ring_buffer: update description for ring_buffer_alloc()

[linux-2.6/mini2440.git] / drivers / net / sonic.c

/*
 * sonic.c
 *
 * (C) 2005 Finn Thain
 *
 * Converted to DMA API, added zero-copy buffer handling, and
 * (from the mac68k project) introduced dhd's support for 16-bit cards.
 *
 * (C) 1996,1998 by Thomas Bogendoerfer (tsbogend@alpha.franken.de)
 *
 * This driver is based on work from Andreas Busse, but most of
 * the code is rewritten.
 *
 * (C) 1995 by Andreas Busse (andy@waldorf-gmbh.de)
 *
 *    Core code included by system sonic drivers
 *
 * And... partially rewritten again by David Huggins-Daines in order
 * to cope with screwed up Macintosh NICs that may or may not use
 * 16-bit DMA.
 *
 * (C) 1999 David Huggins-Daines <dhd@debian.org>
 *
 */

/*
 * Sources: Olivetti M700-10 Risc Personal Computer hardware handbook,
 * National Semiconductors data sheet for the DP83932B Sonic Ethernet
 * controller, and the files "8390.c" and "skeleton.c" in this directory.
 *
 * Additional sources: Nat Semi data sheet for the DP83932C and Nat Semi
 * Application Note AN-746, the files "lance.c" and "ibmlana.c". See also
 * the NetBSD file "sys/arch/mac68k/dev/if_sn.c".
 */



/*
 * Open/initialize the SONIC controller.
 *
 * This routine should set everything up anew at each open, even
 *  registers that "should" only need to be set once at boot, so that
 *  there is non-reboot way to recover if something goes wrong.
 */
static int sonic_open(struct net_device *dev)
{
        struct sonic_local *lp = netdev_priv(dev);
        int i;

        if (sonic_debug > 2)
                printk("sonic_open: initializing sonic driver.\n");

        for (i = 0; i < SONIC_NUM_RRS; i++) {
                struct sk_buff *skb = dev_alloc_skb(SONIC_RBSIZE + 2);
                if (skb == NULL) {
                        while(i > 0) { /* free any that were allocated successfully */
                                i--;
                                dev_kfree_skb(lp->rx_skb[i]);
                                lp->rx_skb[i] = NULL;
                        }
                        printk(KERN_ERR "%s: couldn't allocate receive buffers\n",
                               dev->name);
                        return -ENOMEM;
                }
                /* align IP header unless DMA requires otherwise */
                if (SONIC_BUS_SCALE(lp->dma_bitmode) == 2)
                        skb_reserve(skb, 2);
                lp->rx_skb[i] = skb;
        }

        for (i = 0; i < SONIC_NUM_RRS; i++) {
                dma_addr_t laddr = dma_map_single(lp->device, skb_put(lp->rx_skb[i], SONIC_RBSIZE),
                                                  SONIC_RBSIZE, DMA_FROM_DEVICE);
                if (!laddr) {
                        while(i > 0) { /* free any that were mapped successfully */
                                i--;
                                dma_unmap_single(lp->device, lp->rx_laddr[i], SONIC_RBSIZE, DMA_FROM_DEVICE);
                                lp->rx_laddr[i] = (dma_addr_t)0;
                        }
                        for (i = 0; i < SONIC_NUM_RRS; i++) {
                                dev_kfree_skb(lp->rx_skb[i]);
                                lp->rx_skb[i] = NULL;
                        }
                        printk(KERN_ERR "%s: couldn't map rx DMA buffers\n",
                               dev->name);
                        return -ENOMEM;
                }
                lp->rx_laddr[i] = laddr;
        }

        /*
         * Initialize the SONIC
         */
        sonic_init(dev);

        netif_start_queue(dev);

        if (sonic_debug > 2)
                printk("sonic_open: Initialization done.\n");

        return 0;
}


/*
 * Close the SONIC device
 */
static int sonic_close(struct net_device *dev)
{
        struct sonic_local *lp = netdev_priv(dev);
        int i;

        if (sonic_debug > 2)
                printk("sonic_close\n");

        netif_stop_queue(dev);

