/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * 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 Atheros AR8121/AR8113/AR8114 PCIe Ethernet. */

#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>

#include <net/bpf.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_dl.h>
#include <net/if_llc.h>
#include <net/if_media.h>
#include <net/if_types.h>
#include <net/if_vlan_var.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>

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

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

#include <machine/bus.h>
#include <machine/in_cksum.h>

#include <dev/ale/if_alereg.h>
#include <dev/ale/if_alevar.h>

/* "device miibus" required.  See GENERIC if you get errors here. */
#include "miibus_if.h"

/* For more information about Tx checksum offload issues see ale_encap(). */
#define ALE_CSUM_FEATURES       (CSUM_TCP | CSUM_UDP)

MODULE_DEPEND(ale, pci, 1, 1, 1);
MODULE_DEPEND(ale, ether, 1, 1, 1);
MODULE_DEPEND(ale, miibus, 1, 1, 1);

/* Tunables. */
static int msi_disable = 0;
static int msix_disable = 0;
TUNABLE_INT("hw.ale.msi_disable", &msi_disable);
TUNABLE_INT("hw.ale.msix_disable", &msix_disable);

/*
 * Devices supported by this driver.
 */
static const struct ale_dev {
        uint16_t        ale_vendorid;
        uint16_t        ale_deviceid;
        const char      *ale_name;
} ale_devs[] = {
    { VENDORID_ATHEROS, DEVICEID_ATHEROS_AR81XX,
    "Atheros AR8121/AR8113/AR8114 PCIe Ethernet" },
};

static int      ale_attach(device_t);
static int      ale_check_boundary(struct ale_softc *);
static int      ale_detach(device_t);
static int      ale_dma_alloc(struct ale_softc *);
static void     ale_dma_free(struct ale_softc *);
static void     ale_dmamap_cb(void *, bus_dma_segment_t *, int, int);
static int      ale_encap(struct ale_softc *, struct mbuf **);
static void     ale_get_macaddr(struct ale_softc *);
static void     ale_init(void *);
static void     ale_init_locked(struct ale_softc *);
static void     ale_init_rx_pages(struct ale_softc *);
static void     ale_init_tx_ring(struct ale_softc *);
static void     ale_int_task(void *, int);
static int      ale_intr(void *);
static int      ale_ioctl(if_t, u_long, caddr_t);
static void     ale_mac_config(struct ale_softc *);
static int      ale_miibus_readreg(device_t, int, int);
static void     ale_miibus_statchg(device_t);
static int      ale_miibus_writereg(device_t, int, int, int);
static int      ale_mediachange(if_t);
static void     ale_mediastatus(if_t, struct ifmediareq *);
static void     ale_phy_reset(struct ale_softc *);
static int      ale_probe(device_t);
static void     ale_reset(struct ale_softc *);
static int      ale_resume(device_t);
static void     ale_rx_update_page(struct ale_softc *, struct ale_rx_page **,
    uint32_t, uint32_t *);
static void     ale_rxcsum(struct ale_softc *, struct mbuf *, uint32_t);
static int      ale_rxeof(struct ale_softc *sc, int);
static void     ale_rxfilter(struct ale_softc *);
static void     ale_rxvlan(struct ale_softc *);
static void     ale_setlinkspeed(struct ale_softc *);
static void     ale_setwol(struct ale_softc *);
static int      ale_shutdown(device_t);
static void     ale_start(if_t);
static void     ale_start_locked(if_t);
static void     ale_stats_clear(struct ale_softc *);
static void     ale_stats_update(struct ale_softc *);
static void     ale_stop(struct ale_softc *);
static void     ale_stop_mac(struct ale_softc *);
static int      ale_suspend(device_t);
static void     ale_sysctl_node(struct ale_softc *);
static void     ale_tick(void *);
static void     ale_txeof(struct ale_softc *);
static void     ale_watchdog(struct ale_softc *);
static int      sysctl_int_range(SYSCTL_HANDLER_ARGS, int, int);
static int      sysctl_hw_ale_proc_limit(SYSCTL_HANDLER_ARGS);
static int      sysctl_hw_ale_int_mod(SYSCTL_HANDLER_ARGS);

static device_method_t ale_methods[] = {
        /* Device interface. */
        DEVMETHOD(device_probe,         ale_probe),
        DEVMETHOD(device_attach,        ale_attach),
        DEVMETHOD(device_detach,        ale_detach),
        DEVMETHOD(device_shutdown,      ale_shutdown),
        DEVMETHOD(device_suspend,       ale_suspend),
        DEVMETHOD(device_resume,        ale_resume),

        /* MII interface. */
        DEVMETHOD(miibus_readreg,       ale_miibus_readreg),
        DEVMETHOD(miibus_writereg,      ale_miibus_writereg),
        DEVMETHOD(miibus_statchg,       ale_miibus_statchg),

        DEVMETHOD_END
};

static driver_t ale_driver = {
        "ale",
        ale_methods,
        sizeof(struct ale_softc)
};

DRIVER_MODULE(ale, pci, ale_driver, NULL, NULL);
MODULE_PNP_INFO("U16:vendor;U16:device;D:#", pci, ale, ale_devs,
    nitems(ale_devs));
DRIVER_MODULE(miibus, ale, miibus_driver, NULL, NULL);

static struct resource_spec ale_res_spec_mem[] = {
        { SYS_RES_MEMORY,       PCIR_BAR(0),    RF_ACTIVE },
        { -1,                   0,              0 }
};

static struct resource_spec ale_irq_spec_legacy[] = {
        { SYS_RES_IRQ,          0,              RF_ACTIVE | RF_SHAREABLE },
        { -1,                   0,              0 }
};

static struct resource_spec ale_irq_spec_msi[] = {
        { SYS_RES_IRQ,          1,              RF_ACTIVE },
        { -1,                   0,              0 }
};

static struct resource_spec ale_irq_spec_msix[] = {
        { SYS_RES_IRQ,          1,              RF_ACTIVE },
        { -1,                   0,              0 }
};

static int
ale_miibus_readreg(device_t dev, int phy, int reg)
{
        struct ale_softc *sc;
        uint32_t v;
        int i;

        sc = device_get_softc(dev);

        CSR_WRITE_4(sc, ALE_MDIO, MDIO_OP_EXECUTE | MDIO_OP_READ |
            MDIO_SUP_PREAMBLE | MDIO_CLK_25_4 | MDIO_REG_ADDR(reg));
        for (i = ALE_PHY_TIMEOUT; i > 0; i--) {
                DELAY(5);
                v = CSR_READ_4(sc, ALE_MDIO);
                if ((v & (MDIO_OP_EXECUTE | MDIO_OP_BUSY)) == 0)
                        break;
        }

        if (i == 0) {
                device_printf(sc->ale_dev, "phy read timeout : %d\n", reg);
                return (0);
        }

        return ((v & MDIO_DATA_MASK) >> MDIO_DATA_SHIFT);
}

static int
ale_miibus_writereg(device_t dev, int phy, int reg, int val)
{
        struct ale_softc *sc;
        uint32_t v;
        int i;

        sc = device_get_softc(dev);

        CSR_WRITE_4(sc, ALE_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 = ALE_PHY_TIMEOUT; i > 0; i--) {
                DELAY(5);
                v = CSR_READ_4(sc, ALE_MDIO);
                if ((v & (MDIO_OP_EXECUTE | MDIO_OP_BUSY)) == 0)
                        break;
        }

        if (i == 0)
                device_printf(sc->ale_dev, "phy write timeout : %d\n", reg);

        return (0);
}

static void
ale_miibus_statchg(device_t dev)
{
        struct ale_softc *sc;
        struct mii_data *mii;
        if_t ifp;
        uint32_t reg;

        sc = device_get_softc(dev);
        mii = device_get_softc(sc->ale_miibus);
        ifp = sc->ale_ifp;
        if (mii == NULL || ifp == NULL ||
            (if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0)
                return;

        sc->ale_flags &= ~ALE_FLAG_LINK;
        if ((mii->mii_media_status & (IFM_ACTIVE | IFM_AVALID)) ==
            (IFM_ACTIVE | IFM_AVALID)) {
                switch (IFM_SUBTYPE(mii->mii_media_active)) {
                case IFM_10_T:
                case IFM_100_TX:
                        sc->ale_flags |= ALE_FLAG_LINK;
                        break;
                case IFM_1000_T:
                        if ((sc->ale_flags & ALE_FLAG_FASTETHER) == 0)
                                sc->ale_flags |= ALE_FLAG_LINK;
                        break;
                default:
                        break;
                }
        }

        /* Stop Rx/Tx MACs. */
        ale_stop_mac(sc);

        /* Program MACs with resolved speed/duplex/flow-control. */
        if ((sc->ale_flags & ALE_FLAG_LINK) != 0) {
                ale_mac_config(sc);
                /* Reenable Tx/Rx MACs. */
                reg = CSR_READ_4(sc, ALE_MAC_CFG);
                reg |= MAC_CFG_TX_ENB | MAC_CFG_RX_ENB;
                CSR_WRITE_4(sc, ALE_MAC_CFG, reg);
        }
}

static void
ale_mediastatus(if_t ifp, struct ifmediareq *ifmr)
{
        struct ale_softc *sc;
        struct mii_data *mii;

        sc = if_getsoftc(ifp);
        ALE_LOCK(sc);
        if ((if_getflags(ifp) & IFF_UP) == 0) {
                ALE_UNLOCK(sc);
                return;
        }
        mii = device_get_softc(sc->ale_miibus);

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

static int
ale_mediachange(if_t ifp)
{
        struct ale_softc *sc;
        struct mii_data *mii;
        struct mii_softc *miisc;
        int error;

        sc = if_getsoftc(ifp);
        ALE_LOCK(sc);
        mii = device_get_softc(sc->ale_miibus);
        LIST_FOREACH(miisc, &mii->mii_phys, mii_list)
                PHY_RESET(miisc);
        error = mii_mediachg(mii);
        ALE_UNLOCK(sc);

        return (error);
}

static int
ale_probe(device_t dev)
{
        const struct ale_dev *sp;
        int i;
        uint16_t vendor, devid;

        vendor = pci_get_vendor(dev);
        devid = pci_get_device(dev);
        sp = ale_devs;
        for (i = 0; i < nitems(ale_devs); i++) {
                if (vendor == sp->ale_vendorid &&
                    devid == sp->ale_deviceid) {
                        device_set_desc(dev, sp->ale_name);
                        return (BUS_PROBE_DEFAULT);
                }
                sp++;
        }

        return (ENXIO);
}

static void
ale_get_macaddr(struct ale_softc *sc)
{
        uint32_t ea[2], reg;
        int i, vpdc;

        reg = CSR_READ_4(sc, ALE_SPI_CTRL);
        if ((reg & SPI_VPD_ENB) != 0) {
                reg &= ~SPI_VPD_ENB;
                CSR_WRITE_4(sc, ALE_SPI_CTRL, reg);
        }

        if (pci_find_cap(sc->ale_dev, PCIY_VPD, &vpdc) == 0) {
                /*
                 * PCI VPD capability found, let TWSI reload EEPROM.
                 * This will set ethernet address of controller.
                 */
                CSR_WRITE_4(sc, ALE_TWSI_CTRL, CSR_READ_4(sc, ALE_TWSI_CTRL) |
                    TWSI_CTRL_SW_LD_START);
                for (i = 100; i > 0; i--) {
                        DELAY(1000);
                        reg = CSR_READ_4(sc, ALE_TWSI_CTRL);
                        if ((reg & TWSI_CTRL_SW_LD_START) == 0)
                                break;
                }
                if (i == 0)
                        device_printf(sc->ale_dev,
                            "reloading EEPROM timeout!\n");
        } else {
                if (bootverbose)
                        device_printf(sc->ale_dev,
                            "PCI VPD capability not found!\n");
        }

        ea[0] = CSR_READ_4(sc, ALE_PAR0);
        ea[1] = CSR_READ_4(sc, ALE_PAR1);
        sc->ale_eaddr[0] = (ea[1] >> 8) & 0xFF;
        sc->ale_eaddr[1] = (ea[1] >> 0) & 0xFF;
        sc->ale_eaddr[2] = (ea[0] >> 24) & 0xFF;
        sc->ale_eaddr[3] = (ea[0] >> 16) & 0xFF;
        sc->ale_eaddr[4] = (ea[0] >> 8) & 0xFF;
        sc->ale_eaddr[5] = (ea[0] >> 0) & 0xFF;
}

static void
ale_phy_reset(struct ale_softc *sc)
{

        /* Reset magic from Linux. */
        CSR_WRITE_2(sc, ALE_GPHY_CTRL,
            GPHY_CTRL_HIB_EN | GPHY_CTRL_HIB_PULSE | GPHY_CTRL_SEL_ANA_RESET |
            GPHY_CTRL_PHY_PLL_ON);
        DELAY(1000);
        CSR_WRITE_2(sc, ALE_GPHY_CTRL,
            GPHY_CTRL_EXT_RESET | GPHY_CTRL_HIB_EN | GPHY_CTRL_HIB_PULSE |
            GPHY_CTRL_SEL_ANA_RESET | GPHY_CTRL_PHY_PLL_ON);
        DELAY(1000);

#define ATPHY_DBG_ADDR          0x1D
#define ATPHY_DBG_DATA          0x1E

        /* Enable hibernation mode. */
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            ATPHY_DBG_ADDR, 0x0B);
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            ATPHY_DBG_DATA, 0xBC00);
        /* Set Class A/B for all modes. */
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            ATPHY_DBG_ADDR, 0x00);
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            ATPHY_DBG_DATA, 0x02EF);
        /* Enable 10BT power saving. */
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            ATPHY_DBG_ADDR, 0x12);
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            ATPHY_DBG_DATA, 0x4C04);
        /* Adjust 1000T power. */
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            ATPHY_DBG_ADDR, 0x04);
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            ATPHY_DBG_ADDR, 0x8BBB);
        /* 10BT center tap voltage. */
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            ATPHY_DBG_ADDR, 0x05);
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            ATPHY_DBG_ADDR, 0x2C46);

#undef  ATPHY_DBG_ADDR
#undef  ATPHY_DBG_DATA
        DELAY(1000);
}

static int
ale_attach(device_t dev)
{
        struct ale_softc *sc;
        if_t ifp;
        uint16_t burst;
        int error, i, msic, msixc, pmc;
        uint32_t rxf_len, txf_len;

        error = 0;
        sc = device_get_softc(dev);
        sc->ale_dev = dev;

        mtx_init(&sc->ale_mtx, device_get_nameunit(dev), MTX_NETWORK_LOCK,
            MTX_DEF);
        callout_init_mtx(&sc->ale_tick_ch, &sc->ale_mtx, 0);
        NET_TASK_INIT(&sc->ale_int_task, 0, ale_int_task, sc);

        /* Map the device. */
        pci_enable_busmaster(dev);
        sc->ale_res_spec = ale_res_spec_mem;
        sc->ale_irq_spec = ale_irq_spec_legacy;
        error = bus_alloc_resources(dev, sc->ale_res_spec, sc->ale_res);
        if (error != 0) {
                device_printf(dev, "cannot allocate memory resources.\n");
                goto fail;
        }

