root/drivers/atm/eni.c
// SPDX-License-Identifier: GPL-2.0-only
/* drivers/atm/eni.c - Efficient Networks ENI155P device driver */
 
/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
 

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/atm.h>
#include <linux/atmdev.h>
#include <linux/sonet.h>
#include <linux/skbuff.h>
#include <linux/time.h>
#include <linux/delay.h>
#include <linux/uio.h>
#include <linux/init.h>
#include <linux/atm_eni.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <asm/io.h>
#include <linux/atomic.h>
#include <linux/uaccess.h>
#include <asm/string.h>
#include <asm/byteorder.h>

#include "tonga.h"
#include "midway.h"
#include "suni.h"
#include "eni.h"

/*
 * TODO:
 *
 * Show stoppers
 *  none
 *
 * Minor
 *  - OAM support
 *  - fix bugs listed below
 */

/*
 * KNOWN BUGS:
 *
 * - may run into JK-JK bug and deadlock
 * - should allocate UBR channel first
 * - buffer space allocation algorithm is stupid
 *   (RX: should be maxSDU+maxdelay*rate
 *    TX: should be maxSDU+min(maxSDU,maxdelay*rate) )
 * - doesn't support OAM cells
 * - eni_put_free may hang if not putting memory fragments that _complete_
 *   2^n block (never happens in real life, though)
 */


#if 0
#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
#else
#define DPRINTK(format,args...)
#endif


#ifndef CONFIG_ATM_ENI_TUNE_BURST
#define CONFIG_ATM_ENI_BURST_TX_8W
#define CONFIG_ATM_ENI_BURST_RX_4W
#endif


#ifndef CONFIG_ATM_ENI_DEBUG


#define NULLCHECK(x)

#define EVENT(s,a,b)


static void event_dump(void)
{
}


#else


/* 
 * NULL pointer checking
 */

#define NULLCHECK(x) \
        if ((unsigned long) (x) < 0x30) \
                printk(KERN_CRIT #x "==0x%lx\n",(unsigned long) (x))

/*
 * Very extensive activity logging. Greatly improves bug detection speed but
 * costs a few Mbps if enabled.
 */

#define EV 64

static const char *ev[EV];
static unsigned long ev_a[EV],ev_b[EV];
static int ec = 0;


static void EVENT(const char *s,unsigned long a,unsigned long b)
{
        ev[ec] = s; 
        ev_a[ec] = a;
        ev_b[ec] = b;
        ec = (ec+1) % EV;
}


static void event_dump(void)
{
        int n,i;

        for (n = 0; n < EV; n++) {
                i = (ec+n) % EV;
                printk(KERN_NOTICE);
                printk(ev[i] ? ev[i] : "(null)",ev_a[i],ev_b[i]);
        }
}


#endif /* CONFIG_ATM_ENI_DEBUG */


/*
 * NExx   must not be equal at end
 * EExx   may be equal at end
 * xxPJOK verify validity of pointer jumps
 * xxPMOK operating on a circular buffer of "c" words
 */

#define NEPJOK(a0,a1,b) \
    ((a0) < (a1) ? (b) <= (a0) || (b) > (a1) : (b) <= (a0) && (b) > (a1))
#define EEPJOK(a0,a1,b) \
    ((a0) < (a1) ? (b) < (a0) || (b) >= (a1) : (b) < (a0) && (b) >= (a1))
#define NEPMOK(a0,d,b,c) NEPJOK(a0,(a0+d) & (c-1),b)
#define EEPMOK(a0,d,b,c) EEPJOK(a0,(a0+d) & (c-1),b)


static int tx_complete = 0,dma_complete = 0,queued = 0,requeued = 0,
  backlogged = 0,rx_enqueued = 0,rx_dequeued = 0,pushed = 0,submitted = 0,
  putting = 0;

static struct atm_dev *eni_boards = NULL;

/* Read/write registers on card */
#define eni_in(r)       readl(eni_dev->reg+(r)*4)
#define eni_out(v,r)    writel((v),eni_dev->reg+(r)*4)


/*-------------------------------- utilities --------------------------------*/


static void dump_mem(struct eni_dev *eni_dev)
{
        int i;

        for (i = 0; i < eni_dev->free_len; i++)
                printk(KERN_DEBUG "  %d: %p %d\n",i,
                    eni_dev->free_list[i].start,
                    1 << eni_dev->free_list[i].order);
}


static void dump(struct atm_dev *dev)
{
        struct eni_dev *eni_dev;

        int i;

        eni_dev = ENI_DEV(dev);
        printk(KERN_NOTICE "Free memory\n");
        dump_mem(eni_dev);
        printk(KERN_NOTICE "TX buffers\n");
        for (i = 0; i < NR_CHAN; i++)
                if (eni_dev->tx[i].send)
                        printk(KERN_NOTICE "  TX %d @ %p: %ld\n",i,
                            eni_dev->tx[i].send,eni_dev->tx[i].words*4);
        printk(KERN_NOTICE "RX buffers\n");
        for (i = 0; i < 1024; i++)
                if (eni_dev->rx_map[i] && ENI_VCC(eni_dev->rx_map[i])->rx)
                        printk(KERN_NOTICE "  RX %d @ %p: %ld\n",i,
                            ENI_VCC(eni_dev->rx_map[i])->recv,
                            ENI_VCC(eni_dev->rx_map[i])->words*4);
        printk(KERN_NOTICE "----\n");
}


static void eni_put_free(struct eni_dev *eni_dev, void __iomem *start,
    unsigned long size)
{
        struct eni_free *list;
        int len,order;

        DPRINTK("init 0x%lx+%ld(0x%lx)\n",start,size,size);
        start += eni_dev->base_diff;
        list = eni_dev->free_list;
        len = eni_dev->free_len;
        while (size) {
                if (len >= eni_dev->free_list_size) {
                        printk(KERN_CRIT "eni_put_free overflow (%p,%ld)\n",
                            start,size);
                        break;
                }
                for (order = 0; !(((unsigned long)start | size) & (1 << order)); order++);
                if (MID_MIN_BUF_SIZE > (1 << order)) {
                        printk(KERN_CRIT "eni_put_free: order %d too small\n",
                            order);
                        break;
                }
                list[len].start = (void __iomem *) start;
                list[len].order = order;
                len++;
                start += 1 << order;
                size -= 1 << order;
        }
        eni_dev->free_len = len;
        /*dump_mem(eni_dev);*/
}


static void __iomem *eni_alloc_mem(struct eni_dev *eni_dev, unsigned long *size)
{
        struct eni_free *list;
        void __iomem *start;
        int len,i,order,best_order,index;

        list = eni_dev->free_list;
        len = eni_dev->free_len;
        if (*size < MID_MIN_BUF_SIZE) *size = MID_MIN_BUF_SIZE;
        if (*size > MID_MAX_BUF_SIZE) return NULL;
        for (order = 0; (1 << order) < *size; order++)
                ;
        DPRINTK("trying: %ld->%d\n",*size,order);
        best_order = 65; /* we don't have more than 2^64 of anything ... */
        index = 0; /* silence GCC */
        for (i = 0; i < len; i++)
                if (list[i].order == order) {
                        best_order = order;
                        index = i;
                        break;
                }
                else if (best_order > list[i].order && list[i].order > order) {
                                best_order = list[i].order;
                                index = i;
                        }
        if (best_order == 65) return NULL;
        start = list[index].start-eni_dev->base_diff;
        list[index] = list[--len];
        eni_dev->free_len = len;
        *size = 1 << order;
        eni_put_free(eni_dev,start+*size,(1 << best_order)-*size);
        DPRINTK("%ld bytes (order %d) at 0x%lx\n",*size,order,start);
        memset_io(start,0,*size);       /* never leak data */
        /*dump_mem(eni_dev);*/
        return start;
}


static void eni_free_mem(struct eni_dev *eni_dev, void __iomem *start,
    unsigned long size)
{
        struct eni_free *list;
        int len,i,order;

        start += eni_dev->base_diff;
        list = eni_dev->free_list;
        len = eni_dev->free_len;
        for (order = -1; size; order++) size >>= 1;
        DPRINTK("eni_free_mem: %p+0x%lx (order %d)\n",start,size,order);
        for (i = 0; i < len; i++)
                if (((unsigned long) list[i].start) == ((unsigned long)start^(1 << order)) &&
                    list[i].order == order) {
                        DPRINTK("match[%d]: 0x%lx/0x%lx(0x%x), %d/%d\n",i,
                            list[i].start,start,1 << order,list[i].order,order);
                        list[i] = list[--len];
                        start = (void __iomem *) ((unsigned long) start & ~(unsigned long) (1 << order));
                        order++;
                        i = -1;
                        continue;
                }
        if (len >= eni_dev->free_list_size) {
                printk(KERN_ALERT "eni_free_mem overflow (%p,%d)\n",start,
                    order);
                return;
        }
        list[len].start = start;
        list[len].order = order;
        eni_dev->free_len = len+1;
        /*dump_mem(eni_dev);*/
}


/*----------------------------------- RX ------------------------------------*/


#define ENI_VCC_NOS ((struct atm_vcc *) 1)


static void rx_ident_err(struct atm_vcc *vcc)
{
        struct atm_dev *dev;
        struct eni_dev *eni_dev;
        struct eni_vcc *eni_vcc;

        dev = vcc->dev;
        eni_dev = ENI_DEV(dev);
        /* immediately halt adapter */
        eni_out(eni_in(MID_MC_S) &
            ~(MID_DMA_ENABLE | MID_TX_ENABLE | MID_RX_ENABLE),MID_MC_S);
        /* dump useful information */
        eni_vcc = ENI_VCC(vcc);
        printk(KERN_ALERT DEV_LABEL "(itf %d): driver error - RX ident "
            "mismatch\n",dev->number);
        printk(KERN_ALERT "  VCI %d, rxing %d, words %ld\n",vcc->vci,
            eni_vcc->rxing,eni_vcc->words);
        printk(KERN_ALERT "  host descr 0x%lx, rx pos 0x%lx, descr value "
            "0x%x\n",eni_vcc->descr,eni_vcc->rx_pos,
            (unsigned) readl(eni_vcc->recv+eni_vcc->descr*4));
        printk(KERN_ALERT "  last %p, servicing %d\n",eni_vcc->last,
            eni_vcc->servicing);
        EVENT("---dump ends here---\n",0,0);
        printk(KERN_NOTICE "---recent events---\n");
        event_dump();
        ENI_DEV(dev)->fast = NULL; /* really stop it */
        ENI_DEV(dev)->slow = NULL;
        skb_queue_head_init(&ENI_DEV(dev)->rx_queue);
}


static int do_rx_dma(struct atm_vcc *vcc,struct sk_buff *skb,
    unsigned long skip,unsigned long size,unsigned long eff)
{
        struct eni_dev *eni_dev;
        struct eni_vcc *eni_vcc;
        u32 dma_rd,dma_wr;
        u32 dma[RX_DMA_BUF*2];
        dma_addr_t paddr;
        unsigned long here;
        int i,j;

        eni_dev = ENI_DEV(vcc->dev);
        eni_vcc = ENI_VCC(vcc);
        paddr = 0; /* GCC, shut up */
        if (skb) {
                paddr = dma_map_single(&eni_dev->pci_dev->dev,skb->data,skb->len,
                                       DMA_FROM_DEVICE);
                if (dma_mapping_error(&eni_dev->pci_dev->dev, paddr))
                        goto dma_map_error;
                ENI_PRV_PADDR(skb) = paddr;
                if (paddr & 3)
                        printk(KERN_CRIT DEV_LABEL "(itf %d): VCI %d has "
                            "mis-aligned RX data (0x%lx)\n",vcc->dev->number,
                            vcc->vci,(unsigned long) paddr);
                ENI_PRV_SIZE(skb) = size+skip;
                    /* PDU plus descriptor */
                ATM_SKB(skb)->vcc = vcc;
        }
        j = 0;
        if ((eff && skip) || 1) { /* @@@ actually, skip is always == 1 ... */
                here = (eni_vcc->descr+skip) & (eni_vcc->words-1);
                dma[j++] = (here << MID_DMA_COUNT_SHIFT) | (vcc->vci
                    << MID_DMA_VCI_SHIFT) | MID_DT_JK;
                dma[j++] = 0;
        }
        here = (eni_vcc->descr+size+skip) & (eni_vcc->words-1);
        if (!eff) size += skip;
        else {
                unsigned long words;

                if (!size) {
                        DPRINTK("strange things happen ...\n");
                        EVENT("strange things happen ... (skip=%ld,eff=%ld)\n",
                            size,eff);
                }
                words = eff;
                if (paddr & 15) {
                        unsigned long init;

