/*
 * Sun3 i82586 Ethernet driver
 *
 * Cloned from ni52.c for the Sun3 by Sam Creasey (sammy@sammy.net)
 *
 * Original copyright follows:
 * --------------------------
 *
 * net-3-driver for the NI5210 card (i82586 Ethernet chip)
 *
 * This is an extension to the Linux operating system, and is covered by the
 * same Gnu Public License that covers that work.
 *
 * Alphacode 0.82 (96/09/29) for Linux 2.0.0 (or later)
 * Copyrights (c) 1994,1995,1996 by M.Hipp (hippm@informatik.uni-tuebingen.de)
 * --------------------------
 *
 * Consult ni52.c for further notes from the original driver.
 *
 * This incarnation currently supports the OBIO version of the i82586 chip
 * used in certain sun3 models.  It should be fairly doable to expand this
 * to support VME if I should every acquire such a board.
 *
 */

static int debuglevel = 0; /* debug-printk 0: off 1: a few 2: more */
static int automatic_resume = 0; /* experimental .. better should be zero */
static int rfdadd = 0; /* rfdadd=1 may be better for 8K MEM cards */
static int fifo=0x8;    /* don't change */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <asm/io.h>
#include <asm/idprom.h>
#include <asm/machines.h>
#include <asm/sun3mmu.h>
#include <asm/dvma.h>
#include <asm/byteorder.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>

#include "sun3_82586.h"

#define DRV_NAME "sun3_82586"

#define DEBUG       /* debug on */
#define SYSBUSVAL 0 /* 16 Bit */
#define SUN3_82586_TOTAL_SIZE   PAGE_SIZE

#define sun3_attn586()  {*(volatile unsigned char *)(dev->base_addr) |= IEOB_ATTEN; *(volatile unsigned char *)(dev->base_addr) &= ~IEOB_ATTEN;}
#define sun3_reset586() {*(volatile unsigned char *)(dev->base_addr) = 0; udelay(100); *(volatile unsigned char *)(dev->base_addr) = IEOB_NORSET;}
#define sun3_disint()   {*(volatile unsigned char *)(dev->base_addr) &= ~IEOB_IENAB;}
#define sun3_enaint()   {*(volatile unsigned char *)(dev->base_addr) |= IEOB_IENAB;}
#define sun3_active()   {*(volatile unsigned char *)(dev->base_addr) |= (IEOB_IENAB|IEOB_ONAIR|IEOB_NORSET);}

#define make32(ptr16) (p->memtop + (swab16((unsigned short) (ptr16))) )
#define make24(ptr32) (char *)swab32(( ((unsigned long) (ptr32)) - p->base))
#define make16(ptr32) (swab16((unsigned short) ((unsigned long)(ptr32) - (unsigned long) p->memtop )))

/******************* how to calculate the buffers *****************************

  * IMPORTANT NOTE: if you configure only one NUM_XMIT_BUFFS, the driver works
  * --------------- in a different (more stable?) mode. Only in this mode it's
  *                 possible to configure the driver with 'NO_NOPCOMMANDS'

sizeof(scp)=12; sizeof(scb)=16; sizeof(iscp)=8;
sizeof(scp)+sizeof(iscp)+sizeof(scb) = 36 = INIT
sizeof(rfd) = 24; sizeof(rbd) = 12;
sizeof(tbd) = 8; sizeof(transmit_cmd) = 16;
sizeof(nop_cmd) = 8;

  * if you don't know the driver, better do not change these values: */

#define RECV_BUFF_SIZE 1536 /* slightly oversized */
#define XMIT_BUFF_SIZE 1536 /* slightly oversized */
#define NUM_XMIT_BUFFS 1    /* config for 32K shmem */
#define NUM_RECV_BUFFS_8 4 /* config for 32K shared mem */
#define NUM_RECV_BUFFS_16 9 /* config for 32K shared mem */
#define NUM_RECV_BUFFS_32 16 /* config for 32K shared mem */
#define NO_NOPCOMMANDS      /* only possible with NUM_XMIT_BUFFS=1 */

/**************************************************************************/

/* different DELAYs */
#define DELAY(x) mdelay(32 * x);
#define DELAY_16(); { udelay(16); }
#define DELAY_18(); { udelay(4); }

/* wait for command with timeout: */
#define WAIT_4_SCB_CMD() \
{ int i; \
  for(i=0;i<16384;i++) { \
    if(!p->scb->cmd_cuc) break; \
    DELAY_18(); \
    if(i == 16383) { \
      printk("%s: scb_cmd timed out: %04x,%04x .. disabling i82586!!\n",dev->name,p->scb->cmd_cuc,p->scb->cus); \
       if(!p->reseted) { p->reseted = 1; sun3_reset586(); } } } }

#define WAIT_4_SCB_CMD_RUC() { int i; \
  for(i=0;i<16384;i++) { \
    if(!p->scb->cmd_ruc) break; \
    DELAY_18(); \
    if(i == 16383) { \
      printk("%s: scb_cmd (ruc) timed out: %04x,%04x .. disabling i82586!!\n",dev->name,p->scb->cmd_ruc,p->scb->rus); \
       if(!p->reseted) { p->reseted = 1; sun3_reset586(); } } } }

#define WAIT_4_STAT_COMPL(addr) { int i; \
   for(i=0;i<32767;i++) { \
     if(swab16((addr)->cmd_status) & STAT_COMPL) break; \
     DELAY_16(); DELAY_16(); } }

static int     sun3_82586_probe1(struct net_device *dev,int ioaddr);
static irqreturn_t sun3_82586_interrupt(int irq,void *dev_id);
static int     sun3_82586_open(struct net_device *dev);
static int     sun3_82586_close(struct net_device *dev);
static netdev_tx_t     sun3_82586_send_packet(struct sk_buff *,
                                              struct net_device *);
static struct  net_device_stats *sun3_82586_get_stats(struct net_device *dev);
static void    set_multicast_list(struct net_device *dev);
static void    sun3_82586_timeout(struct net_device *dev, unsigned int txqueue);
#if 0
static void    sun3_82586_dump(struct net_device *,void *);
#endif

