/*      $NetBSD: hme.c,v 1.110 2024/06/29 12:11:11 riastradh Exp $      */

/*-
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Paul Kranenburg.
 *
 * 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, 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * HME Ethernet module driver.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: hme.c,v 1.110 2024/06/29 12:11:11 riastradh Exp $");

/* #define HMEDEBUG */

#include "opt_inet.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/syslog.h>
#include <sys/socket.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/rndsource.h>

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

#ifdef INET
#include <net/if_vlanvar.h>
#include <netinet/in.h>
#include <netinet/if_inarp.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#endif

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

#include <sys/bus.h>

#include <dev/ic/hmereg.h>
#include <dev/ic/hmevar.h>

static void     hme_start(struct ifnet *);
static void     hme_stop(struct ifnet *, int);
static int      hme_ioctl(struct ifnet *, u_long, void *);
static void     hme_tick(void *);
static void     hme_watchdog(struct ifnet *);
static bool     hme_shutdown(device_t, int);
static int      hme_init(struct ifnet *);
static void     hme_meminit(struct hme_softc *);
static void     hme_mifinit(struct hme_softc *);
static void     hme_reset(struct hme_softc *);
static void     hme_chipreset(struct hme_softc *);
static void     hme_setladrf(struct hme_softc *);

/* MII methods & callbacks */
static int      hme_mii_readreg(device_t, int, int, uint16_t *);
static int      hme_mii_writereg(device_t, int, int, uint16_t);
static void     hme_mii_statchg(struct ifnet *);

static int      hme_mediachange(struct ifnet *);

static struct mbuf *hme_get(struct hme_softc *, int, uint32_t);
static int      hme_put(struct hme_softc *, int, struct mbuf *);
static void     hme_read(struct hme_softc *, int, uint32_t);
static int      hme_eint(struct hme_softc *, u_int);
static int      hme_rint(struct hme_softc *);
static int      hme_tint(struct hme_softc *);

#if 0
/* Default buffer copy routines */
static void     hme_copytobuf_contig(struct hme_softc *, void *, int, int);
static void     hme_copyfrombuf_contig(struct hme_softc *, void *, int, int);
#endif

void
hme_config(struct hme_softc *sc)
{
        struct ifnet *ifp = &sc->sc_ethercom.ec_if;
        struct mii_data *mii = &sc->sc_mii;
        struct mii_softc *child;
        bus_dma_tag_t dmatag = sc->sc_dmatag;
        bus_dma_segment_t seg;
        bus_size_t size;
        int rseg, error;

        /*
         * HME common initialization.
         *
         * hme_softc fields that must be initialized by the front-end:
         *
         * the bus tag:
         *      sc_bustag
         *
         * the DMA bus tag:
         *      sc_dmatag
         *
         * the bus handles:
         *      sc_seb          (Shared Ethernet Block registers)
         *      sc_erx          (Receiver Unit registers)
         *      sc_etx          (Transmitter Unit registers)
         *      sc_mac          (MAC registers)
         *      sc_mif          (Management Interface registers)
         *
         * the maximum bus burst size:
         *      sc_burst
         *
         * (notyet:DMA capable memory for the ring descriptors & packet buffers:
         *      rb_membase, rb_dmabase)
         *
         * the local Ethernet address:
         *      sc_enaddr
         *
         */

        /* Make sure the chip is stopped. */
        hme_chipreset(sc);

        /*
         * Allocate descriptors and buffers
         * XXX - do all this differently.. and more configurably,
         * eg. use things as `dma_load_mbuf()' on transmit,
         *     and a pool of `EXTMEM' mbufs (with buffers DMA-mapped
         *     all the time) on the receiver side.
         *
         * Note: receive buffers must be 64-byte aligned.
         * Also, apparently, the buffers must extend to a DMA burst
         * boundary beyond the maximum packet size.
         */
#define _HME_NDESC      128
#define _HME_BUFSZ      1600

        /* Note: the # of descriptors must be a multiple of 16 */
        sc->sc_rb.rb_ntbuf = _HME_NDESC;
        sc->sc_rb.rb_nrbuf = _HME_NDESC;

        /*
         * Allocate DMA capable memory
         * Buffer descriptors must be aligned on a 2048 byte boundary;
         * take this into account when calculating the size. Note that
         * the maximum number of descriptors (256) occupies 2048 bytes,
         * so we allocate that much regardless of _HME_NDESC.
         */
        size =  2048 +                                  /* TX descriptors */
                2048 +                                  /* RX descriptors */
                sc->sc_rb.rb_ntbuf * _HME_BUFSZ +       /* TX buffers */
                sc->sc_rb.rb_nrbuf * _HME_BUFSZ;        /* RX buffers */

        /* Allocate DMA buffer */
        if ((error = bus_dmamem_alloc(dmatag, size,
                                      2048, 0,
                                      &seg, 1, &rseg, BUS_DMA_NOWAIT)) != 0) {
                aprint_error_dev(sc->sc_dev, "DMA buffer alloc error %d\n",
                        error);
                return;
        }

        /* Map DMA memory in CPU addressable space */
        if ((error = bus_dmamem_map(dmatag, &seg, rseg, size,
                                    &sc->sc_rb.rb_membase,
                                    BUS_DMA_NOWAIT | BUS_DMA_COHERENT)) != 0) {
                aprint_error_dev(sc->sc_dev, "DMA buffer map error %d\n",
                        error);
                goto bad_free;
        }

        if ((error = bus_dmamap_create(dmatag, size, 1, size, 0,
                                    BUS_DMA_NOWAIT, &sc->sc_dmamap)) != 0) {
                aprint_error_dev(sc->sc_dev, "DMA map create error %d\n",
                        error);
                goto bad_unmap;
        }

        /* Load the buffer */
        if ((error = bus_dmamap_load(dmatag, sc->sc_dmamap,
            sc->sc_rb.rb_membase, size, NULL,
            BUS_DMA_NOWAIT | BUS_DMA_COHERENT)) != 0) {
                aprint_error_dev(sc->sc_dev, "DMA buffer map load error %d\n",
                        error);
                goto bad_destroy;
        }
        sc->sc_rb.rb_dmabase = sc->sc_dmamap->dm_segs[0].ds_addr;

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

        /* Initialize ifnet structure. */
        strlcpy(ifp->if_xname, device_xname(sc->sc_dev), IFNAMSIZ);
        ifp->if_softc = sc;
        ifp->if_start = hme_start;
        ifp->if_stop = hme_stop;
        ifp->if_ioctl = hme_ioctl;
        ifp->if_init = hme_init;
        ifp->if_watchdog = hme_watchdog;
        ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
        sc->sc_if_flags = ifp->if_flags;
        ifp->if_capabilities |=
            IFCAP_CSUM_TCPv4_Tx | IFCAP_CSUM_TCPv4_Rx |
            IFCAP_CSUM_UDPv4_Tx | IFCAP_CSUM_UDPv4_Rx;
        IFQ_SET_READY(&ifp->if_snd);