        /* Set PHY address. */
        sc->ale_phyaddr = ALE_PHY_ADDR;

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

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

        /* Get PCI and chip id/revision. */
        sc->ale_rev = pci_get_revid(dev);
        if (sc->ale_rev >= 0xF0) {
                /* L2E Rev. B. AR8114 */
                sc->ale_flags |= ALE_FLAG_FASTETHER;
        } else {
                if ((CSR_READ_4(sc, ALE_PHY_STATUS) & PHY_STATUS_100M) != 0) {
                        /* L1E AR8121 */
                        sc->ale_flags |= ALE_FLAG_JUMBO;
                } else {
                        /* L2E Rev. A. AR8113 */
                        sc->ale_flags |= ALE_FLAG_FASTETHER;
                }
        }
        /*
         * All known controllers seems to require 4 bytes alignment
         * of Tx buffers to make Tx checksum offload with custom
         * checksum generation method work.
         */
        sc->ale_flags |= ALE_FLAG_TXCSUM_BUG;
        /*
         * All known controllers seems to have issues on Rx checksum
         * offload for fragmented IP datagrams.
         */
        sc->ale_flags |= ALE_FLAG_RXCSUM_BUG;
        /*
         * Don't use Tx CMB. It is known to cause RRS update failure
         * under certain circumstances. Typical phenomenon of the
         * issue would be unexpected sequence number encountered in
         * Rx handler.
         */
        sc->ale_flags |= ALE_FLAG_TXCMB_BUG;
        sc->ale_chip_rev = CSR_READ_4(sc, ALE_MASTER_CFG) >>
            MASTER_CHIP_REV_SHIFT;
        if (bootverbose) {
                device_printf(dev, "PCI device revision : 0x%04x\n",
                    sc->ale_rev);
                device_printf(dev, "Chip id/revision : 0x%04x\n",
                    sc->ale_chip_rev);
        }
        txf_len = CSR_READ_4(sc, ALE_SRAM_TX_FIFO_LEN);
        rxf_len = CSR_READ_4(sc, ALE_SRAM_RX_FIFO_LEN);
        /*
         * Uninitialized hardware returns an invalid chip id/revision
         * as well as 0xFFFFFFFF for Tx/Rx fifo length.
         */
        if (sc->ale_chip_rev == 0xFFFF || txf_len == 0xFFFFFFFF ||
            rxf_len == 0xFFFFFFF) {
                device_printf(dev,"chip revision : 0x%04x, %u Tx FIFO "
                    "%u Rx FIFO -- not initialized?\n", sc->ale_chip_rev,
                    txf_len, rxf_len);
                error = ENXIO;
                goto fail;
        }
        device_printf(dev, "%u Tx FIFO, %u Rx FIFO\n", txf_len, rxf_len);

        /* Allocate IRQ resources. */
        msixc = pci_msix_count(dev);
        msic = pci_msi_count(dev);
        if (bootverbose) {
                device_printf(dev, "MSIX count : %d\n", msixc);
                device_printf(dev, "MSI count : %d\n", msic);
        }

        /* Prefer MSIX over MSI. */
        if (msix_disable == 0 || msi_disable == 0) {
                if (msix_disable == 0 && msixc == ALE_MSIX_MESSAGES &&
                    pci_alloc_msix(dev, &msixc) == 0) {
                        if (msixc == ALE_MSIX_MESSAGES) {
                                device_printf(dev, "Using %d MSIX messages.\n",
                                    msixc);
                                sc->ale_flags |= ALE_FLAG_MSIX;
                                sc->ale_irq_spec = ale_irq_spec_msix;
                        } else
                                pci_release_msi(dev);
                }
                if (msi_disable == 0 && (sc->ale_flags & ALE_FLAG_MSIX) == 0 &&
                    msic == ALE_MSI_MESSAGES &&
                    pci_alloc_msi(dev, &msic) == 0) {
                        if (msic == ALE_MSI_MESSAGES) {
                                device_printf(dev, "Using %d MSI messages.\n",
                                    msic);
                                sc->ale_flags |= ALE_FLAG_MSI;
                                sc->ale_irq_spec = ale_irq_spec_msi;
                        } else
                                pci_release_msi(dev);
                }
        }

        error = bus_alloc_resources(dev, sc->ale_irq_spec, sc->ale_irq);
        if (error != 0) {
                device_printf(dev, "cannot allocate IRQ resources.\n");
                goto fail;
        }

        /* Get DMA parameters from PCIe device control register. */
        if (pci_find_cap(dev, PCIY_EXPRESS, &i) == 0) {
                sc->ale_flags |= ALE_FLAG_PCIE;
                burst = pci_read_config(dev, i + 0x08, 2);
                /* Max read request size. */
                sc->ale_dma_rd_burst = ((burst >> 12) & 0x07) <<
                    DMA_CFG_RD_BURST_SHIFT;
                /* Max payload size. */
                sc->ale_dma_wr_burst = ((burst >> 5) & 0x07) <<
                    DMA_CFG_WR_BURST_SHIFT;
                if (bootverbose) {
                        device_printf(dev, "Read request size : %d bytes.\n",
                            128 << ((burst >> 12) & 0x07));
                        device_printf(dev, "TLP payload size : %d bytes.\n",
                            128 << ((burst >> 5) & 0x07));
                }
        } else {
                sc->ale_dma_rd_burst = DMA_CFG_RD_BURST_128;
                sc->ale_dma_wr_burst = DMA_CFG_WR_BURST_128;
        }

        /* Create device sysctl node. */
        ale_sysctl_node(sc);

        if ((error = ale_dma_alloc(sc)) != 0)
                goto fail;

        /* Load station address. */
        ale_get_macaddr(sc);

        ifp = sc->ale_ifp = if_alloc(IFT_ETHER);
        if (ifp == NULL) {
                device_printf(dev, "cannot allocate ifnet structure.\n");
                error = ENXIO;
                goto fail;
        }

        if_setsoftc(ifp, sc);
        if_initname(ifp, device_get_name(dev), device_get_unit(dev));
        if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
        if_setioctlfn(ifp, ale_ioctl);
        if_setstartfn(ifp, ale_start);
        if_setinitfn(ifp, ale_init);
        if_setsendqlen(ifp, ALE_TX_RING_CNT - 1);
        if_setsendqready(ifp);
        if_setcapabilities(ifp, IFCAP_RXCSUM | IFCAP_TXCSUM | IFCAP_TSO4);
        if_sethwassist(ifp, ALE_CSUM_FEATURES | CSUM_TSO);
        if (pci_find_cap(dev, PCIY_PMG, &pmc) == 0) {
                sc->ale_flags |= ALE_FLAG_PMCAP;
                if_setcapabilitiesbit(ifp, IFCAP_WOL_MAGIC | IFCAP_WOL_MCAST, 0);
        }
        if_setcapenable(ifp, if_getcapabilities(ifp));

        /* Set up MII bus. */
        error = mii_attach(dev, &sc->ale_miibus, ifp, ale_mediachange,
            ale_mediastatus, BMSR_DEFCAPMASK, sc->ale_phyaddr, MII_OFFSET_ANY,
            MIIF_DOPAUSE);
        if (error != 0) {
                device_printf(dev, "attaching PHYs failed\n");
                goto fail;
        }

        ether_ifattach(ifp, sc->ale_eaddr);

        /* VLAN capability setup. */
        if_setcapabilitiesbit(ifp, IFCAP_VLAN_MTU | IFCAP_VLAN_HWTAGGING |
            IFCAP_VLAN_HWCSUM | IFCAP_VLAN_HWTSO, 0);
        if_setcapenable(ifp, if_getcapabilities(ifp));
        /*
         * Even though controllers supported by ale(3) have Rx checksum
         * offload bug the workaround for fragmented frames seemed to
         * work so far. However it seems Rx checksum offload does not
         * work under certain conditions. So disable Rx checksum offload
         * until I find more clue about it but allow users to override it.
         */
        if_setcapenablebit(ifp, 0, IFCAP_RXCSUM);

        /* Tell the upper layer(s) we support long frames. */
        if_setifheaderlen(ifp, sizeof(struct ether_vlan_header));

        /* Create local taskq. */
        sc->ale_tq = taskqueue_create_fast("ale_taskq", M_WAITOK,
            taskqueue_thread_enqueue, &sc->ale_tq);
        if (sc->ale_tq == NULL) {
                device_printf(dev, "could not create taskqueue.\n");
                ether_ifdetach(ifp);
                error = ENXIO;
                goto fail;
        }
        taskqueue_start_threads(&sc->ale_tq, 1, PI_NET, "%s taskq",
            device_get_nameunit(sc->ale_dev));

        if ((sc->ale_flags & ALE_FLAG_MSIX) != 0)
                msic = ALE_MSIX_MESSAGES;
        else if ((sc->ale_flags & ALE_FLAG_MSI) != 0)
                msic = ALE_MSI_MESSAGES;
        else
                msic = 1;
        for (i = 0; i < msic; i++) {
                error = bus_setup_intr(dev, sc->ale_irq[i],
                    INTR_TYPE_NET | INTR_MPSAFE, ale_intr, NULL, sc,
                    &sc->ale_intrhand[i]);
                if (error != 0)
                        break;
        }
        if (error != 0) {
                device_printf(dev, "could not set up interrupt handler.\n");
                taskqueue_free(sc->ale_tq);
                sc->ale_tq = NULL;
                ether_ifdetach(ifp);
                goto fail;
        }

fail:
        if (error != 0)
                ale_detach(dev);

        return (error);
}

static int
ale_detach(device_t dev)
{
        struct ale_softc *sc;
        if_t ifp;
        int i, msic;

        sc = device_get_softc(dev);

        ifp = sc->ale_ifp;
        if (device_is_attached(dev)) {
                ether_ifdetach(ifp);
                ALE_LOCK(sc);
                ale_stop(sc);
                ALE_UNLOCK(sc);
                callout_drain(&sc->ale_tick_ch);
                taskqueue_drain(sc->ale_tq, &sc->ale_int_task);
        }

        if (sc->ale_tq != NULL) {
                taskqueue_drain(sc->ale_tq, &sc->ale_int_task);
                taskqueue_free(sc->ale_tq);
                sc->ale_tq = NULL;
        }

        if (sc->ale_miibus != NULL) {
                device_delete_child(dev, sc->ale_miibus);
                sc->ale_miibus = NULL;
        }
        bus_generic_detach(dev);
        ale_dma_free(sc);

        if (ifp != NULL) {
                if_free(ifp);
                sc->ale_ifp = NULL;
        }

        if ((sc->ale_flags & ALE_FLAG_MSIX) != 0)
                msic = ALE_MSIX_MESSAGES;
        else if ((sc->ale_flags & ALE_FLAG_MSI) != 0)
                msic = ALE_MSI_MESSAGES;
        else
                msic = 1;
        for (i = 0; i < msic; i++) {
                if (sc->ale_intrhand[i] != NULL) {
                        bus_teardown_intr(dev, sc->ale_irq[i],
                            sc->ale_intrhand[i]);
                        sc->ale_intrhand[i] = NULL;
                }
        }

        bus_release_resources(dev, sc->ale_irq_spec, sc->ale_irq);
        if ((sc->ale_flags & (ALE_FLAG_MSI | ALE_FLAG_MSIX)) != 0)
                pci_release_msi(dev);
        bus_release_resources(dev, sc->ale_res_spec, sc->ale_res);
        mtx_destroy(&sc->ale_mtx);

        return (0);
}

#define ALE_SYSCTL_STAT_ADD32(c, h, n, p, d)    \
            SYSCTL_ADD_UINT(c, h, OID_AUTO, n, CTLFLAG_RD, p, 0, d)

#define ALE_SYSCTL_STAT_ADD64(c, h, n, p, d)    \
            SYSCTL_ADD_UQUAD(c, h, OID_AUTO, n, CTLFLAG_RD, p, d)

static void
ale_sysctl_node(struct ale_softc *sc)
{
        struct sysctl_ctx_list *ctx;
        struct sysctl_oid_list *child, *parent;
        struct sysctl_oid *tree;
        struct ale_hw_stats *stats;
        int error;

        stats = &sc->ale_stats;
        ctx = device_get_sysctl_ctx(sc->ale_dev);
        child = SYSCTL_CHILDREN(device_get_sysctl_tree(sc->ale_dev));

        SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "int_rx_mod",
            CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &sc->ale_int_rx_mod,
            0, sysctl_hw_ale_int_mod, "I", "ale Rx interrupt moderation");
        SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "int_tx_mod",
            CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &sc->ale_int_tx_mod,
            0, sysctl_hw_ale_int_mod, "I", "ale Tx interrupt moderation");
        /* Pull in device tunables. */
        sc->ale_int_rx_mod = ALE_IM_RX_TIMER_DEFAULT;
        error = resource_int_value(device_get_name(sc->ale_dev),
            device_get_unit(sc->ale_dev), "int_rx_mod", &sc->ale_int_rx_mod);
        if (error == 0) {
                if (sc->ale_int_rx_mod < ALE_IM_TIMER_MIN ||
                    sc->ale_int_rx_mod > ALE_IM_TIMER_MAX) {
                        device_printf(sc->ale_dev, "int_rx_mod value out of "
                            "range; using default: %d\n",
                            ALE_IM_RX_TIMER_DEFAULT);
                        sc->ale_int_rx_mod = ALE_IM_RX_TIMER_DEFAULT;
                }
        }
        sc->ale_int_tx_mod = ALE_IM_TX_TIMER_DEFAULT;
        error = resource_int_value(device_get_name(sc->ale_dev),
            device_get_unit(sc->ale_dev), "int_tx_mod", &sc->ale_int_tx_mod);
        if (error == 0) {
                if (sc->ale_int_tx_mod < ALE_IM_TIMER_MIN ||
                    sc->ale_int_tx_mod > ALE_IM_TIMER_MAX) {
                        device_printf(sc->ale_dev, "int_tx_mod value out of "
                            "range; using default: %d\n",
                            ALE_IM_TX_TIMER_DEFAULT);
                        sc->ale_int_tx_mod = ALE_IM_TX_TIMER_DEFAULT;
                }
        }
        SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "process_limit",
            CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
            &sc->ale_process_limit, 0, sysctl_hw_ale_proc_limit, "I",
            "max number of Rx events to process");
        /* Pull in device tunables. */
        sc->ale_process_limit = ALE_PROC_DEFAULT;
        error = resource_int_value(device_get_name(sc->ale_dev),
            device_get_unit(sc->ale_dev), "process_limit",
            &sc->ale_process_limit);
        if (error == 0) {
                if (sc->ale_process_limit < ALE_PROC_MIN ||
                    sc->ale_process_limit > ALE_PROC_MAX) {
                        device_printf(sc->ale_dev,
                            "process_limit value out of range; "
                            "using default: %d\n", ALE_PROC_DEFAULT);
                        sc->ale_process_limit = ALE_PROC_DEFAULT;
                }
        }

