ioc3-eth/meth: Move the SGI drivers

Move the SGI drivers into drivers/net/ethernet/sgi/ and make the
necessary Kconfig and Makefile changes.

CC: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

5 files changed, 2822 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sgi/Kconfig b/drivers/net/ethernet/sgi/Kconfig
new file mode 100644
index 000000000000..3098594ab274
--- /dev/null
+++ b/drivers/net/ethernet/sgi/Kconfig
@@ -0,0 +1,34 @@
+#
+# SGI device configuration
+#
+
+config NET_VENDOR_SGI
+	bool "SGI devices"
+	depends on (PCI && SGI_IP27) || SGI_IP32
+	---help---
+	  If you have a network (Ethernet) card belonging to this class, say Y
+	  and read the Ethernet-HOWTO, available from
+	  <http://www.tldp.org/docs.html#howto>.
+
+	  Note that the answer to this question doesn't directly affect the
+	  kernel: saying N will just cause the configurator to skip all
+	  the questions about SGI devices. If you say Y, you will be asked for
+	  your specific card in the following questions.
+
+if NET_VENDOR_SGI
+
+config SGI_IOC3_ETH
+	bool "SGI IOC3 Ethernet"
+	depends on PCI && SGI_IP27
+	select CRC32
+	select MII
+	---help---
+	  If you have a network (Ethernet) card of this type, say Y and read
+	  the Ethernet-HOWTO, available from
+	  <http://www.tldp.org/docs.html#howto>.
+
+config SGI_O2MACE_ETH
+	tristate "SGI O2 MACE Fast Ethernet support"
+	depends on SGI_IP32=y
+
+endif # NET_VENDOR_SGI
diff --git a/drivers/net/ethernet/sgi/Makefile b/drivers/net/ethernet/sgi/Makefile
new file mode 100644
index 000000000000..e5bedd271e29
--- /dev/null
+++ b/drivers/net/ethernet/sgi/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for the SGI device drivers.
+#
+
+obj-$(CONFIG_SGI_O2MACE_ETH) += meth.o
+obj-$(CONFIG_SGI_IOC3_ETH) += ioc3-eth.o
diff --git a/drivers/net/ethernet/sgi/ioc3-eth.c b/drivers/net/ethernet/sgi/ioc3-eth.c
new file mode 100644
index 000000000000..a234e4504522
--- /dev/null
+++ b/drivers/net/ethernet/sgi/ioc3-eth.c
@@ -0,0 +1,1684 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Driver for SGI's IOC3 based Ethernet cards as found in the PCI card.
+ *
+ * Copyright (C) 1999, 2000, 01, 03, 06 Ralf Baechle
+ * Copyright (C) 1995, 1999, 2000, 2001 by Silicon Graphics, Inc.
+ *
+ * References:
+ *  o IOC3 ASIC specification 4.51, 1996-04-18
+ *  o IEEE 802.3 specification, 2000 edition
+ *  o DP38840A Specification, National Semiconductor, March 1997
+ *
+ * To do:
+ *
+ *  o Handle allocation failures in ioc3_alloc_skb() more gracefully.
+ *  o Handle allocation failures in ioc3_init_rings().
+ *  o Use prefetching for large packets.  What is a good lower limit for
+ *    prefetching?
+ *  o We're probably allocating a bit too much memory.
+ *  o Use hardware checksums.
+ *  o Convert to using a IOC3 meta driver.
+ *  o Which PHYs might possibly be attached to the IOC3 in real live,
+ *    which workarounds are required for them?  Do we ever have Lucent's?
+ *  o For the 2.5 branch kill the mii-tool ioctls.
+ */
+
+#define IOC3_NAME	"ioc3-eth"
+#define IOC3_VERSION	"2.6.3-4"
+
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/crc32.h>
+#include <linux/mii.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/dma-mapping.h>
+#include <linux/gfp.h>
+
+#ifdef CONFIG_SERIAL_8250
+#include <linux/serial_core.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
+#endif
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/skbuff.h>
+#include <net/ip.h>
+
+#include <asm/byteorder.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/uaccess.h>
+#include <asm/sn/types.h>
+#include <asm/sn/ioc3.h>
+#include <asm/pci/bridge.h>
+
+/*
+ * 64 RX buffers.  This is tunable in the range of 16 <= x < 512.  The
+ * value must be a power of two.