/* helper-functions */
static int     init586(struct net_device *dev);
static int     check586(struct net_device *dev,char *where,unsigned size);
static void    alloc586(struct net_device *dev);
static void    startrecv586(struct net_device *dev);
static void   *alloc_rfa(struct net_device *dev,void *ptr);
static void    sun3_82586_rcv_int(struct net_device *dev);
static void    sun3_82586_xmt_int(struct net_device *dev);
static void    sun3_82586_rnr_int(struct net_device *dev);

struct priv
{
        unsigned long base;
        char *memtop;
        long int lock;
        int reseted;
        volatile struct rfd_struct      *rfd_last,*rfd_top,*rfd_first;
        volatile struct scp_struct      *scp;   /* volatile is important */
        volatile struct iscp_struct     *iscp;  /* volatile is important */
        volatile struct scb_struct      *scb;   /* volatile is important */
        volatile struct tbd_struct      *xmit_buffs[NUM_XMIT_BUFFS];
        volatile struct transmit_cmd_struct *xmit_cmds[NUM_XMIT_BUFFS];
#if (NUM_XMIT_BUFFS == 1)
        volatile struct nop_cmd_struct *nop_cmds[2];
#else
        volatile struct nop_cmd_struct *nop_cmds[NUM_XMIT_BUFFS];
#endif
        volatile int            nop_point,num_recv_buffs;
        volatile char           *xmit_cbuffs[NUM_XMIT_BUFFS];
        volatile int            xmit_count,xmit_last;
};

/**********************************************
 * close device
 */
static int sun3_82586_close(struct net_device *dev)
{
        free_irq(dev->irq, dev);

        sun3_reset586(); /* the hard way to stop the receiver */

        netif_stop_queue(dev);

        return 0;
}

/**********************************************
 * open device
 */
static int sun3_82586_open(struct net_device *dev)
{
        int ret;

        sun3_disint();
        alloc586(dev);
        init586(dev);
        startrecv586(dev);
        sun3_enaint();

        ret = request_irq(dev->irq, sun3_82586_interrupt,0,dev->name,dev);
        if (ret)
        {
                sun3_reset586();
                return ret;
        }

        netif_start_queue(dev);

        return 0; /* most done by init */
}

/**********************************************
 * Check to see if there's an 82586 out there.
 */
static int check586(struct net_device *dev,char *where,unsigned size)
{
        struct priv pb;
        struct priv *p = &pb;
        char *iscp_addr;
        int i;

        p->base = (unsigned long) dvma_btov(0);
        p->memtop = (char *)dvma_btov((unsigned long)where);
        p->scp = (struct scp_struct *)(p->base + SCP_DEFAULT_ADDRESS);
        memset((char *)p->scp,0, sizeof(struct scp_struct));
        for(i=0;i<sizeof(struct scp_struct);i++) /* memory was writeable? */
                if(((char *)p->scp)[i])
                        return 0;
        p->scp->sysbus = SYSBUSVAL;                             /* 1 = 8Bit-Bus, 0 = 16 Bit */
        if(p->scp->sysbus != SYSBUSVAL)
                return 0;

        iscp_addr = (char *)dvma_btov((unsigned long)where);

        p->iscp = (struct iscp_struct *) iscp_addr;
        memset((char *)p->iscp,0, sizeof(struct iscp_struct));

        p->scp->iscp = make24(p->iscp);
        p->iscp->busy = 1;

        sun3_reset586();
        sun3_attn586();
        DELAY(1);       /* wait a while... */

        if(p->iscp->busy) /* i82586 clears 'busy' after successful init */
                return 0;

        return 1;
}

/******************************************************************
 * set iscp at the right place, called by sun3_82586_probe1 and open586.
 */
static void alloc586(struct net_device *dev)
{
        struct priv *p = netdev_priv(dev);

        sun3_reset586();
        DELAY(1);

        p->scp  = (struct scp_struct *) (p->base + SCP_DEFAULT_ADDRESS);
        p->iscp = (struct iscp_struct *) dvma_btov(dev->mem_start);
        p->scb  = (struct scb_struct *)  ((char *)p->iscp + sizeof(struct iscp_struct));

        memset((char *) p->iscp,0,sizeof(struct iscp_struct));
        memset((char *) p->scp ,0,sizeof(struct scp_struct));

        p->scp->iscp = make24(p->iscp);
        p->scp->sysbus = SYSBUSVAL;
        p->iscp->scb_offset = make16(p->scb);
        p->iscp->scb_base = make24(dvma_btov(dev->mem_start));

        p->iscp->busy = 1;
        sun3_reset586();
        sun3_attn586();

        DELAY(1);

        if(p->iscp->busy)
                printk("%s: Init-Problems (alloc).\n",dev->name);

        p->reseted = 0;

        memset((char *)p->scb,0,sizeof(struct scb_struct));
}

static int __init sun3_82586_probe(void)
{
        struct net_device *dev;
        unsigned long ioaddr;
        static int found = 0;
        int err = -ENOMEM;

