if_mc.c revision 1.28 1 /* $NetBSD: if_mc.c,v 1.28 2006/12/12 11:46:33 martin Exp $ */
2
3 /*-
4 * Copyright (c) 1997 David Huang <khym (at) azeotrope.org>
5 * All rights reserved.
6 *
7 * Portions of this code are based on code by Denton Gentry <denny1 (at) home.com>,
8 * Charles M. Hannum, Yanagisawa Takeshi <yanagisw (at) 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 1.28 2006/12/12 11:46:33 martin Exp $");
39
40 #include "opt_ddb.h"
41 #include "opt_inet.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 <uvm/uvm_extern.h>
55
56 #include <net/if.h>
57 #include <net/if_dl.h>
58 #include <net/if_ether.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
69
70 #include <uvm/uvm_extern.h>
71
72 #include "bpfilter.h"
73 #if NBPFILTER > 0
74 #include <net/bpf.h>
75 #include <net/bpfdesc.h>
76 #endif
77
78 #include <machine/bus.h>
79 #include <mac68k/dev/if_mcreg.h>
80 #include <mac68k/dev/if_mcvar.h>
81
82 hide void mcwatchdog(struct ifnet *);
83 hide int mcinit(struct mc_softc *);
84 hide int mcstop(struct mc_softc *);
85 hide int mcioctl(struct ifnet *, u_long, caddr_t);
86 hide void mcstart(struct ifnet *);
87 hide void mcreset(struct mc_softc *);
88
89 integrate u_int maceput(struct mc_softc *, struct mbuf *);
90 integrate void mc_tint(struct mc_softc *);
91 integrate void mace_read(struct mc_softc *, caddr_t, int);
92 integrate struct mbuf *mace_get(struct mc_softc *, caddr_t, int);
93 static void mace_calcladrf(struct ethercom *, u_int8_t *);
94 static inline u_int16_t ether_cmp(void *, void *);
95
96
97 /*
98 * Compare two Ether/802 addresses for equality, inlined and
99 * unrolled for speed. Use this like bcmp().
100 *
101 * XXX: Add <machine/inlines.h> for stuff like this?
102 * XXX: or maybe add it to libkern.h instead?
103 *
104 * "I'd love to have an inline assembler version of this."
105 * XXX: Who wanted that? mycroft? I wrote one, but this
106 * version in C is as good as hand-coded assembly. -gwr
107 *
108 * Please do NOT tweak this without looking at the actual
109 * assembly code generated before and after your tweaks!
110 */
111 static inline u_int16_t
112 ether_cmp(void *one, void *two)
113 {
114 u_int16_t *a = (u_short *) one;
115 u_int16_t *b = (u_short *) two;
116 u_int16_t diff;
117
118 #ifdef m68k
119 /*
120 * The post-increment-pointer form produces the best
121 * machine code for m68k. This was carefully tuned
122 * so it compiles to just 8 short (2-byte) op-codes!
123 */
124 diff = *a++ - *b++;
125 diff |= *a++ - *b++;
126 diff |= *a++ - *b++;
127 #else
128 /*
129 * Most modern CPUs do better with a single expresion.
130 * Note that short-cut evaluation is NOT helpful here,
131 * because it just makes the code longer, not faster!
132 */
133 diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]);
134 #endif
135
136 return (diff);
137 }
138
139 #define ETHER_CMP ether_cmp
140
141 /*
142 * Interface exists: make available by filling in network interface
143 * record. System will initialize the interface when it is ready
144 * to accept packets.
145 */
146 int
147 mcsetup(struct mc_softc *sc, u_int8_t *lladdr)
148 {
149 struct ifnet *ifp = &sc->sc_if;
150
151 /* reset the chip and disable all interrupts */
152 NIC_PUT(sc, MACE_BIUCC, SWRST);
153 DELAY(100);
154 NIC_PUT(sc, MACE_IMR, ~0);
155
156 memcpy(sc->sc_enaddr, lladdr, ETHER_ADDR_LEN);
157 printf(": address %s\n", ether_sprintf(lladdr));
158
159 memcpy(ifp->if_xname, sc->sc_dev.dv_xname, IFNAMSIZ);
160 ifp->if_softc = sc;
161 ifp->if_ioctl = mcioctl;
162 ifp->if_start = mcstart;
163 ifp->if_flags =
164 IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS | IFF_MULTICAST;
165 ifp->if_watchdog = mcwatchdog;
166
167 if_attach(ifp);
168 ether_ifattach(ifp, lladdr);
169
170 return (0);
171 }
172
173 hide int
174 mcioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
175 {
176 struct mc_softc *sc = ifp->if_softc;
177 struct ifaddr *ifa;
178 struct ifreq *ifr;
179
180 int s = splnet(), err = 0;
181
182 switch (cmd) {
183
184 case SIOCSIFADDR:
185 ifa = (struct ifaddr *)data;
186 ifp->if_flags |= IFF_UP;
187 switch (ifa->ifa_addr->sa_family) {
188 #ifdef INET
189 case AF_INET:
190 mcinit(sc);
191 arp_ifinit(ifp, ifa);
192 break;
193 #endif
194 default:
195 mcinit(sc);
196 break;
197 }
198 break;
199
200 case SIOCSIFFLAGS:
201 if ((ifp->if_flags & IFF_UP) == 0 &&
202 (ifp->if_flags & IFF_RUNNING) != 0) {
203 /*
204 * If interface is marked down and it is running,
205 * then stop it.
