xref: /netbsd-src/sys/arch/macppc/dev/am79c950.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: am79c950.c,v 1.23 2007/10/17 19:55:17 garbled 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 1.23 2007/10/17 19:55:17 garbled 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 "bpfilter.h"
69 #if NBPFILTER > 0
70 #include <net/bpf.h>
71 #include <net/bpfdesc.h>
72 #endif
73 
74 #include <machine/bus.h>
75 
76 #include <macppc/dev/am79c950reg.h>
77 #include <macppc/dev/if_mcvar.h>
78 
79 hide void	mcwatchdog __P((struct ifnet *));
80 hide int	mcinit __P((struct mc_softc *sc));
81 hide int	mcstop __P((struct mc_softc *sc));
82 hide int	mcioctl __P((struct ifnet *ifp, u_long cmd, void *data));
83 hide void	mcstart __P((struct ifnet *ifp));
84 hide void	mcreset __P((struct mc_softc *sc));
85 
86 integrate u_int	maceput __P((struct mc_softc *sc, struct mbuf *m0));
87 integrate void	mc_tint __P((struct mc_softc *sc));
88 integrate void	mace_read __P((struct mc_softc *, uint8_t *, int));
89 integrate struct mbuf *mace_get __P((struct mc_softc *, uint8_t *, int));
90 static void mace_calcladrf __P((struct ethercom *ac, u_int8_t *af));
91 static inline u_int16_t ether_cmp __P((void *, void *));
92 static int mc_mediachange __P((struct ifnet *));
93 static void mc_mediastatus __P((struct ifnet *, struct ifmediareq *));
94 
95 /*
96  * Compare two Ether/802 addresses for equality, inlined and
97  * unrolled for speed.  Use this like memcmp().
98  *
99  * XXX: Add <machine/inlines.h> for stuff like this?
100  * XXX: or maybe add it to libkern.h instead?
101  *
102  * "I'd love to have an inline assembler version of this."
103  * XXX: Who wanted that? mycroft?  I wrote one, but this
104  * version in C is as good as hand-coded assembly. -gwr
105  *
106  * Please do NOT tweak this without looking at the actual
107  * assembly code generated before and after your tweaks!
108  */
109 static inline u_int16_t
110 ether_cmp(one, two)
111 	void *one, *two;
112 {
113 	register u_int16_t *a = (u_short *) one;
114 	register u_int16_t *b = (u_short *) two;
115 	register u_int16_t diff;
116 
117 #ifdef	m68k
118 	/*
119 	 * The post-increment-pointer form produces the best
120 	 * machine code for m68k.  This was carefully tuned
121 	 * so it compiles to just 8 short (2-byte) op-codes!
122 	 */
123 	diff  = *a++ - *b++;
124 	diff |= *a++ - *b++;
125 	diff |= *a++ - *b++;
126 #else
127 	/*
128 	 * Most modern CPUs do better with a single expresion.
129 	 * Note that short-cut evaluation is NOT helpful here,
130 	 * because it just makes the code longer, not faster!
131 	 */
132 	diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]);
133 #endif
134 
135 	return (diff);
136 }
137 
138 #define ETHER_CMP	ether_cmp
139 
140 /*
141  * Interface exists: make available by filling in network interface
142  * record.  System will initialize the interface when it is ready
143  * to accept packets.
