xref: /netbsd-src/sys/arch/mac68k/dev/if_mc.c (revision 481fca6e59249d8ffcf24fef7cfbe7b131bfb080)
1 /*	$NetBSD: if_mc.c,v 1.16 2000/06/29 08:15:11 mrg 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 "opt_ddb.h"
38 #include "opt_inet.h"
39 #include "opt_ccitt.h"
40 #include "opt_llc.h"
41 #include "opt_ns.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/mbuf.h>
46 #include <sys/buf.h>
47 #include <sys/protosw.h>
48 #include <sys/socket.h>
49 #include <sys/syslog.h>
50 #include <sys/ioctl.h>
51 #include <sys/errno.h>
52 #include <sys/device.h>
53 
54 #include <net/if.h>
55 #include <net/if_dl.h>
56 #include <net/if_ether.h>
57 
58 #ifdef INET
59 #include <netinet/in.h>
60 #include <netinet/if_inarp.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/in_var.h>
63 #include <netinet/ip.h>
64 #endif
65 
66 #ifdef NS
67 #include <netns/ns.h>
68 #include <netns/ns_if.h>
69 #endif
70 
71 #if defined(CCITT) && defined(LLC)
72 #include <sys/socketvar.h>
73 #include <netccitt/x25.h>
74 #include <netccitt/pk.h>
75 #include <netccitt/pk_var.h>
76 #include <netccitt/pk_extern.h>
77 #endif
78 
79 #include <uvm/uvm_extern.h>
80 
81 #include "bpfilter.h"
82 #if NBPFILTER > 0
83 #include <net/bpf.h>
84 #include <net/bpfdesc.h>
85 #endif
86 
87 #include <machine/bus.h>
88 #include <mac68k/dev/if_mcreg.h>
89 #include <mac68k/dev/if_mcvar.h>
90 
91 hide void	mcwatchdog __P((struct ifnet *));
92 hide int	mcinit __P((struct mc_softc *sc));
93 hide int	mcstop __P((struct mc_softc *sc));
94 hide int	mcioctl __P((struct ifnet *ifp, u_long cmd, caddr_t data));
95 hide void	mcstart __P((struct ifnet *ifp));
96 hide void	mcreset __P((struct mc_softc *sc));
97 
98 integrate u_int	maceput __P((struct mc_softc *sc, struct mbuf *m0));
99 integrate void	mc_tint __P((struct mc_softc *sc));
100 integrate void	mace_read __P((struct mc_softc *, caddr_t, int));
101 integrate struct mbuf *mace_get __P((struct mc_softc *, caddr_t, int));
102 static void mace_calcladrf __P((struct ethercom *ac, u_int8_t *af));
103 static inline u_int16_t ether_cmp __P((void *, void *));
104 
105 
106 /*
107  * Compare two Ether/802 addresses for equality, inlined and
108  * unrolled for speed.  Use this like bcmp().
109  *
110  * XXX: Add <machine/inlines.h> for stuff like this?
111  * XXX: or maybe add it to libkern.h instead?
112  *
113  * "I'd love to have an inline assembler version of this."
114  * XXX: Who wanted that? mycroft?  I wrote one, but this
115  * version in C is as good as hand-coded assembly. -gwr
116  *
117  * Please do NOT tweak this without looking at the actual
118  * assembly code generated before and after your tweaks!
119  */
120 static inline u_int16_t
121 ether_cmp(one, two)
122 	void *one, *two;
123 {
124 	register u_int16_t *a = (u_short *) one;
125 	register u_int16_t *b = (u_short *) two;
126 	register u_int16_t diff;
127 
128 #ifdef	m68k
129 	/*
130 	 * The post-increment-pointer form produces the best
131 	 * machine code for m68k.  This was carefully tuned
132 	 * so it compiles to just 8 short (2-byte) op-codes!
133 	 */
134 	diff  = *a++ - *b++;
135 	diff |= *a++ - *b++;
136 	diff |= *a++ - *b++;
137 #else
138 	/*
139 	 * Most modern CPUs do better with a single expresion.
140 	 * Note that short-cut evaluation is NOT helpful here,
141 	 * because it just makes the code longer, not faster!
142 	 */
143 	diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]);
144 #endif
145 
146 	return (diff);
147 }
148 
149 #define ETHER_CMP	ether_cmp
150 
151 /*
152  * Interface exists: make available by filling in network interface
153  * record.  System will initialize the interface when it is ready
154  * to accept packets.