+ */
+#define RX_BUFFS 64
+
+#define ETCSR_FD	((17<<ETCSR_IPGR2_SHIFT) | (11<<ETCSR_IPGR1_SHIFT) | 21)
+#define ETCSR_HD	((21<<ETCSR_IPGR2_SHIFT) | (21<<ETCSR_IPGR1_SHIFT) | 21)
+
+/* Private per NIC data of the driver.  */
+struct ioc3_private {
+	struct ioc3 *regs;
+	unsigned long *rxr;		/* pointer to receiver ring */
+	struct ioc3_etxd *txr;
+	struct sk_buff *rx_skbs[512];
+	struct sk_buff *tx_skbs[128];
+	int rx_ci;			/* RX consumer index */
+	int rx_pi;			/* RX producer index */
+	int tx_ci;			/* TX consumer index */
+	int tx_pi;			/* TX producer index */
+	int txqlen;
+	u32 emcr, ehar_h, ehar_l;
+	spinlock_t ioc3_lock;
+	struct mii_if_info mii;
+
+	struct pci_dev *pdev;
+
+	/* Members used by autonegotiation  */
+	struct timer_list ioc3_timer;
+};
+
+static inline struct net_device *priv_netdev(struct ioc3_private *dev)
+{
+	return (void *)dev - ((sizeof(struct net_device) + 31) & ~31);
+}
+
+static int ioc3_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
+static void ioc3_set_multicast_list(struct net_device *dev);
+static int ioc3_start_xmit(struct sk_buff *skb, struct net_device *dev);
+static void ioc3_timeout(struct net_device *dev);
+static inline unsigned int ioc3_hash(const unsigned char *addr);
+static inline void ioc3_stop(struct ioc3_private *ip);
+static void ioc3_init(struct net_device *dev);
+
+static const char ioc3_str[] = "IOC3 Ethernet";
+static const struct ethtool_ops ioc3_ethtool_ops;
+
+/* We use this to acquire receive skb's that we can DMA directly into. */
+
+#define IOC3_CACHELINE	128UL
+
+static inline unsigned long aligned_rx_skb_addr(unsigned long addr)
+{
+	return (~addr + 1) & (IOC3_CACHELINE - 1UL);
+}
+
+static inline struct sk_buff * ioc3_alloc_skb(unsigned long length,
+	unsigned int gfp_mask)
+{
+	struct sk_buff *skb;
+
+	skb = alloc_skb(length + IOC3_CACHELINE - 1, gfp_mask);
+	if (likely(skb)) {
+		int offset = aligned_rx_skb_addr((unsigned long) skb->data);
+		if (offset)
+			skb_reserve(skb, offset);
+	}
+
+	return skb;
+}
+
+static inline unsigned long ioc3_map(void *ptr, unsigned long vdev)
+{
+#ifdef CONFIG_SGI_IP27
+	vdev <<= 57;   /* Shift to PCI64_ATTR_VIRTUAL */
+
+	return vdev | (0xaUL << PCI64_ATTR_TARG_SHFT) | PCI64_ATTR_PREF |
+	       ((unsigned long)ptr & TO_PHYS_MASK);
+#else
+	return virt_to_bus(ptr);
+#endif
+}
+
+/* BEWARE: The IOC3 documentation documents the size of rx buffers as
+   1644 while it's actually 1664.  This one was nasty to track down ...  */
+#define RX_OFFSET		10
+#define RX_BUF_ALLOC_SIZE	(1664 + RX_OFFSET + IOC3_CACHELINE)
+
+/* DMA barrier to separate cached and uncached accesses.  */
+#define BARRIER()							\
+	__asm__("sync" ::: "memory")
+
+
+#define IOC3_SIZE 0x100000
+
+/*
+ * IOC3 is a big endian device
+ *
+ * Unorthodox but makes the users of these macros more readable - the pointer
+ * to the IOC3's memory mapped registers is expected as struct ioc3 * ioc3
+ * in the environment.
+ */
+#define ioc3_r_mcr()		be32_to_cpu(ioc3->mcr)
+#define ioc3_w_mcr(v)		do { ioc3->mcr = cpu_to_be32(v); } while (0)
+#define ioc3_w_gpcr_s(v)	do { ioc3->gpcr_s = cpu_to_be32(v); } while (0)
+#define ioc3_r_emcr()		be32_to_cpu(ioc3->emcr)
+#define ioc3_w_emcr(v)		do { ioc3->emcr = cpu_to_be32(v); } while (0)
+#define ioc3_r_eisr()		be32_to_cpu(ioc3->eisr)
+#define ioc3_w_eisr(v)		do { ioc3->eisr = cpu_to_be32(v); } while (0)
+#define ioc3_r_eier()		be32_to_cpu(ioc3->eier)
+#define ioc3_w_eier(v)		do { ioc3->eier = cpu_to_be32(v); } while (0)
+#define ioc3_r_ercsr()		be32_to_cpu(ioc3->ercsr)
+#define ioc3_w_ercsr(v)		do { ioc3->ercsr = cpu_to_be32(v); } while (0)
+#define ioc3_r_erbr_h()		be32_to_cpu(ioc3->erbr_h)
+#define ioc3_w_erbr_h(v)	do { ioc3->erbr_h = cpu_to_be32(v); } while (0)
