xref: /netbsd-src/sys/arch/mac68k/dev/if_mc.c (revision d48f14661dda8638fee055ba15d35bdfb29b9fa8)
1 /*	$NetBSD: if_mc.c,v 1.26 2005/12/11 12:18:02 christos 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 1.26 2005/12/11 12:18:02 christos 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(struct ifnet *);
97 hide int	mcinit(struct mc_softc *);
98 hide int	mcstop(struct mc_softc *);
99 hide int	mcioctl(struct ifnet *, u_long, caddr_t);
100 hide void	mcstart(struct ifnet *);
101 hide void	mcreset(struct mc_softc *);
102 
103 integrate u_int	maceput(struct mc_softc *, struct mbuf *);
104 integrate void	mc_tint(struct mc_softc *);
105 integrate void	mace_read(struct mc_softc *, caddr_t, int);
106 integrate struct mbuf *mace_get(struct mc_softc *, caddr_t, int);
107 static void mace_calcladrf(struct ethercom *, u_int8_t *);
108 static inline u_int16_t ether_cmp(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(void *one, void *two)
127 {
128 	u_int16_t *a = (u_short *) one;
129 	u_int16_t *b = (u_short *) two;
130 	u_int16_t diff;
131 
132 #ifdef	m68k
133 	/*
134 	 * The post-increment-pointer form produces the best
135 	 * machine code for m68k.  This was carefully tuned
136 	 * so it compiles to just 8 short (2-byte) op-codes!
137 	 */
138 	diff  = *a++ - *b++;
139 	diff |= *a++ - *b++;
140 	diff |= *a++ - *b++;
141 #else
142 	/*
143 	 * Most modern CPUs do better with a single expresion.
144 	 * Note that short-cut evaluation is NOT helpful here,
145 	 * because it just makes the code longer, not faster!
146 	 */
147 	diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]);
148 #endif
149 
150 	return (diff);
151 }
152 
153 #define ETHER_CMP	ether_cmp
154 
155 /*
156  * Interface exists: make available by filling in network interface
157  * record.  System will initialize the interface when it is ready
158  * to accept packets.
159  */
160 int
161 mcsetup(struct mc_softc	*sc, u_int8_t *lladdr)
162 {
163 	struct ifnet *ifp = &sc->sc_if;
164 
165 	/* reset the chip and disable all interrupts */
166 	NIC_PUT(sc, MACE_BIUCC, SWRST);
167 	DELAY(100);
168 	NIC_PUT(sc, MACE_IMR, ~0);
169 
170 	memcpy(sc->sc_enaddr, lladdr, ETHER_ADDR_LEN);
171 	printf(": address %s\n", ether_sprintf(lladdr));
172 
173 	memcpy(ifp->if_xname, sc->sc_dev.dv_xname, IFNAMSIZ);
174 	ifp->if_softc = sc;
175 	ifp->if_ioctl = mcioctl;
176 	ifp->if_start = mcstart;
177 	ifp->if_flags =
178 	    IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS | IFF_MULTICAST;
179 	ifp->if_watchdog = mcwatchdog;
180 
181 	if_attach(ifp);
182 	ether_ifattach(ifp, lladdr);
183 
184 	return (0);
185 }
186 
187 hide int
188 mcioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
189 {
190 	struct mc_softc *sc = ifp->if_softc;
191 	struct ifaddr *ifa;
192 	struct ifreq *ifr;
193 
194 	int	s = splnet(), err = 0;
195 
196 	switch (cmd) {
197 
198 	case SIOCSIFADDR:
199 		ifa = (struct ifaddr *)data;
200 		ifp->if_flags |= IFF_UP;
201 		switch (ifa->ifa_addr->sa_family) {
202 #ifdef INET
203 		case AF_INET:
204 			mcinit(sc);
205 			arp_ifinit(ifp, ifa);
206 			break;
207 #endif
208 #ifdef NS
209 		case AF_NS:
210 		    {
211 			struct ns_addr *ina = &IA_SNS(ifa)->sns_addr;
212 
213 			if (ns_nullhost(*ina))
214 				ina->x_host =
215 				    *(union ns_host *)LLADDR(ifp->if_sadl);
216 			else {
217 				memcpy(LLADDR(ifp->if_sadl),
218 				    ina->x_host.c_host,
219 				    sizeof(sc->sc_enaddr));
220 			}
221 			/* Set new address. */
222 			mcinit(sc);
223 			break;
224 		    }
225 #endif
226 		default:
227 			mcinit(sc);
228 			break;
229 		}
230 		break;
231 
232 	case SIOCSIFFLAGS:
233 		if ((ifp->if_flags & IFF_UP) == 0 &&
234 		    (ifp->if_flags & IFF_RUNNING) != 0) {
235 			/*
236 			 * If interface is marked down and it is running,
237 			 * then stop it.