155  */
156 int
157 mcsetup(sc, lladdr)
158 	struct mc_softc	*sc;
159 	u_int8_t *lladdr;
160 {
161 	struct ifnet *ifp = &sc->sc_if;
162 
163 	/* reset the chip and disable all interrupts */
164 	NIC_PUT(sc, MACE_BIUCC, SWRST);
165 	DELAY(100);
166 	NIC_PUT(sc, MACE_IMR, ~0);
167 
168 	bcopy(lladdr, sc->sc_enaddr, ETHER_ADDR_LEN);
169 	printf(": address %s\n", ether_sprintf(lladdr));
170 
171 	bcopy(sc->sc_dev.dv_xname, ifp->if_xname, IFNAMSIZ);
172 	ifp->if_softc = sc;
173 	ifp->if_ioctl = mcioctl;
174 	ifp->if_start = mcstart;
175 	ifp->if_flags =
176 	    IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS | IFF_MULTICAST;
177 	ifp->if_watchdog = mcwatchdog;
178 
179 #if NBPFILTER > 0
180 	bpfattach(&ifp->if_bpf, ifp, DLT_EN10MB, sizeof(struct ether_header));
181 #endif
182 	if_attach(ifp);
183 	ether_ifattach(ifp, lladdr);
184 
185 	return (0);
186 }
187 
188 hide int
189 mcioctl(ifp, cmd, data)
190 	struct ifnet *ifp;
191 	u_long cmd;
192 	caddr_t data;
193 {
194 	struct mc_softc *sc = ifp->if_softc;
195 	struct ifaddr *ifa;
196 	struct ifreq *ifr;
197 
198 	int	s = splnet(), err = 0;
199 	int	temp;
200 
201 	switch (cmd) {
202 
203 	case SIOCSIFADDR:
204 		ifa = (struct ifaddr *)data;
205 		ifp->if_flags |= IFF_UP;
206 		switch (ifa->ifa_addr->sa_family) {
207 #ifdef INET
208 		case AF_INET:
209 			mcinit(sc);
210 			arp_ifinit(ifp, ifa);
211 			break;
212 #endif
213 #ifdef NS
214 		case AF_NS:
215 		    {
216 			register struct ns_addr *ina = &IA_SNS(ifa)->sns_addr;
217 
218 			if (ns_nullhost(*ina))
219 				ina->x_host =
220 				    *(union ns_host *)LLADDR(ifp->if_sadl);
221 			else {
222 				bcopy(ina->x_host.c_host,
223 				    LLADDR(ifp->if_sadl),
224 				    sizeof(sc->sc_enaddr));
225 			}
226 			/* Set new address. */
227 			mcinit(sc);
228 			break;
229 		    }
230 #endif
231 		default:
232 			mcinit(sc);
233 			break;
234 		}
235 		break;
236 
237 	case SIOCSIFFLAGS:
238 		if ((ifp->if_flags & IFF_UP) == 0 &&
239 		    (ifp->if_flags & IFF_RUNNING) != 0) {
240 			/*
241 			 * If interface is marked down and it is running,
242 			 * then stop it.
243 			 */
244 			mcstop(sc);
245 			ifp->if_flags &= ~IFF_RUNNING;
246 		} else if ((ifp->if_flags & IFF_UP) != 0 &&
247 		    (ifp->if_flags & IFF_RUNNING) == 0) {
248 			/*
249 			 * If interface is marked up and it is stopped,
250 			 * then start it.
251 			 */
252 			(void)mcinit(sc);
253 		} else {
254 			/*
255 			 * reset the interface to pick up any other changes
256 			 * in flags
257 			 */
258 			temp = ifp->if_flags & IFF_UP;
259 			mcreset(sc);
260 			ifp->if_flags |= temp;
261 			mcstart(ifp);
262 		}
263 		break;
264 
265 	case SIOCADDMULTI:
266 	case SIOCDELMULTI:
267 		ifr = (struct ifreq *) data;
268 		err = (cmd == SIOCADDMULTI) ?
269 		    ether_addmulti(ifr, &sc->sc_ethercom) :
270 		    ether_delmulti(ifr, &sc->sc_ethercom);
271 
272 		if (err == ENETRESET) {
273 			/*
274 			 * Multicast list has changed; set the hardware
275 			 * filter accordingly. But remember UP flag!
