xref: /netbsd-src/sys/arch/macppc/dev/am79c950.c (revision cef8759bd76c1b621f8eab8faa6f208faabc2e15)
1 /*	$NetBSD: am79c950.c,v 1.49 2020/02/04 13:47:34 martin 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 1.49 2020/02/04 13:47:34 martin 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 #include <sys/bus.h>
53 
54 #include <net/if.h>
55 #include <net/if_dl.h>
56 #include <net/if_ether.h>
57 #include <net/if_media.h>
58 #include <net/bpf.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 <macppc/dev/am79c950reg.h>
69 #include <macppc/dev/if_mcvar.h>
70 
71 hide void	mcwatchdog(struct ifnet *);
72 hide int	mcinit(struct mc_softc *);
73 hide int	mcstop(struct mc_softc *);
74 hide int	mcioctl(struct ifnet *, u_long, void *);
75 hide void	mcstart(struct ifnet *);
76 hide void	mcreset(struct mc_softc *);
77 
78 integrate u_int	maceput(struct mc_softc *, struct mbuf *);
79 integrate void	mc_tint(struct mc_softc *);
80 integrate void	mace_read(struct mc_softc *, uint8_t *, int);
81 integrate struct mbuf *mace_get(struct mc_softc *, uint8_t *, int);
82 static void	mace_calcladrf(struct ethercom *, uint8_t *);
83 static inline uint16_t ether_cmp(void *, void *);
84 static int	mc_mediachange(struct ifnet *);
85 static void	mc_mediastatus(struct ifnet *, struct ifmediareq *);
86 
87 /*
88  * Compare two Ether/802 addresses for equality, inlined and
89  * unrolled for speed.  Use this like memcmp().
90  *
91  * XXX: Add <machine/inlines.h> for stuff like this?
92  * XXX: or maybe add it to libkern.h instead?
93  *
94  * "I'd love to have an inline assembler version of this."
95  * XXX: Who wanted that? mycroft?  I wrote one, but this
96  * version in C is as good as hand-coded assembly. -gwr
97  *
98  * Please do NOT tweak this without looking at the actual
99  * assembly code generated before and after your tweaks!
100  */
101 static inline uint16_t
102 ether_cmp(void *one, void *two)
103 {
104 	register uint16_t *a = (u_short *) one;
105 	register uint16_t *b = (u_short *) two;
106 	register uint16_t diff;
107 
108 #ifdef	m68k
109 	/*
110 	 * The post-increment-pointer form produces the best
111 	 * machine code for m68k.  This was carefully tuned
112 	 * so it compiles to just 8 short (2-byte) op-codes!
113 	 */
114 	diff  = *a++ - *b++;
115 	diff |= *a++ - *b++;
116 	diff |= *a++ - *b++;
117 #else
118 	/*
119 	 * Most modern CPUs do better with a single expression.
120 	 * Note that short-cut evaluation is NOT helpful here,
121 	 * because it just makes the code longer, not faster!
122 	 */
123 	diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]);
124 #endif
125 
126 	return diff;
127 }
128 
129 #define ETHER_CMP	ether_cmp
130 
131 /*
132  * Interface exists: make available by filling in network interface
133  * record.  System will initialize the interface when it is ready
134  * to accept packets.
