xref: /netbsd-src/sys/arch/mac68k/dev/if_mc.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: if_mc.c,v 1.3 1997/12/07 17:47:47 scottr 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/param.h>
38 #include <sys/systm.h>
39 #include <sys/mbuf.h>
40 #include <sys/buf.h>
41 #include <sys/protosw.h>
42 #include <sys/socket.h>
43 #include <sys/syslog.h>
44 #include <sys/ioctl.h>
45 #include <sys/errno.h>
46 #include <sys/device.h>
47 
48 #include <net/if.h>
49 #include <net/if_dl.h>
50 #include <net/if_ether.h>
51 
52 #ifdef INET
53 #include <netinet/in.h>
54 #include <netinet/if_inarp.h>
55 #include <netinet/in_systm.h>
56 #include <netinet/in_var.h>
57 #include <netinet/ip.h>
58 #endif
59 
60 #ifdef NS
61 #include <netns/ns.h>
62 #include <netns/ns_if.h>
63 #endif
64 
65 #if defined(CCITT) && defined(LLC)
66 #include <sys/socketvar.h>
67 #include <netccitt/x25.h>
68 #include <netccitt/pk.h>
69 #include <netccitt/pk_var.h>
70 #include <netccitt/pk_extern.h>
71 #endif
72 
73 #include <vm/vm.h>
74 
75 #include "bpfilter.h"
76 #if NBPFILTER > 0
77 #include <net/bpf.h>
78 #include <net/bpfdesc.h>
79 #endif
80 
81 #include <machine/bus.h>
82 #include <mac68k/dev/if_mcreg.h>
83 #include <mac68k/dev/if_mcvar.h>
84 
85 hide void	mcwatchdog __P((struct ifnet *));
86 hide int	mcinit __P((struct mc_softc *sc));
87 hide int	mcstop __P((struct mc_softc *sc));
88 hide int	mcioctl __P((struct ifnet *ifp, u_long cmd, caddr_t data));
89 hide void	mcstart __P((struct ifnet *ifp));
90 hide void	mcreset __P((struct mc_softc *sc));
91 
92 integrate u_int	maceput __P((struct mc_softc *sc, struct mbuf *m0));
93 integrate void	mc_tint __P((struct mc_softc *sc));
94 integrate void	mace_read __P((struct mc_softc *, caddr_t, int));
95 integrate struct mbuf *mace_get __P((struct mc_softc *, caddr_t, int));
96 static void mace_calcladrf __P((struct ethercom *ac, u_int8_t *af));
97 static inline u_int16_t ether_cmp __P((void *, void *));
98 
99 
100 struct cfdriver mc_cd = {
101 	NULL, "mc", DV_IFNET
102 };
103 
104 /*
105  * Compare two Ether/802 addresses for equality, inlined and
106  * unrolled for speed.  Use this like bcmp().
107  *
108  * XXX: Add <machine/inlines.h> for stuff like this?
109  * XXX: or maybe add it to libkern.h instead?
110  *
111  * "I'd love to have an inline assembler version of this."
112  * XXX: Who wanted that? mycroft?  I wrote one, but this
113  * version in C is as good as hand-coded assembly. -gwr
114  *
115  * Please do NOT tweak this without looking at the actual
116  * assembly code generated before and after your tweaks!
117  */
118 static inline u_int16_t
119 ether_cmp(one, two)
120 	void *one, *two;
121 {
122 	register u_int16_t *a = (u_short *) one;
123 	register u_int16_t *b = (u_short *) two;
124 	register u_int16_t diff;
125 
126 #ifdef	m68k
127 	/*
128 	 * The post-increment-pointer form produces the best
129 	 * machine code for m68k.  This was carefully tuned
130 	 * so it compiles to just 8 short (2-byte) op-codes!
131 	 */
132 	diff  = *a++ - *b++;
133 	diff |= *a++ - *b++;
134 	diff |= *a++ - *b++;
135 #else
136 	/*
137 	 * Most modern CPUs do better with a single expresion.
138 	 * Note that short-cut evaluation is NOT helpful here,
139 	 * because it just makes the code longer, not faster!
140 	 */
141 	diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]);
142 #endif
143 
144 	return (diff);
145 }
146 
147 #define ETHER_CMP	ether_cmp
148 
149 /*
150  * Interface exists: make available by filling in network interface
151  * record.  System will initialize the interface when it is ready
152  * to accept packets.