                        init = 4-((paddr & 15) >> 2);
                        if (init > words) init = words;
                        dma[j++] = MID_DT_WORD | (init << MID_DMA_COUNT_SHIFT) |
                            (vcc->vci << MID_DMA_VCI_SHIFT);
                        dma[j++] = paddr;
                        paddr += init << 2;
                        words -= init;
                }
#ifdef CONFIG_ATM_ENI_BURST_RX_16W /* may work with some PCI chipsets ... */
                if (words & ~15) {
                        dma[j++] = MID_DT_16W | ((words >> 4) <<
                            MID_DMA_COUNT_SHIFT) | (vcc->vci <<
                            MID_DMA_VCI_SHIFT);
                        dma[j++] = paddr;
                        paddr += (words & ~15) << 2;
                        words &= 15;
                }
#endif
#ifdef CONFIG_ATM_ENI_BURST_RX_8W  /* works only with *some* PCI chipsets ... */
                if (words & ~7) {
                        dma[j++] = MID_DT_8W | ((words >> 3) <<
                            MID_DMA_COUNT_SHIFT) | (vcc->vci <<
                            MID_DMA_VCI_SHIFT);
                        dma[j++] = paddr;
                        paddr += (words & ~7) << 2;
                        words &= 7;
                }
#endif
#ifdef CONFIG_ATM_ENI_BURST_RX_4W /* recommended */
                if (words & ~3) {
                        dma[j++] = MID_DT_4W | ((words >> 2) <<
                            MID_DMA_COUNT_SHIFT) | (vcc->vci <<
                            MID_DMA_VCI_SHIFT);
                        dma[j++] = paddr;
                        paddr += (words & ~3) << 2;
                        words &= 3;
                }
#endif
#ifdef CONFIG_ATM_ENI_BURST_RX_2W /* probably useless if RX_4W, RX_8W, ... */
                if (words & ~1) {
                        dma[j++] = MID_DT_2W | ((words >> 1) <<
                            MID_DMA_COUNT_SHIFT) | (vcc->vci <<
                            MID_DMA_VCI_SHIFT);
                        dma[j++] = paddr;
                        paddr += (words & ~1) << 2;
                        words &= 1;
                }
#endif
                if (words) {
                        dma[j++] = MID_DT_WORD | (words << MID_DMA_COUNT_SHIFT)
                            | (vcc->vci << MID_DMA_VCI_SHIFT);
                        dma[j++] = paddr;
                }
        }
        if (size != eff) {
                dma[j++] = (here << MID_DMA_COUNT_SHIFT) |
                    (vcc->vci << MID_DMA_VCI_SHIFT) | MID_DT_JK;
                dma[j++] = 0;
        }
        if (!j || j > 2*RX_DMA_BUF) {
                printk(KERN_CRIT DEV_LABEL "!j or j too big!!!\n");
                goto trouble;
        }
        dma[j-2] |= MID_DMA_END;
        j = j >> 1;
        dma_wr = eni_in(MID_DMA_WR_RX);
        dma_rd = eni_in(MID_DMA_RD_RX);
        /*
         * Can I move the dma_wr pointer by 2j+1 positions without overwriting
         * data that hasn't been read (position of dma_rd) yet ?
         */
        if (!NEPMOK(dma_wr,j+j+1,dma_rd,NR_DMA_RX)) { /* @@@ +1 is ugly */
                printk(KERN_WARNING DEV_LABEL "(itf %d): RX DMA full\n",
                    vcc->dev->number);
                goto trouble;
        }
        for (i = 0; i < j; i++) {
                writel(dma[i*2],eni_dev->rx_dma+dma_wr*8);
                writel(dma[i*2+1],eni_dev->rx_dma+dma_wr*8+4);
                dma_wr = (dma_wr+1) & (NR_DMA_RX-1);
        }
        if (skb) {
                ENI_PRV_POS(skb) = eni_vcc->descr+size+1;
                skb_queue_tail(&eni_dev->rx_queue,skb);
                eni_vcc->last = skb;
                rx_enqueued++;
        }
        eni_vcc->descr = here;
        eni_out(dma_wr,MID_DMA_WR_RX);
        return 0;

trouble:
        if (paddr)
                dma_unmap_single(&eni_dev->pci_dev->dev,paddr,skb->len,
                                 DMA_FROM_DEVICE);
dma_map_error:
        if (skb) dev_kfree_skb_irq(skb);
        return -1;
}


static void discard(struct atm_vcc *vcc,unsigned long size)
{
        struct eni_vcc *eni_vcc;

        eni_vcc = ENI_VCC(vcc);
        EVENT("discard (size=%ld)\n",size,0);
        while (do_rx_dma(vcc,NULL,1,size,0)) EVENT("BUSY LOOP",0,0);
            /* could do a full fallback, but that might be more expensive */
        if (eni_vcc->rxing) ENI_PRV_POS(eni_vcc->last) += size+1;
        else eni_vcc->rx_pos = (eni_vcc->rx_pos+size+1) & (eni_vcc->words-1);
}


/*
 * TODO: should check whether direct copies (without DMA setup, dequeuing on
 * interrupt, etc.) aren't much faster for AAL0
 */

static int rx_aal0(struct atm_vcc *vcc)
{
        struct eni_vcc *eni_vcc;
        unsigned long descr;
        unsigned long length;
        struct sk_buff *skb;

        DPRINTK(">rx_aal0\n");
        eni_vcc = ENI_VCC(vcc);
        descr = readl(eni_vcc->recv+eni_vcc->descr*4);
        if ((descr & MID_RED_IDEN) != (MID_RED_RX_ID << MID_RED_SHIFT)) {
                rx_ident_err(vcc);
                return 1;
        }
        if (descr & MID_RED_T) {
                DPRINTK(DEV_LABEL "(itf %d): trashing empty cell\n",
                    vcc->dev->number);
                length = 0;
                atomic_inc(&vcc->stats->rx_err);
        }
        else {
                length = ATM_CELL_SIZE-1; /* no HEC */
        }
        skb = length ? atm_alloc_charge(vcc,length,GFP_ATOMIC) : NULL;
        if (!skb) {
                discard(vcc,length >> 2);
                return 0;
        }
        skb_put(skb,length);
        skb->tstamp = eni_vcc->timestamp;
        DPRINTK("got len %ld\n",length);
        if (do_rx_dma(vcc,skb,1,length >> 2,length >> 2)) return 1;
        eni_vcc->rxing++;
        return 0;
}


static int rx_aal5(struct atm_vcc *vcc)
{
        struct eni_vcc *eni_vcc;
        unsigned long descr;
        unsigned long size,eff,length;
        struct sk_buff *skb;

        EVENT("rx_aal5\n",0,0);
        DPRINTK(">rx_aal5\n");
        eni_vcc = ENI_VCC(vcc);
        descr = readl(eni_vcc->recv+eni_vcc->descr*4);
        if ((descr & MID_RED_IDEN) != (MID_RED_RX_ID << MID_RED_SHIFT)) {
                rx_ident_err(vcc);
                return 1;
        }
        if (descr & (MID_RED_T | MID_RED_CRC_ERR)) {
                if (descr & MID_RED_T) {
                        EVENT("empty cell (descr=0x%lx)\n",descr,0);
                        DPRINTK(DEV_LABEL "(itf %d): trashing empty cell\n",
                            vcc->dev->number);
                        size = 0;
                }
                else {
                        static unsigned long silence = 0;

                        if (time_after(jiffies, silence) || silence == 0) {
                                printk(KERN_WARNING DEV_LABEL "(itf %d): "
                                    "discarding PDU(s) with CRC error\n",
                                    vcc->dev->number);
                                silence = (jiffies+2*HZ)|1;
                        }
                        size = (descr & MID_RED_COUNT)*(ATM_CELL_PAYLOAD >> 2);
                        EVENT("CRC error (descr=0x%lx,size=%ld)\n",descr,
                            size);
                }
                eff = length = 0;
                atomic_inc(&vcc->stats->rx_err);
        }
        else {
                size = (descr & MID_RED_COUNT)*(ATM_CELL_PAYLOAD >> 2);
                DPRINTK("size=%ld\n",size);
                length = readl(eni_vcc->recv+(((eni_vcc->descr+size-1) &
                    (eni_vcc->words-1)))*4) & 0xffff;
                                /* -trailer(2)+header(1) */
                if (length && length <= (size << 2)-8 && length <=
                  ATM_MAX_AAL5_PDU) eff = (length+3) >> 2;
                else {                           /* ^ trailer length (8) */
                        EVENT("bad PDU (descr=0x08%lx,length=%ld)\n",descr,
                            length);
                        printk(KERN_ERR DEV_LABEL "(itf %d): bad AAL5 PDU "
                            "(VCI=%d,length=%ld,size=%ld (descr 0x%lx))\n",
                            vcc->dev->number,vcc->vci,length,size << 2,descr);
                        length = eff = 0;
                        atomic_inc(&vcc->stats->rx_err);
                }
        }
        skb = eff ? atm_alloc_charge(vcc,eff << 2,GFP_ATOMIC) : NULL;
        if (!skb) {
                discard(vcc,size);
                return 0;
        }
        skb_put(skb,length);
        DPRINTK("got len %ld\n",length);
        if (do_rx_dma(vcc,skb,1,size,eff)) return 1;
        eni_vcc->rxing++;
        return 0;
}


static inline int rx_vcc(struct atm_vcc *vcc)
{
        void __iomem *vci_dsc;
        unsigned long tmp;
        struct eni_vcc *eni_vcc;

