xref: /netbsd-src/sys/arch/mac68k/dev/if_mc.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: if_mc.c,v 1.24 2004/10/30 18:08:34 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997 David Huang <khym@azeotrope.org>
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: if_mc.c,v 1.24 2004/10/30 18:08:34 thorpej Exp $");
39 
40 #include "opt_ddb.h"
41 #include "opt_inet.h"
42 #include "opt_ccitt.h"
43 #include "opt_llc.h"
44 #include "opt_ns.h"
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/mbuf.h>
49 #include <sys/buf.h>
50 #include <sys/protosw.h>
51 #include <sys/socket.h>
52 #include <sys/syslog.h>
53 #include <sys/ioctl.h>
54 #include <sys/errno.h>
55 #include <sys/device.h>
56 
57 #include <uvm/uvm_extern.h>
58 
59 #include <net/if.h>
60 #include <net/if_dl.h>
61 #include <net/if_ether.h>
62 
63 #ifdef INET
64 #include <netinet/in.h>
65 #include <netinet/if_inarp.h>
66 #include <netinet/in_systm.h>
67 #include <netinet/in_var.h>
68 #include <netinet/ip.h>
69 #endif
70 
71 #ifdef NS
72 #include <netns/ns.h>
73 #include <netns/ns_if.h>
74 #endif
75 
76 #if defined(CCITT) && defined(LLC)
77 #include <sys/socketvar.h>
78 #include <netccitt/x25.h>
79 #include <netccitt/pk.h>
80 #include <netccitt/pk_var.h>
81 #include <netccitt/pk_extern.h>
82 #endif
83 
84 #include <uvm/uvm_extern.h>
85 
86 #include "bpfilter.h"
87 #if NBPFILTER > 0
88 #include <net/bpf.h>
89 #include <net/bpfdesc.h>
90 #endif
91 
92 #include <machine/bus.h>
93 #include <mac68k/dev/if_mcreg.h>
94 #include <mac68k/dev/if_mcvar.h>
95 
96 hide void	mcwatchdog __P((struct ifnet *));
97 hide int	mcinit __P((struct mc_softc *sc));
98 hide int	mcstop __P((struct mc_softc *sc));
99 hide int	mcioctl __P((struct ifnet *ifp, u_long cmd, caddr_t data));
100 hide void	mcstart __P((struct ifnet *ifp));
101 hide void	mcreset __P((struct mc_softc *sc));
102 
103 integrate u_int	maceput __P((struct mc_softc *sc, struct mbuf *m0));
104 integrate void	mc_tint __P((struct mc_softc *sc));
105 integrate void	mace_read __P((struct mc_softc *, caddr_t, int));
106 integrate struct mbuf *mace_get __P((struct mc_softc *, caddr_t, int));
107 static void mace_calcladrf __P((struct ethercom *ac, u_int8_t *af));
108 static inline u_int16_t ether_cmp __P((void *, void *));
109 
110 
111 /*
112  * Compare two Ether/802 addresses for equality, inlined and
113  * unrolled for speed.  Use this like bcmp().
114  *
115  * XXX: Add <machine/inlines.h> for stuff like this?
116  * XXX: or maybe add it to libkern.h instead?
117  *
118  * "I'd love to have an inline assembler version of this."
119  * XXX: Who wanted that? mycroft?  I wrote one, but this
120  * version in C is as good as hand-coded assembly. -gwr
121  *
122  * Please do NOT tweak this without looking at the actual
123  * assembly code generated before and after your tweaks!
124  */
125 static inline u_int16_t
126 ether_cmp(one, two)
127 	void *one, *two;
128 {
129 	register u_int16_t *a = (u_short *) one;
130 	register u_int16_t *b = (u_short *) two;
131 	register u_int16_t diff;
132 
133 #ifdef	m68k
134 	/*
135 	 * The post-increment-pointer form produces the best
136 	 * machine code for m68k.  This was carefully tuned
137 	 * so it compiles to just 8 short (2-byte) op-codes!
138 	 */
139 	diff  = *a++ - *b++;
140 	diff |= *a++ - *b++;
141 	diff |= *a++ - *b++;
142 #else
143 	/*
144 	 * Most modern CPUs do better with a single expresion.
145 	 * Note that short-cut evaluation is NOT helpful here,
146 	 * because it just makes the code longer, not faster!