        /*
         * stop the SONIC, disable interrupts
         */
        SONIC_WRITE(SONIC_IMR, 0);
        SONIC_WRITE(SONIC_ISR, 0x7fff);
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);

        /* unmap and free skbs that haven't been transmitted */
        for (i = 0; i < SONIC_NUM_TDS; i++) {
                if(lp->tx_laddr[i]) {
                        dma_unmap_single(lp->device, lp->tx_laddr[i], lp->tx_len[i], DMA_TO_DEVICE);
                        lp->tx_laddr[i] = (dma_addr_t)0;
                }
                if(lp->tx_skb[i]) {
                        dev_kfree_skb(lp->tx_skb[i]);
                        lp->tx_skb[i] = NULL;
                }
        }

        /* unmap and free the receive buffers */
        for (i = 0; i < SONIC_NUM_RRS; i++) {
                if(lp->rx_laddr[i]) {
                        dma_unmap_single(lp->device, lp->rx_laddr[i], SONIC_RBSIZE, DMA_FROM_DEVICE);
                        lp->rx_laddr[i] = (dma_addr_t)0;
                }
                if(lp->rx_skb[i]) {
                        dev_kfree_skb(lp->rx_skb[i]);
                        lp->rx_skb[i] = NULL;
                }
        }

        return 0;
}

static void sonic_tx_timeout(struct net_device *dev)
{
        struct sonic_local *lp = netdev_priv(dev);
        int i;
        /*
         * put the Sonic into software-reset mode and
         * disable all interrupts before releasing DMA buffers
         */
        SONIC_WRITE(SONIC_IMR, 0);
        SONIC_WRITE(SONIC_ISR, 0x7fff);
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
        /* We could resend the original skbs. Easier to re-initialise. */
        for (i = 0; i < SONIC_NUM_TDS; i++) {
                if(lp->tx_laddr[i]) {
                        dma_unmap_single(lp->device, lp->tx_laddr[i], lp->tx_len[i], DMA_TO_DEVICE);
                        lp->tx_laddr[i] = (dma_addr_t)0;
                }
                if(lp->tx_skb[i]) {
                        dev_kfree_skb(lp->tx_skb[i]);
                        lp->tx_skb[i] = NULL;
                }
        }
        /* Try to restart the adaptor. */
        sonic_init(dev);
        lp->stats.tx_errors++;
        dev->trans_start = jiffies;
        netif_wake_queue(dev);
}

/*
 * transmit packet
 *
 * Appends new TD during transmission thus avoiding any TX interrupts
 * until we run out of TDs.
 * This routine interacts closely with the ISR in that it may,
 *   set tx_skb[i]
 *   reset the status flags of the new TD
 *   set and reset EOL flags
 *   stop the tx queue
 * The ISR interacts with this routine in various ways. It may,
 *   reset tx_skb[i]
 *   test the EOL and status flags of the TDs
 *   wake the tx queue
 * Concurrently with all of this, the SONIC is potentially writing to
 * the status flags of the TDs.
 * Until some mutual exclusion is added, this code will not work with SMP. However,
 * MIPS Jazz machines and m68k Macs were all uni-processor machines.
 */

static int sonic_send_packet(struct sk_buff *skb, struct net_device *dev)
{
        struct sonic_local *lp = netdev_priv(dev);
        dma_addr_t laddr;
        int length;
        int entry = lp->next_tx;

        if (sonic_debug > 2)
                printk("sonic_send_packet: skb=%p, dev=%p\n", skb, dev);

        length = skb->len;
        if (length < ETH_ZLEN) {
                if (skb_padto(skb, ETH_ZLEN))
                        return 0;
                length = ETH_ZLEN;
        }