        /* check that this machine has an onboard 82586 */
        switch(idprom->id_machtype) {
        case SM_SUN3|SM_3_160:
        case SM_SUN3|SM_3_260:
                /* these machines have 82586 */
                break;

        default:
                return -ENODEV;
        }

        if (found)
                return -ENODEV;

        ioaddr = (unsigned long)ioremap(IE_OBIO, SUN3_82586_TOTAL_SIZE);
        if (!ioaddr)
                return -ENOMEM;
        found = 1;

        dev = alloc_etherdev(sizeof(struct priv));
        if (!dev)
                goto out;
        dev->irq = IE_IRQ;
        dev->base_addr = ioaddr;
        err = sun3_82586_probe1(dev, ioaddr);
        if (err)
                goto out1;
        err = register_netdev(dev);
        if (err)
                goto out2;
        return 0;

out2:
        release_region(ioaddr, SUN3_82586_TOTAL_SIZE);
out1:
        free_netdev(dev);
out:
        iounmap((void __iomem *)ioaddr);
        return err;
}
module_init(sun3_82586_probe);

static const struct net_device_ops sun3_82586_netdev_ops = {
        .ndo_open               = sun3_82586_open,
        .ndo_stop               = sun3_82586_close,
        .ndo_start_xmit         = sun3_82586_send_packet,
        .ndo_set_rx_mode        = set_multicast_list,
        .ndo_tx_timeout         = sun3_82586_timeout,
        .ndo_get_stats          = sun3_82586_get_stats,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_set_mac_address    = eth_mac_addr,
};

static int __init sun3_82586_probe1(struct net_device *dev,int ioaddr)
{
        int i, size, retval;

        if (!request_region(ioaddr, SUN3_82586_TOTAL_SIZE, DRV_NAME))
                return -EBUSY;

        /* copy in the ethernet address from the prom */
        for(i = 0; i < 6 ; i++)
             dev->dev_addr[i] = idprom->id_ethaddr[i];

        printk("%s: SUN3 Intel 82586 found at %lx, ",dev->name,dev->base_addr);

        /*
         * check (or search) IO-Memory, 32K
         */
        size = 0x8000;

        dev->mem_start = (unsigned long)dvma_malloc_align(0x8000, 0x1000);
        dev->mem_end = dev->mem_start + size;

        if(size != 0x2000 && size != 0x4000 && size != 0x8000) {
                printk("\n%s: Illegal memory size %d. Allowed is 0x2000 or 0x4000 or 0x8000 bytes.\n",dev->name,size);
                retval = -ENODEV;
                goto out;
        }
        if(!check586(dev,(char *) dev->mem_start,size)) {
                printk("?memcheck, Can't find memory at 0x%lx with size %d!\n",dev->mem_start,size);
                retval = -ENODEV;
                goto out;
        }

        ((struct priv *)netdev_priv(dev))->memtop =
                                        (char *)dvma_btov(dev->mem_start);
        ((struct priv *)netdev_priv(dev))->base = (unsigned long) dvma_btov(0);
        alloc586(dev);

        /* set number of receive-buffs according to memsize */
        if(size == 0x2000)
                ((struct priv *)netdev_priv(dev))->num_recv_buffs =
                                                        NUM_RECV_BUFFS_8;
        else if(size == 0x4000)
                ((struct priv *)netdev_priv(dev))->num_recv_buffs =
                                                        NUM_RECV_BUFFS_16;
        else
                ((struct priv *)netdev_priv(dev))->num_recv_buffs =
                                                        NUM_RECV_BUFFS_32;

        printk("Memaddr: 0x%lx, Memsize: %d, IRQ %d\n",dev->mem_start,size, dev->irq);

        dev->netdev_ops         = &sun3_82586_netdev_ops;
        dev->watchdog_timeo     = HZ/20;

        dev->if_port            = 0;
        return 0;
out:
        release_region(ioaddr, SUN3_82586_TOTAL_SIZE);
        return retval;
}


static int init586(struct net_device *dev)
{
        void *ptr;
        int i,result=0;
        struct priv *p = netdev_priv(dev);
        volatile struct configure_cmd_struct    *cfg_cmd;
        volatile struct iasetup_cmd_struct *ias_cmd;
        volatile struct tdr_cmd_struct *tdr_cmd;
        volatile struct mcsetup_cmd_struct *mc_cmd;
        struct netdev_hw_addr *ha;
        int num_addrs=netdev_mc_count(dev);

        ptr = (void *) ((char *)p->scb + sizeof(struct scb_struct));

        cfg_cmd = (struct configure_cmd_struct *)ptr; /* configure-command */
        cfg_cmd->cmd_status     = 0;
        cfg_cmd->cmd_cmd        = swab16(CMD_CONFIGURE | CMD_LAST);
        cfg_cmd->cmd_link       = 0xffff;

        cfg_cmd->byte_cnt       = 0x0a; /* number of cfg bytes */
        cfg_cmd->fifo           = fifo; /* fifo-limit (8=tx:32/rx:64) */
        cfg_cmd->sav_bf         = 0x40; /* hold or discard bad recv frames (bit 7) */
        cfg_cmd->adr_len        = 0x2e; /* addr_len |!src_insert |pre-len |loopback */
        cfg_cmd->priority       = 0x00;
        cfg_cmd->ifs            = 0x60;
        cfg_cmd->time_low       = 0x00;
        cfg_cmd->time_high      = 0xf2;
        cfg_cmd->promisc        = 0;
        if(dev->flags & IFF_ALLMULTI) {
                int len = ((char *) p->iscp - (char *) ptr - 8) / 6;
                if(num_addrs > len)     {
                        printk("%s: switching to promisc. mode\n",dev->name);
                        cfg_cmd->promisc = 1;
                }
        }
        if(dev->flags&IFF_PROMISC)
                cfg_cmd->promisc = 1;
        cfg_cmd->carr_coll      = 0x00;

        p->scb->cbl_offset      = make16(cfg_cmd);
        p->scb->cmd_ruc         = 0;

        p->scb->cmd_cuc         = CUC_START; /* cmd.-unit start */
        sun3_attn586();

