/*      $NetBSD: if_age.c,v 1.75 2025/12/16 18:24:47 andvar Exp $ */
/*      $OpenBSD: if_age.c,v 1.1 2009/01/16 05:00:34 kevlo Exp $        */

/*-
 * Copyright (c) 2008, Pyun YongHyeon <yongari@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* Driver for Attansic Technology Corp. L1 Gigabit Ethernet. */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_age.c,v 1.75 2025/12/16 18:24:47 andvar Exp $");

#include "vlan.h"

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/endian.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/queue.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/callout.h>
#include <sys/socket.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/if_ether.h>

#ifdef INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#endif

#include <net/if_types.h>
#include <net/if_vlanvar.h>

#include <net/bpf.h>

#include <dev/mii/mii.h>
#include <dev/mii/miivar.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>
#include <dev/pci/pcidevs.h>

#include <dev/pci/if_agereg.h>

static int      age_match(device_t, cfdata_t, void *);
static void     age_attach(device_t, device_t, void *);
static int      age_detach(device_t, int);

static bool     age_resume(device_t, const pmf_qual_t *);

static int      age_miibus_readreg(device_t, int, int, uint16_t *);
static int      age_miibus_writereg(device_t, int, int, uint16_t);
static void     age_miibus_statchg(struct ifnet *);

static int      age_init(struct ifnet *);
static int      age_ioctl(struct ifnet *, u_long, void *);
static void     age_start(struct ifnet *);
static void     age_watchdog(struct ifnet *);
static bool     age_shutdown(device_t, int);
static void     age_mediastatus(struct ifnet *, struct ifmediareq *);
static int      age_mediachange(struct ifnet *);

static int      age_intr(void *);
static int      age_dma_alloc(struct age_softc *);
static void     age_dma_free(struct age_softc *);
static void     age_get_macaddr(struct age_softc *, uint8_t[]);
static void     age_phy_reset(struct age_softc *);

static int      age_encap(struct age_softc *, struct mbuf *);
static void     age_init_tx_ring(struct age_softc *);
static int      age_init_rx_ring(struct age_softc *);
static void     age_init_rr_ring(struct age_softc *);
static void     age_init_cmb_block(struct age_softc *);
static void     age_init_smb_block(struct age_softc *);
static int      age_newbuf(struct age_softc *, struct age_rxdesc *, int);
static void     age_mac_config(struct age_softc *);
static void     age_txintr(struct age_softc *, int);
static void     age_rxeof(struct age_softc *sc, struct rx_rdesc *);
static void     age_rxintr(struct age_softc *, int);
static void     age_tick(void *);
static void     age_reset(struct age_softc *);
static void     age_stop(struct ifnet *, int);
static void     age_stats_update(struct age_softc *);
static void     age_stop_txmac(struct age_softc *);
static void     age_stop_rxmac(struct age_softc *);
static void     age_rxvlan(struct age_softc *sc);
static void     age_rxfilter(struct age_softc *);

CFATTACH_DECL_NEW(age, sizeof(struct age_softc),
    age_match, age_attach, age_detach, NULL);

int agedebug = 0;
#define DPRINTF(x)      do { if (agedebug) printf x; } while (0)

#define AGE_CSUM_FEATURES       (M_CSUM_TCPv4 | M_CSUM_UDPv4)

static int
age_match(device_t dev, cfdata_t match, void *aux)
{
        struct pci_attach_args *pa = aux;

        return (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_ATTANSIC &&
            PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_ATTANSIC_ETHERNET_GIGA);
}

static void
age_attach(device_t parent, device_t self, void *aux)
{
        struct age_softc *sc = device_private(self);
        struct pci_attach_args *pa = aux;
        pci_intr_handle_t ih;
        const char *intrstr;
        struct ifnet *ifp = &sc->sc_ec.ec_if;
        struct mii_data * const mii = &sc->sc_miibus;
        pcireg_t memtype;
        int error = 0;
        char intrbuf[PCI_INTRSTR_LEN];

        aprint_naive("\n");
        aprint_normal(": Attansic/Atheros L1 Gigabit Ethernet\n");

        sc->sc_dev = self;
        sc->sc_pct = pa->pa_pc;
        sc->sc_pcitag = pa->pa_tag;

        if (pci_dma64_available(pa))
                sc->sc_dmat = pa->pa_dmat64;
        else
                sc->sc_dmat = pa->pa_dmat;

        /*
         * Allocate IO memory
         */
        memtype = pci_mapreg_type(sc->sc_pct, sc->sc_pcitag, AGE_PCIR_BAR);
        switch (memtype) {
        case PCI_MAPREG_TYPE_MEM | PCI_MAPREG_MEM_TYPE_32BIT:
        case PCI_MAPREG_TYPE_MEM | PCI_MAPREG_MEM_TYPE_32BIT_1M:
        case PCI_MAPREG_TYPE_MEM | PCI_MAPREG_MEM_TYPE_64BIT:
                break;
        default:
                aprint_error_dev(self, "invalid base address register\n");
                break;
        }

        if (pci_mapreg_map(pa, AGE_PCIR_BAR, memtype, 0, &sc->sc_mem_bt,
            &sc->sc_mem_bh, NULL, &sc->sc_mem_size) != 0) {
                aprint_error_dev(self, "could not map mem space\n");
                return;
        }

        if (pci_intr_map(pa, &ih) != 0) {
                aprint_error_dev(self, "could not map interrupt\n");
                goto fail;
        }

        /*
         * Allocate IRQ
         */
        intrstr = pci_intr_string(sc->sc_pct, ih, intrbuf, sizeof(intrbuf));
        sc->sc_irq_handle = pci_intr_establish_xname(sc->sc_pct, ih, IPL_NET,
            age_intr, sc, device_xname(self));
        if (sc->sc_irq_handle == NULL) {
                aprint_error_dev(self, "could not establish interrupt");
                if (intrstr != NULL)
                        aprint_error(" at %s", intrstr);
                aprint_error("\n");
                goto fail;
        }
        aprint_normal_dev(self, "%s\n", intrstr);

        /* Set PHY address. */
        sc->age_phyaddr = AGE_PHY_ADDR;

        /* Reset PHY. */
        age_phy_reset(sc);

        /* Reset the ethernet controller. */
        age_reset(sc);

        /* Get PCI and chip id/revision. */
        sc->age_rev = PCI_REVISION(pa->pa_class);
        sc->age_chip_rev = CSR_READ_4(sc, AGE_MASTER_CFG) >>
            MASTER_CHIP_REV_SHIFT;

        aprint_debug_dev(self, "PCI device revision : 0x%04x\n", sc->age_rev);
        aprint_debug_dev(self, "Chip id/revision : 0x%04x\n", sc->age_chip_rev);

        if (agedebug) {
                aprint_debug_dev(self, "%d Tx FIFO, %d Rx FIFO\n",
                    CSR_READ_4(sc, AGE_SRAM_TX_FIFO_LEN),
                    CSR_READ_4(sc, AGE_SRAM_RX_FIFO_LEN));
        }

        /* Set max allowable DMA size. */
        sc->age_dma_rd_burst = DMA_CFG_RD_BURST_128;
        sc->age_dma_wr_burst = DMA_CFG_WR_BURST_128;

        /* Allocate DMA stuffs */
        error = age_dma_alloc(sc);
        if (error)
                goto fail;

        callout_init(&sc->sc_tick_ch, 0);
        callout_setfunc(&sc->sc_tick_ch, age_tick, sc);

        /* Load station address. */
        age_get_macaddr(sc, sc->sc_enaddr);

        aprint_normal_dev(self, "Ethernet address %s\n",
            ether_sprintf(sc->sc_enaddr));

        ifp->if_softc = sc;
        ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
        ifp->if_init = age_init;
        ifp->if_ioctl = age_ioctl;
        ifp->if_start = age_start;
        ifp->if_stop = age_stop;
        ifp->if_watchdog = age_watchdog;
        ifp->if_baudrate = IF_Gbps(1);
        IFQ_SET_MAXLEN(&ifp->if_snd, AGE_TX_RING_CNT - 1);
        IFQ_SET_READY(&ifp->if_snd);
        strlcpy(ifp->if_xname, device_xname(sc->sc_dev), IFNAMSIZ);

        sc->sc_ec.ec_capabilities = ETHERCAP_VLAN_MTU;

        ifp->if_capabilities |= IFCAP_CSUM_IPv4_Rx |
                                IFCAP_CSUM_TCPv4_Rx |
                                IFCAP_CSUM_UDPv4_Rx;
#ifdef AGE_CHECKSUM
        ifp->if_capabilities |= IFCAP_CSUM_IPv4_Tx |
                                IFCAP_CSUM_TCPv4_Tx |
                                IFCAP_CSUM_UDPv4_Tx;
#endif

#if NVLAN > 0
        sc->sc_ec.ec_capabilities |= ETHERCAP_VLAN_HWTAGGING;
        sc->sc_ec.ec_capenable |= ETHERCAP_VLAN_HWTAGGING;
#endif

        /* Set up MII bus. */
        mii->mii_ifp = ifp;
        mii->mii_readreg = age_miibus_readreg;
        mii->mii_writereg = age_miibus_writereg;
        mii->mii_statchg = age_miibus_statchg;

        sc->sc_ec.ec_mii = mii;
        ifmedia_init(&mii->mii_media, 0, age_mediachange, age_mediastatus);
        mii_attach(self, mii, 0xffffffff, MII_PHY_ANY,
           MII_OFFSET_ANY, MIIF_DOPAUSE);

        if (LIST_FIRST(&mii->mii_phys) == NULL) {
                aprint_error_dev(self, "no PHY found!\n");
                ifmedia_add(&mii->mii_media, IFM_ETHER | IFM_MANUAL, 0, NULL);
                ifmedia_set(&mii->mii_media, IFM_ETHER | IFM_MANUAL);
        } else
                ifmedia_set(&mii->mii_media, IFM_ETHER | IFM_AUTO);

        if_attach(ifp);
        if_deferred_start_init(ifp, NULL);
        ether_ifattach(ifp, sc->sc_enaddr);

        if (pmf_device_register1(self, NULL, age_resume, age_shutdown))
                pmf_class_network_register(self, ifp);
        else
                aprint_error_dev(self, "couldn't establish power handler\n");

        return;

fail:
        age_dma_free(sc);
        if (sc->sc_irq_handle != NULL) {
                pci_intr_disestablish(sc->sc_pct, sc->sc_irq_handle);
                sc->sc_irq_handle = NULL;
        }
        if (sc->sc_mem_size) {
                bus_space_unmap(sc->sc_mem_bt, sc->sc_mem_bh, sc->sc_mem_size);
                sc->sc_mem_size = 0;
        }
}

static int
age_detach(device_t self, int flags)
{
        struct age_softc *sc = device_private(self);
        struct ifnet *ifp = &sc->sc_ec.ec_if;
        int s;

        pmf_device_deregister(self);
        s = splnet();
        age_stop(ifp, 0);
        splx(s);

        mii_detach(&sc->sc_miibus, MII_PHY_ANY, MII_OFFSET_ANY);

        ether_ifdetach(ifp);
        if_detach(ifp);
        age_dma_free(sc);

        /* Delete all remaining media. */
        ifmedia_fini(&sc->sc_miibus.mii_media);

        if (sc->sc_irq_handle != NULL) {
                pci_intr_disestablish(sc->sc_pct, sc->sc_irq_handle);
                sc->sc_irq_handle = NULL;
        }
        if (sc->sc_mem_size) {
                bus_space_unmap(sc->sc_mem_bt, sc->sc_mem_bh, sc->sc_mem_size);
                sc->sc_mem_size = 0;
        }
        return 0;
}

/*
 *      Read a PHY register on the MII of the L1.
 */
static int
age_miibus_readreg(device_t dev, int phy, int reg, uint16_t *val)
{
        struct age_softc *sc = device_private(dev);
        uint32_t v;
        int i;

        if (phy != sc->age_phyaddr)
                return -1;