        /*
         * Map the packet data into the logical DMA address space
         */

        laddr = dma_map_single(lp->device, skb->data, length, DMA_TO_DEVICE);
        if (!laddr) {
                printk(KERN_ERR "%s: failed to map tx DMA buffer.\n", dev->name);
                dev_kfree_skb(skb);
                return 1;
        }

        sonic_tda_put(dev, entry, SONIC_TD_STATUS, 0);       /* clear status */
        sonic_tda_put(dev, entry, SONIC_TD_FRAG_COUNT, 1);   /* single fragment */
        sonic_tda_put(dev, entry, SONIC_TD_PKTSIZE, length); /* length of packet */
        sonic_tda_put(dev, entry, SONIC_TD_FRAG_PTR_L, laddr & 0xffff);
        sonic_tda_put(dev, entry, SONIC_TD_FRAG_PTR_H, laddr >> 16);
        sonic_tda_put(dev, entry, SONIC_TD_FRAG_SIZE, length);
        sonic_tda_put(dev, entry, SONIC_TD_LINK,
                sonic_tda_get(dev, entry, SONIC_TD_LINK) | SONIC_EOL);

        /*
         * Must set tx_skb[entry] only after clearing status, and
         * before clearing EOL and before stopping queue
         */
        wmb();
        lp->tx_len[entry] = length;
        lp->tx_laddr[entry] = laddr;
        lp->tx_skb[entry] = skb;

        wmb();
        sonic_tda_put(dev, lp->eol_tx, SONIC_TD_LINK,
                                  sonic_tda_get(dev, lp->eol_tx, SONIC_TD_LINK) & ~SONIC_EOL);
        lp->eol_tx = entry;

        lp->next_tx = (entry + 1) & SONIC_TDS_MASK;
        if (lp->tx_skb[lp->next_tx] != NULL) {
                /* The ring is full, the ISR has yet to process the next TD. */
                if (sonic_debug > 3)
                        printk("%s: stopping queue\n", dev->name);
                netif_stop_queue(dev);
                /* after this packet, wait for ISR to free up some TDAs */
        } else netif_start_queue(dev);

        if (sonic_debug > 2)
                printk("sonic_send_packet: issuing Tx command\n");

        SONIC_WRITE(SONIC_CMD, SONIC_CR_TXP);

        dev->trans_start = jiffies;

        return 0;
}

/*
 * The typical workload of the driver:
 * Handle the network interface interrupts.
 */
static irqreturn_t sonic_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct sonic_local *lp = netdev_priv(dev);
        int status;

        if (!(status = SONIC_READ(SONIC_ISR) & SONIC_IMR_DEFAULT))
                return IRQ_NONE;

        do {
                if (status & SONIC_INT_PKTRX) {
                        if (sonic_debug > 2)
                                printk("%s: packet rx\n", dev->name);
                        sonic_rx(dev);  /* got packet(s) */
                        SONIC_WRITE(SONIC_ISR, SONIC_INT_PKTRX); /* clear the interrupt */
                }

                if (status & SONIC_INT_TXDN) {
                        int entry = lp->cur_tx;
                        int td_status;
                        int freed_some = 0;

                        /* At this point, cur_tx is the index of a TD that is one of:
                         *   unallocated/freed                          (status set   & tx_skb[entry] clear)
                         *   allocated and sent                         (status set   & tx_skb[entry] set  )
                         *   allocated and not yet sent                 (status clear & tx_skb[entry] set  )
                         *   still being allocated by sonic_send_packet (status clear & tx_skb[entry] clear)
                         */

                        if (sonic_debug > 2)
                                printk("%s: tx done\n", dev->name);

                        while (lp->tx_skb[entry] != NULL) {
                                if ((td_status = sonic_tda_get(dev, entry, SONIC_TD_STATUS)) == 0)
                                        break;

                                if (td_status & 0x0001) {
                                        lp->stats.tx_packets++;
                                        lp->stats.tx_bytes += sonic_tda_get(dev, entry, SONIC_TD_PKTSIZE);
                                } else {
                                        lp->stats.tx_errors++;
                                        if (td_status & 0x0642)
                                                lp->stats.tx_aborted_errors++;
                                        if (td_status & 0x0180)
                                                lp->stats.tx_carrier_errors++;
                                        if (td_status & 0x0020)
                                                lp->stats.tx_window_errors++;
                                        if (td_status & 0x0004)
                                                lp->stats.tx_fifo_errors++;
                                }