        WAIT_4_STAT_COMPL(cfg_cmd);

        if((swab16(cfg_cmd->cmd_status) & (STAT_OK|STAT_COMPL)) != (STAT_COMPL|STAT_OK))
        {
                printk("%s: configure command failed: %x\n",dev->name,swab16(cfg_cmd->cmd_status));
                return 1;
        }

        /*
         * individual address setup
         */

        ias_cmd = (struct iasetup_cmd_struct *)ptr;

        ias_cmd->cmd_status     = 0;
        ias_cmd->cmd_cmd        = swab16(CMD_IASETUP | CMD_LAST);
        ias_cmd->cmd_link       = 0xffff;

        memcpy((char *)&ias_cmd->iaddr,(char *) dev->dev_addr,ETH_ALEN);

        p->scb->cbl_offset = make16(ias_cmd);

        p->scb->cmd_cuc = CUC_START; /* cmd.-unit start */
        sun3_attn586();

        WAIT_4_STAT_COMPL(ias_cmd);

        if((swab16(ias_cmd->cmd_status) & (STAT_OK|STAT_COMPL)) != (STAT_OK|STAT_COMPL)) {
                printk("%s (82586): individual address setup command failed: %04x\n",dev->name,swab16(ias_cmd->cmd_status));
                return 1;
        }

        /*
         * TDR, wire check .. e.g. no resistor e.t.c
         */

        tdr_cmd = (struct tdr_cmd_struct *)ptr;

        tdr_cmd->cmd_status     = 0;
        tdr_cmd->cmd_cmd        = swab16(CMD_TDR | CMD_LAST);
        tdr_cmd->cmd_link       = 0xffff;
        tdr_cmd->status         = 0;

        p->scb->cbl_offset = make16(tdr_cmd);
        p->scb->cmd_cuc = CUC_START; /* cmd.-unit start */
        sun3_attn586();

        WAIT_4_STAT_COMPL(tdr_cmd);

        if(!(swab16(tdr_cmd->cmd_status) & STAT_COMPL))
        {
                printk("%s: Problems while running the TDR.\n",dev->name);
        }
        else
        {
                DELAY_16(); /* wait for result */
                result = swab16(tdr_cmd->status);

                p->scb->cmd_cuc = p->scb->cus & STAT_MASK;
                sun3_attn586(); /* ack the interrupts */

                if(result & TDR_LNK_OK)
                        ;
                else if(result & TDR_XCVR_PRB)
                        printk("%s: TDR: Transceiver problem. Check the cable(s)!\n",dev->name);
                else if(result & TDR_ET_OPN)
                        printk("%s: TDR: No correct termination %d clocks away.\n",dev->name,result & TDR_TIMEMASK);
                else if(result & TDR_ET_SRT)
                {
                        if (result & TDR_TIMEMASK) /* time == 0 -> strange :-) */
                                printk("%s: TDR: Detected a short circuit %d clocks away.\n",dev->name,result & TDR_TIMEMASK);
                }
                else
                        printk("%s: TDR: Unknown status %04x\n",dev->name,result);
        }

        /*
         * Multicast setup
         */
        if(num_addrs && !(dev->flags & IFF_PROMISC) )
        {
                mc_cmd = (struct mcsetup_cmd_struct *) ptr;
                mc_cmd->cmd_status = 0;
                mc_cmd->cmd_cmd = swab16(CMD_MCSETUP | CMD_LAST);
                mc_cmd->cmd_link = 0xffff;
                mc_cmd->mc_cnt = swab16(num_addrs * 6);

                i = 0;
                netdev_for_each_mc_addr(ha, dev)
                        memcpy((char *) mc_cmd->mc_list[i++],
                               ha->addr, ETH_ALEN);

                p->scb->cbl_offset = make16(mc_cmd);
                p->scb->cmd_cuc = CUC_START;
                sun3_attn586();

                WAIT_4_STAT_COMPL(mc_cmd);

                if( (swab16(mc_cmd->cmd_status) & (STAT_COMPL|STAT_OK)) != (STAT_COMPL|STAT_OK) )
                        printk("%s: Can't apply multicast-address-list.\n",dev->name);
        }

        /*
         * alloc nop/xmit-cmds
         */
#if (NUM_XMIT_BUFFS == 1)
        for(i=0;i<2;i++)
        {
                p->nop_cmds[i]                  = (struct nop_cmd_struct *)ptr;
                p->nop_cmds[i]->cmd_cmd         = swab16(CMD_NOP);
                p->nop_cmds[i]->cmd_status      = 0;
                p->nop_cmds[i]->cmd_link        = make16((p->nop_cmds[i]));
                ptr = (char *) ptr + sizeof(struct nop_cmd_struct);
        }
#else
        for(i=0;i<NUM_XMIT_BUFFS;i++)
        {
                p->nop_cmds[i]                  = (struct nop_cmd_struct *)ptr;
                p->nop_cmds[i]->cmd_cmd         = swab16(CMD_NOP);
                p->nop_cmds[i]->cmd_status      = 0;
                p->nop_cmds[i]->cmd_link        = make16((p->nop_cmds[i]));
                ptr = (char *) ptr + sizeof(struct nop_cmd_struct);
        }
#endif

