/*      $NetBSD: lance.c,v 1.62 2024/11/17 09:28:34 hannken Exp $       */

/*-
* Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Charles M. Hannum and by Jason R. Thorpe of the Numerical Aerospace
* Simulation Facility, NASA Ames Research Center.
*
* 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.
*/

/*-
* Copyright (c) 1992, 1993
*      The Regents of the University of California.  All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Ralph Campbell and Rick Macklem.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
*      @(#)if_le.c     8.2 (Berkeley) 11/16/93
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: lance.c,v 1.62 2024/11/17 09:28:34 hannken Exp $");

#include <sys/param.h>
#include <sys/systm.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>

#include <dev/ic/lancereg.h>
#include <dev/ic/lancevar.h>

#if defined(_KERNEL_OPT)
#include "opt_ddb.h"
#endif

#ifdef DDB
#define integrate
#define hide
#else
#define integrate       static inline
#define hide            static
#endif

integrate struct mbuf *lance_get(struct lance_softc *, int, int);

hide bool lance_shutdown(device_t, int);

int lance_mediachange(struct ifnet *);
void lance_mediastatus(struct ifnet *, struct ifmediareq *);

static inline uint16_t ether_cmp(void *, void *);

void lance_stop(struct ifnet *, int);
int lance_ioctl(struct ifnet *, u_long, void *);
void lance_watchdog(struct ifnet *);

/*
* Compare two Ether/802 addresses for equality, inlined and
* unrolled for speed.  Use this like memcmp().
*
* XXX: Add <machine/inlines.h> for stuff like this?
* XXX: or maybe add it to libkern.h instead?
*
* "I'd love to have an inline assembler version of this."
* XXX: Who wanted that? mycroft?  I wrote one, but this
* version in C is as good as hand-coded assembly. -gwr
*
* Please do NOT tweak this without looking at the actual
* assembly code generated before and after your tweaks!
*/
static inline uint16_t
ether_cmp(void *one, void *two)
{
       uint16_t *a = (uint16_t *)one;
       uint16_t *b = (uint16_t *)two;
       uint16_t diff;

#ifdef  m68k
       /*
        * The post-increment-pointer form produces the best
        * machine code for m68k.  This was carefully tuned
        * so it compiles to just 8 short (2-byte) op-codes!
        */
       diff  = *a++ - *b++;
       diff |= *a++ - *b++;
       diff |= *a++ - *b++;
#else
       /*
        * Most modern CPUs do better with a single expression.
        * Note that short-cut evaluation is NOT helpful here,
        * because it just makes the code longer, not faster!
        */
       diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]);
#endif

       return (diff);
}

#define ETHER_CMP       ether_cmp

#ifdef LANCE_REVC_BUG
/* Make sure this is short-aligned, for ether_cmp(). */
static uint16_t bcast_enaddr[3] = { ~0, ~0, ~0 };
#endif

void
lance_config(struct lance_softc *sc)
{
       int i, nbuf;
       struct ifnet *ifp = &sc->sc_ethercom.ec_if;

       /* Initialize ifnet structure. */
       strcpy(ifp->if_xname, device_xname(sc->sc_dev));
       ifp->if_softc = sc;
       ifp->if_start = sc->sc_start;
       ifp->if_ioctl = lance_ioctl;
       ifp->if_watchdog = lance_watchdog;
       ifp->if_init = lance_init;
       ifp->if_stop = lance_stop;
       ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
#ifdef LANCE_REVC_BUG
       ifp->if_flags &= ~IFF_MULTICAST;
#endif
       IFQ_SET_READY(&ifp->if_snd);

       /* Initialize ifmedia structures. */
       sc->sc_ethercom.ec_ifmedia = &sc->sc_media;
       ifmedia_init(&sc->sc_media, 0, lance_mediachange, lance_mediastatus);
       if (sc->sc_supmedia != NULL) {
               for (i = 0; i < sc->sc_nsupmedia; i++)
                       ifmedia_add(&sc->sc_media, sc->sc_supmedia[i],
                          0, NULL);
               ifmedia_set(&sc->sc_media, sc->sc_defaultmedia);
       } else {
               ifmedia_add(&sc->sc_media, IFM_ETHER | IFM_MANUAL, 0, NULL);
               ifmedia_set(&sc->sc_media, IFM_ETHER | IFM_MANUAL);
       }