135  */
136 int
137 mcsetup(struct mc_softc *sc, uint8_t *lladdr)
138 {
139 	struct ifnet *ifp = &sc->sc_if;
140 
141 	/* Reset the chip and disable all interrupts */
142 	NIC_PUT(sc, MACE_BIUCC, SWRST);
143 	DELAY(100);
144 	NIC_PUT(sc, MACE_IMR, ~0);
145 
146 	memcpy(sc->sc_enaddr, lladdr, ETHER_ADDR_LEN);
147 	printf(": address %s\n", ether_sprintf(lladdr));
148 
149 	memcpy(ifp->if_xname, device_xname(sc->sc_dev), IFNAMSIZ);
150 	ifp->if_softc = sc;
151 	ifp->if_ioctl = mcioctl;
152 	ifp->if_start = mcstart;
153 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
154 	ifp->if_watchdog = mcwatchdog;
155 
156 	/* Initialize ifmedia structures */
157 	sc->sc_ethercom.ec_ifmedia = &sc->sc_media;
158 	ifmedia_init(&sc->sc_media, 0, mc_mediachange, mc_mediastatus);
159 	ifmedia_add(&sc->sc_media, IFM_ETHER | IFM_MANUAL, 0, NULL);
160 	ifmedia_set(&sc->sc_media, IFM_ETHER | IFM_MANUAL);
161 
162 	if_attach(ifp);
163 	if_deferred_start_init(ifp, NULL);
164 	ether_ifattach(ifp, lladdr);
165 
166 	return 0;
167 }
168 
169 hide int
170 mcioctl(struct ifnet *ifp, u_long cmd, void *data)
171 {
172 	struct mc_softc *sc = ifp->if_softc;
173 	struct ifaddr *ifa;
174 
175 	int	s = splnet(), err = 0;
176 
177 	switch (cmd) {
178 
179 	case SIOCINITIFADDR:
180 		ifa = (struct ifaddr *)data;
181 		ifp->if_flags |= IFF_UP;
182 		mcinit(sc);
183 		switch (ifa->ifa_addr->sa_family) {
184 #ifdef INET
185 		case AF_INET:
186 			arp_ifinit(ifp, ifa);
187 			break;
188 #endif
189 		default:
190 			break;
191 		}
192 		break;
193 
194 	case SIOCSIFFLAGS:
195 		if ((err = ifioctl_common(ifp, cmd, data)) != 0)
196 			break;
197 		/* XXX see the comment in ed_ioctl() about code re-use */
198 		if ((ifp->if_flags & IFF_UP) == 0 &&
199 		    (ifp->if_flags & IFF_RUNNING) != 0) {
200 			/*
201 			 * If interface is marked down and it is running,
202 			 * then stop it.
203 			 */
204 			mcstop(sc);
205 			ifp->if_flags &= ~IFF_RUNNING;
206 		} else if ((ifp->if_flags & IFF_UP) != 0 &&
207 		    (ifp->if_flags & IFF_RUNNING) == 0) {
208 			/*
209 			 * If interface is marked up and it is stopped,
210 			 * then start it.
211 			 */
212 			(void)mcinit(sc);
213 		} else {
214 			/*
215 			 * Reset the interface to pick up any other changes
216 			 * in flags
217 			 */
218 			mcreset(sc);
219 			mcstart(ifp);
220 		}
221 		break;
222 
223 	case SIOCADDMULTI:
224 	case SIOCDELMULTI:
225 		if ((err = ether_ioctl(ifp, cmd, data)) == ENETRESET) {
226 			/*
227 			 * Multicast list has changed; set the hardware
228 			 * filter accordingly. But remember UP flag!
229 			 */
230 			if (ifp->if_flags & IFF_RUNNING)
231 				mcreset(sc);
232 			err = 0;
233 		}
234 		break;
235 
236 	default:
237 		err = ether_ioctl(ifp, cmd, data);
238 		break;
239 	}
240 	splx(s);
241 	return err;
242 }
243 
244 /*
245  * Encapsulate a packet of type family for the local net.
246  */
247 hide void
248 mcstart(struct ifnet *ifp)
249 {
250 	struct mc_softc	*sc = ifp->if_softc;
251 	struct mbuf	*m;
252 
253 	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
254 		return;
255 
256 	while (1) {
257 		if (ifp->if_flags & IFF_OACTIVE)
258 			return;
259 
260 		IF_DEQUEUE(&ifp->if_snd, m);
261 		if (m == 0)
262 			return;
263 
264 		/*
265 		 * If bpf is listening on this interface, let it
266 		 * see the packet before we commit it to the wire.
