Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / ethernet / sgi / meth.c
diff --git a/kernel/drivers/net/ethernet/sgi/meth.c b/kernel/drivers/net/ethernet/sgi/meth.c
new file mode 100644 (file)
index 0000000..5eac523
--- /dev/null
@@ -0,0 +1,881 @@
+/*
+ * meth.c -- O2 Builtin 10/100 Ethernet driver
+ *
+ * Copyright (C) 2001-2003 Ilya Volynets
+ *
+ *     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.
+ */
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/device.h> /* struct device, et al */
+#include <linux/netdevice.h>   /* struct device, and other headers */
+#include <linux/etherdevice.h> /* eth_type_trans */
+#include <linux/ip.h>          /* struct iphdr */
+#include <linux/tcp.h>         /* struct tcphdr */
+#include <linux/skbuff.h>
+#include <linux/mii.h>         /* MII definitions */
+#include <linux/crc32.h>
+
+#include <asm/ip32/mace.h>
+#include <asm/ip32/ip32_ints.h>
+
+#include <asm/io.h>
+
+#include "meth.h"
+
+#ifndef MFE_DEBUG
+#define MFE_DEBUG 0
+#endif
+
+#if MFE_DEBUG>=1
+#define DPRINTK(str,args...) printk(KERN_DEBUG "meth: %s: " str, __func__ , ## args)
+#define MFE_RX_DEBUG 2
+#else
+#define DPRINTK(str,args...)
+#define MFE_RX_DEBUG 0
+#endif
+
+
+static const char *meth_str="SGI O2 Fast Ethernet";
+
+/* The maximum time waited (in jiffies) before assuming a Tx failed. (400ms) */
+#define TX_TIMEOUT (400*HZ/1000)
+
+static int timeout = TX_TIMEOUT;
+module_param(timeout, int, 0);
+
+/*
+ * Maximum number of multicast addresses to filter (vs. Rx-all-multicast).
+ * MACE Ethernet uses a 64 element hash table based on the Ethernet CRC.
+ */
+#define METH_MCF_LIMIT 32
+
+/*
+ * This structure is private to each device. It is used to pass
+ * packets in and out, so there is place for a packet
+ */
+struct meth_private {
+       /* in-memory copy of MAC Control register */
+       u64 mac_ctrl;
+
+       /* in-memory copy of DMA Control register */
+       unsigned long dma_ctrl;
+       /* address of PHY, used by mdio_* functions, initialized in mdio_probe */
+       unsigned long phy_addr;
+       tx_packet *tx_ring;
+       dma_addr_t tx_ring_dma;
+       struct sk_buff *tx_skbs[TX_RING_ENTRIES];
+       dma_addr_t tx_skb_dmas[TX_RING_ENTRIES];
+       unsigned long tx_read, tx_write, tx_count;
+
+       rx_packet *rx_ring[RX_RING_ENTRIES];
+       dma_addr_t rx_ring_dmas[RX_RING_ENTRIES];
+       struct sk_buff *rx_skbs[RX_RING_ENTRIES];
+       unsigned long rx_write;
+
+       /* Multicast filter. */
+       u64 mcast_filter;
+
+       spinlock_t meth_lock;
+};
+
+static void meth_tx_timeout(struct net_device *dev);
+static irqreturn_t meth_interrupt(int irq, void *dev_id);
+
+/* global, initialized in ip32-setup.c */
+char o2meth_eaddr[8]={0,0,0,0,0,0,0,0};
+
+static inline void load_eaddr(struct net_device *dev)
+{
+       int i;
+       u64 macaddr;
+
+       DPRINTK("Loading MAC Address: %pM\n", dev->dev_addr);
+       macaddr = 0;
+       for (i = 0; i < 6; i++)
+               macaddr |= (u64)dev->dev_addr[i] << ((5 - i) * 8);
+
+       mace->eth.mac_addr = macaddr;
+}
+
+/*
+ * Waits for BUSY status of mdio bus to clear
+ */
+#define WAIT_FOR_PHY(___rval)                                  \
+       while ((___rval = mace->eth.phy_data) & MDIO_BUSY) {    \
+               udelay(25);                                     \
+       }
+/*read phy register, return value read */
+static unsigned long mdio_read(struct meth_private *priv, unsigned long phyreg)
+{
+       unsigned long rval;
+       WAIT_FOR_PHY(rval);
+       mace->eth.phy_regs = (priv->phy_addr << 5) | (phyreg & 0x1f);
+       udelay(25);
+       mace->eth.phy_trans_go = 1;
+       udelay(25);
+       WAIT_FOR_PHY(rval);
+       return rval & MDIO_DATA_MASK;
+}
+
+static int mdio_probe(struct meth_private *priv)
+{
+       int i;
+       unsigned long p2, p3, flags;
+       /* check if phy is detected already */
+       if(priv->phy_addr>=0&&priv->phy_addr<32)
+               return 0;
+       spin_lock_irqsave(&priv->meth_lock, flags);
+       for (i=0;i<32;++i){
+               priv->phy_addr=i;
+               p2=mdio_read(priv,2);
+               p3=mdio_read(priv,3);
