// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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".
 */

static unsigned int version_printed;

static int sonic_debug = -1;
module_param(sonic_debug, int, 0);
MODULE_PARM_DESC(sonic_debug, "debug message level");

static void sonic_msg_init(struct net_device *dev)
{
        struct sonic_local *lp = netdev_priv(dev);

        lp->msg_enable = netif_msg_init(sonic_debug, 0);

        if (version_printed++ == 0)
                netif_dbg(lp, drv, dev, "%s", version);
}

static int sonic_alloc_descriptors(struct net_device *dev)
{
        struct sonic_local *lp = netdev_priv(dev);

        /* Allocate a chunk of memory for the descriptors. Note that this
         * must not cross a 64K boundary. It is smaller than one page which
         * means that page alignment is a sufficient condition.
         */
        lp->descriptors =
                dma_alloc_coherent(lp->device,
                                   SIZEOF_SONIC_DESC *
                                   SONIC_BUS_SCALE(lp->dma_bitmode),
                                   &lp->descriptors_laddr, GFP_KERNEL);

        if (!lp->descriptors)
                return -ENOMEM;

        lp->cda = lp->descriptors;
        lp->tda = lp->cda + SIZEOF_SONIC_CDA *
                            SONIC_BUS_SCALE(lp->dma_bitmode);
        lp->rda = lp->tda + SIZEOF_SONIC_TD * SONIC_NUM_TDS *
                            SONIC_BUS_SCALE(lp->dma_bitmode);
        lp->rra = lp->rda + SIZEOF_SONIC_RD * SONIC_NUM_RDS *
                            SONIC_BUS_SCALE(lp->dma_bitmode);

        lp->cda_laddr = lp->descriptors_laddr;
        lp->tda_laddr = lp->cda_laddr + SIZEOF_SONIC_CDA *
                                        SONIC_BUS_SCALE(lp->dma_bitmode);
        lp->rda_laddr = lp->tda_laddr + SIZEOF_SONIC_TD * SONIC_NUM_TDS *
                                        SONIC_BUS_SCALE(lp->dma_bitmode);
        lp->rra_laddr = lp->rda_laddr + SIZEOF_SONIC_RD * SONIC_NUM_RDS *
                                        SONIC_BUS_SCALE(lp->dma_bitmode);

        return 0;
}

/*
 * 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;

        netif_dbg(lp, ifup, dev, "%s: initializing sonic driver\n", __func__);

        spin_lock_init(&lp->lock);

        for (i = 0; i < SONIC_NUM_RRS; i++) {
                struct sk_buff *skb = netdev_alloc_skb(dev, 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 (dma_mapping_error(lp->device, 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, true);

        netif_start_queue(dev);

        netif_dbg(lp, ifup, dev, "%s: Initialization done\n", __func__);

        return 0;
}

/* Wait for the SONIC to become idle. */
static void sonic_quiesce(struct net_device *dev, u16 mask, bool may_sleep)
{
        struct sonic_local * __maybe_unused lp = netdev_priv(dev);
        int i;
        u16 bits;

        for (i = 0; i < 1000; ++i) {
                bits = SONIC_READ(SONIC_CMD) & mask;
                if (!bits)
                        return;
                if (!may_sleep)
                        udelay(20);
                else
                        usleep_range(100, 200);
        }
        WARN_ONCE(1, "command deadline expired! 0x%04x\n", bits);
}

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

        netif_dbg(lp, ifdown, dev, "%s\n", __func__);

        netif_stop_queue(dev);

        /*
         * stop the SONIC, disable interrupts
         */
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS);
        sonic_quiesce(dev, SONIC_CR_ALL, true);

        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, unsigned int txqueue)
{
        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_CMD, SONIC_CR_RXDIS);
        sonic_quiesce(dev, SONIC_CR_ALL, false);

        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, false);
        lp->stats.tx_errors++;
        netif_trans_update(dev); /* prevent tx timeout */
        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.
 */

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;
        unsigned long flags;

        netif_dbg(lp, tx_queued, dev, "%s: skb=%p\n", __func__, skb);

        length = skb->len;
        if (length < ETH_ZLEN) {
                if (skb_padto(skb, ETH_ZLEN))
                        return NETDEV_TX_OK;
                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) {
                pr_err_ratelimited("%s: failed to map tx DMA buffer.\n", dev->name);
                dev_kfree_skb_any(skb);
                return NETDEV_TX_OK;
        }

        spin_lock_irqsave(&lp->lock, flags);

        entry = (lp->eol_tx + 1) & SONIC_TDS_MASK;

