LXR linux-bk/drivers/net/meth.c

   1/*
   2 * meth.c -- O2 Builtin 10/100 Ethernet driver
   3 *
   4 * Copyright (C) 2001 Ilya Volynets
   5 *
   6 *      This program is free software; you can redistribute it and/or
   7 *      modify it under the terms of the GNU General Public License
   8 *      as published by the Free Software Foundation; either version
   9 *      2 of the License, or (at your option) any later version.
  10 */
  11#include <linux/module.h>
  12#include <linux/init.h>
  13
  14#include <linux/sched.h>
  15#include <linux/kernel.h> /* printk() */
  16#include <linux/delay.h>
  17#include <linux/slab.h>
  18#include <linux/errno.h>  /* error codes */
  19#include <linux/types.h>  /* size_t */
  20#include <linux/interrupt.h> /* mark_bh */
  21#include <linux/pci.h>
  22
  23#include <linux/in.h>
  24#include <linux/netdevice.h>   /* struct device, and other headers */
  25#include <linux/etherdevice.h> /* eth_type_trans */
  26#include <linux/ip.h>          /* struct iphdr */
  27#include <linux/tcp.h>         /* struct tcphdr */
  28#include <linux/skbuff.h>
  29#include <linux/mii.h> /*MII definitions */
  30
  31#include <asm/ip32/crime.h>
  32#include <asm/ip32/mace.h>
  33#include <asm/ip32/ip32_ints.h>
  34
  35#include "meth.h"
  36
  37#include <linux/in6.h>
  38#include <asm/checksum.h>
  39
  40#ifndef MFE_DEBUG
  41#define MFE_DEBUG 0
  42#endif
  43
  44#if MFE_DEBUG>=1
  45#define DPRINTK(str,args...) printk (KERN_DEBUG "meth(%ld): %s: " str, jiffies, __FUNCTION__ , ## args)
  46#define MFE_RX_DEBUG 2
  47#else
  48#define DPRINTK(str,args...)
  49#define MFE_RX_DEBUG 0
  50#endif
  51
  52
  53static const char *version="meth.c: Ilya Volynets (ilya@theIlya.com)";
  54static const char *meth_str="SGI O2 Fast Ethernet";
  55MODULE_AUTHOR("Ilya Volynets");
  56MODULE_DESCRIPTION("SGI O2 Builtin Fast Ethernet driver");
  57
  58/* This is a load-time options */
  59/*static int eth = 0;
  60MODULE_PARM(eth, "i");*/
  61
  62#define HAVE_TX_TIMEOUT
  63/* The maximum time waited (in jiffies) before assuming a Tx failed. (400ms) */
  64#define TX_TIMEOUT (400*HZ/1000)
  65
  66#ifdef HAVE_TX_TIMEOUT
  67static int timeout = TX_TIMEOUT;
  68MODULE_PARM(timeout, "i");
  69#endif
  70
  71int meth_eth;
  72
  73/*
  74 * This structure is private to each device. It is used to pass
  75 * packets in and out, so there is place for a packet
  76 */
  77
  78typedef struct meth_private {
  79    struct net_device_stats stats;
  80        volatile struct meth_regs *regs;
  81        u64 mode; /* in-memory copy of MAC control register */
  82        int  phy_addr; /* address of phy, used by mdio_* functions, initialized in mdio_probe*/
  83        tx_packet *tx_ring;
  84        dma_addr_t tx_ring_dma;
  85        int free_space;
  86        struct sk_buff *tx_skbs[TX_RING_ENTRIES];
  87        dma_addr_t      tx_skb_dmas[TX_RING_ENTRIES];
  88        int tx_read,tx_write;
  89        int tx_count;
  90
  91        rx_packet *rx_ring[RX_RING_ENTRIES];
  92        dma_addr_t rx_ring_dmas[RX_RING_ENTRIES];
  93        int rx_write;
  94
  95    spinlock_t meth_lock;
  96} meth_private;
  97
  98extern struct net_device meth_devs[];
  99void meth_tx_timeout (struct net_device *dev);
 100void meth_interrupt(int irq, void *dev_id, struct pt_regs *pregs);
 101        
 102/* global, initialized in ip32-setup.c */
 103char o2meth_eaddr[8]={0,0,0,0,0,0,0,0};
 104
 105static inline void load_eaddr(struct net_device *dev,
 106                              volatile struct meth_regs *regs)
 107{
 108        int i;
 109        DPRINTK("Loading MAC Address: %02x:%02x:%02x:%02x:%02x:%02x\n",
 110                (int)o2meth_eaddr[0]&0xFF,(int)o2meth_eaddr[1]&0xFF,(int)o2meth_eaddr[2]&0xFF,
 111                (int)o2meth_eaddr[3]&0xFF,(int)o2meth_eaddr[4]&0xFF,(int)o2meth_eaddr[5]&0xFF);
 112        //memcpy(dev->dev_addr,o2meth_eaddr+2,6);
 113        for (i=0; i<6; i++)
 114                dev->dev_addr[i]=o2meth_eaddr[i];