+#if MFE_DEBUG>=2
+               switch ((p2<<12)|(p3>>4)){
+               case PHY_QS6612X:
+                       DPRINTK("PHY is QS6612X\n");
+                       break;
+               case PHY_ICS1889:
+                       DPRINTK("PHY is ICS1889\n");
+                       break;
+               case PHY_ICS1890:
+                       DPRINTK("PHY is ICS1890\n");
+                       break;
+               case PHY_DP83840:
+                       DPRINTK("PHY is DP83840\n");
+                       break;
+               }
+#endif
+               if(p2!=0xffff&&p2!=0x0000){
+                       DPRINTK("PHY code: %x\n",(p2<<12)|(p3>>4));
+                       break;
+               }
+       }
+       spin_unlock_irqrestore(&priv->meth_lock, flags);
+       if(priv->phy_addr<32) {
+               return 0;
+       }
+       DPRINTK("Oopsie! PHY is not known!\n");
+       priv->phy_addr=-1;
+       return -ENODEV;
+}
+
+static void meth_check_link(struct net_device *dev)
+{
+       struct meth_private *priv = netdev_priv(dev);
+       unsigned long mii_advertising = mdio_read(priv, 4);
+       unsigned long mii_partner = mdio_read(priv, 5);
+       unsigned long negotiated = mii_advertising & mii_partner;
+       unsigned long duplex, speed;
+
+       if (mii_partner == 0xffff)
+               return;
+
+       speed = (negotiated & 0x0380) ? METH_100MBIT : 0;
+       duplex = ((negotiated & 0x0100) || (negotiated & 0x01C0) == 0x0040) ?
+                METH_PHY_FDX : 0;
+
+       if ((priv->mac_ctrl & METH_PHY_FDX) ^ duplex) {
+               DPRINTK("Setting %s-duplex\n", duplex ? "full" : "half");
+               if (duplex)
+                       priv->mac_ctrl |= METH_PHY_FDX;
+               else
+                       priv->mac_ctrl &= ~METH_PHY_FDX;
+               mace->eth.mac_ctrl = priv->mac_ctrl;
+       }
+
+       if ((priv->mac_ctrl & METH_100MBIT) ^ speed) {
+               DPRINTK("Setting %dMbs mode\n", speed ? 100 : 10);
+               if (duplex)
+                       priv->mac_ctrl |= METH_100MBIT;
+               else
+                       priv->mac_ctrl &= ~METH_100MBIT;
+               mace->eth.mac_ctrl = priv->mac_ctrl;
+       }
+}
+
+
+static int meth_init_tx_ring(struct meth_private *priv)
+{
+       /* Init TX ring */
+       priv->tx_ring = dma_zalloc_coherent(NULL, TX_RING_BUFFER_SIZE,
+                                           &priv->tx_ring_dma, GFP_ATOMIC);
+       if (!priv->tx_ring)
+               return -ENOMEM;
+
+       priv->tx_count = priv->tx_read = priv->tx_write = 0;
+       mace->eth.tx_ring_base = priv->tx_ring_dma;
+       /* Now init skb save area */
+       memset(priv->tx_skbs, 0, sizeof(priv->tx_skbs));
+       memset(priv->tx_skb_dmas, 0, sizeof(priv->tx_skb_dmas));
+       return 0;
+}
+
+static int meth_init_rx_ring(struct meth_private *priv)
+{
+       int i;
+
+       for (i = 0; i < RX_RING_ENTRIES; i++) {
+               priv->rx_skbs[i] = alloc_skb(METH_RX_BUFF_SIZE, 0);
+               /* 8byte status vector + 3quad padding + 2byte padding,
+                * to put data on 64bit aligned boundary */
+               skb_reserve(priv->rx_skbs[i],METH_RX_HEAD);
+               priv->rx_ring[i]=(rx_packet*)(priv->rx_skbs[i]->head);
+               /* I'll need to re-sync it after each RX */
+               priv->rx_ring_dmas[i] =
+                       dma_map_single(NULL, priv->rx_ring[i],
+                                      METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
+               mace->eth.rx_fifo = priv->rx_ring_dmas[i];
+       }
+        priv->rx_write = 0;
+       return 0;
+}
+static void meth_free_tx_ring(struct meth_private *priv)
+{
+       int i;
+
+       /* Remove any pending skb */
+       for (i = 0; i < TX_RING_ENTRIES; i++) {
+               if (priv->tx_skbs[i])
+                       dev_kfree_skb(priv->tx_skbs[i]);
+               priv->tx_skbs[i] = NULL;
+       }
+       dma_free_coherent(NULL, TX_RING_BUFFER_SIZE, priv->tx_ring,
+                         priv->tx_ring_dma);
+}
+
+/* Presumes RX DMA engine is stopped, and RX fifo ring is reset */