        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);

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

        netif_dbg(lp, tx_queued, dev, "%s: issuing Tx command\n", __func__);

        SONIC_WRITE(SONIC_CMD, SONIC_CR_TXP);

        lp->tx_len[entry] = length;
        lp->tx_laddr[entry] = laddr;
        lp->tx_skb[entry] = skb;

        lp->eol_tx = entry;

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

        spin_unlock_irqrestore(&lp->lock, flags);

        return NETDEV_TX_OK;
}

/*
 * 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;
        unsigned long flags;

        /* The lock has two purposes. Firstly, it synchronizes sonic_interrupt()
         * with sonic_send_packet() so that the two functions can share state.
         * Secondly, it makes sonic_interrupt() re-entrant, as that is required
         * by macsonic which must use two IRQs with different priority levels.
         */
        spin_lock_irqsave(&lp->lock, flags);

        status = SONIC_READ(SONIC_ISR) & SONIC_IMR_DEFAULT;
        if (!status) {
                spin_unlock_irqrestore(&lp->lock, flags);

                return IRQ_NONE;
        }

        do {
                SONIC_WRITE(SONIC_ISR, status); /* clear the interrupt(s) */

                if (status & SONIC_INT_PKTRX) {
                        netif_dbg(lp, intr, dev, "%s: packet rx\n", __func__);
                        sonic_rx(dev);  /* got packet(s) */
                }

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

                        /* The state of a Transmit Descriptor may be inferred
                         * from { tx_skb[entry], td_status } as follows.
                         * { clear, clear } => the TD has never been used
                         * { set,   clear } => the TD was handed to SONIC
                         * { set,   set   } => the TD was handed back
                         * { clear, set   } => the TD is available for re-use
                         */

                        netif_dbg(lp, intr, dev, "%s: tx done\n", __func__);

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

                                if (td_status & SONIC_TCR_PTX) {
                                        lp->stats.tx_packets++;
                                        lp->stats.tx_bytes += sonic_tda_get(dev, entry, SONIC_TD_PKTSIZE);
                                } else {
                                        if (td_status & (SONIC_TCR_EXD |
                                            SONIC_TCR_EXC | SONIC_TCR_BCM))
                                                lp->stats.tx_aborted_errors++;
                                        if (td_status &
                                            (SONIC_TCR_NCRS | SONIC_TCR_CRLS))
                                                lp->stats.tx_carrier_errors++;
                                        if (td_status & SONIC_TCR_OWC)
                                                lp->stats.tx_window_errors++;
                                        if (td_status & SONIC_TCR_FU)
                                                lp->stats.tx_fifo_errors++;
                                }

                                /* We must free the original skb */
                                dev_consume_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;
                }

                /*
                 * check error conditions
                 */
                if (status & SONIC_INT_RFO) {
                        netif_dbg(lp, rx_err, dev, "%s: rx fifo overrun\n",
                                  __func__);
                }
                if (status & SONIC_INT_RDE) {
                        netif_dbg(lp, rx_err, dev, "%s: rx descriptors exhausted\n",
                                  __func__);
                }
                if (status & SONIC_INT_RBAE) {
                        netif_dbg(lp, rx_err, dev, "%s: rx buffer area exceeded\n",
                                  __func__);
                }

                /* counter overruns; all counters are 16bit wide */
                if (status & SONIC_INT_FAE)
                        lp->stats.rx_frame_errors += 65536;
                if (status & SONIC_INT_CRC)
                        lp->stats.rx_crc_errors += 65536;
                if (status & SONIC_INT_MP)
                        lp->stats.rx_missed_errors += 65536;

                /* transmit error */
                if (status & SONIC_INT_TXER) {
                        u16 tcr = SONIC_READ(SONIC_TCR);

                        netif_dbg(lp, tx_err, dev, "%s: TXER intr, TCR %04x\n",
                                  __func__, tcr);

                        if (tcr & (SONIC_TCR_EXD | SONIC_TCR_EXC |
                                   SONIC_TCR_FU | SONIC_TCR_BCM)) {
                                /* Aborted transmission. Try again. */
                                netif_stop_queue(dev);
                                SONIC_WRITE(SONIC_CMD, SONIC_CR_TXP);
                        }
                }