144  */
145 int
146 mcsetup(sc, lladdr)
147 	struct mc_softc	*sc;
148 	u_int8_t *lladdr;
149 {
150 	struct ifnet *ifp = &sc->sc_if;
151 
152 	/* reset the chip and disable all interrupts */
153 	NIC_PUT(sc, MACE_BIUCC, SWRST);
154 	DELAY(100);
155 	NIC_PUT(sc, MACE_IMR, ~0);
156 
157 	memcpy(sc->sc_enaddr, lladdr, ETHER_ADDR_LEN);
158 	printf(": address %s\n", ether_sprintf(lladdr));
159 
160 	memcpy(ifp->if_xname, sc->sc_dev.dv_xname, IFNAMSIZ);
161 	ifp->if_softc = sc;
162 	ifp->if_ioctl = mcioctl;
163 	ifp->if_start = mcstart;
164 	ifp->if_flags =
165 	    IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS | IFF_MULTICAST;
166 	ifp->if_watchdog = mcwatchdog;
167 
168 	/* initialize ifmedia structures */
169 	ifmedia_init(&sc->sc_media, 0, mc_mediachange, mc_mediastatus);
170 	ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
171 	ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_MANUAL);
172 
173 	if_attach(ifp);
174 	ether_ifattach(ifp, lladdr);
175 
176 	return (0);
177 }
178 
179 hide int
180 mcioctl(ifp, cmd, data)
181 	struct ifnet *ifp;
182 	u_long cmd;
183 	void *data;
184 {
185 	struct mc_softc *sc = ifp->if_softc;
186 	struct ifaddr *ifa;
187 	struct ifreq *ifr;
188 
189 	int	s = splnet(), err = 0;
190 
191 	switch (cmd) {
192 
193 	case SIOCSIFADDR:
194 		ifa = (struct ifaddr *)data;
195 		ifp->if_flags |= IFF_UP;
196 		switch (ifa->ifa_addr->sa_family) {
197 #ifdef INET
198 		case AF_INET:
199 			mcinit(sc);
200 			arp_ifinit(ifp, ifa);
201 			break;
202 #endif
203 		default:
204 			mcinit(sc);
205 			break;
206 		}
207 		break;
208 
209 	case SIOCSIFFLAGS:
210 		if ((ifp->if_flags & IFF_UP) == 0 &&
211 		    (ifp->if_flags & IFF_RUNNING) != 0) {
212 			/*
213 			 * If interface is marked down and it is running,
214 			 * then stop it.
215 			 */
216 			mcstop(sc);
217 			ifp->if_flags &= ~IFF_RUNNING;
218 		} else if ((ifp->if_flags & IFF_UP) != 0 &&
219 		    (ifp->if_flags & IFF_RUNNING) == 0) {
220 			/*
221 			 * If interface is marked up and it is stopped,
222 			 * then start it.
223 			 */
224 			(void)mcinit(sc);
225 		} else {
226 			/*
227 			 * reset the interface to pick up any other changes
228 			 * in flags
229 			 */
230 			mcreset(sc);
231 			mcstart(ifp);
232 		}
233 		break;
234 
235 	case SIOCADDMULTI:
236 	case SIOCDELMULTI:
237 		if ((err = ether_ioctl(ifp, cmd, data)) == ENETRESET) {
238 			/*
239 			 * Multicast list has changed; set the hardware
240 			 * filter accordingly. But remember UP flag!
241 			 */
242 			if (ifp->if_flags & IFF_RUNNING)
243 				mcreset(sc);
244 			err = 0;
245 		}
246 		break;
247 
248 	case SIOCGIFMEDIA:
249 	case SIOCSIFMEDIA:
250 		ifr = (struct ifreq *) data;
251 		err = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
252 		break;
253 
254 	default:
255 		err = EINVAL;
256 	}
257 	splx(s);
258 	return (err);
259 }
260 
261 /*
262  * Encapsulate a packet of type family for the local net.
263  */
264 hide void
265 mcstart(ifp)
266 	struct ifnet *ifp;
267 {
268 	struct mc_softc	*sc = ifp->if_softc;
269 	struct mbuf	*m;
270 
271 	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
272 		return;
273 
274 	while (1) {
275 		if (ifp->if_flags & IFF_OACTIVE)
276 			return;
277 
278 		IF_DEQUEUE(&ifp->if_snd, m);
279 		if (m == 0)
280 			return;
281 
282 #if NBPFILTER > 0
283 		/*
284 		 * If bpf is listening on this interface, let it
285 		 * see the packet before we commit it to the wire.