+#define ioc3_r_erbr_l()		be32_to_cpu(ioc3->erbr_l)
+#define ioc3_w_erbr_l(v)	do { ioc3->erbr_l = cpu_to_be32(v); } while (0)
+#define ioc3_r_erbar()		be32_to_cpu(ioc3->erbar)
+#define ioc3_w_erbar(v)		do { ioc3->erbar = cpu_to_be32(v); } while (0)
+#define ioc3_r_ercir()		be32_to_cpu(ioc3->ercir)
+#define ioc3_w_ercir(v)		do { ioc3->ercir = cpu_to_be32(v); } while (0)
+#define ioc3_r_erpir()		be32_to_cpu(ioc3->erpir)
+#define ioc3_w_erpir(v)		do { ioc3->erpir = cpu_to_be32(v); } while (0)
+#define ioc3_r_ertr()		be32_to_cpu(ioc3->ertr)
+#define ioc3_w_ertr(v)		do { ioc3->ertr = cpu_to_be32(v); } while (0)
+#define ioc3_r_etcsr()		be32_to_cpu(ioc3->etcsr)
+#define ioc3_w_etcsr(v)		do { ioc3->etcsr = cpu_to_be32(v); } while (0)
+#define ioc3_r_ersr()		be32_to_cpu(ioc3->ersr)
+#define ioc3_w_ersr(v)		do { ioc3->ersr = cpu_to_be32(v); } while (0)
+#define ioc3_r_etcdc()		be32_to_cpu(ioc3->etcdc)
+#define ioc3_w_etcdc(v)		do { ioc3->etcdc = cpu_to_be32(v); } while (0)
+#define ioc3_r_ebir()		be32_to_cpu(ioc3->ebir)
+#define ioc3_w_ebir(v)		do { ioc3->ebir = cpu_to_be32(v); } while (0)
+#define ioc3_r_etbr_h()		be32_to_cpu(ioc3->etbr_h)
+#define ioc3_w_etbr_h(v)	do { ioc3->etbr_h = cpu_to_be32(v); } while (0)
+#define ioc3_r_etbr_l()		be32_to_cpu(ioc3->etbr_l)
+#define ioc3_w_etbr_l(v)	do { ioc3->etbr_l = cpu_to_be32(v); } while (0)
+#define ioc3_r_etcir()		be32_to_cpu(ioc3->etcir)
+#define ioc3_w_etcir(v)		do { ioc3->etcir = cpu_to_be32(v); } while (0)
+#define ioc3_r_etpir()		be32_to_cpu(ioc3->etpir)
+#define ioc3_w_etpir(v)		do { ioc3->etpir = cpu_to_be32(v); } while (0)
+#define ioc3_r_emar_h()		be32_to_cpu(ioc3->emar_h)
+#define ioc3_w_emar_h(v)	do { ioc3->emar_h = cpu_to_be32(v); } while (0)
+#define ioc3_r_emar_l()		be32_to_cpu(ioc3->emar_l)
+#define ioc3_w_emar_l(v)	do { ioc3->emar_l = cpu_to_be32(v); } while (0)
+#define ioc3_r_ehar_h()		be32_to_cpu(ioc3->ehar_h)
+#define ioc3_w_ehar_h(v)	do { ioc3->ehar_h = cpu_to_be32(v); } while (0)
+#define ioc3_r_ehar_l()		be32_to_cpu(ioc3->ehar_l)
+#define ioc3_w_ehar_l(v)	do { ioc3->ehar_l = cpu_to_be32(v); } while (0)
+#define ioc3_r_micr()		be32_to_cpu(ioc3->micr)
+#define ioc3_w_micr(v)		do { ioc3->micr = cpu_to_be32(v); } while (0)
+#define ioc3_r_midr_r()		be32_to_cpu(ioc3->midr_r)
+#define ioc3_w_midr_r(v)	do { ioc3->midr_r = cpu_to_be32(v); } while (0)
+#define ioc3_r_midr_w()		be32_to_cpu(ioc3->midr_w)
+#define ioc3_w_midr_w(v)	do { ioc3->midr_w = cpu_to_be32(v); } while (0)
+
+static inline u32 mcr_pack(u32 pulse, u32 sample)
+{
+	return (pulse << 10) | (sample << 2);
+}
+
+static int nic_wait(struct ioc3 *ioc3)
+{
+	u32 mcr;
+
+        do {
+                mcr = ioc3_r_mcr();
+        } while (!(mcr & 2));
+
+        return mcr & 1;
+}
+
+static int nic_reset(struct ioc3 *ioc3)
+{
+        int presence;
+
+	ioc3_w_mcr(mcr_pack(500, 65));
+	presence = nic_wait(ioc3);
+
+	ioc3_w_mcr(mcr_pack(0, 500));
+	nic_wait(ioc3);
+
+        return presence;
+}
+
+static inline int nic_read_bit(struct ioc3 *ioc3)
+{
+	int result;
+
+	ioc3_w_mcr(mcr_pack(6, 13));
+	result = nic_wait(ioc3);
+	ioc3_w_mcr(mcr_pack(0, 100));
+	nic_wait(ioc3);
+
+	return result;
+}
+
+static inline void nic_write_bit(struct ioc3 *ioc3, int bit)
+{
+	if (bit)
+		ioc3_w_mcr(mcr_pack(6, 110));
+	else
+		ioc3_w_mcr(mcr_pack(80, 30));
+
+	nic_wait(ioc3);
+}
+
+/*
+ * Read a byte from an iButton device
+ */
+static u32 nic_read_byte(struct ioc3 *ioc3)
+{
+	u32 result = 0;
+	int i;
+
+	for (i = 0; i < 8; i++)
+		result = (result >> 1) | (nic_read_bit(ioc3) << 7);
+
+	return result;
+}
+
+/*
+ * Write a byte to an iButton device
+ */
+static void nic_write_byte(struct ioc3 *ioc3, int byte)
+{
+	int i, bit;
+
+	for (i = 8; i; i--) {
+		bit = byte & 1;
+		byte >>= 1;
+