+static void meth_free_rx_ring(struct meth_private *priv)
+{
+       int i;
+
+       for (i = 0; i < RX_RING_ENTRIES; i++) {
+               dma_unmap_single(NULL, priv->rx_ring_dmas[i],
+                                METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
+               priv->rx_ring[i] = 0;
+               priv->rx_ring_dmas[i] = 0;
+               kfree_skb(priv->rx_skbs[i]);
+       }
+}
+
+int meth_reset(struct net_device *dev)
+{
+       struct meth_private *priv = netdev_priv(dev);
+
+       /* Reset card */
+       mace->eth.mac_ctrl = SGI_MAC_RESET;
+       udelay(1);
+       mace->eth.mac_ctrl = 0;
+       udelay(25);
+
+       /* Load ethernet address */
+       load_eaddr(dev);
+       /* Should load some "errata", but later */
+
+       /* Check for device */
+       if (mdio_probe(priv) < 0) {
+               DPRINTK("Unable to find PHY\n");
+               return -ENODEV;
+       }
+
+       /* Initial mode: 10 | Half-duplex | Accept normal packets */
+       priv->mac_ctrl = METH_ACCEPT_MCAST | METH_DEFAULT_IPG;
+       if (dev->flags & IFF_PROMISC)
+               priv->mac_ctrl |= METH_PROMISC;
+       mace->eth.mac_ctrl = priv->mac_ctrl;
+
+       /* Autonegotiate speed and duplex mode */
+       meth_check_link(dev);
+
+       /* Now set dma control, but don't enable DMA, yet */
+       priv->dma_ctrl = (4 << METH_RX_OFFSET_SHIFT) |
+                        (RX_RING_ENTRIES << METH_RX_DEPTH_SHIFT);
+       mace->eth.dma_ctrl = priv->dma_ctrl;
+
+       return 0;
+}
+
+/*============End Helper Routines=====================*/
+
+/*
+ * Open and close
+ */
+static int meth_open(struct net_device *dev)
+{
+       struct meth_private *priv = netdev_priv(dev);
+       int ret;
+
+       priv->phy_addr = -1;    /* No PHY is known yet... */
+
+       /* Initialize the hardware */
+       ret = meth_reset(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Allocate the ring buffers */
+       ret = meth_init_tx_ring(priv);
+       if (ret < 0)
+               return ret;
+       ret = meth_init_rx_ring(priv);
+       if (ret < 0)
+               goto out_free_tx_ring;
+
+       ret = request_irq(dev->irq, meth_interrupt, 0, meth_str, dev);
+       if (ret) {
+               printk(KERN_ERR "%s: Can't get irq %d\n", dev->name, dev->irq);
+               goto out_free_rx_ring;
+       }
+
+       /* Start DMA */
+       priv->dma_ctrl |= METH_DMA_TX_EN | /*METH_DMA_TX_INT_EN |*/
+                         METH_DMA_RX_EN | METH_DMA_RX_INT_EN;
+       mace->eth.dma_ctrl = priv->dma_ctrl;
+
+       DPRINTK("About to start queue\n");
+       netif_start_queue(dev);
+
+       return 0;
+
+out_free_rx_ring:
+       meth_free_rx_ring(priv);
+out_free_tx_ring:
+       meth_free_tx_ring(priv);
+
+       return ret;
+}
+
+static int meth_release(struct net_device *dev)
+{
+       struct meth_private *priv = netdev_priv(dev);
+
+       DPRINTK("Stopping queue\n");
+       netif_stop_queue(dev); /* can't transmit any more */
+       /* shut down DMA */
+       priv->dma_ctrl &= ~(METH_DMA_TX_EN | METH_DMA_TX_INT_EN |
+                           METH_DMA_RX_EN | METH_DMA_RX_INT_EN);
+       mace->eth.dma_ctrl = priv->dma_ctrl;
+       free_irq(dev->irq, dev);
+       meth_free_tx_ring(priv);
+       meth_free_rx_ring(priv);
+
+       return 0;
+}
+
+/*
+ * Receive a packet: retrieve, encapsulate and pass over to upper levels
+ */
+static void meth_rx(struct net_device* dev, unsigned long int_status)
+{
+       struct sk_buff *skb;
+       unsigned long status, flags;
+       struct meth_private *priv = netdev_priv(dev);
+       unsigned long fifo_rptr = (int_status & METH_INT_RX_RPTR_MASK) >> 8;
+
+       spin_lock_irqsave(&priv->meth_lock, flags);
+       priv->dma_ctrl &= ~METH_DMA_RX_INT_EN;
+       mace->eth.dma_ctrl = priv->dma_ctrl;
+       spin_unlock_irqrestore(&priv->meth_lock, flags);
+
+       if (int_status & METH_INT_RX_UNDERFLOW) {
+               fifo_rptr = (fifo_rptr - 1) & 0x0f;
+       }
+       while (priv->rx_write != fifo_rptr) {
+               dma_unmap_single(NULL, priv->rx_ring_dmas[priv->rx_write],
+                                METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
