xref: /netbsd-src/sys/arch/macppc/dev/am79c950.c (revision 7f21db1c0118155e0dd40b75182e30c589d9f63e)
1 /*	$NetBSD: am79c950.c,v 1.28 2010/01/19 22:06:21 pooka Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997 David Huang <khym@bga.com>
5  * All rights reserved.
6  *
7  * Portions of this code are based on code by Denton Gentry <denny1@home.com>,
8  * Charles M. Hannum, Yanagisawa Takeshi <yanagisw@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 1.28 2010/01/19 22:06:21 pooka 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 <uvm/uvm_extern.h>
54 
55 #include <net/if.h>
56 #include <net/if_dl.h>
57 #include <net/if_ether.h>
58 #include <net/if_media.h>
59 
60 #ifdef INET
61 #include <netinet/in.h>
62 #include <netinet/if_inarp.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/in_var.h>
65 #include <netinet/ip.h>
66 #endif
67 
68 #include <net/bpf.h>
69 #include <net/bpfdesc.h>
70 
71 #include <machine/bus.h>
72 
73 #include <macppc/dev/am79c950reg.h>
74 #include <macppc/dev/if_mcvar.h>
75 
76 hide void	mcwatchdog(struct ifnet *);
77 hide int	mcinit(struct mc_softc *sc);
78 hide int	mcstop(struct mc_softc *sc);
79 hide int	mcioctl(struct ifnet *ifp, u_long cmd, void *data);
80 hide void	mcstart(struct ifnet *ifp);
81 hide void	mcreset(struct mc_softc *sc);
82 
83 integrate u_int	maceput(struct mc_softc *sc, struct mbuf *m0);
84 integrate void	mc_tint(struct mc_softc *sc);
85 integrate void	mace_read(struct mc_softc *, uint8_t *, int);
86 integrate struct mbuf *mace_get(struct mc_softc *, uint8_t *, int);
87 static void mace_calcladrf(struct ethercom *ac, u_int8_t *af);
88 static inline u_int16_t ether_cmp(void *, void *);
89 static int mc_mediachange(struct ifnet *);
90 static void mc_mediastatus(struct ifnet *, struct ifmediareq *);
91 
92 /*
93  * Compare two Ether/802 addresses for equality, inlined and
94  * unrolled for speed.  Use this like memcmp().
95  *
96  * XXX: Add <machine/inlines.h> for stuff like this?
97  * XXX: or maybe add it to libkern.h instead?
98  *
99  * "I'd love to have an inline assembler version of this."
100  * XXX: Who wanted that? mycroft?  I wrote one, but this
101  * version in C is as good as hand-coded assembly. -gwr
102  *
103  * Please do NOT tweak this without looking at the actual
104  * assembly code generated before and after your tweaks!
105  */
106 static inline u_int16_t
107 ether_cmp(void *one, void *two)
108 {
109 	register u_int16_t *a = (u_short *) one;
110 	register u_int16_t *b = (u_short *) two;
111 	register u_int16_t diff;
112 
113 #ifdef	m68k
114 	/*
115 	 * The post-increment-pointer form produces the best
116 	 * machine code for m68k.  This was carefully tuned
117 	 * so it compiles to just 8 short (2-byte) op-codes!
118 	 */
119 	diff  = *a++ - *b++;
120 	diff |= *a++ - *b++;
121 	diff |= *a++ - *b++;
122 #else
123 	/*
124 	 * Most modern CPUs do better with a single expresion.
125 	 * Note that short-cut evaluation is NOT helpful here,
126 	 * because it just makes the code longer, not faster!
127 	 */
128 	diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]);
129 #endif
130 
131 	return (diff);
132 }
133 
134 #define ETHER_CMP	ether_cmp
135 
136 /*
137  * Interface exists: make available by filling in network interface
138  * record.  System will initialize the interface when it is ready
139  * to accept packets.