+		nic_write_bit(ioc3, bit);
+	}
+}
+
+static u64 nic_find(struct ioc3 *ioc3, int *last)
+{
+	int a, b, index, disc;
+	u64 address = 0;
+
+	nic_reset(ioc3);
+	/* Search ROM.  */
+	nic_write_byte(ioc3, 0xf0);
+
+	/* Algorithm from ``Book of iButton Standards''.  */
+	for (index = 0, disc = 0; index < 64; index++) {
+		a = nic_read_bit(ioc3);
+		b = nic_read_bit(ioc3);
+
+		if (a && b) {
+			printk("NIC search failed (not fatal).\n");
+			*last = 0;
+			return 0;
+		}
+
+		if (!a && !b) {
+			if (index == *last) {
+				address |= 1UL << index;
+			} else if (index > *last) {
+				address &= ~(1UL << index);
+				disc = index;
+			} else if ((address & (1UL << index)) == 0)
+				disc = index;
+			nic_write_bit(ioc3, address & (1UL << index));
+			continue;
+		} else {
+			if (a)
+				address |= 1UL << index;
+			else
+				address &= ~(1UL << index);
+			nic_write_bit(ioc3, a);
+			continue;
+		}
+	}
+
+	*last = disc;
+
+	return address;
+}
+
+static int nic_init(struct ioc3 *ioc3)
+{
+	const char *unknown = "unknown";
+	const char *type = unknown;
+	u8 crc;
+	u8 serial[6];
+	int save = 0, i;
+
+	while (1) {
+		u64 reg;
+		reg = nic_find(ioc3, &save);
+
+		switch (reg & 0xff) {
+		case 0x91:
+			type = "DS1981U";
+			break;
+		default:
+			if (save == 0) {
+				/* Let the caller try again.  */
+				return -1;
+			}
+			continue;
+		}
+
+		nic_reset(ioc3);
+
+		/* Match ROM.  */
+		nic_write_byte(ioc3, 0x55);
+		for (i = 0; i < 8; i++)
+			nic_write_byte(ioc3, (reg >> (i << 3)) & 0xff);
+
+		reg >>= 8; /* Shift out type.  */
+		for (i = 0; i < 6; i++) {
+			serial[i] = reg & 0xff;
+			reg >>= 8;
+		}
+		crc = reg & 0xff;
+		break;
+	}
+
+	printk("Found %s NIC", type);
+	if (type != unknown)
+		printk (" registration number %pM, CRC %02x", serial, crc);
+	printk(".\n");
+
+	return 0;
+}
+
+/*
+ * Read the NIC (Number-In-a-Can) device used to store the MAC address on
+ * SN0 / SN00 nodeboards and PCI cards.
+ */
+static void ioc3_get_eaddr_nic(struct ioc3_private *ip)
+{
+	struct ioc3 *ioc3 = ip->regs;
+	u8 nic[14];
+	int tries = 2; /* There may be some problem with the battery?  */
+	int i;
+
+	ioc3_w_gpcr_s(1 << 21);
+
+	while (tries--) {
+		if (!nic_init(ioc3))
+			break;
+		udelay(500);
+	}
+
+	if (tries < 0) {
+		printk("Failed to read MAC address\n");
+		return;
+	}
+
+	/* Read Memory.  */
+	nic_write_byte(ioc3, 0xf0);
+	nic_write_byte(ioc3, 0x00);
+	nic_write_byte(ioc3, 0x00);
+
+	for (i = 13; i >= 0; i--)
+		nic[i] = nic_read_byte(ioc3);
+
+	for (i = 2; i < 8; i++)
+		priv_netdev(ip)->dev_addr[i - 2] = nic[i];
+}
+
+/*
+ * Ok, this is hosed by design.  It's necessary to know what machine the
+ * NIC is in in order to know how to read the NIC address.  We also have
+ * to know if it's a PCI card or a NIC in on the node board ...
+ */
+static void ioc3_get_eaddr(struct ioc3_private *ip)
+{
+	ioc3_get_eaddr_nic(ip);
+
+	printk("Ethernet address is %pM.\n", priv_netdev(ip)->dev_addr);
+}
+
+static void __ioc3_set_mac_address(struct net_device *dev)
+{
+	struct ioc3_private *ip = netdev_priv(dev);
+	struct ioc3 *ioc3 = ip->regs;
+
+	ioc3_w_emar_h((dev->dev_addr[5] <<  8) | dev->dev_addr[4]);
+	ioc3_w_emar_l((dev->dev_addr[3] << 24) | (dev->dev_addr[2] << 16) |
+	              (dev->dev_addr[1] <<  8) | dev->dev_addr[0]);
+}
+
+static int ioc3_set_mac_address(struct net_device *dev, void *addr)
+{
+	struct ioc3_private *ip = netdev_priv(dev);
+	struct sockaddr *sa = addr;
+
+	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
+
+	spin_lock_irq(&ip->ioc3_lock);
+	__ioc3_set_mac_address(dev);
+	spin_unlock_irq(&ip->ioc3_lock);
+
+	return 0;
+}
+
+/*
+ * Caller must hold the ioc3_lock ever for MII readers.  This is also
+ * used to protect the transmitter side but it's low contention.