        eni_vcc = ENI_VCC(vcc);
        vci_dsc = ENI_DEV(vcc->dev)->vci+vcc->vci*16;
        EVENT("rx_vcc(1)\n",0,0);
        while (eni_vcc->descr != (tmp = (readl(vci_dsc+4) & MID_VCI_DESCR) >>
            MID_VCI_DESCR_SHIFT)) {
                EVENT("rx_vcc(2: host dsc=0x%lx, nic dsc=0x%lx)\n",
                    eni_vcc->descr,tmp);
                DPRINTK("CB_DESCR %ld REG_DESCR %d\n",ENI_VCC(vcc)->descr,
                    (((unsigned) readl(vci_dsc+4) & MID_VCI_DESCR) >>
                    MID_VCI_DESCR_SHIFT));
                if (ENI_VCC(vcc)->rx(vcc)) return 1;
        }
        /* clear IN_SERVICE flag */
        writel(readl(vci_dsc) & ~MID_VCI_IN_SERVICE,vci_dsc);
        /*
         * If new data has arrived between evaluating the while condition and
         * clearing IN_SERVICE, we wouldn't be notified until additional data
         * follows. So we have to loop again to be sure.
         */
        EVENT("rx_vcc(3)\n",0,0);
        while (ENI_VCC(vcc)->descr != (tmp = (readl(vci_dsc+4) & MID_VCI_DESCR)
            >> MID_VCI_DESCR_SHIFT)) {
                EVENT("rx_vcc(4: host dsc=0x%lx, nic dsc=0x%lx)\n",
                    eni_vcc->descr,tmp);
                DPRINTK("CB_DESCR %ld REG_DESCR %d\n",ENI_VCC(vcc)->descr,
                    (((unsigned) readl(vci_dsc+4) & MID_VCI_DESCR) >>
                    MID_VCI_DESCR_SHIFT));
                if (ENI_VCC(vcc)->rx(vcc)) return 1;
        }
        return 0;
}


static void poll_rx(struct atm_dev *dev)
{
        struct eni_dev *eni_dev;
        struct atm_vcc *curr;

        eni_dev = ENI_DEV(dev);
        while ((curr = eni_dev->fast)) {
                EVENT("poll_rx.fast\n",0,0);
                if (rx_vcc(curr)) return;
                eni_dev->fast = ENI_VCC(curr)->next;
                ENI_VCC(curr)->next = ENI_VCC_NOS;
                barrier();
                ENI_VCC(curr)->servicing--;
        }
        while ((curr = eni_dev->slow)) {
                EVENT("poll_rx.slow\n",0,0);
                if (rx_vcc(curr)) return;
                eni_dev->slow = ENI_VCC(curr)->next;
                ENI_VCC(curr)->next = ENI_VCC_NOS;
                barrier();
                ENI_VCC(curr)->servicing--;
        }
}


static void get_service(struct atm_dev *dev)
{
        struct eni_dev *eni_dev;
        struct atm_vcc *vcc;
        unsigned long vci;

        DPRINTK(">get_service\n");
        eni_dev = ENI_DEV(dev);
        while (eni_in(MID_SERV_WRITE) != eni_dev->serv_read) {
                vci = readl(eni_dev->service+eni_dev->serv_read*4);
                eni_dev->serv_read = (eni_dev->serv_read+1) & (NR_SERVICE-1);
                vcc = eni_dev->rx_map[vci & 1023];
                if (!vcc) {
                        printk(KERN_CRIT DEV_LABEL "(itf %d): VCI %ld not "
                            "found\n",dev->number,vci);
                        continue; /* nasty but we try to go on anyway */
                        /* @@@ nope, doesn't work */
                }
                EVENT("getting from service\n",0,0);
                if (ENI_VCC(vcc)->next != ENI_VCC_NOS) {
                        EVENT("double service\n",0,0);
                        DPRINTK("Grr, servicing VCC %ld twice\n",vci);
                        continue;
                }
                ENI_VCC(vcc)->timestamp = ktime_get_real();
                ENI_VCC(vcc)->next = NULL;
                if (vcc->qos.rxtp.traffic_class == ATM_CBR) {
                        if (eni_dev->fast)
                                ENI_VCC(eni_dev->last_fast)->next = vcc;
                        else eni_dev->fast = vcc;
                        eni_dev->last_fast = vcc;
                }
                else {
                        if (eni_dev->slow)
                                ENI_VCC(eni_dev->last_slow)->next = vcc;
                        else eni_dev->slow = vcc;
                        eni_dev->last_slow = vcc;
                }
                putting++;
                ENI_VCC(vcc)->servicing++;
        }
}


static void dequeue_rx(struct atm_dev *dev)
{
        struct eni_dev *eni_dev;
        struct eni_vcc *eni_vcc;
        struct atm_vcc *vcc;
        struct sk_buff *skb;
        void __iomem *vci_dsc;
        int first;

        eni_dev = ENI_DEV(dev);
        first = 1;
        while (1) {
                skb = skb_dequeue(&eni_dev->rx_queue);
                if (!skb) {
                        if (first) {
                                DPRINTK(DEV_LABEL "(itf %d): RX but not "
                                    "rxing\n",dev->number);
                                EVENT("nothing to dequeue\n",0,0);
                        }
                        break;
                }
                EVENT("dequeued (size=%ld,pos=0x%lx)\n",ENI_PRV_SIZE(skb),
                    ENI_PRV_POS(skb));
                rx_dequeued++;
                vcc = ATM_SKB(skb)->vcc;
                eni_vcc = ENI_VCC(vcc);
                first = 0;
                vci_dsc = eni_dev->vci+vcc->vci*16;
                if (!EEPMOK(eni_vcc->rx_pos,ENI_PRV_SIZE(skb),
                    (readl(vci_dsc+4) & MID_VCI_READ) >> MID_VCI_READ_SHIFT,
                    eni_vcc->words)) {
                        EVENT("requeuing\n",0,0);
                        skb_queue_head(&eni_dev->rx_queue,skb);
                        break;
                }
                eni_vcc->rxing--;
                eni_vcc->rx_pos = ENI_PRV_POS(skb) & (eni_vcc->words-1);
                dma_unmap_single(&eni_dev->pci_dev->dev,ENI_PRV_PADDR(skb),skb->len,
                                 DMA_TO_DEVICE);
                if (!skb->len) dev_kfree_skb_irq(skb);
                else {
                        EVENT("pushing (len=%ld)\n",skb->len,0);
                        if (vcc->qos.aal == ATM_AAL0)
                                *(unsigned long *) skb->data =
                                    ntohl(*(unsigned long *) skb->data);
                        memset(skb->cb,0,sizeof(struct eni_skb_prv));
                        vcc->push(vcc,skb);
                        pushed++;
                }
                atomic_inc(&vcc->stats->rx);
        }
        wake_up(&eni_dev->rx_wait);
}


static int open_rx_first(struct atm_vcc *vcc)
{
        struct eni_dev *eni_dev;
        struct eni_vcc *eni_vcc;
        unsigned long size;

        DPRINTK("open_rx_first\n");
        eni_dev = ENI_DEV(vcc->dev);
        eni_vcc = ENI_VCC(vcc);
        eni_vcc->rx = NULL;
        if (vcc->qos.rxtp.traffic_class == ATM_NONE) return 0;
        size = vcc->qos.rxtp.max_sdu*eni_dev->rx_mult/100;
        if (size > MID_MAX_BUF_SIZE && vcc->qos.rxtp.max_sdu <=
            MID_MAX_BUF_SIZE)
                size = MID_MAX_BUF_SIZE;
        eni_vcc->recv = eni_alloc_mem(eni_dev,&size);
        DPRINTK("rx at 0x%lx\n",eni_vcc->recv);
        eni_vcc->words = size >> 2;
        if (!eni_vcc->recv) return -ENOBUFS;
        eni_vcc->rx = vcc->qos.aal == ATM_AAL5 ? rx_aal5 : rx_aal0;
        eni_vcc->descr = 0;
        eni_vcc->rx_pos = 0;
        eni_vcc->rxing = 0;
        eni_vcc->servicing = 0;
        eni_vcc->next = ENI_VCC_NOS;
        return 0;
}


static int open_rx_second(struct atm_vcc *vcc)
{
        void __iomem *here;
        struct eni_dev *eni_dev;
        struct eni_vcc *eni_vcc;
        unsigned long size;
        int order;

        DPRINTK("open_rx_second\n");
        eni_dev = ENI_DEV(vcc->dev);
        eni_vcc = ENI_VCC(vcc);
        if (!eni_vcc->rx) return 0;
        /* set up VCI descriptor */
        here = eni_dev->vci+vcc->vci*16;
        DPRINTK("loc 0x%x\n",(unsigned) (eni_vcc->recv-eni_dev->ram)/4);
        size = eni_vcc->words >> 8;
        for (order = -1; size; order++) size >>= 1;
        writel(0,here+4); /* descr, read = 0 */
        writel(0,here+8); /* write, state, count = 0 */
        if (eni_dev->rx_map[vcc->vci])
                printk(KERN_CRIT DEV_LABEL "(itf %d): BUG - VCI %d already "
                    "in use\n",vcc->dev->number,vcc->vci);
        eni_dev->rx_map[vcc->vci] = vcc; /* now it counts */
        writel(((vcc->qos.aal != ATM_AAL5 ? MID_MODE_RAW : MID_MODE_AAL5) <<
            MID_VCI_MODE_SHIFT) | MID_VCI_PTI_MODE |
            (((eni_vcc->recv-eni_dev->ram) >> (MID_LOC_SKIP+2)) <<
            MID_VCI_LOCATION_SHIFT) | (order << MID_VCI_SIZE_SHIFT),here);
        return 0;
}


static void close_rx(struct atm_vcc *vcc)
{
        DECLARE_WAITQUEUE(wait,current);
        void __iomem *here;
        struct eni_dev *eni_dev;
        struct eni_vcc *eni_vcc;

        eni_vcc = ENI_VCC(vcc);
        if (!eni_vcc->rx) return;
        eni_dev = ENI_DEV(vcc->dev);
        if (vcc->vpi != ATM_VPI_UNSPEC && vcc->vci != ATM_VCI_UNSPEC) {
                here = eni_dev->vci+vcc->vci*16;
                /* block receiver */
                writel((readl(here) & ~MID_VCI_MODE) | (MID_MODE_TRASH <<
                    MID_VCI_MODE_SHIFT),here);
                /* wait for receiver to become idle */
                udelay(27);
                /* discard pending cell */
                writel(readl(here) & ~MID_VCI_IN_SERVICE,here);
                /* don't accept any new ones */
                eni_dev->rx_map[vcc->vci] = NULL;
                /* wait for RX queue to drain */
                DPRINTK("eni_close: waiting for RX ...\n");
                EVENT("RX closing\n",0,0);
                add_wait_queue(&eni_dev->rx_wait,&wait);
                set_current_state(TASK_UNINTERRUPTIBLE);
                barrier();
                for (;;) {
                        /* transition service->rx: rxing++, servicing-- */
                        if (!eni_vcc->servicing) {
                                barrier();
                                if (!eni_vcc->rxing) break;
                        }
                        EVENT("drain PDUs (rx %ld, serv %ld)\n",eni_vcc->rxing,
                            eni_vcc->servicing);
                        printk(KERN_INFO "%d+%d RX left\n",eni_vcc->servicing,
                            eni_vcc->rxing);
                        schedule();
                        set_current_state(TASK_UNINTERRUPTIBLE);
                }
                for (;;) {
                        int at_end;
                        u32 tmp;