        /* Misc statistics. */
        ALE_SYSCTL_STAT_ADD32(ctx, child, "reset_brk_seq",
            &stats->reset_brk_seq,
            "Controller resets due to broken Rx sequnce number");

        tree = SYSCTL_ADD_NODE(ctx, child, OID_AUTO, "stats",
            CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "ATE statistics");
        parent = SYSCTL_CHILDREN(tree);

        /* Rx statistics. */
        tree = SYSCTL_ADD_NODE(ctx, parent, OID_AUTO, "rx",
            CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Rx MAC statistics");
        child = SYSCTL_CHILDREN(tree);
        ALE_SYSCTL_STAT_ADD32(ctx, child, "good_frames",
            &stats->rx_frames, "Good frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "good_bcast_frames",
            &stats->rx_bcast_frames, "Good broadcast frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "good_mcast_frames",
            &stats->rx_mcast_frames, "Good multicast frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "pause_frames",
            &stats->rx_pause_frames, "Pause control frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "control_frames",
            &stats->rx_control_frames, "Control frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "crc_errs",
            &stats->rx_crcerrs, "CRC errors");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "len_errs",
            &stats->rx_lenerrs, "Frames with length mismatched");
        ALE_SYSCTL_STAT_ADD64(ctx, child, "good_octets",
            &stats->rx_bytes, "Good octets");
        ALE_SYSCTL_STAT_ADD64(ctx, child, "good_bcast_octets",
            &stats->rx_bcast_bytes, "Good broadcast octets");
        ALE_SYSCTL_STAT_ADD64(ctx, child, "good_mcast_octets",
            &stats->rx_mcast_bytes, "Good multicast octets");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "runts",
            &stats->rx_runts, "Too short frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "fragments",
            &stats->rx_fragments, "Fragmented frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_64",
            &stats->rx_pkts_64, "64 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_65_127",
            &stats->rx_pkts_65_127, "65 to 127 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_128_255",
            &stats->rx_pkts_128_255, "128 to 255 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_256_511",
            &stats->rx_pkts_256_511, "256 to 511 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_512_1023",
            &stats->rx_pkts_512_1023, "512 to 1023 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_1024_1518",
            &stats->rx_pkts_1024_1518, "1024 to 1518 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_1519_max",
            &stats->rx_pkts_1519_max, "1519 to max frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "trunc_errs",
            &stats->rx_pkts_truncated, "Truncated frames due to MTU size");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "fifo_oflows",
            &stats->rx_fifo_oflows, "FIFO overflows");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "rrs_errs",
            &stats->rx_rrs_errs, "Return status write-back errors");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "align_errs",
            &stats->rx_alignerrs, "Alignment errors");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "filtered",
            &stats->rx_pkts_filtered,
            "Frames dropped due to address filtering");

        /* Tx statistics. */
        tree = SYSCTL_ADD_NODE(ctx, parent, OID_AUTO, "tx",
            CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Tx MAC statistics");
        child = SYSCTL_CHILDREN(tree);
        ALE_SYSCTL_STAT_ADD32(ctx, child, "good_frames",
            &stats->tx_frames, "Good frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "good_bcast_frames",
            &stats->tx_bcast_frames, "Good broadcast frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "good_mcast_frames",
            &stats->tx_mcast_frames, "Good multicast frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "pause_frames",
            &stats->tx_pause_frames, "Pause control frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "control_frames",
            &stats->tx_control_frames, "Control frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "excess_defers",
            &stats->tx_excess_defer, "Frames with excessive derferrals");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "defers",
            &stats->tx_excess_defer, "Frames with derferrals");
        ALE_SYSCTL_STAT_ADD64(ctx, child, "good_octets",
            &stats->tx_bytes, "Good octets");
        ALE_SYSCTL_STAT_ADD64(ctx, child, "good_bcast_octets",
            &stats->tx_bcast_bytes, "Good broadcast octets");
        ALE_SYSCTL_STAT_ADD64(ctx, child, "good_mcast_octets",
            &stats->tx_mcast_bytes, "Good multicast octets");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_64",
            &stats->tx_pkts_64, "64 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_65_127",
            &stats->tx_pkts_65_127, "65 to 127 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_128_255",
            &stats->tx_pkts_128_255, "128 to 255 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_256_511",
            &stats->tx_pkts_256_511, "256 to 511 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_512_1023",
            &stats->tx_pkts_512_1023, "512 to 1023 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_1024_1518",
            &stats->tx_pkts_1024_1518, "1024 to 1518 bytes frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "frames_1519_max",
            &stats->tx_pkts_1519_max, "1519 to max frames");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "single_colls",
            &stats->tx_single_colls, "Single collisions");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "multi_colls",
            &stats->tx_multi_colls, "Multiple collisions");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "late_colls",
            &stats->tx_late_colls, "Late collisions");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "excess_colls",
            &stats->tx_excess_colls, "Excessive collisions");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "underruns",
            &stats->tx_underrun, "FIFO underruns");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "desc_underruns",
            &stats->tx_desc_underrun, "Descriptor write-back errors");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "len_errs",
            &stats->tx_lenerrs, "Frames with length mismatched");
        ALE_SYSCTL_STAT_ADD32(ctx, child, "trunc_errs",
            &stats->tx_pkts_truncated, "Truncated frames due to MTU size");
}

#undef ALE_SYSCTL_STAT_ADD32
#undef ALE_SYSCTL_STAT_ADD64

struct ale_dmamap_arg {
        bus_addr_t      ale_busaddr;
};

static void
ale_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
        struct ale_dmamap_arg *ctx;

        if (error != 0)
                return;

        KASSERT(nsegs == 1, ("%s: %d segments returned!", __func__, nsegs));

        ctx = (struct ale_dmamap_arg *)arg;
        ctx->ale_busaddr = segs[0].ds_addr;
}

/*
 * Tx descriptors/RXF0/CMB DMA blocks share ALE_DESC_ADDR_HI register
 * which specifies high address region of DMA blocks. Therefore these
 * blocks should have the same high address of given 4GB address
 * space(i.e. crossing 4GB boundary is not allowed).
 */
static int
ale_check_boundary(struct ale_softc *sc)
{
        bus_addr_t rx_cmb_end[ALE_RX_PAGES], tx_cmb_end;
        bus_addr_t rx_page_end[ALE_RX_PAGES], tx_ring_end;

        rx_page_end[0] = sc->ale_cdata.ale_rx_page[0].page_paddr +
            sc->ale_pagesize;
        rx_page_end[1] = sc->ale_cdata.ale_rx_page[1].page_paddr +
            sc->ale_pagesize;
        tx_ring_end = sc->ale_cdata.ale_tx_ring_paddr + ALE_TX_RING_SZ;
        tx_cmb_end = sc->ale_cdata.ale_tx_cmb_paddr + ALE_TX_CMB_SZ;
        rx_cmb_end[0] = sc->ale_cdata.ale_rx_page[0].cmb_paddr + ALE_RX_CMB_SZ;
        rx_cmb_end[1] = sc->ale_cdata.ale_rx_page[1].cmb_paddr + ALE_RX_CMB_SZ;

        if ((ALE_ADDR_HI(tx_ring_end) !=
            ALE_ADDR_HI(sc->ale_cdata.ale_tx_ring_paddr)) ||
            (ALE_ADDR_HI(rx_page_end[0]) !=
            ALE_ADDR_HI(sc->ale_cdata.ale_rx_page[0].page_paddr)) ||
            (ALE_ADDR_HI(rx_page_end[1]) !=
            ALE_ADDR_HI(sc->ale_cdata.ale_rx_page[1].page_paddr)) ||
            (ALE_ADDR_HI(tx_cmb_end) !=
            ALE_ADDR_HI(sc->ale_cdata.ale_tx_cmb_paddr)) ||
            (ALE_ADDR_HI(rx_cmb_end[0]) !=
            ALE_ADDR_HI(sc->ale_cdata.ale_rx_page[0].cmb_paddr)) ||
            (ALE_ADDR_HI(rx_cmb_end[1]) !=
            ALE_ADDR_HI(sc->ale_cdata.ale_rx_page[1].cmb_paddr)))
                return (EFBIG);

        if ((ALE_ADDR_HI(tx_ring_end) != ALE_ADDR_HI(rx_page_end[0])) ||
            (ALE_ADDR_HI(tx_ring_end) != ALE_ADDR_HI(rx_page_end[1])) ||
            (ALE_ADDR_HI(tx_ring_end) != ALE_ADDR_HI(rx_cmb_end[0])) ||
            (ALE_ADDR_HI(tx_ring_end) != ALE_ADDR_HI(rx_cmb_end[1])) ||
            (ALE_ADDR_HI(tx_ring_end) != ALE_ADDR_HI(tx_cmb_end)))
                return (EFBIG);

        return (0);
}

static int
ale_dma_alloc(struct ale_softc *sc)
{
        struct ale_txdesc *txd;
        bus_addr_t lowaddr;
        struct ale_dmamap_arg ctx;
        int error, guard_size, i;

        if ((sc->ale_flags & ALE_FLAG_JUMBO) != 0)
                guard_size = ALE_JUMBO_FRAMELEN;
        else
                guard_size = ALE_MAX_FRAMELEN;
        sc->ale_pagesize = roundup(guard_size + ALE_RX_PAGE_SZ,
            ALE_RX_PAGE_ALIGN);
        lowaddr = BUS_SPACE_MAXADDR;
again:
        /* Create parent DMA tag. */
        error = bus_dma_tag_create(
            bus_get_dma_tag(sc->ale_dev), /* parent */
            1, 0,                       /* alignment, boundary */
            lowaddr,                    /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            BUS_SPACE_MAXSIZE_32BIT,    /* maxsize */
            0,                          /* nsegments */
            BUS_SPACE_MAXSIZE_32BIT,    /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->ale_cdata.ale_parent_tag);
        if (error != 0) {
                device_printf(sc->ale_dev,
                    "could not create parent DMA tag.\n");
                goto fail;
        }

        /* Create DMA tag for Tx descriptor ring. */
        error = bus_dma_tag_create(
            sc->ale_cdata.ale_parent_tag, /* parent */
            ALE_TX_RING_ALIGN, 0,       /* alignment, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            ALE_TX_RING_SZ,             /* maxsize */
            1,                          /* nsegments */
            ALE_TX_RING_SZ,             /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->ale_cdata.ale_tx_ring_tag);
        if (error != 0) {
                device_printf(sc->ale_dev,
                    "could not create Tx ring DMA tag.\n");
                goto fail;
        }

        /* Create DMA tag for Rx pages. */
        for (i = 0; i < ALE_RX_PAGES; i++) {
                error = bus_dma_tag_create(
                    sc->ale_cdata.ale_parent_tag, /* parent */
                    ALE_RX_PAGE_ALIGN, 0,       /* alignment, boundary */
                    BUS_SPACE_MAXADDR,          /* lowaddr */
                    BUS_SPACE_MAXADDR,          /* highaddr */
                    NULL, NULL,                 /* filter, filterarg */
                    sc->ale_pagesize,           /* maxsize */
                    1,                          /* nsegments */
                    sc->ale_pagesize,           /* maxsegsize */
                    0,                          /* flags */
                    NULL, NULL,                 /* lockfunc, lockarg */
                    &sc->ale_cdata.ale_rx_page[i].page_tag);
                if (error != 0) {
                        device_printf(sc->ale_dev,
                            "could not create Rx page %d DMA tag.\n", i);
                        goto fail;
                }
        }

        /* Create DMA tag for Tx coalescing message block. */
        error = bus_dma_tag_create(
            sc->ale_cdata.ale_parent_tag, /* parent */
            ALE_CMB_ALIGN, 0,           /* alignment, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            ALE_TX_CMB_SZ,              /* maxsize */
            1,                          /* nsegments */
            ALE_TX_CMB_SZ,              /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->ale_cdata.ale_tx_cmb_tag);
        if (error != 0) {
                device_printf(sc->ale_dev,
                    "could not create Tx CMB DMA tag.\n");
                goto fail;
        }

        /* Create DMA tag for Rx coalescing message block. */
        for (i = 0; i < ALE_RX_PAGES; i++) {
                error = bus_dma_tag_create(
                    sc->ale_cdata.ale_parent_tag, /* parent */
                    ALE_CMB_ALIGN, 0,           /* alignment, boundary */
                    BUS_SPACE_MAXADDR,          /* lowaddr */
                    BUS_SPACE_MAXADDR,          /* highaddr */
                    NULL, NULL,                 /* filter, filterarg */
                    ALE_RX_CMB_SZ,              /* maxsize */
                    1,                          /* nsegments */
                    ALE_RX_CMB_SZ,              /* maxsegsize */
                    0,                          /* flags */
                    NULL, NULL,                 /* lockfunc, lockarg */
                    &sc->ale_cdata.ale_rx_page[i].cmb_tag);
                if (error != 0) {
                        device_printf(sc->ale_dev,
                            "could not create Rx page %d CMB DMA tag.\n", i);
                        goto fail;
                }
        }

        /* Allocate DMA'able memory and load the DMA map for Tx ring. */
        error = bus_dmamem_alloc(sc->ale_cdata.ale_tx_ring_tag,
            (void **)&sc->ale_cdata.ale_tx_ring,
            BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_COHERENT,
            &sc->ale_cdata.ale_tx_ring_map);
        if (error != 0) {
                device_printf(sc->ale_dev,
                    "could not allocate DMA'able memory for Tx ring.\n");
                goto fail;
        }
        ctx.ale_busaddr = 0;
        error = bus_dmamap_load(sc->ale_cdata.ale_tx_ring_tag,
            sc->ale_cdata.ale_tx_ring_map, sc->ale_cdata.ale_tx_ring,
            ALE_TX_RING_SZ, ale_dmamap_cb, &ctx, 0);
        if (error != 0 || ctx.ale_busaddr == 0) {
                device_printf(sc->ale_dev,
                    "could not load DMA'able memory for Tx ring.\n");
                goto fail;
        }
        sc->ale_cdata.ale_tx_ring_paddr = ctx.ale_busaddr;

        /* Rx pages. */
        for (i = 0; i < ALE_RX_PAGES; i++) {
                error = bus_dmamem_alloc(sc->ale_cdata.ale_rx_page[i].page_tag,
                    (void **)&sc->ale_cdata.ale_rx_page[i].page_addr,
                    BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_COHERENT,
                    &sc->ale_cdata.ale_rx_page[i].page_map);
                if (error != 0) {
                        device_printf(sc->ale_dev,
                            "could not allocate DMA'able memory for "
                            "Rx page %d.\n", i);
                        goto fail;
                }
                ctx.ale_busaddr = 0;
                error = bus_dmamap_load(sc->ale_cdata.ale_rx_page[i].page_tag,
                    sc->ale_cdata.ale_rx_page[i].page_map,
                    sc->ale_cdata.ale_rx_page[i].page_addr,
                    sc->ale_pagesize, ale_dmamap_cb, &ctx, 0);
                if (error != 0 || ctx.ale_busaddr == 0) {
                        device_printf(sc->ale_dev,
                            "could not load DMA'able memory for "
                            "Rx page %d.\n", i);
                        goto fail;
                }
                sc->ale_cdata.ale_rx_page[i].page_paddr = ctx.ale_busaddr;
        }