+               status = priv->rx_ring[priv->rx_write]->status.raw;
+#if MFE_DEBUG
+               if (!(status & METH_RX_ST_VALID)) {
+                       DPRINTK("Not received? status=%016lx\n",status);
+               }
+#endif
+               if ((!(status & METH_RX_STATUS_ERRORS)) && (status & METH_RX_ST_VALID)) {
+                       int len = (status & 0xffff) - 4; /* omit CRC */
+                       /* length sanity check */
+                       if (len < 60 || len > 1518) {
+                               printk(KERN_DEBUG "%s: bogus packet size: %ld, status=%#2Lx.\n",
+                                      dev->name, priv->rx_write,
+                                      priv->rx_ring[priv->rx_write]->status.raw);
+                               dev->stats.rx_errors++;
+                               dev->stats.rx_length_errors++;
+                               skb = priv->rx_skbs[priv->rx_write];
+                       } else {
+                               skb = alloc_skb(METH_RX_BUFF_SIZE, GFP_ATOMIC);
+                               if (!skb) {
+                                       /* Ouch! No memory! Drop packet on the floor */
+                                       DPRINTK("No mem: dropping packet\n");
+                                       dev->stats.rx_dropped++;
+                                       skb = priv->rx_skbs[priv->rx_write];
+                               } else {
+                                       struct sk_buff *skb_c = priv->rx_skbs[priv->rx_write];
+                                       /* 8byte status vector + 3quad padding + 2byte padding,
+                                        * to put data on 64bit aligned boundary */
+                                       skb_reserve(skb, METH_RX_HEAD);
+                                       /* Write metadata, and then pass to the receive level */
+                                       skb_put(skb_c, len);
+                                       priv->rx_skbs[priv->rx_write] = skb;
+                                       skb_c->protocol = eth_type_trans(skb_c, dev);
+                                       dev->stats.rx_packets++;
+                                       dev->stats.rx_bytes += len;
+                                       netif_rx(skb_c);
+                               }
+                       }
+               } else {
+                       dev->stats.rx_errors++;
+                       skb=priv->rx_skbs[priv->rx_write];
+#if MFE_DEBUG>0
+                       printk(KERN_WARNING "meth: RX error: status=0x%016lx\n",status);
+                       if(status&METH_RX_ST_RCV_CODE_VIOLATION)
+                               printk(KERN_WARNING "Receive Code Violation\n");
+                       if(status&METH_RX_ST_CRC_ERR)
+                               printk(KERN_WARNING "CRC error\n");
+                       if(status&METH_RX_ST_INV_PREAMBLE_CTX)
+                               printk(KERN_WARNING "Invalid Preamble Context\n");
+                       if(status&METH_RX_ST_LONG_EVT_SEEN)
+                               printk(KERN_WARNING "Long Event Seen...\n");
+                       if(status&METH_RX_ST_BAD_PACKET)
+                               printk(KERN_WARNING "Bad Packet\n");
+                       if(status&METH_RX_ST_CARRIER_EVT_SEEN)
+                               printk(KERN_WARNING "Carrier Event Seen\n");
+#endif
+               }
+               priv->rx_ring[priv->rx_write] = (rx_packet*)skb->head;
+               priv->rx_ring[priv->rx_write]->status.raw = 0;
+               priv->rx_ring_dmas[priv->rx_write] =
+                       dma_map_single(NULL, priv->rx_ring[priv->rx_write],
+                                      METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
+               mace->eth.rx_fifo = priv->rx_ring_dmas[priv->rx_write];
+               ADVANCE_RX_PTR(priv->rx_write);
+       }
+       spin_lock_irqsave(&priv->meth_lock, flags);
+       /* In case there was underflow, and Rx DMA was disabled */
+       priv->dma_ctrl |= METH_DMA_RX_INT_EN | METH_DMA_RX_EN;