238 			 */
239 			mcstop(sc);
240 			ifp->if_flags &= ~IFF_RUNNING;
241 		} else if ((ifp->if_flags & IFF_UP) != 0 &&
242 		    (ifp->if_flags & IFF_RUNNING) == 0) {
243 			/*
244 			 * If interface is marked up and it is stopped,
245 			 * then start it.
246 			 */
247 			(void)mcinit(sc);
248 		} else {
249 			/*
250 			 * reset the interface to pick up any other changes
251 			 * in flags
252 			 */
253 			mcreset(sc);
254 			mcstart(ifp);
255 		}
256 		break;
257 
258 	case SIOCADDMULTI:
259 	case SIOCDELMULTI:
260 		ifr = (struct ifreq *) data;
261 		err = (cmd == SIOCADDMULTI) ?
262 		    ether_addmulti(ifr, &sc->sc_ethercom) :
263 		    ether_delmulti(ifr, &sc->sc_ethercom);
264 
265 		if (err == ENETRESET) {
266 			/*
267 			 * Multicast list has changed; set the hardware
268 			 * filter accordingly. But remember UP flag!
269 			 */
270 			if (ifp->if_flags & IFF_RUNNING)
271 				mcreset(sc);
272 			err = 0;
273 		}
274 		break;
275 	default:
276 		err = EINVAL;
277 	}
278 	splx(s);
279 	return (err);
280 }
281 
282 /*
283  * Encapsulate a packet of type family for the local net.
284  */
285 hide void
286 mcstart(struct ifnet *ifp)
287 {
288 	struct mc_softc	*sc = ifp->if_softc;
289 	struct mbuf *m;
290 
291 	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
292 		return;
293 
294 	while (1) {
295 		if (ifp->if_flags & IFF_OACTIVE)
296 			return;
297 
298 		IF_DEQUEUE(&ifp->if_snd, m);
299 		if (m == 0)
300 			return;
301 
302 #if NBPFILTER > 0
303 		/*
304 		 * If bpf is listening on this interface, let it
305 		 * see the packet before we commit it to the wire.
306 		 */
307 		if (ifp->if_bpf)
308 			bpf_mtap(ifp->if_bpf, m);
309 #endif
310 
311 		/*
312 		 * Copy the mbuf chain into the transmit buffer.
313 		 */
314 		ifp->if_flags |= IFF_OACTIVE;
315 		maceput(sc, m);
316 
317 		ifp->if_opackets++;		/* # of pkts */
318 	}
319 }
320 
321 /*
322  * reset and restart the MACE.  Called in case of fatal
323  * hardware/software errors.
324  */
325 hide void
326 mcreset(struct mc_softc *sc)
327 {
328 	mcstop(sc);
329 	mcinit(sc);
330 }
331 
332 hide int
333 mcinit(struct mc_softc *sc)
334 {
335 	int s;
336 	u_int8_t maccc, ladrf[8];
337 
338 	if (sc->sc_if.if_flags & IFF_RUNNING)
339 		/* already running */
340 		return (0);
341 
342 	s = splnet();
343 
344 	NIC_PUT(sc, MACE_BIUCC, sc->sc_biucc);
345 	NIC_PUT(sc, MACE_FIFOCC, sc->sc_fifocc);
346 	NIC_PUT(sc, MACE_IMR, ~0); /* disable all interrupts */
347 	NIC_PUT(sc, MACE_PLSCC, sc->sc_plscc);
348 
349 	NIC_PUT(sc, MACE_UTR, RTRD); /* disable reserved test registers */
350 
351 	/* set MAC address */
352 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
353 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
354 		;
355 	NIC_PUT(sc, MACE_IAC, PHYADDR);
356 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_PADR),
357 	    sc->sc_enaddr, ETHER_ADDR_LEN);
358 
359 	/* set logical address filter */
360 	mace_calcladrf(&sc->sc_ethercom, ladrf);
361 
362 	NIC_PUT(sc, MACE_IAC, ADDRCHG);
363 	while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
364 		;
365 	NIC_PUT(sc, MACE_IAC, LOGADDR);
366 	bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_LADRF),
367 	    ladrf, 8);
368 
369 	NIC_PUT(sc, MACE_XMTFC, APADXMT);
370 	/*
371 	 * No need to autostrip padding on receive... Ethernet frames
372 	 * don't have a length field, unlike 802.3 frames, so the MACE
373 	 * can't figure out the length of the packet anyways.