 115        regs->mac_addr= //dev->dev_addr[0]|(dev->dev_addr[1]<<8)|
 116                                        //dev->dev_addr[2]<<16|(dev->dev_addr[3]<<24)|
 117                                        //dev->dev_addr[4]<<32|(dev->dev_addr[5]<<40);
 118        (*(u64*)o2meth_eaddr)>>16;
 119        DPRINTK("MAC, finally is %0lx\n",regs->mac_addr);
 120}
 121
 122/*
 123 *Waits for BUSY status of mdio bus to clear
 124 */
 125#define WAIT_FOR_PHY(___regs, ___rval)                  \
 126        while((___rval=___regs->phy_data)&MDIO_BUSY){   \
 127                udelay(25);                                                             \
 128        }
 129/*read phy register, return value read */
 130static int mdio_read(meth_private *priv,int phyreg)
 131{
 132        volatile meth_regs* regs=priv->regs;
 133        volatile u32 rval;
 134        WAIT_FOR_PHY(regs,rval)
 135        regs->phy_registers=(priv->phy_addr<<5)|(phyreg&0x1f);
 136        udelay(25);
 137        regs->phy_trans_go=1;
 138        udelay(25);
 139        WAIT_FOR_PHY(regs,rval)
 140        return rval&MDIO_DATA_MASK;
 141}
 142
 143/*write phy register */
 144static void mdio_write(meth_private* priv,int pfyreg,int val)
 145{
 146        volatile meth_regs* regs=priv->regs;
 147        int rval;
 148///     DPRINTK("Trying to write value %i to reguster %i\n",val, pfyreg);
 149        spin_lock_irq(&priv->meth_lock);
 150        WAIT_FOR_PHY(regs,rval)
 151        regs->phy_registers=(priv->phy_addr<<5)|(pfyreg&0x1f);
 152        regs->phy_data=val;
 153        udelay(25);
 154        WAIT_FOR_PHY(regs,rval)
 155        spin_unlock_irq(&priv->meth_lock);
 156}
 157
 158/* Modify phy register using given mask and value */
 159static void mdio_update(meth_private* priv,int phyreg, int val, int mask)
 160{
 161        int rval;
 162        DPRINTK("RMW value %i to PHY register %i with mask %i\n",val,phyreg,mask);
 163        rval=mdio_read(priv,phyreg);
 164        rval=(rval&~mask)|(val&mask);
 165        mdio_write(priv,phyreg,rval);
 166}
 167
 168/* handle errata data on MDIO bus */
 169//static void mdio_errata(meth_private *priv)
 170//{
 171        /* Hmmm... what the hell is phyerrata? does it come from sys init parameters in IRIX */
 172//}
 173static int mdio_probe(meth_private *priv)
 174{
 175        int i, p2, p3;
 176        DPRINTK("Detecting PHY kind\n");
 177        /* check if phy is detected already */
 178        if(priv->phy_addr>=0&&priv->phy_addr<32)
 179                return 0;
 180        spin_lock_irq(&priv->meth_lock);
 181        for (i=0;i<32;++i){
 182                priv->phy_addr=(char)i;
 183                p2=mdio_read(priv,2);
 184#ifdef MFE_DEBUG
 185                p3=mdio_read(priv,3);
 186                switch ((p2<<12)|(p3>>4)){
 187                        case PHY_QS6612X:
 188                                DPRINTK("PHY is QS6612X\n");
 189                                break;
 190                        case PHY_ICS1889:
 191                                DPRINTK("PHY is ICS1889\n");
 192                                break;
 193                        case PHY_ICS1890:
 194                                DPRINTK("PHY is ICS1890\n");
 195                                break;
 196                        case PHY_DP83840:
 197                                DPRINTK("PHY is DP83840\n");
 198                                break;
 199                }
 200#endif
 201                if(p2!=0xffff&&p2!=0x0000){
 202                        DPRINTK("PHY code: %x\n",(p2<<12)|(p3>>4));
 203                        break;
 204                }
 205        }
 206        spin_unlock_irq(&priv->meth_lock);
 207        if(priv->phy_addr<32) {
 208                return 0;
 209        }
 210        DPRINTK("Oopsie! PHY is not known!\n");
 211        priv->phy_addr=-1;
 212        return -ENODEV;
 213}
 214
 215static void meth_check_link(struct net_device *dev)
 216{
 217        struct meth_private *priv = (struct meth_private *) dev->priv;