                                /* We must free the original skb */
                                dev_kfree_skb_irq(lp->tx_skb[entry]);
                                lp->tx_skb[entry] = NULL;
                                /* and unmap DMA buffer */
                                dma_unmap_single(lp->device, lp->tx_laddr[entry], lp->tx_len[entry], DMA_TO_DEVICE);
                                lp->tx_laddr[entry] = (dma_addr_t)0;
                                freed_some = 1;

                                if (sonic_tda_get(dev, entry, SONIC_TD_LINK) & SONIC_EOL) {
                                        entry = (entry + 1) & SONIC_TDS_MASK;
                                        break;
                                }
                                entry = (entry + 1) & SONIC_TDS_MASK;
                        }

                        if (freed_some || lp->tx_skb[entry] == NULL)
                                netif_wake_queue(dev);  /* The ring is no longer full */
                        lp->cur_tx = entry;
                        SONIC_WRITE(SONIC_ISR, SONIC_INT_TXDN); /* clear the interrupt */
                }

                /*
                 * check error conditions
                 */
                if (status & SONIC_INT_RFO) {
                        if (sonic_debug > 1)
                                printk("%s: rx fifo overrun\n", dev->name);
                        lp->stats.rx_fifo_errors++;
                        SONIC_WRITE(SONIC_ISR, SONIC_INT_RFO); /* clear the interrupt */
                }
                if (status & SONIC_INT_RDE) {
                        if (sonic_debug > 1)
                                printk("%s: rx descriptors exhausted\n", dev->name);
                        lp->stats.rx_dropped++;
                        SONIC_WRITE(SONIC_ISR, SONIC_INT_RDE); /* clear the interrupt */
                }
                if (status & SONIC_INT_RBAE) {
                        if (sonic_debug > 1)
                                printk("%s: rx buffer area exceeded\n", dev->name);
                        lp->stats.rx_dropped++;
                        SONIC_WRITE(SONIC_ISR, SONIC_INT_RBAE); /* clear the interrupt */
                }

                /* counter overruns; all counters are 16bit wide */
                if (status & SONIC_INT_FAE) {
                        lp->stats.rx_frame_errors += 65536;
                        SONIC_WRITE(SONIC_ISR, SONIC_INT_FAE); /* clear the interrupt */
                }
                if (status & SONIC_INT_CRC) {
                        lp->stats.rx_crc_errors += 65536;
                        SONIC_WRITE(SONIC_ISR, SONIC_INT_CRC); /* clear the interrupt */
                }
                if (status & SONIC_INT_MP) {
                        lp->stats.rx_missed_errors += 65536;
                        SONIC_WRITE(SONIC_ISR, SONIC_INT_MP); /* clear the interrupt */
                }

                /* transmit error */
                if (status & SONIC_INT_TXER) {
                        if ((SONIC_READ(SONIC_TCR) & SONIC_TCR_FU) && (sonic_debug > 2))
                                printk(KERN_ERR "%s: tx fifo underrun\n", dev->name);
                        SONIC_WRITE(SONIC_ISR, SONIC_INT_TXER); /* clear the interrupt */
                }

                /* bus retry */
                if (status & SONIC_INT_BR) {
                        printk(KERN_ERR "%s: Bus retry occurred! Device interrupt disabled.\n",
                                dev->name);
                        /* ... to help debug DMA problems causing endless interrupts. */
                        /* Bounce the eth interface to turn on the interrupt again. */
                        SONIC_WRITE(SONIC_IMR, 0);
                        SONIC_WRITE(SONIC_ISR, SONIC_INT_BR); /* clear the interrupt */
                }

                /* load CAM done */
                if (status & SONIC_INT_LCD)
                        SONIC_WRITE(SONIC_ISR, SONIC_INT_LCD); /* clear the interrupt */
        } while((status = SONIC_READ(SONIC_ISR) & SONIC_IMR_DEFAULT));
        return IRQ_HANDLED;
}