206 */
207 mcstop(sc);
208 ifp->if_flags &= ~IFF_RUNNING;
209 } else if ((ifp->if_flags & IFF_UP) != 0 &&
210 (ifp->if_flags & IFF_RUNNING) == 0) {
211 /*
212 * If interface is marked up and it is stopped,
213 * then start it.
214 */
215 (void)mcinit(sc);
216 } else {
217 /*
218 * reset the interface to pick up any other changes
219 * in flags
220 */
221 mcreset(sc);
222 mcstart(ifp);
223 }
224 break;
225
226 case SIOCADDMULTI:
227 case SIOCDELMULTI:
228 ifr = (struct ifreq *) data;
229 err = (cmd == SIOCADDMULTI) ?
230 ether_addmulti(ifr, &sc->sc_ethercom) :
231 ether_delmulti(ifr, &sc->sc_ethercom);
232
233 if (err == ENETRESET) {
234 /*
235 * Multicast list has changed; set the hardware
236 * filter accordingly. But remember UP flag!
237 */
238 if (ifp->if_flags & IFF_RUNNING)
239 mcreset(sc);
240 err = 0;
241 }
242 break;
243 default:
244 err = EINVAL;
245 }
246 splx(s);
247 return (err);
248 }
249
250 /*
251 * Encapsulate a packet of type family for the local net.
252 */
253 hide void
254 mcstart(struct ifnet *ifp)
255 {
256 struct mc_softc *sc = ifp->if_softc;
257 struct mbuf *m;
258
259 if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
260 return;
261
262 while (1) {
263 if (ifp->if_flags & IFF_OACTIVE)
264 return;
265
266 IF_DEQUEUE(&ifp->if_snd, m);
267 if (m == 0)
268 return;
269
270 #if NBPFILTER > 0
271 /*
272 * If bpf is listening on this interface, let it
273 * see the packet before we commit it to the wire.
274 */
275 if (ifp->if_bpf)
276 bpf_mtap(ifp->if_bpf, m);
277 #endif
278
279 /*
280 * Copy the mbuf chain into the transmit buffer.
281 */
282 ifp->if_flags |= IFF_OACTIVE;
283 maceput(sc, m);
284
285 ifp->if_opackets++; /* # of pkts */
286 }
287 }
288
289 /*
290 * reset and restart the MACE. Called in case of fatal
291 * hardware/software errors.
292 */
293 hide void
294 mcreset(struct mc_softc *sc)
295 {
296 mcstop(sc);
297 mcinit(sc);
298 }
299
300 hide int
301 mcinit(struct mc_softc *sc)
302 {
303 int s;
304 u_int8_t maccc, ladrf[8];
305
306 if (sc->sc_if.if_flags & IFF_RUNNING)
307 /* already running */
308 return (0);
309
310 s = splnet();
311
312 NIC_PUT(sc, MACE_BIUCC, sc->sc_biucc);
313 NIC_PUT(sc, MACE_FIFOCC, sc->sc_fifocc);
314 NIC_PUT(sc, MACE_IMR, ~0); /* disable all interrupts */
315 NIC_PUT(sc, MACE_PLSCC, sc->sc_plscc);
316
317 NIC_PUT(sc, MACE_UTR, RTRD); /* disable reserved test registers */
318
319 /* set MAC address */
320 NIC_PUT(sc, MACE_IAC, ADDRCHG);
321 while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
322 ;
323 NIC_PUT(sc, MACE_IAC, PHYADDR);
324 bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_PADR),
325 sc->sc_enaddr, ETHER_ADDR_LEN);
326
327 /* set logical address filter */
328 mace_calcladrf(&sc->sc_ethercom, ladrf);
329
330 NIC_PUT(sc, MACE_IAC, ADDRCHG);
331 while (NIC_GET(sc, MACE_IAC) & ADDRCHG)
332 ;
333 NIC_PUT(sc, MACE_IAC, LOGADDR);
334 bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_LADRF),
335 ladrf, 8);
336
337 NIC_PUT(sc, MACE_XMTFC, APADXMT);
338 /*
339 * No need to autostrip padding on receive... Ethernet frames
340 * don't have a length field, unlike 802.3 frames, so the MACE
341 * can't figure out the length of the packet anyways.