374 	 */
375 	NIC_PUT(sc, MACE_RCVFC, 0);
376 
377 	maccc = ENXMT | ENRCV;
378 	if (sc->sc_if.if_flags & IFF_PROMISC)
379 		maccc |= PROM;
380 
381 	NIC_PUT(sc, MACE_MACCC, maccc);
382 
383 	if (sc->sc_bus_init)
384 		(*sc->sc_bus_init)(sc);
385 
386 	/*
387 	 * Enable all interrupts except receive, since we use the DMA
388 	 * completion interrupt for that.
389 	 */
390 	NIC_PUT(sc, MACE_IMR, RCVINTM);
391 
392 	/* flag interface as "running" */
393 	sc->sc_if.if_flags |= IFF_RUNNING;
394 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
395 
396 	splx(s);
397 	return (0);
398 }
399 
400 /*
401  * close down an interface and free its buffers
402  * Called on final close of device, or if mcinit() fails
403  * part way through.
404  */
405 hide int
406 mcstop(struct mc_softc *sc)
407 {
408 	int s;
409 
410 	s = splnet();
411 
412 	NIC_PUT(sc, MACE_BIUCC, SWRST);
413 	DELAY(100);
414 
415 	sc->sc_if.if_timer = 0;
416 	sc->sc_if.if_flags &= ~IFF_RUNNING;
417 
418 	splx(s);
419 	return (0);
420 }
421 
422 /*
423  * Called if any Tx packets remain unsent after 5 seconds,
424  * In all cases we just reset the chip, and any retransmission
425  * will be handled by higher level protocol timeouts.
426  */
427 hide void
428 mcwatchdog(struct ifnet *ifp)
429 {
430 	struct mc_softc *sc = ifp->if_softc;
431 
432 	printf("mcwatchdog: resetting chip\n");
433 	mcreset(sc);
434 }
435 
436 /*
437  * stuff packet into MACE (at splnet)
438  */
439 integrate u_int
440 maceput(struct mc_softc *sc, struct mbuf *m)
441 {
442 	struct mbuf *n;
443 	u_int len, totlen = 0;
444 	u_char *buff;
445 
446 	buff = sc->sc_txbuf;
447 
448 	for (; m; m = n) {
449 		u_char *data = mtod(m, u_char *);
450 		len = m->m_len;
451 		totlen += len;
452 		memcpy(buff, data, len);
453 		buff += len;
454 		MFREE(m, n);
455 	}
456 
457 	if (totlen > PAGE_SIZE)
458 		panic("%s: maceput: packet overflow", sc->sc_dev.dv_xname);
459 
460 #if 0
461 	if (totlen < ETHERMIN + sizeof(struct ether_header)) {
462 		int pad = ETHERMIN + sizeof(struct ether_header) - totlen;
463 		memset(sc->sc_txbuf + totlen, 0, pad);
464 		totlen = ETHERMIN + sizeof(struct ether_header);
465 	}
466 #endif
467 
468 	(*sc->sc_putpacket)(sc, totlen);
469 
470 	sc->sc_if.if_timer = 5;	/* 5 seconds to watch for failing to transmit */
471 	return (totlen);
472 }
473 
474 void
475 mcintr(void *arg)
476 {
477 struct mc_softc *sc = arg;
478 	u_int8_t ir;
479 
480 	ir = NIC_GET(sc, MACE_IR) & ~NIC_GET(sc, MACE_IMR);
481 	if (ir & JAB) {
482 #ifdef MCDEBUG
483 		printf("%s: jabber error\n", sc->sc_dev.dv_xname);
484 #endif
485 		sc->sc_if.if_oerrors++;
486 	}
487 
488 	if (ir & BABL) {
489 #ifdef MCDEBUG
490 		printf("%s: babble\n", sc->sc_dev.dv_xname);
491 #endif
492 		sc->sc_if.if_oerrors++;
493 	}
494 
495 	if (ir & CERR) {
496 #ifdef MCDEBUG
497 		printf("%s: collision error\n", sc->sc_dev.dv_xname);
498 #endif
499 		sc->sc_if.if_collisions++;
500 	}
501 
502 	/*
503 	 * Pretend we have carrier; if we don't this will be cleared
504 	 * shortly.