+       mace->eth.dma_ctrl = priv->dma_ctrl;
+       mace->eth.int_stat = METH_INT_RX_THRESHOLD;
+       spin_unlock_irqrestore(&priv->meth_lock, flags);
+}
+
+static int meth_tx_full(struct net_device *dev)
+{
+       struct meth_private *priv = netdev_priv(dev);
+
+       return priv->tx_count >= TX_RING_ENTRIES - 1;
+}
+
+static void meth_tx_cleanup(struct net_device* dev, unsigned long int_status)
+{
+       struct meth_private *priv = netdev_priv(dev);
+       unsigned long status, flags;
+       struct sk_buff *skb;
+       unsigned long rptr = (int_status&TX_INFO_RPTR) >> 16;
+
+       spin_lock_irqsave(&priv->meth_lock, flags);
+
+       /* Stop DMA notification */
+       priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
+       mace->eth.dma_ctrl = priv->dma_ctrl;
+
+       while (priv->tx_read != rptr) {
+               skb = priv->tx_skbs[priv->tx_read];
+               status = priv->tx_ring[priv->tx_read].header.raw;
+#if MFE_DEBUG>=1
+               if (priv->tx_read == priv->tx_write)
+                       DPRINTK("Auchi! tx_read=%d,tx_write=%d,rptr=%d?\n", priv->tx_read, priv->tx_write,rptr);
+#endif
+               if (status & METH_TX_ST_DONE) {
+                       if (status & METH_TX_ST_SUCCESS){
+                               dev->stats.tx_packets++;
+                               dev->stats.tx_bytes += skb->len;
+                       } else {
+                               dev->stats.tx_errors++;
+#if MFE_DEBUG>=1
+                               DPRINTK("TX error: status=%016lx <",status);
+                               if(status & METH_TX_ST_SUCCESS)
+                                       printk(" SUCCESS");
+                               if(status & METH_TX_ST_TOOLONG)
+                                       printk(" TOOLONG");
+                               if(status & METH_TX_ST_UNDERRUN)
+                                       printk(" UNDERRUN");
+                               if(status & METH_TX_ST_EXCCOLL)
+                                       printk(" EXCCOLL");
+                               if(status & METH_TX_ST_DEFER)
+                                       printk(" DEFER");
+                               if(status & METH_TX_ST_LATECOLL)
+                                       printk(" LATECOLL");
+                               printk(" >\n");
+#endif
+                       }
+               } else {
+                       DPRINTK("RPTR points us here, but packet not done?\n");
+                       break;
+               }
+               dev_kfree_skb_irq(skb);
+               priv->tx_skbs[priv->tx_read] = NULL;
+               priv->tx_ring[priv->tx_read].header.raw = 0;
+               priv->tx_read = (priv->tx_read+1)&(TX_RING_ENTRIES-1);
+               priv->tx_count--;
+       }
+
+       /* wake up queue if it was stopped */
+       if (netif_queue_stopped(dev) && !meth_tx_full(dev)) {
+               netif_wake_queue(dev);
+       }
+
+       mace->eth.int_stat = METH_INT_TX_EMPTY | METH_INT_TX_PKT;
+       spin_unlock_irqrestore(&priv->meth_lock, flags);
+}
+
+static void meth_error(struct net_device* dev, unsigned status)
+{
+       struct meth_private *priv = netdev_priv(dev);
+       unsigned long flags;
+
+       printk(KERN_WARNING "meth: error status: 0x%08x\n",status);
+       /* check for errors too... */
+       if (status & (METH_INT_TX_LINK_FAIL))
+               printk(KERN_WARNING "meth: link failure\n");
+       /* Should I do full reset in this case? */
+       if (status & (METH_INT_MEM_ERROR))
+               printk(KERN_WARNING "meth: memory error\n");
+       if (status & (METH_INT_TX_ABORT))
+               printk(KERN_WARNING "meth: aborted\n");
+       if (status & (METH_INT_RX_OVERFLOW))
+               printk(KERN_WARNING "meth: Rx overflow\n");
+       if (status & (METH_INT_RX_UNDERFLOW)) {
+               printk(KERN_WARNING "meth: Rx underflow\n");
+               spin_lock_irqsave(&priv->meth_lock, flags);
+               mace->eth.int_stat = METH_INT_RX_UNDERFLOW;
+               /* more underflow interrupts will be delivered,
+                * effectively throwing us into an infinite loop.