267 		 */
268 		bpf_mtap(ifp, m, BPF_D_OUT);
269 
270 		/* Copy the mbuf chain into the transmit buffer. */
271 		ifp->if_flags |= IFF_OACTIVE;
272 		maceput(sc, m);
273 
274 		if_statinc(ifp, if_opackets);		/* # of pkts */
275 	}
276 }
277 
278 /*
279  * Reset and restart the MACE.  Called in case of fatal
280  * hardware/software errors.
281  */
282 hide void
283 mcreset(struct mc_softc *sc)
284 {
285 	mcstop(sc);
286 	mcinit(sc);
287 }
288 
289 hide int
290 mcinit(struct mc_softc *sc)
291 {
292 	int s;
293 	uint8_t maccc, ladrf[8];
294 
295 	if (sc->sc_if.if_flags & IFF_RUNNING)
296 		/* already running */
297 		return 0;
298 
299 	s = splnet();
300 
301 	NIC_PUT(sc, MACE_BIUCC, sc->sc_biucc);
302 	NIC_PUT(sc, MACE_FIFOCC, sc->sc_fifocc);
303 	NIC_PUT(sc, MACE_IMR, ~0); /* Disable all interrupts */
304 	NIC_PUT(sc, MACE_PLSCC, sc->sc_plscc);
305 
306 	NIC_PUT(sc, MACE_UTR, RTRD); /* Disable reserved test registers */
307 
308 	/* Set MAC address */
309 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
310 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
311 		;
312 	NIC_PUT(sc, MACE_IAC, PHYADDR);
313 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_PADR),
314 	    sc->sc_enaddr, ETHER_ADDR_LEN);
315 
316 	/* Set logical address filter */
317 	mace_calcladrf(&sc->sc_ethercom, ladrf);
318 
319 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
320 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
321 		;
322 	NIC_PUT(sc, MACE_IAC, LOGADDR);
323 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_LADRF),
324 	    ladrf, 8);
325 
326 	NIC_PUT(sc, MACE_XMTFC, APADXMT);
327 	/*
328 	 * No need to autostrip padding on receive... Ethernet frames
329 	 * don't have a length field, unlike 802.3 frames, so the MACE
330 	 * can't figure out the length of the packet anyways.
331 	 */
332 	NIC_PUT(sc, MACE_RCVFC, 0);
333 
334 	maccc = ENXMT | ENRCV;
335 	if (sc->sc_if.if_flags & IFF_PROMISC)
336 		maccc |= PROM;
337 
338 	NIC_PUT(sc, MACE_MACCC, maccc);
339 
340 	if (sc->sc_bus_init)
341 		(*sc->sc_bus_init)(sc);
342 
343 	/*
344 	 * Enable all interrupts except receive, since we use the DMA
345 	 * completion interrupt for that.
346 	 */
347 	NIC_PUT(sc, MACE_IMR, RCVINTM);
348 
349 	/* Flag interface as "running" */
350 	sc->sc_if.if_flags |= IFF_RUNNING;
351 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
352 
353 	splx(s);
354 	return 0;
355 }
356 
357 /*
358  * Close down an interface and free its buffers
359  * Called on final close of device, or if mcinit() fails part way through.
360  */
361 hide int
362 mcstop(struct mc_softc *sc)
363 {
364 	int	s = splnet();
365 
366 	NIC_PUT(sc, MACE_BIUCC, SWRST);
367 	DELAY(100);
368 
369 	sc->sc_if.if_timer = 0;
370 	sc->sc_if.if_flags &= ~IFF_RUNNING;
371 
372 	splx(s);
373 	return 0;
374 }
375 
376 /*
377  * Called if any Tx packets remain unsent after 5 seconds,
378  * In all cases we just reset the chip, and any retransmission
379  * will be handled by higher level protocol timeouts.