153  */
154 int
155 mcsetup(sc, lladdr)
156 	struct mc_softc	*sc;
157 	u_int8_t *lladdr;
158 {
159 	struct ifnet *ifp = &sc->sc_if;
160 
161 	/* reset the chip and disable all interrupts */
162 	NIC_PUT(sc, MACE_BIUCC, SWRST);
163 	DELAY(100);
164 	NIC_PUT(sc, MACE_IMR, ~0);
165 
166 	bcopy(lladdr, sc->sc_enaddr, ETHER_ADDR_LEN);
167 	printf(": address %s\n", ether_sprintf(lladdr));
168 
169 	bcopy(sc->sc_dev.dv_xname, ifp->if_xname, IFNAMSIZ);
170 	ifp->if_softc = sc;
171 	ifp->if_ioctl = mcioctl;
172 	ifp->if_start = mcstart;
173 	ifp->if_flags =
174 	    IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS | IFF_MULTICAST;
175 	ifp->if_watchdog = mcwatchdog;
176 
177 #if NBPFILTER > 0
178 	bpfattach(&ifp->if_bpf, ifp, DLT_EN10MB, sizeof(struct ether_header));
179 #endif
180 	if_attach(ifp);
181 	ether_ifattach(ifp, lladdr);
182 
183 	return (0);
184 }
185 
186 hide int
187 mcioctl(ifp, cmd, data)
188 	struct ifnet *ifp;
189 	u_long cmd;
190 	caddr_t data;
191 {
192 	struct mc_softc *sc = ifp->if_softc;
193 	struct ifaddr *ifa;
194 	struct ifreq *ifr;
195 
196 	int	s = splnet(), err = 0;
197 	int	temp;
198 
199 	switch (cmd) {
200 
201 	case SIOCSIFADDR:
202 		ifa = (struct ifaddr *)data;
203 		ifp->if_flags |= IFF_UP;
204 		switch (ifa->ifa_addr->sa_family) {
205 #ifdef INET
206 		case AF_INET:
207 			mcinit(sc);
208 			arp_ifinit(ifp, ifa);
209 			break;
210 #endif
211 #ifdef NS
212 		case AF_NS:
213 		    {
214 			register struct ns_addr *ina = &IA_SNS(ifa)->sns_addr;
215 
216 			if (ns_nullhost(*ina))
217 				ina->x_host =
218 				    *(union ns_host *)LLADDR(ifp->if_sadl);
219 			else {
220 				bcopy(ina->x_host.c_host,
221 				    LLADDR(ifp->if_sadl),
222 				    sizeof(sc->sc_enaddr));
223 			}
224 			/* Set new address. */
225 			mcinit(sc);
226 			break;
227 		    }
228 #endif
229 		default:
230 			mcinit(sc);
231 			break;
232 		}
233 		break;
234 
235 	case SIOCSIFFLAGS:
236 		if ((ifp->if_flags & IFF_UP) == 0 &&
237 		    (ifp->if_flags & IFF_RUNNING) != 0) {
238 			/*
239 			 * If interface is marked down and it is running,
240 			 * then stop it.
241 			 */
242 			mcstop(sc);
243 			ifp->if_flags &= ~IFF_RUNNING;
244 		} else if ((ifp->if_flags & IFF_UP) != 0 &&
245 		    (ifp->if_flags & IFF_RUNNING) == 0) {
246 			/*
247 			 * If interface is marked up and it is stopped,
248 			 * then start it.
249 			 */
250 			(void)mcinit(sc);
251 		} else {
252 			/*
253 			 * reset the interface to pick up any other changes
254 			 * in flags
255 			 */
256 			temp = ifp->if_flags & IFF_UP;
257 			mcreset(sc);
258 			ifp->if_flags |= temp;
259 			mcstart(ifp);
260 		}
261 		break;
262 
263 	case SIOCADDMULTI:
264 	case SIOCDELMULTI:
265 		ifr = (struct ifreq *) data;
266 		err = (cmd == SIOCADDMULTI) ?
267 		    ether_addmulti(ifr, &sc->sc_ethercom) :
268 		    ether_delmulti(ifr, &sc->sc_ethercom);
269 
270 		if (err == ENETRESET) {
271 			/*
272 			 * Multicast list has changed; set the hardware
273 			 * filter accordingly. But remember UP flag!
