define VRCR_RIPE	0x00000020
+#define VRCR_IPEN	0x00000010
+#define VRCR_DUTF	0x00000008
+#define VRCR_DVTF	0x00000004
+#define VRCR_VTREN	0x00000002
+#define VRCR_VTDEN	0x00000001
+
+#define VTCR_PPCHK	0x00000008
+#define VTCR_GCHK	0x00000004
+#define VTCR_VPPTI	0x00000002
+#define VTCR_VGTI	0x00000001
+
+#define CR		0x00
+#define CFG		0x04
+#define MEAR		0x08
+#define PTSCR		0x0c
+#define	ISR		0x10
+#define	IMR		0x14
+#define	IER		0x18
+#define	IHR		0x1c
+#define TXDP		0x20
+#define TXDP_HI		0x24
+#define TXCFG		0x28
+#define GPIOR		0x2c
+#define RXDP		0x30
+#define RXDP_HI		0x34
+#define RXCFG		0x38
+#define PQCR		0x3c
+#define WCSR		0x40
+#define PCR		0x44
+#define RFCR		0x48
+#define RFDR		0x4c
+
+#define SRR		0x58
+
+#define VRCR		0xbc
+#define VTCR		0xc0
+#define VDR		0xc4
+#define CCSR		0xcc
+
+#define __kick_rx(dev)	writel(CR_RXE, dev->base + CR)
+
+#define kick_rx(dev) do { \
+	dprintk("kick_rx: maybe kicking\n"); \
+	if (test_and_clear_bit(0, &dev->rx_info.idle)) { \
+		dprintk("actually kicking\n"); \
+		writel(dev->rx_info.phy_descs + (4 * DESC_SIZE * dev->rx_info.next_rx), dev->base + RXDP); \
+		if (dev->rx_info.next_rx == dev->rx_info.next_empty) \
+			printk(KERN_DEBUG "%s: uh-oh: next_rx == next_empty???\n", dev->net_dev.name);\
+		__kick_rx(dev); \
+	} \
+} while(0)
+
+#ifdef USE_64BIT_ADDR
+typedef u64	hw_addr_t;
+#else
+typedef u32	hw_addr_t;
+#endif
+
+#define HW_ADDR_LEN	(sizeof(hw_addr_t))
+
+#define LINK		0
+#define BUFPTR		(LINK + HW_ADDR_LEN/4)
+#define CMDSTS		(BUFPTR + HW_ADDR_LEN/4)
+#define EXTSTS		(CMDSTS + 4/4)
+#define DRV_NEXT	(EXTSTS + 4/4)
+
+#define CMDSTS_OWN	0x80000000
+#define CMDSTS_MORE	0x40000000
+#define CMDSTS_INTR	0x20000000
+#define CMDSTS_ERR	0x10000000
+#define CMDSTS_OK	0x08000000
+
+#define CMDSTS_DEST_MASK	0x01800000
+#define CMDSTS_DEST_SELF	0x00800000
+#define CMDSTS_DEST_MULTI	0x01000000
+
+#define DESC_SIZE	8		/* Should be cache line sized */
+
+struct rx_info {
+	spinlock_t	lock;
+	int		up;
+	long		idle;
+
+	struct sk_buff	*skbs[NR_RX_DESC];
+
+	unsigned	next_rx, next_empty;
+
+	u32		*descs;
+	dma_addr_t	phy_descs;
+};
+
+
+struct ns83820 {
+	struct net_device	net_dev;
+	u8			*base;
+
+	struct pci_dev		*pci_dev;
+	struct ns83820		*next_dev;
+
+	struct rx_info		rx_info;
+
+	unsigned		ihr;
+	struct tq_struct	tq_refill;
+
+	/* protects everything below.  irqsave when using. */
+	spinlock_t		misc_lock;
+
+	u32			CFG_cache;
+
+	u32			MEAR_cache;
+	u32			IMR_cache;
+	struct eeprom		ee;
+
+
+	spinlock_t	tx_lock;
+
+	long		tx_idle;
+	u32		tx_done_idx;
+	u32		tx_idx;
+	volatile u32	tx_free_idx;	/* idx of free desc chain */
+	u32		tx_intr_idx;
+
+	struct sk_buff	*tx_skbs[NR_TX_DESC];
+
+	char		pad[16] __attribute__((aligned(16)));
+	u32		*tx_descs;
+	dma_addr_t	tx_phy_descs;
+};
+
+//free = (tx_done_idx + NR_TX_DESC-2 - free_idx) % NR_TX_DESC
+#define start_tx_okay(dev)	\
+	(((NR_TX_DESC-2 + dev->tx_done_idx - dev->tx_free_idx) % NR_TX_DESC) > NR_TX_DESC/2)
+
+static struct ns83820	*ns83820_chain;
+
+
+/* Packet Receiver
+ *
+ * The hardware supports linked lists of receive descriptors for
+ * which ownership is transfered back and forth by means of an
+ * ownership bit.  While the hardware does support the use of a
+ * ring for receive descriptors, we only make use of a chain in
+ * an attempt to reduce bus traffic under heavy load scenarios.
+ * This will also make bugs a bit more obvious.  The current code
+ * only makes use of a single rx chain; I hope to implement
+ * priority based rx for version 1.0.  Goal: even under overload
+ * conditions, still route realtime traffic with as low jitter as
+ * possible.