       switch (sc->sc_memsize) {
       case 8192:
               sc->sc_nrbuf = 4;
               sc->sc_ntbuf = 1;
               break;
       case 16384:
               sc->sc_nrbuf = 8;
               sc->sc_ntbuf = 2;
               break;
       case 32768:
               sc->sc_nrbuf = 16;
               sc->sc_ntbuf = 4;
               break;
       case 65536:
               sc->sc_nrbuf = 32;
               sc->sc_ntbuf = 8;
               break;
       case 131072:
               sc->sc_nrbuf = 64;
               sc->sc_ntbuf = 16;
               break;
       case 262144:
               sc->sc_nrbuf = 128;
               sc->sc_ntbuf = 32;
               break;
       default:
               /* weird memory size; cope with it */
               nbuf = sc->sc_memsize / LEBLEN;
               sc->sc_ntbuf = nbuf / 5;
               sc->sc_nrbuf = nbuf - sc->sc_ntbuf;
       }

       aprint_normal(": address %s\n", ether_sprintf(sc->sc_enaddr));
       aprint_normal_dev(sc->sc_dev,
           "%d receive buffers, %d transmit buffers\n",
           sc->sc_nrbuf, sc->sc_ntbuf);

       /* Make sure the chip is stopped. */
       lance_stop(ifp, 0);

       /* claim 802.1q capability */
       sc->sc_ethercom.ec_capabilities |= ETHERCAP_VLAN_MTU;
       /* Attach the interface. */
       if_attach(ifp);
       ether_ifattach(ifp, sc->sc_enaddr);

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

       sc->sc_rbufaddr = malloc(sc->sc_nrbuf * sizeof(int), M_DEVBUF,
                                       M_WAITOK);
       sc->sc_tbufaddr = malloc(sc->sc_ntbuf * sizeof(int), M_DEVBUF,
                                       M_WAITOK);

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

void
lance_reset(struct lance_softc *sc)
{
       int s;

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

void
lance_stop(struct ifnet *ifp, int disable)
{
       struct lance_softc *sc = ifp->if_softc;

       (*sc->sc_wrcsr)(sc, LE_CSR0, LE_C0_STOP);
}

/*
* Initialization of interface; set up initialization block
* and transmit/receive descriptor rings.
*/
int
lance_init(struct ifnet *ifp)
{
       struct lance_softc *sc = ifp->if_softc;
       int timo;
       u_long a;

       (*sc->sc_wrcsr)(sc, LE_CSR0, LE_C0_STOP);
       DELAY(100);

       /* Newer LANCE chips have a reset register */
       if (sc->sc_hwreset)
               (*sc->sc_hwreset)(sc);

       /* Set the correct byte swapping mode, etc. */
       (*sc->sc_wrcsr)(sc, LE_CSR3, sc->sc_conf3);

       /* Set up LANCE init block. */
       (*sc->sc_meminit)(sc);

       /* Give LANCE the physical address of its init block. */
       a = sc->sc_addr + LE_INITADDR(sc);
       (*sc->sc_wrcsr)(sc, LE_CSR1, a);
       (*sc->sc_wrcsr)(sc, LE_CSR2, a >> 16);

       /* Try to initialize the LANCE. */
       DELAY(100);
       (*sc->sc_wrcsr)(sc, LE_CSR0, LE_C0_INIT);

       /* Wait for initialization to finish. */
       for (timo = 100000; timo; timo--)
               if ((*sc->sc_rdcsr)(sc, LE_CSR0) & LE_C0_IDON)
                       break;

       if ((*sc->sc_rdcsr)(sc, LE_CSR0) & LE_C0_IDON) {
               /* Start the LANCE. */
               (*sc->sc_wrcsr)(sc, LE_CSR0, LE_C0_INEA | LE_C0_STRT);
               ifp->if_flags |= IFF_RUNNING;
               ifp->if_flags &= ~IFF_OACTIVE;
               ifp->if_timer = 0;
               (*sc->sc_start)(ifp);
       } else
               printf("%s: controller failed to initialize\n",
                       device_xname(sc->sc_dev));
       if (sc->sc_hwinit)
               (*sc->sc_hwinit)(sc);

       return (0);
}

/*
* Routine to copy from mbuf chain to transmit buffer in
* network buffer memory.
*/
int
lance_put(struct lance_softc *sc, int boff, struct mbuf *m)
{
       struct mbuf *n;
       int len, tlen = 0;

       for (; m; m = n) {
               len = m->m_len;
               if (len == 0) {
                       n = m_free(m);
                       continue;
               }
               (*sc->sc_copytobuf)(sc, mtod(m, void *), boff, len);
               boff += len;
               tlen += len;
               n = m_free(m);
       }
       if (tlen < LEMINSIZE) {
               (*sc->sc_zerobuf)(sc, boff, LEMINSIZE - tlen);
               tlen = LEMINSIZE;
       }
       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.
*/
integrate struct mbuf *
lance_get(struct lance_softc *sc, int boff, int totlen)
{
       struct mbuf *m, *m0, *newm;
       int len;

