1 /* $NetBSD: if_mc.c,v 1.34 2007/10/17 19:55:13 garbled 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 1.34 2007/10/17 19:55:13 garbled 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 "bpfilter.h" 71 #if NBPFILTER > 0 72 #include <net/bpf.h> 73 #include <net/bpfdesc.h> 74 #endif 75 76 #include <machine/bus.h> 77 #include <mac68k/dev/if_mcreg.h> 78 #include <mac68k/dev/if_mcvar.h> 79 80 hide void mcwatchdog(struct ifnet *); 81 hide int mcinit(struct mc_softc *); 82 hide int mcstop(struct mc_softc *); 83 hide int mcioctl(struct ifnet *, u_long, void *); 84 hide void mcstart(struct ifnet *); 85 hide void mcreset(struct mc_softc *); 86 87 integrate u_int maceput(struct mc_softc *, struct mbuf *); 88 integrate void mc_tint(struct mc_softc *); 89 integrate void mace_read(struct mc_softc *, void *, int); 90 integrate struct mbuf *mace_get(struct mc_softc *, void *, int); 91 static void mace_calcladrf(struct ethercom *, u_int8_t *); 92 static inline u_int16_t ether_cmp(void *, void *); 93 94 95 /* 96 * Compare two Ether/802 addresses for equality, inlined and 97 * unrolled for speed. Use this like bcmp(). 98 * 99 * XXX: Add <machine/inlines.h> for stuff like this? 100 * XXX: or maybe add it to libkern.h instead? 101 * 102 * "I'd love to have an inline assembler version of this." 103 * XXX: Who wanted that? mycroft? I wrote one, but this 104 * version in C is as good as hand-coded assembly. -gwr 105 * 106 * Please do NOT tweak this without looking at the actual 107 * assembly code generated before and after your tweaks! 108 */ 109 static inline u_int16_t 110 ether_cmp(void *one, void *two) 111 { 112 u_int16_t *a = (u_short *) one; 113 u_int16_t *b = (u_short *) two; 114 u_int16_t diff; 115 116 #ifdef m68k 117 /* 118 * The post-increment-pointer form produces the best 119 * machine code for m68k. This was carefully tuned 120 * so it compiles to just 8 short (2-byte) op-codes! 121 */ 122 diff = *a++ - *b++; 123 diff |= *a++ - *b++; 124 diff |= *a++ - *b++; 125 #else 126 /* 127 * Most modern CPUs do better with a single expresion. 128 * Note that short-cut evaluation is NOT helpful here, 129 * because it just makes the code longer, not faster! 130 */ 131 diff = (a[0] - b[0]) | (a[1] - b[1]) | (a[2] - b[2]); 132 #endif 133 134 return (diff); 135 } 136 137 #define ETHER_CMP ether_cmp 138 139 /* 140 * Interface exists: make available by filling in network interface 141 * record. System will initialize the interface when it is ready 142 * to accept packets. 143 */ 144 int 145 mcsetup(struct mc_softc *sc, u_int8_t *lladdr) 146 { 147 struct ifnet *ifp = &sc->sc_if; 148 149 /* reset the chip and disable all interrupts */ 150 NIC_PUT(sc, MACE_BIUCC, SWRST); 151 DELAY(100); 152 NIC_PUT(sc, MACE_IMR, ~0); 153 154 memcpy(sc->sc_enaddr, lladdr, ETHER_ADDR_LEN); 155 printf(": address %s\n", ether_sprintf(lladdr)); 156 157 memcpy(ifp->if_xname, sc->sc_dev.dv_xname, IFNAMSIZ); 158 ifp->if_softc = sc; 159 ifp->if_ioctl = mcioctl; 160 ifp->if_start = mcstart; 161 ifp->if_flags = 162 IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS | IFF_MULTICAST; 163 ifp->if_watchdog = mcwatchdog; 164 165 if_attach(ifp); 166 ether_ifattach(ifp, lladdr); 167 168 return (0); 169 } 170 171 hide int 172 mcioctl(struct ifnet *ifp, u_long cmd, void *data) 173 { 174 