+ */
+#ifdef USE_64BIT_ADDR
+static inline void build_rx_desc64(struct ns83820 *dev, u32 *desc, u64 link, u64 buf, u32 cmdsts, u32 extsts)
+{
+	desc[0] = link;
+	desc[1] = link >> 32;
+	desc[2] = buf;
+	desc[3] = buf >> 32;
+	desc[5] = extsts;
+	mb();
+	desc[4] = cmdsts;
+}
+
+#define build_rx_desc	build_rx_desc64
+#else
+
+static inline void build_rx_desc32(struct ns83820 *dev, u32 *desc, u32 link, u32 buf, u32 cmdsts, u32 extsts)
+{
+	desc[0] = link;
+	desc[1] = buf;
+	desc[3] = extsts;
+	mb();
+	desc[2] = cmdsts;
+}
+
+#define build_rx_desc	build_rx_desc32
+#endif
+
+#define nr_rx_empty(dev) ((NR_RX_DESC-2 + dev->rx_info.next_rx - dev->rx_info.next_empty) % NR_RX_DESC)
+static inline int ns83820_add_rx_skb(struct ns83820 *dev, struct sk_buff *skb)
+{
+	unsigned next_empty;
+	u32 cmdsts;
+	u32 *sg;
+	hw_addr_t buf;
+
+	next_empty = dev->rx_info.next_empty;
+
+	/* don't overrun last rx marker */
+	if (nr_rx_empty(dev) <= 2) {
+		kfree_skb(skb);
+		return 1;
+	}
+
+#if 0
+	dprintk("next_empty[%d] nr_used[%d] next_rx[%d]\n",
+		dev->rx_info.next_empty,
+		dev->rx_info.nr_used,
+		dev->rx_info.next_rx
+		);
+#endif
+
+	sg = dev->rx_info.descs + (next_empty * DESC_SIZE);
+	if (dev->rx_info.skbs[next_empty])
+		BUG();
+	dev->rx_info.skbs[next_empty] = skb;
+
+	dev->rx_info.next_empty = (next_empty + 1) % NR_RX_DESC;
+	cmdsts = RX_BUF_SIZE | CMDSTS_INTR;
+	buf = pci_map_single(dev->pci_dev, skb->tail, RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
+	build_rx_desc(dev, sg, 0, buf, cmdsts, 0);
+	/* update link of previous rx */
+	if (next_empty != dev->rx_info.next_rx)
+		dev->rx_info.descs[((NR_RX_DESC + next_empty - 1) % NR_RX_DESC) * DESC_SIZE] = dev->rx_info.phy_descs + (next_empty * DESC_SIZE * 4);
+
+	return 0;
+}
+
+static int rx_refill(struct ns83820 *dev, int gfp)
+{
+	unsigned i;
+	long flags = 0;
+
+	dprintk("rx_refill(%p)\n", dev);
+	if (gfp == GFP_ATOMIC)
+		spin_lock_irqsave(&dev->rx_info.lock, flags);
+	for (i=0; i<NR_RX_DESC; i++) {
+		struct sk_buff *skb;
+		long res;
+		skb = __dev_alloc_skb(RX_BUF_SIZE+16, gfp);
+		if (!skb)
+			break;
+
+		res = (long)skb->tail & 0xf;
+		res = 0x10 - res;
+		res &= 0xf;
+		skb_reserve(skb, res);
+
+		skb->dev = &dev->net_dev;
+		if (gfp != GFP_ATOMIC)
+			spin_lock_irqsave(&dev->rx_info.lock, flags);
+		res = ns83820_add_rx_skb(dev, skb);
+		if (gfp != GFP_ATOMIC)
+			spin_unlock_irqrestore(&dev->rx_info.lock, flags);
+		if (res) {
+			i = 1;
+			break;
+		}
+	}
+	if (gfp == GFP_ATOMIC)
+		spin_unlock_irqrestore(&dev->rx_info.lock, flags);
+
+	return i ? 0 : -ENOMEM;
+}
+
+/* REFILL */
+static inline void queue_refill(void *_dev)
+{
+	struct ns83820 *dev = _dev;
+
+	rx_refill(dev, GFP_KERNEL);
+	if (dev->rx_info.up)
+		kick_rx(dev);
+}
+
+static inline void clear_rx_desc(struct ns83820 *dev, unsigned i)
+{
+	build_rx_desc(dev, dev->rx_info.descs + (DESC_SIZE * i), 0, 0, CMDSTS_OWN, 0);
+}
+
+static void phy_intr(struct ns83820 *dev)
+{
+	static char *speeds[] = { "10", "100", "1000", "1000(?)" };
+	u32 cfg, new_cfg;
+
+	new_cfg = dev->CFG_cache & ~(CFG_SB | CFG_MODE_1000 | CFG_SPDSTS);
+	cfg = readl(dev->base + CFG) ^ SPDSTS_POLARITY;
+
+	if (cfg & CFG_SPDSTS1)
+		new_cfg |= CFG_MODE_1000 | CFG_SB;
+	else
+		new_cfg &= ~CFG_MODE_1000 | CFG_SB;
+
+	if ((cfg & CFG_LNKSTS) && ((new_cfg ^ dev->CFG_cache) & CFG_MODE_1000)) {
+		writel(new_cfg, dev->base + CFG);
+		dev->CFG_cache = new_cfg;
+	}
+
+	dev->CFG_cache &= ~CFG_SPDSTS;
+	dev->CFG_cache |= cfg & CFG_SPDSTS;
+
+	if (cfg & CFG_LNKSTS) {
+		netif_start_queue(&dev->net_dev);
+		netif_wake_queue(&dev->net_dev);
+	} else {
+		netif_stop_queue(&dev->net_dev);
+	}
+
+	if (cfg & CFG_LNKSTS)
+		printk(KERN_INFO "%s: link now %s mbps, %s duplex and up.\n",
+			dev->net_dev.name,