147 	 */
148 	diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]);
149 #endif
150 
151 	return (diff);
152 }
153 
154 #define ETHER_CMP	ether_cmp
155 
156 /*
157  * Interface exists: make available by filling in network interface
158  * record.  System will initialize the interface when it is ready
159  * to accept packets.
160  */
161 int
162 mcsetup(sc, lladdr)
163 	struct mc_softc	*sc;
164 	u_int8_t *lladdr;
165 {
166 	struct ifnet *ifp = &sc->sc_if;
167 
168 	/* reset the chip and disable all interrupts */
169 	NIC_PUT(sc, MACE_BIUCC, SWRST);
170 	DELAY(100);
171 	NIC_PUT(sc, MACE_IMR, ~0);
172 
173 	bcopy(lladdr, sc->sc_enaddr, ETHER_ADDR_LEN);
174 	printf(": address %s\n", ether_sprintf(lladdr));
175 
176 	bcopy(sc->sc_dev.dv_xname, ifp->if_xname, IFNAMSIZ);
177 	ifp->if_softc = sc;
178 	ifp->if_ioctl = mcioctl;
179 	ifp->if_start = mcstart;
180 	ifp->if_flags =
181 	    IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS | IFF_MULTICAST;
182 	ifp->if_watchdog = mcwatchdog;
183 
184 	if_attach(ifp);
185 	ether_ifattach(ifp, lladdr);
186 
187 	return (0);
188 }
189 
190 hide int
191 mcioctl(ifp, cmd, data)
192 	struct ifnet *ifp;
193 	u_long cmd;
194 	caddr_t data;
195 {
196 	struct mc_softc *sc = ifp->if_softc;
197 	struct ifaddr *ifa;
198 	struct ifreq *ifr;
199 
200 	int	s = splnet(), err = 0;
201 
202 	switch (cmd) {
203 
204 	case SIOCSIFADDR:
205 		ifa = (struct ifaddr *)data;
206 		ifp->if_flags |= IFF_UP;
207 		switch (ifa->ifa_addr->sa_family) {
208 #ifdef INET
209 		case AF_INET:
210 			mcinit(sc);
211 			arp_ifinit(ifp, ifa);
212 			break;
213 #endif
214 #ifdef NS
215 		case AF_NS:
216 		    {
217 			register struct ns_addr *ina = &IA_SNS(ifa)->sns_addr;
218 
219 			if (ns_nullhost(*ina))
220 				ina->x_host =
221 				    *(union ns_host *)LLADDR(ifp->if_sadl);
222 			else {
223 				bcopy(ina->x_host.c_host,
224 				    LLADDR(ifp->if_sadl),
225 				    sizeof(sc->sc_enaddr));
226 			}
227 			/* Set new address. */
228 			mcinit(sc);
229 			break;
230 		    }
231 #endif
232 		default:
233 			mcinit(sc);
234 			break;
235 		}
236 		break;
237 
238 	case SIOCSIFFLAGS:
239 		if ((ifp->if_flags & IFF_UP) == 0 &&
240 		    (ifp->if_flags & IFF_RUNNING) != 0) {
241 			/*
242 			 * If interface is marked down and it is running,
243 			 * then stop it.
244 			 */
245 			mcstop(sc);
246 			ifp->if_flags &= ~IFF_RUNNING;
247 		} else if ((ifp->if_flags & IFF_UP) != 0 &&
248 		    (ifp->if_flags & IFF_RUNNING) == 0) {
249 			/*
250 			 * If interface is marked up and it is stopped,
251 			 * then start it.
252 			 */
253 			(void)mcinit(sc);
254 		} else {
255 			/*
256 			 * reset the interface to pick up any other changes
257 			 * in flags
258 			 */
259 			mcreset(sc);
260 			mcstart(ifp);
261 		}
262 		break;
263 
264 	case SIOCADDMULTI:
265 	case SIOCDELMULTI:
266 		ifr = (struct ifreq *) data;
267 		err = (cmd == SIOCADDMULTI) ?
268 		    ether_addmulti(ifr, &sc->sc_ethercom) :
269 		    ether_delmulti(ifr, &sc->sc_ethercom);
270 
271 		if (err == ENETRESET) {
272 			/*
273 			 * Multicast list has changed; set the hardware
274 			 * filter accordingly. But remember UP flag!