        /* Initialize ifmedia structures and MII info */
        mii->mii_ifp = ifp;
        mii->mii_readreg = hme_mii_readreg;
        mii->mii_writereg = hme_mii_writereg;
        mii->mii_statchg = hme_mii_statchg;

        sc->sc_ethercom.ec_mii = mii;
        ifmedia_init(&mii->mii_media, 0, hme_mediachange, ether_mediastatus);

        hme_mifinit(sc);

        mii_attach(sc->sc_dev, mii, 0xffffffff,
                        MII_PHY_ANY, MII_OFFSET_ANY, MIIF_FORCEANEG);

        child = LIST_FIRST(&mii->mii_phys);
        if (child == NULL) {
                /* No PHY attached */
                ifmedia_add(&mii->mii_media, IFM_ETHER | IFM_MANUAL, 0, NULL);
                ifmedia_set(&mii->mii_media, IFM_ETHER | IFM_MANUAL);
        } else {
                /*
                 * Walk along the list of attached MII devices and
                 * establish an `MII instance' to `phy number'
                 * mapping. We'll use this mapping in media change
                 * requests to determine which phy to use to program
                 * the MIF configuration register.
                 */
                for (; child != NULL; child = LIST_NEXT(child, mii_list)) {
                        /*
                         * Note: we support just two PHYs: the built-in
                         * internal device and an external on the MII
                         * connector.
                         */
                        if (child->mii_phy > 1 || child->mii_inst > 1) {
                                aprint_error_dev(sc->sc_dev,
                                    "cannot accommodate MII device %s"
                                       " at phy %d, instance %d\n",
                                       device_xname(child->mii_dev),
                                       child->mii_phy, child->mii_inst);
                                continue;
                        }

                        sc->sc_phys[child->mii_inst] = child->mii_phy;
                }

                /*
                 * Set the default media to auto negotiation if the phy has
                 * the auto negotiation capability.
                 * XXX; What to do otherwise?
                 */
                if (ifmedia_match(&mii->mii_media, IFM_ETHER | IFM_AUTO, 0))
                        ifmedia_set(&mii->mii_media, IFM_ETHER | IFM_AUTO);
/*
                else
                        ifmedia_set(&sc->sc_mii.mii_media, sc->sc_defaultmedia);
*/
        }

        /* claim 802.1q capability */
        sc->sc_ethercom.ec_capabilities |= ETHERCAP_VLAN_MTU;

        /* Attach the interface. */
        if_attach(ifp);
        if_deferred_start_init(ifp, NULL);
        ether_ifattach(ifp, sc->sc_enaddr);

        if (pmf_device_register1(sc->sc_dev, NULL, NULL, hme_shutdown))
                pmf_class_network_register(sc->sc_dev, ifp);
        else
                aprint_error_dev(sc->sc_dev,
                    "couldn't establish power handler\n");

        rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
                          RND_TYPE_NET, RND_FLAG_DEFAULT);

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

        return;

 bad_destroy:
        bus_dmamap_destroy(dmatag, sc->sc_dmamap);
 bad_unmap:
        bus_dmamem_unmap(dmatag, sc->sc_rb.rb_membase, size);
 bad_free:
        bus_dmamem_free(dmatag, &seg, rseg);
}

void
hme_tick(void *arg)
{
        struct hme_softc *sc = arg;
        int s;

        s = splnet();
        mii_tick(&sc->sc_mii);
        splx(s);

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

void
hme_reset(struct hme_softc *sc)
{
        int s;

        s = splnet();
        (void)hme_init(&sc->sc_ethercom.ec_if);
        splx(s);
}

void
hme_chipreset(struct hme_softc *sc)
{
        bus_space_tag_t t = sc->sc_bustag;
        bus_space_handle_t seb = sc->sc_seb;
        int n;

        /* Mask all interrupts */
        bus_space_write_4(t, seb, HME_SEBI_IMASK, 0xffffffff);

        /* Reset transmitter and receiver */
        bus_space_write_4(t, seb, HME_SEBI_RESET,
                          (HME_SEB_RESET_ETX | HME_SEB_RESET_ERX));

        for (n = 0; n < 20; n++) {
                uint32_t v = bus_space_read_4(t, seb, HME_SEBI_RESET);
                if ((v & (HME_SEB_RESET_ETX | HME_SEB_RESET_ERX)) == 0)
                        return;
                DELAY(20);
        }

        printf("%s: %s: reset failed\n", device_xname(sc->sc_dev), __func__);
}

void
hme_stop(struct ifnet *ifp, int disable)
{
        struct hme_softc *sc;

        sc = ifp->if_softc;

        ifp->if_timer = 0;
        ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);

        callout_stop(&sc->sc_tick_ch);
        mii_down(&sc->sc_mii);

        hme_chipreset(sc);
}

void
hme_meminit(struct hme_softc *sc)
{
        bus_addr_t txbufdma, rxbufdma;
        bus_addr_t dma;
        char *p;
        unsigned int ntbuf, nrbuf, i;
        struct hme_ring *hr = &sc->sc_rb;

        p = hr->rb_membase;
        dma = hr->rb_dmabase;

        ntbuf = hr->rb_ntbuf;
        nrbuf = hr->rb_nrbuf;

        /*
         * Allocate transmit descriptors
         */
        hr->rb_txd = p;
        hr->rb_txddma = dma;
        p += ntbuf * HME_XD_SIZE;
        dma += ntbuf * HME_XD_SIZE;
        /* We have reserved descriptor space until the next 2048 byte boundary.*/
        dma = (bus_addr_t)roundup((u_long)dma, 2048);
        p = (void *)roundup((u_long)p, 2048);

        /*
         * Allocate receive descriptors
         */
        hr->rb_rxd = p;
        hr->rb_rxddma = dma;
        p += nrbuf * HME_XD_SIZE;
        dma += nrbuf * HME_XD_SIZE;
        /* Again move forward to the next 2048 byte boundary.*/
        dma = (bus_addr_t)roundup((u_long)dma, 2048);
        p = (void *)roundup((u_long)p, 2048);


        /*
         * Allocate transmit buffers
         */
        hr->rb_txbuf = p;
        txbufdma = dma;
        p += ntbuf * _HME_BUFSZ;
        dma += ntbuf * _HME_BUFSZ;

        /*
         * Allocate receive buffers
         */
        hr->rb_rxbuf = p;
        rxbufdma = dma;
        p += nrbuf * _HME_BUFSZ;
        dma += nrbuf * _HME_BUFSZ;

        /*
         * Initialize transmit buffer descriptors
         */
        for (i = 0; i < ntbuf; i++) {
                HME_XD_SETADDR(sc->sc_pci, hr->rb_txd, i, txbufdma + i * _HME_BUFSZ);
                HME_XD_SETFLAGS(sc->sc_pci, hr->rb_txd, i, 0);
        }

        /*
         * Initialize receive buffer descriptors
         */
        for (i = 0; i < nrbuf; i++) {
                HME_XD_SETADDR(sc->sc_pci, hr->rb_rxd, i, rxbufdma + i * _HME_BUFSZ);
                HME_XD_SETFLAGS(sc->sc_pci, hr->rb_rxd, i,
                                HME_XD_OWN | HME_XD_ENCODE_RSIZE(_HME_BUFSZ));
        }

        hr->rb_tdhead = hr->rb_tdtail = 0;
        hr->rb_td_nbusy = 0;
        hr->rb_rdtail = 0;
}