+			speeds[((cfg / CFG_SPDSTS0) & 3)],
+			(cfg & CFG_DUPSTS) ? "full" : "half");
+	else
+		printk(KERN_INFO "%s: link now down.\n", dev->net_dev.name);
+}
+
+static int ns83820_setup_rx(struct ns83820 *dev)
+{
+	unsigned i;
+	int ret;
+
+	dprintk("ns83820_setup_rx(%p)\n", dev);
+
+	dev->rx_info.idle = 1;
+	dev->rx_info.next_rx = 0;
+	dev->rx_info.next_empty = 0;
+
+	for (i=0; i<NR_RX_DESC; i++)
+		clear_rx_desc(dev, i);
+
+	writel(0, dev->base + RXDP_HI);
+	writel(dev->rx_info.phy_descs, dev->base + RXDP);
+
+	ret = rx_refill(dev, GFP_KERNEL);
+	if (!ret) {
+		dprintk("starting receiver\n");
+		/* prevent the interrupt handler from stomping on us */
+		spin_lock_irq(&dev->rx_info.lock);
+
+		writel(0x0001, dev->base + CCSR);
+		writel(0, dev->base + RFCR);
+		writel(0x7fc00000, dev->base + RFCR);
+		writel(0xffc00000, dev->base + RFCR);
+
+		dev->rx_info.up = 1;
+
+		phy_intr(dev);
+
+		/* Okay, let it rip */
+		spin_lock(&dev->misc_lock);
+		dev->IMR_cache |= ISR_PHY;
+		dev->IMR_cache |= ISR_RXRCMP;
+		//dev->IMR_cache |= ISR_RXERR;
+		//dev->IMR_cache |= ISR_RXOK;
+		dev->IMR_cache |= ISR_RXORN;
+		dev->IMR_cache |= ISR_RXSOVR;
+		dev->IMR_cache |= ISR_RXDESC;
+		dev->IMR_cache |= ISR_RXIDLE;
+		dev->IMR_cache |= ISR_TXDESC;
+		//dev->IMR_cache |= ISR_TXIDLE;
+
+		writel(dev->IMR_cache, dev->base + IMR);
+		writel(1, dev->base + IER);
+		spin_unlock(&dev->misc_lock);
+
+		kick_rx(dev);
+
+		spin_unlock_irq(&dev->rx_info.lock);
+	}
+	return ret;
+}
+
+static void ns83820_cleanup_rx(struct ns83820 *dev)
+{
+	unsigned i;
+	long flags;
+
+	dprintk("ns83820_cleanup_rx(%p)\n", dev);
+
+	/* disable receive interrupts */
+	spin_lock_irqsave(&dev->misc_lock, flags);
+	dev->IMR_cache &= ~(ISR_RXOK | ISR_RXDESC | ISR_RXERR | ISR_RXEARLY | ISR_RXIDLE);
+	writel(dev->IMR_cache, dev->base + IMR);
+	spin_unlock_irqrestore(&dev->misc_lock, flags);
+
+	/* synchronize with the interrupt handler and kill it */
+	dev->rx_info.up = 0;
+	synchronize_irq();
+
+	/* touch the pci bus... */
+	readl(dev->base + IMR);
+
+	/* assumes the transmitter is already disabled and reset */
+	writel(0, dev->base + RXDP_HI);
+	writel(0, dev->base + RXDP);
+
+	for (i=0; i<NR_RX_DESC; i++) {
+		struct sk_buff *skb = dev->rx_info.skbs[i];
+		dev->rx_info.skbs[i] = NULL;
+		clear_rx_desc(dev, i);
+		if (skb)
+			kfree_skb(skb);
+	}
+}
+
+/* rx_irq
+ *	
+ */
+static void FASTCALL(rx_irq(struct ns83820 *dev));
+static void rx_irq(struct ns83820 *dev)
+{
+	struct rx_info *info = &dev->rx_info;
+	unsigned next_rx;
+	u32 cmdsts, *desc;
+	long flags;
+	int nr = 0;
+
+	dprintk("rx_irq(%p)\n", dev);
+	dprintk("rxdp: %08x, descs: %08lx next_rx[%d]: %p next_empty[%d]: %p\n",
+		readl(dev->base + RXDP),
+		(dev->rx_info.phy_descs),
+		dev->rx_info.next_rx,
+		(dev->rx_info.descs + (DESC_SIZE * dev->rx_info.next_rx)),
+		dev->rx_info.next_empty,
+		(dev->rx_info.descs + (DESC_SIZE * dev->rx_info.next_empty))
+		);
+
+	spin_lock_irqsave(&info->lock, flags);
+	if (!info->up)
+		goto out;
+
+	dprintk("walking descs\n");
+	next_rx = info->next_rx;
+	desc = info->descs + (DESC_SIZE * next_rx);
+	while ((CMDSTS_OWN & (cmdsts = desc[CMDSTS])) &&
+	       (cmdsts != CMDSTS_OWN)) {
+		struct sk_buff *skb;
+		u32 extsts = desc[EXTSTS];
+		dmaaddr_high_t bufptr = *(hw_addr_t *)(desc + BUFPTR);
+
+		dprintk("cmdsts: %08x\n", cmdsts);
+		dprintk("link: %08x\n", desc[LINK]);
+		dprintk("extsts: %08x\n", desc[EXTSTS]);
+
+		skb = info->skbs[next_rx];
+		info->skbs[next_rx] = NULL;
+		info->next_rx = (next_rx + 1) % NR_RX_DESC;
+
+		barrier();
+		clear_rx_desc(dev, next_rx);
+
+		pci_unmap_single(dev->pci_dev, bufptr,
+				 RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
+		if (CMDSTS_OK & cmdsts) {
+#ifndef __i386__