276 			 */
277 			temp = ifp->if_flags & IFF_UP;
278 			mcreset(sc);
279 			ifp->if_flags |= temp;
280 			err = 0;
281 		}
282 		break;
283 	default:
284 		err = EINVAL;
285 	}
286 	splx(s);
287 	return (err);
288 }
289 
290 /*
291  * Encapsulate a packet of type family for the local net.
292  */
293 hide void
294 mcstart(ifp)
295 	struct ifnet *ifp;
296 {
297 	struct mc_softc	*sc = ifp->if_softc;
298 	struct mbuf	*m;
299 
300 	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
301 		return;
302 
303 	while (1) {
304 		if (ifp->if_flags & IFF_OACTIVE)
305 			return;
306 
307 		IF_DEQUEUE(&ifp->if_snd, m);
308 		if (m == 0)
309 			return;
310 
311 #if NBPFILTER > 0
312 		/*
313 		 * If bpf is listening on this interface, let it
314 		 * see the packet before we commit it to the wire.
315 		 */
316 		if (ifp->if_bpf)
317 			bpf_mtap(ifp->if_bpf, m);
318 #endif
319 
320 		/*
321 		 * Copy the mbuf chain into the transmit buffer.
322 		 */
323 		ifp->if_flags |= IFF_OACTIVE;
324 		maceput(sc, m);
325 
326 		ifp->if_opackets++;		/* # of pkts */
327 	}
328 }
329 
330 /*
331  * reset and restart the MACE.  Called in case of fatal
332  * hardware/software errors.
333  */
334 hide void
335 mcreset(sc)
336 	struct mc_softc *sc;
337 {
338 	mcstop(sc);
339 	mcinit(sc);
340 }
341 
342 hide int
343 mcinit(sc)
344 	struct mc_softc *sc;
345 {
346 	int s;
347 	u_int8_t maccc, ladrf[8];
348 
349 	if (sc->sc_if.if_flags & IFF_RUNNING)
350 		/* already running */
351 		return (0);
352 
353 	s = splnet();
354 
355 	NIC_PUT(sc, MACE_BIUCC, sc->sc_biucc);
356 	NIC_PUT(sc, MACE_FIFOCC, sc->sc_fifocc);
357 	NIC_PUT(sc, MACE_IMR, ~0); /* disable all interrupts */
358 	NIC_PUT(sc, MACE_PLSCC, sc->sc_plscc);
359 
360 	NIC_PUT(sc, MACE_UTR, RTRD); /* disable reserved test registers */
361 
362 	/* set MAC address */
363 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
364 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
365 		;
366 	NIC_PUT(sc, MACE_IAC, PHYADDR);
367 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_PADR),
368 	    sc->sc_enaddr, ETHER_ADDR_LEN);
369 
370 	/* set logical address filter */
371 	mace_calcladrf(&sc->sc_ethercom, ladrf);
372 
373 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
374 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
375 		;
376 	NIC_PUT(sc, MACE_IAC, LOGADDR);
377 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_LADRF),
378 	    ladrf, 8);
379 
380 	NIC_PUT(sc, MACE_XMTFC, APADXMT);
381 	/*
382 	 * No need to autostrip padding on receive... Ethernet frames
383 	 * don't have a length field, unlike 802.3 frames, so the MACE
384 	 * can't figure out the length of the packet anyways.
385 	 */
386 	NIC_PUT(sc, MACE_RCVFC, 0);
387 
388 	maccc = ENXMT | ENRCV;
389 	if (sc->sc_if.if_flags & IFF_PROMISC)
390 		maccc |= PROM;
391 
392 	NIC_PUT(sc, MACE_MACCC, maccc);
393 
394 	if (sc->sc_bus_init)
395 		(*sc->sc_bus_init)(sc);
396 
397 	/*
398 	 * Enable all interrupts except receive, since we use the DMA
399 	 * completion interrupt for that.
400 	 */
401 	NIC_PUT(sc, MACE_IMR, RCVINTM);
402 
403 	/* flag interface as "running" */
404 	sc->sc_if.if_flags |= IFF_RUNNING;
405 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
406 
407 	splx(s);
408 	return (0);
409 }
410 
411 /*
412  * close down an interface and free its buffers
413  * Called on final close of device, or if mcinit() fails
414  * part way through.
415  */
416 hide int
417 mcstop(sc)
418 	struct mc_softc *sc;
419 {
420 	int	s = splnet();
421 
422 	NIC_PUT(sc, MACE_BIUCC, SWRST);
423 	DELAY(100);
424 
425 	sc->sc_if.if_timer = 0;
426 	sc->sc_if.if_flags &= ~(IFF_RUNNING | IFF_UP);
427 
428 	splx(s);
429 	return (0);
430 }
431 
432 /*
433  * Called if any Tx packets remain unsent after 5 seconds,
434  * In all cases we just reset the chip, and any retransmission
435  * will be handled by higher level protocol timeouts.