140  */
141 int
142 mcsetup(struct mc_softc *sc, u_int8_t *lladdr)
143 {
144 	struct ifnet *ifp = &sc->sc_if;
145 
146 	/* reset the chip and disable all interrupts */
147 	NIC_PUT(sc, MACE_BIUCC, SWRST);
148 	DELAY(100);
149 	NIC_PUT(sc, MACE_IMR, ~0);
150 
151 	memcpy(sc->sc_enaddr, lladdr, ETHER_ADDR_LEN);
152 	printf(": address %s\n", ether_sprintf(lladdr));
153 
154 	memcpy(ifp->if_xname, sc->sc_dev.dv_xname, IFNAMSIZ);
155 	ifp->if_softc = sc;
156 	ifp->if_ioctl = mcioctl;
157 	ifp->if_start = mcstart;
158 	ifp->if_flags =
159 	    IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS | IFF_MULTICAST;
160 	ifp->if_watchdog = mcwatchdog;
161 
162 	/* initialize ifmedia structures */
163 	ifmedia_init(&sc->sc_media, 0, mc_mediachange, mc_mediastatus);
164 	ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
165 	ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_MANUAL);
166 
167 	if_attach(ifp);
168 	ether_ifattach(ifp, lladdr);
169 
170 	return (0);
171 }
172 
173 hide int
174 mcioctl(struct ifnet *ifp, u_long cmd, void *data)
175 {
176 	struct mc_softc *sc = ifp->if_softc;
177 	struct ifaddr *ifa;
178 	struct ifreq *ifr;
179 
180 	int	s = splnet(), err = 0;
181 
182 	switch (cmd) {
183 
184 	case SIOCINITIFADDR:
185 		ifa = (struct ifaddr *)data;
186 		ifp->if_flags |= IFF_UP;
187 		mcinit(sc);
188 		switch (ifa->ifa_addr->sa_family) {
189 #ifdef INET
190 		case AF_INET:
191 			arp_ifinit(ifp, ifa);
192 			break;
193 #endif
194 		default:
195 			break;
196 		}
197 		break;
198 
199 	case SIOCSIFFLAGS:
200 		if ((err = ifioctl_common(ifp, cmd, data)) != 0)
201 			break;
202 		/* XXX see the comment in ed_ioctl() about code re-use */
203 		if ((ifp->if_flags & IFF_UP) == 0 &&
204 		    (ifp->if_flags & IFF_RUNNING) != 0) {
205 			/*
206 			 * If interface is marked down and it is running,
207 			 * then stop it.
208 			 */
209 			mcstop(sc);
210 			ifp->if_flags &= ~IFF_RUNNING;
211 		} else if ((ifp->if_flags & IFF_UP) != 0 &&
212 		    (ifp->if_flags & IFF_RUNNING) == 0) {
213 			/*
214 			 * If interface is marked up and it is stopped,
215 			 * then start it.
216 			 */
217 			(void)mcinit(sc);
218 		} else {
219 			/*
220 			 * reset the interface to pick up any other changes
221 			 * in flags
222 			 */
223 			mcreset(sc);
224 			mcstart(ifp);
225 		}
226 		break;
227 
228 	case SIOCADDMULTI:
229 	case SIOCDELMULTI:
230 		if ((err = ether_ioctl(ifp, cmd, data)) == ENETRESET) {
231 			/*
232 			 * Multicast list has changed; set the hardware
233 			 * filter accordingly. But remember UP flag!
234 			 */
235 			if (ifp->if_flags & IFF_RUNNING)
236 				mcreset(sc);
237 			err = 0;
238 		}
239 		break;
240 
241 	case SIOCGIFMEDIA:
242 	case SIOCSIFMEDIA:
243 		ifr = (struct ifreq *) data;
244 		err = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
245 		break;
246 
247 	default:
248 		err = ether_ioctl(ifp, cmd, data);
249 		break;
250 	}
251 	splx(s);
252 	return (err);
253 }
254 
255 /*
256  * Encapsulate a packet of type family for the local net.