+			struct sk_buff *tmp;
+#endif
+			int len = cmdsts & 0xffff;
+			if (!skb)
+				BUG();
+			skb_put(skb, len);
+#ifndef __i386__	/* I hate the network stack sometimes */
+			tmp = __dev_alloc_skb(RX_BUF_SIZE+16, GFP_ATOMIC);
+			if (!tmp)
+				goto done;
+			tmp->dev = &dev->net_dev;
+			skb_reserve(tmp, 2);
+			memcpy(skb_put(tmp, len), skb->data, len);
+			kfree_skb(skb);
+			skb = tmp;
+#endif
+			if ((extsts & 0x002a0000) && !(extsts & 0x00540000)) {
+				skb->ip_summed = CHECKSUM_UNNECESSARY;
+			} else {
+				skb->ip_summed = CHECKSUM_NONE;
+			}
+			skb->protocol = eth_type_trans(skb, &dev->net_dev);
+			switch (netif_rx(skb)) {
+			case NET_RX_SUCCESS:
+				dev->ihr = 3;
+				break;
+			case NET_RX_CN_LOW:
+				dev->ihr = 3;
+				break;
+			case NET_RX_CN_MOD:
+				dev->ihr = dev->ihr + 1;
+				break;
+			case NET_RX_CN_HIGH:
+				dev->ihr += dev->ihr/2 + 1;
+				break;
+			case NET_RX_DROP:
+				dev->ihr = 255;
+				break;
+			}
+			if (dev->ihr > 255)
+				dev->ihr = 255;
+#ifndef __i386__
+		done:;
+#endif
+		} else {
+			static int err;
+			if (err++ < 20) {
+				Dprintk("error packet: cmdsts: %08x extsts: %08x\n", cmdsts, extsts);
+			}
+			kfree_skb(skb);
+		}
+
+		nr++;
+		next_rx = info->next_rx;
+		desc = info->descs + (DESC_SIZE * next_rx);
+	}
+	info->next_rx = next_rx;
+
+out:
+	if (0 && !nr) {
+		Dprintk("dazed: cmdsts_f: %08x\n", cmdsts);
+	}
+
+	spin_unlock_irqrestore(&info->lock, flags);
+}
+
+
+/* Packet Transmit code
+ */
+static inline void kick_tx(struct ns83820 *dev)
+{
+	dprintk("kick_tx(%p): tx_idle=%ld, tx_idx=%d free_idx=%d\n",
+		dev, dev->tx_idle, dev->tx_idx, dev->tx_free_idx);
+	writel(CR_TXE, dev->base + CR);
+}
+
+/* no spinlock needed on the transmit irq path as the interrupt handler is serialized */
+static void do_tx_done(struct ns83820 *dev)
+{
+	u32 cmdsts, tx_done_idx, *desc;
+
+	dprintk("do_tx_done(%p)\n", dev);
+	tx_done_idx = dev->tx_done_idx;
+	desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);
+
+	dprintk("tx_done_idx=%d free_idx=%d cmdsts=%08x\n",
+		tx_done_idx, dev->tx_free_idx, desc[CMDSTS]);
+	while ((tx_done_idx != dev->tx_free_idx) &&
+	       !(CMDSTS_OWN & (cmdsts = desc[CMDSTS])) ) {
+		struct sk_buff *skb;
+
+		dprintk("tx_done_idx=%d free_idx=%d cmdsts=%08x\n",
+			tx_done_idx, dev->tx_free_idx, desc[CMDSTS]);
+		skb = dev->tx_skbs[tx_done_idx];
+		dev->tx_skbs[tx_done_idx] = NULL;
+		dprintk("done(%p)\n", skb);
+		if (skb) {
+			pci_unmap_single(dev->pci_dev,
+					*(hw_addr_t *)(desc + BUFPTR),
+					skb->len,
+					PCI_DMA_TODEVICE);
+			dev_kfree_skb_irq(skb);
+		}
+
+		tx_done_idx = (tx_done_idx + 1) % NR_TX_DESC;
+		dev->tx_done_idx = tx_done_idx;
+		desc[CMDSTS] = 0;
+		barrier();
+		desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);
+	}
+
+	/* Allow network stack to resume queueing packets after we've
+	 * finished transmitting at least 1/4 of the packets in the queue.
+	 */
+	if (netif_queue_stopped(&dev->net_dev) && start_tx_okay(dev)) {
+		dprintk("start_queue(%p)\n", dev);
+		netif_start_queue(&dev->net_dev);
+		netif_wake_queue(&dev->net_dev);
+	}
+}
+
+static void ns83820_cleanup_tx(struct ns83820 *dev)
+{
+	unsigned i;
+
+	for (i=0; i<NR_TX_DESC; i++) {
+		struct sk_buff *skb = dev->tx_skbs[i];
+		dev->tx_skbs[i] = NULL;
+		if (skb)
+			dev_kfree_skb(skb);
+	}
+
+	memset(dev->tx_descs, 0, NR_TX_DESC * DESC_SIZE * 4);
+	set_bit(0, &dev->tx_idle);
+}
+
+/* transmit routine.  This code relies on the network layer serializing
+ * its calls in, but will run happily in parallel with the interrupt
+ * handler.  This code currently has provisions for fragmenting tx buffers
+ * while trying to track down a bug in either the zero copy code or
+ * the tx fifo (hence the MAX_FRAG_LEN).