286 		 */
287 		if (ifp->if_bpf)
288 			bpf_mtap(ifp->if_bpf, m);
289 #endif
290 
291 		/*
292 		 * Copy the mbuf chain into the transmit buffer.
293 		 */
294 		ifp->if_flags |= IFF_OACTIVE;
295 		maceput(sc, m);
296 
297 		ifp->if_opackets++;		/* # of pkts */
298 	}
299 }
300 
301 /*
302  * reset and restart the MACE.  Called in case of fatal
303  * hardware/software errors.
304  */
305 hide void
306 mcreset(sc)
307 	struct mc_softc *sc;
308 {
309 	mcstop(sc);
310 	mcinit(sc);
311 }
312 
313 hide int
314 mcinit(sc)
315 	struct mc_softc *sc;
316 {
317 	int s;
318 	u_int8_t maccc, ladrf[8];
319 
320 	if (sc->sc_if.if_flags & IFF_RUNNING)
321 		/* already running */
322 		return (0);
323 
324 	s = splnet();
325 
326 	NIC_PUT(sc, MACE_BIUCC, sc->sc_biucc);
327 	NIC_PUT(sc, MACE_FIFOCC, sc->sc_fifocc);
328 	NIC_PUT(sc, MACE_IMR, ~0); /* disable all interrupts */
329 	NIC_PUT(sc, MACE_PLSCC, sc->sc_plscc);
330 
331 	NIC_PUT(sc, MACE_UTR, RTRD); /* disable reserved test registers */
332 
333 	/* set MAC address */
334 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
335 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
336 		;
337 	NIC_PUT(sc, MACE_IAC, PHYADDR);
338 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_PADR),
339 	    sc->sc_enaddr, ETHER_ADDR_LEN);
340 
341 	/* set logical address filter */
342 	mace_calcladrf(&sc->sc_ethercom, ladrf);
343 
344 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
345 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
346 		;
347 	NIC_PUT(sc, MACE_IAC, LOGADDR);
348 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_LADRF),
349 	    ladrf, 8);
350 
351 	NIC_PUT(sc, MACE_XMTFC, APADXMT);
352 	/*
353 	 * No need to autostrip padding on receive... Ethernet frames
354 	 * don't have a length field, unlike 802.3 frames, so the MACE
355 	 * can't figure out the length of the packet anyways.
356 	 */
357 	NIC_PUT(sc, MACE_RCVFC, 0);
358 
359 	maccc = ENXMT | ENRCV;
360 	if (sc->sc_if.if_flags & IFF_PROMISC)
361 		maccc |= PROM;
362 
363 	NIC_PUT(sc, MACE_MACCC, maccc);
364 
365 	if (sc->sc_bus_init)
366 		(*sc->sc_bus_init)(sc);
367 
368 	/*
369 	 * Enable all interrupts except receive, since we use the DMA
370 	 * completion interrupt for that.
371 	 */
372 	NIC_PUT(sc, MACE_IMR, RCVINTM);
373 
374 	/* flag interface as "running" */
375 	sc->sc_if.if_flags |= IFF_RUNNING;
376 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
377 
378 	splx(s);
379 	return (0);
380 }
381 
382 /*
383  * close down an interface and free its buffers
384  * Called on final close of device, or if mcinit() fails
385  * part way through.
386  */
387 hide int
388 mcstop(sc)
389 	struct mc_softc *sc;
390 {
391 	int	s = splnet();
392 
393 	NIC_PUT(sc, MACE_BIUCC, SWRST);
394 	DELAY(100);
395 
396 	sc->sc_if.if_timer = 0;
397 	sc->sc_if.if_flags &= ~IFF_RUNNING;
398 
399 	splx(s);
400 	return (0);
401 }
402 
403 /*
404  * Called if any Tx packets remain unsent after 5 seconds,
405  * In all cases we just reset the chip, and any retransmission
406  * will be handled by higher level protocol timeouts.