+ */
+static int ioc3_mdio_read(struct net_device *dev, int phy, int reg)
+{
+	struct ioc3_private *ip = netdev_priv(dev);
+	struct ioc3 *ioc3 = ip->regs;
+
+	while (ioc3_r_micr() & MICR_BUSY);
+	ioc3_w_micr((phy << MICR_PHYADDR_SHIFT) | reg | MICR_READTRIG);
+	while (ioc3_r_micr() & MICR_BUSY);
+
+	return ioc3_r_midr_r() & MIDR_DATA_MASK;
+}
+
+static void ioc3_mdio_write(struct net_device *dev, int phy, int reg, int data)
+{
+	struct ioc3_private *ip = netdev_priv(dev);
+	struct ioc3 *ioc3 = ip->regs;
+
+	while (ioc3_r_micr() & MICR_BUSY);
+	ioc3_w_midr_w(data);
+	ioc3_w_micr((phy << MICR_PHYADDR_SHIFT) | reg);
+	while (ioc3_r_micr() & MICR_BUSY);
+}
+
+static int ioc3_mii_init(struct ioc3_private *ip);
+
+static struct net_device_stats *ioc3_get_stats(struct net_device *dev)
+{
+	struct ioc3_private *ip = netdev_priv(dev);
+	struct ioc3 *ioc3 = ip->regs;
+
+	dev->stats.collisions += (ioc3_r_etcdc() & ETCDC_COLLCNT_MASK);
+	return &dev->stats;
+}
+
+static void ioc3_tcpudp_checksum(struct sk_buff *skb, uint32_t hwsum, int len)
+{
+	struct ethhdr *eh = eth_hdr(skb);
+	uint32_t csum, ehsum;
+	unsigned int proto;
+	struct iphdr *ih;
+	uint16_t *ew;
+	unsigned char *cp;
+
+	/*
+	 * Did hardware handle the checksum at all?  The cases we can handle
+	 * are:
+	 *
+	 * - TCP and UDP checksums of IPv4 only.
+	 * - IPv6 would be doable but we keep that for later ...
+	 * - Only unfragmented packets.  Did somebody already tell you
+	 *   fragmentation is evil?
+	 * - don't care about packet size.  Worst case when processing a
+	 *   malformed packet we'll try to access the packet at ip header +
+	 *   64 bytes which is still inside the skb.  Even in the unlikely
+	 *   case where the checksum is right the higher layers will still
+	 *   drop the packet as appropriate.
+	 */
+	if (eh->h_proto != htons(ETH_P_IP))
+		return;
+
+	ih = (struct iphdr *) ((char *)eh + ETH_HLEN);
+	if (ip_is_fragment(ih))
+		return;
+
+	proto = ih->protocol;
+	if (proto != IPPROTO_TCP && proto != IPPROTO_UDP)
+		return;
+
+	/* Same as tx - compute csum of pseudo header  */
+	csum = hwsum +
+	       (ih->tot_len - (ih->ihl << 2)) +
+	       htons((uint16_t)ih->protocol) +
+	       (ih->saddr >> 16) + (ih->saddr & 0xffff) +
+	       (ih->daddr >> 16) + (ih->daddr & 0xffff);
+
+	/* Sum up ethernet dest addr, src addr and protocol  */
+	ew = (uint16_t *) eh;
+	ehsum = ew[0] + ew[1] + ew[2] + ew[3] + ew[4] + ew[5] + ew[6];
+
+	ehsum = (ehsum & 0xffff) + (ehsum >> 16);
+	ehsum = (ehsum & 0xffff) + (ehsum >> 16);
+
+	csum += 0xffff ^ ehsum;
+
+	/* In the next step we also subtract the 1's complement
+	   checksum of the trailing ethernet CRC.  */
+	cp = (char *)eh + len;	/* points at trailing CRC */
+	if (len & 1) {
+		csum += 0xffff ^ (uint16_t) ((cp[1] << 8) | cp[0]);
+		csum += 0xffff ^ (uint16_t) ((cp[3] << 8) | cp[2]);
+	} else {
+		csum += 0xffff ^ (uint16_t) ((cp[0] << 8) | cp[1]);
+		csum += 0xffff ^ (uint16_t) ((cp[2] << 8) | cp[3]);
+	}
+
+	csum = (csum & 0xffff) + (csum >> 16);
+	csum = (csum & 0xffff) + (csum >> 16);
+
+	if (csum == 0xffff)
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+}
+
+static inline void ioc3_rx(struct net_device *dev)
+{
+	struct ioc3_private *ip = netdev_priv(dev);
+	struct sk_buff *skb, *new_skb;
+	struct ioc3 *ioc3 = ip->regs;
+	int rx_entry, n_entry, len;
+	struct ioc3_erxbuf *rxb;
+	unsigned long *rxr;
+	u32 w0, err;
+
+	rxr = (unsigned long *) ip->rxr;		/* Ring base */
+	rx_entry = ip->rx_ci;				/* RX consume index */
+	n_entry = ip->rx_pi;
+
+	skb = ip->rx_skbs[rx_entry];
+	rxb = (struct ioc3_erxbuf *) (skb->data - RX_OFFSET);
+	w0 = be32_to_cpu(rxb->w0);
+
+	while (w0 & ERXBUF_V) {
+		err = be32_to_cpu(rxb->err);		/* It's valid ...  */