505 	 */
506 	sc->sc_havecarrier = 1;
507 
508 	if (ir & XMTINT)
509 		mc_tint(sc);
510 
511 	if (ir & RCVINT)
512 		mc_rint(sc);
513 }
514 
515 integrate void
516 mc_tint(struct mc_softc *sc)
517 {
518 	u_int8_t xmtrc, xmtfs;
519 
520 	xmtrc = NIC_GET(sc, MACE_XMTRC);
521 	xmtfs = NIC_GET(sc, MACE_XMTFS);
522 
523 	if ((xmtfs & XMTSV) == 0)
524 		return;
525 
526 	if (xmtfs & UFLO) {
527 		printf("%s: underflow\n", sc->sc_dev.dv_xname);
528 		mcreset(sc);
529 		return;
530 	}
531 
532 	if (xmtfs & LCOL) {
533 		printf("%s: late collision\n", sc->sc_dev.dv_xname);
534 		sc->sc_if.if_oerrors++;
535 		sc->sc_if.if_collisions++;
536 	}
537 
538 	if (xmtfs & MORE)
539 		/* Real number is unknown. */
540 		sc->sc_if.if_collisions += 2;
541 	else if (xmtfs & ONE)
542 		sc->sc_if.if_collisions++;
543 	else if (xmtfs & RTRY) {
544 		printf("%s: excessive collisions\n", sc->sc_dev.dv_xname);
545 		sc->sc_if.if_collisions += 16;
546 		sc->sc_if.if_oerrors++;
547 	}
548 
549 	if (xmtfs & LCAR) {
550 		sc->sc_havecarrier = 0;
551 		printf("%s: lost carrier\n", sc->sc_dev.dv_xname);
552 		sc->sc_if.if_oerrors++;
553 	}
554 
555 	sc->sc_if.if_flags &= ~IFF_OACTIVE;
556 	sc->sc_if.if_timer = 0;
557 	mcstart(&sc->sc_if);
558 }
559 
560 void
561 mc_rint(struct mc_softc *sc)
562 {
563 #define	rxf	sc->sc_rxframe
564 	u_int len;
565 
566 	len = (rxf.rx_rcvcnt | ((rxf.rx_rcvsts & 0xf) << 8)) - 4;
567 
568 #ifdef MCDEBUG
569 	if (rxf.rx_rcvsts & 0xf0)
570 		printf("%s: rcvcnt %02x rcvsts %02x rntpc 0x%02x rcvcc 0x%02x\n",
571 		    sc->sc_dev.dv_xname, rxf.rx_rcvcnt, rxf.rx_rcvsts,
572 		    rxf.rx_rntpc, rxf.rx_rcvcc);
573 #endif
574 
575 	if (rxf.rx_rcvsts & OFLO) {
576 		printf("%s: receive FIFO overflow\n", sc->sc_dev.dv_xname);
577 		sc->sc_if.if_ierrors++;
578 		return;
579 	}
580 
581 	if (rxf.rx_rcvsts & CLSN)
582 		sc->sc_if.if_collisions++;
583 
584 	if (rxf.rx_rcvsts & FRAM) {
585 #ifdef MCDEBUG
586 		printf("%s: framing error\n", sc->sc_dev.dv_xname);
587 #endif
588 		sc->sc_if.if_ierrors++;
589 		return;
590 	}
591 
592 	if (rxf.rx_rcvsts & FCS) {
593 #ifdef MCDEBUG
594 		printf("%s: frame control checksum error\n", sc->sc_dev.dv_xname);
595 #endif
596 		sc->sc_if.if_ierrors++;
597 		return;
598 	}
599 
600 	mace_read(sc, rxf.rx_frame, len);
601 #undef	rxf
602 }
603 
604 integrate void
605 mace_read(struct mc_softc *sc, caddr_t pkt, int len)
606 {
607 	struct ifnet *ifp = &sc->sc_if;
608 	struct mbuf *m;
609 
610 	if (len <= sizeof(struct ether_header) ||
611 	    len > ETHERMTU + sizeof(struct ether_header)) {
612 #ifdef MCDEBUG
613 		printf("%s: invalid packet size %d; dropping\n",
614 		    sc->sc_dev.dv_xname, len);
615 #endif
616 		ifp->if_ierrors++;
617 		return;
618 	}
619 
620 	m = mace_get(sc, pkt, len);
621 	if (m == NULL) {
622 		ifp->if_ierrors++;
623 		return;
624 	}
625 
626 	ifp->if_ipackets++;
627 
628 #if NBPFILTER > 0
629 	/* Pass the packet to any BPF listeners. */
630 	if (ifp->if_bpf)
631 		bpf_mtap(ifp->if_bpf, m);
632 #endif
633 
634 	/* Pass the packet up. */
635 	(*ifp->if_input)(ifp, m);
636 }
637 
638 /*
639  * Pull data off an interface.
640  * Len is length of data, with local net header stripped.