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

       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);
               (*sc->sc_copyfrombuf)(sc, mtod(m, void *), boff, len);
               boff += len;

               totlen -= len;
               if (totlen > 0) {
                       MGET(newm, M_DONTWAIT, MT_DATA);
                       if (newm == 0)
                               goto bad;
                       MCLAIM(newm, &sc->sc_ethercom.ec_rx_mowner);
                       len = MLEN;
                       m = m->m_next = newm;
               }
       }

       return (m0);

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

/*
* Pass a packet to the higher levels.
*/
void
lance_read(struct lance_softc *sc, int boff, int len)
{
       struct mbuf *m;
       struct ifnet *ifp = &sc->sc_ethercom.ec_if;
       struct ether_header *eh;

       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 LEDEBUG
               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 = lance_get(sc, boff, len);
       if (m == 0) {
               if_statinc(ifp, if_ierrors);
               return;
       }

       eh = mtod(m, struct ether_header *);

#ifdef LANCE_REVC_BUG
       /*
        * The old LANCE (Rev. C) chips have a bug which causes
        * garbage to be inserted in front of the received packet.
        * The work-around is to ignore packets with an invalid
        * destination address (garbage will usually not match).
        * Of course, this precludes multicast support...
        */
       if (ETHER_CMP(eh->ether_dhost, sc->sc_enaddr) &&
           ETHER_CMP(eh->ether_dhost, bcast_enaddr)) {
               m_freem(m);
               return;
       }
#endif

       /*
        * Some lance device does not present IFF_SIMPLEX behavior on multicast
        * packets.  Make sure to drop it if it is from ourselves.
        */
       if (!ETHER_CMP(eh->ether_shost, sc->sc_enaddr)) {
               m_freem(m);
               return;
       }

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

#undef  ifp

void
lance_watchdog(struct ifnet *ifp)
{
       struct lance_softc *sc = ifp->if_softc;

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

       lance_reset(sc);
}

int
lance_mediachange(struct ifnet *ifp)
{
       struct lance_softc *sc = ifp->if_softc;

       if (sc->sc_mediachange)
               return ((*sc->sc_mediachange)(sc));
       return (0);
}

void
lance_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
{
       struct lance_softc *sc = ifp->if_softc;

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

       ifmr->ifm_status = IFM_AVALID;
       if (sc->sc_havecarrier)
               ifmr->ifm_status |= IFM_ACTIVE;

       if (sc->sc_mediastatus)
               (*sc->sc_mediastatus)(sc, ifmr);
}

/*
* Process an ioctl request.
*/
int
lance_ioctl(struct ifnet *ifp, u_long cmd, void *data)
{
       struct lance_softc *sc = ifp->if_softc;
       int s, error = 0;

       s = splnet();

       switch (cmd) {
       default:
               if ((error = ether_ioctl(ifp, cmd, data)) != ENETRESET)
                       break;
               error = 0;
               if (cmd != SIOCADDMULTI && cmd != SIOCDELMULTI)
                       break;
               if (ifp->if_flags & IFF_RUNNING) {
                       /*
                        * Multicast list has changed; set the hardware filter
                        * accordingly.
                        */
                       lance_reset(sc);
               }
               break;

       }

       splx(s);
       return (error);
}

hide bool
lance_shutdown(device_t self, int howto)
{
       struct lance_softc *sc = device_private(self);
       struct ifnet *ifp = &sc->sc_ethercom.ec_if;

       lance_stop(ifp, 0);

       return true;
}

/*
* Set up the logical address filter.
*/
void
lance_setladrf(struct ethercom *ec, uint16_t *af)
{
       struct ifnet *ifp = &ec->ec_if;
       struct ether_multi *enm;
       uint32_t crc;
       struct ether_multistep step;

       /*
        * 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.
        */

       if (ifp->if_flags & IFF_PROMISC)
               goto allmulti;

       af[0] = af[1] = af[2] = af[3] = 0x0000;

       ETHER_LOCK(ec);
       ETHER_FIRST_MULTI(step, ec, enm);
       while (enm != NULL) {
               if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) {
                       /*
                        * 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.)
                        */
                       ETHER_UNLOCK(ec);
                       goto allmulti;
               }

               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. */
               af[crc >> 4] |= 1 << (crc & 0xf);

               ETHER_NEXT_MULTI(step, enm);
       }
       ETHER_UNLOCK(ec);
       ifp->if_flags &= ~IFF_ALLMULTI;
       return;

allmulti:
       ifp->if_flags |= IFF_ALLMULTI;
       af[0] = af[1] = af[2] = af[3] = 0xffff;
}

/*
* 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).
*/

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

void
lance_copytobuf_contig(struct lance_softc *sc, void *from, int boff, int len)
{
       uint8_t *buf = sc->sc_mem;