+                *  Thus I stop processing Rx in this case. */
+               priv->dma_ctrl &= ~METH_DMA_RX_EN;
+               mace->eth.dma_ctrl = priv->dma_ctrl;
+               DPRINTK("Disabled meth Rx DMA temporarily\n");
+               spin_unlock_irqrestore(&priv->meth_lock, flags);
+       }
+       mace->eth.int_stat = METH_INT_ERROR;
+}
+
+/*
+ * The typical interrupt entry point
+ */
+static irqreturn_t meth_interrupt(int irq, void *dev_id)
+{
+       struct net_device *dev = (struct net_device *)dev_id;
+       struct meth_private *priv = netdev_priv(dev);
+       unsigned long status;
+
+       status = mace->eth.int_stat;
+       while (status & 0xff) {
+               /* First handle errors - if we get Rx underflow,
+                * Rx DMA will be disabled, and Rx handler will reenable
+                * it. I don't think it's possible to get Rx underflow,
+                * without getting Rx interrupt */
+               if (status & METH_INT_ERROR) {
+                       meth_error(dev, status);
+               }
+               if (status & (METH_INT_TX_EMPTY | METH_INT_TX_PKT)) {
+                       /* a transmission is over: free the skb */
+                       meth_tx_cleanup(dev, status);
+               }
+               if (status & METH_INT_RX_THRESHOLD) {
+                       if (!(priv->dma_ctrl & METH_DMA_RX_INT_EN))
+                               break;
+                       /* send it to meth_rx for handling */
+                       meth_rx(dev, status);
+               }
+               status = mace->eth.int_stat;
+       }
+
+       return IRQ_HANDLED;
+}
+
+/*
+ * Transmits packets that fit into TX descriptor (are <=120B)
+ */
+static void meth_tx_short_prepare(struct meth_private *priv,
+                                 struct sk_buff *skb)
+{
+       tx_packet *desc = &priv->tx_ring[priv->tx_write];
+       int len = (skb->len < ETH_ZLEN) ? ETH_ZLEN : skb->len;
+
+       desc->header.raw = METH_TX_CMD_INT_EN | (len-1) | ((128-len) << 16);
+       /* maybe I should set whole thing to 0 first... */
+       skb_copy_from_linear_data(skb, desc->data.dt + (120 - len), skb->len);
+       if (skb->len < len)
+               memset(desc->data.dt + 120 - len + skb->len, 0, len-skb->len);
+}
+#define TX_CATBUF1 BIT(25)
+static void meth_tx_1page_prepare(struct meth_private *priv,
+                                 struct sk_buff *skb)
+{
+       tx_packet *desc = &priv->tx_ring[priv->tx_write];
+       void *buffer_data = (void *)(((unsigned long)skb->data + 7) & ~7);
+       int unaligned_len = (int)((unsigned long)buffer_data - (unsigned long)skb->data);
+       int buffer_len = skb->len - unaligned_len;
+       dma_addr_t catbuf;
+
+       desc->header.raw = METH_TX_CMD_INT_EN | TX_CATBUF1 | (skb->len - 1);
+
+       /* unaligned part */
+       if (unaligned_len) {
+               skb_copy_from_linear_data(skb, desc->data.dt + (120 - unaligned_len),
+                             unaligned_len);
+               desc->header.raw |= (128 - unaligned_len) << 16;
+       }
+
+       /* first page */
+       catbuf = dma_map_single(NULL, buffer_data, buffer_len,
+                               DMA_TO_DEVICE);
+       desc->data.cat_buf[0].form.start_addr = catbuf >> 3;
+       desc->data.cat_buf[0].form.len = buffer_len - 1;
+}