/*
 * We have a good packet(s), pass it/them up the network stack.
 */
static void sonic_rx(struct net_device *dev)
{
        struct sonic_local *lp = netdev_priv(dev);
        int status;
        int entry = lp->cur_rx;

        while (sonic_rda_get(dev, entry, SONIC_RD_IN_USE) == 0) {
                struct sk_buff *used_skb;
                struct sk_buff *new_skb;
                dma_addr_t new_laddr;
                u16 bufadr_l;
                u16 bufadr_h;
                int pkt_len;

                status = sonic_rda_get(dev, entry, SONIC_RD_STATUS);
                if (status & SONIC_RCR_PRX) {
                        /* Malloc up new buffer. */
                        new_skb = dev_alloc_skb(SONIC_RBSIZE + 2);
                        if (new_skb == NULL) {
                                printk(KERN_ERR "%s: Memory squeeze, dropping packet.\n", dev->name);
                                lp->stats.rx_dropped++;
                                break;
                        }
                        /* provide 16 byte IP header alignment unless DMA requires otherwise */
                        if(SONIC_BUS_SCALE(lp->dma_bitmode) == 2)
                                skb_reserve(new_skb, 2);

                        new_laddr = dma_map_single(lp->device, skb_put(new_skb, SONIC_RBSIZE),
                                               SONIC_RBSIZE, DMA_FROM_DEVICE);
                        if (!new_laddr) {
                                dev_kfree_skb(new_skb);
                                printk(KERN_ERR "%s: Failed to map rx buffer, dropping packet.\n", dev->name);
                                lp->stats.rx_dropped++;
                                break;
                        }

                        /* now we have a new skb to replace it, pass the used one up the stack */
                        dma_unmap_single(lp->device, lp->rx_laddr[entry], SONIC_RBSIZE, DMA_FROM_DEVICE);
                        used_skb = lp->rx_skb[entry];
                        pkt_len = sonic_rda_get(dev, entry, SONIC_RD_PKTLEN);
                        skb_trim(used_skb, pkt_len);
                        used_skb->protocol = eth_type_trans(used_skb, dev);
                        netif_rx(used_skb);
                        dev->last_rx = jiffies;
                        lp->stats.rx_packets++;
                        lp->stats.rx_bytes += pkt_len;

                        /* and insert the new skb */
                        lp->rx_laddr[entry] = new_laddr;
                        lp->rx_skb[entry] = new_skb;

                        bufadr_l = (unsigned long)new_laddr & 0xffff;
                        bufadr_h = (unsigned long)new_laddr >> 16;
                        sonic_rra_put(dev, entry, SONIC_RR_BUFADR_L, bufadr_l);
                        sonic_rra_put(dev, entry, SONIC_RR_BUFADR_H, bufadr_h);
                } else {
                        /* This should only happen, if we enable accepting broken packets. */
                        lp->stats.rx_errors++;
                        if (status & SONIC_RCR_FAER)
                                lp->stats.rx_frame_errors++;
                        if (status & SONIC_RCR_CRCR)
                                lp->stats.rx_crc_errors++;
                }
                if (status & SONIC_RCR_LPKT) {
                        /*
                         * this was the last packet out of the current receive buffer
                         * give the buffer back to the SONIC
                         */
                        lp->cur_rwp += SIZEOF_SONIC_RR * SONIC_BUS_SCALE(lp->dma_bitmode);
                        if (lp->cur_rwp >= lp->rra_end) lp->cur_rwp = lp->rra_laddr & 0xffff;
                        SONIC_WRITE(SONIC_RWP, lp->cur_rwp);
                        if (SONIC_READ(SONIC_ISR) & SONIC_INT_RBE) {
                                if (sonic_debug > 2)
                                        printk("%s: rx buffer exhausted\n", dev->name);
                                SONIC_WRITE(SONIC_ISR, SONIC_INT_RBE); /* clear the flag */
                        }
                } else
                        printk(KERN_ERR "%s: rx desc without RCR_LPKT. Shouldn't happen !?\n",
                             dev->name);
                /*
                 * give back the descriptor
                 */
                sonic_rda_put(dev, entry, SONIC_RD_LINK,
                        sonic_rda_get(dev, entry, SONIC_RD_LINK) | SONIC_EOL);
                sonic_rda_put(dev, entry, SONIC_RD_IN_USE, 1);
                sonic_rda_put(dev, lp->eol_rx, SONIC_RD_LINK,
                        sonic_rda_get(dev, lp->eol_rx, SONIC_RD_LINK) & ~SONIC_EOL);
                lp->eol_rx = entry;
                lp->cur_rx = entry = (entry + 1) & SONIC_RDS_MASK;
        }
        /*
         * If any worth-while packets have been received, netif_rx()
         * has done a mark_bh(NET_BH) for us and will work on them
         * when we get to the bottom-half routine.
         */
}