struct mc_softc *sc = ifp->if_softc; 175 struct ifaddr *ifa; 176 177 int s = splnet(), err = 0; 178 179 switch (cmd) { 180 181 case SIOCSIFADDR: 182 ifa = (struct ifaddr *)data; 183 ifp->if_flags |= IFF_UP; 184 switch (ifa->ifa_addr->sa_family) { 185 #ifdef INET 186 case AF_INET: 187 mcinit(sc); 188 arp_ifinit(ifp, ifa); 189 break; 190 #endif 191 default: 192 mcinit(sc); 193 break; 194 } 195 break; 196 197 case SIOCSIFFLAGS: 198 if ((ifp->if_flags & IFF_UP) == 0 && 199 (ifp->if_flags & IFF_RUNNING) != 0) { 200 /* 201 * If interface is marked down and it is running, 202 * then stop it. 203 */ 204 mcstop(sc); 205 ifp->if_flags &= ~IFF_RUNNING; 206 } else if ((ifp->if_flags & IFF_UP) != 0 && 207 (ifp->if_flags & IFF_RUNNING) == 0) { 208 /* 209 * If interface is marked up and it is stopped, 210 * then start it. 211 */ 212 (void)mcinit(sc); 213 } else { 214 /* 215 * reset the interface to pick up any other changes 216 * in flags 217 */ 218 mcreset(sc); 219 mcstart(ifp); 220 } 221 break; 222 223 case SIOCADDMULTI: 224 case SIOCDELMULTI: 225 if ((err = ether_ioctl(ifp, cmd, data)) == ENETRESET) { 226 /* 227 * Multicast list has changed; set the hardware 228 * filter accordingly. But remember UP flag! 229 */ 230 if (ifp->if_flags & IFF_RUNNING) 231 mcreset(sc); 232 err = 0; 233 } 234 break; 235 default: 236 err = EINVAL; 237 } 238 splx(s); 239 return (err); 240 } 241 242 /* 243 * Encapsulate a packet of type family for the local net. 244 */ 245 hide void 246 mcstart(struct ifnet *ifp) 247 { 248 struct mc_softc *sc = ifp->if_softc; 249 struct mbuf *m; 250 251 if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING) 252 return; 253 254 while (1) { 255 if (ifp->if_flags & IFF_OACTIVE) 256 return; 257 258 IF_DEQUEUE(&ifp->if_snd, m); 259 if (m == 0) 260 return; 261 262 #if NBPFILTER > 0 263 /* 264 * If bpf is listening on this interface, let it 265 * see the packet before we commit it to the wire. 266 */ 267 if (ifp->if_bpf) 268 bpf_mtap(ifp->if_bpf, m); 269 #endif 270 271 /* 272 * Copy the mbuf chain into the transmit buffer. 273 */ 274 ifp->if_flags |= IFF_OACTIVE; 275 maceput(sc, m); 276 277 ifp->if_opackets++; /* # of pkts */ 278 } 279 } 280 281 /* 282 * reset and restart the MACE. Called in case of fatal 283 * hardware/software errors. 284 */ 285 hide void 286 mcreset(struct mc_softc *sc) 287 { 288 mcstop(sc); 289 mcinit(sc); 290 } 291 292 hide int 293 mcinit(struct mc_softc *sc) 294 { 295 int s; 296 u_int8_t maccc, ladrf[8]; 297 298 if (sc->sc_if.if_flags & IFF_RUNNING) 299 /* already running */ 300 return (0); 301 302 s = splnet(); 303 304 NIC_PUT(sc, MACE_BIUCC, sc->sc_biucc); 305 NIC_PUT(sc, MACE_FIFOCC, sc->sc_fifocc); 306 NIC_PUT(sc, MACE_IMR, ~0); /* disable all interrupts */ 307 NIC_PUT(sc, MACE_PLSCC, sc->sc_plscc); 308 309 NIC_PUT(sc, MACE_UTR, RTRD); /* disable reserved test registers */ 310 311 /* set MAC address */ 312 NIC_PUT(sc, MACE_IAC, ADDRCHG); 313 while (NIC_GET(sc, MACE_IAC) & ADDRCHG) 314 ; 315 NIC_PUT(sc, MACE_IAC, PHYADDR); 316 bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_PADR), 317 sc->sc_enaddr, ETHER_ADDR_LEN); 318 319 /* set logical address filter */ 320 mace_calcladrf(&sc->sc_ethercom, ladrf); 321 322 NIC_PUT(sc, MACE_IAC, ADDRCHG); 323 while (NIC_GET(sc, MACE_IAC) & ADDRCHG) 324 ; 325 NIC_PUT(sc, MACE_IAC, LOGADDR); 326 bus_space_write_multi_1(sc->sc_regt, sc->sc_regh, MACE_REG(MACE_LADRF), 327 ladrf, 8); 328 329 NIC_PUT(sc, MACE_XMTFC, APADXMT); 330 /* 331 * No need to autostrip padding on receive... Ethernet frames 332 * don't have a length field, unlike 802.3 frames, so the MACE 333 * can't figure out the length of the packet anyways. 