                /* 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);
                }

                status = SONIC_READ(SONIC_ISR) & SONIC_IMR_DEFAULT;
        } while (status);

        spin_unlock_irqrestore(&lp->lock, flags);

        return IRQ_HANDLED;
}

/* Return the array index corresponding to a given Receive Buffer pointer. */
static int index_from_addr(struct sonic_local *lp, dma_addr_t addr,
                           unsigned int last)
{
        unsigned int i = last;

        do {
                i = (i + 1) & SONIC_RRS_MASK;
                if (addr == lp->rx_laddr[i])
                        return i;
        } while (i != last);

        return -ENOENT;
}

/* Allocate and map a new skb to be used as a receive buffer. */
static bool sonic_alloc_rb(struct net_device *dev, struct sonic_local *lp,
                           struct sk_buff **new_skb, dma_addr_t *new_addr)
{
        *new_skb = netdev_alloc_skb(dev, SONIC_RBSIZE + 2);
        if (!*new_skb)
                return false;

        if (SONIC_BUS_SCALE(lp->dma_bitmode) == 2)
                skb_reserve(*new_skb, 2);

        *new_addr = dma_map_single(lp->device, skb_put(*new_skb, SONIC_RBSIZE),
                                   SONIC_RBSIZE, DMA_FROM_DEVICE);
        if (!*new_addr) {
                dev_kfree_skb(*new_skb);
                *new_skb = NULL;
                return false;
        }

        return true;
}

/* Place a new receive resource in the Receive Resource Area and update RWP. */
static void sonic_update_rra(struct net_device *dev, struct sonic_local *lp,
                             dma_addr_t old_addr, dma_addr_t new_addr)
{
        unsigned int entry = sonic_rr_entry(dev, SONIC_READ(SONIC_RWP));
        unsigned int end = sonic_rr_entry(dev, SONIC_READ(SONIC_RRP));
        u32 buf;

        /* The resources in the range [RRP, RWP) belong to the SONIC. This loop
         * scans the other resources in the RRA, those in the range [RWP, RRP).
         */
        do {
                buf = (sonic_rra_get(dev, entry, SONIC_RR_BUFADR_H) << 16) |
                      sonic_rra_get(dev, entry, SONIC_RR_BUFADR_L);

                if (buf == old_addr)
                        break;

                entry = (entry + 1) & SONIC_RRS_MASK;
        } while (entry != end);

        WARN_ONCE(buf != old_addr, "failed to find resource!\n");

        sonic_rra_put(dev, entry, SONIC_RR_BUFADR_H, new_addr >> 16);
        sonic_rra_put(dev, entry, SONIC_RR_BUFADR_L, new_addr & 0xffff);

        entry = (entry + 1) & SONIC_RRS_MASK;

        SONIC_WRITE(SONIC_RWP, sonic_rr_addr(dev, entry));
}

/*
 * 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 entry = lp->cur_rx;
        int prev_entry = lp->eol_rx;
        bool rbe = false;

        while (sonic_rda_get(dev, entry, SONIC_RD_IN_USE) == 0) {
                u16 status = sonic_rda_get(dev, entry, SONIC_RD_STATUS);

                /* If the RD has LPKT set, the chip has finished with the RB */
                if ((status & SONIC_RCR_PRX) && (status & SONIC_RCR_LPKT)) {
                        struct sk_buff *new_skb;
                        dma_addr_t new_laddr;
                        u32 addr = (sonic_rda_get(dev, entry,
                                                  SONIC_RD_PKTPTR_H) << 16) |
                                   sonic_rda_get(dev, entry, SONIC_RD_PKTPTR_L);
                        int i = index_from_addr(lp, addr, entry);

                        if (i < 0) {
                                WARN_ONCE(1, "failed to find buffer!\n");
                                break;
                        }

                        if (sonic_alloc_rb(dev, lp, &new_skb, &new_laddr)) {
                                struct sk_buff *used_skb = lp->rx_skb[i];
                                int pkt_len;

                                /* Pass the used buffer up the stack */
                                dma_unmap_single(lp->device, addr, SONIC_RBSIZE,
                                                 DMA_FROM_DEVICE);

                                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);
                                lp->stats.rx_packets++;
                                lp->stats.rx_bytes += pkt_len;