436  */
437 hide void
438 mcwatchdog(ifp)
439 	struct ifnet *ifp;
440 {
441 	struct mc_softc *sc = ifp->if_softc;
442 	int temp;
443 
444 	printf("mcwatchdog: resetting chip\n");
445 	temp = ifp->if_flags & IFF_UP;
446 	mcreset(sc);
447 	ifp->if_flags |= temp;
448 }
449 
450 /*
451  * stuff packet into MACE (at splnet)
452  */
453 integrate u_int
454 maceput(sc, m)
455 	struct mc_softc *sc;
456 	struct mbuf *m;
457 {
458 	struct mbuf *n;
459 	u_int len, totlen = 0;
460 	u_char *buff;
461 
462 	buff = sc->sc_txbuf;
463 
464 	for (; m; m = n) {
465 		u_char *data = mtod(m, u_char *);
466 		len = m->m_len;
467 		totlen += len;
468 		bcopy(data, buff, len);
469 		buff += len;
470 		MFREE(m, n);
471 	}
472 
473 	if (totlen > NBPG)
474 		panic("%s: maceput: packet overflow", sc->sc_dev.dv_xname);
475 
476 #if 0
477 	if (totlen < ETHERMIN + sizeof(struct ether_header)) {
478 		int pad = ETHERMIN + sizeof(struct ether_header) - totlen;
479 		bzero(sc->sc_txbuf + totlen, pad);
480 		totlen = ETHERMIN + sizeof(struct ether_header);
481 	}
482 #endif
483 
484 	(*sc->sc_putpacket)(sc, totlen);
485 
486 	sc->sc_if.if_timer = 5;	/* 5 seconds to watch for failing to transmit */
487 	return (totlen);
488 }
489 
490 void
491 mcintr(arg)
492 	void *arg;
493 {
494 struct mc_softc *sc = arg;
495 	u_int8_t ir;
496 
497 	ir = NIC_GET(sc, MACE_IR) & ~NIC_GET(sc, MACE_IMR);
498 	if (ir & JAB) {
499 #ifdef MCDEBUG
500 		printf("%s: jabber error\n", sc->sc_dev.dv_xname);
501 #endif
502 		sc->sc_if.if_oerrors++;
503 	}
504 
505 	if (ir & BABL) {
506 #ifdef MCDEBUG
507 		printf("%s: babble\n", sc->sc_dev.dv_xname);
508 #endif
509 		sc->sc_if.if_oerrors++;
510 	}
511 
512 	if (ir & CERR) {
513 #ifdef MCDEBUG
514 		printf("%s: collision error\n", sc->sc_dev.dv_xname);
515 #endif
516 		sc->sc_if.if_collisions++;
517 	}
518 
519 	/*
520 	 * Pretend we have carrier; if we don't this will be cleared
521 	 * shortly.
522 	 */
523 	sc->sc_havecarrier = 1;
524 
525 	if (ir & XMTINT)
526 		mc_tint(sc);
527 
528 	if (ir & RCVINT)
529 		mc_rint(sc);
530 }
531 
532 integrate void
533 mc_tint(sc)
534 	struct mc_softc *sc;
535 {
536 	u_int8_t xmtrc, xmtfs;
537 
538 	xmtrc = NIC_GET(sc, MACE_XMTRC);
539 	xmtfs = NIC_GET(sc, MACE_XMTFS);
540 
541 	if ((xmtfs & XMTSV) == 0)
542 		return;
543 
544 	if (xmtfs & UFLO) {
545 		printf("%s: underflow\n", sc->sc_dev.dv_xname);
546 		mcreset(sc);
547 		return;
548 	}
549 
550 	if (xmtfs & LCOL) {
551 		printf("%s: late collision\n", sc->sc_dev.dv_xname);
552 		sc->sc_if.if_oerrors++;
553 		sc->sc_if.if_collisions++;
554 	}
555 
556 	if (xmtfs & MORE)
557 		/* Real number is unknown. */
558 		sc->sc_if.if_collisions += 2;
559 	else if (xmtfs & ONE)
560 		sc->sc_if.if_collisions++;
561 	else if (xmtfs & RTRY) {
562 		printf("%s: excessive collisions\n", sc->sc_dev.dv_xname);
563 		sc->sc_if.if_collisions += 16;