257  */
258 hide void
259 mcstart(struct ifnet *ifp)
260 {
261 	struct mc_softc	*sc = ifp->if_softc;
262 	struct mbuf	*m;
263 
264 	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
265 		return;
266 
267 	while (1) {
268 		if (ifp->if_flags & IFF_OACTIVE)
269 			return;
270 
271 		IF_DEQUEUE(&ifp->if_snd, m);
272 		if (m == 0)
273 			return;
274 
275 		/*
276 		 * If bpf is listening on this interface, let it
277 		 * see the packet before we commit it to the wire.
278 		 */
279 		if (ifp->if_bpf)
280 			bpf_ops->bpf_mtap(ifp->if_bpf, m);
281 
282 		/*
283 		 * Copy the mbuf chain into the transmit buffer.
284 		 */
285 		ifp->if_flags |= IFF_OACTIVE;
286 		maceput(sc, m);
287 
288 		ifp->if_opackets++;		/* # of pkts */
289 	}
290 }
291 
292 /*
293  * reset and restart the MACE.  Called in case of fatal
294  * hardware/software errors.
295  */
296 hide void
297 mcreset(struct mc_softc *sc)
298 {
299 	mcstop(sc);
300 	mcinit(sc);
301 }
302 
303 hide int
304 mcinit(struct mc_softc *sc)
305 {
306 	int s;
307 	u_int8_t maccc, ladrf[8];
308 
309 	if (sc->sc_if.if_flags & IFF_RUNNING)
310 		/* already running */
311 		return (0);
312 
313 	s = splnet();
314 
315 	NIC_PUT(sc, MACE_BIUCC, sc->sc_biucc);
316 	NIC_PUT(sc, MACE_FIFOCC, sc->sc_fifocc);
317 	NIC_PUT(sc, MACE_IMR, ~0); /* disable all interrupts */
318 	NIC_PUT(sc, MACE_PLSCC, sc->sc_plscc);
319 
320 	NIC_PUT(sc, MACE_UTR, RTRD); /* disable reserved test registers */
321 
322 	/* set MAC address */
323 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
324 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
325 		;
326 	NIC_PUT(sc, MACE_IAC, PHYADDR);
327 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_PADR),
328 	    sc->sc_enaddr, ETHER_ADDR_LEN);
329 
330 	/* set logical address filter */
331 	mace_calcladrf(&sc->sc_ethercom, ladrf);
332 
333 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
334 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
335 		;
336 	NIC_PUT(sc, MACE_IAC, LOGADDR);
337 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_LADRF),
338 	    ladrf, 8);
339 
340 	NIC_PUT(sc, MACE_XMTFC, APADXMT);
341 	/*
342 	 * No need to autostrip padding on receive... Ethernet frames
343 	 * don't have a length field, unlike 802.3 frames, so the MACE
344 	 * can't figure out the length of the packet anyways.
345 	 */
346 	NIC_PUT(sc, MACE_RCVFC, 0);
347 
348 	maccc = ENXMT | ENRCV;
349 	if (sc->sc_if.if_flags & IFF_PROMISC)
350 		maccc |= PROM;
351 
352 	NIC_PUT(sc, MACE_MACCC, maccc);
353 
354 	if (sc->sc_bus_init)
355 		(*sc->sc_bus_init)(sc);
356 
357 	/*
358 	 * Enable all interrupts except receive, since we use the DMA
359 	 * completion interrupt for that.
360 	 */
361 	NIC_PUT(sc, MACE_IMR, RCVINTM);
362 
363 	/* flag interface as "running" */
364 	sc->sc_if.if_flags |= IFF_RUNNING;
365 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
366 
367 	splx(s);
368 	return (0);
369 }
370 
371 /*
372  * close down an interface and free its buffers
373  * Called on final close of device, or if mcinit() fails
374  * part way through.