/*
 * Get the current statistics.
 * This may be called with the device open or closed.
 */
static struct net_device_stats *sonic_get_stats(struct net_device *dev)
{
        struct sonic_local *lp = netdev_priv(dev);

        /* read the tally counter from the SONIC and reset them */
        lp->stats.rx_crc_errors += SONIC_READ(SONIC_CRCT);
        SONIC_WRITE(SONIC_CRCT, 0xffff);
        lp->stats.rx_frame_errors += SONIC_READ(SONIC_FAET);
        SONIC_WRITE(SONIC_FAET, 0xffff);
        lp->stats.rx_missed_errors += SONIC_READ(SONIC_MPT);
        SONIC_WRITE(SONIC_MPT, 0xffff);

        return &lp->stats;
}


/*
 * Set or clear the multicast filter for this adaptor.
 */
static void sonic_multicast_list(struct net_device *dev)
{
        struct sonic_local *lp = netdev_priv(dev);
        unsigned int rcr;
        struct dev_mc_list *dmi = dev->mc_list;
        unsigned char *addr;
        int i;

        rcr = SONIC_READ(SONIC_RCR) & ~(SONIC_RCR_PRO | SONIC_RCR_AMC);
        rcr |= SONIC_RCR_BRD;   /* accept broadcast packets */

        if (dev->flags & IFF_PROMISC) { /* set promiscuous mode */
                rcr |= SONIC_RCR_PRO;
        } else {
                if ((dev->flags & IFF_ALLMULTI) || (dev->mc_count > 15)) {
                        rcr |= SONIC_RCR_AMC;
                } else {
                        if (sonic_debug > 2)
                                printk("sonic_multicast_list: mc_count %d\n", dev->mc_count);
                        sonic_set_cam_enable(dev, 1);  /* always enable our own address */
                        for (i = 1; i <= dev->mc_count; i++) {
                                addr = dmi->dmi_addr;
                                dmi = dmi->next;
                                sonic_cda_put(dev, i, SONIC_CD_CAP0, addr[1] << 8 | addr[0]);
                                sonic_cda_put(dev, i, SONIC_CD_CAP1, addr[3] << 8 | addr[2]);
                                sonic_cda_put(dev, i, SONIC_CD_CAP2, addr[5] << 8 | addr[4]);
                                sonic_set_cam_enable(dev, sonic_get_cam_enable(dev) | (1 << i));
                        }
                        SONIC_WRITE(SONIC_CDC, 16);
                        /* issue Load CAM command */
                        SONIC_WRITE(SONIC_CDP, lp->cda_laddr & 0xffff);
                        SONIC_WRITE(SONIC_CMD, SONIC_CR_LCAM);
                }
        }

        if (sonic_debug > 2)
                printk("sonic_multicast_list: setting RCR=%x\n", rcr);

        SONIC_WRITE(SONIC_RCR, rcr);
}


/*
 * Initialize the SONIC ethernet controller.
 */
static int sonic_init(struct net_device *dev)
{
        unsigned int cmd;
        struct sonic_local *lp = netdev_priv(dev);
        int i;