+		if (err & ERXBUF_GOODPKT) {
+			len = ((w0 >> ERXBUF_BYTECNT_SHIFT) & 0x7ff) - 4;
+			skb_trim(skb, len);
+			skb->protocol = eth_type_trans(skb, dev);
+
+			new_skb = ioc3_alloc_skb(RX_BUF_ALLOC_SIZE, GFP_ATOMIC);
+			if (!new_skb) {
+				/* Ouch, drop packet and just recycle packet
+				   to keep the ring filled.  */
+				dev->stats.rx_dropped++;
+				new_skb = skb;
+				goto next;
+			}
+
+			if (likely(dev->features & NETIF_F_RXCSUM))
+				ioc3_tcpudp_checksum(skb,
+					w0 & ERXBUF_IPCKSUM_MASK, len);
+
+			netif_rx(skb);
+
+			ip->rx_skbs[rx_entry] = NULL;	/* Poison  */
+
+			/* Because we reserve afterwards. */
+			skb_put(new_skb, (1664 + RX_OFFSET));
+			rxb = (struct ioc3_erxbuf *) new_skb->data;
+			skb_reserve(new_skb, RX_OFFSET);
+
+			dev->stats.rx_packets++;		/* Statistics */
+			dev->stats.rx_bytes += len;
+		} else {
+			/* The frame is invalid and the skb never
+			   reached the network layer so we can just
+			   recycle it.  */
+			new_skb = skb;
+			dev->stats.rx_errors++;
+		}
+		if (err & ERXBUF_CRCERR)	/* Statistics */
+			dev->stats.rx_crc_errors++;
+		if (err & ERXBUF_FRAMERR)
+			dev->stats.rx_frame_errors++;
+next:
+		ip->rx_skbs[n_entry] = new_skb;
+		rxr[n_entry] = cpu_to_be64(ioc3_map(rxb, 1));
+		rxb->w0 = 0;				/* Clear valid flag */
+		n_entry = (n_entry + 1) & 511;		/* Update erpir */
+
+		/* Now go on to the next ring entry.  */
+		rx_entry = (rx_entry + 1) & 511;
+		skb = ip->rx_skbs[rx_entry];
+		rxb = (struct ioc3_erxbuf *) (skb->data - RX_OFFSET);
+		w0 = be32_to_cpu(rxb->w0);
+	}
+	ioc3_w_erpir((n_entry << 3) | ERPIR_ARM);
+	ip->rx_pi = n_entry;
+	ip->rx_ci = rx_entry;
+}
+
+static inline void ioc3_tx(struct net_device *dev)
+{
+	struct ioc3_private *ip = netdev_priv(dev);
+	unsigned long packets, bytes;
+	struct ioc3 *ioc3 = ip->regs;
+	int tx_entry, o_entry;
+	struct sk_buff *skb;
+	u32 etcir;
+
+	spin_lock(&ip->ioc3_lock);
+	etcir = ioc3_r_etcir();
+
+	tx_entry = (etcir >> 7) & 127;
+	o_entry = ip->tx_ci;
+	packets = 0;
+	bytes = 0;
+
+	while (o_entry != tx_entry) {
+		packets++;
+		skb = ip->tx_skbs[o_entry];
+		bytes += skb->len;
+		dev_kfree_skb_irq(skb);
+		ip->tx_skbs[o_entry] = NULL;
+
+		o_entry = (o_entry + 1) & 127;		/* Next */
+
+		etcir = ioc3_r_etcir();			/* More pkts sent?  */
+		tx_entry = (etcir >> 7) & 127;
+	}
+
+	dev->stats.tx_packets += packets;
+	dev->stats.tx_bytes += bytes;
+	ip->txqlen -= packets;
+
+	if (ip->txqlen < 128)
+		netif_wake_queue(dev);
+
+	ip->tx_ci = o_entry;
+	spin_unlock(&ip->ioc3_lock);
+}
+
+/*
+ * Deal with fatal IOC3 errors.  This condition might be caused by a hard or
+ * software problems, so we should try to recover
+ * more gracefully if this ever happens.  In theory we might be flooded
+ * with such error interrupts if something really goes wrong, so we might
+ * also consider to take the interface down.
+ */
+static void ioc3_error(struct net_device *dev, u32 eisr)
+{
+	struct ioc3_private *ip = netdev_priv(dev);
+	unsigned char *iface = dev->name;
+
+	spin_lock(&ip->ioc3_lock);
+
+	if (eisr & EISR_RXOFLO)
+		printk(KERN_ERR "%s: RX overflow.\n", iface);
+	if (eisr & EISR_RXBUFOFLO)
+		printk(KERN_ERR "%s: RX buffer overflow.\n", iface);
+	if (eisr & EISR_RXMEMERR)
+		printk(KERN_ERR "%s: RX PCI error.\n", iface);
+	if (eisr & EISR_RXPARERR)
+		printk(KERN_ERR "%s: RX SSRAM parity error.\n", iface);
+	if (eisr & EISR_TXBUFUFLO)
+		printk(KERN_ERR "%s: TX buffer underflow.\n", iface);
+	if (eisr & EISR_TXMEMERR)
+		printk(KERN_ERR "%s: TX PCI error.\n", iface);
+
+	ioc3_stop(ip);
+	ioc3_init(dev);
+	ioc3_mii_init(ip);
+
+	netif_wake_queue(dev);
+
+	spin_unlock(&ip->ioc3_lock);
+}
+
+/* The interrupt handler does all of the Rx thread work and cleans up