 218        int mii_partner = mdio_read(priv, 5);
 219        int mii_advertising = mdio_read(priv, 4);
 220        int negotiated = mii_advertising & mii_partner;
 221        int duplex, speed;
 222
 223        if (mii_partner == 0xffff)
 224                return;
 225
 226        duplex = ((negotiated & 0x0100) || (negotiated & 0x01C0) == 0x0040)?METH_PHY_FDX:0;
 227        speed = (negotiated & 0x0380)?METH_100MBIT:0;
 228
 229        if ((priv->mode & METH_PHY_FDX) ^ duplex)
 230        {
 231                DPRINTK("Setting %s-duplex\n", duplex ? "full" : "half");
 232                if (duplex)
 233                        priv->mode |= METH_PHY_FDX;
 234                else
 235                        priv->mode &= ~METH_PHY_FDX;
 236                priv->regs->mac_ctrl = priv->mode;
 237        }
 238
 239        if ((priv->mode & METH_100MBIT) ^ speed)
 240        {
 241                DPRINTK("Setting %dMbs mode\n", speed ? 100 : 10);
 242                if (duplex)
 243                        priv->mode |= METH_100MBIT;
 244                else
 245                        priv->mode &= ~METH_100MBIT;
 246                priv->regs->mac_ctrl = priv->mode;
 247        }
 248}
 249
 250
 251static int meth_init_tx_ring(meth_private *priv)
 252{
 253        /* Init TX ring */
 254        DPRINTK("Initializing TX ring\n");
 255        priv->tx_ring = (tx_packet *) pci_alloc_consistent(NULL,TX_RING_BUFFER_SIZE,&(priv->tx_ring_dma));
 256        if(!priv->tx_ring)
 257                return -ENOMEM;
 258        memset(priv->tx_ring, 0, TX_RING_BUFFER_SIZE);
 259        priv->tx_count = priv->tx_read = priv->tx_write = 0;
 260        priv->regs->tx_ring_base = priv->tx_ring_dma;
 261        priv->free_space = TX_RING_ENTRIES;
 262        /* Now init skb save area */
 263        memset(priv->tx_skbs,0,sizeof(priv->tx_skbs));
 264        memset(priv->tx_skb_dmas,0,sizeof(priv->tx_skb_dmas));
 265        DPRINTK("Done with TX ring init\n");
 266        return 0;
 267}
 268
 269static int meth_init_rx_ring(meth_private *priv)
 270{
 271        int i;
 272        DPRINTK("Initializing RX ring\n");
 273        for(i=0;i<RX_RING_ENTRIES;i++){
 274                DPRINTK("\t1:\t%i\t",i);
 275                /*if(!(priv->rx_ring[i]=get_free_page(GFP_KERNEL)))
 276                        return -ENOMEM;
 277                DPRINTK("\t2:\t%i\n",i);*/
 278                priv->rx_ring[i]=(rx_packet*)pci_alloc_consistent(NULL,METH_RX_BUFF_SIZE,&(priv->rx_ring_dmas[i]));
 279                /* I'll need to re-sync it after each RX */
 280                DPRINTK("\t%p\n",priv->rx_ring[i]);
 281                priv->regs->rx_fifo=priv->rx_ring_dmas[i];
 282        }
 283        priv->rx_write = 0;
 284        DPRINTK("Done with RX ring\n");
 285        return 0;
 286}
 287static void meth_free_tx_ring(meth_private *priv)
 288{
 289        int i;
 290
 291        /* Remove any pending skb */
 292        for (i = 0; i < TX_RING_ENTRIES; i++) {
 293          if (priv->tx_skbs[i])
 294                dev_kfree_skb(priv->tx_skbs[i]);
 295                priv->tx_skbs[i] = NULL;
 296        }
 297        pci_free_consistent(NULL,
 298                            TX_RING_BUFFER_SIZE,
 299                            priv->tx_ring,
 300                            priv->tx_ring_dma);
 301}
 302static void meth_free_rx_ring(meth_private *priv)
 303{
 304        int i;
 305
 306        for(i=0;i<RX_RING_ENTRIES;i++)
 307                pci_free_consistent(NULL,
 308                                    METH_RX_BUFF_SIZE,
 309                                    priv->rx_ring[i],
 310                                    priv->rx_ring_dmas[i]);
 311}
 312
 313int meth_reset(struct net_device *dev)
 314{
 315        struct meth_private *priv = (struct meth_private *) dev->priv;
 316
 317        /* Reset card */
 318        priv->regs->mac_ctrl = SGI_MAC_RESET;
 319        priv->regs->mac_ctrl = 0;
 320        udelay(25);