        /* Tx CMB. */
        error = bus_dmamem_alloc(sc->ale_cdata.ale_tx_cmb_tag,
            (void **)&sc->ale_cdata.ale_tx_cmb,
            BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_COHERENT,
            &sc->ale_cdata.ale_tx_cmb_map);
        if (error != 0) {
                device_printf(sc->ale_dev,
                    "could not allocate DMA'able memory for Tx CMB.\n");
                goto fail;
        }
        ctx.ale_busaddr = 0;
        error = bus_dmamap_load(sc->ale_cdata.ale_tx_cmb_tag,
            sc->ale_cdata.ale_tx_cmb_map, sc->ale_cdata.ale_tx_cmb,
            ALE_TX_CMB_SZ, ale_dmamap_cb, &ctx, 0);
        if (error != 0 || ctx.ale_busaddr == 0) {
                device_printf(sc->ale_dev,
                    "could not load DMA'able memory for Tx CMB.\n");
                goto fail;
        }
        sc->ale_cdata.ale_tx_cmb_paddr = ctx.ale_busaddr;

        /* Rx CMB. */
        for (i = 0; i < ALE_RX_PAGES; i++) {
                error = bus_dmamem_alloc(sc->ale_cdata.ale_rx_page[i].cmb_tag,
                    (void **)&sc->ale_cdata.ale_rx_page[i].cmb_addr,
                    BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_COHERENT,
                    &sc->ale_cdata.ale_rx_page[i].cmb_map);
                if (error != 0) {
                        device_printf(sc->ale_dev, "could not allocate "
                            "DMA'able memory for Rx page %d CMB.\n", i);
                        goto fail;
                }
                ctx.ale_busaddr = 0;
                error = bus_dmamap_load(sc->ale_cdata.ale_rx_page[i].cmb_tag,
                    sc->ale_cdata.ale_rx_page[i].cmb_map,
                    sc->ale_cdata.ale_rx_page[i].cmb_addr,
                    ALE_RX_CMB_SZ, ale_dmamap_cb, &ctx, 0);
                if (error != 0 || ctx.ale_busaddr == 0) {
                        device_printf(sc->ale_dev, "could not load DMA'able "
                            "memory for Rx page %d CMB.\n", i);
                        goto fail;
                }
                sc->ale_cdata.ale_rx_page[i].cmb_paddr = ctx.ale_busaddr;
        }

        /*
         * Tx descriptors/RXF0/CMB DMA blocks share the same
         * high address region of 64bit DMA address space.
         */
        if (lowaddr != BUS_SPACE_MAXADDR_32BIT &&
            (error = ale_check_boundary(sc)) != 0) {
                device_printf(sc->ale_dev, "4GB boundary crossed, "
                    "switching to 32bit DMA addressing mode.\n");
                ale_dma_free(sc);
                /*
                 * Limit max allowable DMA address space to 32bit
                 * and try again.
                 */
                lowaddr = BUS_SPACE_MAXADDR_32BIT;
                goto again;
        }

        /*
         * Create Tx buffer parent tag.
         * AR81xx allows 64bit DMA addressing of Tx buffers so it
         * needs separate parent DMA tag as parent DMA address space
         * could be restricted to be within 32bit address space by
         * 4GB boundary crossing.
         */
        error = bus_dma_tag_create(
            bus_get_dma_tag(sc->ale_dev), /* parent */
            1, 0,                       /* alignment, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            BUS_SPACE_MAXSIZE_32BIT,    /* maxsize */
            0,                          /* nsegments */
            BUS_SPACE_MAXSIZE_32BIT,    /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->ale_cdata.ale_buffer_tag);
        if (error != 0) {
                device_printf(sc->ale_dev,
                    "could not create parent buffer DMA tag.\n");
                goto fail;
        }

        /* Create DMA tag for Tx buffers. */
        error = bus_dma_tag_create(
            sc->ale_cdata.ale_buffer_tag, /* parent */
            1, 0,                       /* alignment, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            ALE_TSO_MAXSIZE,            /* maxsize */
            ALE_MAXTXSEGS,              /* nsegments */
            ALE_TSO_MAXSEGSIZE,         /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->ale_cdata.ale_tx_tag);
        if (error != 0) {
                device_printf(sc->ale_dev, "could not create Tx DMA tag.\n");
                goto fail;
        }

        /* Create DMA maps for Tx buffers. */
        for (i = 0; i < ALE_TX_RING_CNT; i++) {
                txd = &sc->ale_cdata.ale_txdesc[i];
                txd->tx_m = NULL;
                txd->tx_dmamap = NULL;
                error = bus_dmamap_create(sc->ale_cdata.ale_tx_tag, 0,
                    &txd->tx_dmamap);
                if (error != 0) {
                        device_printf(sc->ale_dev,
                            "could not create Tx dmamap.\n");
                        goto fail;
                }
        }

fail:
        return (error);
}

static void
ale_dma_free(struct ale_softc *sc)
{
        struct ale_txdesc *txd;
        int i;

        /* Tx buffers. */
        if (sc->ale_cdata.ale_tx_tag != NULL) {
                for (i = 0; i < ALE_TX_RING_CNT; i++) {
                        txd = &sc->ale_cdata.ale_txdesc[i];
                        if (txd->tx_dmamap != NULL) {
                                bus_dmamap_destroy(sc->ale_cdata.ale_tx_tag,
                                    txd->tx_dmamap);
                                txd->tx_dmamap = NULL;
                        }
                }
                bus_dma_tag_destroy(sc->ale_cdata.ale_tx_tag);
                sc->ale_cdata.ale_tx_tag = NULL;
        }
        /* Tx descriptor ring. */
        if (sc->ale_cdata.ale_tx_ring_tag != NULL) {
                if (sc->ale_cdata.ale_tx_ring_paddr != 0)
                        bus_dmamap_unload(sc->ale_cdata.ale_tx_ring_tag,
                            sc->ale_cdata.ale_tx_ring_map);
                if (sc->ale_cdata.ale_tx_ring != NULL)
                        bus_dmamem_free(sc->ale_cdata.ale_tx_ring_tag,
                            sc->ale_cdata.ale_tx_ring,
                            sc->ale_cdata.ale_tx_ring_map);
                sc->ale_cdata.ale_tx_ring_paddr = 0;
                sc->ale_cdata.ale_tx_ring = NULL;
                bus_dma_tag_destroy(sc->ale_cdata.ale_tx_ring_tag);
                sc->ale_cdata.ale_tx_ring_tag = NULL;
        }
        /* Rx page block. */
        for (i = 0; i < ALE_RX_PAGES; i++) {
                if (sc->ale_cdata.ale_rx_page[i].page_tag != NULL) {
                        if (sc->ale_cdata.ale_rx_page[i].page_paddr != 0)
                                bus_dmamap_unload(
                                    sc->ale_cdata.ale_rx_page[i].page_tag,
                                    sc->ale_cdata.ale_rx_page[i].page_map);
                        if (sc->ale_cdata.ale_rx_page[i].page_addr != NULL)
                                bus_dmamem_free(
                                    sc->ale_cdata.ale_rx_page[i].page_tag,
                                    sc->ale_cdata.ale_rx_page[i].page_addr,
                                    sc->ale_cdata.ale_rx_page[i].page_map);
                        sc->ale_cdata.ale_rx_page[i].page_paddr = 0;
                        sc->ale_cdata.ale_rx_page[i].page_addr = NULL;
                        bus_dma_tag_destroy(
                            sc->ale_cdata.ale_rx_page[i].page_tag);
                        sc->ale_cdata.ale_rx_page[i].page_tag = NULL;
                }
        }
        /* Rx CMB. */
        for (i = 0; i < ALE_RX_PAGES; i++) {
                if (sc->ale_cdata.ale_rx_page[i].cmb_tag != NULL) {
                        if (sc->ale_cdata.ale_rx_page[i].cmb_paddr != 0)
                                bus_dmamap_unload(
                                    sc->ale_cdata.ale_rx_page[i].cmb_tag,
                                    sc->ale_cdata.ale_rx_page[i].cmb_map);
                        if (sc->ale_cdata.ale_rx_page[i].cmb_addr != NULL)
                                bus_dmamem_free(
                                    sc->ale_cdata.ale_rx_page[i].cmb_tag,
                                    sc->ale_cdata.ale_rx_page[i].cmb_addr,
                                    sc->ale_cdata.ale_rx_page[i].cmb_map);
                        sc->ale_cdata.ale_rx_page[i].cmb_paddr = 0;
                        sc->ale_cdata.ale_rx_page[i].cmb_addr = NULL;
                        bus_dma_tag_destroy(
                            sc->ale_cdata.ale_rx_page[i].cmb_tag);
                        sc->ale_cdata.ale_rx_page[i].cmb_tag = NULL;
                }
        }
        /* Tx CMB. */
        if (sc->ale_cdata.ale_tx_cmb_tag != NULL) {
                if (sc->ale_cdata.ale_tx_cmb_paddr != 0)
                        bus_dmamap_unload(sc->ale_cdata.ale_tx_cmb_tag,
                            sc->ale_cdata.ale_tx_cmb_map);
                if (sc->ale_cdata.ale_tx_cmb != NULL)
                        bus_dmamem_free(sc->ale_cdata.ale_tx_cmb_tag,
                            sc->ale_cdata.ale_tx_cmb,
                            sc->ale_cdata.ale_tx_cmb_map);
                sc->ale_cdata.ale_tx_cmb_paddr = 0;
                sc->ale_cdata.ale_tx_cmb = NULL;
                bus_dma_tag_destroy(sc->ale_cdata.ale_tx_cmb_tag);
                sc->ale_cdata.ale_tx_cmb_tag = NULL;
        }
        if (sc->ale_cdata.ale_buffer_tag != NULL) {
                bus_dma_tag_destroy(sc->ale_cdata.ale_buffer_tag);
                sc->ale_cdata.ale_buffer_tag = NULL;
        }
        if (sc->ale_cdata.ale_parent_tag != NULL) {
                bus_dma_tag_destroy(sc->ale_cdata.ale_parent_tag);
                sc->ale_cdata.ale_parent_tag = NULL;
        }
}

static int
ale_shutdown(device_t dev)
{

        return (ale_suspend(dev));
}

/*
 * Note, this driver resets the link speed to 10/100Mbps by
 * restarting auto-negotiation in suspend/shutdown phase but we
 * don't know whether that auto-negotiation would succeed or not
 * as driver has no control after powering off/suspend operation.
 * If the renegotiation fail WOL may not work. Running at 1Gbps
 * will draw more power than 375mA at 3.3V which is specified in
 * PCI specification and that would result in complete
 * shutdowning power to ethernet controller.
 *
 * TODO
 * Save current negotiated media speed/duplex/flow-control to
 * softc and restore the same link again after resuming. PHY
 * handling such as power down/resetting to 100Mbps may be better
 * handled in suspend method in phy driver.
 */
static void
ale_setlinkspeed(struct ale_softc *sc)
{
        struct mii_data *mii;
        int aneg, i;

        mii = device_get_softc(sc->ale_miibus);
        mii_pollstat(mii);
        aneg = 0;
        if ((mii->mii_media_status & (IFM_ACTIVE | IFM_AVALID)) ==
            (IFM_ACTIVE | IFM_AVALID)) {
                switch IFM_SUBTYPE(mii->mii_media_active) {
                case IFM_10_T:
                case IFM_100_TX:
                        return;
                case IFM_1000_T:
                        aneg++;
                        break;
                default:
                        break;
                }
        }
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr, MII_100T2CR, 0);
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            MII_ANAR, ANAR_TX_FD | ANAR_TX | ANAR_10_FD | ANAR_10 | ANAR_CSMA);
        ale_miibus_writereg(sc->ale_dev, sc->ale_phyaddr,
            MII_BMCR, BMCR_RESET | BMCR_AUTOEN | BMCR_STARTNEG);
        DELAY(1000);
        if (aneg != 0) {
                /*
                 * Poll link state until ale(4) get a 10/100Mbps link.
                 */
                for (i = 0; i < MII_ANEGTICKS_GIGE; i++) {
                        mii_pollstat(mii);
                        if ((mii->mii_media_status & (IFM_ACTIVE | IFM_AVALID))
                            == (IFM_ACTIVE | IFM_AVALID)) {
                                switch (IFM_SUBTYPE(
                                    mii->mii_media_active)) {
                                case IFM_10_T:
                                case IFM_100_TX:
                                        ale_mac_config(sc);
                                        return;
                                default:
                                        break;
                                }
                        }
                        ALE_UNLOCK(sc);
                        pause("alelnk", hz);
                        ALE_LOCK(sc);
                }
                if (i == MII_ANEGTICKS_GIGE)
                        device_printf(sc->ale_dev,
                            "establishing a link failed, WOL may not work!");
        }
        /*
         * No link, force MAC to have 100Mbps, full-duplex link.
         * This is the last resort and may/may not work.
         */
        mii->mii_media_status = IFM_AVALID | IFM_ACTIVE;
        mii->mii_media_active = IFM_ETHER | IFM_100_TX | IFM_FDX;
        ale_mac_config(sc);
}

static void
ale_setwol(struct ale_softc *sc)
{
        if_t ifp;
        uint32_t reg, pmcs;
        uint16_t pmstat;
        int pmc;

