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am79c950.c revision 1.38.12.3
      1 /*	$NetBSD: am79c950.c,v 1.38.12.3 2018/09/06 06:55:37 pgoyette Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1997 David Huang <khym (at) bga.com>
      5  * All rights reserved.
      6  *
      7  * Portions of this code are based on code by Denton Gentry <denny1 (at) home.com>,
      8  * Charles M. Hannum, Yanagisawa Takeshi <yanagisw (at) aa.ap.titech.ac.jp>, and
      9  * Jason R. Thorpe.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. The name of the author may not be used to endorse or promote products
     17  *    derived from this software without specific prior written permission
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  *
     30  */
     31 
     32 /*
     33  * Driver for the AMD Am79C940 (MACE) ethernet chip, used for onboard
     34  * ethernet on the Centris/Quadra 660av and Quadra 840av.
     35  */
     36 
     37 #include <sys/cdefs.h>
     38 __KERNEL_RCSID(0, "$NetBSD: am79c950.c,v 1.38.12.3 2018/09/06 06:55:37 pgoyette Exp $");
     39 
     40 #include "opt_inet.h"
     41 
     42 #include <sys/param.h>
     43 #include <sys/systm.h>
     44 #include <sys/mbuf.h>
     45 #include <sys/buf.h>
     46 #include <sys/protosw.h>
     47 #include <sys/socket.h>
     48 #include <sys/syslog.h>
     49 #include <sys/ioctl.h>
     50 #include <sys/errno.h>
     51 #include <sys/device.h>
     52 
     53 #include <net/if.h>
     54 #include <net/if_dl.h>
     55 #include <net/if_ether.h>
     56 #include <net/if_media.h>
     57 #include <net/bpf.h>
     58 
     59 #ifdef INET
     60 #include <netinet/in.h>
     61 #include <netinet/if_inarp.h>
     62 #include <netinet/in_systm.h>
     63 #include <netinet/in_var.h>
     64 #include <netinet/ip.h>
     65 #endif
     66 
     67 #include <sys/bus.h>
     68 
     69 #include <macppc/dev/am79c950reg.h>
     70 #include <macppc/dev/if_mcvar.h>
     71 
     72 hide void	mcwatchdog(struct ifnet *);
     73 hide int	mcinit(struct mc_softc *sc);
     74 hide int	mcstop(struct mc_softc *sc);
     75 hide int	mcioctl(struct ifnet *ifp, u_long cmd, void *data);
     76 hide void	mcstart(struct ifnet *ifp);
     77 hide void	mcreset(struct mc_softc *sc);
     78 
     79 integrate u_int	maceput(struct mc_softc *sc, struct mbuf *m0);
     80 integrate void	mc_tint(struct mc_softc *sc);
     81 integrate void	mace_read(struct mc_softc *, uint8_t *, int);
     82 integrate struct mbuf *mace_get(struct mc_softc *, uint8_t *, int);
     83 static void mace_calcladrf(struct ethercom *ac, u_int8_t *af);
     84 static inline u_int16_t ether_cmp(void *, void *);
     85 static int mc_mediachange(struct ifnet *);
     86 static void mc_mediastatus(struct ifnet *, struct ifmediareq *);
     87 
     88 /*
     89  * Compare two Ether/802 addresses for equality, inlined and
     90  * unrolled for speed.  Use this like memcmp().
     91  *
     92  * XXX: Add <machine/inlines.h> for stuff like this?
     93  * XXX: or maybe add it to libkern.h instead?
     94  *
     95  * "I'd love to have an inline assembler version of this."
     96  * XXX: Who wanted that? mycroft?  I wrote one, but this
     97  * version in C is as good as hand-coded assembly. -gwr
     98  *
     99  * Please do NOT tweak this without looking at the actual
    100  * assembly code generated before and after your tweaks!
    101  */
    102 static inline u_int16_t
    103 ether_cmp(void *one, void *two)
    104 {
    105 	register u_int16_t *a = (u_short *) one;
    106 	register u_int16_t *b = (u_short *) two;
    107 	register u_int16_t diff;
    108 
    109 #ifdef	m68k
    110 	/*
    111 	 * The post-increment-pointer form produces the best
    112 	 * machine code for m68k.  This was carefully tuned
    113 	 * so it compiles to just 8 short (2-byte) op-codes!