 321        DPRINTK("MAC control after reset: %016lx\n", priv->regs->mac_ctrl);
 322
 323        /* Load ethernet address */
 324        load_eaddr(dev, priv->regs);
 325        /* Should load some "errata", but later */
 326        
 327        /* Check for device */
 328        if(mdio_probe(priv) < 0) {
 329                DPRINTK("Unable to find PHY\n");
 330                return -ENODEV;
 331        }
 332
 333        /* Initial mode -- 10|Half-duplex|Accept normal packets */
 334        priv->mode=METH_ACCEPT_MCAST|METH_DEFAULT_IPG;
 335        if(dev->flags | IFF_PROMISC)
 336                priv->mode |= METH_PROMISC;
 337        priv->regs->mac_ctrl = priv->mode;
 338
 339        /* Autonegociate speed and duplex mode */
 340        meth_check_link(dev);
 341
 342        /* Now set dma control, but don't enable DMA, yet */
 343        priv->regs->dma_ctrl= (4 << METH_RX_OFFSET_SHIFT) |
 344                              (RX_RING_ENTRIES << METH_RX_DEPTH_SHIFT);
 345
 346        return(0);
 347}
 348
 349/*============End Helper Routines=====================*/
 350
 351/*
 352 * Open and close
 353 */
 354
 355int meth_open(struct net_device *dev)
 356{
 357        meth_private *priv=dev->priv;
 358        volatile meth_regs *regs=priv->regs;
 359
 360        MOD_INC_USE_COUNT;
 361
 362        /* Start DMA */
 363        regs->dma_ctrl|=
 364                METH_DMA_TX_EN|/*METH_DMA_TX_INT_EN|*/
 365                METH_DMA_RX_EN|METH_DMA_RX_INT_EN;
 366
 367        if(request_irq(dev->irq,meth_interrupt,SA_SHIRQ,meth_str,dev)){
 368                printk(KERN_ERR "%s: Can't get irq %d\n", dev->name, dev->irq);
 369                return -EAGAIN;
 370        }
 371        netif_start_queue(dev);
 372        DPRINTK("Opened... DMA control=0x%08lx\n", regs->dma_ctrl);
 373        return 0;
 374}
 375
 376int meth_release(struct net_device *dev)
 377{
 378    netif_stop_queue(dev); /* can't transmit any more */
 379        /* shut down dma */
 380        ((meth_private*)(dev->priv))->regs->dma_ctrl&=
 381                ~(METH_DMA_TX_EN|METH_DMA_TX_INT_EN|
 382                METH_DMA_RX_EN|METH_DMA_RX_INT_EN);
 383        free_irq(dev->irq, dev);
 384    MOD_DEC_USE_COUNT;
 385    return 0;
 386}
 387
 388/*
 389 * Configuration changes (passed on by ifconfig)
 390 */
 391int meth_config(struct net_device *dev, struct ifmap *map)
 392{
 393    if (dev->flags & IFF_UP) /* can't act on a running interface */
 394        return -EBUSY;
 395
 396    /* Don't allow changing the I/O address */
 397    if (map->base_addr != dev->base_addr) {
 398        printk(KERN_WARNING "meth: Can't change I/O address\n");
 399        return -EOPNOTSUPP;
 400    }
 401
 402    /* Allow changing the IRQ */
 403    if (map->irq != dev->irq) {
 404        printk(KERN_WARNING "meth: Can't change IRQ\n");
 405        return -EOPNOTSUPP;
 406    }
 407        DPRINTK("Configured\n");
 408
 409    /* ignore other fields */
 410    return 0;
 411}
 412
 413/*
 414 * Receive a packet: retrieve, encapsulate and pass over to upper levels
 415 */
 416void meth_rx(struct net_device* dev)
 417{
 418    struct sk_buff *skb;
 419    struct meth_private *priv = (struct meth_private *) dev->priv;
 420        rx_packet *rxb;
 421        DPRINTK("RX...\n");
 422        // TEMP while((rxb=priv->rx_ring[priv->rx_write])->status.raw&0x8000000000000000){
 423        while((rxb=priv->rx_ring[priv->rx_write])->status.raw&0x8000000000000000){
 424                int len=rxb->status.parsed.rx_len - 4; /* omit CRC */
 425                DPRINTK("(%i)\n",priv->rx_write);
 426                /* length sanity check */
 427                if(len < 60 || len > 1518) {
 428                  printk(KERN_DEBUG "%s: bogus packet size: %d, status=%#2x.\n",
 429                         dev->name, priv->rx_write, rxb->status.raw);
 430                  priv->stats.rx_errors++;
 431                  priv->stats.rx_length_errors++;
 432                }
