/* $NetBSD: lance.c,v 1.34 2005/12/24 20:27:30 perry 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation 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 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 */ #ifdef __rtems__ #include #include #endif #include __FBSDID("$FreeBSD: src/sys/dev/le/lance.c,v 1.4 2007/01/20 10:47:16 marius Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef __rtems__ #include #endif devclass_t le_devclass; static void lance_start(struct ifnet *); static void lance_stop(struct lance_softc *); static void lance_init(void *); static void lance_watchdog(void *s); static int lance_mediachange(struct ifnet *); static void lance_mediastatus(struct ifnet *, struct ifmediareq *); #ifndef __rtems__ static int lance_ioctl(struct ifnet *, u_long, caddr_t); #else static int lance_ioctl(struct ifnet *, ioctl_command_t, caddr_t); #endif int lance_config(struct lance_softc *sc, const char* name, int unit) { struct ifnet *ifp; int i, nbuf; if (LE_LOCK_INITIALIZED(sc) == 0) return (ENXIO); ifp = sc->sc_ifp = if_alloc(IFT_ETHER); if (ifp == NULL) return (ENOSPC); callout_init_mtx(&sc->sc_wdog_ch, &sc->sc_mtx, 0); /* Initialize ifnet structure. */ ifp->if_softc = sc; if_initname(ifp, name, unit); ifp->if_start = lance_start; ifp->if_ioctl = lance_ioctl; ifp->if_init = lance_init; ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; #ifdef LANCE_REVC_BUG ifp->if_flags &= ~IFF_MULTICAST; #endif ifp->if_baudrate = IF_Mbps(10); IFQ_SET_MAXLEN(&ifp->if_snd, IFQ_MAXLEN); ifp->if_snd.ifq_drv_maxlen = IFQ_MAXLEN; IFQ_SET_READY(&ifp->if_snd); /* Initialize ifmedia structures. */ 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_MAKEWORD(IFM_ETHER, IFM_MANUAL, 0, 0), 0, NULL); ifmedia_set(&sc->sc_media, IFM_MAKEWORD(IFM_ETHER, IFM_MANUAL, 0, 0)); } #ifdef __rtems__ assert( (sc->sc_nrbuf == 0) == (sc->sc_ntbuf == 0) ); assert( sc->sc_memsize >= (sc->sc_nrbuf + sc->sc_ntbuf)*LEBLEN); /* Only set ring sizes if not defined yet */ if ( sc->sc_nrbuf == 0 ) #endif 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; } if_printf(ifp, "%d receive buffers, %d transmit buffers\n", sc->sc_nrbuf, sc->sc_ntbuf); /* Make sure the chip is stopped. */ LE_LOCK(sc); lance_stop(sc); LE_UNLOCK(sc); return (0); } void lance_attach(struct lance_softc *sc) { struct ifnet *ifp = sc->sc_ifp; /* Attach the interface. */ ether_ifattach(ifp, sc->sc_enaddr); #ifndef __rtems__ /* Claim 802.1q capability. */ ifp->if_data.ifi_hdrlen = sizeof(struct ether_vlan_header); ifp->if_capabilities |= IFCAP_VLAN_MTU; ifp->if_capenable |= IFCAP_VLAN_MTU; #endif } void lance_detach(struct lance_softc *sc) { struct ifnet *ifp = sc->sc_ifp; LE_LOCK(sc); lance_stop(sc); LE_UNLOCK(sc); callout_drain(&sc->sc_wdog_ch); ether_ifdetach(ifp); if_free(ifp); } void lance_suspend(struct lance_softc *sc) { LE_LOCK(sc); lance_stop(sc); LE_UNLOCK(sc); } void lance_resume(struct lance_softc *sc) { LE_LOCK(sc); if (sc->sc_ifp->if_flags & IFF_UP) lance_init_locked(sc); LE_UNLOCK(sc); } static void lance_start(struct ifnet *ifp) { struct lance_softc *sc = ifp->if_softc; LE_LOCK(sc); (*sc->sc_start_locked)(sc); LE_UNLOCK(sc); } static void lance_stop(struct lance_softc *sc) { struct ifnet *ifp = sc->sc_ifp; LE_LOCK_ASSERT(sc, MA_OWNED); /* * Mark the interface down and cancel the watchdog timer. */ ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE); callout_stop(&sc->sc_wdog_ch); sc->sc_wdog_timer = 0; (*sc->sc_wrcsr)(sc, LE_CSR0, LE_C0_STOP); } static void lance_init(void *xsc) { struct lance_softc *sc = (struct lance_softc *)xsc; LE_LOCK(sc); lance_init_locked(sc); LE_UNLOCK(sc); } /* * Initialization of interface; set up initialization block * and transmit/receive descriptor rings. */ void lance_init_locked(struct lance_softc *sc) { struct ifnet *ifp = sc->sc_ifp; u_long a; int timo; LE_LOCK_ASSERT(sc, MA_OWNED); (*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 the current media. This may require the chip to be stopped. */ if (sc->sc_mediachange) (void)(*sc->sc_mediachange)(sc); /* * Update our private copy of the Ethernet address. * We NEED the copy so we can ensure its alignment! */ memcpy(sc->sc_enaddr, IF_LLADDR(ifp), ETHER_ADDR_LEN); /* 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 & 0xffff); (*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_drv_flags |= IFF_DRV_RUNNING; ifp->if_drv_flags &= ~IFF_DRV_OACTIVE; sc->sc_wdog_timer = 0; callout_reset(&sc->sc_wdog_ch, hz, lance_watchdog, sc); (*sc->sc_start_locked)(sc); } else if_printf(ifp, "controller failed to initialize\n"); if (sc->sc_hwinit) (*sc->sc_hwinit)(sc); } /* * 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; LE_LOCK_ASSERT(sc, MA_OWNED); for (; m; m = n) { len = m->m_len; if (len == 0) { n = m_free(m); m = NULL; continue; } (*sc->sc_copytobuf)(sc, mtod(m, caddr_t), boff, len); boff += len; tlen += len; n = m_free(m); m = NULL; } 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. */ struct mbuf * lance_get(struct lance_softc *sc, int boff, int totlen) { struct ifnet *ifp = sc->sc_ifp; struct mbuf *m, *m0, *newm; caddr_t newdata; int len; if (totlen <= ETHER_HDR_LEN || totlen > LEBLEN - ETHER_CRC_LEN) { #ifdef LEDEBUG if_printf(ifp, "invalid packet size %d; dropping\n", totlen); #endif return (NULL); } MGETHDR(m0, M_DONTWAIT, MT_DATA); if (m0 == NULL) return (NULL); m0->m_pkthdr.rcvif = ifp; 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) { newdata = (caddr_t) ALIGN(m->m_data + ETHER_HDR_LEN) - ETHER_HDR_LEN; len -= newdata - m->m_data; m->m_data = newdata; } m->m_len = len = min(totlen, len); (*sc->sc_copyfrombuf)(sc, mtod(m, caddr_t), boff, len); boff += len; totlen -= len; if (totlen > 0) { MGET(newm, M_DONTWAIT, MT_DATA); if (newm == 0) goto bad; len = MLEN; m = m->m_next = newm; } } return (m0); bad: m_freem(m0); return (NULL); } static void lance_watchdog(void *xsc) { struct lance_softc *sc = (struct lance_softc *)xsc; struct ifnet *ifp = sc->sc_ifp; LE_LOCK_ASSERT(sc, MA_OWNED); if (sc->sc_wdog_timer == 0 || --sc->sc_wdog_timer != 0) { callout_reset(&sc->sc_wdog_ch, hz, lance_watchdog, sc); return; } if_printf(ifp, "device timeout\n"); ++ifp->if_oerrors; lance_init_locked(sc); } static int lance_mediachange(struct ifnet *ifp) { struct lance_softc *sc = ifp->if_softc; if (sc->sc_mediachange) { /* * For setting the port in LE_CSR15 the PCnet chips must * be powered down or stopped and unlike documented may * not take effect without an initialization. So don't * invoke (*sc_mediachange) directly here but go through * lance_init_locked(). */ LE_LOCK(sc); lance_stop(sc); lance_init_locked(sc); if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd)) (*sc->sc_start_locked)(sc); LE_UNLOCK(sc); } return (0); } static void lance_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr) { struct lance_softc *sc = ifp->if_softc; LE_LOCK(sc); if (!(ifp->if_flags & IFF_UP)) { LE_UNLOCK(sc); return; } ifmr->ifm_status = IFM_AVALID; if (sc->sc_flags & LE_CARRIER) ifmr->ifm_status |= IFM_ACTIVE; if (sc->sc_mediastatus) (*sc->sc_mediastatus)(sc, ifmr); LE_UNLOCK(sc); } /* * Process an ioctl request. */ static int #ifndef __rtems__ lance_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) #else lance_ioctl(struct ifnet *ifp, ioctl_command_t cmd, caddr_t data) #endif { struct lance_softc *sc = ifp->if_softc; struct ifreq *ifr = (struct ifreq *)data; int error = 0; switch (cmd) { case SIOCSIFFLAGS: LE_LOCK(sc); if (ifp->if_flags & IFF_PROMISC) { if (!(sc->sc_flags & LE_PROMISC)) { sc->sc_flags |= LE_PROMISC; lance_init_locked(sc); } } else if (sc->sc_flags & LE_PROMISC) { sc->sc_flags &= ~LE_PROMISC; lance_init_locked(sc); } if ((ifp->if_flags & IFF_ALLMULTI) && !(sc->sc_flags & LE_ALLMULTI)) { sc->sc_flags |= LE_ALLMULTI; lance_init_locked(sc); } else if (!(ifp->if_flags & IFF_ALLMULTI) && (sc->sc_flags & LE_ALLMULTI)) { sc->sc_flags &= ~LE_ALLMULTI; lance_init_locked(sc); } if (!