+ */
+#define MAX_FRAG_LEN	8192	/* disabled for now */
+static int ns83820_hard_start_xmit(struct sk_buff *skb, struct net_device *_dev)
+{
+	struct ns83820 *dev = (struct ns83820 *)_dev;
+	u32 free_idx, cmdsts, extsts;
+	int nr_free, nr_frags;
+	unsigned tx_done_idx;
+	dmaaddr_high_t buf;
+	unsigned len;
+	skb_frag_t *frag;
+	int stopped = 0;
+	int do_intr = 0;
+	volatile u32 *first_desc;
+
+	dprintk("ns83820_hard_start_xmit\n");
+
+	nr_frags =  skb_shinfo(skb)->nr_frags;
+again:
+	if (__builtin_expect(dev->CFG_cache & CFG_LNKSTS, 0)) {
+		netif_stop_queue(&dev->net_dev);
+		if (__builtin_expect(dev->CFG_cache & CFG_LNKSTS, 0))
+			return 1;
+		netif_start_queue(&dev->net_dev);
+	}
+
+	free_idx = dev->tx_free_idx;
+	tx_done_idx = dev->tx_done_idx;
+	nr_free = (tx_done_idx + NR_TX_DESC-2 - free_idx) % NR_TX_DESC;
+	nr_free -= 1;
+	if ((nr_free <= nr_frags) || (nr_free <= 8192 / MAX_FRAG_LEN)) {
+		dprintk("stop_queue - not enough(%p)\n", dev);
+		netif_stop_queue(&dev->net_dev);
+
+		/* Check again: we may have raced with a tx done irq */
+		if (dev->tx_done_idx != tx_done_idx) {
+			dprintk("restart queue(%p)\n", dev);
+			netif_start_queue(&dev->net_dev);
+			goto again;
+		}
+		return 1;
+	}
+
+	if (free_idx == dev->tx_intr_idx) {
+		do_intr = 1;
+		dev->tx_intr_idx = (dev->tx_intr_idx + NR_TX_DESC/2) % NR_TX_DESC;
+	}
+
+	nr_free -= nr_frags;
+	if (nr_free < 1) {
+		dprintk("stop_queue - last entry(%p)\n", dev);
+		netif_stop_queue(&dev->net_dev);
+		stopped = 1;
+	}
+
+	frag = skb_shinfo(skb)->frags;
+	if (!nr_frags)
+		frag = 0;
+	extsts = 0;
+	if (skb->ip_summed == CHECKSUM_HW) {
+		extsts |= EXTSTS_IPPKT;
+		if (IPPROTO_TCP == skb->nh.iph->protocol)
+			extsts |= EXTSTS_TCPPKT;
+		else if (IPPROTO_UDP == skb->nh.iph->protocol)
+			extsts |= EXTSTS_UDPPKT;
+	}
+
+	len = skb->len;
+	if (nr_frags)
+		len -= skb->data_len;
+	buf = pci_map_single(dev->pci_dev, skb->data, len, PCI_DMA_TODEVICE);
+
+	first_desc = dev->tx_descs + (free_idx * DESC_SIZE);
+
+	for (;;) {
+		volatile u32 *desc = dev->tx_descs + (free_idx * DESC_SIZE);
+		u32 residue = 0;
+#if 0
+		if (len > MAX_FRAG_LEN) {
+			residue = len;
+			/* align the start address of the next fragment */
+			len = MAX_FRAG_LEN;
+			residue -= len;
+		}
+#endif
+
+		dprintk("frag[%3u]: %4u @ 0x%x%08Lx\n", free_idx, len,
+			(unsigned long long)buf);
+		free_idx = (free_idx + 1) % NR_TX_DESC;
+		desc[LINK] = dev->tx_phy_descs + (free_idx * DESC_SIZE * 4);
+		*(hw_addr_t *)(desc + BUFPTR) = buf;
+		desc[EXTSTS] = extsts;
+
+		cmdsts = ((nr_frags|residue) ? CMDSTS_MORE : do_intr ? CMDSTS_INTR : 0);
+		cmdsts |= (desc == first_desc) ? 0 : CMDSTS_OWN;
+		cmdsts |= len;
+		desc[CMDSTS] = cmdsts;
+
+		if (residue) {
+			buf += len;
+			len = residue;
+			continue;
+		}
+
+		if (!nr_frags)
+			break;
+
+		buf = pci_map_single_high(dev->pci_dev, frag->page, 0,
+					  frag->size, PCI_DMA_TODEVICE);
+		dprintk("frag: buf=%08Lx  page=%08lx\n",
+			(long long)buf, (long)(frag->page - mem_map));
+		len = frag->size;
+		frag++;
+		nr_frags--;
+	}
+	dprintk("done pkt\n");
+	dev->tx_skbs[free_idx] = skb;
+	first_desc[CMDSTS] |= CMDSTS_OWN;
+	dev->tx_free_idx = free_idx;
+	kick_tx(dev);
+
+	/* Check again: we may have raced with a tx done irq */
+	if (stopped && (dev->tx_done_idx != tx_done_idx) && start_tx_okay(dev))
+		netif_start_queue(&dev->net_dev);
+
+	return 0;
+}
+
+static void ns83820_irq(int foo, void *data, struct pt_regs *regs)
+{
+	struct ns83820 *dev = data;
+	int count = 0;
+	u32 isr;
+	dprintk("ns83820_irq(%p)\n", dev);
+
+	dev->ihr = 0;
+
+	while (count++ < 32 && (isr = readl(dev->base + ISR))) {
+		dprintk("irq: %08x\n", isr);
+