 433                if(!(rxb->status.raw&METH_RX_STATUS_ERRORS)){
 434                        skb=alloc_skb(len+2,GFP_ATOMIC);/* Should be atomic -- we are in interrupt */
 435                        if(!skb){
 436                                /* Ouch! No memory! Drop packet on the floor */
 437                                DPRINTK("!!!>>>Ouch! Not enough Memory for RX buffer!\n");
 438                                priv->stats.rx_dropped++;
 439                        } else {
 440                                skb_reserve(skb, 2); /* align IP on 16B boundary */  
 441                        memcpy(skb_put(skb, len), rxb->buf, len);
 442                            /* Write metadata, and then pass to the receive level */
 443                            skb->dev = dev;
 444                            skb->protocol = eth_type_trans(skb, dev);
 445                                //skb->ip_summed = CHECKSUM_UNNECESSARY; /* don't check it */
 446                           
 447                                DPRINTK("passing packet\n");
 448                                DPRINTK("len = %d rxb->status = %x\n",
 449                                        len, rxb->status.raw);
 450                                netif_rx(skb);
 451                                dev->last_rx = jiffies;
 452                                priv->stats.rx_packets++;
 453                                priv->stats.rx_bytes+=len;
 454                                DPRINTK("There we go... Whew...\n");
 455                        }
 456                }
 457                priv->regs->rx_fifo=priv->rx_ring_dmas[priv->rx_write];
 458                rxb->status.raw=0;              
 459                priv->rx_write=(priv->rx_write+1)&(RX_RING_ENTRIES-1);
 460        }
 461}
 462
 463static int meth_tx_full(struct net_device *dev)
 464{
 465        struct meth_private *priv = (struct meth_private *) dev->priv;
 466
 467        return(priv->tx_count >= TX_RING_ENTRIES-1);
 468}
 469
 470void meth_tx_cleanup(struct net_device* dev, int rptr)
 471{
 472        meth_private *priv=dev->priv;
 473        tx_packet* status;
 474        struct sk_buff *skb;
 475
 476        spin_lock(&priv->meth_lock);
 477
 478        /* Stop DMA */
 479        priv->regs->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
 480
 481        while(priv->tx_read != rptr){
 482                skb = priv->tx_skbs[priv->tx_read];
 483                status = &priv->tx_ring[priv->tx_read];
 484                if(!status->header.res.sent)
 485                        break;
 486                if(status->header.raw & METH_TX_STATUS_DONE) {
 487                        priv->stats.tx_packets++;
 488                        priv->stats.tx_bytes += skb->len;
 489                }
 490                dev_kfree_skb_irq(skb);
 491                priv->tx_skbs[priv->tx_read] = NULL;
 492                status->header.raw = 0;
 493                priv->tx_read = (priv->tx_read+1)&(TX_RING_ENTRIES-1);
 494                priv->tx_count --;
 495        }
 496
 497        /* wake up queue if it was stopped */
 498        if (netif_queue_stopped(dev) && ! meth_tx_full(dev)) {
 499                netif_wake_queue(dev);
 500        }
 501
 502        spin_unlock(priv->meth_lock);
 503}
 504
 505/*
 506 * The typical interrupt entry point
 507 */
 508void meth_interrupt(int irq, void *dev_id, struct pt_regs *pregs)
 509{
 510        struct meth_private *priv;
 511        union {
 512                u32     reg; /*Whole status register */
 513                struct {
 514                        u32                     :       2,
 515                                rx_seq  :       5,
 516                                tx_read :       9,
 517                                
 518                                rx_read :       8,
 519                                int_mask:       8;
 520                } parsed;
 521        } status;
 522        /*
 523         * As usual, check the "device" pointer for shared handlers.