407  */
408 hide void
409 mcwatchdog(ifp)
410 	struct ifnet *ifp;
411 {
412 	struct mc_softc *sc = ifp->if_softc;
413 
414 	printf("mcwatchdog: resetting chip\n");
415 	mcreset(sc);
416 }
417 
418 /*
419  * stuff packet into MACE (at splnet)
420  */
421 integrate u_int
422 maceput(sc, m)
423 	struct mc_softc *sc;
424 	struct mbuf *m;
425 {
426 	struct mbuf *n;
427 	u_int len, totlen = 0;
428 	u_char *buff;
429 
430 	buff = sc->sc_txbuf;
431 
432 	for (; m; m = n) {
433 		u_char *data = mtod(m, u_char *);
434 		len = m->m_len;
435 		totlen += len;
436 		memcpy(buff, data, len);
437 		buff += len;
438 		MFREE(m, n);
439 	}
440 
441 	if (totlen > PAGE_SIZE)
442 		panic("%s: maceput: packet overflow", sc->sc_dev.dv_xname);
443 
444 #if 0
445 	if (totlen < ETHERMIN + sizeof(struct ether_header)) {
446 		int pad = ETHERMIN + sizeof(struct ether_header) - totlen;
447 		memset(sc->sc_txbuf + totlen, 0, pad);
448 		totlen = ETHERMIN + sizeof(struct ether_header);
449 	}
450 #endif
451 
452 	(*sc->sc_putpacket)(sc, totlen);
453 
454 	sc->sc_if.if_timer = 5;	/* 5 seconds to watch for failing to transmit */
455 	return (totlen);
456 }
457 
458 int
459 mcintr(arg)
460 	void *arg;
461 {
462 	struct mc_softc *sc = arg;
463 	u_int8_t ir;
464 
465 	ir = NIC_GET(sc, MACE_IR) & ~NIC_GET(sc, MACE_IMR);
466 	if (ir == 0)
467 		return 0;
468 
469 	if (ir & JAB) {
470 #ifdef MCDEBUG
471 		printf("%s: jabber error\n", sc->sc_dev.dv_xname);
472 #endif
473 		sc->sc_if.if_oerrors++;
474 	}
475 
476 	if (ir & BABL) {
477 #ifdef MCDEBUG
478 		printf("%s: babble\n", sc->sc_dev.dv_xname);
479 #endif
480 		sc->sc_if.if_oerrors++;
481 	}
482 
483 	if (ir & CERR) {
484 		printf("%s: collision error\n", sc->sc_dev.dv_xname);
485 		sc->sc_if.if_collisions++;
486 	}
487 
488 	/*
489 	 * Pretend we have carrier; if we don't this will be cleared
490 	 * shortly.
491 	 */
492 	sc->sc_havecarrier = 1;
493 
494 	if (ir & XMTINT)
495 		mc_tint(sc);
496 
497 	if (ir & RCVINT)
498 		mc_rint(sc);
499 
500 	return 1;
501 }
502 
503 integrate void
504 mc_tint(sc)
505 	struct mc_softc *sc;
506 {
507 	u_int8_t xmtrc, xmtfs;
508 
509 	xmtrc = NIC_GET(sc, MACE_XMTRC);
510 	xmtfs = NIC_GET(sc, MACE_XMTFS);
511 
512 	if ((xmtfs & XMTSV) == 0)
513 		return;
514 
515 	if (xmtfs & UFLO) {
516 		printf("%s: underflow\n", sc->sc_dev.dv_xname);
517 		mcreset(sc);
518 		return;
519 	}
520 
521 	if (xmtfs & LCOL) {
522 		printf("%s: late collision\n", sc->sc_dev.dv_xname);
523 		sc->sc_if.if_oerrors++;
524 		sc->sc_if.if_collisions++;
525 	}
526 
527 	if (xmtfs & MORE)
528 		/* Real number is unknown. */