        CSR_WRITE_4(sc, AGE_MDIO, MDIO_OP_EXECUTE | MDIO_OP_READ |
            MDIO_SUP_PREAMBLE | MDIO_CLK_25_4 | MDIO_REG_ADDR(reg));
        for (i = AGE_PHY_TIMEOUT; i > 0; i--) {
                DELAY(1);
                v = CSR_READ_4(sc, AGE_MDIO);
                if ((v & (MDIO_OP_EXECUTE | MDIO_OP_BUSY)) == 0)
                        break;
        }

        if (i == 0) {
                printf("%s: phy read timeout: phy %d, reg %d\n",
                        device_xname(sc->sc_dev), phy, reg);
                return ETIMEDOUT;
        }

        *val = (v & MDIO_DATA_MASK) >> MDIO_DATA_SHIFT;
        return 0;
}

/*
 *      Write a PHY register on the MII of the L1.
 */
static int
age_miibus_writereg(device_t dev, int phy, int reg, uint16_t val)
{
        struct age_softc *sc = device_private(dev);
        uint32_t v;
        int i;

        if (phy != sc->age_phyaddr)
                return -1;

        CSR_WRITE_4(sc, AGE_MDIO, MDIO_OP_EXECUTE | MDIO_OP_WRITE |
            (val & MDIO_DATA_MASK) << MDIO_DATA_SHIFT |
            MDIO_SUP_PREAMBLE | MDIO_CLK_25_4 | MDIO_REG_ADDR(reg));

        for (i = AGE_PHY_TIMEOUT; i > 0; i--) {
                DELAY(1);
                v = CSR_READ_4(sc, AGE_MDIO);
                if ((v & (MDIO_OP_EXECUTE | MDIO_OP_BUSY)) == 0)
                        break;
        }

        if (i == 0) {
                printf("%s: phy write timeout: phy %d, reg %d\n",
                    device_xname(sc->sc_dev), phy, reg);
                return ETIMEDOUT;
        }

        return 0;
}

/*
 *      Callback from MII layer when media changes.
 */
static void
age_miibus_statchg(struct ifnet *ifp)
{
        struct age_softc *sc = ifp->if_softc;
        struct mii_data *mii = &sc->sc_miibus;

        if ((ifp->if_flags & IFF_RUNNING) == 0)
                return;

        sc->age_flags &= ~AGE_FLAG_LINK;
        if ((mii->mii_media_status & IFM_AVALID) != 0) {
                switch (IFM_SUBTYPE(mii->mii_media_active)) {
                case IFM_10_T:
                case IFM_100_TX:
                case IFM_1000_T:
                        sc->age_flags |= AGE_FLAG_LINK;
                        break;
                default:
                        break;
                }
        }

        /* Stop Rx/Tx MACs. */
        age_stop_rxmac(sc);
        age_stop_txmac(sc);

        /* Program MACs with resolved speed/duplex/flow-control. */
        if ((sc->age_flags & AGE_FLAG_LINK) != 0) {
                uint32_t reg;

                age_mac_config(sc);
                reg = CSR_READ_4(sc, AGE_MAC_CFG);
                /* Restart DMA engine and Tx/Rx MAC. */
                CSR_WRITE_4(sc, AGE_DMA_CFG, CSR_READ_4(sc, AGE_DMA_CFG) |
                    DMA_CFG_RD_ENB | DMA_CFG_WR_ENB);
                reg |= MAC_CFG_TX_ENB | MAC_CFG_RX_ENB;
                CSR_WRITE_4(sc, AGE_MAC_CFG, reg);
        }
}

/*
 *      Get the current interface media status.
 */
static void
age_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
{
        struct age_softc *sc = ifp->if_softc;
        struct mii_data *mii = &sc->sc_miibus;

        mii_pollstat(mii);
        ifmr->ifm_status = mii->mii_media_status;
        ifmr->ifm_active = mii->mii_media_active;
}

/*
 *      Set hardware to newly-selected media.
 */
static int
age_mediachange(struct ifnet *ifp)
{
        struct age_softc *sc = ifp->if_softc;
        struct mii_data *mii = &sc->sc_miibus;
        int error;

        if (mii->mii_instance != 0) {
                struct mii_softc *miisc;

                LIST_FOREACH(miisc, &mii->mii_phys, mii_list)
                        mii_phy_reset(miisc);
        }
        error = mii_mediachg(mii);

        return error;
}

static int
age_intr(void *arg)
{
        struct age_softc *sc = arg;
        struct ifnet *ifp = &sc->sc_ec.ec_if;
        struct cmb *cmb;
        uint32_t status;

        status = CSR_READ_4(sc, AGE_INTR_STATUS);
        if (status == 0 || (status & AGE_INTRS) == 0)
                return 0;

        cmb = sc->age_rdata.age_cmb_block;
        if (cmb == NULL) {
                /* Happens when bringing up the interface
                 * w/o having a carrier. Ack the interrupt.
                 */
                CSR_WRITE_4(sc, AGE_INTR_STATUS, status);
                return 0;
        }

        bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_cmb_block_map, 0,
            sc->age_cdata.age_cmb_block_map->dm_mapsize,
            BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
        status = le32toh(cmb->intr_status);
        /* ACK/reenable interrupts */
        CSR_WRITE_4(sc, AGE_INTR_STATUS, status);
        while ((status & AGE_INTRS) != 0) {
                sc->age_tpd_cons = (le32toh(cmb->tpd_cons) & TPD_CONS_MASK) >>
                    TPD_CONS_SHIFT;
                sc->age_rr_prod = (le32toh(cmb->rprod_cons) & RRD_PROD_MASK) >>
                    RRD_PROD_SHIFT;

                /* Let hardware know CMB was served. */
                cmb->intr_status = 0;
                bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_cmb_block_map, 0,
                    sc->age_cdata.age_cmb_block_map->dm_mapsize,
                    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);

                if (ifp->if_flags & IFF_RUNNING) {
                        if (status & INTR_CMB_RX)
                                age_rxintr(sc, sc->age_rr_prod);

                        if (status & INTR_CMB_TX)
                                age_txintr(sc, sc->age_tpd_cons);

                        if (status & (INTR_DMA_RD_TO_RST | INTR_DMA_WR_TO_RST)) {
                                if (status & INTR_DMA_RD_TO_RST)
                                        printf("%s: DMA read error! -- "
                                            "resetting\n",
                                            device_xname(sc->sc_dev));
                                if (status & INTR_DMA_WR_TO_RST)
                                        printf("%s: DMA write error! -- "
                                            "resetting\n",
                                            device_xname(sc->sc_dev));
                                age_init(ifp);
                        }

                        if_schedule_deferred_start(ifp);

                        if (status & INTR_SMB)
                                age_stats_update(sc);
                }
                /* check if more interrupts did came in */
                bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_cmb_block_map, 0,
                    sc->age_cdata.age_cmb_block_map->dm_mapsize,
                    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
                status = le32toh(cmb->intr_status);
        }

        return 1;
}

static void
age_get_macaddr(struct age_softc *sc, uint8_t eaddr[])
{
        uint32_t ea[2], reg;
        int i, vpdc;

        reg = CSR_READ_4(sc, AGE_SPI_CTRL);
        if ((reg & SPI_VPD_ENB) != 0) {
                /* Get VPD stored in TWSI EEPROM. */
                reg &= ~SPI_VPD_ENB;
                CSR_WRITE_4(sc, AGE_SPI_CTRL, reg);
        }

        if (pci_get_capability(sc->sc_pct, sc->sc_pcitag,
            PCI_CAP_VPD, &vpdc, NULL)) {
                /*
                 * PCI VPD capability found, let TWSI reload EEPROM.
                 * This will set Ethernet address of controller.
                 */
                CSR_WRITE_4(sc, AGE_TWSI_CTRL, CSR_READ_4(sc, AGE_TWSI_CTRL) |
                    TWSI_CTRL_SW_LD_START);
                for (i = 100; i > 0; i--) {
                        DELAY(1000);
                        reg = CSR_READ_4(sc, AGE_TWSI_CTRL);
                        if ((reg & TWSI_CTRL_SW_LD_START) == 0)
                                break;
                }
                if (i == 0)
                        printf("%s: reloading EEPROM timeout!\n",
                            device_xname(sc->sc_dev));
        } else {
                if (agedebug)
                        printf("%s: PCI VPD capability not found!\n",
                            device_xname(sc->sc_dev));
        }

        ea[0] = CSR_READ_4(sc, AGE_PAR0);
        ea[1] = CSR_READ_4(sc, AGE_PAR1);

        eaddr[0] = (ea[1] >> 8) & 0xFF;
        eaddr[1] = (ea[1] >> 0) & 0xFF;
        eaddr[2] = (ea[0] >> 24) & 0xFF;
        eaddr[3] = (ea[0] >> 16) & 0xFF;
        eaddr[4] = (ea[0] >> 8) & 0xFF;
        eaddr[5] = (ea[0] >> 0) & 0xFF;
}

static void
age_phy_reset(struct age_softc *sc)
{
        uint16_t reg, pn;
        int i, linkup;

        /* Reset PHY. */
        CSR_WRITE_4(sc, AGE_GPHY_CTRL, GPHY_CTRL_RST);
        DELAY(2000);
        CSR_WRITE_4(sc, AGE_GPHY_CTRL, GPHY_CTRL_CLR);
        DELAY(2000);

#define ATPHY_DBG_ADDR          0x1D
#define ATPHY_DBG_DATA          0x1E
#define ATPHY_CDTC              0x16
#define PHY_CDTC_ENB            0x0001
#define PHY_CDTC_POFF           8
#define ATPHY_CDTS              0x1C
#define PHY_CDTS_STAT_OK        0x0000
#define PHY_CDTS_STAT_SHORT     0x0100
#define PHY_CDTS_STAT_OPEN      0x0200
#define PHY_CDTS_STAT_INVAL     0x0300
#define PHY_CDTS_STAT_MASK      0x0300

        /* Check power saving mode. Magic from Linux. */
        age_miibus_writereg(sc->sc_dev, sc->age_phyaddr, MII_BMCR, BMCR_RESET);
        for (linkup = 0, pn = 0; pn < 4; pn++) {
                age_miibus_writereg(sc->sc_dev, sc->age_phyaddr, ATPHY_CDTC,
                    (pn << PHY_CDTC_POFF) | PHY_CDTC_ENB);
                for (i = 200; i > 0; i--) {
                        DELAY(1000);
                        age_miibus_readreg(sc->sc_dev, sc->age_phyaddr,
                            ATPHY_CDTC, &reg);
                        if ((reg & PHY_CDTC_ENB) == 0)
                                break;
                }
                DELAY(1000);
                age_miibus_readreg(sc->sc_dev, sc->age_phyaddr,
                    ATPHY_CDTS, &reg);
                if ((reg & PHY_CDTS_STAT_MASK) != PHY_CDTS_STAT_OPEN) {
                        linkup++;
                        break;
                }
        }
        age_miibus_writereg(sc->sc_dev, sc->age_phyaddr, MII_BMCR,
            BMCR_RESET | BMCR_AUTOEN | BMCR_STARTNEG);
        if (linkup == 0) {
                age_miibus_writereg(sc->sc_dev, sc->age_phyaddr,
                    ATPHY_DBG_ADDR, 0);
                age_miibus_writereg(sc->sc_dev, sc->age_phyaddr,
                    ATPHY_DBG_DATA, 0x124E);
                age_miibus_writereg(sc->sc_dev, sc->age_phyaddr,
                    ATPHY_DBG_ADDR, 1);
                age_miibus_readreg(sc->sc_dev, sc->age_phyaddr,
                    ATPHY_DBG_DATA, &reg);
                age_miibus_writereg(sc->sc_dev, sc->age_phyaddr,
                    ATPHY_DBG_DATA, reg | 0x03);
                /* XXX */
                DELAY(1500 * 1000);
                age_miibus_writereg(sc->sc_dev, sc->age_phyaddr,
                    ATPHY_DBG_ADDR, 0);
                age_miibus_writereg(sc->sc_dev, sc->age_phyaddr,
                    ATPHY_DBG_DATA, 0x024E);
        }