                        tasklet_disable(&eni_dev->task);
                        tmp = readl(eni_dev->vci+vcc->vci*16+4) & MID_VCI_READ;
                        at_end = eni_vcc->rx_pos == tmp >> MID_VCI_READ_SHIFT;
                        tasklet_enable(&eni_dev->task);
                        if (at_end) break;
                        EVENT("drain discard (host 0x%lx, nic 0x%lx)\n",
                            eni_vcc->rx_pos,tmp);
                        printk(KERN_INFO "draining RX: host 0x%lx, nic 0x%x\n",
                            eni_vcc->rx_pos,tmp);
                        schedule();
                        set_current_state(TASK_UNINTERRUPTIBLE);
                }
                set_current_state(TASK_RUNNING);
                remove_wait_queue(&eni_dev->rx_wait,&wait);
        }
        eni_free_mem(eni_dev,eni_vcc->recv,eni_vcc->words << 2);
        eni_vcc->rx = NULL;
}


static int start_rx(struct atm_dev *dev)
{
        struct eni_dev *eni_dev;

        eni_dev = ENI_DEV(dev);
        eni_dev->rx_map = (struct atm_vcc **) get_zeroed_page(GFP_KERNEL);
        if (!eni_dev->rx_map) {
                printk(KERN_ERR DEV_LABEL "(itf %d): couldn't get free page\n",
                    dev->number);
                free_page((unsigned long) eni_dev->free_list);
                return -ENOMEM;
        }
        eni_dev->rx_mult = DEFAULT_RX_MULT;
        eni_dev->fast = eni_dev->last_fast = NULL;
        eni_dev->slow = eni_dev->last_slow = NULL;
        init_waitqueue_head(&eni_dev->rx_wait);
        skb_queue_head_init(&eni_dev->rx_queue);
        eni_dev->serv_read = eni_in(MID_SERV_WRITE);
        eni_out(0,MID_DMA_WR_RX);
        return 0;
}


/*----------------------------------- TX ------------------------------------*/


enum enq_res { enq_ok,enq_next,enq_jam };


static inline void put_dma(int chan,u32 *dma,int *j,dma_addr_t paddr,
    u32 size)
{
        u32 init,words;

        DPRINTK("put_dma: 0x%lx+0x%x\n",(unsigned long) paddr,size);
        EVENT("put_dma: 0x%lx+0x%lx\n",(unsigned long) paddr,size);
#if 0 /* don't complain anymore */
        if (paddr & 3)
                printk(KERN_ERR "put_dma: unaligned addr (0x%lx)\n",paddr);
        if (size & 3)
                printk(KERN_ERR "put_dma: unaligned size (0x%lx)\n",size);
#endif
        if (paddr & 3) {
                init = 4-(paddr & 3);
                if (init > size || size < 7) init = size;
                DPRINTK("put_dma: %lx DMA: %d/%d bytes\n",
                    (unsigned long) paddr,init,size);
                dma[(*j)++] = MID_DT_BYTE | (init << MID_DMA_COUNT_SHIFT) |
                    (chan << MID_DMA_CHAN_SHIFT);
                dma[(*j)++] = paddr;
                paddr += init;
                size -= init;
        }
        words = size >> 2;
        size &= 3;
        if (words && (paddr & 31)) {
                init = 8-((paddr & 31) >> 2);
                if (init > words) init = words;
                DPRINTK("put_dma: %lx DMA: %d/%d words\n",
                    (unsigned long) paddr,init,words);
                dma[(*j)++] = MID_DT_WORD | (init << MID_DMA_COUNT_SHIFT) |
                    (chan << MID_DMA_CHAN_SHIFT);
                dma[(*j)++] = paddr;
                paddr += init << 2;
                words -= init;
        }
#ifdef CONFIG_ATM_ENI_BURST_TX_16W /* may work with some PCI chipsets ... */
        if (words & ~15) {
                DPRINTK("put_dma: %lx DMA: %d*16/%d words\n",
                    (unsigned long) paddr,words >> 4,words);
                dma[(*j)++] = MID_DT_16W | ((words >> 4) << MID_DMA_COUNT_SHIFT)
                    | (chan << MID_DMA_CHAN_SHIFT);
                dma[(*j)++] = paddr;
                paddr += (words & ~15) << 2;
                words &= 15;
        }
#endif
#ifdef CONFIG_ATM_ENI_BURST_TX_8W /* recommended */
        if (words & ~7) {
                DPRINTK("put_dma: %lx DMA: %d*8/%d words\n",
                    (unsigned long) paddr,words >> 3,words);
                dma[(*j)++] = MID_DT_8W | ((words >> 3) << MID_DMA_COUNT_SHIFT)
                    | (chan << MID_DMA_CHAN_SHIFT);
                dma[(*j)++] = paddr;
                paddr += (words & ~7) << 2;
                words &= 7;
        }
#endif
#ifdef CONFIG_ATM_ENI_BURST_TX_4W /* probably useless if TX_8W or TX_16W */
        if (words & ~3) {
                DPRINTK("put_dma: %lx DMA: %d*4/%d words\n",
                    (unsigned long) paddr,words >> 2,words);
                dma[(*j)++] = MID_DT_4W | ((words >> 2) << MID_DMA_COUNT_SHIFT)
                    | (chan << MID_DMA_CHAN_SHIFT);
                dma[(*j)++] = paddr;
                paddr += (words & ~3) << 2;
                words &= 3;
        }
#endif
#ifdef CONFIG_ATM_ENI_BURST_TX_2W /* probably useless if TX_4W, TX_8W, ... */
        if (words & ~1) {
                DPRINTK("put_dma: %lx DMA: %d*2/%d words\n",
                    (unsigned long) paddr,words >> 1,words);
                dma[(*j)++] = MID_DT_2W | ((words >> 1) << MID_DMA_COUNT_SHIFT)
                    | (chan << MID_DMA_CHAN_SHIFT);
                dma[(*j)++] = paddr;
                paddr += (words & ~1) << 2;
                words &= 1;
        }
#endif
        if (words) {
                DPRINTK("put_dma: %lx DMA: %d words\n",(unsigned long) paddr,
                    words);
                dma[(*j)++] = MID_DT_WORD | (words << MID_DMA_COUNT_SHIFT) |
                    (chan << MID_DMA_CHAN_SHIFT);
                dma[(*j)++] = paddr;
                paddr += words << 2;
        }
        if (size) {
                DPRINTK("put_dma: %lx DMA: %d bytes\n",(unsigned long) paddr,
                    size);
                dma[(*j)++] = MID_DT_BYTE | (size << MID_DMA_COUNT_SHIFT) |
                    (chan << MID_DMA_CHAN_SHIFT);
                dma[(*j)++] = paddr;
        }
}


static enum enq_res do_tx(struct sk_buff *skb)
{
        struct atm_vcc *vcc;
        struct eni_dev *eni_dev;
        struct eni_vcc *eni_vcc;
        struct eni_tx *tx;
        dma_addr_t paddr;
        u32 dma_rd,dma_wr;
        u32 size; /* in words */
        int aal5,dma_size,i,j;
        unsigned char skb_data3;

        DPRINTK(">do_tx\n");
        NULLCHECK(skb);
        EVENT("do_tx: skb=0x%lx, %ld bytes\n",(unsigned long) skb,skb->len);
        vcc = ATM_SKB(skb)->vcc;
        NULLCHECK(vcc);
        eni_dev = ENI_DEV(vcc->dev);
        NULLCHECK(eni_dev);
        eni_vcc = ENI_VCC(vcc);
        tx = eni_vcc->tx;
        NULLCHECK(tx);
#if 0 /* Enable this for testing with the "align" program */
        {
                unsigned int hack = *((char *) skb->data)-'0';

                if (hack < 8) {
                        skb->data += hack;
                        skb->len -= hack;
                }
        }
#endif
#if 0 /* should work now */
        if ((unsigned long) skb->data & 3)
                printk(KERN_ERR DEV_LABEL "(itf %d): VCI %d has mis-aligned "
                    "TX data\n",vcc->dev->number,vcc->vci);
#endif
        /*
         * Potential future IP speedup: make hard_header big enough to put
         * segmentation descriptor directly into PDU. Saves: 4 slave writes,
         * 1 DMA xfer & 2 DMA'ed bytes (protocol layering is for wimps :-)
         */

        aal5 = vcc->qos.aal == ATM_AAL5;
        /* check space in buffer */
        if (!aal5)
                size = (ATM_CELL_PAYLOAD >> 2)+TX_DESCR_SIZE;
                        /* cell without HEC plus segmentation header (includes
                           four-byte cell header) */
        else {
                size = skb->len+4*AAL5_TRAILER+ATM_CELL_PAYLOAD-1;
                        /* add AAL5 trailer */
                size = ((size-(size % ATM_CELL_PAYLOAD)) >> 2)+TX_DESCR_SIZE;
                                                /* add segmentation header */
        }
        /*
         * Can I move tx_pos by size bytes without getting closer than TX_GAP
         * to the read pointer ? TX_GAP means to leave some space for what
         * the manual calls "too close".
         */
        if (!NEPMOK(tx->tx_pos,size+TX_GAP,
            eni_in(MID_TX_RDPTR(tx->index)),tx->words)) {
                DPRINTK(DEV_LABEL "(itf %d): TX full (size %d)\n",
                    vcc->dev->number,size);
                return enq_next;
        }
        /* check DMA */
        dma_wr = eni_in(MID_DMA_WR_TX);
        dma_rd = eni_in(MID_DMA_RD_TX);
        dma_size = 3; /* JK for descriptor and final fill, plus final size
                         mis-alignment fix */
DPRINTK("iovcnt = %d\n",skb_shinfo(skb)->nr_frags);
        if (!skb_shinfo(skb)->nr_frags) dma_size += 5;
        else dma_size += 5*(skb_shinfo(skb)->nr_frags+1);
        if (dma_size > TX_DMA_BUF) {
                printk(KERN_CRIT DEV_LABEL "(itf %d): needs %d DMA entries "
                    "(got only %d)\n",vcc->dev->number,dma_size,TX_DMA_BUF);
        }
        DPRINTK("dma_wr is %d, tx_pos is %ld\n",dma_wr,tx->tx_pos);
        if (dma_wr != dma_rd && ((dma_rd+NR_DMA_TX-dma_wr) & (NR_DMA_TX-1)) <
             dma_size) {
                printk(KERN_WARNING DEV_LABEL "(itf %d): TX DMA full\n",
                    vcc->dev->number);
                return enq_jam;
        }
        skb_data3 = skb->data[3];
        paddr = dma_map_single(&eni_dev->pci_dev->dev,skb->data,skb->len,
                               DMA_TO_DEVICE);
        if (dma_mapping_error(&eni_dev->pci_dev->dev, paddr))
                return enq_next;
        ENI_PRV_PADDR(skb) = paddr;
        /* prepare DMA queue entries */
        j = 0;
        eni_dev->dma[j++] = (((tx->tx_pos+TX_DESCR_SIZE) & (tx->words-1)) <<
             MID_DMA_COUNT_SHIFT) | (tx->index << MID_DMA_CHAN_SHIFT) |
             MID_DT_JK;
        j++;
        if (!skb_shinfo(skb)->nr_frags)
                if (aal5) put_dma(tx->index,eni_dev->dma,&j,paddr,skb->len);
                else put_dma(tx->index,eni_dev->dma,&j,paddr+4,skb->len-4);
        else {
DPRINTK("doing direct send\n"); /* @@@ well, this doesn't work anyway */
                for (i = -1; i < skb_shinfo(skb)->nr_frags; i++)
                        if (i == -1)
                                put_dma(tx->index,eni_dev->dma,&j,(unsigned long)
                                    skb->data,
                                    skb_headlen(skb));
                        else
                                put_dma(tx->index,eni_dev->dma,&j,(unsigned long)
                                    skb_frag_page(&skb_shinfo(skb)->frags[i]) +
                                        skb_frag_off(&skb_shinfo(skb)->frags[i]),
                                    skb_frag_size(&skb_shinfo(skb)->frags[i]));
        }
        if (skb->len & 3) {
                put_dma(tx->index, eni_dev->dma, &j, eni_dev->zero.dma,
                        4 - (skb->len & 3));
        }
        /* JK for AAL5 trailer - AAL0 doesn't need it, but who cares ... */
        eni_dev->dma[j++] = (((tx->tx_pos+size) & (tx->words-1)) <<
             MID_DMA_COUNT_SHIFT) | (tx->index << MID_DMA_CHAN_SHIFT) |
             MID_DMA_END | MID_DT_JK;
        j++;
        DPRINTK("DMA at end: %d\n",j);
        /* store frame */
        writel((MID_SEG_TX_ID << MID_SEG_ID_SHIFT) |
            (aal5 ? MID_SEG_AAL5 : 0) | (tx->prescaler << MID_SEG_PR_SHIFT) |
            (tx->resolution << MID_SEG_RATE_SHIFT) |
            (size/(ATM_CELL_PAYLOAD/4)),tx->send+tx->tx_pos*4);
/*printk("dsc = 0x%08lx\n",(unsigned long) readl(tx->send+tx->tx_pos*4));*/
        writel((vcc->vci << MID_SEG_VCI_SHIFT) |
            (aal5 ? 0 : (skb_data3 & 0xf)) |
            (ATM_SKB(skb)->atm_options & ATM_ATMOPT_CLP ? MID_SEG_CLP : 0),
            tx->send+((tx->tx_pos+1) & (tx->words-1))*4);
        DPRINTK("size: %d, len:%d\n",size,skb->len);
        if (aal5)
                writel(skb->len,tx->send+
                    ((tx->tx_pos+size-AAL5_TRAILER) & (tx->words-1))*4);
        j = j >> 1;
        for (i = 0; i < j; i++) {
                writel(eni_dev->dma[i*2],eni_dev->tx_dma+dma_wr*8);
                writel(eni_dev->dma[i*2+1],eni_dev->tx_dma+dma_wr*8+4);
                dma_wr = (dma_wr+1) & (NR_DMA_TX-1);
        }
        ENI_PRV_POS(skb) = tx->tx_pos;
        ENI_PRV_SIZE(skb) = size;
        ENI_VCC(vcc)->txing += size;
        tx->tx_pos = (tx->tx_pos+size) & (tx->words-1);
        DPRINTK("dma_wr set to %d, tx_pos is now %ld\n",dma_wr,tx->tx_pos);
        eni_out(dma_wr,MID_DMA_WR_TX);
        skb_queue_tail(&eni_dev->tx_queue,skb);
        queued++;
        return enq_ok;
}