+		if (isr & ~(ISR_PHY | ISR_RXDESC | ISR_RXEARLY | ISR_RXOK | ISR_RXERR | ISR_TXIDLE | ISR_TXOK | ISR_TXDESC))
+			Dprintk("odd isr? 0x%08x\n", isr);
+
+	if ((ISR_RXEARLY | ISR_RXIDLE | ISR_RXORN | ISR_RXDESC | ISR_RXOK | ISR_RXERR) & isr) {
+ 		if (ISR_RXIDLE & isr) {
+			dev->rx_info.idle = 1;
+			Dprintk("oh dear, we are idle\n");
+		}
+
+		if ((ISR_RXDESC) & isr) {
+			rx_irq(dev);
+			writel(4, dev->base + IHR);
+		}
+
+		if (nr_rx_empty(dev) >= NR_RX_DESC/4) {
+			if (dev->rx_info.up) {
+				rx_refill(dev, GFP_ATOMIC);
+				kick_rx(dev);
+			}
+		}
+
+		if (dev->rx_info.up && nr_rx_empty(dev) > NR_RX_DESC*3/4)
+			schedule_task(&dev->tq_refill);
+		else
+			kick_rx(dev);
+		if (dev->rx_info.idle)
+			Dprintk("BAD\n");
+	}
+
+	if (ISR_RXSOVR & isr)
+		Dprintk("overrun\n");
+	if (ISR_RXORN & isr)
+		Dprintk("overrun\n");
+
+	if ((ISR_RXRCMP & isr) && dev->rx_info.up)
+		writel(CR_RXE, dev->base + CR);
+
+	if (ISR_TXIDLE & isr) {
+		u32 txdp;
+		txdp = readl(dev->base + TXDP);
+		dprintk("txdp: %08x\n", txdp);
+		txdp -= dev->tx_phy_descs;
+		dev->tx_idx = txdp / (DESC_SIZE * 4);
+		if (dev->tx_idx >= NR_TX_DESC) {
+			printk(KERN_ALERT "%s: BUG -- txdp out of range\n", dev->net_dev.name);
+			dev->tx_idx = 0;
+		}
+		if (dev->tx_idx != dev->tx_free_idx)
+			writel(CR_TXE, dev->base + CR);
+			//kick_tx(dev);
+		else
+			dev->tx_idle = 1;
+		mb();
+		if (dev->tx_idx != dev->tx_free_idx)
+			kick_tx(dev);
+	}
+
+	/* Defer tx ring processing until more than a minimum amount of
+	 * work has accumulated
+	 */
+	if ((ISR_TXDESC | ISR_TXIDLE) & isr)
+		do_tx_done(dev);
+
+	if (ISR_PHY & isr)
+		phy_intr(dev);
+	}
+
+#if 0	/* Still working on the interrupt mitigation strategy */
+	if (dev->ihr)
+		writel(dev->ihr, dev->base + IHR);
+#endif
+}
+
+static void ns83820_do_reset(struct ns83820 *dev, u32 which)
+{
+	Dprintk("resetting chip...\n");
+	writel(which, dev->base + CR);
+	do {
+		schedule();
+	} while (readl(dev->base + CR) & which);
+	Dprintk("okay!\n");
+}
+
+static int ns83820_stop(struct net_device *_dev)
+{
+	struct ns83820 *dev = (struct ns83820 *)_dev;
+
+	/* FIXME: protect against interrupt handler? */
+
+	/* disable interrupts */
+	writel(0, dev->base + IMR);
+	writel(0, dev->base + IER);
+	readl(dev->base + IER);
+
+	dev->rx_info.up = 0;
+	synchronize_irq();
+
+	ns83820_do_reset(dev, CR_RST);
+
+	synchronize_irq();
+
+	dev->IMR_cache &= ~(ISR_TXURN | ISR_TXIDLE | ISR_TXERR | ISR_TXDESC | ISR_TXOK);
+	ns83820_cleanup_rx(dev);
+	ns83820_cleanup_tx(dev);
+
+	return 0;
+}
+
+static int ns83820_open(struct net_device *_dev)
+{
+	struct ns83820 *dev = (struct ns83820 *)_dev;
+	unsigned i;
+	u32 desc;
+	int ret;
+
+	dprintk("ns83820_open\n");
+
+	writel(0, dev->base + PQCR);
+
+	ret = ns83820_setup_rx(dev);
+	if (ret)
+		goto failed;
+
+	memset(dev->tx_descs, 0, 4 * NR_TX_DESC * DESC_SIZE);
+	for (i=0; i<NR_TX_DESC; i++) {
+		*(hw_addr_t *)(dev->tx_descs + (i * DESC_SIZE) + LINK)
+				= dev->tx_phy_descs
+				  + ((i+1) % NR_TX_DESC) * DESC_SIZE * 4;
+	}
+
+	dev->tx_idx = 0;
+	dev->tx_done_idx = 0;
+	desc = dev->tx_phy_descs;
+	writel(0, dev->base + TXDP_HI);
+	writel(desc, dev->base + TXDP);
+
+//printk("IMR: %08x / %08x\n", readl(dev->base + IMR), dev->IMR_cache);
+
+	set_bit(0, &dev->tx_idle);
+	netif_start_queue(&dev->net_dev);	/* FIXME: wait for phy to come up */
+
+	return 0;
+
+failed:
+	ns83820_stop(_dev);
+	return ret;
+}
+
+#if 0	/* FIXME: implement this! */
+static void ns83820_tx_timeout(struct net_device *_dev)
+{
+	struct ns83820 *dev = (struct ns83820 *)_dev;
+
+	printk("ns83820_tx_timeout\n");
+}
+#endif
+
+static void ns83820_getmac(struct ns83820 *dev, u8 *mac)
+{
+	unsigned i;
+	for (i=0; i<3; i++) {
+		u32 data;
+#if 0	/* I've left this in as an example of how to use eeprom.h */