#undef ATPHY_DBG_ADDR
#undef ATPHY_DBG_DATA
#undef ATPHY_CDTC
#undef PHY_CDTC_ENB
#undef PHY_CDTC_POFF
#undef ATPHY_CDTS
#undef PHY_CDTS_STAT_OK
#undef PHY_CDTS_STAT_SHORT
#undef PHY_CDTS_STAT_OPEN
#undef PHY_CDTS_STAT_INVAL
#undef PHY_CDTS_STAT_MASK
}

static int
age_dma_alloc(struct age_softc *sc)
{
        struct age_txdesc *txd;
        struct age_rxdesc *rxd;
        int nsegs, error, i;

        /*
         * Create DMA stuffs for TX ring
         */
        error = bus_dmamap_create(sc->sc_dmat, AGE_TX_RING_SZ, 1,
            AGE_TX_RING_SZ, 0, BUS_DMA_NOWAIT, &sc->age_cdata.age_tx_ring_map);
        if (error) {
                sc->age_cdata.age_tx_ring_map = NULL;
                return ENOBUFS;
        }

        /* Allocate DMA'able memory for TX ring */
        error = bus_dmamem_alloc(sc->sc_dmat, AGE_TX_RING_SZ,
            PAGE_SIZE, 0, &sc->age_rdata.age_tx_ring_seg, 1,
            &nsegs, BUS_DMA_NOWAIT);
        if (error) {
                printf("%s: could not allocate DMA'able memory for Tx ring, "
                    "error = %i\n", device_xname(sc->sc_dev), error);
                return error;
        }

        error = bus_dmamem_map(sc->sc_dmat, &sc->age_rdata.age_tx_ring_seg,
            nsegs, AGE_TX_RING_SZ, (void **)&sc->age_rdata.age_tx_ring,
            BUS_DMA_NOWAIT | BUS_DMA_COHERENT);
        if (error)
                return ENOBUFS;

        memset(sc->age_rdata.age_tx_ring, 0, AGE_TX_RING_SZ);

        /*  Load the DMA map for Tx ring. */
        error = bus_dmamap_load(sc->sc_dmat, sc->age_cdata.age_tx_ring_map,
            sc->age_rdata.age_tx_ring, AGE_TX_RING_SZ, NULL, BUS_DMA_NOWAIT);
        if (error) {
                printf("%s: could not load DMA'able memory for Tx ring, "
                    "error = %i\n", device_xname(sc->sc_dev), error);
                bus_dmamem_free(sc->sc_dmat,
                    &sc->age_rdata.age_tx_ring_seg, 1);
                return error;
        }

        sc->age_rdata.age_tx_ring_paddr =
            sc->age_cdata.age_tx_ring_map->dm_segs[0].ds_addr;

        /*
         * Create DMA stuffs for RX ring
         */
        error = bus_dmamap_create(sc->sc_dmat, AGE_RX_RING_SZ, 1,
            AGE_RX_RING_SZ, 0, BUS_DMA_NOWAIT, &sc->age_cdata.age_rx_ring_map);
        if (error) {
                sc->age_cdata.age_rx_ring_map = NULL;
                return ENOBUFS;
        }

        /* Allocate DMA'able memory for RX ring */
        error = bus_dmamem_alloc(sc->sc_dmat, AGE_RX_RING_SZ,
            PAGE_SIZE, 0, &sc->age_rdata.age_rx_ring_seg, 1,
            &nsegs, BUS_DMA_NOWAIT);
        if (error) {
                printf("%s: could not allocate DMA'able memory for Rx ring, "
                    "error = %i.\n", device_xname(sc->sc_dev), error);
                return error;
        }

        error = bus_dmamem_map(sc->sc_dmat, &sc->age_rdata.age_rx_ring_seg,
            nsegs, AGE_RX_RING_SZ, (void **)&sc->age_rdata.age_rx_ring,
            BUS_DMA_NOWAIT | BUS_DMA_COHERENT);
        if (error)
                return ENOBUFS;

        memset(sc->age_rdata.age_rx_ring, 0, AGE_RX_RING_SZ);

        /* Load the DMA map for Rx ring. */
        error = bus_dmamap_load(sc->sc_dmat, sc->age_cdata.age_rx_ring_map,
            sc->age_rdata.age_rx_ring, AGE_RX_RING_SZ, NULL, BUS_DMA_NOWAIT);
        if (error) {
                printf("%s: could not load DMA'able memory for Rx ring, "
                    "error = %i.\n", device_xname(sc->sc_dev), error);
                bus_dmamem_free(sc->sc_dmat,
                    &sc->age_rdata.age_rx_ring_seg, 1);
                return error;
        }

        sc->age_rdata.age_rx_ring_paddr =
            sc->age_cdata.age_rx_ring_map->dm_segs[0].ds_addr;

        /*
         * Create DMA stuffs for RX return ring
         */
        error = bus_dmamap_create(sc->sc_dmat, AGE_RR_RING_SZ, 1,
            AGE_RR_RING_SZ, 0, BUS_DMA_NOWAIT, &sc->age_cdata.age_rr_ring_map);
        if (error) {
                sc->age_cdata.age_rr_ring_map = NULL;
                return ENOBUFS;
        }

        /* Allocate DMA'able memory for RX return ring */
        error = bus_dmamem_alloc(sc->sc_dmat, AGE_RR_RING_SZ,
            PAGE_SIZE, 0, &sc->age_rdata.age_rr_ring_seg, 1,
            &nsegs, BUS_DMA_NOWAIT);
        if (error) {
                printf("%s: could not allocate DMA'able memory for Rx "
                    "return ring, error = %i.\n",
                    device_xname(sc->sc_dev), error);
                return error;
        }

        error = bus_dmamem_map(sc->sc_dmat, &sc->age_rdata.age_rr_ring_seg,
            nsegs, AGE_RR_RING_SZ, (void **)&sc->age_rdata.age_rr_ring,
            BUS_DMA_NOWAIT | BUS_DMA_COHERENT);
        if (error)
                return ENOBUFS;

        memset(sc->age_rdata.age_rr_ring, 0, AGE_RR_RING_SZ);

        /*  Load the DMA map for Rx return ring. */
        error = bus_dmamap_load(sc->sc_dmat, sc->age_cdata.age_rr_ring_map,
            sc->age_rdata.age_rr_ring, AGE_RR_RING_SZ, NULL, BUS_DMA_NOWAIT);
        if (error) {
                printf("%s: could not load DMA'able memory for Rx return ring, "
                    "error = %i\n", device_xname(sc->sc_dev), error);
                bus_dmamem_free(sc->sc_dmat,
                    &sc->age_rdata.age_rr_ring_seg, 1);
                return error;
        }

        sc->age_rdata.age_rr_ring_paddr =
            sc->age_cdata.age_rr_ring_map->dm_segs[0].ds_addr;

        /*
         * Create DMA stuffs for CMB block
         */
        error = bus_dmamap_create(sc->sc_dmat, AGE_CMB_BLOCK_SZ, 1,
            AGE_CMB_BLOCK_SZ, 0, BUS_DMA_NOWAIT,
            &sc->age_cdata.age_cmb_block_map);
        if (error) {
                sc->age_cdata.age_cmb_block_map = NULL;
                return ENOBUFS;
        }

        /* Allocate DMA'able memory for CMB block */
        error = bus_dmamem_alloc(sc->sc_dmat, AGE_CMB_BLOCK_SZ,
            PAGE_SIZE, 0, &sc->age_rdata.age_cmb_block_seg, 1,
            &nsegs, BUS_DMA_NOWAIT);
        if (error) {
                printf("%s: could not allocate DMA'able memory for "
                    "CMB block, error = %i\n", device_xname(sc->sc_dev), error);
                return error;
        }

        error = bus_dmamem_map(sc->sc_dmat, &sc->age_rdata.age_cmb_block_seg,
            nsegs, AGE_CMB_BLOCK_SZ, (void **)&sc->age_rdata.age_cmb_block,
            BUS_DMA_NOWAIT | BUS_DMA_COHERENT);
        if (error)
                return ENOBUFS;

        memset(sc->age_rdata.age_cmb_block, 0, AGE_CMB_BLOCK_SZ);

        /*  Load the DMA map for CMB block. */
        error = bus_dmamap_load(sc->sc_dmat, sc->age_cdata.age_cmb_block_map,
            sc->age_rdata.age_cmb_block, AGE_CMB_BLOCK_SZ, NULL,
            BUS_DMA_NOWAIT);
        if (error) {
                printf("%s: could not load DMA'able memory for CMB block, "
                    "error = %i\n", device_xname(sc->sc_dev), error);
                bus_dmamem_free(sc->sc_dmat,
                    &sc->age_rdata.age_cmb_block_seg, 1);
                return error;
        }

        sc->age_rdata.age_cmb_block_paddr =
            sc->age_cdata.age_cmb_block_map->dm_segs[0].ds_addr;

        /*
         * Create DMA stuffs for SMB block
         */
        error = bus_dmamap_create(sc->sc_dmat, AGE_SMB_BLOCK_SZ, 1,
            AGE_SMB_BLOCK_SZ, 0, BUS_DMA_NOWAIT,
            &sc->age_cdata.age_smb_block_map);
        if (error) {
                sc->age_cdata.age_smb_block_map = NULL;
                return ENOBUFS;
        }

        /* Allocate DMA'able memory for SMB block */
        error = bus_dmamem_alloc(sc->sc_dmat, AGE_SMB_BLOCK_SZ,
            PAGE_SIZE, 0, &sc->age_rdata.age_smb_block_seg, 1,
            &nsegs, BUS_DMA_NOWAIT);
        if (error) {
                printf("%s: could not allocate DMA'able memory for "
                    "SMB block, error = %i\n", device_xname(sc->sc_dev), error);
                return error;
        }

        error = bus_dmamem_map(sc->sc_dmat, &sc->age_rdata.age_smb_block_seg,
            nsegs, AGE_SMB_BLOCK_SZ, (void **)&sc->age_rdata.age_smb_block,
            BUS_DMA_NOWAIT | BUS_DMA_COHERENT);
        if (error)
                return ENOBUFS;

        memset(sc->age_rdata.age_smb_block, 0, AGE_SMB_BLOCK_SZ);

        /*  Load the DMA map for SMB block */
        error = bus_dmamap_load(sc->sc_dmat, sc->age_cdata.age_smb_block_map,
            sc->age_rdata.age_smb_block, AGE_SMB_BLOCK_SZ, NULL,
            BUS_DMA_NOWAIT);
        if (error) {
                printf("%s: could not load DMA'able memory for SMB block, "
                    "error = %i\n", device_xname(sc->sc_dev), error);
                bus_dmamem_free(sc->sc_dmat,
                    &sc->age_rdata.age_smb_block_seg, 1);
                return error;
        }

        sc->age_rdata.age_smb_block_paddr =
            sc->age_cdata.age_smb_block_map->dm_segs[0].ds_addr;

        /*
         * All of the memory we allocated above needs to be within
         * the same 4GB segment.  Make sure this is so.
         *
         * XXX We don't care WHAT 4GB segment they're in, just that
         * XXX they're all in the same one.  Need some bus_dma API
         * XXX help to make this easier to enforce when we actually
         * XXX perform the allocation.
         */
        if (! (AGE_ADDR_HI(sc->age_rdata.age_tx_ring_paddr) ==
               AGE_ADDR_HI(sc->age_rdata.age_rx_ring_paddr)

            && AGE_ADDR_HI(sc->age_rdata.age_tx_ring_paddr) ==
               AGE_ADDR_HI(sc->age_rdata.age_rr_ring_paddr)