+   after the Tx thread.  */
+static irqreturn_t ioc3_interrupt(int irq, void *_dev)
+{
+	struct net_device *dev = (struct net_device *)_dev;
+	struct ioc3_private *ip = netdev_priv(dev);
+	struct ioc3 *ioc3 = ip->regs;
+	const u32 enabled = EISR_RXTIMERINT | EISR_RXOFLO | EISR_RXBUFOFLO |
+	                    EISR_RXMEMERR | EISR_RXPARERR | EISR_TXBUFUFLO |
+	                    EISR_TXEXPLICIT | EISR_TXMEMERR;
+	u32 eisr;
+
+	eisr = ioc3_r_eisr() & enabled;
+
+	ioc3_w_eisr(eisr);
+	(void) ioc3_r_eisr();				/* Flush */
+
+	if (eisr & (EISR_RXOFLO | EISR_RXBUFOFLO | EISR_RXMEMERR |
+	            EISR_RXPARERR | EISR_TXBUFUFLO | EISR_TXMEMERR))
+		ioc3_error(dev, eisr);
+	if (eisr & EISR_RXTIMERINT)
+		ioc3_rx(dev);
+	if (eisr & EISR_TXEXPLICIT)
+		ioc3_tx(dev);
+
+	return IRQ_HANDLED;
+}
+
+static inline void ioc3_setup_duplex(struct ioc3_private *ip)
+{
+	struct ioc3 *ioc3 = ip->regs;
+
+	if (ip->mii.full_duplex) {
+		ioc3_w_etcsr(ETCSR_FD);
+		ip->emcr |= EMCR_DUPLEX;
+	} else {
+		ioc3_w_etcsr(ETCSR_HD);
+		ip->emcr &= ~EMCR_DUPLEX;
+	}
+	ioc3_w_emcr(ip->emcr);
+}
+
+static void ioc3_timer(unsigned long data)
+{
+	struct ioc3_private *ip = (struct ioc3_private *) data;
+
+	/* Print the link status if it has changed */
+	mii_check_media(&ip->mii, 1, 0);
+	ioc3_setup_duplex(ip);
+
+	ip->ioc3_timer.expires = jiffies + ((12 * HZ)/10); /* 1.2s */
+	add_timer(&ip->ioc3_timer);
+}
+
+/*
+ * Try to find a PHY.  There is no apparent relation between the MII addresses
+ * in the SGI documentation and what we find in reality, so we simply probe
+ * for the PHY.  It seems IOC3 PHYs usually live on address 31.  One of my
+ * onboard IOC3s has the special oddity that probing doesn't seem to find it
+ * yet the interface seems to work fine, so if probing fails we for now will
+ * simply default to PHY 31 instead of bailing out.
+ */
+static int ioc3_mii_init(struct ioc3_private *ip)
+{
+	struct net_device *dev = priv_netdev(ip);
+	int i, found = 0, res = 0;
+	int ioc3_phy_workaround = 1;
+	u16 word;
+
+	for (i = 0; i < 32; i++) {
+		word = ioc3_mdio_read(dev, i, MII_PHYSID1);
+
+		if (word != 0xffff && word != 0x0000) {
+			found = 1;
+			break;			/* Found a PHY		*/
+		}
+	}
+
+	if (!found) {
+		if (ioc3_phy_workaround)
+			i = 31;
+		else {
+			ip->mii.phy_id = -1;
+			res = -ENODEV;
+			goto out;
+		}
+	}
+
+	ip->mii.phy_id = i;
+
+out:
+	return res;
+}
+
+static void ioc3_mii_start(struct ioc3_private *ip)
+{
+	ip->ioc3_timer.expires = jiffies + (12 * HZ)/10;  /* 1.2 sec. */
+	ip->ioc3_timer.data = (unsigned long) ip;
+	ip->ioc3_timer.function = ioc3_timer;
+	add_timer(&ip->ioc3_timer);
+}
+
+static inline void ioc3_clean_rx_ring(struct ioc3_private *ip)
+{
+	struct sk_buff *skb;
+	int i;
+
+	for (i = ip->rx_ci; i & 15; i++) {
+		ip->rx_skbs[ip->rx_pi] = ip->rx_skbs[ip->rx_ci];
+		ip->rxr[ip->rx_pi++] = ip->rxr[ip->rx_ci++];
+	}
+	ip->rx_pi &= 511;
+	ip->rx_ci &= 511;
+
+	for (i = ip->rx_ci; i != ip->rx_pi; i = (i+1) & 511) {
+		struct ioc3_erxbuf *rxb;
+		skb = ip->rx_skbs[i];
+		rxb = (struct ioc3_erxbuf *) (skb->data - RX_OFFSET);
+		rxb->w0 = 0;
+	}
+}
+
+static inline void ioc3_clean_tx_ring(struct ioc3_private *ip)
+{
+	struct sk_buff *skb;
+	int i;
+
+	for (i=0; i < 128; i++) {
+		skb = ip->tx_skbs[i];
+		if (skb) {
+			ip->tx_skbs[i] = NULL;
+			dev_kfree_skb_any(skb);
+		}
+		ip->txr[i].cmd = 0;
+	}
+	ip->tx_pi = 0;
+	ip->tx_ci = 0;
+}
+
+static void ioc3_free_rings(struct ioc3_private *ip)
+{
+	struct sk_buff *skb;
+	int rx_entry, n_entry;
+
+	if (ip->txr) {
+		ioc3_clean_tx_ring(ip);
+		free_pages((unsigned long)ip->txr, 2);
+		ip->txr = NULL;
+	}
+
+	if (ip->rxr) {
+		n_entry = ip->rx_ci;
+		rx_entry = ip->rx_pi;
+