564 		sc->sc_if.if_oerrors++;
565 	}
566 
567 	if (xmtfs & LCAR) {
568 		sc->sc_havecarrier = 0;
569 		printf("%s: lost carrier\n", sc->sc_dev.dv_xname);
570 		sc->sc_if.if_oerrors++;
571 	}
572 
573 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
574 	sc->sc_if.if_timer = 0;
575 	mcstart(&sc->sc_if);
576 }
577 
578 void
579 mc_rint(sc)
580 	struct mc_softc *sc;
581 {
582 #define	rxf	sc->sc_rxframe
583 	u_int len;
584 
585 	len = (rxf.rx_rcvcnt | ((rxf.rx_rcvsts & 0xf) << 8)) - 4;
586 
587 #ifdef MCDEBUG
588 	if (rxf.rx_rcvsts & 0xf0)
589 		printf("%s: rcvcnt %02x rcvsts %02x rntpc 0x%02x rcvcc 0x%02x\n",
590 		    sc->sc_dev.dv_xname, rxf.rx_rcvcnt, rxf.rx_rcvsts,
591 		    rxf.rx_rntpc, rxf.rx_rcvcc);
592 #endif
593 
594 	if (rxf.rx_rcvsts & OFLO) {
595 		printf("%s: receive FIFO overflow\n", sc->sc_dev.dv_xname);
596 		sc->sc_if.if_ierrors++;
597 		return;
598 	}
599 
600 	if (rxf.rx_rcvsts & CLSN)
601 		sc->sc_if.if_collisions++;
602 
603 	if (rxf.rx_rcvsts & FRAM) {
604 #ifdef MCDEBUG
605 		printf("%s: framing error\n", sc->sc_dev.dv_xname);
606 #endif
607 		sc->sc_if.if_ierrors++;
608 		return;
609 	}
610 
611 	if (rxf.rx_rcvsts & FCS) {
612 #ifdef MCDEBUG
613 		printf("%s: frame control checksum error\n", sc->sc_dev.dv_xname);
614 #endif
615 		sc->sc_if.if_ierrors++;
616 		return;
617 	}
618 
619 	mace_read(sc, rxf.rx_frame, len);
620 #undef	rxf
621 }
622 
623 integrate void
624 mace_read(sc, pkt, len)
625 	struct mc_softc *sc;
626 	caddr_t pkt;
627 	int len;
628 {
629 	struct ifnet *ifp = &sc->sc_if;
630 #if NBPFILTER > 0
631 	struct ether_header *eh = (struct ether_header *)pkt;
632 #endif
633 	struct mbuf *m;
634 
635 	if (len <= sizeof(struct ether_header) ||
636 	    len > ETHERMTU + sizeof(struct ether_header)) {
637 #ifdef MCDEBUG
638 		printf("%s: invalid packet size %d; dropping\n",
639 		    sc->sc_dev.dv_xname, len);
640 #endif
641 		ifp->if_ierrors++;
642 		return;
643 	}
644 
645 #if NBPFILTER > 0
646 	/*
647 	 * Check if there's a bpf filter listening on this interface.
648 	 * If so, hand off the raw packet to enet, then discard things
649 	 * not destined for us (but be sure to keep broadcast/multicast).
650 	 */
651 	if (ifp->if_bpf) {
652 		bpf_tap(ifp->if_bpf, pkt, len);
653 		if ((ifp->if_flags & IFF_PROMISC) != 0 &&
654 		    (eh->ether_dhost[0] & 1) == 0 && /* !mcast and !bcast */
655 		    ETHER_CMP(eh->ether_dhost, sc->sc_enaddr))
656 			return;
657 	}
658 #endif
659 	m = mace_get(sc, pkt, len);
660 	if (m == NULL) {
661 		ifp->if_ierrors++;
662 		return;
663 	}
664 
665 	ifp->if_ipackets++;
666 
667 	/* Pass the packet up. */
668 	(*ifp->if_input)(ifp, m);
669 }
670 
671 /*
672  * Pull data off an interface.
673  * Len is length of data, with local net header stripped.
674  * We copy the data into mbufs.  When full cluster sized units are present
675  * we copy into clusters.