            && AGE_ADDR_HI(sc->age_rdata.age_tx_ring_paddr) ==
               AGE_ADDR_HI(sc->age_rdata.age_cmb_block_paddr)

            && AGE_ADDR_HI(sc->age_rdata.age_tx_ring_paddr) ==
               AGE_ADDR_HI(sc->age_rdata.age_smb_block_paddr))) {
                aprint_error_dev(sc->sc_dev,
                    "control data allocation constraints failed\n");
                return ENOBUFS;
        }

        /* Create DMA maps for Tx buffers. */
        for (i = 0; i < AGE_TX_RING_CNT; i++) {
                txd = &sc->age_cdata.age_txdesc[i];
                txd->tx_m = NULL;
                txd->tx_dmamap = NULL;
                error = bus_dmamap_create(sc->sc_dmat, AGE_TSO_MAXSIZE,
                    AGE_MAXTXSEGS, AGE_TSO_MAXSEGSIZE, 0, BUS_DMA_NOWAIT,
                    &txd->tx_dmamap);
                if (error) {
                        txd->tx_dmamap = NULL;
                        printf("%s: could not create Tx dmamap, error = %i.\n",
                            device_xname(sc->sc_dev), error);
                        return error;
                }
        }

        /* Create DMA maps for Rx buffers. */
        error = bus_dmamap_create(sc->sc_dmat, MCLBYTES, 1, MCLBYTES, 0,
            BUS_DMA_NOWAIT, &sc->age_cdata.age_rx_sparemap);
        if (error) {
                sc->age_cdata.age_rx_sparemap = NULL;
                printf("%s: could not create spare Rx dmamap, error = %i.\n",
                    device_xname(sc->sc_dev), error);
                return error;
        }
        for (i = 0; i < AGE_RX_RING_CNT; i++) {
                rxd = &sc->age_cdata.age_rxdesc[i];
                rxd->rx_m = NULL;
                rxd->rx_dmamap = NULL;
                error = bus_dmamap_create(sc->sc_dmat, MCLBYTES, 1,
                    MCLBYTES, 0, BUS_DMA_NOWAIT, &rxd->rx_dmamap);
                if (error) {
                        rxd->rx_dmamap = NULL;
                        printf("%s: could not create Rx dmamap, error = %i.\n",
                            device_xname(sc->sc_dev), error);
                        return error;
                }
        }

        return 0;
}

static void
age_dma_free(struct age_softc *sc)
{
        struct age_txdesc *txd;
        struct age_rxdesc *rxd;
        int i;

        /* Tx buffers */
        for (i = 0; i < AGE_TX_RING_CNT; i++) {
                txd = &sc->age_cdata.age_txdesc[i];
                if (txd->tx_dmamap != NULL) {
                        bus_dmamap_destroy(sc->sc_dmat, txd->tx_dmamap);
                        txd->tx_dmamap = NULL;
                }
        }
        /* Rx buffers */
        for (i = 0; i < AGE_RX_RING_CNT; i++) {
                rxd = &sc->age_cdata.age_rxdesc[i];
                if (rxd->rx_dmamap != NULL) {
                        bus_dmamap_destroy(sc->sc_dmat, rxd->rx_dmamap);
                        rxd->rx_dmamap = NULL;
                }
        }
        if (sc->age_cdata.age_rx_sparemap != NULL) {
                bus_dmamap_destroy(sc->sc_dmat, sc->age_cdata.age_rx_sparemap);
                sc->age_cdata.age_rx_sparemap = NULL;
        }

        /* Tx ring. */
        if (sc->age_cdata.age_tx_ring_map != NULL)
                bus_dmamap_unload(sc->sc_dmat, sc->age_cdata.age_tx_ring_map);
        if (sc->age_cdata.age_tx_ring_map != NULL &&
            sc->age_rdata.age_tx_ring != NULL)
                bus_dmamem_free(sc->sc_dmat,
                    &sc->age_rdata.age_tx_ring_seg, 1);
        sc->age_rdata.age_tx_ring = NULL;
        sc->age_cdata.age_tx_ring_map = NULL;

        /* Rx ring. */
        if (sc->age_cdata.age_rx_ring_map != NULL)
                bus_dmamap_unload(sc->sc_dmat, sc->age_cdata.age_rx_ring_map);
        if (sc->age_cdata.age_rx_ring_map != NULL &&
            sc->age_rdata.age_rx_ring != NULL)
                bus_dmamem_free(sc->sc_dmat,
                    &sc->age_rdata.age_rx_ring_seg, 1);
        sc->age_rdata.age_rx_ring = NULL;
        sc->age_cdata.age_rx_ring_map = NULL;

        /* Rx return ring. */
        if (sc->age_cdata.age_rr_ring_map != NULL)
                bus_dmamap_unload(sc->sc_dmat, sc->age_cdata.age_rr_ring_map);
        if (sc->age_cdata.age_rr_ring_map != NULL &&
            sc->age_rdata.age_rr_ring != NULL)
                bus_dmamem_free(sc->sc_dmat,
                    &sc->age_rdata.age_rr_ring_seg, 1);
        sc->age_rdata.age_rr_ring = NULL;
        sc->age_cdata.age_rr_ring_map = NULL;

        /* CMB block */
        if (sc->age_cdata.age_cmb_block_map != NULL)
                bus_dmamap_unload(sc->sc_dmat, sc->age_cdata.age_cmb_block_map);
        if (sc->age_cdata.age_cmb_block_map != NULL &&
            sc->age_rdata.age_cmb_block != NULL)
                bus_dmamem_free(sc->sc_dmat,
                    &sc->age_rdata.age_cmb_block_seg, 1);
        sc->age_rdata.age_cmb_block = NULL;
        sc->age_cdata.age_cmb_block_map = NULL;

        /* SMB block */
        if (sc->age_cdata.age_smb_block_map != NULL)
                bus_dmamap_unload(sc->sc_dmat, sc->age_cdata.age_smb_block_map);
        if (sc->age_cdata.age_smb_block_map != NULL &&
            sc->age_rdata.age_smb_block != NULL)
                bus_dmamem_free(sc->sc_dmat,
                    &sc->age_rdata.age_smb_block_seg, 1);
        sc->age_rdata.age_smb_block = NULL;
        sc->age_cdata.age_smb_block_map = NULL;
}

static void
age_start(struct ifnet *ifp)
{
        struct age_softc *sc = ifp->if_softc;
        struct mbuf *m_head;
        int enq, error;

        if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
                return;
        if ((sc->age_flags & AGE_FLAG_LINK) == 0)
                return;

        enq = 0;
        for (;;) {
                IFQ_POLL(&ifp->if_snd, m_head);
                if (m_head == NULL)
                        break;

                /*
                 * Pack the data into the transmit ring. If we
                 * don't have room, set the OACTIVE flag and wait
                 * for the NIC to drain the ring.
                 */
                if ((error = age_encap(sc, m_head)) != 0) {
                        if (error == EFBIG) {
                                /* This is fatal for the packet. */
                                IFQ_DEQUEUE(&ifp->if_snd, m_head);
                                m_freem(m_head);
                                if_statinc(ifp, if_oerrors);
                                continue;
                        }
                        ifp->if_flags |= IFF_OACTIVE;
                        break;
                }
                IFQ_DEQUEUE(&ifp->if_snd, m_head);
                enq = 1;

                /*
                 * If there's a BPF listener, bounce a copy of this frame
                 * to him.
                 */
                bpf_mtap(ifp, m_head, BPF_D_OUT);
        }

        if (enq) {
                /* Update mbox. */
                AGE_COMMIT_MBOX(sc);
                /* Set a timeout in case the chip goes out to lunch. */
                ifp->if_timer = AGE_TX_TIMEOUT;
        }
}

static void
age_watchdog(struct ifnet *ifp)
{
        struct age_softc *sc = ifp->if_softc;

        if ((sc->age_flags & AGE_FLAG_LINK) == 0) {
                printf("%s: watchdog timeout (missed link)\n",
                    device_xname(sc->sc_dev));
                if_statinc(ifp, if_oerrors);
                age_init(ifp);
                return;
        }

        if (sc->age_cdata.age_tx_cnt == 0) {
                printf("%s: watchdog timeout (missed Tx interrupts) "
                    "-- recovering\n", device_xname(sc->sc_dev));
                age_start(ifp);
                return;
        }

        printf("%s: watchdog timeout\n", device_xname(sc->sc_dev));
        if_statinc(ifp, if_oerrors);
        age_init(ifp);
        age_start(ifp);
}

static bool
age_shutdown(device_t self, int howto)
{
        struct age_softc *sc;
        struct ifnet *ifp;

        sc = device_private(self);
        ifp = &sc->sc_ec.ec_if;
        age_stop(ifp, 1);

        return true;
}

static int
age_ioctl(struct ifnet *ifp, u_long cmd, void *data)
{
        struct age_softc *sc = ifp->if_softc;
        int s, error;

        s = splnet();

        error = ether_ioctl(ifp, cmd, data);
        if (error == ENETRESET) {
                if (ifp->if_flags & IFF_RUNNING)
                        age_rxfilter(sc);
                error = 0;
        }

        splx(s);
        return error;
}

static void
age_mac_config(struct age_softc *sc)
{
        struct mii_data *mii;
        uint32_t reg;

        mii = &sc->sc_miibus;

        reg = CSR_READ_4(sc, AGE_MAC_CFG);
        reg &= ~MAC_CFG_FULL_DUPLEX;
        reg &= ~(MAC_CFG_TX_FC | MAC_CFG_RX_FC);
        reg &= ~MAC_CFG_SPEED_MASK;

        /* Reprogram MAC with resolved speed/duplex. */
        switch (IFM_SUBTYPE(mii->mii_media_active)) {
        case IFM_10_T:
        case IFM_100_TX:
                reg |= MAC_CFG_SPEED_10_100;
                break;
        case IFM_1000_T:
                reg |= MAC_CFG_SPEED_1000;
                break;
        }
        if ((IFM_OPTIONS(mii->mii_media_active) & IFM_FDX) != 0) {
                reg |= MAC_CFG_FULL_DUPLEX;
                if ((IFM_OPTIONS(mii->mii_media_active) & IFM_ETH_TXPAUSE) != 0)
                        reg |= MAC_CFG_TX_FC;
                if ((IFM_OPTIONS(mii->mii_media_active) & IFM_ETH_RXPAUSE) != 0)
                        reg |= MAC_CFG_RX_FC;
        }

        CSR_WRITE_4(sc, AGE_MAC_CFG, reg);
}

static bool
age_resume(device_t dv, const pmf_qual_t *qual)
{
        struct age_softc *sc = device_private(dv);
        uint16_t cmd;

        /*
         * Clear INTx emulation disable for hardware that
         * is set in resume event. From Linux.
         */
        cmd = pci_conf_read(sc->sc_pct, sc->sc_pcitag, PCI_COMMAND_STATUS_REG);
        if ((cmd & PCI_COMMAND_INTERRUPT_DISABLE) != 0) {
                cmd &= ~PCI_COMMAND_INTERRUPT_DISABLE;
                pci_conf_write(sc->sc_pct, sc->sc_pcitag,
                    PCI_COMMAND_STATUS_REG, cmd);
        }

        return true;
}

static int
age_encap(struct age_softc *sc, struct mbuf * const m)
{
        struct age_txdesc *txd, *txd_last;
        struct tx_desc *desc;
        bus_dmamap_t map;
        uint32_t cflags, poff, vtag;
        int error, i, nsegs, prod;

        cflags = vtag = 0;
        poff = 0;

        prod = sc->age_cdata.age_tx_prod;
        txd = &sc->age_cdata.age_txdesc[prod];
        txd_last = txd;
        map = txd->tx_dmamap;

        error = bus_dmamap_load_mbuf(sc->sc_dmat, map, m, BUS_DMA_NOWAIT);
        if (error == EFBIG) {
                struct mbuf *mnew = m_defrag(m, M_NOWAIT);
                if (mnew != NULL) {
                        KASSERT(m == mnew);
                        error = bus_dmamap_load_mbuf(sc->sc_dmat, map, mnew,
                            BUS_DMA_NOWAIT);
                } else {
                        /* Just drop if we can't defrag. */
                        error = EFBIG;
                }
                if (error) {
                        if (error == EFBIG) {
                                printf("%s: Tx packet consumes too many "
                                    "DMA segments, dropping...\n",
                                    device_xname(sc->sc_dev));
                        }
                        return error;
                }
        } else if (error) {
                return error;
        }

        nsegs = map->dm_nsegs;
        KASSERT(nsegs != 0);