342 */
343 NIC_PUT(sc, MACE_RCVFC, 0);
344
345 maccc = ENXMT | ENRCV;
346 if (sc->sc_if.if_flags & IFF_PROMISC)
347 maccc |= PROM;
348
349 NIC_PUT(sc, MACE_MACCC, maccc);
350
351 if (sc->sc_bus_init)
352 (*sc->sc_bus_init)(sc);
353
354 /*
355 * Enable all interrupts except receive, since we use the DMA
356 * completion interrupt for that.
357 */
358 NIC_PUT(sc, MACE_IMR, RCVINTM);
359
360 /* flag interface as "running" */
361 sc->sc_if.if_flags |= IFF_RUNNING;
362 sc->sc_if.if_flags &= ~IFF_OACTIVE;
363
364 splx(s);
365 return (0);
366 }
367
368 /*
369 * close down an interface and free its buffers
370 * Called on final close of device, or if mcinit() fails
371 * part way through.
372 */
373 hide int
374 mcstop(struct mc_softc *sc)
375 {
376 int s;
377
378 s = splnet();
379
380 NIC_PUT(sc, MACE_BIUCC, SWRST);
381 DELAY(100);
382
383 sc->sc_if.if_timer = 0;
384 sc->sc_if.if_flags &= ~IFF_RUNNING;
385
386 splx(s);
387 return (0);
388 }
389
390 /*
391 * Called if any Tx packets remain unsent after 5 seconds,
392 * In all cases we just reset the chip, and any retransmission
393 * will be handled by higher level protocol timeouts.
394 */
395 hide void
396 mcwatchdog(struct ifnet *ifp)
397 {
398 struct mc_softc *sc = ifp->if_softc;
399
400 printf("mcwatchdog: resetting chip\n");
401 mcreset(sc);
402 }
403
404 /*
405 * stuff packet into MACE (at splnet)
406 */
407 integrate u_int
408 maceput(struct mc_softc *sc, struct mbuf *m)
409 {
410 struct mbuf *n;
411 u_int len, totlen = 0;
412 u_char *buff;
413
414 buff = sc->sc_txbuf + (sc->sc_txset == 0 ? 0 : 0x800);
415
416 for (; m; m = n) {
417 u_char *data = mtod(m, u_char *);
418 len = m->m_len;
419 totlen += len;
420 memcpy(buff, data, len);
421 buff += len;
422 MFREE(m, n);
423 }
424
425 if (totlen > PAGE_SIZE)
426 panic("%s: maceput: packet overflow", sc->sc_dev.dv_xname);
427
428 #if 0
429 if (totlen < ETHERMIN + sizeof(struct ether_header)) {
430 int pad = ETHERMIN + sizeof(struct ether_header) - totlen;
431 memset(sc->sc_txbuf + totlen, 0, pad);
432 totlen = ETHERMIN + sizeof(struct ether_header);
433 }
434 #endif
435
436 (*sc->sc_putpacket)(sc, totlen);
437
438 sc->sc_if.if_timer = 5; /* 5 seconds to watch for failing to transmit */
439 return (totlen);
440 }
441
442 void
443 mcintr(void *arg)
444 {
445 struct mc_softc *sc = arg;
446 u_int8_t ir;
447
448 ir = NIC_GET(sc, MACE_IR) & ~NIC_GET(sc, MACE_IMR);
449 if (ir & JAB) {
450 #ifdef MCDEBUG
451 printf("%s: jabber error\n", sc->sc_dev.dv_xname);
452 #endif
453 sc->sc_if.if_oerrors++;
454 }
455
456 if (ir & BABL) {
457 #ifdef MCDEBUG
458 printf("%s: babble\n", sc->sc_dev.dv_xname);
459 #endif
460 sc->sc_if.if_oerrors++;
461 }
462
463 if (ir & CERR) {
464 #ifdef MCDEBUG
465 printf("%s: collision error\n", sc->sc_dev.dv_xname);
466 #endif
467 sc->sc_if.if_collisions++;
468 }
469
470 /*
471 * Pretend we have carrier; if we don't this will be cleared
472 * shortly.