        ptr = alloc_rfa(dev,ptr); /* init receive-frame-area */

        /*
         * alloc xmit-buffs / init xmit_cmds
         */
        for(i=0;i<NUM_XMIT_BUFFS;i++)
        {
                p->xmit_cmds[i] = (struct transmit_cmd_struct *)ptr; /*transmit cmd/buff 0*/
                ptr = (char *) ptr + sizeof(struct transmit_cmd_struct);
                p->xmit_cbuffs[i] = (char *)ptr; /* char-buffs */
                ptr = (char *) ptr + XMIT_BUFF_SIZE;
                p->xmit_buffs[i] = (struct tbd_struct *)ptr; /* TBD */
                ptr = (char *) ptr + sizeof(struct tbd_struct);
                if(ptr > (void *)dev->mem_end)
                {
                        printk("%s: not enough shared-mem for your configuration!\n",dev->name);
                        return 1;
                }
                memset((char *)(p->xmit_cmds[i]) ,0, sizeof(struct transmit_cmd_struct));
                memset((char *)(p->xmit_buffs[i]),0, sizeof(struct tbd_struct));
                p->xmit_cmds[i]->cmd_link = make16(p->nop_cmds[(i+1)%NUM_XMIT_BUFFS]);
                p->xmit_cmds[i]->cmd_status = swab16(STAT_COMPL);
                p->xmit_cmds[i]->cmd_cmd = swab16(CMD_XMIT | CMD_INT);
                p->xmit_cmds[i]->tbd_offset = make16((p->xmit_buffs[i]));
                p->xmit_buffs[i]->next = 0xffff;
                p->xmit_buffs[i]->buffer = make24((p->xmit_cbuffs[i]));
        }

        p->xmit_count = 0;
        p->xmit_last    = 0;
#ifndef NO_NOPCOMMANDS
        p->nop_point    = 0;
#endif

         /*
                * 'start transmitter'
                */
#ifndef NO_NOPCOMMANDS
        p->scb->cbl_offset = make16(p->nop_cmds[0]);
        p->scb->cmd_cuc = CUC_START;
        sun3_attn586();
        WAIT_4_SCB_CMD();
#else
        p->xmit_cmds[0]->cmd_link = make16(p->xmit_cmds[0]);
        p->xmit_cmds[0]->cmd_cmd        = swab16(CMD_XMIT | CMD_SUSPEND | CMD_INT);
#endif

        /*
         * ack. interrupts
         */
        p->scb->cmd_cuc = p->scb->cus & STAT_MASK;
        sun3_attn586();
        DELAY_16();

        sun3_enaint();
        sun3_active();

        return 0;
}

/******************************************************
 * This is a helper routine for sun3_82586_rnr_int() and init586().
 * It sets up the Receive Frame Area (RFA).
 */

static void *alloc_rfa(struct net_device *dev,void *ptr)
{
        volatile struct rfd_struct *rfd = (struct rfd_struct *)ptr;
        volatile struct rbd_struct *rbd;
        int i;
        struct priv *p = netdev_priv(dev);

        memset((char *) rfd,0,sizeof(struct rfd_struct)*(p->num_recv_buffs+rfdadd));
        p->rfd_first = rfd;

        for(i = 0; i < (p->num_recv_buffs+rfdadd); i++) {
                rfd[i].next = make16(rfd + (i+1) % (p->num_recv_buffs+rfdadd) );
                rfd[i].rbd_offset = 0xffff;
        }
        rfd[p->num_recv_buffs-1+rfdadd].last = RFD_SUSP;         /* RU suspend */

        ptr = (void *) (rfd + (p->num_recv_buffs + rfdadd) );

        rbd = (struct rbd_struct *) ptr;
        ptr = (void *) (rbd + p->num_recv_buffs);

         /* clr descriptors */
        memset((char *) rbd,0,sizeof(struct rbd_struct)*(p->num_recv_buffs));

        for(i=0;i<p->num_recv_buffs;i++)
        {
                rbd[i].next = make16((rbd + (i+1) % p->num_recv_buffs));
                rbd[i].size = swab16(RECV_BUFF_SIZE);
                rbd[i].buffer = make24(ptr);
                ptr = (char *) ptr + RECV_BUFF_SIZE;
        }

        p->rfd_top      = p->rfd_first;
        p->rfd_last = p->rfd_first + (p->num_recv_buffs - 1 + rfdadd);

        p->scb->rfa_offset              = make16(p->rfd_first);
        p->rfd_first->rbd_offset        = make16(rbd);

        return ptr;
}


/**************************************************
 * Interrupt Handler ...
 */

static irqreturn_t sun3_82586_interrupt(int irq,void *dev_id)
{
        struct net_device *dev = dev_id;
        unsigned short stat;
        int cnt=0;
        struct priv *p;

        if (!dev) {
                printk ("sun3_82586-interrupt: irq %d for unknown device.\n",irq);
                return IRQ_NONE;
        }
        p = netdev_priv(dev);

        if(debuglevel > 1)
                printk("I");

        WAIT_4_SCB_CMD(); /* wait for last command      */

        while((stat=p->scb->cus & STAT_MASK))
        {
                p->scb->cmd_cuc = stat;
                sun3_attn586();

                if(stat & STAT_FR)       /* received a frame */
                        sun3_82586_rcv_int(dev);

                if(stat & STAT_RNR) /* RU went 'not ready' */
                {
                        printk("(R)");
                        if(p->scb->rus & RU_SUSPEND) /* special case: RU_SUSPEND */
                        {
                                WAIT_4_SCB_CMD();
                                p->scb->cmd_ruc = RUC_RESUME;
                                sun3_attn586();
                                WAIT_4_SCB_CMD_RUC();
                        }
                        else
                        {
                                printk("%s: Receiver-Unit went 'NOT READY': %04x/%02x.\n",dev->name,(int) stat,(int) p->scb->rus);
                                sun3_82586_rnr_int(dev);
                        }
                }

                if(stat & STAT_CX)              /* command with I-bit set complete */
                         sun3_82586_xmt_int(dev);