380  */
381 hide void
382 mcwatchdog(struct ifnet *ifp)
383 {
384 	struct mc_softc *sc = ifp->if_softc;
385 
386 	printf("mcwatchdog: resetting chip\n");
387 	mcreset(sc);
388 }
389 
390 /*
391  * Stuff packet into MACE (at splnet)
392  */
393 integrate u_int
394 maceput(struct mc_softc *sc, struct mbuf *m)
395 {
396 	struct mbuf *n;
397 	u_int len, totlen = 0;
398 	u_char *buff;
399 
400 	buff = sc->sc_txbuf;
401 
402 	for (; m; m = n) {
403 		u_char *data = mtod(m, u_char *);
404 		len = m->m_len;
405 		totlen += len;
406 		memcpy(buff, data, len);
407 		buff += len;
408 		n = m_free(m);
409 	}
410 
411 	if (totlen > PAGE_SIZE)
412 		panic("%s: maceput: packet overflow", device_xname(sc->sc_dev));
413 
414 #if 0
415 	if (totlen < ETHERMIN + sizeof(struct ether_header)) {
416 		int pad = ETHERMIN + sizeof(struct ether_header) - totlen;
417 		memset(sc->sc_txbuf + totlen, 0, pad);
418 		totlen = ETHERMIN + sizeof(struct ether_header);
419 	}
420 #endif
421 
422 	(*sc->sc_putpacket)(sc, totlen);
423 
424 	sc->sc_if.if_timer = 5;	/* 5 seconds to watch for failing to transmit */
425 	return totlen;
426 }
427 
428 int
429 mcintr(void *arg)
430 {
431 	struct mc_softc *sc = arg;
432 	uint8_t ir;
433 
434 	ir = NIC_GET(sc, MACE_IR) & ~NIC_GET(sc, MACE_IMR);
435 	if (ir == 0)
436 		return 0;
437 
438 	if (ir & JAB) {
439 #ifdef MCDEBUG
440 		printf("%s: jabber error\n", device_xname(sc->sc_dev));
441 #endif
442 		if_statinc(&sc->sc_if, if_oerrors);
443 	}
444 
445 	if (ir & BABL) {
446 #ifdef MCDEBUG
447 		printf("%s: babble\n", device_xname(sc->sc_dev));
448 #endif
449 		if_statinc(&sc->sc_if, if_oerrors);
450 	}
451 
452 	if (ir & CERR) {
453 		printf("%s: collision error\n", device_xname(sc->sc_dev));
454 		if_statinc(&sc->sc_if, if_collisions);
455 	}
456 
457 	/*
458 	 * Pretend we have carrier; if we don't this will be cleared
459 	 * shortly.
460 	 */
461 	sc->sc_havecarrier = 1;
462 
463 	if (ir & XMTINT)
464 		mc_tint(sc);
465 
466 	if (ir & RCVINT)
467 		mc_rint(sc);
468 
469 	return 1;
470 }
471 
472 integrate void
473 mc_tint(struct mc_softc *sc)
474 {
475 	uint8_t xmtfs;
476 
477 	(void)NIC_GET(sc, MACE_XMTRC);
478 	xmtfs = NIC_GET(sc, MACE_XMTFS);
479 
480 	if ((xmtfs & XMTSV) == 0)
481 		return;
482 
483 	if (xmtfs & UFLO) {
484 		printf("%s: underflow\n", device_xname(sc->sc_dev));
485 		mcreset(sc);
486 		return;
487 	}
488 
489 	net_stat_ref_t nsr = IF_STAT_GETREF(&sc->sc_if);
490 	if (xmtfs & LCOL) {
491 		printf("%s: late collision\n", device_xname(sc->sc_dev));
492 		if_statinc_ref(nsr, if_oerrors);
493 		if_statinc_ref(nsr, if_collisions);
494 	}
495 
496 	if (xmtfs & MORE)