275 			 */
276 			if (ifp->if_flags & IFF_RUNNING)
277 				mcreset(sc);
278 			err = 0;
279 		}
280 		break;
281 	default:
282 		err = EINVAL;
283 	}
284 	splx(s);
285 	return (err);
286 }
287 
288 /*
289  * Encapsulate a packet of type family for the local net.
290  */
291 hide void
292 mcstart(ifp)
293 	struct ifnet *ifp;
294 {
295 	struct mc_softc	*sc = ifp->if_softc;
296 	struct mbuf	*m;
297 
298 	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
299 		return;
300 
301 	while (1) {
302 		if (ifp->if_flags & IFF_OACTIVE)
303 			return;
304 
305 		IF_DEQUEUE(&ifp->if_snd, m);
306 		if (m == 0)
307 			return;
308 
309 #if NBPFILTER > 0
310 		/*
311 		 * If bpf is listening on this interface, let it
312 		 * see the packet before we commit it to the wire.
313 		 */
314 		if (ifp->if_bpf)
315 			bpf_mtap(ifp->if_bpf, m);
316 #endif
317 
318 		/*
319 		 * Copy the mbuf chain into the transmit buffer.
320 		 */
321 		ifp->if_flags |= IFF_OACTIVE;
322 		maceput(sc, m);
323 
324 		ifp->if_opackets++;		/* # of pkts */
325 	}
326 }
327 
328 /*
329  * reset and restart the MACE.  Called in case of fatal
330  * hardware/software errors.
331  */
332 hide void
333 mcreset(sc)
334 	struct mc_softc *sc;
335 {
336 	mcstop(sc);
337 	mcinit(sc);
338 }
339 
340 hide int
341 mcinit(sc)
342 	struct mc_softc *sc;
343 {
344 	int s;
345 	u_int8_t maccc, ladrf[8];
346 
347 	if (sc->sc_if.if_flags & IFF_RUNNING)
348 		/* already running */
349 		return (0);
350 
351 	s = splnet();
352 
353 	NIC_PUT(sc, MACE_BIUCC, sc->sc_biucc);
354 	NIC_PUT(sc, MACE_FIFOCC, sc->sc_fifocc);
355 	NIC_PUT(sc, MACE_IMR, ~0); /* disable all interrupts */
356 	NIC_PUT(sc, MACE_PLSCC, sc->sc_plscc);
357 
358 	NIC_PUT(sc, MACE_UTR, RTRD); /* disable reserved test registers */
359 
360 	/* set MAC address */
361 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
362 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
363 		;
364 	NIC_PUT(sc, MACE_IAC, PHYADDR);
365 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_PADR),
366 	    sc->sc_enaddr, ETHER_ADDR_LEN);
367 
368 	/* set logical address filter */
369 	mace_calcladrf(&sc->sc_ethercom, ladrf);
370 
371 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
372 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
373 		;
374 	NIC_PUT(sc, MACE_IAC, LOGADDR);
375 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_LADRF),
376 	    ladrf, 8);
377 
378 	NIC_PUT(sc, MACE_XMTFC, APADXMT);
379 	/*
380 	 * No need to autostrip padding on receive... Ethernet frames
381 	 * don't have a length field, unlike 802.3 frames, so the MACE
382 	 * can't figure out the length of the packet anyways.
383 	 */
384 	NIC_PUT(sc, MACE_RCVFC, 0);
385 
386 	maccc = ENXMT | ENRCV;
387 	if (sc->sc_if.if_flags & IFF_PROMISC)
388 		maccc |= PROM;
389 
390 	NIC_PUT(sc, MACE_MACCC, maccc);
391 
392 	if (sc->sc_bus_init)
393 		(*sc->sc_bus_init)(sc);
394 
395 	/*
396 	 * Enable all interrupts except receive, since we use the DMA
397 	 * completion interrupt for that.
398 	 */
399 	NIC_PUT(sc, MACE_IMR, RCVINTM);
400 
401 	/* flag interface as "running" */
402 	sc->sc_if.if_flags |= IFF_RUNNING;
403 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
404 
405 	splx(s);
406 	return (0);
407 }
408 
409 /*
410  * close down an interface and free its buffers
411  * Called on final close of device, or if mcinit() fails
412  * part way through.