375  */
376 hide int
377 mcstop(struct mc_softc *sc)
378 {
379 	int	s = splnet();
380 
381 	NIC_PUT(sc, MACE_BIUCC, SWRST);
382 	DELAY(100);
383 
384 	sc->sc_if.if_timer = 0;
385 	sc->sc_if.if_flags &= ~IFF_RUNNING;
386 
387 	splx(s);
388 	return (0);
389 }
390 
391 /*
392  * Called if any Tx packets remain unsent after 5 seconds,
393  * In all cases we just reset the chip, and any retransmission
394  * will be handled by higher level protocol timeouts.
395  */
396 hide void
397 mcwatchdog(struct ifnet *ifp)
398 {
399 	struct mc_softc *sc = ifp->if_softc;
400 
401 	printf("mcwatchdog: resetting chip\n");
402 	mcreset(sc);
403 }
404 
405 /*
406  * stuff packet into MACE (at splnet)
407  */
408 integrate u_int
409 maceput(struct mc_softc *sc, struct mbuf *m)
410 {
411 	struct mbuf *n;
412 	u_int len, totlen = 0;
413 	u_char *buff;
414 
415 	buff = sc->sc_txbuf;
416 
417 	for (; m; m = n) {
418 		u_char *data = mtod(m, u_char *);
419 		len = m->m_len;
420 		totlen += len;
421 		memcpy(buff, data, len);
422 		buff += len;
423 		MFREE(m, n);
424 	}
425 
426 	if (totlen > PAGE_SIZE)
427 		panic("%s: maceput: packet overflow", sc->sc_dev.dv_xname);
428 
429 #if 0
430 	if (totlen < ETHERMIN + sizeof(struct ether_header)) {
431 		int pad = ETHERMIN + sizeof(struct ether_header) - totlen;
432 		memset(sc->sc_txbuf + totlen, 0, pad);
433 		totlen = ETHERMIN + sizeof(struct ether_header);
434 	}
435 #endif
436 
437 	(*sc->sc_putpacket)(sc, totlen);
438 
439 	sc->sc_if.if_timer = 5;	/* 5 seconds to watch for failing to transmit */
440 	return (totlen);
441 }
442 
443 int
444 mcintr(void *arg)
445 {
446 	struct mc_softc *sc = arg;
447 	u_int8_t ir;
448 
449 	ir = NIC_GET(sc, MACE_IR) & ~NIC_GET(sc, MACE_IMR);
450 	if (ir == 0)
451 		return 0;
452 
453 	if (ir & JAB) {
454 #ifdef MCDEBUG
455 		printf("%s: jabber error\n", sc->sc_dev.dv_xname);
456 #endif
457 		sc->sc_if.if_oerrors++;
458 	}
459 
460 	if (ir & BABL) {
461 #ifdef MCDEBUG
462 		printf("%s: babble\n", sc->sc_dev.dv_xname);
463 #endif
464 		sc->sc_if.if_oerrors++;
465 	}
466 
467 	if (ir & CERR) {
468 		printf("%s: collision error\n", sc->sc_dev.dv_xname);
469 		sc->sc_if.if_collisions++;
470 	}
471 
472 	/*
473 	 * Pretend we have carrier; if we don't this will be cleared
474 	 * shortly.