473 */
474 sc->sc_havecarrier = 1;
475
476 if (ir & XMTINT)
477 mc_tint(sc);
478
479 if (ir & RCVINT)
480 mc_rint(sc);
481 }
482
483 integrate void
484 mc_tint(struct mc_softc *sc)
485 {
486 u_int8_t xmtrc, xmtfs;
487
488 xmtrc = NIC_GET(sc, MACE_XMTRC);
489 xmtfs = NIC_GET(sc, MACE_XMTFS);
490
491 if ((xmtfs & XMTSV) == 0)
492 return;
493
494 if (xmtfs & UFLO) {
495 printf("%s: underflow\n", sc->sc_dev.dv_xname);
496 mcreset(sc);
497 return;
498 }
499
500 if (xmtfs & LCOL) {
501 printf("%s: late collision\n", sc->sc_dev.dv_xname);
502 sc->sc_if.if_oerrors++;
503 sc->sc_if.if_collisions++;
504 }
505
506 if (xmtfs & MORE)
507 /* Real number is unknown. */
508 sc->sc_if.if_collisions += 2;
509 else if (xmtfs & ONE)
510 sc->sc_if.if_collisions++;
511 else if (xmtfs & RTRY) {
512 printf("%s: excessive collisions\n", sc->sc_dev.dv_xname);
513 sc->sc_if.if_collisions += 16;
514 sc->sc_if.if_oerrors++;
515 }
516
517 if (xmtfs & LCAR) {
518 sc->sc_havecarrier = 0;
519 printf("%s: lost carrier\n", sc->sc_dev.dv_xname);
520 sc->sc_if.if_oerrors++;
521 }
522
523 sc->sc_if.if_flags &= ~IFF_OACTIVE;
524 sc->sc_if.if_timer = 0;
525 mcstart(&sc->sc_if);
526 }
527
528 void
529 mc_rint(struct mc_softc *sc)
530 {
531 #define rxf sc->sc_rxframe
532 u_int len;
533
534 len = (rxf.rx_rcvcnt | ((rxf.rx_rcvsts & 0xf) << 8)) - 4;
535
536 #ifdef MCDEBUG
537 if (rxf.rx_rcvsts & 0xf0)
538 printf("%s: rcvcnt %02x rcvsts %02x rntpc 0x%02x rcvcc 0x%02x\n",
539 sc->sc_dev.dv_xname, rxf.rx_rcvcnt, rxf.rx_rcvsts,
540 rxf.rx_rntpc, rxf.rx_rcvcc);
541 #endif
542
543 if (rxf.rx_rcvsts & OFLO) {
544 printf("%s: receive FIFO overflow\n", sc->sc_dev.dv_xname);
545 sc->sc_if.if_ierrors++;
546 return;
547 }
548
549 if (rxf.rx_rcvsts & CLSN)
550 sc->sc_if.if_collisions++;
551
552 if (rxf.rx_rcvsts & FRAM) {
553 #ifdef MCDEBUG
554 printf("%s: framing error\n", sc->sc_dev.dv_xname);
555 #endif
556 sc->sc_if.if_ierrors++;
557 return;
558 }
559
560 if (rxf.rx_rcvsts & FCS) {
561 #ifdef MCDEBUG
562 printf("%s: frame control checksum error\n", sc->sc_dev.dv_xname);
563 #endif
564 sc->sc_if.if_ierrors++;
565 return;
566 }
567
568 mace_read(sc, rxf.rx_frame, len);
569 #undef rxf
570 }
571
572 integrate void
573 mace_read(struct mc_softc *sc, caddr_t pkt, int len)
574 {
575 struct ifnet *ifp = &sc->sc_if;
576 struct mbuf *m;
577
578 if (len <= sizeof(struct ether_header) ||
579 len > ETHERMTU + sizeof(struct ether_header)) {
580 #ifdef MCDEBUG
581 printf("%s: invalid packet size %d; dropping\n",
582 sc->sc_dev.dv_xname, len);
583 #endif
584 ifp->if_ierrors++;
585 return;
586 }
587
588 m = mace_get(sc, pkt, len);
589 if (m == NULL) {
590 ifp->if_ierrors++;
591 return;
592 }
593
594 ifp->if_ipackets++;
595
596 #if NBPFILTER > 0
597 /* Pass the packet to any BPF listeners. */
598 if (ifp->if_bpf)
599 bpf_mtap(ifp->if_bpf, m);
600 #endif
601
602 /* Pass the packet up. */
603 (*ifp->if_input)(ifp, m);
604 }
605
606 /*
607 * Pull data off an interface.