+		data = eeprom_readw(&dev->ee, 0xa + 2 - i);
+#else
+		writel(i*2, dev->base + RFCR);
+		data = readl(dev->base + RFDR);
+#endif
+		*mac++ = data;
+		*mac++ = data >> 8;
+	}
+}
+
+static int ns83820_change_mtu(struct net_device *_dev, int new_mtu)
+{
+	if (new_mtu > RX_BUF_SIZE)
+		return -EINVAL;
+	_dev->mtu = new_mtu;
+	return 0;
+}
+
+static int ns83820_probe(struct pci_dev *pci_dev, const struct pci_device_id *id)
+{
+	struct ns83820 *dev;
+	long addr;
+	int err;
+
+	dev = (struct ns83820 *)alloc_etherdev((sizeof *dev) - (sizeof dev->net_dev));
+	err = -ENOMEM;
+	if (!dev)
+		goto out;
+
+	spin_lock_init(&dev->rx_info.lock);
+	spin_lock_init(&dev->tx_lock);
+	spin_lock_init(&dev->misc_lock);
+	dev->pci_dev = pci_dev;
+
+	dev->ee.cache = &dev->MEAR_cache;
+	dev->ee.lock = &dev->misc_lock;
+	dev->net_dev.owner = THIS_MODULE;
+
+	PREPARE_TQUEUE(&dev->tq_refill, queue_refill, dev);
+
+	err = pci_enable_device(pci_dev);
+	if (err) {
+		printk(KERN_INFO "ns83820: pci_enable_dev: %d\n", err);
+		goto out_free;
+	}
+
+	pci_set_master(pci_dev);
+	addr = pci_resource_start(pci_dev, 1);
+	dev->base = ioremap_nocache(addr, PAGE_SIZE);
+	dev->tx_descs = pci_alloc_consistent(pci_dev,
+			4 * DESC_SIZE * NR_TX_DESC, &dev->tx_phy_descs);
+	dev->rx_info.descs = pci_alloc_consistent(pci_dev,
+			4 * DESC_SIZE * NR_RX_DESC, &dev->rx_info.phy_descs);
+	err = -ENOMEM;
+	if (!dev->base || !dev->tx_descs || !dev->rx_info.descs)
+		goto out_disable;
+
+	dprintk("%p: %08lx  %p: %08lx\n", dev->tx_descs, dev->tx_phy_descs,
+		dev->rx_info.descs, dev->rx_info.phy_descs);
+	/* disable interrupts */
+	writel(0, dev->base + IMR);
+	writel(0, dev->base + IER);
+	readl(dev->base + IER);
+
+	dev->IMR_cache = 0;
+
+	setup_ee_mem_bitbanger(&dev->ee, (long)dev->base + MEAR, 3, 2, 1, 0,
+		0);
+
+	err = request_irq(pci_dev->irq, ns83820_irq, SA_SHIRQ,
+			  dev->net_dev.name, dev);
+	if (err) {
+		printk(KERN_INFO "ns83820: unable to register irq %d\n",
+			pci_dev->irq);
+		goto out_unmap;
+	}
+
+	dev->net_dev.open = ns83820_open;
+	dev->net_dev.stop = ns83820_stop;
+	dev->net_dev.hard_start_xmit = ns83820_hard_start_xmit;
+	dev->net_dev.change_mtu = ns83820_change_mtu;
+	//FIXME: dev->net_dev.tx_timeout = ns83820_tx_timeout;
+
+	lock_kernel();
+	dev->next_dev = ns83820_chain;
+	ns83820_chain = dev;
+	unlock_kernel();
+
+	ns83820_do_reset(dev, CR_RST);
+
+	dprintk("start bist\n");
+	writel(PTSCR_EEBIST_EN, dev->base + PTSCR);
+	do {
+		schedule();
+	} while (readl(dev->base + PTSCR) & PTSCR_EEBIST_EN);
+	dprintk("done bist\n");
+
+	dprintk("start eeload\n");
+	writel(PTSCR_EELOAD_EN, dev->base + PTSCR);
+	do {
+		schedule();
+	} while (readl(dev->base + PTSCR) & PTSCR_EELOAD_EN);
+	dprintk("done eeload\n");
+
+	/* I love config registers */
+	dev->CFG_cache = readl(dev->base + CFG);
+
+	if ((dev->CFG_cache & CFG_PCI64_DET)) {
+		printk("%s: enabling 64 bit PCI.\n", dev->net_dev.name);
+		dev->CFG_cache |= CFG_T64ADDR | CFG_DATA64_EN;
+	} else {
+		printk("%s: disabling 64 bit PCI.\n", dev->net_dev.name);
+		dev->CFG_cache &= ~(CFG_T64ADDR | CFG_DATA64_EN);
+	}
+	dev->CFG_cache &= (CFG_TBI_EN  | CFG_MRM_DIS   | CFG_MWI_DIS |
+			   CFG_T64ADDR | CFG_DATA64_EN | CFG_EXT_125 |
+			   CFG_M64ADDR);
+	dev->CFG_cache |= CFG_PINT_DUPSTS | CFG_PINT_LNKSTS | CFG_PINT_SPDSTS |
+			  CFG_EXTSTS_EN   | CFG_EXD         | CFG_PESEL;
+	dev->CFG_cache |= CFG_REQALG;
+	dev->CFG_cache |= CFG_POW;
+#ifdef USE_64BIT_ADDR
+	dev->CFG_cache |= CFG_M64ADDR;
+	printk("using 64 bit addressing\n");
+#endif
+#ifdef __LITTLE_ENDIAN
+	dev->CFG_cache &= ~CFG_BEM;
+#elif defined(__BIG_ENDIAN)
+	dev->CFG_cache |= CFG_BEM;
+#else
+#error This driver only works for big or little endian!!!