413  */
414 hide int
415 mcstop(sc)
416 	struct mc_softc *sc;
417 {
418 	int	s = splnet();
419 
420 	NIC_PUT(sc, MACE_BIUCC, SWRST);
421 	DELAY(100);
422 
423 	sc->sc_if.if_timer = 0;
424 	sc->sc_if.if_flags &= ~IFF_RUNNING;
425 
426 	splx(s);
427 	return (0);
428 }
429 
430 /*
431  * Called if any Tx packets remain unsent after 5 seconds,
432  * In all cases we just reset the chip, and any retransmission
433  * will be handled by higher level protocol timeouts.
434  */
435 hide void
436 mcwatchdog(ifp)
437 	struct ifnet *ifp;
438 {
439 	struct mc_softc *sc = ifp->if_softc;
440 
441 	printf("mcwatchdog: resetting chip\n");
442 	mcreset(sc);
443 }
444 
445 /*
446  * stuff packet into MACE (at splnet)
447  */
448 integrate u_int
449 maceput(sc, m)
450 	struct mc_softc *sc;
451 	struct mbuf *m;
452 {
453 	struct mbuf *n;
454 	u_int len, totlen = 0;
455 	u_char *buff;
456 
457 	buff = sc->sc_txbuf;
458 
459 	for (; m; m = n) {
460 		u_char *data = mtod(m, u_char *);
461 		len = m->m_len;
462 		totlen += len;
463 		bcopy(data, buff, len);
464 		buff += len;
465 		MFREE(m, n);
466 	}
467 
468 	if (totlen > PAGE_SIZE)
469 		panic("%s: maceput: packet overflow", sc->sc_dev.dv_xname);
470 
471 #if 0
472 	if (totlen < ETHERMIN + sizeof(struct ether_header)) {
473 		int pad = ETHERMIN + sizeof(struct ether_header) - totlen;
474 		bzero(sc->sc_txbuf + totlen, pad);
475 		totlen = ETHERMIN + sizeof(struct ether_header);
476 	}
477 #endif
478 
479 	(*sc->sc_putpacket)(sc, totlen);
480 
481 	sc->sc_if.if_timer = 5;	/* 5 seconds to watch for failing to transmit */
482 	return (totlen);
483 }
484 
485 void
486 mcintr(arg)
487 	void *arg;
488 {
489 struct mc_softc *sc = arg;
490 	u_int8_t ir;
491 
492 	ir = NIC_GET(sc, MACE_IR) & ~NIC_GET(sc, MACE_IMR);
493 	if (ir & JAB) {
494 #ifdef MCDEBUG
495 		printf("%s: jabber error\n", sc->sc_dev.dv_xname);
496 #endif
497 		sc->sc_if.if_oerrors++;
498 	}
499 
500 	if (ir & BABL) {
501 #ifdef MCDEBUG
502 		printf("%s: babble\n", sc->sc_dev.dv_xname);
503 #endif
504 		sc->sc_if.if_oerrors++;
505 	}
506 
507 	if (ir & CERR) {
508 #ifdef MCDEBUG
509 		printf("%s: collision error\n", sc->sc_dev.dv_xname);
510 #endif
511 		sc->sc_if.if_collisions++;
512 	}
513 
514 	/*
515 	 * Pretend we have carrier; if we don't this will be cleared
516 	 * shortly.