641  * We copy the data into mbufs.  When full cluster sized units are present
642  * we copy into clusters.
643  */
644 integrate struct mbuf *
645 mace_get(struct mc_softc *sc, caddr_t pkt, int totlen)
646 {
647 	struct mbuf *m;
648 	struct mbuf *top, **mp;
649 	int len;
650 
651 	MGETHDR(m, M_DONTWAIT, MT_DATA);
652 	if (m == 0)
653 		return (0);
654 	m->m_pkthdr.rcvif = &sc->sc_if;
655 	m->m_pkthdr.len = totlen;
656 	len = MHLEN;
657 	top = 0;
658 	mp = &top;
659 
660 	while (totlen > 0) {
661 		if (top) {
662 			MGET(m, M_DONTWAIT, MT_DATA);
663 			if (m == 0) {
664 				m_freem(top);
665 				return 0;
666 			}
667 			len = MLEN;
668 		}
669 		if (totlen >= MINCLSIZE) {
670 			MCLGET(m, M_DONTWAIT);
671 			if ((m->m_flags & M_EXT) == 0) {
672 				m_free(m);
673 				m_freem(top);
674 				return 0;
675 			}
676 			len = MCLBYTES;
677 		}
678 		m->m_len = len = min(totlen, len);
679 		memcpy(mtod(m, caddr_t), pkt, len);
680 		pkt += len;
681 		totlen -= len;
682 		*mp = m;
683 		mp = &m->m_next;
684 	}
685 
686 	return (top);
687 }
688 
689 /*
690  * Go through the list of multicast addresses and calculate the logical
691  * address filter.
692  */
693 void
694 mace_calcladrf(struct ethercom *ac, u_int8_t *af)
695 {
696 	struct ifnet *ifp = &ac->ec_if;
697 	struct ether_multi *enm;
698 	u_char *cp;
699 	u_int32_t crc;
700 	static const u_int32_t crctab[] = {
701 		0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
702 		0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
703 		0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
704 		0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
705 	};
706 	int len;
707 	struct ether_multistep step;
708 
709 	/*
710 	 * Set up multicast address filter by passing all multicast addresses
711 	 * through a crc generator, and then using the high order 6 bits as an
712 	 * index into the 64 bit logical address filter.  The high order bit
713 	 * selects the word, while the rest of the bits select the bit within
714 	 * the word.
715 	 */
716 
717 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0;
718 	ETHER_FIRST_MULTI(step, ac, enm);
719 	while (enm != NULL) {
720 		if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) {
721 			/*
722 			 * We must listen to a range of multicast addresses.
723 			 * For now, just accept all multicasts, rather than
724 			 * trying to set only those filter bits needed to match
725 			 * the range.  (At this time, the only use of address
726 			 * ranges is for IP multicast routing, for which the
727 			 * range is big enough to require all bits set.)
728 			 */
729 			goto allmulti;
730 		}
731 
732 		cp = enm->enm_addrlo;
733 		crc = 0xffffffff;
734 		for (len = sizeof(enm->enm_addrlo); --len >= 0;) {
735 			crc ^= *cp++;
736 			crc = (crc >> 4) ^ crctab[crc & 0xf];
737 			crc = (crc >> 4) ^ crctab[crc & 0xf];
738 		}
739 		/* Just want the 6 most significant bits. */
740 		crc >>= 26;
741 
742 		/* Set the corresponding bit in the filter. */
743 		af[crc >> 3] |= 1 << (crc & 7);
744 
745 		ETHER_NEXT_MULTI(step, enm);
746 	}
747 	ifp->if_flags &= ~IFF_ALLMULTI;
748 	return;
749 
750 allmulti:
751 	ifp->if_flags |= IFF_ALLMULTI;
752 	*((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0xffffffff;
753 }
754 
755 static u_char bbr4[] = {0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15};
756 #define bbr(v)  ((bbr4[(v)&0xf] << 4) | bbr4[((v)>>4) & 0xf])
757 
758 u_char
759 mc_get_enaddr(bus_space_tag_t t, bus_space_handle_t h, bus_size_t o,
760     u_char *dst)
761 {
762 	int	i;
763 	u_char	b, csum;
764 
765 	/*
766 	 * The XOR of the 8 bytes of the ROM must be 0xff for it to be
767 	 * valid
768 	*/
769 	for (i = 0, csum = 0; i < 8; i++) {
770 		b = bus_space_read_1(t, h, o+16*i);
771 		if (i < ETHER_ADDR_LEN)
772 			dst[i] = bbr(b);
773 		csum ^= b;
774 	}
775 
776 	return csum;
777 }
778