475 	 */
476 	sc->sc_havecarrier = 1;
477 
478 	if (ir & XMTINT)
479 		mc_tint(sc);
480 
481 	if (ir & RCVINT)
482 		mc_rint(sc);
483 
484 	return 1;
485 }
486 
487 integrate void
488 mc_tint(struct mc_softc *sc)
489 {
490 	u_int8_t xmtrc, xmtfs;
491 
492 	xmtrc = NIC_GET(sc, MACE_XMTRC);
493 	xmtfs = NIC_GET(sc, MACE_XMTFS);
494 
495 	if ((xmtfs & XMTSV) == 0)
496 		return;
497 
498 	if (xmtfs & UFLO) {
499 		printf("%s: underflow\n", sc->sc_dev.dv_xname);
500 		mcreset(sc);
501 		return;
502 	}
503 
504 	if (xmtfs & LCOL) {
505 		printf("%s: late collision\n", sc->sc_dev.dv_xname);
506 		sc->sc_if.if_oerrors++;
507 		sc->sc_if.if_collisions++;
508 	}
509 
510 	if (xmtfs & MORE)
511 		/* Real number is unknown. */
512 		sc->sc_if.if_collisions += 2;
513 	else if (xmtfs & ONE)
514 		sc->sc_if.if_collisions++;
515 	else if (xmtfs & RTRY) {
516 		sc->sc_if.if_collisions += 16;
517 		sc->sc_if.if_oerrors++;
518 	}
519 
520 	if (xmtfs & LCAR) {
521 		sc->sc_havecarrier = 0;
522 		printf("%s: lost carrier\n", sc->sc_dev.dv_xname);
523 		sc->sc_if.if_oerrors++;
524 	}
525 
526 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
527 	sc->sc_if.if_timer = 0;
528 	mcstart(&sc->sc_if);
529 }
530 
531 void
532 mc_rint(struct mc_softc *sc)
533 {
534 #define	rxf	sc->sc_rxframe
535 	u_int len;
536 
537 	len = (rxf.rx_rcvcnt | ((rxf.rx_rcvsts & 0xf) << 8)) - 4;
538 
539 #ifdef MCDEBUG
540 	if (rxf.rx_rcvsts & 0xf0)
541 		printf("%s: rcvcnt %02x rcvsts %02x rntpc 0x%02x rcvcc 0x%02x\n",
542 		    sc->sc_dev.dv_xname, rxf.rx_rcvcnt, rxf.rx_rcvsts,
543 		    rxf.rx_rntpc, rxf.rx_rcvcc);
544 #endif
545 
546 	if (rxf.rx_rcvsts & OFLO) {
547 		printf("%s: receive FIFO overflow\n", sc->sc_dev.dv_xname);
548 		sc->sc_if.if_ierrors++;
549 		return;
550 	}
551 
552 	if (rxf.rx_rcvsts & CLSN)
553 		sc->sc_if.if_collisions++;
554 
555 	if (rxf.rx_rcvsts & FRAM) {
556 #ifdef MCDEBUG
557 		printf("%s: framing error\n", sc->sc_dev.dv_xname);
558 #endif
559 		sc->sc_if.if_ierrors++;
560 		return;
561 	}
562 
563 	if (rxf.rx_rcvsts & FCS) {
564 #ifdef MCDEBUG
565 		printf("%s: frame control checksum error\n", sc->sc_dev.dv_xname);
566 #endif
567 		sc->sc_if.if_ierrors++;
568 		return;
569 	}
570 
571 	mace_read(sc, rxf.rx_frame, len);
572 #undef	rxf
573 }
574 
575 integrate void
576 mace_read(struct mc_softc *sc, uint8_t *pkt, int len)
577 {
578 	struct ifnet *ifp = &sc->sc_if;
579 	struct mbuf *m;
580 
581 	if (len <= sizeof(struct ether_header) ||
582 	    len > ETHERMTU + sizeof(struct ether_header)) {
583 #ifdef MCDEBUG
584 		printf("%s: invalid packet size %d; dropping\n",
585 		    sc->sc_dev.dv_xname, len);
586 #endif
587 		ifp->if_ierrors++;
588 		return;
589 	}
590 
591 	m = mace_get(sc, pkt, len);
592 	if (m == NULL) {
593 		ifp->if_ierrors++;
594 		return;
595 	}
596 
597 	ifp->if_ipackets++;
598 
599 	/* Pass this up to any BPF listeners. */
600 	if (ifp->if_bpf)
601 		bpf_ops->bpf_mtap(ifp->if_bpf, m);
602 
603 	/* Pass the packet up. */
604 	(*ifp->if_input)(ifp, m);
605 }
606 
607 /*
608  * Pull data off an interface.
609  * Len is length of data, with local net header stripped.
610  * We copy the data into mbufs.  When full cluster sized units are present
611  * we copy into clusters.