517 	 */
518 	sc->sc_havecarrier = 1;
519 
520 	if (ir & XMTINT)
521 		mc_tint(sc);
522 
523 	if (ir & RCVINT)
524 		mc_rint(sc);
525 }
526 
527 integrate void
528 mc_tint(sc)
529 	struct mc_softc *sc;
530 {
531 	u_int8_t xmtrc, xmtfs;
532 
533 	xmtrc = NIC_GET(sc, MACE_XMTRC);
534 	xmtfs = NIC_GET(sc, MACE_XMTFS);
535 
536 	if ((xmtfs & XMTSV) == 0)
537 		return;
538 
539 	if (xmtfs & UFLO) {
540 		printf("%s: underflow\n", sc->sc_dev.dv_xname);
541 		mcreset(sc);
542 		return;
543 	}
544 
545 	if (xmtfs & LCOL) {
546 		printf("%s: late collision\n", sc->sc_dev.dv_xname);
547 		sc->sc_if.if_oerrors++;
548 		sc->sc_if.if_collisions++;
549 	}
550 
551 	if (xmtfs & MORE)
552 		/* Real number is unknown. */
553 		sc->sc_if.if_collisions += 2;
554 	else if (xmtfs & ONE)
555 		sc->sc_if.if_collisions++;
556 	else if (xmtfs & RTRY) {
557 		printf("%s: excessive collisions\n", sc->sc_dev.dv_xname);
558 		sc->sc_if.if_collisions += 16;
559 		sc->sc_if.if_oerrors++;
560 	}
561 
562 	if (xmtfs & LCAR) {
563 		sc->sc_havecarrier = 0;
564 		printf("%s: lost carrier\n", sc->sc_dev.dv_xname);
565 		sc->sc_if.if_oerrors++;
566 	}
567 
568 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
569 	sc->sc_if.if_timer = 0;
570 	mcstart(&sc->sc_if);
571 }
572 
573 void
574 mc_rint(sc)
575 	struct mc_softc *sc;
576 {
577 #define	rxf	sc->sc_rxframe
578 	u_int len;
579 
580 	len = (rxf.rx_rcvcnt | ((rxf.rx_rcvsts & 0xf) << 8)) - 4;
581 
582 #ifdef MCDEBUG
583 	if (rxf.rx_rcvsts & 0xf0)
584 		printf("%s: rcvcnt %02x rcvsts %02x rntpc 0x%02x rcvcc 0x%02x\n",
585 		    sc->sc_dev.dv_xname, rxf.rx_rcvcnt, rxf.rx_rcvsts,
586 		    rxf.rx_rntpc, rxf.rx_rcvcc);
587 #endif
588 
589 	if (rxf.rx_rcvsts & OFLO) {
590 		printf("%s: receive FIFO overflow\n", sc->sc_dev.dv_xname);
591 		sc->sc_if.if_ierrors++;
592 		return;
593 	}
594 
595 	if (rxf.rx_rcvsts & CLSN)
596 		sc->sc_if.if_collisions++;
597 
598 	if (rxf.rx_rcvsts & FRAM) {
599 #ifdef MCDEBUG
600 		printf("%s: framing error\n", sc->sc_dev.dv_xname);
601 #endif
602 		sc->sc_if.if_ierrors++;
603 		return;
604 	}
605 
606 	if (rxf.rx_rcvsts & FCS) {
607 #ifdef MCDEBUG
608 		printf("%s: frame control checksum error\n", sc->sc_dev.dv_xname);
609 #endif
610 		sc->sc_if.if_ierrors++;
611 		return;
612 	}
613 
614 	mace_read(sc, rxf.rx_frame, len);
615 #undef	rxf
616 }
617 
618 integrate void
619 mace_read(sc, pkt, len)
620 	struct mc_softc *sc;
621 	caddr_t pkt;
622 	int len;
623 {
624 	struct ifnet *ifp = &sc->sc_if;
625 	struct mbuf *m;
626 
627 	if (len <= sizeof(struct ether_header) ||
628 	    len > ETHERMTU + sizeof(struct ether_header)) {
629 #ifdef MCDEBUG
630 		printf("%s: invalid packet size %d; dropping\n",
631 		    sc->sc_dev.dv_xname, len);
632 #endif
633 		ifp->if_ierrors++;
634 		return;
635 	}
636 
637 	m = mace_get(sc, pkt, len);
638 	if (m == NULL) {
639 		ifp->if_ierrors++;
640 		return;
641 	}
642 
643 	ifp->if_ipackets++;
644 
645 #if NBPFILTER > 0
646 	/* Pass the packet to any BPF listeners. */
647 	if (ifp->if_bpf)
648 		bpf_mtap(ifp->if_bpf, m);
649 #endif
650 
651 	/* Pass the packet up. */
652 	(*ifp->if_input)(ifp, m);
653 }
654 
655 /*
656  * Pull data off an interface.
657  * Len is length of data, with local net header stripped.
658  * We copy the data into mbufs.  When full cluster sized units are present
659  * we copy into clusters.