 524         * Then assign "struct device *dev"
 525         */
 526        struct net_device *dev = (struct net_device *)dev_id;
 527        /* ... and check with hw if it's really ours */
 528
 529        if (!dev /*paranoid*/ ) return;
 530
 531        /* Lock the device */
 532        priv = (struct meth_private *) dev->priv;
 533
 534        status.reg = priv->regs->int_flags;
 535    
 536        DPRINTK("Interrupt, status %08x...\n",status.reg);
 537        if (status.parsed.int_mask & METH_INT_RX_THRESHOLD) {
 538                /* send it to meth_rx for handling */
 539                meth_rx(dev);
 540        }
 541
 542        if (status.parsed.int_mask & (METH_INT_TX_EMPTY|METH_INT_TX_PKT)) {
 543                /* a transmission is over: free the skb */
 544                meth_tx_cleanup(dev, status.parsed.tx_read);
 545        }
 546        /* check for errors too... */
 547        if (status.parsed.int_mask & (METH_INT_TX_LINK_FAIL))
 548                printk(KERN_WARNING "meth: link failure\n");
 549        if (status.parsed.int_mask & (METH_INT_MEM_ERROR))
 550                printk(KERN_WARNING "meth: memory error\n");
 551        if (status.parsed.int_mask & (METH_INT_TX_ABORT))
 552                printk(KERN_WARNING "meth: aborted\n");
 553        DPRINTK("Interrupt handling done...\n");
 554        
 555        priv->regs->int_flags=status.reg&0xff; /* clear interrupts */
 556}
 557
 558/*
 559 * Transmits packets that fit into TX descriptor (are <=120B)
 560 */
 561static void meth_tx_short_prepare(meth_private* priv, struct sk_buff* skb)
 562{
 563        tx_packet *desc=&priv->tx_ring[priv->tx_write];
 564        int len = (skb->len<ETH_ZLEN)?ETH_ZLEN:skb->len;
 565
 566        DPRINTK("preparing short packet\n");
 567        /* maybe I should set whole thing to 0 first... */
 568        memcpy(desc->data.dt+(120-len),skb->data,skb->len);
 569        if(skb->len < len)
 570                memset(desc->data.dt+120-len+skb->len,0,len-skb->len);
 571        desc->header.raw=METH_TX_CMD_INT_EN|(len-1)|((128-len)<<16);
 572        DPRINTK("desc=%016lx\n",desc->header.raw);
 573}
 574#define TX_CATBUF1 BIT(25)
 575static void meth_tx_1page_prepare(meth_private* priv, struct sk_buff* skb)
 576{
 577        tx_packet *desc=&priv->tx_ring[priv->tx_write];
 578        void *buffer_data = (void *)(((u64)skb->data + 7ULL) & (~7ULL));
 579        int unaligned_len = (int)((u64)buffer_data - (u64)skb->data);
 580        int buffer_len = skb->len - unaligned_len;
 581        dma_addr_t catbuf;
 582
 583        DPRINTK("preparing 1 page...\n");
 584        DPRINTK("length=%d data=%p\n", skb->len, skb->data);
 585        DPRINTK("unaligned_len=%d\n", unaligned_len);
 586        DPRINTK("buffer_data=%p buffer_len=%d\n",
 587               buffer_data,
 588               buffer_len);
 589
 590        desc->header.raw=METH_TX_CMD_INT_EN|TX_CATBUF1|(skb->len-1);
 591
 592        /* unaligned part */
 593        if(unaligned_len){
 594                memcpy(desc->data.dt+(120-unaligned_len),
 595                       skb->data, unaligned_len);
 596                desc->header.raw |= (128-unaligned_len) << 16;
 597        }
 598
 599        /* first page */
 600        catbuf = pci_map_single(NULL,
 601                                buffer_data,
 602                                buffer_len,
 603                                PCI_DMA_TODEVICE);
 604        DPRINTK("catbuf=%x\n", catbuf);
 605        desc->data.cat_buf[0].form.start_addr = catbuf >> 3;
 606        desc->data.cat_buf[0].form.len = buffer_len-1;
 607        DPRINTK("desc=%016lx\n",desc->header.raw);
 608        DPRINTK("cat_buf[0].raw=%016lx\n",desc->data.cat_buf[0].raw);
 609}
 610#define TX_CATBUF2 BIT(26)
 611static void meth_tx_2page_prepare(meth_private* priv, struct sk_buff* skb)
 612{
 613        tx_packet *desc=&priv->tx_ring[priv->tx_write];