static void poll_tx(struct atm_dev *dev)
{
        struct eni_tx *tx;
        struct sk_buff *skb;
        enum enq_res res;
        int i;

        DPRINTK(">poll_tx\n");
        for (i = NR_CHAN-1; i >= 0; i--) {
                tx = &ENI_DEV(dev)->tx[i];
                if (tx->send)
                        while ((skb = skb_dequeue(&tx->backlog))) {
                                res = do_tx(skb);
                                if (res == enq_ok) continue;
                                DPRINTK("re-queuing TX PDU\n");
                                skb_queue_head(&tx->backlog,skb);
                                requeued++;
                                if (res == enq_jam) return;
                                break;
                        }
        }
}


static void dequeue_tx(struct atm_dev *dev)
{
        struct eni_dev *eni_dev;
        struct atm_vcc *vcc;
        struct sk_buff *skb;
        struct eni_tx *tx;

        NULLCHECK(dev);
        eni_dev = ENI_DEV(dev);
        NULLCHECK(eni_dev);
        while ((skb = skb_dequeue(&eni_dev->tx_queue))) {
                vcc = ATM_SKB(skb)->vcc;
                NULLCHECK(vcc);
                tx = ENI_VCC(vcc)->tx;
                NULLCHECK(ENI_VCC(vcc)->tx);
                DPRINTK("dequeue_tx: next 0x%lx curr 0x%x\n",ENI_PRV_POS(skb),
                    (unsigned) eni_in(MID_TX_DESCRSTART(tx->index)));
                if (ENI_VCC(vcc)->txing < tx->words && ENI_PRV_POS(skb) ==
                    eni_in(MID_TX_DESCRSTART(tx->index))) {
                        skb_queue_head(&eni_dev->tx_queue,skb);
                        break;
                }
                ENI_VCC(vcc)->txing -= ENI_PRV_SIZE(skb);
                dma_unmap_single(&eni_dev->pci_dev->dev,ENI_PRV_PADDR(skb),skb->len,
                                 DMA_TO_DEVICE);
                if (vcc->pop) vcc->pop(vcc,skb);
                else dev_kfree_skb_irq(skb);
                atomic_inc(&vcc->stats->tx);
                wake_up(&eni_dev->tx_wait);
                dma_complete++;
        }
}


static struct eni_tx *alloc_tx(struct eni_dev *eni_dev,int ubr)
{
        int i;

        for (i = !ubr; i < NR_CHAN; i++)
                if (!eni_dev->tx[i].send) return eni_dev->tx+i;
        return NULL;
}


static int comp_tx(struct eni_dev *eni_dev,int *pcr,int reserved,int *pre,
    int *res,int unlimited)
{
        static const int pre_div[] = { 4,16,128,2048 };
            /* 2^(((x+2)^2-(x+2))/2+1) */

        if (unlimited) *pre = *res = 0;
        else {
                if (*pcr > 0) {
                        int div;

                        for (*pre = 0; *pre < 3; (*pre)++)
                                if (TS_CLOCK/pre_div[*pre]/64 <= *pcr) break;
                        div = pre_div[*pre]**pcr;
                        DPRINTK("min div %d\n",div);
                        *res = TS_CLOCK/div-1;
                }
                else {
                        int div;

                        if (!*pcr) *pcr = eni_dev->tx_bw+reserved;
                        for (*pre = 3; *pre >= 0; (*pre)--)
                                if (TS_CLOCK/pre_div[*pre]/64 > -*pcr) break;
                        if (*pre < 3) (*pre)++; /* else fail later */
                        div = pre_div[*pre]*-*pcr;
                        DPRINTK("max div %d\n",div);
                        *res = DIV_ROUND_UP(TS_CLOCK, div)-1;
                }
                if (*res < 0) *res = 0;
                if (*res > MID_SEG_MAX_RATE) *res = MID_SEG_MAX_RATE;
        }
        *pcr = TS_CLOCK/pre_div[*pre]/(*res+1);
        DPRINTK("out pcr: %d (%d:%d)\n",*pcr,*pre,*res);
        return 0;
}


static int reserve_or_set_tx(struct atm_vcc *vcc,struct atm_trafprm *txtp,
    int set_rsv,int set_shp)
{
        struct eni_dev *eni_dev = ENI_DEV(vcc->dev);
        struct eni_vcc *eni_vcc = ENI_VCC(vcc);
        struct eni_tx *tx;
        unsigned long size;
        void __iomem *mem;
        int rate,ubr,unlimited,new_tx;
        int pre,res,order;
        int error;

        rate = atm_pcr_goal(txtp);
        ubr = txtp->traffic_class == ATM_UBR;
        unlimited = ubr && (!rate || rate <= -ATM_OC3_PCR ||
            rate >= ATM_OC3_PCR);
        if (!unlimited) {
                size = txtp->max_sdu*eni_dev->tx_mult/100;
                if (size > MID_MAX_BUF_SIZE && txtp->max_sdu <=
                    MID_MAX_BUF_SIZE)
                        size = MID_MAX_BUF_SIZE;
        }
        else {
                if (eni_dev->ubr) {
                        eni_vcc->tx = eni_dev->ubr;
                        txtp->pcr = ATM_OC3_PCR;
                        return 0;
                }
                size = UBR_BUFFER;
        }
        new_tx = !eni_vcc->tx;
        mem = NULL; /* for gcc */
        if (!new_tx) tx = eni_vcc->tx;
        else {
                mem = eni_alloc_mem(eni_dev,&size);
                if (!mem) return -ENOBUFS;
                tx = alloc_tx(eni_dev,unlimited);
                if (!tx) {
                        eni_free_mem(eni_dev,mem,size);
                        return -EBUSY;
                }
                DPRINTK("got chan %d\n",tx->index);
                tx->reserved = tx->shaping = 0;
                tx->send = mem;
                tx->words = size >> 2;
                skb_queue_head_init(&tx->backlog);
                for (order = 0; size > (1 << (order+10)); order++);
                eni_out((order << MID_SIZE_SHIFT) |
                    ((tx->send-eni_dev->ram) >> (MID_LOC_SKIP+2)),
                    MID_TX_PLACE(tx->index));
                tx->tx_pos = eni_in(MID_TX_DESCRSTART(tx->index)) &
                    MID_DESCR_START;
        }
        error = comp_tx(eni_dev,&rate,tx->reserved,&pre,&res,unlimited);
        if (!error  && txtp->min_pcr > rate) error = -EINVAL;
        if (!error && txtp->max_pcr && txtp->max_pcr != ATM_MAX_PCR &&
            txtp->max_pcr < rate) error = -EINVAL;
        if (!error && !ubr && rate > eni_dev->tx_bw+tx->reserved)
                error = -EINVAL;
        if (!error && set_rsv && !set_shp && rate < tx->shaping)
                error = -EINVAL;
        if (!error && !set_rsv && rate > tx->reserved && !ubr)
                error = -EINVAL;
        if (error) {
                if (new_tx) {
                        tx->send = NULL;
                        eni_free_mem(eni_dev,mem,size);
                }
                return error;
        }
        txtp->pcr = rate;
        if (set_rsv && !ubr) {
                eni_dev->tx_bw += tx->reserved;
                tx->reserved = rate;
                eni_dev->tx_bw -= rate;
        }
        if (set_shp || (unlimited && new_tx)) {
                if (unlimited && new_tx) eni_dev->ubr = tx;
                tx->prescaler = pre;
                tx->resolution = res;
                tx->shaping = rate;
        }
        if (set_shp) eni_vcc->tx = tx;
        DPRINTK("rsv %d shp %d\n",tx->reserved,tx->shaping);
        return 0;
}


static int open_tx_first(struct atm_vcc *vcc)
{
        ENI_VCC(vcc)->tx = NULL;
        if (vcc->qos.txtp.traffic_class == ATM_NONE) return 0;
        ENI_VCC(vcc)->txing = 0;
        return reserve_or_set_tx(vcc,&vcc->qos.txtp,1,1);
}


static int open_tx_second(struct atm_vcc *vcc)
{
        return 0; /* nothing to do */
}


static void close_tx(struct atm_vcc *vcc)
{
        DECLARE_WAITQUEUE(wait,current);
        struct eni_dev *eni_dev;
        struct eni_vcc *eni_vcc;

        eni_vcc = ENI_VCC(vcc);
        if (!eni_vcc->tx) return;
        eni_dev = ENI_DEV(vcc->dev);
        /* wait for TX queue to drain */
        DPRINTK("eni_close: waiting for TX ...\n");
        add_wait_queue(&eni_dev->tx_wait,&wait);
        set_current_state(TASK_UNINTERRUPTIBLE);
        for (;;) {
                int txing;

                tasklet_disable(&eni_dev->task);
                txing = skb_peek(&eni_vcc->tx->backlog) || eni_vcc->txing;
                tasklet_enable(&eni_dev->task);
                if (!txing) break;
                DPRINTK("%d TX left\n",eni_vcc->txing);
                schedule();
                set_current_state(TASK_UNINTERRUPTIBLE);
        }
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&eni_dev->tx_wait,&wait);
        if (eni_vcc->tx != eni_dev->ubr) {
                /*
                 * Looping a few times in here is probably far cheaper than
                 * keeping track of TX completions all the time, so let's poll
                 * a bit ...
                 */
                while (eni_in(MID_TX_RDPTR(eni_vcc->tx->index)) !=
                    eni_in(MID_TX_DESCRSTART(eni_vcc->tx->index)))
                        schedule();
                eni_free_mem(eni_dev,eni_vcc->tx->send,eni_vcc->tx->words << 2);
                eni_vcc->tx->send = NULL;
                eni_dev->tx_bw += eni_vcc->tx->reserved;
        }
        eni_vcc->tx = NULL;
}


static int start_tx(struct atm_dev *dev)
{
        struct eni_dev *eni_dev;
        int i;

        eni_dev = ENI_DEV(dev);
        eni_dev->lost = 0;
        eni_dev->tx_bw = ATM_OC3_PCR;
        eni_dev->tx_mult = DEFAULT_TX_MULT;
        init_waitqueue_head(&eni_dev->tx_wait);
        eni_dev->ubr = NULL;
        skb_queue_head_init(&eni_dev->tx_queue);
        eni_out(0,MID_DMA_WR_TX);
        for (i = 0; i < NR_CHAN; i++) {
                eni_dev->tx[i].send = NULL;
                eni_dev->tx[i].index = i;
        }
        return 0;
}