(ifp->if_flags & IFF_UP) && ifp->if_drv_flags & IFF_DRV_RUNNING) { /* * If interface is marked down and it is running, then * stop it. */ lance_stop(sc); } else if (ifp->if_flags & IFF_UP && !(ifp->if_drv_flags & IFF_DRV_RUNNING)) { /* * If interface is marked up and it is stopped, then * start it. */ lance_init_locked(sc); } #ifdef LEDEBUG if (ifp->if_flags & IFF_DEBUG) sc->sc_flags |= LE_DEBUG; else sc->sc_flags &= ~LE_DEBUG; #endif LE_UNLOCK(sc); break; case SIOCADDMULTI: case SIOCDELMULTI: #ifdef __rtems__ if ( ETHER_SIOCMULTIFRAG( error, cmd, ifr, ifp ) ) break; #endif /* * Multicast list has changed; set the hardware filter * accordingly. */ LE_LOCK(sc); if (ifp->if_drv_flags & IFF_DRV_RUNNING) lance_init_locked(sc); LE_UNLOCK(sc); break; case SIOCGIFMEDIA: case SIOCSIFMEDIA: error = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd); break; default: error = ether_ioctl(ifp, cmd, data); break; } return (error); } /* * Set up the logical address filter. */ void lance_setladrf(struct lance_softc *sc, uint16_t *af) { struct ifnet *ifp = sc->sc_ifp; #ifndef __rtems__ struct ifmultiaddr *ifma; #endif uint32_t crc; /* * 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 || sc->sc_flags & LE_ALLMULTI) { af[0] = af[1] = af[2] = af[3] = 0xffff; return; } af[0] = af[1] = af[2] = af[3] = 0x0000; #ifndef __rtems__ IF_ADDR_LOCK(ifp); TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) { if (ifma->ifma_addr->sa_family != AF_LINK) continue; crc = ether_crc32_le(LLADDR((struct sockaddr_dl *) ifma->ifma_addr), ETHER_ADDR_LEN); /* Just want the 6 most significant bits. */ crc >>= 26; /* Set the corresponding bit in the filter. */ af[crc >> 4] |= LE_HTOLE16(1 << (crc & 0xf)); } IF_ADDR_UNLOCK(ifp); #else { /* UNTESTED */ struct ether_multi *enm; struct ether_multistep step; ETHER_FIRST_MULTI(step, (struct arpcom *)ifp, enm); while ( enm != NULL ) { crc = ether_crc32_le(enm->enm_addrlo, ETHER_ADDR_LEN) >> 26; /* Just want the 6 most significant bits. */ crc >>= 26; /* Set the corresponding bit in the filter. */ af[crc >> 4] |= LE_HTOLE16(1 << (crc & 0xf)); ETHER_NEXT_MULTI( step, enm ); } } #endif } /* * 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) { volatile caddr_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) { volatile caddr_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) { volatile caddr_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. */ static void lance_copytobuf_gap2(struct lance_softc *sc, void *fromv, int boff, int len) { volatile caddr_t buf = sc->sc_mem; caddr_t 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; } static void lance_copyfrombuf_gap2(struct lance_softc *sc, void *tov, int boff, int len) { volatile caddr_t buf = sc->sc_mem; caddr_t 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; } static void lance_zerobuf_gap2(struct lance_softc *sc, int boff, int len) { volatile caddr_t buf = sc->sc_mem; volatile uint16_t *bptr; if ((unsigned)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. */ static void lance_copytobuf_gap16(struct lance_softc *sc, void *fromv, int boff, int len) { volatile caddr_t buf = sc->sc_mem; caddr_t bptr, from = fromv; int xfer; bptr = buf + ((boff << 1) & ~0x1f); boff &= 0xf; xfer = min(len, 16 - boff); while (len > 0) { memcpy(bptr + boff, from, xfer); from += xfer; bptr += 32; boff = 0; len -= xfer; xfer = min(len, 16); } } static void lance_copyfrombuf_gap16(struct lance_softc *sc, void *tov, int boff, int len) { volatile caddr_t buf = sc->sc_mem; caddr_t bptr, to = tov; int xfer; bptr = buf + ((boff << 1) & ~0x1f); boff &= 0xf; xfer = min(len, 16 - boff); while (len > 0) { memcpy(to, bptr + boff, xfer); to += xfer; bptr += 32; boff = 0; len -= xfer; xfer = min(len, 16); } } static void lance_zerobuf_gap16(struct lance_softc *sc, int boff, int len) { volatile caddr_t buf = sc->sc_mem; caddr_t bptr; int xfer; bptr = buf + ((boff << 1) & ~0x1f); boff &= 0xf; xfer = min(len, 16 - boff); while (len > 0) { memset(bptr + boff, 0, xfer); bptr += 32; boff = 0; len -= xfer; xfer = min(len, 16); } } #endif /* Example only */