608 * Len is length of data, with local net header stripped.
609 * We copy the data into mbufs. When full cluster sized units are present
610 * we copy into clusters.
611 */
612 integrate struct mbuf *
613 mace_get(struct mc_softc *sc, caddr_t pkt, int totlen)
614 {
615 struct mbuf *m;
616 struct mbuf *top, **mp;
617 int len;
618
619 MGETHDR(m, M_DONTWAIT, MT_DATA);
620 if (m == 0)
621 return (0);
622 m->m_pkthdr.rcvif = &sc->sc_if;
623 m->m_pkthdr.len = totlen;
624 len = MHLEN;
625 top = 0;
626 mp = ⊤
627
628 while (totlen > 0) {
629 if (top) {
630 MGET(m, M_DONTWAIT, MT_DATA);
631 if (m == 0) {
632 m_freem(top);
633 return 0;
634 }
635 len = MLEN;
636 }
637 if (totlen >= MINCLSIZE) {
638 MCLGET(m, M_DONTWAIT);
639 if ((m->m_flags & M_EXT) == 0) {
640 m_free(m);
641 m_freem(top);
642 return 0;
643 }
644 len = MCLBYTES;
645 }
646 m->m_len = len = min(totlen, len);
647 memcpy(mtod(m, caddr_t), pkt, len);
648 pkt += len;
649 totlen -= len;
650 *mp = m;
651 mp = &m->m_next;
652 }
653
654 return (top);
655 }
656
657 /*
658 * Go through the list of multicast addresses and calculate the logical
659 * address filter.
660 */
661 void
662 mace_calcladrf(struct ethercom *ac, u_int8_t *af)
663 {
664 struct ifnet *ifp = &ac->ec_if;
665 struct ether_multi *enm;
666 u_char *cp;
667 u_int32_t crc;
668 static const u_int32_t crctab[] = {
669 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
670 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
671 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
672 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
673 };
674 int len;
675 struct ether_multistep step;
676
677 /*
678 * Set up multicast address filter by passing all multicast addresses
679 * through a crc generator, and then using the high order 6 bits as an
680 * index into the 64 bit logical address filter. The high order bit
681 * selects the word, while the rest of the bits select the bit within
682 * the word.
683 */
684
685 *((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0;
686 ETHER_FIRST_MULTI(step, ac, enm);
687 while (enm != NULL) {
688 if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) {
689 /*
690 * We must listen to a range of multicast addresses.
691 * For now, just accept all multicasts, rather than
692 * trying to set only those filter bits needed to match
693 * the range. (At this time, the only use of address
694 * ranges is for IP multicast routing, for which the
695 * range is big enough to require all bits set.)
696 */
697 goto allmulti;
698 }
699
700 cp = enm->enm_addrlo;
701 crc = 0xffffffff;
702 for (len = sizeof(enm->enm_addrlo); --len >= 0;) {
703 crc ^= *cp++;
704 crc = (crc >> 4) ^ crctab[crc & 0xf];
705 crc = (crc >> 4) ^ crctab[crc & 0xf];
706 }
707 /* Just want the 6 most significant bits. */
708 crc >>= 26;
709
710 /* Set the corresponding bit in the filter. */
711 af[crc >> 3] |= 1 << (crc & 7);
712
713 ETHER_NEXT_MULTI(step, enm);
714 }
715 ifp->if_flags &= ~IFF_ALLMULTI;
716 return;
717
718 allmulti:
719 ifp->if_flags |= IFF_ALLMULTI;
720 *((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0xffffffff;
721 }
722
723 static u_char bbr4[] = {0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15};
724 #define bbr(v) ((bbr4[(v)&0xf] << 4) | bbr4[((v)>>4) & 0xf])
725
726 u_char
727 mc_get_enaddr(bus_space_tag_t t, bus_space_handle_t h, bus_size_t o,
728 u_char *dst)
729 {
730 int i;
731 u_char b, csum;
732
733 /*
734 * The XOR of the 8 bytes of the ROM must be 0xff for it to be
735 * valid
736 */
737 for (i = 0, csum = 0; i < 8; i++) {
738 b = bus_space_read_1(t, h, o+16*i);
739 if (i < ETHER_ADDR_LEN)
740 dst[i] = bbr(b);
741 csum ^= b;
742 }
743
744 return csum;
745 }
746