/*--------------------------------- common ----------------------------------*/


#if 0 /* may become useful again when tuning things */

static void foo(void)
{
printk(KERN_INFO
  "tx_complete=%d,dma_complete=%d,queued=%d,requeued=%d,sub=%d,\n"
  "backlogged=%d,rx_enqueued=%d,rx_dequeued=%d,putting=%d,pushed=%d\n",
  tx_complete,dma_complete,queued,requeued,submitted,backlogged,
  rx_enqueued,rx_dequeued,putting,pushed);
if (eni_boards) printk(KERN_INFO "loss: %ld\n",ENI_DEV(eni_boards)->lost);
}

#endif


static void bug_int(struct atm_dev *dev,unsigned long reason)
{
        DPRINTK(">bug_int\n");
        if (reason & MID_DMA_ERR_ACK)
                printk(KERN_CRIT DEV_LABEL "(itf %d): driver error - DMA "
                    "error\n",dev->number);
        if (reason & MID_TX_IDENT_MISM)
                printk(KERN_CRIT DEV_LABEL "(itf %d): driver error - ident "
                    "mismatch\n",dev->number);
        if (reason & MID_TX_DMA_OVFL)
                printk(KERN_CRIT DEV_LABEL "(itf %d): driver error - DMA "
                    "overflow\n",dev->number);
        EVENT("---dump ends here---\n",0,0);
        printk(KERN_NOTICE "---recent events---\n");
        event_dump();
}


static irqreturn_t eni_int(int irq,void *dev_id)
{
        struct atm_dev *dev;
        struct eni_dev *eni_dev;
        u32 reason;

        DPRINTK(">eni_int\n");
        dev = dev_id;
        eni_dev = ENI_DEV(dev);
        reason = eni_in(MID_ISA);
        DPRINTK(DEV_LABEL ": int 0x%lx\n",(unsigned long) reason);
        /*
         * Must handle these two right now, because reading ISA doesn't clear
         * them, so they re-occur and we never make it to the tasklet. Since
         * they're rare, we don't mind the occasional invocation of eni_tasklet
         * with eni_dev->events == 0.
         */
        if (reason & MID_STAT_OVFL) {
                EVENT("stat overflow\n",0,0);
                eni_dev->lost += eni_in(MID_STAT) & MID_OVFL_TRASH;
        }
        if (reason & MID_SUNI_INT) {
                EVENT("SUNI int\n",0,0);
                dev->phy->interrupt(dev);
#if 0
                foo();
#endif
        }
        spin_lock(&eni_dev->lock);
        eni_dev->events |= reason;
        spin_unlock(&eni_dev->lock);
        tasklet_schedule(&eni_dev->task);
        return IRQ_HANDLED;
}


static void eni_tasklet(unsigned long data)
{
        struct atm_dev *dev = (struct atm_dev *) data;
        struct eni_dev *eni_dev = ENI_DEV(dev);
        unsigned long flags;
        u32 events;

        DPRINTK("eni_tasklet (dev %p)\n",dev);
        spin_lock_irqsave(&eni_dev->lock,flags);
        events = xchg(&eni_dev->events,0);
        spin_unlock_irqrestore(&eni_dev->lock,flags);
        if (events & MID_RX_DMA_COMPLETE) {
                EVENT("INT: RX DMA complete, starting dequeue_rx\n",0,0);
                dequeue_rx(dev);
                EVENT("dequeue_rx done, starting poll_rx\n",0,0);
                poll_rx(dev);
                EVENT("poll_rx done\n",0,0);
                /* poll_tx ? */
        }
        if (events & MID_SERVICE) {
                EVENT("INT: service, starting get_service\n",0,0);
                get_service(dev);
                EVENT("get_service done, starting poll_rx\n",0,0);
                poll_rx(dev);
                EVENT("poll_rx done\n",0,0);
        }
        if (events & MID_TX_DMA_COMPLETE) {
                EVENT("INT: TX DMA COMPLETE\n",0,0);
                dequeue_tx(dev);
        }
        if (events & MID_TX_COMPLETE) {
                EVENT("INT: TX COMPLETE\n",0,0);
                tx_complete++;
                wake_up(&eni_dev->tx_wait);
                /* poll_rx ? */
        }
        if (events & (MID_DMA_ERR_ACK | MID_TX_IDENT_MISM | MID_TX_DMA_OVFL)) {
                EVENT("bug interrupt\n",0,0);
                bug_int(dev,events);
        }
        poll_tx(dev);
}


/*--------------------------------- entries ---------------------------------*/


static char * const media_name[] = {
    "MMF", "SMF", "MMF", "03?", /*  0- 3 */
    "UTP", "05?", "06?", "07?", /*  4- 7 */
    "TAXI","09?", "10?", "11?", /*  8-11 */
    "12?", "13?", "14?", "15?", /* 12-15 */
    "MMF", "SMF", "18?", "19?", /* 16-19 */
    "UTP", "21?", "22?", "23?", /* 20-23 */
    "24?", "25?", "26?", "27?", /* 24-27 */
    "28?", "29?", "30?", "31?"  /* 28-31 */
};


#define SET_SEPROM \
  ({ if (!error && !pci_error) { \
    pci_error = pci_write_config_byte(eni_dev->pci_dev,PCI_TONGA_CTRL,tonga); \
    udelay(10); /* 10 usecs */ \
  } })
#define GET_SEPROM \
  ({ if (!error && !pci_error) { \
    pci_error = pci_read_config_byte(eni_dev->pci_dev,PCI_TONGA_CTRL,&tonga); \
    udelay(10); /* 10 usecs */ \
  } })


static int get_esi_asic(struct atm_dev *dev)
{
        struct eni_dev *eni_dev;
        unsigned char tonga;
        int error,failed,pci_error;
        int address,i,j;

        eni_dev = ENI_DEV(dev);
        error = pci_error = 0;
        tonga = SEPROM_MAGIC | SEPROM_DATA | SEPROM_CLK;
        SET_SEPROM;
        for (i = 0; i < ESI_LEN && !error && !pci_error; i++) {
                /* start operation */
                tonga |= SEPROM_DATA;
                SET_SEPROM;
                tonga |= SEPROM_CLK;
                SET_SEPROM;
                tonga &= ~SEPROM_DATA;
                SET_SEPROM;
                tonga &= ~SEPROM_CLK;
                SET_SEPROM;
                /* send address */
                address = ((i+SEPROM_ESI_BASE) << 1)+1;
                for (j = 7; j >= 0; j--) {
                        tonga = (address >> j) & 1 ? tonga | SEPROM_DATA :
                            tonga & ~SEPROM_DATA;
                        SET_SEPROM;
                        tonga |= SEPROM_CLK;
                        SET_SEPROM;
                        tonga &= ~SEPROM_CLK;
                        SET_SEPROM;
                }
                /* get ack */
                tonga |= SEPROM_DATA;
                SET_SEPROM;
                tonga |= SEPROM_CLK;
                SET_SEPROM;
                GET_SEPROM;
                failed = tonga & SEPROM_DATA;
                tonga &= ~SEPROM_CLK;
                SET_SEPROM;
                tonga |= SEPROM_DATA;
                SET_SEPROM;
                if (failed) error = -EIO;
                else {
                        dev->esi[i] = 0;
                        for (j = 7; j >= 0; j--) {
                                dev->esi[i] <<= 1;
                                tonga |= SEPROM_DATA;
                                SET_SEPROM;
                                tonga |= SEPROM_CLK;
                                SET_SEPROM;
                                GET_SEPROM;
                                if (tonga & SEPROM_DATA) dev->esi[i] |= 1;
                                tonga &= ~SEPROM_CLK;
                                SET_SEPROM;
                                tonga |= SEPROM_DATA;
                                SET_SEPROM;
                        }
                        /* get ack */
                        tonga |= SEPROM_DATA;
                        SET_SEPROM;
                        tonga |= SEPROM_CLK;
                        SET_SEPROM;
                        GET_SEPROM;
                        if (!(tonga & SEPROM_DATA)) error = -EIO;
                        tonga &= ~SEPROM_CLK;
                        SET_SEPROM;
                        tonga |= SEPROM_DATA;
                        SET_SEPROM;
                }
                /* stop operation */
                tonga &= ~SEPROM_DATA;
                SET_SEPROM;
                tonga |= SEPROM_CLK;
                SET_SEPROM;
                tonga |= SEPROM_DATA;
                SET_SEPROM;
        }
        if (pci_error) {
                printk(KERN_ERR DEV_LABEL "(itf %d): error reading ESI "
                    "(0x%02x)\n",dev->number,pci_error);
                error = -EIO;
        }
        return error;
}


#undef SET_SEPROM
#undef GET_SEPROM


static int get_esi_fpga(struct atm_dev *dev, void __iomem *base)
{
        void __iomem *mac_base;
        int i;

        mac_base = base+EPROM_SIZE-sizeof(struct midway_eprom);
        for (i = 0; i < ESI_LEN; i++) dev->esi[i] = readb(mac_base+(i^3));
        return 0;
}


static int eni_do_init(struct atm_dev *dev)
{
        struct midway_eprom __iomem *eprom;
        struct eni_dev *eni_dev;
        struct pci_dev *pci_dev;
        unsigned long real_base;
        void __iomem *base;
        int error,i,last;