/*
 * Initialization of interface; set up initialization block
 * and transmit/receive descriptor rings.
 */
int
hme_init(struct ifnet *ifp)
{
        struct hme_softc *sc = ifp->if_softc;
        bus_space_tag_t t = sc->sc_bustag;
        bus_space_handle_t seb = sc->sc_seb;
        bus_space_handle_t etx = sc->sc_etx;
        bus_space_handle_t erx = sc->sc_erx;
        bus_space_handle_t mac = sc->sc_mac;
        uint8_t *ea;
        uint32_t v;
        int rc;

        /*
         * Initialization sequence. The numbered steps below correspond
         * to the sequence outlined in section 6.3.5.1 in the Ethernet
         * Channel Engine manual (part of the PCIO manual).
         * See also the STP2002-STQ document from Sun Microsystems.
         */

        /* step 1 & 2. Reset the Ethernet Channel */
        hme_stop(ifp, 0);

        /* Re-initialize the MIF */
        hme_mifinit(sc);

        /* Call MI reset function if any */
        if (sc->sc_hwreset)
                (*sc->sc_hwreset)(sc);

#if 0
        /* Mask all MIF interrupts, just in case */
        bus_space_write_4(t, mif, HME_MIFI_IMASK, 0xffff);
#endif

        /* step 3. Setup data structures in host memory */
        hme_meminit(sc);

        /* step 4. TX MAC registers & counters */
        bus_space_write_4(t, mac, HME_MACI_NCCNT, 0);
        bus_space_write_4(t, mac, HME_MACI_FCCNT, 0);
        bus_space_write_4(t, mac, HME_MACI_EXCNT, 0);
        bus_space_write_4(t, mac, HME_MACI_LTCNT, 0);
        bus_space_write_4(t, mac, HME_MACI_TXSIZE,
            (sc->sc_ethercom.ec_capenable & ETHERCAP_VLAN_MTU) ?
            ETHER_VLAN_ENCAP_LEN + ETHER_MAX_LEN : ETHER_MAX_LEN);
        sc->sc_ec_capenable = sc->sc_ethercom.ec_capenable;

        /* Load station MAC address */
        ea = sc->sc_enaddr;
        bus_space_write_4(t, mac, HME_MACI_MACADDR0, (ea[0] << 8) | ea[1]);
        bus_space_write_4(t, mac, HME_MACI_MACADDR1, (ea[2] << 8) | ea[3]);
        bus_space_write_4(t, mac, HME_MACI_MACADDR2, (ea[4] << 8) | ea[5]);

        /*
         * Init seed for backoff
         * (source suggested by manual: low 10 bits of MAC address)
         */
        v = ((ea[4] << 8) | ea[5]) & 0x3fff;
        bus_space_write_4(t, mac, HME_MACI_RANDSEED, v);


        /* Note: Accepting power-on default for other MAC registers here.. */


        /* step 5. RX MAC registers & counters */
        hme_setladrf(sc);

        /* step 6 & 7. Program Descriptor Ring Base Addresses */
        bus_space_write_4(t, etx, HME_ETXI_RING, sc->sc_rb.rb_txddma);
        bus_space_write_4(t, etx, HME_ETXI_RSIZE, sc->sc_rb.rb_ntbuf);

        bus_space_write_4(t, erx, HME_ERXI_RING, sc->sc_rb.rb_rxddma);
        bus_space_write_4(t, mac, HME_MACI_RXSIZE,
            (sc->sc_ethercom.ec_capenable & ETHERCAP_VLAN_MTU) ?
            ETHER_VLAN_ENCAP_LEN + ETHER_MAX_LEN : ETHER_MAX_LEN);

        /* step 8. Global Configuration & Interrupt Mask */
        bus_space_write_4(t, seb, HME_SEBI_IMASK,
                        ~(
                          /*HME_SEB_STAT_GOTFRAME | HME_SEB_STAT_SENTFRAME |*/
                          HME_SEB_STAT_HOSTTOTX |
                          HME_SEB_STAT_RXTOHOST |
                          HME_SEB_STAT_TXALL |
                          HME_SEB_STAT_TXPERR |
                          HME_SEB_STAT_RCNTEXP |
                          HME_SEB_STAT_MIFIRQ |
                          HME_SEB_STAT_ALL_ERRORS ));

        switch (sc->sc_burst) {
        default:
                v = 0;
                break;
        case 16:
                v = HME_SEB_CFG_BURST16;
                break;
        case 32:
                v = HME_SEB_CFG_BURST32;
                break;
        case 64:
                v = HME_SEB_CFG_BURST64;
                break;
        }
        bus_space_write_4(t, seb, HME_SEBI_CFG, v);

        /* step 9. ETX Configuration: use mostly default values */

        /* Enable DMA */
        v = bus_space_read_4(t, etx, HME_ETXI_CFG);
        v |= HME_ETX_CFG_DMAENABLE;
        bus_space_write_4(t, etx, HME_ETXI_CFG, v);

        /* Transmit Descriptor ring size: in increments of 16 */
        bus_space_write_4(t, etx, HME_ETXI_RSIZE, _HME_NDESC / 16 - 1);


        /* step 10. ERX Configuration */
        v = bus_space_read_4(t, erx, HME_ERXI_CFG);

        /* Encode Receive Descriptor ring size: four possible values */
        switch (_HME_NDESC /*XXX*/) {
        case 32:
                v |= HME_ERX_CFG_RINGSIZE32;
                break;
        case 64:
                v |= HME_ERX_CFG_RINGSIZE64;
                break;
        case 128:
                v |= HME_ERX_CFG_RINGSIZE128;
                break;
        case 256:
                v |= HME_ERX_CFG_RINGSIZE256;
                break;
        default:
                printf("hme: invalid Receive Descriptor ring size\n");
                break;
        }

        /* Enable DMA */
        v |= HME_ERX_CFG_DMAENABLE;

        /* set h/w rx checksum start offset (# of half-words) */
#ifdef INET
        v |= (((ETHER_HDR_LEN + sizeof(struct ip)) / sizeof(uint16_t))
                << HME_ERX_CFG_CSUMSHIFT) &
                HME_ERX_CFG_CSUMSTART;
#endif
        bus_space_write_4(t, erx, HME_ERXI_CFG, v);

        /* step 11. XIF Configuration */
        v = bus_space_read_4(t, mac, HME_MACI_XIF);
        v |= HME_MAC_XIF_OE;
        bus_space_write_4(t, mac, HME_MACI_XIF, v);

        /* step 12. RX_MAC Configuration Register */
        v = bus_space_read_4(t, mac, HME_MACI_RXCFG);
        v |= HME_MAC_RXCFG_ENABLE | HME_MAC_RXCFG_PSTRIP;
        bus_space_write_4(t, mac, HME_MACI_RXCFG, v);

        /* step 13. TX_MAC Configuration Register */
        v = bus_space_read_4(t, mac, HME_MACI_TXCFG);
        v |= (HME_MAC_TXCFG_ENABLE | HME_MAC_TXCFG_DGIVEUP);
        bus_space_write_4(t, mac, HME_MACI_TXCFG, v);

        /* step 14. Issue Transmit Pending command */

        /* Call MI initialization function if any */
        if (sc->sc_hwinit)
                (*sc->sc_hwinit)(sc);