        ALE_LOCK_ASSERT(sc);

        if (pci_find_cap(sc->ale_dev, PCIY_PMG, &pmc) != 0) {
                /* Disable WOL. */
                CSR_WRITE_4(sc, ALE_WOL_CFG, 0);
                reg = CSR_READ_4(sc, ALE_PCIE_PHYMISC);
                reg |= PCIE_PHYMISC_FORCE_RCV_DET;
                CSR_WRITE_4(sc, ALE_PCIE_PHYMISC, reg);
                /* Force PHY power down. */
                CSR_WRITE_2(sc, ALE_GPHY_CTRL,
                    GPHY_CTRL_EXT_RESET | GPHY_CTRL_HIB_EN |
                    GPHY_CTRL_HIB_PULSE | GPHY_CTRL_PHY_PLL_ON |
                    GPHY_CTRL_SEL_ANA_RESET | GPHY_CTRL_PHY_IDDQ |
                    GPHY_CTRL_PCLK_SEL_DIS | GPHY_CTRL_PWDOWN_HW);
                return;
        }

        ifp = sc->ale_ifp;
        if ((if_getcapenable(ifp) & IFCAP_WOL) != 0) {
                if ((sc->ale_flags & ALE_FLAG_FASTETHER) == 0)
                        ale_setlinkspeed(sc);
        }

        pmcs = 0;
        if ((if_getcapenable(ifp) & IFCAP_WOL_MAGIC) != 0)
                pmcs |= WOL_CFG_MAGIC | WOL_CFG_MAGIC_ENB;
        CSR_WRITE_4(sc, ALE_WOL_CFG, pmcs);
        reg = CSR_READ_4(sc, ALE_MAC_CFG);
        reg &= ~(MAC_CFG_DBG | MAC_CFG_PROMISC | MAC_CFG_ALLMULTI |
            MAC_CFG_BCAST);
        if ((if_getcapenable(ifp) & IFCAP_WOL_MCAST) != 0)
                reg |= MAC_CFG_ALLMULTI | MAC_CFG_BCAST;
        if ((if_getcapenable(ifp) & IFCAP_WOL) != 0)
                reg |= MAC_CFG_RX_ENB;
        CSR_WRITE_4(sc, ALE_MAC_CFG, reg);

        if ((if_getcapenable(ifp) & IFCAP_WOL) == 0) {
                /* WOL disabled, PHY power down. */
                reg = CSR_READ_4(sc, ALE_PCIE_PHYMISC);
                reg |= PCIE_PHYMISC_FORCE_RCV_DET;
                CSR_WRITE_4(sc, ALE_PCIE_PHYMISC, reg);
                CSR_WRITE_2(sc, ALE_GPHY_CTRL,
                    GPHY_CTRL_EXT_RESET | GPHY_CTRL_HIB_EN |
                    GPHY_CTRL_HIB_PULSE | GPHY_CTRL_SEL_ANA_RESET |
                    GPHY_CTRL_PHY_IDDQ | GPHY_CTRL_PCLK_SEL_DIS |
                    GPHY_CTRL_PWDOWN_HW);
        }
        /* Request PME. */
        pmstat = pci_read_config(sc->ale_dev, pmc + PCIR_POWER_STATUS, 2);
        pmstat &= ~(PCIM_PSTAT_PME | PCIM_PSTAT_PMEENABLE);
        if ((if_getcapenable(ifp) & IFCAP_WOL) != 0)
                pmstat |= PCIM_PSTAT_PME | PCIM_PSTAT_PMEENABLE;
        pci_write_config(sc->ale_dev, pmc + PCIR_POWER_STATUS, pmstat, 2);
}

static int
ale_suspend(device_t dev)
{
        struct ale_softc *sc;

        sc = device_get_softc(dev);

        ALE_LOCK(sc);
        ale_stop(sc);
        ale_setwol(sc);
        ALE_UNLOCK(sc);

        return (0);
}

static int
ale_resume(device_t dev)
{
        struct ale_softc *sc;
        if_t ifp;
        int pmc;
        uint16_t pmstat;

        sc = device_get_softc(dev);

        ALE_LOCK(sc);
        if (pci_find_cap(sc->ale_dev, PCIY_PMG, &pmc) == 0) {
                /* Disable PME and clear PME status. */
                pmstat = pci_read_config(sc->ale_dev,
                    pmc + PCIR_POWER_STATUS, 2);
                if ((pmstat & PCIM_PSTAT_PMEENABLE) != 0) {
                        pmstat &= ~PCIM_PSTAT_PMEENABLE;
                        pci_write_config(sc->ale_dev,
                            pmc + PCIR_POWER_STATUS, pmstat, 2);
                }
        }
        /* Reset PHY. */
        ale_phy_reset(sc);
        ifp = sc->ale_ifp;
        if ((if_getflags(ifp) & IFF_UP) != 0) {
                if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
                ale_init_locked(sc);
        }
        ALE_UNLOCK(sc);

        return (0);
}

static int
ale_encap(struct ale_softc *sc, struct mbuf **m_head)
{
        struct ale_txdesc *txd, *txd_last;
        struct tx_desc *desc;
        struct mbuf *m;
        struct ip *ip;
        struct tcphdr *tcp;
        bus_dma_segment_t txsegs[ALE_MAXTXSEGS];
        bus_dmamap_t map;
        uint32_t cflags, hdrlen, ip_off, poff, vtag;
        int error, i, nsegs, prod, si;

        ALE_LOCK_ASSERT(sc);

        M_ASSERTPKTHDR((*m_head));

        m = *m_head;
        ip = NULL;
        tcp = NULL;
        cflags = vtag = 0;
        ip_off = poff = 0;
        if ((m->m_pkthdr.csum_flags & (ALE_CSUM_FEATURES | CSUM_TSO)) != 0) {
                /*
                 * AR81xx requires offset of TCP/UDP payload in its Tx
                 * descriptor to perform hardware Tx checksum offload.
                 * Additionally, TSO requires IP/TCP header size and
                 * modification of IP/TCP header in order to make TSO
                 * engine work. This kind of operation takes many CPU
                 * cycles on FreeBSD so fast host CPU is required to
                 * get smooth TSO performance.
                 */
                struct ether_header *eh;

                if (M_WRITABLE(m) == 0) {
                        /* Get a writable copy. */
                        m = m_dup(*m_head, M_NOWAIT);
                        /* Release original mbufs. */
                        m_freem(*m_head);
                        if (m == NULL) {
                                *m_head = NULL;
                                return (ENOBUFS);
                        }
                        *m_head = m;
                }

                /*
                 * Buggy-controller requires 4 byte aligned Tx buffer
                 * to make custom checksum offload work.
                 */
                if ((sc->ale_flags & ALE_FLAG_TXCSUM_BUG) != 0 &&
                    (m->m_pkthdr.csum_flags & ALE_CSUM_FEATURES) != 0 &&
                    (mtod(m, intptr_t) & 3) != 0) {
                        m = m_defrag(*m_head, M_NOWAIT);
                        if (m == NULL) {
                                m_freem(*m_head);
                                *m_head = NULL;
                                return (ENOBUFS);
                        }
                        *m_head = m;
                }

                ip_off = sizeof(struct ether_header);
                m = m_pullup(m, ip_off);
                if (m == NULL) {
                        *m_head = NULL;
                        return (ENOBUFS);
                }
                eh = mtod(m, struct ether_header *);
                /*
                 * Check if hardware VLAN insertion is off.
                 * Additional check for LLC/SNAP frame?
                 */
                if (eh->ether_type == htons(ETHERTYPE_VLAN)) {
                        ip_off = sizeof(struct ether_vlan_header);
                        m = m_pullup(m, ip_off);
                        if (m == NULL) {
                                *m_head = NULL;
                                return (ENOBUFS);
                        }
                }
                m = m_pullup(m, ip_off + sizeof(struct ip));
                if (m == NULL) {
                        *m_head = NULL;
                        return (ENOBUFS);
                }
                ip = (struct ip *)(mtod(m, char *) + ip_off);
                poff = ip_off + (ip->ip_hl << 2);
                if ((m->m_pkthdr.csum_flags & CSUM_TSO) != 0) {
                        /*
                         * XXX
                         * AR81xx requires the first descriptor should
                         * not include any TCP playload for TSO case.
                         * (i.e. ethernet header + IP + TCP header only)
                         * m_pullup(9) above will ensure this too.
                         * However it's not correct if the first mbuf
                         * of the chain does not use cluster.
                         */
                        m = m_pullup(m, poff + sizeof(struct tcphdr));
                        if (m == NULL) {
                                *m_head = NULL;
                                return (ENOBUFS);
                        }
                        ip = (struct ip *)(mtod(m, char *) + ip_off);
                        tcp = (struct tcphdr *)(mtod(m, char *) + poff);
                        m = m_pullup(m, poff + (tcp->th_off << 2));
                        if (m == NULL) {
                                *m_head = NULL;
                                return (ENOBUFS);
                        }
                        /*
                         * AR81xx requires IP/TCP header size and offset as
                         * well as TCP pseudo checksum which complicates
                         * TSO configuration. I guess this comes from the
                         * adherence to Microsoft NDIS Large Send
                         * specification which requires insertion of
                         * pseudo checksum by upper stack. The pseudo
                         * checksum that NDIS refers to doesn't include
                         * TCP payload length so ale(4) should recompute
                         * the pseudo checksum here. Hopefully this wouldn't
                         * be much burden on modern CPUs.
                         * Reset IP checksum and recompute TCP pseudo
                         * checksum as NDIS specification said.
                         */
                        ip->ip_sum = 0;
                        tcp->th_sum = in_pseudo(ip->ip_src.s_addr,
                            ip->ip_dst.s_addr, htons(IPPROTO_TCP));
                }
                *m_head = m;
        }

        si = prod = sc->ale_cdata.ale_tx_prod;
        txd = &sc->ale_cdata.ale_txdesc[prod];
        txd_last = txd;
        map = txd->tx_dmamap;

        error =  bus_dmamap_load_mbuf_sg(sc->ale_cdata.ale_tx_tag, map,
            *m_head, txsegs, &nsegs, 0);
        if (error == EFBIG) {
                m = m_collapse(*m_head, M_NOWAIT, ALE_MAXTXSEGS);
                if (m == NULL) {
                        m_freem(*m_head);
                        *m_head = NULL;
                        return (ENOMEM);
                }
                *m_head = m;
                error = bus_dmamap_load_mbuf_sg(sc->ale_cdata.ale_tx_tag, map,
                    *m_head, txsegs, &nsegs, 0);
                if (error != 0) {
                        m_freem(*m_head);
                        *m_head = NULL;
                        return (error);
                }
        } else if (error != 0)
                return (error);
        if (nsegs == 0) {
                m_freem(*m_head);
                *m_head = NULL;
                return (EIO);
        }

        /* Check descriptor overrun. */
        if (sc->ale_cdata.ale_tx_cnt + nsegs >= ALE_TX_RING_CNT - 3) {
                bus_dmamap_unload(sc->ale_cdata.ale_tx_tag, map);
                return (ENOBUFS);
        }
        bus_dmamap_sync(sc->ale_cdata.ale_tx_tag, map, BUS_DMASYNC_PREWRITE);

        m = *m_head;
        if ((m->m_pkthdr.csum_flags & CSUM_TSO) != 0) {
                /* Request TSO and set MSS. */
                cflags |= ALE_TD_TSO;
                cflags |= ((uint32_t)m->m_pkthdr.tso_segsz << ALE_TD_MSS_SHIFT);
                /* Set IP/TCP header size. */
                cflags |= ip->ip_hl << ALE_TD_IPHDR_LEN_SHIFT;
                cflags |= tcp->th_off << ALE_TD_TCPHDR_LEN_SHIFT;
        } else if ((m->m_pkthdr.csum_flags & ALE_CSUM_FEATURES) != 0) {
                /*
                 * AR81xx supports Tx custom checksum offload feature
                 * that offloads single 16bit checksum computation.
                 * So you can choose one among IP, TCP and UDP.
                 * Normally driver sets checksum start/insertion
                 * position from the information of TCP/UDP frame as
                 * TCP/UDP checksum takes more time than that of IP.
                 * However it seems that custom checksum offload
                 * requires 4 bytes aligned Tx buffers due to hardware
                 * bug.
                 * AR81xx also supports explicit Tx checksum computation
                 * if it is told that the size of IP header and TCP
                 * header(for UDP, the header size does not matter
                 * because it's fixed length). However with this scheme
                 * TSO does not work so you have to choose one either
                 * TSO or explicit Tx checksum offload. I chosen TSO
                 * plus custom checksum offload with work-around which
                 * will cover most common usage for this consumer
                 * ethernet controller. The work-around takes a lot of
                 * CPU cycles if Tx buffer is not aligned on 4 bytes
                 * boundary, though.
                 */
                cflags |= ALE_TD_CXSUM;
                /* Set checksum start offset. */
                cflags |= (poff << ALE_TD_CSUM_PLOADOFFSET_SHIFT);
                /* Set checksum insertion position of TCP/UDP. */
                cflags |= ((poff + m->m_pkthdr.csum_data) <<
                    ALE_TD_CSUM_XSUMOFFSET_SHIFT);
        }

        /* Configure VLAN hardware tag insertion. */
        if ((m->m_flags & M_VLANTAG) != 0) {
                vtag = ALE_TX_VLAN_TAG(m->m_pkthdr.ether_vtag);
                vtag = ((vtag << ALE_TD_VLAN_SHIFT) & ALE_TD_VLAN_MASK);
                cflags |= ALE_TD_INSERT_VLAN_TAG;
        }

        i = 0;
        if ((m->m_pkthdr.csum_flags & CSUM_TSO) != 0) {
                /*
                 * Make sure the first fragment contains
                 * only ethernet and IP/TCP header with options.
                 */
                hdrlen =  poff + (tcp->th_off << 2);
                desc = &sc->ale_cdata.ale_tx_ring[prod];
                desc->addr = htole64(txsegs[i].ds_addr);
                desc->len = htole32(ALE_TX_BYTES(hdrlen) | vtag);
                desc->flags = htole32(cflags);
                sc->ale_cdata.ale_tx_cnt++;
                ALE_DESC_INC(prod, ALE_TX_RING_CNT);
                if (m->m_len - hdrlen > 0) {
                        /* Handle remaining payload of the first fragment. */
                        desc = &sc->ale_cdata.ale_tx_ring[prod];
                        desc->addr = htole64(txsegs[i].ds_addr + hdrlen);
                        desc->len = htole32(ALE_TX_BYTES(m->m_len - hdrlen) |
                            vtag);
                        desc->flags = htole32(cflags);
                        sc->ale_cdata.ale_tx_cnt++;
                        ALE_DESC_INC(prod, ALE_TX_RING_CNT);
                }
                i = 1;
        }
        for (; i < nsegs; i++) {
                desc = &sc->ale_cdata.ale_tx_ring[prod];
                desc->addr = htole64(txsegs[i].ds_addr);
                desc->len = htole32(ALE_TX_BYTES(txsegs[i].ds_len) | vtag);
                desc->flags = htole32(cflags);
                sc->ale_cdata.ale_tx_cnt++;
                ALE_DESC_INC(prod, ALE_TX_RING_CNT);
        }
        /* Update producer index. */
        sc->ale_cdata.ale_tx_prod = prod;
        /* Set TSO header on the first descriptor. */
        if ((m->m_pkthdr.csum_flags & CSUM_TSO) != 0) {
                desc = &sc->ale_cdata.ale_tx_ring[si];
                desc->flags |= htole32(ALE_TD_TSO_HDR);
        }

        /* Finally set EOP on the last descriptor. */
        prod = (prod + ALE_TX_RING_CNT - 1) % ALE_TX_RING_CNT;
        desc = &sc->ale_cdata.ale_tx_ring[prod];
        desc->flags |= htole32(ALE_TD_EOP);

        /* Swap dmamap of the first and the last. */
        txd = &sc->ale_cdata.ale_txdesc[prod];
        map = txd_last->tx_dmamap;
        txd_last->tx_dmamap = txd->tx_dmamap;
        txd->tx_dmamap = map;
        txd->tx_m = m;

        /* Sync descriptors. */
        bus_dmamap_sync(sc->ale_cdata.ale_tx_ring_tag,
            sc->ale_cdata.ale_tx_ring_map,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);

        return (0);
}

static void
ale_start(if_t ifp)
{
        struct ale_softc *sc;

        sc = if_getsoftc(ifp);
        ALE_LOCK(sc);
        ale_start_locked(ifp);
        ALE_UNLOCK(sc);
}

static void
ale_start_locked(if_t ifp)
{
        struct ale_softc *sc;
        struct mbuf *m_head;
        int enq;

        sc = if_getsoftc(ifp);

        ALE_LOCK_ASSERT(sc);