529 		sc->sc_if.if_collisions += 2;
530 	else if (xmtfs & ONE)
531 		sc->sc_if.if_collisions++;
532 	else if (xmtfs & RTRY) {
533 		sc->sc_if.if_collisions += 16;
534 		sc->sc_if.if_oerrors++;
535 	}
536 
537 	if (xmtfs & LCAR) {
538 		sc->sc_havecarrier = 0;
539 		printf("%s: lost carrier\n", sc->sc_dev.dv_xname);
540 		sc->sc_if.if_oerrors++;
541 	}
542 
543 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
544 	sc->sc_if.if_timer = 0;
545 	mcstart(&sc->sc_if);
546 }
547 
548 void
549 mc_rint(sc)
550 	struct mc_softc *sc;
551 {
552 #define	rxf	sc->sc_rxframe
553 	u_int len;
554 
555 	len = (rxf.rx_rcvcnt | ((rxf.rx_rcvsts & 0xf) << 8)) - 4;
556 
557 #ifdef MCDEBUG
558 	if (rxf.rx_rcvsts & 0xf0)
559 		printf("%s: rcvcnt %02x rcvsts %02x rntpc 0x%02x rcvcc 0x%02x\n",
560 		    sc->sc_dev.dv_xname, rxf.rx_rcvcnt, rxf.rx_rcvsts,
561 		    rxf.rx_rntpc, rxf.rx_rcvcc);
562 #endif
563 
564 	if (rxf.rx_rcvsts & OFLO) {
565 		printf("%s: receive FIFO overflow\n", sc->sc_dev.dv_xname);
566 		sc->sc_if.if_ierrors++;
567 		return;
568 	}
569 
570 	if (rxf.rx_rcvsts & CLSN)
571 		sc->sc_if.if_collisions++;
572 
573 	if (rxf.rx_rcvsts & FRAM) {
574 #ifdef MCDEBUG
575 		printf("%s: framing error\n", sc->sc_dev.dv_xname);
576 #endif
577 		sc->sc_if.if_ierrors++;
578 		return;
579 	}
580 
581 	if (rxf.rx_rcvsts & FCS) {
582 #ifdef MCDEBUG
583 		printf("%s: frame control checksum error\n", sc->sc_dev.dv_xname);
584 #endif
585 		sc->sc_if.if_ierrors++;
586 		return;
587 	}
588 
589 	mace_read(sc, rxf.rx_frame, len);
590 #undef	rxf
591 }
592 
593 integrate void
594 mace_read(sc, pkt, len)
595 	struct mc_softc *sc;
596 	uint8_t *pkt;
597 	int len;
598 {
599 	struct ifnet *ifp = &sc->sc_if;
600 	struct mbuf *m;
601 
602 	if (len <= sizeof(struct ether_header) ||
603 	    len > ETHERMTU + sizeof(struct ether_header)) {
604 #ifdef MCDEBUG
605 		printf("%s: invalid packet size %d; dropping\n",
606 		    sc->sc_dev.dv_xname, len);
607 #endif
608 		ifp->if_ierrors++;
609 		return;
610 	}
611 
612 	m = mace_get(sc, pkt, len);
613 	if (m == NULL) {
614 		ifp->if_ierrors++;
615 		return;
616 	}
617 
618 	ifp->if_ipackets++;
619 
620 #if NBPFILTER > 0
621 	/* Pass this up to any BPF listeners. */
622 	if (ifp->if_bpf)
623 		bpf_mtap(ifp->if_bpf, m);
624 #endif
625 
626 	/* Pass the packet up. */
627 	(*ifp->if_input)(ifp, m);
628 }
629 
630 /*
631  * Pull data off an interface.
632  * Len is length of data, with local net header stripped.
633  * We copy the data into mbufs.  When full cluster sized units are present
634  * we copy into clusters.