+#define TX_CATBUF2 BIT(26)
+static void meth_tx_2page_prepare(struct meth_private *priv,
+                                 struct sk_buff *skb)
+{
+       tx_packet *desc = &priv->tx_ring[priv->tx_write];
+       void *buffer1_data = (void *)(((unsigned long)skb->data + 7) & ~7);
+       void *buffer2_data = (void *)PAGE_ALIGN((unsigned long)skb->data);
+       int unaligned_len = (int)((unsigned long)buffer1_data - (unsigned long)skb->data);
+       int buffer1_len = (int)((unsigned long)buffer2_data - (unsigned long)buffer1_data);
+       int buffer2_len = skb->len - buffer1_len - unaligned_len;
+       dma_addr_t catbuf1, catbuf2;
+
+       desc->header.raw = METH_TX_CMD_INT_EN | TX_CATBUF1 | TX_CATBUF2| (skb->len - 1);
+       /* unaligned part */
+       if (unaligned_len){
+               skb_copy_from_linear_data(skb, desc->data.dt + (120 - unaligned_len),
+                             unaligned_len);
+               desc->header.raw |= (128 - unaligned_len) << 16;
+       }
+
+       /* first page */
+       catbuf1 = dma_map_single(NULL, buffer1_data, buffer1_len,
+                                DMA_TO_DEVICE);
+       desc->data.cat_buf[0].form.start_addr = catbuf1 >> 3;
+       desc->data.cat_buf[0].form.len = buffer1_len - 1;
+       /* second page */
+       catbuf2 = dma_map_single(NULL, buffer2_data, buffer2_len,
+                                DMA_TO_DEVICE);
+       desc->data.cat_buf[1].form.start_addr = catbuf2 >> 3;
+       desc->data.cat_buf[1].form.len = buffer2_len - 1;
+}
+
+static void meth_add_to_tx_ring(struct meth_private *priv, struct sk_buff *skb)
+{
+       /* Remember the skb, so we can free it at interrupt time */
+       priv->tx_skbs[priv->tx_write] = skb;
+       if (skb->len <= 120) {
+               /* Whole packet fits into descriptor */
+               meth_tx_short_prepare(priv, skb);
+       } else if (PAGE_ALIGN((unsigned long)skb->data) !=
+                  PAGE_ALIGN((unsigned long)skb->data + skb->len - 1)) {
+               /* Packet crosses page boundary */
+               meth_tx_2page_prepare(priv, skb);
+       } else {
+               /* Packet is in one page */
+               meth_tx_1page_prepare(priv, skb);
+       }
+       priv->tx_write = (priv->tx_write + 1) & (TX_RING_ENTRIES - 1);
+       mace->eth.tx_info = priv->tx_write;
+       priv->tx_count++;
+}
+
+/*
+ * Transmit a packet (called by the kernel)
+ */
+static int meth_tx(struct sk_buff *skb, struct net_device *dev)
+{
+       struct meth_private *priv = netdev_priv(dev);
+       unsigned long flags;
+
+       spin_lock_irqsave(&priv->meth_lock, flags);
+       /* Stop DMA notification */
+       priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
+       mace->eth.dma_ctrl = priv->dma_ctrl;
+
+       meth_add_to_tx_ring(priv, skb);
+       dev->trans_start = jiffies; /* save the timestamp */
+
+       /* If TX ring is full, tell the upper layer to stop sending packets */
+       if (meth_tx_full(dev)) {
+               printk(KERN_DEBUG "TX full: stopping\n");
+               netif_stop_queue(dev);
+       }
+
+       /* Restart DMA notification */
+       priv->dma_ctrl |= METH_DMA_TX_INT_EN;
+       mace->eth.dma_ctrl = priv->dma_ctrl;
+
+       spin_unlock_irqrestore(&priv->meth_lock, flags);
+
+       return NETDEV_TX_OK;
+}
+
+/*
+ * Deal with a transmit timeout.