 614        void *buffer1_data = (void *)(((u64)skb->data + 7ULL) & (~7ULL));
 615        void *buffer2_data = (void *)PAGE_ALIGN((u64)skb->data);
 616        int unaligned_len = (int)((u64)buffer1_data - (u64)skb->data);
 617        int buffer1_len = (int)((u64)buffer2_data - (u64)buffer1_data);
 618        int buffer2_len = skb->len - buffer1_len - unaligned_len;
 619        dma_addr_t catbuf1, catbuf2;
 620
 621        DPRINTK("preparing 2 pages... \n");
 622        DPRINTK("length=%d data=%p\n", skb->len, skb->data);
 623        DPRINTK("unaligned_len=%d\n", unaligned_len);
 624        DPRINTK("buffer1_data=%p buffer1_len=%d\n",
 625               buffer1_data,
 626               buffer1_len);
 627        DPRINTK("buffer2_data=%p buffer2_len=%d\n",
 628               buffer2_data,
 629               buffer2_len);
 630
 631        desc->header.raw=METH_TX_CMD_INT_EN|TX_CATBUF1|TX_CATBUF2|(skb->len-1);
 632        /* unaligned part */
 633        if(unaligned_len){
 634                memcpy(desc->data.dt+(120-unaligned_len),
 635                       skb->data, unaligned_len);
 636                desc->header.raw |= (128-unaligned_len) << 16;
 637        }
 638
 639        /* first page */
 640        catbuf1 = pci_map_single(NULL,
 641                                 buffer1_data,
 642                                 buffer1_len,
 643                                 PCI_DMA_TODEVICE);
 644        DPRINTK("catbuf1=%x\n", catbuf1);
 645        desc->data.cat_buf[0].form.start_addr = catbuf1 >> 3;
 646        desc->data.cat_buf[0].form.len = buffer1_len-1;
 647        /* second page */
 648        catbuf2 = pci_map_single(NULL,
 649                                 buffer2_data,
 650                                 buffer2_len,
 651                                 PCI_DMA_TODEVICE);
 652        DPRINTK("catbuf2=%x\n", catbuf2);
 653        desc->data.cat_buf[1].form.start_addr = catbuf2 >> 3;
 654        desc->data.cat_buf[1].form.len = buffer2_len-1;
 655        DPRINTK("desc=%016lx\n",desc->header.raw);
 656        DPRINTK("cat_buf[0].raw=%016lx\n",desc->data.cat_buf[0].raw);
 657        DPRINTK("cat_buf[1].raw=%016lx\n",desc->data.cat_buf[1].raw);
 658}
 659
 660
 661void meth_add_to_tx_ring(meth_private *priv, struct sk_buff* skb)
 662{
 663        DPRINTK("Transmitting data...\n");
 664        if(skb->len <= 120) {
 665                /* Whole packet fits into descriptor */
 666                meth_tx_short_prepare(priv,skb);
 667        } else if(PAGE_ALIGN((u64)skb->data) !=
 668                  PAGE_ALIGN((u64)skb->data+skb->len-1)) {
 669                /* Packet crosses page boundary */
 670                meth_tx_2page_prepare(priv,skb);
 671        } else {
 672                /* Packet is in one page */
 673                meth_tx_1page_prepare(priv,skb);
 674        }
 675
 676        /* Remember the skb, so we can free it at interrupt time */
 677        priv->tx_skbs[priv->tx_write] = skb;
 678        priv->tx_write = (priv->tx_write+1) & (TX_RING_ENTRIES-1);
 679        priv->regs->tx_info.wptr = priv->tx_write;
 680        priv->tx_count ++;
 681        /* Enable DMA transfer */
 682        priv->regs->dma_ctrl |= METH_DMA_TX_INT_EN;
 683}
 684
 685/*
 686 * Transmit a packet (called by the kernel)
 687 */
 688int meth_tx(struct sk_buff *skb, struct net_device *dev)
 689{
 690        struct meth_private *priv = (struct meth_private *) dev->priv;
 691
 692        spin_lock_irq(&priv->meth_lock);
 693
 694        meth_add_to_tx_ring(priv, skb);
 695        dev->trans_start = jiffies; /* save the timestamp */
 696
 697        /* If TX ring is full, tell the upper layer to stop sending packets */
 698        if (meth_tx_full(dev)) {
 699                DPRINTK("TX full: stopping\n");
 700                netif_stop_queue(dev);
 701        }
 702
 703        spin_unlock_irq(&priv->meth_lock);
 704
 705        return 0;
 706}
 707
 708/*
 709 * Deal with a transmit timeout.