#ifndef NO_NOPCOMMANDS
                if(stat & STAT_CNA)     /* CU went 'not ready' */
                {
                        if(netif_running(dev))
                                printk("%s: oops! CU has left active state. stat: %04x/%02x.\n",dev->name,(int) stat,(int) p->scb->cus);
                }
#endif

                if(debuglevel > 1)
                        printk("%d",cnt++);

                WAIT_4_SCB_CMD(); /* wait for ack. (sun3_82586_xmt_int can be faster than ack!!) */
                if(p->scb->cmd_cuc)      /* timed out? */
                {
                        printk("%s: Acknowledge timed out.\n",dev->name);
                        sun3_disint();
                        break;
                }
        }

        if(debuglevel > 1)
                printk("i");
        return IRQ_HANDLED;
}

/*******************************************************
 * receive-interrupt
 */

static void sun3_82586_rcv_int(struct net_device *dev)
{
        int status,cnt=0;
        unsigned short totlen;
        struct sk_buff *skb;
        struct rbd_struct *rbd;
        struct priv *p = netdev_priv(dev);

        if(debuglevel > 0)
                printk("R");

        for(;(status = p->rfd_top->stat_high) & RFD_COMPL;)
        {
                        rbd = (struct rbd_struct *) make32(p->rfd_top->rbd_offset);

                        if(status & RFD_OK) /* frame received without error? */
                        {
                                if( (totlen = swab16(rbd->status)) & RBD_LAST) /* the first and the last buffer? */
                                {
                                        totlen &= RBD_MASK; /* length of this frame */
                                        rbd->status = 0;
                                        skb = netdev_alloc_skb(dev, totlen + 2);
                                        if(skb != NULL)
                                        {
                                                skb_reserve(skb,2);
                                                skb_put(skb,totlen);
                                                skb_copy_to_linear_data(skb,(char *) p->base+swab32((unsigned long) rbd->buffer),totlen);
                                                skb->protocol=eth_type_trans(skb,dev);
                                                netif_rx(skb);
                                                dev->stats.rx_packets++;
                                        }
                                        else
                                                dev->stats.rx_dropped++;
                                }
                                else
                                {
                                        int rstat;
                                                 /* free all RBD's until RBD_LAST is set */
                                        totlen = 0;
                                        while(!((rstat=swab16(rbd->status)) & RBD_LAST))
                                        {
                                                totlen += rstat & RBD_MASK;
                                                if(!rstat)
                                                {
                                                        printk("%s: Whoops .. no end mark in RBD list\n",dev->name);
                                                        break;
                                                }
                                                rbd->status = 0;
                                                rbd = (struct rbd_struct *) make32(rbd->next);
                                        }
                                        totlen += rstat & RBD_MASK;
                                        rbd->status = 0;
                                        printk("%s: received oversized frame! length: %d\n",dev->name,totlen);
                                        dev->stats.rx_dropped++;
                         }
                }
                else /* frame !(ok), only with 'save-bad-frames' */
                {
                        printk("%s: oops! rfd-error-status: %04x\n",dev->name,status);
                        dev->stats.rx_errors++;
                }
                p->rfd_top->stat_high = 0;
                p->rfd_top->last = RFD_SUSP; /* maybe exchange by RFD_LAST */
                p->rfd_top->rbd_offset = 0xffff;
                p->rfd_last->last = 0;                          /* delete RFD_SUSP      */
                p->rfd_last = p->rfd_top;
                p->rfd_top = (struct rfd_struct *) make32(p->rfd_top->next); /* step to next RFD */
                p->scb->rfa_offset = make16(p->rfd_top);

                if(debuglevel > 0)
                        printk("%d",cnt++);
        }

        if(automatic_resume)
        {
                WAIT_4_SCB_CMD();
                p->scb->cmd_ruc = RUC_RESUME;
                sun3_attn586();
                WAIT_4_SCB_CMD_RUC();
        }

#ifdef WAIT_4_BUSY
        {
                int i;
                for(i=0;i<1024;i++)
                {
                        if(p->rfd_top->status)
                                break;
                        DELAY_16();
                        if(i == 1023)
                                printk("%s: RU hasn't fetched next RFD (not busy/complete)\n",dev->name);
                }
        }
#endif

#if 0
        if(!at_least_one)
        {
                int i;
                volatile struct rfd_struct *rfds=p->rfd_top;
                volatile struct rbd_struct *rbds;
                printk("%s: received a FC intr. without having a frame: %04x %d\n",dev->name,status,old_at_least);
                for(i=0;i< (p->num_recv_buffs+4);i++)
                {
                        rbds = (struct rbd_struct *) make32(rfds->rbd_offset);
                        printk("%04x:%04x ",rfds->status,rbds->status);
                        rfds = (struct rfd_struct *) make32(rfds->next);
                }
                printk("\nerrs: %04x %04x stat: %04x\n",(int)p->scb->rsc_errs,(int)p->scb->ovrn_errs,(int)p->scb->status);
                printk("\nerrs: %04x %04x rus: %02x, cus: %02x\n",(int)p->scb->rsc_errs,(int)p->scb->ovrn_errs,(int)p->scb->rus,(int)p->scb->cus);
        }
        old_at_least = at_least_one;
#endif

        if(debuglevel > 0)
                printk("r");
}

/**********************************************************
 * handle 'Receiver went not ready'.
 */

static void sun3_82586_rnr_int(struct net_device *dev)
{
        struct priv *p = netdev_priv(dev);

        dev->stats.rx_errors++;