        DPRINTK(">eni_init\n");
        dev->ci_range.vpi_bits = 0;
        dev->ci_range.vci_bits = NR_VCI_LD;
        dev->link_rate = ATM_OC3_PCR;
        eni_dev = ENI_DEV(dev);
        pci_dev = eni_dev->pci_dev;
        real_base = pci_resource_start(pci_dev, 0);
        eni_dev->irq = pci_dev->irq;
        if ((error = pci_write_config_word(pci_dev,PCI_COMMAND,
            PCI_COMMAND_MEMORY |
            (eni_dev->asic ? PCI_COMMAND_PARITY | PCI_COMMAND_SERR : 0)))) {
                printk(KERN_ERR DEV_LABEL "(itf %d): can't enable memory "
                    "(0x%02x)\n",dev->number,error);
                return -EIO;
        }
        printk(KERN_NOTICE DEV_LABEL "(itf %d): rev.%d,base=0x%lx,irq=%d,",
            dev->number,pci_dev->revision,real_base,eni_dev->irq);
        if (!(base = ioremap(real_base,MAP_MAX_SIZE))) {
                printk("\n");
                printk(KERN_ERR DEV_LABEL "(itf %d): can't set up page "
                    "mapping\n",dev->number);
                return -ENOMEM;
        }
        eni_dev->ioaddr = base;
        eni_dev->base_diff = real_base - (unsigned long) base;
        /* id may not be present in ASIC Tonga boards - check this @@@ */
        if (!eni_dev->asic) {
                eprom = (base+EPROM_SIZE-sizeof(struct midway_eprom));
                if (readl(&eprom->magic) != ENI155_MAGIC) {
                        printk("\n");
                        printk(KERN_ERR DEV_LABEL
                               "(itf %d): bad magic - expected 0x%x, got 0x%x\n",
                               dev->number, ENI155_MAGIC,
                               (unsigned)readl(&eprom->magic));
                        error = -EINVAL;
                        goto unmap;
                }
        }
        eni_dev->phy = base+PHY_BASE;
        eni_dev->reg = base+REG_BASE;
        eni_dev->ram = base+RAM_BASE;
        last = MAP_MAX_SIZE-RAM_BASE;
        for (i = last-RAM_INCREMENT; i >= 0; i -= RAM_INCREMENT) {
                writel(0x55555555,eni_dev->ram+i);
                if (readl(eni_dev->ram+i) != 0x55555555) last = i;
                else {
                        writel(0xAAAAAAAA,eni_dev->ram+i);
                        if (readl(eni_dev->ram+i) != 0xAAAAAAAA) last = i;
                        else writel(i,eni_dev->ram+i);
                }
        }
        for (i = 0; i < last; i += RAM_INCREMENT)
                if (readl(eni_dev->ram+i) != i) break;
        eni_dev->mem = i;
        memset_io(eni_dev->ram,0,eni_dev->mem);
        /* TODO: should shrink allocation now */
        printk("mem=%dkB (",eni_dev->mem >> 10);
        /* TODO: check for non-SUNI, check for TAXI ? */
        if (!(eni_in(MID_RES_ID_MCON) & 0x200) != !eni_dev->asic) {
                printk(")\n");
                printk(KERN_ERR DEV_LABEL "(itf %d): ERROR - wrong id 0x%x\n",
                    dev->number,(unsigned) eni_in(MID_RES_ID_MCON));
                error = -EINVAL;
                goto unmap;
        }
        error = eni_dev->asic ? get_esi_asic(dev) : get_esi_fpga(dev,base);
        if (error)
                goto unmap;
        for (i = 0; i < ESI_LEN; i++)
                printk("%s%02X",i ? "-" : "",dev->esi[i]);
        printk(")\n");
        printk(KERN_NOTICE DEV_LABEL "(itf %d): %s,%s\n",dev->number,
            eni_in(MID_RES_ID_MCON) & 0x200 ? "ASIC" : "FPGA",
            media_name[eni_in(MID_RES_ID_MCON) & DAUGHTER_ID]);

        error = suni_init(dev);
        if (error)
                goto unmap;
out:
        return error;
unmap:
        iounmap(base);
        goto out;
}

static void eni_do_release(struct atm_dev *dev)
{
        struct eni_dev *ed = ENI_DEV(dev);

        dev->phy->stop(dev);
        dev->phy = NULL;
        iounmap(ed->ioaddr);
}

static int eni_start(struct atm_dev *dev)
{
        struct eni_dev *eni_dev;
        
        void __iomem *buf;
        unsigned long buffer_mem;
        int error;

        DPRINTK(">eni_start\n");
        eni_dev = ENI_DEV(dev);
        if (request_irq(eni_dev->irq,&eni_int,IRQF_SHARED,DEV_LABEL,dev)) {
                printk(KERN_ERR DEV_LABEL "(itf %d): IRQ%d is already in use\n",
                    dev->number,eni_dev->irq);
                error = -EAGAIN;
                goto out;
        }
        pci_set_master(eni_dev->pci_dev);
        if ((error = pci_write_config_word(eni_dev->pci_dev,PCI_COMMAND,
            PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
            (eni_dev->asic ? PCI_COMMAND_PARITY | PCI_COMMAND_SERR : 0)))) {
                printk(KERN_ERR DEV_LABEL "(itf %d): can't enable memory+"
                    "master (0x%02x)\n",dev->number,error);
                goto free_irq;
        }
        if ((error = pci_write_config_byte(eni_dev->pci_dev,PCI_TONGA_CTRL,
            END_SWAP_DMA))) {
                printk(KERN_ERR DEV_LABEL "(itf %d): can't set endian swap "
                    "(0x%02x)\n",dev->number,error);
                goto free_irq;
        }
        /* determine addresses of internal tables */
        eni_dev->vci = eni_dev->ram;
        eni_dev->rx_dma = eni_dev->ram+NR_VCI*16;
        eni_dev->tx_dma = eni_dev->rx_dma+NR_DMA_RX*8;
        eni_dev->service = eni_dev->tx_dma+NR_DMA_TX*8;
        buf = eni_dev->service+NR_SERVICE*4;
        DPRINTK("vci 0x%lx,rx 0x%lx, tx 0x%lx,srv 0x%lx,buf 0x%lx\n",
             eni_dev->vci,eni_dev->rx_dma,eni_dev->tx_dma,
             eni_dev->service,buf);
        spin_lock_init(&eni_dev->lock);
        tasklet_init(&eni_dev->task,eni_tasklet,(unsigned long) dev);
        eni_dev->events = 0;
        /* initialize memory management */
        buffer_mem = eni_dev->mem - (buf - eni_dev->ram);
        eni_dev->free_list_size = buffer_mem/MID_MIN_BUF_SIZE/2;
        eni_dev->free_list = kmalloc_objs(*eni_dev->free_list,
                                          eni_dev->free_list_size + 1);
        if (!eni_dev->free_list) {
                printk(KERN_ERR DEV_LABEL "(itf %d): couldn't get free page\n",
                    dev->number);
                error = -ENOMEM;
                goto free_irq;
        }
        eni_dev->free_len = 0;
        eni_put_free(eni_dev,buf,buffer_mem);
        memset_io(eni_dev->vci,0,16*NR_VCI); /* clear VCI table */
        /*
         * byte_addr  free (k)
         * 0x00000000     512  VCI table
         * 0x00004000     496  RX DMA
         * 0x00005000     492  TX DMA
         * 0x00006000     488  service list
         * 0x00007000     484  buffers
         * 0x00080000       0  end (512kB)
         */
        eni_out(0xffffffff,MID_IE);
        error = start_tx(dev);
        if (error) goto free_list;
        error = start_rx(dev);
        if (error) goto free_list;
        error = dev->phy->start(dev);
        if (error) goto free_list;
        eni_out(eni_in(MID_MC_S) | (1 << MID_INT_SEL_SHIFT) |
            MID_TX_LOCK_MODE | MID_DMA_ENABLE | MID_TX_ENABLE | MID_RX_ENABLE,
            MID_MC_S);
            /* Tonga uses SBus INTReq1 */
        (void) eni_in(MID_ISA); /* clear Midway interrupts */
        return 0;

free_list:
        kfree(eni_dev->free_list);

free_irq:
        free_irq(eni_dev->irq, dev);

out:
        return error;
}


static void eni_close(struct atm_vcc *vcc)
{
        DPRINTK(">eni_close\n");
        if (!ENI_VCC(vcc)) return;
        clear_bit(ATM_VF_READY,&vcc->flags);
        close_rx(vcc);
        close_tx(vcc);
        DPRINTK("eni_close: done waiting\n");
        /* deallocate memory */
        kfree(ENI_VCC(vcc));
        vcc->dev_data = NULL;
        clear_bit(ATM_VF_ADDR,&vcc->flags);
        /*foo();*/
}


static int eni_open(struct atm_vcc *vcc)
{
        struct eni_vcc *eni_vcc;
        int error;
        short vpi = vcc->vpi;
        int vci = vcc->vci;

        DPRINTK(">eni_open\n");
        EVENT("eni_open\n",0,0);
        if (!test_bit(ATM_VF_PARTIAL,&vcc->flags))
                vcc->dev_data = NULL;
        if (vci != ATM_VPI_UNSPEC && vpi != ATM_VCI_UNSPEC)
                set_bit(ATM_VF_ADDR,&vcc->flags);
        if (vcc->qos.aal != ATM_AAL0 && vcc->qos.aal != ATM_AAL5)
                return -EINVAL;
        DPRINTK(DEV_LABEL "(itf %d): open %d.%d\n",vcc->dev->number,vcc->vpi,
            vcc->vci);
        if (!test_bit(ATM_VF_PARTIAL,&vcc->flags)) {
                eni_vcc = kmalloc_obj(struct eni_vcc);
                if (!eni_vcc) return -ENOMEM;
                vcc->dev_data = eni_vcc;
                eni_vcc->tx = NULL; /* for eni_close after open_rx */
                if ((error = open_rx_first(vcc))) {
                        eni_close(vcc);
                        return error;
                }
                if ((error = open_tx_first(vcc))) {
                        eni_close(vcc);
                        return error;
                }
        }
        if (vci == ATM_VPI_UNSPEC || vpi == ATM_VCI_UNSPEC) return 0;
        if ((error = open_rx_second(vcc))) {
                eni_close(vcc);
                return error;
        }
        if ((error = open_tx_second(vcc))) {
                eni_close(vcc);
                return error;
        }
        set_bit(ATM_VF_READY,&vcc->flags);
        /* should power down SUNI while !ref_count @@@ */
        return 0;
}


static int eni_change_qos(struct atm_vcc *vcc,struct atm_qos *qos,int flgs)
{
        struct eni_dev *eni_dev = ENI_DEV(vcc->dev);
        struct eni_tx *tx = ENI_VCC(vcc)->tx;
        struct sk_buff *skb;
        int error,rate,rsv,shp;

        if (qos->txtp.traffic_class == ATM_NONE) return 0;
        if (tx == eni_dev->ubr) return -EBADFD;
        rate = atm_pcr_goal(&qos->txtp);
        if (rate < 0) rate = -rate;
        rsv = shp = 0;
        if ((flgs & ATM_MF_DEC_RSV) && rate && rate < tx->reserved) rsv = 1;
        if ((flgs & ATM_MF_INC_RSV) && (!rate || rate > tx->reserved)) rsv = 1;
        if ((flgs & ATM_MF_DEC_SHP) && rate && rate < tx->shaping) shp = 1;
        if ((flgs & ATM_MF_INC_SHP) && (!rate || rate > tx->shaping)) shp = 1;
        if (!rsv && !shp) return 0;
        error = reserve_or_set_tx(vcc,&qos->txtp,rsv,shp);
        if (error) return error;
        if (shp && !(flgs & ATM_MF_IMMED)) return 0;
        /*
         * Walk through the send buffer and patch the rate information in all
         * segmentation buffer descriptors of this VCC.
         */
        tasklet_disable(&eni_dev->task);
        skb_queue_walk(&eni_dev->tx_queue, skb) {
                void __iomem *dsc;

                if (ATM_SKB(skb)->vcc != vcc) continue;
                dsc = tx->send+ENI_PRV_POS(skb)*4;
                writel((readl(dsc) & ~(MID_SEG_RATE | MID_SEG_PR)) |
                    (tx->prescaler << MID_SEG_PR_SHIFT) |
                    (tx->resolution << MID_SEG_RATE_SHIFT), dsc);
        }
        tasklet_enable(&eni_dev->task);
        return 0;
}


static int eni_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
{
        struct eni_dev *eni_dev = ENI_DEV(dev);

        if (cmd == ENI_MEMDUMP) {
                if (!capable(CAP_NET_ADMIN)) return -EPERM;
                printk(KERN_WARNING "Please use /proc/atm/" DEV_LABEL ":%d "
                    "instead of obsolete ioctl ENI_MEMDUMP\n",dev->number);
                dump(dev);
                return 0;
        }
        if (cmd == ENI_SETMULT) {
                struct eni_multipliers mult;

                if (!capable(CAP_NET_ADMIN)) return -EPERM;
                if (copy_from_user(&mult, arg,
                    sizeof(struct eni_multipliers)))
                        return -EFAULT;
                if ((mult.tx && mult.tx <= 100) || (mult.rx &&mult.rx <= 100) ||
                    mult.tx > 65536 || mult.rx > 65536)
                        return -EINVAL;
                if (mult.tx) eni_dev->tx_mult = mult.tx;
                if (mult.rx) eni_dev->rx_mult = mult.rx;
                return 0;
        }
        if (cmd == ATM_SETCIRANGE) {
                struct atm_cirange ci;

                if (copy_from_user(&ci, arg,sizeof(struct atm_cirange)))
                        return -EFAULT;
                if ((ci.vpi_bits == 0 || ci.vpi_bits == ATM_CI_MAX) &&
                    (ci.vci_bits == NR_VCI_LD || ci.vpi_bits == ATM_CI_MAX))
                    return 0;
                return -EINVAL;
        }
        if (!dev->phy->ioctl) return -ENOIOCTLCMD;
        return dev->phy->ioctl(dev,cmd,arg);
}

static int eni_send(struct atm_vcc *vcc,struct sk_buff *skb)
{
        enum enq_res res;