        /* Set the current media. */
        if ((rc = hme_mediachange(ifp)) != 0)
                return rc;

        /* Start the one second timer. */
        callout_schedule(&sc->sc_tick_ch, hz);

        ifp->if_flags |= IFF_RUNNING;
        ifp->if_flags &= ~IFF_OACTIVE;
        sc->sc_if_flags = ifp->if_flags;
        ifp->if_timer = 0;
        hme_start(ifp);
        return 0;
}

/*
 * Routine to copy from mbuf chain to transmit buffer in
 * network buffer memory.
 * Returns the amount of data copied.
 */
int
hme_put(struct hme_softc *sc, int ri, struct mbuf *m)
        /* ri:                   Ring index */
{
        struct mbuf *n;
        int len, tlen = 0;
        char *bp;

        bp = (char *)sc->sc_rb.rb_txbuf + (ri % sc->sc_rb.rb_ntbuf) * _HME_BUFSZ;
        for (; m; m = n) {
                len = m->m_len;
                if (len == 0) {
                        n = m_free(m);
                        continue;
                }
                memcpy(bp, mtod(m, void *), len);
                bp += len;
                tlen += len;
                n = m_free(m);
        }
        return (tlen);
}

/*
 * Pull data off an interface.
 * Len is length of data, with local net header stripped.
 * We copy the data into mbufs.  When full cluster sized units are present
 * we copy into clusters.
 */
struct mbuf *
hme_get(struct hme_softc *sc, int ri, uint32_t flags)
{
        struct ifnet *ifp = &sc->sc_ethercom.ec_if;
        struct mbuf *m, *m0, *newm;
        char *bp;
        int len, totlen;
#ifdef INET
        int csum_flags;
#endif

        totlen = HME_XD_DECODE_RSIZE(flags);
        MGETHDR(m0, M_DONTWAIT, MT_DATA);
        if (m0 == 0)
                return (0);
        MCLAIM(m0, &sc->sc_ethercom.ec_rx_mowner);
        m_set_rcvif(m0, ifp);
        m0->m_pkthdr.len = totlen;
        len = MHLEN;
        m = m0;

        bp = (char *)sc->sc_rb.rb_rxbuf + (ri % sc->sc_rb.rb_nrbuf) * _HME_BUFSZ;

        while (totlen > 0) {
                if (totlen >= MINCLSIZE) {
                        MCLGET(m, M_DONTWAIT);
                        if ((m->m_flags & M_EXT) == 0)
                                goto bad;
                        len = MCLBYTES;
                }

                if (m == m0) {
                        char *newdata = (char *)
                            ALIGN(m->m_data + sizeof(struct ether_header)) -
                            sizeof(struct ether_header);
                        len -= newdata - m->m_data;
                        m->m_data = newdata;
                }

                m->m_len = len = uimin(totlen, len);
                memcpy(mtod(m, void *), bp, len);
                bp += len;

                totlen -= len;
                if (totlen > 0) {
                        MGET(newm, M_DONTWAIT, MT_DATA);
                        if (newm == 0)
                                goto bad;
                        len = MLEN;
                        m = m->m_next = newm;
                }
        }

#ifdef INET
        /* hardware checksum */
        csum_flags = 0;
        if (ifp->if_csum_flags_rx & (M_CSUM_TCPv4 | M_CSUM_UDPv4)) {
                struct ether_header *eh;
                struct ether_vlan_header *evh;
                struct ip *ip;
                struct udphdr *uh;
                uint16_t *opts;
                int32_t hlen, pktlen;
                uint32_t csum_data;

                eh = mtod(m0, struct ether_header *);
                if (ntohs(eh->ether_type) == ETHERTYPE_IP) {
                        ip = (struct ip *)((char *)eh + ETHER_HDR_LEN);
                        pktlen = m0->m_pkthdr.len - ETHER_HDR_LEN;
                } else if (ntohs(eh->ether_type) == ETHERTYPE_VLAN) {
                        evh = (struct ether_vlan_header *)eh;
                        if (ntohs(evh->evl_proto) != ETHERTYPE_IP)
                                goto swcsum;
                        ip = (struct ip *)((char *)eh + ETHER_HDR_LEN +
                            ETHER_VLAN_ENCAP_LEN);
                        pktlen = m0->m_pkthdr.len -
                            ETHER_HDR_LEN - ETHER_VLAN_ENCAP_LEN;
                } else
                        goto swcsum;

                /* IPv4 only */
                if (ip->ip_v != IPVERSION)
                        goto swcsum;

                hlen = ip->ip_hl << 2;
                if (hlen < sizeof(struct ip))
                        goto swcsum;

                /*
                 * bail if too short, has random trailing garbage, truncated,
                 * fragment, or has ethernet pad.
                 */
                if (ntohs(ip->ip_len) < hlen ||
                    ntohs(ip->ip_len) != pktlen ||
                    (ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK)) != 0)
                        goto swcsum;

                switch (ip->ip_p) {
                case IPPROTO_TCP:
                        if ((ifp->if_csum_flags_rx & M_CSUM_TCPv4) == 0)
                                goto swcsum;
                        if (pktlen < (hlen + sizeof(struct tcphdr)))
                                goto swcsum;
                        csum_flags =
                            M_CSUM_TCPv4 | M_CSUM_DATA | M_CSUM_NO_PSEUDOHDR;
                        break;
                case IPPROTO_UDP:
                        if ((ifp->if_csum_flags_rx & M_CSUM_UDPv4) == 0)
                                goto swcsum;
                        if (pktlen < (hlen + sizeof(struct udphdr)))
                                goto swcsum;
                        uh = (struct udphdr *)((char *)ip + hlen);
                        /* no checksum */
                        if (uh->uh_sum == 0)
                                goto swcsum;
                        csum_flags =
                            M_CSUM_UDPv4 | M_CSUM_DATA | M_CSUM_NO_PSEUDOHDR;
                        break;
                default:
                        goto swcsum;
                }

                /* w/ M_CSUM_NO_PSEUDOHDR, the uncomplemented sum is expected */
                csum_data = ~flags & HME_XD_RXCKSUM;

                /*
                 * If data offset is different from RX cksum start offset,
                 * we have to deduct them.
                 */
                hlen = ((char *)ip + hlen) -
                    ((char *)eh + ETHER_HDR_LEN + sizeof(struct ip));
                if (hlen > 1) {
                        uint32_t optsum;

                        optsum = 0;
                        opts = (uint16_t *)((char *)eh +
                            ETHER_HDR_LEN + sizeof(struct ip));

                        while (hlen > 1) {
                                optsum += ntohs(*opts++);
                                hlen -= 2;
                        }
                        while (optsum >> 16)
                                optsum = (optsum >> 16) + (optsum & 0xffff);

                        /* Deduct the ip opts sum from the hwsum. */
                        csum_data += (uint16_t)~optsum;