334 */ 335 NIC_PUT(sc, MACE_RCVFC, 0); 336 337 maccc = ENXMT | ENRCV; 338 if (sc->sc_if.if_flags & IFF_PROMISC) 339 maccc |= PROM; 340 341 NIC_PUT(sc, MACE_MACCC, maccc); 342 343 if (sc->sc_bus_init) 344 (*sc->sc_bus_init)(sc); 345 346 /* 347 * Enable all interrupts except receive, since we use the DMA 348 * completion interrupt for that. 349 */ 350 NIC_PUT(sc, MACE_IMR, RCVINTM); 351 352 /* flag interface as "running" */ 353 sc->sc_if.if_flags |= IFF_RUNNING; 354 sc->sc_if.if_flags &= ~IFF_OACTIVE; 355 356 splx(s); 357 return (0); 358 } 359 360 /* 361 * close down an interface and free its buffers 362 * Called on final close of device, or if mcinit() fails 363 * part way through. 364 */ 365 hide int 366 mcstop(struct mc_softc *sc) 367 { 368 int s; 369 370 s = splnet(); 371 372 NIC_PUT(sc, MACE_BIUCC, SWRST); 373 DELAY(100); 374 375 sc->sc_if.if_timer = 0; 376 sc->sc_if.if_flags &= ~IFF_RUNNING; 377 378 splx(s); 379 return (0); 380 } 381 382 /* 383 * Called if any Tx packets remain unsent after 5 seconds, 384 * In all cases we just reset the chip, and any retransmission 385 * will be handled by higher level protocol timeouts. 386 */ 387 hide void 388 mcwatchdog(struct ifnet *ifp) 389 { 390 struct mc_softc *sc = ifp->if_softc; 391 392 printf("mcwatchdog: resetting chip\n"); 393 mcreset(sc); 394 } 395 396 /* 397 * stuff packet into MACE (at splnet) 398 */ 399 integrate u_int 400 maceput(struct mc_softc *sc, struct mbuf *m) 401 { 402 struct mbuf *n; 403 u_int len, totlen = 0; 404 u_char *buff; 405 406 buff = (u_char*)sc->sc_txbuf + (sc->sc_txset == 0 ? 0 : 0x800); 407 408 for (; m; m = n) { 409 u_char *data = mtod(m, u_char *); 410 len = m->m_len; 411 totlen += len; 412 memcpy(buff, data, len); 413 buff += len; 414 MFREE(m, n); 415 } 416 417 if (totlen > PAGE_SIZE) 418 panic("%s: maceput: packet overflow", sc->sc_dev.dv_xname); 419 420 #if 0 421 if (totlen < ETHERMIN + sizeof(struct ether_header)) { 422 int pad = ETHERMIN + sizeof(struct ether_header) - totlen; 423 memset(sc->sc_txbuf + totlen, 0, pad); 424 totlen = ETHERMIN + sizeof(struct ether_header); 425 } 426 #endif 427 428 (*sc->sc_putpacket)(sc, totlen); 429 430 sc->sc_if.if_timer = 5; /* 5 seconds to watch for failing to transmit */ 431 return (totlen); 432 } 433 434 void 435 mcintr(void *arg) 436 { 437 struct mc_softc *sc = arg; 438 u_int8_t ir; 439 440 ir = NIC_GET(sc, MACE_IR) & ~NIC_GET(sc, MACE_IMR); 441 if (ir & JAB) { 442 #ifdef MCDEBUG 443 printf("%s: jabber error\n", sc->sc_dev.dv_xname); 444 #endif 445 sc->sc_if.if_oerrors++; 446 } 447 448 if (ir & BABL) { 449 #ifdef MCDEBUG 450 printf("%s: babble\n", sc->sc_dev.dv_xname); 451 #endif 452 sc->sc_if.if_oerrors++; 453 } 454 455 if (ir & CERR) { 456 #ifdef MCDEBUG 457 printf("%s: collision error\n", sc->sc_dev.dv_xname); 458 #endif 459 sc->sc_if.if_collisions++; 460 } 461 462 /* 463 * Pretend we have carrier; if we don't this will be cleared 464 * shortly. 