        /* Reclaim transmitted frames. */
        if (sc->ale_cdata.ale_tx_cnt >= ALE_TX_DESC_HIWAT)
                ale_txeof(sc);

        if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
            IFF_DRV_RUNNING || (sc->ale_flags & ALE_FLAG_LINK) == 0)
                return;

        for (enq = 0; !if_sendq_empty(ifp); ) {
                m_head = if_dequeue(ifp);
                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 (ale_encap(sc, &m_head)) {
                        if (m_head == NULL)
                                break;
                        if_sendq_prepend(ifp, m_head);
                        if_setdrvflagbits(ifp, IFF_DRV_OACTIVE, 0);
                        break;
                }

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

        if (enq > 0) {
                /* Kick. */
                CSR_WRITE_4(sc, ALE_MBOX_TPD_PROD_IDX,
                    sc->ale_cdata.ale_tx_prod);
                /* Set a timeout in case the chip goes out to lunch. */
                sc->ale_watchdog_timer = ALE_TX_TIMEOUT;
        }
}

static void
ale_watchdog(struct ale_softc *sc)
{
        if_t ifp;

        ALE_LOCK_ASSERT(sc);

        if (sc->ale_watchdog_timer == 0 || --sc->ale_watchdog_timer)
                return;

        ifp = sc->ale_ifp;
        if ((sc->ale_flags & ALE_FLAG_LINK) == 0) {
                if_printf(sc->ale_ifp, "watchdog timeout (lost link)\n");
                if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
                if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
                ale_init_locked(sc);
                return;
        }
        if_printf(sc->ale_ifp, "watchdog timeout -- resetting\n");
        if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
        if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
        ale_init_locked(sc);
        if (!if_sendq_empty(ifp))
                ale_start_locked(ifp);
}

static int
ale_ioctl(if_t ifp, u_long cmd, caddr_t data)
{
        struct ale_softc *sc;
        struct ifreq *ifr;
        struct mii_data *mii;
        int error, mask;

        sc = if_getsoftc(ifp);
        ifr = (struct ifreq *)data;
        error = 0;
        switch (cmd) {
        case SIOCSIFMTU:
                if (ifr->ifr_mtu < ETHERMIN || ifr->ifr_mtu > ALE_JUMBO_MTU ||
                    ((sc->ale_flags & ALE_FLAG_JUMBO) == 0 &&
                    ifr->ifr_mtu > ETHERMTU))
                        error = EINVAL;
                else if (if_getmtu(ifp) != ifr->ifr_mtu) {
                        ALE_LOCK(sc);
                        if_setmtu(ifp, ifr->ifr_mtu);
                        if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0) {
                                if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
                                ale_init_locked(sc);
                        }
                        ALE_UNLOCK(sc);
                }
                break;
        case SIOCSIFFLAGS:
                ALE_LOCK(sc);
                if ((if_getflags(ifp) & IFF_UP) != 0) {
                        if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0) {
                                if (((if_getflags(ifp) ^ sc->ale_if_flags)
                                    & (IFF_PROMISC | IFF_ALLMULTI)) != 0)
                                        ale_rxfilter(sc);
                        } else {
                                ale_init_locked(sc);
                        }
                } else {
                        if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0)
                                ale_stop(sc);
                }
                sc->ale_if_flags = if_getflags(ifp);
                ALE_UNLOCK(sc);
                break;
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                ALE_LOCK(sc);
                if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0)
                        ale_rxfilter(sc);
                ALE_UNLOCK(sc);
                break;
        case SIOCSIFMEDIA:
        case SIOCGIFMEDIA:
                mii = device_get_softc(sc->ale_miibus);
                error = ifmedia_ioctl(ifp, ifr, &mii->mii_media, cmd);
                break;
        case SIOCSIFCAP:
                ALE_LOCK(sc);
                mask = ifr->ifr_reqcap ^ if_getcapenable(ifp);
                if ((mask & IFCAP_TXCSUM) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_TXCSUM) != 0) {
                        if_togglecapenable(ifp, IFCAP_TXCSUM);
                        if ((if_getcapenable(ifp) & IFCAP_TXCSUM) != 0)
                                if_sethwassistbits(ifp, ALE_CSUM_FEATURES, 0);
                        else
                                if_sethwassistbits(ifp, 0, ALE_CSUM_FEATURES);
                }
                if ((mask & IFCAP_RXCSUM) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_RXCSUM) != 0)
                        if_togglecapenable(ifp, IFCAP_RXCSUM);
                if ((mask & IFCAP_TSO4) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_TSO4) != 0) {
                        if_togglecapenable(ifp, IFCAP_TSO4);
                        if ((if_getcapenable(ifp) & IFCAP_TSO4) != 0)
                                if_sethwassistbits(ifp, CSUM_TSO, 0);
                        else
                                if_sethwassistbits(ifp, 0, CSUM_TSO);
                }

                if ((mask & IFCAP_WOL_MCAST) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_WOL_MCAST) != 0)
                        if_togglecapenable(ifp, IFCAP_WOL_MCAST);
                if ((mask & IFCAP_WOL_MAGIC) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_WOL_MAGIC) != 0)
                        if_togglecapenable(ifp, IFCAP_WOL_MAGIC);
                if ((mask & IFCAP_VLAN_HWCSUM) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_VLAN_HWCSUM) != 0)
                        if_togglecapenable(ifp, IFCAP_VLAN_HWCSUM);
                if ((mask & IFCAP_VLAN_HWTSO) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_VLAN_HWTSO) != 0)
                        if_togglecapenable(ifp, IFCAP_VLAN_HWTSO);
                if ((mask & IFCAP_VLAN_HWTAGGING) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_VLAN_HWTAGGING) != 0) {
                        if_togglecapenable(ifp, IFCAP_VLAN_HWTAGGING);
                        if ((if_getcapenable(ifp) & IFCAP_VLAN_HWTAGGING) == 0)
                                if_setcapenablebit(ifp, 0, IFCAP_VLAN_HWTSO);
                        ale_rxvlan(sc);
                }
                ALE_UNLOCK(sc);
                VLAN_CAPABILITIES(ifp);
                break;
        default:
                error = ether_ioctl(ifp, cmd, data);
                break;
        }

        return (error);
}

static void
ale_mac_config(struct ale_softc *sc)
{
        struct mii_data *mii;
        uint32_t reg;

        ALE_LOCK_ASSERT(sc);

        mii = device_get_softc(sc->ale_miibus);
        reg = CSR_READ_4(sc, ALE_MAC_CFG);
        reg &= ~(MAC_CFG_FULL_DUPLEX | MAC_CFG_TX_FC | MAC_CFG_RX_FC |
            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, ALE_MAC_CFG, reg);
}

static void
ale_stats_clear(struct ale_softc *sc)
{
        struct smb sb;
        uint32_t *reg;
        int i;

        for (reg = &sb.rx_frames, i = 0; reg <= &sb.rx_pkts_filtered; reg++) {
                CSR_READ_4(sc, ALE_RX_MIB_BASE + i);
                i += sizeof(uint32_t);
        }
        /* Read Tx statistics. */
        for (reg = &sb.tx_frames, i = 0; reg <= &sb.tx_mcast_bytes; reg++) {
                CSR_READ_4(sc, ALE_TX_MIB_BASE + i);
                i += sizeof(uint32_t);
        }
}

static void
ale_stats_update(struct ale_softc *sc)
{
        struct ale_hw_stats *stat;
        struct smb sb, *smb;
        if_t ifp;
        uint32_t *reg;
        int i;

        ALE_LOCK_ASSERT(sc);

        ifp = sc->ale_ifp;
        stat = &sc->ale_stats;
        smb = &sb;

        /* Read Rx statistics. */
        for (reg = &sb.rx_frames, i = 0; reg <= &sb.rx_pkts_filtered; reg++) {
                *reg = CSR_READ_4(sc, ALE_RX_MIB_BASE + i);
                i += sizeof(uint32_t);
        }
        /* Read Tx statistics. */
        for (reg = &sb.tx_frames, i = 0; reg <= &sb.tx_mcast_bytes; reg++) {
                *reg = CSR_READ_4(sc, ALE_TX_MIB_BASE + i);
                i += sizeof(uint32_t);
        }

        /* 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_rrs_errs += smb->rx_rrs_errs;
        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. */
        if_inc_counter(ifp, IFCOUNTER_OPACKETS, smb->tx_frames);

        if_inc_counter(ifp, IFCOUNTER_COLLISIONS, smb->tx_single_colls +
            smb->tx_multi_colls * 2 + smb->tx_late_colls +
            smb->tx_excess_colls * HDPX_CFG_RETRY_DEFAULT);

        if_inc_counter(ifp, IFCOUNTER_OERRORS, smb->tx_late_colls +
            smb->tx_excess_colls + smb->tx_underrun + smb->tx_pkts_truncated);

        if_inc_counter(ifp, IFCOUNTER_IPACKETS, smb->rx_frames);

        if_inc_counter(ifp, IFCOUNTER_IERRORS,
            smb->rx_crcerrs + smb->rx_lenerrs +
            smb->rx_runts + smb->rx_pkts_truncated +
            smb->rx_fifo_oflows + smb->rx_rrs_errs +
            smb->rx_alignerrs);
}

static int
ale_intr(void *arg)
{
        struct ale_softc *sc;
        uint32_t status;

        sc = (struct ale_softc *)arg;

        status = CSR_READ_4(sc, ALE_INTR_STATUS);
        if ((status & ALE_INTRS) == 0)
                return (FILTER_STRAY);
        /* Disable interrupts. */
        CSR_WRITE_4(sc, ALE_INTR_STATUS, INTR_DIS_INT);
        taskqueue_enqueue(sc->ale_tq, &sc->ale_int_task);

        return (FILTER_HANDLED);
}

static void
ale_int_task(void *arg, int pending)
{
        struct ale_softc *sc;
        if_t ifp;
        uint32_t status;
        int more;

        sc = (struct ale_softc *)arg;

        status = CSR_READ_4(sc, ALE_INTR_STATUS);
        ALE_LOCK(sc);
        if (sc->ale_morework != 0)
                status |= INTR_RX_PKT;
        if ((status & ALE_INTRS) == 0)
                goto done;

        /* Acknowledge interrupts but still disable interrupts. */
        CSR_WRITE_4(sc, ALE_INTR_STATUS, status | INTR_DIS_INT);

        ifp = sc->ale_ifp;
        more = 0;
        if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0) {
                more = ale_rxeof(sc, sc->ale_process_limit);
                if (more == EAGAIN)
                        sc->ale_morework = 1;
                else if (more == EIO) {
                        sc->ale_stats.reset_brk_seq++;
                        if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
                        ale_init_locked(sc);
                        ALE_UNLOCK(sc);
                        return;
                }

                if ((status & (INTR_DMA_RD_TO_RST | INTR_DMA_WR_TO_RST)) != 0) {
                        if ((status & INTR_DMA_RD_TO_RST) != 0)
                                device_printf(sc->ale_dev,
                                    "DMA read error! -- resetting\n");
                        if ((status & INTR_DMA_WR_TO_RST) != 0)
                                device_printf(sc->ale_dev,
                                    "DMA write error! -- resetting\n");
                        if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
                        ale_init_locked(sc);
                        ALE_UNLOCK(sc);
                        return;
                }
                if (!if_sendq_empty(ifp))
                        ale_start_locked(ifp);
        }

        if (more == EAGAIN ||
            (CSR_READ_4(sc, ALE_INTR_STATUS) & ALE_INTRS) != 0) {
                ALE_UNLOCK(sc);
                taskqueue_enqueue(sc->ale_tq, &sc->ale_int_task);
                return;
        }

done:
        ALE_UNLOCK(sc);

        /* Re-enable interrupts. */
        CSR_WRITE_4(sc, ALE_INTR_STATUS, 0x7FFFFFFF);
}

static void
ale_txeof(struct ale_softc *sc)
{
        if_t ifp;
        struct ale_txdesc *txd;
        uint32_t cons, prod;
        int prog;

        ALE_LOCK_ASSERT(sc);

        ifp = sc->ale_ifp;

        if (sc->ale_cdata.ale_tx_cnt == 0)
                return;

        bus_dmamap_sync(sc->ale_cdata.ale_tx_ring_tag,
            sc->ale_cdata.ale_tx_ring_map,
            BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
        if ((sc->ale_flags & ALE_FLAG_TXCMB_BUG) == 0) {
                bus_dmamap_sync(sc->ale_cdata.ale_tx_cmb_tag,
                    sc->ale_cdata.ale_tx_cmb_map,
                    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
                prod = *sc->ale_cdata.ale_tx_cmb & TPD_CNT_MASK;
        } else
                prod = CSR_READ_2(sc, ALE_TPD_CONS_IDX);
        cons = sc->ale_cdata.ale_tx_cons;
        /*
         * Go through our Tx list and free mbufs for those
         * frames which have been transmitted.
         */
        for (prog = 0; cons != prod; prog++,
            ALE_DESC_INC(cons, ALE_TX_RING_CNT)) {
                if (sc->ale_cdata.ale_tx_cnt <= 0)
                        break;
                prog++;
                if_setdrvflagbits(ifp, 0, IFF_DRV_OACTIVE);
                sc->ale_cdata.ale_tx_cnt--;
                txd = &sc->ale_cdata.ale_txdesc[cons];
                if (txd->tx_m != NULL) {
                        /* Reclaim transmitted mbufs. */
                        bus_dmamap_sync(sc->ale_cdata.ale_tx_tag,
                            txd->tx_dmamap, BUS_DMASYNC_POSTWRITE);
                        bus_dmamap_unload(sc->ale_cdata.ale_tx_tag,
                            txd->tx_dmamap);
                        m_freem(txd->tx_m);
                        txd->tx_m = NULL;
                }
        }

        if (prog > 0) {
                sc->ale_cdata.ale_tx_cons = cons;
                /*
                 * Unarm watchdog timer only when there is no pending
                 * Tx descriptors in queue.
                 */
                if (sc->ale_cdata.ale_tx_cnt == 0)
                        sc->ale_watchdog_timer = 0;
        }
}

static void
ale_rx_update_page(struct ale_softc *sc, struct ale_rx_page **page,
    uint32_t length, uint32_t *prod)
{
        struct ale_rx_page *rx_page;

        rx_page = *page;
        /* Update consumer position. */
        rx_page->cons += roundup(length + sizeof(struct rx_rs),
            ALE_RX_PAGE_ALIGN);
        if (rx_page->cons >= ALE_RX_PAGE_SZ) {
                /*
                 * End of Rx page reached, let hardware reuse
                 * this page.
                 */
                rx_page->cons = 0;
                *rx_page->cmb_addr = 0;
                bus_dmamap_sync(rx_page->cmb_tag, rx_page->cmb_map,
                    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
                CSR_WRITE_1(sc, ALE_RXF0_PAGE0 + sc->ale_cdata.ale_rx_curp,
                    RXF_VALID);
                /* Switch to alternate Rx page. */
                sc->ale_cdata.ale_rx_curp ^= 1;
                rx_page = *page =
                    &sc->ale_cdata.ale_rx_page[sc->ale_cdata.ale_rx_curp];
                /* Page flipped, sync CMB and Rx page. */
                bus_dmamap_sync(rx_page->page_tag, rx_page->page_map,
                    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
                bus_dmamap_sync(rx_page->cmb_tag, rx_page->cmb_map,
                    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
                /* Sync completed, cache updated producer index. */
                *prod = *rx_page->cmb_addr;
        }
}