+		while (n_entry != rx_entry) {
+			skb = ip->rx_skbs[n_entry];
+			if (skb)
+				dev_kfree_skb_any(skb);
+
+			n_entry = (n_entry + 1) & 511;
+		}
+		free_page((unsigned long)ip->rxr);
+		ip->rxr = NULL;
+	}
+}
+
+static void ioc3_alloc_rings(struct net_device *dev)
+{
+	struct ioc3_private *ip = netdev_priv(dev);
+	struct ioc3_erxbuf *rxb;
+	unsigned long *rxr;
+	int i;
+
+	if (ip->rxr == NULL) {
+		/* Allocate and initialize rx ring.  4kb = 512 entries  */
+		ip->rxr = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
+		rxr = (unsigned long *) ip->rxr;
+		if (!rxr)
+			printk("ioc3_alloc_rings(): get_zeroed_page() failed!\n");
+
+		/* Now the rx buffers.  The RX ring may be larger but
+		   we only allocate 16 buffers for now.  Need to tune
+		   this for performance and memory later.  */
+		for (i = 0; i < RX_BUFFS; i++) {
+			struct sk_buff *skb;
+
+			skb = ioc3_alloc_skb(RX_BUF_ALLOC_SIZE, GFP_ATOMIC);
+			if (!skb) {
+				show_free_areas(0);
+				continue;
+			}
+
+			ip->rx_skbs[i] = skb;
+
+			/* Because we reserve afterwards. */
+			skb_put(skb, (1664 + RX_OFFSET));
+			rxb = (struct ioc3_erxbuf *) skb->data;
+			rxr[i] = cpu_to_be64(ioc3_map(rxb, 1));
+			skb_reserve(skb, RX_OFFSET);
+		}
+		ip->rx_ci = 0;
+		ip->rx_pi = RX_BUFFS;
+	}
+
+	if (ip->txr == NULL) {
+		/* Allocate and initialize tx rings.  16kb = 128 bufs.  */
+		ip->txr = (struct ioc3_etxd *)__get_free_pages(GFP_KERNEL, 2);
+		if (!ip->txr)
+			printk("ioc3_alloc_rings(): __get_free_pages() failed!\n");
+		ip->tx_pi = 0;
+		ip->tx_ci = 0;
+	}
+}
+
+static void ioc3_init_rings(struct net_device *dev)
+{
+	struct ioc3_private *ip = netdev_priv(dev);
+	struct ioc3 *ioc3 = ip->regs;
+	unsigned long ring;
+
+	ioc3_free_rings(ip);
+	ioc3_alloc_rings(dev);
+
+	ioc3_clean_rx_ring(ip);
+	ioc3_clean_tx_ring(ip);
+
+	/* Now the rx ring base, consume & produce registers.  */
+	ring = ioc3_map(ip->rxr, 0);
+	ioc3_w_erbr_h(ring >> 32);
+	ioc3_w_erbr_l(ring & 0xffffffff);
+	ioc3_w_ercir(ip->rx_ci << 3);
+	ioc3_w_erpir((ip->rx_pi << 3) | ERPIR_ARM);
+
+	ring = ioc3_map(ip->txr, 0);
+
+	ip->txqlen = 0;					/* nothing queued  */
+
+	/* Now the tx ring base, consume & produce registers.  */
+	ioc3_w_etbr_h(ring >> 32);
+	ioc3_w_etbr_l(ring & 0xffffffff);
+	ioc3_w_etpir(ip->tx_pi << 7);
+	ioc3_w_etcir(ip->tx_ci << 7);
+	(void) ioc3_r_etcir();				/* Flush */
+}
+
+static inline void ioc3_ssram_disc(struct ioc3_private *ip)
+{
+	struct ioc3 *ioc3 = ip->regs;
+	volatile u32 *ssram0 = &ioc3->ssram[0x0000];
+	volatile u32 *ssram1 = &ioc3->ssram[0x4000];
+	unsigned int pattern = 0x5555;
+
+	/* Assume the larger size SSRAM and enable parity checking */
+	ioc3_w_emcr(ioc3_r_emcr() | (EMCR_BUFSIZ | EMCR_RAMPAR));
+
+	*ssram0 = pattern;
+	*ssram1 = ~pattern & IOC3_SSRAM_DM;
+
+	if ((*ssram0 & IOC3_SSRAM_DM) != pattern ||
+	    (*ssram1 & IOC3_SSRAM_DM) != (~pattern & IOC3_SSRAM_DM)) {
+		/* set ssram size to 64 KB */
+		ip->emcr = EMCR_RAMPAR;
+		ioc3_w_emcr(ioc3_r_emcr() & ~EMCR_BUFSIZ);
+	} else
+		ip->emcr = EMCR_BUFSIZ | EMCR_RAMPAR;
+}
+
+static void ioc3_init(struct net_device *dev)
+{
+	struct ioc3_private *ip = netdev_priv(dev);
+	struct ioc3 *ioc3 = ip->regs;
+
+	del_timer_sync(&ip->ioc3_timer);	/* Kill if running	*/
+
+	ioc3_w_emcr(EMCR_RST);			/* Reset		*/
+	(void) ioc3_r_emcr();			/* Flush WB		*/
+	udelay(4);				/* Give it time ...	*/
+	ioc3_w_emcr(0);
+	(void) ioc3_r_emcr();
+
+	/* Misc registers  */
+#ifdef CONFIG_SGI_IP27
+	ioc3_w_erbar(PCI64_ATTR_BAR >> 32);	/* Barrier on last store */
+#else
+	ioc3_w_erbar(0);			/* Let PCI API get it right */
+#endif
+	(void) ioc3_r_etcdc();			/* Clear on read */
+	ioc3_w_ercsr(15);			/* RX low watermark  */
+	ioc3_w_ertr(0);				/* Interrupt imm