465 */ 466 sc->sc_havecarrier = 1; 467 468 if (ir & XMTINT) 469 mc_tint(sc); 470 471 if (ir & RCVINT) 472 mc_rint(sc); 473 } 474 475 integrate void 476 mc_tint(struct mc_softc *sc) 477 { 478 u_int8_t xmtrc, xmtfs; 479 480 xmtrc = NIC_GET(sc, MACE_XMTRC); 481 xmtfs = NIC_GET(sc, MACE_XMTFS); 482 483 if ((xmtfs & XMTSV) == 0) 484 return; 485 486 if (xmtfs & UFLO) { 487 printf("%s: underflow\n", sc->sc_dev.dv_xname); 488 mcreset(sc); 489 return; 490 } 491 492 if (xmtfs & LCOL) { 493 printf("%s: late collision\n", sc->sc_dev.dv_xname); 494 sc->sc_if.if_oerrors++; 495 sc->sc_if.if_collisions++; 496 } 497 498 if (xmtfs & MORE) 499 /* Real number is unknown. */ 500 sc->sc_if.if_collisions += 2; 501 else if (xmtfs & ONE) 502 sc->sc_if.if_collisions++; 503 else if (xmtfs & RTRY) { 504 printf("%s: excessive collisions\n", sc->sc_dev.dv_xname); 505 sc->sc_if.if_collisions += 16; 506 sc->sc_if.if_oerrors++; 507 } 508 509 if (xmtfs & LCAR) { 510 sc->sc_havecarrier = 0; 511 printf("%s: lost carrier\n", sc->sc_dev.dv_xname); 512 sc->sc_if.if_oerrors++; 513 } 514 515 sc->sc_if.if_flags &= ~IFF_OACTIVE; 516 sc->sc_if.if_timer = 0; 517 mcstart(&sc->sc_if); 518 } 519 520 void 521 mc_rint(struct mc_softc *sc) 522 { 523 #define rxf sc->sc_rxframe 524 u_int len; 525 526 len = (rxf.rx_rcvcnt | ((rxf.rx_rcvsts & 0xf) << 8)) - 4; 527 528 #ifdef MCDEBUG 529 if (rxf.rx_rcvsts & 0xf0) 530 printf("%s: rcvcnt %02x rcvsts %02x rntpc 0x%02x rcvcc 0x%02x\n", 531 sc->sc_dev.dv_xname, rxf.rx_rcvcnt, rxf.rx_rcvsts, 532 rxf.rx_rntpc, rxf.rx_rcvcc); 533 #endif 534 535 if (rxf.rx_rcvsts & OFLO) { 536 printf("%s: receive FIFO overflow\n", sc->sc_dev.dv_xname); 537 sc->sc_if.if_ierrors++; 538 return; 539 } 540 541 if (rxf.rx_rcvsts & CLSN) 542 sc->sc_if.if_collisions++; 543 544 if (rxf.rx_rcvsts & FRAM) { 545 #ifdef MCDEBUG 546 printf("%s: framing error\n", sc->sc_dev.dv_xname); 547 #endif 548 sc->sc_if.if_ierrors++; 549 return; 550 } 551 552 if (rxf.rx_rcvsts & FCS) { 553 #ifdef MCDEBUG 554 printf("%s: frame control checksum error\n", sc->sc_dev.dv_xname); 555 #endif 556 sc->sc_if.if_ierrors++; 557 return; 558 } 559 560 mace_read(sc, rxf.rx_frame, len); 561 #undef rxf 562 } 563 564 integrate void 565 mace_read(struct mc_softc *sc, void *pkt, int len) 566 { 567 struct ifnet *ifp = &sc->sc_if; 568 struct mbuf *m; 569 570 if (len <= sizeof(struct ether_header) || 571 len > ETHERMTU + sizeof(struct ether_header)) { 572 #ifdef MCDEBUG 573 printf("%s: invalid packet size %d; dropping\n", 574 sc->sc_dev.dv_xname, len); 575 #endif 576 ifp->if_ierrors++; 577 return; 578 } 579 580 m = mace_get(sc, pkt, len); 581 if (m == NULL) { 582 ifp->if_ierrors++; 583 return; 584 } 585 586 ifp->if_ipackets++; 587 588 #if NBPFILTER > 0 589 /* Pass the packet to any BPF listeners. */ 590 if (ifp->if_bpf) 591 bpf_mtap(ifp->if_bpf, m); 592 #endif 593 594 /* Pass the packet up. */ 595 (*ifp->if_input)(ifp, m); 596 } 597 598 /* 599 * Pull data off an interface. 600 * Len is length of data, with local net header stripped. 601 * We copy the data into mbufs. When full cluster sized units are present 602 * we copy into clusters. 