        /*
         * put the Sonic into software-reset mode and
         * disable all interrupts
         */
        SONIC_WRITE(SONIC_IMR, 0);
        SONIC_WRITE(SONIC_ISR, 0x7fff);
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);

        /*
         * clear software reset flag, disable receiver, clear and
         * enable interrupts, then completely initialize the SONIC
         */
        SONIC_WRITE(SONIC_CMD, 0);
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS);

        /*
         * initialize the receive resource area
         */
        if (sonic_debug > 2)
                printk("sonic_init: initialize receive resource area\n");

        for (i = 0; i < SONIC_NUM_RRS; i++) {
                u16 bufadr_l = (unsigned long)lp->rx_laddr[i] & 0xffff;
                u16 bufadr_h = (unsigned long)lp->rx_laddr[i] >> 16;
                sonic_rra_put(dev, i, SONIC_RR_BUFADR_L, bufadr_l);
                sonic_rra_put(dev, i, SONIC_RR_BUFADR_H, bufadr_h);
                sonic_rra_put(dev, i, SONIC_RR_BUFSIZE_L, SONIC_RBSIZE >> 1);
                sonic_rra_put(dev, i, SONIC_RR_BUFSIZE_H, 0);
        }

        /* initialize all RRA registers */
        lp->rra_end = (lp->rra_laddr + SONIC_NUM_RRS * SIZEOF_SONIC_RR *
                                        SONIC_BUS_SCALE(lp->dma_bitmode)) & 0xffff;
        lp->cur_rwp = (lp->rra_laddr + (SONIC_NUM_RRS - 1) * SIZEOF_SONIC_RR *
                                        SONIC_BUS_SCALE(lp->dma_bitmode)) & 0xffff;

        SONIC_WRITE(SONIC_RSA, lp->rra_laddr & 0xffff);
        SONIC_WRITE(SONIC_REA, lp->rra_end);
        SONIC_WRITE(SONIC_RRP, lp->rra_laddr & 0xffff);
        SONIC_WRITE(SONIC_RWP, lp->cur_rwp);
        SONIC_WRITE(SONIC_URRA, lp->rra_laddr >> 16);
        SONIC_WRITE(SONIC_EOBC, (SONIC_RBSIZE >> 1) - (lp->dma_bitmode ? 2 : 1));

        /* load the resource pointers */
        if (sonic_debug > 3)
                printk("sonic_init: issuing RRRA command\n");

        SONIC_WRITE(SONIC_CMD, SONIC_CR_RRRA);
        i = 0;
        while (i++ < 100) {
                if (SONIC_READ(SONIC_CMD) & SONIC_CR_RRRA)
                        break;
        }

        if (sonic_debug > 2)
                printk("sonic_init: status=%x i=%d\n", SONIC_READ(SONIC_CMD), i);

        /*
         * Initialize the receive descriptors so that they
         * become a circular linked list, ie. let the last
         * descriptor point to the first again.
         */
        if (sonic_debug > 2)
                printk("sonic_init: initialize receive descriptors\n");
        for (i=0; i<SONIC_NUM_RDS; i++) {
                sonic_rda_put(dev, i, SONIC_RD_STATUS, 0);
                sonic_rda_put(dev, i, SONIC_RD_PKTLEN, 0);
                sonic_rda_put(dev, i, SONIC_RD_PKTPTR_L, 0);
                sonic_rda_put(dev, i, SONIC_RD_PKTPTR_H, 0);
                sonic_rda_put(dev, i, SONIC_RD_SEQNO, 0);
                sonic_rda_put(dev, i, SONIC_RD_IN_USE, 1);
                sonic_rda_put(dev, i, SONIC_RD_LINK,
                        lp->rda_laddr +
                        ((i+1) * SIZEOF_SONIC_RD * SONIC_BUS_SCALE(lp->dma_bitmode)));
        }
        /* fix last descriptor */
        sonic_rda_put(dev, SONIC_NUM_RDS - 1, SONIC_RD_LINK,
                (lp->rda_laddr & 0xffff) | SONIC_EOL);
        lp->eol_rx = SONIC_NUM_RDS - 1;
        lp->cur_rx = 0;
        SONIC_WRITE(SONIC_URDA, lp->rda_laddr >> 16);
        SONIC_WRITE(SONIC_CRDA, lp->rda_laddr & 0xffff);