    114 	 */
    115 	diff  = *a++ - *b++;
    116 	diff |= *a++ - *b++;
    117 	diff |= *a++ - *b++;
    118 #else
    119 	/*
    120 	 * Most modern CPUs do better with a single expresion.
    121 	 * Note that short-cut evaluation is NOT helpful here,
    122 	 * because it just makes the code longer, not faster!
    123 	 */
    124 	diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]);
    125 #endif
    126 
    127 	return (diff);
    128 }
    129 
    130 #define ETHER_CMP	ether_cmp
    131 
    132 /*
    133  * Interface exists: make available by filling in network interface
    134  * record.  System will initialize the interface when it is ready
    135  * to accept packets.
    136  */
    137 int
    138 mcsetup(struct mc_softc *sc, u_int8_t *lladdr)
    139 {
    140 	struct ifnet *ifp = &sc->sc_if;
    141 
    142 	/* reset the chip and disable all interrupts */
    143 	NIC_PUT(sc, MACE_BIUCC, SWRST);
    144 	DELAY(100);
    145 	NIC_PUT(sc, MACE_IMR, ~0);
    146 
    147 	memcpy(sc->sc_enaddr, lladdr, ETHER_ADDR_LEN);
    148 	printf(": address %s\n", ether_sprintf(lladdr));
    149 
    150 	memcpy(ifp->if_xname, device_xname(sc->sc_dev), IFNAMSIZ);
    151 	ifp->if_softc = sc;
    152 	ifp->if_ioctl = mcioctl;
    153 	ifp->if_start = mcstart;
    154 	ifp->if_flags =
    155 	    IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS | IFF_MULTICAST;
    156 	ifp->if_watchdog = mcwatchdog;
    157 
    158 	/* initialize ifmedia structures */
    159 	ifmedia_init(&sc->sc_media, 0, mc_mediachange, mc_mediastatus);
    160 	ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
    161 	ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_MANUAL);
    162 
    163 	if_attach(ifp);
    164 	if_deferred_start_init(ifp, NULL);
    165 	ether_ifattach(ifp, lladdr);
    166 
    167 	return (0);
    168 }
    169 
    170 hide int
    171 mcioctl(struct ifnet *ifp, u_long cmd, void *data)
    172 {
    173 	struct mc_softc *sc = ifp->if_softc;
    174 	struct ifaddr *ifa;
    175 	struct ifreq *ifr;
    176 
    177 	int	s = splnet(), err = 0;
    178 
    179 	switch (cmd) {
    180 
    181 	case SIOCINITIFADDR:
    182 		ifa = (struct ifaddr *)data;
    183 		ifp->if_flags |= IFF_UP;
    184 		mcinit(sc);
    185 		switch (ifa->ifa_addr->sa_family) {
    186 #ifdef INET
    187 		case AF_INET:
    188 			arp_ifinit(ifp, ifa);
    189 			break;
    190 #endif
    191 		default:
    192 			break;
    193 		}
    194 		break;
    195 
    196 	case SIOCSIFFLAGS:
    197 		if ((err = ifioctl_common(ifp, cmd, data)) != 0)
    198 			break;
    199 		/* XXX see the comment in ed_ioctl() about code re-use */
    200 		if ((ifp->if_flags & IFF_UP) == 0 &&
    201 		    (ifp->if_flags & IFF_RUNNING) != 0) {
    202 			/*
    203 			 * If interface is marked down and it is running,
    204 			 * then stop it.
    205 			 */
    206 			mcstop(sc);
    207 			ifp->if_flags &= ~IFF_RUNNING;
    208 		} else if ((ifp->if_flags & IFF_UP) != 0 &&
    209 		    (ifp->if_flags & IFF_RUNNING) == 0) {
    210 			/*
    211 			 * If interface is marked up and it is stopped,
    212 			 * then start it.
    213 			 */
    214 			(void)mcinit(sc);
    215 		} else {
    216 			/*
    217 			 * reset the interface to pick up any other changes
    218 			 * in flags
    219 			 */
    220 			mcreset(sc);
    221 			mcstart(ifp);
    222 		}
    223 		break;
    224 
    225 	case SIOCADDMULTI:
    226 	case SIOCDELMULTI:
    227 		if ((err = ether_ioctl(ifp, cmd, data)) == ENETRESET) {
    228 			/*
    229 			 * Multicast list has changed; set the hardware
    230 			 * filter accordingly. But remember UP flag!