        /* Check descriptor overrun. */
        if (sc->age_cdata.age_tx_cnt + nsegs >= AGE_TX_RING_CNT - 2) {
                bus_dmamap_unload(sc->sc_dmat, map);
                return ENOBUFS;
        }
        bus_dmamap_sync(sc->sc_dmat, map, 0, map->dm_mapsize,
            BUS_DMASYNC_PREWRITE);

        /* Configure Tx IP/TCP/UDP checksum offload. */
        if ((m->m_pkthdr.csum_flags & AGE_CSUM_FEATURES) != 0) {
                cflags |= AGE_TD_CSUM;
                if ((m->m_pkthdr.csum_flags & M_CSUM_TCPv4) != 0)
                        cflags |= AGE_TD_TCPCSUM;
                if ((m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0)
                        cflags |= AGE_TD_UDPCSUM;
                /* Set checksum start offset. */
                cflags |= (poff << AGE_TD_CSUM_PLOADOFFSET_SHIFT);
        }

#if NVLAN > 0
        /* Configure VLAN hardware tag insertion. */
        if (vlan_has_tag(m)) {
                vtag = AGE_TX_VLAN_TAG(htons(vlan_get_tag(m)));
                vtag = ((vtag << AGE_TD_VLAN_SHIFT) & AGE_TD_VLAN_MASK);
                cflags |= AGE_TD_INSERT_VLAN_TAG;
        }
#endif

        desc = NULL;
        KASSERT(nsegs > 0);
        for (i = 0; ; i++) {
                desc = &sc->age_rdata.age_tx_ring[prod];
                desc->addr = htole64(map->dm_segs[i].ds_addr);
                desc->len =
                    htole32(AGE_TX_BYTES(map->dm_segs[i].ds_len) | vtag);
                desc->flags = htole32(cflags);
                sc->age_cdata.age_tx_cnt++;
                if (i == (nsegs - 1))
                        break;

                /* Sync this descriptor and go to the next one */
                bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_tx_ring_map,
                    prod * sizeof(struct tx_desc), sizeof(struct tx_desc),
                    BUS_DMASYNC_PREWRITE);
                AGE_DESC_INC(prod, AGE_TX_RING_CNT);
        }

        /* Set EOP on the last descriptor and sync it. */
        desc->flags |= htole32(AGE_TD_EOP);
        bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_tx_ring_map,
            prod * sizeof(struct tx_desc), sizeof(struct tx_desc),
            BUS_DMASYNC_PREWRITE);

        if (nsegs > 1) {
                /* Swap dmamap of the first and the last. */
                txd = &sc->age_cdata.age_txdesc[prod];
                map = txd_last->tx_dmamap;
                txd_last->tx_dmamap = txd->tx_dmamap;
                txd->tx_dmamap = map;
                txd->tx_m = m;
                KASSERT(txd_last->tx_m == NULL);
        } else {
                KASSERT(txd_last == &sc->age_cdata.age_txdesc[prod]);
                txd_last->tx_m = m;
        }

        /* Update producer index. */
        AGE_DESC_INC(prod, AGE_TX_RING_CNT);
        sc->age_cdata.age_tx_prod = prod;

        return 0;
}

static void
age_txintr(struct age_softc *sc, int tpd_cons)
{
        struct ifnet *ifp = &sc->sc_ec.ec_if;
        struct age_txdesc *txd;
        int cons, prog;

        if (sc->age_cdata.age_tx_cnt <= 0) {
                if (ifp->if_timer != 0)
                        printf("timer running without packets\n");
                if (sc->age_cdata.age_tx_cnt)
                        printf("age_tx_cnt corrupted\n");
        }

        /*
         * Go through our Tx list and free mbufs for those
         * frames which have been transmitted.
         */
        cons = sc->age_cdata.age_tx_cons;
        for (prog = 0; cons != tpd_cons; AGE_DESC_INC(cons, AGE_TX_RING_CNT)) {
                if (sc->age_cdata.age_tx_cnt <= 0)
                        break;
                prog++;
                ifp->if_flags &= ~IFF_OACTIVE;
                sc->age_cdata.age_tx_cnt--;
                txd = &sc->age_cdata.age_txdesc[cons];
                /*
                 * Clear Tx descriptors, it's not required but would
                 * help debugging in case of Tx issues.
                 */
                bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_tx_ring_map,
                    cons * sizeof(struct tx_desc), sizeof(struct tx_desc),
                    BUS_DMASYNC_POSTWRITE);
                txd->tx_desc->addr = 0;
                txd->tx_desc->len = 0;
                txd->tx_desc->flags = 0;

                if (txd->tx_m == NULL)
                        continue;
                /* Reclaim transmitted mbufs. */
                bus_dmamap_unload(sc->sc_dmat, txd->tx_dmamap);
                m_freem(txd->tx_m);
                txd->tx_m = NULL;
        }

        if (prog > 0) {
                sc->age_cdata.age_tx_cons = cons;

                /*
                 * Unarm watchdog timer only when there are no pending
                 * Tx descriptors in queue.
                 */
                if (sc->age_cdata.age_tx_cnt == 0)
                        ifp->if_timer = 0;
        }
}

/* Receive a frame. */
static void
age_rxeof(struct age_softc *sc, struct rx_rdesc *rxrd)
{
        struct ifnet *ifp = &sc->sc_ec.ec_if;
        struct age_rxdesc *rxd;
        struct rx_desc *desc;
        struct mbuf *mp, *m;
        uint32_t status, index;
        int count, nsegs, pktlen;
        int rx_cons;

        status = le32toh(rxrd->flags);
        index = le32toh(rxrd->index);
        rx_cons = AGE_RX_CONS(index);
        nsegs = AGE_RX_NSEGS(index);

        sc->age_cdata.age_rxlen = AGE_RX_BYTES(le32toh(rxrd->len));
        if ((status & AGE_RRD_ERROR) != 0 &&
            (status & (AGE_RRD_CRC | AGE_RRD_CODE | AGE_RRD_DRIBBLE |
            AGE_RRD_RUNT | AGE_RRD_OFLOW | AGE_RRD_TRUNC)) != 0) {
                /*
                 * We want to pass the following frames to upper
                 * layer regardless of error status of Rx return
                 * ring.
                 *
                 *  o IP/TCP/UDP checksum is bad.
                 *  o frame length and protocol specific length
                 *     does not match.
                 */
                sc->age_cdata.age_rx_cons += nsegs;
                sc->age_cdata.age_rx_cons %= AGE_RX_RING_CNT;
                return;
        }

        pktlen = 0;
        for (count = 0; count < nsegs; count++,
            AGE_DESC_INC(rx_cons, AGE_RX_RING_CNT)) {
                rxd = &sc->age_cdata.age_rxdesc[rx_cons];
                mp = rxd->rx_m;
                desc = rxd->rx_desc;
                /* Add a new receive buffer to the ring. */
                if (age_newbuf(sc, rxd, 0) != 0) {
                        if_statinc(ifp, if_iqdrops);
                        /* Reuse Rx buffers. */
                        if (sc->age_cdata.age_rxhead != NULL) {
                                m_freem(sc->age_cdata.age_rxhead);
                                AGE_RXCHAIN_RESET(sc);
                        }
                        break;
                }

                /* The length of the first mbuf is computed last. */
                if (count != 0) {
                        mp->m_len = AGE_RX_BYTES(le32toh(desc->len));
                        pktlen += mp->m_len;
                }

                /* Chain received mbufs. */
                if (sc->age_cdata.age_rxhead == NULL) {
                        sc->age_cdata.age_rxhead = mp;
                        sc->age_cdata.age_rxtail = mp;
                } else {
                        m_remove_pkthdr(mp);
                        sc->age_cdata.age_rxprev_tail =
                            sc->age_cdata.age_rxtail;
                        sc->age_cdata.age_rxtail->m_next = mp;
                        sc->age_cdata.age_rxtail = mp;
                }

                if (count == nsegs - 1) {
                        /*
                         * It seems that L1 controller has no way
                         * to tell hardware to strip CRC bytes.
                         */
                        sc->age_cdata.age_rxlen -= ETHER_CRC_LEN;
                        if (nsegs > 1) {
                                /* Remove the CRC bytes in chained mbufs. */
                                pktlen -= ETHER_CRC_LEN;
                                if (mp->m_len <= ETHER_CRC_LEN) {
                                        sc->age_cdata.age_rxtail =
                                            sc->age_cdata.age_rxprev_tail;
                                        sc->age_cdata.age_rxtail->m_len -=
                                            (ETHER_CRC_LEN - mp->m_len);
                                        sc->age_cdata.age_rxtail->m_next = NULL;
                                        m_freem(mp);
                                } else {
                                        mp->m_len -= ETHER_CRC_LEN;
                                }
                        }

                        m = sc->age_cdata.age_rxhead;
                        KASSERT(m->m_flags & M_PKTHDR);
                        m_set_rcvif(m, ifp);
                        m->m_pkthdr.len = sc->age_cdata.age_rxlen;
                        /* Set the first mbuf length. */
                        m->m_len = sc->age_cdata.age_rxlen - pktlen;

                        /*
                         * Set checksum information.
                         * It seems that L1 controller can compute partial
                         * checksum. The partial checksum value can be used
                         * to accelerate checksum computation for fragmented
                         * TCP/UDP packets. Upper network stack already
                         * takes advantage of the partial checksum value in
                         * IP reassembly stage. But I'm not sure the
                         * correctness of the partial hardware checksum
                         * assistance due to lack of data sheet. If it is
                         * proven to work on L1 I'll enable it.
                         */
                        if (status & AGE_RRD_IPV4) {
                                if (status & AGE_RRD_IPCSUM_NOK)
                                        m->m_pkthdr.csum_flags |=
                                            M_CSUM_IPv4_BAD;
                                if ((status & (AGE_RRD_TCP | AGE_RRD_UDP)) &&
                                    (status & AGE_RRD_TCP_UDPCSUM_NOK)) {
                                        m->m_pkthdr.csum_flags |=
                                            M_CSUM_TCP_UDP_BAD;
                                }
                                /*
                                 * Don't mark bad checksum for TCP/UDP frames
                                 * as fragmented frames may always have set
                                 * bad checksummed bit of descriptor status.
                                 */
                        }
#if NVLAN > 0
                        /* Check for VLAN tagged frames. */
                        if (status & AGE_RRD_VLAN) {
                                uint32_t vtag = AGE_RX_VLAN(le32toh(rxrd->vtags));
                                vlan_set_tag(m, AGE_RX_VLAN_TAG(vtag));
                        }
#endif

                        /* Pass it on. */
                        if_percpuq_enqueue(ifp->if_percpuq, m);