        WAIT_4_SCB_CMD();               /* wait for the last cmd, WAIT_4_FULLSTAT?? */
        p->scb->cmd_ruc = RUC_ABORT; /* usually the RU is in the 'no resource'-state .. abort it now. */
        sun3_attn586();
        WAIT_4_SCB_CMD_RUC();           /* wait for accept cmd. */

        alloc_rfa(dev,(char *)p->rfd_first);
/* maybe add a check here, before restarting the RU */
        startrecv586(dev); /* restart RU */

        printk("%s: Receive-Unit restarted. Status: %04x\n",dev->name,p->scb->rus);

}

/**********************************************************
 * handle xmit - interrupt
 */

static void sun3_82586_xmt_int(struct net_device *dev)
{
        int status;
        struct priv *p = netdev_priv(dev);

        if(debuglevel > 0)
                printk("X");

        status = swab16(p->xmit_cmds[p->xmit_last]->cmd_status);
        if(!(status & STAT_COMPL))
                printk("%s: strange .. xmit-int without a 'COMPLETE'\n",dev->name);

        if(status & STAT_OK)
        {
                dev->stats.tx_packets++;
                dev->stats.collisions += (status & TCMD_MAXCOLLMASK);
        }
        else
        {
                dev->stats.tx_errors++;
                if(status & TCMD_LATECOLL) {
                        printk("%s: late collision detected.\n",dev->name);
                        dev->stats.collisions++;
                }
                else if(status & TCMD_NOCARRIER) {
                        dev->stats.tx_carrier_errors++;
                        printk("%s: no carrier detected.\n",dev->name);
                }
                else if(status & TCMD_LOSTCTS)
                        printk("%s: loss of CTS detected.\n",dev->name);
                else if(status & TCMD_UNDERRUN) {
                        dev->stats.tx_fifo_errors++;
                        printk("%s: DMA underrun detected.\n",dev->name);
                }
                else if(status & TCMD_MAXCOLL) {
                        printk("%s: Max. collisions exceeded.\n",dev->name);
                        dev->stats.collisions += 16;
                }
        }

#if (NUM_XMIT_BUFFS > 1)
        if( (++p->xmit_last) == NUM_XMIT_BUFFS)
                p->xmit_last = 0;
#endif
        netif_wake_queue(dev);
}

/***********************************************************
 * (re)start the receiver
 */

static void startrecv586(struct net_device *dev)
{
        struct priv *p = netdev_priv(dev);

        WAIT_4_SCB_CMD();
        WAIT_4_SCB_CMD_RUC();
        p->scb->rfa_offset = make16(p->rfd_first);
        p->scb->cmd_ruc = RUC_START;
        sun3_attn586();         /* start cmd. */
        WAIT_4_SCB_CMD_RUC();   /* wait for accept cmd. (no timeout!!) */
}

static void sun3_82586_timeout(struct net_device *dev, unsigned int txqueue)
{
        struct priv *p = netdev_priv(dev);
#ifndef NO_NOPCOMMANDS
        if(p->scb->cus & CU_ACTIVE) /* COMMAND-UNIT active? */
        {
                netif_wake_queue(dev);
#ifdef DEBUG
                printk("%s: strange ... timeout with CU active?!?\n",dev->name);
                printk("%s: X0: %04x N0: %04x N1: %04x %d\n",dev->name,(int)swab16(p->xmit_cmds[0]->cmd_status),(int)swab16(p->nop_cmds[0]->cmd_status),(int)swab16(p->nop_cmds[1]->cmd_status),(int)p->nop_point);
#endif
                p->scb->cmd_cuc = CUC_ABORT;
                sun3_attn586();
                WAIT_4_SCB_CMD();
                p->scb->cbl_offset = make16(p->nop_cmds[p->nop_point]);
                p->scb->cmd_cuc = CUC_START;
                sun3_attn586();
                WAIT_4_SCB_CMD();
                netif_trans_update(dev); /* prevent tx timeout */
                return 0;
        }
#endif
        {
#ifdef DEBUG
                printk("%s: xmitter timed out, try to restart! stat: %02x\n",dev->name,p->scb->cus);
                printk("%s: command-stats: %04x %04x\n",dev->name,swab16(p->xmit_cmds[0]->cmd_status),swab16(p->xmit_cmds[1]->cmd_status));
                printk("%s: check, whether you set the right interrupt number!\n",dev->name);
#endif
                sun3_82586_close(dev);
                sun3_82586_open(dev);
        }
        netif_trans_update(dev); /* prevent tx timeout */
}

/******************************************************
 * send frame

 */

static netdev_tx_t
sun3_82586_send_packet(struct sk_buff *skb, struct net_device *dev)
{
        int len,i;
#ifndef NO_NOPCOMMANDS
        int next_nop;
#endif
        struct priv *p = netdev_priv(dev);

        if(skb->len > XMIT_BUFF_SIZE)
        {
                printk("%s: Sorry, max. framelength is %d bytes. The length of your frame is %d bytes.\n",dev->name,XMIT_BUFF_SIZE,skb->len);
                return NETDEV_TX_OK;
        }

        netif_stop_queue(dev);

#if(NUM_XMIT_BUFFS > 1)
        if(test_and_set_bit(0,(void *) &p->lock)) {
                printk("%s: Queue was locked\n",dev->name);
                return NETDEV_TX_BUSY;
        }
        else
#endif
        {
                len = skb->len;
                if (len < ETH_ZLEN) {
                        memset((void *)p->xmit_cbuffs[p->xmit_count], 0,
                               ETH_ZLEN);
                        len = ETH_ZLEN;
                }
                skb_copy_from_linear_data(skb, (void *)p->xmit_cbuffs[p->xmit_count], skb->len);