    231 			 */
    232 			if (ifp->if_flags & IFF_RUNNING)
    233 				mcreset(sc);
    234 			err = 0;
    235 		}
    236 		break;
    237 
    238 	case SIOCGIFMEDIA:
    239 	case SIOCSIFMEDIA:
    240 		ifr = (struct ifreq *) data;
    241 		err = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
    242 		break;
    243 
    244 	default:
    245 		err = ether_ioctl(ifp, cmd, data);
    246 		break;
    247 	}
    248 	splx(s);
    249 	return (err);
    250 }
    251 
    252 /*
    253  * Encapsulate a packet of type family for the local net.
    254  */
    255 hide void
    256 mcstart(struct ifnet *ifp)
    257 {
    258 	struct mc_softc	*sc = ifp->if_softc;
    259 	struct mbuf	*m;
    260 
    261 	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
    262 		return;
    263 
    264 	while (1) {
    265 		if (ifp->if_flags & IFF_OACTIVE)
    266 			return;
    267 
    268 		IF_DEQUEUE(&ifp->if_snd, m);
    269 		if (m == 0)
    270 			return;
    271 
    272 		/*
    273 		 * If bpf is listening on this interface, let it
    274 		 * see the packet before we commit it to the wire.
    275 		 */
    276 		bpf_mtap(ifp, m, BPF_D_OUT);
    277 
    278 		/*
    279 		 * Copy the mbuf chain into the transmit buffer.
    280 		 */
    281 		ifp->if_flags |= IFF_OACTIVE;
    282 		maceput(sc, m);
    283 
    284 		ifp->if_opackets++;		/* # of pkts */
    285 	}
    286 }
    287 
    288 /*
    289  * reset and restart the MACE.  Called in case of fatal
    290  * hardware/software errors.
    291  */
    292 hide void
    293 mcreset(struct mc_softc *sc)
    294 {
    295 	mcstop(sc);
    296 	mcinit(sc);
    297 }
    298 
    299 hide int
    300 mcinit(struct mc_softc *sc)
    301 {
    302 	int s;
    303 	u_int8_t maccc, ladrf[8];
    304 
    305 	if (sc->sc_if.if_flags & IFF_RUNNING)
    306 		/* already running */
    307 		return (0);
    308 
    309 	s = splnet();
    310 
    311 	NIC_PUT(sc, MACE_BIUCC, sc->sc_biucc);
    312 	NIC_PUT(sc, MACE_FIFOCC, sc->sc_fifocc);
    313 	NIC_PUT(sc, MACE_IMR, ~0); /* disable all interrupts */
    314 	NIC_PUT(sc, MACE_PLSCC, sc->sc_plscc);
    315 
    316 	NIC_PUT(sc, MACE_UTR, RTRD); /* disable reserved test registers */
    317 
    318 	/* set MAC address */
    319 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
    320 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
    321 		;
    322 	NIC_PUT(sc, MACE_IAC, PHYADDR);
    323 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_PADR),
    324 	    sc->sc_enaddr, ETHER_ADDR_LEN);
    325 
    326 	/* set logical address filter */
    327 	mace_calcladrf(&sc->sc_ethercom, ladrf);
    328 
    329 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
    330 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
    331 		;
    332 	NIC_PUT(sc, MACE_IAC, LOGADDR);
    333 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_LADRF),
    334 	    ladrf, 8);
    335 
    336 	NIC_PUT(sc, MACE_XMTFC, APADXMT);
    337 	/*
    338 	 * No need to autostrip padding on receive... Ethernet frames
    339 	 * don't have a length field, unlike 802.3 frames, so the MACE
    340 	 * can't figure out the length of the packet anyways.
    341 	 */
    342 	NIC_PUT(sc, MACE_RCVFC, 0);
    343 
    344 	maccc = ENXMT | ENRCV;
    345 	if (sc->sc_if.if_flags & IFF_PROMISC)
    346 		maccc |= PROM;
    347 
    348 	NIC_PUT(sc, MACE_MACCC, maccc);
    349 
    350 	if (sc->sc_bus_init)
    351 		(*sc->sc_bus_init)(sc);
    352 
    353 	/*
    354 	 * Enable all interrupts except receive, since we use the DMA
    355 	 * completion interrupt for that.