                        while (csum_data >> 16)
                                csum_data =
                                    (csum_data >> 16) + (csum_data & 0xffff);
                }
                m0->m_pkthdr.csum_data = csum_data;
        }
swcsum:
        m0->m_pkthdr.csum_flags = csum_flags;
#endif

        return (m0);

bad:
        m_freem(m0);
        return (0);
}

/*
 * Pass a packet to the higher levels.
 */
void
hme_read(struct hme_softc *sc, int ix, uint32_t flags)
{
        struct ifnet *ifp = &sc->sc_ethercom.ec_if;
        struct mbuf *m;
        int len;

        len = HME_XD_DECODE_RSIZE(flags);
        if (len <= sizeof(struct ether_header) ||
            len > ((sc->sc_ethercom.ec_capenable & ETHERCAP_VLAN_MTU) ?
            ETHER_VLAN_ENCAP_LEN + ETHERMTU + sizeof(struct ether_header) :
            ETHERMTU + sizeof(struct ether_header))) {
#ifdef HMEDEBUG
                printf("%s: invalid packet size %d; dropping\n",
                    device_xname(sc->sc_dev), len);
#endif
                if_statinc(ifp, if_ierrors);
                return;
        }

        /* Pull packet off interface. */
        m = hme_get(sc, ix, flags);
        if (m == 0) {
                if_statinc(ifp, if_ierrors);
                return;
        }

        /* Pass the packet up. */
        if_percpuq_enqueue(ifp->if_percpuq, m);
}

void
hme_start(struct ifnet *ifp)
{
        struct hme_softc *sc = ifp->if_softc;
        void *txd = sc->sc_rb.rb_txd;
        struct mbuf *m;
        unsigned int txflags;
        unsigned int ri, len, obusy;
        unsigned int ntbuf = sc->sc_rb.rb_ntbuf;

        if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
                return;

        ri = sc->sc_rb.rb_tdhead;
        obusy = sc->sc_rb.rb_td_nbusy;

        for (;;) {
                IFQ_DEQUEUE(&ifp->if_snd, m);
                if (m == 0)
                        break;

                /*
                 * If BPF is listening on this interface, let it see the
                 * packet before we commit it to the wire.
                 */
                bpf_mtap(ifp, m, BPF_D_OUT);

#ifdef INET
                /* collect bits for h/w csum, before hme_put frees the mbuf */
                if (ifp->if_csum_flags_tx & (M_CSUM_TCPv4 | M_CSUM_UDPv4) &&
                    m->m_pkthdr.csum_flags & (M_CSUM_TCPv4 | M_CSUM_UDPv4)) {
                        struct ether_header *eh;
                        uint16_t offset, start;

                        eh = mtod(m, struct ether_header *);
                        switch (ntohs(eh->ether_type)) {
                        case ETHERTYPE_IP:
                                start = ETHER_HDR_LEN;
                                break;
                        case ETHERTYPE_VLAN:
                                start = ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
                                break;
                        default:
                                /* unsupported, drop it */
                                m_free(m);
                                continue;
                        }
                        start += M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data);
                        offset = M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data)
                            + start;
                        txflags = HME_XD_TXCKSUM |
                                  (offset << HME_XD_TXCSSTUFFSHIFT) |
                                  (start << HME_XD_TXCSSTARTSHIFT);
                } else
#endif
                        txflags = 0;

                /*
                 * Copy the mbuf chain into the transmit buffer.
                 */
                len = hme_put(sc, ri, m);

                /*
                 * Initialize transmit registers and start transmission
                 */
                HME_XD_SETFLAGS(sc->sc_pci, txd, ri,
                        HME_XD_OWN | HME_XD_SOP | HME_XD_EOP |
                        HME_XD_ENCODE_TSIZE(len) | txflags);

                /*if (sc->sc_rb.rb_td_nbusy <= 0)*/
                bus_space_write_4(sc->sc_bustag, sc->sc_etx, HME_ETXI_PENDING,
                                  HME_ETX_TP_DMAWAKEUP);

                if (++ri == ntbuf)
                        ri = 0;

                if (++sc->sc_rb.rb_td_nbusy == ntbuf) {
                        ifp->if_flags |= IFF_OACTIVE;
                        break;
                }
        }

        if (obusy != sc->sc_rb.rb_td_nbusy) {
                sc->sc_rb.rb_tdhead = ri;
                ifp->if_timer = 5;
        }
}

/*
 * Transmit interrupt.
 */
int
hme_tint(struct hme_softc *sc)
{
        struct ifnet *ifp = &sc->sc_ethercom.ec_if;
        bus_space_tag_t t = sc->sc_bustag;
        bus_space_handle_t mac = sc->sc_mac;
        unsigned int ri, txflags;

        net_stat_ref_t nsr = IF_STAT_GETREF(ifp);

        /*
         * Unload collision counters
         */
        if_statadd_ref(ifp, nsr, if_collisions,
                bus_space_read_4(t, mac, HME_MACI_NCCNT) +
                bus_space_read_4(t, mac, HME_MACI_FCCNT));
        if_statadd_ref(ifp, nsr, if_oerrors,
                bus_space_read_4(t, mac, HME_MACI_EXCNT) +
                bus_space_read_4(t, mac, HME_MACI_LTCNT));

        /*
         * then clear the hardware counters.
         */
        bus_space_write_4(t, mac, HME_MACI_NCCNT, 0);
        bus_space_write_4(t, mac, HME_MACI_FCCNT, 0);
        bus_space_write_4(t, mac, HME_MACI_EXCNT, 0);
        bus_space_write_4(t, mac, HME_MACI_LTCNT, 0);

        /* Fetch current position in the transmit ring */
        ri = sc->sc_rb.rb_tdtail;

        for (;;) {
                if (sc->sc_rb.rb_td_nbusy <= 0)
                        break;

                txflags = HME_XD_GETFLAGS(sc->sc_pci, sc->sc_rb.rb_txd, ri);

                if (txflags & HME_XD_OWN)
                        break;

                ifp->if_flags &= ~IFF_OACTIVE;
                if_statinc_ref(ifp, nsr, if_opackets);

                if (++ri == sc->sc_rb.rb_ntbuf)
                        ri = 0;

                --sc->sc_rb.rb_td_nbusy;
        }

        IF_STAT_PUTREF(ifp);

        /* Update ring */
        sc->sc_rb.rb_tdtail = ri;

        if_schedule_deferred_start(ifp);

        if (sc->sc_rb.rb_td_nbusy == 0)
                ifp->if_timer = 0;

        return (1);
}

/*
 * Receive interrupt.
 */
int
hme_rint(struct hme_softc *sc)
{
        struct ifnet *ifp = &sc->sc_ethercom.ec_if;
        bus_space_tag_t t = sc->sc_bustag;
        bus_space_handle_t mac = sc->sc_mac;
        void *xdr = sc->sc_rb.rb_rxd;
        unsigned int nrbuf = sc->sc_rb.rb_nrbuf;
        unsigned int ri;
        uint32_t flags;

        ri = sc->sc_rb.rb_rdtail;

        /*
         * Process all buffers with valid data.
         */
        for (;;) {
                flags = HME_XD_GETFLAGS(sc->sc_pci, xdr, ri);
                if (flags & HME_XD_OWN)
                        break;

                if (flags & HME_XD_OFL) {
                        printf("%s: buffer overflow, ri=%d; flags=0x%x\n",
                                        device_xname(sc->sc_dev), ri, flags);
                } else
                        hme_read(sc, ri, flags);