                        /* Reset mbuf chains. */
                        AGE_RXCHAIN_RESET(sc);
                }
        }

        if (count != nsegs) {
                sc->age_cdata.age_rx_cons += nsegs;
                sc->age_cdata.age_rx_cons %= AGE_RX_RING_CNT;
        } else
                sc->age_cdata.age_rx_cons = rx_cons;
}

static void
age_rxintr(struct age_softc *sc, int rr_prod)
{
        struct rx_rdesc *rxrd;
        int rr_cons, nsegs, pktlen, prog;

        rr_cons = sc->age_cdata.age_rr_cons;
        if (rr_cons == rr_prod)
                return;

        bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_rr_ring_map, 0,
            sc->age_cdata.age_rr_ring_map->dm_mapsize,
            BUS_DMASYNC_POSTREAD);

        for (prog = 0; rr_cons != rr_prod; prog++) {
                rxrd = &sc->age_rdata.age_rr_ring[rr_cons];
                nsegs = AGE_RX_NSEGS(le32toh(rxrd->index));
                if (nsegs == 0)
                        break;
                /*
                 * Check number of segments against received bytes
                 * Non-matching value would indicate that hardware
                 * is still trying to update Rx return descriptors.
                 * I'm not sure whether this check is really needed.
                 */
                pktlen = AGE_RX_BYTES(le32toh(rxrd->len));
                if (nsegs != ((pktlen + (MCLBYTES - ETHER_ALIGN - 1)) /
                    (MCLBYTES - ETHER_ALIGN)))
                        break;

                /* Received a frame. */
                age_rxeof(sc, rxrd);

                /* Clear return ring. */
                rxrd->index = 0;
                AGE_DESC_INC(rr_cons, AGE_RR_RING_CNT);
        }

        if (prog > 0) {
                /* Update the consumer index. */
                sc->age_cdata.age_rr_cons = rr_cons;

                /* Sync descriptors. */
                bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_rr_ring_map, 0,
                    sc->age_cdata.age_rr_ring_map->dm_mapsize,
                    BUS_DMASYNC_PREWRITE);

                /* Notify hardware availability of new Rx buffers. */
                AGE_COMMIT_MBOX(sc);
        }
}

static void
age_tick(void *xsc)
{
        struct age_softc *sc = xsc;
        struct mii_data *mii = &sc->sc_miibus;
        int s;

        s = splnet();
        mii_tick(mii);
        splx(s);

        callout_schedule(&sc->sc_tick_ch, hz);
}

static void
age_reset(struct age_softc *sc)
{
        uint32_t reg;
        int i;

        CSR_WRITE_4(sc, AGE_MASTER_CFG, MASTER_RESET);
        CSR_READ_4(sc, AGE_MASTER_CFG);
        DELAY(1000);
        for (i = AGE_RESET_TIMEOUT; i > 0; i--) {
                if ((reg = CSR_READ_4(sc, AGE_IDLE_STATUS)) == 0)
                        break;
                DELAY(10);
        }

        if (i == 0)
                printf("%s: reset timeout(0x%08x)!\n", device_xname(sc->sc_dev),
                    reg);

        /* Initialize PCIe module. From Linux. */
        CSR_WRITE_4(sc, 0x12FC, 0x6500);
        CSR_WRITE_4(sc, 0x1008, CSR_READ_4(sc, 0x1008) | 0x8000);
}

static int
age_init(struct ifnet *ifp)
{
        struct age_softc *sc = ifp->if_softc;
        struct mii_data *mii;
        uint8_t eaddr[ETHER_ADDR_LEN];
        bus_addr_t paddr;
        uint32_t reg, fsize;
        uint32_t rxf_hi, rxf_lo, rrd_hi, rrd_lo;
        int error;

        /*
         * Cancel any pending I/O.
         */
        age_stop(ifp, 0);

        /*
         * Reset the chip to a known state.
         */
        age_reset(sc);

        /* Initialize descriptors. */
        error = age_init_rx_ring(sc);
        if (error != 0) {
                printf("%s: no memory for Rx buffers.\n", device_xname(sc->sc_dev));
                age_stop(ifp, 0);
                return error;
        }
        age_init_rr_ring(sc);
        age_init_tx_ring(sc);
        age_init_cmb_block(sc);
        age_init_smb_block(sc);

        /* Reprogram the station address. */
        memcpy(eaddr, CLLADDR(ifp->if_sadl), sizeof(eaddr));
        CSR_WRITE_4(sc, AGE_PAR0,
            eaddr[2] << 24 | eaddr[3] << 16 | eaddr[4] << 8 | eaddr[5]);
        CSR_WRITE_4(sc, AGE_PAR1, eaddr[0] << 8 | eaddr[1]);

        /* Set descriptor base addresses. */
        paddr = sc->age_rdata.age_tx_ring_paddr;
        CSR_WRITE_4(sc, AGE_DESC_ADDR_HI, AGE_ADDR_HI(paddr));
        paddr = sc->age_rdata.age_rx_ring_paddr;
        CSR_WRITE_4(sc, AGE_DESC_RD_ADDR_LO, AGE_ADDR_LO(paddr));
        paddr = sc->age_rdata.age_rr_ring_paddr;
        CSR_WRITE_4(sc, AGE_DESC_RRD_ADDR_LO, AGE_ADDR_LO(paddr));
        paddr = sc->age_rdata.age_tx_ring_paddr;
        CSR_WRITE_4(sc, AGE_DESC_TPD_ADDR_LO, AGE_ADDR_LO(paddr));
        paddr = sc->age_rdata.age_cmb_block_paddr;
        CSR_WRITE_4(sc, AGE_DESC_CMB_ADDR_LO, AGE_ADDR_LO(paddr));
        paddr = sc->age_rdata.age_smb_block_paddr;
        CSR_WRITE_4(sc, AGE_DESC_SMB_ADDR_LO, AGE_ADDR_LO(paddr));

        /* Set Rx/Rx return descriptor counter. */
        CSR_WRITE_4(sc, AGE_DESC_RRD_RD_CNT,
            ((AGE_RR_RING_CNT << DESC_RRD_CNT_SHIFT) &
            DESC_RRD_CNT_MASK) |
            ((AGE_RX_RING_CNT << DESC_RD_CNT_SHIFT) & DESC_RD_CNT_MASK));

        /* Set Tx descriptor counter. */
        CSR_WRITE_4(sc, AGE_DESC_TPD_CNT,
            (AGE_TX_RING_CNT << DESC_TPD_CNT_SHIFT) & DESC_TPD_CNT_MASK);

        /* Tell hardware that we're ready to load descriptors. */
        CSR_WRITE_4(sc, AGE_DMA_BLOCK, DMA_BLOCK_LOAD);

        /*
         * Initialize mailbox register.
         * Updated producer/consumer index information is exchanged
         * through this mailbox register. However Tx producer and
         * Rx return consumer/Rx producer are all shared such that
         * it's hard to separate code path between Tx and Rx without
         * locking. If L1 hardware have a separate mail box register
         * for Tx and Rx consumer/producer management we could have
         * independent Tx/Rx handler which in turn Rx handler could have
         * been run without any locking.
        */
        AGE_COMMIT_MBOX(sc);

        /* Configure IPG/IFG parameters. */
        CSR_WRITE_4(sc, AGE_IPG_IFG_CFG,
            ((IPG_IFG_IPG2_DEFAULT << IPG_IFG_IPG2_SHIFT) & IPG_IFG_IPG2_MASK) |
            ((IPG_IFG_IPG1_DEFAULT << IPG_IFG_IPG1_SHIFT) & IPG_IFG_IPG1_MASK) |
            ((IPG_IFG_MIFG_DEFAULT << IPG_IFG_MIFG_SHIFT) & IPG_IFG_MIFG_MASK) |
            ((IPG_IFG_IPGT_DEFAULT << IPG_IFG_IPGT_SHIFT) & IPG_IFG_IPGT_MASK));

        /* Set parameters for half-duplex media. */
        CSR_WRITE_4(sc, AGE_HDPX_CFG,
            ((HDPX_CFG_LCOL_DEFAULT << HDPX_CFG_LCOL_SHIFT) &
            HDPX_CFG_LCOL_MASK) |
            ((HDPX_CFG_RETRY_DEFAULT << HDPX_CFG_RETRY_SHIFT) &
            HDPX_CFG_RETRY_MASK) | HDPX_CFG_EXC_DEF_EN |
            ((HDPX_CFG_ABEBT_DEFAULT << HDPX_CFG_ABEBT_SHIFT) &
            HDPX_CFG_ABEBT_MASK) |
            ((HDPX_CFG_JAMIPG_DEFAULT << HDPX_CFG_JAMIPG_SHIFT) &
             HDPX_CFG_JAMIPG_MASK));

        /* Configure interrupt moderation timer. */
        sc->age_int_mod = AGE_IM_TIMER_DEFAULT;
        CSR_WRITE_2(sc, AGE_IM_TIMER, AGE_USECS(sc->age_int_mod));
        reg = CSR_READ_4(sc, AGE_MASTER_CFG);
        reg &= ~MASTER_MTIMER_ENB;
        if (AGE_USECS(sc->age_int_mod) == 0)
                reg &= ~MASTER_ITIMER_ENB;
        else
                reg |= MASTER_ITIMER_ENB;
        CSR_WRITE_4(sc, AGE_MASTER_CFG, reg);
        if (agedebug)
                printf("%s: interrupt moderation is %d us.\n",
                    device_xname(sc->sc_dev), sc->age_int_mod);
        CSR_WRITE_2(sc, AGE_INTR_CLR_TIMER, AGE_USECS(1000));

        /* Set Maximum frame size but don't let MTU be less than ETHER_MTU. */
        if (ifp->if_mtu < ETHERMTU)
                sc->age_max_frame_size = ETHERMTU;
        else
                sc->age_max_frame_size = ifp->if_mtu;
        sc->age_max_frame_size += ETHER_HDR_LEN +
            sizeof(struct ether_vlan_header) + ETHER_CRC_LEN;
        CSR_WRITE_4(sc, AGE_FRAME_SIZE, sc->age_max_frame_size);

        /* Configure jumbo frame. */
        fsize = roundup(sc->age_max_frame_size, sizeof(uint64_t));
        CSR_WRITE_4(sc, AGE_RXQ_JUMBO_CFG,
            (((fsize / sizeof(uint64_t)) <<
            RXQ_JUMBO_CFG_SZ_THRESH_SHIFT) & RXQ_JUMBO_CFG_SZ_THRESH_MASK) |
            ((RXQ_JUMBO_CFG_LKAH_DEFAULT <<
            RXQ_JUMBO_CFG_LKAH_SHIFT) & RXQ_JUMBO_CFG_LKAH_MASK) |
            ((AGE_USECS(8) << RXQ_JUMBO_CFG_RRD_TIMER_SHIFT) &
            RXQ_JUMBO_CFG_RRD_TIMER_MASK));

        /* Configure flow-control parameters. From Linux. */
        if ((sc->age_flags & AGE_FLAG_PCIE) != 0) {
                /*
                 * Magic workaround for old-L1.
                 * Don't know which hw revision requires this magic.
                 */
                CSR_WRITE_4(sc, 0x12FC, 0x6500);
                /*
                 * Another magic workaround for flow-control mode
                 * change. From Linux.
                 */
                CSR_WRITE_4(sc, 0x1008, CSR_READ_4(sc, 0x1008) | 0x8000);
        }
        /*
         * TODO
         *  Should understand pause parameter relationships between FIFO
         *  size and number of Rx descriptors and Rx return descriptors.
         *
         *  Magic parameters came from Linux.
         */
        switch (sc->age_chip_rev) {
        case 0x8001:
        case 0x9001:
        case 0x9002:
        case 0x9003:
                rxf_hi = AGE_RX_RING_CNT / 16;
                rxf_lo = (AGE_RX_RING_CNT * 7) / 8;
                rrd_hi = (AGE_RR_RING_CNT * 7) / 8;
                rrd_lo = AGE_RR_RING_CNT / 16;
                break;
        default:
                reg = CSR_READ_4(sc, AGE_SRAM_RX_FIFO_LEN);
                rxf_lo = reg / 16;
                if (rxf_lo < 192)
                        rxf_lo = 192;
                rxf_hi = (reg * 7) / 8;
                if (rxf_hi < rxf_lo)
                        rxf_hi = rxf_lo + 16;
                reg = CSR_READ_4(sc, AGE_SRAM_RRD_LEN);
                rrd_lo = reg / 8;
                rrd_hi = (reg * 7) / 8;
                if (rrd_lo < 2)
                        rrd_lo = 2;
                if (rrd_hi < rrd_lo)
                        rrd_hi = rrd_lo + 3;
                break;
        }
        CSR_WRITE_4(sc, AGE_RXQ_FIFO_PAUSE_THRESH,
            ((rxf_lo << RXQ_FIFO_PAUSE_THRESH_LO_SHIFT) &
            RXQ_FIFO_PAUSE_THRESH_LO_MASK) |
            ((rxf_hi << RXQ_FIFO_PAUSE_THRESH_HI_SHIFT) &
            RXQ_FIFO_PAUSE_THRESH_HI_MASK));
        CSR_WRITE_4(sc, AGE_RXQ_RRD_PAUSE_THRESH,
            ((rrd_lo << RXQ_RRD_PAUSE_THRESH_LO_SHIFT) &
            RXQ_RRD_PAUSE_THRESH_LO_MASK) |
            ((rrd_hi << RXQ_RRD_PAUSE_THRESH_HI_SHIFT) &
            RXQ_RRD_PAUSE_THRESH_HI_MASK));