/*
 * It seems that AR81xx 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.
 * In addition, the Rx feature of controller that requires copying
 * for every frames effectively nullifies one of most nice offload
 * capability of controller.
 */
static void
ale_rxcsum(struct ale_softc *sc, struct mbuf *m, uint32_t status)
{
        if_t ifp;
        struct ip *ip;
        char *p;

        ifp = sc->ale_ifp;
        m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED;
        if ((status & ALE_RD_IPCSUM_NOK) == 0)
                m->m_pkthdr.csum_flags |= CSUM_IP_VALID;

        if ((sc->ale_flags & ALE_FLAG_RXCSUM_BUG) == 0) {
                if (((status & ALE_RD_IPV4_FRAG) == 0) &&
                    ((status & (ALE_RD_TCP | ALE_RD_UDP)) != 0) &&
                    ((status & ALE_RD_TCP_UDPCSUM_NOK) == 0)) {
                        m->m_pkthdr.csum_flags |=
                            CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
                        m->m_pkthdr.csum_data = 0xffff;
                }
        } else {
                if ((status & (ALE_RD_TCP | ALE_RD_UDP)) != 0 &&
                    (status & ALE_RD_TCP_UDPCSUM_NOK) == 0) {
                        p = mtod(m, char *);
                        p += ETHER_HDR_LEN;
                        if ((status & ALE_RD_802_3) != 0)
                                p += LLC_SNAPFRAMELEN;
                        if ((if_getcapenable(ifp) & IFCAP_VLAN_HWTAGGING) == 0 &&
                            (status & ALE_RD_VLAN) != 0)
                                p += ETHER_VLAN_ENCAP_LEN;
                        ip = (struct ip *)p;
                        if (ip->ip_off != 0 && (status & ALE_RD_IPV4_DF) == 0)
                                return;
                        m->m_pkthdr.csum_flags |= CSUM_DATA_VALID |
                            CSUM_PSEUDO_HDR;
                        m->m_pkthdr.csum_data = 0xffff;
                }
        }
        /*
         * Don't mark bad checksum for TCP/UDP frames
         * as fragmented frames may always have set
         * bad checksummed bit of frame status.
         */
}

/* Process received frames. */
static int
ale_rxeof(struct ale_softc *sc, int count)
{
        struct ale_rx_page *rx_page;
        struct rx_rs *rs;
        if_t ifp;
        struct mbuf *m;
        uint32_t length, prod, seqno, status, vtags;
        int prog;

        ifp = sc->ale_ifp;
        rx_page = &sc->ale_cdata.ale_rx_page[sc->ale_cdata.ale_rx_curp];
        bus_dmamap_sync(rx_page->cmb_tag, rx_page->cmb_map,
            BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
        bus_dmamap_sync(rx_page->page_tag, rx_page->page_map,
            BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
        /*
         * Don't directly access producer index as hardware may
         * update it while Rx handler is in progress. It would
         * be even better if there is a way to let hardware
         * know how far driver processed its received frames.
         * Alternatively, hardware could provide a way to disable
         * CMB updates until driver acknowledges the end of CMB
         * access.
         */
        prod = *rx_page->cmb_addr;
        for (prog = 0; prog < count; prog++) {
                if (rx_page->cons >= prod)
                        break;
                rs = (struct rx_rs *)(rx_page->page_addr + rx_page->cons);
                seqno = ALE_RX_SEQNO(le32toh(rs->seqno));
                if (sc->ale_cdata.ale_rx_seqno != seqno) {
                        /*
                         * Normally I believe this should not happen unless
                         * severe driver bug or corrupted memory. However
                         * it seems to happen under certain conditions which
                         * is triggered by abrupt Rx events such as initiation
                         * of bulk transfer of remote host. It's not easy to
                         * reproduce this and I doubt it could be related
                         * with FIFO overflow of hardware or activity of Tx
                         * CMB updates. I also remember similar behaviour
                         * seen on RealTek 8139 which uses resembling Rx
                         * scheme.
                         */
                        if (bootverbose)
                                device_printf(sc->ale_dev,
                                    "garbled seq: %u, expected: %u -- "
                                    "resetting!\n", seqno,
                                    sc->ale_cdata.ale_rx_seqno);
                        return (EIO);
                }
                /* Frame received. */
                sc->ale_cdata.ale_rx_seqno++;
                length = ALE_RX_BYTES(le32toh(rs->length));
                status = le32toh(rs->flags);
                if ((status & ALE_RD_ERROR) != 0) {
                        /*
                         * We want to pass the following frames to upper
                         * layer regardless of error status of Rx return
                         * status.
                         *
                         *  o IP/TCP/UDP checksum is bad.
                         *  o frame length and protocol specific length
                         *     does not match.
                         */
                        if ((status & (ALE_RD_CRC | ALE_RD_CODE |
                            ALE_RD_DRIBBLE | ALE_RD_RUNT | ALE_RD_OFLOW |
                            ALE_RD_TRUNC)) != 0) {
                                ale_rx_update_page(sc, &rx_page, length, &prod);
                                continue;
                        }
                }
                /*
                 * m_devget(9) is major bottle-neck of ale(4)(It comes
                 * from hardware limitation). For jumbo frames we could
                 * get a slightly better performance if driver use
                 * m_getjcl(9) with proper buffer size argument. However
                 * that would make code more complicated and I don't
                 * think users would expect good Rx performance numbers
                 * on these low-end consumer ethernet controller.
                 */
                m = m_devget((char *)(rs + 1), length - ETHER_CRC_LEN,
                    ETHER_ALIGN, ifp, NULL);
                if (m == NULL) {
                        if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
                        ale_rx_update_page(sc, &rx_page, length, &prod);
                        continue;
                }
                if ((if_getcapenable(ifp) & IFCAP_RXCSUM) != 0 &&
                    (status & ALE_RD_IPV4) != 0)
                        ale_rxcsum(sc, m, status);
                if ((if_getcapenable(ifp) & IFCAP_VLAN_HWTAGGING) != 0 &&
                    (status & ALE_RD_VLAN) != 0) {
                        vtags = ALE_RX_VLAN(le32toh(rs->vtags));
                        m->m_pkthdr.ether_vtag = ALE_RX_VLAN_TAG(vtags);
                        m->m_flags |= M_VLANTAG;
                }

                /* Pass it to upper layer. */
                ALE_UNLOCK(sc);
                if_input(ifp, m);
                ALE_LOCK(sc);

                ale_rx_update_page(sc, &rx_page, length, &prod);
        }

        return (count > 0 ? 0 : EAGAIN);
}

static void
ale_tick(void *arg)
{
        struct ale_softc *sc;
        struct mii_data *mii;

        sc = (struct ale_softc *)arg;

        ALE_LOCK_ASSERT(sc);

        mii = device_get_softc(sc->ale_miibus);
        mii_tick(mii);
        ale_stats_update(sc);
        /*
         * Reclaim Tx buffers that have been transferred. It's not
         * needed here but it would release allocated mbuf chains
         * faster and limit the maximum delay to a hz.
         */
        ale_txeof(sc);
        ale_watchdog(sc);
        callout_reset(&sc->ale_tick_ch, hz, ale_tick, sc);
}

static void
ale_reset(struct ale_softc *sc)
{
        uint32_t reg;
        int i;

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

        CSR_WRITE_4(sc, ALE_MASTER_CFG, MASTER_RESET);
        for (i = ALE_RESET_TIMEOUT; i > 0; i--) {
                DELAY(10);
                if ((CSR_READ_4(sc, ALE_MASTER_CFG) & MASTER_RESET) == 0)
                        break;
        }
        if (i == 0)
                device_printf(sc->ale_dev, "master reset timeout!\n");

        for (i = ALE_RESET_TIMEOUT; i > 0; i--) {
                if ((reg = CSR_READ_4(sc, ALE_IDLE_STATUS)) == 0)
                        break;
                DELAY(10);
        }

        if (i == 0)
                device_printf(sc->ale_dev, "reset timeout(0x%08x)!\n", reg);
}

static void
ale_init(void *xsc)
{
        struct ale_softc *sc;

        sc = (struct ale_softc *)xsc;
        ALE_LOCK(sc);
        ale_init_locked(sc);
        ALE_UNLOCK(sc);
}

static void
ale_init_locked(struct ale_softc *sc)
{
        if_t ifp;
        struct mii_data *mii;
        uint8_t eaddr[ETHER_ADDR_LEN];
        bus_addr_t paddr;
        uint32_t reg, rxf_hi, rxf_lo;

        ALE_LOCK_ASSERT(sc);

        ifp = sc->ale_ifp;
        mii = device_get_softc(sc->ale_miibus);

        if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0)
                return;
        /*
         * Cancel any pending I/O.
         */
        ale_stop(sc);
        /*
         * Reset the chip to a known state.
         */
        ale_reset(sc);
        /* Initialize Tx descriptors, DMA memory blocks. */
        ale_init_rx_pages(sc);
        ale_init_tx_ring(sc);

        /* Reprogram the station address. */
        bcopy(if_getlladdr(ifp), eaddr, ETHER_ADDR_LEN);
        CSR_WRITE_4(sc, ALE_PAR0,
            eaddr[2] << 24 | eaddr[3] << 16 | eaddr[4] << 8 | eaddr[5]);
        CSR_WRITE_4(sc, ALE_PAR1, eaddr[0] << 8 | eaddr[1]);
        /*
         * Clear WOL status and disable all WOL feature as WOL
         * would interfere Rx operation under normal environments.
         */
        CSR_READ_4(sc, ALE_WOL_CFG);
        CSR_WRITE_4(sc, ALE_WOL_CFG, 0);
        /*
         * Set Tx descriptor/RXF0/CMB base addresses. They share
         * the same high address part of DMAable region.
         */
        paddr = sc->ale_cdata.ale_tx_ring_paddr;
        CSR_WRITE_4(sc, ALE_TPD_ADDR_HI, ALE_ADDR_HI(paddr));
        CSR_WRITE_4(sc, ALE_TPD_ADDR_LO, ALE_ADDR_LO(paddr));
        CSR_WRITE_4(sc, ALE_TPD_CNT,
            (ALE_TX_RING_CNT << TPD_CNT_SHIFT) & TPD_CNT_MASK);
        /* Set Rx page base address, note we use single queue. */
        paddr = sc->ale_cdata.ale_rx_page[0].page_paddr;
        CSR_WRITE_4(sc, ALE_RXF0_PAGE0_ADDR_LO, ALE_ADDR_LO(paddr));
        paddr = sc->ale_cdata.ale_rx_page[1].page_paddr;
        CSR_WRITE_4(sc, ALE_RXF0_PAGE1_ADDR_LO, ALE_ADDR_LO(paddr));
        /* Set Tx/Rx CMB addresses. */
        paddr = sc->ale_cdata.ale_tx_cmb_paddr;
        CSR_WRITE_4(sc, ALE_TX_CMB_ADDR_LO, ALE_ADDR_LO(paddr));
        paddr = sc->ale_cdata.ale_rx_page[0].cmb_paddr;
        CSR_WRITE_4(sc, ALE_RXF0_CMB0_ADDR_LO, ALE_ADDR_LO(paddr));
        paddr = sc->ale_cdata.ale_rx_page[1].cmb_paddr;
        CSR_WRITE_4(sc, ALE_RXF0_CMB1_ADDR_LO, ALE_ADDR_LO(paddr));
        /* Mark RXF0 is valid. */
        CSR_WRITE_1(sc, ALE_RXF0_PAGE0, RXF_VALID);
        CSR_WRITE_1(sc, ALE_RXF0_PAGE1, RXF_VALID);
        /*
         * No need to initialize RFX1/RXF2/RXF3. We don't use
         * multi-queue yet.
         */

        /* Set Rx page size, excluding guard frame size. */
        CSR_WRITE_4(sc, ALE_RXF_PAGE_SIZE, ALE_RX_PAGE_SZ);
        /* Tell hardware that we're ready to load DMA blocks. */
        CSR_WRITE_4(sc, ALE_DMA_BLOCK, DMA_BLOCK_LOAD);

        /* Set Rx/Tx interrupt trigger threshold. */
        CSR_WRITE_4(sc, ALE_INT_TRIG_THRESH, (1 << INT_TRIG_RX_THRESH_SHIFT) |
            (4 << INT_TRIG_TX_THRESH_SHIFT));
        /*
         * XXX
         * Set interrupt trigger timer, its purpose and relation
         * with interrupt moderation mechanism is not clear yet.
         */
        CSR_WRITE_4(sc, ALE_INT_TRIG_TIMER,
            ((ALE_USECS(10) << INT_TRIG_RX_TIMER_SHIFT) |
            (ALE_USECS(1000) << INT_TRIG_TX_TIMER_SHIFT)));

        /* Configure interrupt moderation timer. */
        reg = ALE_USECS(sc->ale_int_rx_mod) << IM_TIMER_RX_SHIFT;
        reg |= ALE_USECS(sc->ale_int_tx_mod) << IM_TIMER_TX_SHIFT;
        CSR_WRITE_4(sc, ALE_IM_TIMER, reg);
        reg = CSR_READ_4(sc, ALE_MASTER_CFG);
        reg &= ~(MASTER_CHIP_REV_MASK | MASTER_CHIP_ID_MASK);
        reg &= ~(MASTER_IM_RX_TIMER_ENB | MASTER_IM_TX_TIMER_ENB);
        if (ALE_USECS(sc->ale_int_rx_mod) != 0)
                reg |= MASTER_IM_RX_TIMER_ENB;
        if (ALE_USECS(sc->ale_int_tx_mod) != 0)
                reg |= MASTER_IM_TX_TIMER_ENB;
        CSR_WRITE_4(sc, ALE_MASTER_CFG, reg);
        CSR_WRITE_2(sc, ALE_INTR_CLR_TIMER, ALE_USECS(1000));