676  */
677 integrate struct mbuf *
678 mace_get(sc, pkt, totlen)
679 	struct mc_softc *sc;
680 	caddr_t pkt;
681 	int totlen;
682 {
683 	register struct mbuf *m;
684 	struct mbuf *top, **mp;
685 	int len;
686 
687 	MGETHDR(m, M_DONTWAIT, MT_DATA);
688 	if (m == 0)
689 		return (0);
690 	m->m_pkthdr.rcvif = &sc->sc_if;
691 	m->m_pkthdr.len = totlen;
692 	len = MHLEN;
693 	top = 0;
694 	mp = &top;
695 
696 	while (totlen > 0) {
697 		if (top) {
698 			MGET(m, M_DONTWAIT, MT_DATA);
699 			if (m == 0) {
700 				m_freem(top);
701 				return 0;
702 			}
703 			len = MLEN;
704 		}
705 		if (totlen >= MINCLSIZE) {
706 			MCLGET(m, M_DONTWAIT);
707 			if ((m->m_flags & M_EXT) == 0) {
708 				m_free(m);
709 				m_freem(top);
710 				return 0;
711 			}
712 			len = MCLBYTES;
713 		}
714 		m->m_len = len = min(totlen, len);
715 		bcopy(pkt, mtod(m, caddr_t), len);
716 		pkt += len;
717 		totlen -= len;
718 		*mp = m;
719 		mp = &m->m_next;
720 	}
721 
722 	return (top);
723 }
724 
725 /*
726  * Go through the list of multicast addresses and calculate the logical
727  * address filter.
728  */
729 void
730 mace_calcladrf(ac, af)
731 	struct ethercom *ac;
732 	u_int8_t *af;
733 {
734 	struct ifnet *ifp = &ac->ec_if;
735 	struct ether_multi *enm;
736 	register u_char *cp;
737 	register u_int32_t crc;
738 	static const u_int32_t crctab[] = {
739 		0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
740 		0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
741 		0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
742 		0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
743 	};
744 	register int len;
745 	struct ether_multistep step;
746 
747 	/*
748 	 * Set up multicast address filter by passing all multicast addresses
749 	 * through a crc generator, and then using the high order 6 bits as an
750 	 * index into the 64 bit logical address filter.  The high order bit
751 	 * selects the word, while the rest of the bits select the bit within
752 	 * the word.
753 	 */
754 
755 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0;
756 	ETHER_FIRST_MULTI(step, ac, enm);
757 	while (enm != NULL) {
758 		if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) {
759 			/*
760 			 * We must listen to a range of multicast addresses.
761 			 * For now, just accept all multicasts, rather than
762 			 * trying to set only those filter bits needed to match
763 			 * the range.  (At this time, the only use of address
764 			 * ranges is for IP multicast routing, for which the
765 			 * range is big enough to require all bits set.)
766 			 */
767 			goto allmulti;
768 		}
769 
770 		cp = enm->enm_addrlo;
771 		crc = 0xffffffff;
772 		for (len = sizeof(enm->enm_addrlo); --len >= 0;) {
773 			crc ^= *cp++;
774 			crc = (crc >> 4) ^ crctab[crc & 0xf];
775 			crc = (crc >> 4) ^ crctab[crc & 0xf];
776 		}
777 		/* Just want the 6 most significant bits. */
778 		crc >>= 26;
779 
780 		/* Set the corresponding bit in the filter. */
781 		af[crc >> 3] |= 1 << (crc & 7);
782 
783 		ETHER_NEXT_MULTI(step, enm);
784 	}
785 	ifp->if_flags &= ~IFF_ALLMULTI;
786 	return;
787 
788 allmulti:
789 	ifp->if_flags |= IFF_ALLMULTI;
790 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0xffffffff;
791 }
792 
793 static u_char bbr4[] = {0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15};
794 #define bbr(v)  ((bbr4[(v)&0xf] << 4) | bbr4[((v)>>4) & 0xf])
795 
796 u_char
797 mc_get_enaddr(t, h, o, dst)
798 	bus_space_tag_t t;
799 	bus_space_handle_t h;
800 	bus_size_t o;
801 	u_char *dst;
802 {
803 	int	i;
804 	u_char	b, csum;
805 
806 	/*
807 	 * The XOR of the 8 bytes of the ROM must be 0xff for it to be
808 	 * valid
809 	*/
810 	for (i = 0, csum = 0; i < 8; i++) {
811 		b = bus_space_read_1(t, h, o+16*i);
812 		if (i < ETHER_ADDR_LEN)
813 			dst[i] = bbr(b);
814 		csum ^= b;
815 	}
816 
817 	return csum;
818 }
819