    356 	 */
    357 	NIC_PUT(sc, MACE_IMR, RCVINTM);
    358 
    359 	/* flag interface as "running" */
    360 	sc->sc_if.if_flags |= IFF_RUNNING;
    361 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
    362 
    363 	splx(s);
    364 	return (0);
    365 }
    366 
    367 /*
    368  * close down an interface and free its buffers
    369  * Called on final close of device, or if mcinit() fails
    370  * part way through.
    371  */
    372 hide int
    373 mcstop(struct mc_softc *sc)
    374 {
    375 	int	s = splnet();
    376 
    377 	NIC_PUT(sc, MACE_BIUCC, SWRST);
    378 	DELAY(100);
    379 
    380 	sc->sc_if.if_timer = 0;
    381 	sc->sc_if.if_flags &= ~IFF_RUNNING;
    382 
    383 	splx(s);
    384 	return (0);
    385 }
    386 
    387 /*
    388  * Called if any Tx packets remain unsent after 5 seconds,
    389  * In all cases we just reset the chip, and any retransmission
    390  * will be handled by higher level protocol timeouts.
    391  */
    392 hide void
    393 mcwatchdog(struct ifnet *ifp)
    394 {
    395 	struct mc_softc *sc = ifp->if_softc;
    396 
    397 	printf("mcwatchdog: resetting chip\n");
    398 	mcreset(sc);
    399 }
    400 
    401 /*
    402  * stuff packet into MACE (at splnet)
    403  */
    404 integrate u_int
    405 maceput(struct mc_softc *sc, struct mbuf *m)
    406 {
    407 	struct mbuf *n;
    408 	u_int len, totlen = 0;
    409 	u_char *buff;
    410 
    411 	buff = sc->sc_txbuf;
    412 
    413 	for (; m; m = n) {
    414 		u_char *data = mtod(m, u_char *);
    415 		len = m->m_len;
    416 		totlen += len;
    417 		memcpy(buff, data, len);
    418 		buff += len;
    419 		n = m_free(m);
    420 	}
    421 
    422 	if (totlen > PAGE_SIZE)
    423 		panic("%s: maceput: packet overflow", device_xname(sc->sc_dev));
    424 
    425 #if 0
    426 	if (totlen < ETHERMIN + sizeof(struct ether_header)) {
    427 		int pad = ETHERMIN + sizeof(struct ether_header) - totlen;
    428 		memset(sc->sc_txbuf + totlen, 0, pad);
    429 		totlen = ETHERMIN + sizeof(struct ether_header);
    430 	}
    431 #endif
    432 
    433 	(*sc->sc_putpacket)(sc, totlen);
    434 
    435 	sc->sc_if.if_timer = 5;	/* 5 seconds to watch for failing to transmit */
    436 	return (totlen);
    437 }
    438 
    439 int
    440 mcintr(void *arg)
    441 {
    442 	struct mc_softc *sc = arg;
    443 	u_int8_t ir;
    444 
    445 	ir = NIC_GET(sc, MACE_IR) & ~NIC_GET(sc, MACE_IMR);
    446 	if (ir == 0)
    447 		return 0;
    448 
    449 	if (ir & JAB) {
    450 #ifdef MCDEBUG
    451 		printf("%s: jabber error\n", device_xname(sc->sc_dev));
    452 #endif
    453 		sc->sc_if.if_oerrors++;
    454 	}
    455 
    456 	if (ir & BABL) {
    457 #ifdef MCDEBUG
    458 		printf("%s: babble\n", device_xname(sc->sc_dev));
    459 #endif
    460 		sc->sc_if.if_oerrors++;
    461 	}
    462 
    463 	if (ir & CERR) {
    464 		printf("%s: collision error\n", device_xname(sc->sc_dev));
    465 		sc->sc_if.if_collisions++;
    466 	}
    467 
    468 	/*
    469 	 * Pretend we have carrier; if we don't this will be cleared
    470 	 * shortly.