        DPRINTK(">eni_send\n");
        if (!ENI_VCC(vcc)->tx) {
                if (vcc->pop) vcc->pop(vcc,skb);
                else dev_kfree_skb(skb);
                return -EINVAL;
        }
        if (!skb) {
                printk(KERN_CRIT "!skb in eni_send ?\n");
                if (vcc->pop) vcc->pop(vcc,skb);
                return -EINVAL;
        }
        if (vcc->qos.aal == ATM_AAL0) {
                if (skb->len != ATM_CELL_SIZE-1) {
                        if (vcc->pop) vcc->pop(vcc,skb);
                        else dev_kfree_skb(skb);
                        return -EINVAL;
                }
                *(u32 *) skb->data = htonl(*(u32 *) skb->data);
        }
        submitted++;
        ATM_SKB(skb)->vcc = vcc;
        tasklet_disable_in_atomic(&ENI_DEV(vcc->dev)->task);
        res = do_tx(skb);
        tasklet_enable(&ENI_DEV(vcc->dev)->task);
        if (res == enq_ok) return 0;
        skb_queue_tail(&ENI_VCC(vcc)->tx->backlog,skb);
        backlogged++;
        tasklet_schedule(&ENI_DEV(vcc->dev)->task);
        return 0;
}

static void eni_phy_put(struct atm_dev *dev,unsigned char value,
    unsigned long addr)
{
        writel(value,ENI_DEV(dev)->phy+addr*4);
}



static unsigned char eni_phy_get(struct atm_dev *dev,unsigned long addr)
{
        return readl(ENI_DEV(dev)->phy+addr*4);
}


static int eni_proc_read(struct atm_dev *dev,loff_t *pos,char *page)
{
        struct sock *s;
        static const char *signal[] = { "LOST","unknown","okay" };
        struct eni_dev *eni_dev = ENI_DEV(dev);
        struct atm_vcc *vcc;
        int left,i;

        left = *pos;
        if (!left)
                return sprintf(page,DEV_LABEL "(itf %d) signal %s, %dkB, "
                    "%d cps remaining\n",dev->number,signal[(int) dev->signal],
                    eni_dev->mem >> 10,eni_dev->tx_bw);
        if (!--left)
                return sprintf(page,"%4sBursts: TX"
#if !defined(CONFIG_ATM_ENI_BURST_TX_16W) && \
    !defined(CONFIG_ATM_ENI_BURST_TX_8W) && \
    !defined(CONFIG_ATM_ENI_BURST_TX_4W) && \
    !defined(CONFIG_ATM_ENI_BURST_TX_2W)
                    " none"
#endif
#ifdef CONFIG_ATM_ENI_BURST_TX_16W
                    " 16W"
#endif
#ifdef CONFIG_ATM_ENI_BURST_TX_8W
                    " 8W"
#endif
#ifdef CONFIG_ATM_ENI_BURST_TX_4W
                    " 4W"
#endif
#ifdef CONFIG_ATM_ENI_BURST_TX_2W
                    " 2W"
#endif
                    ", RX"
#if !defined(CONFIG_ATM_ENI_BURST_RX_16W) && \
    !defined(CONFIG_ATM_ENI_BURST_RX_8W) && \
    !defined(CONFIG_ATM_ENI_BURST_RX_4W) && \
    !defined(CONFIG_ATM_ENI_BURST_RX_2W)
                    " none"
#endif
#ifdef CONFIG_ATM_ENI_BURST_RX_16W
                    " 16W"
#endif
#ifdef CONFIG_ATM_ENI_BURST_RX_8W
                    " 8W"
#endif
#ifdef CONFIG_ATM_ENI_BURST_RX_4W
                    " 4W"
#endif
#ifdef CONFIG_ATM_ENI_BURST_RX_2W
                    " 2W"
#endif
#ifndef CONFIG_ATM_ENI_TUNE_BURST
                    " (default)"
#endif
                    "\n","");
        if (!--left) 
                return sprintf(page,"%4sBuffer multipliers: tx %d%%, rx %d%%\n",
                    "",eni_dev->tx_mult,eni_dev->rx_mult);
        for (i = 0; i < NR_CHAN; i++) {
                struct eni_tx *tx = eni_dev->tx+i;

                if (!tx->send) continue;
                if (!--left) {
                        return sprintf(page, "tx[%d]:    0x%lx-0x%lx "
                            "(%6ld bytes), rsv %d cps, shp %d cps%s\n",i,
                            (unsigned long) (tx->send - eni_dev->ram),
                            tx->send-eni_dev->ram+tx->words*4-1,tx->words*4,
                            tx->reserved,tx->shaping,
                            tx == eni_dev->ubr ? " (UBR)" : "");
                }
                if (--left) continue;
                return sprintf(page,"%10sbacklog %u packets\n","",
                    skb_queue_len(&tx->backlog));
        }
        read_lock(&vcc_sklist_lock);
        for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
                struct hlist_head *head = &vcc_hash[i];

                sk_for_each(s, head) {
                        struct eni_vcc *eni_vcc;
                        int length;

                        vcc = atm_sk(s);
                        if (vcc->dev != dev)
                                continue;
                        eni_vcc = ENI_VCC(vcc);
                        if (--left) continue;
                        length = sprintf(page,"vcc %4d: ",vcc->vci);
                        if (eni_vcc->rx) {
                                length += sprintf(page+length, "0x%lx-0x%lx "
                                    "(%6ld bytes)",
                                    (unsigned long) (eni_vcc->recv - eni_dev->ram),
                                    eni_vcc->recv-eni_dev->ram+eni_vcc->words*4-1,
                                    eni_vcc->words*4);
                                if (eni_vcc->tx) length += sprintf(page+length,", ");
                        }
                        if (eni_vcc->tx)
                                length += sprintf(page+length,"tx[%d], txing %d bytes",
                                    eni_vcc->tx->index,eni_vcc->txing);
                        page[length] = '\n';
                        read_unlock(&vcc_sklist_lock);
                        return length+1;
                }
        }
        read_unlock(&vcc_sklist_lock);
        for (i = 0; i < eni_dev->free_len; i++) {
                struct eni_free *fe = eni_dev->free_list+i;
                unsigned long offset;

                if (--left) continue;
                offset = (unsigned long) eni_dev->ram+eni_dev->base_diff;
                return sprintf(page,"free      %p-%p (%6d bytes)\n",
                    fe->start-offset,fe->start-offset+(1 << fe->order)-1,
                    1 << fe->order);
        }
        return 0;
}


static const struct atmdev_ops ops = {
        .open           = eni_open,
        .close          = eni_close,
        .ioctl          = eni_ioctl,
        .send           = eni_send,
        .phy_put        = eni_phy_put,
        .phy_get        = eni_phy_get,
        .change_qos     = eni_change_qos,
        .proc_read      = eni_proc_read
};


static int eni_init_one(struct pci_dev *pci_dev,
                        const struct pci_device_id *ent)
{
        struct atm_dev *dev;
        struct eni_dev *eni_dev;
        struct eni_zero *zero;
        int rc;

        rc = pci_enable_device(pci_dev);
        if (rc < 0)
                goto out;

        rc = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32));
        if (rc < 0)
                goto err_disable;

        rc = -ENOMEM;
        eni_dev = kmalloc_obj(struct eni_dev);
        if (!eni_dev)
                goto err_disable;

        zero = &eni_dev->zero;
        zero->addr = dma_alloc_coherent(&pci_dev->dev,
                                        ENI_ZEROES_SIZE, &zero->dma, GFP_KERNEL);
        if (!zero->addr)
                goto err_kfree;

        dev = atm_dev_register(DEV_LABEL, &pci_dev->dev, &ops, -1, NULL);
        if (!dev)
                goto err_free_consistent;

        dev->dev_data = eni_dev;
        pci_set_drvdata(pci_dev, dev);
        eni_dev->pci_dev = pci_dev;
        eni_dev->asic = ent->driver_data;

        rc = eni_do_init(dev);
        if (rc < 0)
                goto err_unregister;

        rc = eni_start(dev);
        if (rc < 0)
                goto err_eni_release;

        eni_dev->more = eni_boards;
        eni_boards = dev;
out:
        return rc;

err_eni_release:
        dev->phy = NULL;
        iounmap(ENI_DEV(dev)->ioaddr);
err_unregister:
        atm_dev_deregister(dev);
err_free_consistent:
        dma_free_coherent(&pci_dev->dev, ENI_ZEROES_SIZE, zero->addr, zero->dma);
err_kfree:
        kfree(eni_dev);
err_disable:
        pci_disable_device(pci_dev);
        goto out;
}


static const struct pci_device_id eni_pci_tbl[] = {
        { PCI_VDEVICE(EF, PCI_DEVICE_ID_EF_ATM_FPGA), 0 /* FPGA */ },
        { PCI_VDEVICE(EF, PCI_DEVICE_ID_EF_ATM_ASIC), 1 /* ASIC */ },
        { 0, }
};
MODULE_DEVICE_TABLE(pci,eni_pci_tbl);


static void eni_remove_one(struct pci_dev *pdev)
{
        struct atm_dev *dev = pci_get_drvdata(pdev);
        struct eni_dev *ed = ENI_DEV(dev);
        struct eni_zero *zero = &ed->zero;

        eni_do_release(dev);
        atm_dev_deregister(dev);
        dma_free_coherent(&pdev->dev, ENI_ZEROES_SIZE, zero->addr, zero->dma);
        kfree(ed);
        pci_disable_device(pdev);
}


static struct pci_driver eni_driver = {
        .name           = DEV_LABEL,
        .id_table       = eni_pci_tbl,
        .probe          = eni_init_one,
        .remove         = eni_remove_one,
};


static int __init eni_init(void)
{
        struct sk_buff *skb; /* dummy for sizeof */

        BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct eni_skb_prv));
        return pci_register_driver(&eni_driver);
}


module_init(eni_init);
/* @@@ since exit routine not defined, this module can not be unloaded */

MODULE_DESCRIPTION("Efficient Networks ENI155P ATM NIC driver");
MODULE_LICENSE("GPL");