        /* Configure RxQ. */
        CSR_WRITE_4(sc, AGE_RXQ_CFG,
            ((RXQ_CFG_RD_BURST_DEFAULT << RXQ_CFG_RD_BURST_SHIFT) &
            RXQ_CFG_RD_BURST_MASK) |
            ((RXQ_CFG_RRD_BURST_THRESH_DEFAULT <<
            RXQ_CFG_RRD_BURST_THRESH_SHIFT) & RXQ_CFG_RRD_BURST_THRESH_MASK) |
            ((RXQ_CFG_RD_PREF_MIN_IPG_DEFAULT <<
            RXQ_CFG_RD_PREF_MIN_IPG_SHIFT) & RXQ_CFG_RD_PREF_MIN_IPG_MASK) |
            RXQ_CFG_CUT_THROUGH_ENB | RXQ_CFG_ENB);

        /* Configure TxQ. */
        CSR_WRITE_4(sc, AGE_TXQ_CFG,
            ((TXQ_CFG_TPD_BURST_DEFAULT << TXQ_CFG_TPD_BURST_SHIFT) &
            TXQ_CFG_TPD_BURST_MASK) |
            ((TXQ_CFG_TX_FIFO_BURST_DEFAULT << TXQ_CFG_TX_FIFO_BURST_SHIFT) &
            TXQ_CFG_TX_FIFO_BURST_MASK) |
            ((TXQ_CFG_TPD_FETCH_DEFAULT <<
            TXQ_CFG_TPD_FETCH_THRESH_SHIFT) & TXQ_CFG_TPD_FETCH_THRESH_MASK) |
            TXQ_CFG_ENB);

        /* Configure DMA parameters. */
        CSR_WRITE_4(sc, AGE_DMA_CFG,
            DMA_CFG_ENH_ORDER | DMA_CFG_RCB_64 |
            sc->age_dma_rd_burst | DMA_CFG_RD_ENB |
            sc->age_dma_wr_burst | DMA_CFG_WR_ENB);

        /* Configure CMB DMA write threshold. */
        CSR_WRITE_4(sc, AGE_CMB_WR_THRESH,
            ((CMB_WR_THRESH_RRD_DEFAULT << CMB_WR_THRESH_RRD_SHIFT) &
            CMB_WR_THRESH_RRD_MASK) |
            ((CMB_WR_THRESH_TPD_DEFAULT << CMB_WR_THRESH_TPD_SHIFT) &
            CMB_WR_THRESH_TPD_MASK));

        /* Set CMB/SMB timer and enable them. */
        CSR_WRITE_4(sc, AGE_CMB_WR_TIMER,
            ((AGE_USECS(2) << CMB_WR_TIMER_TX_SHIFT) & CMB_WR_TIMER_TX_MASK) |
            ((AGE_USECS(2) << CMB_WR_TIMER_RX_SHIFT) & CMB_WR_TIMER_RX_MASK));

        /* Request SMB updates for every seconds. */
        CSR_WRITE_4(sc, AGE_SMB_TIMER, AGE_USECS(1000 * 1000));
        CSR_WRITE_4(sc, AGE_CSMB_CTRL, CSMB_CTRL_SMB_ENB | CSMB_CTRL_CMB_ENB);

        /*
         * Disable all WOL bits as WOL can interfere normal Rx
         * operation.
         */
        CSR_WRITE_4(sc, AGE_WOL_CFG, 0);

        /*
         * Configure Tx/Rx MACs.
         *  - Auto-padding for short frames.
         *  - Enable CRC generation.
         *  Start with full-duplex/1000Mbps media. Actual reconfiguration
         *  of MAC is followed after link establishment.
         */
        CSR_WRITE_4(sc, AGE_MAC_CFG,
            MAC_CFG_TX_CRC_ENB | MAC_CFG_TX_AUTO_PAD |
            MAC_CFG_FULL_DUPLEX | MAC_CFG_SPEED_1000 |
            ((MAC_CFG_PREAMBLE_DEFAULT << MAC_CFG_PREAMBLE_SHIFT) &
            MAC_CFG_PREAMBLE_MASK));

        /* Set up the receive filter. */
        age_rxfilter(sc);
        age_rxvlan(sc);

        reg = CSR_READ_4(sc, AGE_MAC_CFG);
        reg |= MAC_CFG_RXCSUM_ENB;

        /* Ack all pending interrupts and clear it. */
        CSR_WRITE_4(sc, AGE_INTR_STATUS, 0);
        CSR_WRITE_4(sc, AGE_INTR_MASK, AGE_INTRS);

        /* Finally enable Tx/Rx MAC. */
        CSR_WRITE_4(sc, AGE_MAC_CFG, reg | MAC_CFG_TX_ENB | MAC_CFG_RX_ENB);

        sc->age_flags &= ~AGE_FLAG_LINK;

        /* Switch to the current media. */
        mii = &sc->sc_miibus;
        mii_mediachg(mii);

        callout_schedule(&sc->sc_tick_ch, hz);

        ifp->if_flags |= IFF_RUNNING;
        ifp->if_flags &= ~IFF_OACTIVE;

        return 0;
}

static void
age_stop(struct ifnet *ifp, int disable)
{
        struct age_softc *sc = ifp->if_softc;
        struct age_txdesc *txd;
        struct age_rxdesc *rxd;
        uint32_t reg;
        int i;

        callout_stop(&sc->sc_tick_ch);

        /*
         * Mark the interface down and cancel the watchdog timer.
         */
        ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
        ifp->if_timer = 0;

        sc->age_flags &= ~AGE_FLAG_LINK;

        mii_down(&sc->sc_miibus);

        /*
         * Disable interrupts.
         */
        CSR_WRITE_4(sc, AGE_INTR_MASK, 0);
        CSR_WRITE_4(sc, AGE_INTR_STATUS, 0xFFFFFFFF);

        /* Stop CMB/SMB updates. */
        CSR_WRITE_4(sc, AGE_CSMB_CTRL, 0);

        /* Stop Rx/Tx MAC. */
        age_stop_rxmac(sc);
        age_stop_txmac(sc);

        /* Stop DMA. */
        CSR_WRITE_4(sc, AGE_DMA_CFG,
            CSR_READ_4(sc, AGE_DMA_CFG) & ~(DMA_CFG_RD_ENB | DMA_CFG_WR_ENB));

        /* Stop TxQ/RxQ. */
        CSR_WRITE_4(sc, AGE_TXQ_CFG,
            CSR_READ_4(sc, AGE_TXQ_CFG) & ~TXQ_CFG_ENB);
        CSR_WRITE_4(sc, AGE_RXQ_CFG,
            CSR_READ_4(sc, AGE_RXQ_CFG) & ~RXQ_CFG_ENB);
        for (i = AGE_RESET_TIMEOUT; i > 0; i--) {
                if ((reg = CSR_READ_4(sc, AGE_IDLE_STATUS)) == 0)
                        break;
                DELAY(10);
        }
        if (i == 0)
                printf("%s: stopping Rx/Tx MACs timed out(0x%08x)!\n",
                    device_xname(sc->sc_dev), reg);

        /* Reclaim Rx buffers that have been processed. */
        if (sc->age_cdata.age_rxhead != NULL)
                m_freem(sc->age_cdata.age_rxhead);
        AGE_RXCHAIN_RESET(sc);

        /*
         * Free RX and TX mbufs still in the queues.
         */
        for (i = 0; i < AGE_RX_RING_CNT; i++) {
                rxd = &sc->age_cdata.age_rxdesc[i];
                if (rxd->rx_m != NULL) {
                        bus_dmamap_unload(sc->sc_dmat, rxd->rx_dmamap);
                        m_freem(rxd->rx_m);
                        rxd->rx_m = NULL;
                }
        }
        for (i = 0; i < AGE_TX_RING_CNT; i++) {
                txd = &sc->age_cdata.age_txdesc[i];
                if (txd->tx_m != NULL) {
                        bus_dmamap_unload(sc->sc_dmat, txd->tx_dmamap);
                        m_freem(txd->tx_m);
                        txd->tx_m = NULL;
                }
        }
}

static void
age_stats_update(struct age_softc *sc)
{
        struct ifnet *ifp = &sc->sc_ec.ec_if;
        struct age_stats *stat;
        struct smb *smb;

        stat = &sc->age_stat;

        bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_smb_block_map, 0,
            sc->age_cdata.age_smb_block_map->dm_mapsize,
            BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);

        smb = sc->age_rdata.age_smb_block;
        if (smb->updated == 0)
                return;

        /* Rx stats. */
        stat->rx_frames += smb->rx_frames;
        stat->rx_bcast_frames += smb->rx_bcast_frames;
        stat->rx_mcast_frames += smb->rx_mcast_frames;
        stat->rx_pause_frames += smb->rx_pause_frames;
        stat->rx_control_frames += smb->rx_control_frames;
        stat->rx_crcerrs += smb->rx_crcerrs;
        stat->rx_lenerrs += smb->rx_lenerrs;
        stat->rx_bytes += smb->rx_bytes;
        stat->rx_runts += smb->rx_runts;
        stat->rx_fragments += smb->rx_fragments;
        stat->rx_pkts_64 += smb->rx_pkts_64;
        stat->rx_pkts_65_127 += smb->rx_pkts_65_127;
        stat->rx_pkts_128_255 += smb->rx_pkts_128_255;
        stat->rx_pkts_256_511 += smb->rx_pkts_256_511;
        stat->rx_pkts_512_1023 += smb->rx_pkts_512_1023;
        stat->rx_pkts_1024_1518 += smb->rx_pkts_1024_1518;
        stat->rx_pkts_1519_max += smb->rx_pkts_1519_max;
        stat->rx_pkts_truncated += smb->rx_pkts_truncated;
        stat->rx_fifo_oflows += smb->rx_fifo_oflows;
        stat->rx_desc_oflows += smb->rx_desc_oflows;
        stat->rx_alignerrs += smb->rx_alignerrs;
        stat->rx_bcast_bytes += smb->rx_bcast_bytes;
        stat->rx_mcast_bytes += smb->rx_mcast_bytes;
        stat->rx_pkts_filtered += smb->rx_pkts_filtered;