    471 	 */
    472 	sc->sc_havecarrier = 1;
    473 
    474 	if (ir & XMTINT)
    475 		mc_tint(sc);
    476 
    477 	if (ir & RCVINT)
    478 		mc_rint(sc);
    479 
    480 	return 1;
    481 }
    482 
    483 integrate void
    484 mc_tint(struct mc_softc *sc)
    485 {
    486 	u_int8_t xmtfs;
    487 
    488 	(void)NIC_GET(sc, MACE_XMTRC);
    489 	xmtfs = NIC_GET(sc, MACE_XMTFS);
    490 
    491 	if ((xmtfs & XMTSV) == 0)
    492 		return;
    493 
    494 	if (xmtfs & UFLO) {
    495 		printf("%s: underflow\n", device_xname(sc->sc_dev));
    496 		mcreset(sc);
    497 		return;
    498 	}
    499 
    500 	if (xmtfs & LCOL) {
    501 		printf("%s: late collision\n", device_xname(sc->sc_dev));
    502 		sc->sc_if.if_oerrors++;
    503 		sc->sc_if.if_collisions++;
    504 	}
    505 
    506 	if (xmtfs & MORE)
    507 		/* Real number is unknown. */
    508 		sc->sc_if.if_collisions += 2;
    509 	else if (xmtfs & ONE)
    510 		sc->sc_if.if_collisions++;
    511 	else if (xmtfs & RTRY) {
    512 		sc->sc_if.if_collisions += 16;
    513 		sc->sc_if.if_oerrors++;
    514 	}
    515 
    516 	if (xmtfs & LCAR) {
    517 		sc->sc_havecarrier = 0;
    518 		printf("%s: lost carrier\n", device_xname(sc->sc_dev));
    519 		sc->sc_if.if_oerrors++;
    520 	}
    521 
    522 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
    523 	sc->sc_if.if_timer = 0;
    524 	if_schedule_deferred_start(&sc->sc_if);
    525 }
    526 
    527 void
    528 mc_rint(struct mc_softc *sc)
    529 {
    530 #define	rxf	sc->sc_rxframe
    531 	u_int len;
    532 
    533 	len = (rxf.rx_rcvcnt | ((rxf.rx_rcvsts & 0xf) << 8)) - 4;
    534 
    535 #ifdef MCDEBUG
    536 	if (rxf.rx_rcvsts & 0xf0)
    537 		printf("%s: rcvcnt %02x rcvsts %02x rntpc 0x%02x rcvcc 0x%02x\n",
    538 		    device_xname(sc->sc_dev), rxf.rx_rcvcnt, rxf.rx_rcvsts,
    539 		    rxf.rx_rntpc, rxf.rx_rcvcc);
    540 #endif
    541 
    542 	if (rxf.rx_rcvsts & OFLO) {
    543 		printf("%s: receive FIFO overflow\n", device_xname(sc->sc_dev));
    544 		sc->sc_if.if_ierrors++;
    545 		return;
    546 	}
    547 
    548 	if (rxf.rx_rcvsts & CLSN)
    549 		sc->sc_if.if_collisions++;
    550 
    551 	if (rxf.rx_rcvsts & FRAM) {
    552 #ifdef MCDEBUG
    553 		printf("%s: framing error\n", device_xname(sc->sc_dev));
    554 #endif
    555 		sc->sc_if.if_ierrors++;
    556 		return;
    557 	}
    558 
    559 	if (rxf.rx_rcvsts & FCS) {
    560 #ifdef MCDEBUG
    561 		printf("%s: frame control checksum error\n", device_xname(sc->sc_dev));
    562 #endif
    563 		sc->sc_if.if_ierrors++;
    564 		return;
    565 	}
    566 
    567 	mace_read(sc, rxf.rx_frame, len);
    568 #undef	rxf
    569 }
    570 
    571 integrate void
    572 mace_read(struct mc_softc *sc, uint8_t *pkt, int len)
    573 {
    574 	struct ifnet *ifp = &sc->sc_if;
    575 	struct mbuf *m;
    576 
    577 	if (len <= sizeof(struct ether_header) ||
    578 	    len > ETHERMTU + sizeof(struct ether_header)) {
    579 #ifdef MCDEBUG
    580 		printf("%s: invalid packet size %d; dropping\n",
    581 		    device_xname(sc->sc_dev), len);
    582 #endif
    583 		ifp->if_ierrors++;
    584 		return;
    585 	}
    586 
    587 	m = mace_get(sc, pkt, len);
    588 	if (m == NULL) {
    589 		ifp->if_ierrors++;
    590 		return;
    591 	}
    592 
    593 	/* Pass the packet up. */
    594 	if_percpuq_enqueue(ifp->if_percpuq, m);
    595 }
    596 
    597 /*
    598  * Pull data off an interface.
    599  * Len is length of data, with local net header stripped.
    600  * We copy the data into mbufs.  When full cluster sized units are present
    601  * we copy into clusters.