+#endif
+
+	writel(dev->CFG_cache, dev->base + CFG);
+	dprintk("CFG: %08x\n", dev->CFG_cache);
+
+	if (readl(dev->base + SRR))
+		writel(readl(dev->base+0x20c) | 0xfe00, dev->base + 0x20c);
+
+	/* Note!  The DMA burst size interacts with packet
+	 * transmission, such that the largest packet that
+	 * can be transmitted is 8192 - FLTH - burst size.
+	 * If only the transmit fifo was larger...
+	 */
+	writel(TXCFG_CSI | TXCFG_HBI | TXCFG_ATP | TXCFG_MXDMA1024
+		| ((1600 / 32) * 0x100),
+		dev->base + TXCFG);
+
+	/* Flush the interrupt holdoff timer */
+	writel(0x000, dev->base + IHR);
+	writel(0x100, dev->base + IHR);
+
+	/* Set Rx to full duplex, don't accept runt, errored, long or length
+	 * range errored packets.  Set MXDMA to 7 => 512 word burst
+	 */
+	writel(RXCFG_AEP | RXCFG_ARP | RXCFG_AIRL | RXCFG_RX_FD
+		| RXCFG_ALP
+		| RXCFG_MXDMA | 0, dev->base + RXCFG);
+
+	/* Disable priority queueing */
+	writel(0, dev->base + PQCR);
+
+	/* Enable IP checksum validation and detetion of VLAN headers.
+	 * Note: do not set the reject options as at least the 0x102
+	 * revision of the chip does not properly accept IP fragments
+	 * at least for UDP.
+	 */
+	writel(VRCR_IPEN | VRCR_VTDEN, dev->base + VRCR);
+
+	/* Enable per-packet TCP/UDP/IP checksumming */
+	writel(VTCR_PPCHK, dev->base + VTCR);
+
+	/* Disable Pause frames */
+	writel(0, dev->base + PCR);
+
+	/* Disable Wake On Lan */
+	writel(0, dev->base + WCSR);
+
+	ns83820_getmac(dev, dev->net_dev.dev_addr);
+
+	/* Yes, we support dumb IP checksum on transmit */
+	dev->net_dev.features |= NETIF_F_SG;
+	dev->net_dev.features |= NETIF_F_IP_CSUM;
+#if defined(USE_64BIT_ADDR) || defined(CONFIG_HIGHMEM4G)
+	dev->net_dev.features |= NETIF_F_HIGHDMA;
+#endif
+
+	register_netdev(&dev->net_dev);
+
+	printk(KERN_INFO "%s: ns83820.c v" VERSION ": DP83820 %02x:%02x:%02x:%02x:%02x:%02x pciaddr=0x%08lx irq=%d rev 0x%x\n",
+		dev->net_dev.name,
+		dev->net_dev.dev_addr[0], dev->net_dev.dev_addr[1],
+		dev->net_dev.dev_addr[2], dev->net_dev.dev_addr[3],
+		dev->net_dev.dev_addr[4], dev->net_dev.dev_addr[5],
+		addr, pci_dev->irq,
+		(unsigned)readl(dev->base + SRR)
+		);
+
+	return 0;
+
+out_unmap:
+	iounmap(dev->base);
+out_disable:
+	pci_free_consistent(pci_dev, 4 * DESC_SIZE * NR_TX_DESC, dev->tx_descs, dev->tx_phy_descs);
+	pci_free_consistent(pci_dev, 4 * DESC_SIZE * NR_RX_DESC, dev->rx_info.descs, dev->rx_info.phy_descs);
+	pci_disable_device(pci_dev);
+out_free:
+	kfree(dev);
+out:
+	return err;
+}
+
+static struct pci_device_id pci_device_id[] __devinitdata = {
+	{ 0x100b, 0x0022, PCI_ANY_ID, PCI_ANY_ID, 0, 0, },
+	{ 0, },
+};
+
+static struct pci_driver driver = {
+	name:		"ns83820",
+	id_table:	pci_device_id,
+	probe:		ns83820_probe,
+#if 0	/* FIXME: implement */
+	remove:		,
+	suspend:	,
+	resume:		,
+#endif
+};
+
+
+static int __init ns83820_init(void)
+{
+	printk(KERN_INFO "ns83820.c: National Semiconductor DP83820 10/100/100 driver.\n");
+	return pci_module_init(&driver);
+}
+
+static void ns83820_exit(void)
+{
+	struct ns83820	*dev;
+
+	for (dev = ns83820_chain; dev; ) {
+		struct ns83820 *next = dev->next_dev;
+
+		writel(0, dev->base + IMR);	/* paranoia */
+		writel(0, dev->base + IER);
+		readl(dev->base + IER);
+
+		unregister_netdev(&dev->net_dev);
+		free_irq(dev->pci_dev->irq, dev);
+		iounmap(dev->base);
+		pci_free_consistent(dev->pci_dev, 4 * DESC_SIZE * NR_TX_DESC,
+				dev->tx_descs, dev->tx_phy_descs);
+		pci_free_consistent(dev->pci_dev, 4 * DESC_SIZE * NR_RX_DESC,
+				dev->rx_info.descs, dev->rx_info.phy_descs);
+		pci_disable_device(dev->pci_dev);
+		kfree(dev);
+		dev = next;
+	}
+	pci_unregister_driver(&driver);
+	ns83820_chain = NULL;
+}
+
+MODULE_AUTHOR("Benjamin LaHaise <bcrl@redhat.com>");
+MODULE_DESCRIPTION("National Semiconductor DP83820 10/100/1000 driver");
+MODULE_DEVICE_TABLE(pci, pci_device_id);
+module_init(ns83820_init);
+module_exit(ns83820_exit);

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TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)