                /* This buffer can be used by the hardware again */
                HME_XD_SETFLAGS(sc->sc_pci, xdr, ri,
                                HME_XD_OWN | HME_XD_ENCODE_RSIZE(_HME_BUFSZ));

                if (++ri == nrbuf)
                        ri = 0;
        }

        sc->sc_rb.rb_rdtail = ri;

        /* Read error counters ... */
        if_statadd(ifp, if_ierrors,
            bus_space_read_4(t, mac, HME_MACI_STAT_LCNT) +
            bus_space_read_4(t, mac, HME_MACI_STAT_ACNT) +
            bus_space_read_4(t, mac, HME_MACI_STAT_CCNT) +
            bus_space_read_4(t, mac, HME_MACI_STAT_CVCNT));

        /* ... then clear the hardware counters. */
        bus_space_write_4(t, mac, HME_MACI_STAT_LCNT, 0);
        bus_space_write_4(t, mac, HME_MACI_STAT_ACNT, 0);
        bus_space_write_4(t, mac, HME_MACI_STAT_CCNT, 0);
        bus_space_write_4(t, mac, HME_MACI_STAT_CVCNT, 0);
        return (1);
}

int
hme_eint(struct hme_softc *sc, u_int status)
{
        struct ifnet *ifp = &sc->sc_ethercom.ec_if;
        char bits[128];

        if ((status & HME_SEB_STAT_MIFIRQ) != 0) {
                bus_space_tag_t t = sc->sc_bustag;
                bus_space_handle_t mif = sc->sc_mif;
                uint32_t cf, st, sm;
                cf = bus_space_read_4(t, mif, HME_MIFI_CFG);
                st = bus_space_read_4(t, mif, HME_MIFI_STAT);
                sm = bus_space_read_4(t, mif, HME_MIFI_SM);
                printf("%s: XXXlink status changed: cfg=%x, stat %x, sm %x\n",
                        device_xname(sc->sc_dev), cf, st, sm);
                return (1);
        }

        /* Receive error counters rolled over */
        net_stat_ref_t nsr = IF_STAT_GETREF(ifp);
        if (status & HME_SEB_STAT_ACNTEXP)
                if_statadd_ref(ifp, nsr, if_ierrors, 0xff);
        if (status & HME_SEB_STAT_CCNTEXP)
                if_statadd_ref(ifp, nsr, if_ierrors, 0xff);
        if (status & HME_SEB_STAT_LCNTEXP)
                if_statadd_ref(ifp, nsr, if_ierrors, 0xff);
        if (status & HME_SEB_STAT_CVCNTEXP)
                if_statadd_ref(ifp, nsr, if_ierrors, 0xff);
        IF_STAT_PUTREF(ifp);

        /* RXTERR locks up the interface, so do a reset */
        if (status & HME_SEB_STAT_RXTERR)
                hme_reset(sc);

        snprintb(bits, sizeof(bits), HME_SEB_STAT_BITS, status);
        printf("%s: status=%s\n", device_xname(sc->sc_dev), bits);

        return (1);
}

int
hme_intr(void *v)
{
        struct hme_softc *sc = v;
        bus_space_tag_t t = sc->sc_bustag;
        bus_space_handle_t seb = sc->sc_seb;
        uint32_t status;
        int r = 0;

        status = bus_space_read_4(t, seb, HME_SEBI_STAT);

        if ((status & HME_SEB_STAT_ALL_ERRORS) != 0)
                r |= hme_eint(sc, status);

        if ((status & (HME_SEB_STAT_TXALL | HME_SEB_STAT_HOSTTOTX)) != 0)
                r |= hme_tint(sc);

        if ((status & HME_SEB_STAT_RXTOHOST) != 0)
                r |= hme_rint(sc);

        rnd_add_uint32(&sc->rnd_source, status);

        return (r);
}


void
hme_watchdog(struct ifnet *ifp)
{
        struct hme_softc *sc = ifp->if_softc;

        log(LOG_ERR, "%s: device timeout\n", device_xname(sc->sc_dev));
        if_statinc(ifp, if_oerrors);

        hme_reset(sc);
}

/*
 * Initialize the MII Management Interface
 */
void
hme_mifinit(struct hme_softc *sc)
{
        bus_space_tag_t t = sc->sc_bustag;
        bus_space_handle_t mif = sc->sc_mif;
        bus_space_handle_t mac = sc->sc_mac;
        int instance, phy;
        uint32_t v;

        if (sc->sc_mii.mii_media.ifm_cur != NULL) {
                instance = IFM_INST(sc->sc_mii.mii_media.ifm_cur->ifm_media);
                phy = sc->sc_phys[instance];
        } else
                /* No media set yet, pick phy arbitrarily.. */
                phy = HME_PHYAD_EXTERNAL;

        /* Configure the MIF in frame mode, no poll, current phy select */
        v = 0;
        if (phy == HME_PHYAD_EXTERNAL)
                v |= HME_MIF_CFG_PHY;
        bus_space_write_4(t, mif, HME_MIFI_CFG, v);

        /* If an external transceiver is selected, enable its MII drivers */
        v = bus_space_read_4(t, mac, HME_MACI_XIF);
        v &= ~HME_MAC_XIF_MIIENABLE;
        if (phy == HME_PHYAD_EXTERNAL)
                v |= HME_MAC_XIF_MIIENABLE;
        bus_space_write_4(t, mac, HME_MACI_XIF, v);
}

/*
 * MII interface
 */
static int
hme_mii_readreg(device_t self, int phy, int reg, uint16_t *val)
{
        struct hme_softc *sc = device_private(self);
        bus_space_tag_t t = sc->sc_bustag;
        bus_space_handle_t mif = sc->sc_mif;
        bus_space_handle_t mac = sc->sc_mac;
        uint32_t v, xif_cfg, mifi_cfg;
        int n, rv;

        /* We can at most have two PHYs */
        if (phy != HME_PHYAD_EXTERNAL && phy != HME_PHYAD_INTERNAL)
                return -1;

        /* Select the desired PHY in the MIF configuration register */
        v = mifi_cfg = bus_space_read_4(t, mif, HME_MIFI_CFG);
        v &= ~HME_MIF_CFG_PHY;
        if (phy == HME_PHYAD_EXTERNAL)
                v |= HME_MIF_CFG_PHY;
        bus_space_write_4(t, mif, HME_MIFI_CFG, v);

        /* Enable MII drivers on external transceiver */
        v = xif_cfg = bus_space_read_4(t, mac, HME_MACI_XIF);
        if (phy == HME_PHYAD_EXTERNAL)
                v |= HME_MAC_XIF_MIIENABLE;
        else
                v &= ~HME_MAC_XIF_MIIENABLE;
        bus_space_write_4(t, mac, HME_MACI_XIF, v);

#if 0
/* This doesn't work reliably; the MDIO_1 bit is off most of the time */
        /*
         * Check whether a transceiver is connected by testing
         * the MIF configuration register's MDI_X bits. Note that
         * MDI_0 (int) == 0x100 and MDI_1 (ext) == 0x200; see hmereg.h
         */
        mif_mdi_bit = 1 << (8 + (1 - phy));
        delay(100);
        v = bus_space_read_4(t, mif, HME_MIFI_CFG);
        if ((v & mif_mdi_bit) == 0) {
                rv = -1;
                goto out;
        }
#endif