        /* Set Maximum frame size of controller. */
        if (if_getmtu(ifp) < ETHERMTU)
                sc->ale_max_frame_size = ETHERMTU;
        else
                sc->ale_max_frame_size = if_getmtu(ifp);
        sc->ale_max_frame_size += ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN +
            ETHER_CRC_LEN;
        CSR_WRITE_4(sc, ALE_FRAME_SIZE, sc->ale_max_frame_size);
        /* Configure IPG/IFG parameters. */
        CSR_WRITE_4(sc, ALE_IPG_IFG_CFG,
            ((IPG_IFG_IPGT_DEFAULT << IPG_IFG_IPGT_SHIFT) & IPG_IFG_IPGT_MASK) |
            ((IPG_IFG_MIFG_DEFAULT << IPG_IFG_MIFG_SHIFT) & IPG_IFG_MIFG_MASK) |
            ((IPG_IFG_IPG1_DEFAULT << IPG_IFG_IPG1_SHIFT) & IPG_IFG_IPG1_MASK) |
            ((IPG_IFG_IPG2_DEFAULT << IPG_IFG_IPG2_SHIFT) & IPG_IFG_IPG2_MASK));
        /* Set parameters for half-duplex media. */
        CSR_WRITE_4(sc, ALE_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 Tx jumbo frame parameters. */
        if ((sc->ale_flags & ALE_FLAG_JUMBO) != 0) {
                if (if_getmtu(ifp) < ETHERMTU)
                        reg = sc->ale_max_frame_size;
                else if (if_getmtu(ifp) < 6 * 1024)
                        reg = (sc->ale_max_frame_size * 2) / 3;
                else
                        reg = sc->ale_max_frame_size / 2;
                CSR_WRITE_4(sc, ALE_TX_JUMBO_THRESH,
                    roundup(reg, TX_JUMBO_THRESH_UNIT) >>
                    TX_JUMBO_THRESH_UNIT_SHIFT);
        }
        /* Configure TxQ. */
        reg = (128 << (sc->ale_dma_rd_burst >> DMA_CFG_RD_BURST_SHIFT))
            << TXQ_CFG_TX_FIFO_BURST_SHIFT;
        reg |= (TXQ_CFG_TPD_BURST_DEFAULT << TXQ_CFG_TPD_BURST_SHIFT) &
            TXQ_CFG_TPD_BURST_MASK;
        CSR_WRITE_4(sc, ALE_TXQ_CFG, reg | TXQ_CFG_ENHANCED_MODE | TXQ_CFG_ENB);

        /* Configure Rx jumbo frame & flow control parameters. */
        if ((sc->ale_flags & ALE_FLAG_JUMBO) != 0) {
                reg = roundup(sc->ale_max_frame_size, RX_JUMBO_THRESH_UNIT);
                CSR_WRITE_4(sc, ALE_RX_JUMBO_THRESH,
                    (((reg >> RX_JUMBO_THRESH_UNIT_SHIFT) <<
                    RX_JUMBO_THRESH_MASK_SHIFT) & RX_JUMBO_THRESH_MASK) |
                    ((RX_JUMBO_LKAH_DEFAULT << RX_JUMBO_LKAH_SHIFT) &
                    RX_JUMBO_LKAH_MASK));
                reg = CSR_READ_4(sc, ALE_SRAM_RX_FIFO_LEN);
                rxf_hi = (reg * 7) / 10;
                rxf_lo = (reg * 3)/ 10;
                CSR_WRITE_4(sc, ALE_RX_FIFO_PAUSE_THRESH,
                    ((rxf_lo << RX_FIFO_PAUSE_THRESH_LO_SHIFT) &
                    RX_FIFO_PAUSE_THRESH_LO_MASK) |
                    ((rxf_hi << RX_FIFO_PAUSE_THRESH_HI_SHIFT) &
                    RX_FIFO_PAUSE_THRESH_HI_MASK));
        }

        /* Disable RSS. */
        CSR_WRITE_4(sc, ALE_RSS_IDT_TABLE0, 0);
        CSR_WRITE_4(sc, ALE_RSS_CPU, 0);

        /* Configure RxQ. */
        CSR_WRITE_4(sc, ALE_RXQ_CFG,
            RXQ_CFG_ALIGN_32 | RXQ_CFG_CUT_THROUGH_ENB | RXQ_CFG_ENB);

        /* Configure DMA parameters. */
        reg = 0;
        if ((sc->ale_flags & ALE_FLAG_TXCMB_BUG) == 0)
                reg |= DMA_CFG_TXCMB_ENB;
        CSR_WRITE_4(sc, ALE_DMA_CFG,
            DMA_CFG_OUT_ORDER | DMA_CFG_RD_REQ_PRI | DMA_CFG_RCB_64 |
            sc->ale_dma_rd_burst | reg |
            sc->ale_dma_wr_burst | DMA_CFG_RXCMB_ENB |
            ((DMA_CFG_RD_DELAY_CNT_DEFAULT << DMA_CFG_RD_DELAY_CNT_SHIFT) &
            DMA_CFG_RD_DELAY_CNT_MASK) |
            ((DMA_CFG_WR_DELAY_CNT_DEFAULT << DMA_CFG_WR_DELAY_CNT_SHIFT) &
            DMA_CFG_WR_DELAY_CNT_MASK));

        /*
         * Hardware can be configured to issue SMB interrupt based
         * on programmed interval. Since there is a callout that is
         * invoked for every hz in driver we use that instead of
         * relying on periodic SMB interrupt.
         */
        CSR_WRITE_4(sc, ALE_SMB_STAT_TIMER, ALE_USECS(0));
        /* Clear MAC statistics. */
        ale_stats_clear(sc);

        /*
         * Configure Tx/Rx MACs.
         *  - Auto-padding for short frames.
         *  - Enable CRC generation.
         *  Actual reconfiguration of MAC for resolved speed/duplex
         *  is followed after detection of link establishment.
         *  AR81xx always does checksum computation regardless of
         *  MAC_CFG_RXCSUM_ENB bit. In fact, setting the bit will
         *  cause Rx handling issue for fragmented IP datagrams due
         *  to silicon bug.
         */
        reg = MAC_CFG_TX_CRC_ENB | MAC_CFG_TX_AUTO_PAD | MAC_CFG_FULL_DUPLEX |
            ((MAC_CFG_PREAMBLE_DEFAULT << MAC_CFG_PREAMBLE_SHIFT) &
            MAC_CFG_PREAMBLE_MASK);
        if ((sc->ale_flags & ALE_FLAG_FASTETHER) != 0)
                reg |= MAC_CFG_SPEED_10_100;
        else
                reg |= MAC_CFG_SPEED_1000;
        CSR_WRITE_4(sc, ALE_MAC_CFG, reg);

        /* Set up the receive filter. */
        ale_rxfilter(sc);
        ale_rxvlan(sc);

        /* Acknowledge all pending interrupts and clear it. */
        CSR_WRITE_4(sc, ALE_INTR_MASK, ALE_INTRS);
        CSR_WRITE_4(sc, ALE_INTR_STATUS, 0xFFFFFFFF);
        CSR_WRITE_4(sc, ALE_INTR_STATUS, 0);

        if_setdrvflagbits(ifp, IFF_DRV_RUNNING, 0);
        if_setdrvflagbits(ifp, 0, IFF_DRV_OACTIVE);

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

        callout_reset(&sc->ale_tick_ch, hz, ale_tick, sc);
}

static void
ale_stop(struct ale_softc *sc)
{
        if_t ifp;
        struct ale_txdesc *txd;
        uint32_t reg;
        int i;

        ALE_LOCK_ASSERT(sc);
        /*
         * Mark the interface down and cancel the watchdog timer.
         */
        ifp = sc->ale_ifp;
        if_setdrvflagbits(ifp, 0, (IFF_DRV_RUNNING | IFF_DRV_OACTIVE));
        sc->ale_flags &= ~ALE_FLAG_LINK;
        callout_stop(&sc->ale_tick_ch);
        sc->ale_watchdog_timer = 0;
        ale_stats_update(sc);
        /* Disable interrupts. */
        CSR_WRITE_4(sc, ALE_INTR_MASK, 0);
        CSR_WRITE_4(sc, ALE_INTR_STATUS, 0xFFFFFFFF);
        /* Disable queue processing and DMA. */
        reg = CSR_READ_4(sc, ALE_TXQ_CFG);
        reg &= ~TXQ_CFG_ENB;
        CSR_WRITE_4(sc, ALE_TXQ_CFG, reg);
        reg = CSR_READ_4(sc, ALE_RXQ_CFG);
        reg &= ~RXQ_CFG_ENB;
        CSR_WRITE_4(sc, ALE_RXQ_CFG, reg);
        reg = CSR_READ_4(sc, ALE_DMA_CFG);
        reg &= ~(DMA_CFG_TXCMB_ENB | DMA_CFG_RXCMB_ENB);
        CSR_WRITE_4(sc, ALE_DMA_CFG, reg);
        DELAY(1000);
        /* Stop Rx/Tx MACs. */
        ale_stop_mac(sc);
        /* Disable interrupts which might be touched in taskq handler. */
        CSR_WRITE_4(sc, ALE_INTR_STATUS, 0xFFFFFFFF);

        /*
         * Free TX mbufs still in the queues.
         */
        for (i = 0; i < ALE_TX_RING_CNT; i++) {
                txd = &sc->ale_cdata.ale_txdesc[i];
                if (txd->tx_m != NULL) {
                        bus_dmamap_sync(sc->ale_cdata.ale_tx_tag,
                            txd->tx_dmamap, BUS_DMASYNC_POSTWRITE);
                        bus_dmamap_unload(sc->ale_cdata.ale_tx_tag,
                            txd->tx_dmamap);
                        m_freem(txd->tx_m);
                        txd->tx_m = NULL;
                }
        }
}

static void
ale_stop_mac(struct ale_softc *sc)
{
        uint32_t reg;
        int i;

        ALE_LOCK_ASSERT(sc);

        reg = CSR_READ_4(sc, ALE_MAC_CFG);
        if ((reg & (MAC_CFG_TX_ENB | MAC_CFG_RX_ENB)) != 0) {
                reg &= ~(MAC_CFG_TX_ENB | MAC_CFG_RX_ENB);
                CSR_WRITE_4(sc, ALE_MAC_CFG, reg);
        }

        for (i = ALE_TIMEOUT; i > 0; i--) {
                reg = CSR_READ_4(sc, ALE_IDLE_STATUS);
                if (reg == 0)
                        break;
                DELAY(10);
        }
        if (i == 0)
                device_printf(sc->ale_dev,
                    "could not disable Tx/Rx MAC(0x%08x)!\n", reg);
}

static void
ale_init_tx_ring(struct ale_softc *sc)
{
        struct ale_txdesc *txd;
        int i;

        ALE_LOCK_ASSERT(sc);

        sc->ale_cdata.ale_tx_prod = 0;
        sc->ale_cdata.ale_tx_cons = 0;
        sc->ale_cdata.ale_tx_cnt = 0;

        bzero(sc->ale_cdata.ale_tx_ring, ALE_TX_RING_SZ);
        bzero(sc->ale_cdata.ale_tx_cmb, ALE_TX_CMB_SZ);
        for (i = 0; i < ALE_TX_RING_CNT; i++) {
                txd = &sc->ale_cdata.ale_txdesc[i];
                txd->tx_m = NULL;
        }
        *sc->ale_cdata.ale_tx_cmb = 0;
        bus_dmamap_sync(sc->ale_cdata.ale_tx_cmb_tag,
            sc->ale_cdata.ale_tx_cmb_map,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        bus_dmamap_sync(sc->ale_cdata.ale_tx_ring_tag,
            sc->ale_cdata.ale_tx_ring_map,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
}

static void
ale_init_rx_pages(struct ale_softc *sc)
{
        struct ale_rx_page *rx_page;
        int i;

        ALE_LOCK_ASSERT(sc);

        sc->ale_morework = 0;
        sc->ale_cdata.ale_rx_seqno = 0;
        sc->ale_cdata.ale_rx_curp = 0;

        for (i = 0; i < ALE_RX_PAGES; i++) {
                rx_page = &sc->ale_cdata.ale_rx_page[i];
                bzero(rx_page->page_addr, sc->ale_pagesize);
                bzero(rx_page->cmb_addr, ALE_RX_CMB_SZ);
                rx_page->cons = 0;
                *rx_page->cmb_addr = 0;
                bus_dmamap_sync(rx_page->page_tag, rx_page->page_map,
                    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
                bus_dmamap_sync(rx_page->cmb_tag, rx_page->cmb_map,
                    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        }
}

static void
ale_rxvlan(struct ale_softc *sc)
{
        if_t ifp;
        uint32_t reg;

        ALE_LOCK_ASSERT(sc);

        ifp = sc->ale_ifp;
        reg = CSR_READ_4(sc, ALE_MAC_CFG);
        reg &= ~MAC_CFG_VLAN_TAG_STRIP;
        if ((if_getcapenable(ifp) & IFCAP_VLAN_HWTAGGING) != 0)
                reg |= MAC_CFG_VLAN_TAG_STRIP;
        CSR_WRITE_4(sc, ALE_MAC_CFG, reg);
}

static u_int
ale_hash_maddr(void *arg, struct sockaddr_dl *sdl, u_int cnt)
{
        uint32_t crc, *mchash = arg;

        crc = ether_crc32_be(LLADDR(sdl), ETHER_ADDR_LEN);
        mchash[crc >> 31] |= 1 << ((crc >> 26) & 0x1f);

        return (1);
}

static void
ale_rxfilter(struct ale_softc *sc)
{
        if_t ifp;
        uint32_t mchash[2];
        uint32_t rxcfg;

        ALE_LOCK_ASSERT(sc);

        ifp = sc->ale_ifp;

        rxcfg = CSR_READ_4(sc, ALE_MAC_CFG);
        rxcfg &= ~(MAC_CFG_ALLMULTI | MAC_CFG_BCAST | MAC_CFG_PROMISC);
        if ((if_getflags(ifp) & IFF_BROADCAST) != 0)
                rxcfg |= MAC_CFG_BCAST;
        if ((if_getflags(ifp) & (IFF_PROMISC | IFF_ALLMULTI)) != 0) {
                if ((if_getflags(ifp) & IFF_PROMISC) != 0)
                        rxcfg |= MAC_CFG_PROMISC;
                if ((if_getflags(ifp) & IFF_ALLMULTI) != 0)
                        rxcfg |= MAC_CFG_ALLMULTI;
                CSR_WRITE_4(sc, ALE_MAR0, 0xFFFFFFFF);
                CSR_WRITE_4(sc, ALE_MAR1, 0xFFFFFFFF);
                CSR_WRITE_4(sc, ALE_MAC_CFG, rxcfg);
                return;
        }

        /* Program new filter. */
        bzero(mchash, sizeof(mchash));
        if_foreach_llmaddr(ifp, ale_hash_maddr, &mchash);

        CSR_WRITE_4(sc, ALE_MAR0, mchash[0]);
        CSR_WRITE_4(sc, ALE_MAR1, mchash[1]);
        CSR_WRITE_4(sc, ALE_MAC_CFG, rxcfg);
}

static int
sysctl_int_range(SYSCTL_HANDLER_ARGS, int low, int high)
{
        int error, value;

        if (arg1 == NULL)
                return (EINVAL);
        value = *(int *)arg1;
        error = sysctl_handle_int(oidp, &value, 0, req);
        if (error || req->newptr == NULL)
                return (error);
        if (value < low || value > high)
                return (EINVAL);
        *(int *)arg1 = value;

        return (0);
}

static int
sysctl_hw_ale_proc_limit(SYSCTL_HANDLER_ARGS)
{
        return (sysctl_int_range(oidp, arg1, arg2, req,
            ALE_PROC_MIN, ALE_PROC_MAX));
}

static int
sysctl_hw_ale_int_mod(SYSCTL_HANDLER_ARGS)
{

        return (sysctl_int_range(oidp, arg1, arg2, req,
            ALE_IM_TIMER_MIN, ALE_IM_TIMER_MAX));
}