 710 */
 711
 712void meth_tx_timeout (struct net_device *dev)
 713{
 714        struct meth_private *priv = (struct meth_private *) dev->priv;
 715        
 716        printk(KERN_WARNING "%s: transmit timed out\n", dev->name);
 717
 718        /* Protect against concurrent rx interrupts */
 719        spin_lock_irq(&priv->meth_lock);
 720
 721        /* Try to reset the adaptor. */
 722        meth_reset(dev);
 723
 724        priv->stats.tx_errors++;
 725
 726        /* Clear all rings */
 727        meth_free_tx_ring(priv);
 728        meth_free_rx_ring(priv);
 729        meth_init_tx_ring(priv);
 730        meth_init_rx_ring(priv);
 731
 732        /* Restart dma */
 733        priv->regs->dma_ctrl|=METH_DMA_TX_EN|METH_DMA_RX_EN|METH_DMA_RX_INT_EN;
 734
 735        /* Enable interrupt */
 736        spin_unlock_irq(&priv->meth_lock);
 737
 738        dev->trans_start = jiffies;
 739        netif_wake_queue(dev);
 740
 741        return;
 742}
 743
 744/*
 745 * Ioctl commands 
 746 */
 747int meth_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 748{
 749 
 750    DPRINTK("ioctl\n");
 751    return 0;
 752}
 753
 754/*
 755 * Return statistics to the caller
 756 */
 757struct net_device_stats *meth_stats(struct net_device *dev)
 758{
 759    struct meth_private *priv = (struct meth_private *) dev->priv;
 760    return &priv->stats;
 761}
 762
 763/*
 764 * The init function (sometimes called probe).
 765 * It is invoked by register_netdev()
 766 */
 767int meth_init(struct net_device *dev)
 768{
 769        meth_private *priv;
 770        int ret;
 771        /* 
 772         * Then, assign other fields in dev, using ether_setup() and some
 773         * hand assignments
 774         */
 775        ether_setup(dev); /* assign some of the fields */
 776
 777        dev->open            = meth_open;
 778        dev->stop            = meth_release;
 779        dev->set_config      = meth_config;
 780        dev->hard_start_xmit = meth_tx;
 781        dev->do_ioctl        = meth_ioctl;
 782        dev->get_stats       = meth_stats;
 783#ifdef HAVE_TX_TIMEOUT
 784        dev->tx_timeout      = meth_tx_timeout;
 785        dev->watchdog_timeo  = timeout;
 786#endif
 787        dev->irq                 = MACE_ETHERNET_IRQ;
 788        SET_MODULE_OWNER(dev);
 789
 790        /*
 791         * Then, allocate the priv field. This encloses the statistics
 792         * and a few private fields.
 793         */
 794        priv = kmalloc(sizeof(struct meth_private), GFP_KERNEL);
 795        if (priv == NULL)
 796                return -ENOMEM;
 797        dev->priv=priv;
 798        memset(priv, 0, sizeof(struct meth_private));
 799        spin_lock_init(&((struct meth_private *) dev->priv)->meth_lock);
 800        /*
 801         * Make the usual checks: check_region(), probe irq, ...  -ENODEV
 802         * should be returned if no device found.  No resource should be
 803         * grabbed: this is done on open(). 
 804         */
 805        priv->regs=(meth_regs*)SGI_MFE;
 806        dev->base_addr=SGI_MFE;
 807        priv->phy_addr = -1; /* No phy is known yet... */
 808
 809        /* Initialize the hardware */
 810        if((ret=meth_reset(dev)) < 0)
 811                return ret;
 812
 813        /* Allocate the ring buffers */
 814        if((ret=meth_init_tx_ring(priv))<0||(ret=meth_init_rx_ring(priv))<0){
 815                meth_free_tx_ring(priv);
 816                meth_free_rx_ring(priv);
 817                return ret;
 818        }
 819
 820        printk("SGI O2 Fast Ethernet rev. %ld\n", priv->regs->mac_ctrl >> 29);
 821
 822    return 0;
 823}
 824
 825/*
 826 * The devices
 827 */
 828
 829struct net_device meth_devs[1] = {
 830    { init: meth_init, }  /* init, nothing more */
 831};
 832
 833/*
 834 * Finally, the module stuff
 835 */
 836
 837int meth_init_module(void)
 838{
 839        int result, device_present = 0;
 840
 841        strcpy(meth_devs[0].name, "eth%d");
 842
 843        if ( (result = register_netdev(meth_devs)) )
 844                printk("meth: error %i registering device \"%s\"\n",
 845                       result, meth_devs->name);
 846        else device_present++;
 847        
 848        return device_present ? 0 : -ENODEV;
 849}
 850
 851void meth_cleanup(void)
 852{
 853    kfree(meth_devs->priv);
 854    unregister_netdev(meth_devs);
 855    return;
 856}
 857
 858module_init(meth_init_module);
 859module_exit(meth_cleanup);
 860