        /* Tx stats. */
        stat->tx_frames += smb->tx_frames;
        stat->tx_bcast_frames += smb->tx_bcast_frames;
        stat->tx_mcast_frames += smb->tx_mcast_frames;
        stat->tx_pause_frames += smb->tx_pause_frames;
        stat->tx_excess_defer += smb->tx_excess_defer;
        stat->tx_control_frames += smb->tx_control_frames;
        stat->tx_deferred += smb->tx_deferred;
        stat->tx_bytes += smb->tx_bytes;
        stat->tx_pkts_64 += smb->tx_pkts_64;
        stat->tx_pkts_65_127 += smb->tx_pkts_65_127;
        stat->tx_pkts_128_255 += smb->tx_pkts_128_255;
        stat->tx_pkts_256_511 += smb->tx_pkts_256_511;
        stat->tx_pkts_512_1023 += smb->tx_pkts_512_1023;
        stat->tx_pkts_1024_1518 += smb->tx_pkts_1024_1518;
        stat->tx_pkts_1519_max += smb->tx_pkts_1519_max;
        stat->tx_single_colls += smb->tx_single_colls;
        stat->tx_multi_colls += smb->tx_multi_colls;
        stat->tx_late_colls += smb->tx_late_colls;
        stat->tx_excess_colls += smb->tx_excess_colls;
        stat->tx_underrun += smb->tx_underrun;
        stat->tx_desc_underrun += smb->tx_desc_underrun;
        stat->tx_lenerrs += smb->tx_lenerrs;
        stat->tx_pkts_truncated += smb->tx_pkts_truncated;
        stat->tx_bcast_bytes += smb->tx_bcast_bytes;
        stat->tx_mcast_bytes += smb->tx_mcast_bytes;

        /* Update counters in ifnet. */
        net_stat_ref_t nsr = IF_STAT_GETREF(ifp);

        if_statadd_ref(ifp, nsr, if_opackets, smb->tx_frames);

        if_statadd_ref(ifp, nsr, if_collisions,
            smb->tx_single_colls +
            smb->tx_multi_colls + smb->tx_late_colls +
            smb->tx_excess_colls * HDPX_CFG_RETRY_DEFAULT);

        if_statadd_ref(ifp, nsr, if_oerrors,
            smb->tx_excess_colls +
            smb->tx_late_colls + smb->tx_underrun +
            smb->tx_pkts_truncated);

        if_statadd_ref(ifp, nsr, if_ierrors,
            smb->rx_crcerrs + smb->rx_lenerrs +
            smb->rx_runts + smb->rx_pkts_truncated +
            smb->rx_fifo_oflows + smb->rx_desc_oflows +
            smb->rx_alignerrs);

        IF_STAT_PUTREF(ifp);

        /* Update done, clear. */
        smb->updated = 0;

        bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_smb_block_map, 0,
            sc->age_cdata.age_smb_block_map->dm_mapsize,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
}

static void
age_stop_txmac(struct age_softc *sc)
{
        uint32_t reg;
        int i;

        reg = CSR_READ_4(sc, AGE_MAC_CFG);
        if ((reg & MAC_CFG_TX_ENB) != 0) {
                reg &= ~MAC_CFG_TX_ENB;
                CSR_WRITE_4(sc, AGE_MAC_CFG, reg);
        }
        /* Stop Tx DMA engine. */
        reg = CSR_READ_4(sc, AGE_DMA_CFG);
        if ((reg & DMA_CFG_RD_ENB) != 0) {
                reg &= ~DMA_CFG_RD_ENB;
                CSR_WRITE_4(sc, AGE_DMA_CFG, reg);
        }
        for (i = AGE_RESET_TIMEOUT; i > 0; i--) {
                if ((CSR_READ_4(sc, AGE_IDLE_STATUS) &
                    (IDLE_STATUS_TXMAC | IDLE_STATUS_DMARD)) == 0)
                        break;
                DELAY(10);
        }
        if (i == 0)
                printf("%s: stopping TxMAC timeout!\n", device_xname(sc->sc_dev));
}

static void
age_stop_rxmac(struct age_softc *sc)
{
        uint32_t reg;
        int i;

        reg = CSR_READ_4(sc, AGE_MAC_CFG);
        if ((reg & MAC_CFG_RX_ENB) != 0) {
                reg &= ~MAC_CFG_RX_ENB;
                CSR_WRITE_4(sc, AGE_MAC_CFG, reg);
        }
        /* Stop Rx DMA engine. */
        reg = CSR_READ_4(sc, AGE_DMA_CFG);
        if ((reg & DMA_CFG_WR_ENB) != 0) {
                reg &= ~DMA_CFG_WR_ENB;
                CSR_WRITE_4(sc, AGE_DMA_CFG, reg);
        }
        for (i = AGE_RESET_TIMEOUT; i > 0; i--) {
                if ((CSR_READ_4(sc, AGE_IDLE_STATUS) &
                    (IDLE_STATUS_RXMAC | IDLE_STATUS_DMAWR)) == 0)
                        break;
                DELAY(10);
        }
        if (i == 0)
                printf("%s: stopping RxMAC timeout!\n", device_xname(sc->sc_dev));
}

static void
age_init_tx_ring(struct age_softc *sc)
{
        struct age_ring_data *rd;
        struct age_txdesc *txd;
        int i;

        sc->age_cdata.age_tx_prod = 0;
        sc->age_cdata.age_tx_cons = 0;
        sc->age_cdata.age_tx_cnt = 0;

        rd = &sc->age_rdata;
        memset(rd->age_tx_ring, 0, AGE_TX_RING_SZ);
        for (i = 0; i < AGE_TX_RING_CNT; i++) {
                txd = &sc->age_cdata.age_txdesc[i];
                txd->tx_desc = &rd->age_tx_ring[i];
                txd->tx_m = NULL;
        }
        bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_tx_ring_map, 0,
            sc->age_cdata.age_tx_ring_map->dm_mapsize, BUS_DMASYNC_PREWRITE);
}

static int
age_init_rx_ring(struct age_softc *sc)
{
        struct age_ring_data *rd;
        struct age_rxdesc *rxd;
        int i;

        sc->age_cdata.age_rx_cons = AGE_RX_RING_CNT - 1;
        rd = &sc->age_rdata;
        memset(rd->age_rx_ring, 0, AGE_RX_RING_SZ);
        for (i = 0; i < AGE_RX_RING_CNT; i++) {
                rxd = &sc->age_cdata.age_rxdesc[i];
                rxd->rx_m = NULL;
                rxd->rx_desc = &rd->age_rx_ring[i];
                if (age_newbuf(sc, rxd, 1) != 0)
                        return ENOBUFS;
        }

        bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_rx_ring_map, 0,
            sc->age_cdata.age_rx_ring_map->dm_mapsize, BUS_DMASYNC_PREWRITE);

        return 0;
}

static void
age_init_rr_ring(struct age_softc *sc)
{
        struct age_ring_data *rd;

        sc->age_cdata.age_rr_cons = 0;
        AGE_RXCHAIN_RESET(sc);

        rd = &sc->age_rdata;
        memset(rd->age_rr_ring, 0, AGE_RR_RING_SZ);
        bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_rr_ring_map, 0,
            sc->age_cdata.age_rr_ring_map->dm_mapsize, BUS_DMASYNC_PREWRITE);
}

static void
age_init_cmb_block(struct age_softc *sc)
{
        struct age_ring_data *rd;

        rd = &sc->age_rdata;
        memset(rd->age_cmb_block, 0, AGE_CMB_BLOCK_SZ);
        bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_cmb_block_map, 0,
            sc->age_cdata.age_cmb_block_map->dm_mapsize,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
}

static void
age_init_smb_block(struct age_softc *sc)
{
        struct age_ring_data *rd;

        rd = &sc->age_rdata;
        memset(rd->age_smb_block, 0, AGE_SMB_BLOCK_SZ);
        bus_dmamap_sync(sc->sc_dmat, sc->age_cdata.age_smb_block_map, 0,
            sc->age_cdata.age_smb_block_map->dm_mapsize, BUS_DMASYNC_PREWRITE);
}

static int
age_newbuf(struct age_softc *sc, struct age_rxdesc *rxd, int init)
{
        struct rx_desc *desc;
        struct mbuf *m;
        bus_dmamap_t map;
        int error;

        MGETHDR(m, M_DONTWAIT, MT_DATA);
        if (m == NULL)
                return ENOBUFS;
        MCLGET(m, M_DONTWAIT);
        if (!(m->m_flags & M_EXT)) {
                 m_freem(m);
                 return ENOBUFS;
        }

        m->m_len = m->m_pkthdr.len = MCLBYTES;
        m_adj(m, ETHER_ALIGN);

        error = bus_dmamap_load_mbuf(sc->sc_dmat,
            sc->age_cdata.age_rx_sparemap, m, BUS_DMA_NOWAIT);

        if (error != 0) {
                m_freem(m);

                if (init)
                        printf("%s: can't load RX mbuf\n", device_xname(sc->sc_dev));
                return error;
        }

        if (rxd->rx_m != NULL) {
                bus_dmamap_sync(sc->sc_dmat, rxd->rx_dmamap, 0,
                    rxd->rx_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);
                bus_dmamap_unload(sc->sc_dmat, rxd->rx_dmamap);
        }
        map = rxd->rx_dmamap;
        rxd->rx_dmamap = sc->age_cdata.age_rx_sparemap;
        sc->age_cdata.age_rx_sparemap = map;
        rxd->rx_m = m;

        desc = rxd->rx_desc;
        desc->addr = htole64(rxd->rx_dmamap->dm_segs[0].ds_addr);
        desc->len =
            htole32((rxd->rx_dmamap->dm_segs[0].ds_len & AGE_RD_LEN_MASK) <<
            AGE_RD_LEN_SHIFT);

        return 0;
}

static void
age_rxvlan(struct age_softc *sc)
{
        uint32_t reg;

        reg = CSR_READ_4(sc, AGE_MAC_CFG);
        reg &= ~MAC_CFG_VLAN_TAG_STRIP;
        if (sc->sc_ec.ec_capenable & ETHERCAP_VLAN_HWTAGGING)
                reg |= MAC_CFG_VLAN_TAG_STRIP;
        CSR_WRITE_4(sc, AGE_MAC_CFG, reg);
}

static void
age_rxfilter(struct age_softc *sc)
{
        struct ethercom *ec = &sc->sc_ec;
        struct ifnet *ifp = &sc->sc_ec.ec_if;
        struct ether_multi *enm;
        struct ether_multistep step;
        uint32_t crc;
        uint32_t mchash[2];
        uint32_t rxcfg;

        rxcfg = CSR_READ_4(sc, AGE_MAC_CFG);
        rxcfg &= ~(MAC_CFG_ALLMULTI | MAC_CFG_BCAST | MAC_CFG_PROMISC);
        ifp->if_flags &= ~IFF_ALLMULTI;

        /*
         * Always accept broadcast frames.
         */
        rxcfg |= MAC_CFG_BCAST;

        /* Program new filter. */
        if ((ifp->if_flags & IFF_PROMISC) != 0)
                goto update;

        memset(mchash, 0, sizeof(mchash));

        ETHER_LOCK(ec);
        ETHER_FIRST_MULTI(step, ec, enm);
        while (enm != NULL) {
                if (memcmp(enm->enm_addrlo, enm->enm_addrhi, ETHER_ADDR_LEN)) {
                        /* XXX Use ETHER_F_ALLMULTI in future. */
                        ifp->if_flags |= IFF_ALLMULTI;
                        ETHER_UNLOCK(ec);
                        goto update;
                }
                crc = ether_crc32_be(enm->enm_addrlo, ETHER_ADDR_LEN);
                mchash[crc >> 31] |= 1U << ((crc >> 26) & 0x1f);
                ETHER_NEXT_MULTI(step, enm);
        }
        ETHER_UNLOCK(ec);

update:
        if ((ifp->if_flags & (IFF_PROMISC | IFF_ALLMULTI)) != 0) {
                if (ifp->if_flags & IFF_PROMISC) {
                        rxcfg |= MAC_CFG_PROMISC;
                        /* XXX Use ETHER_F_ALLMULTI in future. */
                        ifp->if_flags |= IFF_ALLMULTI;
                } else
                        rxcfg |= MAC_CFG_ALLMULTI;
                mchash[0] = mchash[1] = 0xFFFFFFFF;
        }
        CSR_WRITE_4(sc, AGE_MAR0, mchash[0]);
        CSR_WRITE_4(sc, AGE_MAR1, mchash[1]);
        CSR_WRITE_4(sc, AGE_MAC_CFG, rxcfg);
}