274 			 */
275 			temp = ifp->if_flags & IFF_UP;
276 			mcreset(sc);
277 			ifp->if_flags |= temp;
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 | IFF_UP);
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 	int temp;
441 
442 	printf("mcwatchdog: resetting chip\n");
443 	temp = ifp->if_flags & IFF_UP;
444 	mcreset(sc);
445 	ifp->if_flags |= temp;
446 }
447 
448 /*
449  * stuff packet into MACE (at splnet)
450  */
451 integrate u_int
452 maceput(sc, m)
453 	struct mc_softc *sc;
454 	struct mbuf *m;
455 {
456 	struct mbuf *n;
457 	u_int len, totlen = 0;
458 	u_char *buff;
459 
460 	buff = sc->sc_txbuf;
461 
462 	for (; m; m = n) {
463 		u_char *data = mtod(m, u_char *);
464 		len = m->m_len;
465 		totlen += len;
466 		bcopy(data, buff, len);
467 		buff += len;
468 		MFREE(m, n);
469 	}
470 
471 	if (totlen > NBPG)
472 		panic("%s: maceput: packet overflow", sc->sc_dev.dv_xname);
473 
474 #if 0
475 	if (totlen < ETHERMIN + sizeof(struct ether_header)) {
476 		int pad = ETHERMIN + sizeof(struct ether_header) - totlen;
477 		bzero(sc->sc_txbuf + totlen, pad);
478 		totlen = ETHERMIN + sizeof(struct ether_header);
479 	}
480 #endif
481 
482 	(*sc->sc_putpacket)(sc, totlen);
483 
484 	sc->sc_if.if_timer = 5;	/* 5 seconds to watch for failing to transmit */
485 	return (totlen);
486 }
487 
488 void
489 mcintr(arg)
490 	void *arg;
491 {
492 struct mc_softc *sc = arg;
493 	u_int8_t ir;
494 
495 	ir = NIC_GET(sc, MACE_IR) & ~NIC_GET(sc, MACE_IMR);
496 	if (ir & JAB) {
497 #ifdef MCDEBUG
498 		printf("%s: jabber error\n", sc->sc_dev.dv_xname);
499 #endif
500 		sc->sc_if.if_oerrors++;
501 	}
502 
503 	if (ir & BABL) {
504 #ifdef MCDEBUG
505 		printf("%s: babble\n", sc->sc_dev.dv_xname);
506 #endif
507 		sc->sc_if.if_oerrors++;
508 	}
509 
510 	if (ir & CERR) {
511 		printf("%s: collision error\n", sc->sc_dev.dv_xname);
512 		sc->sc_if.if_collisions++;
513 	}
514 
515 	/*
516 	 * Pretend we have carrier; if we don't this will be cleared
517 	 * shortly.
518 	 */
519 	sc->sc_havecarrier = 1;
520 
521 	if (ir & XMTINT)
522 		mc_tint(sc);
523 
524 	if (ir & RCVINT)
525 		mc_rint(sc);
526 }
527 
528 integrate void
529 mc_tint(sc)
530 	struct mc_softc *sc;
531 {
532 	u_int8_t xmtrc, xmtfs;
533 
534 	xmtrc = NIC_GET(sc, MACE_XMTRC);
535 	xmtfs = NIC_GET(sc, MACE_XMTFS);
536 
537 	if ((xmtfs & XMTSV) == 0)
538 		return;
539 
540 	if (xmtfs & UFLO) {
541 		printf("%s: underflow\n", sc->sc_dev.dv_xname);
542 		mcreset(sc);
543 		return;
544 	}
545 
546 	if (xmtfs & LCOL) {
547 		printf("%s: late collision\n", sc->sc_dev.dv_xname);
548 		sc->sc_if.if_oerrors++;
549 		sc->sc_if.if_collisions++;
550 	}
551 
552 	if (xmtfs & MORE)
553 		/* Real number is unknown. */
554 		sc->sc_if.if_collisions += 2;
555 	else if (xmtfs & ONE)
556 		sc->sc_if.if_collisions++;
557 	else if (xmtfs & RTRY) {
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 integrate 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 ether_header *eh = (struct ether_header *)pkt;
626 	struct mbuf *m;
627 
628 	if (len <= sizeof(struct ether_header) ||
629 	    len > ETHERMTU + sizeof(struct ether_header)) {
630 #ifdef MCDEBUG
631 		printf("%s: invalid packet size %d; dropping\n",
632 		    sc->sc_dev.dv_xname, len);
633 #endif
634 		ifp->if_ierrors++;
635 		return;
636 	}
637 
638 #if NBPFILTER > 0
639 	/*
640 	 * Check if there's a bpf filter listening on this interface.
641 	 * If so, hand off the raw packet to enet, then discard things
642 	 * not destined for us (but be sure to keep broadcast/multicast).
643 	 */
644 	if (ifp->if_bpf) {
645 		bpf_tap(ifp->if_bpf, pkt, len);
646 		if ((ifp->if_flags & IFF_PROMISC) != 0 &&
647 		    (eh->ether_dhost[0] & 1) == 0 && /* !mcast and !bcast */
648 		    ETHER_CMP(eh->ether_dhost, sc->sc_enaddr))
649 			return;
650 	}
651 #endif
652 	m = mace_get(sc, pkt, len);
653 	if (m == NULL) {
654 		ifp->if_ierrors++;
655 		return;
656 	}
657 
658 	ifp->if_ipackets++;
659 
660 	/* Pass the packet up, with the ether header sort-of removed. */
661 	m_adj(m, sizeof(struct ether_header));
662 	ether_input(ifp, eh, m);
663 }
664 
665 /*
666  * Pull data off an interface.