612  */
613 integrate struct mbuf *
614 mace_get(struct mc_softc *sc, uint8_t *pkt, int totlen)
615 {
616 	register struct mbuf *m;
617 	struct mbuf *top, **mp;
618 	int len;
619 
620 	MGETHDR(m, M_DONTWAIT, MT_DATA);
621 	if (m == 0)
622 		return (0);
623 	m->m_pkthdr.rcvif = &sc->sc_if;
624 	m->m_pkthdr.len = totlen;
625 	len = MHLEN;
626 	top = 0;
627 	mp = &top;
628 
629 	while (totlen > 0) {
630 		if (top) {
631 			MGET(m, M_DONTWAIT, MT_DATA);
632 			if (m == 0) {
633 				m_freem(top);
634 				return 0;
635 			}
636 			len = MLEN;
637 		}
638 		if (totlen >= MINCLSIZE) {
639 			MCLGET(m, M_DONTWAIT);
640 			if ((m->m_flags & M_EXT) == 0) {
641 				m_free(m);
642 				m_freem(top);
643 				return 0;
644 			}
645 			len = MCLBYTES;
646 		}
647 		m->m_len = len = min(totlen, len);
648 		memcpy(mtod(m, void *), pkt, len);
649 		pkt += len;
650 		totlen -= len;
651 		*mp = m;
652 		mp = &m->m_next;
653 	}
654 
655 	return (top);
656 }
657 
658 /*
659  * Go through the list of multicast addresses and calculate the logical
660  * address filter.
661  */
662 void
663 mace_calcladrf(struct ethercom *ac, u_int8_t *af)
664 {
665 	struct ifnet *ifp = &ac->ec_if;
666 	struct ether_multi *enm;
667 	register u_char *cp, c;
668 	register u_int32_t crc;
669 	register int i, len;
670 	struct ether_multistep step;
671 
672 	/*
673 	 * Set up multicast address filter by passing all multicast addresses
674 	 * through a crc generator, and then using the high order 6 bits as an
675 	 * index into the 64 bit logical address filter.  The high order bit
676 	 * selects the word, while the rest of the bits select the bit within
677 	 * the word.
678 	 */
679 
680 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0;
681 
682 	ETHER_FIRST_MULTI(step, ac, enm);
683 	while (enm != NULL) {
684 		if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) {
685 			/*
686 			 * We must listen to a range of multicast addresses.
687 			 * For now, just accept all multicasts, rather than
688 			 * trying to set only those filter bits needed to match
689 			 * the range.  (At this time, the only use of address
690 			 * ranges is for IP multicast routing, for which the
691 			 * range is big enough to require all bits set.)
692 			 */
693 			goto allmulti;
694 		}
695 
696 		cp = enm->enm_addrlo;
697 		crc = 0xffffffff;
698 		for (len = sizeof(enm->enm_addrlo); --len >= 0;) {
699 			c = *cp++;
700 			for (i = 8; --i >= 0;) {
701 				if ((crc & 0x01) ^ (c & 0x01)) {
702 					crc >>= 1;
703 					crc ^= 0xedb88320;
704 				} else
705 					crc >>= 1;
706 				c >>= 1;
707 			}
708 		}
709 		/* Just want the 6 most significant bits. */
710 		crc >>= 26;
711 
712 		/* Set the corresponding bit in the filter. */
713 		af[crc >> 3] |= 1 << (crc & 7);
714 
715 		ETHER_NEXT_MULTI(step, enm);
716 	}
717 	ifp->if_flags &= ~IFF_ALLMULTI;
718 	return;
719 
720 allmulti:
721 	ifp->if_flags |= IFF_ALLMULTI;
722 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0xffffffff;
723 }
724 
725 int
726 mc_mediachange(struct ifnet *ifp)
727 {
728 	return EINVAL;
729 }
730 
731 void
732 mc_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
733 {
734 	struct mc_softc *sc = ifp->if_softc;
735 
736 	if ((ifp->if_flags & IFF_UP) == 0)
737 		return;
738 
739 	if (sc->sc_havecarrier)
740 		ifmr->ifm_status |= IFM_ACTIVE;
741 }
742