#if (NUM_XMIT_BUFFS == 1)
#       ifdef NO_NOPCOMMANDS

#ifdef DEBUG
                if(p->scb->cus & CU_ACTIVE)
                {
                        printk("%s: Hmmm .. CU is still running and we wanna send a new packet.\n",dev->name);
                        printk("%s: stat: %04x %04x\n",dev->name,p->scb->cus,swab16(p->xmit_cmds[0]->cmd_status));
                }
#endif

                p->xmit_buffs[0]->size = swab16(TBD_LAST | len);
                for(i=0;i<16;i++)
                {
                        p->xmit_cmds[0]->cmd_status = 0;
                        WAIT_4_SCB_CMD();
                        if( (p->scb->cus & CU_STATUS) == CU_SUSPEND)
                                p->scb->cmd_cuc = CUC_RESUME;
                        else
                        {
                                p->scb->cbl_offset = make16(p->xmit_cmds[0]);
                                p->scb->cmd_cuc = CUC_START;
                        }

                        sun3_attn586();
                        if(!i)
                                dev_kfree_skb(skb);
                        WAIT_4_SCB_CMD();
                        if( (p->scb->cus & CU_ACTIVE)) /* test it, because CU sometimes doesn't start immediately */
                                break;
                        if(p->xmit_cmds[0]->cmd_status)
                                break;
                        if(i==15)
                                printk("%s: Can't start transmit-command.\n",dev->name);
                }
#       else
                next_nop = (p->nop_point + 1) & 0x1;
                p->xmit_buffs[0]->size = swab16(TBD_LAST | len);

                p->xmit_cmds[0]->cmd_link        = p->nop_cmds[next_nop]->cmd_link
                        = make16((p->nop_cmds[next_nop]));
                p->xmit_cmds[0]->cmd_status = p->nop_cmds[next_nop]->cmd_status = 0;

                p->nop_cmds[p->nop_point]->cmd_link = make16((p->xmit_cmds[0]));
                p->nop_point = next_nop;
                dev_kfree_skb(skb);
#       endif
#else
                p->xmit_buffs[p->xmit_count]->size = swab16(TBD_LAST | len);
                if( (next_nop = p->xmit_count + 1) == NUM_XMIT_BUFFS )
                        next_nop = 0;

                p->xmit_cmds[p->xmit_count]->cmd_status = 0;
                /* linkpointer of xmit-command already points to next nop cmd */
                p->nop_cmds[next_nop]->cmd_link = make16((p->nop_cmds[next_nop]));
                p->nop_cmds[next_nop]->cmd_status = 0;

                p->nop_cmds[p->xmit_count]->cmd_link = make16((p->xmit_cmds[p->xmit_count]));
                p->xmit_count = next_nop;

                {
                        unsigned long flags;
                        local_irq_save(flags);
                        if(p->xmit_count != p->xmit_last)
                                netif_wake_queue(dev);
                        p->lock = 0;
                        local_irq_restore(flags);
                }
                dev_kfree_skb(skb);
#endif
        }
        return NETDEV_TX_OK;
}

/*******************************************
 * Someone wanna have the statistics
 */

static struct net_device_stats *sun3_82586_get_stats(struct net_device *dev)
{
        struct priv *p = netdev_priv(dev);
        unsigned short crc,aln,rsc,ovrn;

        crc = swab16(p->scb->crc_errs); /* get error-statistic from the ni82586 */
        p->scb->crc_errs = 0;
        aln = swab16(p->scb->aln_errs);
        p->scb->aln_errs = 0;
        rsc = swab16(p->scb->rsc_errs);
        p->scb->rsc_errs = 0;
        ovrn = swab16(p->scb->ovrn_errs);
        p->scb->ovrn_errs = 0;

        dev->stats.rx_crc_errors += crc;
        dev->stats.rx_fifo_errors += ovrn;
        dev->stats.rx_frame_errors += aln;
        dev->stats.rx_dropped += rsc;

        return &dev->stats;
}

/********************************************************
 * Set MC list ..
 */

static void set_multicast_list(struct net_device *dev)
{
        netif_stop_queue(dev);
        sun3_disint();
        alloc586(dev);
        init586(dev);
        startrecv586(dev);
        sun3_enaint();
        netif_wake_queue(dev);
}

#if 0
/*
 * DUMP .. we expect a not running CMD unit and enough space
 */
void sun3_82586_dump(struct net_device *dev,void *ptr)
{
        struct priv *p = netdev_priv(dev);
        struct dump_cmd_struct *dump_cmd = (struct dump_cmd_struct *) ptr;
        int i;

        p->scb->cmd_cuc = CUC_ABORT;
        sun3_attn586();
        WAIT_4_SCB_CMD();
        WAIT_4_SCB_CMD_RUC();

        dump_cmd->cmd_status = 0;
        dump_cmd->cmd_cmd = CMD_DUMP | CMD_LAST;
        dump_cmd->dump_offset = make16((dump_cmd + 1));
        dump_cmd->cmd_link = 0xffff;

        p->scb->cbl_offset = make16(dump_cmd);
        p->scb->cmd_cuc = CUC_START;
        sun3_attn586();
        WAIT_4_STAT_COMPL(dump_cmd);

        if( (dump_cmd->cmd_status & (STAT_COMPL|STAT_OK)) != (STAT_COMPL|STAT_OK) )
                                printk("%s: Can't get dump information.\n",dev->name);

        for(i=0;i<170;i++) {
                printk("%02x ",(int) ((unsigned char *) (dump_cmd + 1))[i]);
                if(i % 24 == 23)
                        printk("\n");
        }
        printk("\n");
}
#endif