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

void
lance_copyfrombuf_contig(struct lance_softc *sc, void *to, int boff, int len)
{
       uint8_t *buf = sc->sc_mem;

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

void
lance_zerobuf_contig(struct lance_softc *sc, int boff, int len)
{
       uint8_t *buf = sc->sc_mem;

       /*
        * Just let memset() do the work
        */
       memset(buf + boff, 0, len);
}

#if 0
/*
* Examples only; duplicate these and tweak (if necessary) in
* machine-specific front-ends.
*/

/*
* gap2: two bytes of data followed by two bytes of pad.
*
* Buffers must be 4-byte aligned.  The code doesn't worry about
* doing an extra byte.
*/

void
lance_copytobuf_gap2(struct lance_softc *sc, void *fromv, int boff, int len)
{
       volatile void *buf = sc->sc_mem;
       void *from = fromv;
       volatile uint16_t *bptr;

       if (boff & 0x1) {
               /* handle unaligned first byte */
               bptr = ((volatile uint16_t *)buf) + (boff - 1);
               *bptr = (*from++ << 8) | (*bptr & 0xff);
               bptr += 2;
               len--;
       } else
               bptr = ((volatile uint16_t *)buf) + boff;
       while (len > 1) {
               *bptr = (from[1] << 8) | (from[0] & 0xff);
               bptr += 2;
               from += 2;
               len -= 2;
       }
       if (len == 1)
               *bptr = (uint16_t)*from;
}

void
lance_copyfrombuf_gap2(struct lance_softc *sc, void *tov, int boff, int len)
{
       volatile void *buf = sc->sc_mem;
       void *to = tov;
       volatile uint16_t *bptr;
       uint16_t tmp;

       if (boff & 0x1) {
               /* handle unaligned first byte */
               bptr = ((volatile uint16_t *)buf) + (boff - 1);
               *to++ = (*bptr >> 8) & 0xff;
               bptr += 2;
               len--;
       } else
               bptr = ((volatile uint16_t *)buf) + boff;
       while (len > 1) {
               tmp = *bptr;
               *to++ = tmp & 0xff;
               *to++ = (tmp >> 8) & 0xff;
               bptr += 2;
               len -= 2;
       }
       if (len == 1)
               *to = *bptr & 0xff;
}

void
lance_zerobuf_gap2(struct lance_softc *sc, int boff, int len)
{
       volatile void *buf = sc->sc_mem;
       volatile uint16_t *bptr;

       if ((unsigned int)boff & 0x1) {
               bptr = ((volatile uint16_t *)buf) + (boff - 1);
               *bptr &= 0xff;
               bptr += 2;
               len--;
       } else
               bptr = ((volatile uint16_t *)buf) + boff;
       while (len > 0) {
               *bptr = 0;
               bptr += 2;
               len -= 2;
       }
}

/*
* gap16: 16 bytes of data followed by 16 bytes of pad.
*
* Buffers must be 32-byte aligned.
*/

void
lance_copytobuf_gap16(struct lance_softc *sc, void *fromv, int boff, int len)
{
       volatile uint8_t *buf = sc->sc_mem;
       void *from = fromv;
       uint8_t *bptr;
       int xfer;

       bptr = buf + ((boff << 1) & ~0x1f);
       boff &= 0xf;
       xfer = uimin(len, 16 - boff);
       while (len > 0) {
               memcpy(bptr + boff, from, xfer);
               from += xfer;
               bptr += 32;
               boff = 0;
               len -= xfer;
               xfer = uimin(len, 16);
       }
}

void
lance_copyfrombuf_gap16(struct lance_softc *sc, void *tov, int boff, int len)
{
       volatile uint8_t *buf = sc->sc_mem;
       void *to = tov;
       uint8_t *bptr;
       int xfer;

       bptr = buf + ((boff << 1) & ~0x1f);
       boff &= 0xf;
       xfer = uimin(len, 16 - boff);
       while (len > 0) {
               memcpy(to, bptr + boff, xfer);
               to += xfer;
               bptr += 32;
               boff = 0;
               len -= xfer;
               xfer = uimin(len, 16);
       }
}

void
lance_zerobuf_gap16(struct lance_softc *sc, int boff, int len)
{
       volatile uint8_t *buf = sc->sc_mem;
       uint8_t *bptr;
       int xfer;

       bptr = buf + ((boff << 1) & ~0x1f);
       boff &= 0xf;
       xfer = uimin(len, 16 - boff);
       while (len > 0) {
               memset(bptr + boff, 0, xfer);
               bptr += 32;
               boff = 0;
               len -= xfer;
               xfer = uimin(len, 16);
       }
}
#endif /* Example only */