667  * Len is length of data, with local net header stripped.
668  * We copy the data into mbufs.  When full cluster sized units are present
669  * we copy into clusters.
670  */
671 integrate struct mbuf *
672 mace_get(sc, pkt, totlen)
673 	struct mc_softc *sc;
674 	caddr_t pkt;
675 	int totlen;
676 {
677 	register struct mbuf *m;
678 	struct mbuf *top, **mp;
679 	int len;
680 
681 	MGETHDR(m, M_DONTWAIT, MT_DATA);
682 	if (m == 0)
683 		return (0);
684 	m->m_pkthdr.rcvif = &sc->sc_if;
685 	m->m_pkthdr.len = totlen;
686 	len = MHLEN;
687 	top = 0;
688 	mp = &top;
689 
690 	while (totlen > 0) {
691 		if (top) {
692 			MGET(m, M_DONTWAIT, MT_DATA);
693 			if (m == 0) {
694 				m_freem(top);
695 				return 0;
696 			}
697 			len = MLEN;
698 		}
699 		if (totlen >= MINCLSIZE) {
700 			MCLGET(m, M_DONTWAIT);
701 			if ((m->m_flags & M_EXT) == 0) {
702 				m_free(m);
703 				m_freem(top);
704 				return 0;
705 			}
706 			len = MCLBYTES;
707 		}
708 		m->m_len = len = min(totlen, len);
709 		bcopy(pkt, mtod(m, caddr_t), len);
710 		pkt += len;
711 		totlen -= len;
712 		*mp = m;
713 		mp = &m->m_next;
714 	}
715 
716 	return (top);
717 }
718 
719 /*
720  * Go through the list of multicast addresses and calculate the logical
721  * address filter.
722  */
723 void
724 mace_calcladrf(ac, af)
725 	struct ethercom *ac;
726 	u_int8_t *af;
727 {
728 	struct ifnet *ifp = &ac->ec_if;
729 	struct ether_multi *enm;
730 	register u_char *cp, c;
731 	register u_int32_t crc;
732 	register int i, len;
733 	struct ether_multistep step;
734 
735 	/*
736 	 * Set up multicast address filter by passing all multicast addresses
737 	 * through a crc generator, and then using the high order 6 bits as an
738 	 * index into the 64 bit logical address filter.  The high order bit
739 	 * selects the word, while the rest of the bits select the bit within
740 	 * the word.
741 	 */
742 
743 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0;
744 
745 	ETHER_FIRST_MULTI(step, ac, enm);
746 	while (enm != NULL) {
747 		if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) {
748 			/*
749 			 * We must listen to a range of multicast addresses.
750 			 * For now, just accept all multicasts, rather than
751 			 * trying to set only those filter bits needed to match
752 			 * the range.  (At this time, the only use of address
753 			 * ranges is for IP multicast routing, for which the
754 			 * range is big enough to require all bits set.)
755 			 */
756 			goto allmulti;
757 		}
758 
759 		cp = enm->enm_addrlo;
760 		crc = 0xffffffff;
761 		for (len = sizeof(enm->enm_addrlo); --len >= 0;) {
762 			c = *cp++;
763 			for (i = 8; --i >= 0;) {
764 				if ((crc & 0x01) ^ (c & 0x01)) {
765 					crc >>= 1;
766 					crc ^= 0xedb88320;
767 				} else
768 					crc >>= 1;
769 				c >>= 1;
770 			}
771 		}
772 		/* Just want the 6 most significant bits. */
773 		crc >>= 26;
774 
775 		/* Set the corresponding bit in the filter. */
776 		af[crc >> 3] |= 1 << (crc & 7);
777 
778 		ETHER_NEXT_MULTI(step, enm);
779 	}
780 	ifp->if_flags &= ~IFF_ALLMULTI;
781 	return;
782 
783 allmulti:
784 	ifp->if_flags |= IFF_ALLMULTI;
785 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0xffffffff;
786 }
787 
788 static u_char bbr4[] = {0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15};
789 #define bbr(v)  ((bbr4[(v)&0xf] << 4) | bbr4[((v)>>4) & 0xf])
790 
791 u_char
792 mc_get_enaddr(t, h, o, dst)
793 	bus_space_tag_t t;
794 	bus_space_handle_t h;
795 	vm_offset_t o;
796 	u_char *dst;
797 {
798 	int	i;
799 	u_char	b, csum;
800 
801 	/*
802 	 * The XOR of the 8 bytes of the ROM must be 0xff for it to be
803 	 * valid
804 	*/
805 	for (i = 0, csum = 0; i < 8; i++) {
806 		b = bus_space_read_1(t, h, o+16*i);
807 		if (i < ETHER_ADDR_LEN)
808 			dst[i] = bbr(b);
809 		csum ^= b;
810 	}
811 
812 	return csum;
813 }
814