660  */
661 integrate struct mbuf *
662 mace_get(sc, pkt, totlen)
663 	struct mc_softc *sc;
664 	caddr_t pkt;
665 	int totlen;
666 {
667 	register struct mbuf *m;
668 	struct mbuf *top, **mp;
669 	int len;
670 
671 	MGETHDR(m, M_DONTWAIT, MT_DATA);
672 	if (m == 0)
673 		return (0);
674 	m->m_pkthdr.rcvif = &sc->sc_if;
675 	m->m_pkthdr.len = totlen;
676 	len = MHLEN;
677 	top = 0;
678 	mp = &top;
679 
680 	while (totlen > 0) {
681 		if (top) {
682 			MGET(m, M_DONTWAIT, MT_DATA);
683 			if (m == 0) {
684 				m_freem(top);
685 				return 0;
686 			}
687 			len = MLEN;
688 		}
689 		if (totlen >= MINCLSIZE) {
690 			MCLGET(m, M_DONTWAIT);
691 			if ((m->m_flags & M_EXT) == 0) {
692 				m_free(m);
693 				m_freem(top);
694 				return 0;
695 			}
696 			len = MCLBYTES;
697 		}
698 		m->m_len = len = min(totlen, len);
699 		bcopy(pkt, mtod(m, caddr_t), len);
700 		pkt += len;
701 		totlen -= len;
702 		*mp = m;
703 		mp = &m->m_next;
704 	}
705 
706 	return (top);
707 }
708 
709 /*
710  * Go through the list of multicast addresses and calculate the logical
711  * address filter.
712  */
713 void
714 mace_calcladrf(ac, af)
715 	struct ethercom *ac;
716 	u_int8_t *af;
717 {
718 	struct ifnet *ifp = &ac->ec_if;
719 	struct ether_multi *enm;
720 	register u_char *cp;
721 	register u_int32_t crc;
722 	static const u_int32_t crctab[] = {
723 		0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
724 		0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
725 		0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
726 		0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
727 	};
728 	register int len;
729 	struct ether_multistep step;
730 
731 	/*
732 	 * Set up multicast address filter by passing all multicast addresses
733 	 * through a crc generator, and then using the high order 6 bits as an
734 	 * index into the 64 bit logical address filter.  The high order bit
735 	 * selects the word, while the rest of the bits select the bit within
736 	 * the word.
737 	 */
738 
739 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0;
740 	ETHER_FIRST_MULTI(step, ac, enm);
741 	while (enm != NULL) {
742 		if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) {
743 			/*
744 			 * We must listen to a range of multicast addresses.
745 			 * For now, just accept all multicasts, rather than
746 			 * trying to set only those filter bits needed to match
747 			 * the range.  (At this time, the only use of address
748 			 * ranges is for IP multicast routing, for which the
749 			 * range is big enough to require all bits set.)
750 			 */
751 			goto allmulti;
752 		}
753 
754 		cp = enm->enm_addrlo;
755 		crc = 0xffffffff;
756 		for (len = sizeof(enm->enm_addrlo); --len >= 0;) {
757 			crc ^= *cp++;
758 			crc = (crc >> 4) ^ crctab[crc & 0xf];
759 			crc = (crc >> 4) ^ crctab[crc & 0xf];
760 		}
761 		/* Just want the 6 most significant bits. */
762 		crc >>= 26;
763 
764 		/* Set the corresponding bit in the filter. */
765 		af[crc >> 3] |= 1 << (crc & 7);
766 
767 		ETHER_NEXT_MULTI(step, enm);
768 	}
769 	ifp->if_flags &= ~IFF_ALLMULTI;
770 	return;
771 
772 allmulti:
773 	ifp->if_flags |= IFF_ALLMULTI;
774 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0xffffffff;
775 }
776 
777 static u_char bbr4[] = {0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15};
778 #define bbr(v)  ((bbr4[(v)&0xf] << 4) | bbr4[((v)>>4) & 0xf])
779 
780 u_char
781 mc_get_enaddr(t, h, o, dst)
782 	bus_space_tag_t t;
783 	bus_space_handle_t h;
784 	bus_size_t o;
785 	u_char *dst;
786 {
787 	int	i;
788 	u_char	b, csum;
789 
790 	/*
791 	 * The XOR of the 8 bytes of the ROM must be 0xff for it to be
792 	 * valid
793 	*/
794 	for (i = 0, csum = 0; i < 8; i++) {
795 		b = bus_space_read_1(t, h, o+16*i);
796 		if (i < ETHER_ADDR_LEN)
797 			dst[i] = bbr(b);
798 		csum ^= b;
799 	}
800 
801 	return csum;
802 }
803