        /*
         * initialize transmit descriptors
         */
        if (sonic_debug > 2)
                printk("sonic_init: initialize transmit descriptors\n");
        for (i = 0; i < SONIC_NUM_TDS; i++) {
                sonic_tda_put(dev, i, SONIC_TD_STATUS, 0);
                sonic_tda_put(dev, i, SONIC_TD_CONFIG, 0);
                sonic_tda_put(dev, i, SONIC_TD_PKTSIZE, 0);
                sonic_tda_put(dev, i, SONIC_TD_FRAG_COUNT, 0);
                sonic_tda_put(dev, i, SONIC_TD_LINK,
                        (lp->tda_laddr & 0xffff) +
                        (i + 1) * SIZEOF_SONIC_TD * SONIC_BUS_SCALE(lp->dma_bitmode));
                lp->tx_skb[i] = NULL;
        }
        /* fix last descriptor */
        sonic_tda_put(dev, SONIC_NUM_TDS - 1, SONIC_TD_LINK,
                (lp->tda_laddr & 0xffff));

        SONIC_WRITE(SONIC_UTDA, lp->tda_laddr >> 16);
        SONIC_WRITE(SONIC_CTDA, lp->tda_laddr & 0xffff);
        lp->cur_tx = lp->next_tx = 0;
        lp->eol_tx = SONIC_NUM_TDS - 1;

        /*
         * put our own address to CAM desc[0]
         */
        sonic_cda_put(dev, 0, SONIC_CD_CAP0, dev->dev_addr[1] << 8 | dev->dev_addr[0]);
        sonic_cda_put(dev, 0, SONIC_CD_CAP1, dev->dev_addr[3] << 8 | dev->dev_addr[2]);
        sonic_cda_put(dev, 0, SONIC_CD_CAP2, dev->dev_addr[5] << 8 | dev->dev_addr[4]);
        sonic_set_cam_enable(dev, 1);

        for (i = 0; i < 16; i++)
                sonic_cda_put(dev, i, SONIC_CD_ENTRY_POINTER, i);

        /*
         * initialize CAM registers
         */
        SONIC_WRITE(SONIC_CDP, lp->cda_laddr & 0xffff);
        SONIC_WRITE(SONIC_CDC, 16);

        /*
         * load the CAM
         */
        SONIC_WRITE(SONIC_CMD, SONIC_CR_LCAM);

        i = 0;
        while (i++ < 100) {
                if (SONIC_READ(SONIC_ISR) & SONIC_INT_LCD)
                        break;
        }
        if (sonic_debug > 2) {
                printk("sonic_init: CMD=%x, ISR=%x\n, i=%d",
                       SONIC_READ(SONIC_CMD), SONIC_READ(SONIC_ISR), i);
        }

        /*
         * enable receiver, disable loopback
         * and enable all interrupts
         */
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RXEN | SONIC_CR_STP);
        SONIC_WRITE(SONIC_RCR, SONIC_RCR_DEFAULT);
        SONIC_WRITE(SONIC_TCR, SONIC_TCR_DEFAULT);
        SONIC_WRITE(SONIC_ISR, 0x7fff);
        SONIC_WRITE(SONIC_IMR, SONIC_IMR_DEFAULT);

        cmd = SONIC_READ(SONIC_CMD);
        if ((cmd & SONIC_CR_RXEN) == 0 || (cmd & SONIC_CR_STP) == 0)
                printk(KERN_ERR "sonic_init: failed, status=%x\n", cmd);

        if (sonic_debug > 2)
                printk("sonic_init: new status=%x\n",
                       SONIC_READ(SONIC_CMD));

        return 0;
}

MODULE_LICENSE("GPL");