+ */
+static void meth_tx_timeout(struct net_device *dev)
+{
+       struct meth_private *priv = netdev_priv(dev);
+       unsigned long flags;
+
+       printk(KERN_WARNING "%s: transmit timed out\n", dev->name);
+
+       /* Protect against concurrent rx interrupts */
+       spin_lock_irqsave(&priv->meth_lock,flags);
+
+       /* Try to reset the interface. */
+       meth_reset(dev);
+
+       dev->stats.tx_errors++;
+
+       /* Clear all rings */
+       meth_free_tx_ring(priv);
+       meth_free_rx_ring(priv);
+       meth_init_tx_ring(priv);
+       meth_init_rx_ring(priv);
+
+       /* Restart dma */
+       priv->dma_ctrl |= METH_DMA_TX_EN | METH_DMA_RX_EN | METH_DMA_RX_INT_EN;
+       mace->eth.dma_ctrl = priv->dma_ctrl;
+
+       /* Enable interrupt */
+       spin_unlock_irqrestore(&priv->meth_lock, flags);
+
+       dev->trans_start = jiffies; /* prevent tx timeout */
+       netif_wake_queue(dev);
+}
+
+/*
+ * Ioctl commands
+ */
+static int meth_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
+{
+       /* XXX Not yet implemented */
+       switch(cmd) {
+       case SIOCGMIIPHY:
+       case SIOCGMIIREG:
+       case SIOCSMIIREG:
+       default:
+               return -EOPNOTSUPP;
+       }
+}
+
+static void meth_set_rx_mode(struct net_device *dev)
+{
+       struct meth_private *priv = netdev_priv(dev);
+       unsigned long flags;
+
+       netif_stop_queue(dev);
+       spin_lock_irqsave(&priv->meth_lock, flags);
+       priv->mac_ctrl &= ~METH_PROMISC;
+
+       if (dev->flags & IFF_PROMISC) {
+               priv->mac_ctrl |= METH_PROMISC;
+               priv->mcast_filter = 0xffffffffffffffffUL;
+       } else if ((netdev_mc_count(dev) > METH_MCF_LIMIT) ||
+                  (dev->flags & IFF_ALLMULTI)) {
+               priv->mac_ctrl |= METH_ACCEPT_AMCAST;
+               priv->mcast_filter = 0xffffffffffffffffUL;
+       } else {
+               struct netdev_hw_addr *ha;
+               priv->mac_ctrl |= METH_ACCEPT_MCAST;
+
+               netdev_for_each_mc_addr(ha, dev)
+                       set_bit((ether_crc(ETH_ALEN, ha->addr) >> 26),
+                               (volatile unsigned long *)&priv->mcast_filter);
+       }
+
+       /* Write the changes to the chip registers. */
+       mace->eth.mac_ctrl = priv->mac_ctrl;
+       mace->eth.mcast_filter = priv->mcast_filter;
+
+       /* Done! */
+       spin_unlock_irqrestore(&priv->meth_lock, flags);
+       netif_wake_queue(dev);
+}
+
+static const struct net_device_ops meth_netdev_ops = {
+       .ndo_open               = meth_open,
+       .ndo_stop               = meth_release,
+       .ndo_start_xmit         = meth_tx,
+       .ndo_do_ioctl           = meth_ioctl,
+       .ndo_tx_timeout         = meth_tx_timeout,
+       .ndo_change_mtu         = eth_change_mtu,
+       .ndo_validate_addr      = eth_validate_addr,
+       .ndo_set_mac_address    = eth_mac_addr,
+       .ndo_set_rx_mode        = meth_set_rx_mode,
+};
+
+/*
+ * The init function.
+ */
+static int meth_probe(struct platform_device *pdev)
+{
+       struct net_device *dev;
+       struct meth_private *priv;
+       int err;
+
+       dev = alloc_etherdev(sizeof(struct meth_private));
+       if (!dev)
+               return -ENOMEM;
+
+       dev->netdev_ops         = &meth_netdev_ops;
+       dev->watchdog_timeo     = timeout;
+       dev->irq                = MACE_ETHERNET_IRQ;
+       dev->base_addr          = (unsigned long)&mace->eth;
+       memcpy(dev->dev_addr, o2meth_eaddr, ETH_ALEN);
+
+       priv = netdev_priv(dev);
+       spin_lock_init(&priv->meth_lock);
+       SET_NETDEV_DEV(dev, &pdev->dev);
+
+       err = register_netdev(dev);
+       if (err) {
+               free_netdev(dev);
+               return err;
+       }
+
+       printk(KERN_INFO "%s: SGI MACE Ethernet rev. %d\n",
+              dev->name, (unsigned int)(mace->eth.mac_ctrl >> 29));
+       return 0;
+}
+
+static int __exit meth_remove(struct platform_device *pdev)
+{
+       struct net_device *dev = platform_get_drvdata(pdev);
+
+       unregister_netdev(dev);
+       free_netdev(dev);
+
+       return 0;
+}
+
+static struct platform_driver meth_driver = {
+       .probe  = meth_probe,
+       .remove = __exit_p(meth_remove),
+       .driver = {
+               .name   = "meth",
+       }
+};
+
+module_platform_driver(meth_driver);
+
+MODULE_AUTHOR("Ilya Volynets <ilya@theIlya.com>");
+MODULE_DESCRIPTION("SGI O2 Builtin Fast Ethernet driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:meth");