497 		/* Real number is unknown. */
498 		if_statadd_ref(nsr, if_collisions, 2);
499 	else if (xmtfs & ONE)
500 		if_statinc_ref(nsr, if_collisions);
501 	else if (xmtfs & RTRY) {
502 		if_statadd_ref(nsr, if_collisions, 16);
503 		if_statinc_ref(nsr, if_oerrors);
504 	}
505 
506 	if (xmtfs & LCAR) {
507 		sc->sc_havecarrier = 0;
508 		printf("%s: lost carrier\n", device_xname(sc->sc_dev));
509 		if_statinc_ref(nsr, if_oerrors);
510 	}
511 	IF_STAT_PUTREF(&sc->sc_if);
512 
513 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
514 	sc->sc_if.if_timer = 0;
515 	if_schedule_deferred_start(&sc->sc_if);
516 }
517 
518 void
519 mc_rint(struct mc_softc *sc)
520 {
521 #define	rxf	sc->sc_rxframe
522 	u_int len;
523 
524 	len = (rxf.rx_rcvcnt | ((rxf.rx_rcvsts & 0xf) << 8)) - 4;
525 
526 #ifdef MCDEBUG
527 	if (rxf.rx_rcvsts & 0xf0)
528 		printf("%s: rcvcnt %02x rcvsts %02x rntpc 0x%02x rcvcc 0x%02x\n",
529 		    device_xname(sc->sc_dev), rxf.rx_rcvcnt, rxf.rx_rcvsts,
530 		    rxf.rx_rntpc, rxf.rx_rcvcc);
531 #endif
532 
533 	if (rxf.rx_rcvsts & OFLO) {
534 		printf("%s: receive FIFO overflow\n", device_xname(sc->sc_dev));
535 		if_statinc(&sc->sc_if, if_ierrors);
536 		return;
537 	}
538 
539 	if (rxf.rx_rcvsts & CLSN)
540 		if_statinc(&sc->sc_if, if_collisions);
541 
542 	if (rxf.rx_rcvsts & FRAM) {
543 #ifdef MCDEBUG
544 		printf("%s: framing error\n", device_xname(sc->sc_dev));
545 #endif
546 		if_statinc(&sc->sc_if, if_ierrors);
547 		return;
548 	}
549 
550 	if (rxf.rx_rcvsts & FCS) {
551 #ifdef MCDEBUG
552 		printf("%s: frame control checksum error\n",
553 		    device_xname(sc->sc_dev));
554 #endif
555 		if_statinc(&sc->sc_if, if_ierrors);
556 		return;
557 	}
558 
559 	mace_read(sc, rxf.rx_frame, len);
560 #undef	rxf
561 }
562 
563 integrate void
564 mace_read(struct mc_softc *sc, uint8_t *pkt, int len)
565 {
566 	struct ifnet *ifp = &sc->sc_if;
567 	struct mbuf *m;
568 
569 	if (len <= sizeof(struct ether_header) ||
570 	    len > ETHERMTU + sizeof(struct ether_header)) {
571 #ifdef MCDEBUG
572 		printf("%s: invalid packet size %d; dropping\n",
573 		    device_xname(sc->sc_dev), len);
574 #endif
575 		if_statinc(ifp, if_ierrors);
576 		return;
577 	}
578 
579 	m = mace_get(sc, pkt, len);
580 	if (m == NULL) {
581 		if_statinc(ifp, if_ierrors);
582 		return;
583 	}
584 
585 	/* Pass the packet up. */
586 	if_percpuq_enqueue(ifp->if_percpuq, m);
587 }
588 
589 /*
590  * Pull data off an interface.
591  * Len is length of data, with local net header stripped.
592  * We copy the data into mbufs.  When full cluster sized units are present
593  * we copy into clusters.