                                lp->rx_skb[i] = new_skb;
                                lp->rx_laddr[i] = new_laddr;
                        } else {
                                /* Failed to obtain a new buffer so re-use it */
                                new_laddr = addr;
                                lp->stats.rx_dropped++;
                        }
                        /* If RBE is already asserted when RWP advances then
                         * it's safe to clear RBE after processing this packet.
                         */
                        rbe = rbe || SONIC_READ(SONIC_ISR) & SONIC_INT_RBE;
                        sonic_update_rra(dev, lp, addr, new_laddr);
                }
                /*
                 * give back the descriptor
                 */
                sonic_rda_put(dev, entry, SONIC_RD_STATUS, 0);
                sonic_rda_put(dev, entry, SONIC_RD_IN_USE, 1);

                prev_entry = entry;
                entry = (entry + 1) & SONIC_RDS_MASK;
        }

        lp->cur_rx = entry;

        if (prev_entry != lp->eol_rx) {
                /* Advance the EOL flag to put descriptors back into service */
                sonic_rda_put(dev, prev_entry, SONIC_RD_LINK, SONIC_EOL |
                              sonic_rda_get(dev, prev_entry, SONIC_RD_LINK));
                sonic_rda_put(dev, lp->eol_rx, SONIC_RD_LINK, ~SONIC_EOL &
                              sonic_rda_get(dev, lp->eol_rx, SONIC_RD_LINK));
                lp->eol_rx = prev_entry;
        }

        if (rbe)
                SONIC_WRITE(SONIC_ISR, SONIC_INT_RBE);
}


/*
 * 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 netdev_hw_addr *ha;
        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) ||
                    (netdev_mc_count(dev) > 15)) {
                        rcr |= SONIC_RCR_AMC;
                } else {
                        unsigned long flags;

                        netif_dbg(lp, ifup, dev, "%s: mc_count %d\n", __func__,
                                  netdev_mc_count(dev));
                        sonic_set_cam_enable(dev, 1);  /* always enable our own address */
                        i = 1;
                        netdev_for_each_mc_addr(ha, dev) {
                                addr = ha->addr;
                                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));
                                i++;
                        }
                        SONIC_WRITE(SONIC_CDC, 16);
                        SONIC_WRITE(SONIC_CDP, lp->cda_laddr & 0xffff);

                        /* LCAM and TXP commands can't be used simultaneously */
                        spin_lock_irqsave(&lp->lock, flags);
                        sonic_quiesce(dev, SONIC_CR_TXP, false);
                        SONIC_WRITE(SONIC_CMD, SONIC_CR_LCAM);
                        sonic_quiesce(dev, SONIC_CR_LCAM, false);
                        spin_unlock_irqrestore(&lp->lock, flags);
                }
        }

        netif_dbg(lp, ifup, dev, "%s: setting RCR=%x\n", __func__, rcr);

        SONIC_WRITE(SONIC_RCR, rcr);
}


/*
 * Initialize the SONIC ethernet controller.
 */
static int sonic_init(struct net_device *dev, bool may_sleep)
{
        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);

        /* While in reset mode, clear CAM Enable register */
        SONIC_WRITE(SONIC_CE, 0);

        /*
         * 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 | SONIC_CR_STP);
        sonic_quiesce(dev, SONIC_CR_ALL, may_sleep);

        /*
         * initialize the receive resource area
         */
        netif_dbg(lp, ifup, dev, "%s: initialize receive resource area\n",
                  __func__);

        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 */
        SONIC_WRITE(SONIC_RSA, sonic_rr_addr(dev, 0));
        SONIC_WRITE(SONIC_REA, sonic_rr_addr(dev, SONIC_NUM_RRS));
        SONIC_WRITE(SONIC_RRP, sonic_rr_addr(dev, 0));
        SONIC_WRITE(SONIC_RWP, sonic_rr_addr(dev, SONIC_NUM_RRS - 1));
        SONIC_WRITE(SONIC_URRA, lp->rra_laddr >> 16);
        SONIC_WRITE(SONIC_EOBC, (SONIC_RBSIZE >> 1) - (lp->dma_bitmode ? 2 : 1));

        /* load the resource pointers */
        netif_dbg(lp, ifup, dev, "%s: issuing RRRA command\n", __func__);

        SONIC_WRITE(SONIC_CMD, SONIC_CR_RRRA);
        sonic_quiesce(dev, SONIC_CR_RRRA, may_sleep);

        /*
         * Initialize the receive descriptors so that they
         * become a circular linked list, ie. let the last
         * descriptor point to the first again.
         */
        netif_dbg(lp, ifup, dev, "%s: initialize receive descriptors\n",
                  __func__);

        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
         */
        netif_dbg(lp, ifup, dev, "%s: initialize transmit descriptors\n",
                  __func__);

        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 = 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);
        sonic_quiesce(dev, SONIC_CR_LCAM, may_sleep);

        /*
         * enable receiver, disable loopback
         * and enable all interrupts
         */
        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);
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RXEN);

        netif_dbg(lp, ifup, dev, "%s: new status=%x\n", __func__,
                  SONIC_READ(SONIC_CMD));

        return 0;
}

MODULE_LICENSE("GPL");