635  */
636 integrate struct mbuf *
637 mace_get(sc, pkt, totlen)
638 	struct mc_softc *sc;
639 	uint8_t *pkt;
640 	int totlen;
641 {
642 	register struct mbuf *m;
643 	struct mbuf *top, **mp;
644 	int len;
645 
646 	MGETHDR(m, M_DONTWAIT, MT_DATA);
647 	if (m == 0)
648 		return (0);
649 	m->m_pkthdr.rcvif = &sc->sc_if;
650 	m->m_pkthdr.len = totlen;
651 	len = MHLEN;
652 	top = 0;
653 	mp = &top;
654 
655 	while (totlen > 0) {
656 		if (top) {
657 			MGET(m, M_DONTWAIT, MT_DATA);
658 			if (m == 0) {
659 				m_freem(top);
660 				return 0;
661 			}
662 			len = MLEN;
663 		}
664 		if (totlen >= MINCLSIZE) {
665 			MCLGET(m, M_DONTWAIT);
666 			if ((m->m_flags & M_EXT) == 0) {
667 				m_free(m);
668 				m_freem(top);
669 				return 0;
670 			}
671 			len = MCLBYTES;
672 		}
673 		m->m_len = len = min(totlen, len);
674 		memcpy(mtod(m, void *), pkt, len);
675 		pkt += len;
676 		totlen -= len;
677 		*mp = m;
678 		mp = &m->m_next;
679 	}
680 
681 	return (top);
682 }
683 
684 /*
685  * Go through the list of multicast addresses and calculate the logical
686  * address filter.
687  */
688 void
689 mace_calcladrf(ac, af)
690 	struct ethercom *ac;
691 	u_int8_t *af;
692 {
693 	struct ifnet *ifp = &ac->ec_if;
694 	struct ether_multi *enm;
695 	register u_char *cp, c;
696 	register u_int32_t crc;
697 	register int i, len;
698 	struct ether_multistep step;
699 
700 	/*
701 	 * Set up multicast address filter by passing all multicast addresses
702 	 * through a crc generator, and then using the high order 6 bits as an
703 	 * index into the 64 bit logical address filter.  The high order bit
704 	 * selects the word, while the rest of the bits select the bit within
705 	 * the word.
706 	 */
707 
708 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0;
709 
710 	ETHER_FIRST_MULTI(step, ac, enm);
711 	while (enm != NULL) {
712 		if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) {
713 			/*
714 			 * We must listen to a range of multicast addresses.
715 			 * For now, just accept all multicasts, rather than
716 			 * trying to set only those filter bits needed to match
717 			 * the range.  (At this time, the only use of address
718 			 * ranges is for IP multicast routing, for which the
719 			 * range is big enough to require all bits set.)
720 			 */
721 			goto allmulti;
722 		}
723 
724 		cp = enm->enm_addrlo;
725 		crc = 0xffffffff;
726 		for (len = sizeof(enm->enm_addrlo); --len >= 0;) {
727 			c = *cp++;
728 			for (i = 8; --i >= 0;) {
729 				if ((crc & 0x01) ^ (c & 0x01)) {
730 					crc >>= 1;
731 					crc ^= 0xedb88320;
732 				} else
733 					crc >>= 1;
734 				c >>= 1;
735 			}
736 		}
737 		/* Just want the 6 most significant bits. */
738 		crc >>= 26;
739 
740 		/* Set the corresponding bit in the filter. */
741 		af[crc >> 3] |= 1 << (crc & 7);
742 
743 		ETHER_NEXT_MULTI(step, enm);
744 	}
745 	ifp->if_flags &= ~IFF_ALLMULTI;
746 	return;
747 
748 allmulti:
749 	ifp->if_flags |= IFF_ALLMULTI;
750 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0xffffffff;
751 }
752 
753 int
754 mc_mediachange(ifp)
755 	struct ifnet *ifp;
756 {
757 	return EINVAL;
758 }
759 
760 void
761 mc_mediastatus(ifp, ifmr)
762 	struct ifnet *ifp;
763 	struct ifmediareq *ifmr;
764 {
765 	struct mc_softc *sc = ifp->if_softc;
766 
767 	if ((ifp->if_flags & IFF_UP) == 0)
768 		return;
769 
770 	if (sc->sc_havecarrier)
771 		ifmr->ifm_status |= IFM_ACTIVE;
772 }
773