    602  */
    603 integrate struct mbuf *
    604 mace_get(struct mc_softc *sc, uint8_t *pkt, int totlen)
    605 {
    606 	register struct mbuf *m;
    607 	struct mbuf *top, **mp;
    608 	int len;
    609 
    610 	MGETHDR(m, M_DONTWAIT, MT_DATA);
    611 	if (m == 0)
    612 		return (0);
    613 	m_set_rcvif(m, &sc->sc_if);
    614 	m->m_pkthdr.len = totlen;
    615 	len = MHLEN;
    616 	top = 0;
    617 	mp = &top;
    618 
    619 	while (totlen > 0) {
    620 		if (top) {
    621 			MGET(m, M_DONTWAIT, MT_DATA);
    622 			if (m == 0) {
    623 				m_freem(top);
    624 				return 0;
    625 			}
    626 			len = MLEN;
    627 		}
    628 		if (totlen >= MINCLSIZE) {
    629 			MCLGET(m, M_DONTWAIT);
    630 			if ((m->m_flags & M_EXT) == 0) {
    631 				m_free(m);
    632 				m_freem(top);
    633 				return 0;
    634 			}
    635 			len = MCLBYTES;
    636 		}
    637 		m->m_len = len = uimin(totlen, len);
    638 		memcpy(mtod(m, void *), pkt, len);
    639 		pkt += len;
    640 		totlen -= len;
    641 		*mp = m;
    642 		mp = &m->m_next;
    643 	}
    644 
    645 	return (top);
    646 }
    647 
    648 /*
    649  * Go through the list of multicast addresses and calculate the logical
    650  * address filter.
    651  */
    652 void
    653 mace_calcladrf(struct ethercom *ac, u_int8_t *af)
    654 {
    655 	struct ifnet *ifp = &ac->ec_if;
    656 	struct ether_multi *enm;
    657 	register u_char *cp, c;
    658 	register u_int32_t crc;
    659 	register int i, len;
    660 	struct ether_multistep step;
    661 
    662 	/*
    663 	 * Set up multicast address filter by passing all multicast addresses
    664 	 * through a crc generator, and then using the high order 6 bits as an
    665 	 * index into the 64 bit logical address filter.  The high order bit
    666 	 * selects the word, while the rest of the bits select the bit within
    667 	 * the word.
    668 	 */
    669 
    670 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0;
    671 
    672 	ETHER_FIRST_MULTI(step, ac, enm);
    673 	while (enm != NULL) {
    674 		if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) {
    675 			/*
    676 			 * We must listen to a range of multicast addresses.
    677 			 * For now, just accept all multicasts, rather than
    678 			 * trying to set only those filter bits needed to match
    679 			 * the range.  (At this time, the only use of address
    680 			 * ranges is for IP multicast routing, for which the
    681 			 * range is big enough to require all bits set.)
    682 			 */
    683 			goto allmulti;
    684 		}
    685 
    686 		cp = enm->enm_addrlo;
    687 		crc = 0xffffffff;
    688 		for (len = sizeof(enm->enm_addrlo); --len >= 0;) {
    689 			c = *cp++;
    690 			for (i = 8; --i >= 0;) {
    691 				if ((crc & 0x01) ^ (c & 0x01)) {
    692 					crc >>= 1;
    693 					crc ^= 0xedb88320;
    694 				} else
    695 					crc >>= 1;
    696 				c >>= 1;
    697 			}
    698 		}
    699 		/* Just want the 6 most significant bits. */
    700 		crc >>= 26;
    701 
    702 		/* Set the corresponding bit in the filter. */
    703 		af[crc >> 3] |= 1 << (crc & 7);
    704 
    705 		ETHER_NEXT_MULTI(step, enm);
    706 	}
    707 	ifp->if_flags &= ~IFF_ALLMULTI;
    708 	return;
    709 
    710 allmulti:
    711 	ifp->if_flags |= IFF_ALLMULTI;
    712 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0xffffffff;
    713 }
    714 
    715 int
    716 mc_mediachange(struct ifnet *ifp)
    717 {
    718 	return EINVAL;
    719 }
    720 
    721 void
    722 mc_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
    723 {
    724 	struct mc_softc *sc = ifp->if_softc;
    725 
    726 	if ((ifp->if_flags & IFF_UP) == 0)
    727 		return;
    728 
    729 	if (sc->sc_havecarrier)
    730 		ifmr->ifm_status |= IFM_ACTIVE;
    731 }
    732