594  */
595 integrate struct mbuf *
596 mace_get(struct mc_softc *sc, uint8_t *pkt, int totlen)
597 {
598 	register struct mbuf *m;
599 	struct mbuf *top, **mp;
600 	int len;
601 
602 	MGETHDR(m, M_DONTWAIT, MT_DATA);
603 	if (m == 0)
604 		return 0;
605 	m_set_rcvif(m, &sc->sc_if);
606 	m->m_pkthdr.len = totlen;
607 	len = MHLEN;
608 	top = 0;
609 	mp = &top;
610 
611 	while (totlen > 0) {
612 		if (top) {
613 			MGET(m, M_DONTWAIT, MT_DATA);
614 			if (m == 0) {
615 				m_freem(top);
616 				return 0;
617 			}
618 			len = MLEN;
619 		}
620 		if (totlen >= MINCLSIZE) {
621 			MCLGET(m, M_DONTWAIT);
622 			if ((m->m_flags & M_EXT) == 0) {
623 				m_free(m);
624 				m_freem(top);
625 				return 0;
626 			}
627 			len = MCLBYTES;
628 		}
629 		m->m_len = len = uimin(totlen, len);
630 		memcpy(mtod(m, void *), pkt, len);
631 		pkt += len;
632 		totlen -= len;
633 		*mp = m;
634 		mp = &m->m_next;
635 	}
636 
637 	return top;
638 }
639 
640 /*
641  * Go through the list of multicast addresses and calculate the logical
642  * address filter.
643  */
644 void
645 mace_calcladrf(struct ethercom *ec, uint8_t *af)
646 {
647 	struct ifnet *ifp = &ec->ec_if;
648 	struct ether_multi *enm;
649 	register u_char *cp, c;
650 	register uint32_t crc;
651 	register int i, len;
652 	struct ether_multistep step;
653 
654 	/*
655 	 * Set up multicast address filter by passing all multicast addresses
656 	 * through a crc generator, and then using the high order 6 bits as an
657 	 * index into the 64 bit logical address filter.  The high order bit
658 	 * selects the word, while the rest of the bits select the bit within
659 	 * the word.
660 	 */
661 
662 	*((uint32_t *)af) = *((uint32_t *)af + 1) = 0;
663 
664 	ETHER_LOCK(ec);
665 	ETHER_FIRST_MULTI(step, ec, enm);
666 	while (enm != NULL) {
667 		if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) {
668 			/*
669 			 * We must listen to a range of multicast addresses.
670 			 * For now, just accept all multicasts, rather than
671 			 * trying to set only those filter bits needed to match
672 			 * the range.  (At this time, the only use of address
673 			 * ranges is for IP multicast routing, for which the
674 			 * range is big enough to require all bits set.)
675 			 */
676 			ETHER_UNLOCK(ec);
677 			goto allmulti;
678 		}
679 
680 		cp = enm->enm_addrlo;
681 		crc = 0xffffffff;
682 		for (len = sizeof(enm->enm_addrlo); --len >= 0;) {
683 			c = *cp++;
684 			for (i = 8; --i >= 0;) {
685 				if ((crc & 0x01) ^ (c & 0x01)) {
686 					crc >>= 1;
687 					crc ^= 0xedb88320;
688 				} else
689 					crc >>= 1;
690 				c >>= 1;
691 			}
692 		}
693 		/* Just want the 6 most significant bits. */
694 		crc >>= 26;
695 
696 		/* Set the corresponding bit in the filter. */
697 		af[crc >> 3] |= 1 << (crc & 7);
698 
699 		ETHER_NEXT_MULTI(step, enm);
700 	}
701 	ETHER_UNLOCK(ec);
702 	ifp->if_flags &= ~IFF_ALLMULTI;
703 	return;
704 
705 allmulti:
706 	ifp->if_flags |= IFF_ALLMULTI;
707 	*((uint32_t *)af) = *((uint32_t *)af + 1) = 0xffffffff;
708 }
709 
710 int
711 mc_mediachange(struct ifnet *ifp)
712 {
713 	return EINVAL;
714 }
715 
716 void
717 mc_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
718 {
719 	struct mc_softc *sc = ifp->if_softc;
720 
721 	if ((ifp->if_flags & IFF_UP) == 0)
722 		return;
723 
724 	if (sc->sc_havecarrier)
725 		ifmr->ifm_status |= IFM_ACTIVE;
726 }
727