603 */ 604 integrate struct mbuf * 605 mace_get(struct mc_softc *sc, void *pkt, int totlen) 606 { 607 struct mbuf *m; 608 struct mbuf *top, **mp; 609 int len; 610 611 MGETHDR(m, M_DONTWAIT, MT_DATA); 612 if (m == 0) 613 return (0); 614 m->m_pkthdr.rcvif = &sc->sc_if; 615 m->m_pkthdr.len = totlen; 616 len = MHLEN; 617 top = 0; 618 mp = ⊤ 619 620 while (totlen > 0) { 621 if (top) { 622 MGET(m, M_DONTWAIT, MT_DATA); 623 if (m == 0) { 624 m_freem(top); 625 return 0; 626 } 627 len = MLEN; 628 } 629 if (totlen >= MINCLSIZE) { 630 MCLGET(m, M_DONTWAIT); 631 if ((m->m_flags & M_EXT) == 0) { 632 m_free(m); 633 m_freem(top); 634 return 0; 635 } 636 len = MCLBYTES; 637 } 638 m->m_len = len = min(totlen, len); 639 memcpy(mtod(m, void *), pkt, len); 640 pkt = (char*)pkt + len; 641 totlen -= len; 642 *mp = m; 643 mp = &m->m_next; 644 } 645 646 return (top); 647 } 648 649 /* 650 * Go through the list of multicast addresses and calculate the logical 651 * address filter. 652 */ 653 void 654 mace_calcladrf(struct ethercom *ac, u_int8_t *af) 655 { 656 struct ifnet *ifp = &ac->ec_if; 657 struct ether_multi *enm; 658 u_char *cp; 659 u_int32_t crc; 660 static const u_int32_t crctab[] = { 661 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, 662 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c, 663 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c, 664 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c 665 }; 666 int len; 667 struct ether_multistep step; 668 669 /* 670 * Set up multicast address filter by passing all multicast addresses 671 * through a crc generator, and then using the high order 6 bits as an 672 * index into the 64 bit logical address filter. The high order bit 673 * selects the word, while the rest of the bits select the bit within 674 * the word. 675 */ 676 677 *((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0; 678 ETHER_FIRST_MULTI(step, ac, enm); 679 while (enm != NULL) { 680 if (ETHER_CMP(enm->enm_addrlo, enm->enm_addrhi)) { 681 /* 682 * We must listen to a range of multicast addresses. 683 * For now, just accept all multicasts, rather than 684 * trying to set only those filter bits needed to match 685 * the range. (At this time, the only use of address 686 * ranges is for IP multicast routing, for which the 687 * range is big enough to require all bits set.) 688 */ 689 goto allmulti; 690 } 691 692 cp = enm->enm_addrlo; 693 crc = 0xffffffff; 694 for (len = sizeof(enm->enm_addrlo); --len >= 0;) { 695 crc ^= *cp++; 696 crc = (crc >> 4) ^ crctab[crc & 0xf]; 697 crc = (crc >> 4) ^ crctab[crc & 0xf]; 698 } 699 /* Just want the 6 most significant bits. */ 700 crc >>= 26; 701 702 /* Set the corresponding bit in the filter. */ 703 af[crc >> 3] |= 1 << (crc & 7); 704 705 ETHER_NEXT_MULTI(step, enm); 706 } 707 ifp->if_flags &= ~IFF_ALLMULTI; 708 return; 709 710 allmulti: 711 ifp->if_flags |= IFF_ALLMULTI; 712 *((u_int32_t *)af) = *((u_int32_t *)af + 1) = 0xffffffff; 713 } 714 715 static u_char bbr4[] = {0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15}; 716 #define bbr(v) ((bbr4[(v)&0xf] << 4) | bbr4[((v)>>4) & 0xf]) 717 718 u_char 719 mc_get_enaddr(bus_space_tag_t t, bus_space_handle_t h, bus_size_t o, 720 u_char *dst) 721 { 722 int i; 723 u_char b, csum; 724 725 /* 726 * The XOR of the 8 bytes of the ROM must be 0xff for it to be 727 * valid 728 */ 729 for (i = 0, csum = 0; i < 8; i++) { 730 b = bus_space_read_1(t, h, o+16*i); 731 if (i < ETHER_ADDR_LEN) 732 dst[i] = bbr(b); 733 csum ^= b; 734 } 735 736 return csum; 737 } 738