        /* Construct the frame command */
        v = (MII_COMMAND_START << HME_MIF_FO_ST_SHIFT) |
            HME_MIF_FO_TAMSB |
            (MII_COMMAND_READ << HME_MIF_FO_OPC_SHIFT) |
            (phy << HME_MIF_FO_PHYAD_SHIFT) |
            (reg << HME_MIF_FO_REGAD_SHIFT);

        bus_space_write_4(t, mif, HME_MIFI_FO, v);
        for (n = 0; n < 100; n++) {
                DELAY(1);
                v = bus_space_read_4(t, mif, HME_MIFI_FO);
                if (v & HME_MIF_FO_TALSB) {
                        *val = v & HME_MIF_FO_DATA;
                        rv = 0;
                        goto out;
                }
        }

        rv = ETIMEDOUT;
        printf("%s: mii_read timeout\n", device_xname(sc->sc_dev));

out:
        /* Restore MIFI_CFG register */
        bus_space_write_4(t, mif, HME_MIFI_CFG, mifi_cfg);
        /* Restore XIF register */
        bus_space_write_4(t, mac, HME_MACI_XIF, xif_cfg);
        return rv;
}

static int
hme_mii_writereg(device_t self, int phy, int reg, uint16_t val)
{
        struct hme_softc *sc = device_private(self);
        bus_space_tag_t t = sc->sc_bustag;
        bus_space_handle_t mif = sc->sc_mif;
        bus_space_handle_t mac = sc->sc_mac;
        uint32_t v, xif_cfg, mifi_cfg;
        int n, rv;

        /* We can at most have two PHYs */
        if (phy != HME_PHYAD_EXTERNAL && phy != HME_PHYAD_INTERNAL)
                return -1;

        /* Select the desired PHY in the MIF configuration register */
        v = mifi_cfg = bus_space_read_4(t, mif, HME_MIFI_CFG);
        v &= ~HME_MIF_CFG_PHY;
        if (phy == HME_PHYAD_EXTERNAL)
                v |= HME_MIF_CFG_PHY;
        bus_space_write_4(t, mif, HME_MIFI_CFG, v);

        /* Enable MII drivers on external transceiver */
        v = xif_cfg = bus_space_read_4(t, mac, HME_MACI_XIF);
        if (phy == HME_PHYAD_EXTERNAL)
                v |= HME_MAC_XIF_MIIENABLE;
        else
                v &= ~HME_MAC_XIF_MIIENABLE;
        bus_space_write_4(t, mac, HME_MACI_XIF, v);

#if 0
/* This doesn't work reliably; the MDIO_1 bit is off most of the time */
        /*
         * Check whether a transceiver is connected by testing
         * the MIF configuration register's MDI_X bits. Note that
         * MDI_0 (int) == 0x100 and MDI_1 (ext) == 0x200; see hmereg.h
         */
        mif_mdi_bit = 1 << (8 + (1 - phy));
        delay(100);
        v = bus_space_read_4(t, mif, HME_MIFI_CFG);
        if ((v & mif_mdi_bit) == 0) {
                rv = -1;
                goto out;
        }
#endif

        /* Construct the frame command */
        v = (MII_COMMAND_START << HME_MIF_FO_ST_SHIFT)  |
            HME_MIF_FO_TAMSB                            |
            (MII_COMMAND_WRITE << HME_MIF_FO_OPC_SHIFT) |
            (phy << HME_MIF_FO_PHYAD_SHIFT)             |
            (reg << HME_MIF_FO_REGAD_SHIFT)             |
            (val & HME_MIF_FO_DATA);

        bus_space_write_4(t, mif, HME_MIFI_FO, v);
        for (n = 0; n < 100; n++) {
                DELAY(1);
                v = bus_space_read_4(t, mif, HME_MIFI_FO);
                if (v & HME_MIF_FO_TALSB) {
                        rv = 0;
                        goto out;
                }
        }

        rv = ETIMEDOUT;
        printf("%s: mii_write timeout\n", device_xname(sc->sc_dev));
out:
        /* Restore MIFI_CFG register */
        bus_space_write_4(t, mif, HME_MIFI_CFG, mifi_cfg);
        /* Restore XIF register */
        bus_space_write_4(t, mac, HME_MACI_XIF, xif_cfg);

        return rv;
}

static void
hme_mii_statchg(struct ifnet *ifp)
{
        struct hme_softc *sc = ifp->if_softc;
        bus_space_tag_t t = sc->sc_bustag;
        bus_space_handle_t mac = sc->sc_mac;
        uint32_t v;

#ifdef HMEDEBUG
        if (sc->sc_debug)
                printf("hme_mii_statchg: status change\n");
#endif

        /* Set the MAC Full Duplex bit appropriately */
        /* Apparently the hme chip is SIMPLEX if working in full duplex mode,
           but not otherwise. */
        v = bus_space_read_4(t, mac, HME_MACI_TXCFG);
        if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_FDX) != 0) {
                v |= HME_MAC_TXCFG_FULLDPLX;
                sc->sc_ethercom.ec_if.if_flags |= IFF_SIMPLEX;
        } else {
                v &= ~HME_MAC_TXCFG_FULLDPLX;
                sc->sc_ethercom.ec_if.if_flags &= ~IFF_SIMPLEX;
        }
        sc->sc_if_flags = sc->sc_ethercom.ec_if.if_flags;
        bus_space_write_4(t, mac, HME_MACI_TXCFG, v);
}

int
hme_mediachange(struct ifnet *ifp)
{
        struct hme_softc *sc = ifp->if_softc;
        bus_space_tag_t t = sc->sc_bustag;
        bus_space_handle_t mif = sc->sc_mif;
        bus_space_handle_t mac = sc->sc_mac;
        int instance = IFM_INST(sc->sc_mii.mii_media.ifm_cur->ifm_media);
        int phy = sc->sc_phys[instance];
        int rc;
        uint32_t v;

#ifdef HMEDEBUG
        if (sc->sc_debug)
                printf("hme_mediachange: phy = %d\n", phy);
#endif

        /* Select the current PHY in the MIF configuration register */
        v = bus_space_read_4(t, mif, HME_MIFI_CFG);
        v &= ~HME_MIF_CFG_PHY;
        if (phy == HME_PHYAD_EXTERNAL)
                v |= HME_MIF_CFG_PHY;
        bus_space_write_4(t, mif, HME_MIFI_CFG, v);

        /* If an external transceiver is selected, enable its MII drivers */
        v = bus_space_read_4(t, mac, HME_MACI_XIF);
        v &= ~HME_MAC_XIF_MIIENABLE;
        if (phy == HME_PHYAD_EXTERNAL)
                v |= HME_MAC_XIF_MIIENABLE;
        bus_space_write_4(t, mac, HME_MACI_XIF, v);

        if ((rc = mii_mediachg(&sc->sc_mii)) == ENXIO)
                return 0;
        return rc;
}

/*
 * Process an ioctl request.
 */
int
hme_ioctl(struct ifnet *ifp, unsigned long cmd, void *data)
{
        struct hme_softc *sc = ifp->if_softc;
        struct ifaddr *ifa = (struct ifaddr *)data;
        int s, error = 0;

        s = splnet();

        switch (cmd) {

        case SIOCINITIFADDR:
                switch (ifa->ifa_addr->sa_family) {
#ifdef INET
                case AF_INET:
                        if (ifp->if_flags & IFF_UP)
                                hme_setladrf(sc);
                        else {
                                ifp->if_flags |= IFF_UP;
                                error = hme_init(ifp);
                        }
                        arp_ifinit(ifp, ifa);
                        break;
#endif
                default:
                        ifp->if_flags |= IFF_UP;
                        error = hme_init(ifp);
                        break;
                }
                break;

        case SIOCSIFFLAGS:
#ifdef HMEDEBUG
                {
                        struct ifreq *ifr = data;
                        sc->sc_debug =
                            (ifr->ifr_flags & IFF_DEBUG) != 0 ? 1 : 0;
                }
#endif
                if ((error = ifioctl_common(ifp, cmd, data)) != 0)
                        break;

                switch (ifp->if_flags & (IFF_UP | IFF_RUNNING)) {
                case IFF_RUNNING:
                        /*
                         * If interface is marked down and it is running, then
                         * stop it.
                         */
                        hme_stop(ifp, 0);
                        ifp->if_flags &= ~IFF_RUNNING;
                        break;
                case IFF_UP:
                        /*
                         * If interface is marked up and it is stopped, then
                         * start it.
                         */
                        error = hme_init(ifp);
                        break;
                case IFF_UP | IFF_RUNNING:
                        /*
                         * If setting debug or promiscuous mode, do not reset
                         * the chip; for everything else, call hme_init()
                         * which will trigger a reset.
                         */
#define RESETIGN (IFF_CANTCHANGE | IFF_DEBUG)
                        if (ifp->if_flags != sc->sc_if_flags) {
                                if ((ifp->if_flags & (~RESETIGN))
                                    == (sc->sc_if_flags & (~RESETIGN)))
                                        hme_setladrf(sc);
                                else
                                        error = hme_init(ifp);
                        }
#undef RESETIGN
                        break;
                case 0:
                        break;
                }

                if (sc->sc_ec_capenable != sc->sc_ethercom.ec_capenable)
                        error = hme_init(ifp);

                break;

        default:
                if ((error = ether_ioctl(ifp, cmd, data)) != ENETRESET)
                        break;

                error = 0;

                if (cmd != SIOCADDMULTI && cmd != SIOCDELMULTI)
                        ;
                else if (ifp->if_flags & IFF_RUNNING) {
                        /*
                         * Multicast list has changed; set the hardware filter
                         * accordingly.
                         */
                        hme_setladrf(sc);
                }
                break;
        }

        sc->sc_if_flags = ifp->if_flags;
        splx(s);
        return (error);
}

bool
hme_shutdown(device_t self, int howto)
{
        struct hme_softc *sc;
        struct ifnet *ifp;

        sc = device_private(self);
        ifp = &sc->sc_ethercom.ec_if;
        hme_stop(ifp, 1);

        return true;
}

/*
 * Set up the logical address filter.
 */
void
hme_setladrf(struct hme_softc *sc)
{
        struct ifnet *ifp = &sc->sc_ethercom.ec_if;
        struct ether_multi *enm;
        struct ether_multistep step;
        struct ethercom *ec = &sc->sc_ethercom;
        bus_space_tag_t t = sc->sc_bustag;
        bus_space_handle_t mac = sc->sc_mac;
        uint32_t v;
        uint32_t crc;
        uint32_t hash[4];

        /* Clear hash table */
        hash[3] = hash[2] = hash[1] = hash[0] = 0;

        /* Get current RX configuration */
        v = bus_space_read_4(t, mac, HME_MACI_RXCFG);

        if ((ifp->if_flags & IFF_PROMISC) != 0) {
                /* Turn on promiscuous mode; turn off the hash filter */
                v |= HME_MAC_RXCFG_PMISC;
                v &= ~HME_MAC_RXCFG_HENABLE;
                ifp->if_flags |= IFF_ALLMULTI;
                goto chipit;
        }

        /* Turn off promiscuous mode; turn on the hash filter */
        v &= ~HME_MAC_RXCFG_PMISC;
        v |= HME_MAC_RXCFG_HENABLE;

        /*
         * Set up multicast address filter by passing all multicast addresses
         * through a crc generator, and then using the high order 6 bits as an
         * index into the 64 bit logical address filter.  The high order bit
         * selects the word, while the rest of the bits select the bit within
         * the word.
         */

        ETHER_LOCK(ec);
        ETHER_FIRST_MULTI(step, ec, enm);
        while (enm != NULL) {
                if (memcmp(enm->enm_addrlo, enm->enm_addrhi, ETHER_ADDR_LEN)) {
                        /*
                         * We must listen to a range of multicast addresses.
                         * For now, just accept all multicasts, rather than
                         * trying to set only those filter bits needed to match
                         * the range.  (At this time, the only use of address
                         * ranges is for IP multicast routing, for which the
                         * range is big enough to require all bits set.)
                         */
                        hash[3] = hash[2] = hash[1] = hash[0] = 0xffff;
                        ifp->if_flags |= IFF_ALLMULTI;
                        ETHER_UNLOCK(ec);
                        goto chipit;
                }

                crc = ether_crc32_le(enm->enm_addrlo, ETHER_ADDR_LEN);

                /* Just want the 6 most significant bits. */
                crc >>= 26;

                /* Set the corresponding bit in the filter. */
                hash[crc >> 4] |= 1 << (crc & 0xf);

                ETHER_NEXT_MULTI(step, enm);
        }
        ETHER_UNLOCK(ec);

        ifp->if_flags &= ~IFF_ALLMULTI;

chipit:
        /* Now load the hash table into the chip */
        bus_space_write_4(t, mac, HME_MACI_HASHTAB0, hash[0]);
        bus_space_write_4(t, mac, HME_MACI_HASHTAB1, hash[1]);
        bus_space_write_4(t, mac, HME_MACI_HASHTAB2, hash[2]);
        bus_space_write_4(t, mac, HME_MACI_HASHTAB3, hash[3]);
        bus_space_write_4(t, mac, HME_MACI_RXCFG, v);
}

/*
 * Routines for accessing the transmit and receive buffers.
 * The various CPU and adapter configurations supported by this
 * driver require three different access methods for buffers
 * and descriptors:
 *      (1) contig (contiguous data; no padding),
 *      (2) gap2 (two bytes of data followed by two bytes of padding),
 *      (3) gap16 (16 bytes of data followed by 16 bytes of padding).
 */

#if 0
/*
 * contig: contiguous data with no padding.
 *
 * Buffers may have any alignment.
 */

void
hme_copytobuf_contig(struct hme_softc *sc, void *from, int ri, int len)
{
        volatile void *buf = sc->sc_rb.rb_txbuf + (ri * _HME_BUFSZ);

        /*
         * Just call memcpy() to do the work.
         */
        memcpy(buf, from, len);
}

void
hme_copyfrombuf_contig(struct hme_softc *sc, void *to, int boff, int len)
{
        volatile void *buf = sc->sc_rb.rb_rxbuf + (ri * _HME_BUFSZ);

        /*
         * Just call memcpy() to do the work.
         */
        memcpy(to, buf, len);
}
#endif